diff options
Diffstat (limited to 'pkg')
| -rw-r--r-- | pkg/abi/linux/BUILD | 1 | ||||
| -rw-r--r-- | pkg/abi/linux/netfilter.go | 4 | ||||
| -rw-r--r-- | pkg/abi/linux/netfilter_ipv6.go | 310 | ||||
| -rw-r--r-- | pkg/abi/linux/netfilter_test.go | 3 | ||||
| -rw-r--r-- | pkg/abi/linux/socket.go | 5 |
5 files changed, 321 insertions, 2 deletions
diff --git a/pkg/abi/linux/BUILD b/pkg/abi/linux/BUILD index 05ca5342f..b5c5cc20b 100644 --- a/pkg/abi/linux/BUILD +++ b/pkg/abi/linux/BUILD @@ -41,6 +41,7 @@ go_library( "mm.go", "netdevice.go", "netfilter.go", + "netfilter_ipv6.go", "netlink.go", "netlink_route.go", "poll.go", diff --git a/pkg/abi/linux/netfilter.go b/pkg/abi/linux/netfilter.go index 9c27f7bb2..91e35366f 100644 --- a/pkg/abi/linux/netfilter.go +++ b/pkg/abi/linux/netfilter.go @@ -412,7 +412,7 @@ func (ke *KernelIPTGetEntries) SizeBytes() int { func (ke *KernelIPTGetEntries) MarshalBytes(dst []byte) { ke.IPTGetEntries.MarshalBytes(dst) marshalledUntil := ke.IPTGetEntries.SizeBytes() - for i := 0; i < len(ke.Entrytable); i++ { + for i := range ke.Entrytable { ke.Entrytable[i].MarshalBytes(dst[marshalledUntil:]) marshalledUntil += ke.Entrytable[i].SizeBytes() } @@ -422,7 +422,7 @@ func (ke *KernelIPTGetEntries) MarshalBytes(dst []byte) { func (ke *KernelIPTGetEntries) UnmarshalBytes(src []byte) { ke.IPTGetEntries.UnmarshalBytes(src) unmarshalledUntil := ke.IPTGetEntries.SizeBytes() - for i := 0; i < len(ke.Entrytable); i++ { + for i := range ke.Entrytable { ke.Entrytable[i].UnmarshalBytes(src[unmarshalledUntil:]) unmarshalledUntil += ke.Entrytable[i].SizeBytes() } diff --git a/pkg/abi/linux/netfilter_ipv6.go b/pkg/abi/linux/netfilter_ipv6.go new file mode 100644 index 000000000..9bb9efb10 --- /dev/null +++ b/pkg/abi/linux/netfilter_ipv6.go @@ -0,0 +1,310 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package linux + +import ( + "io" + + "gvisor.dev/gvisor/pkg/usermem" + "gvisor.dev/gvisor/tools/go_marshal/marshal" + "gvisor.dev/gvisor/tools/go_marshal/primitive" +) + +// This file contains structures required to support IPv6 netfilter and +// ip6tables. Some constants and structs are equal to their IPv4 analogues, and +// are only distinguished by context (e.g. whether used on an IPv4 of IPv6 +// socket). + +// Socket options for SOL_SOCLET. These correspond to values in +// include/uapi/linux/netfilter_ipv6/ip6_tables.h. +const ( + IP6T_BASE_CTL = 64 + IP6T_SO_SET_REPLACE = IPT_BASE_CTL + IP6T_SO_SET_ADD_COUNTERS = IPT_BASE_CTL + 1 + IP6T_SO_SET_MAX = IPT_SO_SET_ADD_COUNTERS + + IP6T_SO_GET_INFO = IPT_BASE_CTL + IP6T_SO_GET_ENTRIES = IPT_BASE_CTL + 1 + IP6T_SO_GET_REVISION_MATCH = IPT_BASE_CTL + 4 + IP6T_SO_GET_REVISION_TARGET = IPT_BASE_CTL + 5 + IP6T_SO_GET_MAX = IP6T_SO_GET_REVISION_TARGET +) + +// IP6T_ORIGINAL_DST is the ip6tables SOL_IPV6 socket option. Corresponds to +// the value in include/uapi/linux/netfilter_ipv6/ip6_tables.h. +// TODO(gvisor.dev/issue/3549): Support IPv6 original destination. +const IP6T_ORIGINAL_DST = 80 + +// IP6TReplace is the argument for the IP6T_SO_SET_REPLACE sockopt. It +// corresponds to struct ip6t_replace in +// include/uapi/linux/netfilter_ipv6/ip6_tables.h. +// +// +marshal +type IP6TReplace struct { + Name TableName + ValidHooks uint32 + NumEntries uint32 + Size uint32 + HookEntry [NF_INET_NUMHOOKS]uint32 + Underflow [NF_INET_NUMHOOKS]uint32 + NumCounters uint32 + Counters uint64 // This is really a *XTCounters. + // Entries is omitted here because it would cause IP6TReplace to be an + // extra byte longer (see http://www.catb.org/esr/structure-packing/). + // Entries [0]IP6TEntry +} + +// SizeOfIP6TReplace is the size of an IP6TReplace. +const SizeOfIP6TReplace = 96 + +// KernelIP6TGetEntries is identical to IP6TGetEntries, but includes the +// Entrytable field. This has been manually made marshal.Marshallable since it +// is dynamically sized. +type KernelIP6TGetEntries struct { + IPTGetEntries + Entrytable []KernelIP6TEntry +} + +// SizeBytes implements marshal.Marshallable.SizeBytes. +func (ke *KernelIP6TGetEntries) SizeBytes() int { + res := ke.IPTGetEntries.SizeBytes() + for _, entry := range ke.Entrytable { + res += entry.SizeBytes() + } + return res +} + +// MarshalBytes implements marshal.Marshallable.MarshalBytes. +func (ke *KernelIP6TGetEntries) MarshalBytes(dst []byte) { + ke.IPTGetEntries.MarshalBytes(dst) + marshalledUntil := ke.IPTGetEntries.SizeBytes() + for i := range ke.Entrytable { + ke.Entrytable[i].MarshalBytes(dst[marshalledUntil:]) + marshalledUntil += ke.Entrytable[i].SizeBytes() + } +} + +// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes. +func (ke *KernelIP6TGetEntries) UnmarshalBytes(src []byte) { + ke.IPTGetEntries.UnmarshalBytes(src) + unmarshalledUntil := ke.IPTGetEntries.SizeBytes() + for i := range ke.Entrytable { + ke.Entrytable[i].UnmarshalBytes(src[unmarshalledUntil:]) + unmarshalledUntil += ke.Entrytable[i].SizeBytes() + } +} + +// Packed implements marshal.Marshallable.Packed. +func (ke *KernelIP6TGetEntries) Packed() bool { + // KernelIP6TGetEntries isn't packed because the ke.Entrytable contains + // an indirection to the actual data we want to marshal (the slice data + // pointer), and the memory for KernelIP6TGetEntries contains the slice + // header which we don't want to marshal. + return false +} + +// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. +func (ke *KernelIP6TGetEntries) MarshalUnsafe(dst []byte) { + // Fall back to safe Marshal because the type in not packed. + ke.MarshalBytes(dst) +} + +// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe. +func (ke *KernelIP6TGetEntries) UnmarshalUnsafe(src []byte) { + // Fall back to safe Unmarshal because the type in not packed. + ke.UnmarshalBytes(src) +} + +// CopyIn implements marshal.Marshallable.CopyIn. +func (ke *KernelIP6TGetEntries) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) { + buf := task.CopyScratchBuffer(ke.SizeBytes()) // escapes: okay. + length, err := task.CopyInBytes(addr, buf) // escapes: okay. + // Unmarshal unconditionally. If we had a short copy-in, this results + // in a partially unmarshalled struct. + ke.UnmarshalBytes(buf) // escapes: fallback. + return length, err +} + +// CopyOut implements marshal.Marshallable.CopyOut. +func (ke *KernelIP6TGetEntries) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) { + // Type KernelIP6TGetEntries doesn't have a packed layout in memory, + // fall back to MarshalBytes. + return task.CopyOutBytes(addr, ke.marshalAll(task)) +} + +// CopyOutN implements marshal.Marshallable.CopyOutN. +func (ke *KernelIP6TGetEntries) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) { + // Type KernelIP6TGetEntries doesn't have a packed layout in memory, fall + // back to MarshalBytes. + return task.CopyOutBytes(addr, ke.marshalAll(task)[:limit]) +} + +func (ke *KernelIP6TGetEntries) marshalAll(task marshal.Task) []byte { + buf := task.CopyScratchBuffer(ke.SizeBytes()) + ke.MarshalBytes(buf) + return buf +} + +// WriteTo implements io.WriterTo.WriteTo. +func (ke *KernelIP6TGetEntries) WriteTo(w io.Writer) (int64, error) { + buf := make([]byte, ke.SizeBytes()) + ke.MarshalBytes(buf) + length, err := w.Write(buf) + return int64(length), err +} + +var _ marshal.Marshallable = (*KernelIP6TGetEntries)(nil) + +// IP6TEntry is an iptables rule. It corresponds to struct ip6t_entry in +// include/uapi/linux/netfilter_ipv6/ip6_tables.h. +// +// +marshal +type IP6TEntry struct { + // IPv6 is used to filter packets based on the IPv6 header. + IPv6 IP6TIP + + // NFCache relates to kernel-internal caching and isn't used by + // userspace. + NFCache uint32 + + // TargetOffset is the byte offset from the beginning of this IPTEntry + // to the start of the entry's target. + TargetOffset uint16 + + // NextOffset is the byte offset from the beginning of this IPTEntry to + // the start of the next entry. It is thus also the size of the entry. + NextOffset uint16 + + // Comeback is a return pointer. It is not used by userspace. + Comeback uint32 + + _ [4]byte + + // Counters holds the packet and byte counts for this rule. + Counters XTCounters + + // Elems holds the data for all this rule's matches followed by the + // target. It is variable length -- users have to iterate over any + // matches and use TargetOffset and NextOffset to make sense of the + // data. + // + // Elems is omitted here because it would cause IPTEntry to be an extra + // byte larger (see http://www.catb.org/esr/structure-packing/). + // + // Elems [0]byte +} + +// SizeOfIP6TEntry is the size of an IP6TEntry. +const SizeOfIP6TEntry = 168 + +// KernelIP6TEntry is identical to IP6TEntry, but includes the Elems field. +// KernelIP6TEntry itself is not Marshallable but it implements some methods of +// marshal.Marshallable that help in other implementations of Marshallable. +type KernelIP6TEntry struct { + Entry IP6TEntry + + // Elems holds the data for all this rule's matches followed by the + // target. It is variable length -- users have to iterate over any + // matches and use TargetOffset and NextOffset to make sense of the + // data. + Elems primitive.ByteSlice +} + +// SizeBytes implements marshal.Marshallable.SizeBytes. +func (ke *KernelIP6TEntry) SizeBytes() int { + return ke.Entry.SizeBytes() + ke.Elems.SizeBytes() +} + +// MarshalBytes implements marshal.Marshallable.MarshalBytes. +func (ke *KernelIP6TEntry) MarshalBytes(dst []byte) { + ke.Entry.MarshalBytes(dst) + ke.Elems.MarshalBytes(dst[ke.Entry.SizeBytes():]) +} + +// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes. +func (ke *KernelIP6TEntry) UnmarshalBytes(src []byte) { + ke.Entry.UnmarshalBytes(src) + ke.Elems.UnmarshalBytes(src[ke.Entry.SizeBytes():]) +} + +// IP6TIP contains information for matching a packet's IP header. +// It corresponds to struct ip6t_ip6 in +// include/uapi/linux/netfilter_ipv6/ip6_tables.h. +// +// +marshal +type IP6TIP struct { + // Src is the source IP address. + Src Inet6Addr + + // Dst is the destination IP address. + Dst Inet6Addr + + // SrcMask is the source IP mask. + SrcMask Inet6Addr + + // DstMask is the destination IP mask. + DstMask Inet6Addr + + // InputInterface is the input network interface. + InputInterface [IFNAMSIZ]byte + + // OutputInterface is the output network interface. + OutputInterface [IFNAMSIZ]byte + + // InputInterfaceMask is the input interface mask. + InputInterfaceMask [IFNAMSIZ]byte + + // OuputInterfaceMask is the output interface mask. + OutputInterfaceMask [IFNAMSIZ]byte + + // Protocol is the transport protocol. + Protocol uint16 + + // TOS matches TOS flags when Flags indicates filtering by TOS. + TOS uint8 + + // Flags define matching behavior for the IP header. + Flags uint8 + + // InverseFlags invert the meaning of fields in struct IPTIP. See the + // IP6T_INV_* flags. + InverseFlags uint8 + + // Linux defines in6_addr (Inet6Addr for us) as the union of a + // 16-element byte array and a 4-element 32-bit integer array, so the + // whole struct is 4-byte aligned. + _ [3]byte +} + +const SizeOfIP6TIP = 136 + +// Flags in IP6TIP.InverseFlags. Corresponding constants are in +// include/uapi/linux/netfilter_ipv6/ip6_tables.h. +const ( + // Invert the meaning of InputInterface. + IP6T_INV_VIA_IN = 0x01 + // Invert the meaning of OutputInterface. + IP6T_INV_VIA_OUT = 0x02 + // Invert the meaning of TOS. + IP6T_INV_TOS = 0x04 + // Invert the meaning of Src. + IP6T_INV_SRCIP = 0x08 + // Invert the meaning of Dst. + IP6T_INV_DSTIP = 0x10 + // Invert the meaning of the IPT_F_FRAG flag. + IP6T_INV_FRAG = 0x20 + // Enable all flags. + IP6T_INV_MASK = 0x7F +) diff --git a/pkg/abi/linux/netfilter_test.go b/pkg/abi/linux/netfilter_test.go index 565dd550e..bf73271c6 100644 --- a/pkg/abi/linux/netfilter_test.go +++ b/pkg/abi/linux/netfilter_test.go @@ -36,6 +36,9 @@ func TestSizes(t *testing.T) { {XTEntryTarget{}, SizeOfXTEntryTarget}, {XTErrorTarget{}, SizeOfXTErrorTarget}, {XTStandardTarget{}, SizeOfXTStandardTarget}, + {IP6TReplace{}, SizeOfIP6TReplace}, + {IP6TEntry{}, SizeOfIP6TEntry}, + {IP6TIP{}, SizeOfIP6TIP}, } for _, tc := range testCases { diff --git a/pkg/abi/linux/socket.go b/pkg/abi/linux/socket.go index 693996c01..e37c8727d 100644 --- a/pkg/abi/linux/socket.go +++ b/pkg/abi/linux/socket.go @@ -259,6 +259,11 @@ type InetMulticastRequestWithNIC struct { InterfaceIndex int32 } +// Inet6Addr is struct in6_addr, from uapi/linux/in6.h. +// +// +marshal +type Inet6Addr [16]byte + // SockAddrInet6 is struct sockaddr_in6, from uapi/linux/in6.h. type SockAddrInet6 struct { Family uint16 |