Author: kib Date: Mon May 15 17:34:17 2017 New Revision: 318299 URL: https://svnweb.freebsd.org/changeset/base/318299
Log: Simplify cleanup on failure in realpath(3). If realpath() allocated memory for result and failed, the memory is freed in each place where return is performed. More, the function needs to track the allocation status, to not free user-supplied buffer. Consolidate the memory handling in the wrapper, freeing the buffer if the actual worker failed. Reviewed by: emaste (previous version) Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Differential revision: https://reviews.freebsd.org/D10670 Modified: head/lib/libc/stdlib/realpath.c Modified: head/lib/libc/stdlib/realpath.c ============================================================================== --- head/lib/libc/stdlib/realpath.c Mon May 15 17:14:53 2017 (r318298) +++ head/lib/libc/stdlib/realpath.c Mon May 15 17:34:17 2017 (r318299) @@ -47,32 +47,16 @@ __FBSDID("$FreeBSD$"); * components. Returns (resolved) on success, or (NULL) on failure, * in which case the path which caused trouble is left in (resolved). */ -char * -realpath(const char * __restrict path, char * __restrict resolved) +static char * +realpath1(const char *path, char *resolved) { struct stat sb; char *p, *q; size_t left_len, resolved_len, next_token_len; unsigned symlinks; - int m; ssize_t slen; char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX]; - if (path == NULL) { - errno = EINVAL; - return (NULL); - } - if (path[0] == '\0') { - errno = ENOENT; - return (NULL); - } - if (resolved == NULL) { - resolved = malloc(PATH_MAX); - if (resolved == NULL) - return (NULL); - m = 1; - } else - m = 0; symlinks = 0; if (path[0] == '/') { resolved[0] = '/'; @@ -83,20 +67,14 @@ realpath(const char * __restrict path, c left_len = strlcpy(left, path + 1, sizeof(left)); } else { if (getcwd(resolved, PATH_MAX) == NULL) { - if (m) - free(resolved); - else { - resolved[0] = '.'; - resolved[1] = '\0'; - } + resolved[0] = '.'; + resolved[1] = '\0'; return (NULL); } resolved_len = strlen(resolved); left_len = strlcpy(left, path, sizeof(left)); } if (left_len >= sizeof(left) || resolved_len >= PATH_MAX) { - if (m) - free(resolved); errno = ENAMETOOLONG; return (NULL); } @@ -125,8 +103,6 @@ realpath(const char * __restrict path, c if (resolved[resolved_len - 1] != '/') { if (resolved_len + 1 >= PATH_MAX) { - if (m) - free(resolved); errno = ENAMETOOLONG; return (NULL); } @@ -158,27 +134,18 @@ realpath(const char * __restrict path, c */ resolved_len = strlcat(resolved, next_token, PATH_MAX); if (resolved_len >= PATH_MAX) { - if (m) - free(resolved); errno = ENAMETOOLONG; return (NULL); } - if (lstat(resolved, &sb) != 0) { - if (m) - free(resolved); + if (lstat(resolved, &sb) != 0) return (NULL); - } if (S_ISLNK(sb.st_mode)) { if (symlinks++ > MAXSYMLINKS) { - if (m) - free(resolved); errno = ELOOP; return (NULL); } slen = readlink(resolved, symlink, sizeof(symlink)); if (slen <= 0 || slen >= sizeof(symlink)) { - if (m) - free(resolved); if (slen < 0) { /* keep errno from readlink(2) call */ } else if (slen == 0) { @@ -207,8 +174,6 @@ realpath(const char * __restrict path, c if (p != NULL) { if (symlink[slen - 1] != '/') { if (slen + 1 >= sizeof(symlink)) { - if (m) - free(resolved); errno = ENAMETOOLONG; return (NULL); } @@ -218,16 +183,12 @@ realpath(const char * __restrict path, c left_len = strlcat(symlink, left, sizeof(symlink)); if (left_len >= sizeof(symlink)) { - if (m) - free(resolved); errno = ENAMETOOLONG; return (NULL); } } left_len = strlcpy(left, symlink, sizeof(left)); } else if (!S_ISDIR(sb.st_mode) && p != NULL) { - if (m) - free(resolved); errno = ENOTDIR; return (NULL); } @@ -241,3 +202,29 @@ realpath(const char * __restrict path, c resolved[resolved_len - 1] = '\0'; return (resolved); } + +char * +realpath(const char * __restrict path, char * __restrict resolved) +{ + char *m, *res; + + if (path == NULL) { + errno = EINVAL; + return (NULL); + } + if (path[0] == '\0') { + errno = ENOENT; + return (NULL); + } + if (resolved != NULL) { + m = NULL; + } else { + m = resolved = malloc(PATH_MAX); + if (resolved == NULL) + return (NULL); + } + res = realpath1(path, resolved); + if (res == NULL) + free(m); + return (res); +} _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
