diff options
author | Mithun Iyer <iyerm@google.com> | 2021-04-05 21:51:31 -0700 |
---|---|---|
committer | gVisor bot <gvisor-bot@google.com> | 2021-04-05 21:53:41 -0700 |
commit | 56c69fb0e7f96e5bd5da9e0d29a78e05dd3e2bba (patch) | |
tree | c231730c05bf555753b19577edf05e7235a9569e /pkg/sentry/syscalls/linux/vfs2 | |
parent | 7a7fcf2dbaa7bdcdb9b523358de91c71d5cb05d8 (diff) |
Fix listen backlog handling to be in parity with Linux
- Change the accept queue full condition for a listening endpoint
to only honor completed (and delivered) connections.
- Use syncookies if the number of incomplete connections is beyond
listen backlog. This also cleans up the SynThreshold option code
as that is no longer used with this change.
- Added a new stack option to unconditionally generate syncookies.
Similar to sysctl -w net.ipv4.tcp_syncookies=2 on Linux.
- Enable keeping of incomplete connections beyond listen backlog.
- Drop incoming SYNs only if the accept queue is filled up.
- Drop incoming ACKs that complete handshakes when accept queue is full
- Enable the stack to accept one more connection than programmed by
listen backlog.
- Handle backlog argument being zero, negative for listen, as Linux.
- Add syscall and packetimpact tests to reflect the changes above.
- Remove TCPConnectBacklog test which is polling for completed
connections on the client side which is not reflective of whether
the accept queue is filled up by the test. The modified syscall test
in this CL addresses testing of connecting sockets.
Fixes #3153
PiperOrigin-RevId: 366935921
Diffstat (limited to 'pkg/sentry/syscalls/linux/vfs2')
-rw-r--r-- | pkg/sentry/syscalls/linux/vfs2/socket.go | 14 |
1 files changed, 0 insertions, 14 deletions
diff --git a/pkg/sentry/syscalls/linux/vfs2/socket.go b/pkg/sentry/syscalls/linux/vfs2/socket.go index a87a66146..7cc0be892 100644 --- a/pkg/sentry/syscalls/linux/vfs2/socket.go +++ b/pkg/sentry/syscalls/linux/vfs2/socket.go @@ -35,12 +35,6 @@ import ( "gvisor.dev/gvisor/pkg/hostarch" ) -// minListenBacklog is the minimum reasonable backlog for listening sockets. -const minListenBacklog = 8 - -// maxListenBacklog is the maximum allowed backlog for listening sockets. -const maxListenBacklog = 1024 - // maxAddrLen is the maximum socket address length we're willing to accept. const maxAddrLen = 200 @@ -386,14 +380,6 @@ func Listen(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal return 0, nil, syserror.ENOTSOCK } - // Per Linux, the backlog is silently capped to reasonable values. - if backlog <= 0 { - backlog = minListenBacklog - } - if backlog > maxListenBacklog { - backlog = maxListenBacklog - } - return 0, nil, s.Listen(t, int(backlog)).ToError() } |