Merge release-20190806.1-244-g6a98237 (automated)

1 files changed, 2637 insertions, 0 deletions

diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go
new file mode 100755
index 000000000..48f5c6f30
--- /dev/null
+++ b/pkg/sentry/socket/netstack/netstack.go
@@ -0,0 +1,2637 @@
+// 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 netstack provides an implementation of the socket.Socket interface
+// that is backed by a tcpip.Endpoint.
+//
+// It does not depend on any particular endpoint implementation, and thus can
+// be used to expose certain endpoints to the sentry while leaving others out,
+// for example, TCP endpoints and Unix-domain endpoints.
+//
+// Lock ordering: netstack => mm: ioSequencePayload copies user memory inside
+// tcpip.Endpoint.Write(). Netstack is allowed to (and does) hold locks during
+// this operation.
+package netstack
+
+import (
+	"bytes"
+	"io"
+	"math"
+	"reflect"
+	"sync"
+	"syscall"
+	"time"
+
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/binary"
+	"gvisor.dev/gvisor/pkg/log"
+	"gvisor.dev/gvisor/pkg/metric"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
+	"gvisor.dev/gvisor/pkg/sentry/context"
+	"gvisor.dev/gvisor/pkg/sentry/fs"
+	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
+	"gvisor.dev/gvisor/pkg/sentry/inet"
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
+	"gvisor.dev/gvisor/pkg/sentry/safemem"
+	"gvisor.dev/gvisor/pkg/sentry/socket"
+	"gvisor.dev/gvisor/pkg/sentry/socket/netfilter"
+	"gvisor.dev/gvisor/pkg/sentry/unimpl"
+	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/syserr"
+	"gvisor.dev/gvisor/pkg/syserror"
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/buffer"
+	"gvisor.dev/gvisor/pkg/tcpip/stack"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
+	"gvisor.dev/gvisor/pkg/waiter"
+)
+
+func mustCreateMetric(name, description string) *tcpip.StatCounter {
+	var cm tcpip.StatCounter
+	metric.MustRegisterCustomUint64Metric(name, false /* sync */, description, cm.Value)
+	return &cm
+}
+
+// Metrics contains metrics exported by netstack.
+var Metrics = tcpip.Stats{
+	UnknownProtocolRcvdPackets: mustCreateMetric("/netstack/unknown_protocol_received_packets", "Number of packets received by netstack that were for an unknown or unsupported protocol."),
+	MalformedRcvdPackets:       mustCreateMetric("/netstack/malformed_received_packets", "Number of packets received by netstack that were deemed malformed."),
+	DroppedPackets:             mustCreateMetric("/netstack/dropped_packets", "Number of packets dropped by netstack due to full queues."),
+	ICMP: tcpip.ICMPStats{
+		V4PacketsSent: tcpip.ICMPv4SentPacketStats{
+			ICMPv4PacketStats: tcpip.ICMPv4PacketStats{
+				Echo:           mustCreateMetric("/netstack/icmp/v4/packets_sent/echo", "Total number of ICMPv4 echo packets sent by netstack."),
+				EchoReply:      mustCreateMetric("/netstack/icmp/v4/packets_sent/echo_reply", "Total number of ICMPv4 echo reply packets sent by netstack."),
+				DstUnreachable: mustCreateMetric("/netstack/icmp/v4/packets_sent/dst_unreachable", "Total number of ICMPv4 destination unreachable packets sent by netstack."),
+				SrcQuench:      mustCreateMetric("/netstack/icmp/v4/packets_sent/src_quench", "Total number of ICMPv4 source quench packets sent by netstack."),
+				Redirect:       mustCreateMetric("/netstack/icmp/v4/packets_sent/redirect", "Total number of ICMPv4 redirect packets sent by netstack."),
+				TimeExceeded:   mustCreateMetric("/netstack/icmp/v4/packets_sent/time_exceeded", "Total number of ICMPv4 time exceeded packets sent by netstack."),
+				ParamProblem:   mustCreateMetric("/netstack/icmp/v4/packets_sent/param_problem", "Total number of ICMPv4 parameter problem packets sent by netstack."),
+				Timestamp:      mustCreateMetric("/netstack/icmp/v4/packets_sent/timestamp", "Total number of ICMPv4 timestamp packets sent by netstack."),
+				TimestampReply: mustCreateMetric("/netstack/icmp/v4/packets_sent/timestamp_reply", "Total number of ICMPv4 timestamp reply packets sent by netstack."),
+				InfoRequest:    mustCreateMetric("/netstack/icmp/v4/packets_sent/info_request", "Total number of ICMPv4 information request packets sent by netstack."),
+				InfoReply:      mustCreateMetric("/netstack/icmp/v4/packets_sent/info_reply", "Total number of ICMPv4 information reply packets sent by netstack."),
+			},
+			Dropped: mustCreateMetric("/netstack/icmp/v4/packets_sent/dropped", "Total number of ICMPv4 packets dropped by netstack due to link layer errors."),
+		},
+		V4PacketsReceived: tcpip.ICMPv4ReceivedPacketStats{
+			ICMPv4PacketStats: tcpip.ICMPv4PacketStats{
+				Echo:           mustCreateMetric("/netstack/icmp/v4/packets_received/echo", "Total number of ICMPv4 echo packets received by netstack."),
+				EchoReply:      mustCreateMetric("/netstack/icmp/v4/packets_received/echo_reply", "Total number of ICMPv4 echo reply packets received by netstack."),
+				DstUnreachable: mustCreateMetric("/netstack/icmp/v4/packets_received/dst_unreachable", "Total number of ICMPv4 destination unreachable packets received by netstack."),
+				SrcQuench:      mustCreateMetric("/netstack/icmp/v4/packets_received/src_quench", "Total number of ICMPv4 source quench packets received by netstack."),
+				Redirect:       mustCreateMetric("/netstack/icmp/v4/packets_received/redirect", "Total number of ICMPv4 redirect packets received by netstack."),
+				TimeExceeded:   mustCreateMetric("/netstack/icmp/v4/packets_received/time_exceeded", "Total number of ICMPv4 time exceeded packets received by netstack."),
+				ParamProblem:   mustCreateMetric("/netstack/icmp/v4/packets_received/param_problem", "Total number of ICMPv4 parameter problem packets received by netstack."),
+				Timestamp:      mustCreateMetric("/netstack/icmp/v4/packets_received/timestamp", "Total number of ICMPv4 timestamp packets received by netstack."),
+				TimestampReply: mustCreateMetric("/netstack/icmp/v4/packets_received/timestamp_reply", "Total number of ICMPv4 timestamp reply packets received by netstack."),
+				InfoRequest:    mustCreateMetric("/netstack/icmp/v4/packets_received/info_request", "Total number of ICMPv4 information request packets received by netstack."),
+				InfoReply:      mustCreateMetric("/netstack/icmp/v4/packets_received/info_reply", "Total number of ICMPv4 information reply packets received by netstack."),
+			},
+			Invalid: mustCreateMetric("/netstack/icmp/v4/packets_received/invalid", "Total number of ICMPv4 packets received that the transport layer could not parse."),
+		},
+		V6PacketsSent: tcpip.ICMPv6SentPacketStats{
+			ICMPv6PacketStats: tcpip.ICMPv6PacketStats{
+				EchoRequest:     mustCreateMetric("/netstack/icmp/v6/packets_sent/echo_request", "Total number of ICMPv6 echo request packets sent by netstack."),
+				EchoReply:       mustCreateMetric("/netstack/icmp/v6/packets_sent/echo_reply", "Total number of ICMPv6 echo reply packets sent by netstack."),
+				DstUnreachable:  mustCreateMetric("/netstack/icmp/v6/packets_sent/dst_unreachable", "Total number of ICMPv6 destination unreachable packets sent by netstack."),
+				PacketTooBig:    mustCreateMetric("/netstack/icmp/v6/packets_sent/packet_too_big", "Total number of ICMPv6 packet too big packets sent by netstack."),
+				TimeExceeded:    mustCreateMetric("/netstack/icmp/v6/packets_sent/time_exceeded", "Total number of ICMPv6 time exceeded packets sent by netstack."),
+				ParamProblem:    mustCreateMetric("/netstack/icmp/v6/packets_sent/param_problem", "Total number of ICMPv6 parameter problem packets sent by netstack."),
+				RouterSolicit:   mustCreateMetric("/netstack/icmp/v6/packets_sent/router_solicit", "Total number of ICMPv6 router solicit packets sent by netstack."),
+				RouterAdvert:    mustCreateMetric("/netstack/icmp/v6/packets_sent/router_advert", "Total number of ICMPv6 router advert packets sent by netstack."),
+				NeighborSolicit: mustCreateMetric("/netstack/icmp/v6/packets_sent/neighbor_solicit", "Total number of ICMPv6 neighbor solicit packets sent by netstack."),
+				NeighborAdvert:  mustCreateMetric("/netstack/icmp/v6/packets_sent/neighbor_advert", "Total number of ICMPv6 neighbor advert packets sent by netstack."),
+				RedirectMsg:     mustCreateMetric("/netstack/icmp/v6/packets_sent/redirect_msg", "Total number of ICMPv6 redirect message packets sent by netstack."),
+			},
+			Dropped: mustCreateMetric("/netstack/icmp/v6/packets_sent/dropped", "Total number of ICMPv6 packets dropped by netstack due to link layer errors."),
+		},
+		V6PacketsReceived: tcpip.ICMPv6ReceivedPacketStats{
+			ICMPv6PacketStats: tcpip.ICMPv6PacketStats{
+				EchoRequest:     mustCreateMetric("/netstack/icmp/v6/packets_received/echo_request", "Total number of ICMPv6 echo request packets received by netstack."),
+				EchoReply:       mustCreateMetric("/netstack/icmp/v6/packets_received/echo_reply", "Total number of ICMPv6 echo reply packets received by netstack."),
+				DstUnreachable:  mustCreateMetric("/netstack/icmp/v6/packets_received/dst_unreachable", "Total number of ICMPv6 destination unreachable packets received by netstack."),
+				PacketTooBig:    mustCreateMetric("/netstack/icmp/v6/packets_received/packet_too_big", "Total number of ICMPv6 packet too big packets received by netstack."),
+				TimeExceeded:    mustCreateMetric("/netstack/icmp/v6/packets_received/time_exceeded", "Total number of ICMPv6 time exceeded packets received by netstack."),
+				ParamProblem:    mustCreateMetric("/netstack/icmp/v6/packets_received/param_problem", "Total number of ICMPv6 parameter problem packets received by netstack."),
+				RouterSolicit:   mustCreateMetric("/netstack/icmp/v6/packets_received/router_solicit", "Total number of ICMPv6 router solicit packets received by netstack."),
+				RouterAdvert:    mustCreateMetric("/netstack/icmp/v6/packets_received/router_advert", "Total number of ICMPv6 router advert packets received by netstack."),
+				NeighborSolicit: mustCreateMetric("/netstack/icmp/v6/packets_received/neighbor_solicit", "Total number of ICMPv6 neighbor solicit packets received by netstack."),
+				NeighborAdvert:  mustCreateMetric("/netstack/icmp/v6/packets_received/neighbor_advert", "Total number of ICMPv6 neighbor advert packets received by netstack."),
+				RedirectMsg:     mustCreateMetric("/netstack/icmp/v6/packets_received/redirect_msg", "Total number of ICMPv6 redirect message packets received by netstack."),
+			},
+			Invalid: mustCreateMetric("/netstack/icmp/v6/packets_received/invalid", "Total number of ICMPv6 packets received that the transport layer could not parse."),
+		},
+	},
+	IP: tcpip.IPStats{
+		PacketsReceived:          mustCreateMetric("/netstack/ip/packets_received", "Total number of IP packets received from the link layer in nic.DeliverNetworkPacket."),
+		InvalidAddressesReceived: mustCreateMetric("/netstack/ip/invalid_addresses_received", "Total number of IP packets received with an unknown or invalid destination address."),
+		PacketsDelivered:         mustCreateMetric("/netstack/ip/packets_delivered", "Total number of incoming IP packets that are successfully delivered to the transport layer via HandlePacket."),
+		PacketsSent:              mustCreateMetric("/netstack/ip/packets_sent", "Total number of IP packets sent via WritePacket."),
+		OutgoingPacketErrors:     mustCreateMetric("/netstack/ip/outgoing_packet_errors", "Total number of IP packets which failed to write to a link-layer endpoint."),
