diff options
Diffstat (limited to '')
-rw-r--r-- | libblkid/canonicalize.c | 247 |
1 files changed, 0 insertions, 247 deletions
diff --git a/libblkid/canonicalize.c b/libblkid/canonicalize.c deleted file mode 100644 index 1e8aff4f2..000000000 --- a/libblkid/canonicalize.c +++ /dev/null @@ -1,247 +0,0 @@ -/* - * canonicalize.c -- canonicalize pathname by removing symlinks - * Copyright (C) 1993 Rick Sladkey <jrs@world.std.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU Library Public License as published by - * the Free Software Foundation; either version 2, or (at your option) - * any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU Library Public License for more details. - * - */ - -/* - * This routine is part of libc. We include it nevertheless, - * since the libc version has some security flaws. - * - * TODO: use canonicalize_file_name() when exist in glibc - */ -#include <stdio.h> -#include <string.h> -#include <ctype.h> -#include <unistd.h> -#include <errno.h> -#include <stdlib.h> - -#include "canonicalize.h" - -#ifndef MAXSYMLINKS -# define MAXSYMLINKS 256 -#endif - -static char * -myrealpath(const char *path, char *resolved_path, int maxreslth) { - int readlinks = 0; - char *npath; - char link_path[PATH_MAX+1]; - int n; - char *buf = NULL; - - npath = resolved_path; - - /* If it's a relative pathname use getcwd for starters. */ - if (*path != '/') { - if (!getcwd(npath, maxreslth-2)) - return NULL; - npath += strlen(npath); - if (npath[-1] != '/') - *npath++ = '/'; - } else { - *npath++ = '/'; - path++; - } - - /* Expand each slash-separated pathname component. */ - while (*path != '\0') { - /* Ignore stray "/" */ - if (*path == '/') { - path++; - continue; - } - if (*path == '.' && (path[1] == '\0' || path[1] == '/')) { - /* Ignore "." */ - path++; - continue; - } - if (*path == '.' && path[1] == '.' && - (path[2] == '\0' || path[2] == '/')) { - /* Backup for ".." */ - path += 2; - while (npath > resolved_path+1 && - (--npath)[-1] != '/') - ; - continue; - } - /* Safely copy the next pathname component. */ - while (*path != '\0' && *path != '/') { - if (npath-resolved_path > maxreslth-2) { - errno = ENAMETOOLONG; - goto err; - } - *npath++ = *path++; - } - - /* Protect against infinite loops. */ - if (readlinks++ > MAXSYMLINKS) { - errno = ELOOP; - goto err; - } - - /* See if last pathname component is a symlink. */ - *npath = '\0'; - n = readlink(resolved_path, link_path, PATH_MAX); - if (n < 0) { - /* EINVAL means the file exists but isn't a symlink. */ - if (errno != EINVAL) - goto err; - } else { - int m; - char *newbuf; - - /* Note: readlink doesn't add the null byte. */ - link_path[n] = '\0'; - if (*link_path == '/') - /* Start over for an absolute symlink. */ - npath = resolved_path; - else - /* Otherwise back up over this component. */ - while (*(--npath) != '/') - ; - - /* Insert symlink contents into path. */ - m = strlen(path); - newbuf = malloc(m + n + 1); - if (!newbuf) - goto err; - memcpy(newbuf, link_path, n); - memcpy(newbuf + n, path, m + 1); - free(buf); - path = buf = newbuf; - } - *npath++ = '/'; - } - /* Delete trailing slash but don't whomp a lone slash. */ - if (npath != resolved_path+1 && npath[-1] == '/') - npath--; - /* Make sure it's null terminated. */ - *npath = '\0'; - - free(buf); - return resolved_path; - - err: - free(buf); - return NULL; -} - -/* - * Converts private "dm-N" names to "/dev/mapper/<name>" - * - * Since 2.6.29 (patch 784aae735d9b0bba3f8b9faef4c8b30df3bf0128) kernel sysfs - * provides the real DM device names in /sys/block/<ptname>/dm/name - */ -char * -canonicalize_dm_name(const char *ptname) -{ - FILE *f; - size_t sz; - char path[256], name[256], *res = NULL; - - snprintf(path, sizeof(path), "/sys/block/%s/dm/name", ptname); - if (!(f = fopen(path, "r"))) - return NULL; - - /* read "<name>\n" from sysfs */ - if (fgets(name, sizeof(name), f) && (sz = strlen(name)) > 1) { - name[sz - 1] = '\0'; - snprintf(path, sizeof(path), "/dev/mapper/%s", name); - res = strdup(path); - } - fclose(f); - return res; -} - -char * -canonicalize_path(const char *path) -{ - char canonical[PATH_MAX+2]; - char *p; - - if (path == NULL) - return NULL; - - if (!myrealpath(path, canonical, PATH_MAX+1)) - return strdup(path); - - - p = strrchr(canonical, '/'); - if (p && strncmp(p, "/dm-", 4) == 0 && isdigit(*(p + 4))) { - p = canonicalize_dm_name(p+1); - if (p) - return p; - } - - return strdup(canonical); -} - -char * -canonicalize_path_restricted(const char *path) -{ - char canonical[PATH_MAX+2]; - char *p = NULL; - int errsv; - uid_t euid; - gid_t egid; - - if (path == NULL) - return NULL; - - euid = geteuid(); - egid = getegid(); - - /* drop permissions */ - if (setegid(getgid()) < 0 || seteuid(getuid()) < 0) - return NULL; - - errsv = errno = 0; - - if (myrealpath(path, canonical, PATH_MAX+1)) { - p = strrchr(canonical, '/'); - if (p && strncmp(p, "/dm-", 4) == 0 && isdigit(*(p + 4))) - p = canonicalize_dm_name(p+1); - else - p = NULL; - if (!p) - p = strdup(canonical); - } else - errsv = errno; - - /* restore */ - if (setegid(egid) < 0 || seteuid(euid) < 0) { - free(p); - return NULL; - } - - errno = errsv; - return p; -} - - -#ifdef TEST_PROGRAM_CANONICALIZE -int main(int argc, char **argv) -{ - if (argc < 2) { - fprintf(stderr, "usage: %s <device>\n", argv[0]); - exit(EXIT_FAILURE); - } - - fprintf(stdout, "orig: %s\n", argv[1]); - fprintf(stdout, "real: %s\n", canonicalize_path(argv[1])); - - exit(EXIT_SUCCESS); -} -#endif |