diff options
Diffstat (limited to 'pkg/sentry/fs/proc/net.go')
| -rw-r--r-- | pkg/sentry/fs/proc/net.go | 169 |
1 files changed, 157 insertions, 12 deletions
diff --git a/pkg/sentry/fs/proc/net.go b/pkg/sentry/fs/proc/net.go index caa1a5c4d..37694620c 100644 --- a/pkg/sentry/fs/proc/net.go +++ b/pkg/sentry/fs/proc/net.go @@ -20,6 +20,7 @@ import ( "time" "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/binary" "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/sentry/context" "gvisor.dev/gvisor/pkg/sentry/fs" @@ -55,9 +56,8 @@ func (p *proc) newNetDir(ctx context.Context, k *kernel.Kernel, msrc *fs.MountSo "psched": newStaticProcInode(ctx, msrc, []byte(fmt.Sprintf("%08x %08x %08x %08x\n", uint64(time.Microsecond/time.Nanosecond), 64, 1000000, uint64(time.Second/time.Nanosecond)))), "ptype": newStaticProcInode(ctx, msrc, []byte("Type Device Function")), "route": newStaticProcInode(ctx, msrc, []byte("Iface Destination Gateway Flags RefCnt Use Metric Mask MTU Window IRTT")), - "tcp": newStaticProcInode(ctx, msrc, []byte(" sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode")), - - "udp": newStaticProcInode(ctx, msrc, []byte(" sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode ref pointer drops")), + "tcp": seqfile.NewSeqFileInode(ctx, &netTCP{k: k}, msrc), + "udp": newStaticProcInode(ctx, msrc, []byte(" sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode ref pointer drops")), "unix": seqfile.NewSeqFileInode(ctx, &netUnix{k: k}, msrc), } @@ -210,10 +210,6 @@ func (n *netUnix) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]s } var buf bytes.Buffer - // Header - fmt.Fprintf(&buf, "Num RefCount Protocol Flags Type St Inode Path\n") - - // Entries for _, se := range n.k.ListSockets() { s := se.Sock.Get() if s == nil { @@ -222,6 +218,7 @@ func (n *netUnix) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]s } sfile := s.(*fs.File) if family, _, _ := sfile.FileOperations.(socket.Socket).Type(); family != linux.AF_UNIX { + s.DecRef() // Not a unix socket. continue } @@ -281,12 +278,160 @@ func (n *netUnix) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]s } fmt.Fprintf(&buf, "\n") - sfile.DecRef() + s.DecRef() + } + + data := []seqfile.SeqData{ + { + Buf: []byte("Num RefCount Protocol Flags Type St Inode Path\n"), + Handle: n, + }, + { + Buf: buf.Bytes(), + Handle: n, + }, + } + return data, 0 +} + +// netTCP implements seqfile.SeqSource for /proc/net/tcp. +// +// +stateify savable +type netTCP struct { + k *kernel.Kernel +} + +// NeedsUpdate implements seqfile.SeqSource.NeedsUpdate. +func (*netTCP) NeedsUpdate(generation int64) bool { + return true +} + +// ReadSeqFileData implements seqfile.SeqSource.ReadSeqFileData. +func (n *netTCP) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) { + t := kernel.TaskFromContext(ctx) + + if h != nil { + return nil, 0 + } + + var buf bytes.Buffer + for _, se := range n.k.ListSockets() { + s := se.Sock.Get() + if s == nil { + log.Debugf("Couldn't resolve weakref %+v in socket table, racing with destruction?", se.Sock) + continue + } + sfile := s.(*fs.File) + sops, ok := sfile.FileOperations.(socket.Socket) + if !ok { + panic(fmt.Sprintf("Found non-socket file in socket table: %+v", sfile)) + } + if family, stype, _ := sops.Type(); !