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paopao-ce/pkg/util/iploc/iploc.go

145 lines
3.2 KiB

package iploc
import (
_ "embed"
"encoding/binary"
"net"
"strings"
"github.com/yinheli/mahonia"
)
// Note: This file is a modified version of https://github.com/yinheli/qqwry.
//go:embed qqwry.dat
var qqwry []byte
const (
cIndexLen = 7
cRedirectMode1 = 0x01
cRedirectMode2 = 0x02
)
// Find get country and city base ip. return empty country
// and city when ip that pass from argument is empty string
// or invalid ip address that net.ParseIP(...).To4 return nil
// eg: "::1"
func Find(ip string) (string, string) {
ip = strings.Trim(ip, " ")
if len(ip) == 0 {
return "", ""
}
to4 := net.ParseIP(ip).To4()
// If ip is "::1", To4 returns nil.
if to4 == nil {
return "", ""
}
offset := searchIndex(binary.BigEndian.Uint32(to4))
if offset <= 0 {
return "", ""
}
var country, area []byte
mode := readMode(offset + 4)
if mode == cRedirectMode1 {
countryOffset := readUInt24(offset + 5)
mode = readMode(countryOffset)
if mode == cRedirectMode2 {
c := readUInt24(countryOffset + 1)
country = readString(c)
countryOffset += 4
} else {
country = readString(countryOffset)
countryOffset += uint32(len(country) + 1)
}
area = readArea(countryOffset)
} else if mode == cRedirectMode2 {
countryOffset := readUInt24(offset + 5)
country = readString(countryOffset)
area = readArea(offset + 8)
} else {
country = readString(offset + 4)
area = readArea(offset + uint32(5+len(country)))
}
enc := mahonia.NewDecoder("gbk")
Country := enc.ConvertString(string(country))
City := enc.ConvertString(string(area))
return Country, City
}
func readMode(offset uint32) byte {
return qqwry[offset]
}
func readArea(offset uint32) []byte {
mode := readMode(offset)
if mode == cRedirectMode1 || mode == cRedirectMode2 {
areaOffset := readUInt24(offset + 1)
if areaOffset == 0 {
return []byte("")
} else {
return readString(areaOffset)
}
} else {
return readString(offset)
}
}
func readString(offset uint32) []byte {
data := make([]byte, 0, 30)
for {
if qqwry[offset] == 0 {
break
}
data = append(data, qqwry[offset])
offset++
}
return data
}
func searchIndex(ip uint32) uint32 {
header := qqwry[:8]
start := binary.LittleEndian.Uint32(header[:4])
end := binary.LittleEndian.Uint32(header[4:])
for {
mid := getMiddleOffset(start, end)
buf := qqwry[mid : mid+cIndexLen]
ipaddr := binary.LittleEndian.Uint32(buf[:4])
if end-start == cIndexLen {
offset := byte3ToUInt32(buf[4:])
// TODO: 这里可能有bug需要优化
if ip < binary.LittleEndian.Uint32(qqwry[end:end+4]) {
return offset
} else {
return 0
}
}
// 找到的比较大,向前移
if ipaddr > ip {
end = mid
} else if ipaddr < ip { // 找到的比较小,向后移
start = mid
} else {
return byte3ToUInt32(buf[4:])
}
}
}
func readUInt24(offset uint32) uint32 {
return byte3ToUInt32(qqwry[offset : offset+3])
}
func getMiddleOffset(start uint32, end uint32) uint32 {
records := ((end - start) / cIndexLen) >> 1
return start + records*cIndexLen
}
func byte3ToUInt32(data []byte) uint32 {
i := uint32(data[0]) & 0xff
i |= (uint32(data[1]) << 8) & 0xff00
i |= (uint32(data[2]) << 16) & 0xff0000
return i
}