goircd/client.go
Sergey Matveev b7fb219307 Many fixes and additions
* NAMES and WALLOPS command
* -cloak option
* -v renamed to -verbose
* -passwords renamed to -passwd
* -debug option prints traffic messages
* without -verbose only startup/shutdown and error messages are printed
* -timestamped option provides timestamps in printed messages, as
  earlier. No timestamps is useful for running under daemontools
* passwords are stored in SHA256-hashed format
* state files replaced with state directory with files
* removed many unnecessary pointers and locks
* graceful shutdown with all clients notification
* fixed time structure printing in log files, instead of short human
  readable timestamp
* PART is sent to the user itself, to notify his client about leaving
* log messages are printed to stdout, instead of stderr, for
  friendliness with daemontools logger
* ability to configure newly created directories and files with
  -perm-state-dir, -perm-state-file, -perm-log-file
2020-11-07 16:52:53 +03:00

463 lines
10 KiB
Go

/*
goircd -- minimalistic simple Internet Relay Chat (IRC) server
Copyright (C) 2014-2020 Sergey Matveev <stargrave@stargrave.org>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, version 3 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package main
import (
"bytes"
"crypto/sha256"
"crypto/subtle"
"encoding/hex"
"fmt"
"io/ioutil"
"log"
"net"
"regexp"
"sort"
"strings"
"sync"
"time"
)
const (
BufSize = 1500
MaxOutBuf = 128
)
var (
CRLF []byte = []byte{'\x0d', '\x0a'}
RENickname = regexp.MustCompile("^[a-zA-Z0-9-]{1,24}$")
clients map[*Client]struct{} = make(map[*Client]struct{})
clientsLock sync.RWMutex
clientsWG sync.WaitGroup
)
type Client struct {
conn net.Conn
registered bool
nickname string
username string
realname string
password string
away string
recvTimestamp time.Time
sendTimestamp time.Time
outBuf chan string
alive bool
sync.Mutex
}
func (c *Client) Host() string {
if *cloak != "" {
return *cloak
}
addr := c.conn.RemoteAddr().String()
if host, _, err := net.SplitHostPort(addr); err == nil {
addr = host
}
if domains, err := net.LookupAddr(addr); err == nil {
addr = strings.TrimSuffix(domains[0], ".")
}
return addr
}
func (c *Client) String() string {
return strings.Join([]string{c.nickname, "!", c.username, "@", c.Host()}, "")
}
func NewClient(conn net.Conn, events chan ClientEvent) *Client {
c := Client{
conn: conn,
nickname: "*",
username: "",
recvTimestamp: time.Now(),
sendTimestamp: time.Now(),
alive: true,
outBuf: make(chan string, MaxOutBuf),
}
clientsWG.Add(2)
go c.MsgSender()
go c.Processor(events)
return &c
}
func (c *Client) Close() {
c.Lock()
if c.alive {
close(c.outBuf)
c.alive = false
}
c.Unlock()
}
func (c *Client) Processor(events chan ClientEvent) {
events <- ClientEvent{c, EventNew, ""}
if *verbose {
log.Println(c, "connected")
}
buf := make([]byte, BufSize*2)
var n, prev, i int
var msg string
var err error
for {
if prev == BufSize {
log.Println(c, "input buffer size exceeded, kicking him")
break
}
n, err = c.conn.Read(buf[prev:])
if err != nil {
break
}
prev += n
CheckMore:
i = bytes.Index(buf[:prev], CRLF)
if i == -1 {
continue
}
if *debug {
log.Println(c, "<-", msg)
}
msg = string(buf[:i])
if *debug {
log.Println(c, "->", msg)
}
events <- ClientEvent{c, EventMsg, msg}
copy(buf, buf[i+2:prev])
prev -= (i + 2)
goto CheckMore
}
c.Close()
if *verbose {
log.Println(c, "disconnected")
}
events <- ClientEvent{c, EventDel, ""}
clientsWG.Done()
}
func (c *Client) MsgSender() {
var err error
for msg := range c.outBuf {
if *debug {
log.Println(c, "<-", msg)
}
if _, err = c.conn.Write(append([]byte(msg), CRLF...)); err != nil {
if *verbose {
log.Println(c, "error writing", err)
}
break
}
}
c.conn.Close()
clientsWG.Done()
}
func (c *Client) Msg(text string) {
c.Lock()
defer c.Unlock()
if !c.alive {
return
}
if len(c.outBuf) == MaxOutBuf {
log.Println(c, "output buffer size exceeded, kicking him")
if c.alive {
close(c.outBuf)
c.alive = false
}
return
}
c.outBuf <- text
}
func (c *Client) Reply(text string) {
c.Msg(":" + *hostname + " " + text)
}
func (c *Client) ReplyParts(code string, text ...string) {
parts := []string{code}
for _, t := range text {
parts = append(parts, t)
}
parts[len(parts)-1] = ":" + parts[len(parts)-1]
c.Reply(strings.Join(parts, " "))
}
func (c *Client) ReplyNicknamed(code string, text ...string) {
c.ReplyParts(code, append([]string{c.nickname}, text...)...)
