package home import ( "bytes" "fmt" "net" "sort" "strings" "sync" "time" "github.com/AdguardTeam/AdGuardHome/internal/aghnet" "github.com/AdguardTeam/AdGuardHome/internal/dhcpd" "github.com/AdguardTeam/AdGuardHome/internal/dnsforward" "github.com/AdguardTeam/AdGuardHome/internal/filtering" "github.com/AdguardTeam/AdGuardHome/internal/querylog" "github.com/AdguardTeam/dnsproxy/proxy" "github.com/AdguardTeam/dnsproxy/upstream" "github.com/AdguardTeam/golibs/errors" "github.com/AdguardTeam/golibs/log" "github.com/AdguardTeam/golibs/netutil" "github.com/AdguardTeam/golibs/stringutil" ) const clientsUpdatePeriod = 10 * time.Minute var webHandlersRegistered = false // Client contains information about persistent clients. type Client struct { // upstreamConfig is the custom upstream config for this client. If // it's nil, it has not been initialized yet. If it's non-nil and // empty, there are no valid upstreams. If it's non-nil and non-empty, // these upstream must be used. upstreamConfig *proxy.UpstreamConfig Name string IDs []string Tags []string BlockedServices []string Upstreams []string UseOwnSettings bool FilteringEnabled bool SafeSearchEnabled bool SafeBrowsingEnabled bool ParentalEnabled bool UseOwnBlockedServices bool } type clientSource uint // Client sources. The order determines the priority. const ( ClientSourceWHOIS clientSource = iota ClientSourceARP ClientSourceRDNS ClientSourceDHCP ClientSourceHostsFile ) // clientSourceConf is used to configure where the runtime clients will be // obtained from. type clientSourcesConf struct { WHOIS bool `yaml:"whois"` ARP bool `yaml:"arp"` RDNS bool `yaml:"rdns"` DHCP bool `yaml:"dhcp"` HostsFile bool `yaml:"hosts"` } // RuntimeClient information type RuntimeClient struct { WHOISInfo *RuntimeClientWHOISInfo Host string Source clientSource } // RuntimeClientWHOISInfo is the filtered WHOIS data for a runtime client. type RuntimeClientWHOISInfo struct { City string `json:"city,omitempty"` Country string `json:"country,omitempty"` Orgname string `json:"orgname,omitempty"` } type clientsContainer struct { // TODO(a.garipov): Perhaps use a number of separate indices for // different types (string, net.IP, and so on). list map[string]*Client // name -> client idIndex map[string]*Client // ID -> client // ipToRC is the IP address to *RuntimeClient map. ipToRC *netutil.IPMap lock sync.Mutex allTags *stringutil.Set // dhcpServer is used for looking up clients IP addresses by MAC addresses dhcpServer *dhcpd.Server // 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 testing bool // if TRUE, this object is used for internal tests } // Init initializes clients container // dhcpServer: optional // Note: this function must be called only once func (clients *clientsContainer) Init( objects []*clientObject, dhcpServer *dhcpd.Server, etcHosts *aghnet.HostsContainer, arpdb aghnet.ARPDB, ) { if clients.list != nil { log.Fatal("clients.list != nil") } clients.list = make(map[string]*Client) clients.idIndex = make(map[string]*Client) clients.ipToRC = netutil.NewIPMap(0) clients.allTags = stringutil.NewSet(clientTags...) clients.dhcpServer = dhcpServer clients.etcHosts = etcHosts clients.arpdb = arpdb clients.addFromConfig(objects) if clients.testing { return } clients.updateFromDHCP(true) if clients.dhcpServer != nil { clients.dhcpServer.SetOnLeaseChanged(clients.onDHCPLeaseChanged) } if clients.etcHosts != nil { go clients.handleHostsUpdates() } } func (clients *clientsContainer) handleHostsUpdates() { for upd := range clients.etcHosts.Upd() { clients.addFromHostsFile(upd) } } // Start - start the module func (clients *clientsContainer) Start() { if !clients.testing { if !webHandlersRegistered { webHandlersRegistered = true clients.registerWebHandlers() } go clients.periodicUpdate() } } // Reload reloads runtime clients. func (clients *clientsContainer) Reload() { if clients.arpdb != nil { clients.addFromSystemARP() } } type clientObject struct { Name string `yaml:"name"` Tags []string `yaml:"tags"` IDs []string `yaml:"ids"` BlockedServices []string `yaml:"blocked_services"` Upstreams []string `yaml:"upstreams"` UseGlobalSettings bool `yaml:"use_global_settings"` FilteringEnabled bool `yaml:"filtering_enabled"` ParentalEnabled bool `yaml:"parental_enabled"` SafeSearchEnabled bool `yaml:"safesearch_enabled"` SafeBrowsingEnabled bool `yaml:"safebrowsing_enabled"` UseGlobalBlockedServices bool `yaml:"use_global_blocked_services"` } // addFromConfig initializes the clients container with objects from the // configuration file. func (clients *clientsContainer) addFromConfig(objects []*clientObject) { for _, o := range objects { cli := &Client{ Name: o.Name, IDs: o.IDs, Upstreams: o.Upstreams, UseOwnSettings: !o.UseGlobalSettings, FilteringEnabled: o.FilteringEnabled, ParentalEnabled: o.ParentalEnabled, SafeSearchEnabled: o.SafeSearchEnabled, SafeBrowsingEnabled: o.SafeBrowsingEnabled, UseOwnBlockedServices: !o.UseGlobalBlockedServices, } for _, s := range o.BlockedServices { if filtering.BlockedSvcKnown(s) { cli.BlockedServices = append(cli.BlockedServices, s) } else { log.Info("clients: skipping unknown blocked service %q", s) } } 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) } } sort.Strings(cli.Tags) _, err := clients.Add(cli) if err != nil { log.Error("clients: adding clients %s: %s", cli.Name, err) } } } // 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, Tags: stringutil.CloneSlice(cli.Tags), IDs: stringutil.CloneSlice(cli.IDs), BlockedServices: stringutil.CloneSlice(cli.BlockedServices), Upstreams: stringutil.CloneSlice(cli.Upstreams), UseGlobalSettings: !cli.UseOwnSettings, FilteringEnabled: cli.FilteringEnabled, ParentalEnabled: cli.ParentalEnabled, SafeSearchEnabled: cli.SafeSearchEnabled, SafeBrowsingEnabled: cli.SafeBrowsingEnabled, UseGlobalBlockedServices: !cli.UseOwnBlockedServices, } 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. sort.Slice(objs, func(i, j int) bool { return objs[i].Name < objs[j].Name }) return objs } func (clients *clientsContainer) periodicUpdate() { defer log.OnPanic("clients container") for { clients.Reload() time.Sleep(clientsUpdatePeriod) } } func (clients *clientsContainer) onDHCPLeaseChanged(flags int) { switch flags { case dhcpd.LeaseChangedAdded, dhcpd.LeaseChangedAddedStatic, dhcpd.LeaseChangedRemovedStatic: clients.updateFromDHCP(true) case dhcpd.LeaseChangedRemovedAll: clients.updateFromDHCP(false) } } // Exists checks if client with this IP address already exists. func (clients *clientsContainer) Exists(ip net.IP, source clientSource) (ok bool) { clients.lock.Lock() defer clients.lock.Unlock() _, ok = clients.findLocked(ip.String()) if ok { return true } rc, ok := clients.findRuntimeClientLocked(ip) if !ok { return false } // Return false if the new source has higher priority. return source <= rc.Source } func toQueryLogWHOIS(wi *RuntimeClientWHOISInfo) (cw *querylog.ClientWHOIS) { if wi == nil { return &querylog.ClientWHOIS{} } return &querylog.ClientWHOIS{ City: wi.City, Country: wi.Country, Orgname: wi.Orgname, } } // 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 { c, art = clients.clientOrArtificial(net.ParseIP(id), 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 net.IP, id string, ) (c *querylog.Client, art bool) { defer func() { c.Disallowed, c.DisallowedRule = clients.dnsServer.IsBlockedClient(ip, id) if