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author | kib <kib@FreeBSD.org> | 2010-04-20 10:16:44 +0000 |
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committer | kib <kib@FreeBSD.org> | 2010-04-20 10:16:44 +0000 |
commit | 0be03f320b674f387da392d9e4fece5b67a79ae1 (patch) | |
tree | 49cd6b92975d51b11b3034ce84d086a90b7f707b /lib/libc | |
parent | df535bd79d3648211cc1b5783e543ab3c1bea2bc (diff) | |
download | FreeBSD-src-0be03f320b674f387da392d9e4fece5b67a79ae1.zip FreeBSD-src-0be03f320b674f387da392d9e4fece5b67a79ae1.tar.gz |
Slightly modernize realpath(3).
SUSv4 requires that implementation returns EINVAL if supplied path is NULL,
and ENOENT if path is empty string [1].
Bring prototype in conformance with SUSv4, adding restrict keywords.
Allow the resolved path buffer pointer be NULL, in which case realpath(3)
allocates storage with malloc().
PR: kern/121897 [1]
MFC after: 2 weeks
Diffstat (limited to 'lib/libc')
-rw-r--r-- | lib/libc/stdlib/realpath.3 | 19 | ||||
-rw-r--r-- | lib/libc/stdlib/realpath.c | 54 |
2 files changed, 65 insertions, 8 deletions
diff --git a/lib/libc/stdlib/realpath.3 b/lib/libc/stdlib/realpath.3 index 4205a3d..371ee3b2 100644 --- a/lib/libc/stdlib/realpath.3 +++ b/lib/libc/stdlib/realpath.3 @@ -31,7 +31,7 @@ .\" @(#)realpath.3 8.2 (Berkeley) 2/16/94 .\" $FreeBSD$ .\" -.Dd February 16, 1994 +.Dd April 19, 2010 .Dt REALPATH 3 .Os .Sh NAME @@ -43,7 +43,7 @@ .In sys/param.h .In stdlib.h .Ft "char *" -.Fn realpath "const char *pathname" "char resolved_path[PATH_MAX]" +.Fn realpath "const char *pathname" "char *resolved_path" .Sh DESCRIPTION The .Fn realpath @@ -64,7 +64,8 @@ argument .Em must refer to a buffer capable of storing at least .Dv PATH_MAX -characters. +characters, or be +.Dv NULL . .Pp The .Fn realpath @@ -82,6 +83,13 @@ The function returns .Fa resolved_path on success. +If the function was supplied +.Dv NULL +as +.Fa resolved_path , +and operation did not cause errors, the returned value is +a null-terminated string in a buffer allocated by a call to +.Fn malloc 3 . If an error occurs, .Fn realpath returns @@ -89,6 +97,11 @@ returns and .Fa resolved_path contains the pathname which caused the problem. +If +.Fa resolved_path +was +.Dv NULL , +then information of the failed pathname component is lost. .Sh ERRORS The function .Fn realpath diff --git a/lib/libc/stdlib/realpath.c b/lib/libc/stdlib/realpath.c index 3082f5f..31c93e6 100644 --- a/lib/libc/stdlib/realpath.c +++ b/lib/libc/stdlib/realpath.c @@ -43,23 +43,37 @@ __FBSDID("$FreeBSD$"); #include "un-namespace.h" /* - * char *realpath(const char *path, char resolved[PATH_MAX]); - * * Find the real name of path, by removing all ".", ".." and symlink * 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 *path, char resolved[PATH_MAX]) +realpath(const char * __restrict path, char * __restrict resolved) { struct stat sb; char *p, *q, *s; size_t left_len, resolved_len; unsigned symlinks; - int serrno, slen; + int serrno, slen, m; 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); + } serrno = errno; + if (resolved == NULL) { + resolved = malloc(PATH_MAX); + if (resolved == NULL) + return (NULL); + m = 1; + } else + m = 0; + symlinks = 0; if (path[0] == '/') { resolved[0] = '/'; @@ -71,12 +85,19 @@ realpath(const char *path, char resolved[PATH_MAX]) } else { if (getcwd(resolved, PATH_MAX) == NULL) { strlcpy(resolved, ".", PATH_MAX); + if (m) { + serrno = errno; + free(resolved); + errno = serrno; + } 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); } @@ -92,6 +113,8 @@ realpath(const char *path, char resolved[PATH_MAX]) p = strchr(left, '/'); s = p ? p : left + left_len; if (s - left >= sizeof(next_token)) { + if (m) + free(resolved); errno = ENAMETOOLONG; return (NULL); } @@ -102,6 +125,8 @@ realpath(const char *path, char resolved[PATH_MAX]) memmove(left, s + 1, left_len + 1); if (resolved[resolved_len - 1] != '/') { if (resolved_len + 1 >= PATH_MAX) { + if (m) + free(resolved); errno = ENAMETOOLONG; return (NULL); } @@ -133,6 +158,8 @@ realpath(const char *path, char resolved[PATH_MAX]) */ resolved_len = strlcat(resolved, next_token, PATH_MAX); if (resolved_len >= PATH_MAX) { + if (m) + free(resolved); errno = ENAMETOOLONG; return (NULL); } @@ -141,16 +168,29 @@ realpath(const char *path, char resolved[PATH_MAX]) errno = serrno; return (resolved); } + if (m) { + serrno = errno; + free(resolved); + errno = serrno; + } 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) - 1); - if (slen < 0) + if (slen < 0) { + if (m) { + serrno = errno; + free(resolved); + errno = serrno; + } return (NULL); + } symlink[slen] = '\0'; if (symlink[0] == '/') { resolved[1] = 0; @@ -171,6 +211,8 @@ realpath(const char *path, char resolved[PATH_MAX]) if (p != NULL) { if (symlink[slen - 1] != '/') { if (slen + 1 >= sizeof(symlink)) { + if (m) + free(resolved); errno = ENAMETOOLONG; return (NULL); } @@ -179,6 +221,8 @@ realpath(const char *path, char resolved[PATH_MAX]) } left_len = strlcat(symlink, left, sizeof(left)); if (left_len >= sizeof(left)) { + if (m) + free(resolved); errno = ENAMETOOLONG; return (NULL); } |