mirror of
https://github.com/XTLS/Xray-core.git
synced 2024-12-12 14:56:04 +03:00
305 lines
6.9 KiB
Go
305 lines
6.9 KiB
Go
package strmatcher
|
|
|
|
import (
|
|
"math/bits"
|
|
"regexp"
|
|
"sort"
|
|
"strings"
|
|
"unsafe"
|
|
)
|
|
|
|
// PrimeRK is the prime base used in Rabin-Karp algorithm.
|
|
const PrimeRK = 16777619
|
|
|
|
// calculate the rolling murmurHash of given string
|
|
func RollingHash(s string) uint32 {
|
|
h := uint32(0)
|
|
for i := len(s) - 1; i >= 0; i-- {
|
|
h = h*PrimeRK + uint32(s[i])
|
|
}
|
|
return h
|
|
}
|
|
|
|
// A MphMatcherGroup is divided into three parts:
|
|
// 1. `full` and `domain` patterns are matched by Rabin-Karp algorithm and minimal perfect hash table;
|
|
// 2. `substr` patterns are matched by ac automaton;
|
|
// 3. `regex` patterns are matched with the regex library.
|
|
type MphMatcherGroup struct {
|
|
ac *ACAutomaton
|
|
otherMatchers []matcherEntry
|
|
rules []string
|
|
level0 []uint32
|
|
level0Mask int
|
|
level1 []uint32
|
|
level1Mask int
|
|
count uint32
|
|
ruleMap *map[string]uint32
|
|
}
|
|
|
|
func (g *MphMatcherGroup) AddFullOrDomainPattern(pattern string, t Type) {
|
|
h := RollingHash(pattern)
|
|
switch t {
|
|
case Domain:
|
|
(*g.ruleMap)["."+pattern] = h*PrimeRK + uint32('.')
|
|
fallthrough
|
|
case Full:
|
|
(*g.ruleMap)[pattern] = h
|
|
default:
|
|
}
|
|
}
|
|
|
|
func NewMphMatcherGroup() *MphMatcherGroup {
|
|
return &MphMatcherGroup{
|
|
ac: nil,
|
|
otherMatchers: nil,
|
|
rules: nil,
|
|
level0: nil,
|
|
level0Mask: 0,
|
|
level1: nil,
|
|
level1Mask: 0,
|
|
count: 1,
|
|
ruleMap: &map[string]uint32{},
|
|
}
|
|
}
|
|
|
|
// AddPattern adds a pattern to MphMatcherGroup
|
|
func (g *MphMatcherGroup) AddPattern(pattern string, t Type) (uint32, error) {
|
|
switch t {
|
|
case Substr:
|
|
if g.ac == nil {
|
|
g.ac = NewACAutomaton()
|
|
}
|
|
g.ac.Add(pattern, t)
|
|
case Full, Domain:
|
|
pattern = strings.ToLower(pattern)
|
|
g.AddFullOrDomainPattern(pattern, t)
|
|
case Regex:
|
|
r, err := regexp.Compile(pattern)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
g.otherMatchers = append(g.otherMatchers, matcherEntry{
|
|
m: ®exMatcher{pattern: r},
|
|
id: g.count,
|
|
})
|
|
default:
|
|
panic("Unknown type")
|
|
}
|
|
return g.count, nil
|
|
}
|
|
|
|
// Build builds a minimal perfect hash table and ac automaton from insert rules
|
|
func (g *MphMatcherGroup) Build() {
|
|
if g.ac != nil {
|
|
g.ac.Build()
|
|
}
|
|
keyLen := len(*g.ruleMap)
|
|
if keyLen == 0 {
|
|
keyLen = 1
|
|
(*g.ruleMap)["empty___"] = RollingHash("empty___")
|
|
}
|
|
g.level0 = make([]uint32, nextPow2(keyLen/4))
|
|
g.level0Mask = len(g.level0) - 1
|
|
g.level1 = make([]uint32, nextPow2(keyLen))
|
|
g.level1Mask = len(g.level1) - 1
|
|
sparseBuckets := make([][]int, len(g.level0))
|
|
var ruleIdx int
|
|
for rule, hash := range *g.ruleMap {
