soju/upstream.go
2020-02-06 19:22:04 +01:00

311 lines
6.7 KiB
Go

package jounce
import (
"crypto/tls"
"fmt"
"io"
"net"
"strconv"
"strings"
"time"
"gopkg.in/irc.v3"
)
const (
rpl_localusers = "265"
rpl_globalusers = "266"
rpl_topicwhotime = "333"
)
type modeSet string
func (ms modeSet) Has(c byte) bool {
return strings.IndexByte(string(ms), c) >= 0
}
func (ms *modeSet) Add(c byte) {
if !ms.Has(c) {
*ms += modeSet(c)
}
}
func (ms *modeSet) Del(c byte) {
i := strings.IndexByte(string(*ms), c)
if i >= 0 {
*ms = (*ms)[:i] + (*ms)[i+1:]
}
}
func (ms *modeSet) Apply(s string) error {
var plusMinus byte
for i := 0; i < len(s); i++ {
switch c := s[i]; c {
case '+', '-':
plusMinus = c
default:
switch plusMinus {
case '+':
ms.Add(c)
case '-':
ms.Del(c)
default:
return fmt.Errorf("malformed modestring %q: missing plus/minus", s)
}
}
}
return nil
}
type channelStatus byte
const (
channelPublic channelStatus = '='
channelSecret channelStatus = '@'
channelPrivate channelStatus = '*'
)
func parseChannelStatus(s string) (channelStatus, error) {
if len(s) > 1 {
return 0, fmt.Errorf("invalid channel status %q: more than one character", s)
}
switch cs := channelStatus(s[0]); cs {
case channelPublic, channelSecret, channelPrivate:
return cs, nil
default:
return 0, fmt.Errorf("invalid channel status %q: unknown status", s)
}
}
type membership byte
const (
membershipFounder membership = '~'
membershipProtected membership = '&'
membershipOperator membership = '@'
membershipHalfOp membership = '%'
membershipVoice membership = '+'
)
const stdMembershipPrefixes = "~&@%+"
func parseMembershipPrefix(s string) (prefix membership, nick string) {
// TODO: any prefix from PREFIX RPL_ISUPPORT
if strings.IndexByte(stdMembershipPrefixes, s[0]) >= 0 {
return membership(s[0]), s[1:]
} else {
return 0, s
}
}
type upstreamChannel struct {
Name string
Topic string
TopicWho string
TopicTime time.Time
Status channelStatus
Members map[string]membership
}
type upstreamConn struct {
upstream *Upstream
net net.Conn
irc *irc.Conn
srv *Server
serverName string
availableUserModes string
availableChannelModes string
channelModesWithParam string
registered bool
modes modeSet
channels map[string]*upstreamChannel
}
func (c *upstreamConn) getChannel(name string) (*upstreamChannel, error) {
ch, ok := c.channels[name]
if !ok {
return nil, fmt.Errorf("unknown channel %q", name)
}
return ch, nil
}
func (c *upstreamConn) handleMessage(msg *irc.Message) error {
switch msg.Command {
case "PING":
// TODO: handle params
return c.irc.WriteMessage(&irc.Message{
Command: "PONG",
Params: []string{c.srv.Hostname},
})
case "MODE":
if len(msg.Params) < 2 {
return newNeedMoreParamsError(msg.Command)
}
if nick := msg.Params[0]; nick != c.upstream.Nick {
return fmt.Errorf("received MODE message for unknow nick %q", nick)
}
return c.modes.Apply(msg.Params[1])
case "NOTICE":
c.srv.Logger.Printf("%q: %v", c.upstream.Addr, msg)
case irc.RPL_WELCOME:
c.registered = true
c.srv.Logger.Printf("Connection to %q registered", c.upstream.Addr)
for _, ch := range c.upstream.Channels {
err := c.irc.WriteMessage(&irc.Message{
Command: "JOIN",
Params: []string{ch},
})
if err != nil {
return err
}
}
case irc.RPL_MYINFO:
