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-rw-r--r--pkg/sentry/socket/netfilter/extensions.go63
-rw-r--r--pkg/sentry/socket/netfilter/ipv4.go4
-rw-r--r--pkg/sentry/socket/netfilter/ipv6.go4
-rw-r--r--pkg/sentry/socket/netfilter/netfilter.go52
-rw-r--r--pkg/sentry/socket/netfilter/targets.go201
-rw-r--r--pkg/tcpip/network/ipv4/ipv4_test.go14
-rw-r--r--pkg/tcpip/network/ipv6/ipv6_test.go14
-rw-r--r--pkg/tcpip/stack/iptables.go75
-rw-r--r--pkg/tcpip/stack/iptables_targets.go54
-rw-r--r--pkg/tcpip/stack/iptables_types.go41
-rw-r--r--pkg/tcpip/stack/stack.go10
11 files changed, 300 insertions, 232 deletions
diff --git a/pkg/sentry/socket/netfilter/extensions.go b/pkg/sentry/socket/netfilter/extensions.go
index 549787955..e0976fed0 100644
--- a/pkg/sentry/socket/netfilter/extensions.go
+++ b/pkg/sentry/socket/netfilter/extensions.go
@@ -100,24 +100,43 @@ func unmarshalMatcher(match linux.XTEntryMatch, filter stack.IPHeaderFilter, buf
// marshalTarget and unmarshalTarget can be used.
type targetMaker interface {
// id uniquely identifies the target.
- id() stack.TargetID
+ id() targetID
- // marshal converts from a stack.Target to an ABI struct.
- marshal(target stack.Target) []byte
+ // marshal converts from a target to an ABI struct.
+ marshal(target target) []byte
- // unmarshal converts from the ABI matcher struct to a stack.Target.
- unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error)
+ // unmarshal converts from the ABI matcher struct to a target.
+ unmarshal(buf []byte, filter stack.IPHeaderFilter) (target, *syserr.Error)
}
-// targetMakers maps the TargetID of supported targets to the targetMaker that
+// 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
+}
+
+// target extends a stack.Target, allowing it to be used with the extension
+// system. The sentry only uses targets, never stack.Targets directly.
+type target interface {
+ stack.Target
+ id() targetID
+}
+
+// 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{}
+var targetMakers = map[targetID]targetMaker{}
func targetRevision(name string, netProto tcpip.NetworkProtocolNumber, rev uint8) (uint8, bool) {
- tid := stack.TargetID{
- Name: name,
- NetworkProtocol: netProto,
- Revision: rev,
+ tid := targetID{
+ name: name,
+ networkProtocol: netProto,
+ revision: rev,
}
if _, ok := targetMakers[tid]; !ok {
return 0, false
@@ -126,8 +145,8 @@ func targetRevision(name string, netProto tcpip.NetworkProtocolNumber, rev uint8
// 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)
+ if name == otherID.name && netProto == otherID.networkProtocol && otherID.revision > rev {
+ rev = uint8(otherID.revision)
}
}
return rev, true
@@ -142,19 +161,21 @@ func registerTargetMaker(tm targetMaker) {
targetMakers[tm.id()] = tm
}
-func marshalTarget(target stack.Target) []byte {
- targetMaker, ok := targetMakers[target.ID()]
+func marshalTarget(tgt stack.Target) []byte {
+ // The sentry only uses targets, never stack.Targets directly.
+ target := tgt.(target)
+ targetMaker, ok := targetMakers[target.id()]
if !ok {
- panic(fmt.Sprintf("unknown target of type %T with id %+v.", target, target.ID()))
+ 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,
+func unmarshalTarget(target linux.XTEntryTarget, filter stack.IPHeaderFilter, buf []byte) (target, *syserr.Error) {
+ tid := targetID{
+ name: target.Name.String(),
+ networkProtocol: filter.NetworkProtocol(),
+ revision: target.Revision,
}
targetMaker, ok := targetMakers[tid]
if !ok {
diff --git a/pkg/sentry/socket/netfilter/ipv4.go b/pkg/sentry/socket/netfilter/ipv4.go
index b560fae0d..70c561cce 100644
--- a/pkg/sentry/socket/netfilter/ipv4.go
+++ b/pkg/sentry/socket/netfilter/ipv4.go
@@ -46,13 +46,13 @@ func convertNetstackToBinary4(stk *stack.Stack, tablename linux.TableName) (linu
return linux.KernelIPTGetEntries{}, linux.IPTGetinfo{}, fmt.Errorf("table name %q too long", tablename)
}
- table, ok := stk.IPTables().GetTable(tablename.String(), false)
+ id, ok := nameToID[tablename.String()]
if !ok {
return linux.KernelIPTGetEntries{}, linux.IPTGetinfo{}, fmt.Errorf("couldn't find table %q", tablename)
}
// Setup the info struct.