}
func (c *Client) ReplyNotEnoughParameters(command string) {
c.ReplyNicknamed("461", command, "Not enough parameters")
}
func (c *Client) ReplyNoChannel(channel string) {
c.ReplyNicknamed("403", channel, "No such channel")
}
func (c *Client) ReplyNoNickChan(channel string) {
c.ReplyNicknamed("401", channel, "No such nick/channel")
}
func (c *Client) SendLusers() {
lusers := 0
clientsLock.RLock()
for client := range clients {
if client.registered {
lusers++
}
}
clientsLock.RUnlock()
c.ReplyNicknamed(
"251",
fmt.Sprintf("There are %d users and 0 invisible on 1 servers",
lusers,
))
}
func (c *Client) SendMotd() {
if motd == nil {
c.ReplyNicknamed("422", "MOTD File is missing")
return
}
motdText, err := ioutil.ReadFile(*motd)
if err != nil {
log.Printf("can not read motd file %s: %v", *motd, err)
c.ReplyNicknamed("422", "Error reading MOTD File")
return
}
c.ReplyNicknamed("375", "- "+*hostname+" Message of the day -")
for _, s := range strings.Split(strings.TrimSuffix(string(motdText), "\n"), "\n") {
c.ReplyNicknamed("372", "- "+s)
}
c.ReplyNicknamed("376", "End of /MOTD command")
}
func (c *Client) Join(cmd string) {
args := strings.Split(cmd, " ")
rs := strings.Split(args[0], ",")
keys := []string{}
if len(args) > 1 {
keys = strings.Split(args[1], ",")
}
RoomCycle:
for n, roomName := range rs {
if !RERoom.MatchString(roomName) {
c.ReplyNoChannel(roomName)
continue
}
var key string
if (n < len(keys)) && (keys[n] != "") {
key = keys[n]
}
roomsLock.RLock()
for roomNameExisting, room := range rooms {
if roomName != roomNameExisting {
continue
}
if (room.key != "") && (room.key != key) {
c.ReplyNicknamed("475", roomName, "Cannot join channel (+k)")
roomsLock.RUnlock()
return
}
room.events <- ClientEvent{c, EventNew, ""}
roomsLock.RUnlock()
continue RoomCycle
}
roomsLock.RUnlock()
roomNew := RoomRegister(roomName)
if *verbose {
log.Println("room", roomName, "created")
}
if key != "" {
roomNew.key = key
roomNew.StateSave()
}
roomNew.events <- ClientEvent{c, EventNew, ""}
}
}
func (client *Client) SendWhois(nicknames []string) {
var c *Client
for _, nickname := range nicknames {
nickname = strings.ToLower(nickname)
clientsLock.RLock()
for c = range clients {
if strings.ToLower(c.nickname) == nickname {
clientsLock.RUnlock()
goto Found
}
}
clientsLock.RUnlock()
client.ReplyNoNickChan(nickname)
continue
Found:
var host string
if *cloak != "" {
host = *cloak
} else {
host, _, err := net.SplitHostPort(c.conn.RemoteAddr().String())
if err != nil {
log.Printf("can't parse RemoteAddr %q: %v", host, err)
host = "Unknown"
}
}
client.ReplyNicknamed("311", c.nickname, c.username, host, "*", c.realname)
client.ReplyNicknamed("312", c.nickname, *hostname, *hostname)
if c.away != "" {
client.ReplyNicknamed("301", c.nickname, c.away)
}
subscriptions := make([]string, 0)
roomsLock.RLock()
for _, room := range rooms {
for subscriber := range room.members {
if subscriber.nickname == nickname {
subscriptions = append(subscriptions, room.name)
}
}