+	},
+	TCP: tcpip.TCPStats{
+		ActiveConnectionOpenings:           mustCreateMetric("/netstack/tcp/active_connection_openings", "Number of connections opened successfully via Connect."),
+		PassiveConnectionOpenings:          mustCreateMetric("/netstack/tcp/passive_connection_openings", "Number of connections opened successfully via Listen."),
+		ListenOverflowSynDrop:              mustCreateMetric("/netstack/tcp/listen_overflow_syn_drop", "Number of times the listen queue overflowed and a SYN was dropped."),
+		ListenOverflowAckDrop:              mustCreateMetric("/netstack/tcp/listen_overflow_ack_drop", "Number of times the listen queue overflowed and the final ACK in the handshake was dropped."),
+		ListenOverflowSynCookieSent:        mustCreateMetric("/netstack/tcp/listen_overflow_syn_cookie_sent", "Number of times a SYN cookie was sent."),
+		ListenOverflowSynCookieRcvd:        mustCreateMetric("/netstack/tcp/listen_overflow_syn_cookie_rcvd", "Number of times a SYN cookie was received."),
+		ListenOverflowInvalidSynCookieRcvd: mustCreateMetric("/netstack/tcp/listen_overflow_invalid_syn_cookie_rcvd", "Number of times an invalid SYN cookie was received."),
+		FailedConnectionAttempts:           mustCreateMetric("/netstack/tcp/failed_connection_attempts", "Number of calls to Connect or Listen (active and passive openings, respectively) that end in an error."),
+		ValidSegmentsReceived:              mustCreateMetric("/netstack/tcp/valid_segments_received", "Number of TCP segments received that the transport layer successfully parsed."),
+		InvalidSegmentsReceived:            mustCreateMetric("/netstack/tcp/invalid_segments_received", "Number of TCP segments received that the transport layer could not parse."),
+		SegmentsSent:                       mustCreateMetric("/netstack/tcp/segments_sent", "Number of TCP segments sent."),
+		ResetsSent:                         mustCreateMetric("/netstack/tcp/resets_sent", "Number of TCP resets sent."),
+		ResetsReceived:                     mustCreateMetric("/netstack/tcp/resets_received", "Number of TCP resets received."),
+		Retransmits:                        mustCreateMetric("/netstack/tcp/retransmits", "Number of TCP segments retransmitted."),
+		FastRecovery:                       mustCreateMetric("/netstack/tcp/fast_recovery", "Number of times fast recovery was used to recover from packet loss."),
+		SACKRecovery:                       mustCreateMetric("/netstack/tcp/sack_recovery", "Number of times SACK recovery was used to recover from packet loss."),
+		SlowStartRetransmits:               mustCreateMetric("/netstack/tcp/slow_start_retransmits", "Number of segments retransmitted in slow start mode."),
+		FastRetransmit:                     mustCreateMetric("/netstack/tcp/fast_retransmit", "Number of TCP segments which were fast retransmitted."),
+		Timeouts:                           mustCreateMetric("/netstack/tcp/timeouts", "Number of times RTO expired."),
+		ChecksumErrors:                     mustCreateMetric("/netstack/tcp/checksum_errors", "Number of segments dropped due to bad checksums."),
+	},
+	UDP: tcpip.UDPStats{
+		PacketsReceived:          mustCreateMetric("/netstack/udp/packets_received", "Number of UDP datagrams received via HandlePacket."),
+		UnknownPortErrors:        mustCreateMetric("/netstack/udp/unknown_port_errors", "Number of incoming UDP datagrams dropped because they did not have a known destination port."),
+		ReceiveBufferErrors:      mustCreateMetric("/netstack/udp/receive_buffer_errors", "Number of incoming UDP datagrams dropped due to the receiving buffer being in an invalid state."),
+		MalformedPacketsReceived: mustCreateMetric("/netstack/udp/malformed_packets_received", "Number of incoming UDP datagrams dropped due to the UDP header being in a malformed state."),
+		PacketsSent:              mustCreateMetric("/netstack/udp/packets_sent", "Number of UDP datagrams sent via sendUDP."),
+	},
+}
+
+const sizeOfInt32 int = 4
+
+var errStackType = syserr.New("expected but did not receive a netstack.Stack", linux.EINVAL)
+
+// ntohs converts a 16-bit number from network byte order to host byte order. It
+// assumes that the host is little endian.
+func ntohs(v uint16) uint16 {
+	return v<<8 | v>>8
+}
+
+// htons converts a 16-bit number from host byte order to network byte order. It
+// assumes that the host is little endian.
+func htons(v uint16) uint16 {
+	return ntohs(v)
+}
+
+// commonEndpoint represents the intersection of a tcpip.Endpoint and a
+// transport.Endpoint.
+type commonEndpoint interface {
+	// GetLocalAddress implements tcpip.Endpoint.GetLocalAddress and
+	// transport.Endpoint.GetLocalAddress.
+	GetLocalAddress() (tcpip.FullAddress, *tcpip.Error)
+
+	// GetRemoteAddress implements tcpip.Endpoint.GetRemoteAddress and
+	// transport.Endpoint.GetRemoteAddress.
+	GetRemoteAddress() (tcpip.FullAddress, *tcpip.Error)
+
+	// Readiness implements tcpip.Endpoint.Readiness and
+	// transport.Endpoint.Readiness.
+	Readiness(mask waiter.EventMask) waiter.EventMask
+
+	// SetSockOpt implements tcpip.Endpoint.SetSockOpt and
+	// transport.Endpoint.SetSockOpt.
+	SetSockOpt(interface{}) *tcpip.Error
+
+	// SetSockOptInt implements tcpip.Endpoint.SetSockOptInt and
+	// transport.Endpoint.SetSockOptInt.
+	SetSockOptInt(opt tcpip.SockOpt, v int) *tcpip.Error
+
+	// GetSockOpt implements tcpip.Endpoint.GetSockOpt and
+	// transport.Endpoint.GetSockOpt.
+	GetSockOpt(interface{}) *tcpip.Error
+
+	// GetSockOptInt implements tcpip.Endpoint.GetSockOptInt and
+	// transport.Endpoint.GetSockOpt.
+	GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error)
+}
+
+// SocketOperations encapsulates all the state needed to represent a network stack
+// endpoint in the kernel context.
+//
+// +stateify savable
+type SocketOperations struct {
+	fsutil.FilePipeSeek             `state:"nosave"`
+	fsutil.FileNotDirReaddir        `state:"nosave"`
+	fsutil.FileNoopFlush            `state:"nosave"`
+	fsutil.FileNoFsync              `state:"nosave"`
+	fsutil.FileNoMMap               `state:"nosave"`
+	fsutil.FileUseInodeUnstableAttr `state:"nosave"`
+	socket.SendReceiveTimeout
+	*waiter.Queue
+
+	family   int
+	Endpoint tcpip.Endpoint
+	skType   linux.SockType
+	protocol int
+
+	// readMu protects access to the below fields.
+	readMu sync.Mutex `state:"nosave"`
+	// readView contains the remaining payload from the last packet.
+	readView buffer.View
+	// readCM holds control message information for the last packet read
+	// from Endpoint.
+	readCM tcpip.ControlMessages
+	sender tcpip.FullAddress
+
+	// sockOptTimestamp corresponds to SO_TIMESTAMP. When true, timestamps
+	// of returned messages can be returned via control messages. When
+	// false, the same timestamp is instead stored and can be read via the
+	// SIOCGSTAMP ioctl. It is protected by readMu. See socket(7).
+	sockOptTimestamp bool
+	// timestampValid indicates whether timestamp for SIOCGSTAMP has been
+	// set. It is protected by readMu.
+	timestampValid bool
+	// timestampNS holds the timestamp to use with SIOCTSTAMP. It is only
+	// valid when timestampValid is true. It is protected by readMu.
+	timestampNS int64
+
+	// sockOptInq corresponds to TCP_INQ. It is implemented at this level
+	// because it takes into account data from readView.
+	sockOptInq bool
+}
+
+// New creates a new endpoint socket.
+func New(t *kernel.Task, family int, skType linux.SockType, protocol int, queue *waiter.Queue, endpoint tcpip.Endpoint) (*fs.File, *syserr.Error) {
+	if skType == linux.SOCK_STREAM {
+		if err := endpoint.SetSockOpt(tcpip.DelayOption(1)); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+	}
+
+	dirent := socket.NewDirent(t, netstackDevice)
+	defer dirent.DecRef()
+	return fs.NewFile(t, dirent, fs.FileFlags{Read: true, Write: true, NonSeekable: true}, &SocketOperations{
+		Queue:    queue,
+		family:   family,
+		Endpoint: endpoint,
+		skType:   skType,
+		protocol: protocol,
+	}), nil
+}
+
+var sockAddrInetSize = int(binary.Size(linux.SockAddrInet{}))
+var sockAddrInet6Size = int(binary.Size(linux.SockAddrInet6{}))
+
+// bytesToIPAddress converts an IPv4 or IPv6 address from the user to the
+// netstack representation taking any addresses into account.
+func bytesToIPAddress(addr []byte) tcpip.Address {
+	if bytes.Equal(addr, make([]byte, 4)) || bytes.Equal(addr, make([]byte, 16)) {
+		return ""
+	}
+	return tcpip.Address(addr)
+}
+
+// AddressAndFamily reads an sockaddr struct from the given address and
+// converts it to the FullAddress format. It supports AF_UNIX, AF_INET and
+// AF_INET6 addresses.
+//
+// strict indicates whether addresses with the AF_UNSPEC family are accepted of not.
+//
+// AddressAndFamily returns an address, its family.
+func AddressAndFamily(sfamily int, addr []byte, strict bool) (tcpip.FullAddress, uint16, *syserr.Error) {
+	// Make sure we have at least 2 bytes for the address family.
+	if len(addr) < 2 {
+		return tcpip.FullAddress{}, 0, syserr.ErrInvalidArgument
+	}
+
+	family := usermem.ByteOrder.Uint16(addr)
+	if family != uint16(sfamily) && (!strict && family != linux.AF_UNSPEC) {
+		return tcpip.FullAddress{}, family, syserr.ErrAddressFamilyNotSupported
+	}
+
+	// Get the rest of the fields based on the address family.
+	switch family {
+	case linux.AF_UNIX:
+		path := addr[2:]
+		if len(path) > linux.UnixPathMax {
+			return tcpip.FullAddress{}, family, syserr.ErrInvalidArgument
+		}
+		// Drop the terminating NUL (if one exists) and everything after
+		// it for filesystem (non-abstract) addresses.
+		if len(path) > 0 && path[0] != 0 {
+			if n := bytes.IndexByte(path[1:], 0); n >= 0 {
+				path = path[:n+1]
+			}
+		}
+		return tcpip.FullAddress{
+			Addr: tcpip.Address(path),
+		}, family, nil
+
+	case linux.AF_INET:
+		var a linux.SockAddrInet
+		if len(addr) < sockAddrInetSize {
+			return tcpip.FullAddress{}, family, syserr.ErrInvalidArgument
+		}
+		binary.Unmarshal(addr[:sockAddrInetSize], usermem.ByteOrder, &a)
+
+		out := tcpip.FullAddress{
+			Addr: bytesToIPAddress(a.Addr[:]),
+			Port: ntohs(a.Port),
+		}
+		return out, family, nil
+
+	case linux.AF_INET6:
+		var a linux.SockAddrInet6
+		if len(addr) < sockAddrInet6Size {
+			return tcpip.FullAddress{}, family, syserr.ErrInvalidArgument
+		}
+		binary.Unmarshal(addr[:sockAddrInet6Size], usermem.ByteOrder, &a)
+
+		out := tcpip.FullAddress{
+			Addr: bytesToIPAddress(a.Addr[:]),
+			Port: ntohs(a.Port),
+		}
+		if isLinkLocal(out.Addr) {
+			out.NIC = tcpip.NICID(a.Scope_id)
+		}
+		return out, family, nil
+
+	case linux.AF_UNSPEC:
+		return tcpip.FullAddress{}, family, nil
+
+	default:
+		return tcpip.FullAddress{}, 0, syserr.ErrAddressFamilyNotSupported
+	}
+}
+
+func (s *SocketOperations) isPacketBased() bool {
+	return s.skType == linux.SOCK_DGRAM || s.skType == linux.SOCK_SEQPACKET || s.skType == linux.SOCK_RDM || s.skType == linux.SOCK_RAW
+}
+
+// fetchReadView updates the readView field of the socket if it's currently
+// empty. It assumes that the socket is locked.
+func (s *SocketOperations) fetchReadView() *syserr.Error {
+	if len(s.readView) > 0 {
+		return nil
+	}
+
+	s.readView = nil
+	s.sender = tcpip.FullAddress{}
+
+	v, cms, err := s.Endpoint.Read(&s.sender)
+	if err != nil {
+		return syserr.TranslateNetstackError(err)
+	}
+
+	s.readView = v
+	s.readCM = cms
+
+	return nil
+}
+
+// Release implements fs.FileOperations.Release.
