Merge release-20200907.0-157-gca3087472 (automated)

19 files changed, 436 insertions, 79 deletions

diff --git a/pkg/abi/linux/linux_abi_autogen_unsafe.go b/pkg/abi/linux/linux_abi_autogen_unsafe.go
index 0e3091d63..2047d7884 100644
--- a/pkg/abi/linux/linux_abi_autogen_unsafe.go
+++ b/pkg/abi/linux/linux_abi_autogen_unsafe.go
@@ -1181,7 +1181,7 @@ func (s *Statx) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (s *Statx) WriteTo(writer io.Writer) (int64, error) {
-    if !s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() {
+    if !s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() {
         // Type Statx doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, s.SizeBytes())
         s.MarshalBytes(buf)
@@ -1574,7 +1574,7 @@ func (f *FUSEHeaderIn) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (f *FUSEHeaderIn) Packed() bool {
-    return f.Unique.Packed() && f.Opcode.Packed()
+    return f.Opcode.Packed() && f.Unique.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
@@ -1589,7 +1589,7 @@ func (f *FUSEHeaderIn) MarshalUnsafe(dst []byte) {
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
 func (f *FUSEHeaderIn) UnmarshalUnsafe(src []byte) {
-    if f.Opcode.Packed() && f.Unique.Packed() {
+    if f.Unique.Packed() && f.Opcode.Packed() {
         safecopy.CopyOut(unsafe.Pointer(f), src)
     } else {
         // Type FUSEHeaderIn doesn't have a packed layout in memory, fallback to UnmarshalBytes.
@@ -1656,7 +1656,7 @@ func (f *FUSEHeaderIn) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, e
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (f *FUSEHeaderIn) WriteTo(writer io.Writer) (int64, error) {
-    if !f.Unique.Packed() && f.Opcode.Packed() {
+    if !f.Opcode.Packed() && f.Unique.Packed() {
         // Type FUSEHeaderIn doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, f.SizeBytes())
         f.MarshalBytes(buf)
@@ -4431,7 +4431,7 @@ func (i *IPTEntry) MarshalUnsafe(dst []byte) {
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
 func (i *IPTEntry) UnmarshalUnsafe(src []byte) {
-    if i.Counters.Packed() && i.IP.Packed() {
+    if i.IP.Packed() && i.Counters.Packed() {
         safecopy.CopyOut(unsafe.Pointer(i), src)
     } else {
         // Type IPTEntry doesn't have a packed layout in memory, fallback to UnmarshalBytes.
@@ -4442,7 +4442,7 @@ func (i *IPTEntry) UnmarshalUnsafe(src []byte) {
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
 func (i *IPTEntry) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
-    if !i.IP.Packed() && i.Counters.Packed() {
+    if !i.Counters.Packed() && i.IP.Packed() {
         // Type IPTEntry doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := cc.CopyScratchBuffer(i.SizeBytes()) // escapes: okay.
         i.MarshalBytes(buf) // escapes: fallback.
@@ -4604,7 +4604,7 @@ func (i *IPTIP) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (i *IPTIP) Packed() bool {
-    return i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() && i.Src.Packed()
+    return i.SrcMask.Packed() && i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
@@ -4686,7 +4686,7 @@ func (i *IPTIP) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (i *IPTIP) WriteTo(writer io.Writer) (int64, error) {
-    if !i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() && i.Src.Packed() {
+    if !i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() {
         // Type IPTIP doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, i.SizeBytes())
         i.MarshalBytes(buf)
@@ -5592,7 +5592,7 @@ func (i *IP6TIP) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (i *IP6TIP) Packed() bool {
-    return i.SrcMask.Packed() && i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed()
+    return i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
@@ -5618,7 +5618,7 @@ func (i *IP6TIP) UnmarshalUnsafe(src []byte) {
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
 func (i *IP6TIP) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
-    if !i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() {
+    if !i.SrcMask.Packed() && i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed() {
         // Type IP6TIP doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := cc.CopyScratchBuffer(i.SizeBytes()) // escapes: okay.
         i.MarshalBytes(buf) // escapes: fallback.
@@ -5648,7 +5648,7 @@ func (i *IP6TIP) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error)
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
 func (i *IP6TIP) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
-    if !i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() {
+    if !i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() {
         // Type IP6TIP doesn't have a packed layout in memory, fall back to UnmarshalBytes.
         buf := cc.CopyScratchBuffer(i.SizeBytes()) // escapes: okay.
         length, err := cc.CopyInBytes(addr, buf) // escapes: okay.
@@ -5674,7 +5674,7 @@ func (i *IP6TIP) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error)
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (i *IP6TIP) WriteTo(writer io.Writer) (int64, error) {
-    if !i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() {
+    if !i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() {
         // Type IP6TIP doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, i.SizeBytes())
         i.MarshalBytes(buf)
@@ -6193,7 +6193,7 @@ func (r *Rusage) UnmarshalUnsafe(src []byte) {
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
 func (r *Rusage) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
-    if !r.STime.Packed() && r.UTime.Packed() {
+    if !r.UTime.Packed() && r.STime.Packed() {
         // Type Rusage doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := cc.CopyScratchBuffer(r.SizeBytes()) // escapes: okay.
         r.MarshalBytes(buf) // escapes: fallback.
@@ -6249,7 +6249,7 @@ func (r *Rusage) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error)
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (r *Rusage) WriteTo(writer io.Writer) (int64, error) {
-    if !r.STime.Packed() && r.UTime.Packed() {
+    if !r.UTime.Packed() && r.STime.Packed() {
         // Type Rusage doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, r.SizeBytes())
         r.MarshalBytes(buf)
@@ -6314,7 +6314,7 @@ func (s *SemidDS) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (s *SemidDS) Packed() bool {
-    return s.SemCTime.Packed() && s.SemPerm.Packed() && s.SemOTime.Packed()
+    return s.SemOTime.Packed() && s.SemCTime.Packed() && s.SemPerm.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
@@ -6340,7 +6340,7 @@ func (s *SemidDS) UnmarshalUnsafe(src []byte) {
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
 func (s *SemidDS) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
-    if !s.SemOTime.Packed() && s.SemCTime.Packed() && s.SemPerm.Packed() {
+    if !s.SemPerm.Packed() && s.SemOTime.Packed() && s.SemCTime.Packed() {
         // Type SemidDS doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := cc.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
         s.MarshalBytes(buf) // escapes: fallback.
@@ -6661,12 +6661,12 @@ func (s *ShmidDS) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (s *ShmidDS) Packed() bool {
-    return s.ShmPerm.Packed() && s.ShmAtime.Packed() && s.ShmDtime.Packed() && s.ShmCtime.Packed()
+    return s.ShmDtime.Packed() && s.ShmCtime.Packed() && s.ShmPerm.Packed() && s.ShmAtime.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
 func (s *ShmidDS) MarshalUnsafe(dst []byte) {
-    if s.ShmCtime.Packed() && s.ShmPerm.Packed() && s.ShmAtime.Packed() && s.ShmDtime.Packed() {
+    if s.ShmPerm.Packed() && s.ShmAtime.Packed() && s.ShmDtime.Packed() && s.ShmCtime.Packed() {
         safecopy.CopyIn(dst, unsafe.Pointer(s))
     } else {
         // Type ShmidDS doesn't have a packed layout in memory, fallback to MarshalBytes.
@@ -6676,7 +6676,7 @@ func (s *ShmidDS) MarshalUnsafe(dst []byte) {
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
 func (s *ShmidDS) UnmarshalUnsafe(src []byte) {
-    if s.ShmPerm.Packed() && s.ShmAtime.Packed() && s.ShmDtime.Packed() && s.ShmCtime.Packed() {
+    if s.ShmCtime.Packed() && s.ShmPerm.Packed() && s.ShmAtime.Packed() && s.ShmDtime.Packed() {
         safecopy.CopyOut(unsafe.Pointer(s), src)
