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// SPDX-FileCopyrightText: V <v@anomalous.eu>
// SPDX-FileCopyrightText: edef <edef@edef.eu>
// SPDX-License-Identifier: OSL-3.0
package main
import (
"bufio"
"bytes"
"crypto/tls"
"io"
"log"
"net"
"net/http"
"sync"
)
type sidedConn struct {
net.Conn
Side
}
type Proxy struct {
store *Store
tlsConfig *tls.Config
exiting chan struct{}
wg sync.WaitGroup
}
func NewProxy(store *Store, tlsConfig *tls.Config) *Proxy {
return &Proxy{
store: store,
tlsConfig: tlsConfig,
exiting: make(chan struct{}),
}
}
func (p *Proxy) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
if req.Method != http.MethodConnect {
log.Printf("%s - invalid request %s %s", req.RemoteAddr, req.Method, req.RequestURI)
http.Error(resp, "405 I'm a proxy", http.StatusMethodNotAllowed)
return
}
host := req.URL.Hostname()
log.Printf("%s - new connection to %s", req.RemoteAddr, host)
server, err := tls.DialWithDialer(
&net.Dialer{Cancel: req.Context().Done()},
"tcp", net.JoinHostPort(host, "6697"),
p.tlsConfig,
)
if err != nil {
log.Printf("%s - failed connection %v", req.RemoteAddr, err)
resp.WriteHeader(http.StatusBadGateway)
return
}
session := OpenSession(p.store, host)
resp.WriteHeader(http.StatusOK)
// http.Server's Shutdown "does not attempt to close nor wait for hijacked connections",
// so we have to bump the waitgroup prior to calling Hijack()
p.wg.Add(1)
defer p.wg.Done()
// XXX: bufio.ReadWriter might still contain data
// I think it's impossible for err to be non-nil
client, _, _ := resp.(http.Hijacker).Hijack()
p.proxy(session, sidedConn{client, SideClient}, sidedConn{server, SideServer})
}
func (p *Proxy) proxy(session *Session, a, b sidedConn) {
ch := make(chan func())
pipe := func(r, w sidedConn) {
scanner := bufio.NewScanner(r)
scanner.Split(scanIRCLines)
for scanner.Scan() {
session.Write(r.Side, string(dropLineEnding(scanner.Bytes())))
_, err := w.Write(scanner.Bytes())
if err != nil {
ch <- func() { session.Close(w.Side, err.Error()) }
return
}
}
err := scanner.Err()
if err == nil {
err = io.EOF
}
ch <- func() { session.Close(r.Side, err.Error()) }
}
go pipe(a, b)
go pipe(b, a)
done := func() { session.Close(SideProxy, "shutting down") }
select {
case <-p.exiting:
a.Close()
b.Close()
<-ch
<-ch
case done = <-ch:
a.Close()
b.Close()
<-ch
}
done()
}
func (p *Proxy) Shutdown() {
close(p.exiting)
p.wg.Wait()
p.store.Close()
}
func scanIRCLines(data []byte, atEOF bool) (advance int, token []byte, err error) {
if atEOF && len(data) == 0 {
return 0, nil, nil
}
if i := bytes.IndexByte(data, '\n'); i >= 0 {
// we have a full newline-terminated line
return i + 1, data[:i+1], nil
}
if atEOF {
return 0, nil, io.ErrUnexpectedEOF
}
return 0, nil, nil // request more data
}
// on a buffer known to end in \n, drop \n or \r\n
func dropLineEnding(data []byte) []byte {
n := len(data)
if n > 1 && data[n-1] == '\r' {
return data[:n-2]
}
return data[:n-1]
}
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