status-go/vendor/github.com/multiformats/go-multiaddr/protocols.go

143 lines
3.9 KiB
Go

package multiaddr
import (
"encoding/binary"
"fmt"
"strings"
)
// Protocol is a Multiaddr protocol description structure.
type Protocol struct {
Code int
Size int // a size of -1 indicates a length-prefixed variable size
Name string
VCode []byte
Path bool // indicates a path protocol (eg unix, http)
Transcoder Transcoder
}
// You **MUST** register your multicodecs with
// https://github.com/multiformats/multicodec before adding them here.
//
// TODO: Use a single source of truth for all multicodecs instead of
// distributing them like this...
const (
P_IP4 = 0x0004
P_TCP = 0x0006
P_UDP = 0x0111
P_DCCP = 0x0021
P_IP6 = 0x0029
P_QUIC = 0x01CC
P_SCTP = 0x0084
P_UDT = 0x012D
P_UTP = 0x012E
P_UNIX = 0x0190
P_IPFS = 0x01A5
P_HTTP = 0x01E0
P_HTTPS = 0x01BB
P_ONION = 0x01BC
)
// These are special sizes
const (
LengthPrefixedVarSize = -1
)
// Protocols is the list of multiaddr protocols supported by this module.
var Protocols = []Protocol{
Protocol{P_IP4, 32, "ip4", CodeToVarint(P_IP4), false, TranscoderIP4},
Protocol{P_TCP, 16, "tcp", CodeToVarint(P_TCP), false, TranscoderPort},
Protocol{P_UDP, 16, "udp", CodeToVarint(P_UDP), false, TranscoderPort},
Protocol{P_DCCP, 16, "dccp", CodeToVarint(P_DCCP), false, TranscoderPort},
Protocol{P_IP6, 128, "ip6", CodeToVarint(P_IP6), false, TranscoderIP6},
// these require varint:
Protocol{P_SCTP, 16, "sctp", CodeToVarint(P_SCTP), false, TranscoderPort},
Protocol{P_ONION, 96, "onion", CodeToVarint(P_ONION), false, TranscoderOnion},
Protocol{P_UTP, 0, "utp", CodeToVarint(P_UTP), false, nil},
Protocol{P_UDT, 0, "udt", CodeToVarint(P_UDT), false, nil},
Protocol{P_QUIC, 0, "quic", CodeToVarint(P_QUIC), false, nil},
Protocol{P_HTTP, 0, "http", CodeToVarint(P_HTTP), false, nil},
Protocol{P_HTTPS, 0, "https", CodeToVarint(P_HTTPS), false, nil},
Protocol{P_IPFS, LengthPrefixedVarSize, "ipfs", CodeToVarint(P_IPFS), false, TranscoderIPFS},
Protocol{P_UNIX, LengthPrefixedVarSize, "unix", CodeToVarint(P_UNIX), true, TranscoderUnix},
}
func AddProtocol(p Protocol) error {
for _, pt := range Protocols {
if pt.Code == p.Code {
return fmt.Errorf("protocol code %d already taken by %q", p.Code, pt.Name)
}
if pt.Name == p.Name {
return fmt.Errorf("protocol by the name %q already exists", p.Name)
}
}
Protocols = append(Protocols, p)
return nil
}
// ProtocolWithName returns the Protocol description with given string name.
func ProtocolWithName(s string) Protocol {
for _, p := range Protocols {
if p.Name == s {
return p
}
}
return Protocol{}
}
// ProtocolWithCode returns the Protocol description with given protocol code.
func ProtocolWithCode(c int) Protocol {
for _, p := range Protocols {
if p.Code == c {
return p
}
}
return Protocol{}
}
// ProtocolsWithString returns a slice of protocols matching given string.
func ProtocolsWithString(s string) ([]Protocol, error) {
s = strings.Trim(s, "/")
sp := strings.Split(s, "/")
if len(sp) == 0 {
return nil, nil
}
t := make([]Protocol, len(sp))
for i, name := range sp {
p := ProtocolWithName(name)
if p.Code == 0 {
return nil, fmt.Errorf("no protocol with name: %s", name)
}
t[i] = p
}
return t, nil
}
// CodeToVarint converts an integer to a varint-encoded []byte
func CodeToVarint(num int) []byte {
buf := make([]byte, (num/7)+1) // varint package is uint64
n := binary.PutUvarint(buf, uint64(num))
return buf[:n]
}
// VarintToCode converts a varint-encoded []byte to an integer protocol code
func VarintToCode(buf []byte) int {
num, _, err := ReadVarintCode(buf)
if err != nil {
panic(err)
}
return num
}
// ReadVarintCode reads a varint code from the beginning of buf.
// returns the code, and the number of bytes read.
func ReadVarintCode(buf []byte) (int, int, error) {
num, n := binary.Uvarint(buf)
if n < 0 {
return 0, 0, fmt.Errorf("varints larger than uint64 not yet supported")
}
return int(num), n, nil
}