zgrab2/conn.go

95 lines
2.6 KiB
Go

package zgrab2
import (
"net"
"time"
"context"
)
// TimeoutConnection wraps an existing net.Conn connection, overriding the Read/Write methods to use the configured timeouts
type TimeoutConnection struct {
net.Conn
Timeout time.Duration
}
// TimeoutConnection.Read calls Read() on the underlying connection, using any configured deadlines
func (c *TimeoutConnection) Read(b []byte) (n int, err error) {
if c.Timeout > 0 {
if err = c.Conn.SetReadDeadline(time.Now().Add(c.Timeout)); err != nil {
return 0, err
}
}
return c.Conn.Read(b)
}
// TimeoutConnection.Write calls Write() on the underlying connection, using any configured deadlines
func (c *TimeoutConnection) Write(b []byte) (n int, err error) {
if c.Timeout > 0 {
if err = c.Conn.SetWriteDeadline(time.Now().Add(c.Timeout)); err != nil {
return 0, err
}
}
return c.Conn.Write(b)
}
// DialTimeoutConnection dials the target and returns a net.Conn that uses the configured timeouts for Read/Write operations.
func DialTimeoutConnection(proto string, target string, timeout time.Duration) (net.Conn, error) {
var conn net.Conn
var err error
if timeout > 0 {
conn, err = net.DialTimeout(proto, target, timeout)
} else {
conn, err = net.Dial(proto, target)
}
if err != nil {
if conn != nil {
conn.Close()
}
return nil, err
}
return &TimeoutConnection{
Conn: conn,
Timeout: timeout,
}, nil
}
// Dialer provides Dial and DialContext methods to get connections with the given timeout.
type Dialer struct {
// Timeout is the maximum time to wait for a connection or I/O.
Timeout time.Duration
// dialer is an auxiliary dialer used for DialContext (the result gets wrapped in a TimeoutConnection).
Dialer *net.Dialer
}
// DialContext wraps the connection returned by net.Dialer.DialContext() with a TimeoutConnection.
func (d *Dialer) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
// ensure that our aux dialer is up-to-date
d.Dialer.Timeout = d.Timeout
d.Dialer.KeepAlive = d.Timeout
ret, err := d.Dialer.DialContext(ctx, network, address)
if err != nil {
return nil, err
}
return &TimeoutConnection{
Conn: ret,
Timeout: d.Timeout,
}, nil
}
// Dial returns a connection with the configured timeout.
func (d *Dialer) Dial(proto string, target string) (net.Conn, error) {
return DialTimeoutConnection(proto, target, d.Timeout)
}
// GetTimeoutConnectionDialer gets a Dialer that dials connections with the given timeout.
func GetTimeoutConnectionDialer(timeout time.Duration) *Dialer {
return &Dialer{
Timeout: timeout,
Dialer: &net.Dialer{
Timeout: timeout,
KeepAlive: timeout,
DualStack: true,
},
}
}