AdGuardHome/internal/home/clients.go

899 lines
22 KiB
Go

package home
import (
"bytes"
"fmt"
"net"
"net/netip"
"strings"
"sync"
"time"
"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
"github.com/AdguardTeam/AdGuardHome/internal/dhcpd"
"github.com/AdguardTeam/AdGuardHome/internal/dhcpsvc"
"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
"github.com/AdguardTeam/AdGuardHome/internal/filtering"
"github.com/AdguardTeam/AdGuardHome/internal/querylog"
"github.com/AdguardTeam/AdGuardHome/internal/whois"
"github.com/AdguardTeam/dnsproxy/proxy"
"github.com/AdguardTeam/dnsproxy/upstream"
"github.com/AdguardTeam/golibs/errors"
"github.com/AdguardTeam/golibs/log"
"github.com/AdguardTeam/golibs/stringutil"
"golang.org/x/exp/maps"
"golang.org/x/exp/slices"
)
// DHCP is an interface for accesing DHCP lease data the [clientsContainer]
// needs.
type DHCP interface {
// Leases returns all the DHCP leases.
Leases() (leases []*dhcpsvc.Lease)
// HostByIP returns the hostname of the DHCP client with the given IP
// address. The address will be netip.Addr{} if there is no such client,
// due to an assumption that a DHCP client must always have an IP address.
HostByIP(ip netip.Addr) (host string)
// MACByIP returns the MAC address for the given IP address leased. It
// returns nil if there is no such client, due to an assumption that a DHCP
// client must always have a MAC address.
MACByIP(ip netip.Addr) (mac net.HardwareAddr)
}
// clientsContainer is the storage of all runtime and persistent clients.
type clientsContainer struct {
// TODO(a.garipov): Perhaps use a number of separate indices for different
// types (string, netip.Addr, and so on).
list map[string]*Client // name -> client
idIndex map[string]*Client // ID -> client
// ipToRC is the IP address to *RuntimeClient map.
ipToRC map[netip.Addr]*RuntimeClient
allTags *stringutil.Set
// dhcpServer is used for looking up clients IP addresses by MAC addresses
dhcpServer dhcpd.Interface
// dnsServer is used for checking clients IP status access list status
dnsServer *dnsforward.Server
// etcHosts contains list of rewrite rules taken from the operating system's
// hosts database.
etcHosts *aghnet.HostsContainer
// arpdb stores the neighbors retrieved from ARP.
arpdb aghnet.ARPDB
// lock protects all fields.
//
// TODO(a.garipov): Use a pointer and describe which fields are protected in
// more detail. Use sync.RWMutex.
lock sync.Mutex
// safeSearchCacheSize is the size of the safe search cache to use for
// persistent clients.
safeSearchCacheSize uint
// safeSearchCacheTTL is the TTL of the safe search cache to use for
// persistent clients.
safeSearchCacheTTL time.Duration
// testing is a flag that disables some features for internal tests.
//
// TODO(a.garipov): Awful. Remove.
testing bool
}
// Init initializes clients container
// dhcpServer: optional
// Note: this function must be called only once
func (clients *clientsContainer) Init(
objects []*clientObject,
dhcpServer dhcpd.Interface,
etcHosts *aghnet.HostsContainer,
arpdb aghnet.ARPDB,
filteringConf *filtering.Config,
) (err error) {
if clients.list != nil {
log.Fatal("clients.list != nil")
}
clients.list = make(map[string]*Client)
clients.idIndex = make(map[string]*Client)
clients.ipToRC = map[netip.Addr]*RuntimeClient{}
clients.allTags = stringutil.NewSet(clientTags...)
clients.dhcpServer = dhcpServer
clients.etcHosts = etcHosts
clients.arpdb = arpdb
err = clients.addFromConfig(objects, filteringConf)
if err != nil {
// Don't wrap the error, because it's informative enough as is.
