diff options
-rw-r--r-- | pkg/abi/linux/linux_abi_autogen_unsafe.go | 10 | ||||
-rw-r--r-- | pkg/tcpip/stack/ndp.go | 96 | ||||
-rw-r--r-- | pkg/tcpip/stack/nic.go | 38 | ||||
-rw-r--r-- | pkg/tcpip/stack/route.go | 4 | ||||
-rw-r--r-- | pkg/tcpip/stack/stack.go | 7 |
5 files changed, 111 insertions, 44 deletions
diff --git a/pkg/abi/linux/linux_abi_autogen_unsafe.go b/pkg/abi/linux/linux_abi_autogen_unsafe.go index 22c92b100..2b5ccacc3 100644 --- a/pkg/abi/linux/linux_abi_autogen_unsafe.go +++ b/pkg/abi/linux/linux_abi_autogen_unsafe.go @@ -124,7 +124,7 @@ func (s *Statx) UnmarshalBytes(src []byte) { // Packed implements marshal.Marshallable.Packed. //go:nosplit func (s *Statx) Packed() bool { - return s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() + return s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() } // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. @@ -138,7 +138,7 @@ func (s *Statx) MarshalUnsafe(dst []byte) { // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe. func (s *Statx) UnmarshalUnsafe(src []byte) { - if s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() { + if s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() { safecopy.CopyOut(unsafe.Pointer(s), src) } else { s.UnmarshalBytes(src) @@ -148,7 +148,7 @@ func (s *Statx) UnmarshalUnsafe(src []byte) { // CopyOutN implements marshal.Marshallable.CopyOutN. //go:nosplit func (s *Statx) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) { - if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() { + if !s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() { // Type Statx doesn't have a packed layout in memory, fall back to MarshalBytes. buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay. s.MarshalBytes(buf) // escapes: fallback. @@ -178,7 +178,7 @@ func (s *Statx) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) { // CopyIn implements marshal.Marshallable.CopyIn. //go:nosplit func (s *Statx) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) { - if !s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() { + if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() { // Type Statx doesn't have a packed layout in memory, fall back to UnmarshalBytes. buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay. length, err := task.CopyInBytes(addr, buf) // escapes: okay. @@ -204,7 +204,7 @@ func (s *Statx) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) { // WriteTo implements io.WriterTo.WriteTo. func (s *Statx) WriteTo(w io.Writer) (int64, error) { - if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() { + if !s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() { // Type Statx doesn't have a packed layout in memory, fall back to MarshalBytes. buf := make([]byte, s.SizeBytes()) s.MarshalBytes(buf) diff --git a/pkg/tcpip/stack/ndp.go b/pkg/tcpip/stack/ndp.go index ae7a8f740..e28c23d66 100644 --- a/pkg/tcpip/stack/ndp.go +++ b/pkg/tcpip/stack/ndp.go @@ -467,8 +467,17 @@ type ndpState struct { // The default routers discovered through Router Advertisements. defaultRouters map[tcpip.Address]defaultRouterState - // The timer used to send the next router solicitation message. - rtrSolicitTimer *time.Timer + rtrSolicit struct { + // The timer used to send the next router solicitation message. + timer *time.Timer + + // Used to let the Router Solicitation timer know that it has been stopped. + // + // Must only be read from or written to while protected by the lock of + // the NIC this ndpState is associated with. MUST be set when the timer is + // set. + done *bool + } // The on-link prefixes discovered through Router Advertisements' Prefix // Information option. @@ -648,13 +657,14 @@ func (ndp *ndpState) startDuplicateAddressDetection(addr tcpip.Address, ref *ref // as starting a goroutine but we use a timer that fires immediately so we can // reset it for the next DAD iteration. timer = time.AfterFunc(0, func() { - ndp.nic.mu.RLock() + ndp.nic.mu.Lock() + defer ndp.nic.mu.Unlock() + if done { // If we reach this