diff options
Diffstat (limited to 'pkg/tcpip')
-rw-r--r-- | pkg/tcpip/stack/iptables.go | 42 | ||||
-rw-r--r-- | pkg/tcpip/stack/iptables_types.go | 15 | ||||
-rw-r--r-- | pkg/tcpip/stack/stack.go | 23 | ||||
-rw-r--r-- | pkg/tcpip/transport/icmp/endpoint.go | 5 | ||||
-rw-r--r-- | pkg/tcpip/transport/packet/endpoint.go | 5 | ||||
-rw-r--r-- | pkg/tcpip/transport/raw/endpoint.go | 5 | ||||
-rw-r--r-- | pkg/tcpip/transport/tcp/endpoint.go | 5 | ||||
-rw-r--r-- | pkg/tcpip/transport/tcp/snd.go | 31 | ||||
-rw-r--r-- | pkg/tcpip/transport/udp/endpoint.go | 5 |
9 files changed, 79 insertions, 57 deletions
diff --git a/pkg/tcpip/stack/iptables.go b/pkg/tcpip/stack/iptables.go index d989dbe91..4e9b404c8 100644 --- a/pkg/tcpip/stack/iptables.go +++ b/pkg/tcpip/stack/iptables.go @@ -43,11 +43,11 @@ const HookUnset = -1 // DefaultTables returns a default set of tables. Each chain is set to accept // all packets. -func DefaultTables() IPTables { +func DefaultTables() *IPTables { // TODO(gvisor.dev/issue/170): We may be able to swap out some strings for // iotas. - return IPTables{ - Tables: map[string]Table{ + return &IPTables{ + tables: map[string]Table{ TablenameNat: Table{ Rules: []Rule{ Rule{Target: AcceptTarget{}}, @@ -106,7 +106,7 @@ func DefaultTables() IPTables { UserChains: map[string]int{}, }, }, - Priorities: map[Hook][]string{ + priorities: map[Hook][]string{ Input: []string{TablenameNat, TablenameFilter}, Prerouting: []string{TablenameMangle, TablenameNat}, Output: []string{TablenameMangle, TablenameNat, TablenameFilter}, @@ -158,6 +158,36 @@ func EmptyNatTable() Table { } } +// GetTable returns table by name. +func (it *IPTables) GetTable(name string) (Table, bool) { + it.mu.RLock() + defer it.mu.RUnlock() + t, ok := it.tables[name] + return t, ok +} + +// ReplaceTable replaces or inserts table by name. +func (it *IPTables) ReplaceTable(name string, table Table) { + it.mu.Lock() + defer it.mu.Unlock() + it.tables[name] = table +} + +// ModifyTables acquires write-lock and calls fn with internal name-to-table +// map. This function can be used to update multiple tables atomically. +func (it *IPTables) ModifyTables(fn func(map[string]Table)) { + it.mu.Lock() + defer it.mu.Unlock() + fn(it.tables) +} + +// GetPriorities returns slice of priorities associated with hook. +func (it *IPTables) GetPriorities(hook Hook) []string { + it.mu.RLock() + defer it.mu.RUnlock() + return it.priorities[hook] +} + // A chainVerdict is what a table decides should be done with a packet. type chainVerdict int @@ -184,8 +214,8 @@ func (it *IPTables) Check(hook Hook, pkt *PacketBuffer, gso *GSO, r *Route, addr it.connections.HandlePacket(pkt, hook, gso, r) // Go through each table containing the hook. - for _, tablename := range it.Priorities[hook] { - table := it.Tables[tablename] + for _, tablename := range it.GetPriorities(hook) { + table, _ := it.GetTable(tablename) ruleIdx := table.BuiltinChains[hook] switch verdict := it.checkChain(hook, pkt, table, ruleIdx, gso, r, address, nicName); verdict { // If the table returns Accept, move on to the next table. diff --git a/pkg/tcpip/stack/iptables_types.go b/pkg/tcpip/stack/iptables_types.go index af72b9c46..4a6a5c6f1 100644 --- a/pkg/tcpip/stack/iptables_types.go +++ b/pkg/tcpip/stack/iptables_types.go @@ -16,6 +16,7 @@ package stack import ( "strings" + "sync" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/header" @@ -78,13 +79,17 @@ const ( // IPTables holds all the tables for a netstack. type IPTables struct { - // Tables maps table names to tables. User tables have arbitrary names. - Tables map[string]Table + // mu protects tables and priorities. + mu sync.RWMutex - // Priorities maps each hook to