diff options
-rw-r--r-- | pkg/abi/linux/netfilter.go | 21 | ||||
-rw-r--r-- | pkg/sentry/socket/netfilter/extensions.go | 72 | ||||
-rw-r--r-- | pkg/sentry/socket/netfilter/ipv4.go | 23 | ||||
-rw-r--r-- | pkg/sentry/socket/netfilter/ipv6.go | 23 | ||||
-rw-r--r-- | pkg/sentry/socket/netfilter/netfilter.go | 26 | ||||
-rw-r--r-- | pkg/sentry/socket/netfilter/targets.go | 393 | ||||
-rw-r--r-- | pkg/sentry/socket/netstack/netstack.go | 20 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv4/ipv4_test.go | 6 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv6/ipv6_test.go | 6 | ||||
-rw-r--r-- | pkg/tcpip/stack/iptables.go | 48 | ||||
-rw-r--r-- | pkg/tcpip/stack/iptables_targets.go | 81 | ||||
-rw-r--r-- | pkg/tcpip/stack/iptables_types.go | 43 | ||||
-rw-r--r-- | test/syscalls/linux/ip6tables.cc | 32 | ||||
-rw-r--r-- | test/syscalls/linux/iptables.cc | 26 |
14 files changed, 586 insertions, 234 deletions
diff --git a/pkg/abi/linux/netfilter.go b/pkg/abi/linux/netfilter.go index 1c5b34711..b521144d9 100644 --- a/pkg/abi/linux/netfilter.go +++ b/pkg/abi/linux/netfilter.go @@ -265,6 +265,18 @@ type KernelXTEntryMatch struct { Data []byte } +// XTGetRevision corresponds to xt_get_revision in +// include/uapi/linux/netfilter/x_tables.h +// +// +marshal +type XTGetRevision struct { + Name ExtensionName + Revision uint8 +} + +// SizeOfXTGetRevision is the size of an XTGetRevision. +const SizeOfXTGetRevision = 30 + // XTEntryTarget holds a target for a rule. For example, it can specify that // packets matching the rule should DROP, ACCEPT, or use an extension target. // iptables-extension(8) has a list of possible targets. @@ -285,6 +297,13 @@ type XTEntryTarget struct { // SizeOfXTEntryTarget is the size of an XTEntryTarget. const SizeOfXTEntryTarget = 32 +// KernelXTEntryTarget is identical to XTEntryTarget, but contains a +// variable-length Data field. +type KernelXTEntryTarget struct { + XTEntryTarget + Data []byte +} + // XTStandardTarget is a built-in target, one of ACCEPT, DROP, JUMP, QUEUE, // RETURN, or jump. It corresponds to struct xt_standard_target in // include/uapi/linux/netfilter/x_tables.h. @@ -510,6 +529,8 @@ type IPTReplace struct { const SizeOfIPTReplace = 96 // ExtensionName holds the name of a netfilter extension. +// +// +marshal type ExtensionName [XT_EXTENSION_MAXNAMELEN]byte // String implements fmt.Stringer. diff --git a/pkg/sentry/socket/netfilter/extensions.go b/pkg/sentry/socket/netfilter/extensions.go index 0336a32d8..549787955 100644 --- a/pkg/sentry/socket/netfilter/extensions.go +++ b/pkg/sentry/socket/netfilter/extensions.go @@ -19,6 +19,8 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/binary" + "gvisor.dev/gvisor/pkg/syserr" + "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/stack" "gvisor.dev/gvisor/pkg/usermem" ) @@ -37,7 +39,7 @@ type matchMaker interface { // name is the matcher name as stored in the xt_entry_match struct. name() string - // marshal converts from an stack.Matcher to an ABI struct. + // marshal converts from a stack.Matcher to an ABI struct. marshal(matcher stack.Matcher) []byte // unmarshal converts from the ABI matcher struct to an @@ -93,3 +95,71 @@ func unmarshalMatcher(match linux.XTEntryMatch, filter stack.IPHeaderFilter, buf } return matchMaker.unmarshal(buf, filter) } + +// targetMaker knows how to (un)marshal a target. Once registered, +// marshalTarget and unmarshalTarget can be used. +type targetMaker interface { + // id uniquely identifies the target. + id() stack.TargetID + + // marshal converts from a stack.Target to an ABI struct. + marshal(target stack.Target) []byte + + // unmarshal converts from the ABI matcher struct to a stack.Target. + unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error) +} + +// targetMakers maps the TargetID of supported targets to the targetMaker that +// marshals and unmarshals it. It is immutable after package initialization. +var targetMakers = map[stack.TargetID]targetMaker{} + +func targetRevision(name string, netProto tcpip.NetworkProtocolNumber, rev uint8) (uint8, bool) { + tid := stack.TargetID{ + Name: name, + NetworkProtocol: netProto, + Revision: rev, + } + if _, ok := targetMakers[tid]; !ok { + return 0, false + } + + // Return the highest supported revision unless rev is higher. + for _, other := range targetMakers { + otherID := other.id() + if name == otherID.Name && netProto == otherID.NetworkProtocol && otherID.Revision > rev { + rev = uint8(otherID.Revision) + } + } + return rev, true +} + +// registerTargetMaker should be called by target extensions to register them +// with the netfilter package. +func registerTargetMaker(tm targetMaker) { + if _, ok := targetMakers[tm.id()]; ok { + panic(fmt.Sprintf("multiple targets registered with name %q.", tm.id())) + } + targetMakers[tm.id()] = tm +} + +func marshalTarget(target stack.Target) []byte { + targetMaker, ok := targetMakers[target.ID()] + if !ok { + panic(fmt.Sprintf("unknown target of type %T with id %+v.", target, target.ID())) + } + return targetMaker.marshal(target) +} + +func unmarshalTarget(target linux.XTEntryTarget, filter stack.IPHeaderFilter, buf []byte) (stack.Target, *syserr.Error) { + tid := stack.TargetID{ + Name: target.Name.String(), + NetworkProtocol: filter.NetworkProtocol(), + Revision: target.Revision, + } + targetMaker, ok := targetMakers[tid] + if !ok { + nflog("unsupported target with name %q", target.Name.String()) + return nil, syserr.ErrInvalidArgument + } + return targetMaker.unmarshal(buf, filter) +} diff --git a/pkg/sentry/socket/netfilter/ipv4.go b/pkg/sentry/socket/netfilter/ipv4.go index e4c55a100..b560fae0d 100644 --- a/pkg/sentry/socket/netfilter/ipv4.go +++ b/pkg/sentry/socket/netfilter/ipv4.go @@ -181,18 +181,23 @@ func modifyEntries4(stk *stack.Stack, optVal []byte, replace *linux.IPTReplace, nflog("entry doesn't have enough room for its target (only %d bytes remain)", len(optVal)) return nil, syserr.ErrInvalidArgument } - target, err := parseTarget(filter, optVal[:targetSize]) - if err != nil { - nflog("failed to parse target: %v", err) - return nil, syserr.ErrInvalidArgument - } - optVal = optVal[targetSize:] - table.Rules = append(table.Rules, stack.Rule{ + rule := stack.Rule{ Filter: filter, - Target: target, Matchers: matchers, - }) + } + + { + target, err := parseTarget(filter, optVal[:targetSize], false /* ipv6 */) + if err != nil { + nflog("failed to parse target: %v", err) + return nil, err + } + rule.Target = target + } + optVal = optVal[targetSize:] + + table.Rules = append(table.Rules, rule) offsets[offset] = int(entryIdx) offset += uint32(entry.NextOffset) diff --git a/pkg/sentry/socket/netfilter/ipv6.go b/pkg/sentry/socket/netfilter/ipv6.go index 3b2c1becd..4253f7bf4 100644 --- a/pkg/sentry/socket/netfilter/ipv6.go +++ b/pkg/sentry/socket/netfilter/ipv6.go @@ -184,18 +184,23 @@ func modifyEntries6(stk *stack.Stack, optVal []byte, replace *linux.IPTReplace, nflog("entry doesn't have enough room for its target (only %d bytes remain)", len(optVal)) return nil, syserr.ErrInvalidArgument } - target, err := parseTarget(filter, optVal[:targetSize]) - if err != nil { - nflog("failed to parse target: %v", err) - return nil, syserr.ErrInvalidArgument - } - optVal = optVal[targetSize:] - table.Rules = append(table.Rules, stack.Rule{ + rule := stack.Rule{ Filter: filter, - Target: target, Matchers: matchers, - }) + } + + { + target, err := parseTarget(filter, optVal[:targetSize], true /* ipv6 */) + if err != nil { + nflog("failed to parse target: %v", err) + return nil, err + } + rule.Target = target + } + optVal = optVal[targetSize:] + + table.Rules = append(table.Rules, rule) offsets[offset] = int(entryIdx) offset += uint32(entry.NextOffset) diff --git a/pkg/sentry/socket/netfilter/netfilter.go b/pkg/sentry/socket/netfilter/netfilter.go index 871ea80ee..94cb80437 100644 --- a/pkg/sentry/socket/netfilter/netfilter.go +++ b/pkg/sentry/socket/netfilter/netfilter.go @@ -25,6 +25,7 @@ import ( "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/syserr" + "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/stack" "gvisor.dev/gvisor/pkg/usermem" ) @@ -199,7 +200,7 @@ func SetEntries(stk *stack.Stack, optVal []byte, ipv6 bool) *syserr.Error { // Check the user chains. for ruleIdx, rule := range table.Rules { - if _, ok := rule.Target.(stack.UserChainTarget); !ok { + if _, ok := rule.Target.(*stack.UserChainTarget); !ok { continue } @@ -220,7 +221,7 @@ func SetEntries(stk *stack.Stack, optVal []byte, ipv6 bool) *syserr.Error { // Set each jump to point to the appropriate rule. Right now they hold byte // offsets. for ruleIdx, rule := range table.Rules { - jump, ok := rule.Target.(JumpTarget) + jump, ok := rule.Target.(*JumpTarget) if !ok { continue } @@ -311,7 +312,7 @@ func validUnderflow(rule stack.Rule, ipv6 bool) bool { return false } switch rule.Target.(type) { - case stack.AcceptTarget, stack.DropTarget: + case *stack.AcceptTarget, *stack.DropTarget: return true default: return false @@ -322,7 +323,7 @@ func isUnconditionalAccept(rule stack.Rule, ipv6 bool) bool { if !validUnderflow(rule, ipv6) { return false } - _, ok := rule.Target.(stack.AcceptTarget) + _, ok := rule.Target.(*stack.AcceptTarget) return ok } @@ -341,3 +342,20 @@ func hookFromLinux(hook int) stack.Hook { } panic(fmt.Sprintf("Unknown hook %d does not correspond to a builtin chain", hook)) } + +// TargetRevision returns a linux.XTGetRevision for a given target. It sets +// Revision to the highest supported value, unless the provided revision number +// is larger. +func TargetRevision(t *kernel.Task, revPtr usermem.Addr, netProto tcpip.NetworkProtocolNumber) (linux.XTGetRevision, *syserr.Error) { + // Read in the target name and version. + var rev linux.XTGetRevision + if _, err := rev.CopyIn(t, revPtr); err != nil { + return linux.XTGetRevision{}, syserr.FromError(err) + } + maxSupported, ok := targetRevision(rev.Name.String(), netProto, rev.Revision) + if !ok { + return linux.XTGetRevision{}, syserr.ErrProtocolNotSupported + } + rev.Revision = maxSupported + return rev, nil +} diff --git a/pkg/sentry/socket/netfilter/targets.go b/pkg/sentry/socket/netfilter/targets.go index 87e41abd8..e3b108e93 100644 --- a/pkg/sentry/socket/netfilter/targets.go +++ b/pkg/sentry/socket/netfilter/targets.go @@ -15,255 +15,276 @@ package netfilter import ( - "errors" "fmt" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/binary" + "gvisor.dev/gvisor/pkg/syserr" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/header" "gvisor.dev/gvisor/pkg/tcpip/stack" "gvisor.dev/gvisor/pkg/usermem" ) -// errorTargetName