[thirdparty/systemd.git] / src / resolve / resolved-dnssd.c


#include "conf-files.h"
#include "conf-parser.h"
#include "resolved-dnssd.h"
#include "resolved-dns-rr.h"
#include "resolved-manager.h"
#include "specifier.h"
#include "strv.h"

const char* const dnssd_service_dirs[] = {
        "/etc/systemd/dnssd",
        "/run/systemd/dnssd",
        "/usr/lib/systemd/dnssd",
#if HAVE_SPLIT_USR
        "/lib/systemd/dnssd",
#endif
    NULL
};

DnssdTxtData *dnssd_txtdata_free(DnssdTxtData *txt_data) {
        if (!txt_data)
                return NULL;

        dns_resource_record_unref(txt_data->rr);
        dns_txt_item_free_all(txt_data->txt);

        return mfree(txt_data);
}

DnssdTxtData *dnssd_txtdata_free_all(DnssdTxtData *txt_data) {
        DnssdTxtData *next;

        if (!txt_data)
                return NULL;

        next = txt_data->items_next;

        dnssd_txtdata_free(txt_data);

        return dnssd_txtdata_free_all(next);
}

DnssdService *dnssd_service_free(DnssdService *service) {
        if (!service)
                return NULL;

        if (service->manager)
                hashmap_remove(service->manager->dnssd_services, service->name);

        dns_resource_record_unref(service->ptr_rr);
        dns_resource_record_unref(service->srv_rr);

        dnssd_txtdata_free_all(service->txt_data_items);

        free(service->filename);
        free(service->name);
        free(service->type);
        free(service->name_template);

        return mfree(service);
}

static int dnssd_service_load(Manager *manager, const char *filename) {
        _cleanup_(dnssd_service_freep) DnssdService *service = NULL;
        _cleanup_(dnssd_txtdata_freep) DnssdTxtData *txt_data = NULL;
        char *d;
        const char *dropin_dirname;
        int r;

        assert(manager);
        assert(filename);

        service = new0(DnssdService, 1);
        if (!service)
                return log_oom();

        service->filename = strdup(filename);
        if (!service->filename)
                return log_oom();

        service->name = strdup(basename(filename));
        if (!service->name)
                return log_oom();

        d = endswith(service->name, ".dnssd");
        if (!d)
                return -EINVAL;

        assert(streq(d, ".dnssd"));

        *d = '\0';

        dropin_dirname = strjoina(service->name, ".dnssd.d");

        r = config_parse_many(filename, dnssd_service_dirs, dropin_dirname,
                              "Service\0",
                              config_item_perf_lookup, resolved_dnssd_gperf_lookup,
                              false, service);
        if (r < 0)
                return r;

        if (!service->name_template) {
                log_error("%s doesn't define service instance name", service->name);
                return -EINVAL;
        }

        if (!service->type) {
                log_error("%s doesn't define service type", service->name);
                return -EINVAL;
        }

        if (LIST_IS_EMPTY(service->txt_data_items)) {
                txt_data = new0(DnssdTxtData, 1);
                if (!txt_data)
                        return log_oom();

                r = dns_txt_item_new_empty(&txt_data->txt);
                if (r < 0)
                        return r;

                LIST_PREPEND(items, service->txt_data_items, txt_data);
                txt_data = NULL;
        }

        r = hashmap_ensure_allocated(&manager->dnssd_services, &string_hash_ops);
        if (r < 0)
                return r;

        r = hashmap_put(manager->dnssd_services, service->name, service);
        if (r < 0)
                return r;

        service->manager = manager;

        r = dnssd_update_rrs(service);
        if (r < 0)
                return r;

        service = NULL;

        return 0;
}

static int specifier_dnssd_host_name(char specifier, void *data, void *userdata, char **ret) {
        DnssdService *s  = (DnssdService *) userdata;
        char *n;

        assert(s);
        assert(s->manager);
        assert(s->manager->llmnr_hostname);

        n = strdup(s->manager->llmnr_hostname);
        if (!n)
                return -ENOMEM;

        *ret = n;
        return 0;
}

int dnssd_render_instance_name(DnssdService *s, char **ret_name) {
        static const Specifier specifier_table[] = {
                { 'b', specifier_boot_id,         NULL },
                { 'H', specifier_dnssd_host_name, NULL },
                { 'm', specifier_machine_id,      NULL },
                { 'v', specifier_kernel_release,  NULL },
                {}
        };
        _cleanup_free_ char *name = NULL;
        int r;

        assert(s);
        assert(s->name_template);

        r = specifier_printf(s->name_template, specifier_table, s, &name);
        if (r < 0)
                return log_debug_errno(r, "Failed to replace specifiers: %m");

        if (!dns_service_name_is_valid(name)) {
                log_debug("Service instance name '%s' is invalid.", name);
                return -EINVAL;
        }

        *ret_name = TAKE_PTR(name);

        return 0;
}

int dnssd_load(Manager *manager) {
        _cleanup_strv_free_ char **files = NULL;
        char **f;
        int r;

        assert(manager);

        if (manager->mdns_support != RESOLVE_SUPPORT_YES)
                return 0;

        r = conf_files_list_strv(&files, ".dnssd", NULL, 0, dnssd_service_dirs);
        if (r < 0)
                return log_error_errno(r, "Failed to enumerate .dnssd files: %m");

