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|
- /* Copyright (c) 2003, Roger Dingledine
- * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2017, The Tor Project, Inc. */
- /* See LICENSE for licensing information */
- /**
- * \file util.c
- * \brief Common functions for strings, IO, network, data structures,
- * process control.
- **/
- #include "orconfig.h"
- #ifdef HAVE_FCNTL_H
- #include <fcntl.h>
- #endif
- #define UTIL_PRIVATE
- #include "util.h"
- #include "torlog.h"
- #include "crypto.h"
- #include "torint.h"
- #include "container.h"
- #include "address.h"
- #include "sandbox.h"
- #include "backtrace.h"
- #include "util_process.h"
- #include "util_format.h"
- #ifdef _WIN32
- #include <io.h>
- #include <direct.h>
- #include <process.h>
- #include <tchar.h>
- #include <winbase.h>
- #else
- #include <dirent.h>
- #include <pwd.h>
- #include <grp.h>
- #endif
- /* math.h needs this on Linux */
- #ifndef _USE_ISOC99_
- #define _USE_ISOC99_ 1
- #endif
- #include <math.h>
- #include <stdlib.h>
- #include <stdio.h>
- #include <string.h>
- #include <assert.h>
- #include <signal.h>
- #ifdef HAVE_NETINET_IN_H
- #include <netinet/in.h>
- #endif
- #ifdef HAVE_ARPA_INET_H
- #include <arpa/inet.h>
- #endif
- #ifdef HAVE_ERRNO_H
- #include <errno.h>
- #endif
- #ifdef HAVE_SYS_SOCKET_H
- #include <sys/socket.h>
- #endif
- #ifdef HAVE_SYS_TIME_H
- #include <sys/time.h>
- #endif
- #ifdef HAVE_UNISTD_H
- #include <unistd.h>
- #endif
- #ifdef HAVE_SYS_STAT_H
- #include <sys/stat.h>
- #endif
- #ifdef HAVE_SYS_FCNTL_H
- #include <sys/fcntl.h>
- #endif
- #ifdef HAVE_TIME_H
- #include <time.h>
- #endif
- #ifdef HAVE_MALLOC_MALLOC_H
- #include <malloc/malloc.h>
- #endif
- #ifdef HAVE_MALLOC_H
- #if !defined(OpenBSD) && !defined(__FreeBSD__)
- /* OpenBSD has a malloc.h, but for our purposes, it only exists in order to
- * scold us for being so stupid as to autodetect its presence. To be fair,
- * they've done this since 1996, when autoconf was only 5 years old. */
- #include <malloc.h>
- #endif
- #endif
- #ifdef HAVE_MALLOC_NP_H
- #include <malloc_np.h>
- #endif
- #ifdef HAVE_SYS_WAIT_H
- #include <sys/wait.h>
- #endif
- #if defined(HAVE_SYS_PRCTL_H) && defined(__linux__)
- #include <sys/prctl.h>
- #endif
- #ifdef __clang_analyzer__
- #undef MALLOC_ZERO_WORKS
- #endif
- /* =====
- * Memory management
- * ===== */
- #ifdef USE_DMALLOC
- #undef strndup
- #include <dmalloc.h>
- /* Macro to pass the extra dmalloc args to another function. */
- #define DMALLOC_FN_ARGS , file, line
- #if defined(HAVE_DMALLOC_STRDUP)
- /* the dmalloc_strdup should be fine as defined */
- #elif defined(HAVE_DMALLOC_STRNDUP)
- #define dmalloc_strdup(file, line, string, xalloc_b) \
- dmalloc_strndup(file, line, (string), -1, xalloc_b)
- #else
- #error "No dmalloc_strdup or equivalent"
- #endif
- #else /* not using dmalloc */
- #define DMALLOC_FN_ARGS
- #endif
- /** Allocate a chunk of <b>size</b> bytes of memory, and return a pointer to
- * result. On error, log and terminate the process. (Same as malloc(size),
- * but never returns NULL.)
- *
- * <b>file</b> and <b>line</b> are used if dmalloc is enabled, and
- * ignored otherwise.
- */
- void *
- tor_malloc_(size_t size DMALLOC_PARAMS)
- {
- void *result;
- tor_assert(size < SIZE_T_CEILING);
- #ifndef MALLOC_ZERO_WORKS
- /* Some libc mallocs don't work when size==0. Override them. */
- if (size==0) {
- size=1;
- }
- #endif
- #ifdef USE_DMALLOC
- result = dmalloc_malloc(file, line, size, DMALLOC_FUNC_MALLOC, 0, 0);
- #else
- result = raw_malloc(size);
- #endif
- if (PREDICT_UNLIKELY(result == NULL)) {
- /* LCOV_EXCL_START */
- log_err(LD_MM,"Out of memory on malloc(). Dying.");
- /* If these functions die within a worker process, they won't call
- * spawn_exit, but that's ok, since the parent will run out of memory soon
- * anyway. */
- exit(1);
- /* LCOV_EXCL_STOP */
- }
- return result;
- }
- /** Allocate a chunk of <b>size</b> bytes of memory, fill the memory with
- * zero bytes, and return a pointer to the result. Log and terminate
- * the process on error. (Same as calloc(size,1), but never returns NULL.)
- */
- void *
- tor_malloc_zero_(size_t size DMALLOC_PARAMS)
- {
- /* You may ask yourself, "wouldn't it be smart to use calloc instead of
- * malloc+memset? Perhaps libc's calloc knows some nifty optimization trick
- * we don't!" Indeed it does, but its optimizations are only a big win when
- * we're allocating something very big (it knows if it just got the memory
- * from the OS in a pre-zeroed state). We don't want to use tor_malloc_zero
- * for big stuff, so we don't bother with calloc. */
- void *result = tor_malloc_(size DMALLOC_FN_ARGS);
- memset(result, 0, size);
- return result;
- }
- /* The square root of SIZE_MAX + 1. If a is less than this, and b is less
- * than this, then a*b is less than SIZE_MAX. (For example, if size_t is
- * 32 bits, then SIZE_MAX is 0xffffffff and this value is 0x10000. If a and
- * b are less than this, then their product is at most (65535*65535) ==
- * 0xfffe0001. */
- #define SQRT_SIZE_MAX_P1 (((size_t)1) << (sizeof(size_t)*4))
- /** Return non-zero if and only if the product of the arguments is exact,
- * and cannot overflow. */
- int
- size_mul_check(const size_t x, const size_t y)
- {
- /* This first check is equivalent to
- (x < SQRT_SIZE_MAX_P1 && y < SQRT_SIZE_MAX_P1)
- Rationale: if either one of x or y is >= SQRT_SIZE_MAX_P1, then it
- will have some bit set in its most significant half.
- */
- return ((x|y) < SQRT_SIZE_MAX_P1 ||
- y == 0 ||
- x <= SIZE_MAX / y);
- }
- /** Allocate a chunk of <b>nmemb</b>*<b>size</b> bytes of memory, fill
- * the memory with zero bytes, and return a pointer to the result.
- * Log and terminate the process on error. (Same as
- * calloc(<b>nmemb</b>,<b>size</b>), but never returns NULL.)
- * The second argument (<b>size</b>) should preferably be non-zero
- * and a compile-time constant.
- */
- void *
- tor_calloc_(size_t nmemb, size_t size DMALLOC_PARAMS)
- {
- tor_assert(size_mul_check(nmemb, size));
- return tor_malloc_zero_((nmemb * size) DMALLOC_FN_ARGS);
- }
- /** Change the size of the memory block pointed to by <b>ptr</b> to <b>size</b>
- * bytes long; return the new memory block. On error, log and
- * terminate. (Like realloc(ptr,size), but never returns NULL.)
- */
- void *
- tor_realloc_(void *ptr, size_t size DMALLOC_PARAMS)
- {
- void *result;
- tor_assert(size < SIZE_T_CEILING);
- #ifndef MALLOC_ZERO_WORKS
- /* Some libc mallocs don't work when size==0. Override them. */
- if (size==0) {
- size=1;
- }
- #endif
- #ifdef USE_DMALLOC
- result = dmalloc_realloc(file, line, ptr, size, DMALLOC_FUNC_REALLOC, 0);
- #else
- result = raw_realloc(ptr, size);
- #endif
- if (PREDICT_UNLIKELY(result == NULL)) {
- /* LCOV_EXCL_START */
- log_err(LD_MM,"Out of memory on realloc(). Dying.");
- exit(1);
- /* LCOV_EXCL_STOP */
- }
- return result;
- }
- /**
- * Try to realloc <b>ptr</b> so that it takes up sz1 * sz2 bytes. Check for
- * overflow. Unlike other allocation functions, return NULL on overflow.
- */
- void *
- tor_reallocarray_(void *ptr, size_t sz1, size_t sz2 DMALLOC_PARAMS)
- {
- /* XXXX we can make this return 0, but we would need to check all the
- * reallocarray users. */
- tor_assert(size_mul_check(sz1, sz2));
- return tor_realloc(ptr, (sz1 * sz2) DMALLOC_FN_ARGS);
- }
- /** Return a newly allocated copy of the NUL-terminated string s. On
- * error, log and terminate. (Like strdup(s), but never returns
- * NULL.)
- */
- char *
- tor_strdup_(const char *s DMALLOC_PARAMS)
- {
- char *duplicate;
- tor_assert(s);
- #ifdef USE_DMALLOC
- duplicate = dmalloc_strdup(file, line, s, 0);
- #else
- duplicate = raw_strdup(s);
- #endif
- if (PREDICT_UNLIKELY(duplicate == NULL)) {
- /* LCOV_EXCL_START */
- log_err(LD_MM,"Out of memory on strdup(). Dying.");
- exit(1);
- /* LCOV_EXCL_STOP */
- }
- return duplicate;
- }
- /** Allocate and return a new string containing the first <b>n</b>
- * characters of <b>s</b>. If <b>s</b> is longer than <b>n</b>
- * characters, only the first <b>n</b> are copied. The result is
- * always NUL-terminated. (Like strndup(s,n), but never returns
- * NULL.)
- */
- char *
- tor_strndup_(const char *s, size_t n DMALLOC_PARAMS)
- {
- char *duplicate;
- tor_assert(s);
- tor_assert(n < SIZE_T_CEILING);
- duplicate = tor_malloc_((n+1) DMALLOC_FN_ARGS);
- /* Performance note: Ordinarily we prefer strlcpy to strncpy. But
- * this function gets called a whole lot, and platform strncpy is
- * much faster than strlcpy when strlen(s) is much longer than n.
- */
- strncpy(duplicate, s, n);
- duplicate[n]='\0';
- return duplicate;
- }
- /** Allocate a chunk of <b>len</b> bytes, with the same contents as the
- * <b>len</b> bytes starting at <b>mem</b>. */
- void *
- tor_memdup_(const void *mem, size_t len DMALLOC_PARAMS)
- {
- char *duplicate;
- tor_assert(len < SIZE_T_CEILING);
- tor_assert(mem);
- duplicate = tor_malloc_(len DMALLOC_FN_ARGS);
- memcpy(duplicate, mem, len);
- return duplicate;
- }
- /** As tor_memdup(), but add an extra 0 byte at the end of the resulting
- * memory. */
- void *
- tor_memdup_nulterm_(const void *mem, size_t len DMALLOC_PARAMS)
- {
- char *duplicate;
- tor_assert(len < SIZE_T_CEILING+1);
- tor_assert(mem);
- duplicate = tor_malloc_(len+1 DMALLOC_FN_ARGS);
- memcpy(duplicate, mem, len);
- duplicate[len] = '\0';
- return duplicate;
- }
- /** Helper for places that need to take a function pointer to the right
- * spelling of "free()". */
- void
- tor_free_(void *mem)
- {
- tor_free(mem);
- }
- DISABLE_GCC_WARNING(aggregate-return)
- /** Call the platform malloc info function, and dump the results to the log at
- * level <b>severity</b>. If no such function exists, do nothing. */
- void
- tor_log_mallinfo(int severity)
- {
- #ifdef HAVE_MALLINFO
- struct mallinfo mi;
- memset(&mi, 0, sizeof(mi));
- mi = mallinfo();
- tor_log(severity, LD_MM,
- "mallinfo() said: arena=%d, ordblks=%d, smblks=%d, hblks=%d, "
- "hblkhd=%d, usmblks=%d, fsmblks=%d, uordblks=%d, fordblks=%d, "
- "keepcost=%d",
- mi.arena, mi.ordblks, mi.smblks, mi.hblks,
- mi.hblkhd, mi.usmblks, mi.fsmblks, mi.uordblks, mi.fordblks,
- mi.keepcost);
- #else
- (void)severity;
- #endif
- #ifdef USE_DMALLOC
- dmalloc_log_changed(0, /* Since the program started. */
- 1, /* Log info about non-freed pointers. */
- 0, /* Do not log info about freed pointers. */
- 0 /* Do not log individual pointers. */
- );
- #endif
- }
- ENABLE_GCC_WARNING(aggregate-return)
- /* =====
- * Math
- * ===== */
- /**
- * Returns the natural logarithm of d base e. We defined this wrapper here so
- * to avoid conflicts with old versions of tor_log(), which were named log().
- */
- double
- tor_mathlog(double d)
- {
- return log(d);
- }
- /** Return the long integer closest to <b>d</b>. We define this wrapper
- * here so that not all users of math.h need to use the right incantations
- * to get the c99 functions. */
- long
- tor_lround(double d)
- {
- #if defined(HAVE_LROUND)
- return lround(d);
- #elif defined(HAVE_RINT)
- return (long)rint(d);
- #else
- return (long)(d > 0 ? d + 0.5 : ceil(d - 0.5));
- #endif
- }
- /** Return the 64-bit integer closest to d. We define this wrapper here so
- * that not all users of math.h need to use the right incantations to get the
- * c99 functions. */
- int64_t
- tor_llround(double d)
- {
- #if defined(HAVE_LLROUND)
- return (int64_t)llround(d);
- #elif defined(HAVE_RINT)
- return (int64_t)rint(d);
- #else
- return (int64_t)(d > 0 ? d + 0.5 : ceil(d - 0.5));
- #endif
- }
- /** Returns floor(log2(u64)). If u64 is 0, (incorrectly) returns 0. */
- int
- tor_log2(uint64_t u64)
- {
- int r = 0;
- if (u64 >= (U64_LITERAL(1)<<32)) {
- u64 >>= 32;
- r = 32;
- }
- if (u64 >= (U64_LITERAL(1)<<16)) {
- u64 >>= 16;
- r += 16;
- }
- if (u64 >= (U64_LITERAL(1)<<8)) {
- u64 >>= 8;
- r += 8;
- }
- if (u64 >= (U64_LITERAL(1)<<4)) {
- u64 >>= 4;
- r += 4;
- }
- if (u64 >= (U64_LITERAL(1)<<2)) {
- u64 >>= 2;
- r += 2;
- }
- if (u64 >= (U64_LITERAL(1)<<1)) {
- u64 >>= 1;
- r += 1;
- }
- return r;
- }
- /** Return the power of 2 in range [1,UINT64_MAX] closest to <b>u64</b>. If
- * there are two powers of 2 equally close, round down. */
- uint64_t
- round_to_power_of_2(uint64_t u64)
- {
- int lg2;
- uint64_t low;
- uint64_t high;
- if (u64 == 0)
- return 1;
- lg2 = tor_log2(u64);
- low = U64_LITERAL(1) << lg2;
- if (lg2 == 63)
- return low;
- high = U64_LITERAL(1) << (lg2+1);
- if (high - u64 < u64 - low)
- return high;
- else
- return low;
- }
- /** Return the lowest x such that x is at least <b>number</b>, and x modulo
- * <b>divisor</b> == 0. If no such x can be expressed as an unsigned, return
- * UINT_MAX */
- unsigned
- round_to_next_multiple_of(unsigned number, unsigned divisor)
- {
- tor_assert(divisor > 0);
- if (UINT_MAX - divisor + 1 < number)
- return UINT_MAX;
- number += divisor - 1;
- number -= number % divisor;
- return number;
- }
- /** Return the lowest x such that x is at least <b>number</b>, and x modulo
- * <b>divisor</b> == 0. If no such x can be expressed as a uint32_t, return
- * UINT32_MAX */
- uint32_t
- round_uint32_to_next_multiple_of(uint32_t number, uint32_t divisor)
- {
- tor_assert(divisor > 0);
- if (UINT32_MAX - divisor + 1 < number)
- return UINT32_MAX;
- number += divisor - 1;
- number -= number % divisor;
- return number;
- }
- /** Return the lowest x such that x is at least <b>number</b>, and x modulo
- * <b>divisor</b> == 0. If no such x can be expressed as a uint64_t, return
- * UINT64_MAX */
- uint64_t
- round_uint64_to_next_multiple_of(uint64_t number, uint64_t divisor)
- {
- tor_assert(divisor > 0);
- if (UINT64_MAX - divisor + 1 < number)
- return UINT64_MAX;
- number += divisor - 1;
- number -= number % divisor;
- return number;
- }
- /** Transform a random value <b>p</b> from the uniform distribution in
- * [0.0, 1.0[ into a Laplace distributed value with location parameter
- * <b>mu</b> and scale parameter <b>b</b>. Truncate the final result
- * to be an integer in [INT64_MIN, INT64_MAX]. */
- int64_t
- sample_laplace_distribution(double mu, double b, double p)
- {
- double result;
- tor_assert(p >= 0.0 && p < 1.0);
- /* This is the "inverse cumulative distribution function" from:
- * http://en.wikipedia.org/wiki/Laplace_distribution */
- if (p <= 0.0) {
- /* Avoid taking log(0.0) == -INFINITY, as some processors or compiler
- * options can cause the program to trap. */
- return INT64_MIN;
- }
- result = mu - b * (p > 0.5 ? 1.0 : -1.0)
- * tor_mathlog(1.0 - 2.0 * fabs(p - 0.5));
- return clamp_double_to_int64(result);
- }
- /** Add random noise between INT64_MIN and INT64_MAX coming from a Laplace
- * distribution with mu = 0 and b = <b>delta_f</b>/<b>epsilon</b> to
- * <b>signal</b> based on the provided <b>random</b> value in [0.0, 1.0[.
- * The epsilon value must be between ]0.0, 1.0]. delta_f must be greater
- * than 0. */
- int64_t
- add_laplace_noise(int64_t signal_, double random_, double delta_f,
- double epsilon)
- {
- int64_t noise;
- /* epsilon MUST be between ]0.0, 1.0] */
- tor_assert(epsilon > 0.0 && epsilon <= 1.0);
- /* delta_f MUST be greater than 0. */
- tor_assert(delta_f > 0.0);
- /* Just add noise, no further signal */
- noise = sample_laplace_distribution(0.0,
- delta_f / epsilon,
- random_);
- /* Clip (signal + noise) to [INT64_MIN, INT64_MAX] */
- if (noise > 0 && INT64_MAX - noise < signal_)
- return INT64_MAX;
- else if (noise < 0 && INT64_MIN - noise > signal_)
- return INT64_MIN;
- else
- return signal_ + noise;
- }
- /* Helper: return greatest common divisor of a,b */
- static uint64_t
- gcd64(uint64_t a, uint64_t b)
- {
- while (b) {
- uint64_t t = b;
- b = a % b;
- a = t;
- }
- return a;
- }
- /* Given a fraction *<b>numer</b> / *<b>denom</b>, simplify it.
- * Requires that the denominator is greater than 0. */
- void
- simplify_fraction64(uint64_t *numer, uint64_t *denom)
- {
- tor_assert(denom);
- uint64_t gcd = gcd64(*numer, *denom);
- *numer /= gcd;
- *denom /= gcd;
- }
- /** Return the number of bits set in <b>v</b>. */
- int
- n_bits_set_u8(uint8_t v)
- {
- static const int nybble_table[] = {
- 0, /* 0000 */
- 1, /* 0001 */
- 1, /* 0010 */
- 2, /* 0011 */
- 1, /* 0100 */
- 2, /* 0101 */
- 2, /* 0110 */
- 3, /* 0111 */
- 1, /* 1000 */
- 2, /* 1001 */
- 2, /* 1010 */
- 3, /* 1011 */
- 2, /* 1100 */
- 3, /* 1101 */
- 3, /* 1110 */
- 4, /* 1111 */
- };
- return nybble_table[v & 15] + nybble_table[v>>4];
- }
- /* =====
- * String manipulation
- * ===== */
- /** Remove from the string <b>s</b> every character which appears in
- * <b>strip</b>. */
- void
- tor_strstrip(char *s, const char *strip)
- {
- char *readp = s;
- while (*readp) {
- if (strchr(strip, *readp)) {
- ++readp;
- } else {
- *s++ = *readp++;
- }
- }
- *s = '\0';
- }
- /** Return a pointer to a NUL-terminated hexadecimal string encoding
- * the first <b>fromlen</b> bytes of <b>from</b>. (fromlen must be \<= 32.) The
- * result does not need to be deallocated, but repeated calls to
- * hex_str will trash old results.
- */
- const char *
- hex_str(const char *from, size_t fromlen)
- {
- static char buf[65];
- if (fromlen>(sizeof(buf)-1)/2)
- fromlen = (sizeof(buf)-1)/2;
- base16_encode(buf,sizeof(buf),from,fromlen);
- return buf;
- }
- /** Convert all alphabetic characters in the nul-terminated string <b>s</b> to
- * lowercase. */
- void
- tor_strlower(char *s)
- {
- while (*s) {
- *s = TOR_TOLOWER(*s);
- ++s;
- }
- }
- /** Convert all alphabetic characters in the nul-terminated string <b>s</b> to
- * lowercase. */
- void
- tor_strupper(char *s)
- {
- while (*s) {
- *s = TOR_TOUPPER(*s);
- ++s;
- }
- }
- /** Return 1 if every character in <b>s</b> is printable, else return 0.
- */
- int
- tor_strisprint(const char *s)
- {
- while (*s) {
- if (!TOR_ISPRINT(*s))
- return 0;
- s++;
- }
- return 1;
- }
- /** Return 1 if no character in <b>s</b> is uppercase, else return 0.
- */
- int
- tor_strisnonupper(const char *s)
- {
- while (*s) {
- if (TOR_ISUPPER(*s))
- return 0;
- s++;
- }
- return 1;
- }
- /** Return true iff every character in <b>s</b> is whitespace space; else
- * return false. */
- int
- tor_strisspace(const char *s)
- {
- while (*s) {
- if (!TOR_ISSPACE(*s))
- return 0;
- s++;
- }
- return 1;
- }
- /** As strcmp, except that either string may be NULL. The NULL string is
- * considered to be before any non-NULL string. */
- int
- strcmp_opt(const char *s1, const char *s2)
- {
- if (!s1) {
- if (!s2)
- return 0;
- else
- return -1;
- } else if (!s2) {
- return 1;
- } else {
- return strcmp(s1, s2);
- }
- }
- /** Compares the first strlen(s2) characters of s1 with s2. Returns as for
- * strcmp.
