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;
+}