+
+ start = sanp = dest + rlen;
+ /* This loop iterates once per filename component in p, pointing at
+ * the start of the name (past any prior slash) for each iteration. */
+ while (*p) {
+ /* discard leading or extra slashes */
+ if (*p == '/') {
+ p++;
+ continue;
+ }
+ if (drop_dot_dirs) {
+ if (*p == '.' && (p[1] == '/' || p[1] == '\0')) {
+ /* skip "." component */
+ p++;
+ continue;
+ }
+ }
+ if (*p == '.' && p[1] == '.' && (p[2] == '/' || p[2] == '\0')) {
+ /* ".." component followed by slash or end */
+ if (depth <= 0 || sanp != start) {
+ p += 2;
+ if (sanp != start) {
+ /* back up sanp one level */
+ --sanp; /* now pointing at slash */
+ while (sanp > start && sanp[-1] != '/')
+ sanp--;
+ }
+ continue;
+ }
+ /* allow depth levels of .. at the beginning */
+ depth--;
+ /* move the virtual beginning to leave the .. alone */
+ start = sanp + 3;
+ }
+ /* copy one component through next slash */
+ while (*p && (*sanp++ = *p++) != '/') {}
+ }
+ if (sanp == dest) {
+ /* ended up with nothing, so put in "." component */
+ *sanp++ = '.';
+ }
+ *sanp = '\0';
+
+ return dest;
+}
+
+/* Like chdir(), but it keeps track of the current directory (in the
+ * global "curr_dir"), and ensures that the path size doesn't overflow.
+ * Also cleans the path using the clean_fname() function. */
+int change_dir(const char *dir, int set_path_only)
+{
+ static int initialised;
+ unsigned int len;
+
+ if (!initialised) {
+ initialised = 1;
+ if (getcwd(curr_dir, sizeof curr_dir - 1) == NULL) {
+ rsyserr(FERROR, errno, "getcwd()");
+ exit_cleanup(RERR_FILESELECT);
+ }
+ curr_dir_len = strlen(curr_dir);
+ }
+
+ if (!dir) /* this call was probably just to initialize */
+ return 0;
+
+ len = strlen(dir);
+ if (len == 1 && *dir == '.')
+ return 1;
+
+ if (*dir == '/') {
+ if (len >= sizeof curr_dir) {
+ errno = ENAMETOOLONG;
+ return 0;
+ }
+ if (!set_path_only && chdir(dir))
+ return 0;
+ memcpy(curr_dir, dir, len + 1);
+ } else {
+ if (curr_dir_len + 1 + len >= sizeof curr_dir) {
+ errno = ENAMETOOLONG;
+ return 0;
+ }
+ curr_dir[curr_dir_len] = '/';
+ memcpy(curr_dir + curr_dir_len + 1, dir, len + 1);
+
+ if (!set_path_only && chdir(curr_dir)) {
+ curr_dir[curr_dir_len] = '\0';
+ return 0;
+ }
+ }
+
+ curr_dir_len = clean_fname(curr_dir, CFN_COLLAPSE_DOT_DOT_DIRS);
+ if (sanitize_paths) {
+ if (module_dirlen > curr_dir_len)
+ module_dirlen = curr_dir_len;
+ curr_dir_depth = count_dir_elements(curr_dir + module_dirlen);
+ }
+
+ if (DEBUG_GTE(CHDIR, 1) && !set_path_only)
+ rprintf(FINFO, "[%s] change_dir(%s)\n", who_am_i(), curr_dir);
+
+ return 1;