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-rw-r--r--libmenu/canonicalize.c326
1 files changed, 326 insertions, 0 deletions
diff --git a/libmenu/canonicalize.c b/libmenu/canonicalize.c
new file mode 100644
index 0000000..82082e9
--- /dev/null
+++ b/libmenu/canonicalize.c
@@ -0,0 +1,326 @@
+/* Return the canonical absolute name of a given file.
+ * Copyright (C) 1996-2001, 2002 Free Software Foundation, Inc.
+ * This file is part of the GNU C Library.
+ *
+ * Copyright (C) 2002 Red Hat, Inc. (trivial port to GLib)
+ *
+ * The GNU C Library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * The GNU C Library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with the GNU C Library; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307 USA.
+ */
+
+#include <config.h>
+
+#include "canonicalize.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <limits.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <stddef.h>
+
+/* Return the canonical absolute name of file NAME. A canonical name
+ does not contain any `.', `..' components nor any repeated path
+ separators ('/') or symlinks. All path components must exist. If
+ RESOLVED is null, the result is malloc'd; otherwise, if the
+ canonical name is PATH_MAX chars or more, returns null with `errno'
+ set to ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars,
+ returns the name in RESOLVED. If the name cannot be resolved and
+ RESOLVED is non-NULL, it contains the path of the first component
+ that cannot be resolved. If the path can be resolved, RESOLVED
+ holds the same value as the value returned. */
+
+static char* menu_realpath(const char* name, char* resolved)
+{
+ char* rpath = NULL;
+ char* dest = NULL;
+ char* extra_buf = NULL;
+ const char* start;
+ const char* end;
+ const char* rpath_limit;
+ long int path_max;
+ int num_links = 0;
+
+ if (name == NULL)
+ {
+ /* As per Single Unix Specification V2 we must return an error if
+ * either parameter is a null pointer. We extend this to allow
+ * the RESOLVED parameter to be NULL in case the we are expected to
+ * allocate the room for the return value. */
+ errno = EINVAL;
+ return NULL;
+ }
+
+ if (name[0] == '\0')
+ {
+ /* As per Single Unix Specification V2 we must return an error if
+ * the name argument points to an empty string. */
+ errno = ENOENT;
+ return NULL;
+ }
+
+ #ifdef PATH_MAX
+ path_max = PATH_MAX;
+ #else
+ path_max = pathconf(name, _PC_PATH_MAX);
+
+ if (path_max <= 0)
+ {
+ path_max = 1024;
+ }
+ #endif
+
+ rpath = resolved ? g_alloca(path_max) : g_malloc(path_max);
+ rpath_limit = rpath + path_max;
+
+ if (name[0] != G_DIR_SEPARATOR)
+ {
+ if (!getcwd(rpath, path_max))
+ {
+ rpath[0] = '\0';
+ goto error;
+ }
+
+ dest = strchr(rpath, '\0');
+ }
+ else
+ {
+ rpath[0] = G_DIR_SEPARATOR;
+ dest = rpath + 1;
+ }
+
+ for (start = end = name; *start; start = end)
+ {
+ struct stat st;
+ int n;
+
+ /* Skip sequence of multiple path-separators. */
+ while (*start == G_DIR_SEPARATOR)
+ {
+ ++start;
+ }
+
+ /* Find end of path component. */
+ for (end = start; *end && *end != G_DIR_SEPARATOR; ++end)
+ {
+ /* Nothing. */;
+ }
+
+ if (end - start == 0)
+ {
+ break;
+ }
+ else if (end - start == 1 && start[0] == '.')
+ {
+ /* nothing */;
+ }
+ else if (end - start == 2 && start[0] == '.' && start[1] == '.')
