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path: root/tun/tcp_offload_linux.go
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Diffstat (limited to 'tun/tcp_offload_linux.go')
-rw-r--r--tun/tcp_offload_linux.go108
1 files changed, 54 insertions, 54 deletions
diff --git a/tun/tcp_offload_linux.go b/tun/tcp_offload_linux.go
index a040e6f..e807f00 100644
--- a/tun/tcp_offload_linux.go
+++ b/tun/tcp_offload_linux.go
@@ -95,28 +95,28 @@ func newFlowKey(pkt []byte, srcAddr, dstAddr, tcphOffset int) flowKey {
// lookupOrInsert looks up a flow for the provided packet and metadata,
// returning the packets found for the flow, or inserting a new one if none
// is found.
-func (t *tcpGROTable) lookupOrInsert(pkt []byte, srcAddrOffset, dstAddrOffset, tcphOffset, tcphLen, buffsIndex int) ([]tcpGROItem, bool) {
+func (t *tcpGROTable) lookupOrInsert(pkt []byte, srcAddrOffset, dstAddrOffset, tcphOffset, tcphLen, bufsIndex int) ([]tcpGROItem, bool) {
key := newFlowKey(pkt, srcAddrOffset, dstAddrOffset, tcphOffset)
items, ok := t.itemsByFlow[key]
if ok {
return items, ok
}
// TODO: insert() performs another map lookup. This could be rearranged to avoid.
- t.insert(pkt, srcAddrOffset, dstAddrOffset, tcphOffset, tcphLen, buffsIndex)
+ t.insert(pkt, srcAddrOffset, dstAddrOffset, tcphOffset, tcphLen, bufsIndex)
return nil, false
}
// insert an item in the table for the provided packet and packet metadata.
-func (t *tcpGROTable) insert(pkt []byte, srcAddrOffset, dstAddrOffset, tcphOffset, tcphLen, buffsIndex int) {
+func (t *tcpGROTable) insert(pkt []byte, srcAddrOffset, dstAddrOffset, tcphOffset, tcphLen, bufsIndex int) {
key := newFlowKey(pkt, srcAddrOffset, dstAddrOffset, tcphOffset)
item := tcpGROItem{
- key: key,
- buffsIndex: uint16(buffsIndex),
- gsoSize: uint16(len(pkt[tcphOffset+tcphLen:])),
- iphLen: uint8(tcphOffset),
- tcphLen: uint8(tcphLen),
- sentSeq: binary.BigEndian.Uint32(pkt[tcphOffset+4:]),
- pshSet: pkt[tcphOffset+tcpFlagsOffset]&tcpFlagPSH != 0,
+ key: key,
+ bufsIndex: uint16(bufsIndex),
+ gsoSize: uint16(len(pkt[tcphOffset+tcphLen:])),
+ iphLen: uint8(tcphOffset),
+ tcphLen: uint8(tcphLen),
+ sentSeq: binary.BigEndian.Uint32(pkt[tcphOffset+4:]),
+ pshSet: pkt[tcphOffset+tcpFlagsOffset]&tcpFlagPSH != 0,
}
items, ok := t.itemsByFlow[key]
if !ok {
@@ -140,14 +140,14 @@ func (t *tcpGROTable) deleteAt(key flowKey, i int) {
// tcpGROItem represents bookkeeping data for a TCP packet during the lifetime
// of a GRO evaluation across a vector of packets.
type tcpGROItem struct {
- key flowKey
- sentSeq uint32 // the sequence number
- buffsIndex uint16 // the index into the original buffs slice
- numMerged uint16 // the number of packets merged into this item
- gsoSize uint16 // payload size
- iphLen uint8 // ip header len
- tcphLen uint8 // tcp header len
- pshSet bool // psh flag is set
+ key flowKey
+ sentSeq uint32 // the sequence number
+ bufsIndex uint16 // the index into the original bufs slice
+ numMerged uint16 // the number of packets merged into this item
+ gsoSize uint16 // payload size
+ iphLen uint8 // ip header len
+ tcphLen uint8 // tcp header len
+ pshSet bool // psh flag is set
}
func (t *tcpGROTable) newItems() []tcpGROItem {
@@ -177,8 +177,8 @@ const (
// tcpPacketsCanCoalesce evaluates if pkt can be coalesced with the packet
// described by item. This function makes considerations that match the kernel's
// GRO self tests, which can be found in tools/testing/selftests/net/gro.c.
