diff options
Diffstat (limited to 'pkg/sentry/socket/netstack')
| -rw-r--r-- | pkg/sentry/socket/netstack/netstack.go | 40 | ||||
| -rw-r--r-- | pkg/sentry/socket/netstack/provider.go | 53 |
2 files changed, 86 insertions, 7 deletions
diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go index 0ae573b45..debf9bce0 100644 --- a/pkg/sentry/socket/netstack/netstack.go +++ b/pkg/sentry/socket/netstack/netstack.go @@ -53,6 +53,7 @@ import ( "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" + "gvisor.dev/gvisor/pkg/tcpip/header" "gvisor.dev/gvisor/pkg/tcpip/stack" "gvisor.dev/gvisor/pkg/tcpip/transport/tcp" "gvisor.dev/gvisor/pkg/tcpip/transport/udp" @@ -296,6 +297,7 @@ func New(t *kernel.Task, family int, skType linux.SockType, protocol int, queue var sockAddrInetSize = int(binary.Size(linux.SockAddrInet{})) var sockAddrInet6Size = int(binary.Size(linux.SockAddrInet6{})) +var sockAddrLinkSize = int(binary.Size(linux.SockAddrLink{})) // bytesToIPAddress converts an IPv4 or IPv6 address from the user to the // netstack representation taking any addresses into account. @@ -307,12 +309,12 @@ func bytesToIPAddress(addr []byte) tcpip.Address { } // AddressAndFamily reads an sockaddr struct from the given address and -// converts it to the FullAddress format. It supports AF_UNIX, AF_INET and -// AF_INET6 addresses. +// converts it to the FullAddress format. It supports AF_UNIX, AF_INET, +// AF_INET6, and AF_PACKET addresses. // // strict indicates whether addresses with the AF_UNSPEC family are accepted of not. // -// AddressAndFamily returns an address, its family. +// AddressAndFamily returns an address and its family. func AddressAndFamily(sfamily int, addr []byte, strict bool) (tcpip.FullAddress, uint16, *syserr.Error) { // Make sure we have at least 2 bytes for the address family. if len(addr) < 2 { @@ -371,6 +373,22 @@ func AddressAndFamily(sfamily int, addr []byte, strict bool) (tcpip.FullAddress, } return out, family, nil + case linux.AF_PACKET: + var a linux.SockAddrLink + if len(addr) < sockAddrLinkSize { + return tcpip.FullAddress{}, family, syserr.ErrInvalidArgument + } + binary.Unmarshal(addr[:sockAddrLinkSize], usermem.ByteOrder, &a) + if a.Family != linux.AF_PACKET || a.HardwareAddrLen != header.EthernetAddressSize { + return tcpip.FullAddress{}, family, syserr.ErrInvalidArgument + } + + // TODO(b/129292371): Return protocol too. + return tcpip.FullAddress{ + NIC: tcpip.NICID(a.InterfaceIndex), + Addr: tcpip.Address(a.HardwareAddr[:header.EthernetAddressSize]), + }, family, nil + case linux.AF_UNSPEC: return tcpip.FullAddress{}, family, nil @@ -1951,12 +1969,14 @@ func ConvertAddress(family int, addr tcpip.FullAddress) (linux.SockAddr, uint32) return &out, uint32(2 + l) } return &out, uint32(3 + l) + case linux.AF_INET: var out linux.SockAddrInet copy(out.Addr[:], addr.Addr) out.Family = linux.AF_INET out.Port = htons(addr.Port) - return &out, uint32(binary.Size(out)) + return &out, uint32(sockAddrInetSize) + case linux.AF_INET6: var out linux.SockAddrInet6 if len(addr.Addr) == 4 { @@ -1972,7 +1992,17 @@ func ConvertAddress(family int, addr tcpip.FullAddress) (linux.SockAddr, uint32) if isLinkLocal(addr.Addr) { out.Scope_id = uint32(addr.NIC) } - return &out, uint32(binary.Size(out)) + return &out, uint32(sockAddrInet6Size) + + case linux.AF_PACKET: + // TODO(b/129292371): Return protocol too. + var out linux.SockAddrLink + out.Family = linux.AF_PACKET + out.InterfaceIndex = int32(addr.NIC) + out.HardwareAddrLen = header.EthernetAddressSize + copy(out.HardwareAddr[:], addr.Addr) + return &out, uint32(sockAddrLinkSize) + default: return nil, 0 } diff --git a/pkg/sentry/socket/netstack/provider.go b/pkg/sentry/socket/netstack/provider.go index 357a664cc..2d2c1ba2a 100644 --- a/pkg/sentry/socket/netstack/provider.go +++ b/pkg/sentry/socket/netstack/provider.go @@ -62,6 +62,10 @@ func getTransportProtocol(ctx context.Context, stype linux.SockType, protocol in } case linux.SOCK_RAW: + // TODO(b/142504697): "In order to create a raw socket, a + // process must have the CAP_NET_RAW capability in the user + // namespace that governs its network namespace." - raw(7) + // Raw sockets require CAP_NET_RAW. creds := auth.CredentialsFromContext(ctx) if !creds.HasCapability(linux.CAP_NET_RAW) { @@ -85,7 +89,8 @@ func getTransportProtocol(ctx context.Context, stype linux.SockType, protocol in return 0, true, syserr.ErrProtocolNotSupported } -// Socket creates a new socket object for the AF_INET or AF_INET6 family. +// Socket creates a new socket object for the AF_INET, AF_INET6, or AF_PACKET +// family. func (p *provider) Socket(t *kernel.Task, stype linux.SockType, protocol int) (*fs.File, *syserr.Error) { // Fail right away if we don't have a stack. stack := t.NetworkContext() @@ -99,6 +104,12 @@ func (p *provider) Socket(t *kernel.Task, stype linux.SockType, protocol int) (* return nil, nil } + // Packet sockets are handled separately, since they are neither INET + // nor INET6 specific. + if p.family == linux.AF_PACKET { + return packetSocket(t, eps, stype, protocol) + } + // Figure out the transport protocol. transProto, associated, err := getTransportProtocol(t, stype, protocol) if err != nil { @@ -121,12 +132,47 @@ func (p *provider) Socket(t *kernel.Task, stype linux.SockType, protocol int) (* return New(t, p.family, stype, int(transProto), wq, ep) } +func packetSocket(t *kernel.Task, epStack *Stack, stype linux.SockType, protocol int) (*fs.File, *syserr.Error) { + // TODO(b/142504697): "In order to create a packet socket, a process + // must have the CAP_NET_RAW capability in the user namespace that + // governs its network namespace." - packet(7) + + // Packet sockets require CAP_NET_RAW. + creds := auth.CredentialsFromContext(t) + if !creds.HasCapability(linux.CAP_NET_RAW) { + return nil, syserr.ErrNotPermitted + } + + // "cooked" packets don't contain link layer information. + var cooked bool + switch stype { + case linux.SOCK_DGRAM: + cooked = true + case linux.SOCK_RAW: + cooked = false + default: + return nil, syserr.ErrProtocolNotSupported + } + + // protocol is passed in network byte order, but netstack wants it in + // host order. + netProto := tcpip.NetworkProtocolNumber(ntohs(uint16(protocol))) + + wq := &waiter.Queue{} + ep, err := epStack.Stack.NewPacketEndpoint(cooked, netProto, wq) + if err != nil { + return nil, syserr.TranslateNetstackError(err) + } + + return New(t, linux.AF_PACKET, stype, protocol, wq, ep) +} + // Pair just returns nil sockets (not supported). func (*provider) Pair(*kernel.Task, linux.SockType, int) (*fs.File, *fs.File, *syserr.Error) { return nil, nil, nil } -// init registers socket providers for AF_INET and AF_INET6. +// init registers socket providers for AF_INET, AF_INET6, and AF_PACKET. func init() { // Providers backed by netstack. p := []provider{ @@ -138,6 +184,9 @@ func init() { family: linux.AF_INET6, netProto: ipv6.ProtocolNumber, }, + { + family: linux.AF_PACKET, + }, } for i := range p { |