(family == linux.AF_INET && stype == linux.SOCK_STREAM) { + s.DecRef() + // Not tcp4 sockets. + continue + } + + // Linux's documentation for the fields below can be found at + // https://www.kernel.org/doc/Documentation/networking/proc_net_tcp.txt. + // For Linux's implementation, see net/ipv4/tcp_ipv4.c:get_tcp4_sock(). + // Note that the header doesn't contain labels for all the fields. + + // Field: sl; entry number. + fmt.Fprintf(&buf, "%4d: ", se.ID) + + portBuf := make([]byte, 2) + + // Field: local_adddress. + var localAddr linux.SockAddrInet + if local, _, err := sops.GetSockName(t); err == nil { + localAddr = local.(linux.SockAddrInet) + } + binary.LittleEndian.PutUint16(portBuf, localAddr.Port) + fmt.Fprintf(&buf, "%08X:%04X ", + binary.LittleEndian.Uint32(localAddr.Addr[:]), + portBuf) + + // Field: rem_address. + var remoteAddr linux.SockAddrInet + if remote, _, err := sops.GetPeerName(t); err == nil { + remoteAddr = remote.(linux.SockAddrInet) + } + binary.LittleEndian.PutUint16(portBuf, remoteAddr.Port) + fmt.Fprintf(&buf, "%08X:%04X ", + binary.LittleEndian.Uint32(remoteAddr.Addr[:]), + portBuf) + + // Field: state; socket state. + fmt.Fprintf(&buf, "%02X ", sops.State()) + + // Field: tx_queue, rx_queue; number of packets in the transmit and + // receive queue. Unimplemented. + fmt.Fprintf(&buf, "%08X:%08X ", 0, 0) + + // Field: tr, tm->when; timer active state and number of jiffies + // until timer expires. Unimplemented. + fmt.Fprintf(&buf, "%02X:%08X ", 0, 0) + + // Field: retrnsmt; number of unrecovered RTO timeouts. + // Unimplemented. + fmt.Fprintf(&buf, "%08X ", 0) + + // Field: uid. + uattr, err := sfile.Dirent.Inode.UnstableAttr(ctx) + if err != nil { + log.Warningf("Failed to retrieve unstable attr for socket file: %v", err) + fmt.Fprintf(&buf, "%5d ", 0) + } else { + fmt.Fprintf(&buf, "%5d ", uint32(uattr.Owner.UID.In(t.UserNamespace()).OrOverflow())) + } + + // Field: timeout; number of unanswered 0-window probes. + // Unimplemented. + fmt.Fprintf(&buf, "%8d ", 0) + + // Field: inode. + fmt.Fprintf(&buf, "%8d ", sfile.InodeID()) + + // Field: refcount. Don't count the ref we obtain while deferencing + // the weakref to this socket. + fmt.Fprintf(&buf, "%d ", sfile.ReadRefs()-1) + + // Field: Socket struct address. Redacted due to the same reason as + // the 'Num' field in /proc/net/unix, see netUnix.ReadSeqFileData. + fmt.Fprintf(&buf, "%#016p ", (*socket.Socket)(nil)) + + // Field: retransmit timeout. Unimplemented. + fmt.Fprintf(&buf, "%d ", 0) + + // Field: predicted tick of soft clock (delayed ACK control data). + // Unimplemented. + fmt.Fprintf(&buf, "%d ", 0) + + // Field: (ack.quick<<1)|ack.pingpong, Unimplemented. + fmt.Fprintf(&buf, "%d ", 0) + + // Field: sending congestion window, Unimplemented. + fmt.Fprintf(&buf, "%d ", 0) + + // Field: Slow start size threshold, -1 if threshold >= 0xFFFF. + // Unimplemented, report as large threshold. + fmt.Fprintf(&buf, "%d", -1) + + fmt.Fprintf(&buf, "\n") + + s.DecRef() } - data := []seqfile.SeqData{{ - Buf: buf.Bytes(), - Handle: (*netUnix)(nil), - }} + data := []seqfile.SeqData{ + { + Buf: []byte(" sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode \n"), + Handle: n, + }, + { + Buf: buf.Bytes(), + Handle: n, + }, + } return data, 0 } |