+/*
+ * Copyright (c) 2003 Constantin S. Svintsoff <kostik@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: src/lib/libc/stdlib/realpath.c,v 1.20 2003/05/28 08:23:01 fjoe Exp $");
+
+#include "namespace.h"
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/mount.h>
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/attr.h>
+#include <sys/vnode.h>
+#include "un-namespace.h"
+
+struct attrs {
+ u_int32_t len;
+ attrreference_t name;
+ dev_t dev;
+ fsobj_type_t type;
+ fsobj_id_t id;
+ char buf[PATH_MAX];
+};
+
+#ifndef BUILDING_VARIANT
+__private_extern__ struct attrlist _rp_alist = {
+ ATTR_BIT_MAP_COUNT,
+ 0,
+ ATTR_CMN_NAME | ATTR_CMN_DEVID | ATTR_CMN_OBJTYPE | ATTR_CMN_OBJID,
+ 0,
+ 0,
+ 0,
+ 0,
+};
+#else /* BUILDING_VARIANT */
+__private_extern__ struct attrlist _rp_alist;
+#endif /* BUILDING_VARIANT */
+
+extern char * __private_getcwd(char *, size_t, int);
+
+/*
+ * 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])
+{
+ struct attrs attrs;
+ struct stat sb;
+ char *p, *q, *s;
+ size_t left_len, resolved_len, save_resolved_len;
+ unsigned symlinks;
+ int serrno, slen, useattrs, islink;
+ char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX];
+ dev_t dev, lastdev;
+ struct statfs sfs;
+ static dev_t rootdev;
+ static int rootdev_inited = 0;
+ ino_t inode;
+
+ if (path == NULL) {
+ errno = EINVAL;
+ return (NULL);
+ }
+#if __DARWIN_UNIX03
+ if (*path == 0) {
+ errno = ENOENT;
+ return (NULL);
+ }
+#endif /* __DARWIN_UNIX03 */
+ if (!rootdev_inited) {
+ rootdev_inited = 1;
+ if (stat("/", &sb) < 0) {
+ return (NULL);
+ }
+ rootdev = sb.st_dev;
+ }
+ serrno = errno;
+ 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 !defined(VARIANT_DARWINEXTSN) && __DARWIN_UNIX03
+ /* 4447159: don't use GETPATH, so this will fail if */
+ /* if parent directories are not readable, as per POSIX */
+ if (__private_getcwd(resolved, PATH_MAX, 0) == NULL)
+#else /* VARIANT_DARWINEXTSN || !__DARWIN_UNIX03 */
+ if (__private_getcwd(resolved, PATH_MAX, 1) == NULL)
+#endif /* !VARIANT_DARWINEXTSN && __DARWIN_UNIX03 */
+ {
+ strlcpy(resolved, ".", PATH_MAX);
+ return (NULL);
+ }
+ resolved_len = strlen(resolved);
+ left_len = strlcpy(left, path, sizeof(left));
+ }
+ if (left_len >= sizeof(left) || resolved_len >= PATH_MAX) {
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ if (resolved_len > 1) {
+ if (stat(resolved, &sb) < 0) {
+ return (NULL);
+ }
+ lastdev = sb.st_dev;
+ } else
+ lastdev = rootdev;
+
+ /*
+ * 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)) {
+ 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) {
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ resolved[resolved_len++] = '/';
+ resolved[resolved_len] = '\0';
+ }
+ if (next_token[0] == '\0')
+ 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;
+ }
+
+ /*
+ * Save resolved_len, so that we can later null out
+ * the the appended next_token, and replace with the
+ * real name (matters on case-insensitive filesystems).
+ */
+ save_resolved_len = resolved_len;
+
+ /*
+ * Append the next path component and lstat() it. If
+ * lstat() fails we still can return successfully if
+ * there are no more path components left.