return err
}
clients.safeSearchCacheSize = filteringConf.SafeSearchCacheSize
clients.safeSearchCacheTTL = time.Minute * time.Duration(filteringConf.CacheTime)
if clients.testing {
return nil
}
if clients.dhcpServer != nil {
clients.dhcpServer.SetOnLeaseChanged(clients.onDHCPLeaseChanged)
clients.onDHCPLeaseChanged(dhcpd.LeaseChangedAdded)
}
if clients.etcHosts != nil {
go clients.handleHostsUpdates()
}
return nil
}
func (clients *clientsContainer) handleHostsUpdates() {
for upd := range clients.etcHosts.Upd() {
clients.addFromHostsFile(upd)
}
}
// webHandlersRegistered prevents a [clientsContainer] from regisering its web
// handlers more than once.
//
// TODO(a.garipov): Refactor HTTP handler registration logic.
var webHandlersRegistered = false
// Start starts the clients container.
func (clients *clientsContainer) Start() {
if clients.testing {
return
}
if !webHandlersRegistered {
webHandlersRegistered = true
clients.registerWebHandlers()
}
go clients.periodicUpdate()
}
// reloadARP reloads runtime clients from ARP, if configured.
func (clients *clientsContainer) reloadARP() {
if clients.arpdb != nil {
clients.addFromSystemARP()
}
}
// clientObject is the YAML representation of a persistent client.
type clientObject struct {
SafeSearchConf filtering.SafeSearchConfig `yaml:"safe_search"`
// BlockedServices is the configuration of blocked services of a client.
BlockedServices *filtering.BlockedServices `yaml:"blocked_services"`
Name string `yaml:"name"`
IDs []string `yaml:"ids"`
Tags []string `yaml:"tags"`
Upstreams []string `yaml:"upstreams"`
UseGlobalSettings bool `yaml:"use_global_settings"`
FilteringEnabled bool `yaml:"filtering_enabled"`
ParentalEnabled bool `yaml:"parental_enabled"`
SafeBrowsingEnabled bool `yaml:"safebrowsing_enabled"`
UseGlobalBlockedServices bool `yaml:"use_global_blocked_services"`
IgnoreQueryLog bool `yaml:"ignore_querylog"`
IgnoreStatistics bool `yaml:"ignore_statistics"`
}
// addFromConfig initializes the clients container with objects from the
// configuration file.
func (clients *clientsContainer) addFromConfig(
objects []*clientObject,
filteringConf *filtering.Config,
) (err error) {
for _, o := range objects {
cli := &Client{
Name: o.Name,
IDs: o.IDs,
Upstreams: o.Upstreams,
UseOwnSettings: !o.UseGlobalSettings,
FilteringEnabled: o.FilteringEnabled,
ParentalEnabled: o.ParentalEnabled,
safeSearchConf: o.SafeSearchConf,
SafeBrowsingEnabled: o.SafeBrowsingEnabled,
UseOwnBlockedServices: !o.UseGlobalBlockedServices,
IgnoreQueryLog: o.IgnoreQueryLog,
IgnoreStatistics: o.IgnoreStatistics,
}
if o.SafeSearchConf.Enabled {
o.SafeSearchConf.CustomResolver = safeSearchResolver{}
err = cli.setSafeSearch(
o.SafeSearchConf,
filteringConf.SafeSearchCacheSize,
time.Minute*time.Duration(filteringConf.CacheTime),
)
if err != nil {
log.Error("clients: init client safesearch %q: %s", cli.Name, err)
continue
}
}
err = o.BlockedServices.Validate()
if err != nil {
return fmt.Errorf("clients: init client blocked services %q: %w", cli.Name, err)
}
cli.BlockedServices = o.BlockedServices.Clone()
for _, t := range o.Tags {
if clients.allTags.Has(t) {
cli.Tags = append(cli.Tags, t)
} else {
log.Info("clients: skipping unknown tag %q", t)
}
}
slices.Sort(cli.Tags)
_, err = clients.Add(cli)
if err != nil {
log.Error("clients: adding clients %s: %s", cli.Name, err)
}
}
return nil
}
// forConfig returns all currently known persistent clients as objects for the
// configuration file.