c.WHOIS == nil { c.WHOIS = &querylog.ClientWHOIS{} } }() client, ok := clients.Find(id) if ok { return &querylog.Client{ Name: client.Name, }, false } if ip == nil { // Technically should never happen, but still. return &querylog.Client{ Name: "", }, true } var rc *RuntimeClient rc, ok = clients.FindRuntimeClient(ip) if ok { return &querylog.Client{ Name: rc.Host, WHOIS: toQueryLogWHOIS(rc.WHOISInfo), }, false } return &querylog.Client{ Name: "", }, true } 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 } c.IDs = stringutil.CloneSlice(c.IDs) c.Tags = stringutil.CloneSlice(c.Tags) c.BlockedServices = stringutil.CloneSlice(c.BlockedServices) c.Upstreams = stringutil.CloneSlice(c.Upstreams) return c, 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, }, ) if err != nil { return nil, err } c.upstreamConfig = conf return conf, nil } // findLocked searches for a client by its ID. For internal use only. func (clients *clientsContainer) findLocked(id string) (c *Client, ok bool) { c, ok = clients.idIndex[id] if ok { return c, true } ip := net.ParseIP(id) if ip == nil { return nil, false } for _, c = range clients.list { for _, id := range c.IDs { _, ipnet, err := net.ParseCIDR(id) if err != nil { continue } if ipnet.Contains(ip) { return c, true } } } if clients.dhcpServer == nil { return nil, false } macFound := clients.dhcpServer.FindMACbyIP(ip) if macFound == nil { return nil, false } for _, c = range clients.list { for _, id := range c.IDs { hwAddr, err := net.ParseMAC(id) if err != nil { continue } if bytes.Equal(hwAddr, macFound) { return c, true } } } return nil, false } // findRuntimeClientLocked finds a runtime client by their IP address. For // internal use only. func (clients *clientsContainer) findRuntimeClientLocked(ip net.IP) (rc *RuntimeClient, ok bool) { var v interface{} v, ok = clients.ipToRC.Get(ip) if !ok { return nil, false } rc, ok = v.(*RuntimeClient) if !ok { log.Error("clients: bad type %T in ipToRC for %s", v, ip) return nil, false } return rc, true } // FindRuntimeClient finds a runtime client by their IP. func (clients *clientsContainer) FindRuntimeClient(ip net.IP) (rc *RuntimeClient, ok bool) { if ip == nil { return nil, false } clients.lock.Lock() defer clients.lock.Unlock() return clients.findRuntimeClientLocked(ip) } // 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 { // Normalize structured data. var ip net.IP var ipnet *net.IPNet var mac net.HardwareAddr if ip = net.ParseIP(id); ip != nil { c.IDs[i] = ip.String() } else if ip, ipnet, err = net.ParseCIDR(id); err == nil { ipnet.IP = ip c.IDs[i] = ipnet.String() } else if mac, err = net.ParseMAC(id); err == nil { c.IDs[i] = mac.String() } else if err = dnsforward.ValidateClientID(id); err == nil { c.IDs[i] = strings.ToLower(id) } else { return fmt.Errorf("invalid clientid at index %d: %q", i, id) } } for _, t := range c.Tags { if !clients.allTags.Has(t) { return fmt.Errorf("invalid tag: %q", t) } } sort.Strings(c.Tags) err = dnsforward.ValidateUpstreams(c.Upstreams) 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 *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) } } // update Name index clients.list[c.Name] = c // update ID index for _, id := range c.IDs { clients.idIndex[id] = c } log.Debug("clients: added %q: ID:%q [%d]", c.Name, c.IDs, len(clients.list)) return true, nil } // 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 } // update Name index delete(clients.list, name) // update ID index for _, id := range c.IDs { delete(clients.idIndex, id) } return true } // equalStringSlices returns true if the slices are equal. func equalStringSlices(a, b []string) (ok bool) { if len(a) != len(b) { return