+func (s *SocketOperations) Release() {
+	s.Endpoint.Close()
+}
+
+// Read implements fs.FileOperations.Read.
+func (s *SocketOperations) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, _ int64) (int64, error) {
+	if dst.NumBytes() == 0 {
+		return 0, nil
+	}
+	n, _, _, _, _, err := s.nonBlockingRead(ctx, dst, false, false, false)
+	if err == syserr.ErrWouldBlock {
+		return int64(n), syserror.ErrWouldBlock
+	}
+	if err != nil {
+		return 0, err.ToError()
+	}
+	return int64(n), nil
+}
+
+// WriteTo implements fs.FileOperations.WriteTo.
+func (s *SocketOperations) WriteTo(ctx context.Context, _ *fs.File, dst io.Writer, count int64, dup bool) (int64, error) {
+	s.readMu.Lock()
+
+	// Copy as much data as possible.
+	done := int64(0)
+	for count > 0 {
+		// This may return a blocking error.
+		if err := s.fetchReadView(); err != nil {
+			s.readMu.Unlock()
+			return done, err.ToError()
+		}
+
+		// Write to the underlying file.
+		n, err := dst.Write(s.readView)
+		done += int64(n)
+		count -= int64(n)
+		if dup {
+			// That's all we support for dup. This is generally
+			// supported by any Linux system calls, but the
+			// expectation is that now a caller will call read to
+			// actually remove these bytes from the socket.
+			break
+		}
+
+		// Drop that part of the view.
+		s.readView.TrimFront(n)
+		if err != nil {
+			s.readMu.Unlock()
+			return done, err
+		}
+	}
+
+	s.readMu.Unlock()
+	return done, nil
+}
+
+// ioSequencePayload implements tcpip.Payload.
+//
+// t copies user memory bytes on demand based on the requested size.
+type ioSequencePayload struct {
+	ctx context.Context
+	src usermem.IOSequence
+}
+
+// FullPayload implements tcpip.Payloader.FullPayload
+func (i *ioSequencePayload) FullPayload() ([]byte, *tcpip.Error) {
+	return i.Payload(int(i.src.NumBytes()))
+}
+
+// Payload implements tcpip.Payloader.Payload.
+func (i *ioSequencePayload) Payload(size int) ([]byte, *tcpip.Error) {
+	if max := int(i.src.NumBytes()); size > max {
+		size = max
+	}
+	v := buffer.NewView(size)
+	if _, err := i.src.CopyIn(i.ctx, v); err != nil {
+		return nil, tcpip.ErrBadAddress
+	}
+	return v, nil
+}
+
+// DropFirst drops the first n bytes from underlying src.
+func (i *ioSequencePayload) DropFirst(n int) {
+	i.src = i.src.DropFirst(int(n))
+}
+
+// Write implements fs.FileOperations.Write.
+func (s *SocketOperations) Write(ctx context.Context, _ *fs.File, src usermem.IOSequence, _ int64) (int64, error) {
+	f := &ioSequencePayload{ctx: ctx, src: src}
+	n, resCh, err := s.Endpoint.Write(f, tcpip.WriteOptions{})
+	if err == tcpip.ErrWouldBlock {
+		return 0, syserror.ErrWouldBlock
+	}
+
+	if resCh != nil {
+		t := ctx.(*kernel.Task)
+		if err := t.Block(resCh); err != nil {
+			return 0, syserr.FromError(err).ToError()
+		}
+
+		n, _, err = s.Endpoint.Write(f, tcpip.WriteOptions{})
+	}
+
+	if err != nil {
+		return 0, syserr.TranslateNetstackError(err).ToError()
+	}
+
+	if int64(n) < src.NumBytes() {
+		return int64(n), syserror.ErrWouldBlock
+	}
+
+	return int64(n), nil
+}
+
+// readerPayload implements tcpip.Payloader.
+//
+// It allocates a view and reads from a reader on-demand, based on available
+// capacity in the endpoint.
+type readerPayload struct {
+	ctx   context.Context
+	r     io.Reader
+	count int64
+	err   error
+}
+
+// FullPayload implements tcpip.Payloader.FullPayload.
+func (r *readerPayload) FullPayload() ([]byte, *tcpip.Error) {
+	return r.Payload(int(r.count))
+}
+
+// Payload implements tcpip.Payloader.Payload.
+func (r *readerPayload) Payload(size int) ([]byte, *tcpip.Error) {
+	if size > int(r.count) {
+		size = int(r.count)
+	}
+	v := buffer.NewView(size)
+	n, err := r.r.Read(v)
+	if n > 0 {
+		// We ignore the error here. It may re-occur on subsequent
+		// reads, but for now we can enqueue some amount of data.
+		r.count -= int64(n)
+		return v[:n], nil
+	}
+	if err == syserror.ErrWouldBlock {
+		return nil, tcpip.ErrWouldBlock
+	} else if err != nil {
+		r.err = err // Save for propation.
+		return nil, tcpip.ErrBadAddress
+	}
+
+	// There is no data and no error. Return an error, which will propagate
+	// r.err, which will be nil. This is the desired result: (0, nil).
+	return nil, tcpip.ErrBadAddress
+}
+
+// ReadFrom implements fs.FileOperations.ReadFrom.
+func (s *SocketOperations) ReadFrom(ctx context.Context, _ *fs.File, r io.Reader, count int64) (int64, error) {
+	f := &readerPayload{ctx: ctx, r: r, count: count}
+	n, resCh, err := s.Endpoint.Write(f, tcpip.WriteOptions{
+		// Reads may be destructive but should be very fast,
+		// so we can't release the lock while copying data.
+		Atomic: true,
+	})
+	if err == tcpip.ErrWouldBlock {
+		return 0, syserror.ErrWouldBlock
+	}
+
+	if resCh != nil {
+		t := ctx.(*kernel.Task)
+		if err := t.Block(resCh); err != nil {
+			return 0, syserr.FromError(err).ToError()
+		}
+
+		n, _, err = s.Endpoint.Write(f, tcpip.WriteOptions{
+			Atomic: true, // See above.
+		})
+	}
+	if err == tcpip.ErrWouldBlock {
+		return n, syserror.ErrWouldBlock
+	} else if err != nil {
+		return int64(n), f.err // Propagate error.
+	}
+
+	return int64(n), nil
+}
+
+// Readiness returns a mask of ready events for socket s.
+func (s *SocketOperations) Readiness(mask waiter.EventMask) waiter.EventMask {
+	r := s.Endpoint.Readiness(mask)
+
+	// Check our cached value iff the caller asked for readability and the
+	// endpoint itself is currently not readable.
+	if (mask & ^r & waiter.EventIn) != 0 {
+		s.readMu.Lock()
+		if len(s.readView) > 0 {
+			r |= waiter.EventIn
+		}
+		s.readMu.Unlock()
+	}
+
+	return r
+}
+
+// Connect implements the linux syscall connect(2) for sockets backed by
+// tpcip.Endpoint.
+func (s *SocketOperations) Connect(t *kernel.Task, sockaddr []byte, blocking bool) *syserr.Error {
+	addr, family, err := AddressAndFamily(s.family, sockaddr, false /* strict */)
+	if err != nil {
+		return err
+	}
+
+	if family == linux.AF_UNSPEC {
+		err := s.Endpoint.Disconnect()
+		if err == tcpip.ErrNotSupported {
+			return syserr.ErrAddressFamilyNotSupported
+		}
+		return syserr.TranslateNetstackError(err)
+	}
+	// Always return right away in the non-blocking case.
+	if !blocking {
+		return syserr.TranslateNetstackError(s.Endpoint.Connect(addr))
+	}
+
+	// Register for notification when the endpoint becomes writable, then
+	// initiate the connection.
+	e, ch := waiter.NewChannelEntry(nil)
+	s.EventRegister(&e, waiter.EventOut)
+	defer s.EventUnregister(&e)
+
+	if err := s.Endpoint.Connect(addr); err != tcpip.ErrConnectStarted && err != tcpip.ErrAlreadyConnecting {
+		return syserr.TranslateNetstackError(err)
+	}
+
+	// It's pending, so we have to wait for a notification, and fetch the
+	// result once the wait completes.
+	if err := t.Block(ch); err != nil {
+		return syserr.FromError(err)
+	}
+
+	// Call Connect() again after blocking to find connect's result.
+	return syserr.TranslateNetstackError(s.Endpoint.Connect(addr))
+}
+
+// Bind implements the linux syscall bind(2) for sockets backed by
+// tcpip.Endpoint.
+func (s *SocketOperations) Bind(t *kernel.Task, sockaddr []byte) *syserr.Error {
+	addr, _, err := AddressAndFamily(s.family, sockaddr, true /* strict */)
+	if err != nil {
+		return err
+	}
+
+	// Issue the bind request to the endpoint.
+	return syserr.TranslateNetstackError(s.Endpoint.Bind(addr))
+}
+
+// Listen implements the linux syscall listen(2) for sockets backed by
+// tcpip.Endpoint.
+func (s *SocketOperations) Listen(t *kernel.Task, backlog int) *syserr.Error {
+	return syserr.TranslateNetstackError(s.Endpoint.Listen(backlog))
+}
+
+// blockingAccept implements a blocking version of accept(2), that is, if no
+// connections are ready to be accept, it will block until one becomes ready.
+func (s *SocketOperations) blockingAccept(t *kernel.Task) (tcpip.Endpoint, *waiter.Queue, *syserr.Error) {
+	// Register for notifications.
+	e, ch := waiter.NewChannelEntry(nil)
+	s.EventRegister(&e, waiter.EventIn)
+	defer s.EventUnregister(&e)
+
+	// Try to accept the connection again; if it fails, then wait until we
+	// get a notification.
+	for {
+		if ep, wq, err := s.Endpoint.Accept(); err != tcpip.ErrWouldBlock {
+			return ep, wq, syserr.TranslateNetstackError(err)
+		}
+
+		if err := t.Block(ch); err != nil {
+			return nil, nil, syserr.FromError(err)
+		}
+	}
+}
+
+// Accept implements the linux syscall accept(2) for sockets backed by
+// tcpip.Endpoint.
+func (s *SocketOperations) Accept(t *kernel.Task, peerRequested bool, flags int, blocking bool) (int32, linux.SockAddr, uint32, *syserr.Error) {
+	// Issue the accept request to get the new endpoint.
+	ep, wq, terr := s.Endpoint.Accept()
+	if terr != nil {
+		if terr != tcpip.ErrWouldBlock || !blocking {
+			return 0, nil, 0, syserr.TranslateNetstackError(terr)
+		}
+
+		var err *syserr.Error
+		ep, wq, err = s.blockingAccept(t)
+		if err != nil {
+			return 0, nil, 0, err
+		}
+	}
+
+	ns, err := New(t, s.family, s.skType, s.protocol, wq, ep)
+	if err != nil {
+		return 0, nil, 0, err
+	}
+	defer ns.DecRef()
+
+	if flags&linux.SOCK_NONBLOCK != 0 {
+		flags := ns.Flags()
+		flags.NonBlocking = true
+		ns.SetFlags(flags.Settable())
+	}
+
+	var addr linux.SockAddr
+	var addrLen uint32
+	if peerRequested {
+		// Get address of the peer and write it to peer slice.
+		var err *syserr.Error
+		addr, addrLen, err = ns.FileOperations.(*SocketOperations).GetPeerName(t)
+		if err != nil {
+			return 0, nil, 0, err
+		}
+	}
+
+	fd, e := t.NewFDFrom(0, ns, kernel.FDFlags{
+		CloseOnExec: flags&linux.SOCK_CLOEXEC != 0,
+	})
+
+	t.Kernel().RecordSocket(ns)
+
+	return fd, addr, addrLen, syserr.FromError(e)
+}
+
+// ConvertShutdown converts Linux shutdown flags into tcpip shutdown flags.
+func ConvertShutdown(how int) (tcpip.ShutdownFlags, *syserr.Error) {
+	var f tcpip.ShutdownFlags
+	switch how {
+	case linux.SHUT_RD:
+		f = tcpip.ShutdownRead
+	case linux.SHUT_WR:
+		f = tcpip.ShutdownWrite
+	case linux.SHUT_RDWR:
+		f = tcpip.ShutdownRead | tcpip.ShutdownWrite
+	default:
+		return 0, syserr.ErrInvalidArgument
+	}
+	return f, nil
+}
+
+// Shutdown implements the linux syscall shutdown(2) for sockets backed by
+// tcpip.Endpoint.
