package home import ( "bytes" "fmt" "net" "os/exec" "runtime" "sort" "strings" "sync" "time" "github.com/AdguardTeam/AdGuardHome/internal/agherr" "github.com/AdguardTeam/AdGuardHome/internal/dhcpd" "github.com/AdguardTeam/AdGuardHome/internal/dnsfilter" "github.com/AdguardTeam/AdGuardHome/internal/dnsforward" "github.com/AdguardTeam/AdGuardHome/internal/querylog" "github.com/AdguardTeam/AdGuardHome/internal/util" "github.com/AdguardTeam/dnsproxy/proxy" "github.com/AdguardTeam/dnsproxy/upstream" "github.com/AdguardTeam/golibs/log" "github.com/AdguardTeam/golibs/utils" ) const clientsUpdatePeriod = 10 * time.Minute var webHandlersRegistered = false // Client contains information about persistent clients. type Client struct { IDs []string Tags []string Name string UseOwnSettings bool // false: use global settings FilteringEnabled bool SafeSearchEnabled bool SafeBrowsingEnabled bool ParentalEnabled bool UseOwnBlockedServices bool // false: use global settings BlockedServices []string Upstreams []string // list of upstream servers to be used for the client's requests // Custom upstream config for this client // nil: not yet initialized // not nil, but empty: initialized, no good upstreams // not nil, not empty: Upstreams ready to be used upstreamConfig *proxy.UpstreamConfig } type clientSource uint // Client sources. The order determines the priority. const ( ClientSourceWHOIS clientSource = iota ClientSourceRDNS ClientSourceDHCP ClientSourceARP ClientSourceHostsFile ) // RuntimeClient information type RuntimeClient struct { Host string Source clientSource WhoisInfo *RuntimeClientWhoisInfo } // 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 map[string]*RuntimeClient // IP -> runtime client lock sync.Mutex allTags map[string]bool // 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 autoHosts *util.AutoHosts // get entries from system hosts-files 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, autoHosts *util.AutoHosts) { if clients.list != nil { log.Fatal("clients.list != nil") } clients.list = make(map[string]*Client) clients.idIndex = make(map[string]*Client) clients.ipToRC = make(map[string]*RuntimeClient) clients.allTags = make(map[string]bool) for _, t := range clientTags { clients.allTags[t] = false } clients.dhcpServer = dhcpServer clients.autoHosts = autoHosts clients.addFromConfig(objects) if !clients.testing { clients.addFromDHCP() if clients.dhcpServer != nil { clients.dhcpServer.SetOnLeaseChanged(clients.onDHCPLeaseChanged) } clients.autoHosts.SetOnChanged(clients.onHostsChanged) } } // 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() { clients.addFromSystemARP() } type clientObject struct { Name string `yaml:"name"` Tags []string `yaml:"tags"` IDs []string `yaml:"ids"` 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"` BlockedServices []string `yaml:"blocked_services"` Upstreams []string `yaml:"upstreams"` } func (clients *clientsContainer) tagKnown(tag string) bool { _, ok := clients.allTags[tag] return ok } func (clients *clientsContainer) addFromConfig(objects []clientObject) { for _, cy := range objects { cli := &Client{ Name: cy.Name, IDs: cy.IDs, UseOwnSettings: !cy.UseGlobalSettings, FilteringEnabled: cy.FilteringEnabled, ParentalEnabled: cy.ParentalEnabled, SafeSearchEnabled: cy.SafeSearchEnabled, SafeBrowsingEnabled: cy.SafeBrowsingEnabled, UseOwnBlockedServices: !cy.UseGlobalBlockedServices, Upstreams: cy.Upstreams, } for _, s := range cy.BlockedServices { if !dnsfilter.BlockedSvcKnown(s) { log.Debug("clients: skipping unknown blocked-service %q", s) continue } cli.BlockedServices = append(cli.BlockedServices, s) } for _, t := range cy.Tags { if !clients.tagKnown(t) { log.Debug("clients: skipping unknown tag %q", t) continue } cli.Tags = append(cli.Tags, t) } sort.Strings(cli.Tags) _, err := clients.Add(cli) if err != nil { log.Tracef("clientAdd: %s", err) } } } // WriteDiskConfig - write configuration func (clients *clientsContainer) WriteDiskConfig(objects *[]clientObject) { clients.lock.Lock() for _, cli := range clients.list { cy := clientObject{ Name: cli.Name, UseGlobalSettings: !cli.UseOwnSettings, FilteringEnabled: cli.FilteringEnabled, ParentalEnabled: cli.ParentalEnabled, SafeSearchEnabled: cli.SafeSearchEnabled, SafeBrowsingEnabled: cli.SafeBrowsingEnabled, UseGlobalBlockedServices: !cli.UseOwnBlockedServices, } cy.Tags = copyStrings(cli.Tags) cy.IDs = copyStrings(cli.IDs) cy.BlockedServices = copyStrings(cli.BlockedServices) cy.Upstreams = copyStrings(cli.Upstreams) *objects = append(*objects, cy) } clients.lock.Unlock() } func (clients *clientsContainer) periodicUpdate() { for { clients.Reload() time.Sleep(clientsUpdatePeriod) } } func (clients *clientsContainer) onDHCPLeaseChanged(flags int) { switch flags { case dhcpd.LeaseChangedAdded, dhcpd.LeaseChangedAddedStatic, dhcpd.LeaseChangedRemovedStatic: clients.addFromDHCP() } } func (clients *clientsContainer) onHostsChanged() { clients.addFromHostsFile() } // Exists checks if client with this ID already exists. func (clients *clientsContainer) Exists(id string, source clientSource) (ok bool) { clients.lock.Lock() defer clients.lock.Unlock() _, ok = clients.findLocked(id) if ok { return true } var rc *RuntimeClient rc, ok = clients.ipToRC[id] if !ok { return false } // Return false if the new source has higher priority. return source <= rc.Source } func copyStrings(a []string) (b []string) { return append(b, a...) } 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. err is always nil. func (clients *clientsContainer) findMultiple(ids []string) (c *querylog.Client, err error) { for _, id := range ids { var name string var foundIDs []string whois := &querylog.ClientWhois{} c, ok := clients.Find(id) if ok { name = c.Name foundIDs = c.IDs } else { var rc RuntimeClient rc, ok = clients.FindRuntimeClient(id) if !ok { continue } foundIDs = []string{rc.Host} whois = toQueryLogWhois(rc.WhoisInfo) } ip := net.ParseIP(id) disallowed, disallowedRule := clients.dnsServer.IsBlockedIP(ip) return &querylog.Client{ Name: name, DisallowedRule: disallowedRule, Whois: whois, IDs: foundIDs, Disallowed: disallowed, }, nil } return nil, nil } 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 = copyStrings(c.IDs) c.Tags = copyStrings(c.Tags) c.BlockedServices = copyStrings(c.BlockedServices) c.Upstreams = copyStrings(c.Upstreams) return c, true } // FindUpstreams looks for upstreams configured for the client // If no client found for this IP, or if no custom upstreams are configured, // this method returns nil func (clients *clientsContainer) FindUpstreams(ip string) *proxy.UpstreamConfig { clients.lock.Lock() defer clients.lock.Unlock() c, ok := clients.findLocked(ip) if !ok { return nil } if len(c.Upstreams) == 0 { return nil } if c.upstreamConfig == nil { conf, err := proxy.ParseUpstreamsConfig( c.Upstreams, upstream.Options{ Bootstrap: config.DNS.BootstrapDNS, Timeout: dnsforward.DefaultTimeout, }, ) if err == nil { c.upstreamConfig = &conf } } return c.upstreamConfig } // 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 } // FindRuntimeClient finds a runtime client by their IP. func (clients *clientsContainer) FindRuntimeClient(ip string) (RuntimeClient, bool) { ipAddr := net.ParseIP(ip) if ipAddr == nil { return RuntimeClient{}, false } clients.lock.Lock() defer clients.lock.Unlock() rc, ok := clients.ipToRC[ip] if ok { return *rc, true } return RuntimeClient{}, false } // check validates the client. func (clients *clientsContainer) check(c *Client) (err error) { switch { case c == nil: return agherr.Error("client is nil") case c.Name == "": return agherr.Error("invalid name") case len(c.IDs) == 0: return agherr.