- entries, info := getEntries4(table, tablename)
+ entries, info := getEntries4(stk.IPTables().GetTable(id, false), tablename)
return entries, info, nil
}
diff --git a/pkg/sentry/socket/netfilter/ipv6.go b/pkg/sentry/socket/netfilter/ipv6.go
index 4253f7bf4..5dbb604f0 100644
--- a/pkg/sentry/socket/netfilter/ipv6.go
+++ b/pkg/sentry/socket/netfilter/ipv6.go
@@ -46,13 +46,13 @@ func convertNetstackToBinary6(stk *stack.Stack, tablename linux.TableName) (linu
return linux.KernelIP6TGetEntries{}, linux.IPTGetinfo{}, fmt.Errorf("table name %q too long", tablename)
}
- table, ok := stk.IPTables().GetTable(tablename.String(), true)
+ id, ok := nameToID[tablename.String()]
if !ok {
return linux.KernelIP6TGetEntries{}, linux.IPTGetinfo{}, fmt.Errorf("couldn't find table %q", tablename)
}
// Setup the info struct, which is the same in IPv4 and IPv6.
- entries, info := getEntries6(table, tablename)
+ entries, info := getEntries6(stk.IPTables().GetTable(id, true), tablename)
return entries, info, nil
}
diff --git a/pkg/sentry/socket/netfilter/netfilter.go b/pkg/sentry/socket/netfilter/netfilter.go
index 904a12e38..a237f8f6d 100644
--- a/pkg/sentry/socket/netfilter/netfilter.go
+++ b/pkg/sentry/socket/netfilter/netfilter.go
@@ -42,6 +42,45 @@ func nflog(format string, args ...interface{}) {
}
}
+// Table names.
+const (
+ natTable = "nat"
+ mangleTable = "mangle"
+ filterTable = "filter"
+)
+
+// nameToID is immutable.
+var nameToID = map[string]stack.TableID{
+ natTable: stack.NATID,
+ mangleTable: stack.MangleID,
+ filterTable: stack.FilterID,
+}
+
+// DefaultLinuxTables returns the rules of stack.DefaultTables() wrapped for
+// compatability with netfilter extensions.
+func DefaultLinuxTables() *stack.IPTables {
+ tables := stack.DefaultTables()
+ tables.VisitTargets(func(oldTarget stack.Target) stack.Target {
+ switch val := oldTarget.(type) {
+ case *stack.AcceptTarget:
+ return &acceptTarget{AcceptTarget: *val}
+ case *stack.DropTarget:
+ return &dropTarget{DropTarget: *val}
+ case *stack.ErrorTarget:
+ return &errorTarget{ErrorTarget: *val}
+ case *stack.UserChainTarget:
+ return &userChainTarget{UserChainTarget: *val}
+ case *stack.ReturnTarget:
+ return &returnTarget{ReturnTarget: *val}
+ case *stack.RedirectTarget:
+ return &redirectTarget{RedirectTarget: *val}
+ default:
+ panic(fmt.Sprintf("Unknown rule in default iptables of type %T", val))
+ }
+ })
+ return tables
+}
+
// GetInfo returns information about iptables.
func GetInfo(t *kernel.Task, stack *stack.Stack, outPtr usermem.Addr, ipv6 bool) (linux.IPTGetinfo, *syserr.Error) {
// Read in the struct and table name.
@@ -144,9 +183,9 @@ func SetEntries(stk *stack.Stack, optVal []byte, ipv6 bool) *syserr.Error {
// TODO(gvisor.dev/issue/170): Support other tables.
var table stack.Table
switch replace.Name.String() {
- case stack.FilterTable:
+ case filterTable:
table = stack.EmptyFilterTable()
- case stack.NATTable:
+ case natTable:
table = stack.EmptyNATTable()
default:
nflog("we don't yet support writing to the %q table (gvisor.dev/issue/170)", replace.Name.String())
@@ -177,7 +216,7 @@ func SetEntries(stk *stack.Stack, optVal []byte, ipv6 bool) *syserr.Error {
}
if offset == replace.Underflow[hook] {
if !validUnderflow(table.Rules[ruleIdx], ipv6) {
- nflog("underflow for hook %d isn't an unconditional ACCEPT or DROP", ruleIdx)
+ nflog("underflow for hook %d isn't an unconditional ACCEPT or DROP: %+v", ruleIdx)
return syserr.ErrInvalidArgument
}
table.Underflows[hk] = ruleIdx
@@ -253,8 +292,7 @@ func SetEntries(stk *stack.Stack, optVal []byte, ipv6 bool) *syserr.Error {
// - There are no chains without an unconditional final rule.
