/* Copyright (c) 2003-2004, Roger Dingledine * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. * Copyright (c) 2007-2015, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file util.h * \brief Headers for util.c **/ #ifndef TOR_UTIL_H #define TOR_UTIL_H #include "orconfig.h" #include "torint.h" #include "compat.h" #include "di_ops.h" #include "testsupport.h" #include #include #ifdef _WIN32 /* for the correct alias to struct stat */ #include #endif #ifndef O_BINARY #define O_BINARY 0 #endif #ifndef O_TEXT #define O_TEXT 0 #endif /* Replace assert() with a variant that sends failures to the log before * calling assert() normally. */ #ifdef NDEBUG /* Nobody should ever want to build with NDEBUG set. 99% of our asserts will * be outside the critical path anyway, so it's silly to disable bug-checking * throughout the entire program just because a few asserts are slowing you * down. Profile, optimize the critical path, and keep debugging on. * * And I'm not just saying that because some of our asserts check * security-critical properties. */ #error "Sorry; we don't support building with NDEBUG." #endif /** Like assert(3), but send assertion failures to the log as well as to * stderr. */ #define tor_assert(expr) STMT_BEGIN \ if (PREDICT_UNLIKELY(!(expr))) { \ tor_assertion_failed_(SHORT_FILE__, __LINE__, __func__, #expr); \ abort(); \ } STMT_END void tor_assertion_failed_(const char *fname, unsigned int line, const char *func, const char *expr); /* If we're building with dmalloc, we want all of our memory allocation * functions to take an extra file/line pair of arguments. If not, not. * We define DMALLOC_PARAMS to the extra parameters to insert in the * function prototypes, and DMALLOC_ARGS to the extra arguments to add * to calls. */ #ifdef USE_DMALLOC #define DMALLOC_PARAMS , const char *file, const int line #define DMALLOC_ARGS , SHORT_FILE__, __LINE__ #else #define DMALLOC_PARAMS #define DMALLOC_ARGS #endif /** Define this if you want Tor to crash when any problem comes up, * so you can get a coredump and track things down. */ // #define tor_fragile_assert() tor_assert(0) #define tor_fragile_assert() /* Memory management */ void *tor_malloc_(size_t size DMALLOC_PARAMS) ATTR_MALLOC; void *tor_malloc_zero_(size_t size DMALLOC_PARAMS) ATTR_MALLOC; void *tor_calloc_(size_t nmemb, size_t size DMALLOC_PARAMS) ATTR_MALLOC; void *tor_realloc_(void *ptr, size_t size DMALLOC_PARAMS); void *tor_reallocarray_(void *ptr, size_t size1, size_t size2 DMALLOC_PARAMS); char *tor_strdup_(const char *s DMALLOC_PARAMS) ATTR_MALLOC ATTR_NONNULL((1)); char *tor_strndup_(const char *s, size_t n DMALLOC_PARAMS) ATTR_MALLOC ATTR_NONNULL((1)); void *tor_memdup_(const void *mem, size_t len DMALLOC_PARAMS) ATTR_MALLOC ATTR_NONNULL((1)); void *tor_memdup_nulterm_(const void *mem, size_t len DMALLOC_PARAMS) ATTR_MALLOC ATTR_NONNULL((1)); void tor_free_(void *mem); #ifdef USE_DMALLOC extern int dmalloc_free(const char *file, const int line, void *pnt, const int func_id); #define tor_free(p) STMT_BEGIN \ if (PREDICT_LIKELY((p)!=NULL)) { \ dmalloc_free(SHORT_FILE__, __LINE__, (p), 0); \ (p)=NULL; \ } \ STMT_END #else /** Release memory allocated by tor_malloc, tor_realloc, tor_strdup, etc. * Unlike the free() function, tor_free() will still work on NULL pointers, * and it sets the pointer value to NULL after freeing it. * * This is a macro. If you need a function pointer to release memory from * tor_malloc(), use tor_free_(). */ #define tor_free(p) STMT_BEGIN \ if (PREDICT_LIKELY((p)!