syncthing/vendor/github.com/jackpal/gateway/gateway_common.go

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package gateway
import (
"errors"
"net"
"strings"
)
var errNoGateway = errors.New("no gateway found")
func parseWindowsRoutePrint(output []byte) (net.IP, error) {
// Windows route output format is always like this:
// ===========================================================================
// Active Routes:
// Network Destination Netmask Gateway Interface Metric
// 0.0.0.0 0.0.0.0 192.168.1.1 192.168.1.100 20
// ===========================================================================
// I'm trying to pick the active route,
// then jump 2 lines and pick the third IP
// Not using regex because output is quite standard from Windows XP to 8 (NEEDS TESTING)
lines := strings.Split(string(output), "\n")
for idx, line := range lines {
if strings.HasPrefix(line, "Active Routes:") {
if len(lines) <= idx+2 {
return nil, errNoGateway
}
fields := strings.Fields(lines[idx+2])
if len(fields) < 3 {
return nil, errNoGateway
}
ip := net.ParseIP(fields[2])
if ip != nil {
return ip, nil
}
}
}
return nil, errNoGateway
}
func parseLinuxIPRoute(output []byte) (net.IP, error) {
// Linux '/usr/bin/ip route show' format looks like this:
// default via 192.168.178.1 dev wlp3s0 metric 303
// 192.168.178.0/24 dev wlp3s0 proto kernel scope link src 192.168.178.76 metric 303
lines := strings.Split(string(output), "\n")
for _, line := range lines {
fields := strings.Fields(line)
if len(fields) >= 3 && fields[0] == "default" {
ip := net.ParseIP(fields[2])
if ip != nil {
return ip, nil
}
}
}
return nil, errNoGateway
}
func parseLinuxRoute(output []byte) (net.IP, error) {
// Linux route out format is always like this:
// Kernel IP routing table
// Destination Gateway Genmask Flags Metric Ref Use Iface
// 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
lines := strings.Split(string(output), "\n")
for _, line := range lines {
fields := strings.Fields(line)
if len(fields) >= 2 && fields[0] == "0.0.0.0" {
ip := net.ParseIP(fields[1])
if ip != nil {
return ip, nil
}
}
}
return nil, errNoGateway
}
func parseDarwinRouteGet(output []byte) (net.IP, error) {
// Darwin route out format is always like this:
// route to: default
// destination: default
// mask: default
// gateway: 192.168.1.1
lines := strings.Split(string(output), "\n")
for _, line := range lines {
fields := strings.Fields(line)
if len(fields) >= 2 && fields[0] == "gateway:" {
ip := net.ParseIP(fields[1])
if ip != nil {
return ip, nil
}
}
}
return nil, errNoGateway
}
func parseBSDSolarisNetstat(output []byte) (net.IP, error) {
// netstat -rn produces the following on FreeBSD:
// Routing tables
//
// Internet:
// Destination Gateway Flags Netif Expire
// default 10.88.88.2 UGS em0
// 10.88.88.0/24 link#1 U em0
// 10.88.88.148 link#1 UHS lo0
// 127.0.0.1 link#2 UH lo0
//
// Internet6:
// Destination Gateway Flags Netif Expire
// ::/96 ::1 UGRS lo0
// ::1 link#2 UH lo0
// ::ffff:0.0.0.0/96 ::1 UGRS lo0
// fe80::/10 ::1 UGRS lo0
// ...
outputLines := strings.Split(string(output), "\n")
for _, line := range outputLines {
fields := strings.Fields(line)
if len(fields) >= 2 && fields[0] == "default" {
ip := net.ParseIP(fields[1])
if ip != nil {
return ip, nil
}
}
}
return nil, errNoGateway
}