From 0b8d306e64f89e0d63a558f69a846d36beeea51d Mon Sep 17 00:00:00 2001 From: Kevin Krakauer Date: Thu, 17 Sep 2020 21:52:54 -0700 Subject: ip6tables: filter table support `ip6tables -t filter` is now usable. NAT support will come in a future CL. #3549 PiperOrigin-RevId: 332381801 --- pkg/sentry/socket/netfilter/netfilter.go | 4 ++++ pkg/sentry/socket/netfilter/tcp_matcher.go | 32 ++++++++++++++++++++++-------- pkg/sentry/socket/netfilter/udp_matcher.go | 32 +++++++++++++++++++++--------- 3 files changed, 51 insertions(+), 17 deletions(-) (limited to 'pkg/sentry') diff --git a/pkg/sentry/socket/netfilter/netfilter.go b/pkg/sentry/socket/netfilter/netfilter.go index 3e1735079..871ea80ee 100644 --- a/pkg/sentry/socket/netfilter/netfilter.go +++ b/pkg/sentry/socket/netfilter/netfilter.go @@ -146,6 +146,10 @@ func SetEntries(stk *stack.Stack, optVal []byte, ipv6 bool) *syserr.Error { case stack.FilterTable: table = stack.EmptyFilterTable() case stack.NATTable: + if ipv6 { + nflog("IPv6 redirection not yet supported (gvisor.dev/issue/3549)") + return syserr.ErrInvalidArgument + } table = stack.EmptyNATTable() default: nflog("we don't yet support writing to the %q table (gvisor.dev/issue/170)", replace.Name.String()) diff --git a/pkg/sentry/socket/netfilter/tcp_matcher.go b/pkg/sentry/socket/netfilter/tcp_matcher.go index 0bfd6c1f4..844acfede 100644 --- a/pkg/sentry/socket/netfilter/tcp_matcher.go +++ b/pkg/sentry/socket/netfilter/tcp_matcher.go @@ -97,17 +97,33 @@ func (*TCPMatcher) Name() string { // Match implements Matcher.Match. func (tm *TCPMatcher) Match(hook stack.Hook, pkt *stack.PacketBuffer, interfaceName string) (bool, bool) { - netHeader := header.IPv4(pkt.NetworkHeader().View()) + // TODO(gvisor.dev/issue/170): Proto checks should ultimately be moved + // into the stack.Check codepath as matchers are added. + switch pkt.NetworkProtocolNumber { + case header.IPv4ProtocolNumber: + netHeader := header.IPv4(pkt.NetworkHeader().View()) + if netHeader.TransportProtocol() != header.TCPProtocolNumber { + return false, false + } - if netHeader.TransportProtocol() != header.TCPProtocolNumber { - return false, false - } + // We don't match fragments. + if frag := netHeader.FragmentOffset(); frag != 0 { + if frag == 1 { + return false, true + } + return false, false + } - // We dont't match fragments. - if frag := netHeader.FragmentOffset(); frag != 0 { - if frag == 1 { - return false, true + case header.IPv6ProtocolNumber: + // As in Linux, we do not perform an IPv6 fragment check. See + // xt_action_param.fragoff in + // include/linux/netfilter/x_tables.h. + if header.IPv6(pkt.NetworkHeader().View()).TransportProtocol() != header.TCPProtocolNumber { + return false, false } + + default: + // We don't know the network protocol. return false, false } diff --git a/pkg/sentry/socket/netfilter/udp_matcher.go b/pkg/sentry/socket/netfilter/udp_matcher.go index 7ed05461d..63201201c 100644 --- a/pkg/sentry/socket/netfilter/udp_matcher.go +++ b/pkg/sentry/socket/netfilter/udp_matcher.go @@ -94,19 +94,33 @@ func (*UDPMatcher) Name() string { // Match implements Matcher.Match. func (um *UDPMatcher) Match(hook stack.Hook, pkt *stack.PacketBuffer, interfaceName string) (bool, bool) { - netHeader := header.IPv4(pkt.NetworkHeader().View()) - // TODO(gvisor.dev/issue/170): Proto checks should ultimately be moved // into the stack.Check codepath as matchers are added. - if netHeader.TransportProtocol() != header.UDPProtocolNumber { - return false, false - } + switch pkt.NetworkProtocolNumber { + case header.IPv4ProtocolNumber: + netHeader := header.IPv4(pkt.NetworkHeader().View()) + if netHeader.TransportProtocol() != header.UDPProtocolNumber { + return false, false + } - // We dont't match fragments. - if frag := netHeader.FragmentOffset(); frag != 0 { - if frag == 1 { - return false, true + // We don't match fragments. + if frag := netHeader.FragmentOffset(); frag != 0 { + if frag == 1 { + return false, true + } + return false, false } + + case header.IPv6ProtocolNumber: + // As in Linux, we do not perform an IPv6 fragment check. See + // xt_action_param.fragoff in + // include/linux/netfilter/x_tables.h. + if header.IPv6(pkt.NetworkHeader().View()).TransportProtocol() != header.UDPProtocolNumber { + return false, false + } + + default: + // We don't know the network protocol. return false, false } -- cgit v1.2.3