     } else {
         // Type ShmidDS doesn't have a packed layout in memory, fallback to UnmarshalBytes.
@@ -6717,7 +6717,7 @@ func (s *ShmidDS) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
 func (s *ShmidDS) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
-    if !s.ShmCtime.Packed() && s.ShmPerm.Packed() && s.ShmAtime.Packed() && s.ShmDtime.Packed() {
+    if !s.ShmPerm.Packed() && s.ShmAtime.Packed() && s.ShmDtime.Packed() && s.ShmCtime.Packed() {
         // Type ShmidDS doesn't have a packed layout in memory, fall back to UnmarshalBytes.
         buf := cc.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
         length, err := cc.CopyInBytes(addr, buf) // escapes: okay.
@@ -6743,7 +6743,7 @@ func (s *ShmidDS) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error)
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (s *ShmidDS) WriteTo(writer io.Writer) (int64, error) {
-    if !s.ShmPerm.Packed() && s.ShmAtime.Packed() && s.ShmDtime.Packed() && s.ShmCtime.Packed() {
+    if !s.ShmAtime.Packed() && s.ShmDtime.Packed() && s.ShmCtime.Packed() && s.ShmPerm.Packed() {
         // Type ShmidDS doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, s.SizeBytes())
         s.MarshalBytes(buf)
@@ -8769,7 +8769,7 @@ func (i *Itimerspec) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (i *Itimerspec) Packed() bool {
-    return i.Value.Packed() && i.Interval.Packed()
+    return i.Interval.Packed() && i.Value.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
@@ -8914,7 +8914,7 @@ func (i *ItimerVal) MarshalUnsafe(dst []byte) {
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
 func (i *ItimerVal) UnmarshalUnsafe(src []byte) {
-    if i.Value.Packed() && i.Interval.Packed() {
+    if i.Interval.Packed() && i.Value.Packed() {
         safecopy.CopyOut(unsafe.Pointer(i), src)
     } else {
         // Type ItimerVal doesn't have a packed layout in memory, fallback to UnmarshalBytes.
@@ -8955,7 +8955,7 @@ func (i *ItimerVal) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, err
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
 func (i *ItimerVal) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
-    if !i.Value.Packed() && i.Interval.Packed() {
+    if !i.Interval.Packed() && i.Value.Packed() {
         // Type ItimerVal doesn't have a packed layout in memory, fall back to UnmarshalBytes.
         buf := cc.CopyScratchBuffer(i.SizeBytes()) // escapes: okay.
         length, err := cc.CopyInBytes(addr, buf) // escapes: okay.
@@ -9128,7 +9128,7 @@ func (t *Tms) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (t *Tms) Packed() bool {
-    return t.CSTime.Packed() && t.UTime.Packed() && t.STime.Packed() && t.CUTime.Packed()
+    return t.UTime.Packed() && t.STime.Packed() && t.CUTime.Packed() && t.CSTime.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
@@ -9143,7 +9143,7 @@ func (t *Tms) MarshalUnsafe(dst []byte) {
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
 func (t *Tms) UnmarshalUnsafe(src []byte) {
-    if t.CSTime.Packed() && t.UTime.Packed() && t.STime.Packed() && t.CUTime.Packed() {
+    if t.UTime.Packed() && t.STime.Packed() && t.CUTime.Packed() && t.CSTime.Packed() {
         safecopy.CopyOut(unsafe.Pointer(t), src)
     } else {
         // Type Tms doesn't have a packed layout in memory, fallback to UnmarshalBytes.
@@ -9154,7 +9154,7 @@ func (t *Tms) UnmarshalUnsafe(src []byte) {
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
 func (t *Tms) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
-    if !t.UTime.Packed() && t.STime.Packed() && t.CUTime.Packed() && t.CSTime.Packed() {
+    if !t.CSTime.Packed() && t.UTime.Packed() && t.STime.Packed() && t.CUTime.Packed() {
         // Type Tms doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := cc.CopyScratchBuffer(t.SizeBytes()) // escapes: okay.
         t.MarshalBytes(buf) // escapes: fallback.
@@ -9210,7 +9210,7 @@ func (t *Tms) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (t *Tms) WriteTo(writer io.Writer) (int64, error) {
-    if !t.CUTime.Packed() && t.CSTime.Packed() && t.UTime.Packed() && t.STime.Packed() {
+    if !t.UTime.Packed() && t.STime.Packed() && t.CUTime.Packed() && t.CSTime.Packed() {
         // Type Tms doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, t.SizeBytes())
         t.MarshalBytes(buf)
diff --git a/pkg/abi/linux/linux_amd64_abi_autogen_unsafe.go b/pkg/abi/linux/linux_amd64_abi_autogen_unsafe.go
index e37845c06..71c0e3639 100644
--- a/pkg/abi/linux/linux_amd64_abi_autogen_unsafe.go
+++ b/pkg/abi/linux/linux_amd64_abi_autogen_unsafe.go
@@ -293,7 +293,7 @@ func (s *Stat) Packed() bool {
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
 func (s *Stat) MarshalUnsafe(dst []byte) {
-    if s.ATime.Packed() && s.MTime.Packed() && s.CTime.Packed() {
+    if s.CTime.Packed() && s.ATime.Packed() && s.MTime.Packed() {
         safecopy.CopyIn(dst, unsafe.Pointer(s))
     } else {
         // Type Stat doesn't have a packed layout in memory, fallback to MarshalBytes.
@@ -314,7 +314,7 @@ func (s *Stat) UnmarshalUnsafe(src []byte) {
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
 func (s *Stat) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
-    if !s.CTime.Packed() && s.ATime.Packed() && s.MTime.Packed() {
+    if !s.ATime.Packed() && s.MTime.Packed() && s.CTime.Packed() {
         // Type Stat doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := cc.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
         s.MarshalBytes(buf) // escapes: fallback.
diff --git a/pkg/abi/linux/linux_arm64_abi_autogen_unsafe.go b/pkg/abi/linux/linux_arm64_abi_autogen_unsafe.go
index d1c1aa5bd..98f0a1afd 100644
--- a/pkg/abi/linux/linux_arm64_abi_autogen_unsafe.go
+++ b/pkg/abi/linux/linux_arm64_abi_autogen_unsafe.go
@@ -295,7 +295,7 @@ func (s *Stat) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (s *Stat) Packed() bool {
-    return s.CTime.Packed() && s.ATime.Packed() && s.MTime.Packed()
+    return s.ATime.Packed() && s.MTime.Packed() && s.CTime.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
@@ -310,7 +310,7 @@ func (s *Stat) MarshalUnsafe(dst []byte) {
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
 func (s *Stat) UnmarshalUnsafe(src []byte) {
-    if s.CTime.Packed() && s.ATime.Packed() && s.MTime.Packed() {
+    if s.ATime.Packed() && s.MTime.Packed() && s.CTime.Packed() {
         safecopy.CopyOut(unsafe.Pointer(s), src)
     } else {
         // Type Stat doesn't have a packed layout in memory, fallback to UnmarshalBytes.
@@ -321,7 +321,7 @@ func (s *Stat) UnmarshalUnsafe(src []byte) {
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
 func (s *Stat) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
-    if !s.CTime.Packed() && s.ATime.Packed() && s.MTime.Packed() {
+    if !s.ATime.Packed() && s.MTime.Packed() && s.CTime.Packed() {
         // Type Stat doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := cc.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
         s.MarshalBytes(buf) // escapes: fallback.
@@ -351,7 +351,7 @@ func (s *Stat) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
 func (s *Stat) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
-    if !s.ATime.Packed() && s.MTime.Packed() && s.CTime.Packed() {
+    if !s.CTime.Packed() && s.ATime.Packed() && s.MTime.Packed() {
         // Type Stat doesn't have a packed layout in memory, fall back to UnmarshalBytes.
         buf := cc.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
         length, err := cc.CopyInBytes(addr, buf) // escapes: okay.
@@ -377,7 +377,7 @@ func (s *Stat) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (s *Stat) WriteTo(writer io.Writer) (int64, error) {
-    if !s.MTime.Packed() && s.CTime.Packed() && s.ATime.Packed() {
+    if !s.CTime.Packed() && s.ATime.Packed() && s.MTime.Packed() {
         // Type Stat doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, s.SizeBytes())
         s.MarshalBytes(buf)
diff --git a/pkg/sentry/fs/proc/proc_state_autogen.go b/pkg/sentry/fs/proc/proc_state_autogen.go
index 37ce12115..f7f65fa43 100644
--- a/pkg/sentry/fs/proc/proc_state_autogen.go
+++ b/pkg/sentry/fs/proc/proc_state_autogen.go
@@ -876,6 +876,60 @@ func (x *tcpRecoveryFile) StateLoad(m state.Source) {
 	m.LoadWait(1, &x.stack)
 }
 