// - There are no chains without an unconditional underflow rule.
- return syserr.TranslateNetstackError(stk.IPTables().ReplaceTable(replace.Name.String(), table, ipv6))
-
+ return syserr.TranslateNetstackError(stk.IPTables().ReplaceTable(nameToID[replace.Name.String()], table, ipv6))
}
// parseMatchers parses 0 or more matchers from optVal. optVal should contain
@@ -308,7 +346,7 @@ func validUnderflow(rule stack.Rule, ipv6 bool) bool {
return false
}
switch rule.Target.(type) {
- case *stack.AcceptTarget, *stack.DropTarget:
+ case *acceptTarget, *dropTarget:
return true
default:
return false
@@ -319,7 +357,7 @@ func isUnconditionalAccept(rule stack.Rule, ipv6 bool) bool {
if !validUnderflow(rule, ipv6) {
return false
}
- _, ok := rule.Target.(*stack.AcceptTarget)
+ _, ok := rule.Target.(*acceptTarget)
return ok
}
diff --git a/pkg/sentry/socket/netfilter/targets.go b/pkg/sentry/socket/netfilter/targets.go
index 0e14447fe..2dea3b419 100644
--- a/pkg/sentry/socket/netfilter/targets.go
+++ b/pkg/sentry/socket/netfilter/targets.go
@@ -26,6 +26,15 @@ import (
"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"
+
+// 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 and/or IP for packets.
+const RedirectTargetName = "REDIRECT"
+
func init() {
// Standard targets include ACCEPT, DROP, RETURN, and JUMP.
registerTargetMaker(&standardTargetMaker{
@@ -52,25 +61,92 @@ func init() {
})
}
+// The stack package provides some basic, useful targets for us. The following
+// types wrap them for compatibility with the extension system.
+
+type acceptTarget struct {
+ stack.AcceptTarget
+}
+
+func (at *acceptTarget) id() targetID {
+ return targetID{
+ networkProtocol: at.NetworkProtocol,
+ }
+}
+
+type dropTarget struct {
+ stack.DropTarget
+}
+
+func (dt *dropTarget) id() targetID {
+ return targetID{
+ networkProtocol: dt.NetworkProtocol,
+ }
+}
+
+type errorTarget struct {
+ stack.ErrorTarget
+}
+
+func (et *errorTarget) id() targetID {
+ return targetID{
+ name: ErrorTargetName,
+ networkProtocol: et.NetworkProtocol,
+ }
+}
+
+type userChainTarget struct {
+ stack.UserChainTarget
+}
+
+func (uc *userChainTarget) id() targetID {
+ return targetID{
+ name: ErrorTargetName,
+ networkProtocol: uc.NetworkProtocol,
+ }
+}
+
+type returnTarget struct {
+ stack.ReturnTarget
+}
+
+func (rt *returnTarget) id() targetID {
+ return targetID{
+ networkProtocol: rt.NetworkProtocol,
+ }
+}
+
+type redirectTarget struct {
+ stack.RedirectTarget
+}
+
+func (rt *redirectTarget) id() targetID {
+ return targetID{
+ name: RedirectTargetName,
+ networkProtocol: rt.NetworkProtocol,
+ }
+}
+
type standardTargetMaker struct {
NetworkProtocol tcpip.NetworkProtocolNumber
}
-func (sm *standardTargetMaker) id() stack.TargetID {
+func (sm *standardTargetMaker) id() targetID {
// Standard targets have the empty string as a name and no revisions.
- return stack.TargetID{
- NetworkProtocol: sm.NetworkProtocol,
+ return targetID{
+ networkProtocol: sm.NetworkProtocol,
}
}
-func (*standardTargetMaker) marshal(target stack.Target) []byte {
+
+func (*standardTargetMaker) marshal(target target) []byte {
// Translate verdicts the same way as the iptables tool.
var verdict int32
switch tg := target.(type) {
- case *stack.AcceptTarget:
+ case *acceptTarget:
verdict = -linux.NF_ACCEPT - 1
- case *stack.DropTarget:
+ case *dropTarget:
verdict = -linux.NF_DROP - 1
- case *stack.ReturnTarget:
+ case *returnTarget:
verdict = linux.NF_RETURN
case *JumpTarget:
verdict = int32(tg.Offset)
@@ -90,7 +166,7 @@ func (*standardTargetMaker) marshal(target stack.Target) []byte {
return binary.Marshal(ret, usermem.ByteOrder, xt)
}
-func (*standardTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error) {
+func (*standardTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (target, *syserr.Error) {
if len(buf) != linux.SizeOfXTStandardTarget {
nflog("buf has wrong size for standard target %d", len(buf))
return nil, syserr.ErrInvalidArgument
@@ -114,20 +190,20 @@ type errorTargetMaker struct {
NetworkProtocol tcpip.NetworkProtocolNumber
}
-func (em *errorTargetMaker) id() stack.TargetID {
+func (em *errorTargetMaker) id() targetID {
// Error targets have no revision.
