From 2d2831e3541c8ae3c84f17cfd1bf0a26f2027044 Mon Sep 17 00:00:00 2001 From: Rahat Mahmood Date: Thu, 6 Jun 2019 15:03:44 -0700 Subject: Track and export socket state. This is necessary for implementing network diagnostic interfaces like /proc/net/{tcp,udp,unix} and sock_diag(7). For pass-through endpoints such as hostinet, we obtain the socket state from the backend. For netstack, we add explicit tracking of TCP states. PiperOrigin-RevId: 251934850 --- pkg/sentry/socket/hostinet/socket.go | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'pkg/sentry/socket/hostinet/socket.go') diff --git a/pkg/sentry/socket/hostinet/socket.go b/pkg/sentry/socket/hostinet/socket.go index 41f9693bb..0d75580a3 100644 --- a/pkg/sentry/socket/hostinet/socket.go +++ b/pkg/sentry/socket/hostinet/socket.go @@ -19,7 +19,9 @@ import ( "syscall" "gvisor.googlesource.com/gvisor/pkg/abi/linux" + "gvisor.googlesource.com/gvisor/pkg/binary" "gvisor.googlesource.com/gvisor/pkg/fdnotifier" + "gvisor.googlesource.com/gvisor/pkg/log" "gvisor.googlesource.com/gvisor/pkg/sentry/context" "gvisor.googlesource.com/gvisor/pkg/sentry/fs" "gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil" @@ -519,6 +521,28 @@ func translateIOSyscallError(err error) error { return err } +// State implements socket.Socket.State. +func (s *socketOperations) State() uint32 { + info := linux.TCPInfo{} + buf, err := getsockopt(s.fd, syscall.SOL_TCP, syscall.TCP_INFO, linux.SizeOfTCPInfo) + if err != nil { + if err != syscall.ENOPROTOOPT { + log.Warningf("Failed to get TCP socket info from %+v: %v", s, err) + } + // For non-TCP sockets, silently ignore the failure. + return 0 + } + if len(buf) != linux.SizeOfTCPInfo { + // Unmarshal below will panic if getsockopt returns a buffer of + // unexpected size. + log.Warningf("Failed to get TCP socket info from %+v: getsockopt(2) returned %d bytes, expecting %d bytes.", s, len(buf), linux.SizeOfTCPInfo) + return 0 + } + + binary.Unmarshal(buf, usermem.ByteOrder, &info) + return uint32(info.State) +} + type socketProvider struct { family int } -- cgit v1.2.3