-func tcpPacketsCanCoalesce(pkt []byte, iphLen, tcphLen uint8, seq uint32, pshSet bool, gsoSize uint16, item tcpGROItem, buffs [][]byte, buffsOffset int) canCoalesce {
- pktTarget := buffs[item.buffsIndex][buffsOffset:]
+func tcpPacketsCanCoalesce(pkt []byte, iphLen, tcphLen uint8, seq uint32, pshSet bool, gsoSize uint16, item tcpGROItem, bufs [][]byte, bufsOffset int) canCoalesce {
+ pktTarget := bufs[item.bufsIndex][bufsOffset:]
if tcphLen != item.tcphLen {
// cannot coalesce with unequal tcp options len
return coalesceUnavailable
@@ -262,18 +262,18 @@ const (
)
// coalesceTCPPackets attempts to coalesce pkt with the packet described by
-// item, returning the outcome. This function may swap buffs elements in the
-// event of a prepend as item's buffs index is already being tracked for writing
+// item, returning the outcome. This function may swap bufs elements in the
+// event of a prepend as item's bufs index is already being tracked for writing
// to a Device.
-func coalesceTCPPackets(mode canCoalesce, pkt []byte, pktBuffsIndex int, gsoSize uint16, seq uint32, pshSet bool, item *tcpGROItem, buffs [][]byte, buffsOffset int, isV6 bool) coalesceResult {
+func coalesceTCPPackets(mode canCoalesce, pkt []byte, pktBuffsIndex int, gsoSize uint16, seq uint32, pshSet bool, item *tcpGROItem, bufs [][]byte, bufsOffset int, isV6 bool) coalesceResult {
var pktHead []byte // the packet that will end up at the front
headersLen := item.iphLen + item.tcphLen
- coalescedLen := len(buffs[item.buffsIndex][buffsOffset:]) + len(pkt) - int(headersLen)
+ coalescedLen := len(bufs[item.bufsIndex][bufsOffset:]) + len(pkt) - int(headersLen)
// Copy data
if mode == coalescePrepend {
pktHead = pkt
- if cap(pkt)-buffsOffset < coalescedLen {
+ if cap(pkt)-bufsOffset < coalescedLen {
// We don't want to allocate a new underlying array if capacity is
// too small.
return coalesceInsufficientCap
@@ -282,7 +282,7 @@ func coalesceTCPPackets(mode canCoalesce, pkt []byte, pktBuffsIndex int, gsoSize
return coalescePSHEnding
}
if item.numMerged == 0 {
- if !tcpChecksumValid(buffs[item.buffsIndex][buffsOffset:], item.iphLen, isV6) {
+ if !tcpChecksumValid(bufs[item.bufsIndex][bufsOffset:], item.iphLen, isV6) {
return coalesceItemInvalidCSum
}
}
@@ -291,20 +291,20 @@ func coalesceTCPPackets(mode canCoalesce, pkt []byte, pktBuffsIndex int, gsoSize
}
item.sentSeq = seq
extendBy := coalescedLen - len(pktHead)
- buffs[pktBuffsIndex] = append(buffs[pktBuffsIndex], make([]byte, extendBy)...)
- copy(buffs[pktBuffsIndex][buffsOffset+len(pkt):], buffs[item.buffsIndex][buffsOffset+int(headersLen):])
- // Flip the slice headers in buffs as part of prepend. The index of item
+ bufs[pktBuffsIndex] = append(bufs[pktBuffsIndex], make([]byte, extendBy)...)
+ copy(bufs[pktBuffsIndex][bufsOffset+len(pkt):], bufs[item.bufsIndex][bufsOffset+int(headersLen):])
+ // Flip the slice headers in bufs as part of prepend. The index of item
// is already being tracked for writing.
- buffs[item.buffsIndex], buffs[pktBuffsIndex] = buffs[pktBuffsIndex], buffs[item.buffsIndex]
+ bufs[item.bufsIndex], bufs[pktBuffsIndex] = bufs[pktBuffsIndex], bufs[item.bufsIndex]
} else {
- pktHead = buffs[item.buffsIndex][buffsOffset:]
- if cap(pktHead)-buffsOffset < coalescedLen {
+ pktHead = bufs[item.bufsIndex][bufsOffset:]
+ if cap(pktHead)-bufsOffset < coalescedLen {
// We don't want to allocate a new underlying array if capacity is
// too small.
return coalesceInsufficientCap
}
if item.numMerged == 0 {
- if !tcpChecksumValid(buffs[item.buffsIndex][buffsOffset:], item.iphLen, isV6) {
+ if !tcpChecksumValid(bufs[item.bufsIndex][bufsOffset:], item.iphLen, isV6) {
return coalesceItemInvalidCSum
}
}
@@ -317,8 +317,8 @@ func coalesceTCPPackets(mode canCoalesce, pkt []byte, pktBuffsIndex int, gsoSize
pktHead[item.iphLen+tcpFlagsOffset] |= tcpFlagPSH
}
extendBy := len(pkt) - int(headersLen)
- buffs[item.buffsIndex] = append(buffs[item.buffsIndex], make([]byte, extendBy)...)
- copy(buffs[item.buffsIndex][buffsOffset+len(pktHead):], pkt[headersLen:])
+ bufs[item.bufsIndex] = append(bufs[item.bufsIndex], make([]byte, extendBy)...)
+ copy(bufs[item.bufsIndex][bufsOffset+len(pktHead):], pkt[headersLen:])
}
if gsoSize > item.gsoSize {
@@ -344,7 +344,7 @@ func coalesceTCPPackets(mode canCoalesce, pkt []byte, pktBuffsIndex int, gsoSize
iphCSum := ^checksum(pktHead[:item.iphLen], 0) // compute checksum
binary.BigEndian.PutUint16(pktHead[10:], iphCSum) // set checksum field
}
- hdr.encode(buffs[item.buffsIndex][buffsOffset-virtioNetHdrLen:])
+ hdr.encode(bufs[item.bufsIndex][bufsOffset-virtioNetHdrLen:])
// Calculate the pseudo header checksum and place it at the TCP checksum
// offset. Downstream checksum offloading will combine this with computation
@@ -355,9 +355,9 @@ func coalesceTCPPackets(mode canCoalesce, pkt []byte, pktBuffsIndex int, gsoSize
addrLen = 16
addrOffset = ipv6SrcAddrOffset
}
- srcAddrAt := buffsOffset + addrOffset
- srcAddr := buffs[item.buffsIndex][srcAddrAt : srcAddrAt+addrLen]
- dstAddr := buffs[item.buffsIndex][srcAddrAt+addrLen : srcAddrAt+addrLen*2]
+ srcAddrAt := bufsOffset + addrOffset
+ srcAddr := bufs[item.bufsIndex][srcAddrAt : srcAddrAt+addrLen]
+ dstAddr := bufs[item.bufsIndex][srcAddrAt+addrLen : srcAddrAt+addrLen*2]
psum := pseudoHeaderChecksumNoFold(unix.IPPROTO_TCP, srcAddr, dstAddr, uint16(coalescedLen-int(item.iphLen)))
binary.BigEndian.PutUint16(pktHead[hdr.csumStart+hdr.csumOffset:], checksum([]byte{}, psum))
@@ -375,12 +375,12 @@ const (
maxUint16 = 1<<16 - 1
)
-// tcpGRO evaluates the TCP packet at pktI in buffs for coalescing with
+// tcpGRO evaluates the TCP packet at pktI in bufs for coalescing with
// existing packets tracked in table. It will return false when pktI is not
-// coalesced, otherwise true. This indicates to the caller if buffs[pktI]
+// coalesced, otherwise true. This indicates to the caller if bufs[pktI]
// should be written to the Device.
-func tcpGRO(buffs [][]byte, offset int, pktI int, table *tcpGROTable, isV6 bool) (pktCoalesced bool) {
- pkt := buffs[pktI][offset:]
+func tcpGRO(bufs [][]byte, offset int, pktI int, table *tcpGROTable, isV6 bool) (pktCoalesced bool) {
+ pkt := bufs[pktI][offset:]
if len(pkt) > maxUint16 {
// A valid IPv4 or IPv6 packet will never exceed this.
return false
@@ -452,9 +452,9 @@ func tcpGRO(buffs [][]byte, offset int, pktI int, table *tcpGROTable, isV6 bool)
// sequence number perspective, however once an item is inserted into
// the table it is never compared across other items later.
item := items[i]
- can := tcpPacketsCanCoalesce(pkt, uint8(iphLen), uint8(tcphLen), seq, pshSet, gsoSize, item, buffs, offset)
+ can := tcpPacketsCanCoalesce(pkt, uint8(iphLen), uint8(tcphLen), seq, pshSet, gsoSize, item, bufs, offset)
if can != coalesceUnavailable {
- result := coalesceTCPPackets(can, pkt, pktI, gsoSize, seq, pshSet, &item, buffs, offset, isV6)
+ result := coalesceTCPPackets(can, pkt, pktI, gsoSize, seq, pshSet, &item, bufs, offset, isV6)
switch result {
case coalesceSuccess:
table.updateAt(item, i)
@@ -500,25 +500,25 @@ func isTCP6NoEH(b []byte) bool {
return true
}
-// handleGRO evaluates buffs for GRO, and writes the indices of the resulting
+// handleGRO evaluates bufs for GRO, and writes the indices of the resulting
// packets into toWrite. toWrite, tcp4Table, and tcp6Table should initially be
// empty (but non-nil), and are passed in to save allocs as the caller may reset
// and recycle them across vectors of packets.
-func handleGRO(buffs [][]byte, offset int, tcp4Table, tcp6Table *tcpGROTable, toWrite *[]int) error {
- for i := range buffs {
- if offset < virtioNetHdrLen || offset > len(buffs[i])-1 {
+func handleGRO(bufs [][]byte, offset int, tcp4Table, tcp6Table *tcpGROTable, toWrite *[]int) error {
+ for i := range bufs {
+ if offset < virtioNetHdrLen || offset > len(bufs[i])-1 {
return errors.New("invalid offset")
}
var coalesced bool
switch {
- case isTCP4(buffs[i][offset:]):
- coalesced = tcpGRO(buffs, offset, i, tcp4Table, false)
- case isTCP6NoEH(buffs[i][offset:]): // ipv6 packets w/extension headers do not coalesce
- coalesced = tcpGRO(buffs, offset, i, tcp6Table, true)
+ case isTCP4(bufs[i][offset:]):
+ coalesced = tcpGRO(bufs, offset, i, tcp4Table, false)
+ case isTCP6NoEH(bufs[i][offset:]): // ipv6 packets w/extension headers do not coalesce
+ coalesced = tcpGRO(bufs, offset, i, tcp6Table, true)
}
if !coalesced {
hdr := virtioNetHdr{}
- err := hdr.encode(buffs[i][offset-virtioNetHdrLen:])
+ err := hdr.encode(bufs[i][offset-virtioNetHdrLen:])
if err != nil {
return err
}
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