tcp: add initial timeout limit for incoming connections

Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/tcp.c

@@ -43,7 +43,7 @@ static int tcp_open(URLContext *h, const char *uri, int flags)
     char buf[256];
     int ret;
     socklen_t optlen;
-    int timeout = 100;
+    int timeout = 100, listen_timeout = -1;
     char hostname[1024],proto[1024],path[1024];
     char portstr[10];
 
@@ -59,6 +59,9 @@ static int tcp_open(URLContext *h, const char *uri, int flags)
         if (av_find_info_tag(buf, sizeof(buf), "timeout", p)) {
             timeout = strtol(buf, NULL, 10);
         }
+        if (av_find_info_tag(buf, sizeof(buf), "listen_timeout", p)) {
+            listen_timeout = strtol(buf, NULL, 10);
+        }
     }
     hints.ai_family = AF_UNSPEC;
     hints.ai_socktype = SOCK_STREAM;
@@ -87,6 +90,7 @@ static int tcp_open(URLContext *h, const char *uri, int flags)
     if (listen_socket) {
         int fd1;
         int reuse = 1;
+        struct pollfd lp = { fd, POLLIN, 0 };
         setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse));
         ret = bind(fd, cur_ai->ai_addr, cur_ai->ai_addrlen);
         if (ret) {
@@ -98,6 +102,11 @@ static int tcp_open(URLContext *h, const char *uri, int flags)
             ret = ff_neterrno();
             goto fail1;
         }
+        ret = poll(&lp, 1, listen_timeout >= 0 ? listen_timeout : -1);
+        if (ret <= 0) {
+            ret = AVERROR(ETIMEDOUT);
+            goto fail1;
+        }
         fd1 = accept(fd, NULL, NULL);
         if (fd1 < 0) {
             ret = ff_neterrno();