From 6f5114446a7952d8b2b3098b2845e660d38d4fe1 Mon Sep 17 00:00:00 2001 From: Marek Majkowski Date: Fri, 25 Sep 2020 13:20:28 +0200 Subject: [PATCH] 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. --- runsc/sandbox/network.go | 13 +++++++++++-- 1 file 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