package home import ( "fmt" "net" "net/netip" "slices" "strings" "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/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" "golang.org/x/exp/maps" ) // 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 { // TODO(a.garipov): Perhaps use a number of separate indices for different // types (string, netip.Addr, and so on). list map[string]*persistentClient // name -> client clientIndex *clientIndex // ipToRC maps IP addresses to runtime client information. ipToRC map[netip.Addr]*client.Runtime allTags *stringutil.Set // dhcp is the DHCP service implementation. dhcp DHCP // 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 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 } // 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) { if clients.list != nil { log.Fatal("clients.list != nil") } clients.list = map[string]*persistentClient{} clients.ipToRC = map[netip.Addr]*client.Runtime{} clients.clientIndex = NewClientIndex() clients.allTags = stringutil.NewSet(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 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, allTags *stringutil.Set, ) (cli *persistentClient, err error) { cli = &persistentClient{ 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 == UID{}) { cli.UID, err = NewUID() if err != nil { return nil, fmt.Errorf("generating uid: %w", err) } } if o.SafeSearchConf.Enabled { o.SafeSearchConf.CustomResolver = safeSearchResolver{} 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) } } 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.setTags(o.Tags, allTags) 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 *persistentClient cli, err = o.toPersistent(filteringConf, clients.allTags) if err != nil { return fmt.Errorf("clients: init persistent client at index %d: %w", i, err) } _, err = clients.add(cli) if err != nil { log.Error("clients: adding client at index %d %s: %s", i, 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: cli.ids(), Tags: stringutil.CloneSlice(cli.Tags), Upstreams: stringutil.CloneSlice(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, } 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) (res int) { return strings.Compare(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) } } // 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. 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, ok := clients.ipToRC[ip] if ok { 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.dnsServer.IsBlockedClient(ip, id) if c.WHOIS == nil { c.WHOIS = &whois.Info{} } }() cli, ok := clients.find(id) if ok { return &querylog.Client{ Name: cli.Name, IgnoreQueryLog: cli.IgnoreQueryLog, }, false } var rc *client.Runtime rc, ok = clients.findRuntimeClient(ip) if ok { _, 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 *persistentClient, 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 [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 *persistentClient, ok bool) { c, ok = clients.clientIndex.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 *persistentClient, ok bool) { foundMAC := clients.dhcp.MACByIP(ip) if foundMAC == nil { return nil, false } for _, c = range clients.list { _, found := slices.BinarySearchFunc(c.MACs, foundMAC, slices.Compare[net.HardwareAddr]) if found { return c, true } } return nil, false } // 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, ok bool) { if ip == (netip.Addr{}) { return nil, false } clients.lock.Lock() defer clients.lock.Unlock() rc, ok = clients.ipToRC[ip] return rc, ok } // findRuntimeClient finds a runtime client by their IP. func (clients *clientsContainer) findRuntimeClient(ip netip.Addr) (rc *client.Runtime, ok bool) { rc, ok = clients.runtimeClient(ip) host := clients.dhcp.HostByIP(ip) if host != "" { if !ok { rc = &client.Runtime{} } rc.SetInfo(client.SourceDHCP, []string{host}) return rc, true } return rc, ok } // check validates the client. It also sorts the client tags. func (clients *clientsContainer) check(c *persistentClient) (err error) { switch { case c == nil: return errors.Error("client is nil") case c.Name == "": return errors.Error("invalid name") case c.idsLen() == 0: return errors.Error("id required") default: // Go on. } for _, t := range c.Tags { if !clients.allTags.Has(t) { return fmt.Errorf("invalid tag: %q", t) } } // TODO(s.chzhen): Move to the constructor. slices.Sort(c.Tags) _, err = proxy.ParseUpstreamsConfig(c.Upstreams, &upstream.Options{}) if err != nil { return fmt.Errorf("invalid upstream servers: %w", err) } return nil } // add adds a new client object. ok is false if such client already exists or // if an error occurred. func (clients *clientsContainer) add(c *persistentClient) (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 err = clients.clientIndex.clashes(c) if err != nil { // Don't wrap the error since it's informative enough as is. return false, err } clients.addLocked(c) log.Debug("clients: added %q: ID:%q [%d]", c.Name, c.ids(), len(clients.list)) return true, nil } // addLocked c to the indexes. clients.lock is expected to be locked. func (clients *clientsContainer) addLocked(c *persistentClient) { // update Name index clients.list[c.Name] = c // update ID index clients.clientIndex.add(c) } // remove removes a client. ok is false if there is no such client. func (clients *clientsContainer) remove(name string) (ok bool) { clients.lock.Lock() defer clients.lock.Unlock() var c *persistentClient c, ok = clients.list[name] if !ok { return false } clients.removeLocked(c) return true } // removeLocked removes c from the indexes. clients.lock is expected to be // locked. func (clients *clientsContainer) removeLocked(c *persistentClient) { if err := c.closeUpstreams(); err != nil { log.Error("client container: removing client %s: %s", c.Name, err) } // Update the name index. delete(clients.list, c.Name) // Update the ID index. clients.clientIndex.del(c) } // update updates a client by its name. func (clients *clientsContainer) update(prev, c *persistentClient) (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") } } if c.equalIDs(prev) { clients.removeLocked(prev) clients.addLocked(c) return nil } // Check the ID index. err = clients.clientIndex.clashes(c) if err != nil { // Don't wrap the error since it's informative enough as is. return err } clients.removeLocked(prev) clients.addLocked(c) return nil } // 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, ok := clients.ipToRC[ip] if !ok { // Create a RuntimeClient implicitly so that we don't do this check // again. rc = &client.Runtime{} clients.ipToRC[ip] = 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, ok := clients.ipToRC[ip] if !ok { if src < client.SourceDHCP { if clients.dhcp.HostByIP(ip) != "" { return false } } rc = &client.Runtime{} clients.ipToRC[ip] = rc } rc.SetInfo(src, []string{host}) log.Debug("clients: adding client info %s -> %q %q [%d]", ip, src, host, len(clients.ipToRC)) return true } // rmHostsBySrc removes all entries that match the specified source. func (clients *clientsContainer) rmHostsBySrc(src client.Source) { n := 0 for ip, rc := range clients.ipToRC { rc.Unset(src) if rc.IsEmpty() { 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 *hostsfile.DefaultStorage) { clients.lock.Lock() defer clients.lock.Unlock() clients.rmHostsBySrc(client.SourceHostsFile) n := 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) { n++ } return true }) 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 = 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() clients.rmHostsBySrc(client.SourceARP) 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) { persistent := maps.Values(clients.list) slices.SortFunc(persistent, func(a, b *persistentClient) (res int) { return strings.Compare(a.Name, b.Name) }) var errs []error for _, cli := range persistent { if err = cli.closeUpstreams(); err != nil { errs = append(errs, err) } } return errors.Join(errs...) }