is used to mark targets as error targets. Error targets -// shouldn't be reached - an error has occurred if we fall through to one. -const errorTargetName = "ERROR" +func init() { + // Standard targets include ACCEPT, DROP, RETURN, and JUMP. + registerTargetMaker(&standardTargetMaker{ + NetworkProtocol: header.IPv4ProtocolNumber, + }) + registerTargetMaker(&standardTargetMaker{ + NetworkProtocol: header.IPv6ProtocolNumber, + }) + + // Both user chains and actual errors are represented in iptables by + // error targets. + registerTargetMaker(&errorTargetMaker{ + NetworkProtocol: header.IPv4ProtocolNumber, + }) + registerTargetMaker(&errorTargetMaker{ + NetworkProtocol: header.IPv6ProtocolNumber, + }) + + registerTargetMaker(&redirectTargetMaker{ + NetworkProtocol: header.IPv4ProtocolNumber, + }) +} -// redirectTargetName is used to mark targets as redirect targets. Redirect -// targets should be reached for only NAT and Mangle tables. These targets will -// change the destination port/destination IP for packets. -const redirectTargetName = "REDIRECT" +type standardTargetMaker struct { + NetworkProtocol tcpip.NetworkProtocolNumber +} -func marshalTarget(target stack.Target) []byte { +func (sm *standardTargetMaker) id() stack.TargetID { + // Standard targets have the empty string as a name and no revisions. + return stack.TargetID{ + NetworkProtocol: sm.NetworkProtocol, + } +} +func (*standardTargetMaker) marshal(target stack.Target) []byte { + // Translate verdicts the same way as the iptables tool. + var verdict int32 switch tg := target.(type) { - case stack.AcceptTarget: - return marshalStandardTarget(stack.RuleAccept) - case stack.DropTarget: - return marshalStandardTarget(stack.RuleDrop) - case stack.ErrorTarget: - return marshalErrorTarget(errorTargetName) - case stack.UserChainTarget: - return marshalErrorTarget(tg.Name) - case stack.ReturnTarget: - return marshalStandardTarget(stack.RuleReturn) - case stack.RedirectTarget: - return marshalRedirectTarget(tg) - case JumpTarget: - return marshalJumpTarget(tg) + case *stack.AcceptTarget: + verdict = -linux.NF_ACCEPT - 1 + case *stack.DropTarget: + verdict = -linux.NF_DROP - 1 + case *stack.ReturnTarget: + verdict = linux.NF_RETURN + case *JumpTarget: + verdict = int32(tg.Offset) default: panic(fmt.Errorf("unknown target of type %T", target)) } -} - -func marshalStandardTarget(verdict stack.RuleVerdict) []byte { - nflog("convert to binary: marshalling standard target") // The target's name will be the empty string. - target := linux.XTStandardTarget{ + xt := linux.XTStandardTarget{ Target: linux.XTEntryTarget{ TargetSize: linux.SizeOfXTStandardTarget, }, - Verdict: translateFromStandardVerdict(verdict), + Verdict: verdict, } ret := make([]byte, 0, linux.SizeOfXTStandardTarget) - return binary.Marshal(ret, usermem.ByteOrder, target) + return binary.Marshal(ret, usermem.ByteOrder, xt) +} + +func (*standardTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error) { + if len(buf) != linux.SizeOfXTStandardTarget { + nflog("buf has wrong size for standard target %d", len(buf)) + return nil, syserr.ErrInvalidArgument + } + var standardTarget linux.XTStandardTarget + buf = buf[:linux.SizeOfXTStandardTarget] + binary.Unmarshal(buf, usermem.ByteOrder, &standardTarget) + + if standardTarget.Verdict < 0 { + // A Verdict < 0 indicates a non-jump verdict. + return translateToStandardTarget(standardTarget.Verdict, filter.NetworkProtocol()) + } + // A verdict >= 0 indicates a jump. + return &JumpTarget{ + Offset: uint32(standardTarget.Verdict), + NetworkProtocol: filter.NetworkProtocol(), + }, nil +} + +type errorTargetMaker struct { + NetworkProtocol tcpip.NetworkProtocolNumber +} + +func (em *errorTargetMaker) id() stack.TargetID { + // Error targets have no revision. + return stack.TargetID{ + Name: stack.ErrorTargetName, + NetworkProtocol: em.NetworkProtocol, + } } -func marshalErrorTarget(errorName string) []byte { +func (*errorTargetMaker) marshal(target stack.Target) []byte { + var errorName string + switch tg := target.(type) { + case *stack.ErrorTarget: + errorName = stack.ErrorTargetName + case *stack.UserChainTarget: + errorName = tg.Name + default: + panic(fmt.Sprintf("errorMakerTarget cannot marshal unknown type %T", target)) + } + // This is an error target named error - target := linux.XTErrorTarget{ + xt := linux.XTErrorTarget{ Target: linux.XTEntryTarget{ TargetSize: linux.SizeOfXTErrorTarget, }, } - copy(target.Name[:], errorName) - copy(target.Target.Name[:], errorTargetName) + copy(xt.Name[:], errorName) + copy(xt.Target.Name[:], stack.ErrorTargetName) ret := make([]byte, 0, linux.SizeOfXTErrorTarget) - return binary.Marshal(ret, usermem.ByteOrder, target) + return binary.Marshal(ret, usermem.ByteOrder, xt) +} + +func (*errorTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error) { + if len(buf) != linux.SizeOfXTErrorTarget { + nflog("buf has insufficient size for error target %d", len(buf)) + return nil, syserr.ErrInvalidArgument + } + var errorTarget linux.XTErrorTarget + buf = buf[:linux.SizeOfXTErrorTarget] + binary.Unmarshal(buf, usermem.ByteOrder, &errorTarget) + + // Error targets are used in 2 cases: + // * An actual error case. These rules have an error + // named