Index: head/lib/libc/stdlib/realpath.c =================================================================== --- head/lib/libc/stdlib/realpath.c (revision 318297) +++ head/lib/libc/stdlib/realpath.c (revision 318298) @@ -1,235 +1,243 @@ /* * Copyright (c) 2003 Constantin S. Svintsoff * * 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 __FBSDID("$FreeBSD$"); #include "namespace.h" #include #include #include #include #include #include #include "un-namespace.h" /* * 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; + char *p, *q; + size_t left_len, resolved_len, next_token_len; unsigned symlinks; - int m, slen; + int m; + ssize_t 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); + + next_token_len = p ? p - left : left_len; + memcpy(next_token, left, next_token_len); + next_token[next_token_len] = '\0'; + + if (p != NULL) { + left_len -= next_token_len + 1; + memmove(left, p + 1, left_len + 1); + } else { + left[0] = '\0'; + left_len = 0; } - 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. */ 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) { + slen = readlink(resolved, symlink, sizeof(symlink)); + if (slen <= 0 || slen >= sizeof(symlink)) { if (m) free(resolved); + if (slen < 0) { + /* keep errno from readlink(2) call */ + } else if (slen == 0) { + errno = ENOENT; + } else { + errno = ENAMETOOLONG; + } return (NULL); } symlink[slen] = '\0'; if (symlink[0] == '/') { resolved[1] = 0; resolved_len = 1; - } else if (resolved_len > 1) { + } else { /* 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 (left_len >= sizeof(symlink)) { if (m) free(resolved); errno = ENAMETOOLONG; return (NULL); } } left_len = strlcpy(left, symlink, sizeof(left)); } else if (!S_ISDIR(sb.st_mode) && p != NULL) { if (m) free(resolved); errno = ENOTDIR; return (NULL); } } /* * 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); }