+func (x *ipForwarding) StateTypeName() string {
+	return "pkg/sentry/fs/proc.ipForwarding"
+}
+
+func (x *ipForwarding) StateFields() []string {
+	return []string{
+		"SimpleFileInode",
+		"stack",
+		"enabled",
+	}
+}
+
+func (x *ipForwarding) beforeSave() {}
+
+func (x *ipForwarding) StateSave(m state.Sink) {
+	x.beforeSave()
+	m.Save(0, &x.SimpleFileInode)
+	m.Save(1, &x.stack)
+	m.Save(2, &x.enabled)
+}
+
+func (x *ipForwarding) StateLoad(m state.Source) {
+	m.Load(0, &x.SimpleFileInode)
+	m.LoadWait(1, &x.stack)
+	m.Load(2, &x.enabled)
+	m.AfterLoad(x.afterLoad)
+}
+
+func (x *ipForwardingFile) StateTypeName() string {
+	return "pkg/sentry/fs/proc.ipForwardingFile"
+}
+
+func (x *ipForwardingFile) StateFields() []string {
+	return []string{
+		"ipf",
+		"stack",
+	}
+}
+
+func (x *ipForwardingFile) beforeSave() {}
+
+func (x *ipForwardingFile) StateSave(m state.Sink) {
+	x.beforeSave()
+	m.Save(0, &x.ipf)
+	m.Save(1, &x.stack)
+}
+
+func (x *ipForwardingFile) afterLoad() {}
+
+func (x *ipForwardingFile) StateLoad(m state.Source) {
+	m.Load(0, &x.ipf)
+	m.LoadWait(1, &x.stack)
+}
+
 func (x *taskDir) StateTypeName() string {
 	return "pkg/sentry/fs/proc.taskDir"
 }
@@ -1467,6 +1521,8 @@ func init() {
 	state.Register((*tcpSackFile)(nil))
 	state.Register((*tcpRecovery)(nil))
 	state.Register((*tcpRecoveryFile)(nil))
+	state.Register((*ipForwarding)(nil))
+	state.Register((*ipForwardingFile)(nil))
 	state.Register((*taskDir)(nil))
 	state.Register((*subtasks)(nil))
 	state.Register((*subtasksFile)(nil))
diff --git a/pkg/sentry/fs/proc/sys_net.go b/pkg/sentry/fs/proc/sys_net.go
index 8615b60f0..e555672ad 100644
--- a/pkg/sentry/fs/proc/sys_net.go
+++ b/pkg/sentry/fs/proc/sys_net.go
@@ -26,6 +26,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs/ramfs"
 	"gvisor.dev/gvisor/pkg/sentry/inet"
 	"gvisor.dev/gvisor/pkg/sync"
+	"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
 	"gvisor.dev/gvisor/pkg/usermem"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
@@ -54,7 +55,7 @@ type tcpMemInode struct {
 