func (clients *clientsContainer) forConfig() (objs []*clientObject) {
clients.lock.Lock()
defer clients.lock.Unlock()
objs = make([]*clientObject, 0, len(clients.list))
for _, cli := range clients.list {
o := &clientObject{
Name: cli.Name,
BlockedServices: cli.BlockedServices.Clone(),
IDs: stringutil.CloneSlice(cli.IDs),
Tags: stringutil.CloneSlice(cli.Tags),
Upstreams: stringutil.CloneSlice(cli.Upstreams),
UseGlobalSettings: !cli.UseOwnSettings,
FilteringEnabled: cli.FilteringEnabled,
ParentalEnabled: cli.ParentalEnabled,
SafeSearchConf: cli.safeSearchConf,
SafeBrowsingEnabled: cli.SafeBrowsingEnabled,
UseGlobalBlockedServices: !cli.UseOwnBlockedServices,
IgnoreQueryLog: cli.IgnoreQueryLog,
IgnoreStatistics: cli.IgnoreStatistics,
}
objs = append(objs, o)
}
// Maps aren't guaranteed to iterate in the same order each time, so the
// above loop can generate different orderings when writing to the config
// file: this produces lots of diffs in config files, so sort objects by
// name before writing.
slices.SortStableFunc(objs, func(a, b *clientObject) (sortsBefore bool) {
return a.Name < b.Name
})
return objs
}
// arpClientsUpdatePeriod defines how often ARP clients are updated.
const arpClientsUpdatePeriod = 10 * time.Minute
func (clients *clientsContainer) periodicUpdate() {
defer log.OnPanic("clients container")
for {
clients.reloadARP()
time.Sleep(arpClientsUpdatePeriod)
}
}
// onDHCPLeaseChanged is a callback for the DHCP server. It updates the list of
// runtime clients using the DHCP server's leases.
//
// TODO(e.burkov): Remove when switched to dhcpsvc.
func (clients *clientsContainer) onDHCPLeaseChanged(flags int) {
if clients.dhcpServer == nil || !config.Clients.Sources.DHCP {
return
}
clients.lock.Lock()
defer clients.lock.Unlock()
clients.rmHostsBySrc(ClientSourceDHCP)
if flags == dhcpd.LeaseChangedRemovedAll {
return
}
leases := clients.dhcpServer.Leases(dhcpd.LeasesAll)
n := 0
for _, l := range leases {
if l.Hostname == "" {
continue
}
ok := clients.addHostLocked(l.IP, l.Hostname, ClientSourceDHCP)
if ok {
n++
}
}
log.Debug("clients: added %d client aliases from dhcp", n)
}
// clientSource checks if client with this IP address already exists and returns
// the source which updated it last. It returns [ClientSourceNone] if the
// client doesn't exist.
func (clients *clientsContainer) clientSource(ip netip.Addr) (src clientSource) {
clients.lock.Lock()
defer clients.lock.Unlock()
_, ok := clients.findLocked(ip.String())
if ok {
return ClientSourcePersistent
}
rc, ok := clients.ipToRC[ip]
if ok {
return rc.Source
}
return ClientSourceNone
}
// findMultiple is a wrapper around Find to make it a valid client finder for
// the query log. c is never nil; if no information about the client is found,
// it returns an artificial client record by only setting the blocking-related
// fields. err is always nil.
func (clients *clientsContainer) findMultiple(ids []string) (c *querylog.Client, err error) {
var artClient *querylog.Client
var art bool
for _, id := range ids {
ip, _ := netip.ParseAddr(id)
c, art = clients.clientOrArtificial(ip, id)
if art {
artClient = c
continue
}
return c, nil
}
return artClient, nil
}
// clientOrArtificial returns information about one client. If art is true,
// this is an artificial client record, meaning that we currently don't have any
// records about this client besides maybe whether or not it is blocked. c is
// never nil.
