+ ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
+ if (ret < 0)
+ return ret;
+ cq = query_shm;
+ query.data = (char *)query_shm + sizeof(*cq);
+ query.size = cq->query_size;
+ cq->handler(fd, &query);
+ return shm_detach(query_shm);
+}
+
+static int execute_server_command(fd_set *rfds)
+{
+ char buf[8];
+ size_t n;
+ int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
+
+ if (ret < 0 || n == 0)
+ return ret;
+ buf[n] = '\0';
+ if (strcmp(buf, "new"))
+ return -E_BAD_CMD;
+ return open_next_audio_file();
+}
+
+/* returns 0 if no data available, 1 else */
+static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
+{
+ uint32_t cookie;
+ int query_shmid;
+ char buf[sizeof(cookie) + sizeof(query_shmid)];
+ size_t n;
+ int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
+
+ if (ret < 0)
+ goto err;
+ if (n == 0)
+ return 0;
+ if (n != sizeof(buf)) {
+ PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
+ ret, (long unsigned) sizeof(buf));
+ return 1;
+ }
+ cookie = *(uint32_t *)buf;
+ if (cookie != expected_cookie) {
+ PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
+ (unsigned)cookie, (unsigned)expected_cookie);
+ return 1;
+ }
+ query_shmid = *(int *)(buf + sizeof(cookie));
+ if (query_shmid < 0) {
+ PARA_WARNING_LOG("received invalid query shmid %d)\n",
+ query_shmid);
+ return 1;
+ }
+ ret = call_callback(fd, query_shmid);
+ if (ret >= 0)
+ return 1;
+err:
+ PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
+ return 1;
+}
+
+/** Shutdown connection if query has not arrived until this many seconds. */
+#define AFS_CLIENT_TIMEOUT 3
+
+static void command_post_select(struct sched *s, struct task *t)
+{
+ struct command_task *ct = container_of(t, struct command_task, task);
+ struct sockaddr_un unix_addr;
+ struct afs_client *client, *tmp;
+ int fd, ret;
+
+ ret = execute_server_command(&s->rfds);
+ if (ret < 0) {
+ PARA_EMERG_LOG("%s\n", para_strerror(-ret));
+ sched_shutdown();