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