- return stack.TargetID{
- Name: stack.ErrorTargetName,
- NetworkProtocol: em.NetworkProtocol,
+ return targetID{
+ name: ErrorTargetName,
+ networkProtocol: em.NetworkProtocol,
}
}
-func (*errorTargetMaker) marshal(target stack.Target) []byte {
+func (*errorTargetMaker) marshal(target target) []byte {
var errorName string
switch tg := target.(type) {
- case *stack.ErrorTarget:
- errorName = stack.ErrorTargetName
- case *stack.UserChainTarget:
+ case *errorTarget:
+ errorName = ErrorTargetName
+ case *userChainTarget:
errorName = tg.Name
default:
panic(fmt.Sprintf("errorMakerTarget cannot marshal unknown type %T", target))
@@ -140,37 +216,38 @@ func (*errorTargetMaker) marshal(target stack.Target) []byte {
},
}
copy(xt.Name[:], errorName)
- copy(xt.Target.Name[:], stack.ErrorTargetName)
+ copy(xt.Target.Name[:], ErrorTargetName)
ret := make([]byte, 0, linux.SizeOfXTErrorTarget)
return binary.Marshal(ret, usermem.ByteOrder, xt)
}
-func (*errorTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error) {
+func (*errorTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (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
+ var errTgt linux.XTErrorTarget
buf = buf[:linux.SizeOfXTErrorTarget]
- binary.Unmarshal(buf, usermem.ByteOrder, &errorTarget)
+ binary.Unmarshal(buf, usermem.ByteOrder, &errTgt)
// 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.
+ // * 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 stack.ErrorTargetName:
- return &stack.ErrorTarget{NetworkProtocol: filter.NetworkProtocol()}, nil
+ switch name := errTgt.Name.String(); name {
+ case ErrorTargetName:
+ return &errorTarget{stack.ErrorTarget{
+ NetworkProtocol: filter.NetworkProtocol(),
+ }}, nil
default:
// User defined chain.
- return &stack.UserChainTarget{
+ return &userChainTarget{stack.UserChainTarget{
Name: name,
NetworkProtocol: filter.NetworkProtocol(),
- }, nil
+ }}, nil
}
}
@@ -178,22 +255,22 @@ type redirectTargetMaker struct {
NetworkProtocol tcpip.NetworkProtocolNumber
}
-func (rm *redirectTargetMaker) id() stack.TargetID {
- return stack.TargetID{
- Name: stack.RedirectTargetName,
- NetworkProtocol: rm.NetworkProtocol,
+func (rm *redirectTargetMaker) id() targetID {
+ return targetID{
+ name: RedirectTargetName,
+ networkProtocol: rm.NetworkProtocol,
}
}
-func (*redirectTargetMaker) marshal(target stack.Target) []byte {
- rt := target.(*stack.RedirectTarget)
+func (*redirectTargetMaker) marshal(target target) []byte {
+ rt := target.(*redirectTarget)
// This is a redirect target named redirect
xt := linux.XTRedirectTarget{
Target: linux.XTEntryTarget{
TargetSize: linux.SizeOfXTRedirectTarget,
},
}
- copy(xt.Target.Name[:], stack.RedirectTargetName)
+ copy(xt.Target.Name[:], RedirectTargetName)
ret := make([]byte, 0, linux.SizeOfXTRedirectTarget)
xt.NfRange.RangeSize = 1
@@ -203,7 +280,7 @@ func (*redirectTargetMaker) marshal(target stack.Target) []byte {
return binary.Marshal(ret, usermem.ByteOrder, xt)
}
-func (*redirectTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error) {
+func (*redirectTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (target, *syserr.Error) {
if len(buf) < linux.SizeOfXTRedirectTarget {
nflog("redirectTargetMaker: buf has insufficient size for redirect target %d", len(buf))
return nil, syserr.ErrInvalidArgument
@@ -214,15 +291,17 @@ func (*redirectTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (
return nil, syserr.ErrInvalidArgument
}
- var redirectTarget linux.XTRedirectTarget
+ var rt linux.XTRedirectTarget
buf = buf[:linux.SizeOfXTRedirectTarget]
- binary.Unmarshal(buf, usermem.ByteOrder, &redirectTarget)
+ binary.Unmarshal(buf, usermem.ByteOrder, &rt)
// Copy linux.XTRedirectTarget to stack.RedirectTarget.
