- /* Resolve the canonical path of the first part of the path */
- while (try_path != NULL && next != end) {
- /*
- * If there is not any '/' left, we want to try with
- * the full path
- */
- next = strpbrk(next + 1, "/");
- if (next == NULL) {
- next = end;
- }
-
- /* Cut the part we will be trying to resolve */
- cut_path = strndup(path, next - path);
- if (cut_path == NULL) {
- PERROR("strndup");
- goto error;
- }
-
- /* Try to resolve this part */
- try_path = realpath((char *)cut_path, NULL);
- if (try_path == NULL) {
- /*
- * There was an error, we just want to be assured it
- * is linked to an unexistent directory, if it's another
- * reason, we spawn an error
- */
- switch (errno) {
- case ENOENT:
- /* Ignore the error */
- break;
- default:
- PERROR("realpath (partial_realpath)");
- goto error;
- break;
- }
- } else {
- /* Save the place we are before trying the next step */
- free(try_path_prev);
- try_path_prev = try_path;
- prev = next;
- }
-
- /* Free the allocated memory */
- free(cut_path);
- };
-
- /* Allocate memory for the resolved path if necessary */
- if (resolved_path == NULL) {
- resolved_path = zmalloc(size);
- if (resolved_path == NULL) {
- PERROR("zmalloc resolved path");
- goto error;
- }
- }
-
- /*
- * If we were able to solve at least partially the path, we can concatenate
- * what worked and what didn't work
- */
- if (try_path_prev != NULL) {
- /* If we risk to concatenate two '/', we remove one of them */
- if (try_path_prev[strlen(try_path_prev) - 1] == '/' && prev[0] == '/') {
- try_path_prev[strlen(try_path_prev) - 1] = '\0';
- }
-
- /*
- * Duplicate the memory used by prev in case resolved_path and
- * path are pointers for the same memory space
- */
- cut_path = strdup(prev);
- if (cut_path == NULL) {
- PERROR("strdup");
- goto error;
- }
-
- /* Concatenate the strings */
- snprintf(resolved_path, size, "%s%s", try_path_prev, cut_path);
-
- /* Free the allocated memory */
- free(cut_path);
- free(try_path_prev);
- /*
- * Else, we just copy the path in our resolved_path to
- * return it as is
- */
- } else {
- strncpy(resolved_path, path, size);
- }
-
- /* Then we return the 'partially' resolved path */
- return resolved_path;
-
-error:
- free(resolved_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
- * symlinks and relatives paths at the start of the string, and
- * implements functionnalities to resolve the './' and '../' strings
- * in the middle of a path. This function is only necessary because
- * realpath(3) does not accept to resolve unexistent paths.
- * The returned string was allocated in the function, it is thus of
- * the responsibility of the caller to free this memory.
- */
-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) {
- goto error;
- }
-
- /* Allocate memory for the absolute_path */
- absolute_path = zmalloc(PATH_MAX);
- if (absolute_path == NULL) {
- PERROR("zmalloc expand path");
- goto error;
- }
-
- /*
- * If the path is not already absolute nor explicitly relative,
- * consider we're in the current directory
- */
- if (*path != '/' && strncmp(path, "./", 2) != 0 &&
- strncmp(path, "../", 3) != 0) {
- snprintf(absolute_path, PATH_MAX, "./%s", path);
- /* Else, we just copy the path */
- } else {
- strncpy(absolute_path, path, PATH_MAX);
- }
-
- /* Resolve partially our path */
- absolute_path = utils_partial_realpath(absolute_path,
- absolute_path, PATH_MAX);
-
- /* As long as we find '/./' in the working_path string */
- while ((next = strstr(absolute_path, "/./"))) {
-
- /* We prepare the start_path not containing it */
- start_path = strndup(absolute_path, next - absolute_path);
- if (!start_path) {
- PERROR("strndup");
- goto error;
- }
- /* 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 working_path string */
- while ((next = strstr(absolute_path, "/../"))) {
- /* We find the last level of directory */
- previous = absolute_path;
- while ((slash = strpbrk(previous, "/")) && slash != next) {
- previous = slash + 1;
- }
-
- /* Then we prepare the start_path not containing it */
- start_path = strndup(absolute_path, previous - absolute_path);
- if (!start_path) {
- PERROR("strndup");
- goto error;
- }
-
- /* And we concatenate it with the part after the '/../' */
- snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 4);
-
- /* We can free the memory used for the start path*/
- free(start_path);
-
- /* Then we verify for symlinks using partial_realpath */
- absolute_path = utils_partial_realpath(absolute_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;