Pull request: 2179 ipset subdomains
Merge in DNS/adguard-home from 2179-ipset-subdomains to master Closes #2179. Squashed commit of the following: commit de17caac4c2ea2bc7931f162c6dfa7822a71554f Author: Ainar Garipov <A.Garipov@AdGuard.COM> Date: Fri Jan 29 18:34:46 2021 +0300 dnsforward: imp code, docs commit e5ab957560bcfba80feac4b72f9b22535ecd4c7d Author: Ainar Garipov <A.Garipov@AdGuard.COM> Date: Tue Jan 26 20:43:31 2021 +0300 dnsforward: imp code commit 2b84d27b752832885e4896d0e75de2576e2b965b Author: David Sheets <sheets@alum.mit.edu> Date: Tue Oct 6 16:34:06 2020 +0100 dnsforward: support subdomain matching in ipset This is a squash of all commits in #2179.
This commit is contained in:
Ainar Garipov
369
internal/dnsforward/ipset_linux.go
Normal file
369
internal/dnsforward/ipset_linux.go
Normal file
@@ -0,0 +1,369 @@
|
||||
// +build linux
|
||||
|
||||
package dnsforward
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"net"
|
||||
"strings"
|
||||
"sync"
|
||||
|
||||
"github.com/AdguardTeam/AdGuardHome/internal/agherr"
|
||||
"github.com/AdguardTeam/golibs/log"
|
||||
"github.com/digineo/go-ipset/v2"
|
||||
"github.com/mdlayher/netlink"
|
||||
"github.com/miekg/dns"
|
||||
"github.com/ti-mo/netfilter"
|
||||
)
|
||||
|
||||
// TODO(a.garipov): Cover with unit tests as well as document how to test it
|
||||
// manually. The original PR by @dsheets on Github contained an integration
|
||||
// test, but unfortunately I didn't have the time to properly refactor it and
|
||||
// check it in.
|
||||
//
|
||||
// See https://github.com/AdguardTeam/AdGuardHome/issues/2611.
|
||||
|
||||
// ipsetProps contains one Linux Netfilter ipset properties.
|
||||
type ipsetProps struct {
|
||||
name string
|
||||
family netfilter.ProtoFamily
|
||||
}
|
||||
|
||||
// ipsetCtx is the Linux Netfilter ipset context.
|
||||
type ipsetCtx struct {
|
||||
// mu protects all properties below.
|
||||
mu *sync.Mutex
|
||||
|
||||
nameToIpset map[string]ipsetProps
|
||||
domainToIpsets map[string][]ipsetProps
|
||||
|
||||
addedIPs map[[16]byte]struct{}
|
||||
|
||||
ipv4Conn *ipset.Conn
|
||||
ipv6Conn *ipset.Conn
|
||||
}
|
||||
|
||||
// dialNetfilter establishes connections to Linux's netfilter module.
|
||||
func (c *ipsetCtx) dialNetfilter(config *netlink.Config) (err error) {
|
||||
// The kernel API does not actually require two sockets but package
|
||||
// github.com/digineo/go-ipset does.
|
||||
//
|
||||
// TODO(a.garipov): Perhaps we can ditch package ipset altogether and
|
||||
// just use packages netfilter and netlink.
|
||||
c.ipv4Conn, err = ipset.Dial(netfilter.ProtoIPv4, config)
|
||||
if err != nil {
|
||||
return fmt.Errorf("dialing v4: %w", err)
|
||||
}
|
||||
|
||||
c.ipv6Conn, err = ipset.Dial(netfilter.ProtoIPv6, config)
|
||||
if err != nil {
|
||||
return fmt.Errorf("dialing v6: %w", err)
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// ipsetProps returns the properties of an ipset with the given name.
|
||||
func (c *ipsetCtx) ipsetProps(name string) (set ipsetProps, err error) {
|
||||
// The family doesn't seem to matter when we use a header query, so
|
||||
// query only the IPv4 one.
