From 59e2c9f16a9a4cce2ecf8b6449a47316fdf76ca2 Mon Sep 17 00:00:00 2001 From: Ian Lewis Date: Tue, 27 Oct 2020 00:16:14 -0700 Subject: Add basic address deletion to netlink Updates #3921 PiperOrigin-RevId: 339195417 --- pkg/sentry/socket/hostinet/stack.go | 13 +++-- pkg/sentry/socket/netlink/route/protocol.go | 56 +++++++++++++++++++ pkg/sentry/socket/netstack/stack.go | 85 ++++++++++++++++++++++------- 3 files changed, 130 insertions(+), 24 deletions(-) (limited to 'pkg/sentry/socket') diff --git a/pkg/sentry/socket/hostinet/stack.go b/pkg/sentry/socket/hostinet/stack.go index 144ed593c..7e7857ac3 100644 --- a/pkg/sentry/socket/hostinet/stack.go +++ b/pkg/sentry/socket/hostinet/stack.go @@ -324,7 +324,12 @@ func (s *Stack) InterfaceAddrs() map[int32][]inet.InterfaceAddr { } // AddInterfaceAddr implements inet.Stack.AddInterfaceAddr. -func (s *Stack) AddInterfaceAddr(idx int32, addr inet.InterfaceAddr) error { +func (s *Stack) AddInterfaceAddr(int32, inet.InterfaceAddr) error { + return syserror.EACCES +} + +// RemoveInterfaceAddr implements inet.Stack.RemoveInterfaceAddr. +func (s *Stack) RemoveInterfaceAddr(int32, inet.InterfaceAddr) error { return syserror.EACCES } @@ -359,7 +364,7 @@ func (s *Stack) TCPSACKEnabled() (bool, error) { } // SetTCPSACKEnabled implements inet.Stack.SetTCPSACKEnabled. -func (s *Stack) SetTCPSACKEnabled(enabled bool) error { +func (s *Stack) SetTCPSACKEnabled(bool) error { return syserror.EACCES } @@ -369,7 +374,7 @@ func (s *Stack) TCPRecovery() (inet.TCPLossRecovery, error) { } // SetTCPRecovery implements inet.Stack.SetTCPRecovery. -func (s *Stack) SetTCPRecovery(recovery inet.TCPLossRecovery) error { +func (s *Stack) SetTCPRecovery(inet.TCPLossRecovery) error { return syserror.EACCES } @@ -495,6 +500,6 @@ func (s *Stack) Forwarding(protocol tcpip.NetworkProtocolNumber) bool { } // SetForwarding implements inet.Stack.SetForwarding. -func (s *Stack) SetForwarding(protocol tcpip.NetworkProtocolNumber, enable bool) error { +func (s *Stack) SetForwarding(tcpip.NetworkProtocolNumber, bool) error { return syserror.EACCES } diff --git a/pkg/sentry/socket/netlink/route/protocol.go b/pkg/sentry/socket/netlink/route/protocol.go index c71cce064..22216158e 100644 --- a/pkg/sentry/socket/netlink/route/protocol.go +++ b/pkg/sentry/socket/netlink/route/protocol.go @@ -423,6 +423,11 @@ func (p *Protocol) newAddr(ctx context.Context, msg *netlink.Message, ms *netlin } attrs = rest + // NOTE: A netlink message will contain multiple header attributes. + // Both the IFA_ADDRESS and IFA_LOCAL attributes are typically sent + // with IFA_ADDRESS being a prefix address and IFA_LOCAL being the + // local interface address. We add the local interface address here + // and ignore the IFA_ADDRESS. switch ahdr.Type { case linux.IFA_LOCAL: err := stack.AddInterfaceAddr(int32(ifa.Index), inet.InterfaceAddr{ @@ -439,8 +444,57 @@ func (p *Protocol) newAddr(ctx context.Context, msg *netlink.Message, ms *netlin } else if err != nil { return syserr.ErrInvalidArgument } + case linux.IFA_ADDRESS: + default: + return syserr.ErrNotSupported + } + } + return nil +} + +// delAddr handles RTM_DELADDR requests. +func (p *Protocol) delAddr(ctx context.Context, msg *netlink.Message, ms *netlink.MessageSet) *syserr.Error { + stack := inet.StackFromContext(ctx) + if stack == nil { + // No network stack. + return syserr.ErrProtocolNotSupported + } + + var ifa linux.InterfaceAddrMessage + attrs, ok := msg.GetData(&ifa) + if !ok { + return syserr.ErrInvalidArgument + } + + for !attrs.Empty() { + ahdr, value, rest, ok := attrs.ParseFirst() + if !ok { + return syserr.ErrInvalidArgument + } + attrs = rest + + // NOTE: A netlink message will contain multiple header attributes. + // Both the IFA_ADDRESS and IFA_LOCAL attributes are typically sent + // with IFA_ADDRESS being a prefix address and IFA_LOCAL being the + // local interface address. We use the local interface address to + // remove the address and ignore the IFA_ADDRESS. + switch ahdr.Type { + case linux.IFA_LOCAL: + err := stack.RemoveInterfaceAddr(int32(ifa.Index), inet.InterfaceAddr{ + Family: ifa.Family, + PrefixLen: ifa.PrefixLen, + Flags: ifa.Flags, + Addr: value, + }) + if err != nil { + return syserr.ErrInvalidArgument + } + case linux.IFA_ADDRESS: + default: + return syserr.ErrNotSupported } } + return nil } @@ -485,6 +539,8 @@ func (p *Protocol) ProcessMessage(ctx context.Context, msg *netlink.Message, ms return p.dumpRoutes(ctx, msg, ms) case linux.RTM_NEWADDR: return p.newAddr(ctx, msg, ms) + case linux.RTM_DELADDR: + return p.delAddr(ctx, msg, ms) default: return syserr.ErrNotSupported } diff --git a/pkg/sentry/socket/netstack/stack.go b/pkg/sentry/socket/netstack/stack.go index 1028d2a6e..fa9ac9059 100644 --- a/pkg/sentry/socket/netstack/stack.go +++ b/pkg/sentry/socket/netstack/stack.go @@ -100,56 +100,101 @@ func (s *Stack) InterfaceAddrs() map[int32][]inet.InterfaceAddr { return nicAddrs } -// AddInterfaceAddr implements inet.Stack.AddInterfaceAddr. -func (s *Stack) AddInterfaceAddr(idx int32, addr inet.InterfaceAddr) error { +// convertAddr converts an InterfaceAddr to a ProtocolAddress. +func convertAddr(addr inet.InterfaceAddr) (tcpip.ProtocolAddress, error) { var ( - protocol tcpip.NetworkProtocolNumber - address tcpip.Address + protocol tcpip.NetworkProtocolNumber + address tcpip.Address + protocolAddress tcpip.ProtocolAddress ) switch addr.Family { case linux.AF_INET: - if len(addr.Addr) < header.IPv4AddressSize { - return syserror.EINVAL + if len(addr.Addr) != header.IPv4AddressSize { + return protocolAddress, syserror.EINVAL } if addr.PrefixLen > header.IPv4AddressSize*8 { - return syserror.EINVAL + return protocolAddress, syserror.EINVAL } protocol = ipv4.ProtocolNumber - address = tcpip.Address(addr.Addr[:header.IPv4AddressSize]) - + address = tcpip.Address(addr.Addr) case linux.AF_INET6: - if len(addr.Addr) < header.IPv6AddressSize { - return syserror.EINVAL + if len(addr.Addr) != header.IPv6AddressSize { + return protocolAddress, syserror.EINVAL } if addr.PrefixLen > header.IPv6AddressSize*8 { - return syserror.EINVAL + return protocolAddress, syserror.EINVAL } protocol = ipv6.ProtocolNumber - address = tcpip.Address(addr.Addr[:header.IPv6AddressSize]) - + address = tcpip.Address(addr.Addr) default: - return syserror.ENOTSUP + return protocolAddress, syserror.ENOTSUP } - protocolAddress := tcpip.ProtocolAddress{ + protocolAddress = tcpip.ProtocolAddress{ Protocol: protocol, AddressWithPrefix: tcpip.AddressWithPrefix{ Address: address, PrefixLen: int(addr.PrefixLen), }, } + return protocolAddress, nil +} + +// AddInterfaceAddr implements inet.Stack.AddInterfaceAddr. +func (s *Stack) AddInterfaceAddr(idx int32, addr inet.InterfaceAddr) error { + protocolAddress, err := convertAddr(addr) + if err != nil { + return err + } // Attach address to interface. - if err := s.Stack.AddProtocolAddressWithOptions(tcpip.NICID(idx), protocolAddress, stack.CanBePrimaryEndpoint); err != nil { + nicID := tcpip.NICID(idx) + if err := s.Stack.AddProtocolAddressWithOptions(nicID, protocolAddress, stack.CanBePrimaryEndpoint); err != nil { + return syserr.TranslateNetstackError(err).ToError() + } + + // Add route for local network if it doesn't exist already. + localRoute := tcpip.Route{ + Destination: protocolAddress.AddressWithPrefix.Subnet(), + Gateway: "", // No gateway for local network. + NIC: nicID, + } + + for _, rt := range s.Stack.GetRouteTable() { + if rt.Equal(localRoute) { + return nil + } + } + + // Local route does not exist yet. Add it. + s.Stack.AddRoute(localRoute) + + return nil +} + +// RemoveInterfaceAddr implements inet.Stack.RemoveInterfaceAddr. +func (s *Stack) RemoveInterfaceAddr(idx int32, addr inet.InterfaceAddr) error { + protocolAddress, err := convertAddr(addr) + if err != nil { + return err + } + + // Remove addresses matching the address and prefix. + nicID := tcpip.NICID(idx) + if err := s.Stack.RemoveAddress(nicID, protocolAddress.AddressWithPrefix.Address); err != nil { return syserr.TranslateNetstackError(err).ToError() } - // Add route for local network. - s.Stack.AddRoute(tcpip.Route{ + // Remove the corresponding local network route if it exists. + localRoute := tcpip.Route{ Destination: protocolAddress.AddressWithPrefix.Subnet(), Gateway: "", // No gateway for local network. - NIC: tcpip.NICID(idx), + NIC: nicID, + } + s.Stack.RemoveRoutes(func(rt tcpip.Route) bool { + return rt.Equal(localRoute) }) + return nil } -- cgit v1.2.3