1 files changed, 412 insertions, 0 deletions
diff --git a/pkg/sentry/strace/socket.go b/pkg/sentry/strace/socket.go
new file mode 100644
index 000000000..dbe53b9a2
--- /dev/null
+++ b/pkg/sentry/strace/socket.go
@@ -0,0 +1,412 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package strace
+
+import (
+	"fmt"
+	"strings"
+
+	"gvisor.googlesource.com/gvisor/pkg/abi"
+	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
+	"gvisor.googlesource.com/gvisor/pkg/binary"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/socket/control"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/socket/epsocket"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/socket/netlink"
+	slinux "gvisor.googlesource.com/gvisor/pkg/sentry/syscalls/linux"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
+)
+
+// SocketFamily are the possible socket(2) families.
+var SocketFamily = abi.ValueSet{
+	linux.AF_UNSPEC:     "AF_UNSPEC",
+	linux.AF_UNIX:       "AF_UNIX",
+	linux.AF_INET:       "AF_INET",
+	linux.AF_AX25:       "AF_AX25",
+	linux.AF_IPX:        "AF_IPX",
+	linux.AF_APPLETALK:  "AF_APPLETALK",
+	linux.AF_NETROM:     "AF_NETROM",
+	linux.AF_BRIDGE:     "AF_BRIDGE",
+	linux.AF_ATMPVC:     "AF_ATMPVC",
+	linux.AF_X25:        "AF_X25",
+	linux.AF_INET6:      "AF_INET6",
+	linux.AF_ROSE:       "AF_ROSE",
+	linux.AF_DECnet:     "AF_DECnet",
+	linux.AF_NETBEUI:    "AF_NETBEUI",
+	linux.AF_SECURITY:   "AF_SECURITY",
+	linux.AF_KEY:        "AF_KEY",
+	linux.AF_NETLINK:    "AF_NETLINK",
+	linux.AF_PACKET:     "AF_PACKET",
+	linux.AF_ASH:        "AF_ASH",
+	linux.AF_ECONET:     "AF_ECONET",
+	linux.AF_ATMSVC:     "AF_ATMSVC",
+	linux.AF_RDS:        "AF_RDS",
+	linux.AF_SNA:        "AF_SNA",
+	linux.AF_IRDA:       "AF_IRDA",
+	linux.AF_PPPOX:      "AF_PPPOX",
+	linux.AF_WANPIPE:    "AF_WANPIPE",
+	linux.AF_LLC:        "AF_LLC",
+	linux.AF_IB:         "AF_IB",
+	linux.AF_MPLS:       "AF_MPLS",
+	linux.AF_CAN:        "AF_CAN",
+	linux.AF_TIPC:       "AF_TIPC",
+	linux.AF_BLUETOOTH:  "AF_BLUETOOTH",
+	linux.AF_IUCV:       "AF_IUCV",
+	linux.AF_RXRPC:      "AF_RXRPC",
+	linux.AF_ISDN:       "AF_ISDN",
+	linux.AF_PHONET:     "AF_PHONET",
+	linux.AF_IEEE802154: "AF_IEEE802154",
+	linux.AF_CAIF:       "AF_CAIF",
+	linux.AF_ALG:        "AF_ALG",
+	linux.AF_NFC:        "AF_NFC",
+	linux.AF_VSOCK:      "AF_VSOCK",
+}
+
+// SocketType are the possible socket(2) types.
+var SocketType = abi.ValueSet{
+	linux.SOCK_STREAM:    "SOCK_STREAM",
+	linux.SOCK_DGRAM:     "SOCK_DGRAM",
+	linux.SOCK_RAW:       "SOCK_RAW",
+	linux.SOCK_RDM:       "SOCK_RDM",
+	linux.SOCK_SEQPACKET: "SOCK_SEQPACKET",
+	linux.SOCK_DCCP:      "SOCK_DCCP",
+	linux.SOCK_PACKET:    "SOCK_PACKET",
+}
+
+// SocketFlagSet are the possible socket(2) flags.
+var SocketFlagSet = abi.FlagSet{
+	{
+		Flag: linux.SOCK_CLOEXEC,
+		Name: "SOCK_CLOEXEC",
+	},
+	{
+		Flag: linux.SOCK_NONBLOCK,
+		Name: "SOCK_NONBLOCK",
+	},
+}
+
+// ipProtocol are the possible socket(2) types for INET and INET6 sockets.