- */
- int
- strcmpstart(const char *s1, const char *s2)
- {
- size_t n = strlen(s2);
- return strncmp(s1, s2, n);
- }
- /** Compare the s1_len-byte string <b>s1</b> with <b>s2</b>,
- * without depending on a terminating nul in s1. Sorting order is first by
- * length, then lexically; return values are as for strcmp.
- */
- int
- strcmp_len(const char *s1, const char *s2, size_t s1_len)
- {
- size_t s2_len = strlen(s2);
- if (s1_len < s2_len)
- return -1;
- if (s1_len > s2_len)
- return 1;
- return fast_memcmp(s1, s2, s2_len);
- }
- /** Compares the first strlen(s2) characters of s1 with s2. Returns as for
- * strcasecmp.
- */
- int
- strcasecmpstart(const char *s1, const char *s2)
- {
- size_t n = strlen(s2);
- return strncasecmp(s1, s2, n);
- }
- /** Compares the last strlen(s2) characters of s1 with s2. Returns as for
- * strcmp.
- */
- int
- strcmpend(const char *s1, const char *s2)
- {
- size_t n1 = strlen(s1), n2 = strlen(s2);
- if (n2>n1)
- return strcmp(s1,s2);
- else
- return strncmp(s1+(n1-n2), s2, n2);
- }
- /** Compares the last strlen(s2) characters of s1 with s2. Returns as for
- * strcasecmp.
- */
- int
- strcasecmpend(const char *s1, const char *s2)
- {
- size_t n1 = strlen(s1), n2 = strlen(s2);
- if (n2>n1) /* then they can't be the same; figure out which is bigger */
- return strcasecmp(s1,s2);
- else
- return strncasecmp(s1+(n1-n2), s2, n2);
- }
- /** Compare the value of the string <b>prefix</b> with the start of the
- * <b>memlen</b>-byte memory chunk at <b>mem</b>. Return as for strcmp.
- *
- * [As fast_memcmp(mem, prefix, strlen(prefix)) but returns -1 if memlen is
- * less than strlen(prefix).]
- */
- int
- fast_memcmpstart(const void *mem, size_t memlen,
- const char *prefix)
- {
- size_t plen = strlen(prefix);
- if (memlen < plen)
- return -1;
- return fast_memcmp(mem, prefix, plen);
- }
- /** Return a pointer to the first char of s that is not whitespace and
- * not a comment, or to the terminating NUL if no such character exists.
- */
- const char *
- eat_whitespace(const char *s)
- {
- tor_assert(s);
- while (1) {
- switch (*s) {
- case '\0':
- default:
- return s;
- case ' ':
- case '\t':
- case '\n':
- case '\r':
- ++s;
- break;
- case '#':
- ++s;
- while (*s && *s != '\n')
- ++s;
- }
- }
- }
- /** Return a pointer to the first char of s that is not whitespace and
- * not a comment, or to the terminating NUL if no such character exists.
- */
- const char *
- eat_whitespace_eos(const char *s, const char *eos)
- {
- tor_assert(s);
- tor_assert(eos && s <= eos);
- while (s < eos) {
- switch (*s) {
- case '\0':
- default:
- return s;
- case ' ':
- case '\t':
- case '\n':
- case '\r':
- ++s;
- break;
- case '#':
- ++s;
- while (s < eos && *s && *s != '\n')
- ++s;
- }
- }
- return s;
- }
- /** Return a pointer to the first char of s that is not a space or a tab
- * or a \\r, or to the terminating NUL if no such character exists. */
- const char *
- eat_whitespace_no_nl(const char *s)
- {
- while (*s == ' ' || *s == '\t' || *s == '\r')
- ++s;
- return s;
- }
- /** As eat_whitespace_no_nl, but stop at <b>eos</b> whether we have
- * found a non-whitespace character or not. */
- const char *
- eat_whitespace_eos_no_nl(const char *s, const char *eos)
- {
- while (s < eos && (*s == ' ' || *s == '\t' || *s == '\r'))
- ++s;
- return s;
- }
- /** Return a pointer to the first char of s that is whitespace or <b>#</b>,
- * or to the terminating NUL if no such character exists.
- */
- const char *
- find_whitespace(const char *s)
- {
- /* tor_assert(s); */
- while (1) {
- switch (*s)
- {
- case '\0':
- case '#':
- case ' ':
- case '\r':
- case '\n':
- case '\t':
- return s;
- default:
- ++s;
- }
- }
- }
- /** As find_whitespace, but stop at <b>eos</b> whether we have found a
- * whitespace or not. */
- const char *
- find_whitespace_eos(const char *s, const char *eos)
- {
- /* tor_assert(s); */
- while (s < eos) {
- switch (*s)
- {
- case '\0':
- case '#':
- case ' ':
- case '\r':
- case '\n':
- case '\t':
- return s;
- default:
- ++s;
- }
- }
- return s;
- }
- /** Return the first occurrence of <b>needle</b> in <b>haystack</b> that
- * occurs at the start of a line (that is, at the beginning of <b>haystack</b>
- * or immediately after a newline). Return NULL if no such string is found.
- */
- const char *
- find_str_at_start_of_line(const char *haystack, const char *needle)
- {
- size_t needle_len = strlen(needle);
- do {
- if (!strncmp(haystack, needle, needle_len))
- return haystack;
- haystack = strchr(haystack, '\n');
- if (!haystack)
- return NULL;
- else
- ++haystack;
- } while (*haystack);
- return NULL;
- }
- /** Returns true if <b>string</b> could be a C identifier.
- A C identifier must begin with a letter or an underscore and the
- rest of its characters can be letters, numbers or underscores. No
- length limit is imposed. */
- int
- string_is_C_identifier(const char *string)
- {
- size_t iter;
- size_t length = strlen(string);
- if (!length)
- return 0;
- for (iter = 0; iter < length ; iter++) {
- if (iter == 0) {
- if (!(TOR_ISALPHA(string[iter]) ||
- string[iter] == '_'))
- return 0;
- } else {
- if (!(TOR_ISALPHA(string[iter]) ||
- TOR_ISDIGIT(string[iter]) ||
- string[iter] == '_'))
- return 0;
- }
- }
- return 1;
- }
- /** Return true iff the 'len' bytes at 'mem' are all zero. */
- int
- tor_mem_is_zero(const char *mem, size_t len)
- {
- static const char ZERO[] = {
- 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
- };
- while (len >= sizeof(ZERO)) {
- /* It's safe to use fast_memcmp here, since the very worst thing an
- * attacker could learn is how many initial bytes of a secret were zero */
- if (fast_memcmp(mem, ZERO, sizeof(ZERO)))
- return 0;
- len -= sizeof(ZERO);
- mem += sizeof(ZERO);
- }
- /* Deal with leftover bytes. */
- if (len)
- return fast_memeq(mem, ZERO, len);
- return 1;
- }
- /** Return true iff the DIGEST_LEN bytes in digest are all zero. */
- int
- tor_digest_is_zero(const char *digest)
- {
- static const uint8_t ZERO_DIGEST[] = {
- 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0
- };
- return tor_memeq(digest, ZERO_DIGEST, DIGEST_LEN);
- }
- /** Return true if <b>string</b> is a valid 'key=[value]' string.
- * "value" is optional, to indicate the empty string. Log at logging
- * <b>severity</b> if something ugly happens. */
- int
- string_is_key_value(int severity, const char *string)
- {
- /* position of equal sign in string */
- const char *equal_sign_pos = NULL;
- tor_assert(string);
- if (strlen(string) < 2) { /* "x=" is shortest args string */
- tor_log(severity, LD_GENERAL, "'%s' is too short to be a k=v value.",
- escaped(string));
- return 0;
- }
- equal_sign_pos = strchr(string, '=');
- if (!equal_sign_pos) {
- tor_log(severity, LD_GENERAL, "'%s' is not a k=v value.", escaped(string));
- return 0;
- }
- /* validate that the '=' is not in the beginning of the string. */
- if (equal_sign_pos == string) {
- tor_log(severity, LD_GENERAL, "'%s' is not a valid k=v value.",
- escaped(string));
- return 0;
- }
- return 1;
- }
- /** Return true if <b>string</b> represents a valid IPv4 adddress in
- * 'a.b.c.d' form.
- */
- int
- string_is_valid_ipv4_address(const char *string)
- {
- struct in_addr addr;
- return (tor_inet_pton(AF_INET,string,&addr) == 1);
- }
- /** Return true if <b>string</b> represents a valid IPv6 address in
- * a form that inet_pton() can parse.
- */
- int
- string_is_valid_ipv6_address(const char *string)
- {
- struct in6_addr addr;
- return (tor_inet_pton(AF_INET6,string,&addr) == 1);
- }
- /** Return true iff <b>string</b> matches a pattern of DNS names
- * that we allow Tor clients to connect to.
- *
- * Note: This allows certain technically invalid characters ('_') to cope
- * with misconfigured zones that have been encountered in the wild.
- */
- int
- string_is_valid_hostname(const char *string)
- {
- int result = 1;
- smartlist_t *components;
- components = smartlist_new();
- smartlist_split_string(components,string,".",0,0);
- SMARTLIST_FOREACH_BEGIN(components, char *, c) {
- if ((c[0] == '-') || (*c == '_')) {
- result = 0;
- break;
- }
- /* Allow a single terminating '.' used rarely to indicate domains
- * are FQDNs rather than relative. */
- if ((c_sl_idx > 0) && (c_sl_idx + 1 == c_sl_len) && !*c) {
- continue;
- }
- do {
- if ((*c >= 'a' && *c <= 'z') ||
- (*c >= 'A' && *c <= 'Z') ||
- (*c >= '0' && *c <= '9') ||
- (*c == '-') || (*c == '_'))
- c++;
- else
- result = 0;
- } while (result && *c);
- } SMARTLIST_FOREACH_END(c);
- SMARTLIST_FOREACH_BEGIN(components, char *, c) {
- tor_free(c);
- } SMARTLIST_FOREACH_END(c);
- smartlist_free(components);
- return result;
- }
- /** Return true iff the DIGEST256_LEN bytes in digest are all zero. */
- int
- tor_digest256_is_zero(const char *digest)
- {
- return tor_mem_is_zero(digest, DIGEST256_LEN);
- }
- /* Helper: common code to check whether the result of a strtol or strtoul or
- * strtoll is correct. */
- #define CHECK_STRTOX_RESULT() \
- /* Did an overflow occur? */ \
- if (errno == ERANGE) \
- goto err; \
- /* Was at least one character converted? */ \
- if (endptr == s) \
- goto err; \
- /* Were there unexpected unconverted characters? */ \
- if (!next && *endptr) \
- goto err; \
- /* Illogical (max, min) inputs? */ \
- if (BUG(max < min)) \
- goto err; \
- /* Is r within limits? */ \
- if (r < min || r > max) \
- goto err; \
- if (ok) *ok = 1; \
- if (next) *next = endptr; \
- return r; \
- err: \
- if (ok) *ok = 0; \
- if (next) *next = endptr; \
- return 0
- /** Extract a long from the start of <b>s</b>, in the given numeric
- * <b>base</b>. If <b>base</b> is 0, <b>s</b> is parsed as a decimal,
- * octal, or hex number in the syntax of a C integer literal. If
- * there is unconverted data and <b>next</b> is provided, set
- * *<b>next</b> to the first unconverted character. An error has
- * occurred if no characters are converted; or if there are
- * unconverted characters and <b>next</b> is NULL; or if the parsed
- * value is not between <b>min</b> and <b>max</b>. When no error
- * occurs, return the parsed value and set *<b>ok</b> (if provided) to
- * 1. When an error occurs, return 0 and set *<b>ok</b> (if provided)
- * to 0.
- */
- long
- tor_parse_long(const char *s, int base, long min, long max,
- int *ok, char **next)
- {
- char *endptr;
- long r;
- if (base < 0) {
- if (ok)
- *ok = 0;
- return 0;
- }
- errno = 0;
- r = strtol(s, &endptr, base);
- CHECK_STRTOX_RESULT();
- }
- /** As tor_parse_long(), but return an unsigned long. */
- unsigned long
- tor_parse_ulong(const char *s, int base, unsigned long min,
- unsigned long max, int *ok, char **next)
- {
- char *endptr;
- unsigned long r;
- if (base < 0) {
- if (ok)
- *ok = 0;
- return 0;
- }
- errno = 0;
- r = strtoul(s, &endptr, base);
- CHECK_STRTOX_RESULT();
- }
- /** As tor_parse_long(), but return a double. */
- double
- tor_parse_double(const char *s, double min, double max, int *ok, char **next)
- {
- char *endptr;
- double r;
- errno = 0;
- r = strtod(s, &endptr);
- CHECK_STRTOX_RESULT();
- }
- /** As tor_parse_long, but return a uint64_t. Only base 10 is guaranteed to
- * work for now. */
- uint64_t
- tor_parse_uint64(const char *s, int base, uint64_t min,
- uint64_t max, int *ok, char **next)
- {
- char *endptr;
- uint64_t r;
- if (base < 0) {
- if (ok)
- *ok = 0;
- return 0;
- }
- errno = 0;
- #ifdef HAVE_STRTOULL
- r = (uint64_t)strtoull(s, &endptr, base);
- #elif defined(_WIN32)
- #if defined(_MSC_VER) && _MSC_VER < 1300
- tor_assert(base <= 10);
- r = (uint64_t)_atoi64(s);
- endptr = (char*)s;
- while (TOR_ISSPACE(*endptr)) endptr++;
- while (TOR_ISDIGIT(*endptr)) endptr++;
- #else
- r = (uint64_t)_strtoui64(s, &endptr, base);
- #endif
- #elif SIZEOF_LONG == 8
- r = (uint64_t)strtoul(s, &endptr, base);
- #else
- #error "I don't know how to parse 64-bit numbers."
- #endif
- CHECK_STRTOX_RESULT();
- }
- /** Allocate and return a new string representing the contents of <b>s</b>,
- * surrounded by quotes and using standard C escapes.
- *
- * Generally, we use this for logging values that come in over the network to
- * keep them from tricking users, and for sending certain values to the
- * controller.
- *
- * We trust values from the resolver, OS, configuration file, and command line
- * to not be maliciously ill-formed. We validate incoming routerdescs and
- * SOCKS requests and addresses from BEGIN cells as they're parsed;
- * afterwards, we trust them as non-malicious.
- */
- char *
- esc_for_log(const char *s)
- {
- const char *cp;
- char *result, *outp;
- size_t len = 3;
- if (!s) {
- return tor_strdup("(null)");
- }
- for (cp = s; *cp; ++cp) {
- switch (*cp) {
- case '\\':
- case '\"':
- case '\'':
- case '\r':
- case '\n':
- case '\t':
- len += 2;
- break;
- default:
- if (TOR_ISPRINT(*cp) && ((uint8_t)*cp)<127)
- ++len;
- else
- len += 4;
- break;
- }
- }
- tor_assert(len <= SSIZE_MAX);
- result = outp = tor_malloc(len);
- *outp++ = '\"';
- for (cp = s; *cp; ++cp) {
- /* This assertion should always succeed, since we will write at least
- * one char here, and two chars for closing quote and nul later */
- tor_assert((outp-result) < (ssize_t)len-2);
- switch (*cp) {
- case '\\':
- case '\"':
- case '\'':
- *outp++ = '\\';
- *outp++ = *cp;
- break;
- case '\n':
- *outp++ = '\\';
- *outp++ = 'n';
- break;
- case '\t':
- *outp++ = '\\';
- *outp++ = 't';
- break;
- case '\r':
- *outp++ = '\\';
- *outp++ = 'r';
- break;
- default:
- if (TOR_ISPRINT(*cp) && ((uint8_t)*cp)<127) {
- *outp++ = *cp;
- } else {
- tor_assert((outp-result) < (ssize_t)len-4);
- tor_snprintf(outp, 5, "\\%03o", (int)(uint8_t) *cp);
- outp += 4;
- }
- break;
- }
- }
- tor_assert((outp-result) <= (ssize_t)len-2);
- *outp++ = '\"';
- *outp++ = 0;
- return result;
- }
- /** Similar to esc_for_log. Allocate and return a new string representing
- * the first n characters in <b>chars</b>, surround by quotes and using
- * standard C escapes. If a NUL character is encountered in <b>chars</b>,
- * the resulting string will be terminated there.
- */
- char *
- esc_for_log_len(const char *chars, size_t n)
- {
- char *string = tor_strndup(chars, n);
- char *string_escaped = esc_for_log(string);
- tor_free(string);
- return string_escaped;
- }
- /** Allocate and return a new string representing the contents of <b>s</b>,
- * surrounded by quotes and using standard C escapes.
- *
- * THIS FUNCTION IS NOT REENTRANT. Don't call it from outside the main
- * thread. Also, each call invalidates the last-returned value, so don't
- * try log_warn(LD_GENERAL, "%s %s", escaped(a), escaped(b));
- */
- const char *
- escaped(const char *s)
- {
- static char *escaped_val_ = NULL;
- tor_free(escaped_val_);
- if (s)
- escaped_val_ = esc_for_log(s);
- else
- escaped_val_ = NULL;
- return escaped_val_;
- }
- /** Return a newly allocated string equal to <b>string</b>, except that every
- * character in <b>chars_to_escape</b> is preceded by a backslash. */
- char *
- tor_escape_str_for_pt_args(const char *string, const char *chars_to_escape)
- {
- char *new_string = NULL;
- char *new_cp = NULL;
- size_t length, new_length;
- tor_assert(string);
- length = strlen(string);
- if (!length) /* If we were given the empty string, return the same. */
- return tor_strdup("");
- /* (new_length > SIZE_MAX) => ((length * 2) + 1 > SIZE_MAX) =>
- (length*2 > SIZE_MAX - 1) => (length > (SIZE_MAX - 1)/2) */
- if (length > (SIZE_MAX - 1)/2) /* check for overflow */
- return NULL;
- /* this should be enough even if all characters must be escaped */
- new_length = (length * 2) + 1;
- new_string = new_cp = tor_malloc(new_length);
- while (*string) {
- if (strchr(chars_to_escape, *string))
- *new_cp++ = '\\';
- *new_cp++ = *string++;
- }
- *new_cp = '\0'; /* NUL-terminate the new string */
- return new_string;
- }
- /* =====
- * Time
- * ===== */
- #define TOR_USEC_PER_SEC 1000000
- /** Return the difference between start->tv_sec and end->tv_sec.
- * Returns INT64_MAX on overflow and underflow.
- */
- static int64_t
- tv_secdiff_impl(const struct timeval *start, const struct timeval *end)
- {
- const int64_t s = (int64_t)start->tv_sec;
- const int64_t e = (int64_t)end->tv_sec;
- /* This may not be the most efficient way of implemeting this check,
- * but it's easy to see that it's correct and doesn't overflow */
- if (s > 0 && e < INT64_MIN + s) {
- /* s is positive: equivalent to e - s < INT64_MIN, but without any
- * overflow */
- return INT64_MAX;
- } else if (s < 0 && e > INT64_MAX + s) {
- /* s is negative: equivalent to e - s > INT64_MAX, but without any
- * overflow */
- return INT64_MAX;
- }
- return e - s;
- }
- /** Return the number of microseconds elapsed between *start and *end.
- * Returns LONG_MAX on overflow and underflow.
- */
- long
- tv_udiff(const struct timeval *start, const struct timeval *end)
- {
- /* Sanity check tv_usec */
- if (start->tv_usec > TOR_USEC_PER_SEC || start->tv_usec < 0) {
- log_warn(LD_GENERAL, "comparing times on microsecond detail with bad "
- "start tv_usec: " I64_FORMAT " microseconds",
- I64_PRINTF_ARG(start->tv_usec));
- return LONG_MAX;
- }
- if (end->tv_usec > TOR_USEC_PER_SEC || end->tv_usec < 0) {
- log_warn(LD_GENERAL, "comparing times on microsecond detail with bad "
- "end tv_usec: " I64_FORMAT " microseconds",
- I64_PRINTF_ARG(end->tv_usec));
- return LONG_MAX;
- }
- /* Some BSDs have struct timeval.tv_sec 64-bit, but time_t (and long) 32-bit
- */
- int64_t udiff;
- const int64_t secdiff = tv_secdiff_impl(start, end);
- /* end->tv_usec - start->tv_usec can be up to 1 second either way */
- if (secdiff > (int64_t)(LONG_MAX/1000000 - 1) ||
- secdiff < (int64_t)(LONG_MIN/1000000 + 1)) {
- log_warn(LD_GENERAL, "comparing times on microsecond detail too far "
- "apart: " I64_FORMAT " seconds", I64_PRINTF_ARG(secdiff));
- return LONG_MAX;
- }
- /* we'll never get an overflow here, because we check that both usecs are
- * between 0 and TV_USEC_PER_SEC. */
- udiff = secdiff*1000000 + ((int64_t)end->tv_usec - (int64_t)start->tv_usec);
- /* Some compilers are smart enough to work out this is a no-op on L64 */
- #if SIZEOF_LONG < 8
- if (udiff > (int64_t)LONG_MAX || udiff < (int64_t)LONG_MIN) {
- return LONG_MAX;
- }
- #endif
- return (long)udiff;
- }
- /** Return the number of milliseconds elapsed between *start and *end.
- * If the tv_usec difference is 500, rounds away from zero.
- * Returns LONG_MAX on overflow and underflow.
- */
- long
- tv_mdiff(const struct timeval *start, const struct timeval *end)
- {
- /* Sanity check tv_usec */
- if (start->tv_usec > TOR_USEC_PER_SEC || start->tv_usec < 0) {
- log_warn(LD_GENERAL, "comparing times on millisecond detail with bad "
- "start tv_usec: " I64_FORMAT " microseconds",
- I64_PRINTF_ARG(start->tv_usec));
- return LONG_MAX;
- }
- if (end->tv_usec > TOR_USEC_PER_SEC || end->tv_usec < 0) {
- log_warn(LD_GENERAL, "comparing times on millisecond detail with bad "
- "end tv_usec: " I64_FORMAT " microseconds",
- I64_PRINTF_ARG(end->tv_usec));
- return LONG_MAX;
- }
- /* Some BSDs have struct timeval.tv_sec 64-bit, but time_t (and long) 32-bit
- */
- int64_t mdiff;
- const int64_t secdiff = tv_secdiff_impl(start, end);
- /* end->tv_usec - start->tv_usec can be up to 1 second either way, but the
- * mdiff calculation may add another temporary second for rounding.
- * Whether this actually causes overflow depends on the compiler's constant
- * folding and order of operations. */
- if (secdiff > (int64_t)(LONG_MAX/1000 - 2) ||
- secdiff < (int64_t)(LONG_MIN/1000 + 1)) {
- log_warn(LD_GENERAL, "comparing times on millisecond detail too far "
- "apart: " I64_FORMAT " seconds", I64_PRINTF_ARG(secdiff));
- return LONG_MAX;
- }
- /* Subtract and round */
- mdiff = secdiff*1000 +
- /* We add a million usec here to ensure that the result is positive,
- * so that the round-towards-zero behavior of the division will give
- * the right result for rounding to the nearest msec. Later we subtract
- * 1000 in order to get the correct result.