func (clients *clientsContainer) clientOrArtificial(
ip netip.Addr,
id string,
) (c *querylog.Client, art bool) {
defer func() {
c.Disallowed, c.DisallowedRule = clients.dnsServer.IsBlockedClient(ip, id)
if c.WHOIS == nil {
c.WHOIS = &whois.Info{}
}
}()
client, ok := clients.Find(id)
if ok {
return &querylog.Client{
Name: client.Name,
IgnoreQueryLog: client.IgnoreQueryLog,
}, false
}
var rc *RuntimeClient
rc, ok = clients.findRuntimeClient(ip)
if ok {
return &querylog.Client{
Name: rc.Host,
WHOIS: rc.WHOIS,
}, false
}
return &querylog.Client{
Name: "",
}, true
}
// Find returns a shallow copy of the client if there is one found.
func (clients *clientsContainer) Find(id string) (c *Client, ok bool) {
clients.lock.Lock()
defer clients.lock.Unlock()
c, ok = clients.findLocked(id)
if !ok {
return nil, false
}
return c.ShallowClone(), true
}
// shouldCountClient is a wrapper around Find to make it a valid client
// information finder for the statistics. If no information about the client
// is found, it returns true.
func (clients *clientsContainer) shouldCountClient(ids []string) (y bool) {
clients.lock.Lock()
defer clients.lock.Unlock()
for _, id := range ids {
client, ok := clients.findLocked(id)
if ok {
return !client.IgnoreStatistics
}
}
return true
}
// findUpstreams returns upstreams configured for the client, identified either
// by its IP address or its ClientID. upsConf is nil if the client isn't found
// or if the client has no custom upstreams.
func (clients *clientsContainer) findUpstreams(
id string,
) (upsConf *proxy.UpstreamConfig, err error) {
clients.lock.Lock()
defer clients.lock.Unlock()
c, ok := clients.findLocked(id)
if !ok {
return nil, nil
}
upstreams := stringutil.FilterOut(c.Upstreams, dnsforward.IsCommentOrEmpty)
if len(upstreams) == 0 {
return nil, nil
}
if c.upstreamConfig != nil {
return c.upstreamConfig, nil
}
var conf *proxy.UpstreamConfig
conf, err = proxy.ParseUpstreamsConfig(
upstreams,
&upstream.Options{
Bootstrap: config.DNS.BootstrapDNS,
Timeout: config.DNS.UpstreamTimeout.Duration,
HTTPVersions: dnsforward.UpstreamHTTPVersions(config.DNS.UseHTTP3Upstreams),
PreferIPv6: config.DNS.BootstrapPreferIPv6,
},
)
if err != nil {
return nil, err
}
c.upstreamConfig = conf
return conf, nil
}
// findLocked searches for a client by its ID. clients.lock is expected to be
// locked.
func (clients *clientsContainer) findLocked(id string) (c *Client, ok bool) {
c, ok = clients.idIndex[id]
if ok {
return c, true
}
ip, err := netip.ParseAddr(id)
if err != nil {
return nil, false
}
for _, c = range clients.list {
for _, id := range c.IDs {
var subnet netip.Prefix
subnet, err = netip.ParsePrefix(id)
if err != nil {
continue
}
if subnet.Contains(ip) {
return c, true
}
}
}
if clients.dhcpServer != nil {
return clients.findDHCP(ip)
}
return nil, false
}
// findDHCP searches for a client by its MAC, if the DHCP server is active and
// there is such client. clients.lock is expected to be locked.
func (clients *clientsContainer) findDHCP(ip netip.Addr) (c *Client, ok bool) {
foundMAC := clients.dhcpServer.FindMACbyIP(ip)
if foundMAC == nil {
return nil, false
}
for _, c = range clients.list {
for _, id := range c.IDs {
mac, err := net.ParseMAC(id)
if err != nil {
continue
}
if bytes.Equal(mac, foundMAC) {
return c, true
}
}
}
return nil, false
}
// findRuntimeClient finds a runtime client by their IP.
func (clients *clientsContainer) findRuntimeClient(ip netip.Addr) (rc *RuntimeClient, ok bool) {
if ip == (netip.Addr{}) {
return nil, false
}
clients.lock.Lock()
defer clients.lock.Unlock()
rc, ok = clients.ipToRC[ip]
return rc, ok
}
// check validates the client.
func (clients *clientsContainer) check(c *Client) (err error) {
switch {
case c == nil:
return errors.Error("client is nil")
case c.Name == "":
return errors.Error("invalid name")
case len(c.IDs) == 0:
return errors.Error("id required")
default:
// Go on.
