From c3036641f04608bba39e8fe3d482b735a473b4b0 Mon Sep 17 00:00:00 2001 From: Dmitry Rozhkov Date: Mon, 23 Oct 2017 14:46:13 +0300 Subject: [PATCH] resolved: implement D-Bus API for DNS-SD --- src/libsystemd/sd-bus/bus-common-errors.h | 2 + src/resolve/meson.build | 2 + src/resolve/resolved-bus.c | 184 ++++++++++++++++++++++ src/resolve/resolved-dns-scope.c | 2 + src/resolve/resolved-dns-zone.c | 3 + src/resolve/resolved-dnssd-bus.c | 132 ++++++++++++++++ src/resolve/resolved-dnssd-bus.h | 29 ++++ src/resolve/resolved-dnssd.c | 35 ++++ src/resolve/resolved-dnssd.h | 3 + 9 files changed, 392 insertions(+) create mode 100644 src/resolve/resolved-dnssd-bus.c create mode 100644 src/resolve/resolved-dnssd-bus.h diff --git a/src/libsystemd/sd-bus/bus-common-errors.h b/src/libsystemd/sd-bus/bus-common-errors.h index 7317b174b3..42c0f528f0 100644 --- a/src/libsystemd/sd-bus/bus-common-errors.h +++ b/src/libsystemd/sd-bus/bus-common-errors.h @@ -83,6 +83,8 @@ #define BUS_ERROR_NO_SUCH_LINK "org.freedesktop.resolve1.NoSuchLink" #define BUS_ERROR_LINK_BUSY "org.freedesktop.resolve1.LinkBusy" #define BUS_ERROR_NETWORK_DOWN "org.freedesktop.resolve1.NetworkDown" +#define BUS_ERROR_NO_SUCH_DNSSD_SERVICE "org.freedesktop.resolve1.NoSuchDnssdService" +#define BUS_ERROR_DNSSD_SERVICE_EXISTS "org.freedesktop.resolve1.DnssdServiceExists" #define _BUS_ERROR_DNS "org.freedesktop.resolve1.DnsError." #define BUS_ERROR_NO_SUCH_TRANSFER "org.freedesktop.import1.NoSuchTransfer" diff --git a/src/resolve/meson.build b/src/resolve/meson.build index 2a9e9aa7f8..b01c46cf65 100644 --- a/src/resolve/meson.build +++ b/src/resolve/meson.build @@ -37,6 +37,8 @@ systemd_resolved_only_sources = files(''' resolved-manager.h resolved-dnssd.c resolved-dnssd.h + resolved-dnssd-bus.c + resolved-dnssd-bus.h resolved-conf.c resolved-conf.h resolved-resolv-conf.c diff --git a/src/resolve/resolved-bus.c b/src/resolve/resolved-bus.c index 700a7d5ee0..bcfe434e40 100644 --- a/src/resolve/resolved-bus.c +++ b/src/resolve/resolved-bus.c @@ -25,7 +25,10 @@ #include "resolved-bus.h" #include "resolved-def.h" #include "resolved-dns-synthesize.h" +#include "resolved-dnssd.h" +#include "resolved-dnssd-bus.h" #include "resolved-link-bus.h" +#include "utf8.h" static int reply_query_state(DnsQuery *q) { @@ -1581,6 +1584,177 @@ static int bus_method_reset_server_features(sd_bus_message *message, void *userd return sd_bus_reply_method_return(message, NULL); } +static int on_bus_track(sd_bus_track *t, void *userdata) { + DnssdService *s = userdata; + + assert(t); + assert(s); + + log_debug("Client of active request vanished, destroying DNS-SD service."); + dnssd_service_free(s); + + return 0; +} + +static int bus_method_register_service(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_(dnssd_service_freep) DnssdService *service = NULL; + _cleanup_(sd_bus_track_unrefp) sd_bus_track *bus_track = NULL; + _cleanup_free_ char *path = NULL; + _cleanup_free_ char *instance_name = NULL; + Manager *m = userdata; + DnssdService *s = NULL; + DnsTxtItem *last = NULL; + const char *name; + const char *name_template; + const char *type; + int r; + + assert(message); + assert(m); + + if (m->mdns_support != RESOLVE_SUPPORT_YES) + return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Support for MulticastDNS is disabled"); + + service = new0(DnssdService, 1); + if (!service) + return log_oom(); + + r = sd_bus_message_read(message, "sssqqq", &name, &name_template, &type, + &service->port, &service->priority, + &service->weight); + if (r < 0) + return r; + + s = hashmap_get(m->dnssd_services, name); + if (s) + return sd_bus_error_setf(error, BUS_ERROR_DNSSD_SERVICE_EXISTS, "DNS-SD service '%s' exists already", name); + + if (!dnssd_srv_type_is_valid(type)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "DNS-SD service type '%s' is invalid", type); + + service->name = strdup(name); + if (!service->name) + return log_oom(); + + service->name_template = strdup(name_template); + if (!service->name_template) + return log_oom(); + + service->type = strdup(type); + if (!service->type) + return log_oom(); + + r = dnssd_render_instance_name(service, &instance_name); + if (r < 0) + return r; + + r = sd_bus_message_enter_container(message, SD_BUS_TYPE_ARRAY, "{say}"); + if (r < 0) + return sd_bus_error_set_errno(error, r); + + while ((r = sd_bus_message_enter_container(message, SD_BUS_TYPE_DICT_ENTRY, "say")) > 0) { + const char *key; + const void *value; + size_t size; + DnsTxtItem *i; + + r = sd_bus_message_read(message, "s", &key); + if (r < 0) + return sd_bus_error_set_errno(error, r); + + if (strlen_ptr(key) == 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Keys in DNS-SD TXT RRs can't be empty"); + + if (!ascii_is_valid(key)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "TXT key '%s' contains non-ASCII symbols", key); + + r = sd_bus_message_read_array(message, 'y', &value, &size); + if (r < 0) + return sd_bus_error_set_errno(error, r); + + r = dnssd_txt_item_new_from_data(key, value, size, &i); + if (r < 0) + return sd_bus_error_set_errno(error, r); + + LIST_INSERT_AFTER(items, service->txt, last, i); + last = i; + } + + r = sd_bus_message_exit_container(message); + if (r < 0) + return sd_bus_error_set_errno(error, r); + + if (!service->txt) { + r = dns_txt_item_new_empty(&service->txt); + if (r < 0) + return sd_bus_error_set_errno(error, r); + } + + r = sd_bus_path_encode("/org/freedesktop/resolve1/dnssd", service->name, &path); + if (r < 0) + return r; + + r = hashmap_ensure_allocated(&m->dnssd_services, &string_hash_ops); + if (r < 0) + return r; + + r = hashmap_put(m->dnssd_services, service->name, service); + if (r < 0) + return r; + + r = sd_bus_track_new(sd_bus_message_get_bus(message), &bus_track, on_bus_track, service); + if (r < 0) + return r; + + r = sd_bus_track_add_sender(bus_track, message); + if (r < 0) + return r; + + service->manager = m; + + service = NULL; + + manager_refresh_rrs(m); + + return sd_bus_reply_method_return(message, "o", path); +} + +static int call_dnssd_method(Manager *m, sd_bus_message *message, sd_bus_message_handler_t handler, sd_bus_error *error) { + _cleanup_free_ char *name = NULL; + DnssdService *s = NULL; + const char *path; + int r; + + assert(m); + assert(message); + assert(handler); + + r = sd_bus_message_read(message, "o", &path); + if (r < 0) + return r; + + r = sd_bus_path_decode(path, "/org/freedesktop/resolve1/dnssd", &name); + if (r == 0) + return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_DNSSD_SERVICE, "DNS-SD service with object path '%s' does not exist", path); + if (r < 0) + return r; + + s = hashmap_get(m->dnssd_services, name); + if (!s) + return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_DNSSD_SERVICE, "DNS-SD service '%s' not known", name); + + return handler(message, s, error); +} + +static int bus_method_unregister_service(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Manager *m = userdata; + + assert(message); + assert(m); + + return call_dnssd_method(m, message, bus_dnssd_method_unregister, error); +} + static const sd_bus_vtable resolve_vtable[] = { SD_BUS_VTABLE_START(0), SD_BUS_PROPERTY("LLMNRHostname", "s", NULL, offsetof(Manager, llmnr_hostname), 0), @@ -1609,6 +1783,8 @@ static const sd_bus_vtable resolve_vtable[] = { SD_BUS_METHOD("SetLinkDNSSECNegativeTrustAnchors", "ias", NULL, bus_method_set_link_dnssec_negative_trust_anchors, 