stack.ErrorTargetName. The last entry of the table + // is usually an error case to catch any packets that + // somehow fall through every rule. + // * To mark the start of a user defined chain. These + // rules have an error with the name of the chain. + switch name := errorTarget.Name.String(); name { + case stack.ErrorTargetName: + return &stack.ErrorTarget{NetworkProtocol: filter.NetworkProtocol()}, nil + default: + // User defined chain. + return &stack.UserChainTarget{ + Name: name, + NetworkProtocol: filter.NetworkProtocol(), + }, nil + } } -func marshalRedirectTarget(rt stack.RedirectTarget) []byte { +type redirectTargetMaker struct { + NetworkProtocol tcpip.NetworkProtocolNumber +} + +func (rm *redirectTargetMaker) id() stack.TargetID { + return stack.TargetID{ + Name: stack.RedirectTargetName, + NetworkProtocol: rm.NetworkProtocol, + } +} + +func (*redirectTargetMaker) marshal(target stack.Target) []byte { + rt := target.(*stack.RedirectTarget) // This is a redirect target named redirect - target := linux.XTRedirectTarget{ + xt := linux.XTRedirectTarget{ Target: linux.XTEntryTarget{ TargetSize: linux.SizeOfXTRedirectTarget, }, } - copy(target.Target.Name[:], redirectTargetName) + copy(xt.Target.Name[:], stack.RedirectTargetName) ret := make([]byte, 0, linux.SizeOfXTRedirectTarget) - target.NfRange.RangeSize = 1 + xt.NfRange.RangeSize = 1 if rt.RangeProtoSpecified { - target.NfRange.RangeIPV4.Flags |= linux.NF_NAT_RANGE_PROTO_SPECIFIED + xt.NfRange.RangeIPV4.Flags |= linux.NF_NAT_RANGE_PROTO_SPECIFIED } - // Convert port from little endian to big endian. - port := make([]byte, 2) - binary.LittleEndian.PutUint16(port, rt.MinPort) - target.NfRange.RangeIPV4.MinPort = binary.BigEndian.Uint16(port) - binary.LittleEndian.PutUint16(port, rt.MaxPort) - target.NfRange.RangeIPV4.MaxPort = binary.BigEndian.Uint16(port) - return binary.Marshal(ret, usermem.ByteOrder, target) + xt.NfRange.RangeIPV4.MinPort = htons(rt.MinPort) + xt.NfRange.RangeIPV4.MaxPort = htons(rt.MaxPort) + return binary.Marshal(ret, usermem.ByteOrder, xt) } -func marshalJumpTarget(jt JumpTarget) []byte { - nflog("convert to binary: marshalling jump target") +func (*redirectTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error) { + if len(buf) < linux.SizeOfXTRedirectTarget { + nflog("redirectTargetMaker: buf has insufficient size for redirect target %d", len(buf)) + return nil, syserr.ErrInvalidArgument + } - // The target's name will be the empty string. - target := linux.XTStandardTarget{ - Target: linux.XTEntryTarget{ - TargetSize: linux.SizeOfXTStandardTarget, - }, - // Verdict is overloaded by the ABI. When positive, it holds - // the jump offset from the start of the table. - Verdict: int32(jt.Offset), + if p := filter.Protocol; p != header.TCPProtocolNumber && p != header.UDPProtocolNumber { + nflog("redirectTargetMaker: bad proto %d", p) + return nil, syserr.ErrInvalidArgument } - ret := make([]byte, 0, linux.SizeOfXTStandardTarget) - return binary.Marshal(ret, usermem.ByteOrder, target) -} + var redirectTarget linux.XTRedirectTarget + buf = buf[:linux.SizeOfXTRedirectTarget] + binary.Unmarshal(buf, usermem.ByteOrder, &redirectTarget) -// translateFromStandardVerdict translates verdicts the same way as the iptables -// tool. -func translateFromStandardVerdict(verdict stack.RuleVerdict) int32 { - switch verdict { - case stack.RuleAccept: - return -linux.NF_ACCEPT - 1 - case stack.RuleDrop: - return -linux.NF_DROP - 1 - case stack.RuleReturn: - return linux.NF_RETURN - default: - // TODO(gvisor.dev/issue/170): Support Jump. - panic(fmt.Sprintf("unknown standard verdict: %d", verdict)) + // Copy linux.XTRedirectTarget to stack.RedirectTarget. + target := stack.RedirectTarget{NetworkProtocol: filter.NetworkProtocol()} + + // RangeSize should be 1. + nfRange := redirectTarget.NfRange + if nfRange.RangeSize != 1 { + nflog("redirectTargetMaker: bad rangesize %d", nfRange.RangeSize) + return nil, syserr.ErrInvalidArgument } + + // TODO(gvisor.dev/issue/170): Check if the flags are valid. + // Also check if we need to map ports or IP. + // For now, redirect target only supports destination port change. + // Port range and IP range are not supported yet. + if nfRange.RangeIPV4.Flags&linux.NF_NAT_RANGE_PROTO_SPECIFIED == 0 { + nflog("redirectTargetMaker: invalid range flags %d", nfRange.RangeIPV4.Flags) + return nil, syserr.ErrInvalidArgument + } + target.RangeProtoSpecified = true + + target.MinIP = tcpip.Address(nfRange.RangeIPV4.MinIP[:]) + target.MaxIP = tcpip.Address(nfRange.RangeIPV4.MaxIP[:]) + + // TODO(gvisor.dev/issue/170): Port range is not supported yet. + if nfRange.RangeIPV4.MinPort != nfRange.RangeIPV4.MaxPort { + nflog("redirectTargetMaker: MinPort != MaxPort (%d, %d)", nfRange.RangeIPV4.MinPort, nfRange.RangeIPV4.MaxPort) + return nil, syserr.ErrInvalidArgument + } + + target.MinPort = ntohs(nfRange.RangeIPV4.MinPort) + target.MaxPort = ntohs(nfRange.RangeIPV4.MaxPort) + + return &target, nil } // translateToStandardTarget translates from the value in a // linux.XTStandardTarget to an stack.Verdict. -func translateToStandardTarget(val int32) (stack.Target, error) { +func translateToStandardTarget(val int32, netProto tcpip.NetworkProtocolNumber) (stack.Target, *syserr.Error) { // TODO(gvisor.dev/issue/170): Support