Swallow SO_RCVBUFFORCE and SO_SNDBUFFORCE errors on SOCK_RAW sockets

In --network=sandbox mode, we create SOCK_RAW sockets on the given
network device. The code tries to force-set 4MiB rcv and snd buffers
on it, but in certain situations it might fail. There is no reason
for refusing the sandbox startup in such case - we should bump the
buffers to max availabe size and just move on.

1 files changed, 11 insertions, 2 deletions

diff --git a/runsc/sandbox/network.go b/runsc/sandbox/network.go
index 0b9f39466..8f66dd1f8 100644
--- a/runsc/sandbox/network.go
+++ b/runsc/sandbox/network.go
@@ -309,11 +309,20 @@ func createSocket(iface net.Interface, ifaceLink netlink.Link, enableGSO bool) (
 	const bufSize = 4 << 20 // 4MB.
 
 	if err := syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_RCVBUFFORCE, bufSize); err != nil {
-		return nil, fmt.Errorf("failed to increase socket rcv buffer to %d: %v", bufSize, err)
+		syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_RCVBUF, bufSize)
+		sz, _ := syscall.GetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_RCVBUF)
+
+		if sz < bufSize {
+			log.Warningf("Failed to increase rcv buffer to %d on SOCK_RAW on %s. Current buffer %d: %v", bufSize, iface.Name, sz, err)
+		}
 	}
 
 	if err := syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_SNDBUFFORCE, bufSize); err != nil {
-		return nil, fmt.Errorf("failed to increase socket snd buffer to %d: %v", bufSize, err)
+		syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_SNDBUF, bufSize)
+		sz, _ := syscall.GetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_SNDBUF)
+		if sz < bufSize {
+			log.Warningf("Failed to increase snd buffer to %d on SOCK_RAW on %s. Curent buffer %d: %v", bufSize, iface.Name, sz, err)
+		}
 	}
 
 	return &socketEntry{deviceFile, gsoMaxSize}, nil