|
|
n := int(hash) & g.level0Mask
|
|
g.rules = append(g.rules, rule)
|
|
sparseBuckets[n] = append(sparseBuckets[n], ruleIdx)
|
|
ruleIdx++
|
|
}
|
|
g.ruleMap = nil
|
|
var buckets []indexBucket
|
|
for n, vals := range sparseBuckets {
|
|
if len(vals) > 0 {
|
|
buckets = append(buckets, indexBucket{n, vals})
|
|
}
|
|
}
|
|
sort.Sort(bySize(buckets))
|
|
|
|
occ := make([]bool, len(g.level1))
|
|
var tmpOcc []int
|
|
for _, bucket := range buckets {
|
|
seed := uint32(0)
|
|
for {
|
|
findSeed := true
|
|
tmpOcc = tmpOcc[:0]
|
|
for _, i := range bucket.vals {
|
|
n := int(strhashFallback(unsafe.Pointer(&g.rules[i]), uintptr(seed))) & g.level1Mask
|
|
if occ[n] {
|
|
for _, n := range tmpOcc {
|
|
occ[n] = false
|
|
}
|
|
seed++
|
|
findSeed = false
|
|
break
|
|
}
|
|
occ[n] = true
|
|
tmpOcc = append(tmpOcc, n)
|
|
g.level1[n] = uint32(i)
|
|
}
|
|
if findSeed {
|
|
g.level0[bucket.n] = seed
|
|
break
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
func nextPow2(v int) int {
|
|
if v <= 1 {
|
|
return 1
|
|
}
|
|
const MaxUInt = ^uint(0)
|
|
n := (MaxUInt >> bits.LeadingZeros(uint(v))) + 1
|
|
return int(n)
|
|
}
|
|
|
|
// Lookup searches for s in t and returns its index and whether it was found.
|
|
func (g *MphMatcherGroup) Lookup(h uint32, s string) bool {
|
|
i0 := int(h) & g.level0Mask
|
|
seed := g.level0[i0]
|
|
i1 := int(strhashFallback(unsafe.Pointer(&s), uintptr(seed))) & g.level1Mask
|
|
n := g.level1[i1]
|
|
return s == g.rules[int(n)]
|
|
}
|
|
|
|
// Match implements IndexMatcher.Match.
|
|
func (g *MphMatcherGroup) Match(pattern string) []uint32 {
|
|
result := []uint32{}
|
|
hash := uint32(0)
|
|
for i := len(pattern) - 1; i >= 0; i-- {
|
|
hash = hash*PrimeRK + uint32(pattern[i])
|
|
if pattern[i] == '.' {
|
|
if g.Lookup(hash, pattern[i:]) {
|
|
result = append(result, 1)
|
|
return result
|
|
}
|
|
}
|
|
}
|
|
if g.Lookup(hash, pattern) {
|
|
result = append(result, 1)
|
|
return result
|
|
}
|
|
if g.ac != nil && g.ac.Match(pattern) {
|
|
result = append(result, 1)
|
|
return result
|
|
}
|
|
for _, e := range g.otherMatchers {
|
|
if e.m.Match(pattern) {
|
|
result = append(result, e.id)
|
|
return result
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
type indexBucket struct {
|
|
n int
|
|
vals []int
|
|
}
|
|
|
|
type bySize []indexBucket
|
|
|
|
func (s bySize) Len() int { return len(s) }
|
|
func (s bySize) Less(i, j int) bool { return len(s[i].vals) > len(s[j].vals) }
|
|
func (s bySize) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
|
|
|
|
type stringStruct struct {
|
|
str unsafe.Pointer
|
|
len int
|
|
}
|
|
|
|
func strhashFallback(a unsafe.Pointer, h uintptr) uintptr {
|
|
x := (*stringStruct)(a)
|
|
return memhashFallback(x.str, h, uintptr(x.len))
|
|
}
|
|
|
|
const (
|
|
// Constants for multiplication: four random odd 64-bit numbers.