other verdicts. switch val { case -linux.NF_ACCEPT - 1: - return stack.AcceptTarget{}, nil + return &stack.AcceptTarget{NetworkProtocol: netProto}, nil case -linux.NF_DROP - 1: - return stack.DropTarget{}, nil + return &stack.DropTarget{NetworkProtocol: netProto}, nil case -linux.NF_QUEUE - 1: - return nil, errors.New("unsupported iptables verdict QUEUE") + nflog("unsupported iptables verdict QUEUE") + return nil, syserr.ErrInvalidArgument case linux.NF_RETURN: - return stack.ReturnTarget{}, nil + return &stack.ReturnTarget{NetworkProtocol: netProto}, nil default: - return nil, fmt.Errorf("unknown iptables verdict %d", val) + nflog("unknown iptables verdict %d", val) + return nil, syserr.ErrInvalidArgument } } // parseTarget parses a target from optVal. optVal should contain only the // target. -func parseTarget(filter stack.IPHeaderFilter, optVal []byte) (stack.Target, error) { +func parseTarget(filter stack.IPHeaderFilter, optVal []byte, ipv6 bool) (stack.Target, *syserr.Error) { nflog("set entries: parsing target of size %d", len(optVal)) if len(optVal) < linux.SizeOfXTEntryTarget { - return nil, fmt.Errorf("optVal has insufficient size for entry target %d", len(optVal)) + nflog("optVal has insufficient size for entry target %d", len(optVal)) + return nil, syserr.ErrInvalidArgument } var target linux.XTEntryTarget buf := optVal[:linux.SizeOfXTEntryTarget] binary.Unmarshal(buf, usermem.ByteOrder, &target) - switch target.Name.String() { - case "": - // Standard target. - if len(optVal) != linux.SizeOfXTStandardTarget { - return nil, fmt.Errorf("optVal has wrong size for standard target %d", len(optVal)) - } - var standardTarget linux.XTStandardTarget - buf = optVal[:linux.SizeOfXTStandardTarget] - binary.Unmarshal(buf, usermem.ByteOrder, &standardTarget) - - if standardTarget.Verdict < 0 { - // A Verdict < 0 indicates a non-jump verdict. - return translateToStandardTarget(standardTarget.Verdict) - } - // A verdict >= 0 indicates a jump. - return JumpTarget{Offset: uint32(standardTarget.Verdict)}, nil - - case errorTargetName: - // Error target. - if len(optVal) != linux.SizeOfXTErrorTarget { - return nil, fmt.Errorf("optVal has insufficient size for error target %d", len(optVal)) - } - var errorTarget linux.XTErrorTarget - buf = optVal[:linux.SizeOfXTErrorTarget] - binary.Unmarshal(buf, usermem.ByteOrder, &errorTarget) - - // Error targets are used in 2 cases: - // * An actual error case. These rules have an error - // named errorTargetName. The last entry of the table - // is usually an error case to catch any packets that - // somehow fall through every rule. - // * To mark the start of a user defined chain. These - // rules have an error with the name of the chain. - switch name := errorTarget.Name.String(); name { - case errorTargetName: - nflog("set entries: error target") - return stack.ErrorTarget{}, nil - default: - // User defined chain. - nflog("set entries: user-defined target %q", name) - return stack.UserChainTarget{Name: name}, nil - } - - case redirectTargetName: - // Redirect target. - if len(optVal) < linux.SizeOfXTRedirectTarget { - return nil, fmt.Errorf("netfilter.SetEntries: optVal has insufficient size for redirect target %d", len(optVal)) - } - - if p := filter.Protocol; p != header.TCPProtocolNumber && p != header.UDPProtocolNumber { - return nil, fmt.Errorf("netfilter.SetEntries: bad proto %d", p) - } - - var redirectTarget linux.XTRedirectTarget - buf = optVal[:linux.SizeOfXTRedirectTarget] - binary.Unmarshal(buf, usermem.ByteOrder, &redirectTarget) - - // Copy linux.XTRedirectTarget to stack.RedirectTarget. - var target stack.RedirectTarget - nfRange := redirectTarget.NfRange - - // RangeSize should be 1. - if nfRange.RangeSize != 1 { - return nil, fmt.Errorf("netfilter.SetEntries: bad rangesize %d", nfRange.RangeSize) - } - - // TODO(gvisor.dev/issue/170): Check if the flags are valid. - // Also check if we need to map ports or IP. - // For now, redirect target only supports destination port change. - // Port range and IP range are not supported yet. - if nfRange.RangeIPV4.Flags&linux.NF_NAT_RANGE_PROTO_SPECIFIED == 0 { - return nil, fmt.Errorf("netfilter.SetEntries: invalid range flags %d", nfRange.RangeIPV4.Flags) - } - target.RangeProtoSpecified = true - - target.MinIP = tcpip.Address(nfRange.RangeIPV4.MinIP[:]) - target.MaxIP = tcpip.Address(nfRange.RangeIPV4.MaxIP[:]) - - // TODO(gvisor.dev/issue/170): Port range is not supported yet. - if nfRange.RangeIPV4.MinPort != nfRange.RangeIPV4.MaxPort { - return nil, fmt.Errorf("netfilter.SetEntries: minport != maxport (%d, %d)", nfRange.RangeIPV4.MinPort, nfRange.RangeIPV4.MaxPort) - } - - // Convert port from big endian to little endian. - port := make([]byte, 2) - binary.BigEndian.PutUint16(port, nfRange.RangeIPV4.MinPort) - target.MinPort = binary.LittleEndian.Uint16(port) - - binary.BigEndian.PutUint16(port, nfRange.RangeIPV4.MaxPort) - target.MaxPort = binary.LittleEndian.Uint16(port) - return target, nil - } - // Unknown target. - return nil, fmt.Errorf("unknown target %q doesn't exist or isn't supported yet", target.Name.String()) + return unmarshalTarget(target, filter, optVal) } // JumpTarget implements stack.Target. @@ -274,9 +295,31 @@ type JumpTarget struct { // RuleNum is the rule