}
for i, id := range c.IDs {
var norm string
norm, err = normalizeClientIdentifier(id)
if err != nil {
return fmt.Errorf("client at index %d: %w", i, err)
}
c.IDs[i] = norm
}
for _, t := range c.Tags {
if !clients.allTags.Has(t) {
return fmt.Errorf("invalid tag: %q", t)
}
}
slices.Sort(c.Tags)
err = dnsforward.ValidateUpstreams(c.Upstreams)
if err != nil {
return fmt.Errorf("invalid upstream servers: %w", err)
}
return nil
}
// normalizeClientIdentifier returns a normalized version of idStr. If idStr
// cannot be normalized, it returns an error.
func normalizeClientIdentifier(idStr string) (norm string, err error) {
if idStr == "" {
return "", errors.Error("clientid is empty")
}
var ip netip.Addr
if ip, err = netip.ParseAddr(idStr); err == nil {
return ip.String(), nil
}
var subnet netip.Prefix
if subnet, err = netip.ParsePrefix(idStr); err == nil {
return subnet.String(), nil
}
var mac net.HardwareAddr
if mac, err = net.ParseMAC(idStr); err == nil {
return mac.String(), nil
}
if err = dnsforward.ValidateClientID(idStr); err == nil {
return strings.ToLower(idStr), nil
}
return "", fmt.Errorf("bad client identifier %q", idStr)
}
// Add adds a new client object. ok is false if such client already exists or
// if an error occurred.
func (clients *clientsContainer) Add(c *Client) (ok bool, err error) {
err = clients.check(c)
if err != nil {
return false, err
}
clients.lock.Lock()
defer clients.lock.Unlock()
// check Name index
_, ok = clients.list[c.Name]
if ok {
return false, nil
}
// check ID index
for _, id := range c.IDs {
var c2 *Client
c2, ok = clients.idIndex[id]
if ok {
return false, fmt.Errorf("another client uses the same ID (%q): %q", id, c2.Name)
}
}
clients.add(c)
log.Debug("clients: added %q: ID:%q [%d]", c.Name, c.IDs, len(clients.list))
return true, nil
}
// add c to the indexes. clients.lock is expected to be locked.
func (clients *clientsContainer) add(c *Client) {
// update Name index
clients.list[c.Name] = c
// update ID index
for _, id := range c.IDs {
clients.idIndex[id] = c
}
}
// Del removes a client. ok is false if there is no such client.
func (clients *clientsContainer) Del(name string) (ok bool) {
clients.lock.Lock()
defer clients.lock.Unlock()
var c *Client
c, ok = clients.list[name]
if !ok {
return false
}
if err := c.closeUpstreams(); err != nil {
log.Error("client container: removing client %s: %s", name, err)
}
clients.del(c)
return true
}
// del removes c from the indexes. clients.lock is expected to be locked.
func (clients *clientsContainer) del(c *Client) {
// update Name index
delete(clients.list, c.Name)
// update ID index
for _, id := range c.IDs {
delete(clients.idIndex, id)
}
}
// Update updates a client by its name.
func (clients *clientsContainer) Update(prev, c *Client) (err error) {
err = clients.check(c)
if err != nil {
// Don't wrap the error since it's informative enough as is.
return err
}
clients.lock.Lock()
defer clients.lock.Unlock()
// Check the name index.
if prev.Name != c.Name {
_, ok := clients.list[c.Name]
if ok {
return errors.Error("client already exists")
}
}
// Check the ID index.
if !slices.Equal(prev.IDs, c.IDs) {
for _, id := range c.IDs {
existing, ok := clients.idIndex[id]
if ok && existing != prev {
return fmt.Errorf("id %q is used by client with name %q", id, existing.Name)
}
}
}
clients.del(prev)
clients.add(c)
return nil
}
// setWHOISInfo sets the WHOIS information for a client.
