soju/server.go
Simon Ser bdb132ad98
Implement rate limiting for upstream messages
Allow up to 10 outgoing messages in a burst, then throttle to 1 message
each 2 seconds.

Closes: https://todo.sr.ht/~emersion/soju/87
2020-08-19 19:42:33 +02:00

188 lines
3.8 KiB
Go

package soju
import (
"fmt"
"log"
"net"
"net/http"
"sync"
"sync/atomic"
"time"
"gopkg.in/irc.v3"
"nhooyr.io/websocket"
"git.sr.ht/~emersion/soju/config"
)
// TODO: make configurable
var retryConnectDelay = time.Minute
var connectTimeout = 15 * time.Second
var writeTimeout = 10 * time.Second
var upstreamMessageDelay = 2 * time.Second
var upstreamMessageBurst = 10
type Logger interface {
Print(v ...interface{})
Printf(format string, v ...interface{})
}
type prefixLogger struct {
logger Logger
prefix string
}
var _ Logger = (*prefixLogger)(nil)
func (l *prefixLogger) Print(v ...interface{}) {
v = append([]interface{}{l.prefix}, v...)
l.logger.Print(v...)
}
func (l *prefixLogger) Printf(format string, v ...interface{}) {
v = append([]interface{}{l.prefix}, v...)
l.logger.Printf("%v"+format, v...)
}
type Server struct {
Hostname string
Logger Logger
RingCap int
HistoryLimit int
LogPath string
Debug bool
HTTPOrigins []string
AcceptProxyIPs config.IPSet
Identd *Identd // can be nil
db *DB
lock sync.Mutex
users map[string]*user
}
func NewServer(db *DB) *Server {
return &Server{
Logger: log.New(log.Writer(), "", log.LstdFlags),
RingCap: 4096,
HistoryLimit: 1000,
users: make(map[string]*user),
db: db,
}
}
func (s *Server) prefix() *irc.Prefix {
return &irc.Prefix{Name: s.Hostname}
}
func (s *Server) Run() error {
users, err := s.db.ListUsers()
if err != nil {
return err
}
s.lock.Lock()
for i := range users {
s.addUserLocked(&users[i])
}
s.lock.Unlock()
select {}
}
func (s *Server) createUser(user *User) (*user, error) {
s.lock.Lock()
defer s.lock.Unlock()
if _, ok := s.users[user.Username]; ok {
return nil, fmt.Errorf("user %q already exists", user.Username)
}
err := s.db.StoreUser(user)
if err != nil {
return nil, fmt.Errorf("could not create user in db: %v", err)
}
return s.addUserLocked(user), nil
}
func (s *Server) getUser(name string) *user {
s.lock.Lock()
u := s.users[name]
s.lock.Unlock()
return u
}
func (s *Server) addUserLocked(user *User) *user {
s.Logger.Printf("starting bouncer for user %q", user.Username)
u := newUser(s, user)
s.users[u.Username] = u
go func() {
u.run()
s.lock.Lock()
delete(s.users, u.Username)
s.lock.Unlock()
}()
return u
}
var lastDownstreamID uint64 = 0
func (s *Server) handle(ic ircConn) {
id := atomic.AddUint64(&lastDownstreamID, 1)
dc := newDownstreamConn(s, ic, id)
if err := dc.runUntilRegistered(); err != nil {
dc.logger.Print(err)
} else {
dc.user.events <- eventDownstreamConnected{dc}
if err := dc.readMessages(dc.user.events); err != nil {
dc.logger.Print(err)
}
dc.user.events <- eventDownstreamDisconnected{dc}
}
dc.Close()
}
func (s *Server) Serve(ln net.Listener) error {
for {
conn, err := ln.Accept()
if err != nil {
return fmt.Errorf("failed to accept connection: %v", err)
}
go s.handle(newNetIRCConn(conn))
}
}
func (s *Server) ServeHTTP(w http.ResponseWriter, req *http.Request) {
conn, err := websocket.Accept(w, req, &websocket.AcceptOptions{
OriginPatterns: s.HTTPOrigins,
Subprotocols: []string{"irc"},
})
if err != nil {
s.Logger.Printf("failed to serve HTTP connection: %v", err)
return
}
isProxy := false
if host, _, err := net.SplitHostPort(req.RemoteAddr); err == nil {
if ip := net.ParseIP(host); ip != nil {
isProxy = s.AcceptProxyIPs.Contains(ip)
}
}
// Only trust X-Forwarded-* header fields if this is a trusted proxy IP
// to prevent users from spoofing the remote address
remoteAddr := req.RemoteAddr
forwardedHost := req.Header.Get("X-Forwarded-For")
forwardedPort := req.Header.Get("X-Forwarded-Port")
if isProxy && forwardedHost != "" && forwardedPort != "" {
remoteAddr = net.JoinHostPort(forwardedHost, forwardedPort)
}
s.handle(newWebsocketIRCConn(conn, remoteAddr))
}