0), SD_BUS_METHOD("RevertLink", "i", NULL, bus_method_revert_link, 0), + SD_BUS_METHOD("RegisterService", "sssqqqa{say}", "o", bus_method_register_service, 0), + SD_BUS_METHOD("UnregisterService", "o", NULL, bus_method_unregister_service, 0), SD_BUS_VTABLE_END, }; @@ -1681,6 +1857,14 @@ int manager_connect_bus(Manager *m) { if (r < 0) return log_error_errno(r, "Failed to register link enumerator: %m"); + r = sd_bus_add_fallback_vtable(m->bus, NULL, "/org/freedesktop/resolve1/dnssd", "org.freedesktop.resolve1.DnssdService", dnssd_vtable, dnssd_object_find, m); + if (r < 0) + return log_error_errno(r, "Failed to register dnssd objects: %m"); + + r = sd_bus_add_node_enumerator(m->bus, NULL, "/org/freedesktop/resolve1/dnssd", dnssd_node_enumerator, m); + if (r < 0) + return log_error_errno(r, "Failed to register dnssd enumerator: %m"); + r = sd_bus_request_name(m->bus, "org.freedesktop.resolve1", 0); if (r < 0) return log_error_errno(r, "Failed to register name: %m"); diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c index dcef094b07..5448575d5a 100644 --- a/src/resolve/resolved-dns-scope.c +++ b/src/resolve/resolved-dns-scope.c @@ -1205,6 +1205,8 @@ int dns_scope_add_dnssd_services(DnsScope *scope) { scope->announced = false; HASHMAP_FOREACH(service, scope->manager->dnssd_services, i) { + service->withdrawn = false; + r = dns_zone_put(&scope->zone, scope, service->ptr_rr, false); if (r < 0) log_warning_errno(r, "Failed to add PTR record to MDNS zone: %m"); diff --git a/src/resolve/resolved-dns-zone.c b/src/resolve/resolved-dns-zone.c index ca92699f82..0ed7166e01 100644 --- a/src/resolve/resolved-dns-zone.c +++ b/src/resolve/resolved-dns-zone.c @@ -23,6 +23,7 @@ #include "list.h" #include "resolved-dns-packet.h" #include "resolved-dns-zone.h" +#include "resolved-dnssd.h" #include "string-util.h" /* Never allow more than 1K entries */ @@ -525,6 +526,8 @@ void dns_zone_item_conflict(DnsZoneItem *i) { /* Withdraw the conflict item */ i->state = DNS_ZONE_ITEM_WITHDRAWN; + dnssd_signal_conflict(i->scope->manager, dns_resource_key_name(i->rr->key)); + /* Maybe change the hostname */ if (manager_is_own_hostname(i->scope->manager, dns_resource_key_name(i->rr->key)) > 0) manager_next_hostname(i->scope->manager); diff --git a/src/resolve/resolved-dnssd-bus.c b/src/resolve/resolved-dnssd-bus.c new file mode 100644 index 0000000000..7a9f0bccbb --- /dev/null +++ b/src/resolve/resolved-dnssd-bus.c @@ -0,0 +1,132 @@ +/*** + This file is part of systemd. + + Copyright 2017 Dmitry Rozhkov + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see . +***/ + +#include "alloc-util.h" +#include "resolved-dnssd.h" +#include "resolved-dnssd-bus.h" +#include "resolved-link.h" +#include "strv.h" + +int bus_dnssd_method_unregister(sd_bus_message *message, void *userdata, sd_bus_error *error) { + DnssdService *s = userdata; + Manager *m; + Iterator i; + Link *l; + int r; + + assert(message); + assert(s); + + m = s->manager; + + HASHMAP_FOREACH(l, m->links, i) { + if (l->mdns_ipv4_scope) { + r = dns_scope_announce(l->mdns_ipv4_scope, true); + if (r < 0) + log_warning_errno(r, "Failed to send goodbye messages in IPv4 scope: %m"); + + dns_zone_remove_rr(&l->mdns_ipv4_scope->zone, s->ptr_rr); + dns_zone_remove_rr(&l->mdns_ipv4_scope->zone, s->srv_rr); + dns_zone_remove_rr(&l->mdns_ipv4_scope->zone, s->txt_rr); + } + + if (l->mdns_ipv6_scope) { + r = dns_scope_announce(l->mdns_ipv6_scope, true); + if (r < 0) + log_warning_errno(r, "Failed to send goodbye messages in IPv6 scope: %m"); + + dns_zone_remove_rr(&l->mdns_ipv6_scope->zone, s->ptr_rr); + dns_zone_remove_rr(&l->mdns_ipv6_scope->zone, s->srv_rr); + dns_zone_remove_rr(&l->mdns_ipv6_scope->zone, s->txt_rr); + } + } + + dnssd_service_free(s); + + manager_refresh_rrs(m); + + return