147 lines
4.2 KiB
Go
147 lines
4.2 KiB
Go
package gateway
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import (
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"errors"
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"net"
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"strings"
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)
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var errNoGateway = errors.New("no gateway found")
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func parseWindowsRoutePrint(output []byte) (net.IP, error) {
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// Windows route output format is always like this:
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// ===========================================================================
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// Active Routes:
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// Network Destination Netmask Gateway Interface Metric
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// 0.0.0.0 0.0.0.0 192.168.1.1 192.168.1.100 20
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// ===========================================================================
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// I'm trying to pick the active route,
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// then jump 2 lines and pick the third IP
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// Not using regex because output is quite standard from Windows XP to 8 (NEEDS TESTING)
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lines := strings.Split(string(output), "\n")
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for idx, line := range lines {
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if strings.HasPrefix(line, "Active Routes:") {
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if len(lines) <= idx+2 {
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return nil, errNoGateway
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}
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fields := strings.Fields(lines[idx+2])
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if len(fields) < 3 {
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return nil, errNoGateway
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}
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ip := net.ParseIP(fields[2])
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if ip != nil {
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return ip, nil
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}
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}
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}
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return nil, errNoGateway
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}
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func parseLinuxIPRouteShow(output []byte) (net.IP, error) {
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// Linux '/usr/bin/ip route show' format looks like this:
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// default via 192.168.178.1 dev wlp3s0 metric 303
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// 192.168.178.0/24 dev wlp3s0 proto kernel scope link src 192.168.178.76 metric 303
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lines := strings.Split(string(output), "\n")
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for _, line := range lines {
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fields := strings.Fields(line)
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if len(fields) >= 3 && fields[0] == "default" {
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ip := net.ParseIP(fields[2])
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if ip != nil {
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return ip, nil
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}
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}
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}
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return nil, errNoGateway
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}
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func parseLinuxIPRouteGet(output []byte) (net.IP, error) {
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// Linux '/usr/bin/ip route get 8.8.8.8' format looks like this:
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// 8.8.8.8 via 10.0.1.1 dev eth0 src 10.0.1.36 uid 2000
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lines := strings.Split(string(output), "\n")
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for _, line := range lines {
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fields := strings.Fields(line)
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if len(fields) >= 2 && fields[1] == "via" {
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ip := net.ParseIP(fields[2])
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if ip != nil {
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return ip, nil
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}
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}
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}
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return nil, errNoGateway
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}
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func parseLinuxRoute(output []byte) (net.IP, error) {
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// Linux route out format is always like this:
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// Kernel IP routing table
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// Destination Gateway Genmask Flags Metric Ref Use Iface
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// 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
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lines := strings.Split(string(output), "\n")
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for _, line := range lines {
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fields := strings.Fields(line)
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if len(fields) >= 2 && fields[0] == "0.0.0.0" {
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ip := net.ParseIP(fields[1])
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if ip != nil {
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return ip, nil
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}
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}
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}
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return nil, errNoGateway
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}
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func parseDarwinRouteGet(output []byte) (net.IP, error) {
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// Darwin route out format is always like this:
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// route to: default
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// destination: default
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// mask: default
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// gateway: 192.168.1.1
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lines := strings.Split(string(output), "\n")
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for _, line := range lines {
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fields := strings.Fields(line)
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if len(fields) >= 2 && fields[0] == "gateway:" {
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ip := net.ParseIP(fields[1])
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if ip != nil {
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return ip, nil
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}
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}
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}
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return nil, errNoGateway
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}
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func parseBSDSolarisNetstat(output []byte) (net.IP, error) {
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// netstat -rn produces the following on FreeBSD:
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// Routing tables
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//
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// Internet:
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// Destination Gateway Flags Netif Expire
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// default 10.88.88.2 UGS em0
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// 10.88.88.0/24 link#1 U em0
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// 10.88.88.148 link#1 UHS lo0
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// 127.0.0.1 link#2 UH lo0
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//
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// Internet6:
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// Destination Gateway Flags Netif Expire
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// ::/96 ::1 UGRS lo0
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// ::1 link#2 UH lo0
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// ::ffff:0.0.0.0/96 ::1 UGRS lo0
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// fe80::/10 ::1 UGRS lo0
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// ...
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outputLines := strings.Split(string(output), "\n")
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for _, line := range outputLines {
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fields := strings.Fields(line)
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if len(fields) >= 2 && fields[0] == "default" {
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ip := net.ParseIP(fields[1])
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if ip != nil {
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return ip, nil
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}
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}
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}
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return nil, errNoGateway
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}
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