/
capture_listener.go
117 lines (93 loc) · 2.16 KB
/
capture_listener.go
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// SPDX-FileCopyrightText: 2023 Steffen Vogel <post@steffenvogel.de>
// SPDX-License-Identifier: Apache-2.0
package gont
import (
"errors"
"fmt"
"io"
"net"
"strings"
"sync"
"go.uber.org/zap"
)
var _ io.Writer = (*captureListener)(nil)
type captureListener struct {
listener net.Listener
Conns chan net.Conn
connsLock sync.RWMutex
conns map[net.Conn]any
logger *zap.Logger
}
func newCaptureListener(addr string) (*captureListener, error) {
var network, address string
if addrParts := strings.SplitN(addr, ":", 2); len(addrParts) == 1 {
network = "tcp"
address = addrParts[0]
} else {
network = addrParts[0]
address = addrParts[1]
}
lst, err := net.Listen(network, address)
if err != nil {
return nil, fmt.Errorf("failed to listen: %w", err)
}
cs := &captureListener{
listener: lst,
Conns: make(chan net.Conn),
conns: map[net.Conn]any{},
logger: zap.L().Named("capture.socket").With(
zap.String("addr", addr),
),
}
go cs.listen()
return cs, nil
}
func (cs *captureListener) Close() error {
return cs.listener.Close()
}
func (cs *captureListener) Write(b []byte) (n int, err error) {
cs.connsLock.RLock()
defer cs.connsLock.RUnlock()
for c := range cs.conns {
if n, err = c.Write(b); err != nil {
logger := cs.logger.With(zap.String("remote", c.RemoteAddr().String()))
if errors.Is(err, net.ErrClosed) {
logger.Debug("Connection closed")
} else {
logger.Error("Failed to write to connection. Closing...", zap.Error(err))
if err := c.Close(); err != nil {
logger.Error("Failed to close connection")
}
}
cs.connsLock.RUnlock()
cs.removeConn(c)
cs.connsLock.RLock()
}
}
return n, nil
}
func (cs *captureListener) listen() {
for {
c, err := cs.listener.Accept()
if err != nil {
continue
}
cs.logger.Debug("New connection",
zap.String("remote", c.RemoteAddr().String()))
select {
case cs.Conns <- c:
default:
}
cs.addConn(c)
}
}
func (cs *captureListener) addConn(c net.Conn) {
cs.connsLock.Lock()
cs.conns[c] = nil
cs.connsLock.Unlock()
}
func (cs *captureListener) removeConn(c net.Conn) {
cs.connsLock.Lock()
delete(cs.conns, c)
cs.connsLock.Unlock()
}