mirror of
https://github.com/autc04/Retro68.git
synced 2024-08-31 09:29:37 +00:00
201 lines
4.7 KiB
Go
201 lines
4.7 KiB
Go
// Copyright 2016 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package net
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import (
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"errors"
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"internal/itoa"
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"os"
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)
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// If the ifindex is zero, interfaceTable returns mappings of all
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// network interfaces. Otherwise it returns a mapping of a specific
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// interface.
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func interfaceTable(ifindex int) ([]Interface, error) {
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if ifindex == 0 {
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n, err := interfaceCount()
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if err != nil {
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return nil, err
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}
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ifcs := make([]Interface, n)
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for i := range ifcs {
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ifc, err := readInterface(i)
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if err != nil {
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return nil, err
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}
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ifcs[i] = *ifc
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}
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return ifcs, nil
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}
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ifc, err := readInterface(ifindex - 1)
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if err != nil {
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return nil, err
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}
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return []Interface{*ifc}, nil
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}
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func readInterface(i int) (*Interface, error) {
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ifc := &Interface{
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Index: i + 1, // Offset the index by one to suit the contract
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Name: netdir + "/ipifc/" + itoa.Itoa(i), // Name is the full path to the interface path in plan9
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}
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ifcstat := ifc.Name + "/status"
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ifcstatf, err := open(ifcstat)
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if err != nil {
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return nil, err
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}
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defer ifcstatf.close()
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line, ok := ifcstatf.readLine()
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if !ok {
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return nil, errors.New("invalid interface status file: " + ifcstat)
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}
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fields := getFields(line)
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if len(fields) < 4 {
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return nil, errors.New("invalid interface status file: " + ifcstat)
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}
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device := fields[1]
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mtustr := fields[3]
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mtu, _, ok := dtoi(mtustr)
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if !ok {
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return nil, errors.New("invalid status file of interface: " + ifcstat)
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}
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ifc.MTU = mtu
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// Not a loopback device ("/dev/null") or packet interface (e.g. "pkt2")
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if stringsHasPrefix(device, netdir+"/") {
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deviceaddrf, err := open(device + "/addr")
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if err != nil {
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return nil, err
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}
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defer deviceaddrf.close()
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line, ok = deviceaddrf.readLine()
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if !ok {
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return nil, errors.New("invalid address file for interface: " + device + "/addr")
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}
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if len(line) > 0 && len(line)%2 == 0 {
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ifc.HardwareAddr = make([]byte, len(line)/2)
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var ok bool
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for i := range ifc.HardwareAddr {
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j := (i + 1) * 2
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ifc.HardwareAddr[i], ok = xtoi2(line[i*2:j], 0)
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if !ok {
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ifc.HardwareAddr = ifc.HardwareAddr[:i]
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break
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}
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}
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}
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ifc.Flags = FlagUp | FlagBroadcast | FlagMulticast
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} else {
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ifc.Flags = FlagUp | FlagMulticast | FlagLoopback
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}
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return ifc, nil
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}
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func interfaceCount() (int, error) {
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d, err := os.Open(netdir + "/ipifc")
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if err != nil {
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return -1, err
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}
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defer d.Close()
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names, err := d.Readdirnames(0)
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if err != nil {
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return -1, err
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}
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// Assumes that numbered files in ipifc are strictly
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// the incrementing numbered directories for the
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// interfaces
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c := 0
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for _, name := range names {
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if _, _, ok := dtoi(name); !ok {
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continue
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}
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c++
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}
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return c, nil
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}
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// If the ifi is nil, interfaceAddrTable returns addresses for all
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// network interfaces. Otherwise it returns addresses for a specific
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// interface.
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func interfaceAddrTable(ifi *Interface) ([]Addr, error) {
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var ifcs []Interface
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if ifi == nil {
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var err error
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ifcs, err = interfaceTable(0)
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if err != nil {
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return nil, err
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}
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} else {
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ifcs = []Interface{*ifi}
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}
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var addrs []Addr
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for _, ifc := range ifcs {
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status := ifc.Name + "/status"
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statusf, err := open(status)
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if err != nil {
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return nil, err
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}
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defer statusf.close()
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// Read but ignore first line as it only contains the table header.
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// See https://9p.io/magic/man2html/3/ip
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if _, ok := statusf.readLine(); !ok {
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return nil, errors.New("cannot read header line for interface: " + status)
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}
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for line, ok := statusf.readLine(); ok; line, ok = statusf.readLine() {
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fields := getFields(line)
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if len(fields) < 1 {
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return nil, errors.New("cannot parse IP address for interface: " + status)
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}
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addr := fields[0]
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ip := ParseIP(addr)
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if ip == nil {
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return nil, errors.New("cannot parse IP address for interface: " + status)
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}
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// The mask is represented as CIDR relative to the IPv6 address.
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// Plan 9 internal representation is always IPv6.
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maskfld := fields[1]
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maskfld = maskfld[1:]
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pfxlen, _, ok := dtoi(maskfld)
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if !ok {
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return nil, errors.New("cannot parse network mask for interface: " + status)
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}
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var mask IPMask
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if ip.To4() != nil { // IPv4 or IPv6 IPv4-mapped address
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mask = CIDRMask(pfxlen-8*len(v4InV6Prefix), 8*IPv4len)
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}
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if ip.To16() != nil && ip.To4() == nil { // IPv6 address
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mask = CIDRMask(pfxlen, 8*IPv6len)
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}
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addrs = append(addrs, &IPNet{IP: ip, Mask: mask})
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}
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}
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return addrs, nil
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}
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// interfaceMulticastAddrTable returns addresses for a specific
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// interface.
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func interfaceMulticastAddrTable(ifi *Interface) ([]Addr, error) {
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return nil, nil
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}
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