- target := stack.RedirectTarget{NetworkProtocol: filter.NetworkProtocol()}
+ target := redirectTarget{stack.RedirectTarget{
+ NetworkProtocol: filter.NetworkProtocol(),
+ }}
// RangeSize should be 1.
- nfRange := redirectTarget.NfRange
+ nfRange := rt.NfRange
if nfRange.RangeSize != 1 {
nflog("redirectTargetMaker: bad rangesize %d", nfRange.RangeSize)
return nil, syserr.ErrInvalidArgument
@@ -264,15 +343,15 @@ type nfNATTargetMaker struct {
NetworkProtocol tcpip.NetworkProtocolNumber
}
-func (rm *nfNATTargetMaker) id() stack.TargetID {
- return stack.TargetID{
- Name: stack.RedirectTargetName,
- NetworkProtocol: rm.NetworkProtocol,
+func (rm *nfNATTargetMaker) id() targetID {
+ return targetID{
+ name: RedirectTargetName,
+ networkProtocol: rm.NetworkProtocol,
}
}
-func (*nfNATTargetMaker) marshal(target stack.Target) []byte {
- rt := target.(*stack.RedirectTarget)
+func (*nfNATTargetMaker) marshal(target target) []byte {
+ rt := target.(*redirectTarget)
nt := nfNATTarget{
Target: linux.XTEntryTarget{
TargetSize: nfNATMarhsalledSize,
@@ -281,7 +360,7 @@ func (*nfNATTargetMaker) marshal(target stack.Target) []byte {
Flags: linux.NF_NAT_RANGE_PROTO_SPECIFIED,
},
}
- copy(nt.Target.Name[:], stack.RedirectTargetName)
+ copy(nt.Target.Name[:], RedirectTargetName)
copy(nt.Range.MinAddr[:], rt.Addr)
copy(nt.Range.MaxAddr[:], rt.Addr)
@@ -292,7 +371,7 @@ func (*nfNATTargetMaker) marshal(target stack.Target) []byte {
return binary.Marshal(ret, usermem.ByteOrder, nt)
}
-func (*nfNATTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (stack.Target, *syserr.Error) {
+func (*nfNATTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (target, *syserr.Error) {
if size := nfNATMarhsalledSize; len(buf) < size {
nflog("nfNATTargetMaker: buf has insufficient size (%d) for nfNAT target (%d)", len(buf), size)
return nil, syserr.ErrInvalidArgument
@@ -324,29 +403,35 @@ func (*nfNATTargetMaker) unmarshal(buf []byte, filter stack.IPHeaderFilter) (sta
return nil, syserr.ErrInvalidArgument
}
- target := stack.RedirectTarget{
+ target := redirectTarget{stack.RedirectTarget{
NetworkProtocol: filter.NetworkProtocol(),
Addr: tcpip.Address(natRange.MinAddr[:]),
Port: ntohs(natRange.MinProto),
- }
+ }}
return &target, nil
}
// translateToStandardTarget translates from the value in a
// linux.XTStandardTarget to an stack.Verdict.
-func translateToStandardTarget(val int32, netProto tcpip.NetworkProtocolNumber) (stack.Target, *syserr.Error) {
+func translateToStandardTarget(val int32, netProto tcpip.NetworkProtocolNumber) (target, *syserr.Error) {
// TODO(gvisor.dev/issue/170): Support other verdicts.
switch val {
case -linux.NF_ACCEPT - 1:
- return &stack.AcceptTarget{NetworkProtocol: netProto}, nil
+ return &acceptTarget{stack.AcceptTarget{
+ NetworkProtocol: netProto,
+ }}, nil
case -linux.NF_DROP - 1:
- return &stack.DropTarget{NetworkProtocol: netProto}, nil
+ return &dropTarget{stack.DropTarget{
+ NetworkProtocol: netProto,
+ }}, nil
case -linux.NF_QUEUE - 1:
nflog("unsupported iptables verdict QUEUE")
return nil, syserr.ErrInvalidArgument
case linux.NF_RETURN:
- return &stack.ReturnTarget{NetworkProtocol: netProto}, nil
+ return &returnTarget{stack.ReturnTarget{
+ NetworkProtocol: netProto,
+ }}, nil
default:
nflog("unknown iptables verdict %d", val)
return nil, syserr.ErrInvalidArgument
@@ -382,9 +467,9 @@ type JumpTarget struct {
}
// ID implements Target.ID.