|
||||
//
|
||||
// TODO(a.garipov): Find out if this is a bug or a feature.
|
||||
res, err := c.ipv4Conn.Header(name)
|
||||
if err != nil {
|
||||
return set, err
|
||||
}
|
||||
|
||||
if res == nil || res.Family == nil {
|
||||
return set, agherr.Error("empty response or no family data")
|
||||
}
|
||||
|
||||
family := netfilter.ProtoFamily(res.Family.Value)
|
||||
if family != netfilter.ProtoIPv4 && family != netfilter.ProtoIPv6 {
|
||||
return set, fmt.Errorf("unexpected ipset family %s", family)
|
||||
}
|
||||
|
||||
return ipsetProps{
|
||||
name: name,
|
||||
family: family,
|
||||
}, nil
|
||||
}
|
||||
|
||||
// ipsets returns currently known ipsets.
|
||||
func (c *ipsetCtx) ipsets(names []string) (sets []ipsetProps, err error) {
|
||||
for _, name := range names {
|
||||
set, ok := c.nameToIpset[name]
|
||||
if ok {
|
||||
sets = append(sets, set)
|
||||
|
||||
continue
|
||||
}
|
||||
|
||||
var err error
|
||||
set, err = c.ipsetProps(name)
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("querying ipset %q: %w", name, err)
|
||||
}
|
||||
|
||||
c.nameToIpset[name] = set
|
||||
sets = append(sets, set)
|
||||
}
|
||||
|
||||
return sets, nil
|
||||
}
|
||||
|
||||
// parseIpsetConfig parses one ipset configuration string.
|
||||
func parseIpsetConfig(cfgStr string) (hosts, ipsetNames []string, err error) {
|
||||
cfgStr = strings.TrimSpace(cfgStr)
|
||||
hostsAndNames := strings.Split(cfgStr, "/")
|
||||
if len(hostsAndNames) != 2 {
|
||||
return nil, nil, fmt.Errorf("invalid value %q: expected one slash", cfgStr)
|
||||
}
|
||||
|
||||
hosts = strings.Split(hostsAndNames[0], ",")
|
||||
ipsetNames = strings.Split(hostsAndNames[1], ",")
|
||||
|
||||
if len(ipsetNames) == 0 {
|
||||
log.Info("ipset: resolutions for %q will not be stored", hosts)
|
||||
|
||||
return nil, nil, nil
|
||||
}
|
||||
|
||||
for i := range ipsetNames {
|
||||
ipsetNames[i] = strings.TrimSpace(ipsetNames[i])
|
||||
if len(ipsetNames[i]) == 0 {
|
||||
return nil, nil, fmt.Errorf("invalid value %q: empty ipset name", cfgStr)
|
||||
}
|
||||
}
|
||||
|
||||
for i := range hosts {
|
||||
hosts[i] = strings.TrimSpace(hosts[i])
|
||||
hosts[i] = strings.ToLower(hosts[i])
|
||||
if len(hosts[i]) == 0 {
|
||||
log.Info("ipset: root catchall in %q", ipsetNames)
|
||||
}
|
||||
}
|
||||
|
||||
return hosts, ipsetNames, nil
|
||||
}
|
||||
|
||||
// init initializes the ipset context. It is not safe for concurrent use.
|
||||
//
|
||||
// TODO(a.garipov): Rewrite into a simple constructor?
