123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295 |
- /* Copyright (c) 2003, Roger Dingledine
- * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2019, The Tor Project, Inc. */
- /* See LICENSE for licensing information */
- /**
- * \file path.c
- *
- * \brief Manipulate strings that contain filesystem paths.
- **/
- #include "lib/fs/path.h"
- #include "lib/malloc/malloc.h"
- #include "lib/log/log.h"
- #include "lib/log/util_bug.h"
- #include "lib/string/printf.h"
- #include "lib/string/util_string.h"
- #include "lib/string/compat_ctype.h"
- #include "lib/fs/userdb.h"
- #ifdef HAVE_UNISTD_H
- #include <unistd.h>
- #endif
- #include <errno.h>
- #include <string.h>
- /** Removes enclosing quotes from <b>path</b> and unescapes quotes between the
- * enclosing quotes. Backslashes are not unescaped. Return the unquoted
- * <b>path</b> on success or 0 if <b>path</b> is not quoted correctly. */
- char *
- get_unquoted_path(const char *path)
- {
- size_t len = strlen(path);
- if (len == 0) {
- return tor_strdup("");
- }
- int has_start_quote = (path[0] == '\"');
- int has_end_quote = (len > 0 && path[len-1] == '\"');
- if (has_start_quote != has_end_quote || (len == 1 && has_start_quote)) {
- return NULL;
- }
- char *unquoted_path = tor_malloc(len - has_start_quote - has_end_quote + 1);
- char *s = unquoted_path;
- size_t i;
- for (i = has_start_quote; i < len - has_end_quote; i++) {
- if (path[i] == '\"' && (i > 0 && path[i-1] == '\\')) {
- *(s-1) = path[i];
- } else if (path[i] != '\"') {
- *s++ = path[i];
- } else { /* unescaped quote */
- tor_free(unquoted_path);
- return NULL;
- }
- }
- *s = '\0';
- return unquoted_path;
- }
- /** 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 /* !(defined(_WIN32)) */
- 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 /* !(defined(HAVE_PWD_H)) */
- log_warn(LD_CONFIG, "Couldn't expand homedir on system without pwd.h");
- return tor_strdup(filename);
- #endif /* defined(HAVE_PWD_H) */
- }
- 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 /* defined(_WIN32) */
- }
- /** 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 /* defined(_WIN32) */
- else
- return 1;
- }
- /** 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. */
- void
- clean_fname_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 /* !(defined(_WIN32)) */
- (void)name;
- #endif /* defined(_WIN32) */
- }
- /** Modify <b>fname</b> to contain the name of its parent directory. Doesn't
- * actually examine the filesystem; does a purely syntactic modification.
- *
- * The parent of the root director is considered to be iteself.
- *
- * Path separators are the forward slash (/) everywhere and additionally
- * the backslash (\) on Win32.
- *
- * Cuts off any number of trailing path separators but otherwise ignores
- * them for purposes of finding the parent directory.
- *
- * Returns 0 if a parent directory was successfully found, -1 otherwise (fname
- * did not have any path separators or only had them at the end).
- * */
- int
- get_parent_directory(char *fname)
- {
- char *cp;
- int at_end = 1;
- tor_assert(fname);
- #ifdef _WIN32
- /* If we start with, say, c:, then don't consider that the start of the path
- */
- if (fname[0] && fname[1] == ':') {
- fname += 2;
- }
- #endif /* defined(_WIN32) */
- /* Now we want to remove all path-separators at the end of the string,
- * and to remove the end of the string starting with the path separator
- * before the last non-path-separator. In perl, this would be
- * s#[/]*$##; s#/[^/]*$##;
- * on a unixy platform.
- */
- cp = fname + strlen(fname);
- at_end = 1;
- while (--cp >= fname) {
- int is_sep = (*cp == '/'
- #ifdef _WIN32
- || *cp == '\\'
- #endif
- );
- if (is_sep) {
- if (cp == fname) {
- /* This is the first separator in the file name; don't remove it! */
- cp[1] = '\0';
- return 0;
- }
- *cp = '\0';
- if (! at_end)
- return 0;
- } else {
- at_end = 0;
- }
- }
- return -1;
- }
- #ifndef _WIN32
- /** Return a newly allocated string containing the output of getcwd(). Return
- * NULL on failure. (We can't just use getcwd() into a PATH_MAX buffer, since
- * Hurd hasn't got a PATH_MAX.)
- */
- static char *
- alloc_getcwd(void)
- {
- #ifdef HAVE_GET_CURRENT_DIR_NAME
- /* Glibc makes this nice and simple for us. */
- char *cwd = get_current_dir_name();
- char *result = NULL;
- if (cwd) {
- /* We make a copy here, in case tor_malloc() is not malloc(). */
- result = tor_strdup(cwd);
- raw_free(cwd); // alias for free to avoid tripping check-spaces.
- }
- return result;
- #else /* !(defined(HAVE_GET_CURRENT_DIR_NAME)) */
- size_t size = 1024;
- char *buf = NULL;
- char *ptr = NULL;
- while (ptr == NULL) {
- buf = tor_realloc(buf, size);
- ptr = getcwd(buf, size);
- if (ptr == NULL && errno != ERANGE) {
- tor_free(buf);
- return NULL;
- }
- size *= 2;
- }
- return buf;
- #endif /* defined(HAVE_GET_CURRENT_DIR_NAME) */
- }
- #endif /* !defined(_WIN32) */
- /** Expand possibly relative path <b>fname</b> to an absolute path.
- * Return a newly allocated string, possibly equal to <b>fname</b>. */
- char *
- make_path_absolute(char *fname)
- {
- #ifdef _WIN32
- char *absfname_malloced = _fullpath(NULL, fname, 1);
- /* We don't want to assume that tor_free can free a string allocated
- * with malloc. On failure, return fname (it's better than nothing). */
- char *absfname = tor_strdup(absfname_malloced ? absfname_malloced : fname);
- if (absfname_malloced) raw_free(absfname_malloced);
- return absfname;
- #else /* !(defined(_WIN32)) */
- char *absfname = NULL, *path = NULL;
- tor_assert(fname);
- if (fname[0] == '/') {
- absfname = tor_strdup(fname);
- } else {
- path = alloc_getcwd();
- if (path) {
- tor_asprintf(&absfname, "%s/%s", path, fname);
- tor_free(path);
- } else {
- /* LCOV_EXCL_START Can't make getcwd fail. */
- /* If getcwd failed, the best we can do here is keep using the
- * relative path. (Perhaps / isn't readable by this UID/GID.) */
- log_warn(LD_GENERAL, "Unable to find current working directory: %s",
- strerror(errno));
- absfname = tor_strdup(fname);
- /* LCOV_EXCL_STOP */
- }
- }
- return absfname;
- #endif /* defined(_WIN32) */
- }
|