if len(msg.Params) < 5 {
return newNeedMoreParamsError(msg.Command)
}
c.serverName = msg.Params[1]
c.availableUserModes = msg.Params[3]
c.availableChannelModes = msg.Params[4]
if len(msg.Params) > 5 {
c.channelModesWithParam = msg.Params[5]
}
case "JOIN":
if len(msg.Params) < 1 {
return newNeedMoreParamsError(msg.Command)
}
for _, ch := range strings.Split(msg.Params[0], ",") {
c.srv.Logger.Printf("Joined channel %q", ch)
c.channels[ch] = &upstreamChannel{
Name: ch,
Members: make(map[string]membership),
}
}
case irc.RPL_TOPIC, irc.RPL_NOTOPIC:
if len(msg.Params) < 3 {
return newNeedMoreParamsError(msg.Command)
}
ch, err := c.getChannel(msg.Params[1])
if err != nil {
return err
}
if msg.Command == irc.RPL_TOPIC {
ch.Topic = msg.Params[2]
} else {
ch.Topic = ""
}
case "TOPIC":
if len(msg.Params) < 1 {
return newNeedMoreParamsError(msg.Command)
}
ch, err := c.getChannel(msg.Params[0])
if err != nil {
return err
}
if len(msg.Params) > 1 {
ch.Topic = msg.Params[1]
} else {
ch.Topic = ""
}
case rpl_topicwhotime:
if len(msg.Params) < 4 {
return newNeedMoreParamsError(msg.Command)
}
ch, err := c.getChannel(msg.Params[1])
if err != nil {
return err
}
ch.TopicWho = msg.Params[2]
sec, err := strconv.ParseInt(msg.Params[3], 10, 64)
if err != nil {
return fmt.Errorf("failed to parse topic time: %v", err)
}
ch.TopicTime = time.Unix(sec, 0)
case irc.RPL_NAMREPLY:
if len(msg.Params) < 4 {
return newNeedMoreParamsError(msg.Command)
}
ch, err := c.getChannel(msg.Params[2])
if err != nil {
return err
}
status, err := parseChannelStatus(msg.Params[1])
if err != nil {
return err
}
ch.Status = status
for _, s := range strings.Split(msg.Params[3], " ") {
membership, nick := parseMembershipPrefix(s)
ch.Members[nick] = membership
}
case irc.RPL_ENDOFNAMES:
// TODO
case irc.RPL_YOURHOST, irc.RPL_CREATED:
// Ignore
case irc.RPL_LUSERCLIENT, irc.RPL_LUSEROP, irc.RPL_LUSERUNKNOWN, irc.RPL_LUSERCHANNELS, irc.RPL_LUSERME:
// Ignore
case irc.RPL_MOTDSTART, irc.RPL_MOTD, irc.RPL_ENDOFMOTD:
// Ignore
case rpl_localusers, rpl_globalusers:
// Ignore
case irc.RPL_STATSVLINE, irc.RPL_STATSPING, irc.RPL_STATSBLINE, irc.RPL_STATSDLINE:
// Ignore
default:
c.srv.Logger.Printf("Unhandled upstream message: %v", msg)
}
return nil
}
func connect(s *Server, upstream *Upstream) error {
s.Logger.Printf("Connecting to %v", upstream.Addr)
netConn, err := tls.Dial("tcp", upstream.Addr, nil)
if err != nil {
return fmt.Errorf("failed to dial %q: %v", upstream.Addr, err)
}
c := upstreamConn{
upstream: upstream,
net: netConn,
irc: irc.NewConn(netConn),
srv: s,
channels: make(map[string]*upstreamChannel),
}
defer netConn.Close()
err = c.irc.WriteMessage(&irc.Message{
Command: "NICK",
Params: []string{upstream.Nick},
})
if err != nil {
return err
}
err = c.irc.WriteMessage(&irc.Message{
Command: "USER",
Params: []string{upstream.Username, "0", "*", upstream.Realname},
})
if err != nil {
return err
}
for {
msg, err := c.irc.ReadMessage()
if err == io.EOF {
break
} else if err != nil {
return fmt.Errorf("failed to read IRC command: %v", err)
}
if err := c.handleMessage(msg); err != nil {
c.srv.Logger.Printf("Failed to handle message %q from %q: %v", msg, upstream.Addr, err)
}
}
return netConn.Close()
}