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goip/ipv6wry/client.go

139 lines
2.6 KiB

package ipv6wry
import (
_ "embed"
"encoding/binary"
"log"
)
var (
header []byte
country []byte
area []byte
v6ip uint64
offset uint32
start uint32
end uint32
)
//go:embed ipv6wry.db
var datBuff []byte
type Client struct {
Offset uint32
ItemLen uint32
IndexLen uint32
}
func New() *Client {
c := &Client{}
buf := datBuff[0:8]
start := binary.LittleEndian.Uint32(buf[:4])
end := binary.LittleEndian.Uint32(buf[4:])
num := int64((end-start)/7 + 1)
log.Printf("ipv6wry.db 共加载:%d 条ip记录\n", num)
return c
}
// ReadData 从文件中读取数据
func (c *Client) readData(length uint32) (rs []byte) {
end := c.Offset + length
dataNum := uint32(len(datBuff))
if c.Offset > dataNum {
return nil
}
if end > dataNum {
end = dataNum
}
rs = datBuff[c.Offset:end]
c.Offset = end
return rs
}
func (c *Client) getAddr() ([]byte, []byte) {
mode := c.readData(1)[0]
if mode == 0x01 {
// [IP][0x01][国家和地区信息的绝对偏移地址]
c.Offset = byteToUInt32(c.readData(3))
return c.getAddr()
}
// [IP][0x02][信息的绝对偏移][...] or [IP][国家][...]
_offset := c.Offset - 1
c1 := c.readArea(_offset)
if mode == 0x02 {
c.Offset = 4 + _offset
} else {
c.Offset = _offset + uint32(1+len(c1))
}
c2 := c.readArea(c.Offset)
return c1, c2
}
func (c *Client) readArea(offset uint32) []byte {
c.Offset = offset
mode := c.readData(1)[0]
if mode == 0x01 || mode == 0x02 {
return c.readArea(byteToUInt32(c.readData(3)))
}
c.Offset = offset
return c.readString()
}
func (c *Client) readString() []byte {
data := make([]byte, 0)
for {
buf := c.readData(1)
if buf[0] == 0 {
break
}
data = append(data, buf[0])
}
return data
}
func (c *Client) searchIndex(ip uint64) uint32 {
c.ItemLen = 8
c.IndexLen = 11
header = datBuff[8:24]
start = binary.LittleEndian.Uint32(header[8:])
counts := binary.LittleEndian.Uint32(header[:8])
end = start + counts*c.IndexLen
buf := make([]byte, c.IndexLen)
for {
mid := start + c.IndexLen*(((end-start)/c.IndexLen)>>1)
buf = datBuff[mid : mid+c.IndexLen]
_ip := binary.LittleEndian.Uint64(buf[:c.ItemLen])
if end-start == c.IndexLen {
if ip >= binary.LittleEndian.Uint64(datBuff[end:end+c.ItemLen]) {
buf = datBuff[end : end+c.IndexLen]
}
return byteToUInt32(buf[c.ItemLen:])
}
if _ip > ip {
end = mid
} else if _ip < ip {
start = mid
} else if _ip == ip {
return byteToUInt32(buf[c.ItemLen:])
}
}
}
func byteToUInt32(data []byte) uint32 {
i := uint32(data[0]) & 0xff
i |= (uint32(data[1]) << 8) & 0xff00
i |= (uint32(data[2]) << 16) & 0xff0000
return i
}