+var ipProtocol = abi.ValueSet{
+	linux.IPPROTO_IP:      "IPPROTO_IP",
+	linux.IPPROTO_ICMP:    "IPPROTO_ICMP",
+	linux.IPPROTO_IGMP:    "IPPROTO_IGMP",
+	linux.IPPROTO_IPIP:    "IPPROTO_IPIP",
+	linux.IPPROTO_TCP:     "IPPROTO_TCP",
+	linux.IPPROTO_EGP:     "IPPROTO_EGP",
+	linux.IPPROTO_PUP:     "IPPROTO_PUP",
+	linux.IPPROTO_UDP:     "IPPROTO_UDP",
+	linux.IPPROTO_IDP:     "IPPROTO_IDP",
+	linux.IPPROTO_TP:      "IPPROTO_TP",
+	linux.IPPROTO_DCCP:    "IPPROTO_DCCP",
+	linux.IPPROTO_IPV6:    "IPPROTO_IPV6",
+	linux.IPPROTO_RSVP:    "IPPROTO_RSVP",
+	linux.IPPROTO_GRE:     "IPPROTO_GRE",
+	linux.IPPROTO_ESP:     "IPPROTO_ESP",
+	linux.IPPROTO_AH:      "IPPROTO_AH",
+	linux.IPPROTO_MTP:     "IPPROTO_MTP",
+	linux.IPPROTO_BEETPH:  "IPPROTO_BEETPH",
+	linux.IPPROTO_ENCAP:   "IPPROTO_ENCAP",
+	linux.IPPROTO_PIM:     "IPPROTO_PIM",
+	linux.IPPROTO_COMP:    "IPPROTO_COMP",
+	linux.IPPROTO_SCTP:    "IPPROTO_SCTP",
+	linux.IPPROTO_UDPLITE: "IPPROTO_UDPLITE",
+	linux.IPPROTO_MPLS:    "IPPROTO_MPLS",
+	linux.IPPROTO_RAW:     "IPPROTO_RAW",
+}
+
+// SocketProtocol are the possible socket(2) protocols for each protocol family.
+var SocketProtocol = map[int32]abi.ValueSet{
+	linux.AF_INET:  ipProtocol,
+	linux.AF_INET6: ipProtocol,
+	linux.AF_NETLINK: {
+		linux.NETLINK_ROUTE:          "NETLINK_ROUTE",
+		linux.NETLINK_UNUSED:         "NETLINK_UNUSED",
+		linux.NETLINK_USERSOCK:       "NETLINK_USERSOCK",
+		linux.NETLINK_FIREWALL:       "NETLINK_FIREWALL",
+		linux.NETLINK_SOCK_DIAG:      "NETLINK_SOCK_DIAG",
+		linux.NETLINK_NFLOG:          "NETLINK_NFLOG",
+		linux.NETLINK_XFRM:           "NETLINK_XFRM",
+		linux.NETLINK_SELINUX:        "NETLINK_SELINUX",
+		linux.NETLINK_ISCSI:          "NETLINK_ISCSI",
+		linux.NETLINK_AUDIT:          "NETLINK_AUDIT",
+		linux.NETLINK_FIB_LOOKUP:     "NETLINK_FIB_LOOKUP",
+		linux.NETLINK_CONNECTOR:      "NETLINK_CONNECTOR",
+		linux.NETLINK_NETFILTER:      "NETLINK_NETFILTER",
+		linux.NETLINK_IP6_FW:         "NETLINK_IP6_FW",
+		linux.NETLINK_DNRTMSG:        "NETLINK_DNRTMSG",
+		linux.NETLINK_KOBJECT_UEVENT: "NETLINK_KOBJECT_UEVENT",
+		linux.NETLINK_GENERIC:        "NETLINK_GENERIC",
+		linux.NETLINK_SCSITRANSPORT:  "NETLINK_SCSITRANSPORT",
+		linux.NETLINK_ECRYPTFS:       "NETLINK_ECRYPTFS",
+		linux.NETLINK_RDMA:           "NETLINK_RDMA",
+		linux.NETLINK_CRYPTO:         "NETLINK_CRYPTO",
+	},
+}
+
+var controlMessageType = map[int32]string{
+	linux.SCM_RIGHTS:      "SCM_RIGHTS",
+	linux.SCM_CREDENTIALS: "SCM_CREDENTIALS",
+	linux.SO_TIMESTAMP:    "SO_TIMESTAMP",
+}
+
+func cmsghdr(t *kernel.Task, addr usermem.Addr, length uint64, maxBytes uint64) string {
+	if length > maxBytes {
+		return fmt.Sprintf("%#x (error decoding control: invalid length (%d))", addr, length)
+	}
+
+	buf := make([]byte, length)
+	if _, err := t.CopyIn(addr, &buf); err != nil {
+		return fmt.Sprintf("%#x (error decoding control: %v)", addr, err)
+	}
+
+	var strs []string
+
+	for i := 0; i < len(buf); {
+		if i+linux.SizeOfControlMessageHeader > len(buf) {
+			strs = append(strs, "{invalid control message (too short)}")
+			break
+		}
+
+		var h linux.ControlMessageHeader
+		binary.Unmarshal(buf[i:i+linux.SizeOfControlMessageHeader], usermem.ByteOrder, &h)
+
+		var skipData bool
+		level := "SOL_SOCKET"
+		if h.Level != linux.SOL_SOCKET {
+			skipData = true
+			level = fmt.Sprint(h.Level)
+		}
+
+		typ, ok := controlMessageType[h.Type]
+		if !ok {