sd_bus_reply_method_return(message, NULL); +} + +const sd_bus_vtable dnssd_vtable[] = { + SD_BUS_VTABLE_START(0), + + SD_BUS_METHOD("Unregister", NULL, NULL, bus_dnssd_method_unregister, 0), + SD_BUS_SIGNAL("Conflicted", NULL, 0), + + SD_BUS_VTABLE_END +}; + +int dnssd_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) { + _cleanup_free_ char *name = NULL; + Manager *m = userdata; + DnssdService *service; + int r; + + assert(bus); + assert(path); + assert(interface); + assert(found); + assert(m); + + r = sd_bus_path_decode(path, "/org/freedesktop/resolve1/dnssd", &name); + if (r <= 0) + return 0; + + service = hashmap_get(m->dnssd_services, name); + if (!service) + return 0; + + *found = service; + return 1; +} + +int dnssd_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) { + _cleanup_strv_free_ char **l = NULL; + Manager *m = userdata; + DnssdService *service; + Iterator i; + unsigned c = 0; + int r; + + assert(bus); + assert(path); + assert(m); + assert(nodes); + + l = new0(char*, hashmap_size(m->dnssd_services) + 1); + if (!l) + return -ENOMEM; + + HASHMAP_FOREACH(service, m->dnssd_services, i) { + char *p; + + r = sd_bus_path_encode("/org/freedesktop/resolve1/dnssd", service->name, &p); + if (r < 0) + return r; + + l[c++] = p; + } + + l[c] = NULL; + *nodes = l; + l = NULL; + + return 1; +} diff --git a/src/resolve/resolved-dnssd-bus.h b/src/resolve/resolved-dnssd-bus.h new file mode 100644 index 0000000000..ab915c86f9 --- /dev/null +++ b/src/resolve/resolved-dnssd-bus.h @@ -0,0 +1,29 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2017 Dmitry Rozhkov + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see . +***/ + +#include "sd-bus.h" + +extern const sd_bus_vtable dnssd_vtable[]; + +int dnssd_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error); +int dnssd_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error); + +int bus_dnssd_method_unregister(sd_bus_message *message, void *userdata, sd_bus_error *error); diff --git a/src/resolve/resolved-dnssd.c b/src/resolve/resolved-dnssd.c index f565460e9c..6d0ab39a9d 100644 --- a/src/resolve/resolved-dnssd.c +++ b/src/resolve/resolved-dnssd.c @@ -314,3 +314,38 @@ int dnssd_txt_item_new_from_data(const char *key, const void *data, const size_t return 0; } + +void dnssd_signal_conflict(Manager *manager, const char *name) { + Iterator i; + DnssdService *s; + int r; + + HASHMAP_FOREACH(s, manager->dnssd_services, i) { + if (s->withdrawn) + continue; + + if (dns_name_equal(dns_resource_key_name(s->srv_rr->key), name)) { + _cleanup_free_ char *path = NULL; + + s->withdrawn = true; + + r = sd_bus_path_encode("/org/freedesktop/resolve1/dnssd", s->name, &path); + if (r < 0) { + log_error_errno(r, "Can't get D-BUS object path: %m"); + return; + } + + r = sd_bus_emit_signal(manager->bus, + path, + "org.freedesktop.resolve1.DnssdService", + "Conflicted", + NULL); + if (r < 0) { + log_error_errno(r, "Cannot emit signal: %m"); + return; + } + + break; + } + } +} diff --git a/src/resolve/resolved-dnssd.h b/src/resolve/resolved-dnssd.h index b723698d3a..4040190cf4 100644 --- a/src/resolve/resolved-dnssd.h +++ b/src/resolve/resolved-dnssd.h @@ -45,6 +45,8 @@ struct DnssdService { DnsResourceRecord *txt_rr; Manager *manager; + + bool withdrawn:1; }; DnssdService *dnssd_service_free(DnssdService *service); @@ -56,3 +58,4 @@ int dnssd_load(Manager *manager); int dnssd_txt_item_new_from_string(const char *key, const char *value, DnsTxtItem **ret_item); int dnssd_txt_item_new_from_data(const char *key, const void *value, const size_t size, DnsTxtItem **ret_item); int dnssd_update_rrs(DnssdService *s); +void dnssd_signal_conflict(Manager *manager, const char *name);