+func (s *SocketOperations) Shutdown(t *kernel.Task, how int) *syserr.Error {
+	f, err := ConvertShutdown(how)
+	if err != nil {
+		return err
+	}
+
+	// Issue shutdown request.
+	return syserr.TranslateNetstackError(s.Endpoint.Shutdown(f))
+}
+
+// GetSockOpt implements the linux syscall getsockopt(2) for sockets backed by
+// tcpip.Endpoint.
+func (s *SocketOperations) GetSockOpt(t *kernel.Task, level, name int, outPtr usermem.Addr, outLen int) (interface{}, *syserr.Error) {
+	// TODO(b/78348848): Unlike other socket options, SO_TIMESTAMP is
+	// implemented specifically for netstack.SocketOperations rather than
+	// commonEndpoint. commonEndpoint should be extended to support socket
+	// options where the implementation is not shared, as unix sockets need
+	// their own support for SO_TIMESTAMP.
+	if level == linux.SOL_SOCKET && name == linux.SO_TIMESTAMP {
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+		val := int32(0)
+		s.readMu.Lock()
+		defer s.readMu.Unlock()
+		if s.sockOptTimestamp {
+			val = 1
+		}
+		return val, nil
+	}
+	if level == linux.SOL_TCP && name == linux.TCP_INQ {
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+		val := int32(0)
+		s.readMu.Lock()
+		defer s.readMu.Unlock()
+		if s.sockOptInq {
+			val = 1
+		}
+		return val, nil
+	}
+
+	if s.skType == linux.SOCK_RAW && level == linux.IPPROTO_IP {
+		switch name {
+		case linux.IPT_SO_GET_INFO:
+			if outLen < linux.SizeOfIPTGetinfo {
+				return nil, syserr.ErrInvalidArgument
+			}
+
+			info, err := netfilter.GetInfo(t, s.Endpoint, outPtr)
+			if err != nil {
+				return nil, err
+			}
+			return info, nil
+
+		case linux.IPT_SO_GET_ENTRIES:
+			if outLen < linux.SizeOfIPTGetEntries {
+				return nil, syserr.ErrInvalidArgument
+			}
+
+			entries, err := netfilter.GetEntries(t, s.Endpoint, outPtr, outLen)
+			if err != nil {
+				return nil, err
+			}
+			return entries, nil
+
+		}
+	}
+
+	return GetSockOpt(t, s, s.Endpoint, s.family, s.skType, level, name, outLen)
+}
+
+// GetSockOpt can be used to implement the linux syscall getsockopt(2) for
+// sockets backed by a commonEndpoint.
+func GetSockOpt(t *kernel.Task, s socket.Socket, ep commonEndpoint, family int, skType linux.SockType, level, name, outLen int) (interface{}, *syserr.Error) {
+	switch level {
+	case linux.SOL_SOCKET:
+		return getSockOptSocket(t, s, ep, family, skType, name, outLen)
+
+	case linux.SOL_TCP:
+		return getSockOptTCP(t, ep, name, outLen)
+
+	case linux.SOL_IPV6:
+		return getSockOptIPv6(t, ep, name, outLen)
+
+	case linux.SOL_IP:
+		return getSockOptIP(t, ep, name, outLen)
+
+	case linux.SOL_UDP,
+		linux.SOL_ICMPV6,
+		linux.SOL_RAW,
+		linux.SOL_PACKET:
+
+		t.Kernel().EmitUnimplementedEvent(t)
+	}
+
+	return nil, syserr.ErrProtocolNotAvailable
+}
+
+// getSockOptSocket implements GetSockOpt when level is SOL_SOCKET.
+func getSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, family int, skType linux.SockType, name, outLen int) (interface{}, *syserr.Error) {
+	// TODO(b/124056281): Stop rejecting short optLen values in getsockopt.
+	switch name {
+	case linux.SO_ERROR:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		// Get the last error and convert it.
+		err := ep.GetSockOpt(tcpip.ErrorOption{})
+		if err == nil {
+			return int32(0), nil
+		}
+		return int32(syserr.TranslateNetstackError(err).ToLinux().Number()), nil
+
+	case linux.SO_PEERCRED:
+		if family != linux.AF_UNIX || outLen < syscall.SizeofUcred {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		tcred := t.Credentials()
+		return syscall.Ucred{
+			Pid: int32(t.ThreadGroup().ID()),
+			Uid: uint32(tcred.EffectiveKUID.In(tcred.UserNamespace).OrOverflow()),
+			Gid: uint32(tcred.EffectiveKGID.In(tcred.UserNamespace).OrOverflow()),
+		}, nil
+
+	case linux.SO_PASSCRED:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.PasscredOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(v), nil
+
+	case linux.SO_SNDBUF:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		size, err := ep.GetSockOptInt(tcpip.SendBufferSizeOption)
+		if err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		if size > math.MaxInt32 {
+			size = math.MaxInt32
+		}
+
+		return int32(size), nil
+
+	case linux.SO_RCVBUF:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		size, err := ep.GetSockOptInt(tcpip.ReceiveBufferSizeOption)
+		if err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		if size > math.MaxInt32 {
+			size = math.MaxInt32
+		}
+
+		return int32(size), nil
+
+	case linux.SO_REUSEADDR:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.ReuseAddressOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(v), nil
+
+	case linux.SO_REUSEPORT:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.ReusePortOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(v), nil
+
+	case linux.SO_BINDTODEVICE:
+		var v tcpip.BindToDeviceOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+		if len(v) == 0 {
+			return []byte{}, nil
+		}
+		if outLen < linux.IFNAMSIZ {
+			return nil, syserr.ErrInvalidArgument
+		}
+		return append([]byte(v), 0), nil
+
+	case linux.SO_BROADCAST:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.BroadcastOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(v), nil
+
+	case linux.SO_KEEPALIVE:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.KeepaliveEnabledOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(v), nil
+
+	case linux.SO_LINGER:
+		if outLen < linux.SizeOfLinger {
+			return nil, syserr.ErrInvalidArgument
+		}
+		return linux.Linger{}, nil
+
+	case linux.SO_SNDTIMEO:
+		// TODO(igudger): Linux allows shorter lengths for partial results.
+		if outLen < linux.SizeOfTimeval {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		return linux.NsecToTimeval(s.SendTimeout()), nil
+
+	case linux.SO_RCVTIMEO:
+		// TODO(igudger): Linux allows shorter lengths for partial results.
+		if outLen < linux.SizeOfTimeval {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		return linux.NsecToTimeval(s.RecvTimeout()), nil
+
+	case linux.SO_OOBINLINE:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.OutOfBandInlineOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(v), nil
+
+	default:
+		socket.GetSockOptEmitUnimplementedEvent(t, name)
+	}
+	return nil, syserr.ErrProtocolNotAvailable
+}
+
+// getSockOptTCP implements GetSockOpt when level is SOL_TCP.
+func getSockOptTCP(t *kernel.Task, ep commonEndpoint, name, outLen int) (interface{}, *syserr.Error) {
+	switch name {
+	case linux.TCP_NODELAY:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.DelayOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		if v == 0 {
+			return int32(1), nil
+		}
+		return int32(0), nil
+
+	case linux.TCP_CORK:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.CorkOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(v), nil
+
+	case linux.TCP_QUICKACK:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.QuickAckOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(v), nil
+
+	case linux.TCP_MAXSEG:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.MaxSegOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(v), nil
+
+	case linux.TCP_KEEPIDLE:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.KeepaliveIdleOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(time.Duration(v) / time.Second), nil
+
+	case linux.TCP_KEEPINTVL:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.KeepaliveIntervalOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(time.Duration(v) / time.Second), nil
+
+	case linux.TCP_INFO:
+		var v tcpip.TCPInfoOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		// TODO(b/64800844): Translate fields once they are added to
+		// tcpip.TCPInfoOption.
+		info := linux.TCPInfo{}
+
+		// Linux truncates the output binary to outLen.
+		ib := binary.Marshal(nil, usermem.ByteOrder, &info)
+		if len(ib) > outLen {
+			ib = ib[:outLen]
+		}
+
+		return ib, nil
+
+	case linux.TCP_CC_INFO,
+		linux.TCP_NOTSENT_LOWAT,
+		linux.TCP_ZEROCOPY_RECEIVE:
+
+		t.Kernel().EmitUnimplementedEvent(t)
+
+	case linux.TCP_CONGESTION:
+		if outLen <= 0 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.CongestionControlOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		// We match linux behaviour here where it returns the lower of
+		// TCP_CA_NAME_MAX bytes or the value of the option length.
+		//
+		// This is Linux's net/tcp.h TCP_CA_NAME_MAX.
+		const tcpCANameMax = 16
+
+		toCopy := tcpCANameMax
+		if outLen < tcpCANameMax {
+			toCopy = outLen
+		}
+		b := make([]byte, toCopy)
+		copy(b, v)
+		return b, nil
+
+	default:
+		emitUnimplementedEventTCP(t, name)
+	}
+	return nil, syserr.ErrProtocolNotAvailable
+}
+
+// getSockOptIPv6 implements GetSockOpt when level is SOL_IPV6.
+func getSockOptIPv6(t *kernel.Task, ep commonEndpoint, name, outLen int) (interface{}, *syserr.Error) {
+	switch name {
+	case linux.IPV6_V6ONLY:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.V6OnlyOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(v), nil
+
+	case linux.IPV6_PATHMTU:
+		t.Kernel().EmitUnimplementedEvent(t)
+
+	default:
+		emitUnimplementedEventIPv6(t, name)
+	}
+	return nil, syserr.ErrProtocolNotAvailable
+}
+
+// getSockOptIP implements GetSockOpt when level is SOL_IP.
+func getSockOptIP(t *kernel.Task, ep commonEndpoint, name, outLen int) (interface{}, *syserr.Error) {
+	switch name {
+	case linux.IP_MULTICAST_TTL:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.MulticastTTLOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(v), nil
+
+	case linux.IP_MULTICAST_IF:
+		if outLen < len(linux.InetAddr{}) {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.MulticastInterfaceOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		a, _ := ConvertAddress(linux.AF_INET, tcpip.FullAddress{Addr: v.InterfaceAddr})
+
+		return a.(*linux.SockAddrInet).Addr, nil
+
+	case linux.IP_MULTICAST_LOOP:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.MulticastLoopOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		if v {
+			return int32(1), nil
+		}
+		return int32(0), nil
+
+	default:
+		emitUnimplementedEventIP(t, name)
+	}
+	return nil, syserr.ErrProtocolNotAvailable
+}
+
+// SetSockOpt implements the linux syscall setsockopt(2) for sockets backed by
+// tcpip.Endpoint.
+func (s *SocketOperations) SetSockOpt(t *kernel.Task, level int, name int, optVal []byte) *syserr.Error {
+	// TODO(b/78348848): Unlike other socket options, SO_TIMESTAMP is
+	// implemented specifically for netstack.SocketOperations rather than
+	// commonEndpoint. commonEndpoint should be extended to support socket
+	// options where the implementation is not shared, as unix sockets need
+	// their own support for SO_TIMESTAMP.
+	if level == linux.SOL_SOCKET && name == linux.SO_TIMESTAMP {
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+		s.readMu.Lock()
+		defer s.readMu.Unlock()
+		s.sockOptTimestamp = usermem.ByteOrder.Uint32(optVal) != 0
+		return nil
+	}
+	if level == linux.SOL_TCP && name == linux.TCP_INQ {
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+		s.readMu.Lock()
+		defer s.readMu.Unlock()
+		s.sockOptInq = usermem.ByteOrder.Uint32(optVal) != 0
+		return nil
+	}
+
+	return SetSockOpt(t, s, s.Endpoint, level, name, optVal)
+}
+
+// SetSockOpt can be used to implement the linux syscall setsockopt(2) for
+// sockets backed by a commonEndpoint.
+func SetSockOpt(t *kernel.Task, s socket.Socket, ep commonEndpoint, level int, name int, optVal []byte) *syserr.Error {
+	switch level {
+	case linux.SOL_SOCKET:
+		return setSockOptSocket(t, s, ep, name, optVal)
+
+	case linux.SOL_TCP:
+		return setSockOptTCP(t, ep, name, optVal)
+
+	case linux.SOL_IPV6:
+		return setSockOptIPv6(t, ep, name, optVal)
+
+	case linux.SOL_IP:
+		return setSockOptIP(t, ep, name, optVal)
+
+	case linux.SOL_UDP,
+		linux.SOL_ICMPV6,
+		linux.SOL_RAW,
+		linux.SOL_PACKET:
+
+		t.Kernel().EmitUnimplementedEvent(t)
+	}
+
+	// Default to the old behavior; hand off to network stack.