+			skipData = true
+			typ = fmt.Sprint(h.Type)
+		}
+
+		if h.Length > uint64(len(buf)-i) {
+			strs = append(strs, fmt.Sprintf(
+				"{level=%s, type=%s, length=%d, content extends beyond buffer}",
+				level,
+				typ,
+				h.Length,
+			))
+			break
+		}
+
+		i += linux.SizeOfControlMessageHeader
+		width := t.Arch().Width()
+		length := int(h.Length) - linux.SizeOfControlMessageHeader
+
+		if skipData {
+			strs = append(strs, fmt.Sprintf("{level=%s, type=%s, length=%d}", level, typ, h.Length))
+			i += control.AlignUp(length, width)
+			continue
+		}
+
+		switch h.Type {
+		case linux.SCM_RIGHTS:
+			rightsSize := control.AlignDown(length, linux.SizeOfControlMessageRight)
+
+			numRights := rightsSize / linux.SizeOfControlMessageRight
+			fds := make(linux.ControlMessageRights, numRights)
+			binary.Unmarshal(buf[i:i+rightsSize], usermem.ByteOrder, &fds)
+
+			rights := make([]string, 0, len(fds))
+			for _, fd := range fds {
+				rights = append(rights, fmt.Sprint(fd))
+			}
+
+			strs = append(strs, fmt.Sprintf(
+				"{level=%s, type=%s, length=%d, content: %s}",
+				level,
+				typ,
+				h.Length,
+				strings.Join(rights, ","),
+			))
+
+		case linux.SCM_CREDENTIALS:
+			if length < linux.SizeOfControlMessageCredentials {
+				strs = append(strs, fmt.Sprintf(
+					"{level=%s, type=%s, length=%d, content too short}",
+					level,
+					typ,
+					h.Length,
+				))
+				break
+			}
+
+			var creds linux.ControlMessageCredentials
+			binary.Unmarshal(buf[i:i+linux.SizeOfControlMessageCredentials], usermem.ByteOrder, &creds)
+
+			strs = append(strs, fmt.Sprintf(
+				"{level=%s, type=%s, length=%d, pid: %d, uid: %d, gid: %d}",
+				level,
+				typ,
+				h.Length,
+				creds.PID,
+				creds.UID,
+				creds.GID,
+			))
+
+		case linux.SO_TIMESTAMP:
+			if length < linux.SizeOfTimeval {
+				strs = append(strs, fmt.Sprintf(
+					"{level=%s, type=%s, length=%d, content too short}",
+					level,
+					typ,
+					h.Length,
+				))
+				break
+			}
+
+			var tv linux.Timeval
+			binary.Unmarshal(buf[i:i+linux.SizeOfTimeval], usermem.ByteOrder, &tv)
+
+			strs = append(strs, fmt.Sprintf(
+				"{level=%s, type=%s, length=%d, Sec: %d, Usec: %d}",
+				level,
+				typ,
+				h.Length,
+				tv.Sec,
+				tv.Usec,
+			))
+
+		default:
+			panic("unreachable")
+		}
+		i += control.AlignUp(length, width)
+	}
+
+	return fmt.Sprintf("%#x %s", addr, strings.Join(strs, ", "))
+}
+
+func msghdr(t *kernel.Task, addr usermem.Addr, printContent bool, maxBytes uint64) string {
+	var msg slinux.MessageHeader64
+	if err := slinux.CopyInMessageHeader64(t, addr, &msg); err != nil {
+		return fmt.Sprintf("%#x (error decoding msghdr: %v)", addr, err)
+	}
+	s := fmt.Sprintf(
+		"%#x {name=%#x, namelen=%d, iovecs=%s",
+		addr,
+		msg.Name,
+		msg.NameLen,
+		iovecs(t, usermem.Addr(msg.Iov), int(msg.IovLen), printContent, maxBytes),
+	)
+	if printContent {
+		s = fmt.Sprintf("%s, control={%s}", s, cmsghdr(t, usermem.Addr(msg.Control), msg.ControlLen, maxBytes))
+	} else {
+		s = fmt.Sprintf("%s, control=%#x, control_len=%d", s, msg.Control, msg.ControlLen)
+	}
+	return fmt.Sprintf("%s, flags=%d}", s, msg.Flags)
+}
+
+func sockAddr(t *kernel.Task, addr usermem.Addr, length uint32) string {
+	if addr == 0 {
+		return "null"
+	}
+
+	b, err := slinux.CaptureAddress(t, addr, length)
+	if err != nil {
+		return fmt.Sprintf("%#x {error reading address: %v}", addr, err)
+	}
+
+	// Extract address family.