 	// size stores the tcp buffer size during save, and sets the buffer
 	// size in netstack in restore. We must save/restore this here, since
-	// netstack itself is stateless.
+	// a netstack instance is created on restore.
 	size inet.TCPBufferSize
 
 	// mu protects against concurrent reads/writes to files based on this
@@ -258,6 +259,9 @@ func (f *tcpSackFile) Write(ctx context.Context, _ *fs.File, src usermem.IOSeque
 	if src.NumBytes() == 0 {
 		return 0, nil
 	}
+
+	// Only consider size of one memory page for input for performance reasons.
+	// We are only reading if it's zero or not anyway.
 	src = src.TakeFirst(usermem.PageSize - 1)
 
 	var v int32
@@ -383,11 +387,125 @@ func (p *proc) newSysNetCore(ctx context.Context, msrc *fs.MountSource, s inet.S
 	return newProcInode(ctx, d, msrc, fs.SpecialDirectory, nil)
 }
 
+// ipForwarding implements fs.InodeOperations.
+//
+// ipForwarding is used to enable/disable packet forwarding of netstack.
+//
+// +stateify savable
+type ipForwarding struct {
+	fsutil.SimpleFileInode
+
+	stack inet.Stack `state:"wait"`
+
+	// enabled stores the IPv4 forwarding state on save.
+	// We must save/restore this here, since a netstack instance
+	// is created on restore.
+	enabled *bool
+}
+
+func newIPForwardingInode(ctx context.Context, msrc *fs.MountSource, s inet.Stack) *fs.Inode {
+	ipf := &ipForwarding{
+		SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(0444), linux.PROC_SUPER_MAGIC),
+		stack:           s,
+	}
+	sattr := fs.StableAttr{
+		DeviceID:  device.ProcDevice.DeviceID(),
+		InodeID:   device.ProcDevice.NextIno(),
+		BlockSize: usermem.PageSize,
+		Type:      fs.SpecialFile,
+	}
+	return fs.NewInode(ctx, ipf, msrc, sattr)
+}
+
+// Truncate implements fs.InodeOperations.Truncate. Truncate is called when
+// O_TRUNC is specified for any kind of existing Dirent but is not called via
+// (f)truncate for proc files.
+func (*ipForwarding) Truncate(context.Context, *fs.Inode, int64) error {
+	return nil
+}
+
+// +stateify savable
+type ipForwardingFile struct {
+	fsutil.FileGenericSeek          `state:"nosave"`
+	fsutil.FileNoIoctl              `state:"nosave"`
+	fsutil.FileNoMMap               `state:"nosave"`
+	fsutil.FileNoSplice             `state:"nosave"`
+	fsutil.FileNoopFlush            `state:"nosave"`
+	fsutil.FileNoopFsync            `state:"nosave"`
+	fsutil.FileNoopRelease          `state:"nosave"`
+	fsutil.FileNotDirReaddir        `state:"nosave"`
+	fsutil.FileUseInodeUnstableAttr `state:"nosave"`
+	waiter.AlwaysReady              `state:"nosave"`
+
+	ipf *ipForwarding
+
+	stack inet.Stack `state:"wait"`
+}
+
+// GetFile implements fs.InodeOperations.GetFile.
+func (ipf *ipForwarding) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) {
+	flags.Pread = true
+	flags.Pwrite = true
+	return fs.NewFile(ctx, dirent, flags, &ipForwardingFile{
+		stack: ipf.stack,
+		ipf:   ipf,
+	}), nil
+}
+
+// Read implements fs.FileOperations.Read.
+func (f *ipForwardingFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, offset int64) (int64, error) {
+	if offset != 0 {
+		return 0, io.EOF
+	}
+
+	if f.ipf.enabled == nil {
+		enabled := f.stack.Forwarding(ipv4.ProtocolNumber)
+		f.ipf.enabled = &enabled
+	}
+
+	val := "0\n"
+	if *f.ipf.enabled {
+		// Technically, this is not quite compatible with Linux. Linux
+		// stores these as an integer, so if you write "2" into
+		// ip_forward, you should get 2 back.
+		val = "1\n"
+	}
+	n, err := dst.CopyOut(ctx, []byte(val))
+	return int64(n), err
+}
+
+// Write implements fs.FileOperations.Write.
+//
+// Offset is ignored, multiple writes are not supported.
+func (f *ipForwardingFile) Write(ctx context.Context, _ *fs.File, src usermem.IOSequence, offset int64) (int64, error) {
+	if src.NumBytes() == 0 {
+		return 0, nil
+	}
+
+	// Only consider size of one memory page for input for performance reasons.
+	// We are only reading if it's zero or not anyway.
+	src = src.TakeFirst(usermem.PageSize - 1)
+
+	var v int32
+	n, err := usermem.CopyInt32StringInVec(ctx, src.IO, src.Addrs, &v, src.Opts)
+	if err != nil {
+		return n, err
+	}
+	if f.ipf.enabled == nil {
+		f.ipf.enabled = new(bool)
+	}
+	*f.ipf.enabled = v != 0
+	return n, f.stack.SetForwarding(ipv4.ProtocolNumber, *f.ipf.enabled)
+}
+
 func (p *proc) newSysNetIPv4Dir(ctx context.Context, msrc *fs.MountSource, s inet.Stack) *fs.Inode {
 	contents := map[string]*fs.Inode{
 		// Add tcp_sack.
 		"tcp_sack": newTCPSackInode(ctx, msrc, s),
 
