+++ /dev/null
-/*
- * 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 <limits.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;
- 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. */
- link_path = malloc(PATH_MAX+1);
- if (!link_path)
- return NULL;
- 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(link_path);
- free(buf);
- return resolved_path;
-
- err:
- free(link_path);
- 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;
- char *p;
-
- if (path == NULL)
- return NULL;
-
- canonical = malloc(PATH_MAX+2);
- if (!canonical)
- return NULL;
- if (!myrealpath(path, canonical, PATH_MAX+1)) {
- free(canonical);
- return strdup(path);
- }
-
-
- p = strrchr(canonical, '/');
- if (p && strncmp(p, "/dm-", 4) == 0 && isdigit(*(p + 4))) {
- p = canonicalize_dm_name(p+1);
- if (p) {
- free(canonical);
- return p;
- }
- }
-
- return canonical;
-}
-
-
Code Review / stor4nfv.git / blobdiff