to jump to. RuleNum int + + // NetworkProtocol is the network protocol the target is used with. + NetworkProtocol tcpip.NetworkProtocolNumber +} + +// ID implements Target.ID. +func (jt *JumpTarget) ID() stack.TargetID { + return stack.TargetID{ + NetworkProtocol: jt.NetworkProtocol, + } } // Action implements stack.Target.Action. func (jt JumpTarget) Action(*stack.PacketBuffer, *stack.ConnTrack, stack.Hook, *stack.GSO, *stack.Route, tcpip.Address) (stack.RuleVerdict, int) { return stack.RuleJump, jt.RuleNum } + +func ntohs(port uint16) uint16 { + buf := make([]byte, 2) + binary.BigEndian.PutUint16(buf, port) + return usermem.ByteOrder.Uint16(buf) +} + +func htons(port uint16) uint16 { + buf := make([]byte, 2) + usermem.ByteOrder.PutUint16(buf, port) + return binary.BigEndian.Uint16(buf) +} diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go index 6fede181a..20f66fbf1 100644 --- a/pkg/sentry/socket/netstack/netstack.go +++ b/pkg/sentry/socket/netstack/netstack.go @@ -1719,6 +1719,26 @@ func getSockOptIP(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, name in } return &entries, nil + case linux.IPT_SO_GET_REVISION_TARGET: + if outLen < linux.SizeOfXTGetRevision { + return nil, syserr.ErrInvalidArgument + } + + // Only valid for raw IPv4 sockets. + if family, skType, _ := s.Type(); family != linux.AF_INET || skType != linux.SOCK_RAW { + return nil, syserr.ErrProtocolNotAvailable + } + + stack := inet.StackFromContext(t) + if stack == nil { + return nil, syserr.ErrNoDevice + } + ret, err := netfilter.TargetRevision(t, outPtr, header.IPv4ProtocolNumber) + if err != nil { + return nil, err + } + return &ret, nil + default: emitUnimplementedEventIP(t, name) } diff --git a/pkg/tcpip/network/ipv4/ipv4_test.go b/pkg/tcpip/network/ipv4/ipv4_test.go index 0b3ed9483..277560e35 100644 --- a/pkg/tcpip/network/ipv4/ipv4_test.go +++ b/pkg/tcpip/network/ipv4/ipv4_test.go @@ -1040,7 +1040,7 @@ func TestWriteStats(t *testing.T) { t.Fatalf("failed to find filter table") } ruleIdx := filter.BuiltinChains[stack.Output] - filter.Rules[ruleIdx].Target = stack.DropTarget{} + filter.Rules[ruleIdx].Target = &stack.DropTarget{} if err := ipt.ReplaceTable(stack.FilterTable, filter, false /* ipv6 */); err != nil { t.Fatalf("failed to replace table: %s", err) } @@ -1062,10 +1062,10 @@ func TestWriteStats(t *testing.T) { } // We'll match and DROP the last packet. ruleIdx := filter.BuiltinChains[stack.Output] - filter.Rules[ruleIdx].Target = stack.DropTarget{} + filter.Rules[ruleIdx].Target = &stack.DropTarget{} filter.Rules[ruleIdx].Matchers = []stack.Matcher{&limitedMatcher{nPackets - 1}} // Make sure the next rule is ACCEPT. - filter.Rules[ruleIdx+1].Target = stack.AcceptTarget{} + filter.Rules[ruleIdx+1].Target = &stack.AcceptTarget{} if err := ipt.ReplaceTable(stack.FilterTable, filter, false /* ipv6 */); err != nil { t.Fatalf("failed to replace table: %s", err) } diff --git a/pkg/tcpip/network/ipv6/ipv6_test.go b/pkg/tcpip/network/ipv6/ipv6_test.go index d85b5c00f..94344057e 100644 --- a/pkg/tcpip/network/ipv6/ipv6_test.go +++ b/pkg/tcpip/network/ipv6/ipv6_test.go @@ -1748,7 +1748,7 @@ func TestWriteStats(t *testing.T) { t.Fatalf("failed to find filter table") } ruleIdx := filter.BuiltinChains[stack.Output] - filter.Rules[ruleIdx].Target = stack.DropTarget{} + filter.Rules[ruleIdx].Target = &stack.DropTarget{} if err := ipt.ReplaceTable(stack.FilterTable, filter, true /* ipv6 */); err != nil { t.Fatalf("failed to replace table: %v", err) } @@ -1770,10 +1770,10 @@ func TestWriteStats(t *testing.T) { } // We'll match and DROP the last packet. ruleIdx := filter.BuiltinChains[stack.Output] - filter.Rules[ruleIdx].Target = stack.DropTarget{} + filter.Rules[ruleIdx].Target = &stack.DropTarget{} filter.Rules[ruleIdx].Matchers = []stack.Matcher{&limitedMatcher{nPackets - 1}} // Make sure the next rule is ACCEPT. - filter.Rules[ruleIdx+1].Target = stack.AcceptTarget{} + filter.Rules[ruleIdx+1].Target = &stack.AcceptTarget{} if err := ipt.ReplaceTable(stack.FilterTable, filter, true /* ipv6 */); err != nil { t.Fatalf("failed to replace table: %v", err) } diff --git a/pkg/tcpip/stack/iptables.go b/pkg/tcpip/stack/iptables.go index 4a521eca9..faa503b00 100644 --- a/pkg/tcpip/stack/iptables.go +++ b/pkg/tcpip/stack/iptables.go @@ -60,11 +60,11 @@ func DefaultTables() *IPTables { v4Tables: [numTables]Table{ natID: Table{ Rules: []Rule{ - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: ErrorTarget{}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}}, + Rule{Target: &ErrorTarget{NetworkProtocol: header.IPv4ProtocolNumber}}, }, BuiltinChains: [NumHooks]int{ Prerouting: 0, @@ -83,9 +83,9 @@ func DefaultTables() *IPTables { }, mangleID: Table{ Rules: []Rule{ - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: ErrorTarget{}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}}, + Rule{Target: &ErrorTarget{NetworkProtocol: header.IPv4ProtocolNumber}}, }, BuiltinChains: [NumHooks]int{ Prerouting: 0, @@ -101,10 +101,10 @@ func DefaultTables() *IPTables { }, filterID: Table{ Rules: []Rule{ - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: ErrorTarget{}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}}, + Rule{Target: &ErrorTarget{NetworkProtocol: header.IPv4ProtocolNumber}}, }, BuiltinChains: [NumHooks]int{ Prerouting: HookUnset, @@ -125,11 +125,11 @@ func DefaultTables() *IPTables { v6Tables: [numTables]Table{ natID: Table{ Rules: []Rule{ - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: ErrorTarget{}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}}, + Rule{Target: &ErrorTarget{NetworkProtocol: header.IPv6ProtocolNumber}}, }, BuiltinChains: [NumHooks]int{ Prerouting: 0, @@ -148,9 +148,9 @@ func DefaultTables() *IPTables { }, mangleID: Table{ Rules: []Rule{ - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: ErrorTarget{}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}}, + Rule{Target: &ErrorTarget{NetworkProtocol: header.IPv6ProtocolNumber}}, }, BuiltinChains: [NumHooks]int{ Prerouting: 0, @@ -166,10 +166,10 @@ func DefaultTables() *IPTables { }, filterID: Table{ Rules: []Rule{ - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: AcceptTarget{}}, - Rule{Target: ErrorTarget{}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}}, + Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}}, + Rule{Target: &ErrorTarget{NetworkProtocol: header.IPv6ProtocolNumber}}, }, BuiltinChains: [NumHooks]int{ Prerouting: HookUnset, diff --git a/pkg/tcpip/stack/iptables_targets.go b/pkg/tcpip/stack/iptables_targets.go index 5f1b2af64..8581dd5e8 100644 --- a/pkg/tcpip/stack/iptables_targets.go +++ b/pkg/tcpip/stack/iptables_targets.go @@ -21,7 +21,17 @@ import ( ) // AcceptTarget accepts packets. -type AcceptTarget struct{} +type AcceptTarget struct { + // NetworkProtocol is the network protocol the target is used with. + NetworkProtocol tcpip.NetworkProtocolNumber +} + +// ID implements Target.ID. +func (at *AcceptTarget) ID() TargetID { + return TargetID{ + NetworkProtocol: at.NetworkProtocol, + } +} // Action implements Target.Action. func (AcceptTarget) Action(*PacketBuffer, *ConnTrack, Hook, *GSO, *Route, tcpip.Address) (RuleVerdict, int) { @@ -29,16 +39,41 @@ func (AcceptTarget) Action(*PacketBuffer, *ConnTrack, Hook, *GSO, *Route, tcpip. } // DropTarget drops packets. -type DropTarget struct{} +type DropTarget struct { + // NetworkProtocol is the network protocol the target is used with. + NetworkProtocol tcpip.NetworkProtocolNumber +} + +// ID implements Target.ID. +func (dt *DropTarget) ID() TargetID { + return TargetID{ + NetworkProtocol: dt.NetworkProtocol, + } +} // Action implements Target.Action. func (DropTarget) Action(*PacketBuffer, *ConnTrack, Hook, *GSO, *Route, tcpip.Address) (RuleVerdict, int) { return RuleDrop, 0 } +// ErrorTargetName is used to mark targets as error targets. Error targets +// shouldn't be reached - an error has occurred if we fall through to one. +const ErrorTargetName = "ERROR" + // ErrorTarget logs an error and drops the packet. It represents a target that // should be unreachable. -type ErrorTarget struct{} +type ErrorTarget struct { + // NetworkProtocol is the network protocol the target is used with. + NetworkProtocol tcpip.NetworkProtocolNumber +} + +// ID implements Target.ID. +func (et *ErrorTarget) ID() TargetID { + return TargetID{ + Name: ErrorTargetName, + NetworkProtocol: et.NetworkProtocol, + } +} // Action implements Target.Action. func (ErrorTarget) Action(*PacketBuffer, *ConnTrack, Hook, *GSO, *Route, tcpip.Address) (RuleVerdict, int) { @@ -48,7 +83,19 @@ func (ErrorTarget) Action(*PacketBuffer, *ConnTrack, Hook, *GSO, *Route, tcpip.A // UserChainTarget marks a rule as the beginning of a user chain. type UserChainTarget struct { + // Name is the chain name. Name string + + // NetworkProtocol is the network protocol the target is used with. + NetworkProtocol tcpip.NetworkProtocolNumber +} + +// ID implements Target.ID. +func (uc *UserChainTarget) ID() TargetID { + return TargetID{ + Name: ErrorTargetName, + NetworkProtocol: uc.NetworkProtocol, + } } // Action implements Target.Action. @@ -58,13 +105,28 @@ func (UserChainTarget) Action(*PacketBuffer, *ConnTrack, Hook, *GSO, *Route, tcp // ReturnTarget returns from the current chain. If the chain is a built-in, the // hook's underflow should be called. -type ReturnTarget struct{} +type ReturnTarget struct { + // NetworkProtocol is the network protocol the target is used with. + NetworkProtocol tcpip.NetworkProtocolNumber +} + +// ID implements Target.ID. +func (rt *ReturnTarget) ID() TargetID { + return TargetID{ + NetworkProtocol: rt.NetworkProtocol, + } +} // Action implements Target.Action. func (ReturnTarget) Action(*PacketBuffer, *ConnTrack, Hook, *GSO, *Route, tcpip.Address) (RuleVerdict, int) { return RuleReturn, 0 } +// RedirectTargetName is used to mark targets as redirect targets. Redirect +// targets should be reached for only NAT and Mangle tables. These targets will +// change the destination port/destination IP for packets. +const RedirectTargetName = "REDIRECT" + // RedirectTarget redirects the packet by modifying the destination port/IP. // Min and Max values for IP and Ports in the struct indicate the range of // values which can be used to redirect. @@ -86,6 +148,17 @@ type RedirectTarget struct { // MaxPort indicates port used to redirect. MaxPort uint16 + + // NetworkProtocol is the network protocol the target is used with. + NetworkProtocol tcpip.NetworkProtocolNumber +} + +// ID implements Target.ID. +func (rt *RedirectTarget) ID() TargetID { + return TargetID{ + Name: RedirectTargetName, + NetworkProtocol: rt.NetworkProtocol, + } } // Action implements Target.Action. diff --git a/pkg/tcpip/stack/iptables_types.go b/pkg/tcpip/stack/iptables_types.go index 093ee6881..7b3f3e88b 100644 --- a/pkg/tcpip/stack/iptables_types.go +++ b/pkg/tcpip/stack/iptables_types.go @@ -104,8 +104,20 @@ type IPTables struct { reaperDone chan struct{} } -// A Table defines a set of chains and hooks into the network stack. It is -// really just a list of rules. +// A Table defines a set of chains and hooks into the network stack. +// +// It is a list of Rules, entry points (BuiltinChains), and error handlers +// (Underflows). As packets traverse netstack, they hit hooks. When a packet +// hits a hook, iptables compares it to Rules starting from that hook's entry +// point. So if a packet hits the Input hook, we look up the corresponding +// entry point in BuiltinChains and jump to that point. +// +// If the Rule doesn't match the packet, iptables continues to the next Rule. +// If a Rule does match, it can issue a verdict on the packet (e.g. RuleAccept +// or RuleDrop) that causes the packet to stop traversing iptables. It can also +// jump to other rules or perform custom actions based on Rule.Target. +// +// Underflow Rules are invoked when a chain returns without reaching a verdict. // // +stateify savable type Table struct { @@ -260,6 +272,18 @@ func (fl IPHeaderFilter) match(pkt *PacketBuffer, hook Hook, nicName string) boo return true } +// NetworkProtocol returns the protocol (IPv4 or IPv6) on to which the header +// applies. +func (fl IPHeaderFilter) NetworkProtocol() tcpip.NetworkProtocolNumber { + switch len(fl.Src) { + case header.IPv4AddressSize: + return header.IPv4ProtocolNumber + case header.IPv6AddressSize: + return header.IPv6ProtocolNumber + } + panic(fmt.Sprintf("invalid address in IPHeaderFilter: %s", fl.Src)) +} + // filterAddress returns whether addr matches the filter. func filterAddress(addr, mask, filterAddr tcpip.Address, invert bool) bool { matches := true @@ -285,8 +309,23 @@ type Matcher interface { Match(hook Hook, packet *PacketBuffer, interfaceName string) (matches bool, hotdrop bool) } +// A TargetID uniquely identifies a target. +type TargetID struct { + // Name is the target name as stored in the xt_entry_target struct. + Name string + + // NetworkProtocol is the protocol to which the target applies. + NetworkProtocol tcpip.NetworkProtocolNumber + + // Revision is the version of the target. + Revision uint8 +} + // A Target is the interface for taking an action for a packet. type Target interface { + // ID uniquely identifies the Target. + ID() TargetID + // Action takes an action on the packet and returns a verdict on how // traversal should (or should not) continue. If the return value is // Jump, it also returns the index of the rule to jump to. diff --git a/test/syscalls/linux/ip6tables.cc b/test/syscalls/linux/ip6tables.cc index 97297ee2b..f08f2dc55 100644 --- a/test/syscalls/linux/ip6tables.cc +++ b/test/syscalls/linux/ip6tables.cc @@ -82,6 +82,38 @@ TEST(IP6TablesBasic, GetEntriesErrorPrecedence) { SyscallFailsWithErrno(EINVAL)); } +TEST(IP6TablesBasic, GetRevision) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + int sock; + ASSERT_THAT(sock = socket(AF_INET6, SOCK_RAW, IPPROTO_RAW), + SyscallSucceeds()); + + struct xt_get_revision rev = { + .name = "REDIRECT", + .revision = 0, + }; + socklen_t rev_len = sizeof(rev); + + // TODO(gvisor.dev/issue/3549): IPv6 redirect support. + const int retval = + getsockopt(sock, SOL_IPV6, IP6T_SO_GET_REVISION_TARGET, &rev, &rev_len); + if (IsRunningOnGvisor()) { + EXPECT_THAT(retval, SyscallFailsWithErrno(ENOPROTOOPT)); + return; + } + + // Revision 0 exists. + EXPECT_THAT(retval, SyscallSucceeds()); + EXPECT_EQ(rev.revision, 0); + + // Revisions > 0 don't exist. + rev.revision = 1; + EXPECT_THAT( + getsockopt(sock, SOL_IPV6, IP6T_SO_GET_REVISION_TARGET, &rev, &rev_len), + SyscallFailsWithErrno(EPROTONOSUPPORT)); +} + // This tests the initial state of a machine with empty ip6tables via // getsockopt(IP6T_SO_GET_INFO). We don't have a guarantee that the iptables are // empty when running in native, but we can test that gVisor has the same diff --git a/test/syscalls/linux/iptables.cc b/test/syscalls/linux/iptables.cc index 83b6a164a..7ee10bbde 100644 --- a/test/syscalls/linux/iptables.cc +++ b/test/syscalls/linux/iptables.cc @@ -117,6 +117,32 @@ TEST(IPTablesBasic, OriginalDstErrors) { SyscallFailsWithErrno(ENOTCONN)); } +TEST(IPTablesBasic, GetRevision) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + int sock; + ASSERT_THAT(sock = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP), + SyscallSucceeds()); + + struct xt_get_revision rev = { + .name = "REDIRECT", + .revision = 0, + }; + socklen_t rev_len = sizeof(rev); + + // Revision 0 exists. + EXPECT_THAT( + getsockopt(sock, SOL_IP, IPT_SO_GET_REVISION_TARGET, &rev, &rev_len), + SyscallSucceeds()); + EXPECT_EQ(rev.revision, 0); + + // Revisions > 0 don't exist. + rev.revision = 1; + EXPECT_THAT( + getsockopt(sock, SOL_IP, IPT_SO_GET_REVISION_TARGET, &rev, &rev_len), + SyscallFailsWithErrno(EPROTONOSUPPORT)); +} + // Fixture for iptables tests. class IPTablesTest : public ::testing::Test { protected: |