+	return syserr.TranslateNetstackError(ep.SetSockOpt(struct{}{}))
+}
+
+// setSockOptSocket implements SetSockOpt when level is SOL_SOCKET.
+func setSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, name int, optVal []byte) *syserr.Error {
+	switch name {
+	case linux.SO_SNDBUF:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		return syserr.TranslateNetstackError(ep.SetSockOptInt(tcpip.SendBufferSizeOption, int(v)))
+
+	case linux.SO_RCVBUF:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		return syserr.TranslateNetstackError(ep.SetSockOptInt(tcpip.ReceiveBufferSizeOption, int(v)))
+
+	case linux.SO_REUSEADDR:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.ReuseAddressOption(v)))
+
+	case linux.SO_REUSEPORT:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.ReusePortOption(v)))
+
+	case linux.SO_BINDTODEVICE:
+		n := bytes.IndexByte(optVal, 0)
+		if n == -1 {
+			n = len(optVal)
+		}
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.BindToDeviceOption(optVal[:n])))
+
+	case linux.SO_BROADCAST:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.BroadcastOption(v)))
+
+	case linux.SO_PASSCRED:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.PasscredOption(v)))
+
+	case linux.SO_KEEPALIVE:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.KeepaliveEnabledOption(v)))
+
+	case linux.SO_SNDTIMEO:
+		if len(optVal) < linux.SizeOfTimeval {
+			return syserr.ErrInvalidArgument
+		}
+
+		var v linux.Timeval
+		binary.Unmarshal(optVal[:linux.SizeOfTimeval], usermem.ByteOrder, &v)
+		if v.Usec < 0 || v.Usec >= int64(time.Second/time.Microsecond) {
+			return syserr.ErrDomain
+		}
+		s.SetSendTimeout(v.ToNsecCapped())
+		return nil
+
+	case linux.SO_RCVTIMEO:
+		if len(optVal) < linux.SizeOfTimeval {
+			return syserr.ErrInvalidArgument
+		}
+
+		var v linux.Timeval
+		binary.Unmarshal(optVal[:linux.SizeOfTimeval], usermem.ByteOrder, &v)
+		if v.Usec < 0 || v.Usec >= int64(time.Second/time.Microsecond) {
+			return syserr.ErrDomain
+		}
+		s.SetRecvTimeout(v.ToNsecCapped())
+		return nil
+
+	case linux.SO_OOBINLINE:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+
+		if v == 0 {
+			socket.SetSockOptEmitUnimplementedEvent(t, name)
+		}
+
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.OutOfBandInlineOption(v)))
+
+	case linux.SO_LINGER:
+		if len(optVal) < linux.SizeOfLinger {
+			return syserr.ErrInvalidArgument
+		}
+
+		var v linux.Linger
+		binary.Unmarshal(optVal[:linux.SizeOfLinger], usermem.ByteOrder, &v)
+
+		if v != (linux.Linger{}) {
+			socket.SetSockOptEmitUnimplementedEvent(t, name)
+		}
+
+		return nil
+
+	default:
+		socket.SetSockOptEmitUnimplementedEvent(t, name)
+	}
+
+	// Default to the old behavior; hand off to network stack.
+	return syserr.TranslateNetstackError(ep.SetSockOpt(struct{}{}))
+}
+
+// setSockOptTCP implements SetSockOpt when level is SOL_TCP.
+func setSockOptTCP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *syserr.Error {
+	switch name {
+	case linux.TCP_NODELAY:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		var o tcpip.DelayOption
+		if v == 0 {
+			o = 1
+		}
+		return syserr.TranslateNetstackError(ep.SetSockOpt(o))
+
+	case linux.TCP_CORK:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.CorkOption(v)))
+
+	case linux.TCP_QUICKACK:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.QuickAckOption(v)))
+
+	case linux.TCP_MAXSEG:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.MaxSegOption(v)))
+
+	case linux.TCP_KEEPIDLE:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		if v < 1 || v > linux.MAX_TCP_KEEPIDLE {
+			return syserr.ErrInvalidArgument
+		}
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.KeepaliveIdleOption(time.Second * time.Duration(v))))
+
+	case linux.TCP_KEEPINTVL:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		if v < 1 || v > linux.MAX_TCP_KEEPINTVL {
+			return syserr.ErrInvalidArgument
+		}
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.KeepaliveIntervalOption(time.Second * time.Duration(v))))
+
+	case linux.TCP_CONGESTION:
+		v := tcpip.CongestionControlOption(optVal)
+		if err := ep.SetSockOpt(v); err != nil {
+			return syserr.TranslateNetstackError(err)
+		}
+		return nil
+
+	case linux.TCP_REPAIR_OPTIONS:
+		t.Kernel().EmitUnimplementedEvent(t)
+
+	default:
+		emitUnimplementedEventTCP(t, name)
+	}
+
+	// Default to the old behavior; hand off to network stack.
+	return syserr.TranslateNetstackError(ep.SetSockOpt(struct{}{}))
+}
+
+// setSockOptIPv6 implements SetSockOpt when level is SOL_IPV6.
+func setSockOptIPv6(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *syserr.Error {
+	switch name {
+	case linux.IPV6_V6ONLY:
+		if len(optVal) < sizeOfInt32 {
+			return syserr.ErrInvalidArgument
+		}
+
+		v := usermem.ByteOrder.Uint32(optVal)
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.V6OnlyOption(v)))
+
+	case linux.IPV6_ADD_MEMBERSHIP,
+		linux.IPV6_DROP_MEMBERSHIP,
+		linux.IPV6_IPSEC_POLICY,
+		linux.IPV6_JOIN_ANYCAST,
+		linux.IPV6_LEAVE_ANYCAST,
+		linux.IPV6_PKTINFO,
+		linux.IPV6_ROUTER_ALERT,
+		linux.IPV6_XFRM_POLICY,
+		linux.MCAST_BLOCK_SOURCE,
+		linux.MCAST_JOIN_GROUP,
+		linux.MCAST_JOIN_SOURCE_GROUP,
+		linux.MCAST_LEAVE_GROUP,
+		linux.MCAST_LEAVE_SOURCE_GROUP,
+		linux.MCAST_UNBLOCK_SOURCE:
+
+		t.Kernel().EmitUnimplementedEvent(t)
+
+	default:
+		emitUnimplementedEventIPv6(t, name)
+	}
+
+	// Default to the old behavior; hand off to network stack.
+	return syserr.TranslateNetstackError(ep.SetSockOpt(struct{}{}))
+}
+
+var (
+	inetMulticastRequestSize        = int(binary.Size(linux.InetMulticastRequest{}))
+	inetMulticastRequestWithNICSize = int(binary.Size(linux.InetMulticastRequestWithNIC{}))
+)
+
+// copyInMulticastRequest copies in a variable-size multicast request. The
+// kernel determines which structure was passed by its length. IP_MULTICAST_IF
+// supports ip_mreqn, ip_mreq and in_addr, while IP_ADD_MEMBERSHIP and
+// IP_DROP_MEMBERSHIP only support ip_mreqn and ip_mreq. To handle this,
+// allowAddr controls whether in_addr is accepted or rejected.
+func copyInMulticastRequest(optVal []byte, allowAddr bool) (linux.InetMulticastRequestWithNIC, *syserr.Error) {
+	if len(optVal) < len(linux.InetAddr{}) {
+		return linux.InetMulticastRequestWithNIC{}, syserr.ErrInvalidArgument
+	}
+
+	if len(optVal) < inetMulticastRequestSize {
+		if !allowAddr {
+			return linux.InetMulticastRequestWithNIC{}, syserr.ErrInvalidArgument
+		}
+
+		var req linux.InetMulticastRequestWithNIC
+		copy(req.InterfaceAddr[:], optVal)
+		return req, nil
+	}
+
+	if len(optVal) >= inetMulticastRequestWithNICSize {
+		var req linux.InetMulticastRequestWithNIC
+		binary.Unmarshal(optVal[:inetMulticastRequestWithNICSize], usermem.ByteOrder, &req)
+		return req, nil
+	}
+
+	var req linux.InetMulticastRequestWithNIC
+	binary.Unmarshal(optVal[:inetMulticastRequestSize], usermem.ByteOrder, &req.InetMulticastRequest)
+	return req, nil
+}
+
+// parseIntOrChar copies either a 32-bit int or an 8-bit uint out of buf.
+//
+// net/ipv4/ip_sockglue.c:do_ip_setsockopt does this for its socket options.
+func parseIntOrChar(buf []byte) (int32, *syserr.Error) {
+	if len(buf) == 0 {
+		return 0, syserr.ErrInvalidArgument
+	}
+
+	if len(buf) >= sizeOfInt32 {
+		return int32(usermem.ByteOrder.Uint32(buf)), nil
+	}
+
+	return int32(buf[0]), nil
+}
+
+// setSockOptIP implements SetSockOpt when level is SOL_IP.
+func setSockOptIP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *syserr.Error {
+	switch name {
+	case linux.IP_MULTICAST_TTL:
+		v, err := parseIntOrChar(optVal)
+		if err != nil {
+			return err
+		}
+
+		if v == -1 {
+			// Linux translates -1 to 1.
+			v = 1
+		}
+		if v < 0 || v > 255 {
+			return syserr.ErrInvalidArgument
+		}
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.MulticastTTLOption(v)))
+
+	case linux.IP_ADD_MEMBERSHIP:
+		req, err := copyInMulticastRequest(optVal, false /* allowAddr */)
+		if err != nil {
+			return err
+		}
+
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.AddMembershipOption{
+			NIC: tcpip.NICID(req.InterfaceIndex),
+			// TODO(igudger): Change AddMembership to use the standard
+			// any address representation.
+			InterfaceAddr: tcpip.Address(req.InterfaceAddr[:]),
+			MulticastAddr: tcpip.Address(req.MulticastAddr[:]),
+		}))
+
+	case linux.IP_DROP_MEMBERSHIP:
+		req, err := copyInMulticastRequest(optVal, false /* allowAddr */)
+		if err != nil {
+			return err
+		}
+
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.RemoveMembershipOption{
+			NIC: tcpip.NICID(req.InterfaceIndex),
+			// TODO(igudger): Change DropMembership to use the standard
+			// any address representation.
+			InterfaceAddr: tcpip.Address(req.InterfaceAddr[:]),
+			MulticastAddr: tcpip.Address(req.MulticastAddr[:]),
+		}))
+
+	case linux.IP_MULTICAST_IF:
+		req, err := copyInMulticastRequest(optVal, true /* allowAddr */)
+		if err != nil {
+			return err
+		}
+
+		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.MulticastInterfaceOption{
+			NIC:           tcpip.NICID(req.InterfaceIndex),
+			InterfaceAddr: bytesToIPAddress(req.InterfaceAddr[:]),
+		}))
+
+	case linux.IP_MULTICAST_LOOP:
+		v, err := parseIntOrChar(optVal)
+		if err != nil {
+			return err
+		}
+
+		return syserr.TranslateNetstackError(ep.SetSockOpt(
+			tcpip.MulticastLoopOption(v != 0),
+		))
+
+	case linux.MCAST_JOIN_GROUP:
+		// FIXME(b/124219304): Implement MCAST_JOIN_GROUP.
+		t.Kernel().EmitUnimplementedEvent(t)
+		return syserr.ErrInvalidArgument
+
+	case linux.IP_ADD_SOURCE_MEMBERSHIP,
+		linux.IP_BIND_ADDRESS_NO_PORT,
+		linux.IP_BLOCK_SOURCE,
+		linux.IP_CHECKSUM,
+		linux.IP_DROP_SOURCE_MEMBERSHIP,
+		linux.IP_FREEBIND,
+		linux.IP_HDRINCL,
+		linux.IP_IPSEC_POLICY,
+		linux.IP_MINTTL,
+		linux.IP_MSFILTER,
+		linux.IP_MTU_DISCOVER,
+		linux.IP_MULTICAST_ALL,
+		linux.IP_NODEFRAG,
+		linux.IP_OPTIONS,
+		linux.IP_PASSSEC,
+		linux.IP_PKTINFO,
+		linux.IP_RECVERR,
+		linux.IP_RECVFRAGSIZE,
+		linux.IP_RECVOPTS,
+		linux.IP_RECVORIGDSTADDR,
+		linux.IP_RECVTOS,
+		linux.IP_RECVTTL,
+		linux.IP_RETOPTS,
+		linux.IP_TOS,
+		linux.IP_TRANSPARENT,
+		linux.IP_TTL,
+		linux.IP_UNBLOCK_SOURCE,
+		linux.IP_UNICAST_IF,
+		linux.IP_XFRM_POLICY,
+		linux.MCAST_BLOCK_SOURCE,
+		linux.MCAST_JOIN_SOURCE_GROUP,
+		linux.MCAST_LEAVE_GROUP,
+		linux.MCAST_LEAVE_SOURCE_GROUP,
+		linux.MCAST_MSFILTER,
+		linux.MCAST_UNBLOCK_SOURCE:
+
+		t.Kernel().EmitUnimplementedEvent(t)
+	}
+
+	// Default to the old behavior; hand off to network stack.
