/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2007 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ /* * 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. */ /* * http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/stdlib/realpath.c * $OpenBSD: realpath.c,v 1.13 2005/08/08 08:05:37 espie Exp $ */ #include <stdio.h> #include <unistd.h> #include <string.h> #include <limits.h> #include <errno.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/param.h> /* * char *s_realpath(const char *path, char resolved_path[MAXPATHLEN]); * * 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). * * DEVINFO: For libdevinfo we have added code to special case symlinks into * /devices - the path below that point is known to not point to any * additional symlinks. This knowledge allows us to avoid causing attach. */ char * s_realpath(const char *path, char *resolved) { struct stat sb; char *p, *q, *s; size_t left_len, resolved_len; unsigned symlinks; int serrno, slen; char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX]; 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 (getcwd(resolved, PATH_MAX) == NULL) { (void) 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); } /* * 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); } (void) memcpy(next_token, left, s - left); next_token[s - left] = '\0'; left_len -= s - left; if (p != NULL) (void) 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; } /* * 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); } /* * DEVINFO: Check if link points into /devices and resolve * without causing attach if that is the case - there are no * further symlinks in /devices. */ if (strcmp(resolved, "/devices") == 0) { resolved[resolved_len] = '/'; resolved_len = strlcat(resolved, left, sizeof (left)); left_len = 0; continue; } if (lstat(resolved, &sb) != 0) { if (errno == ENOENT && p == NULL) { errno = serrno; return (resolved); } return (NULL); } if (S_ISLNK(sb.st_mode)) { 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; } 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)); } } /* * 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); }
