rtsp: do not race accept() and select()

rtsp.c

@@ -59,6 +59,7 @@ static int please_shutdown = 0;
 static pthread_t playing_thread = 0;
 
 typedef struct {
+ int fd;
  stream_cfg stream;
  SOCKADDR remote;
 } rtsp_conn_info;
@@ -634,33 +635,22 @@ static int rtsp_auth(char **nonce, rtsp_message *req, rtsp_message *resp) {
  return 1;
 }
 
-static void *rtsp_conversation_thread_func(void *vfd) {
+static void *rtsp_conversation_thread_func(void *pconn) {
  // SIGUSR1 is used to interrupt this thread if blocked for read
  sigset_t set;
  sigemptyset(&set);
  sigaddset(&set, SIGUSR1);
  pthread_sigmask(SIG_UNBLOCK, &set, NULL);
 
- rtsp_conn_info conn;
- memset(&conn, 0, sizeof(conn));
-
- int fd = *(int*)vfd;
- socklen_t slen = sizeof(conn.remote);
-
- debug(1, "new RTSP connection\n");
- fd = accept(fd, (struct sockaddr *)&conn.remote, &slen);
- if (fd < 0) {
- perror("failed to accept connection");
- goto shutdown;
- }
+ rtsp_conn_info *conn = pconn;
 
  rtsp_message *req, *resp;
  char *hdr, *auth_nonce = NULL;
- while ((req = rtsp_read_request(fd))) {
+ while ((req = rtsp_read_request(conn->fd))) {
  resp = msg_init();
  resp->respcode = 400;
 
- apple_challenge(fd, req, resp);
+ apple_challenge(conn->fd, req, resp);
  hdr = msg_get_header(req, "CSeq");
  if (hdr)
  msg_add_header(resp, "CSeq", hdr);
@@ -672,21 +662,20 @@ static void *rtsp_conversation_thread_func(void *vfd) {
  struct method_handler *mh;
  for (mh=method_handlers; mh->method; mh++) {
  if (!strcmp(mh->method, req->method)) {
- mh->handler(&conn, req, resp);
+ mh->handler(conn, req, resp);
  break;
  }
  }
 
 respond:
- msg_write_response(fd, resp);
+ msg_write_response(conn->fd, resp);
  msg_free(req);
  msg_free(resp);
  }
 
-shutdown:
  debug(1, "closing RTSP connection\n");
- if (fd > 0)
- close(fd);
+ if (conn->fd > 0)
+ close(conn->fd);
  if (rtsp_playing()) {
  rtp_shutdown();
  player_stop();
@@ -695,6 +684,7 @@ static void *rtsp_conversation_thread_func(void *vfd) {
  }
  if (auth_nonce)
  free(auth_nonce);
+ free(conn);
  debug(2, "terminating RTSP thread\n");
  return NULL;
 }
@@ -802,20 +792,27 @@ void rtsp_listen_loop(void) {
  break;
  }
 
- debug(2, "new connection coming.\n");
-
  for (i=0; i<nsock; i++) {
  if (FD_ISSET(sockfd[i], &fds)) {
  acceptfd = sockfd[i];
  break;
  }
  }
 
- // for now, we do not track these and let them die of natural causes.
- // XXX: this leaks threads; they need to be culled with pthread_tryjoin_np.
- // XXX: acceptfd could change before the thread is up. which should never happen, but still.
- pthread_t rtsp_conversation_thread;
- pthread_create(&rtsp_conversation_thread, NULL, rtsp_conversation_thread_func, &acceptfd);
+ rtsp_conn_info *conn = malloc(sizeof(rtsp_conn_info));
+ memset(conn, 0, sizeof(rtsp_conn_info));
+ socklen_t slen = sizeof(conn->remote);
+
+ debug(1, "new RTSP connection\n");
+ conn->fd = accept(acceptfd, (struct sockaddr *)&conn->remote, &slen);
+ if (conn->fd < 0) {
+ perror("failed to accept connection");
+ } else {
+ // for now, we do not track these and let them die of natural causes.
+ // XXX: this leaks threads; they need to be culled with pthread_tryjoin_np.
+ pthread_t rtsp_conversation_thread;
+ pthread_create(&rtsp_conversation_thread, NULL, rtsp_conversation_thread_func, conn);
+ }
 
  for (i=0; i<nsock; i++)
  FD_SET(sockfd[i], &fds);