+/// Read an invitation file from the confbase sub-directory, and immediately delete it.
+bool invitation_read(meshlink_handle_t *mesh, const char *conf_subdir, const char *name, config_t *config, void *key) {
+ if(!mesh->confbase && !conf_subdir) {
+ return false;
+ }
+
+ char path[PATH_MAX];
+ char used_path[PATH_MAX];
+ make_invitation_path(mesh, conf_subdir, name, path, sizeof(path));
+ make_used_invitation_path(mesh, conf_subdir, name, used_path, sizeof(used_path));
+
+ // Atomically rename the invitation file
+ if(rename(path, used_path)) {
+ if(errno == ENOENT) {
+ logger(mesh, MESHLINK_ERROR, "Peer tried to use non-existing invitation %s\n", name);
+ } else {
+ logger(mesh, MESHLINK_ERROR, "Error trying to rename invitation %s\n", name);
+ }
+
+ return false;
+ }
+
+ FILE *f = fopen(used_path, "r");
+
+ if(!f) {
+ logger(mesh, MESHLINK_ERROR, "Failed to open `%s': %s", path, strerror(errno));
+ return false;
+ }
+
+ // Check the timestamp
+ struct stat st;
+
+ if(fstat(fileno(f), &st)) {
+ logger(mesh, MESHLINK_ERROR, "Could not stat invitation file %s\n", name);
+ fclose(f);
+ unlink(used_path);
+ return false;
+ }
+
+ if(time(NULL) > st.st_mtime + mesh->invitation_timeout) {
+ logger(mesh, MESHLINK_ERROR, "Peer tried to use an outdated invitation file %s\n", name);
+ fclose(f);
+ unlink(used_path);
+ return false;
+ }
+
+ if(!config_read_file(mesh, f, config, key)) {
+ logger(mesh, MESHLINK_ERROR, "Failed to read `%s': %s", path, strerror(errno));
+ fclose(f);
+ unlink(used_path);
+ return false;
+ }
+
+ if(fclose(f)) {
+ logger(mesh, MESHLINK_ERROR, "Failed to close `%s': %s", path, strerror(errno));
+ return false;
+ }
+
+ unlink(used_path);
+ return true;
+}
+
+/// Write an invitation file.
+bool invitation_write(meshlink_handle_t *mesh, const char *conf_subdir, const char *name, const config_t *config, void *key) {
+ if(!mesh->confbase && !conf_subdir) {
+ return false;
+ }
+
+ char path[PATH_MAX];
+ make_invitation_path(mesh, conf_subdir, name, path, sizeof(path));
+
+ FILE *f = fopen(path, "w");
+
+ if(!f) {
+ logger(mesh, MESHLINK_ERROR, "Failed to open `%s': %s", path, strerror(errno));
+ return false;
+ }
+
+ if(!config_write_file(mesh, f, config, key)) {
+ logger(mesh, MESHLINK_ERROR, "Failed to write `%s': %s", path, strerror(errno));
+ fclose(f);
+ return false;
+ }
+
+ if(fclose(f)) {
+ logger(mesh, MESHLINK_ERROR, "Failed to close `%s': %s", path, strerror(errno));
+ return false;
+ }