Fix: utils_expand_path now works for paths that ends with '/.' or '/..'

[lttng-tools.git] / src / common / utils.c

diff --git a/src/common/utils.c b/src/common/utils.c
index d28e31349df3cd3bf383e8d366c119db52305c57..ce25f232d5209b7c08b644ce21a7fa526d70a244 100644 (file)
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2013 - Raphaël Beamonte <raphael.beamonte@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License, version 2 only, as
@@ -163,73 +164,6 @@ error:
        return NULL;
 }
 
-/*
- * Resolve the './' and '../' strings in the middle of a path using
- * our very own way to do it, so that it works even if the directory
- * does not exist
- */
-LTTNG_HIDDEN
-char *utils_resolve_relative(const char *path)
-{
-       char *next, *previous, *slash, *start_path, *absolute_path = NULL;
-
-       /* Safety net */
-       if (path == NULL) {
-               goto error;
-       }
-
-       /* Allocate memory for the absolute path */
-       absolute_path = zmalloc(PATH_MAX);
-       if (absolute_path == NULL) {
-               PERROR("zmalloc expand path");
-               goto error;
-       }
-
-       /* Copy the path in the absolute path */
-       strncpy(absolute_path, path, PATH_MAX);
-
-       /* As long as we find '/./' in the path string */
-       while ((next = strstr(absolute_path, "/./"))) {
-
-               /* We prepare the start_path not containing it */
-               start_path = strndup(absolute_path, next - absolute_path);
-
-               /* And we concatenate it with the part after this string */
-               snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 2);
-
-               free(start_path);
-       }
-
-       /* As long as we find '/../' in the path string */
-       while ((next = strstr(absolute_path, "/../"))) {
-               /* If the path starts with '/../', there's a problem */
-               if (next == absolute_path) {
-                       ERR("%s: Path cannot be resolved", path);
-                       goto error;
-               }
-
-               /* We find the last level of directory */
-               previous = absolute_path;
-               while ((slash = strpbrk(previous + 1, "/")) && slash != next) {
-                       previous = slash;
-               }
-
-               /* Then we prepare the start_path not containing it */
-               start_path = strndup(absolute_path, previous - absolute_path);
-
-               /* And we concatenate it with the part after the '/../' */
-               snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 3);
-
-               free(start_path);
-       }
-
-       return absolute_path;
-
-error:
-       free(absolute_path);
-       return NULL;
-}
-
 /*
  * Make a full resolution of the given path even if it doesn't exist.
  * This function uses the utils_partial_realpath function to resolve
@@ -244,6 +178,8 @@ LTTNG_HIDDEN
 char *utils_expand_path(const char *path)
 {
        char *next, *previous, *slash, *start_path, *absolute_path = NULL;
+       char *last_token;
+       int is_dot, is_dotdot;
 
        /* Safety net */
        if (path == NULL) {
@@ -264,7 +200,7 @@ char *utils_expand_path(const char *path)
        if (*path != '/' && strncmp(path, "./", 2) != 0 &&
                        strncmp(path, "../", 3) != 0) {
                snprintf(absolute_path, PATH_MAX, "./%s", path);
-               /* Else, we just copy the path */
+       /* Else, we just copy the path */
        } else {
                strncpy(absolute_path, path, PATH_MAX);
        }
@@ -307,6 +243,31 @@ char *utils_expand_path(const char *path)
                                absolute_path, PATH_MAX);
        }
 
+       /* Identify the last token */
+       last_token = strrchr(absolute_path, '/');
+
+       /* Verify that this token is not a relative path */
+       is_dotdot = (strcmp(last_token, "/..") == 0);
+       is_dot = (strcmp(last_token, "/.") == 0);
+
+       /* If it is, take action */
+       if (is_dot || is_dotdot) {
+               /* For both, remove this token */
+               *last_token = '\0';
+
+               /* If it was a reference to parent directory, go back one more time */
+               if (is_dotdot) {
+                       last_token = strrchr(absolute_path, '/');
+
+                       /* If there was only one level left, we keep the first '/' */
+                       if (last_token == absolute_path) {
+                               last_token++;
+                       }
+
+                       *last_token = '\0';
+               }
+       }
+
        return absolute_path;
 
 error: