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net/packet: represent IP6 as two uint64s.

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For the operations we perform on these types (mostly net6.Contains),
this encoding is much faster.

Part of #19.

name                   old time/op    new time/op    delta
Filter/icmp4-8           27.5ns ± 1%    28.0ns ± 2%   +1.89%  (p=0.016 n=5+5)
Filter/tcp4_syn_in-8     38.8ns ± 2%    38.3ns ± 1%   -1.24%  (p=0.024 n=5+5)
Filter/tcp4_syn_out-8    27.6ns ±12%    24.6ns ± 1%     ~     (p=0.063 n=5+5)
Filter/udp4_in-8         71.5ns ± 5%    65.9ns ± 1%   -7.94%  (p=0.008 n=5+5)
Filter/udp4_out-8         132ns ±13%     119ns ± 1%  -10.29%  (p=0.008 n=5+5)
Filter/icmp6-8            169ns ±10%      54ns ± 1%  -68.35%  (p=0.008 n=5+5)
Filter/tcp6_syn_in-8      149ns ± 6%      43ns ± 1%  -71.11%  (p=0.008 n=5+5)
Filter/tcp6_syn_out-8    37.7ns ± 4%    24.3ns ± 3%  -35.51%  (p=0.008 n=5+5)
Filter/udp6_in-8          179ns ± 5%     103ns ± 1%  -42.75%  (p=0.008 n=5+5)
Filter/udp6_out-8         156ns ± 3%     191ns ± 1%  +22.54%  (p=0.008 n=5+5)

Signed-off-by: David Anderson <danderson@tailscale.com>
This commit is contained in:
David Anderson
2020-11-12 02:56:15 -08:00
parent 04ff3c91ee
commit 2d604b3791
3 changed files with 42 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

40
wgengine/filter/match6.go
View File

@@ -6,6 +6,7 @@ package filter
import (
"fmt"
"math/bits"
"strings"
"inet.af/netaddr"
@@ -14,16 +15,24 @@ import (
type net6 struct {
ip packet.IP6
bits uint8
mask packet.IP6
}
func net6FromIPPrefix(pfx netaddr.IPPrefix) net6 {
if !pfx.IP.Is6() {
panic("net6FromIPPrefix given non-ipv6 prefix")
}
var mask packet.IP6
if pfx.Bits > 64 {
mask.Hi = ^uint64(0)
mask.Lo = (^uint64(0) << (128 - pfx.Bits))
} else {
mask.Hi = (^uint64(0) << (64 - pfx.Bits))
}
return net6{
ip: packet.IP6FromNetaddr(pfx.IP),
bits: pfx.Bits,
mask: mask,
}
}
@@ -37,33 +46,22 @@ func nets6FromIPPrefixes(pfxs []netaddr.IPPrefix) (ret []net6) {
}
func (n net6) Contains(ip packet.IP6) bool {
// Implementation stolen from inet.af/netaddr
bits := n.bits
for i := 0; bits > 0 && i < len(n.ip); i++ {
m := uint8(255)
if bits < 8 {
zeros := 8 - bits
m = m >> zeros << zeros
}
if n.ip[i]&m != ip[i]&m {
return false
}
if bits < 8 {
break
}
bits -= 8
}
return true
return ((n.ip.Hi&n.mask.Hi) == (ip.Hi&n.mask.Hi) &&
(n.ip.Lo&n.mask.Lo) == (ip.Lo&n.mask.Lo))
}
func (n net6) Bits() int {
return 128 - bits.TrailingZeros64(n.mask.Hi) - bits.TrailingZeros64(n.mask.Lo)
}
func (n net6) String() string {
switch n.bits {
switch n.Bits() {
case 128:
return n.ip.String()
case 0:
return "*"
default:
return fmt.Sprintf("%s/%d", n.ip, n.bits)
return fmt.Sprintf("%s/%d", n.ip, n.Bits())
}
}