X-Git-Url: http://andersk.mit.edu/gitweb/gssapi-openssh.git/blobdiff_plain/665a873d320a97fed924de9a5bc7781a495e4fc1..d5efc78afe35c0cdd3b43799024062d31edb61c6:/openssh/openbsd-compat/realpath.c diff --git a/openssh/openbsd-compat/realpath.c b/openssh/openbsd-compat/realpath.c index 8430bec..ec801d4 100644 --- a/openssh/openbsd-compat/realpath.c +++ b/openssh/openbsd-compat/realpath.c @@ -1,7 +1,9 @@ -/* OPENBSD ORIGINAL: lib/libc/stdlib/realpath.c */ - /* - * Copyright (c) 2003 Constantin S. Svintsoff + * Copyright (c) 1994 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Jan-Simon Pendry. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -11,14 +13,11 @@ * 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 + * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS 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) @@ -32,165 +31,132 @@ #if !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH) +#if defined(LIBC_SCCS) && !defined(lint) +static char *rcsid = "$OpenBSD: realpath.c,v 1.5 2001/06/27 00:58:56 lebel Exp $"; +#endif /* LIBC_SCCS and not lint */ + #include #include #include +#include #include #include #include /* - * char *realpath(const char *path, char resolved[PATH_MAX]); + * MAXSYMLINKS + */ +#ifndef MAXSYMLINKS +#define MAXSYMLINKS 5 +#endif + +/* + * char *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). */ char * -realpath(const char *path, char resolved[PATH_MAX]) +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]; + int fd, n, rootd, serrno = 0; + char *p, *q, wbuf[MAXPATHLEN], start[MAXPATHLEN]; + int symlinks = 0; - 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) { - 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; + /* Save the starting point. */ + getcwd(start,MAXPATHLEN); + if ((fd = open(".", O_RDONLY)) < 0) { + (void)strcpy(resolved, "."); return (NULL); } + close(fd); /* - * Iterate over path components in `left'. + * Find the dirname and basename from the path to be resolved. + * Change directory to the dirname component. + * lstat the basename part. + * if it is a symlink, read in the value and loop. + * if it is a directory, then change to that directory. + * get the current directory name and append the basename. */ - 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; + strlcpy(resolved, path, MAXPATHLEN); +loop: + q = strrchr(resolved, '/'); + if (q != NULL) { + p = q + 1; + if (q == resolved) + q = "/"; + else { + do { + --q; + } while (q > resolved && *q == '/'); + q[1] = '\0'; + q = resolved; } + if (chdir(q) < 0) + goto err1; + } else + p = resolved; - /* - * 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 (lstat(resolved, &sb) != 0) { - if (errno == ENOENT && p == NULL) { - errno = serrno; - return (resolved); - } - return (NULL); - } + /* Deal with the last component. */ + if (lstat(p, &sb) == 0) { 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); - } + if (++symlinks > MAXSYMLINKS) { + serrno = ELOOP; + goto err1; } - left_len = strlcpy(left, symlink, sizeof(left)); + n = readlink(p, resolved, MAXPATHLEN-1); + if (n < 0) + goto err1; + resolved[n] = '\0'; + goto loop; + } + if (S_ISDIR(sb.st_mode)) { + if (chdir(p) < 0) + goto err1; + p = ""; } } /* - * Remove trailing slash except when the resolved pathname - * is a single "/". + * Save the last component name and get the full pathname of + * the current directory. + */ + (void)strcpy(wbuf, p); + if (getcwd(resolved, MAXPATHLEN) == 0) + goto err1; + + /* + * Join the two strings together, ensuring that the right thing + * happens if the last component is empty, or the dirname is root. */ - if (resolved_len > 1 && resolved[resolved_len - 1] == '/') - resolved[resolved_len - 1] = '\0'; + if (resolved[0] == '/' && resolved[1] == '\0') + rootd = 1; + else + rootd = 0; + + if (*wbuf) { + if (strlen(resolved) + strlen(wbuf) + rootd + 1 > MAXPATHLEN) { + serrno = ENAMETOOLONG; + goto err1; + } + if (rootd == 0) + (void)strcat(resolved, "/"); + (void)strcat(resolved, wbuf); + } + + /* Go back to where we came from. */ + if (chdir(start) < 0) { + serrno = errno; + goto err2; + } return (resolved); + +err1: chdir(start); +err2: errno = serrno; + return (NULL); } #endif /* !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH) */