diff options
| author | Kevin Krakauer <krakauer@google.com> | 2021-07-12 22:34:44 -0700 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2021-07-12 22:37:11 -0700 |
| commit | e35d20f79c4604c41a3b912b41aae322adf96bc7 (patch) | |
| tree | 3134a6c001ae3368be2021b6d06e95cd5174918a /pkg/sentry/socket/netstack/netstack.go | |
| parent | 520795aaad701854e9ffe84de1108954cf2b77f8 (diff) | |
netstack: move SO_SNDBUF/RCVBUF clamping logic out of //pkg/tcpip
- Keeps Linux-specific behavior out of //pkg/tcpip
- Makes it clearer that clamping is done only for setsockopt calls from users
- Removes code duplication
PiperOrigin-RevId: 384389809
Diffstat (limited to 'pkg/sentry/socket/netstack/netstack.go')
| -rw-r--r-- | pkg/sentry/socket/netstack/netstack.go | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go index 5d5c4ebbd..ea736e446 100644 --- a/pkg/sentry/socket/netstack/netstack.go +++ b/pkg/sentry/socket/netstack/netstack.go @@ -1682,6 +1682,26 @@ func SetSockOpt(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, level int return nil } +func clampBufSize(newSz, min, max int64) int64 { + // packetOverheadFactor is used to multiply the value provided by the user on + // a setsockopt(2) for setting the send/receive buffer sizes sockets. + const packetOverheadFactor = 2 + + if newSz > max { + newSz = max + } + + if newSz < math.MaxInt32/packetOverheadFactor { + newSz *= packetOverheadFactor + if newSz < min { + newSz = min + } + } else { + newSz = math.MaxInt32 + } + return newSz +} + // setSockOptSocket implements SetSockOpt when level is SOL_SOCKET. func setSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, name int, optVal []byte) *syserr.Error { switch name { @@ -1691,7 +1711,9 @@ func setSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, nam } v := hostarch.ByteOrder.Uint32(optVal) - ep.SocketOptions().SetSendBufferSize(int64(v), true /* notify */) + min, max := ep.SocketOptions().SendBufferLimits() + clamped := clampBufSize(int64(v), min, max) + ep.SocketOptions().SetSendBufferSize(clamped, true /* notify */) return nil case linux.SO_RCVBUF: @@ -1700,7 +1722,9 @@ func setSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, nam } v := hostarch.ByteOrder.Uint32(optVal) - ep.SocketOptions().SetReceiveBufferSize(int64(v), true /* notify */) + min, max := ep.SocketOptions().ReceiveBufferLimits() + clamped := clampBufSize(int64(v), min, max) + ep.SocketOptions().SetReceiveBufferSize(clamped, true /* notify */) return nil case linux.SO_REUSEADDR: |