+		// Add ip_forward.
+		"ip_forward": newIPForwardingInode(ctx, msrc, s),
+
 		// The following files are simple stubs until they are
 		// implemented in netstack, most of these files are
 		// configuration related. We use the value closest to the
diff --git a/pkg/sentry/fs/proc/sys_net_state.go b/pkg/sentry/fs/proc/sys_net_state.go
index 6eba709c6..4cb4741af 100644
--- a/pkg/sentry/fs/proc/sys_net_state.go
+++ b/pkg/sentry/fs/proc/sys_net_state.go
@@ -14,7 +14,11 @@
 
 package proc
 
-import "fmt"
+import (
+	"fmt"
+
+	"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
+)
 
 // beforeSave is invoked by stateify.
 func (t *tcpMemInode) beforeSave() {
@@ -40,3 +44,12 @@ func (s *tcpSack) afterLoad() {
 		}
 	}
 }
+
+// afterLoad is invoked by stateify.
+func (ipf *ipForwarding) afterLoad() {
+	if ipf.enabled != nil {
+		if err := ipf.stack.SetForwarding(ipv4.ProtocolNumber, *ipf.enabled); err != nil {
+			panic(fmt.Sprintf("failed to set IPv4 forwarding [%v]: %v", *ipf.enabled, err))
+		}
+	}
+}
diff --git a/pkg/sentry/fsimpl/proc/proc_state_autogen.go b/pkg/sentry/fsimpl/proc/proc_state_autogen.go
index 1a13f066a..60a5644f3 100644
--- a/pkg/sentry/fsimpl/proc/proc_state_autogen.go
+++ b/pkg/sentry/fsimpl/proc/proc_state_autogen.go
@@ -1376,6 +1376,35 @@ func (x *tcpMemData) StateLoad(m state.Source) {
 	m.LoadWait(2, &x.stack)
 }
 
+func (x *ipForwarding) StateTypeName() string {
+	return "pkg/sentry/fsimpl/proc.ipForwarding"
+}
+
+func (x *ipForwarding) StateFields() []string {
+	return []string{
+		"DynamicBytesFile",
+		"stack",
+		"enabled",
+	}
+}
+
+func (x *ipForwarding) beforeSave() {}
+
+func (x *ipForwarding) StateSave(m state.Sink) {
+	x.beforeSave()
+	m.Save(0, &x.DynamicBytesFile)
+	m.Save(1, &x.stack)
+	m.Save(2, &x.enabled)
+}
+
+func (x *ipForwarding) afterLoad() {}
+
+func (x *ipForwarding) StateLoad(m state.Source) {
+	m.Load(0, &x.DynamicBytesFile)
+	m.LoadWait(1, &x.stack)
+	m.Load(2, &x.enabled)
+}
+
 func init() {
 	state.Register((*fdDirInodeRefs)(nil))
 	state.Register((*fdInfoDirInodeRefs)(nil))
@@ -1425,4 +1454,5 @@ func init() {
 	state.Register((*tcpSackData)(nil))
 	state.Register((*tcpRecoveryData)(nil))
 	state.Register((*tcpMemData)(nil))
+	state.Register((*ipForwarding)(nil))
 }
diff --git a/pkg/sentry/fsimpl/proc/tasks_sys.go b/pkg/sentry/fsimpl/proc/tasks_sys.go
index 9e0966efe..a3ffbb15e 100644
--- a/pkg/sentry/fsimpl/proc/tasks_sys.go
+++ b/pkg/sentry/fsimpl/proc/tasks_sys.go
@@ -27,6 +27,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
+	"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
 	"gvisor.dev/gvisor/pkg/usermem"
 )
 
@@ -67,6 +68,7 @@ func (fs *filesystem) newSysNetDir(root *auth.Credentials, k *kernel.Kernel) *ke
 				"tcp_rmem":     fs.newDentry(root, fs.NextIno(), 0644, &tcpMemData{stack: stack, dir: tcpRMem}),
 				"tcp_sack":     fs.newDentry(root, fs.NextIno(), 0644, &tcpSackData{stack: stack}),
 				"tcp_wmem":     fs.newDentry(root, fs.NextIno(), 0644, &tcpMemData{stack: stack, dir: tcpWMem}),
+				"ip_forward":   fs.newDentry(root, fs.NextIno(), 0444, &ipForwarding{stack: stack}),
 