|
|
m1 = 16877499708836156737
|
|
m2 = 2820277070424839065
|
|
m3 = 9497967016996688599
|
|
m4 = 15839092249703872147
|
|
)
|
|
|
|
var hashkey = [4]uintptr{1, 1, 1, 1}
|
|
|
|
func memhashFallback(p unsafe.Pointer, seed, s uintptr) uintptr {
|
|
h := uint64(seed + s*hashkey[0])
|
|
tail:
|
|
switch {
|
|
case s == 0:
|
|
case s < 4:
|
|
h ^= uint64(*(*byte)(p))
|
|
h ^= uint64(*(*byte)(add(p, s>>1))) << 8
|
|
h ^= uint64(*(*byte)(add(p, s-1))) << 16
|
|
h = rotl31(h*m1) * m2
|
|
case s <= 8:
|
|
h ^= uint64(readUnaligned32(p))
|
|
h ^= uint64(readUnaligned32(add(p, s-4))) << 32
|
|
h = rotl31(h*m1) * m2
|
|
case s <= 16:
|
|
h ^= readUnaligned64(p)
|
|
h = rotl31(h*m1) * m2
|
|
h ^= readUnaligned64(add(p, s-8))
|
|
h = rotl31(h*m1) * m2
|
|
case s <= 32:
|
|
h ^= readUnaligned64(p)
|
|
h = rotl31(h*m1) * m2
|
|
h ^= readUnaligned64(add(p, 8))
|
|
h = rotl31(h*m1) * m2
|
|
h ^= readUnaligned64(add(p, s-16))
|
|
h = rotl31(h*m1) * m2
|
|
h ^= readUnaligned64(add(p, s-8))
|
|
h = rotl31(h*m1) * m2
|
|
default:
|
|
v1 := h
|
|
v2 := uint64(seed * hashkey[1])
|
|
v3 := uint64(seed * hashkey[2])
|
|
v4 := uint64(seed * hashkey[3])
|
|
for s >= 32 {
|
|
v1 ^= readUnaligned64(p)
|
|
v1 = rotl31(v1*m1) * m2
|
|
p = add(p, 8)
|
|
v2 ^= readUnaligned64(p)
|
|
v2 = rotl31(v2*m2) * m3
|
|
p = add(p, 8)
|
|
v3 ^= readUnaligned64(p)
|
|
v3 = rotl31(v3*m3) * m4
|
|
p = add(p, 8)
|
|
v4 ^= readUnaligned64(p)
|
|
v4 = rotl31(v4*m4) * m1
|
|
p = add(p, 8)
|
|
s -= 32
|
|
}
|
|
h = v1 ^ v2 ^ v3 ^ v4
|
|
goto tail
|
|
}
|
|
|
|
h ^= h >> 29
|
|
h *= m3
|
|
h ^= h >> 32
|
|
return uintptr(h)
|
|
}
|
|
|
|
func add(p unsafe.Pointer, x uintptr) unsafe.Pointer {
|
|
return unsafe.Pointer(uintptr(p) + x)
|
|
}
|
|
|
|
func readUnaligned32(p unsafe.Pointer) uint32 {
|
|
q := (*[4]byte)(p)
|
|
return uint32(q[0]) | uint32(q[1])<<8 | uint32(q[2])<<16 | uint32(q[3])<<24
|
|
}
|
|
|
|
func rotl31(x uint64) uint64 {
|
|
return (x << 31) | (x >> (64 - 31))
|
|
}
|
|
|
|
func readUnaligned64(p unsafe.Pointer) uint64 {
|
|
q := (*[8]byte)(p)
|
|
return uint64(q[0]) | uint64(q[1])<<8 | uint64(q[2])<<16 | uint64(q[3])<<24 | uint64(q[4])<<32 | uint64(q[5])<<40 | uint64(q[6])<<48 | uint64(q[7])<<56
|
|
}
|