-func (jt *JumpTarget) ID() stack.TargetID {
- return stack.TargetID{
- NetworkProtocol: jt.NetworkProtocol,
+func (jt *JumpTarget) id() targetID {
+ return targetID{
+ networkProtocol: jt.NetworkProtocol,
}
}
diff --git a/pkg/tcpip/network/ipv4/ipv4_test.go b/pkg/tcpip/network/ipv4/ipv4_test.go
index 61672a5ff..c7f434591 100644
--- a/pkg/tcpip/network/ipv4/ipv4_test.go
+++ b/pkg/tcpip/network/ipv4/ipv4_test.go
@@ -2178,13 +2178,10 @@ func TestWriteStats(t *testing.T) {
// Install Output DROP rule.
t.Helper()
ipt := stk.IPTables()
- filter, ok := ipt.GetTable(stack.FilterTable, false /* ipv6 */)
- if !ok {
- t.Fatalf("failed to find filter table")
- }
+ filter := ipt.GetTable(stack.FilterID, false /* ipv6 */)
ruleIdx := filter.BuiltinChains[stack.Output]
filter.Rules[ruleIdx].Target = &stack.DropTarget{}
- if err := ipt.ReplaceTable(stack.FilterTable, filter, false /* ipv6 */); err != nil {
+ if err := ipt.ReplaceTable(stack.FilterID, filter, false /* ipv6 */); err != nil {
t.Fatalf("failed to replace table: %s", err)
}
},
@@ -2199,17 +2196,14 @@ func TestWriteStats(t *testing.T) {
// of the 3 packets.
t.Helper()
ipt := stk.IPTables()
- filter, ok := ipt.GetTable(stack.FilterTable, false /* ipv6 */)
- if !ok {
- t.Fatalf("failed to find filter table")
- }
+ filter := ipt.GetTable(stack.FilterID, false /* ipv6 */)
// We'll match and DROP the last packet.
ruleIdx := filter.BuiltinChains[stack.Output]
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{}
- if err := ipt.ReplaceTable(stack.FilterTable, filter, false /* ipv6 */); err != nil {
+ if err := ipt.ReplaceTable(stack.FilterID, 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 c593c0004..1bfcdde25 100644
--- a/pkg/tcpip/network/ipv6/ipv6_test.go
+++ b/pkg/tcpip/network/ipv6/ipv6_test.go
@@ -2360,13 +2360,10 @@ func TestWriteStats(t *testing.T) {
// Install Output DROP rule.
t.Helper()
ipt := stk.IPTables()
- filter, ok := ipt.GetTable(stack.FilterTable, true /* ipv6 */)
- if !ok {
- t.Fatalf("failed to find filter table")
- }
+ filter := ipt.GetTable(stack.FilterID, true /* ipv6 */)
ruleIdx := filter.BuiltinChains[stack.Output]
filter.Rules[ruleIdx].Target = &stack.DropTarget{}
- if err := ipt.ReplaceTable(stack.FilterTable, filter, true /* ipv6 */); err != nil {
+ if err := ipt.ReplaceTable(stack.FilterID, filter, true /* ipv6 */); err != nil {
t.Fatalf("failed to replace table: %v", err)
}
},
@@ -2381,17 +2378,14 @@ func TestWriteStats(t *testing.T) {
// of the 3 packets.
t.Helper()
ipt := stk.IPTables()
- filter, ok := ipt.GetTable(stack.FilterTable, true /* ipv6 */)
- if !ok {
- t.Fatalf("failed to find filter table")
- }
+ filter := ipt.GetTable(stack.FilterID, true /* ipv6 */)
// We'll match and DROP the last packet.
ruleIdx := filter.BuiltinChains[stack.Output]
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{}
- if err := ipt.ReplaceTable(stack.FilterTable, filter, true /* ipv6 */); err != nil {
+ if err := ipt.ReplaceTable(stack.FilterID, 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 8d6d9a7f1..df6bd1315 100644
--- a/pkg/tcpip/stack/iptables.go
+++ b/pkg/tcpip/stack/iptables.go
@@ -22,30 +22,17 @@ import (
"gvisor.dev/gvisor/pkg/tcpip/header"
)
-// tableID is an index into IPTables.tables.
-type tableID int
+// TableID identifies a specific table.
+type TableID int
+// Each value identifies a specfic table.
const (
- natID tableID = iota
- mangleID
- filterID
- numTables
+ NATID TableID = iota
+ MangleID
+ FilterID
+ NumTables
)
-// Table names.
-const (
- NATTable = "nat"
- MangleTable = "mangle"
- FilterTable = "filter"
-)
-
-// nameToID is immutable.
-var nameToID = map[string]tableID{
- NATTable: natID,
- MangleTable: mangleID,
- FilterTable: filterID,
-}
-
// HookUnset indicates that there is no hook set for an entrypoint or
// underflow.
const HookUnset = -1
@@ -57,8 +44,8 @@ const reaperDelay = 5 * time.Second
// all packets.
func DefaultTables() *IPTables {
return &IPTables{
- v4Tables: [numTables]Table{
- natID: Table{
+ v4Tables: [NumTables]Table{
+ NATID: Table{
Rules: []Rule{
Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
@@ -81,7 +68,7 @@ func DefaultTables() *IPTables {
Postrouting: 3,
},
},
- mangleID: Table{
+ MangleID: Table{
Rules: []Rule{
Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
@@ -99,7 +86,7 @@ func DefaultTables() *IPTables {
Postrouting: HookUnset,
},
},
- filterID: Table{
+ FilterID: Table{
Rules: []Rule{
Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv4ProtocolNumber}},
@@ -122,8 +109,8 @@ func DefaultTables() *IPTables {
},
},
},
- v6Tables: [numTables]Table{
- natID: Table{
+ v6Tables: [NumTables]Table{
+ NATID: Table{
Rules: []Rule{
Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
@@ -146,7 +133,7 @@ func DefaultTables() *IPTables {
Postrouting: 3,
},
},
- mangleID: Table{
+ MangleID: Table{
Rules: []Rule{
Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
@@ -164,7 +151,7 @@ func DefaultTables() *IPTables {
Postrouting: HookUnset,
},
},
- filterID: Table{
+ FilterID: Table{
Rules: []Rule{
Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
Rule{Target: &AcceptTarget{NetworkProtocol: header.IPv6ProtocolNumber}},
@@ -187,10 +174,10 @@ func DefaultTables() *IPTables {
},
},
},
- priorities: [NumHooks][]tableID{
- Prerouting: []tableID{mangleID, natID},
- Input: []tableID{natID, filterID},
- Output: []tableID{mangleID, natID, filterID},
+ priorities: [NumHooks][]TableID{
+ Prerouting: []TableID{MangleID, NATID},
+ Input: []TableID{NATID, FilterID},
+ Output: []TableID{MangleID, NATID, FilterID},
},
connections: ConnTrack{
seed: generateRandUint32(),
@@ -229,26 +216,20 @@ func EmptyNATTable() Table {
}
}
-// GetTable returns a table by name.
-func (it *IPTables) GetTable(name string, ipv6 bool) (Table, bool) {
- id, ok := nameToID[name]
- if !ok {
- return Table{}, false
- }
+// GetTable returns a table with the given id and IP version. It panics when an
+// invalid id is provided.
+func (it *IPTables) GetTable(id TableID, ipv6 bool) Table {
it.mu.RLock()
defer it.mu.RUnlock()
if ipv6 {
- return it.v6Tables[id], true
+ return it.v6Tables[id]
}
- return it.v4Tables[id], true
+ return it.v4Tables[id]
}
-// ReplaceTable replaces or inserts table by name.
-func (it *IPTables) ReplaceTable(name string, table Table, ipv6 bool) *tcpip.Error {
- id, ok := nameToID[name]
- if !ok {
- return tcpip.ErrInvalidOptionValue
- }
+// ReplaceTable replaces or inserts table by name. It panics when an invalid id
+// is provided.
+func (it *IPTables) ReplaceTable(id TableID, table Table, ipv6 bool) *tcpip.Error {
it.mu.Lock()
defer it.mu.Unlock()
// If iptables is being enabled, initialize the conntrack table and
@@ -311,7 +292,7 @@ func (it *IPTables) Check(hook Hook, pkt *PacketBuffer, gso *GSO, r *Route, prer
for _, tableID := range priorities {
// If handlePacket already NATed the packet, we don't need to
// check the NAT table.
- if tableID == natID && pkt.NatDone {
+ if tableID == NATID && pkt.NatDone {
continue
}
var table Table
diff --git a/pkg/tcpip/stack/iptables_targets.go b/pkg/tcpip/stack/iptables_targets.go
index 538c4625d..94a5df329 100644
--- a/pkg/tcpip/stack/iptables_targets.go
+++ b/pkg/tcpip/stack/iptables_targets.go
@@ -26,13 +26,6 @@ type AcceptTarget struct {
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) {
return RuleAccept, 0
@@ -44,22 +37,11 @@ type DropTarget struct {
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 {
@@ -67,14 +49,6 @@ type ErrorTarget struct {
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) {
log.Debugf("ErrorTarget triggered.")
@@ -90,14 +64,6 @@ type UserChainTarget struct {
NetworkProtocol tcpip.NetworkProtocolNumber
}
-// ID implements Target.ID.