+ {
+ /* Back up to previous component, ignore if at root already. */
+ if (dest > rpath + 1)
+ {
+ while ((--dest)[-1] != G_DIR_SEPARATOR)
+ {
+ /* Nothing. */;
+ }
+ }
+ }
+ else
+ {
+ size_t new_size;
+
+ if (dest[-1] != G_DIR_SEPARATOR)
+ {
+ *dest++ = G_DIR_SEPARATOR;
+ }
+
+ if (dest + (end - start) >= rpath_limit)
+ {
+ char* new_rpath;
+ ptrdiff_t dest_offset = dest - rpath;
+
+ if (resolved)
+ {
+ #ifdef ENAMETOOLONG
+ errno = ENAMETOOLONG;
+ #else
+ /* Uh... just pick something */
+ errno = EINVAL;
+ #endif
+
+ if (dest > rpath + 1)
+ {
+ dest--;
+ }
+
+ *dest = '\0';
+ goto error;
+ }
+
+ new_size = rpath_limit - rpath;
+
+ if (end - start + 1 > path_max)
+ {
+ new_size += end - start + 1;
+ }
+ else
+ {
+ new_size += path_max;
+ }
+
+ new_rpath = (char*) realloc(rpath, new_size);
+
+ if (new_rpath == NULL)
+ {
+ goto error;
+ }
+
+ rpath = new_rpath;
+ rpath_limit = rpath + new_size;
+
+ dest = rpath + dest_offset;
+ }
+
+ memcpy(dest, start, end - start);
+ dest = dest + (end - start);
+ *dest = '\0';
+
+ if (stat(rpath, &st) < 0)
+ {
+ goto error;
+ }
+
+ if (S_ISLNK(st.st_mode))
+ {
+ char* buf = alloca(path_max);
+ size_t len;
+
+ if (++num_links > MAXSYMLINKS)
+ {
+ errno = ELOOP;
+ goto error;
+ }
+
+ n = readlink(rpath, buf, path_max);
+
+ if (n < 0)
+ {
+ goto error;
+ }
+
+ buf[n] = '\0';
+
+
+
+ if (!extra_buf)
+ {
+ extra_buf = g_alloca(path_max);
+ }
+
+ len = strlen(end);
+
+ if ((long int) (n + len) >= path_max)
+ {
+ #ifdef ENAMETOOLONG
+ errno = ENAMETOOLONG;
+ #else
+ /* Uh... just pick something */
+ errno = EINVAL;
+ #endif
+
+ goto error;
+ }
+
+ /* Careful here, end may be a pointer into extra_buf... */
+ g_memmove(&extra_buf[n], end, len + 1);
+ name = end = memcpy(extra_buf, buf, n);
+
+ if (buf[0] == G_DIR_SEPARATOR)
+ {
+ dest = rpath + 1; /* It's an absolute symlink */
+ }
+ else
+ {
+ /* Back up to previous component, ignore if at root already: */
+ if (dest > rpath + 1)
+ {
+ while ((--dest)[-1] != G_DIR_SEPARATOR)
+ {
+ /* Nothing. */;
+ }
+ }
+ }
+ }
+ }
+ }
+
+ if (dest > rpath + 1 && dest[-1] == G_DIR_SEPARATOR)
+ {
+ --dest;
+ }
+
+ *dest = '\0';
+
+ return resolved ? memcpy(resolved, rpath, dest - rpath + 1) : rpath;
+
+ error:
+
+ if (resolved)
+ {
+ strcpy(resolved, rpath);
+ }
+ else
+ {
+ g_free(rpath);
+ }
+
+ return NULL;
+}
+
+char* menu_canonicalize_file_name(const char* name, gboolean allow_missing_basename)
+{
+ char* retval;
+
+ retval = menu_realpath(name, NULL);
+
+ /* We could avoid some system calls by using the second
+ * argument to realpath() instead of doing realpath
+ * all over again, but who cares really. we'll see if
+ * it's ever in a profile.
+ */
+ if (allow_missing_basename && retval == NULL)
+ {
+ char* dirname;
+ char* canonical_dirname;
+
+ dirname = g_path_get_dirname(name);
+ canonical_dirname = menu_realpath(dirname, NULL);
+ g_free(dirname);
+
+ if (canonical_dirname)
+ {
+ char* basename;
+
+ basename = g_path_get_basename(name);
+ retval = g_build_filename(canonical_dirname, basename, NULL);
+ g_free(basename);
+ g_free(canonical_dirname);
+ }
+ }
+
+ return retval;
+}