+ */
+ resolved_len = strlcat(resolved, next_token, PATH_MAX);
+ if (resolved_len >= PATH_MAX) {
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ if (getattrlist(resolved, &_rp_alist, &attrs, sizeof(attrs), FSOPT_NOFOLLOW) == 0) {
+ useattrs = 1;
+ islink = (attrs.type == VLNK);
+ dev = attrs.dev;
+ inode = attrs.id.fid_objno;
+ } else if (errno == ENOTSUP || errno == EINVAL) {
+ if ((useattrs = lstat(resolved, &sb)) == 0) {
+ islink = S_ISLNK(sb.st_mode);
+ dev = sb.st_dev;
+ inode = sb.st_ino;
+ }
+ } else
+ useattrs = -1;
+ if (useattrs < 0) {
+#if !__DARWIN_UNIX03
+ if (errno == ENOENT && p == NULL) {
+ errno = serrno;
+ return (resolved);
+ }
+#endif /* !__DARWIN_UNIX03 */
+ return (NULL);
+ }
+ if (dev != lastdev) {
+ /*
+ * We have crossed a mountpoint. For volumes like UDF
+ * the getattrlist name may not match the actual
+ * mountpoint, so we just copy the mountpoint directly.
+ * (3703138). However, the mountpoint may not be
+ * accessible, as when chroot-ed, so check first.
+ * There may be a file on the chroot-ed volume with
+ * the same name as the mountpoint, so compare device
+ * and inode numbers.
+ */
+ lastdev = dev;
+ if (statfs(resolved, &sfs) == 0 && lstat(sfs.f_mntonname, &sb) == 0 && dev == sb.st_dev && inode == sb.st_ino) {
+ /*
+ * However, it's possible that the mountpoint
+ * path matches, even though it isn't the real
+ * path in the chroot-ed environment, so check
+ * that each component of the mountpoint
+ * is a directory (and not a symlink)
+ */
+ char temp[MNAMELEN];
+ char *cp;
+ int ok = 1;
+
+ strcpy(temp, sfs.f_mntonname);
+ for(;;) {
+ if ((cp = strrchr(temp, '/')) == NULL) {
+ ok = 0;
+ break;
+ }
+ if (cp <= temp)
+ break;
+ *cp = 0;
+ if (lstat(temp, &sb) < 0 || (sb.st_mode & S_IFMT) != S_IFDIR) {
+ ok = 0;
+ break;
+ }
+ }
+ if (ok) {
+ resolved_len = strlcpy(resolved, sfs.f_mntonname, PATH_MAX);
+ continue;
+ }
+ }
+ /* if we fail, use the other methods. */
+ }
+ if (islink) {
+ if (symlinks++ > MAXSYMLINKS) {
+ errno = ELOOP;
+ return (NULL);
+ }
+ slen = readlink(resolved, symlink, sizeof(symlink) - 1);
+ if (slen < 0) {
+ return (NULL);
+ }
+ symlink[slen] = '\0';
+ if (symlink[0] == '/') {
+ resolved[1] = 0;
+ resolved_len = 1;
+ lastdev = rootdev;
+ } 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)) {
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ symlink[slen] = '/';
+ symlink[slen + 1] = 0;
+ }
+ left_len = strlcat(symlink, left, sizeof(left));
+ if (left_len >= sizeof(left)) {
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ }
+ left_len = strlcpy(left, symlink, sizeof(left));
+ } else if (useattrs) {
+ /*
+ * attrs already has the real name.
+ */
+
+ resolved[save_resolved_len] = '\0';
+ resolved_len = strlcat(resolved, (const char *)&attrs.name + attrs.name.attr_dataoffset, PATH_MAX);
+ if (resolved_len >= PATH_MAX) {
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ }
+ /*
+ * For the case of useattrs == 0, we could scan the directory
+ * and try to match the inode. There are many problems with
+ * this: (1) the directory may not be readable, (2) for multiple
+ * hard links, we would find the first, but not necessarily
+ * the one specified in the path, (3) we can't try to do
+ * a case-insensitive search to match the right one in (2),
+ * because the underlying filesystem may do things like
+ * decompose composed characters. For most cases, doing
+ * nothing is the right thing when useattrs == 0, so we punt
+ * for now.
+ */
+ }
+
+ /*
+ * 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);
+}
projects / apple / libc.git / blobdiff