=NULL)) { \ free(p); \ (p)=NULL; \ } \ STMT_END #endif #define tor_malloc(size) tor_malloc_(size DMALLOC_ARGS) #define tor_malloc_zero(size) tor_malloc_zero_(size DMALLOC_ARGS) #define tor_calloc(nmemb,size) tor_calloc_(nmemb, size DMALLOC_ARGS) #define tor_realloc(ptr, size) tor_realloc_(ptr, size DMALLOC_ARGS) #define tor_reallocarray(ptr, sz1, sz2) \ tor_reallocarray_((ptr), (sz1), (sz2) DMALLOC_ARGS) #define tor_strdup(s) tor_strdup_(s DMALLOC_ARGS) #define tor_strndup(s, n) tor_strndup_(s, n DMALLOC_ARGS) #define tor_memdup(s, n) tor_memdup_(s, n DMALLOC_ARGS) #define tor_memdup_nulterm(s, n) tor_memdup_nulterm_(s, n DMALLOC_ARGS) void tor_log_mallinfo(int severity); /** Return the offset of member within the type tp, in bytes */ #if defined(__GNUC__) && __GNUC__ > 3 #define STRUCT_OFFSET(tp, member) __builtin_offsetof(tp, member) #else #define STRUCT_OFFSET(tp, member) \ ((off_t) (((char*)&((tp*)0)->member)-(char*)0)) #endif /** Macro: yield a pointer to the field at position off within the * structure st. Example: * 
 *   struct a { int foo; int bar; } x;
 *   off_t bar_offset = STRUCT_OFFSET(struct a, bar);
 *   int *bar_p = STRUCT_VAR_P(&x, bar_offset);
 *   *bar_p = 3;
 *
*/ #define STRUCT_VAR_P(st, off) ((void*) ( ((char*)(st)) + (off) ) ) /** Macro: yield a pointer to an enclosing structure given a pointer to * a substructure at offset off. Example: * 
 *   struct base { ... };
 *   struct subtype { int x; struct base b; } x;
 *   struct base *bp = &x.base;
 *   struct *sp = SUBTYPE_P(bp, struct subtype, b);
 *
*/ #define SUBTYPE_P(p, subtype, basemember) \ ((void*) ( ((char*)(p)) - STRUCT_OFFSET(subtype, basemember) )) /* Logic */ /** Macro: true if two values have the same boolean value. */ #define bool_eq(a,b) (!(a)==!(b)) /** Macro: true if two values have different boolean values. */ #define bool_neq(a,b) (!(a)!=!(b)) /* Math functions */ double tor_mathlog(double d) ATTR_CONST; long tor_lround(double d) ATTR_CONST; int64_t tor_llround(double d) ATTR_CONST; int tor_log2(uint64_t u64) ATTR_CONST; uint64_t round_to_power_of_2(uint64_t u64); unsigned round_to_next_multiple_of(unsigned number, unsigned divisor); uint32_t round_uint32_to_next_multiple_of(uint32_t number, uint32_t divisor); uint64_t round_uint64_to_next_multiple_of(uint64_t number, uint64_t divisor); int64_t round_int64_to_next_multiple_of(int64_t number, int64_t divisor); int64_t sample_laplace_distribution(double mu, double b, double p); int64_t add_laplace_noise(int64_t signal, double random, double delta_f, double epsilon); int n_bits_set_u8(uint8_t v); /* Compute the CEIL of a divided by b, for nonnegative a * and positive b. Works on integer types only. Not defined if a+b can * overflow. */ #define CEIL_DIV(a,b) (((a)+(b)-1)/(b)) /* Return v if it's between min and max. Otherwise * return min if v is smaller than min, or max if * b is larger than max. * * Requires that min is no more than max. May evaluate any of * its arguments more than once! */ #define CLAMP(min,v,max) \ ( ((v) < (min)) ? (min) : \ ((v) > (max)) ? (max) : \ (v) ) /* String manipulation */ /** Allowable characters in a hexadecimal string. */ #define HEX_CHARACTERS "0123456789ABCDEFabcdef" void tor_strlower(char *s) ATTR_NONNULL((1)); void tor_strupper(char *s) ATTR_NONNULL((1)); int tor_strisprint(const char *s) ATTR_NONNULL((1)); int tor_strisnonupper(const char *s) ATTR_NONNULL((1)); int strcmp_opt(const char *s1, const char *s2); int strcmpstart(const char *s1, const char *s2) ATTR_NONNULL((1,2)); int strcmp_len(const char *s1, const char *s2, size_t len) ATTR_NONNULL((1,2)); int strcasecmpstart(const char *s1, const char *s2) ATTR_NONNULL((1,2)); int strcmpend(const char *s1, const char *s2) ATTR_NONNULL((1,2)); int strcasecmpend(const char *s1, const char *s2) ATTR_NONNULL((1,2)); int fast_memcmpstart(const void *mem, size_t memlen, const char *prefix); void tor_strclear(char *s); void tor_strstrip(char *s, const char *strip) ATTR_NONNULL((1,2)); long tor_parse_long(const char *s, int base, long min, long max, int *ok, char **next); unsigned long tor_parse_ulong(const char *s, int base, unsigned long min, unsigned long max, int *ok, char **next); double tor_parse_double(const char *s, double min, double max, int *ok, char **next); uint64_t tor_parse_uint64(const char *s, int base, uint64_t min, uint64_t max, int *ok, char **next); const char *hex_str(const char *from, size_t fromlen) ATTR_NONNULL((1)); const char *eat_whitespace(const char *s); const char *eat_whitespace_eos(const char *s, const char *eos); const char *eat_whitespace_no_nl(const char *s); const char *eat_whitespace_eos_no_nl(const char *s, const char *eos); const char *find_whitespace(const char *s); const char *find_whitespace_eos(const char *s, const char *eos); const char *find_str_at_start_of_line(const char *haystack, const char *needle); int string_is_C_identifier(const char *string); int string_is_key_value(int severity, const char *string); int string_is_valid_hostname(const char *string); int string_is_valid_ipv4_address(const char *string); int string_is_valid_ipv6_address(const char *string); int tor_mem_is_zero(const char *mem, size_t len); int tor_digest_is_zero(const char *digest); int tor_digest256_is_zero(const char *digest); char *esc_for_log(const char *string) ATTR_MALLOC; char *esc_for_log_len(const char *chars, size_t n) ATTR_MALLOC; const char *escaped(const char *string); char *tor_escape_str_for_pt_args(const char *string, const char *chars_to_escape); struct smartlist_t; int tor_vsscanf(const char *buf, const char *pattern, va_list ap) \ CHECK_SCANF(2, 0); int tor_sscanf(const char *buf, const char *pattern, ...) CHECK_SCANF(2, 3); void smartlist_add_asprintf(struct smartlist_t *sl, const char *pattern, ...) CHECK_PRINTF(2, 3); void smartlist_add_vasprintf(struct smartlist_t *sl, const char *pattern, va_list args) CHECK_PRINTF(2, 0); int hex_decode_digit(char c); void base16_encode(char *dest, size_t destlen, const char *src, size_t srclen); int base16_decode(char *dest, size_t destlen, const char *src, size_t srclen); /* Time helpers */ long tv_udiff(const struct timeval *start, const struct timeval *end); long tv_mdiff(const struct timeval *start, const struct timeval *end); int64_t tv_to_msec(const struct timeval *tv); int tor_timegm(const struct tm *tm, time_t *time_out); #define RFC1123_TIME_LEN 29 void format_rfc1123_time(char *buf, time_t t); int parse_rfc1123_time(const char *buf, time_t *t); #define ISO_TIME_LEN 19 #define ISO_TIME_USEC_LEN (ISO_TIME_LEN+7) void format_local_iso_time(char *buf, time_t t); void format_iso_time(char *buf, time_t t); void format_iso_time_nospace(char *buf, time_t t); void format_iso_time_nospace_usec(char *buf, const struct timeval *tv); int parse_iso_time_(const char *cp, time_t *t, int strict); int parse_iso_time(const char *buf, time_t *t); int parse_http_time(const char *buf, struct tm *tm); int format_time_interval(char *out, size_t out_len, long interval); /* Cached time */ #ifdef TIME_IS_FAST #define approx_time() time(NULL) #define update_approx_time(t) STMT_NIL #else time_t approx_time(void); void update_approx_time(time_t now); #endif /* Rate-limiter */ /** A ratelim_t remembers how often an event is occurring, and how often * it's allowed to occur. Typical usage is something like: * 
    if (possibly_very_frequent_event()) {
      const int INTERVAL = 300;
      static ratelim_t warning_limit = RATELIM_INIT(INTERVAL);
      char *m;
      if ((m = rate_limit_log(&warning_limit, approx_time()))) {
        log_warn(LD_GENERAL, "The event occurred!%s", m);
        tor_free(m);
      }
    }
As a convenience wrapper for logging, you can replace the above with: 
   if (possibly_very_frequent_event()) {
     static ratelim_t warning_limit = RATELIM_INIT(300);
     log_fn_ratelim(&warning_limit, LOG_WARN, LD_GENERAL,
                    "The event occurred!");
   }