point, it means that the DAD timer fired after // another goroutine already obtained the NIC lock and stopped DAD // before this function obtained the NIC lock. Simply return here and do // nothing further. - ndp.nic.mu.RUnlock() return } @@ -665,15 +675,23 @@ func (ndp *ndpState) startDuplicateAddressDetection(addr tcpip.Address, ref *ref } dadDone := remaining == 0 - ndp.nic.mu.RUnlock() var err *tcpip.Error if !dadDone { - err = ndp.sendDADPacket(addr) + // Use the unspecified address as the source address when performing DAD. + ref := ndp.nic.getRefOrCreateTempLocked(header.IPv6ProtocolNumber, header.IPv6Any, NeverPrimaryEndpoint) + + // Do not hold the lock when sending packets which may be a long running + // task or may block link address resolution. We know this is safe + // because immediately after obtaining the lock again, we check if DAD + // has been stopped before doing any work with the NIC. Note, DAD would be + // stopped if the NIC was disabled or removed, or if the address was + // removed. + ndp.nic.mu.Unlock() + err = ndp.sendDADPacket(addr, ref) + ndp.nic.mu.Lock() } - ndp.nic.mu.Lock() - defer ndp.nic.mu.Unlock() if done { // If we reach this point, it means that DAD was stopped after we released // the NIC's read lock and before we obtained the write lock. @@ -721,17 +739,24 @@ func (ndp *ndpState) startDuplicateAddressDetection(addr tcpip.Address, ref *ref // addr. // // addr must be a tentative IPv6 address on ndp's NIC. -func (ndp *ndpState) sendDADPacket(addr tcpip.Address) *tcpip.Error { +// +// The NIC ndp belongs to MUST NOT be locked. +func (ndp *ndpState) sendDADPacket(addr tcpip.Address, ref *referencedNetworkEndpoint) *tcpip.Error { snmc := header.SolicitedNodeAddr(addr) - // Use the unspecified address as the source address when performing DAD. - ref := ndp.nic.getRefOrCreateTemp(header.IPv6ProtocolNumber, header.IPv6Any, NeverPrimaryEndpoint, forceSpoofing) - r := makeRoute(header.IPv6ProtocolNumber, header.IPv6Any, snmc, ndp.nic.linkEP.LinkAddress(), ref, false, false) + r := makeRoute(header.IPv6ProtocolNumber, ref.ep.ID().LocalAddress, snmc, ndp.nic.linkEP.LinkAddress(), ref, false, false) defer r.Release() // Route should resolve immediately since snmc is a multicast address so a // remote link address can be calculated without a resolution process. if c, err := r.Resolve(nil); err != nil { + // Do not consider the NIC being unknown or disabled as a fatal error. + // Since this method is required to be called when the NIC is not locked, + // the NIC could have been disabled or removed by another goroutine. + if err == tcpip.ErrUnknownNICID || err != tcpip.ErrInvalidEndpointState { + return err + } + panic(fmt.Sprintf("ndp: error when resolving route to send NDP NS for DAD (%s -> %s on NIC(%d)): %s", header.IPv6Any, snmc, ndp.nic.ID(), err)) } else if c != nil { panic(fmt.Sprintf("ndp: route resolution not immediate for route to send NDP NS for DAD (%s -> %s on NIC(%d))", header.IPv6Any, snmc, ndp.nic.ID())) @@ -1816,7 +1841,7 @@ func (ndp *ndpState) cleanupState(hostOnly bool) { // // The NIC ndp belongs to MUST be locked. func (ndp *ndpState) startSolicitingRouters() { - if ndp.rtrSolicitTimer != nil { + if ndp.rtrSolicit.timer != nil { // We are already soliciting routers. return } @@ -1833,14 +1858,27 @@ func (ndp *ndpState) startSolicitingRouters() { delay = time.Duration(rand.Int63n(int64(ndp.configs.MaxRtrSolicitationDelay))) } - ndp.rtrSolicitTimer = time.AfterFunc(delay, func() { + var done bool + ndp.rtrSolicit.done = &done + ndp.rtrSolicit.timer = time.AfterFunc(delay, func() { + ndp.nic.mu.Lock() + if done { + // If we reach this point, it means that the RS timer fired after another + // goroutine already obtained the NIC lock and stopped solicitations. + // Simply return here and do nothing further. + ndp.nic.mu.Unlock() + return + } + // As per RFC 4861 section 4.1, the source of the RS is an address assigned // to the sending interface, or the unspecified address if no address is // assigned to