AdGuardHome/internal/home/clients.go

736 lines
20 KiB
Go

package home
import (
"fmt"
"net"
"net/netip"
"slices"
"sync"
"time"
"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
"github.com/AdguardTeam/AdGuardHome/internal/arpdb"
"github.com/AdguardTeam/AdGuardHome/internal/client"
"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/schedule"
"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/hostsfile"
"github.com/AdguardTeam/golibs/log"
"github.com/AdguardTeam/golibs/stringutil"
)
// DHCP is an interface for accessing 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 a hostname.
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 {
// storage stores information about persistent clients.
storage *client.Storage
// runtimeIndex stores information about runtime clients.
runtimeIndex *client.RuntimeIndex
// dhcp is the DHCP service implementation.
dhcp DHCP
// clientChecker checks if a client is blocked by the current access
// settings.
clientChecker BlockedClientChecker
// 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 arpdb.Interface
// 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
}
// BlockedClientChecker checks if a client is blocked by the current access
// settings.
type BlockedClientChecker interface {
IsBlockedClient(ip netip.Addr, clientID string) (blocked bool, rule string)
}
// Init initializes clients container
// dhcpServer: optional
// Note: this function must be called only once
func (clients *clientsContainer) Init(
objects []*clientObject,
dhcpServer DHCP,
etcHosts *aghnet.HostsContainer,
arpDB arpdb.Interface,
filteringConf *filtering.Config,
) (err error) {
// TODO(s.chzhen): Refactor it.
if clients.storage != nil {
return errors.Error("clients container already initialized")
}
clients.runtimeIndex = client.NewRuntimeIndex()
clients.storage = client.NewStorage(&client.Config{
AllowedTags: clientTags,
})
// TODO(e.burkov): Use [dhcpsvc] implementation when it's ready.
clients.dhcp = 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
}
// The clients.etcHosts may be nil even if config.Clients.Sources.HostsFile
// is true, because of the deprecated option --no-etc-hosts.
//
// TODO(e.burkov): The option should probably be returned, since hosts file
// currently used not only for clients' information enrichment, but also in
// the filtering module and upstream addresses resolution.
if config.Clients.Sources.HostsFile && clients.etcHosts != nil {
go clients.handleHostsUpdates()
}
return nil
}
// handleHostsUpdates receives the updates from the hosts container and adds
// them to the clients container. It is intended to be used as a goroutine.
func (clients *clientsContainer) handleHostsUpdates() {
for upd := range clients.etcHosts.Upd() {
clients.addFromHostsFile(upd)
}
}
// webHandlersRegistered prevents a [clientsContainer] from registering 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"`
// UID is the unique identifier of the persistent client.
UID client.UID `yaml:"uid"`
// UpstreamsCacheSize is the DNS cache size (in bytes).
//
// TODO(d.kolyshev): Use [datasize.Bytesize].
UpstreamsCacheSize uint32 `yaml:"upstreams_cache_size"`
// UpstreamsCacheEnabled indicates if the DNS cache is enabled.
UpstreamsCacheEnabled bool `yaml:"upstreams_cache_enabled"`
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"`
}
// toPersistent returns an initialized persistent client if there are no errors.
func (o *clientObject) toPersistent(
filteringConf *filtering.Config,
) (cli *client.Persistent, err error) {
cli = &client.Persistent{
Name: o.Name,
Upstreams: o.Upstreams,
UID: o.UID,
UseOwnSettings: !o.UseGlobalSettings,
FilteringEnabled: o.FilteringEnabled,
ParentalEnabled: o.ParentalEnabled,
SafeSearchConf: o.SafeSearchConf,
SafeBrowsingEnabled: o.SafeBrowsingEnabled,
UseOwnBlockedServices: !o.UseGlobalBlockedServices,
IgnoreQueryLog: o.IgnoreQueryLog,
IgnoreStatistics: o.IgnoreStatistics,
UpstreamsCacheEnabled: o.UpstreamsCacheEnabled,
UpstreamsCacheSize: o.UpstreamsCacheSize,
}
err = cli.SetIDs(o.IDs)
if err != nil {
return nil, fmt.Errorf("parsing ids: %w", err)
}
if (cli.UID == client.UID{}) {
cli.UID, err = client.NewUID()
if err != nil {
return nil, fmt.Errorf("generating uid: %w", err)
}
}
if o.SafeSearchConf.Enabled {
err = cli.SetSafeSearch(
o.SafeSearchConf,
filteringConf.SafeSearchCacheSize,
time.Minute*time.Duration(filteringConf.CacheTime),
)
if err != nil {
return nil, fmt.Errorf("init safesearch %q: %w", cli.Name, err)
}
}
if o.BlockedServices == nil {
o.BlockedServices = &filtering.BlockedServices{
Schedule: schedule.EmptyWeekly(),
}
}
err = o.BlockedServices.Validate()
if err != nil {
return nil, fmt.Errorf("init blocked services %q: %w", cli.Name, err)
}
cli.BlockedServices = o.BlockedServices.Clone()
cli.Tags = slices.Clone(o.Tags)
return cli, nil
}
// addFromConfig initializes the clients container with objects from the
// configuration file.
