diff options
author | Kevin Krakauer <krakauer@google.com> | 2019-07-12 18:08:03 -0700 |
---|---|---|
committer | gVisor bot <gvisor-bot@google.com> | 2019-07-12 18:09:12 -0700 |
commit | 9b4d3280e172063a6563d9e72a75b500442ed9b9 (patch) | |
tree | 01e4fb8d506559a5ed5c6c3652265ec833230277 /pkg/sentry | |
parent | 17bab652afebdc43d77969431b9147cca039f61e (diff) |
Add IPPROTO_RAW, which allows raw sockets to write IP headers.
iptables also relies on IPPROTO_RAW in a way. It opens such a socket to
manipulate the kernel's tables, but it doesn't actually use any of the
functionality. Blegh.
PiperOrigin-RevId: 257903078
Diffstat (limited to 'pkg/sentry')
-rw-r--r-- | pkg/sentry/socket/epsocket/provider.go | 35 |
1 files changed, 21 insertions, 14 deletions
diff --git a/pkg/sentry/socket/epsocket/provider.go b/pkg/sentry/socket/epsocket/provider.go index 6d2b5d038..421f93dc4 100644 --- a/pkg/sentry/socket/epsocket/provider.go +++ b/pkg/sentry/socket/epsocket/provider.go @@ -40,42 +40,49 @@ type provider struct { } // getTransportProtocol figures out transport protocol. Currently only TCP, -// UDP, and ICMP are supported. -func getTransportProtocol(ctx context.Context, stype linux.SockType, protocol int) (tcpip.TransportProtocolNumber, *syserr.Error) { +// UDP, and ICMP are supported. The bool return value is true when this socket +// is associated with a transport protocol. This is only false for SOCK_RAW, +// IPPROTO_IP sockets. +func getTransportProtocol(ctx context.Context, stype linux.SockType, protocol int) (tcpip.TransportProtocolNumber, bool, *syserr.Error) { switch stype { case linux.SOCK_STREAM: if protocol != 0 && protocol != syscall.IPPROTO_TCP { - return 0, syserr.ErrInvalidArgument + return 0, true, syserr.ErrInvalidArgument } - return tcp.ProtocolNumber, nil + return tcp.ProtocolNumber, true, nil case linux.SOCK_DGRAM: switch protocol { case 0, syscall.IPPROTO_UDP: - return udp.ProtocolNumber, nil + return udp.ProtocolNumber, true, nil case syscall.IPPROTO_ICMP: - return header.ICMPv4ProtocolNumber, nil + return header.ICMPv4ProtocolNumber, true, nil case syscall.IPPROTO_ICMPV6: - return header.ICMPv6ProtocolNumber, nil + return header.ICMPv6ProtocolNumber, true, nil } case linux.SOCK_RAW: // Raw sockets require CAP_NET_RAW. creds := auth.CredentialsFromContext(ctx) if !creds.HasCapability(linux.CAP_NET_RAW) { - return 0, syserr.ErrPermissionDenied + return 0, true, syserr.ErrPermissionDenied } switch protocol { case syscall.IPPROTO_ICMP: - return header.ICMPv4ProtocolNumber, nil + return header.ICMPv4ProtocolNumber, true, nil case syscall.IPPROTO_UDP: - return header.UDPProtocolNumber, nil + return header.UDPProtocolNumber, true, nil case syscall.IPPROTO_TCP: - return header.TCPProtocolNumber, nil + return header.TCPProtocolNumber, true, nil + // IPPROTO_RAW signifies that the raw socket isn't assigned to + // a transport protocol. Users will be able to write packets' + // IP headers and won't receive anything. + case syscall.IPPROTO_RAW: + return tcpip.TransportProtocolNumber(0), false, nil } } - return 0, syserr.ErrProtocolNotSupported + return 0, true, syserr.ErrProtocolNotSupported } // Socket creates a new socket object for the AF_INET or AF_INET6 family. @@ -93,7 +100,7 @@ func (p *provider) Socket(t *kernel.Task, stype linux.SockType, protocol int) (* } // Figure out the transport protocol. - transProto, err := getTransportProtocol(t, stype, protocol) + transProto, associated, err := getTransportProtocol(t, stype, protocol) if err != nil { return nil, err } @@ -103,7 +110,7 @@ func (p *provider) Socket(t *kernel.Task, stype linux.SockType, protocol int) (* var e *tcpip.Error wq := &waiter.Queue{} if stype == linux.SOCK_RAW { - ep, e = eps.Stack.NewRawEndpoint(transProto, p.netProto, wq) + ep, e = eps.Stack.NewRawEndpoint(transProto, p.netProto, wq, associated) } else { ep, e = eps.Stack.NewEndpoint(transProto, p.netProto, wq) } |