[rtems commit] ilibcsupport: Add realpath call.
Chris Johns
chrisj at rtems.org
Fri Oct 24 22:59:00 UTC 2014
Module: rtems
Branch: master
Commit: ea9232d01667c5a943d715ddee61f21beb764e81
Changeset: http://git.rtems.org/rtems/commit/?id=ea9232d01667c5a943d715ddee61f21beb764e81
Author: Chris Johns <chrisj at rtems.org>
Date: Fri Oct 24 16:05:59 2014 -0700
ilibcsupport: Add realpath call.
---
cpukit/libcsupport/Makefile.am | 2 +-
cpukit/libcsupport/src/realpath.c | 253 +++++++++++++++++++++++++++++++++++++
2 files changed, 254 insertions(+), 1 deletions(-)
diff --git a/cpukit/libcsupport/Makefile.am b/cpukit/libcsupport/Makefile.am
index d39f8f9..40e0800 100644
--- a/cpukit/libcsupport/Makefile.am
+++ b/cpukit/libcsupport/Makefile.am
@@ -119,7 +119,7 @@ TERMINAL_IDENTIFICATION_C_FILES += src/ttyname.c
LIBC_GLUE_C_FILES = src/__getpid.c src/__gettod.c src/__times.c \
src/truncate.c src/access.c src/stat.c src/lstat.c src/pathconf.c \
src/newlibc_reent.c src/newlibc_init.c src/newlibc_exit.c \
- src/kill_noposix.c src/utsname.c
+ src/kill_noposix.c src/utsname.c src/realpath.c
BSD_LIBC_C_FILES = src/strlcpy.c src/strlcat.c src/issetugid.c
diff --git a/cpukit/libcsupport/src/realpath.c b/cpukit/libcsupport/src/realpath.c
new file mode 100644
index 0000000..dff0838
--- /dev/null
+++ b/cpukit/libcsupport/src/realpath.c
@@ -0,0 +1,253 @@
+/*
+ * Copyright (c) 2003 Constantin S. Svintsoff <kostik at iclub.nsu.ru>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The names of the authors may not be used to endorse or promote
+ * products derived from this software without specific prior written
+ * permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)realpath.c 8.1 (Berkeley) 2/16/94";
+#endif /* LIBC_SCCS and not lint */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD: release/9.1.0/lib/libc/stdlib/realpath.c 240647 2012-09-18 13:03:00Z emaste $");
+
+#if !defined(__rtems__)
+#include "namespace.h"
+#endif
+#include <sys/param.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#if !defined(__rtems__)
+#include "un-namespace.h"
+#endif
+
+/*
+ * 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 * __restrict path, char * __restrict resolved)
+{
+ struct stat sb;
+ char *p, *q, *s;
+ size_t left_len, resolved_len;
+ unsigned symlinks;
+ int m, 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] = '/';
+ resolved[1] = '\0';
+ if (path[1] == '\0')
+ return (resolved);
+ resolved_len = 1;
+ 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';
+ }
+ 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);
+ }
+
+ /*
+ * Iterate over path components in `left'.
+ */
+ while (left_len != 0) {
+ /*
+ * Extract the next path component and adjust `left'
+ * and its length.
+ */
+ p = strchr(left, '/');
+ s = p ? p : left + left_len;
+ if (s - left >= sizeof(next_token)) {
+ if (m)
+ free(resolved);
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ memcpy(next_token, left, s - left);
+ next_token[s - left] = '\0';
+ left_len -= s - left;
+ if (p != NULL)
+ 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);
+ }
+ resolved[resolved_len++] = '/';
+ resolved[resolved_len] = '\0';
+ }
+ if (next_token[0] == '\0') {
+ /*
+ * Handle consequential slashes. The path
+ * before slash shall point to a directory.
+ *
+ * Only the trailing slashes are not covered
+ * by other checks in the loop, but we verify
+ * the prefix for any (rare) "//" or "/\0"
+ * occurence to not implement lookahead.
+ */
+ if (lstat(resolved, &sb) != 0) {
+ if (m)
+ free(resolved);
+ return (NULL);
+ }
+ if (!S_ISDIR(sb.st_mode)) {
+ if (m)
+ free(resolved);
+ errno = ENOTDIR;
+ return (NULL);
+ }
+ continue;
+ }
+ else if (strcmp(next_token, ".") == 0)
+ continue;
+ else if (strcmp(next_token, "..") == 0) {
+ /*
+ * Strip the last path component except when we have
+ * single "/"
+ */
+ if (resolved_len > 1) {
+ resolved[resolved_len - 1] = '\0';
+ q = strrchr(resolved, '/') + 1;
+ *q = '\0';
+ resolved_len = q - resolved;
+ }
+ continue;
+ }
+
+ /*
+ * Append the next path component and lstat() it.
+ */
+ 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);
+ 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 (m)
+ free(resolved);
+ return (NULL);
+ }
+ symlink[slen] = '\0';
+ if (symlink[0] == '/') {
+ resolved[1] = 0;
+ resolved_len = 1;
+ } else if (resolved_len > 1) {
+ /* Strip the last path component. */
+ resolved[resolved_len - 1] = '\0';
+ q = strrchr(resolved, '/') + 1;
+ *q = '\0';
+ resolved_len = q - resolved;
+ }
+
+ /*
+ * If there are any path components left, then
+ * append them to symlink. The result is placed
+ * in `left'.
+ */
+ if (p != NULL) {
+ if (symlink[slen - 1] != '/') {
+ if (slen + 1 >= sizeof(symlink)) {
+ if (m)
+ free(resolved);
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ symlink[slen] = '/';
+ symlink[slen + 1] = 0;
+ }
+ left_len = strlcat(symlink, left,
+ sizeof(symlink));
+ if (left_len >= sizeof(left)) {
+ if (m)
+ free(resolved);
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ }
+ left_len = strlcpy(left, symlink, sizeof(left));
+ }
+ }
+
+ /*
+ * Remove trailing slash except when the resolved pathname
+ * is a single "/".
+ */
+ if (resolved_len > 1 && resolved[resolved_len - 1] == '/')
+ resolved[resolved_len - 1] = '\0';
+ return (resolved);
+}
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