|
||||
func (c *ipsetCtx) init(ipsetConfig []string) (err error) {
|
||||
c.mu = &sync.Mutex{}
|
||||
c.nameToIpset = make(map[string]ipsetProps)
|
||||
c.domainToIpsets = make(map[string][]ipsetProps)
|
||||
c.addedIPs = make(map[[16]byte]struct{})
|
||||
|
||||
err = c.dialNetfilter(&netlink.Config{})
|
||||
if err != nil {
|
||||
return fmt.Errorf("ipset: dialing netfilter: %w", err)
|
||||
}
|
||||
|
||||
for i, cfgStr := range ipsetConfig {
|
||||
var hosts, ipsetNames []string
|
||||
hosts, ipsetNames, err = parseIpsetConfig(cfgStr)
|
||||
if err != nil {
|
||||
return fmt.Errorf("ipset: config line at index %d: %w", i, err)
|
||||
}
|
||||
|
||||
var ipsets []ipsetProps
|
||||
ipsets, err = c.ipsets(ipsetNames)
|
||||
if err != nil {
|
||||
return fmt.Errorf("ipset: getting ipsets config line at index %d: %w", i, err)
|
||||
}
|
||||
|
||||
for _, host := range hosts {
|
||||
c.domainToIpsets[host] = append(c.domainToIpsets[host], ipsets...)
|
||||
}
|
||||
}
|
||||
|
||||
log.Debug("ipset: added %d domains for %d ipsets", len(c.domainToIpsets), len(c.nameToIpset))
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// Close closes the Linux Netfilter connections.
|
||||
func (c *ipsetCtx) Close() (err error) {
|
||||
var errors []error
|
||||
err = c.ipv4Conn.Close()
|
||||
if err != nil {
|
||||
errors = append(errors, err)
|
||||
}
|
||||
|
||||
err = c.ipv6Conn.Close()
|
||||
if err != nil {
|
||||
errors = append(errors, err)
|
||||
}
|
||||
|
||||
if len(errors) != 0 {
|
||||
return agherr.Many("closing ipsets", errors...)
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// ipFromRR returns an IP address from a DNS resource record.
|
||||
func ipFromRR(rr dns.RR) (ip net.IP) {
|
||||
switch a := rr.(type) {
|
||||
case *dns.A:
|
||||
return a.A
|
||||
case *dns.AAAA:
|
||||
return a.AAAA
|
||||
default:
|
||||
return nil
|
||||
}
|
||||
}
|
||||
|
||||
// lookupHost find the ipsets for the host, taking subdomain wildcards into
|
||||
// account.
|
||||
func (c *ipsetCtx) lookupHost(host string) (sets []ipsetProps) {
|
||||
// Search for matching ipset hosts starting with most specific
|
||||
// subdomain. We could use a trie here but the simple, inefficient
|
||||
// solution isn't that expensive. ~75 % for 10 subdomains vs 0, but
|
||||
// still sub-microsecond on a Core i7.
|
||||
//
|
||||
// TODO(a.garipov): Re-add benchmarks from the original PR.
|
||||
for i := 0; i != -1; i++ {
|
||||
host = host[i:]
|
||||
sets = c.domainToIpsets[host]
|
||||
if sets != nil {
|
||||
return sets
|
||||
}
|
||||
|
||||
i = strings.Index(host, ".")
|
||||
}
|
||||
|
||||
// Check the root catch-all one.
|
||||
return c.domainToIpsets[""]
|
||||
}
|
||||
|
||||
// addIPs adds the IP addresses for the host to the ipset. set must be same
|
||||
// family as set's family.
|
||||
func (c *ipsetCtx) addIPs(host string, set ipsetProps, ips []net.IP) (err error) {
|
||||
if len(ips) == 0 {
|
||||
return
|
||||
}
|
||||
|
||||
entries := make([]*ipset.Entry, 0, len(ips))
|
||||
for _, ip := range ips {
|
||||
entries = append(entries, ipset.NewEntry(ipset.EntryIP(ip)))
|
||||
}
|
||||
|
||||
var conn *ipset.Conn
|
||||
switch set.family {
|
||||
case netfilter.ProtoIPv4:
|
||||
conn = c.ipv4Conn
|
||||
case netfilter.ProtoIPv6:
|
||||
conn = c.ipv6Conn
|
||||
default:
|
||||
return fmt.Errorf("unexpected family %s for ipset %q", set.family, set.name)
|
||||
}
|
||||
|
||||
err = conn.Add(set.name, entries...)