}
roomsLock.RUnlock()
sort.Strings(subscriptions)
client.ReplyNicknamed("319", c.nickname, strings.Join(subscriptions, " "))
client.ReplyNicknamed("318", c.nickname, "End of /WHOIS list")
}
}
func (c *Client) SendList(cols []string) {
var rs []string
if (len(cols) > 1) && (cols[1] != "") {
rs = strings.Split(strings.Split(cols[1], " ")[0], ",")
} else {
rs = make([]string, 0)
roomsLock.RLock()
for r := range rooms {
rs = append(rs, r)
}
roomsLock.RUnlock()
}
sort.Strings(rs)
roomsLock.RLock()
for _, r := range rs {
if room, found := rooms[r]; found {
c.ReplyNicknamed(
"322",
r,
fmt.Sprintf("%d", len(room.members)),
room.topic,
)
}
}
roomsLock.RUnlock()
c.ReplyNicknamed("323", "End of /LIST")
}
func (c *Client) Register(cmd string, cols []string) {
switch cmd {
case "PASS":
if len(cols) == 1 || len(cols[1]) < 1 {
c.ReplyNotEnoughParameters("PASS")
return
}
password := strings.TrimPrefix(cols[1], ":")
c.password = password
case "NICK":
if len(cols) == 1 || len(cols[1]) < 1 {
c.ReplyParts("431", "No nickname given")
return
}
nickname := cols[1]
// Compatibility with some clients prepending colons to nickname
nickname = strings.TrimPrefix(nickname, ":")
nickname = strings.ToLower(nickname)
if !RENickname.MatchString(nickname) {
c.ReplyParts("432", "*", cols[1], "Erroneous nickname")
return
}
clientsLock.RLock()
for existingClient := range clients {
if existingClient.nickname == nickname {
clientsLock.RUnlock()
c.ReplyParts("433", "*", nickname, "Nickname is already in use")
return
}
}
clientsLock.RUnlock()
c.nickname = nickname
case "USER":
if len(cols) == 1 {
c.ReplyNotEnoughParameters("USER")
return
}
args := strings.SplitN(cols[1], " ", 4)
if len(args) < 4 {
c.ReplyNotEnoughParameters("USER")
return
}
c.username = args[0]
realname := strings.TrimLeft(args[3], ":")
c.realname = realname
}
if c.nickname != "*" && c.username != "" {
if *passwords != "" {
authenticated := false
if c.password == "" {
c.ReplyParts("462", "You may not register")
c.Close()
return
}
contents, err := ioutil.ReadFile(*passwords)
if err != nil {
log.Fatalf("can not read passwords file %s: %s", *passwords, err)
return
}
for n, entry := range strings.Split(string(contents), "\n") {
if entry == "" || strings.HasPrefix(entry, "#") {
continue
}
cols := strings.Split(entry, ":")
if len(cols) != 2 {
log.Fatalf("bad passwords format: %s:%d", *passwords, n)
continue
}
if cols[0] != c.nickname {
continue
}
h := sha256.Sum256([]byte(c.password))
authenticated = subtle.ConstantTimeCompare(
[]byte(hex.EncodeToString(h[:])),
[]byte(cols[1]),
) == 1
break
}
if !authenticated {
c.ReplyParts("462", "You may not register")
c.Close()
return
}
}
c.registered = true
c.ReplyNicknamed("001", "Hi, welcome to IRC")
c.ReplyNicknamed("002", "Your host is "+*hostname+", running goircd "+Version)
c.ReplyNicknamed("003", "This server was created sometime")
c.ReplyNicknamed("004", *hostname+" goircd o o")
c.SendLusers()
c.SendMotd()
if *verbose {
log.Println(c, "logged in")
}
}
}