 				// The following files are simple stubs until they are implemented in
 				// netstack, most of these files are configuration related. We use the
@@ -354,3 +356,63 @@ func (d *tcpMemData) writeSizeLocked(size inet.TCPBufferSize) error {
 		panic(fmt.Sprintf("unknown tcpMemFile type: %v", d.dir))
 	}
 }
+
+// ipForwarding implements vfs.WritableDynamicBytesSource for
+// /proc/sys/net/ipv4/ip_forwarding.
+//
+// +stateify savable
+type ipForwarding struct {
+	kernfs.DynamicBytesFile
+
+	stack   inet.Stack `state:"wait"`
+	enabled *bool
+}
+
+var _ vfs.WritableDynamicBytesSource = (*ipForwarding)(nil)
+
+// Generate implements vfs.DynamicBytesSource.Generate.
+func (ipf *ipForwarding) Generate(ctx context.Context, buf *bytes.Buffer) error {
+	if ipf.enabled == nil {
+		enabled := ipf.stack.Forwarding(ipv4.ProtocolNumber)
+		ipf.enabled = &enabled
+	}
+
+	val := "0\n"
+	if *ipf.enabled {
+		// Technically, this is not quite compatible with Linux. Linux stores these
+		// as an integer, so if you write "2" into tcp_sack, you should get 2 back.
+		// Tough luck.
+		val = "1\n"
+	}
+	buf.WriteString(val)
+
+	return nil
+}
+
+// Write implements vfs.WritableDynamicBytesSource.Write.
+func (ipf *ipForwarding) Write(ctx context.Context, src usermem.IOSequence, offset int64) (int64, error) {
+	if offset != 0 {
+		// No need to handle partial writes thus far.
+		return 0, syserror.EINVAL
+	}
+	if src.NumBytes() == 0 {
+		return 0, nil
+	}
+
+	// Limit input size so as not to impact performance if input size is large.
+	src = src.TakeFirst(usermem.PageSize - 1)
+
+	var v int32
+	n, err := usermem.CopyInt32StringInVec(ctx, src.IO, src.Addrs, &v, src.Opts)
+	if err != nil {
+		return 0, err
+	}
+	if ipf.enabled == nil {
+		ipf.enabled = new(bool)
+	}
+	*ipf.enabled = v != 0
+	if err := ipf.stack.SetForwarding(ipv4.ProtocolNumber, *ipf.enabled); err != nil {
+		return 0, err
+	}
+	return n, nil
+}
diff --git a/pkg/sentry/inet/inet.go b/pkg/sentry/inet/inet.go
index c0b4831d1..fbe6d6aa6 100644
--- a/pkg/sentry/inet/inet.go
+++ b/pkg/sentry/inet/inet.go
@@ -15,7 +15,10 @@
 // Package inet defines semantics for IP stacks.
 package inet
 
-import "gvisor.dev/gvisor/pkg/tcpip/stack"
+import (
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/stack"
+)
 
 // Stack represents a TCP/IP stack.
 type Stack interface {
@@ -80,6 +83,12 @@ type Stack interface {
 	// RestoreCleanupEndpoints adds endpoints to cleanup tracking. This is useful
 	// for restoring a stack after a save.
 	RestoreCleanupEndpoints([]stack.TransportEndpoint)
+
+	// Forwarding returns if packet forwarding between NICs is enabled.
+	Forwarding(protocol tcpip.NetworkProtocolNumber) bool
+
+	// SetForwarding enables or disables packet forwarding between NICs.
+	SetForwarding(protocol tcpip.NetworkProtocolNumber, enable bool) error
 }
 
 // Interface contains information about a network interface.
diff --git a/pkg/sentry/inet/test_stack.go b/pkg/sentry/inet/test_stack.go
index 9771f01fc..1779cc6f3 100644
--- a/pkg/sentry/inet/test_stack.go
+++ b/pkg/sentry/inet/test_stack.go
@@ -14,7 +14,10 @@
 
 package inet
 
-import "gvisor.dev/gvisor/pkg/tcpip/stack"
+import (
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/stack"
+)
 
 // TestStack is a dummy implementation of Stack for tests.
 type TestStack struct {
@@ -26,6 +29,7 @@ type TestStack struct {
 	TCPSendBufSize    TCPBufferSize
 	TCPSACKFlag       bool
 	Recovery          TCPLossRecovery
+	IPForwarding      bool
 }
 
 // NewTestStack returns a TestStack with no network interfaces. The value of
@@ -128,3 +132,14 @@ func (s *TestStack) CleanupEndpoints() []stack.TransportEndpoint {
 
 // RestoreCleanupEndpoints implements inet.Stack.RestoreCleanupEndpoints.
 func (s *TestStack) RestoreCleanupEndpoints([]stack.TransportEndpoint) {}
+
+// Forwarding implements inet.Stack.Forwarding.
+func (s *TestStack) Forwarding(protocol tcpip.NetworkProtocolNumber) bool {
+	return s.IPForwarding
+}
+
+// SetForwarding implements inet.Stack.SetForwarding.
+func (s *TestStack) SetForwarding(protocol tcpip.NetworkProtocolNumber, enable bool) error {
+	s.IPForwarding = enable
+	return nil
+}
diff --git a/pkg/sentry/kernel/seqatomic_taskgoroutineschedinfo_unsafe.go b/pkg/sentry/kernel/seqatomic_taskgoroutineschedinfo_unsafe.go
index 90148bbb2..4e10436e6 100644
--- a/pkg/sentry/kernel/seqatomic_taskgoroutineschedinfo_unsafe.go
+++ b/pkg/sentry/kernel/seqatomic_taskgoroutineschedinfo_unsafe.go
@@ -1,11 +1,11 @@
 package kernel
 
 import (
-	"fmt"
 	"reflect"
 	"strings"
 	"unsafe"
 