the sending interface. - ref := ndp.nic.primaryIPv6Endpoint(header.IPv6AllRoutersMulticastAddress) + ref := ndp.nic.primaryIPv6EndpointRLocked(header.IPv6AllRoutersMulticastAddress) if ref == nil { - ref = ndp.nic.getRefOrCreateTemp(header.IPv6ProtocolNumber, header.IPv6Any, NeverPrimaryEndpoint, forceSpoofing) + ref = ndp.nic.getRefOrCreateTempLocked(header.IPv6ProtocolNumber, header.IPv6Any, NeverPrimaryEndpoint) } + ndp.nic.mu.Unlock() + localAddr := ref.ep.ID().LocalAddress r := makeRoute(header.IPv6ProtocolNumber, localAddr, header.IPv6AllRoutersMulticastAddress, ndp.nic.linkEP.LinkAddress(), ref, false, false) defer r.Release() @@ -1849,6 +1887,13 @@ func (ndp *ndpState) startSolicitingRouters() { // header.IPv6AllRoutersMulticastAddress is a multicast address so a // remote link address can be calculated without a resolution process. if c, err := r.Resolve(nil); err != nil { + // Do not consider the NIC being unknown or disabled as a fatal error. + // Since this method is required to be called when the NIC is not locked, + // the NIC could have been disabled or removed by another goroutine. + if err == tcpip.ErrUnknownNICID || err == tcpip.ErrInvalidEndpointState { + return + } + panic(fmt.Sprintf("ndp: error when resolving route to send NDP RS (%s -> %s on NIC(%d)): %s", header.IPv6Any, header.IPv6AllRoutersMulticastAddress, ndp.nic.ID(), err)) } else if c != nil { panic(fmt.Sprintf("ndp: route resolution not immediate for route to send NDP RS (%s -> %s on NIC(%d))", header.IPv6Any, header.IPv6AllRoutersMulticastAddress, ndp.nic.ID())) @@ -1893,17 +1938,18 @@ func (ndp *ndpState) startSolicitingRouters() { } ndp.nic.mu.Lock() - defer ndp.nic.mu.Unlock() - if remaining == 0 { - ndp.rtrSolicitTimer = nil - } else if ndp.rtrSolicitTimer != nil { + if done || remaining == 0 { + ndp.rtrSolicit.timer = nil + ndp.rtrSolicit.done = nil + } else if ndp.rtrSolicit.timer != nil { // Note, we need to explicitly check to make sure that // the timer field is not nil because if it was nil but // we still reached this point, then we know the NIC // was requested to stop soliciting routers so we don't // need to send the next Router Solicitation message. - ndp.rtrSolicitTimer.Reset(ndp.configs.RtrSolicitationInterval) + ndp.rtrSolicit.timer.Reset(ndp.configs.RtrSolicitationInterval) } + ndp.nic.mu.Unlock() }) } @@ -1913,13 +1959,15 @@ func (ndp *ndpState) startSolicitingRouters() { // // The NIC ndp belongs to MUST be locked. func (ndp *ndpState) stopSolicitingRouters() { - if ndp.rtrSolicitTimer == nil { + if ndp.rtrSolicit.timer == nil { // Nothing to do. return } - ndp.rtrSolicitTimer.Stop() - ndp.rtrSolicitTimer = nil + *ndp.rtrSolicit.done = true + ndp.rtrSolicit.timer.Stop() + ndp.rtrSolicit.timer = nil + ndp.rtrSolicit.done = nil } // initializeTempAddrState initializes state related to temporary SLAAC diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index d756ae6f5..644c0d437 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -457,8 +457,20 @@ type ipv6AddrCandidate struct { // remoteAddr must be a valid IPv6 address. func (n *NIC) primaryIPv6Endpoint(remoteAddr tcpip.Address) *referencedNetworkEndpoint { n.mu.RLock() - defer n.mu.RUnlock() + ref := n.primaryIPv6EndpointRLocked(remoteAddr) + n.mu.RUnlock() + return ref +} +// primaryIPv6EndpointLocked returns an IPv6 endpoint following Source Address +// Selection (RFC 6724 section 5). +// +// Note, only rules 1-3 and 7 are followed. +// +// remoteAddr must be a valid IPv6 address. +// +// n.mu MUST be read locked. +func (n *NIC) primaryIPv6EndpointRLocked(remoteAddr tcpip.Address) *referencedNetworkEndpoint { primaryAddrs := n.mu.primary[header.IPv6ProtocolNumber] if len(primaryAddrs) == 0 { @@ -568,11 +580,6 @@ const ( // promiscuous indicates that the NIC's promiscuous flag should be observed // when getting a NIC's referenced network endpoint. promiscuous - - // forceSpoofing indicates that the NIC should be assumed to be spoofing, - // regardless of what the NIC's spoofing flag is when