Fix WebSocket connection close handling

src/client.c

@@ -85,7 +85,7 @@ int client_request_handler(sock *client, unsigned long client_num, unsigned int
 
     clock_gettime(CLOCK_MONOTONIC, &begin);
 
-    ret = sock_poll_read(&client, NULL, 1, CLIENT_TIMEOUT * 1000);
+    ret = sock_poll_read(&client, NULL, NULL, 1, NULL, NULL, CLIENT_TIMEOUT * 1000);
 
     http_add_header_field(&res.hdr, "Date", http_get_date(buf0, sizeof(buf0)));
     http_add_header_field(&res.hdr, "Server", SERVER_STR);

src/lib/sock.c

@@ -120,7 +120,7 @@ int sock_check(sock *s) {
     return recv(s->socket, &buf, 1, MSG_PEEK | MSG_DONTWAIT) == 1;
 }
 
-int sock_poll(sock *sockets[], sock *ready[], short events, int n_sock, int timeout_ms) {
+int sock_poll(sock *sockets[], sock *ready[], sock *error[], int n_sock, int *n_ready, int *n_error, short events, int timeout_ms) {
     struct pollfd fds[n_sock];
     for (int i = 0; i < n_sock; i++) {
         fds[i].fd = sockets[i]->socket;
@@ -128,20 +128,23 @@ int sock_poll(sock *sockets[], sock *ready[], short events, int n_sock, int time
     }
 
     int ret = poll(fds, n_sock, timeout_ms);
-    if (ret < 0 || ready == NULL) return ret;
+    if (ret < 0 || ready == NULL || error == NULL) return ret;
 
-    int j = 0;
+    *n_ready = 0, *n_error = 0;
     for (int i = 0; i < n_sock; i++) {
         if (fds[i].revents & events)
-            ready[j++] = sockets[i];
-    }
-    return j;
+            ready[(*n_ready)++] = sockets[i];
+        if (fds[i].revents & (POLLERR | POLLHUP | POLLNVAL))
+            error[(*n_error)++] = sockets[i];
     }
 
-int sock_poll_read(sock *sockets[], sock *readable[], int n_sock, int timeout_ms) {
-    return sock_poll(sockets, readable, POLLIN, n_sock, timeout_ms);
+    return ret;
 }
 
-int sock_poll_write(sock *sockets[], sock *writable[], int n_sock, int timeout_ms) {
-    return sock_poll(sockets, writable, POLLOUT, n_sock, timeout_ms);
+int sock_poll_read(sock *sockets[], sock *readable[], sock *error[], int n_sock, int *n_readable, int *n_error, int timeout_ms) {
+    return sock_poll(sockets, readable, error, n_sock, n_readable, n_error, POLLIN, timeout_ms);
+}
+
+int sock_poll_write(sock *sockets[], sock *writable[], sock *error[], int n_sock, int *n_writable, int *n_error, int timeout_ms) {
+    return sock_poll(sockets, writable, error, n_sock, n_writable, n_error, POLLOUT, timeout_ms);
 }

src/lib/sock.h

@@ -38,10 +38,10 @@ int sock_close(sock *s);
 
 int sock_check(sock *s);
 
-int sock_poll(sock *sockets[], sock *readable[], short events, int n_sock, int timeout_ms);
+int sock_poll(sock *sockets[], sock *ready[], sock *error[], int n_sock, int *n_ready, int *n_error, short events, int timeout_ms);
 
-int sock_poll_read(sock *sockets[], sock *readable[], int n_sock, int timeout_ms);
+int sock_poll_read(sock *sockets[], sock *readable[], sock *error[], int n_sock, int *n_readable, int *n_error, int timeout_ms);
 
-int sock_poll_write(sock *sockets[], sock *writable[], int n_sock, int timeout_ms);
+int sock_poll_write(sock *sockets[], sock *writable[], sock *error[], int n_sock, int *n_writable, int *n_error, int timeout_ms);
 
 #endif //SESIMOS_SOCK_H

src/lib/websocket.c

@@ -145,29 +145,32 @@ int ws_send_frame_header(sock *s, ws_frame *frame) {
 
 int ws_handle_connection(sock *s1, sock *s2) {
     sock *poll_socks[2] = {s1, s2};
-    sock *readable[2];
-    int n_sock = 2;
+    sock *readable[2], *error[2];
+    int n_sock = 2, n_readable = 0, n_error = 0;
     ws_frame frame;
     char buf[CHUNK_SIZE];
-    int poll, closes = 0;
+    int closes = 0;
     long ret;
 
     signal(SIGINT, ws_terminate);
     signal(SIGTERM, ws_terminate);
 
     while (!terminate && closes != 3) {
-        poll = sock_poll_read(poll_socks, readable, n_sock, WS_TIMEOUT * 1000);
+        ret = sock_poll_read(poll_socks, readable, error, n_sock, &n_readable, &n_error, WS_TIMEOUT * 1000);
         if (terminate) {
             break;
-        } else if (poll < 0) {
+        } else if (ret < 0) {
             print(ERR_STR "Unable to poll sockets: %s" CLR_STR, strerror(errno));
             return -1;
-        } else if (poll == 0) {
+        } else if (n_readable == 0) {
             print(ERR_STR "Connection timed out" CLR_STR);
             return -2;
+        } else if (n_error > 0) {
+            print(ERR_STR "Peer closed connection" CLR_STR);
+            return -3;
         }
 
-        for (int i = 0; i < poll; i++) {
+        for (int i = 0; i < n_readable; i++) {
             sock *s = readable[i];
             sock *o = (s == s1) ? s2 : s1;
             if (ws_recv_frame_header(s, &frame) != 0) return -3;
@@ -188,10 +191,10 @@ int ws_handle_connection(sock *s1, sock *s2) {
                 ret = sock_splice(o, s, buf, sizeof(buf), frame.len);
                 if (ret < 0) {
                     print(ERR_STR "Unable to forward data in WebSocket: %s" CLR_STR, strerror(errno));
-                    return -3;
+                    return -4;
                 } else if (ret != frame.len) {
                     print(ERR_STR "Unable to forward correct number of bytes in WebSocket" CLR_STR);
-                    return -3;
+                    return -4;
                 }
             }
         }