+	"fmt"
 	"gvisor.dev/gvisor/pkg/sync"
 )
 
diff --git a/pkg/sentry/platform/ring0/defs_impl_arm64.go b/pkg/sentry/platform/ring0/defs_impl_arm64.go
index f567ef868..0350d1080 100644
--- a/pkg/sentry/platform/ring0/defs_impl_arm64.go
+++ b/pkg/sentry/platform/ring0/defs_impl_arm64.go
@@ -1,10 +1,9 @@
 package ring0
 
 import (
-	"gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables"
-
 	"fmt"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
+	"gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables"
 	"gvisor.dev/gvisor/pkg/usermem"
 	"io"
 	"reflect"
diff --git a/pkg/sentry/socket/hostinet/stack.go b/pkg/sentry/socket/hostinet/stack.go
index fda3dcb35..faa61160e 100644
--- a/pkg/sentry/socket/hostinet/stack.go
+++ b/pkg/sentry/socket/hostinet/stack.go
@@ -30,6 +30,9 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/inet"
 	"gvisor.dev/gvisor/pkg/syserr"
 	"gvisor.dev/gvisor/pkg/syserror"
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
+	"gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
 	"gvisor.dev/gvisor/pkg/usermem"
 )
@@ -59,6 +62,8 @@ type Stack struct {
 	tcpSACKEnabled bool
 	netDevFile     *os.File
 	netSNMPFile    *os.File
+	ipv4Forwarding bool
+	ipv6Forwarding bool
 }
 
 // NewStack returns an empty Stack containing no configuration.
@@ -118,6 +123,13 @@ func (s *Stack) Configure() error {
 		s.netSNMPFile = f
 	}
 
+	s.ipv6Forwarding = false
+	if ipForwarding, err := ioutil.ReadFile("/proc/sys/net/ipv6/conf/all/forwarding"); err == nil {
+		s.ipv6Forwarding = strings.TrimSpace(string(ipForwarding)) != "0"
+	} else {
+		log.Warningf("Failed to read if ipv6 forwarding is enabled, setting to false")
+	}
+
 	return nil
 }
 
@@ -468,3 +480,21 @@ func (s *Stack) CleanupEndpoints() []stack.TransportEndpoint { return nil }
 
 // RestoreCleanupEndpoints implements inet.Stack.RestoreCleanupEndpoints.
 func (s *Stack) RestoreCleanupEndpoints([]stack.TransportEndpoint) {}
+
+// Forwarding implements inet.Stack.Forwarding.
+func (s *Stack) Forwarding(protocol tcpip.NetworkProtocolNumber) bool {
+	switch protocol {
+	case ipv4.ProtocolNumber:
+		return s.ipv4Forwarding
+	case ipv6.ProtocolNumber:
+		return s.ipv6Forwarding
+	default:
+		log.Warningf("Forwarding(%v) failed: unsupported protocol", protocol)
+		return false
+	}
+}
+
+// SetForwarding implements inet.Stack.SetForwarding.
+func (s *Stack) SetForwarding(protocol tcpip.NetworkProtocolNumber, enable bool) error {
+	return syserror.EACCES
+}
diff --git a/pkg/sentry/socket/netstack/stack.go b/pkg/sentry/socket/netstack/stack.go
index 36144e1eb..1028d2a6e 100644
--- a/pkg/sentry/socket/netstack/stack.go
+++ b/pkg/sentry/socket/netstack/stack.go
@@ -412,3 +412,24 @@ func (s *Stack) CleanupEndpoints() []stack.TransportEndpoint {
 func (s *Stack) RestoreCleanupEndpoints(es []stack.TransportEndpoint) {
 	s.Stack.RestoreCleanupEndpoints(es)
 }
+
+// Forwarding implements inet.Stack.Forwarding.
+func (s *Stack) Forwarding(protocol tcpip.NetworkProtocolNumber) bool {
+	switch protocol {
+	case ipv4.ProtocolNumber, ipv6.ProtocolNumber:
+		return s.Stack.Forwarding(protocol)
+	default:
+		panic(fmt.Sprintf("Forwarding(%v) failed: unsupported protocol", protocol))
+	}
+}
+
+// SetForwarding implements inet.Stack.SetForwarding.
+func (s *Stack) SetForwarding(protocol tcpip.NetworkProtocolNumber, enable bool) error {
+	switch protocol {
+	case ipv4.ProtocolNumber, ipv6.ProtocolNumber:
+		s.Stack.SetForwarding(protocol, enable)
+	default:
+		panic(fmt.Sprintf("SetForwarding(%v) failed: unsupported protocol", protocol))
+	}
+	return nil
+}
diff --git a/pkg/sentry/time/seqatomic_parameters_unsafe.go b/pkg/sentry/time/seqatomic_parameters_unsafe.go
index 2cb001080..5eb560f57 100644
--- a/pkg/sentry/time/seqatomic_parameters_unsafe.go
+++ b/pkg/sentry/time/seqatomic_parameters_unsafe.go
@@ -1,11 +1,11 @@
 package time
 
 import (
-	"fmt"
 	"reflect"
 	"strings"
 	"unsafe"
 
+	"fmt"
 	"gvisor.dev/gvisor/pkg/sync"
 )
 
diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go
index 2b83c421e..7430b8fcd 100644
--- a/pkg/tcpip/network/ipv6/icmp.go
+++ b/pkg/tcpip/network/ipv6/icmp.go
@@ -477,7 +477,7 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer, hasFragme
 		stack := r.Stack()
 
 		// Is the networking stack operating as a router?
-		if !stack.Forwarding() {
+		if !stack.Forwarding(ProtocolNumber) {
 			// ... No, silently drop the packet.
 			received.RouterOnlyPacketsDroppedByHost.Increment()
 			return
diff --git a/pkg/tcpip/stack/ndp.go b/pkg/tcpip/stack/ndp.go
index b0873d1af..97ca00d16 100644
--- a/pkg/tcpip/stack/ndp.go
+++ b/pkg/tcpip/stack/ndp.go
@@ -817,7 +817,7 @@ func (ndp *ndpState) handleRA(ip tcpip.Address, ra header.NDPRouterAdvert) {
 	// per-interface basis; it is a stack-wide configuration, so we check
 	// stack's forwarding flag to determine if the NIC is a routing
 	// interface.
-	if !ndp.configs.HandleRAs || ndp.nic.stack.forwarding {
+	if !ndp.configs.HandleRAs || ndp.nic.stack.Forwarding(header.IPv6ProtocolNumber) {
 		return
 	}
 