getting a NIC's - // referenced network endpoint. - forceSpoofing ) func (n *NIC) getRef(protocol tcpip.NetworkProtocolNumber, dst tcpip.Address) *referencedNetworkEndpoint { @@ -591,8 +598,6 @@ func (n *NIC) findEndpoint(protocol tcpip.NetworkProtocolNumber, address tcpip.A // or spoofing. Promiscuous mode will only be checked if promiscuous is true. // Similarly, spoofing will only be checked if spoofing is true. func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address tcpip.Address, peb PrimaryEndpointBehavior, tempRef getRefBehaviour) *referencedNetworkEndpoint { - id := NetworkEndpointID{address} - n.mu.RLock() var spoofingOrPromiscuous bool @@ -601,11 +606,9 @@ func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address t spoofingOrPromiscuous = n.mu.spoofing case promiscuous: spoofingOrPromiscuous = n.mu.promiscuous - case forceSpoofing: - spoofingOrPromiscuous = true } - if ref, ok := n.mu.endpoints[id]; ok { + if ref, ok := n.mu.endpoints[NetworkEndpointID{address}]; ok { // An endpoint with this id exists, check if it can be used and return it. switch ref.getKind() { case permanentExpired: @@ -654,11 +657,18 @@ func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address t // endpoint, create a new "temporary" endpoint. It will only exist while // there's a route through it. n.mu.Lock() - if ref, ok := n.mu.endpoints[id]; ok { + ref := n.getRefOrCreateTempLocked(protocol, address, peb) + n.mu.Unlock() + return ref +} + +/// getRefOrCreateTempLocked returns an existing endpoint for address or creates +/// and returns a temporary endpoint. +func (n *NIC) getRefOrCreateTempLocked(protocol tcpip.NetworkProtocolNumber, address tcpip.Address, peb PrimaryEndpointBehavior) *referencedNetworkEndpoint { + if ref, ok := n.mu.endpoints[NetworkEndpointID{address}]; ok { // No need to check the type as we are ok with expired endpoints at this // point. if ref.tryIncRef() { - n.mu.Unlock() return ref } // tryIncRef failing means the endpoint is scheduled to be removed once the @@ -670,7 +680,6 @@ func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address t // Add a new temporary endpoint. netProto, ok := n.stack.networkProtocols[protocol] if !ok { - n.mu.Unlock() return nil } ref, _ := n.addAddressLocked(tcpip.ProtocolAddress{ @@ -681,7 +690,6 @@ func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address t }, }, peb, temporary, static, false) - n.mu.Unlock() return ref } diff --git a/pkg/tcpip/stack/route.go b/pkg/tcpip/stack/route.go index f5b6ca0b9..d65f8049e 100644 --- a/pkg/tcpip/stack/route.go +++ b/pkg/tcpip/stack/route.go @@ -113,6 +113,8 @@ func (r *Route) GSOMaxSize() uint32 { // If address resolution is required, ErrNoLinkAddress and a notification channel is // returned for the top level caller to block. Channel is closed once address resolution // is complete (success or not). +// +// The NIC r uses must not be locked. func (r *Route) Resolve(waker *sleep.Waker) (<-chan struct{}, *tcpip.Error) { if !r.IsResolutionRequired() { // Nothing to do if there is no cache (which does the resolution on cache miss) or @@ -148,6 +150,8 @@ func (r *Route) RemoveWaker(waker *sleep.Waker) { // IsResolutionRequired returns true if Resolve() must be called to resolve // the link address before the this route can be written to. +// +// The NIC r uses must not be locked. func (r *Route) IsResolutionRequired() bool { return r.ref.isValidForOutgoing() && r.ref.linkCache != nil && r.RemoteLinkAddress == "" } diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go index 294ce8775..648791302 100644 --- a/pkg/tcpip/stack/stack.go +++ b/pkg/tcpip/stack/stack.go @@ -1017,6 +1017,13 @@ func (s *Stack) RemoveNIC(id tcpip.NICID) *tcpip.Error { s.mu.Lock() defer s.mu.Unlock() + return s.removeNICLocked(id) +} + +// removeNICLocked removes NIC and all related routes from the network stack. +// +// s.mu must be locked. +func (s *Stack) removeNICLocked(id tcpip.NICID) *tcpip.Error { nic, ok := s.nics[id] if !ok { return tcpip.ErrUnknownNICID |