- * We'll never get an overflow here, because we check that both usecs are
- * between 0 and TV_USEC_PER_SEC. */
- ((int64_t)end->tv_usec - (int64_t)start->tv_usec + 500 + 1000000) / 1000
- - 1000;
- /* Some compilers are smart enough to work out this is a no-op on L64 */
- #if SIZEOF_LONG < 8
- if (mdiff > (int64_t)LONG_MAX || mdiff < (int64_t)LONG_MIN) {
- return LONG_MAX;
- }
- #endif
- return (long)mdiff;
- }
- /**
- * Converts timeval to milliseconds.
- */
- int64_t
- tv_to_msec(const struct timeval *tv)
- {
- int64_t conv = ((int64_t)tv->tv_sec)*1000L;
- /* Round ghetto-style */
- conv += ((int64_t)tv->tv_usec+500)/1000L;
- return conv;
- }
- /** Yield true iff <b>y</b> is a leap-year. */
- #define IS_LEAPYEAR(y) (!(y % 4) && ((y % 100) || !(y % 400)))
- /** Helper: Return the number of leap-days between Jan 1, y1 and Jan 1, y2. */
- static int
- n_leapdays(int year1, int year2)
- {
- --year1;
- --year2;
- return (year2/4 - year1/4) - (year2/100 - year1/100)
- + (year2/400 - year1/400);
- }
- /** Number of days per month in non-leap year; used by tor_timegm and
- * parse_rfc1123_time. */
- static const int days_per_month[] =
- { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
- /** Compute a time_t given a struct tm. The result is given in UTC, and
- * does not account for leap seconds. Return 0 on success, -1 on failure.
- */
- int
- tor_timegm(const struct tm *tm, time_t *time_out)
- {
- /* This is a pretty ironclad timegm implementation, snarfed from Python2.2.
- * It's way more brute-force than fiddling with tzset().
- *
- * We use int64_t rather than time_t to avoid overflow on multiplication on
- * platforms with 32-bit time_t. Since year is clipped to INT32_MAX, and
- * since 365 * 24 * 60 * 60 is approximately 31 million, it's not possible
- * for INT32_MAX years to overflow int64_t when converted to seconds. */
- int64_t year, days, hours, minutes, seconds;
- int i, invalid_year, dpm;
- /* Initialize time_out to 0 for now, to avoid bad usage in case this function
- fails and the caller ignores the return value. */
- tor_assert(time_out);
- *time_out = 0;
- /* avoid int overflow on addition */
- if (tm->tm_year < INT32_MAX-1900) {
- year = tm->tm_year + 1900;
- } else {
- /* clamp year */
- year = INT32_MAX;
- }
- invalid_year = (year < 1970 || tm->tm_year >= INT32_MAX-1900);
- if (tm->tm_mon >= 0 && tm->tm_mon <= 11) {
- dpm = days_per_month[tm->tm_mon];
- if (tm->tm_mon == 1 && !invalid_year && IS_LEAPYEAR(tm->tm_year)) {
- dpm = 29;
- }
- } else {
- /* invalid month - default to 0 days per month */
- dpm = 0;
- }
- if (invalid_year ||
- tm->tm_mon < 0 || tm->tm_mon > 11 ||
- tm->tm_mday < 1 || tm->tm_mday > dpm ||
- tm->tm_hour < 0 || tm->tm_hour > 23 ||
- tm->tm_min < 0 || tm->tm_min > 59 ||
- tm->tm_sec < 0 || tm->tm_sec > 60) {
- log_warn(LD_BUG, "Out-of-range argument to tor_timegm");
- return -1;
- }
- days = 365 * (year-1970) + n_leapdays(1970,(int)year);
- for (i = 0; i < tm->tm_mon; ++i)
- days += days_per_month[i];
- if (tm->tm_mon > 1 && IS_LEAPYEAR(year))
- ++days;
- days += tm->tm_mday - 1;
- hours = days*24 + tm->tm_hour;
- minutes = hours*60 + tm->tm_min;
- seconds = minutes*60 + tm->tm_sec;
- /* Check that "seconds" will fit in a time_t. On platforms where time_t is
- * 32-bit, this check will fail for dates in and after 2038.
- *
- * We already know that "seconds" can't be negative because "year" >= 1970 */
- #if SIZEOF_TIME_T < 8
- if (seconds < TIME_MIN || seconds > TIME_MAX) {
- log_warn(LD_BUG, "Result does not fit in tor_timegm");
- return -1;
- }
- #endif
- *time_out = (time_t)seconds;
- return 0;
- }
- /* strftime is locale-specific, so we need to replace those parts */
- /** A c-locale array of 3-letter names of weekdays, starting with Sun. */
- static const char *WEEKDAY_NAMES[] =
- { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };
- /** A c-locale array of 3-letter names of months, starting with Jan. */
- static const char *MONTH_NAMES[] =
- { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
- "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
- /** Set <b>buf</b> to the RFC1123 encoding of the UTC value of <b>t</b>.
- * The buffer must be at least RFC1123_TIME_LEN+1 bytes long.
- *
- * (RFC1123 format is "Fri, 29 Sep 2006 15:54:20 GMT". Note the "GMT"
- * rather than "UTC".)
- */
- void
- format_rfc1123_time(char *buf, time_t t)
- {
- struct tm tm;
- tor_gmtime_r(&t, &tm);
- strftime(buf, RFC1123_TIME_LEN+1, "___, %d ___ %Y %H:%M:%S GMT", &tm);
- tor_assert(tm.tm_wday >= 0);
- tor_assert(tm.tm_wday <= 6);
- memcpy(buf, WEEKDAY_NAMES[tm.tm_wday], 3);
- tor_assert(tm.tm_mon >= 0);
- tor_assert(tm.tm_mon <= 11);
- memcpy(buf+8, MONTH_NAMES[tm.tm_mon], 3);
- }
- /** Parse the (a subset of) the RFC1123 encoding of some time (in UTC) from
- * <b>buf</b>, and store the result in *<b>t</b>.
- *
- * Note that we only accept the subset generated by format_rfc1123_time above,
- * not the full range of formats suggested by RFC 1123.
- *
- * Return 0 on success, -1 on failure.
- */
- int
- parse_rfc1123_time(const char *buf, time_t *t)
- {
- struct tm tm;
- char month[4];
- char weekday[4];
- int i, m, invalid_year;
- unsigned tm_mday, tm_year, tm_hour, tm_min, tm_sec;
- unsigned dpm;
- if (strlen(buf) != RFC1123_TIME_LEN)
- return -1;
- memset(&tm, 0, sizeof(tm));
- if (tor_sscanf(buf, "%3s, %2u %3s %u %2u:%2u:%2u GMT", weekday,
- &tm_mday, month, &tm_year, &tm_hour,
- &tm_min, &tm_sec) < 7) {
- char *esc = esc_for_log(buf);
- log_warn(LD_GENERAL, "Got invalid RFC1123 time %s", esc);
- tor_free(esc);
- return -1;
- }
- m = -1;
- for (i = 0; i < 12; ++i) {
- if (!strcmp(month, MONTH_NAMES[i])) {
- m = i;
- break;
- }
- }
- if (m<0) {
- char *esc = esc_for_log(buf);
- log_warn(LD_GENERAL, "Got invalid RFC1123 time %s: No such month", esc);
- tor_free(esc);
- return -1;
- }
- tm.tm_mon = m;
- invalid_year = (tm_year >= INT32_MAX || tm_year < 1970);
- tor_assert(m >= 0 && m <= 11);
- dpm = days_per_month[m];
- if (m == 1 && !invalid_year && IS_LEAPYEAR(tm_year)) {
- dpm = 29;
- }
- if (invalid_year || tm_mday < 1 || tm_mday > dpm ||
- tm_hour > 23 || tm_min > 59 || tm_sec > 60) {
- char *esc = esc_for_log(buf);
- log_warn(LD_GENERAL, "Got invalid RFC1123 time %s", esc);
- tor_free(esc);
- return -1;
- }
- tm.tm_mday = (int)tm_mday;
- tm.tm_year = (int)tm_year;
- tm.tm_hour = (int)tm_hour;
- tm.tm_min = (int)tm_min;
- tm.tm_sec = (int)tm_sec;
- if (tm.tm_year < 1970) {
- /* LCOV_EXCL_START
- * XXXX I think this is dead code; we already checked for
- * invalid_year above. */
- tor_assert_nonfatal_unreached();
- char *esc = esc_for_log(buf);
- log_warn(LD_GENERAL,
- "Got invalid RFC1123 time %s. (Before 1970)", esc);
- tor_free(esc);
- return -1;
- /* LCOV_EXCL_STOP */
- }
- tm.tm_year -= 1900;
- return tor_timegm(&tm, t);
- }
- /** Set <b>buf</b> to the ISO8601 encoding of the local value of <b>t</b>.
- * The buffer must be at least ISO_TIME_LEN+1 bytes long.
- *
- * (ISO8601 format is 2006-10-29 10:57:20)
- */
- void
- format_local_iso_time(char *buf, time_t t)
- {
- struct tm tm;
- strftime(buf, ISO_TIME_LEN+1, "%Y-%m-%d %H:%M:%S", tor_localtime_r(&t, &tm));
- }
- /** Set <b>buf</b> to the ISO8601 encoding of the GMT value of <b>t</b>.
- * The buffer must be at least ISO_TIME_LEN+1 bytes long.
- */
- void
- format_iso_time(char *buf, time_t t)
- {
- struct tm tm;
- strftime(buf, ISO_TIME_LEN+1, "%Y-%m-%d %H:%M:%S", tor_gmtime_r(&t, &tm));
- }
- /** As format_iso_time, but use the yyyy-mm-ddThh:mm:ss format to avoid
- * embedding an internal space. */
- void
- format_iso_time_nospace(char *buf, time_t t)
- {
- format_iso_time(buf, t);
- buf[10] = 'T';
- }
- /** As format_iso_time_nospace, but include microseconds in decimal
- * fixed-point format. Requires that buf be at least ISO_TIME_USEC_LEN+1
- * bytes long. */
- void
- format_iso_time_nospace_usec(char *buf, const struct timeval *tv)
- {
- tor_assert(tv);
- format_iso_time_nospace(buf, (time_t)tv->tv_sec);
- tor_snprintf(buf+ISO_TIME_LEN, 8, ".%06d", (int)tv->tv_usec);
- }
- /** Given an ISO-formatted UTC time value (after the epoch) in <b>cp</b>,
- * parse it and store its value in *<b>t</b>. Return 0 on success, -1 on
- * failure. Ignore extraneous stuff in <b>cp</b> after the end of the time
- * string, unless <b>strict</b> is set. If <b>nospace</b> is set,
- * expect the YYYY-MM-DDTHH:MM:SS format. */
- int
- parse_iso_time_(const char *cp, time_t *t, int strict, int nospace)
- {
- struct tm st_tm;
- unsigned int year=0, month=0, day=0, hour=0, minute=0, second=0;
- int n_fields;
- char extra_char, separator_char;
- n_fields = tor_sscanf(cp, "%u-%2u-%2u%c%2u:%2u:%2u%c",
- &year, &month, &day,
- &separator_char,
- &hour, &minute, &second, &extra_char);
- if (strict ? (n_fields != 7) : (n_fields < 7)) {
- char *esc = esc_for_log(cp);
- log_warn(LD_GENERAL, "ISO time %s was unparseable", esc);
- tor_free(esc);
- return -1;
- }
- if (separator_char != (nospace ? 'T' : ' ')) {
- char *esc = esc_for_log(cp);
- log_warn(LD_GENERAL, "ISO time %s was unparseable", esc);
- tor_free(esc);
- return -1;
- }
- if (year < 1970 || month < 1 || month > 12 || day < 1 || day > 31 ||
- hour > 23 || minute > 59 || second > 60 || year >= INT32_MAX) {
- char *esc = esc_for_log(cp);
- log_warn(LD_GENERAL, "ISO time %s was nonsensical", esc);
- tor_free(esc);
- return -1;
- }
- st_tm.tm_year = (int)year-1900;
- st_tm.tm_mon = month-1;
- st_tm.tm_mday = day;
- st_tm.tm_hour = hour;
- st_tm.tm_min = minute;
- st_tm.tm_sec = second;
- st_tm.tm_wday = 0; /* Should be ignored. */
- if (st_tm.tm_year < 70) {
- /* LCOV_EXCL_START
- * XXXX I think this is dead code; we already checked for
- * year < 1970 above. */
- tor_assert_nonfatal_unreached();
- char *esc = esc_for_log(cp);
- log_warn(LD_GENERAL, "Got invalid ISO time %s. (Before 1970)", esc);
- tor_free(esc);
- return -1;
- /* LCOV_EXCL_STOP */
- }
- return tor_timegm(&st_tm, t);
- }
- /** Given an ISO-formatted UTC time value (after the epoch) in <b>cp</b>,
- * parse it and store its value in *<b>t</b>. Return 0 on success, -1 on
- * failure. Reject the string if any characters are present after the time.
- */
- int
- parse_iso_time(const char *cp, time_t *t)
- {
- return parse_iso_time_(cp, t, 1, 0);
- }
- /**
- * As parse_iso_time, but parses a time encoded by format_iso_time_nospace().
- */
- int
- parse_iso_time_nospace(const char *cp, time_t *t)
- {
- return parse_iso_time_(cp, t, 1, 1);
- }
- /** Given a <b>date</b> in one of the three formats allowed by HTTP (ugh),
- * parse it into <b>tm</b>. Return 0 on success, negative on failure. */
- int
- parse_http_time(const char *date, struct tm *tm)
- {
- const char *cp;
- char month[4];
- char wkday[4];
- int i;
- unsigned tm_mday, tm_year, tm_hour, tm_min, tm_sec;
- tor_assert(tm);
- memset(tm, 0, sizeof(*tm));
- /* First, try RFC1123 or RFC850 format: skip the weekday. */
- if ((cp = strchr(date, ','))) {
- ++cp;
- if (*cp != ' ')
- return -1;
- ++cp;
- if (tor_sscanf(cp, "%2u %3s %4u %2u:%2u:%2u GMT",
- &tm_mday, month, &tm_year,
- &tm_hour, &tm_min, &tm_sec) == 6) {
- /* rfc1123-date */
- tm_year -= 1900;
- } else if (tor_sscanf(cp, "%2u-%3s-%2u %2u:%2u:%2u GMT",
- &tm_mday, month, &tm_year,
- &tm_hour, &tm_min, &tm_sec) == 6) {
- /* rfc850-date */
- } else {
- return -1;
- }
- } else {
- /* No comma; possibly asctime() format. */
- if (tor_sscanf(date, "%3s %3s %2u %2u:%2u:%2u %4u",
- wkday, month, &tm_mday,
- &tm_hour, &tm_min, &tm_sec, &tm_year) == 7) {
- tm_year -= 1900;
- } else {
- return -1;
- }
- }
- tm->tm_mday = (int)tm_mday;
- tm->tm_year = (int)tm_year;
- tm->tm_hour = (int)tm_hour;
- tm->tm_min = (int)tm_min;
- tm->tm_sec = (int)tm_sec;
- tm->tm_wday = 0; /* Leave this unset. */
- month[3] = '\0';
- /* Okay, now decode the month. */
- /* set tm->tm_mon to dummy value so the check below fails. */
- tm->tm_mon = -1;
- for (i = 0; i < 12; ++i) {
- if (!strcasecmp(MONTH_NAMES[i], month)) {
- tm->tm_mon = i;
- }
- }
- if (tm->tm_year < 0 ||
- tm->tm_mon < 0 || tm->tm_mon > 11 ||
- tm->tm_mday < 1 || tm->tm_mday > 31 ||
- tm->tm_hour < 0 || tm->tm_hour > 23 ||
- tm->tm_min < 0 || tm->tm_min > 59 ||
- tm->tm_sec < 0 || tm->tm_sec > 60)
- return -1; /* Out of range, or bad month. */
- return 0;
- }
- /** Given an <b>interval</b> in seconds, try to write it to the
- * <b>out_len</b>-byte buffer in <b>out</b> in a human-readable form.
- * Return 0 on success, -1 on failure.
- */
- int
- format_time_interval(char *out, size_t out_len, long interval)
- {
- /* We only report seconds if there's no hours. */
- long sec = 0, min = 0, hour = 0, day = 0;
- /* -LONG_MIN is LONG_MAX + 1, which causes signed overflow */
- if (interval < -LONG_MAX)
- interval = LONG_MAX;
- else if (interval < 0)
- interval = -interval;
- if (interval >= 86400) {
- day = interval / 86400;
- interval %= 86400;
- }
- if (interval >= 3600) {
- hour = interval / 3600;
- interval %= 3600;
- }
- if (interval >= 60) {
- min = interval / 60;
- interval %= 60;
- }
- sec = interval;
- if (day) {
- return tor_snprintf(out, out_len, "%ld days, %ld hours, %ld minutes",
- day, hour, min);
- } else if (hour) {
- return tor_snprintf(out, out_len, "%ld hours, %ld minutes", hour, min);
- } else if (min) {
- return tor_snprintf(out, out_len, "%ld minutes, %ld seconds", min, sec);
- } else {
- return tor_snprintf(out, out_len, "%ld seconds", sec);
- }
- }
- /* =====
- * Cached time
- * ===== */
- #ifndef TIME_IS_FAST
- /** Cached estimate of the current time. Updated around once per second;
- * may be a few seconds off if we are really busy. This is a hack to avoid
- * calling time(NULL) (which not everybody has optimized) on critical paths.
- */
- static time_t cached_approx_time = 0;
- /** Return a cached estimate of the current time from when
- * update_approx_time() was last called. This is a hack to avoid calling
- * time(NULL) on critical paths: please do not even think of calling it
- * anywhere else. */
- time_t
- approx_time(void)
- {
- return cached_approx_time;
- }
- /** Update the cached estimate of the current time. This function SHOULD be
- * called once per second, and MUST be called before the first call to
- * get_approx_time. */
- void
- update_approx_time(time_t now)
- {
- cached_approx_time = now;
- }
- #endif
- /* =====
- * Rate limiting
- * ===== */
- /** If the rate-limiter <b>lim</b> is ready at <b>now</b>, return the number
- * of calls to rate_limit_is_ready (including this one!) since the last time
- * rate_limit_is_ready returned nonzero. Otherwise return 0.
- * If the call number hits <b>RATELIM_TOOMANY</b> limit, drop a warning
- * about this event and stop counting. */
- static int
- rate_limit_is_ready(ratelim_t *lim, time_t now)
- {
- if (lim->rate + lim->last_allowed <= now) {
- int res = lim->n_calls_since_last_time + 1;
- lim->last_allowed = now;
- lim->n_calls_since_last_time = 0;
- return res;
- } else {
- if (lim->n_calls_since_last_time <= RATELIM_TOOMANY) {
- ++lim->n_calls_since_last_time;
- }
- return 0;
- }
- }
- /** If the rate-limiter <b>lim</b> is ready at <b>now</b>, return a newly
- * allocated string indicating how many messages were suppressed, suitable to
- * append to a log message. Otherwise return NULL. */
- char *
- rate_limit_log(ratelim_t *lim, time_t now)
- {
- int n;
- if ((n = rate_limit_is_ready(lim, now))) {
- if (n == 1) {
- return tor_strdup("");
- } else {
- char *cp=NULL;
- const char *opt_over = (n >= RATELIM_TOOMANY) ? "over " : "";
- /* XXXX this is not exactly correct: the messages could have occurred
- * any time between the old value of lim->allowed and now. */
- tor_asprintf(&cp,
- " [%s%d similar message(s) suppressed in last %d seconds]",
- opt_over, n-1, lim->rate);
- return cp;
- }
- } else {
- return NULL;
- }
- }
- /* =====
- * File helpers
- * ===== */
- /** Write <b>count</b> bytes from <b>buf</b> to <b>fd</b>. <b>isSocket</b>
- * must be 1 if fd was returned by socket() or accept(), and 0 if fd
- * was returned by open(). Return the number of bytes written, or -1
- * on error. Only use if fd is a blocking fd. */
- ssize_t
- write_all(tor_socket_t fd, const char *buf, size_t count, int isSocket)
- {
- size_t written = 0;
- ssize_t result;
- tor_assert(count < SSIZE_MAX);
- while (written != count) {
- if (isSocket)
- result = tor_socket_send(fd, buf+written, count-written, 0);
- else
- result = write((int)fd, buf+written, count-written);
- if (result<0)
- return -1;
- written += result;
- }
- return (ssize_t)count;
- }
- /** Read from <b>fd</b> to <b>buf</b>, until we get <b>count</b> bytes
- * or reach the end of the file. <b>isSocket</b> must be 1 if fd
- * was returned by socket() or accept(), and 0 if fd was returned by
- * open(). Return the number of bytes read, or -1 on error. Only use
- * if fd is a blocking fd. */
- ssize_t
- read_all(tor_socket_t fd, char *buf, size_t count, int isSocket)
- {
- size_t numread = 0;
- ssize_t result;
- if (count > SIZE_T_CEILING || count > SSIZE_MAX) {
- errno = EINVAL;
- return -1;
- }
- while (numread < count) {
- if (isSocket)
- result = tor_socket_recv(fd, buf+numread, count-numread, 0);
- else
- result = read((int)fd, buf+numread, count-numread);
- if (result<0)
- return -1;
- else if (result == 0)
- break;
- numread += result;
- }
- return (ssize_t)numread;
- }
- /*
- * Filesystem operations.
- */
- /** Clean up <b>name</b> so that we can use it in a call to "stat". On Unix,
- * we do nothing. On Windows, we remove a trailing slash, unless the path is
- * the root of a disk. */
- static void
- clean_name_for_stat(char *name)
- {
- #ifdef _WIN32
- size_t len = strlen(name);
- if (!len)
- return;
- if (name[len-1]=='\\' || name[len-1]=='/') {
- if (len == 1 || (len==3 && name[1]==':'))
- return;
- name[len-1]='\0';
- }
- #else
- (void)name;
- #endif
- }
- /** Wrapper for unlink() to make it mockable for the test suite; returns 0
- * if unlinking the file succeeded, -1 and sets errno if unlinking fails.
- */
- MOCK_IMPL(int,
- tor_unlink,(const char *pathname))
- {
- return unlink(pathname);
- }
- /** Return:
- * FN_ERROR if filename can't be read, is NULL, or is zero-length,
- * FN_NOENT if it doesn't exist,
- * FN_FILE if it is a non-empty regular file, or a FIFO on unix-like systems,
- * FN_EMPTY for zero-byte regular files,
- * FN_DIR if it's a directory, and
- * FN_ERROR for any other file type.