-func (uc *UserChainTarget) ID() TargetID {
- return TargetID{
- Name: ErrorTargetName,
- NetworkProtocol: uc.NetworkProtocol,
- }
-}
-
// Action implements Target.Action.
func (*UserChainTarget) Action(*PacketBuffer, *ConnTrack, Hook, *GSO, *Route, tcpip.Address) (RuleVerdict, int) {
panic("UserChainTarget should never be called.")
@@ -110,23 +76,11 @@ type ReturnTarget struct {
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.
// TODO(gvisor.dev/issue/170): Other flags need to be added after we support
// them.
@@ -141,14 +95,6 @@ type RedirectTarget struct {
NetworkProtocol tcpip.NetworkProtocolNumber
}
-// ID implements Target.ID.
-func (rt *RedirectTarget) ID() TargetID {
- return TargetID{
- Name: RedirectTargetName,
- NetworkProtocol: rt.NetworkProtocol,
- }
-}
-
// Action implements Target.Action.
// TODO(gvisor.dev/issue/170): Parse headers without copying. The current
// implementation only works for PREROUTING and calls pkt.Clone(), neither
diff --git a/pkg/tcpip/stack/iptables_types.go b/pkg/tcpip/stack/iptables_types.go
index 7b3f3e88b..4b86c1be9 100644
--- a/pkg/tcpip/stack/iptables_types.go
+++ b/pkg/tcpip/stack/iptables_types.go
@@ -37,7 +37,6 @@ import (
// ----->[Prerouting]----->routing----->[Forward]---------[Postrouting]----->
type Hook uint
-// These values correspond to values in include/uapi/linux/netfilter.h.
const (
// Prerouting happens before a packet is routed to applications or to
// be forwarded.
@@ -86,8 +85,8 @@ type IPTables struct {
mu sync.RWMutex
// v4Tables and v6tables map tableIDs to tables. They hold builtin
// tables only, not user tables. mu must be locked for accessing.
- v4Tables [numTables]Table
- v6Tables [numTables]Table
+ v4Tables [NumTables]Table
+ v6Tables [NumTables]Table
// modified is whether tables have been modified at least once. It is
// used to elide the iptables performance overhead for workloads that
// don't utilize iptables.
@@ -96,7 +95,7 @@ type IPTables struct {
// priorities maps each hook to a list of table names. The order of the
// list is the order in which each table should be visited for that
// hook. It is immutable.
- priorities [NumHooks][]tableID
+ priorities [NumHooks][]TableID
connections ConnTrack
@@ -104,6 +103,24 @@ type IPTables struct {
reaperDone chan struct{}
}
+// VisitTargets traverses all the targets of all tables and replaces each with
+// transform(target).
+func (it *IPTables) VisitTargets(transform func(Target) Target) {
+ it.mu.Lock()
+ defer it.mu.Unlock()
+
+ for tid := range it.v4Tables {
+ for i, rule := range it.v4Tables[tid].Rules {
+ it.v4Tables[tid].Rules[i].Target = transform(rule.Target)
+ }
+ }
+ for tid := range it.v6Tables {
+ for i, rule := range it.v6Tables[tid].Rules {
+ it.v6Tables[tid].Rules[i].Target = transform(rule.Target)
+ }
+ }
+}
+
// 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
@@ -169,7 +186,6 @@ type IPHeaderFilter struct {
// CheckProtocol determines whether the Protocol field should be
// checked during matching.
- // TODO(gvisor.dev/issue/3549): Check this field during matching.
CheckProtocol bool
// Dst matches the destination IP address.
@@ -309,23 +325,8 @@ 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/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go
index e8f1c110e..25ea6b459 100644
--- a/pkg/tcpip/stack/stack.go
+++ b/pkg/tcpip/stack/stack.go
@@ -518,6 +518,10 @@ type Options struct {
//
// RandSource must be thread-safe.
RandSource mathrand.Source
+
+ // IPTables are the initial iptables rules. If nil, iptables will allow
+ // all traffic.
+ IPTables *IPTables
}
// TransportEndpointInfo holds useful information about a transport endpoint
@@ -620,6 +624,10 @@ func New(opts Options) *Stack {
randSrc = &lockedRandomSource{src: mathrand.NewSource(generateRandInt64())}
}
+ if opts.IPTables == nil {
+ opts.IPTables = DefaultTables()
+ }
+
opts.NUDConfigs.resetInvalidFields()
s := &Stack{
@@ -633,7 +641,7 @@ func New(opts Options) *Stack {
clock: clock,
stats: opts.Stats.FillIn(),
handleLocal: opts.HandleLocal,
- tables: DefaultTables(),
+ tables: opts.IPTables,
icmpRateLimiter: NewICMPRateLimiter(),
seed: generateRandUint32(),
nudConfigs: opts.NUDConfigs,
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-16 09:37:26 +0000