+	return syserr.TranslateNetstackError(ep.SetSockOpt(struct{}{}))
+}
+
+// emitUnimplementedEventTCP emits unimplemented event if name is valid. This
+// function contains names that are common between Get and SetSockOpt when
+// level is SOL_TCP.
+func emitUnimplementedEventTCP(t *kernel.Task, name int) {
+	switch name {
+	case linux.TCP_CONGESTION,
+		linux.TCP_CORK,
+		linux.TCP_DEFER_ACCEPT,
+		linux.TCP_FASTOPEN,
+		linux.TCP_FASTOPEN_CONNECT,
+		linux.TCP_FASTOPEN_KEY,
+		linux.TCP_FASTOPEN_NO_COOKIE,
+		linux.TCP_KEEPCNT,
+		linux.TCP_KEEPIDLE,
+		linux.TCP_KEEPINTVL,
+		linux.TCP_LINGER2,
+		linux.TCP_MAXSEG,
+		linux.TCP_QUEUE_SEQ,
+		linux.TCP_QUICKACK,
+		linux.TCP_REPAIR,
+		linux.TCP_REPAIR_QUEUE,
+		linux.TCP_REPAIR_WINDOW,
+		linux.TCP_SAVED_SYN,
+		linux.TCP_SAVE_SYN,
+		linux.TCP_SYNCNT,
+		linux.TCP_THIN_DUPACK,
+		linux.TCP_THIN_LINEAR_TIMEOUTS,
+		linux.TCP_TIMESTAMP,
+		linux.TCP_ULP,
+		linux.TCP_USER_TIMEOUT,
+		linux.TCP_WINDOW_CLAMP:
+
+		t.Kernel().EmitUnimplementedEvent(t)
+	}
+}
+
+// emitUnimplementedEventIPv6 emits unimplemented event if name is valid. It
+// contains names that are common between Get and SetSockOpt when level is
+// SOL_IPV6.
+func emitUnimplementedEventIPv6(t *kernel.Task, name int) {
+	switch name {
+	case linux.IPV6_2292DSTOPTS,
+		linux.IPV6_2292HOPLIMIT,
+		linux.IPV6_2292HOPOPTS,
+		linux.IPV6_2292PKTINFO,
+		linux.IPV6_2292PKTOPTIONS,
+		linux.IPV6_2292RTHDR,
+		linux.IPV6_ADDR_PREFERENCES,
+		linux.IPV6_AUTOFLOWLABEL,
+		linux.IPV6_DONTFRAG,
+		linux.IPV6_DSTOPTS,
+		linux.IPV6_FLOWINFO,
+		linux.IPV6_FLOWINFO_SEND,
+		linux.IPV6_FLOWLABEL_MGR,
+		linux.IPV6_FREEBIND,
+		linux.IPV6_HOPOPTS,
+		linux.IPV6_MINHOPCOUNT,
+		linux.IPV6_MTU,
+		linux.IPV6_MTU_DISCOVER,
+		linux.IPV6_MULTICAST_ALL,
+		linux.IPV6_MULTICAST_HOPS,
+		linux.IPV6_MULTICAST_IF,
+		linux.IPV6_MULTICAST_LOOP,
+		linux.IPV6_RECVDSTOPTS,
+		linux.IPV6_RECVERR,
+		linux.IPV6_RECVFRAGSIZE,
+		linux.IPV6_RECVHOPLIMIT,
+		linux.IPV6_RECVHOPOPTS,
+		linux.IPV6_RECVORIGDSTADDR,
+		linux.IPV6_RECVPATHMTU,
+		linux.IPV6_RECVPKTINFO,
+		linux.IPV6_RECVRTHDR,
+		linux.IPV6_RECVTCLASS,
+		linux.IPV6_RTHDR,
+		linux.IPV6_RTHDRDSTOPTS,
+		linux.IPV6_TCLASS,
+		linux.IPV6_TRANSPARENT,
+		linux.IPV6_UNICAST_HOPS,
+		linux.IPV6_UNICAST_IF,
+		linux.MCAST_MSFILTER,
+		linux.IPV6_ADDRFORM:
+
+		t.Kernel().EmitUnimplementedEvent(t)
+	}
+}
+
+// emitUnimplementedEventIP emits unimplemented event if name is valid. It
+// contains names that are common between Get and SetSockOpt when level is
+// SOL_IP.
+func emitUnimplementedEventIP(t *kernel.Task, name int) {
+	switch name {
+	case linux.IP_TOS,
+		linux.IP_TTL,
+		linux.IP_HDRINCL,
+		linux.IP_OPTIONS,
+		linux.IP_ROUTER_ALERT,
+		linux.IP_RECVOPTS,
+		linux.IP_RETOPTS,
+		linux.IP_PKTINFO,
+		linux.IP_PKTOPTIONS,
+		linux.IP_MTU_DISCOVER,
+		linux.IP_RECVERR,
+		linux.IP_RECVTTL,
+		linux.IP_RECVTOS,
+		linux.IP_MTU,
+		linux.IP_FREEBIND,
+		linux.IP_IPSEC_POLICY,
+		linux.IP_XFRM_POLICY,
+		linux.IP_PASSSEC,
+		linux.IP_TRANSPARENT,
+		linux.IP_ORIGDSTADDR,
+		linux.IP_MINTTL,
+		linux.IP_NODEFRAG,
+		linux.IP_CHECKSUM,
+		linux.IP_BIND_ADDRESS_NO_PORT,
+		linux.IP_RECVFRAGSIZE,
+		linux.IP_MULTICAST_IF,
+		linux.IP_MULTICAST_TTL,
+		linux.IP_MULTICAST_LOOP,
+		linux.IP_ADD_MEMBERSHIP,
+		linux.IP_DROP_MEMBERSHIP,
+		linux.IP_UNBLOCK_SOURCE,
+		linux.IP_BLOCK_SOURCE,
+		linux.IP_ADD_SOURCE_MEMBERSHIP,
+		linux.IP_DROP_SOURCE_MEMBERSHIP,
+		linux.IP_MSFILTER,
+		linux.MCAST_JOIN_GROUP,
+		linux.MCAST_BLOCK_SOURCE,
+		linux.MCAST_UNBLOCK_SOURCE,
+		linux.MCAST_LEAVE_GROUP,
+		linux.MCAST_JOIN_SOURCE_GROUP,
+		linux.MCAST_LEAVE_SOURCE_GROUP,
+		linux.MCAST_MSFILTER,
+		linux.IP_MULTICAST_ALL,
+		linux.IP_UNICAST_IF:
+
+		t.Kernel().EmitUnimplementedEvent(t)
+	}
+}
+
+// isLinkLocal determines if the given IPv6 address is link-local. This is the
+// case when it has the fe80::/10 prefix. This check is used to determine when
+// the NICID is relevant for a given IPv6 address.
+func isLinkLocal(addr tcpip.Address) bool {
+	return len(addr) >= 2 && addr[0] == 0xfe && addr[1]&0xc0 == 0x80
+}
+
+// ConvertAddress converts the given address to a native format.
+func ConvertAddress(family int, addr tcpip.FullAddress) (linux.SockAddr, uint32) {
+	switch family {
+	case linux.AF_UNIX:
+		var out linux.SockAddrUnix
+		out.Family = linux.AF_UNIX
+		l := len([]byte(addr.Addr))
+		for i := 0; i < l; i++ {
+			out.Path[i] = int8(addr.Addr[i])
+		}
+
+		// Linux returns the used length of the address struct (including the
+		// null terminator) for filesystem paths. The Family field is 2 bytes.
+		// It is sometimes allowed to exclude the null terminator if the
+		// address length is the max. Abstract and empty paths always return
+		// the full exact length.
+		if l == 0 || out.Path[0] == 0 || l == len(out.Path) {
+			return &out, uint32(2 + l)
+		}
+		return &out, uint32(3 + l)
+	case linux.AF_INET:
+		var out linux.SockAddrInet
+		copy(out.Addr[:], addr.Addr)
+		out.Family = linux.AF_INET
+		out.Port = htons(addr.Port)
+		return &out, uint32(binary.Size(out))
+	case linux.AF_INET6:
+		var out linux.SockAddrInet6
+		if len(addr.Addr) == 4 {
+			// Copy address is v4-mapped format.
+			copy(out.Addr[12:], addr.Addr)
+			out.Addr[10] = 0xff
+			out.Addr[11] = 0xff
+		} else {
+			copy(out.Addr[:], addr.Addr)
+		}
+		out.Family = linux.AF_INET6
+		out.Port = htons(addr.Port)
+		if isLinkLocal(addr.Addr) {
+			out.Scope_id = uint32(addr.NIC)
+		}
+		return &out, uint32(binary.Size(out))
+	default:
+		return nil, 0
+	}
+}
+
+// GetSockName implements the linux syscall getsockname(2) for sockets backed by
+// tcpip.Endpoint.
+func (s *SocketOperations) GetSockName(t *kernel.Task) (linux.SockAddr, uint32, *syserr.Error) {
+	addr, err := s.Endpoint.GetLocalAddress()
+	if err != nil {
+		return nil, 0, syserr.TranslateNetstackError(err)
+	}
+
+	a, l := ConvertAddress(s.family, addr)
+	return a, l, nil
+}
+
+// GetPeerName implements the linux syscall getpeername(2) for sockets backed by
+// tcpip.Endpoint.
+func (s *SocketOperations) GetPeerName(t *kernel.Task) (linux.SockAddr, uint32, *syserr.Error) {
+	addr, err := s.Endpoint.GetRemoteAddress()
+	if err != nil {
+		return nil, 0, syserr.TranslateNetstackError(err)
+	}
+
+	a, l := ConvertAddress(s.family, addr)
+	return a, l, nil
+}
+
+// coalescingRead is the fast path for non-blocking, non-peek, stream-based
+// case. It coalesces as many packets as possible before returning to the
+// caller.
+//
+// Precondition: s.readMu must be locked.
+func (s *SocketOperations) coalescingRead(ctx context.Context, dst usermem.IOSequence, discard bool) (int, *syserr.Error) {
+	var err *syserr.Error
+	var copied int
+
+	// Copy as many views as possible into the user-provided buffer.
+	for dst.NumBytes() != 0 {
+		err = s.fetchReadView()
+		if err != nil {
+			break
+		}
+
+		var n int
+		var e error
+		if discard {
+			n = len(s.readView)
+			if int64(n) > dst.NumBytes() {
+				n = int(dst.NumBytes())
+			}
+		} else {
+			n, e = dst.CopyOut(ctx, s.readView)
+			// Set the control message, even if 0 bytes were read.
+			if e == nil {
+				s.updateTimestamp()
+			}
+		}
+		copied += n
+		s.readView.TrimFront(n)
+		dst = dst.DropFirst(n)
+		if e != nil {
+			err = syserr.FromError(e)
+			break
+		}
+	}
+
+	// If we managed to copy something, we must deliver it.
+	if copied > 0 {
+		s.Endpoint.ModerateRecvBuf(copied)
+		return copied, nil
+	}
+
+	return 0, err
+}
+
+func (s *SocketOperations) fillCmsgInq(cmsg *socket.ControlMessages) {
+	if !s.sockOptInq {
+		return
+	}
+	rcvBufUsed, err := s.Endpoint.GetSockOptInt(tcpip.ReceiveQueueSizeOption)
+	if err != nil {
+		return
+	}
+	cmsg.IP.HasInq = true
+	cmsg.IP.Inq = int32(len(s.readView) + rcvBufUsed)
+}
+
+// nonBlockingRead issues a non-blocking read.
+//
+// TODO(b/78348848): Support timestamps for stream sockets.
+func (s *SocketOperations) nonBlockingRead(ctx context.Context, dst usermem.IOSequence, peek, trunc, senderRequested bool) (int, int, linux.SockAddr, uint32, socket.ControlMessages, *syserr.Error) {
+	isPacket := s.isPacketBased()
+
+	// Fast path for regular reads from stream (e.g., TCP) endpoints. Note
+	// that senderRequested is ignored for stream sockets.
+	if !peek && !isPacket {
+		// TCP sockets discard the data if MSG_TRUNC is set.
