- if(strlen(fn) == 0)
- /* User just pressed enter. */
- fn = xstrdup(filename);
- }
-
- if((strchr(fn, '/') == NULL) || (fn[0] != '/'))
- {
- /* The directory is a relative path or a filename. */
- char *p;
-
- directory = get_current_dir_name();
- asprintf(&p, "%s/%s", directory, fn);
- free(fn);
- free(directory);
- fn = p;
- }
-
- umask(0077); /* Disallow everything for group and other */
-
- /* Open it first to keep the inode busy */
- if((r = fopen(fn, mode)) == NULL)
- {
- fprintf(stderr, _("Error opening file `%s': %s\n"),
- fn, strerror(errno));
- free(fn);
- return NULL;
- }
-
- /* Then check the file for nasty attacks */
- if(!is_safe_path(fn)) /* Do not permit any directories that are
- readable or writeable by other users. */
- {
- fprintf(stderr, _("The file `%s' (or any of the leading directories) has unsafe permissions.\n"
- "I will not create or overwrite this file.\n"),
- fn);
- fclose(r);
- free(fn);
- return NULL;
- }
-
- free(fn);
-
- return r;
+ FILE *fw = fopen(tmpname, "w");
+
+ if(!fw) {
+ logger(mesh, MESHLINK_ERROR, "Cannot open temporary file %s: %s", tmpname, strerror(errno));
+ fclose(fr);
+ return false;
+ }
+
+ char buf[4096];
+ char *sep;
+ bool found = false;
+
+ while(readline(fr, buf, sizeof buf)) {
+ if(!*buf || *buf == '#')
+ goto copy;
+
+ sep = strchr(buf, ' ');
+ if(!sep)
+ goto copy;
+
+ *sep = 0;
+ if(strcmp(buf, key)) {
+ *sep = ' ';
+ goto copy;
+ }
+
+ if(!value) {
+ found = true;
+ continue;
+ }
+
+ // We found the key and the value. Keep one copy around.
+ if(sep[1] == '=' && sep[2] == ' ' && !strcmp(sep + 3, value)) {
+ if(found)
+ continue;
+ found = true;
+ }
+
+ // We found the key but with a different value, delete it if wanted.
+ if(!found && replace)
+ continue;
+
+ *sep = ' ';
+
+copy:
+ fprintf(fw, "%s\n", buf);
+ }
+
+ if(ferror(fr))
+ error = true;
+
+ fclose(fr);
+
+ // Add new key/value pair if necessary
+ if(!found && value)
+ fprintf(fw, "%s = %s\n", key, value);
+
+ if(ferror(fw))
+ error = true;
+
+ if(fclose(fw))
+ error = true;
+
+ // If any error occured during reading or writing, exit.
+ if(error) {
+ unlink(tmpname);
+ return false;
+ }
+
+ // Try to atomically replace the old config file with the new one.
+#ifdef HAVE_MINGW
+ char bakname[PATH_MAX];
+ snprintf(bakname, sizeof bakname, "%s.bak", filename);
+ if(rename(filename, bakname) || rename(tmpname, filename)) {
+ rename(bakname, filename);
+#else
+ if(rename(tmpname, filename)) {
+#endif
+ return false;
+ } else {
+#ifdef HAVE_MINGW
+ unlink(bakname);
+#endif
+ return true;
+ }
+}
+
+bool append_config_file(meshlink_handle_t *mesh, const char *name, const char *key, const char *value) {
+ return modify_config_file(mesh, name, key, value, false);