|
||||
if err != nil {
|
||||
return fmt.Errorf("adding %q%s to ipset %q: %w", host, ips, set.name, err)
|
||||
}
|
||||
|
||||
log.Debug("ipset: added %s%s to ipset %s", host, ips, set.name)
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// skipIpsetProcessing returns true when the ipset processing can be skipped for
|
||||
// this request.
|
||||
func (c *ipsetCtx) skipIpsetProcessing(ctx *dnsContext) (ok bool) {
|
||||
if len(c.domainToIpsets) == 0 || ctx == nil || !ctx.responseFromUpstream {
|
||||
return true
|
||||
}
|
||||
|
||||
req := ctx.proxyCtx.Req
|
||||
if req == nil || len(req.Question) == 0 {
|
||||
return true
|
||||
}
|
||||
|
||||
qt := req.Question[0].Qtype
|
||||
return qt != dns.TypeA && qt != dns.TypeAAAA && qt != dns.TypeANY
|
||||
}
|
||||
|
||||
// process adds the resolved IP addresses to the domain's ipsets, if any.
|
||||
func (c *ipsetCtx) process(ctx *dnsContext) (rc resultCode) {
|
||||
if c == nil {
|
||||
return resultCodeSuccess
|
||||
}
|
||||
|
||||
c.mu.Lock()
|
||||
defer c.mu.Unlock()
|
||||
|
||||
if c.skipIpsetProcessing(ctx) {
|
||||
log.Debug("ipset: skipped processing for request")
|
||||
|
||||
return resultCodeSuccess
|
||||
}
|
||||
|
||||
req := ctx.proxyCtx.Req
|
||||
host := req.Question[0].Name
|
||||
host = strings.TrimSuffix(host, ".")
|
||||
host = strings.ToLower(host)
|
||||
sets := c.lookupHost(host)
|
||||
if len(sets) == 0 {
|
||||
return resultCodeSuccess
|
||||
}
|
||||
|
||||
log.Debug("ipset: found ipsets %+v for host %s", sets, host)
|
||||
|
||||
if ctx.proxyCtx.Res == nil {
|
||||
return resultCodeSuccess
|
||||
}
|
||||
|
||||
ans := ctx.proxyCtx.Res.Answer
|
||||
l := len(ans)
|
||||
v4s := make([]net.IP, 0, l)
|
||||
v6s := make([]net.IP, 0, l)
|
||||
for _, rr := range ans {
|
||||
ip := ipFromRR(rr)
|
||||
if ip == nil {
|
||||
continue
|
||||
}
|
||||
|
||||
var iparr [16]byte
|
||||
copy(iparr[:], ip.To16())
|
||||
if _, added := c.addedIPs[iparr]; added {
|
||||
continue
|
||||
}
|
||||
|
||||
if ip.To4() == nil {
|
||||
v6s = append(v6s, ip)
|
||||
|
||||
continue
|
||||
}
|
||||
|
||||
v4s = append(v4s, ip)
|
||||
}
|
||||
|
||||
var err error
|
||||
setLoop:
|
||||
for _, set := range sets {
|
||||
switch set.family {
|
||||
case netfilter.ProtoIPv4:
|
||||
err = c.addIPs(host, set, v4s)
|
||||
if err != nil {
|
||||
break setLoop
|
||||
}
|
||||
case netfilter.ProtoIPv6:
|
||||
err = c.addIPs(host, set, v6s)
|
||||
if err != nil {
|
||||
break setLoop
|
||||
}
|
||||
default:
|
||||
err = fmt.Errorf("unexpected family %s for ipset %q", set.family, set.name)
|
||||
break setLoop
|
||||
}
|
||||
}
|
||||
if err != nil {
|
||||
log.Error("ipset: adding host ips: %s", err)
|
||||
}
|
||||
|
||||
return resultCodeSuccess
|
||||
}
|
||||
Reference in New Issue
Block a user