+		//
+		// This behavior is documented in man 7 tcp:
+		// Since version 2.4, Linux supports the use of MSG_TRUNC in the flags
+		// argument of recv(2) (and recvmsg(2)). This flag causes the received
+		// bytes of data to be discarded, rather than passed back in a
+		// caller-supplied  buffer.
+		s.readMu.Lock()
+		n, err := s.coalescingRead(ctx, dst, trunc)
+		s.readMu.Unlock()
+		cmsg := s.controlMessages()
+		s.fillCmsgInq(&cmsg)
+		return n, 0, nil, 0, cmsg, err
+	}
+
+	s.readMu.Lock()
+	defer s.readMu.Unlock()
+
+	if err := s.fetchReadView(); err != nil {
+		return 0, 0, nil, 0, socket.ControlMessages{}, err
+	}
+
+	if !isPacket && peek && trunc {
+		// MSG_TRUNC with MSG_PEEK on a TCP socket returns the
+		// amount that could be read.
+		rql, err := s.Endpoint.GetSockOptInt(tcpip.ReceiveQueueSizeOption)
+		if err != nil {
+			return 0, 0, nil, 0, socket.ControlMessages{}, syserr.TranslateNetstackError(err)
+		}
+		available := len(s.readView) + int(rql)
+		bufLen := int(dst.NumBytes())
+		if available < bufLen {
+			return available, 0, nil, 0, socket.ControlMessages{}, nil
+		}
+		return bufLen, 0, nil, 0, socket.ControlMessages{}, nil
+	}
+
+	n, err := dst.CopyOut(ctx, s.readView)
+	// Set the control message, even if 0 bytes were read.
+	if err == nil {
+		s.updateTimestamp()
+	}
+	var addr linux.SockAddr
+	var addrLen uint32
+	if isPacket && senderRequested {
+		addr, addrLen = ConvertAddress(s.family, s.sender)
+	}
+
+	if peek {
+		if l := len(s.readView); trunc && l > n {
+			// isPacket must be true.
+			return l, linux.MSG_TRUNC, addr, addrLen, s.controlMessages(), syserr.FromError(err)
+		}
+
+		if isPacket || err != nil {
+			return n, 0, addr, addrLen, s.controlMessages(), syserr.FromError(err)
+		}
+
+		// We need to peek beyond the first message.
+		dst = dst.DropFirst(n)
+		num, err := dst.CopyOutFrom(ctx, safemem.FromVecReaderFunc{func(dsts [][]byte) (int64, error) {
+			n, _, err := s.Endpoint.Peek(dsts)
+			// TODO(b/78348848): Handle peek timestamp.
+			if err != nil {
+				return int64(n), syserr.TranslateNetstackError(err).ToError()
+			}
+			return int64(n), nil
+		}})
+		n += int(num)
+		if err == syserror.ErrWouldBlock && n > 0 {
+			// We got some data, so no need to return an error.
+			err = nil
+		}
+		return n, 0, nil, 0, s.controlMessages(), syserr.FromError(err)
+	}
+
+	var msgLen int
+	if isPacket {
+		msgLen = len(s.readView)
+		s.readView = nil
+	} else {
+		msgLen = int(n)
+		s.readView.TrimFront(int(n))
+	}
+
+	var flags int
+	if msgLen > int(n) {
+		flags |= linux.MSG_TRUNC
+	}
+
+	if trunc {
+		n = msgLen
+	}
+
+	cmsg := s.controlMessages()
+	s.fillCmsgInq(&cmsg)
+	return n, flags, addr, addrLen, cmsg, syserr.FromError(err)
+}
+
+func (s *SocketOperations) controlMessages() socket.ControlMessages {
+	return socket.ControlMessages{IP: tcpip.ControlMessages{HasTimestamp: s.readCM.HasTimestamp && s.sockOptTimestamp, Timestamp: s.readCM.Timestamp}}
+}
+
+// updateTimestamp sets the timestamp for SIOCGSTAMP. It should be called after
+// successfully writing packet data out to userspace.
+//
+// Precondition: s.readMu must be locked.
+func (s *SocketOperations) updateTimestamp() {
+	// Save the SIOCGSTAMP timestamp only if SO_TIMESTAMP is disabled.
+	if !s.sockOptTimestamp {
+		s.timestampValid = true
+		s.timestampNS = s.readCM.Timestamp
+	}
+}
+
+// RecvMsg implements the linux syscall recvmsg(2) for sockets backed by
+// tcpip.Endpoint.
+func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags int, haveDeadline bool, deadline ktime.Time, senderRequested bool, controlDataLen uint64) (n int, msgFlags int, senderAddr linux.SockAddr, senderAddrLen uint32, controlMessages socket.ControlMessages, err *syserr.Error) {
+	trunc := flags&linux.MSG_TRUNC != 0
+	peek := flags&linux.MSG_PEEK != 0
+	dontWait := flags&linux.MSG_DONTWAIT != 0
+	waitAll := flags&linux.MSG_WAITALL != 0
+	if senderRequested && !s.isPacketBased() {
+		// Stream sockets ignore the sender address.
+		senderRequested = false
+	}
+	n, msgFlags, senderAddr, senderAddrLen, controlMessages, err = s.nonBlockingRead(t, dst, peek, trunc, senderRequested)
+
+	if s.isPacketBased() && err == syserr.ErrClosedForReceive && flags&linux.MSG_DONTWAIT != 0 {
+		// In this situation we should return EAGAIN.
+		return 0, 0, nil, 0, socket.ControlMessages{}, syserr.ErrTryAgain
+	}
+
+	if err != nil && (err != syserr.ErrWouldBlock || dontWait) {
+		// Read failed and we should not retry.
+		return 0, 0, nil, 0, socket.ControlMessages{}, err
+	}
+
+	if err == nil && (dontWait || !waitAll || s.isPacketBased() || int64(n) >= dst.NumBytes()) {
+		// We got all the data we need.
+		return
+	}
+
+	// Don't overwrite any data we received.
+	dst = dst.DropFirst(n)
+
+	// We'll have to block. Register for notifications and keep trying to
+	// send all the data.
+	e, ch := waiter.NewChannelEntry(nil)
+	s.EventRegister(&e, waiter.EventIn)
+	defer s.EventUnregister(&e)
+
+	for {
+		var rn int
+		rn, msgFlags, senderAddr, senderAddrLen, controlMessages, err = s.nonBlockingRead(t, dst, peek, trunc, senderRequested)
+		n += rn
+		if err != nil && err != syserr.ErrWouldBlock {
+			// Always stop on errors other than would block as we generally
+			// won't be able to get any more data. Eat the error if we got
+			// any data.
+			if n > 0 {
+				err = nil
+			}
+			return
+		}
+		if err == nil && (s.isPacketBased() || !waitAll || int64(rn) >= dst.NumBytes()) {
+			// We got all the data we need.
+			return
+		}
+		dst = dst.DropFirst(rn)
+
+		if err := t.BlockWithDeadline(ch, haveDeadline, deadline); err != nil {
+			if n > 0 {
+				return n, msgFlags, senderAddr, senderAddrLen, controlMessages, nil
+			}
+			if err == syserror.ETIMEDOUT {
+				return 0, 0, nil, 0, socket.ControlMessages{}, syserr.ErrTryAgain
+			}
+			return 0, 0, nil, 0, socket.ControlMessages{}, syserr.FromError(err)
+		}
+	}
+}
+
+// SendMsg implements the linux syscall sendmsg(2) for sockets backed by
+// tcpip.Endpoint.
+func (s *SocketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, haveDeadline bool, deadline ktime.Time, controlMessages socket.ControlMessages) (int, *syserr.Error) {
+	// Reject Unix control messages.
+	if !controlMessages.Unix.Empty() {
+		return 0, syserr.ErrInvalidArgument
+	}
+
+	var addr *tcpip.FullAddress
+	if len(to) > 0 {
+		addrBuf, _, err := AddressAndFamily(s.family, to, true /* strict */)
+		if err != nil {
+			return 0, err
+		}
+
+		addr = &addrBuf
+	}
+
+	opts := tcpip.WriteOptions{
+		To:          addr,
+		More:        flags&linux.MSG_MORE != 0,
+		EndOfRecord: flags&linux.MSG_EOR != 0,
+	}
+
+	v := &ioSequencePayload{t, src}
+	n, resCh, err := s.Endpoint.Write(v, opts)
+	if resCh != nil {
+		if err := t.Block(resCh); err != nil {
+			return 0, syserr.FromError(err)
+		}
+		n, _, err = s.Endpoint.Write(v, opts)
+	}
+	dontWait := flags&linux.MSG_DONTWAIT != 0
+	if err == nil && (n >= v.src.NumBytes() || dontWait) {
+		// Complete write.
+		return int(n), nil
+	}
+	if err != nil && (err != tcpip.ErrWouldBlock || dontWait) {
+		return int(n), syserr.TranslateNetstackError(err)
+	}
+
+	// We'll have to block. Register for notification and keep trying to
+	// send all the data.
+	e, ch := waiter.NewChannelEntry(nil)
+	s.EventRegister(&e, waiter.EventOut)
+	defer s.EventUnregister(&e)
+
+	v.DropFirst(int(n))
+	total := n
+	for {
+		n, _, err = s.Endpoint.Write(v, opts)
+		v.DropFirst(int(n))
+		total += n
+
+		if err != nil && err != tcpip.ErrWouldBlock && total == 0 {
+			return 0, syserr.TranslateNetstackError(err)
+		}
+
+		if err == nil && v.src.NumBytes() == 0 || err != nil && err != tcpip.ErrWouldBlock {
+			return int(total), nil
+		}
+
+		if err := t.BlockWithDeadline(ch, haveDeadline, deadline); err != nil {
+			if err == syserror.ETIMEDOUT {
+				return int(total), syserr.ErrTryAgain
+			}
+			// handleIOError will consume errors from t.Block if needed.
+			return int(total), syserr.FromError(err)
+		}
+	}
+}
+
+// Ioctl implements fs.FileOperations.Ioctl.
+func (s *SocketOperations) Ioctl(ctx context.Context, _ *fs.File, io usermem.IO, args arch.SyscallArguments) (uintptr, error) {
+	// SIOCGSTAMP is implemented by netstack rather than all commonEndpoint
+	// sockets.
+	// TODO(b/78348848): Add a commonEndpoint method to support SIOCGSTAMP.
+	switch args[1].Int() {
+	case syscall.SIOCGSTAMP:
+		s.readMu.Lock()
+		defer s.readMu.Unlock()
+		if !s.timestampValid {
+			return 0, syserror.ENOENT
+		}
+
+		tv := linux.NsecToTimeval(s.timestampNS)
+		_, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), &tv, usermem.IOOpts{
+			AddressSpaceActive: true,
+		})
+		return 0, err
+
+	case linux.TIOCINQ:
+		v, terr := s.Endpoint.GetSockOptInt(tcpip.ReceiveQueueSizeOption)
+		if terr != nil {
+			return 0, syserr.TranslateNetstackError(terr).ToError()
+		}
+
+		// Add bytes removed from the endpoint but not yet sent to the caller.
+		v += len(s.readView)
+
+		if v > math.MaxInt32 {
+			v = math.MaxInt32
+		}
+
+		// Copy result to user-space.
+		_, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), int32(v), usermem.IOOpts{
+			AddressSpaceActive: true,
+		})
+		return 0, err
+	}
+
+	return Ioctl(ctx, s.Endpoint, io, args)
+}
+
+// Ioctl performs a socket ioctl.
+func Ioctl(ctx context.Context, ep commonEndpoint, io usermem.IO, args arch.SyscallArguments) (uintptr, error) {
+	switch arg := int(args[1].Int()); arg {
+	case syscall.SIOCGIFFLAGS,
+		syscall.SIOCGIFADDR,
+		syscall.SIOCGIFBRDADDR,
+		syscall.SIOCGIFDSTADDR,
+		syscall.SIOCGIFHWADDR,
+		syscall.SIOCGIFINDEX,
+		syscall.SIOCGIFMAP,
+		syscall.SIOCGIFMETRIC,
+		syscall.SIOCGIFMTU,
+		syscall.SIOCGIFNAME,
+		syscall.SIOCGIFNETMASK,
+		syscall.SIOCGIFTXQLEN:
+
+		var ifr linux.IFReq
+		if _, err := usermem.CopyObjectIn(ctx, io, args[2].Pointer(), &ifr, usermem.IOOpts{
+			AddressSpaceActive: true,
+		}); err != nil {
+			return 0, err
+		}
+		if err := interfaceIoctl(ctx, io, arg, &ifr); err != nil {
+			return 0, err.ToError()
+		}
+		_, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), &ifr, usermem.IOOpts{
+			AddressSpaceActive: true,
+		})
+		return 0, err
+
+	case syscall.SIOCGIFCONF:
+		// Return a list of interface addresses or the buffer size
+		// necessary to hold the list.
