net: lib: websocket: call socket poll for websocket

If we couldn't send all (or any data) via the socket,
invoke poll instead of blindly retrying and flooding the socket.

Signed-off-by: Andrey Dodonov <[email protected]>

subsys/net/lib/websocket/websocket.c

@@ -544,19 +544,39 @@ static int websocket_ioctl_vmeth(void *obj, unsigned int request, va_list args)
 }
 
 #if !defined(CONFIG_NET_TEST)
-static int sendmsg_all(int sock, const struct msghdr *message, int flags)
+static int sendmsg_all(int sock, const struct msghdr *message, int flags, int32_t timeout)
 {
 	int ret, i;
 	size_t offset = 0;
 	size_t total_len = 0;
+	int64_t timestamp = k_uptime_get();
 
 	for (i = 0; i < message->msg_iovlen; i++) {
 		total_len += message->msg_iov[i].iov_len;
 	}
 
 	while (offset < total_len) {
 		ret = zsock_sendmsg(sock, message, flags);
-		if (ret < 0) {
+
+		if ((ret == 0) || (ret < 0 && errno == EAGAIN)) {
+			struct zsock_pollfd pfd;
+			int pollres;
+
+			timeout -= (int32_t)k_uptime_delta(&timestamp);
+			if (timeout < 0) {
+				/* timeout, make poll return immediately */
+				timeout = 0;
+			}
+
+			pfd.fd = sock;
+			pfd.events = ZSOCK_POLLOUT;
+			pollres = zsock_poll(&pfd, 1, timeout);
+			if (pollres >= 0) {
+				continue;
+			} else {
+				return -errno;
+			}
+		} else if (ret < 0) {
 			return -errno;
 		}
 
@@ -623,7 +643,7 @@ static int websocket_prepare_and_send(struct websocket_context *ctx,
 	}
 
 	return sendmsg_all(ctx->real_sock, &msg,
-			   K_TIMEOUT_EQ(tout, K_NO_WAIT) ? MSG_DONTWAIT : 0);
+			   K_TIMEOUT_EQ(tout, K_NO_WAIT) ? MSG_DONTWAIT : 0, timeout);
 #endif /* CONFIG_NET_TEST */
 }