+	if len(b) < 2 {
+		return fmt.Sprintf("%#x {address too short: %d bytes}", addr, len(b))
+	}
+	family := usermem.ByteOrder.Uint16(b)
+
+	familyStr := SocketFamily.Parse(uint64(family))
+
+	switch family {
+	case linux.AF_INET, linux.AF_INET6, linux.AF_UNIX:
+		fa, err := epsocket.GetAddress(int(family), b)
+		if err != nil {
+			return fmt.Sprintf("%#x {Family: %s, error extracting address: %v}", addr, familyStr, err)
+		}
+
+		if family == linux.AF_UNIX {
+			return fmt.Sprintf("%#x {Family: %s, Addr: %q}", addr, familyStr, string(fa.Addr))
+		}
+
+		return fmt.Sprintf("%#x {Family: %s, Addr: %v, Port: %d}", addr, familyStr, fa.Addr, fa.Port)
+	case linux.AF_NETLINK:
+		sa, err := netlink.ExtractSockAddr(b)
+		if err != nil {
+			return fmt.Sprintf("%#x {Family: %s, error extracting address: %v}", addr, familyStr, err)
+		}
+		return fmt.Sprintf("%#x {Family: %s, PortID: %d, Groups: %d}", addr, familyStr, sa.PortID, sa.Groups)
+	default:
+		return fmt.Sprintf("%#x {Family: %s, family addr format unknown}", addr, familyStr)
+	}
+}
+
+func postSockAddr(t *kernel.Task, addr usermem.Addr, lengthPtr usermem.Addr) string {
+	if addr == 0 {
+		return "null"
+	}
+
+	if lengthPtr == 0 {
+		return fmt.Sprintf("%#x {length null}", addr)
+	}
+
+	l, err := copySockLen(t, lengthPtr)
+	if err != nil {
+		return fmt.Sprintf("%#x {error reading length: %v}", addr, err)
+	}
+
+	return sockAddr(t, addr, l)
+}
+
+func copySockLen(t *kernel.Task, addr usermem.Addr) (uint32, error) {
+	// socklen_t is 32-bits.
+	var l uint32
+	_, err := t.CopyIn(addr, &l)
+	return l, err
+}
+
+func sockLenPointer(t *kernel.Task, addr usermem.Addr) string {
+	if addr == 0 {
+		return "null"
+	}
+	l, err := copySockLen(t, addr)
+	if err != nil {
+		return fmt.Sprintf("%#x {error reading length: %v}", addr, err)
+	}
+	return fmt.Sprintf("%#x {length=%v}", addr, l)
+}
+
+func sockType(stype int32) string {
+	s := SocketType.Parse(uint64(stype & linux.SOCK_TYPE_MASK))
+	if flags := SocketFlagSet.Parse(uint64(stype &^ linux.SOCK_TYPE_MASK)); flags != "" {
+		s += "|" + flags
+	}
+	return s
+}
+
+func sockProtocol(family, protocol int32) string {
+	protocols, ok := SocketProtocol[family]
+	if !ok {
+		return fmt.Sprintf("%#x", protocol)
+	}
+	return protocols.Parse(uint64(protocol))
+}
+
+func sockFlags(flags int32) string {
+	if flags == 0 {
+		return "0"
+	}
+	return SocketFlagSet.Parse(uint64(flags))
+}