+		var ifc linux.IFConf
+		if _, err := usermem.CopyObjectIn(ctx, io, args[2].Pointer(), &ifc, usermem.IOOpts{
+			AddressSpaceActive: true,
+		}); err != nil {
+			return 0, err
+		}
+
+		if err := ifconfIoctl(ctx, io, &ifc); err != nil {
+			return 0, err
+		}
+
+		_, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), ifc, usermem.IOOpts{
+			AddressSpaceActive: true,
+		})
+
+		return 0, err
+
+	case linux.TIOCINQ:
+		v, terr := ep.GetSockOptInt(tcpip.ReceiveQueueSizeOption)
+		if terr != nil {
+			return 0, syserr.TranslateNetstackError(terr).ToError()
+		}
+
+		if v > math.MaxInt32 {
+			v = math.MaxInt32
+		}
+		// Copy result to user-space.
+		_, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), int32(v), usermem.IOOpts{
+			AddressSpaceActive: true,
+		})
+		return 0, err
+
+	case linux.TIOCOUTQ:
+		v, terr := ep.GetSockOptInt(tcpip.SendQueueSizeOption)
+		if terr != nil {
+			return 0, syserr.TranslateNetstackError(terr).ToError()
+		}
+
+		if v > math.MaxInt32 {
+			v = math.MaxInt32
+		}
+
+		// Copy result to user-space.
+		_, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), int32(v), usermem.IOOpts{
+			AddressSpaceActive: true,
+		})
+		return 0, err
+
+	case linux.SIOCGIFMEM, linux.SIOCGIFPFLAGS, linux.SIOCGMIIPHY, linux.SIOCGMIIREG:
+		unimpl.EmitUnimplementedEvent(ctx)
+	}
+
+	return 0, syserror.ENOTTY
+}
+
+// interfaceIoctl implements interface requests.
+func interfaceIoctl(ctx context.Context, io usermem.IO, arg int, ifr *linux.IFReq) *syserr.Error {
+	var (
+		iface inet.Interface
+		index int32
+		found bool
+	)
+
+	// Find the relevant device.
+	stack := inet.StackFromContext(ctx)
+	if stack == nil {
+		return syserr.ErrNoDevice
+	}
+
+	// SIOCGIFNAME uses ifr.ifr_ifindex rather than ifr.ifr_name to
+	// identify a device.
+	if arg == syscall.SIOCGIFNAME {
+		// Gets the name of the interface given the interface index
+		// stored in ifr_ifindex.
+		index = int32(usermem.ByteOrder.Uint32(ifr.Data[:4]))
+		if iface, ok := stack.Interfaces()[index]; ok {
+			ifr.SetName(iface.Name)
+			return nil
+		}
+		return syserr.ErrNoDevice
+	}
+
+	// Find the relevant device.
+	for index, iface = range stack.Interfaces() {
+		if iface.Name == ifr.Name() {
+			found = true
+			break
+		}
+	}
+	if !found {
+		return syserr.ErrNoDevice
+	}
+
+	switch arg {
+	case syscall.SIOCGIFINDEX:
+		// Copy out the index to the data.
+		usermem.ByteOrder.PutUint32(ifr.Data[:], uint32(index))
+
+	case syscall.SIOCGIFHWADDR:
+		// Copy the hardware address out.
+		ifr.Data[0] = 6 // IEEE802.2 arp type.
+		ifr.Data[1] = 0
+		n := copy(ifr.Data[2:], iface.Addr)
+		for i := 2 + n; i < len(ifr.Data); i++ {
+			ifr.Data[i] = 0 // Clear padding.
+		}
+		usermem.ByteOrder.PutUint16(ifr.Data[:2], uint16(n))
+
+	case syscall.SIOCGIFFLAGS:
+		f, err := interfaceStatusFlags(stack, iface.Name)
+		if err != nil {
+			return err
+		}
+		// Drop the flags that don't fit in the size that we need to return. This
+		// matches Linux behavior.
+		usermem.ByteOrder.PutUint16(ifr.Data[:2], uint16(f))
+
+	case syscall.SIOCGIFADDR:
+		// Copy the IPv4 address out.
+		for _, addr := range stack.InterfaceAddrs()[index] {
+			// This ioctl is only compatible with AF_INET addresses.
+			if addr.Family != linux.AF_INET {
+				continue
+			}
+			copy(ifr.Data[4:8], addr.Addr)
+			break
+		}
+
+	case syscall.SIOCGIFMETRIC:
+		// Gets the metric of the device. As per netdevice(7), this
+		// always just sets ifr_metric to 0.
+		usermem.ByteOrder.PutUint32(ifr.Data[:4], 0)
+
+	case syscall.SIOCGIFMTU:
+		// Gets the MTU of the device.
+		usermem.ByteOrder.PutUint32(ifr.Data[:4], iface.MTU)
+
+	case syscall.SIOCGIFMAP:
+		// Gets the hardware parameters of the device.
+		// TODO(gvisor.dev/issue/505): Implement.
+
+	case syscall.SIOCGIFTXQLEN:
+		// Gets the transmit queue length of the device.
+		// TODO(gvisor.dev/issue/505): Implement.
+
+	case syscall.SIOCGIFDSTADDR:
+		// Gets the destination address of a point-to-point device.
+		// TODO(gvisor.dev/issue/505): Implement.
+
+	case syscall.SIOCGIFBRDADDR:
+		// Gets the broadcast address of a device.
+		// TODO(gvisor.dev/issue/505): Implement.
+
+	case syscall.SIOCGIFNETMASK:
+		// Gets the network mask of a device.
+		for _, addr := range stack.InterfaceAddrs()[index] {
+			// This ioctl is only compatible with AF_INET addresses.
+			if addr.Family != linux.AF_INET {
+				continue
+			}
+			// Populate ifr.ifr_netmask (type sockaddr).
+			usermem.ByteOrder.PutUint16(ifr.Data[0:2], uint16(linux.AF_INET))
+			usermem.ByteOrder.PutUint16(ifr.Data[2:4], 0)
+			var mask uint32 = 0xffffffff << (32 - addr.PrefixLen)
+			// Netmask is expected to be returned as a big endian
+			// value.
+			binary.BigEndian.PutUint32(ifr.Data[4:8], mask)
+			break
+		}
+
+	default:
+		// Not a valid call.
+		return syserr.ErrInvalidArgument
+	}
+
+	return nil
+}
+
+// ifconfIoctl populates a struct ifconf for the SIOCGIFCONF ioctl.
+func ifconfIoctl(ctx context.Context, io usermem.IO, ifc *linux.IFConf) error {
+	// If Ptr is NULL, return the necessary buffer size via Len.
+	// Otherwise, write up to Len bytes starting at Ptr containing ifreq
+	// structs.
+	stack := inet.StackFromContext(ctx)
+	if stack == nil {
+		return syserr.ErrNoDevice.ToError()
+	}
+
+	if ifc.Ptr == 0 {
+		ifc.Len = int32(len(stack.Interfaces())) * int32(linux.SizeOfIFReq)
+		return nil
+	}
+
+	max := ifc.Len
+	ifc.Len = 0
+	for key, ifaceAddrs := range stack.InterfaceAddrs() {
+		iface := stack.Interfaces()[key]
+		for _, ifaceAddr := range ifaceAddrs {
+			// Don't write past the end of the buffer.
+			if ifc.Len+int32(linux.SizeOfIFReq) > max {
+				break
+			}
+			if ifaceAddr.Family != linux.AF_INET {
+				continue
+			}
+
+			// Populate ifr.ifr_addr.
+			ifr := linux.IFReq{}
+			ifr.SetName(iface.Name)
+			usermem.ByteOrder.PutUint16(ifr.Data[0:2], uint16(ifaceAddr.Family))
+			usermem.ByteOrder.PutUint16(ifr.Data[2:4], 0)
+			copy(ifr.Data[4:8], ifaceAddr.Addr[:4])
+
+			// Copy the ifr to userspace.
+			dst := uintptr(ifc.Ptr) + uintptr(ifc.Len)
+			ifc.Len += int32(linux.SizeOfIFReq)
+			if _, err := usermem.CopyObjectOut(ctx, io, usermem.Addr(dst), ifr, usermem.IOOpts{
+				AddressSpaceActive: true,
+			}); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// interfaceStatusFlags returns status flags for an interface in the stack.
+// Flag values and meanings are described in greater detail in netdevice(7) in
+// the SIOCGIFFLAGS section.
+func interfaceStatusFlags(stack inet.Stack, name string) (uint32, *syserr.Error) {
+	// We should only ever be passed a netstack.Stack.
+	epstack, ok := stack.(*Stack)
+	if !ok {
+		return 0, errStackType
+	}
+
+	// Find the NIC corresponding to this interface.
+	for _, info := range epstack.Stack.NICInfo() {
+		if info.Name == name {
+			return nicStateFlagsToLinux(info.Flags), nil
+		}
+	}
+	return 0, syserr.ErrNoDevice
+}
+
+func nicStateFlagsToLinux(f stack.NICStateFlags) uint32 {
+	var rv uint32
+	if f.Up {
+		rv |= linux.IFF_UP | linux.IFF_LOWER_UP
+	}
+	if f.Running {
+		rv |= linux.IFF_RUNNING
+	}
+	if f.Promiscuous {
+		rv |= linux.IFF_PROMISC
+	}
+	if f.Loopback {
+		rv |= linux.IFF_LOOPBACK
+	}
+	return rv
+}
+
+// State implements socket.Socket.State. State translates the internal state
+// returned by netstack to values defined by Linux.
+func (s *SocketOperations) State() uint32 {
+	if s.family != linux.AF_INET && s.family != linux.AF_INET6 {
+		// States not implemented for this socket's family.
+		return 0
+	}
+
+	switch {
+	case s.skType == linux.SOCK_STREAM && s.protocol == 0 || s.protocol == syscall.IPPROTO_TCP:
+		// TCP socket.
+		switch tcp.EndpointState(s.Endpoint.State()) {
+		case tcp.StateEstablished:
+			return linux.TCP_ESTABLISHED
+		case tcp.StateSynSent:
+			return linux.TCP_SYN_SENT
+		case tcp.StateSynRecv:
+			return linux.TCP_SYN_RECV
+		case tcp.StateFinWait1:
+			return linux.TCP_FIN_WAIT1
+		case tcp.StateFinWait2:
+			return linux.TCP_FIN_WAIT2
+		case tcp.StateTimeWait:
+			return linux.TCP_TIME_WAIT
+		case tcp.StateClose, tcp.StateInitial, tcp.StateBound, tcp.StateConnecting, tcp.StateError:
+			return linux.TCP_CLOSE
+		case tcp.StateCloseWait:
+			return linux.TCP_CLOSE_WAIT
+		case tcp.StateLastAck:
+			return linux.TCP_LAST_ACK
+		case tcp.StateListen:
+			return linux.TCP_LISTEN
+		case tcp.StateClosing:
+			return linux.TCP_CLOSING
+		default:
+			// Internal or unknown state.
+			return 0
+		}
+	case s.skType == linux.SOCK_DGRAM && s.protocol == 0 || s.protocol == syscall.IPPROTO_UDP:
+		// UDP socket.
+		switch udp.EndpointState(s.Endpoint.State()) {
+		case udp.StateInitial, udp.StateBound, udp.StateClosed:
+			return linux.TCP_CLOSE
+		case udp.StateConnected:
+			return linux.TCP_ESTABLISHED
+		default:
+			return 0
+		}
+	case s.skType == linux.SOCK_DGRAM && s.protocol == syscall.IPPROTO_ICMP || s.protocol == syscall.IPPROTO_ICMPV6:
+		// TODO(b/112063468): Export states for ICMP sockets.
+	case s.skType == linux.SOCK_RAW:
+		// TODO(b/112063468): Export states for raw sockets.
+	default:
+		// Unknown transport protocol, how did we make this socket?
+		log.Warningf("Unknown transport protocol for an existing socket: family=%v, type=%v, protocol=%v, internal type %v", s.family, s.skType, s.protocol, reflect.TypeOf(s.Endpoint).Elem())
+		return 0
+	}
+
+	return 0
+}
+
+// Type implements socket.Socket.Type.
+func (s *SocketOperations) Type() (family int, skType linux.SockType, protocol int) {
+	return s.family, s.skType, s.protocol
+}