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] = id } else { return fmt.Errorf("invalid client id at index %d: %q", i, id) } } for _, t := range c.Tags { if !clients.tagKnown(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 agherr.Error("client not found") } // First, check the name index. if prev.Name != c.Name { _, ok = clients.list[c.Name] if ok { return agherr.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 string, wi *RuntimeClientWhoisInfo) { clients.lock.Lock() defer clients.lock.Unlock() _, ok := clients.findLocked(ip) if ok { log.Debug("clients: client for %s is already created, ignore whois info", ip) return } rc, ok := clients.ipToRC[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[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 is // taken into account. ok is true if the pairing was added. func (clients *clientsContainer) AddHost(ip, host string, src clientSource) (ok bool, err error) { clients.lock.Lock() defer clients.lock.Unlock() ok = clients.addHostLocked(ip, host, src) return ok, nil } // addHostLocked adds a new IP-hostname pairing. For internal use only. func (clients *clientsContainer) addHostLocked(ip, host string, src clientSource) (ok bool) { var rc *RuntimeClient rc, ok = clients.ipToRC[ip] if ok { if rc.Source > src { return false } rc.Source = src } else { rc = &RuntimeClient{ Host: host, Source: src, WhoisInfo: &RuntimeClientWhoisInfo{}, } clients.ipToRC[ip] = rc } log.Debug("clients: added %q -> %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 k, v := range clients.ipToRC { if v.Source == src { delete(clients.ipToRC, k) 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 := clients.autoHosts.List() clients.lock.Lock() defer clients.lock.Unlock() clients.rmHostsBySrc(ClientSourceHostsFile) n := 0 for ip, names := range hosts { for _, name := range names { ok := clients.addHostLocked(ip, name, ClientSourceHostsFile) if ok { 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 runtime.GOOS == "windows" { return } cmd := exec.Command("arp", "-a") log.Tracef("executing %q %q", cmd.Path, cmd.Args) data, err := cmd.Output() if err != nil || cmd.ProcessState.ExitCode() != 0 { log.Debug("command %q has failed: %q code:%d", cmd.Path, err, cmd.ProcessState.ExitCode()) return } clients.lock.Lock() defer clients.lock.Unlock() clients.rmHostsBySrc(ClientSourceARP) n := 0 // TODO(a.garipov): Rewrite to use bufio.Scanner. lines := strings.Split(string(data), "\n") for _, ln := range lines { open := strings.Index(ln, " (") close := strings.Index(ln, ") ") if open == -1 || close == -1 || open >= close { continue } host := ln[:open] ip := ln[open+2 : close] if utils.IsValidHostname(host) != nil || net.ParseIP(ip) == nil { continue } ok := clients.addHostLocked(ip, host, ClientSourceARP) if ok { n++ } } log.Debug("clients: added %d client aliases from 'arp -a' command output", n) } // addFromDHCP adds the clients that have a non-empty hostname from the DHCP // server. func (clients *clientsContainer) addFromDHCP() { if clients.dhcpServer == nil { return } clients.lock.Lock() defer clients.lock.Unlock() clients.rmHostsBySrc(ClientSourceDHCP) leases := clients.dhcpServer.Leases(dhcpd.LeasesAll) n := 0 for _, l := range leases { if l.Hostname == "" { continue } ok := clients.addHostLocked(l.IP.String(), l.Hostname, ClientSourceDHCP) if ok { n++ } } log.Debug("clients: added %d client aliases from dhcp", n) }