func (clients *clientsContainer) setWHOISInfo(ip netip.Addr, wi *whois.Info) {
clients.lock.Lock()
defer clients.lock.Unlock()
_, ok := clients.findLocked(ip.String())
if ok {
log.Debug("clients: client for %s is already created, ignore whois info", ip)
return
}
// TODO(e.burkov): Consider storing WHOIS information separately and
// potentially get rid of [RuntimeClient].
rc, ok := clients.ipToRC[ip]
if !ok {
// Create a RuntimeClient implicitly so that we don't do this check
// again.
rc = &RuntimeClient{
Source: ClientSourceWHOIS,
}
clients.ipToRC[ip] = rc
log.Debug("clients: set whois info for runtime client with ip %s: %+v", ip, wi)
} else {
log.Debug("clients: set whois info for runtime client %s: %+v", rc.Host, wi)
}
rc.WHOIS = wi
}
// AddHost adds a new IP-hostname pairing. The priorities of the sources are
// taken into account. ok is true if the pairing was added.
func (clients *clientsContainer) AddHost(
ip netip.Addr,
host string,
src clientSource,
) (ok bool) {
clients.lock.Lock()
defer clients.lock.Unlock()
return clients.addHostLocked(ip, host, src)
}
// addHostLocked adds a new IP-hostname pairing. clients.lock is expected to be
// locked.
func (clients *clientsContainer) addHostLocked(
ip netip.Addr,
host string,
src clientSource,
) (ok bool) {
rc, ok := clients.ipToRC[ip]
if !ok {
rc = &RuntimeClient{
WHOIS: &whois.Info{},
}
clients.ipToRC[ip] = rc
} else if src < rc.Source {
return false
}
rc.Host = host
rc.Source = src
log.Debug("clients: added %s -> %q [%d]", ip, host, len(clients.ipToRC))
return true
}
// rmHostsBySrc removes all entries that match the specified source.
func (clients *clientsContainer) rmHostsBySrc(src clientSource) {
n := 0
for ip, rc := range clients.ipToRC {
if rc.Source == src {
delete(clients.ipToRC, ip)
n++
}
}
log.Debug("clients: removed %d client aliases", n)
}
// addFromHostsFile fills the client-hostname pairing index from the system's
// hosts files.
func (clients *clientsContainer) addFromHostsFile(hosts aghnet.HostsRecords) {
clients.lock.Lock()
defer clients.lock.Unlock()
clients.rmHostsBySrc(ClientSourceHostsFile)
n := 0
for ip, rec := range hosts {
clients.addHostLocked(ip, rec.Canonical, ClientSourceHostsFile)
n++
}
log.Debug("clients: added %d client aliases from system hosts file", n)
}
// addFromSystemARP adds the IP-hostname pairings from the output of the arp -a
// command.
func (clients *clientsContainer) addFromSystemARP() {
if err := clients.arpdb.Refresh(); err != nil {
log.Error("refreshing arp container: %s", err)
clients.arpdb = aghnet.EmptyARPDB{}
return
}
ns := clients.arpdb.Neighbors()
if len(ns) == 0 {
log.Debug("refreshing arp container: the update is empty")
return
}
clients.lock.Lock()
defer clients.lock.Unlock()
clients.rmHostsBySrc(ClientSourceARP)
added := 0
for _, n := range ns {
if clients.addHostLocked(n.IP, n.Name, ClientSourceARP) {
added++
}
}
log.Debug("clients: added %d client aliases from arp neighborhood", added)
}
// close gracefully closes all the client-specific upstream configurations of
// the persistent clients.
func (clients *clientsContainer) close() (err error) {
persistent := maps.Values(clients.list)
slices.SortFunc(persistent, func(a, b *Client) (less bool) { return a.Name < b.Name })
var errs []error
for _, cli := range persistent {
if err = cli.closeUpstreams(); err != nil {
errs = append(errs, err)
}
}
if len(errs) > 0 {
return errors.List("closing client specific upstreams", errs...)
}
return nil
}