- * On FN_ERROR and FN_NOENT, sets errno. (errno is not set when FN_ERROR
- * is returned due to an unhandled file type.) */
- file_status_t
- file_status(const char *fname)
- {
- struct stat st;
- char *f;
- int r;
- if (!fname || strlen(fname) == 0) {
- return FN_ERROR;
- }
- f = tor_strdup(fname);
- clean_name_for_stat(f);
- log_debug(LD_FS, "stat()ing %s", f);
- r = stat(sandbox_intern_string(f), &st);
- tor_free(f);
- if (r) {
- if (errno == ENOENT) {
- return FN_NOENT;
- }
- return FN_ERROR;
- }
- if (st.st_mode & S_IFDIR) {
- return FN_DIR;
- } else if (st.st_mode & S_IFREG) {
- if (st.st_size > 0) {
- return FN_FILE;
- } else if (st.st_size == 0) {
- return FN_EMPTY;
- } else {
- return FN_ERROR;
- }
- #ifndef _WIN32
- } else if (st.st_mode & S_IFIFO) {
- return FN_FILE;
- #endif
- } else {
- return FN_ERROR;
- }
- }
- /** Check whether <b>dirname</b> exists and is private. If yes return 0.
- * If <b>dirname</b> does not exist:
- * - if <b>check</b>&CPD_CREATE, try to create it and return 0 on success.
- * - if <b>check</b>&CPD_CHECK, and we think we can create it, return 0.
- * - if <b>check</b>&CPD_CHECK is false, and the directory exists, return 0.
- * - otherwise, return -1.
- * If CPD_GROUP_OK is set, then it's okay if the directory
- * is group-readable, but in all cases we create the directory mode 0700.
- * If CPD_GROUP_READ is set, existing directory behaves as CPD_GROUP_OK and
- * if the directory is created it will use mode 0750 with group read
- * permission. Group read privileges also assume execute permission
- * as norm for directories. If CPD_CHECK_MODE_ONLY is set, then we don't
- * alter the directory permissions if they are too permissive:
- * we just return -1.
- * When effective_user is not NULL, check permissions against the given user
- * and its primary group.
- */
- MOCK_IMPL(int,
- check_private_dir,(const char *dirname, cpd_check_t check,
- const char *effective_user))
- {
- int r;
- struct stat st;
- tor_assert(dirname);
- #ifndef _WIN32
- int fd;
- const struct passwd *pw = NULL;
- uid_t running_uid;
- gid_t running_gid;
- /*
- * Goal is to harden the implementation by removing any
- * potential for race between stat() and chmod().
- * chmod() accepts filename as argument. If an attacker can move
- * the file between stat() and chmod(), a potential race exists.
- *
- * Several suggestions taken from:
- * https://developer.apple.com/library/mac/documentation/
- * Security/Conceptual/SecureCodingGuide/Articles/RaceConditions.html
- */
- /* Open directory.
- * O_NOFOLLOW to ensure that it does not follow symbolic links */
- fd = open(sandbox_intern_string(dirname), O_NOFOLLOW);
- /* Was there an error? Maybe the directory does not exist? */
- if (fd == -1) {
- if (errno != ENOENT) {
- /* Other directory error */
- log_warn(LD_FS, "Directory %s cannot be read: %s", dirname,
- strerror(errno));
- return -1;
- }
- /* Received ENOENT: Directory does not exist */
- /* Should we create the directory? */
- if (check & CPD_CREATE) {
- log_info(LD_GENERAL, "Creating directory %s", dirname);
- if (check & CPD_GROUP_READ) {
- r = mkdir(dirname, 0750);
- } else {
- r = mkdir(dirname, 0700);
- }
- /* check for mkdir() error */
- if (r) {
- log_warn(LD_FS, "Error creating directory %s: %s", dirname,
- strerror(errno));
- return -1;
- }
- /* we just created the directory. try to open it again.
- * permissions on the directory will be checked again below.*/
- fd = open(sandbox_intern_string(dirname), O_NOFOLLOW);
- if (fd == -1) {
- log_warn(LD_FS, "Could not reopen recently created directory %s: %s",
- dirname,
- strerror(errno));
- return -1;
- } else {
- close(fd);
- }
- } else if (!(check & CPD_CHECK)) {
- log_warn(LD_FS, "Directory %s does not exist.", dirname);
- return -1;
- }
- /* XXXX In the case where check==CPD_CHECK, we should look at the
- * parent directory a little harder. */
- return 0;
- }
- tor_assert(fd >= 0);
- //f = tor_strdup(dirname);
- //clean_name_for_stat(f);
- log_debug(LD_FS, "stat()ing %s", dirname);
- //r = stat(sandbox_intern_string(f), &st);
- r = fstat(fd, &st);
- if (r == -1) {
- log_warn(LD_FS, "fstat() on directory %s failed.", dirname);
- close(fd);
- return -1;
- }
- //tor_free(f);
- /* check that dirname is a directory */
- if (!(st.st_mode & S_IFDIR)) {
- log_warn(LD_FS, "%s is not a directory", dirname);
- close(fd);
- return -1;
- }
- if (effective_user) {
- /* Look up the user and group information.
- * If we have a problem, bail out. */
- pw = tor_getpwnam(effective_user);
- if (pw == NULL) {
- log_warn(LD_CONFIG, "Error setting configured user: %s not found",
- effective_user);
- close(fd);
- return -1;
- }
- running_uid = pw->pw_uid;
- running_gid = pw->pw_gid;
- } else {
- running_uid = getuid();
- running_gid = getgid();
- }
- if (st.st_uid != running_uid) {
- const struct passwd *pw_uid = NULL;
- char *process_ownername = NULL;
- pw_uid = tor_getpwuid(running_uid);
- process_ownername = pw_uid ? tor_strdup(pw_uid->pw_name) :
- tor_strdup("<unknown>");
- pw_uid = tor_getpwuid(st.st_uid);
- log_warn(LD_FS, "%s is not owned by this user (%s, %d) but by "
- "%s (%d). Perhaps you are running Tor as the wrong user?",
- dirname, process_ownername, (int)running_uid,
- pw ? pw->pw_name : "<unknown>", (int)st.st_uid);
- tor_free(process_ownername);
- close(fd);
- return -1;
- }
- if ( (check & (CPD_GROUP_OK|CPD_GROUP_READ))
- && (st.st_gid != running_gid) && (st.st_gid != 0)) {
- struct group *gr;
- char *process_groupname = NULL;
- gr = getgrgid(running_gid);
- process_groupname = gr ? tor_strdup(gr->gr_name) : tor_strdup("<unknown>");
- gr = getgrgid(st.st_gid);
- log_warn(LD_FS, "%s is not owned by this group (%s, %d) but by group "
- "%s (%d). Are you running Tor as the wrong user?",
- dirname, process_groupname, (int)running_gid,
- gr ? gr->gr_name : "<unknown>", (int)st.st_gid);
- tor_free(process_groupname);
- close(fd);
- return -1;
- }
- unsigned unwanted_bits = 0;
- if (check & (CPD_GROUP_OK|CPD_GROUP_READ)) {
- unwanted_bits = 0027;
- } else {
- unwanted_bits = 0077;
- }
- unsigned check_bits_filter = ~0;
- if (check & CPD_RELAX_DIRMODE_CHECK) {
- check_bits_filter = 0022;
- }
- if ((st.st_mode & unwanted_bits & check_bits_filter) != 0) {
- unsigned new_mode;
- if (check & CPD_CHECK_MODE_ONLY) {
- log_warn(LD_FS, "Permissions on directory %s are too permissive.",
- dirname);
- close(fd);
- return -1;
- }
- log_warn(LD_FS, "Fixing permissions on directory %s", dirname);
- new_mode = st.st_mode;
- new_mode |= 0700; /* Owner should have rwx */
- if (check & CPD_GROUP_READ) {
- new_mode |= 0050; /* Group should have rx */
- }
- new_mode &= ~unwanted_bits; /* Clear the bits that we didn't want set...*/
- if (fchmod(fd, new_mode)) {
- log_warn(LD_FS, "Could not chmod directory %s: %s", dirname,
- strerror(errno));
- close(fd);
- return -1;
- } else {
- close(fd);
- return 0;
- }
- }
- close(fd);
- #else
- /* Win32 case: we can't open() a directory. */
- (void)effective_user;
- char *f = tor_strdup(dirname);
- clean_name_for_stat(f);
- log_debug(LD_FS, "stat()ing %s", f);
- r = stat(sandbox_intern_string(f), &st);
- tor_free(f);
- if (r) {
- if (errno != ENOENT) {
- log_warn(LD_FS, "Directory %s cannot be read: %s", dirname,
- strerror(errno));
- return -1;
- }
- if (check & CPD_CREATE) {
- log_info(LD_GENERAL, "Creating directory %s", dirname);
- r = mkdir(dirname);
- if (r) {
- log_warn(LD_FS, "Error creating directory %s: %s", dirname,
- strerror(errno));
- return -1;
- }
- } else if (!(check & CPD_CHECK)) {
- log_warn(LD_FS, "Directory %s does not exist.", dirname);
- return -1;
- }
- return 0;
- }
- if (!(st.st_mode & S_IFDIR)) {
- log_warn(LD_FS, "%s is not a directory", dirname);
- return -1;
- }
- #endif
- return 0;
- }
- /** Create a file named <b>fname</b> with the contents <b>str</b>. Overwrite
- * the previous <b>fname</b> if possible. Return 0 on success, -1 on failure.
- *
- * This function replaces the old file atomically, if possible. This
- * function, and all other functions in util.c that create files, create them
- * with mode 0600.
- */
- MOCK_IMPL(int,
- write_str_to_file,(const char *fname, const char *str, int bin))
- {
- #ifdef _WIN32
- if (!bin && strchr(str, '\r')) {
- log_warn(LD_BUG,
- "We're writing a text string that already contains a CR to %s",
- escaped(fname));
- }
- #endif
- return write_bytes_to_file(fname, str, strlen(str), bin);
- }
- /** Represents a file that we're writing to, with support for atomic commit:
- * we can write into a temporary file, and either remove the file on
- * failure, or replace the original file on success. */
- struct open_file_t {
- char *tempname; /**< Name of the temporary file. */
- char *filename; /**< Name of the original file. */
- unsigned rename_on_close:1; /**< Are we using the temporary file or not? */
- unsigned binary:1; /**< Did we open in binary mode? */
- int fd; /**< fd for the open file. */
- FILE *stdio_file; /**< stdio wrapper for <b>fd</b>. */
- };
- /** Try to start writing to the file in <b>fname</b>, passing the flags
- * <b>open_flags</b> to the open() syscall, creating the file (if needed) with
- * access value <b>mode</b>. If the O_APPEND flag is set, we append to the
- * original file. Otherwise, we open a new temporary file in the same
- * directory, and either replace the original or remove the temporary file
- * when we're done.
- *
- * Return the fd for the newly opened file, and store working data in
- * *<b>data_out</b>. The caller should not close the fd manually:
- * instead, call finish_writing_to_file() or abort_writing_to_file().
- * Returns -1 on failure.
- *
- * NOTE: When not appending, the flags O_CREAT and O_TRUNC are treated
- * as true and the flag O_EXCL is treated as false.
- *
- * NOTE: Ordinarily, O_APPEND means "seek to the end of the file before each
- * write()". We don't do that.
- */
- int
- start_writing_to_file(const char *fname, int open_flags, int mode,
- open_file_t **data_out)
- {
- open_file_t *new_file = tor_malloc_zero(sizeof(open_file_t));
- const char *open_name;
- int append = 0;
- tor_assert(fname);
- tor_assert(data_out);
- #if (O_BINARY != 0 && O_TEXT != 0)
- tor_assert((open_flags & (O_BINARY|O_TEXT)) != 0);
- #endif
- new_file->fd = -1;
- new_file->filename = tor_strdup(fname);
- if (open_flags & O_APPEND) {
- open_name = fname;
- new_file->rename_on_close = 0;
- append = 1;
- open_flags &= ~O_APPEND;
- } else {
- tor_asprintf(&new_file->tempname, "%s.tmp", fname);
- open_name = new_file->tempname;
- /* We always replace an existing temporary file if there is one. */
- open_flags |= O_CREAT|O_TRUNC;
- open_flags &= ~O_EXCL;
- new_file->rename_on_close = 1;
- }
- #if O_BINARY != 0
- if (open_flags & O_BINARY)
- new_file->binary = 1;
- #endif
- new_file->fd = tor_open_cloexec(open_name, open_flags, mode);
- if (new_file->fd < 0) {
- log_warn(LD_FS, "Couldn't open \"%s\" (%s) for writing: %s",
- open_name, fname, strerror(errno));
- goto err;
- }
- if (append) {
- if (tor_fd_seekend(new_file->fd) < 0) {
- log_warn(LD_FS, "Couldn't seek to end of file \"%s\": %s", open_name,
- strerror(errno));
- goto err;
- }
- }
- *data_out = new_file;
- return new_file->fd;
- err:
- if (new_file->fd >= 0)
- close(new_file->fd);
- *data_out = NULL;
- tor_free(new_file->filename);
- tor_free(new_file->tempname);
- tor_free(new_file);
- return -1;
- }
- /** Given <b>file_data</b> from start_writing_to_file(), return a stdio FILE*
- * that can be used to write to the same file. The caller should not mix
- * stdio calls with non-stdio calls. */
- FILE *
- fdopen_file(open_file_t *file_data)
- {
- tor_assert(file_data);
- if (file_data->stdio_file)
- return file_data->stdio_file;
- tor_assert(file_data->fd >= 0);
- if (!(file_data->stdio_file = fdopen(file_data->fd,
- file_data->binary?"ab":"a"))) {
- log_warn(LD_FS, "Couldn't fdopen \"%s\" [%d]: %s", file_data->filename,
- file_data->fd, strerror(errno));
- }
- return file_data->stdio_file;
- }
- /** Combines start_writing_to_file with fdopen_file(): arguments are as
- * for start_writing_to_file, but */
- FILE *
- start_writing_to_stdio_file(const char *fname, int open_flags, int mode,
- open_file_t **data_out)
- {
- FILE *res;
- if (start_writing_to_file(fname, open_flags, mode, data_out)<0)
- return NULL;
- if (!(res = fdopen_file(*data_out))) {
- abort_writing_to_file(*data_out);
- *data_out = NULL;
- }
- return res;
- }
- /** Helper function: close and free the underlying file and memory in
- * <b>file_data</b>. If we were writing into a temporary file, then delete
- * that file (if abort_write is true) or replaces the target file with
- * the temporary file (if abort_write is false). */
- static int
- finish_writing_to_file_impl(open_file_t *file_data, int abort_write)
- {
- int r = 0;
- tor_assert(file_data && file_data->filename);
- if (file_data->stdio_file) {
- if (fclose(file_data->stdio_file)) {
- log_warn(LD_FS, "Error closing \"%s\": %s", file_data->filename,
- strerror(errno));
- abort_write = r = -1;
- }
- } else if (file_data->fd >= 0 && close(file_data->fd) < 0) {
- log_warn(LD_FS, "Error flushing \"%s\": %s", file_data->filename,
- strerror(errno));
- abort_write = r = -1;
- }
- if (file_data->rename_on_close) {
- tor_assert(file_data->tempname && file_data->filename);
- if (!abort_write) {
- tor_assert(strcmp(file_data->filename, file_data->tempname));
- if (replace_file(file_data->tempname, file_data->filename)) {
- log_warn(LD_FS, "Error replacing \"%s\": %s", file_data->filename,
- strerror(errno));
- abort_write = r = -1;
- }
- }
- if (abort_write) {
- int res = unlink(file_data->tempname);
- if (res != 0) {
- /* We couldn't unlink and we'll leave a mess behind */
- log_warn(LD_FS, "Failed to unlink %s: %s",
- file_data->tempname, strerror(errno));
- r = -1;
- }
- }
- }
- tor_free(file_data->filename);
- tor_free(file_data->tempname);
- tor_free(file_data);
- return r;
- }
- /** Finish writing to <b>file_data</b>: close the file handle, free memory as
- * needed, and if using a temporary file, replace the original file with
- * the temporary file. */
- int
- finish_writing_to_file(open_file_t *file_data)
- {
- return finish_writing_to_file_impl(file_data, 0);
- }
- /** Finish writing to <b>file_data</b>: close the file handle, free memory as
- * needed, and if using a temporary file, delete it. */
- int
- abort_writing_to_file(open_file_t *file_data)
- {
- return finish_writing_to_file_impl(file_data, 1);
- }
- /** Helper: given a set of flags as passed to open(2), open the file
- * <b>fname</b> and write all the sized_chunk_t structs in <b>chunks</b> to
- * the file. Do so as atomically as possible e.g. by opening temp files and
- * renaming. */
- static int
- write_chunks_to_file_impl(const char *fname, const smartlist_t *chunks,
- int open_flags)
- {
- open_file_t *file = NULL;
- int fd;
- ssize_t result;
- fd = start_writing_to_file(fname, open_flags, 0600, &file);
- if (fd<0)
- return -1;
- SMARTLIST_FOREACH(chunks, sized_chunk_t *, chunk,
- {
- result = write_all(fd, chunk->bytes, chunk->len, 0);
- if (result < 0) {
- log_warn(LD_FS, "Error writing to \"%s\": %s", fname,
- strerror(errno));
- goto err;
- }
- tor_assert((size_t)result == chunk->len);
- });
- return finish_writing_to_file(file);
- err:
- abort_writing_to_file(file);
- return -1;
- }
- /** Given a smartlist of sized_chunk_t, write them to a file
- * <b>fname</b>, overwriting or creating the file as necessary.
- * If <b>no_tempfile</b> is 0 then the file will be written
- * atomically. */
- int
- write_chunks_to_file(const char *fname, const smartlist_t *chunks, int bin,
- int no_tempfile)
- {
- int flags = OPEN_FLAGS_REPLACE|(bin?O_BINARY:O_TEXT);
- if (no_tempfile) {
- /* O_APPEND stops write_chunks_to_file from using tempfiles */
- flags |= O_APPEND;
- }
- return write_chunks_to_file_impl(fname, chunks, flags);
- }
- /** Write <b>len</b> bytes, starting at <b>str</b>, to <b>fname</b>
- using the open() flags passed in <b>flags</b>. */
- static int
- write_bytes_to_file_impl(const char *fname, const char *str, size_t len,
- int flags)
- {
- int r;
- sized_chunk_t c = { str, len };
- smartlist_t *chunks = smartlist_new();
- smartlist_add(chunks, &c);
- r = write_chunks_to_file_impl(fname, chunks, flags);
- smartlist_free(chunks);
- return r;
- }
- /** As write_str_to_file, but does not assume a NUL-terminated
- * string. Instead, we write <b>len</b> bytes, starting at <b>str</b>. */
- MOCK_IMPL(int,
- write_bytes_to_file,(const char *fname, const char *str, size_t len,
- int bin))
- {
- return write_bytes_to_file_impl(fname, str, len,
- OPEN_FLAGS_REPLACE|(bin?O_BINARY:O_TEXT));
- }
- /** As write_bytes_to_file, but if the file already exists, append the bytes
- * to the end of the file instead of overwriting it. */
- int
- append_bytes_to_file(const char *fname, const char *str, size_t len,
- int bin)
- {
- return write_bytes_to_file_impl(fname, str, len,
- OPEN_FLAGS_APPEND|(bin?O_BINARY:O_TEXT));
- }
- /** Like write_str_to_file(), but also return -1 if there was a file
- already residing in <b>fname</b>. */
- int
- write_bytes_to_new_file(const char *fname, const char *str, size_t len,
- int bin)
- {
- return write_bytes_to_file_impl(fname, str, len,
- OPEN_FLAGS_DONT_REPLACE|
- (bin?O_BINARY:O_TEXT));
- }
- /**
- * Read the contents of the open file <b>fd</b> presuming it is a FIFO
- * (or similar) file descriptor for which the size of the file isn't
- * known ahead of time. Return NULL on failure, and a NUL-terminated
- * string on success. On success, set <b>sz_out</b> to the number of
- * bytes read.
- */
- char *
- read_file_to_str_until_eof(int fd, size_t max_bytes_to_read, size_t *sz_out)
- {
- ssize_t r;
- size_t pos = 0;
- char *string = NULL;
- size_t string_max = 0;
- if (max_bytes_to_read+1 >= SIZE_T_CEILING) {
- errno = EINVAL;
- return NULL;
- }
- do {
- /* XXXX This "add 1K" approach is a little goofy; if we care about
- * performance here, we should be doubling. But in practice we shouldn't
- * be using this function on big files anyway. */
- string_max = pos + 1024;
- if (string_max > max_bytes_to_read)
- string_max = max_bytes_to_read + 1;
- string = tor_realloc(string, string_max);
- r = read(fd, string + pos, string_max - pos - 1);
- if (r < 0) {
- int save_errno = errno;
- tor_free(string);
- errno = save_errno;
- return NULL;
- }
- pos += r;
- } while (r > 0 && pos < max_bytes_to_read);
- tor_assert(pos < string_max);
- *sz_out = pos;
- string[pos] = '\0';
- return string;
- }
- /** Read the contents of <b>filename</b> into a newly allocated
- * string; return the string on success or NULL on failure.
- *
- * If <b>stat_out</b> is provided, store the result of stat()ing the
- * file into <b>stat_out</b>.
- *
- * If <b>flags</b> & RFTS_BIN, open the file in binary mode.
- * If <b>flags</b> & RFTS_IGNORE_MISSING, don't warn if the file
- * doesn't exist.
- */
- /*
- * This function <em>may</em> return an erroneous result if the file
- * is modified while it is running, but must not crash or overflow.
- * Right now, the error case occurs when the file length grows between
- * the call to stat and the call to read_all: the resulting string will
- * be truncated.
