-/*
- * 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 inresolved[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;
- char *resolved;
-
- if (path == NULL) {
- errno = EINVAL;
- return (NULL);
- }
-#if __DARWIN_UNIX03
- if (*path == 0) {
- errno = ENOENT;
- return (NULL);
- }
-#endif /* __DARWIN_UNIX03 */
- /*
- * Extension to the standard; if inresolved == NULL, allocate memory
- */
- if (!inresolved) {
- if ((resolved = malloc(PATH_MAX)) == NULL) return (NULL);
- } else {
- resolved = inresolved;
- }
- if (!rootdev_inited) {
- rootdev_inited = 1;
- if (stat("/", &sb) < 0) {
-error_return:
- if (!inresolved) {
- int e = errno;
- free(resolved);
- errno = e;
- }
- 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);
- goto error_return;
- }
- resolved_len = strlen(resolved);
- left_len = strlcpy(left, path, sizeof(left));
- }
- if (left_len >= sizeof(left) || resolved_len >= PATH_MAX) {
- errno = ENAMETOOLONG;
- goto error_return;
- }
- if (resolved_len > 1) {
- if (stat(resolved, &sb) < 0) {
- goto error_return;
- }
- 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;
- goto error_return;
- }
- 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;
- goto error_return;
- }
- 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;
- goto error_return;
- }
- 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 */
- goto error_return;
- }
- 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[sizeof(sfs.f_mntonname)];
- 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;
- goto error_return;
- }
- slen = readlink(resolved, symlink, sizeof(symlink) - 1);
- if (slen < 0) {
- goto error_return;
- }
- 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;
- goto error_return;
- }
- symlink[slen] = '/';
- symlink[slen + 1] = 0;
- }
- left_len = strlcat(symlink, left, sizeof(left));
- if (left_len >= sizeof(left)) {
- errno = ENAMETOOLONG;
- goto error_return;
- }
- }
- 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;
- goto error_return;
- }
- }
- /*
- * 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