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go
index 204bfc433..be274773c 100644
--- a/pkg/tcpip/stack/nic.go
+++ b/pkg/tcpip/stack/nic.go
@@ -337,7 +337,7 @@ func (n *NIC) enable() *tcpip.Error {
 	// does. That is, routers do not learn from RAs (e.g. on-link prefixes
 	// and default routers). Therefore, soliciting RAs from other routers on
 	// a link is unnecessary for routers.
-	if !n.stack.forwarding {
+	if !n.stack.Forwarding(header.IPv6ProtocolNumber) {
 		n.mu.ndp.startSolicitingRouters()
 	}
 
@@ -1303,7 +1303,7 @@ func (n *NIC) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcp
 	// packet and forward it to the NIC.
 	//
 	// TODO: Should we be forwarding the packet even if promiscuous?
-	if n.stack.Forwarding() {
+	if n.stack.Forwarding(protocol) {
 		r, err := n.stack.FindRoute(0, "", dst, protocol, false /* multicastLoop */)
 		if err != nil {
 			n.stack.stats.IP.InvalidDestinationAddressesReceived.Increment()
@@ -1330,6 +1330,7 @@ func (n *NIC) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcp
 		// n doesn't have a destination endpoint.
 		// Send the packet out of n.
 		// TODO(b/128629022): move this logic to route.WritePacket.
+		// TODO(gvisor.dev/issue/1085): According to the RFC, we must decrease the TTL field for ipv4/ipv6.
 		if ch, err := r.Resolve(nil); err != nil {
 			if err == tcpip.ErrWouldBlock {
 				n.stack.forwarder.enqueue(ch, n, &r, protocol, pkt)
diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go
index 6a683545d..68cf77de2 100644
--- a/pkg/tcpip/stack/stack.go
+++ b/pkg/tcpip/stack/stack.go
@@ -405,6 +405,13 @@ type Stack struct {
 	networkProtocols   map[tcpip.NetworkProtocolNumber]NetworkProtocol
 	linkAddrResolvers  map[tcpip.NetworkProtocolNumber]LinkAddressResolver
 
+	// forwarding contains the whether packet forwarding is enabled or not for
+	// different network protocols.
+	forwarding struct {
+		sync.RWMutex
+		protocols map[tcpip.NetworkProtocolNumber]bool
+	}
+
 	// rawFactory creates raw endpoints. If nil, raw endpoints are
 	// disabled. It is set during Stack creation and is immutable.
 	rawFactory RawFactory
@@ -415,9 +422,8 @@ type Stack struct {
 
 	linkAddrCache *linkAddrCache
 
-	mu         sync.RWMutex
-	nics       map[tcpip.NICID]*NIC
-	forwarding bool
+	mu   sync.RWMutex
+	nics map[tcpip.NICID]*NIC
 
 	// cleanupEndpointsMu protects cleanupEndpoints.
 	cleanupEndpointsMu sync.Mutex
@@ -749,6 +755,7 @@ func New(opts Options) *Stack {
 			Max:     DefaultMaxBufferSize,
 		},
 	}
+	s.forwarding.protocols = make(map[tcpip.NetworkProtocolNumber]bool)
 
 	// Add specified network protocols.
 	for _, netProto := range opts.NetworkProtocols {
@@ -866,46 +873,42 @@ func (s *Stack) Stats() tcpip.Stats {
 	return s.stats
 }
 
-// SetForwarding enables or disables the packet forwarding between NICs.
-//
-// When forwarding becomes enabled, any host-only state on all NICs will be
-// cleaned up and if IPv6 is enabled, NDP Router Solicitations will be started.
-// When forwarding becomes disabled and if IPv6 is enabled, NDP Router
-// Solicitations will be stopped.
-func (s *Stack) SetForwarding(enable bool) {
-	// TODO(igudger, bgeffon): Expose via /proc/sys/net/ipv4/ip_forward.
-	s.mu.Lock()
-	defer s.mu.Unlock()
+// SetForwarding enables or disables packet forwarding between NICs.
+func (s *Stack) SetForwarding(protocol tcpip.NetworkProtocolNumber, enable bool) {
+	s.forwarding.Lock()
+	defer s.forwarding.Unlock()
 
-	// If forwarding status didn't change, do nothing further.
-	if s.forwarding == enable {
+	// If this stack does not support the protocol, do nothing.
+	if _, ok := s.networkProtocols[protocol]; !ok {
 		return
 	}
 
-	s.forwarding = enable
-
-	// If this stack does not support IPv6, do nothing further.
-	if _, ok := s.networkProtocols[header.IPv6ProtocolNumber]; !ok {
+	// If the forwarding value for this protocol hasn't changed then do
+	// nothing.
+	if forwarding := s.forwarding.protocols[protocol]; forwarding == enable {
 		return
 	}
 
-	if enable {
-		for _, nic := range s.nics {
-			nic.becomeIPv6Router()
-		}
-	} else {
-		for _, nic := range s.nics {
-			nic.becomeIPv6Host()
+	s.forwarding.protocols[protocol] = enable
+
+	if protocol == header.IPv6ProtocolNumber {
+		if enable {
+			for _, nic := range s.nics {
+				nic.becomeIPv6Router()
+			}
+		} else {
+			for _, nic := range s.nics {
+				nic.becomeIPv6Host()
+			}
 		}
 	}
 }
 
-// Forwarding returns if the packet forwarding between NICs is enabled.
-func (s *Stack) Forwarding() bool {
-	// TODO(igudger, bgeffon): Expose via /proc/sys/net/ipv4/ip_forward.
-	s.mu.RLock()
-	defer s.mu.RUnlock()
-	return s.forwarding
+// Forwarding returns if packet forwarding between NICs is enabled.
+func (s *Stack) Forwarding(protocol tcpip.NetworkProtocolNumber) bool {
+	s.forwarding.RLock()
+	defer s.forwarding.RUnlock()
+	return s.forwarding.protocols[protocol]
 }
 
 // SetRouteTable assigns the route table to be used by this stack. It