- */
- MOCK_IMPL(char *,
- read_file_to_str, (const char *filename, int flags, struct stat *stat_out))
- {
- int fd; /* router file */
- struct stat statbuf;
- char *string;
- ssize_t r;
- int bin = flags & RFTS_BIN;
- tor_assert(filename);
- fd = tor_open_cloexec(filename,O_RDONLY|(bin?O_BINARY:O_TEXT),0);
- if (fd<0) {
- int severity = LOG_WARN;
- int save_errno = errno;
- if (errno == ENOENT && (flags & RFTS_IGNORE_MISSING))
- severity = LOG_INFO;
- log_fn(severity, LD_FS,"Could not open \"%s\": %s",filename,
- strerror(errno));
- errno = save_errno;
- return NULL;
- }
- if (fstat(fd, &statbuf)<0) {
- int save_errno = errno;
- close(fd);
- log_warn(LD_FS,"Could not fstat \"%s\".",filename);
- errno = save_errno;
- return NULL;
- }
- #ifndef _WIN32
- /** When we detect that we're reading from a FIFO, don't read more than
- * this many bytes. It's insane overkill for most uses. */
- #define FIFO_READ_MAX (1024*1024)
- if (S_ISFIFO(statbuf.st_mode)) {
- size_t sz = 0;
- string = read_file_to_str_until_eof(fd, FIFO_READ_MAX, &sz);
- int save_errno = errno;
- if (string && stat_out) {
- statbuf.st_size = sz;
- memcpy(stat_out, &statbuf, sizeof(struct stat));
- }
- close(fd);
- if (!string)
- errno = save_errno;
- return string;
- }
- #endif
- if ((uint64_t)(statbuf.st_size)+1 >= SIZE_T_CEILING) {
- close(fd);
- errno = EINVAL;
- return NULL;
- }
- string = tor_malloc((size_t)(statbuf.st_size+1));
- r = read_all(fd,string,(size_t)statbuf.st_size,0);
- if (r<0) {
- int save_errno = errno;
- log_warn(LD_FS,"Error reading from file \"%s\": %s", filename,
- strerror(errno));
- tor_free(string);
- close(fd);
- errno = save_errno;
- return NULL;
- }
- string[r] = '\0'; /* NUL-terminate the result. */
- #if defined(_WIN32) || defined(__CYGWIN__)
- if (!bin && strchr(string, '\r')) {
- log_debug(LD_FS, "We didn't convert CRLF to LF as well as we hoped "
- "when reading %s. Coping.",
- filename);
- tor_strstrip(string, "\r");
- r = strlen(string);
- }
- if (!bin) {
- statbuf.st_size = (size_t) r;
- } else
- #endif
- if (r != statbuf.st_size) {
- /* Unless we're using text mode on win32, we'd better have an exact
- * match for size. */
- int save_errno = errno;
- log_warn(LD_FS,"Could read only %d of %ld bytes of file \"%s\".",
- (int)r, (long)statbuf.st_size,filename);
- tor_free(string);
- close(fd);
- errno = save_errno;
- return NULL;
- }
- close(fd);
- if (stat_out) {
- memcpy(stat_out, &statbuf, sizeof(struct stat));
- }
- return string;
- }
- #define TOR_ISODIGIT(c) ('0' <= (c) && (c) <= '7')
- /** Given a c-style double-quoted escaped string in <b>s</b>, extract and
- * decode its contents into a newly allocated string. On success, assign this
- * string to *<b>result</b>, assign its length to <b>size_out</b> (if
- * provided), and return a pointer to the position in <b>s</b> immediately
- * after the string. On failure, return NULL.
- */
- const char *
- unescape_string(const char *s, char **result, size_t *size_out)
- {
- const char *cp;
- char *out;
- if (s[0] != '\"')
- return NULL;
- cp = s+1;
- while (1) {
- switch (*cp) {
- case '\0':
- case '\n':
- return NULL;
- case '\"':
- goto end_of_loop;
- case '\\':
- if (cp[1] == 'x' || cp[1] == 'X') {
- if (!(TOR_ISXDIGIT(cp[2]) && TOR_ISXDIGIT(cp[3])))
- return NULL;
- cp += 4;
- } else if (TOR_ISODIGIT(cp[1])) {
- cp += 2;
- if (TOR_ISODIGIT(*cp)) ++cp;
- if (TOR_ISODIGIT(*cp)) ++cp;
- } else if (cp[1] == 'n' || cp[1] == 'r' || cp[1] == 't' || cp[1] == '"'
- || cp[1] == '\\' || cp[1] == '\'') {
- cp += 2;
- } else {
- return NULL;
- }
- break;
- default:
- ++cp;
- break;
- }
- }
- end_of_loop:
- out = *result = tor_malloc(cp-s + 1);
- cp = s+1;
- while (1) {
- switch (*cp)
- {
- case '\"':
- *out = '\0';
- if (size_out) *size_out = out - *result;
- return cp+1;
- case '\0':
- /* LCOV_EXCL_START -- we caught this in parse_config_from_line. */
- tor_fragile_assert();
- tor_free(*result);
- return NULL;
- /* LCOV_EXCL_STOP */
- case '\\':
- switch (cp[1])
- {
- case 'n': *out++ = '\n'; cp += 2; break;
- case 'r': *out++ = '\r'; cp += 2; break;
- case 't': *out++ = '\t'; cp += 2; break;
- case 'x': case 'X':
- {
- int x1, x2;
- x1 = hex_decode_digit(cp[2]);
- x2 = hex_decode_digit(cp[3]);
- if (x1 == -1 || x2 == -1) {
- /* LCOV_EXCL_START */
- /* we caught this above in the initial loop. */
- tor_assert_nonfatal_unreached();
- tor_free(*result);
- return NULL;
- /* LCOV_EXCL_STOP */
- }
- *out++ = ((x1<<4) + x2);
- cp += 4;
- }
- break;
- case '0': case '1': case '2': case '3': case '4': case '5':
- case '6': case '7':
- {
- int n = cp[1]-'0';
- cp += 2;
- if (TOR_ISODIGIT(*cp)) { n = n*8 + *cp-'0'; cp++; }
- if (TOR_ISODIGIT(*cp)) { n = n*8 + *cp-'0'; cp++; }
- if (n > 255) { tor_free(*result); return NULL; }
- *out++ = (char)n;
- }
- break;
- case '\'':
- case '\"':
- case '\\':
- case '\?':
- *out++ = cp[1];
- cp += 2;
- break;
- default:
- /* LCOV_EXCL_START */
- /* we caught this above in the initial loop. */
- tor_assert_nonfatal_unreached();
- tor_free(*result); return NULL;
- /* LCOV_EXCL_STOP */
- }
- break;
- default:
- *out++ = *cp++;
- }
- }
- }
- /** Given a string containing part of a configuration file or similar format,
- * advance past comments and whitespace and try to parse a single line. If we
- * parse a line successfully, set *<b>key_out</b> to a new string holding the
- * key portion and *<b>value_out</b> to a new string holding the value portion
- * of the line, and return a pointer to the start of the next line. If we run
- * out of data, return a pointer to the end of the string. If we encounter an
- * error, return NULL and set *<b>err_out</b> (if provided) to an error
- * message.
- */
- const char *
- parse_config_line_from_str_verbose(const char *line, char **key_out,
- char **value_out,
- const char **err_out)
- {
- /*
- See torrc_format.txt for a description of the (silly) format this parses.
- */
- const char *key, *val, *cp;
- int continuation = 0;
- tor_assert(key_out);
- tor_assert(value_out);
- *key_out = *value_out = NULL;
- key = val = NULL;
- /* Skip until the first keyword. */
- while (1) {
- while (TOR_ISSPACE(*line))
- ++line;
- if (*line == '#') {
- while (*line && *line != '\n')
- ++line;
- } else {
- break;
- }
- }
- if (!*line) { /* End of string? */
- *key_out = *value_out = NULL;
- return line;
- }
- /* Skip until the next space or \ followed by newline. */
- key = line;
- while (*line && !TOR_ISSPACE(*line) && *line != '#' &&
- ! (line[0] == '\\' && line[1] == '\n'))
- ++line;
- *key_out = tor_strndup(key, line-key);
- /* Skip until the value. */
- while (*line == ' ' || *line == '\t')
- ++line;
- val = line;
- /* Find the end of the line. */
- if (*line == '\"') { // XXX No continuation handling is done here
- if (!(line = unescape_string(line, value_out, NULL))) {
- if (err_out)
- *err_out = "Invalid escape sequence in quoted string";
- return NULL;
- }
- while (*line == ' ' || *line == '\t')
- ++line;
- if (*line == '\r' && *(++line) == '\n')
- ++line;
- if (*line && *line != '#' && *line != '\n') {
- if (err_out)
- *err_out = "Excess data after quoted string";
- return NULL;
- }
- } else {
- /* Look for the end of the line. */
- while (*line && *line != '\n' && (*line != '#' || continuation)) {
- if (*line == '\\' && line[1] == '\n') {
- continuation = 1;
- line += 2;
- } else if (*line == '#') {
- do {
- ++line;
- } while (*line && *line != '\n');
- if (*line == '\n')
- ++line;
- } else {
- ++line;
- }
- }
- if (*line == '\n') {
- cp = line++;
- } else {
- cp = line;
- }
- /* Now back cp up to be the last nonspace character */
- while (cp>val && TOR_ISSPACE(*(cp-1)))
- --cp;
- tor_assert(cp >= val);
- /* Now copy out and decode the value. */
- *value_out = tor_strndup(val, cp-val);
- if (continuation) {
- char *v_out, *v_in;
- v_out = v_in = *value_out;
- while (*v_in) {
- if (*v_in == '#') {
- do {
- ++v_in;
- } while (*v_in && *v_in != '\n');
- if (*v_in == '\n')
- ++v_in;
- } else if (v_in[0] == '\\' && v_in[1] == '\n') {
- v_in += 2;
- } else {
- *v_out++ = *v_in++;
- }
- }
- *v_out = '\0';
- }
- }
- if (*line == '#') {
- do {
- ++line;
- } while (*line && *line != '\n');
- }
- while (TOR_ISSPACE(*line)) ++line;
- return line;
- }
- /** Expand any homedir prefix on <b>filename</b>; return a newly allocated
- * string. */
- char *
- expand_filename(const char *filename)
- {
- tor_assert(filename);
- #ifdef _WIN32
- /* Might consider using GetFullPathName() as described here:
- * http://etutorials.org/Programming/secure+programming/
- * Chapter+3.+Input+Validation/3.7+Validating+Filenames+and+Paths/
- */
- return tor_strdup(filename);
- #else
- if (*filename == '~') {
- char *home, *result=NULL;
- const char *rest;
- if (filename[1] == '/' || filename[1] == '\0') {
- home = getenv("HOME");
- if (!home) {
- log_warn(LD_CONFIG, "Couldn't find $HOME environment variable while "
- "expanding \"%s\"; defaulting to \"\".", filename);
- home = tor_strdup("");
- } else {
- home = tor_strdup(home);
- }
- rest = strlen(filename)>=2?(filename+2):"";
- } else {
- #ifdef HAVE_PWD_H
- char *username, *slash;
- slash = strchr(filename, '/');
- if (slash)
- username = tor_strndup(filename+1,slash-filename-1);
- else
- username = tor_strdup(filename+1);
- if (!(home = get_user_homedir(username))) {
- log_warn(LD_CONFIG,"Couldn't get homedir for \"%s\"",username);
- tor_free(username);
- return NULL;
- }
- tor_free(username);
- rest = slash ? (slash+1) : "";
- #else
- log_warn(LD_CONFIG, "Couldn't expand homedir on system without pwd.h");
- return tor_strdup(filename);
- #endif
- }
- tor_assert(home);
- /* Remove trailing slash. */
- if (strlen(home)>1 && !strcmpend(home,PATH_SEPARATOR)) {
- home[strlen(home)-1] = '\0';
- }
- tor_asprintf(&result,"%s"PATH_SEPARATOR"%s",home,rest);
- tor_free(home);
- return result;
- } else {
- return tor_strdup(filename);
- }
- #endif
- }
- #define MAX_SCANF_WIDTH 9999
- /** Helper: given an ASCII-encoded decimal digit, return its numeric value.
- * NOTE: requires that its input be in-bounds. */
- static int
- digit_to_num(char d)
- {
- int num = ((int)d) - (int)'0';
- tor_assert(num <= 9 && num >= 0);
- return num;
- }
- /** Helper: Read an unsigned int from *<b>bufp</b> of up to <b>width</b>
- * characters. (Handle arbitrary width if <b>width</b> is less than 0.) On
- * success, store the result in <b>out</b>, advance bufp to the next
- * character, and return 0. On failure, return -1. */
- static int
- scan_unsigned(const char **bufp, unsigned long *out, int width, unsigned base)
- {
- unsigned long result = 0;
- int scanned_so_far = 0;
- const int hex = base==16;
- tor_assert(base == 10 || base == 16);
- if (!bufp || !*bufp || !out)
- return -1;
- if (width<0)
- width=MAX_SCANF_WIDTH;
- while (**bufp && (hex?TOR_ISXDIGIT(**bufp):TOR_ISDIGIT(**bufp))
- && scanned_so_far < width) {
- unsigned digit = hex?hex_decode_digit(*(*bufp)++):digit_to_num(*(*bufp)++);
- // Check for overflow beforehand, without actually causing any overflow
- // This preserves functionality on compilers that don't wrap overflow
- // (i.e. that trap or optimise away overflow)
- // result * base + digit > ULONG_MAX
- // result * base > ULONG_MAX - digit
- if (result > (ULONG_MAX - digit)/base)
- return -1; /* Processing this digit would overflow */
- result = result * base + digit;
- ++scanned_so_far;
- }
- if (!scanned_so_far) /* No actual digits scanned */
- return -1;
- *out = result;
- return 0;
- }
- /** Helper: Read an signed int from *<b>bufp</b> of up to <b>width</b>
- * characters. (Handle arbitrary width if <b>width</b> is less than 0.) On
- * success, store the result in <b>out</b>, advance bufp to the next
- * character, and return 0. On failure, return -1. */
- static int
- scan_signed(const char **bufp, long *out, int width)
- {
- int neg = 0;
- unsigned long result = 0;
- if (!bufp || !*bufp || !out)
- return -1;
- if (width<0)
- width=MAX_SCANF_WIDTH;
- if (**bufp == '-') {
- neg = 1;
- ++*bufp;
- --width;
- }
- if (scan_unsigned(bufp, &result, width, 10) < 0)
- return -1;
- if (neg && result > 0) {
- if (result > ((unsigned long)LONG_MAX) + 1)
- return -1; /* Underflow */
- else if (result == ((unsigned long)LONG_MAX) + 1)
- *out = LONG_MIN;
- else {
- /* We once had a far more clever no-overflow conversion here, but
- * some versions of GCC apparently ran it into the ground. Now
- * we just check for LONG_MIN explicitly.
- */
- *out = -(long)result;
- }
- } else {
- if (result > LONG_MAX)
- return -1; /* Overflow */
- *out = (long)result;
- }
- return 0;
- }
- /** Helper: Read a decimal-formatted double from *<b>bufp</b> of up to
- * <b>width</b> characters. (Handle arbitrary width if <b>width</b> is less
- * than 0.) On success, store the result in <b>out</b>, advance bufp to the
- * next character, and return 0. On failure, return -1. */
- static int
- scan_double(const char **bufp, double *out, int width)
- {
- int neg = 0;
- double result = 0;
- int scanned_so_far = 0;
- if (!bufp || !*bufp || !out)
- return -1;
- if (width<0)
- width=MAX_SCANF_WIDTH;
- if (**bufp == '-') {
- neg = 1;
- ++*bufp;
- }
- while (**bufp && TOR_ISDIGIT(**bufp) && scanned_so_far < width) {
- const int digit = digit_to_num(*(*bufp)++);
- result = result * 10 + digit;
- ++scanned_so_far;
- }
- if (**bufp == '.') {
- double fracval = 0, denominator = 1;
- ++*bufp;
- ++scanned_so_far;
- while (**bufp && TOR_ISDIGIT(**bufp) && scanned_so_far < width) {
- const int digit = digit_to_num(*(*bufp)++);
- fracval = fracval * 10 + digit;
- denominator *= 10;
- ++scanned_so_far;
- }
- result += fracval / denominator;
- }
- if (!scanned_so_far) /* No actual digits scanned */
- return -1;
- *out = neg ? -result : result;
- return 0;
- }
- /** Helper: copy up to <b>width</b> non-space characters from <b>bufp</b> to
- * <b>out</b>. Make sure <b>out</b> is nul-terminated. Advance <b>bufp</b>
- * to the next non-space character or the EOS. */
- static int
- scan_string(const char **bufp, char *out, int width)
- {
- int scanned_so_far = 0;
- if (!bufp || !out || width < 0)
- return -1;
- while (**bufp && ! TOR_ISSPACE(**bufp) && scanned_so_far < width) {
- *out++ = *(*bufp)++;
- ++scanned_so_far;
- }
- *out = '\0';
- return 0;
- }
- /** Locale-independent, minimal, no-surprises scanf variant, accepting only a
- * restricted pattern format. For more info on what it supports, see
- * tor_sscanf() documentation. */
- int
- tor_vsscanf(const char *buf, const char *pattern, va_list ap)
- {
- int n_matched = 0;
- while (*pattern) {
- if (*pattern != '%') {
- if (*buf == *pattern) {
- ++buf;
- ++pattern;
- continue;
- } else {
- return n_matched;
- }
- } else {
- int width = -1;
- int longmod = 0;
- ++pattern;
- if (TOR_ISDIGIT(*pattern)) {
- width = digit_to_num(*pattern++);
- while (TOR_ISDIGIT(*pattern)) {
- width *= 10;
- width += digit_to_num(*pattern++);
- if (width > MAX_SCANF_WIDTH)
- return -1;
- }
- if (!width) /* No zero-width things. */
- return -1;
- }
- if (*pattern == 'l') {
- longmod = 1;
- ++pattern;
- }
- if (*pattern == 'u' || *pattern == 'x') {
- unsigned long u;
- const int base = (*pattern == 'u') ? 10 : 16;
- if (!*buf)
- return n_matched;
- if (scan_unsigned(&buf, &u, width, base)<0)
- return n_matched;
- if (longmod) {
- unsigned long *out = va_arg(ap, unsigned long *);
- *out = u;
- } else {
- unsigned *out = va_arg(ap, unsigned *);
- if (u > UINT_MAX)
- return n_matched;
- *out = (unsigned) u;
- }
- ++pattern;
- ++n_matched;
- } else if (*pattern == 'f') {
- double *d = va_arg(ap, double *);
- if (!longmod)
- return -1; /* float not supported */
- if (!*buf)
- return n_matched;
- if (scan_double(&buf, d, width)<0)
- return n_matched;
- ++pattern;
- ++n_matched;
- } else if (*pattern == 'd') {
- long lng=0;
- if (scan_signed(&buf, &lng, width)<0)
- return n_matched;
- if (longmod) {
- long *out = va_arg(ap, long *);
- *out = lng;
- } else {
- int *out = va_arg(ap, int *);
- #if LONG_MAX > INT_MAX
- if (lng < INT_MIN || lng > INT_MAX)
- return n_matched;
- #endif
- *out = (int)lng;
- }
- ++pattern;
- ++n_matched;
- } else if (*pattern == 's') {
- char *s = va_arg(ap, char *);
- if (longmod)
- return -1;
- if (width < 0)
- return -1;
- if (scan_string(&buf, s, width)<0)
- return n_matched;
- ++pattern;
- ++n_matched;
- } else if (*pattern == 'c') {
- char *ch = va_arg(ap, char *);
- if (longmod)
- return -1;
- if (width != -1)
- return -1;
- if (!*buf)
- return n_matched;
- *ch = *buf++;
- ++pattern;
- ++n_matched;
- } else if (*pattern == '%') {
- if (*buf != '%')
- return n_matched;
- if (longmod)
- return -1;
- ++buf;
- ++pattern;
- } else {
- return -1; /* Unrecognized pattern component. */
- }
- }
- }
- return n_matched;
- }
- /** Minimal sscanf replacement: parse <b>buf</b> according to <b>pattern</b>
- * and store the results in the corresponding argument fields. Differs from
- * sscanf in that:
- * <ul><li>It only handles %u, %lu, %x, %lx, %[NUM]s, %d, %ld, %lf, and %c.
- * <li>It only handles decimal inputs for %lf. (12.3, not 1.23e1)
- * <li>It does not handle arbitrarily long widths.
- * <li>Numbers do not consume any space characters.
- * <li>It is locale-independent.
- * <li>%u and %x do not consume any space.
- * <li>It returns -1 on malformed patterns.</ul>
- *
- * (As with other locale-independent functions, we need this to parse data that
- * is in ASCII without worrying that the C library's locale-handling will make
- * miscellaneous characters look like numbers, spaces, and so on.)
- */
- int
- tor_sscanf(const char *buf, const char *pattern, ...)
- {
- int r;
- va_list ap;
- va_start(ap, pattern);
- r = tor_vsscanf(buf, pattern, ap);
- va_end(ap);
- return r;
- }
- /** Append the string produced by tor_asprintf(<b>pattern</b>, <b>...</b>)
- * to <b>sl</b>. */
- void
- smartlist_add_asprintf(struct smartlist_t *sl, const char *pattern, ...)
- {
- va_list ap;
- va_start(ap, pattern);
- smartlist_add_vasprintf(sl, pattern, ap);
- va_end(ap);
- }
- /** va_list-based backend of smartlist_add_asprintf. */
- void
- smartlist_add_vasprintf(struct smartlist_t *sl, const char *pattern,
- va_list args)
- {
- char *str = NULL;
- tor_vasprintf(&str, pattern, args);
- tor_assert(str != NULL);
- smartlist_add(sl, str);
- }
- /** Append a copy of string to sl */
- void
- smartlist_add_strdup(struct smartlist_t *sl, const char *string)
- {
- char *copy;
- copy = tor_strdup(string);
- smartlist_add(sl, copy);
- }
- /** Return a new list containing the filenames in the directory <b>dirname</b>.
- * Return NULL on error or if <b>dirname</b> is not a directory.
- */
- MOCK_IMPL(smartlist_t *,
- tor_listdir, (const char *dirname))
- {
- smartlist_t *result;
- #ifdef _WIN32
- char *pattern=NULL;
- TCHAR tpattern[MAX_PATH] = {0};
- char name[MAX_PATH*2+1] = {0};
- HANDLE handle;
- WIN32_FIND_DATA findData;
- tor_asprintf(&pattern, "%s\\*", dirname);
- #ifdef UNICODE
- mbstowcs(tpattern,pattern,MAX_PATH);
- #else
- strlcpy(tpattern, pattern, MAX_PATH);
- #endif
- if (INVALID_HANDLE_VALUE == (handle = FindFirstFile(tpattern, &findData))) {
- tor_free(pattern);
- return NULL;
- }
- result = smartlist_new();
- while (1) {
- #ifdef UNICODE
- wcstombs(name,findData.cFileName,MAX_PATH);
- name[sizeof(name)-1] = '\0';
- #else
- strlcpy(name,findData.cFileName,sizeof(name));
- #endif
- if (strcmp(name, ".") &&
- strcmp(name, "..")) {
- smartlist_add_strdup(result, name);
- }
- if (!FindNextFile(handle, &findData)) {
- DWORD err;
- if ((err = GetLastError()) != ERROR_NO_MORE_FILES) {
- char *errstr = format_win32_error(err);
- log_warn(LD_FS, "Error reading directory '%s': %s", dirname, errstr);
- tor_free(errstr);
- }
- break;
- }
- }
- FindClose(handle);
- tor_free(pattern);
- #else
- const char *prot_dname = sandbox_intern_string(dirname);
- DIR *d;
- struct dirent *de;
- if (!(d = opendir(prot_dname)))
- return NULL;
- result = smartlist_new();
- while ((de = readdir(d))) {
- if (!strcmp(de->d_name, ".") ||
- !strcmp(de->d_name, ".."))