false } for i := range a { if a[i] != b[i] { return false } } return true } // Update updates a client by its name. func (clients *clientsContainer) Update(name string, c *Client) (err error) { err = clients.check(c) if err != nil { return err } clients.lock.Lock() defer clients.lock.Unlock() prev, ok := clients.list[name] if !ok { return errors.Error("client not found") } // First, check the name index. if prev.Name != c.Name { _, ok = clients.list[c.Name] if ok { return errors.Error("client already exists") } } // Second, check the IP index. if !equalStringSlices(prev.IDs, c.IDs) { for _, id := range c.IDs { c2, ok2 := clients.idIndex[id] if ok2 && c2 != prev { return fmt.Errorf("another client uses the same id (%q): %q", id, c2.Name) } } // update ID index for _, id := range prev.IDs { delete(clients.idIndex, id) } for _, id := range c.IDs { clients.idIndex[id] = prev } } // update Name index if prev.Name != c.Name { delete(clients.list, prev.Name) clients.list[c.Name] = prev } // update upstreams cache c.upstreamConfig = nil *prev = *c return nil } // SetWHOISInfo sets the WHOIS information for a client. func (clients *clientsContainer) SetWHOISInfo(ip net.IP, wi *RuntimeClientWHOISInfo) { 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 } rc, ok := clients.findRuntimeClientLocked(ip) if ok { rc.WHOISInfo = wi log.Debug("clients: set whois info for runtime client %s: %+v", rc.Host, wi) return } // Create a RuntimeClient implicitly so that we don't do this check // again. rc = &RuntimeClient{ Source: ClientSourceWHOIS, } rc.WHOISInfo = wi clients.ipToRC.Set(ip, rc) log.Debug("clients: set whois info for runtime client with ip %s: %+v", ip, 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 net.IP, host string, src clientSource) (ok bool, err error) { clients.lock.Lock() defer clients.lock.Unlock() return clients.addHostLocked(ip, host, src), nil } // addHostLocked adds a new IP-hostname pairing. For internal use only. func (clients *clientsContainer) addHostLocked(ip net.IP, host string, src clientSource) (ok bool) { rc, ok := clients.findRuntimeClientLocked(ip) if ok { if rc.Source > src { return false } rc.Host = host rc.Source = src } else { rc = &RuntimeClient{ Host: host, Source: src, WHOISInfo: &RuntimeClientWHOISInfo{}, } clients.ipToRC.Set(ip, rc) } log.Debug("clients: added %s -> %q [%d]", ip, host, clients.ipToRC.Len()) return true } // rmHostsBySrc removes all entries that match the specified source. func (clients *clientsContainer) rmHostsBySrc(src clientSource) { n := 0 clients.ipToRC.Range(func(ip net.IP, v interface{}) (cont bool) { rc, ok := v.(*RuntimeClient) if !ok { log.Error("clients: bad type %T in ipToRC for %s", v, ip) return true } if rc.Source == src { clients.ipToRC.Del(ip) n++ } return true }) 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 *netutil.IPMap) { clients.lock.Lock() defer clients.lock.Unlock() clients.rmHostsBySrc(ClientSourceHostsFile) n := 0 hosts.Range(func(ip net.IP, v interface{}) (cont bool) { rec, ok := v.(*aghnet.HostsRecord) if !ok { log.Error("dns: bad type %T in ipToRC for %s", v, ip) return true } clients.addHostLocked(ip, rec.Canonical, ClientSourceHostsFile) 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 = 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) } // updateFromDHCP adds the clients that have a non-empty hostname from the DHCP // server. func (clients *clientsContainer) updateFromDHCP(add bool) { if clients.dhcpServer == nil || !config.Clients.Sources.DHCP { return } clients.lock.Lock() defer clients.lock.Unlock() clients.rmHostsBySrc(ClientSourceDHCP) if !add { 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) }