syncthing/lib/osutil/ping.go
Jakob Borg 4e4b9a872a
lib/dialer: Preserve nilness in error handling (fixes #6368) (#6369)
Also the call site where it shouldn't anyway be looking at the conn when
the err is non-nil.
2020-02-26 13:16:18 +01:00

41 lines
1.1 KiB
Go

// Copyright (C) 2015 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
package osutil
import (
"context"
"net/url"
"time"
"github.com/syncthing/syncthing/lib/dialer"
)
// TCPPing returns the duration required to establish a TCP connection
// to the given host. ICMP packets require root privileges, hence why we use
// tcp.
func TCPPing(ctx context.Context, address string) (time.Duration, error) {
start := time.Now()
ctx, cancel := context.WithTimeout(ctx, time.Second)
defer cancel()
conn, err := dialer.DialContext(ctx, "tcp", address)
if err == nil {
conn.Close()
}
return time.Since(start), err
}
// GetLatencyForURL parses the given URL, tries opening a TCP connection to it
// and returns the time it took to establish the connection.
func GetLatencyForURL(ctx context.Context, addr string) (time.Duration, error) {
uri, err := url.Parse(addr)
if err != nil {
return 0, err
}
return TCPPing(ctx, uri.Host)
}