- continue;
- smartlist_add_strdup(result, de->d_name);
- }
- closedir(d);
- #endif
- return result;
- }
- /** Return true iff <b>filename</b> is a relative path. */
- int
- path_is_relative(const char *filename)
- {
- if (filename && filename[0] == '/')
- return 0;
- #ifdef _WIN32
- else if (filename && filename[0] == '\\')
- return 0;
- else if (filename && strlen(filename)>3 && TOR_ISALPHA(filename[0]) &&
- filename[1] == ':' && filename[2] == '\\')
- return 0;
- #endif
- else
- return 1;
- }
- /* =====
- * Process helpers
- * ===== */
- #ifndef _WIN32
- /* Based on code contributed by christian grothoff */
- /** True iff we've called start_daemon(). */
- static int start_daemon_called = 0;
- /** True iff we've called finish_daemon(). */
- static int finish_daemon_called = 0;
- /** Socketpair used to communicate between parent and child process while
- * daemonizing. */
- static int daemon_filedes[2];
- /** Start putting the process into daemon mode: fork and drop all resources
- * except standard fds. The parent process never returns, but stays around
- * until finish_daemon is called. (Note: it's safe to call this more
- * than once: calls after the first are ignored.)
- */
- void
- start_daemon(void)
- {
- pid_t pid;
- if (start_daemon_called)
- return;
- start_daemon_called = 1;
- if (pipe(daemon_filedes)) {
- /* LCOV_EXCL_START */
- log_err(LD_GENERAL,"pipe failed; exiting. Error was %s", strerror(errno));
- exit(1);
- /* LCOV_EXCL_STOP */
- }
- pid = fork();
- if (pid < 0) {
- /* LCOV_EXCL_START */
- log_err(LD_GENERAL,"fork failed. Exiting.");
- exit(1);
- /* LCOV_EXCL_STOP */
- }
- if (pid) { /* Parent */
- int ok;
- char c;
- close(daemon_filedes[1]); /* we only read */
- ok = -1;
- while (0 < read(daemon_filedes[0], &c, sizeof(char))) {
- if (c == '.')
- ok = 1;
- }
- fflush(stdout);
- if (ok == 1)
- exit(0);
- else
- exit(1); /* child reported error */
- } else { /* Child */
- close(daemon_filedes[0]); /* we only write */
- pid = setsid(); /* Detach from controlling terminal */
- /*
- * Fork one more time, so the parent (the session group leader) can exit.
- * This means that we, as a non-session group leader, can never regain a
- * controlling terminal. This part is recommended by Stevens's
- * _Advanced Programming in the Unix Environment_.
- */
- if (fork() != 0) {
- exit(0);
- }
- set_main_thread(); /* We are now the main thread. */
- return;
- }
- }
- /** Finish putting the process into daemon mode: drop standard fds, and tell
- * the parent process to exit. (Note: it's safe to call this more than once:
- * calls after the first are ignored. Calls start_daemon first if it hasn't
- * been called already.)
- */
- void
- finish_daemon(const char *desired_cwd)
- {
- int nullfd;
- char c = '.';
- if (finish_daemon_called)
- return;
- if (!start_daemon_called)
- start_daemon();
- finish_daemon_called = 1;
- if (!desired_cwd)
- desired_cwd = "/";
- /* Don't hold the wrong FS mounted */
- if (chdir(desired_cwd) < 0) {
- log_err(LD_GENERAL,"chdir to \"%s\" failed. Exiting.",desired_cwd);
- exit(1);
- }
- nullfd = tor_open_cloexec("/dev/null", O_RDWR, 0);
- if (nullfd < 0) {
- /* LCOV_EXCL_START */
- log_err(LD_GENERAL,"/dev/null can't be opened. Exiting.");
- exit(1);
- /* LCOV_EXCL_STOP */
- }
- /* close fds linking to invoking terminal, but
- * close usual incoming fds, but redirect them somewhere
- * useful so the fds don't get reallocated elsewhere.
- */
- if (dup2(nullfd,0) < 0 ||
- dup2(nullfd,1) < 0 ||
- dup2(nullfd,2) < 0) {
- /* LCOV_EXCL_START */
- log_err(LD_GENERAL,"dup2 failed. Exiting.");
- exit(1);
- /* LCOV_EXCL_STOP */
- }
- if (nullfd > 2)
- close(nullfd);
- /* signal success */
- if (write(daemon_filedes[1], &c, sizeof(char)) != sizeof(char)) {
- log_err(LD_GENERAL,"write failed. Exiting.");
- }
- close(daemon_filedes[1]);
- }
- #else
- /* defined(_WIN32) */
- void
- start_daemon(void)
- {
- }
- void
- finish_daemon(const char *cp)
- {
- (void)cp;
- }
- #endif
- /** Write the current process ID, followed by NL, into <b>filename</b>.
- */
- void
- write_pidfile(const char *filename)
- {
- FILE *pidfile;
- if ((pidfile = fopen(filename, "w")) == NULL) {
- log_warn(LD_FS, "Unable to open \"%s\" for writing: %s", filename,
- strerror(errno));
- } else {
- #ifdef _WIN32
- fprintf(pidfile, "%d\n", (int)_getpid());
- #else
- fprintf(pidfile, "%d\n", (int)getpid());
- #endif
- fclose(pidfile);
- }
- }
- #ifdef _WIN32
- HANDLE
- load_windows_system_library(const TCHAR *library_name)
- {
- TCHAR path[MAX_PATH];
- unsigned n;
- n = GetSystemDirectory(path, MAX_PATH);
- if (n == 0 || n + _tcslen(library_name) + 2 >= MAX_PATH)
- return 0;
- _tcscat(path, TEXT("\\"));
- _tcscat(path, library_name);
- return LoadLibrary(path);
- }
- #endif
- /** Format a single argument for being put on a Windows command line.
- * Returns a newly allocated string */
- static char *
- format_win_cmdline_argument(const char *arg)
- {
- char *formatted_arg;
- char need_quotes;
- const char *c;
- int i;
- int bs_counter = 0;
- /* Backslash we can point to when one is inserted into the string */
- const char backslash = '\\';
- /* Smartlist of *char */
- smartlist_t *arg_chars;
- arg_chars = smartlist_new();
- /* Quote string if it contains whitespace or is empty */
- need_quotes = (strchr(arg, ' ') || strchr(arg, '\t') || '\0' == arg[0]);
- /* Build up smartlist of *chars */
- for (c=arg; *c != '\0'; c++) {
- if ('"' == *c) {
- /* Double up backslashes preceding a quote */
- for (i=0; i<(bs_counter*2); i++)
- smartlist_add(arg_chars, (void*)&backslash);
- bs_counter = 0;
- /* Escape the quote */
- smartlist_add(arg_chars, (void*)&backslash);
- smartlist_add(arg_chars, (void*)c);
- } else if ('\\' == *c) {
- /* Count backslashes until we know whether to double up */
- bs_counter++;
- } else {
- /* Don't double up slashes preceding a non-quote */
- for (i=0; i<bs_counter; i++)
- smartlist_add(arg_chars, (void*)&backslash);
- bs_counter = 0;
- smartlist_add(arg_chars, (void*)c);
- }
- }
- /* Don't double up trailing backslashes */
- for (i=0; i<bs_counter; i++)
- smartlist_add(arg_chars, (void*)&backslash);
- /* Allocate space for argument, quotes (if needed), and terminator */
- const size_t formatted_arg_len = smartlist_len(arg_chars) +
- (need_quotes ? 2 : 0) + 1;
- formatted_arg = tor_malloc_zero(formatted_arg_len);
- /* Add leading quote */
- i=0;
- if (need_quotes)
- formatted_arg[i++] = '"';
- /* Add characters */
- SMARTLIST_FOREACH(arg_chars, char*, ch,
- {
- formatted_arg[i++] = *ch;
- });
- /* Add trailing quote */
- if (need_quotes)
- formatted_arg[i++] = '"';
- formatted_arg[i] = '\0';
- smartlist_free(arg_chars);
- return formatted_arg;
- }
- /** Format a command line for use on Windows, which takes the command as a
- * string rather than string array. Follows the rules from "Parsing C++
- * Command-Line Arguments" in MSDN. Algorithm based on list2cmdline in the
- * Python subprocess module. Returns a newly allocated string */
- char *
- tor_join_win_cmdline(const char *argv[])
- {
- smartlist_t *argv_list;
- char *joined_argv;
- int i;
- /* Format each argument and put the result in a smartlist */
- argv_list = smartlist_new();
- for (i=0; argv[i] != NULL; i++) {
- smartlist_add(argv_list, (void *)format_win_cmdline_argument(argv[i]));
- }
- /* Join the arguments with whitespace */
- joined_argv = smartlist_join_strings(argv_list, " ", 0, NULL);
- /* Free the newly allocated arguments, and the smartlist */
- SMARTLIST_FOREACH(argv_list, char *, arg,
- {
- tor_free(arg);
- });
- smartlist_free(argv_list);
- return joined_argv;
- }
- /* As format_{hex,dex}_number_sigsafe, but takes a <b>radix</b> argument
- * in range 2..16 inclusive. */
- static int
- format_number_sigsafe(unsigned long x, char *buf, int buf_len,
- unsigned int radix)
- {
- unsigned long tmp;
- int len;
- char *cp;
- /* NOT tor_assert. This needs to be safe to run from within a signal handler,
- * and from within the 'tor_assert() has failed' code. */
- if (radix < 2 || radix > 16)
- return 0;
- /* Count how many digits we need. */
- tmp = x;
- len = 1;
- while (tmp >= radix) {
- tmp /= radix;
- ++len;
- }
- /* Not long enough */
- if (!buf || len >= buf_len)
- return 0;
- cp = buf + len;
- *cp = '\0';
- do {
- unsigned digit = (unsigned) (x % radix);
- tor_assert(cp > buf);
- --cp;
- *cp = "0123456789ABCDEF"[digit];
- x /= radix;
- } while (x);
- /* NOT tor_assert; see above. */
- if (cp != buf) {
- abort(); // LCOV_EXCL_LINE
- }
- return len;
- }
- /**
- * Helper function to output hex numbers from within a signal handler.
- *
- * Writes the nul-terminated hexadecimal digits of <b>x</b> into a buffer
- * <b>buf</b> of size <b>buf_len</b>, and return the actual number of digits
- * written, not counting the terminal NUL.
- *
- * If there is insufficient space, write nothing and return 0.
- *
- * This accepts an unsigned int because format_helper_exit_status() needs to
- * call it with a signed int and an unsigned char, and since the C standard
- * does not guarantee that an int is wider than a char (an int must be at
- * least 16 bits but it is permitted for a char to be that wide as well), we
- * can't assume a signed int is sufficient to accomodate an unsigned char.
- * Thus, format_helper_exit_status() will still need to emit any require '-'
- * on its own.
- *
- * For most purposes, you'd want to use tor_snprintf("%x") instead of this
- * function; it's designed to be used in code paths where you can't call
- * arbitrary C functions.
- */
- int
- format_hex_number_sigsafe(unsigned long x, char *buf, int buf_len)
- {
- return format_number_sigsafe(x, buf, buf_len, 16);
- }
- /** As format_hex_number_sigsafe, but format the number in base 10. */
- int
- format_dec_number_sigsafe(unsigned long x, char *buf, int buf_len)
- {
- return format_number_sigsafe(x, buf, buf_len, 10);
- }
- #ifndef _WIN32
- /** Format <b>child_state</b> and <b>saved_errno</b> as a hex string placed in
- * <b>hex_errno</b>. Called between fork and _exit, so must be signal-handler
- * safe.
- *
- * <b>hex_errno</b> must have at least HEX_ERRNO_SIZE+1 bytes available.
- *
- * The format of <b>hex_errno</b> is: "CHILD_STATE/ERRNO\n", left-padded
- * with spaces. CHILD_STATE indicates where
- * in the processs of starting the child process did the failure occur (see
- * CHILD_STATE_* macros for definition), and SAVED_ERRNO is the value of
- * errno when the failure occurred.
- *
- * On success return the number of characters added to hex_errno, not counting
- * the terminating NUL; return -1 on error.
- */
- STATIC int
- format_helper_exit_status(unsigned char child_state, int saved_errno,
- char *hex_errno)
- {
- unsigned int unsigned_errno;
- int written, left;
- char *cur;
- size_t i;
- int res = -1;
- /* Fill hex_errno with spaces, and a trailing newline (memset may
- not be signal handler safe, so we can't use it) */
- for (i = 0; i < (HEX_ERRNO_SIZE - 1); i++)
- hex_errno[i] = ' ';
- hex_errno[HEX_ERRNO_SIZE - 1] = '\n';
- /* Convert errno to be unsigned for hex conversion */
- if (saved_errno < 0) {
- // Avoid overflow on the cast to unsigned int when result is INT_MIN
- // by adding 1 to the signed int negative value,
- // then, after it has been negated and cast to unsigned,
- // adding the original 1 back (the double-addition is intentional).
- // Otherwise, the cast to signed could cause a temporary int
- // to equal INT_MAX + 1, which is undefined.
- unsigned_errno = ((unsigned int) -(saved_errno + 1)) + 1;
- } else {
- unsigned_errno = (unsigned int) saved_errno;
- }
- /*
- * Count how many chars of space we have left, and keep a pointer into the
- * current point in the buffer.
- */
- left = HEX_ERRNO_SIZE+1;
- cur = hex_errno;
- /* Emit child_state */
- written = format_hex_number_sigsafe(child_state, cur, left);
- if (written <= 0)
- goto err;
- /* Adjust left and cur */
- left -= written;
- cur += written;
- if (left <= 0)
- goto err;
- /* Now the '/' */
- *cur = '/';
- /* Adjust left and cur */
- ++cur;
- --left;
- if (left <= 0)
- goto err;
- /* Need minus? */
- if (saved_errno < 0) {
- *cur = '-';
- ++cur;
- --left;
- if (left <= 0)
- goto err;
- }
- /* Emit unsigned_errno */
- written = format_hex_number_sigsafe(unsigned_errno, cur, left);
- if (written <= 0)
- goto err;
- /* Adjust left and cur */
- left -= written;
- cur += written;
- /* Check that we have enough space left for a newline and a NUL */
- if (left <= 1)
- goto err;
- /* Emit the newline and NUL */
- *cur++ = '\n';
- *cur++ = '\0';
- res = (int)(cur - hex_errno - 1);
- goto done;
- err:
- /*
- * In error exit, just write a '\0' in the first char so whatever called
- * this at least won't fall off the end.
- */
- *hex_errno = '\0';
- done:
- return res;
- }
- #endif
- /* Maximum number of file descriptors, if we cannot get it via sysconf() */
- #define DEFAULT_MAX_FD 256
- /** Terminate the process of <b>process_handle</b>, if that process has not
- * already exited.
- *
- * Return 0 if we succeeded in terminating the process (or if the process
- * already exited), and -1 if we tried to kill the process but failed.
- *
- * Based on code originally borrowed from Python's os.kill. */
- int
- tor_terminate_process(process_handle_t *process_handle)
- {
- #ifdef _WIN32
- if (tor_get_exit_code(process_handle, 0, NULL) == PROCESS_EXIT_RUNNING) {
- HANDLE handle = process_handle->pid.hProcess;
- if (!TerminateProcess(handle, 0))
- return -1;
- else
- return 0;
- }
- #else /* Unix */
- if (process_handle->waitpid_cb) {
- /* We haven't got a waitpid yet, so we can just kill off the process. */
- return kill(process_handle->pid, SIGTERM);
- }
- #endif
- return 0; /* We didn't need to kill the process, so report success */
- }
- /** Return the Process ID of <b>process_handle</b>. */
- int
- tor_process_get_pid(process_handle_t *process_handle)
- {
- #ifdef _WIN32
- return (int) process_handle->pid.dwProcessId;
- #else
- return (int) process_handle->pid;
- #endif
- }
- #ifdef _WIN32
- HANDLE
- tor_process_get_stdout_pipe(process_handle_t *process_handle)
- {
- return process_handle->stdout_pipe;
- }
- #else
- /* DOCDOC tor_process_get_stdout_pipe */
- int
- tor_process_get_stdout_pipe(process_handle_t *process_handle)
- {
- return process_handle->stdout_pipe;
- }
- #endif
- /* DOCDOC process_handle_new */
- static process_handle_t *
- process_handle_new(void)
- {
- process_handle_t *out = tor_malloc_zero(sizeof(process_handle_t));
- #ifdef _WIN32
- out->stdin_pipe = INVALID_HANDLE_VALUE;
- out->stdout_pipe = INVALID_HANDLE_VALUE;
- out->stderr_pipe = INVALID_HANDLE_VALUE;
- #else
- out->stdin_pipe = -1;
- out->stdout_pipe = -1;
- out->stderr_pipe = -1;
- #endif
- return out;
- }
- #ifndef _WIN32
- /** Invoked when a process that we've launched via tor_spawn_background() has
- * been found to have terminated.
- */
- static void
- process_handle_waitpid_cb(int status, void *arg)
- {
- process_handle_t *process_handle = arg;
- process_handle->waitpid_exit_status = status;
- clear_waitpid_callback(process_handle->waitpid_cb);
- if (process_handle->status == PROCESS_STATUS_RUNNING)
- process_handle->status = PROCESS_STATUS_NOTRUNNING;
- process_handle->waitpid_cb = 0;
- }
- #endif
- /**
- * @name child-process states
- *
- * Each of these values represents a possible state that a child process can
- * be in. They're used to determine what to say when telling the parent how
- * far along we were before failure.
- *
- * @{
- */
- #define CHILD_STATE_INIT 0
- #define CHILD_STATE_PIPE 1
- #define CHILD_STATE_MAXFD 2
- #define CHILD_STATE_FORK 3
- #define CHILD_STATE_DUPOUT 4
- #define CHILD_STATE_DUPERR 5
- #define CHILD_STATE_DUPIN 6
- #define CHILD_STATE_CLOSEFD 7
- #define CHILD_STATE_EXEC 8
- #define CHILD_STATE_FAILEXEC 9
- /** @} */
- /** Start a program in the background. If <b>filename</b> contains a '/', then
- * it will be treated as an absolute or relative path. Otherwise, on
- * non-Windows systems, the system path will be searched for <b>filename</b>.
- * On Windows, only the current directory will be searched. Here, to search the
- * system path (as well as the application directory, current working
- * directory, and system directories), set filename to NULL.
- *
- * The strings in <b>argv</b> will be passed as the command line arguments of
- * the child program (following convention, argv[0] should normally be the
- * filename of the executable, and this must be the case if <b>filename</b> is
- * NULL). The last element of argv must be NULL. A handle to the child process
- * will be returned in process_handle (which must be non-NULL). Read
- * process_handle.status to find out if the process was successfully launched.
- * For convenience, process_handle.status is returned by this function.
- *
- * Some parts of this code are based on the POSIX subprocess module from
- * Python, and example code from
- * http://msdn.microsoft.com/en-us/library/ms682499%28v=vs.85%29.aspx.
- */
- int
- tor_spawn_background(const char *const filename, const char **argv,
- process_environment_t *env,
- process_handle_t **process_handle_out)
- {
- #ifdef _WIN32
- HANDLE stdout_pipe_read = NULL;
- HANDLE stdout_pipe_write = NULL;
- HANDLE stderr_pipe_read = NULL;
- HANDLE stderr_pipe_write = NULL;
- HANDLE stdin_pipe_read = NULL;
- HANDLE stdin_pipe_write = NULL;
- process_handle_t *process_handle;
- int status;
- STARTUPINFOA siStartInfo;
- BOOL retval = FALSE;
- SECURITY_ATTRIBUTES saAttr;
- char *joined_argv;
- saAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
- saAttr.bInheritHandle = TRUE;
- /* TODO: should we set explicit security attributes? (#2046, comment 5) */
- saAttr.lpSecurityDescriptor = NULL;
- /* Assume failure to start process */
- status = PROCESS_STATUS_ERROR;
- /* Set up pipe for stdout */
- if (!CreatePipe(&stdout_pipe_read, &stdout_pipe_write, &saAttr, 0)) {
- log_warn(LD_GENERAL,
- "Failed to create pipe for stdout communication with child process: %s",
- format_win32_error(GetLastError()));
- return status;
- }
- if (!SetHandleInformation(stdout_pipe_read, HANDLE_FLAG_INHERIT, 0)) {
- log_warn(LD_GENERAL,
- "Failed to configure pipe for stdout communication with child "
- "process: %s", format_win32_error(GetLastError()));
- return status;
- }
- /* Set up pipe for stderr */
- if (!CreatePipe(&stderr_pipe_read, &stderr_pipe_write, &saAttr, 0)) {
- log_warn(LD_GENERAL,
- "Failed to create pipe for stderr communication with child process: %s",
- format_win32_error(GetLastError()));
- return status;
- }
- if (!SetHandleInformation(stderr_pipe_read, HANDLE_FLAG_INHERIT, 0)) {
- log_warn(LD_GENERAL,
- "Failed to configure pipe for stderr communication with child "
- "process: %s", format_win32_error(GetLastError()));
- return status;
- }
- /* Set up pipe for stdin */
- if (!CreatePipe(&stdin_pipe_read, &stdin_pipe_write, &saAttr, 0)) {
- log_warn(LD_GENERAL,
- "Failed to create pipe for stdin communication with child process: %s",
- format_win32_error(GetLastError()));
- return status;
- }
- if (!SetHandleInformation(stdin_pipe_write, HANDLE_FLAG_INHERIT, 0)) {
- log_warn(LD_GENERAL,
- "Failed to configure pipe for stdin communication with child "
- "process: %s", format_win32_error(GetLastError()));
- return status;
- }
- /* Create the child process */
- /* Windows expects argv to be a whitespace delimited string, so join argv up
- */
- joined_argv = tor_join_win_cmdline(argv);
- process_handle = process_handle_new();
- process_handle->status = status;
- ZeroMemory(&(process_handle->pid), sizeof(PROCESS_INFORMATION));
- ZeroMemory(&siStartInfo, sizeof(STARTUPINFO));
- siStartInfo.cb = sizeof(STARTUPINFO);
- siStartInfo.hStdError = stderr_pipe_write;
- siStartInfo.hStdOutput = stdout_pipe_write;
- siStartInfo.hStdInput = stdin_pipe_read;
- siStartInfo.dwFlags |= STARTF_USESTDHANDLES;
- /* Create the child process */
- retval = CreateProcessA(filename, // module name
- joined_argv, // command line
- /* TODO: should we set explicit security attributes? (#2046, comment 5) */
- NULL, // process security attributes
- NULL, // primary thread security attributes
- TRUE, // handles are inherited
- /*(TODO: set CREATE_NEW CONSOLE/PROCESS_GROUP to make GetExitCodeProcess()
- * work?) */
- CREATE_NO_WINDOW, // creation flags
- (env==NULL) ? NULL : env->windows_environment_block,
- NULL, // use parent's current directory
- &siStartInfo, // STARTUPINFO pointer
- &(process_handle->pid)); // receives PROCESS_INFORMATION
- tor_free(joined_argv);
- if (!retval) {
- log_warn(LD_GENERAL,
- "Failed to create child process %s: %s", filename?filename:argv[0],
- format_win32_error(GetLastError()));
- tor_free(process_handle);
- } else {
- /* TODO: Close hProcess and hThread in process_handle->pid? */
- process_handle->stdout_pipe = stdout_pipe_read;
- process_handle->stderr_pipe = stderr_pipe_read;
- process_handle->stdin_pipe = stdin_pipe_write;
- status = process_handle->status = PROCESS_STATUS_RUNNING;
- }
- /* TODO: Close pipes on exit */
- *process_handle_out = process_handle;
- return status;
- #else // _WIN32
- pid_t pid;
- int stdout_pipe[2];
- int stderr_pipe[2];
- int stdin_pipe[2];
- int fd, retval;
- ssize_t nbytes;
- process_handle_t *process_handle;
- int status;
- const char *error_message = SPAWN_ERROR_MESSAGE;
- size_t error_message_length;
- /* Represents where in the process of spawning the program is;
- this is used for printing out the error message */
- unsigned char child_state = CHILD_STATE_INIT;
- char hex_errno[HEX_ERRNO_SIZE + 2]; /* + 1 should be sufficient actually */
- static int max_fd = -1;
- status = PROCESS_STATUS_ERROR;
- /* We do the strlen here because strlen() is not signal handler safe,
- and we are not allowed to use unsafe functions between fork and exec */
- error_message_length = strlen(error_message);
- child_state = CHILD_STATE_PIPE;
- /* Set up pipe for redirecting stdout, stderr, and stdin of child */
- retval = pipe(stdout_pipe);
- if (-1 == retval) {
- log_warn(LD_GENERAL,
- "Failed to set up pipe for stdout communication with child process: %s",
- strerror(errno));
- return status;
- }
- retval = pipe(stderr_pipe);
- if (-1 == retval) {
- log_warn(LD_GENERAL,
- "Failed to set up pipe for stderr communication with child process: %s",
- strerror(errno));
- close(stdout_pipe[0]);
- close(stdout_pipe[1]);
- return status;
- }
- retval = pipe(stdin_pipe);
- if (-1 == retval) {
- log_warn(LD_GENERAL,
- "Failed to set up pipe for stdin communication with child process: %s",
- strerror(errno));
- close(stdout_pipe[0]);
- close(stdout_pipe[1]);
- close(stderr_pipe[0]);
- close(stderr_pipe[1]);
- return status;
- }
- child_state = CHILD_STATE_MAXFD;
- #ifdef _SC_OPEN_MAX
- if (-1 == max_fd) {
- max_fd = (int) sysconf(_SC_OPEN_MAX);
- if (max_fd == -1) {
- max_fd = DEFAULT_MAX_FD;
- log_warn(LD_GENERAL,
- "Cannot find maximum file descriptor, assuming %d", max_fd);
- }
- }
- #else
- max_fd = DEFAULT_MAX_FD;
- #endif
- child_state = CHILD_STATE_FORK;
- pid = fork();
- if (0 == pid) {
- /* In child */
- #if defined(HAVE_SYS_PRCTL_H) && defined(__linux__)
- /* Attempt to have the kernel issue a SIGTERM if the parent
- * goes away. Certain attributes of the binary being execve()ed
- * will clear this during the execve() call, but it's better
- * than nothing.