func (clients *clientsContainer) addFromConfig(
objects []*clientObject,
filteringConf *filtering.Config,
) (err error) {
for i, o := range objects {
var cli *client.Persistent
cli, err = o.toPersistent(filteringConf)
if err != nil {
return fmt.Errorf("clients: init persistent client at index %d: %w", i, err)
}
err = clients.storage.Add(cli)
if err != nil {
return fmt.Errorf("adding client %q at index %d: %w", cli.Name, i, 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, clients.storage.Size())
clients.storage.RangeByName(func(cli *client.Persistent) (cont bool) {
objs = append(objs, &clientObject{
Name: cli.Name,
BlockedServices: cli.BlockedServices.Clone(),
IDs: cli.IDs(),
Tags: slices.Clone(cli.Tags),
Upstreams: slices.Clone(cli.Upstreams),
UID: cli.UID,
UseGlobalSettings: !cli.UseOwnSettings,
FilteringEnabled: cli.FilteringEnabled,
ParentalEnabled: cli.ParentalEnabled,
SafeSearchConf: cli.SafeSearchConf,
SafeBrowsingEnabled: cli.SafeBrowsingEnabled,
UseGlobalBlockedServices: !cli.UseOwnBlockedServices,
IgnoreQueryLog: cli.IgnoreQueryLog,
IgnoreStatistics: cli.IgnoreStatistics,
UpstreamsCacheEnabled: cli.UpstreamsCacheEnabled,
UpstreamsCacheSize: cli.UpstreamsCacheSize,
})
return true
})
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)
}
}
// clientSource checks if client with this IP address already exists and returns
// the source which updated it last. It returns [client.SourceNone] if the
// client doesn't exist. Note that it is only used in tests.
func (clients *clientsContainer) clientSource(ip netip.Addr) (src client.Source) {
clients.lock.Lock()
defer clients.lock.Unlock()
_, ok := clients.findLocked(ip.String())
if ok {
return client.SourcePersistent
}
rc := clients.runtimeIndex.Client(ip)
if rc != nil {
src, _ = rc.Info()
}
if src < client.SourceDHCP && clients.dhcp.HostByIP(ip) != "" {
src = client.SourceDHCP
}
return src
}
// findMultiple is a wrapper around [clientsContainer.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.clientChecker.IsBlockedClient(ip, id)
if c.WHOIS == nil {
c.WHOIS = &whois.Info{}
}
}()
cli, ok := clients.storage.FindLoose(ip, id)
if ok {
return &querylog.Client{
Name: cli.Name,
IgnoreQueryLog: cli.IgnoreQueryLog,
}, false
}
rc := clients.findRuntimeClient(ip)
if rc != nil {
_, host := rc.Info()
return &querylog.Client{
Name: 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.Persistent, ok bool) {
clients.lock.Lock()
defer clients.lock.Unlock()
c, ok = clients.findLocked(id)
if !ok {
return nil, false
}
return c, true
}
// shouldCountClient is a wrapper around [clientsContainer.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
}
// type check
var _ dnsforward.ClientsContainer = (*clientsContainer)(nil)
// UpstreamConfigByID implements the [dnsforward.ClientsContainer] interface for
// *clientsContainer. upsConf is nil if the client isn't found or if the client
// has no custom upstreams.
func (clients *clientsContainer) UpstreamConfigByID(
id string,
bootstrap upstream.Resolver,
) (conf *proxy.CustomUpstreamConfig, err error) {
clients.lock.Lock()
defer clients.lock.Unlock()
c, ok := clients.findLocked(id)
if !ok {
return nil, nil
} else if c.UpstreamConfig != nil {
return c.UpstreamConfig, nil
}
upstreams := stringutil.FilterOut(c.Upstreams, dnsforward.IsCommentOrEmpty)
if len(upstreams) == 0 {
return nil, nil
}
var upsConf *proxy.UpstreamConfig
upsConf, err = proxy.ParseUpstreamsConfig(
upstreams,
&upstream.Options{
Bootstrap: bootstrap,
Timeout: config.DNS.UpstreamTimeout.Duration,
HTTPVersions: dnsforward.UpstreamHTTPVersions(config.DNS.UseHTTP3Upstreams),
PreferIPv6: config.DNS.BootstrapPreferIPv6,
},
)
if err != nil {
// Don't wrap the error since it's informative enough as is.
return nil, err
}
conf = proxy.NewCustomUpstreamConfig(
upsConf,
c.UpstreamsCacheEnabled,
int(c.UpstreamsCacheSize),
config.DNS.EDNSClientSubnet.Enabled,
)
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.Persistent, ok bool) {
c, ok = clients.storage.Find(id)
if ok {
return c, true
}
ip, err := netip.ParseAddr(id)
if err != nil {
return nil, false
}
// TODO(e.burkov): Iterate through clients.list only once.