*/ typedef struct ratelim_t { int rate; time_t last_allowed; int n_calls_since_last_time; } ratelim_t; #define RATELIM_INIT(r) { (r), 0, 0 } char *rate_limit_log(ratelim_t *lim, time_t now); /* File helpers */ ssize_t write_all(tor_socket_t fd, const char *buf, size_t count,int isSocket); ssize_t read_all(tor_socket_t fd, char *buf, size_t count, int isSocket); /** Status of an I/O stream. */ enum stream_status { IO_STREAM_OKAY, IO_STREAM_EAGAIN, IO_STREAM_TERM, IO_STREAM_CLOSED }; const char *stream_status_to_string(enum stream_status stream_status); enum stream_status get_string_from_pipe(FILE *stream, char *buf, size_t count); /** Return values from file_status(); see that function's documentation * for details. */ typedef enum { FN_ERROR, FN_NOENT, FN_FILE, FN_DIR, FN_EMPTY } file_status_t; file_status_t file_status(const char *filename); /** Possible behaviors for check_private_dir() on encountering a nonexistent * directory; see that function's documentation for details. */ typedef unsigned int cpd_check_t; #define CPD_NONE 0 #define CPD_CREATE 1 #define CPD_CHECK 2 #define CPD_GROUP_OK 4 #define CPD_GROUP_READ 8 #define CPD_CHECK_MODE_ONLY 16 int check_private_dir(const char *dirname, cpd_check_t check, const char *effective_user); #define OPEN_FLAGS_REPLACE (O_WRONLY|O_CREAT|O_TRUNC) #define OPEN_FLAGS_APPEND (O_WRONLY|O_CREAT|O_APPEND) #define OPEN_FLAGS_DONT_REPLACE (O_CREAT|O_EXCL|O_APPEND|O_WRONLY) typedef struct open_file_t open_file_t; int start_writing_to_file(const char *fname, int open_flags, int mode, open_file_t **data_out); FILE *start_writing_to_stdio_file(const char *fname, int open_flags, int mode, open_file_t **data_out); FILE *fdopen_file(open_file_t *file_data); int finish_writing_to_file(open_file_t *file_data); int abort_writing_to_file(open_file_t *file_data); int write_str_to_file(const char *fname, const char *str, int bin); MOCK_DECL(int, write_bytes_to_file,(const char *fname, const char *str, size_t len, int bin)); /** An ad-hoc type to hold a string of characters and a count; used by * write_chunks_to_file. */ typedef struct sized_chunk_t { const char *bytes; size_t len; } sized_chunk_t; int write_chunks_to_file(const char *fname, const struct smartlist_t *chunks, int bin, int no_tempfile); int append_bytes_to_file(const char *fname, const char *str, size_t len, int bin); int write_bytes_to_new_file(const char *fname, const char *str, size_t len, int bin); /** Flag for read_file_to_str: open the file in binary mode. */ #define RFTS_BIN 1 /** Flag for read_file_to_str: it's okay if the file doesn't exist. */ #define RFTS_IGNORE_MISSING 2 #ifndef _WIN32 struct stat; #endif char *read_file_to_str(const char *filename, int flags, struct stat *stat_out) ATTR_MALLOC; char *read_file_to_str_until_eof(int fd, size_t max_bytes_to_read, size_t *sz_out) ATTR_MALLOC; const char *parse_config_line_from_str_verbose(const char *line, char **key_out, char **value_out, const char **err_out); #define parse_config_line_from_str(line,key_out,value_out) \ parse_config_line_from_str_verbose((line),(key_out),(value_out),NULL) char *expand_filename(const char *filename); struct smartlist_t *tor_listdir(const char *dirname); int path_is_relative(const char *filename); /* Process helpers */ void start_daemon(void); void finish_daemon(const char *desired_cwd); void write_pidfile(char *filename); /* Port forwarding */ void tor_check_port_forwarding(const char *filename, struct smartlist_t *ports_to_forward, time_t now); typedef struct process_handle_t process_handle_t; typedef struct process_environment_t process_environment_t; int tor_spawn_background(const char *const filename, const char **argv, process_environment_t *env, process_handle_t **process_handle_out); #define SPAWN_ERROR_MESSAGE "ERR: Failed to spawn background process - code " #ifdef _WIN32 HANDLE load_windows_system_library(const TCHAR *library_name); #endif int environment_variable_names_equal(const char *s1, const char *s2); /* DOCDOC process_environment_t */ struct process_environment_t { /** A pointer to a sorted empty-string-terminated sequence of * NUL-terminated strings of the form "NAME=VALUE". */ char *windows_environment_block; /** A pointer to a NULL-terminated array of pointers to * NUL-terminated strings of the form "NAME=VALUE". */ char **unixoid_environment_block; }; process_environment_t *process_environment_make(struct smartlist_t *env_vars); void process_environment_free(process_environment_t *env); struct smartlist_t *get_current_process_environment_variables(void); void set_environment_variable_in_smartlist(struct smartlist_t *env_vars, const char *new_var, void (*free_old)(void*), int free_p); /* Values of process_handle_t.status. PROCESS_STATUS_NOTRUNNING must be * 0 because tor_check_port_forwarding depends on this being the initial * statue of the static instance of process_handle_t */ #define PROCESS_STATUS_NOTRUNNING 0 #define PROCESS_STATUS_RUNNING 1 #define PROCESS_STATUS_ERROR -1 #ifdef UTIL_PRIVATE struct waitpid_callback_t; /** Structure to represent the state of a process with which Tor is * communicating. The contents of this structure are private to util.c */ struct process_handle_t { /** One of the PROCESS_STATUS_* values */ int status; #ifdef _WIN32 HANDLE stdout_pipe; HANDLE stderr_pipe; PROCESS_INFORMATION pid; #else int stdout_pipe; int stderr_pipe; FILE *stdout_handle; FILE *stderr_handle; pid_t pid; /** If the process has not given us a SIGCHLD yet, this has the * waitpid_callback_t that gets invoked once it has. Otherwise this * contains NULL. */ struct waitpid_callback_t *waitpid_cb; /** The exit status reported by waitpid. */ int waitpid_exit_status; #endif // _WIN32 }; #endif /* Return values of tor_get_exit_code() */ #define PROCESS_EXIT_RUNNING 1 #define PROCESS_EXIT_EXITED 0 #define PROCESS_EXIT_ERROR -1 int tor_get_exit_code(process_handle_t *process_handle, int block, int *exit_code); int tor_split_lines(struct smartlist_t *sl, char *buf, int len); #ifdef _WIN32 ssize_t tor_read_all_handle(HANDLE h, char *buf, size_t count, const process_handle_t *process); #else ssize_t tor_read_all_handle(FILE *h, char *buf, size_t count, const process_handle_t *process, int *eof); #endif ssize_t tor_read_all_from_process_stdout( const process_handle_t *process_handle, char *buf, size_t count); ssize_t tor_read_all_from_process_stderr( const process_handle_t *process_handle, char *buf, size_t count); char *tor_join_win_cmdline(const char *argv[]); int tor_process_get_pid(process_handle_t *process_handle); #ifdef _WIN32 HANDLE tor_process_get_stdout_pipe(process_handle_t *process_handle); #else FILE *tor_process_get_stdout_pipe(process_handle_t *process_handle); #endif #ifdef _WIN32 MOCK_DECL(struct smartlist_t *, tor_get_lines_from_handle,(HANDLE *handle, enum stream_status *stream_status)); #else MOCK_DECL(struct smartlist_t *, tor_get_lines_from_handle,(FILE *handle, enum stream_status *stream_status)); #endif int tor_terminate_process(process_handle_t *process_handle); MOCK_DECL(void, tor_process_handle_destroy,(process_handle_t *process_handle, int also_terminate_process)); /* ===== Insecure rng */ typedef struct tor_weak_rng_t { uint32_t state; } tor_weak_rng_t; #define TOR_WEAK_RNG_INIT {383745623} #define TOR_WEAK_RANDOM_MAX (INT_MAX) void tor_init_weak_random(tor_weak_rng_t *weak_rng, unsigned seed); int32_t tor_weak_random(tor_weak_rng_t *weak_rng); int32_t tor_weak_random_range(tor_weak_rng_t *rng, int32_t top); /** Randomly return true according to rng with probability 1 in * n */ #define tor_weak_random_one_in_n(rng, n) (0==tor_weak_random_range((rng),(n))) int format_hex_number_sigsafe(unsigned long x, char *buf, int max_len); int format_dec_number_sigsafe(unsigned long x, char *buf, int max_len); #ifdef UTIL_PRIVATE /* Prototypes for private functions only used by util.c (and unit tests) */ #ifndef _WIN32 STATIC int format_helper_exit_status(unsigned char child_state, int saved_errno, char *hex_errno); /* Space for hex values of child state, a slash, saved_errno (with leading minus) and newline (no null) */ #define HEX_ERRNO_SIZE (sizeof(char) * 2 + 1 + \ 1 + sizeof(int) * 2 + 1) #endif #endif const char *libor_get_digests(void); #define ARRAY_LENGTH(x) ((sizeof(x)) / sizeof(x[0])) #endif