Handle peer shutdown correctly in ipc_sendrecv_with_fds

msgq/visionipc/visionipc.cc

@@ -90,7 +90,11 @@ int ipc_sendrecv_with_fds(bool send, int fd, void *buf, size_t buf_size, int* fd
     return sendmsg(fd, &msg, 0);
   } else {
     int r = recvmsg(fd, &msg, 0);
-    if (r < 0) return r;
+    if (r <= 0) {
+      // r == 0: peer closed connection (EOF)
+      // r < 0: error occurred (check errno)
+      return r;
+    }
 
     int recv_fds = 0;
     if (msg.msg_controllen > 0) {

msgq/visionipc/visionipc_client.cc

@@ -55,9 +55,14 @@ bool VisionIpcClient::connect(bool blocking){
   int fds[VISIONIPC_MAX_FDS];
   VisionBuf bufs[VISIONIPC_MAX_FDS];
   r = ipc_sendrecv_with_fds(false, socket_fd, &bufs, sizeof(bufs), fds, VISIONIPC_MAX_FDS, &num_buffers);
-  if (r < 0) {
+  if (r <= 0) {
     // only expected error is server shutting down
-    assert(errno == ECONNRESET);
+    if (r == 0) {
+      LOGE("server closed connection");
+    } else {
+      assert(errno == ECONNRESET);
+      LOGE("recv failed: %d", errno);
+    }
     close(socket_fd);
     return false;
   }
@@ -135,9 +140,14 @@ std::set<VisionStreamType> VisionIpcClient::getAvailableStreams(const std::strin
 
   VisionStreamType available_streams[VISION_STREAM_MAX] = {};
   r = ipc_sendrecv_with_fds(false, socket_fd, &available_streams, sizeof(available_streams), nullptr, 0, nullptr);
-  if (r < 0) {
-    // only expected error is server shutting down
-    assert(errno == ECONNRESET);
+  if (r <= 0) {
+     if (r == 0) {
+      LOGE("server closed connection");
+    } else {
+      // only expected error is server shutting down
+      assert(errno == ECONNRESET);
+      LOGE("recv failed: %d", errno);
+    }
     close(socket_fd);
     return {};
   }