a list of table names. The order of the + // tables maps table names to tables. User tables have arbitrary names. mu + // needs to be locked for accessing. + tables map[string]Table + + // priorities maps each hook to a list of table names. The order of the // list is the order in which each table should be visited for that - // hook. - Priorities map[Hook][]string + // hook. mu needs to be locked for accessing. + priorities map[Hook][]string connections ConnTrackTable } diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go index 8af06cb9a..294ce8775 100644 --- a/pkg/tcpip/stack/stack.go +++ b/pkg/tcpip/stack/stack.go @@ -424,12 +424,8 @@ type Stack struct { // handleLocal allows non-loopback interfaces to loop packets. handleLocal bool - // tablesMu protects iptables. - tablesMu sync.RWMutex - - // tables are the iptables packet filtering and manipulation rules. The are - // protected by tablesMu.` - tables IPTables + // tables are the iptables packet filtering and manipulation rules. + tables *IPTables // resumableEndpoints is a list of endpoints that need to be resumed if the // stack is being restored. @@ -676,6 +672,7 @@ func New(opts Options) *Stack { clock: clock, stats: opts.Stats.FillIn(), handleLocal: opts.HandleLocal, + tables: DefaultTables(), icmpRateLimiter: NewICMPRateLimiter(), seed: generateRandUint32(), ndpConfigs: opts.NDPConfigs, @@ -1741,18 +1738,8 @@ func (s *Stack) IsInGroup(nicID tcpip.NICID, multicastAddr tcpip.Address) (bool, } // IPTables returns the stack's iptables. -func (s *Stack) IPTables() IPTables { - s.tablesMu.RLock() - t := s.tables - s.tablesMu.RUnlock() - return t -} - -// SetIPTables sets the stack's iptables. -func (s *Stack) SetIPTables(ipt IPTables) { - s.tablesMu.Lock() - s.tables = ipt - s.tablesMu.Unlock() +func (s *Stack) IPTables() *IPTables { + return s.tables } // ICMPLimit returns the maximum number of ICMP messages that can be sent diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go index 29ff68df3..3bc72bc19 100644 --- a/pkg/tcpip/transport/icmp/endpoint.go +++ b/pkg/tcpip/transport/icmp/endpoint.go @@ -140,11 +140,6 @@ func (e *endpoint) SetOwner(owner tcpip.PacketOwner) { e.owner = owner } -// IPTables implements tcpip.Endpoint.IPTables. -func (e *endpoint) IPTables() (stack.IPTables, error) { - return e.stack.IPTables(), nil -} - // Read reads data from the endpoint. This method does not block if // there is no data pending. func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, *tcpip.Error) { diff --git a/pkg/tcpip/transport/packet/endpoint.go b/pkg/tcpip/transport/packet/endpoint.go index bab2d63ae..baf08eda6 100644 --- a/pkg/tcpip/transport/packet/endpoint.go +++ b/pkg/tcpip/transport/packet/endpoint.go @@ -132,11 +132,6 @@ func (ep *endpoint) Close() { // ModerateRecvBuf implements tcpip.Endpoint.ModerateRecvBuf. func (ep *endpoint) ModerateRecvBuf(copied int) {} -// IPTables implements tcpip.Endpoint.IPTables. -func (ep *endpoint) IPTables() (stack.IPTables, error) { - return ep.stack.IPTables(), nil -} - // Read implements tcpip.Endpoint.Read. func (ep *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, *tcpip.Error) { ep.rcvMu.Lock() diff --git a/pkg/tcpip/transport/raw/endpoint.go b/pkg/tcpip/transport/raw/endpoint.go index 25a17940d..21c34fac2 100644 --- a/pkg/tcpip/transport/raw/endpoint.go +++ b/pkg/tcpip/transport/raw/endpoint.go @@ -166,11 +166,6 @@ func (e *endpoint) SetOwner(owner tcpip.PacketOwner) { e.owner = owner } -// IPTables implements tcpip.Endpoint.IPTables. -func (e *endpoint) IPTables() (stack.IPTables, error) { - return e.stack.IPTables(), nil -} - // Read implements tcpip.Endpoint.Read. func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, *tcpip.Error) { if !e.associated { diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go index d048ef90c..edca98160 100644 --- a/pkg/tcpip/transport/tcp/endpoint.go +++ b/pkg/tcpip/transport/tcp/endpoint.go @@ -1172,11 +1172,6 @@ func (e *endpoint) SetOwner(owner tcpip.PacketOwner) { e.owner = owner } -// IPTables implements tcpip.Endpoint.IPTables. -func (e *endpoint) IPTables() (stack.IPTables, error) { - return e.stack.IPTables(), nil -} - // Read reads data from the endpoint. func (e *endpoint) Read(*tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, *tcpip.Error) { e.LockUser() diff --git a/pkg/tcpip/transport/tcp/snd.go b/pkg/tcpip/transport/tcp/snd.go index 3a19c4468..acacb42e4 100644 --- a/pkg/tcpip/transport/tcp/snd.go +++ b/pkg/tcpip/transport/tcp/snd.go @@ -618,6 +618,20 @@ func (s *sender) splitSeg(seg *segment, size int) { nSeg.data.TrimFront(size) nSeg.sequenceNumber.UpdateForward(seqnum.Size(size)) s.writeList.InsertAfter(seg, nSeg) + + // The segment being split does not carry PUSH flag because it is + // followed by the newly split segment. + // RFC1122 section 4.2.2.2: MUST set the PSH bit in the last buffered + // segment (i.e., when there is no more queued data to be sent). + // Linux removes PSH flag only when the segment is being split over MSS + // and retains it when we are splitting the segment over lack of sender + // window space. + // ref: net/ipv4/tcp_output.c::tcp_write_xmit(), tcp_mss_split_point() + // ref: net/ipv4/tcp_output.c::tcp_write_wakeup(), tcp_snd_wnd_test() + if seg.data.Size() > s.maxPayloadSize { + seg.flags ^= header.TCPFlagPsh + } + seg.data.CapLength(size) } @@ -739,7 +753,7 @@ func (s *sender) maybeSendSegment(seg *segment, limit int, end seqnum.Value) (se if !s.isAssignedSequenceNumber(seg) { // Merge segments if allowed. if seg.data.Size() != 0 { - available := int(seg.sequenceNumber.Size(end)) + available := int(s.sndNxt.Size(end)) if available > limit { available = limit } @@ -782,8 +796,11 @@ func (s *sender) maybeSendSegment(seg *segment, limit int, end seqnum.Value) (se // sent all at once. return false } - if atomic.LoadUint32(&s.ep.cork) != 0 { - // Hold back the segment until full. + // With TCP_CORK, hold back until minimum of the available + // send space and MSS. + // TODO(gvisor.dev/issue/2833): Drain the held segments after a + // timeout. + if seg.data.Size() < s.maxPayloadSize && atomic.LoadUint32(&s.ep.cork) != 0 { return false } } @@ -843,9 +860,17 @@ func (s *sender) maybeSendSegment(seg *segment, limit int, end seqnum.Value) (se if available == 0 { return false } + + // The segment size limit is computed as a function of sender congestion + // window and MSS. When sender congestion window is > 1, this limit can + // be larger than MSS. Ensure that the currently available send space + // is not greater than minimum of this limit and MSS. if available > limit { available = limit } + if available > s.maxPayloadSize { + available = s.maxPayloadSize + } if seg.data.Size() > available { s.splitSeg(seg, available) diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go index 79faa7869..663af8fec 100644 --- a/pkg/tcpip/transport/udp/endpoint.go +++ b/pkg/tcpip/transport/udp/endpoint.go @@ -247,11 +247,6 @@ func (e *endpoint) Close() { // ModerateRecvBuf implements tcpip.Endpoint.ModerateRecvBuf. func (e *endpoint) ModerateRecvBuf(copied int) {} -// IPTables implements tcpip.Endpoint.IPTables. -func (e *endpoint) IPTables() (stack.IPTables, error) { - return e.stack.IPTables(), nil -} - // Read reads data from the endpoint. This method does not block if // there is no data pending. func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, *tcpip.Error) { |