- */
- prctl(PR_SET_PDEATHSIG, SIGTERM);
- #endif
- child_state = CHILD_STATE_DUPOUT;
- /* Link child stdout to the write end of the pipe */
- retval = dup2(stdout_pipe[1], STDOUT_FILENO);
- if (-1 == retval)
- goto error;
- child_state = CHILD_STATE_DUPERR;
- /* Link child stderr to the write end of the pipe */
- retval = dup2(stderr_pipe[1], STDERR_FILENO);
- if (-1 == retval)
- goto error;
- child_state = CHILD_STATE_DUPIN;
- /* Link child stdin to the read end of the pipe */
- retval = dup2(stdin_pipe[0], STDIN_FILENO);
- if (-1 == retval)
- goto error;
- child_state = CHILD_STATE_CLOSEFD;
- close(stderr_pipe[0]);
- close(stderr_pipe[1]);
- close(stdout_pipe[0]);
- close(stdout_pipe[1]);
- close(stdin_pipe[0]);
- close(stdin_pipe[1]);
- /* Close all other fds, including the read end of the pipe */
- /* XXX: We should now be doing enough FD_CLOEXEC setting to make
- * this needless. */
- for (fd = STDERR_FILENO + 1; fd < max_fd; fd++) {
- close(fd);
- }
- child_state = CHILD_STATE_EXEC;
- /* Call the requested program. We need the cast because
- execvp doesn't define argv as const, even though it
- does not modify the arguments */
- if (env)
- execve(filename, (char *const *) argv, env->unixoid_environment_block);
- else {
- static char *new_env[] = { NULL };
- execve(filename, (char *const *) argv, new_env);
- }
- /* If we got here, the exec or open(/dev/null) failed */
- child_state = CHILD_STATE_FAILEXEC;
- error:
- {
- /* XXX: are we leaking fds from the pipe? */
- int n;
- n = format_helper_exit_status(child_state, errno, hex_errno);
- if (n >= 0) {
- /* Write the error message. GCC requires that we check the return
- value, but there is nothing we can do if it fails */
- /* TODO: Don't use STDOUT, use a pipe set up just for this purpose */
- nbytes = write(STDOUT_FILENO, error_message, error_message_length);
- nbytes = write(STDOUT_FILENO, hex_errno, n);
- }
- }
- (void) nbytes;
- _exit(255);
- /* Never reached, but avoids compiler warning */
- return status; // LCOV_EXCL_LINE
- }
- /* In parent */
- if (-1 == pid) {
- log_warn(LD_GENERAL, "Failed to fork child process: %s", strerror(errno));
- close(stdin_pipe[0]);
- close(stdin_pipe[1]);
- close(stdout_pipe[0]);
- close(stdout_pipe[1]);
- close(stderr_pipe[0]);
- close(stderr_pipe[1]);
- return status;
- }
- process_handle = process_handle_new();
- process_handle->status = status;
- process_handle->pid = pid;
- /* TODO: If the child process forked but failed to exec, waitpid it */
- /* Return read end of the pipes to caller, and close write end */
- process_handle->stdout_pipe = stdout_pipe[0];
- retval = close(stdout_pipe[1]);
- if (-1 == retval) {
- log_warn(LD_GENERAL,
- "Failed to close write end of stdout pipe in parent process: %s",
- strerror(errno));
- }
- process_handle->waitpid_cb = set_waitpid_callback(pid,
- process_handle_waitpid_cb,
- process_handle);
- process_handle->stderr_pipe = stderr_pipe[0];
- retval = close(stderr_pipe[1]);
- if (-1 == retval) {
- log_warn(LD_GENERAL,
- "Failed to close write end of stderr pipe in parent process: %s",
- strerror(errno));
- }
- /* Return write end of the stdin pipe to caller, and close the read end */
- process_handle->stdin_pipe = stdin_pipe[1];
- retval = close(stdin_pipe[0]);
- if (-1 == retval) {
- log_warn(LD_GENERAL,
- "Failed to close read end of stdin pipe in parent process: %s",
- strerror(errno));
- }
- status = process_handle->status = PROCESS_STATUS_RUNNING;
- /* Set stdin/stdout/stderr pipes to be non-blocking */
- if (fcntl(process_handle->stdout_pipe, F_SETFL, O_NONBLOCK) < 0 ||
- fcntl(process_handle->stderr_pipe, F_SETFL, O_NONBLOCK) < 0 ||
- fcntl(process_handle->stdin_pipe, F_SETFL, O_NONBLOCK) < 0) {
- log_warn(LD_GENERAL, "Failed to set stderror/stdout/stdin pipes "
- "nonblocking in parent process: %s", strerror(errno));
- }
- *process_handle_out = process_handle;
- return process_handle->status;
- #endif // _WIN32
- }
- /** Destroy all resources allocated by the process handle in
- * <b>process_handle</b>.
- * If <b>also_terminate_process</b> is true, also terminate the
- * process of the process handle. */
- MOCK_IMPL(void,
- tor_process_handle_destroy,(process_handle_t *process_handle,
- int also_terminate_process))
- {
- if (!process_handle)
- return;
- if (also_terminate_process) {
- if (tor_terminate_process(process_handle) < 0) {
- const char *errstr =
- #ifdef _WIN32
- format_win32_error(GetLastError());
- #else
- strerror(errno);
- #endif
- log_notice(LD_GENERAL, "Failed to terminate process with "
- "PID '%d' ('%s').", tor_process_get_pid(process_handle),
- errstr);
- } else {
- log_info(LD_GENERAL, "Terminated process with PID '%d'.",
- tor_process_get_pid(process_handle));
- }
- }
- process_handle->status = PROCESS_STATUS_NOTRUNNING;
- #ifdef _WIN32
- if (process_handle->stdout_pipe)
- CloseHandle(process_handle->stdout_pipe);
- if (process_handle->stderr_pipe)
- CloseHandle(process_handle->stderr_pipe);
- if (process_handle->stdin_pipe)
- CloseHandle(process_handle->stdin_pipe);
- #else
- close(process_handle->stdout_pipe);
- close(process_handle->stderr_pipe);
- close(process_handle->stdin_pipe);
- clear_waitpid_callback(process_handle->waitpid_cb);
- #endif
- memset(process_handle, 0x0f, sizeof(process_handle_t));
- tor_free(process_handle);
- }
- /** Get the exit code of a process specified by <b>process_handle</b> and store
- * it in <b>exit_code</b>, if set to a non-NULL value. If <b>block</b> is set
- * to true, the call will block until the process has exited. Otherwise if
- * the process is still running, the function will return
- * PROCESS_EXIT_RUNNING, and exit_code will be left unchanged. Returns
- * PROCESS_EXIT_EXITED if the process did exit. If there is a failure,
- * PROCESS_EXIT_ERROR will be returned and the contents of exit_code (if
- * non-NULL) will be undefined. N.B. Under *nix operating systems, this will
- * probably not work in Tor, because waitpid() is called in main.c to reap any
- * terminated child processes.*/
- int
- tor_get_exit_code(process_handle_t *process_handle,
- int block, int *exit_code)
- {
- #ifdef _WIN32
- DWORD retval;
- BOOL success;
- if (block) {
- /* Wait for the process to exit */
- retval = WaitForSingleObject(process_handle->pid.hProcess, INFINITE);
- if (retval != WAIT_OBJECT_0) {
- log_warn(LD_GENERAL, "WaitForSingleObject() failed (%d): %s",
- (int)retval, format_win32_error(GetLastError()));
- return PROCESS_EXIT_ERROR;
- }
- } else {
- retval = WaitForSingleObject(process_handle->pid.hProcess, 0);
- if (WAIT_TIMEOUT == retval) {
- /* Process has not exited */
- return PROCESS_EXIT_RUNNING;
- } else if (retval != WAIT_OBJECT_0) {
- log_warn(LD_GENERAL, "WaitForSingleObject() failed (%d): %s",
- (int)retval, format_win32_error(GetLastError()));
- return PROCESS_EXIT_ERROR;
- }
- }
- if (exit_code != NULL) {
- success = GetExitCodeProcess(process_handle->pid.hProcess,
- (PDWORD)exit_code);
- if (!success) {
- log_warn(LD_GENERAL, "GetExitCodeProcess() failed: %s",
- format_win32_error(GetLastError()));
- return PROCESS_EXIT_ERROR;
- }
- }
- #else
- int stat_loc;
- int retval;
- if (process_handle->waitpid_cb) {
- /* We haven't processed a SIGCHLD yet. */
- retval = waitpid(process_handle->pid, &stat_loc, block?0:WNOHANG);
- if (retval == process_handle->pid) {
- clear_waitpid_callback(process_handle->waitpid_cb);
- process_handle->waitpid_cb = NULL;
- process_handle->waitpid_exit_status = stat_loc;
- }
- } else {
- /* We already got a SIGCHLD for this process, and handled it. */
- retval = process_handle->pid;
- stat_loc = process_handle->waitpid_exit_status;
- }
- if (!block && 0 == retval) {
- /* Process has not exited */
- return PROCESS_EXIT_RUNNING;
- } else if (retval != process_handle->pid) {
- log_warn(LD_GENERAL, "waitpid() failed for PID %d: %s",
- (int)process_handle->pid, strerror(errno));
- return PROCESS_EXIT_ERROR;
- }
- if (!WIFEXITED(stat_loc)) {
- log_warn(LD_GENERAL, "Process %d did not exit normally",
- (int)process_handle->pid);
- return PROCESS_EXIT_ERROR;
- }
- if (exit_code != NULL)
- *exit_code = WEXITSTATUS(stat_loc);
- #endif // _WIN32
- return PROCESS_EXIT_EXITED;
- }
- /** Helper: return the number of characters in <b>s</b> preceding the first
- * occurrence of <b>ch</b>. If <b>ch</b> does not occur in <b>s</b>, return
- * the length of <b>s</b>. Should be equivalent to strspn(s, "ch"). */
- static inline size_t
- str_num_before(const char *s, char ch)
- {
- const char *cp = strchr(s, ch);
- if (cp)
- return cp - s;
- else
- return strlen(s);
- }
- /** Return non-zero iff getenv would consider <b>s1</b> and <b>s2</b>
- * to have the same name as strings in a process's environment. */
- int
- environment_variable_names_equal(const char *s1, const char *s2)
- {
- size_t s1_name_len = str_num_before(s1, '=');
- size_t s2_name_len = str_num_before(s2, '=');
- return (s1_name_len == s2_name_len &&
- tor_memeq(s1, s2, s1_name_len));
- }
- /** Free <b>env</b> (assuming it was produced by
- * process_environment_make). */
- void
- process_environment_free(process_environment_t *env)
- {
- if (env == NULL) return;
- /* As both an optimization hack to reduce consing on Unixoid systems
- * and a nice way to ensure that some otherwise-Windows-specific
- * code will always get tested before changes to it get merged, the
- * strings which env->unixoid_environment_block points to are packed
- * into env->windows_environment_block. */
- tor_free(env->unixoid_environment_block);
- tor_free(env->windows_environment_block);
- tor_free(env);
- }
- /** Make a process_environment_t containing the environment variables
- * specified in <b>env_vars</b> (as C strings of the form
- * "NAME=VALUE"). */
- process_environment_t *
- process_environment_make(struct smartlist_t *env_vars)
- {
- process_environment_t *env = tor_malloc_zero(sizeof(process_environment_t));
- size_t n_env_vars = smartlist_len(env_vars);
- size_t i;
- size_t total_env_length;
- smartlist_t *env_vars_sorted;
- tor_assert(n_env_vars + 1 != 0);
- env->unixoid_environment_block = tor_calloc(n_env_vars + 1, sizeof(char *));
- /* env->unixoid_environment_block is already NULL-terminated,
- * because we assume that NULL == 0 (and check that during compilation). */
- total_env_length = 1; /* terminating NUL of terminating empty string */
- for (i = 0; i < n_env_vars; ++i) {
- const char *s = smartlist_get(env_vars, i);
- size_t slen = strlen(s);
- tor_assert(slen + 1 != 0);
- tor_assert(slen + 1 < SIZE_MAX - total_env_length);
- total_env_length += slen + 1;
- }
- env->windows_environment_block = tor_malloc_zero(total_env_length);
- /* env->windows_environment_block is already
- * (NUL-terminated-empty-string)-terminated. */
- /* Some versions of Windows supposedly require that environment
- * blocks be sorted. Or maybe some Windows programs (or their
- * runtime libraries) fail to look up strings in non-sorted
- * environment blocks.
- *
- * Also, sorting strings makes it easy to find duplicate environment
- * variables and environment-variable strings without an '=' on all
- * OSes, and they can cause badness. Let's complain about those. */
- env_vars_sorted = smartlist_new();
- smartlist_add_all(env_vars_sorted, env_vars);
- smartlist_sort_strings(env_vars_sorted);
- /* Now copy the strings into the environment blocks. */
- {
- char *cp = env->windows_environment_block;
- const char *prev_env_var = NULL;
- for (i = 0; i < n_env_vars; ++i) {
- const char *s = smartlist_get(env_vars_sorted, i);
- size_t slen = strlen(s);
- size_t s_name_len = str_num_before(s, '=');
- if (s_name_len == slen) {
- log_warn(LD_GENERAL,
- "Preparing an environment containing a variable "
- "without a value: %s",
- s);
- }
- if (prev_env_var != NULL &&
- environment_variable_names_equal(s, prev_env_var)) {
- log_warn(LD_GENERAL,
- "Preparing an environment containing two variables "
- "with the same name: %s and %s",
- prev_env_var, s);
- }
- prev_env_var = s;
- /* Actually copy the string into the environment. */
- memcpy(cp, s, slen+1);
- env->unixoid_environment_block[i] = cp;
- cp += slen+1;
- }
- tor_assert(cp == env->windows_environment_block + total_env_length - 1);
- }
- smartlist_free(env_vars_sorted);
- return env;
- }
- /** Return a newly allocated smartlist containing every variable in
- * this process's environment, as a NUL-terminated string of the form
- * "NAME=VALUE". Note that on some/many/most/all OSes, the parent
- * process can put strings not of that form in our environment;
- * callers should try to not get crashed by that.
- *
- * The returned strings are heap-allocated, and must be freed by the
- * caller. */
- struct smartlist_t *
- get_current_process_environment_variables(void)
- {
- smartlist_t *sl = smartlist_new();
- char **environ_tmp; /* Not const char ** ? Really? */
- for (environ_tmp = get_environment(); *environ_tmp; ++environ_tmp) {
- smartlist_add_strdup(sl, *environ_tmp);
- }
- return sl;
- }
- /** For each string s in <b>env_vars</b> such that
- * environment_variable_names_equal(s, <b>new_var</b>), remove it; if
- * <b>free_p</b> is non-zero, call <b>free_old</b>(s). If
- * <b>new_var</b> contains '=', insert it into <b>env_vars</b>. */
- void
- set_environment_variable_in_smartlist(struct smartlist_t *env_vars,
- const char *new_var,
- void (*free_old)(void*),
- int free_p)
- {
- SMARTLIST_FOREACH_BEGIN(env_vars, const char *, s) {
- if (environment_variable_names_equal(s, new_var)) {
- SMARTLIST_DEL_CURRENT(env_vars, s);
- if (free_p) {
- free_old((void *)s);
- }
- }
- } SMARTLIST_FOREACH_END(s);
- if (strchr(new_var, '=') != NULL) {
- smartlist_add(env_vars, (void *)new_var);
- }
- }
- #ifdef _WIN32
- /** Read from a handle <b>h</b> into <b>buf</b>, up to <b>count</b> bytes. If
- * <b>hProcess</b> is NULL, the function will return immediately if there is
- * nothing more to read. Otherwise <b>hProcess</b> should be set to the handle
- * to the process owning the <b>h</b>. In this case, the function will exit
- * only once the process has exited, or <b>count</b> bytes are read. Returns
- * the number of bytes read, or -1 on error. */
- ssize_t
- tor_read_all_handle(HANDLE h, char *buf, size_t count,
- const process_handle_t *process)
- {
- size_t numread = 0;
- BOOL retval;
- DWORD byte_count;
- BOOL process_exited = FALSE;
- if (count > SIZE_T_CEILING || count > SSIZE_MAX)
- return -1;
- while (numread < count) {
- /* Check if there is anything to read */
- retval = PeekNamedPipe(h, NULL, 0, NULL, &byte_count, NULL);
- if (!retval) {
- log_warn(LD_GENERAL,
- "Failed to peek from handle: %s",
- format_win32_error(GetLastError()));
- return -1;
- } else if (0 == byte_count) {
- /* Nothing available: process exited or it is busy */
- /* Exit if we don't know whether the process is running */
- if (NULL == process)
- break;
- /* The process exited and there's nothing left to read from it */
- if (process_exited)
- break;
- /* If process is not running, check for output one more time in case
- it wrote something after the peek was performed. Otherwise keep on
- waiting for output */
- tor_assert(process != NULL);
- byte_count = WaitForSingleObject(process->pid.hProcess, 0);
- if (WAIT_TIMEOUT != byte_count)
- process_exited = TRUE;
- continue;
- }
- /* There is data to read; read it */
- retval = ReadFile(h, buf+numread, count-numread, &byte_count, NULL);
- tor_assert(byte_count + numread <= count);
- if (!retval) {
- log_warn(LD_GENERAL, "Failed to read from handle: %s",
- format_win32_error(GetLastError()));
- return -1;
- } else if (0 == byte_count) {
- /* End of file */
- break;
- }
- numread += byte_count;
- }
- return (ssize_t)numread;
- }
- #else
- /** Read from a handle <b>fd</b> into <b>buf</b>, up to <b>count</b> bytes. If
- * <b>process</b> is NULL, the function will return immediately if there is
- * nothing more to read. Otherwise data will be read until end of file, or
- * <b>count</b> bytes are read. Returns the number of bytes read, or -1 on
- * error. Sets <b>eof</b> to true if <b>eof</b> is not NULL and the end of the
- * file has been reached. */
- ssize_t
- tor_read_all_handle(int fd, char *buf, size_t count,
- const process_handle_t *process,
- int *eof)
- {
- size_t numread = 0;
- ssize_t result;
- if (eof)
- *eof = 0;
- if (count > SIZE_T_CEILING || count > SSIZE_MAX)
- return -1;
- while (numread < count) {
- result = read(fd, buf+numread, count-numread);
- if (result == 0) {
- log_debug(LD_GENERAL, "read() reached end of file");
- if (eof)
- *eof = 1;
- break;
- } else if (result < 0 && errno == EAGAIN) {
- if (process)
- continue;
- else
- break;
- } else if (result < 0) {
- log_warn(LD_GENERAL, "read() failed: %s", strerror(errno));
- return -1;
- }
- numread += result;
- }
- log_debug(LD_GENERAL, "read() read %d bytes from handle", (int)numread);
- return (ssize_t)numread;
- }
- #endif
- /** Read from stdout of a process until the process exits. */
- ssize_t
- tor_read_all_from_process_stdout(const process_handle_t *process_handle,
- char *buf, size_t count)
- {
- #ifdef _WIN32
- return tor_read_all_handle(process_handle->stdout_pipe, buf, count,
- process_handle);
- #else
- return tor_read_all_handle(process_handle->stdout_pipe, buf, count,
- process_handle, NULL);
- #endif
- }
- /** Read from stdout of a process until the process exits. */
- ssize_t
- tor_read_all_from_process_stderr(const process_handle_t *process_handle,
- char *buf, size_t count)
- {
- #ifdef _WIN32
- return tor_read_all_handle(process_handle->stderr_pipe, buf, count,
- process_handle);
- #else
- return tor_read_all_handle(process_handle->stderr_pipe, buf, count,
- process_handle, NULL);
- #endif
- }
- /** Split buf into lines, and add to smartlist. The buffer <b>buf</b> will be
- * modified. The resulting smartlist will consist of pointers to buf, so there
- * is no need to free the contents of sl. <b>buf</b> must be a NUL-terminated
- * string. <b>len</b> should be set to the length of the buffer excluding the
- * NUL. Non-printable characters (including NUL) will be replaced with "." */
- int
- tor_split_lines(smartlist_t *sl, char *buf, int len)
- {
- /* Index in buf of the start of the current line */
- int start = 0;
- /* Index in buf of the current character being processed */
- int cur = 0;
- /* Are we currently in a line */
- char in_line = 0;
- /* Loop over string */
- while (cur < len) {
- /* Loop until end of line or end of string */
- for (; cur < len; cur++) {
- if (in_line) {
- if ('\r' == buf[cur] || '\n' == buf[cur]) {
- /* End of line */
- buf[cur] = '\0';
- /* Point cur to the next line */
- cur++;
- /* Line starts at start and ends with a nul */
- break;
- } else {
- if (!TOR_ISPRINT(buf[cur]))
- buf[cur] = '.';
- }
- } else {
- if ('\r' == buf[cur] || '\n' == buf[cur]) {
- /* Skip leading vertical space */
- ;
- } else {
- in_line = 1;
- start = cur;
- if (!TOR_ISPRINT(buf[cur]))
- buf[cur] = '.';
- }
- }
- }
- /* We are at the end of the line or end of string. If in_line is true there
- * is a line which starts at buf+start and ends at a NUL. cur points to
- * the character after the NUL. */
- if (in_line)
- smartlist_add(sl, (void *)(buf+start));
- in_line = 0;
- }
- return smartlist_len(sl);
- }
- /** Return a string corresponding to <b>stream_status</b>. */
- const char *
- stream_status_to_string(enum stream_status stream_status)
- {
- switch (stream_status) {
- case IO_STREAM_OKAY:
- return "okay";
- case IO_STREAM_EAGAIN:
- return "temporarily unavailable";
- case IO_STREAM_TERM:
- return "terminated";
- case IO_STREAM_CLOSED:
- return "closed";
- default:
- tor_fragile_assert();
- return "unknown";
- }
- }
- /* DOCDOC */
- static void
- log_portfw_spawn_error_message(const char *buf,
- const char *executable, int *child_status)
- {
- /* Parse error message */
- int retval, child_state, saved_errno;
- retval = tor_sscanf(buf, SPAWN_ERROR_MESSAGE "%x/%x",
- &child_state, &saved_errno);
- if (retval == 2) {
- log_warn(LD_GENERAL,
- "Failed to start child process \"%s\" in state %d: %s",
- executable, child_state, strerror(saved_errno));
- if (child_status)
- *child_status = 1;
- } else {
- /* Failed to parse message from child process, log it as a
- warning */
- log_warn(LD_GENERAL,
- "Unexpected message from port forwarding helper \"%s\": %s",
- executable, buf);
- }
- }
- #ifdef _WIN32
- /** Return a smartlist containing lines outputted from
- * <b>handle</b>. Return NULL on error, and set
- * <b>stream_status_out</b> appropriately. */
- MOCK_IMPL(smartlist_t *,
- tor_get_lines_from_handle, (HANDLE *handle,
- enum stream_status *stream_status_out))
- {
- int pos;
- char stdout_buf[600] = {0};
- smartlist_t *lines = NULL;
- tor_assert(stream_status_out);
- *stream_status_out = IO_STREAM_TERM;
- pos = tor_read_all_handle(handle, stdout_buf, sizeof(stdout_buf) - 1, NULL);
- if (pos < 0) {
- *stream_status_out = IO_STREAM_TERM;
- return NULL;
- }
- if (pos == 0) {
- *stream_status_out = IO_STREAM_EAGAIN;
- return NULL;
- }
- /* End with a null even if there isn't a \r\n at the end */
- /* TODO: What if this is a partial line? */
- stdout_buf[pos] = '\0';
- /* Split up the buffer */
- lines = smartlist_new();
- tor_split_lines(lines, stdout_buf, pos);
- /* Currently 'lines' is populated with strings residing on the
- stack. Replace them with their exact copies on the heap: */
- SMARTLIST_FOREACH(lines, char *, line,
- SMARTLIST_REPLACE_CURRENT(lines, line, tor_strdup(line)));
- *stream_status_out = IO_STREAM_OKAY;
- return lines;
- }
- /** Read from stream, and send lines to log at the specified log level.