return clients.findDHCP(ip)
}
// 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.Persistent, ok bool) {
foundMAC := clients.dhcp.MACByIP(ip)
if foundMAC == nil {
return nil, false
}
return clients.storage.FindByMAC(foundMAC)
}
// runtimeClient returns a runtime client from internal index. Note that it
// doesn't include DHCP clients.
func (clients *clientsContainer) runtimeClient(ip netip.Addr) (rc *client.Runtime) {
if ip == (netip.Addr{}) {
return nil
}
clients.lock.Lock()
defer clients.lock.Unlock()
return clients.runtimeIndex.Client(ip)
}
// findRuntimeClient finds a runtime client by their IP.
func (clients *clientsContainer) findRuntimeClient(ip netip.Addr) (rc *client.Runtime) {
rc = clients.runtimeClient(ip)
host := clients.dhcp.HostByIP(ip)
if host != "" {
if rc == nil {
rc = client.NewRuntime(ip)
}
rc.SetInfo(client.SourceDHCP, []string{host})
return rc
}
return rc
}
// setWHOISInfo sets the WHOIS information for a client. clients.lock is
// expected to be locked.
func (clients *clientsContainer) setWHOISInfo(ip netip.Addr, wi *whois.Info) {
_, ok := clients.findLocked(ip.String())
if ok {
log.Debug("clients: client for %s is already created, ignore whois info", ip)
return
}
rc := clients.runtimeIndex.Client(ip)
if rc == nil {
// Create a RuntimeClient implicitly so that we don't do this check
// again.
rc = client.NewRuntime(ip)
clients.runtimeIndex.Add(rc)
log.Debug("clients: set whois info for runtime client with ip %s: %+v", ip, wi)
} else {
host, _ := rc.Info()
log.Debug("clients: set whois info for runtime client %s: %+v", host, wi)
}
rc.SetWHOIS(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.
//
// TODO(a.garipov): Only used in internal tests. Consider removing.
func (clients *clientsContainer) addHost(
ip netip.Addr,
host string,
src client.Source,
) (ok bool) {
clients.lock.Lock()
defer clients.lock.Unlock()
return clients.addHostLocked(ip, host, src)
}
// type check
var _ client.AddressUpdater = (*clientsContainer)(nil)
// UpdateAddress implements the [client.AddressUpdater] interface for
// *clientsContainer
func (clients *clientsContainer) UpdateAddress(ip netip.Addr, host string, info *whois.Info) {
// Common fast path optimization.
if host == "" && info == nil {
return
}
clients.lock.Lock()
defer clients.lock.Unlock()
if host != "" {
ok := clients.addHostLocked(ip, host, client.SourceRDNS)
if !ok {
log.Debug("clients: host for client %q already set with higher priority source", ip)
}
}
if info != nil {
clients.setWHOISInfo(ip, info)
}
}
// addHostLocked adds a new IP-hostname pairing. clients.lock is expected to be
// locked.
func (clients *clientsContainer) addHostLocked(
ip netip.Addr,
host string,
src client.Source,
) (ok bool) {
rc := clients.runtimeIndex.Client(ip)
if rc == nil {
if src < client.SourceDHCP {
if clients.dhcp.HostByIP(ip) != "" {
return false
}
}
rc = client.NewRuntime(ip)
clients.runtimeIndex.Add(rc)
}
rc.SetInfo(src, []string{host})
log.Debug(
"clients: adding client info %s -> %q %q [%d]",
ip,
src,
host,
clients.runtimeIndex.Size(),
)
return true
}
// addFromHostsFile fills the client-hostname pairing index from the system's
// hosts files.
func (clients *clientsContainer) addFromHostsFile(hosts *hostsfile.DefaultStorage) {
clients.lock.Lock()
defer clients.lock.Unlock()
deleted := clients.runtimeIndex.DeleteBySource(client.SourceHostsFile)
log.Debug("clients: removed %d client aliases from system hosts file", deleted)
added := 0
hosts.RangeNames(func(addr netip.Addr, names []string) (cont bool) {
// Only the first name of the first record is considered a canonical
// hostname for the IP address.
//
// TODO(e.burkov): Consider using all the names from all the records.
if clients.addHostLocked(addr, names[0], client.SourceHostsFile) {
added++
}
return true
})
log.Debug("clients: added %d client aliases from system hosts file", added)
}
// 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 = arpdb.Empty{}
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()
deleted := clients.runtimeIndex.DeleteBySource(client.SourceARP)
log.Debug("clients: removed %d client aliases from arp neighborhood", deleted)
added := 0
for _, n := range ns {
if clients.addHostLocked(n.IP, n.Name, client.SourceARP) {
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) {
return clients.storage.CloseUpstreams()
}