- * Returns -1 if there is a error reading, and 0 otherwise.
- * If the generated stream is flushed more often than on new lines, or
- * a read exceeds 256 bytes, lines will be truncated. This should be fixed,
- * along with the corresponding problem on *nix (see bug #2045).
- */
- static int
- log_from_handle(HANDLE *pipe, int severity)
- {
- char buf[256];
- int pos;
- smartlist_t *lines;
- pos = tor_read_all_handle(pipe, buf, sizeof(buf) - 1, NULL);
- if (pos < 0) {
- /* Error */
- log_warn(LD_GENERAL, "Failed to read data from subprocess");
- return -1;
- }
- if (0 == pos) {
- /* There's nothing to read (process is busy or has exited) */
- log_debug(LD_GENERAL, "Subprocess had nothing to say");
- return 0;
- }
- /* End with a null even if there isn't a \r\n at the end */
- /* TODO: What if this is a partial line? */
- buf[pos] = '\0';
- log_debug(LD_GENERAL, "Subprocess had %d bytes to say", pos);
- /* Split up the buffer */
- lines = smartlist_new();
- tor_split_lines(lines, buf, pos);
- /* Log each line */
- SMARTLIST_FOREACH(lines, char *, line,
- {
- log_fn(severity, LD_GENERAL, "Port forwarding helper says: %s", line);
- });
- smartlist_free(lines);
- return 0;
- }
- #else
- /** Return a smartlist containing lines outputted from
- * <b>fd</b>. Return NULL on error, and set
- * <b>stream_status_out</b> appropriately. */
- MOCK_IMPL(smartlist_t *,
- tor_get_lines_from_handle, (int fd, enum stream_status *stream_status_out))
- {
- enum stream_status stream_status;
- char stdout_buf[400];
- smartlist_t *lines = NULL;
- while (1) {
- memset(stdout_buf, 0, sizeof(stdout_buf));
- stream_status = get_string_from_pipe(fd,
- stdout_buf, sizeof(stdout_buf) - 1);
- if (stream_status != IO_STREAM_OKAY)
- goto done;
- if (!lines) lines = smartlist_new();
- smartlist_add_strdup(lines, stdout_buf);
- }
- done:
- *stream_status_out = stream_status;
- return lines;
- }
- /** Read from fd, and send lines to log at the specified log level.
- * Returns 1 if stream is closed normally, -1 if there is a error reading, and
- * 0 otherwise. Handles lines from tor-fw-helper and
- * tor_spawn_background() specially.
- */
- static int
- log_from_pipe(int fd, int severity, const char *executable,
- int *child_status)
- {
- char buf[256];
- enum stream_status r;
- for (;;) {
- r = get_string_from_pipe(fd, buf, sizeof(buf) - 1);
- if (r == IO_STREAM_CLOSED) {
- return 1;
- } else if (r == IO_STREAM_EAGAIN) {
- return 0;
- } else if (r == IO_STREAM_TERM) {
- return -1;
- }
- tor_assert(r == IO_STREAM_OKAY);
- /* Check if buf starts with SPAWN_ERROR_MESSAGE */
- if (strcmpstart(buf, SPAWN_ERROR_MESSAGE) == 0) {
- log_portfw_spawn_error_message(buf, executable, child_status);
- } else {
- log_fn(severity, LD_GENERAL, "Port forwarding helper says: %s", buf);
- }
- }
- /* We should never get here */
- return -1;
- }
- #endif
- /** Reads from <b>fd</b> and stores input in <b>buf_out</b> making
- * sure it's below <b>count</b> bytes.
- * If the string has a trailing newline, we strip it off.
- *
- * This function is specifically created to handle input from managed
- * proxies, according to the pluggable transports spec. Make sure it
- * fits your needs before using it.
- *
- * Returns:
- * IO_STREAM_CLOSED: If the stream is closed.
- * IO_STREAM_EAGAIN: If there is nothing to read and we should check back
- * later.
- * IO_STREAM_TERM: If something is wrong with the stream.
- * IO_STREAM_OKAY: If everything went okay and we got a string
- * in <b>buf_out</b>. */
- enum stream_status
- get_string_from_pipe(int fd, char *buf_out, size_t count)
- {
- ssize_t ret;
- tor_assert(count <= INT_MAX);
- ret = read(fd, buf_out, count);
- if (ret == 0)
- return IO_STREAM_CLOSED;
- else if (ret < 0 && errno == EAGAIN)
- return IO_STREAM_EAGAIN;
- else if (ret < 0)
- return IO_STREAM_TERM;
- if (buf_out[ret - 1] == '\n') {
- /* Remove the trailing newline */
- buf_out[ret - 1] = '\0';
- } else
- buf_out[ret] = '\0';
- return IO_STREAM_OKAY;
- }
- /** Parse a <b>line</b> from tor-fw-helper and issue an appropriate
- * log message to our user. */
- static void
- handle_fw_helper_line(const char *executable, const char *line)
- {
- smartlist_t *tokens = smartlist_new();
- char *message = NULL;
- char *message_for_log = NULL;
- const char *external_port = NULL;
- const char *internal_port = NULL;
- const char *result = NULL;
- int port = 0;
- int success = 0;
- if (strcmpstart(line, SPAWN_ERROR_MESSAGE) == 0) {
- /* We need to check for SPAWN_ERROR_MESSAGE again here, since it's
- * possible that it got sent after we tried to read it in log_from_pipe.
- *
- * XXX Ideally, we should be using one of stdout/stderr for the real
- * output, and one for the output of the startup code. We used to do that
- * before cd05f35d2c.
- */
- int child_status;
- log_portfw_spawn_error_message(line, executable, &child_status);
- goto done;
- }
- smartlist_split_string(tokens, line, NULL,
- SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, -1);
- if (smartlist_len(tokens) < 5)
- goto err;
- if (strcmp(smartlist_get(tokens, 0), "tor-fw-helper") ||
- strcmp(smartlist_get(tokens, 1), "tcp-forward"))
- goto err;
- external_port = smartlist_get(tokens, 2);
- internal_port = smartlist_get(tokens, 3);
- result = smartlist_get(tokens, 4);
- if (smartlist_len(tokens) > 5) {
- /* If there are more than 5 tokens, they are part of [<message>].
- Let's use a second smartlist to form the whole message;
- strncat loops suck. */
- int i;
- int message_words_n = smartlist_len(tokens) - 5;
- smartlist_t *message_sl = smartlist_new();
- for (i = 0; i < message_words_n; i++)
- smartlist_add(message_sl, smartlist_get(tokens, 5+i));
- tor_assert(smartlist_len(message_sl) > 0);
- message = smartlist_join_strings(message_sl, " ", 0, NULL);
- /* wrap the message in log-friendly wrapping */
- tor_asprintf(&message_for_log, " ('%s')", message);
- smartlist_free(message_sl);
- }
- port = atoi(external_port);
- if (port < 1 || port > 65535)
- goto err;
- port = atoi(internal_port);
- if (port < 1 || port > 65535)
- goto err;
- if (!strcmp(result, "SUCCESS"))
- success = 1;
- else if (!strcmp(result, "FAIL"))
- success = 0;
- else
- goto err;
- if (!success) {
- log_warn(LD_GENERAL, "Tor was unable to forward TCP port '%s' to '%s'%s. "
- "Please make sure that your router supports port "
- "forwarding protocols (like NAT-PMP). Note that if '%s' is "
- "your ORPort, your relay will be unable to receive inbound "
- "traffic.", external_port, internal_port,
- message_for_log ? message_for_log : "",
- internal_port);
- } else {
- log_info(LD_GENERAL,
- "Tor successfully forwarded TCP port '%s' to '%s'%s.",
- external_port, internal_port,
- message_for_log ? message_for_log : "");
- }
- goto done;
- err:
- log_warn(LD_GENERAL, "tor-fw-helper sent us a string we could not "
- "parse (%s).", line);
- done:
- SMARTLIST_FOREACH(tokens, char *, cp, tor_free(cp));
- smartlist_free(tokens);
- tor_free(message);
- tor_free(message_for_log);
- }
- /** Read what tor-fw-helper has to say in its stdout and handle it
- * appropriately */
- static int
- handle_fw_helper_output(const char *executable,
- process_handle_t *process_handle)
- {
- smartlist_t *fw_helper_output = NULL;
- enum stream_status stream_status = 0;
- fw_helper_output =
- tor_get_lines_from_handle(tor_process_get_stdout_pipe(process_handle),
- &stream_status);
- if (!fw_helper_output) { /* didn't get any output from tor-fw-helper */
- /* if EAGAIN we should retry in the future */
- return (stream_status == IO_STREAM_EAGAIN) ? 0 : -1;
- }
- /* Handle the lines we got: */
- SMARTLIST_FOREACH_BEGIN(fw_helper_output, char *, line) {
- handle_fw_helper_line(executable, line);
- tor_free(line);
- } SMARTLIST_FOREACH_END(line);
- smartlist_free(fw_helper_output);
- return 0;
- }
- /** Spawn tor-fw-helper and ask it to forward the ports in
- * <b>ports_to_forward</b>. <b>ports_to_forward</b> contains strings
- * of the form "<external port>:<internal port>", which is the format
- * that tor-fw-helper expects. */
- void
- tor_check_port_forwarding(const char *filename,
- smartlist_t *ports_to_forward,
- time_t now)
- {
- /* When fw-helper succeeds, how long do we wait until running it again */
- #define TIME_TO_EXEC_FWHELPER_SUCCESS 300
- /* When fw-helper failed to start, how long do we wait until running it again
- */
- #define TIME_TO_EXEC_FWHELPER_FAIL 60
- /* Static variables are initialized to zero, so child_handle.status=0
- * which corresponds to it not running on startup */
- static process_handle_t *child_handle=NULL;
- static time_t time_to_run_helper = 0;
- int stderr_status, retval;
- int stdout_status = 0;
- tor_assert(filename);
- /* Start the child, if it is not already running */
- if ((!child_handle || child_handle->status != PROCESS_STATUS_RUNNING) &&
- time_to_run_helper < now) {
- /*tor-fw-helper cli looks like this: tor_fw_helper -p :5555 -p 4555:1111 */
- const char **argv; /* cli arguments */
- int args_n, status;
- int argv_index = 0; /* index inside 'argv' */
- tor_assert(smartlist_len(ports_to_forward) > 0);
- /* check for overflow during 'argv' allocation:
- (len(ports_to_forward)*2 + 2)*sizeof(char*) > SIZE_MAX ==
- len(ports_to_forward) > (((SIZE_MAX/sizeof(char*)) - 2)/2) */
- if ((size_t) smartlist_len(ports_to_forward) >
- (((SIZE_MAX/sizeof(char*)) - 2)/2)) {
- log_warn(LD_GENERAL,
- "Overflow during argv allocation. This shouldn't happen.");
- return;
- }
- /* check for overflow during 'argv_index' increase:
- ((len(ports_to_forward)*2 + 2) > INT_MAX) ==
- len(ports_to_forward) > (INT_MAX - 2)/2 */
- if (smartlist_len(ports_to_forward) > (INT_MAX - 2)/2) {
- log_warn(LD_GENERAL,
- "Overflow during argv_index increase. This shouldn't happen.");
- return;
- }
- /* Calculate number of cli arguments: one for the filename, two
- for each smartlist element (one for "-p" and one for the
- ports), and one for the final NULL. */
- args_n = 1 + 2*smartlist_len(ports_to_forward) + 1;
- argv = tor_calloc(args_n, sizeof(char *));
- argv[argv_index++] = filename;
- SMARTLIST_FOREACH_BEGIN(ports_to_forward, const char *, port) {
- argv[argv_index++] = "-p";
- argv[argv_index++] = port;
- } SMARTLIST_FOREACH_END(port);
- argv[argv_index] = NULL;
- /* Assume tor-fw-helper will succeed, start it later*/
- time_to_run_helper = now + TIME_TO_EXEC_FWHELPER_SUCCESS;
- if (child_handle) {
- tor_process_handle_destroy(child_handle, 1);
- child_handle = NULL;
- }
- #ifdef _WIN32
- /* Passing NULL as lpApplicationName makes Windows search for the .exe */
- status = tor_spawn_background(NULL, argv, NULL, &child_handle);
- #else
- status = tor_spawn_background(filename, argv, NULL, &child_handle);
- #endif
- tor_free_((void*)argv);
- argv=NULL;
- if (PROCESS_STATUS_ERROR == status) {
- log_warn(LD_GENERAL, "Failed to start port forwarding helper %s",
- filename);
- time_to_run_helper = now + TIME_TO_EXEC_FWHELPER_FAIL;
- return;
- }
- log_info(LD_GENERAL,
- "Started port forwarding helper (%s) with pid '%d'",
- filename, tor_process_get_pid(child_handle));
- }
- /* If child is running, read from its stdout and stderr) */
- if (child_handle && PROCESS_STATUS_RUNNING == child_handle->status) {
- /* Read from stdout/stderr and log result */
- retval = 0;
- #ifdef _WIN32
- stderr_status = log_from_handle(child_handle->stderr_pipe, LOG_INFO);
- #else
- stderr_status = log_from_pipe(child_handle->stderr_pipe,
- LOG_INFO, filename, &retval);
- #endif
- if (handle_fw_helper_output(filename, child_handle) < 0) {
- log_warn(LD_GENERAL, "Failed to handle fw helper output.");
- stdout_status = -1;
- retval = -1;
- }
- if (retval) {
- /* There was a problem in the child process */
- time_to_run_helper = now + TIME_TO_EXEC_FWHELPER_FAIL;
- }
- /* Combine the two statuses in order of severity */
- if (-1 == stdout_status || -1 == stderr_status)
- /* There was a failure */
- retval = -1;
- #ifdef _WIN32
- else if (!child_handle || tor_get_exit_code(child_handle, 0, NULL) !=
- PROCESS_EXIT_RUNNING) {
- /* process has exited or there was an error */
- /* TODO: Do something with the process return value */
- /* TODO: What if the process output something since
- * between log_from_handle and tor_get_exit_code? */
- retval = 1;
- }
- #else
- else if (1 == stdout_status || 1 == stderr_status)
- /* stdout or stderr was closed, the process probably
- * exited. It will be reaped by waitpid() in main.c */
- /* TODO: Do something with the process return value */
- retval = 1;
- #endif
- else
- /* Both are fine */
- retval = 0;
- /* If either pipe indicates a failure, act on it */
- if (0 != retval) {
- if (1 == retval) {
- log_info(LD_GENERAL, "Port forwarding helper terminated");
- child_handle->status = PROCESS_STATUS_NOTRUNNING;
- } else {
- log_warn(LD_GENERAL, "Failed to read from port forwarding helper");
- child_handle->status = PROCESS_STATUS_ERROR;
- }
- /* TODO: The child might not actually be finished (maybe it failed or
- closed stdout/stderr), so maybe we shouldn't start another? */
- }
- }
- }
- /** Initialize the insecure RNG <b>rng</b> from a seed value <b>seed</b>. */
- void
- tor_init_weak_random(tor_weak_rng_t *rng, unsigned seed)
- {
- rng->state = (uint32_t)(seed & 0x7fffffff);
- }
- /** Return a randomly chosen value in the range 0..TOR_WEAK_RANDOM_MAX based
- * on the RNG state of <b>rng</b>. This entropy will not be cryptographically
- * strong; do not rely on it for anything an adversary should not be able to
- * predict. */
- int32_t
- tor_weak_random(tor_weak_rng_t *rng)
- {
- /* Here's a linear congruential generator. OpenBSD and glibc use these
- * parameters; they aren't too bad, and should have maximal period over the
- * range 0..INT32_MAX. We don't want to use the platform rand() or random(),
- * since some platforms have bad weak RNGs that only return values in the
- * range 0..INT16_MAX, which just isn't enough. */
- rng->state = (rng->state * 1103515245 + 12345) & 0x7fffffff;
- return (int32_t) rng->state;
- }
- /** Return a random number in the range [0 , <b>top</b>). {That is, the range
- * of integers i such that 0 <= i < top.} Chooses uniformly. Requires that
- * top is greater than 0. This randomness is not cryptographically strong; do
- * not rely on it for anything an adversary should not be able to predict. */
- int32_t
- tor_weak_random_range(tor_weak_rng_t *rng, int32_t top)
- {
- /* We don't want to just do tor_weak_random() % top, since random() is often
- * implemented with an LCG whose modulus is a power of 2, and those are
- * cyclic in their low-order bits. */
- int divisor, result;
- tor_assert(top > 0);
- divisor = TOR_WEAK_RANDOM_MAX / top;
- do {
- result = (int32_t)(tor_weak_random(rng) / divisor);
- } while (result >= top);
- return result;
- }
- /** Cast a given double value to a int64_t. Return 0 if number is NaN.
- * Returns either INT64_MIN or INT64_MAX if number is outside of the int64_t
- * range. */
- int64_t
- clamp_double_to_int64(double number)
- {
- int exponent;
- /* NaN is a special case that can't be used with the logic below. */
- if (isnan(number)) {
- return 0;
- }
- /* Time to validate if result can overflows a int64_t value. Fun with
- * float! Find that exponent exp such that
- * number == x * 2^exp
- * for some x with abs(x) in [0.5, 1.0). Note that this implies that the
- * magnitude of number is strictly less than 2^exp.
- *
- * If number is infinite, the call to frexp is legal but the contents of
- * are exponent unspecified. */
- frexp(number, &exponent);
- /* If the magnitude of number is strictly less than 2^63, the truncated
- * version of number is guaranteed to be representable. The only
- * representable integer for which this is not the case is INT64_MIN, but
- * it is covered by the logic below. */
- if (isfinite(number) && exponent <= 63) {
- return (int64_t)number;
- }
- /* Handle infinities and finite numbers with magnitude >= 2^63. */
- return signbit(number) ? INT64_MIN : INT64_MAX;
- }
- /** Return a uint64_t value from <b>a</b> in network byte order. */
- uint64_t
- tor_htonll(uint64_t a)
- {
- #ifdef WORDS_BIGENDIAN
- /* Big endian. */
- return a;
- #else /* WORDS_BIGENDIAN */
- /* Little endian. The worst... */
- return htonl((uint32_t)(a>>32)) |
- (((uint64_t)htonl((uint32_t)a))<<32);
- #endif /* WORDS_BIGENDIAN */
- }
- /** Return a uint64_t value from <b>a</b> in host byte order. */
- uint64_t
- tor_ntohll(uint64_t a)
- {
- return tor_htonll(a);
- }
|