        STRV_FOREACH_BACKWARDS(f, files) {
                r = dnssd_service_load(manager, *f);
                if (r < 0)
                        log_warning_errno(r, "Failed to load '%s': %m", *f);;
        }

        return 0;
}

int dnssd_update_rrs(DnssdService *s) {
        _cleanup_free_ char *n = NULL;
        _cleanup_free_ char *service_name = NULL;
        _cleanup_free_ char *full_name = NULL;
        DnssdTxtData *txt_data;
        int r;

        assert(s);
        assert(s->txt_data_items);
        assert(s->manager);

        s->ptr_rr = dns_resource_record_unref(s->ptr_rr);
        s->srv_rr = dns_resource_record_unref(s->srv_rr);
        LIST_FOREACH(items, txt_data, s->txt_data_items)
                txt_data->rr = dns_resource_record_unref(txt_data->rr);

        r = dnssd_render_instance_name(s, &n);
        if (r < 0)
                return r;

        r = dns_name_concat(s->type, "local", &service_name);
        if (r < 0)
                return r;
        r = dns_name_concat(n, service_name, &full_name);
        if (r < 0)
                return r;

        LIST_FOREACH(items, txt_data, s->txt_data_items) {
                txt_data->rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_TXT,
                                                            full_name);
                if (!txt_data->rr)
                        goto oom;

                txt_data->rr->ttl = MDNS_DEFAULT_TTL;
                txt_data->rr->txt.items = dns_txt_item_copy(txt_data->txt);
                if (!txt_data->rr->txt.items)
                        goto oom;
        }

        s->ptr_rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_PTR,
                                                 service_name);
        if (!s->ptr_rr)
                goto oom;

        s->ptr_rr->ttl = MDNS_DEFAULT_TTL;
        s->ptr_rr->ptr.name = strdup(full_name);
        if (!s->ptr_rr->ptr.name)
                goto oom;

        s->srv_rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_SRV,
                                                 full_name);
        if (!s->srv_rr)
                goto oom;

        s->srv_rr->ttl = MDNS_DEFAULT_TTL;
        s->srv_rr->srv.priority = s->priority;
        s->srv_rr->srv.weight = s->weight;
        s->srv_rr->srv.port = s->port;
        s->srv_rr->srv.name = strdup(s->manager->mdns_hostname);
        if (!s->srv_rr->srv.name)
                goto oom;

        return 0;

oom:
        LIST_FOREACH(items, txt_data, s->txt_data_items)
                txt_data->rr = dns_resource_record_unref(txt_data->rr);
        s->ptr_rr = dns_resource_record_unref(s->ptr_rr);
        s->srv_rr = dns_resource_record_unref(s->srv_rr);
        return -ENOMEM;
}

int dnssd_txt_item_new_from_string(const char *key, const char *value, DnsTxtItem **ret_item) {
        size_t length;
        DnsTxtItem *i;

        length = strlen(key);

        if (!isempty(value))
                length += strlen(value) + 1; /* length of value plus '=' */

        i = malloc0(offsetof(DnsTxtItem, data) + length + 1); /* for safety reasons we add an extra NUL byte */
        if (!i)
                return -ENOMEM;

        memcpy(i->data, key, strlen(key));
        if (!isempty(value)) {
                memcpy(i->data + strlen(key), "=", 1);
                memcpy(i->data + strlen(key) + 1, value, strlen(value));
        }
        i->length = length;

        *ret_item = TAKE_PTR(i);

        return 0;
}

int dnssd_txt_item_new_from_data(const char *key, const void *data, const size_t size, DnsTxtItem **ret_item) {
        size_t length;
        DnsTxtItem *i;

        length = strlen(key);

        if (size > 0)
                length += size + 1; /* size of date plus '=' */

        i = malloc0(offsetof(DnsTxtItem, data) + length + 1); /* for safety reasons we add an extra NUL byte */
        if (!i)
                return -ENOMEM;

        memcpy(i->data, key, strlen(key));
        if (size > 0) {
                memcpy(i->data + strlen(key), "=", 1);
                memcpy(i->data + strlen(key) + 1, data, size);
        }
        i->length = length;

        *ret_item = TAKE_PTR(i);

        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;
                }
        }
}
Commit	Line	Data
6501dd31 DR	1
	2	#include "conf-files.h"
	3	#include "conf-parser.h"
	4	#include "resolved-dnssd.h"
	5	#include "resolved-dns-rr.h"
	6	#include "resolved-manager.h"
	7	#include "specifier.h"
	8	#include "strv.h"
	9
	10	const char* const dnssd_service_dirs[] = {
	11	"/etc/systemd/dnssd",
	12	"/run/systemd/dnssd",
	13	"/usr/lib/systemd/dnssd",
545cdb90	14	#if HAVE_SPLIT_USR
6501dd31 DR	15	"/lib/systemd/dnssd",
	16	#endif
	17	NULL
	18	};
	19
400f54fb DR	20	DnssdTxtData dnssd_txtdata_free(DnssdTxtData txt_data) {
	21	if (!txt_data)
	22	return NULL;
	23
	24	dns_resource_record_unref(txt_data->rr);
	25	dns_txt_item_free_all(txt_data->txt);
	26
	27	return mfree(txt_data);
	28	}
	29
	30	DnssdTxtData dnssd_txtdata_free_all(DnssdTxtData txt_data) {
	31	DnssdTxtData *next;
	32
	33	if (!txt_data)
	34	return NULL;
	35
	36	next = txt_data->items_next;
	37
	38	dnssd_txtdata_free(txt_data);
	39
	40	return dnssd_txtdata_free_all(next);
	41	}
	42
6501dd31 DR	43	DnssdService dnssd_service_free(DnssdService service) {
	44	if (!service)
	45	return NULL;
	46
	47	if (service->manager)
	48	hashmap_remove(service->manager->dnssd_services, service->name);
	49
	50	dns_resource_record_unref(service->ptr_rr);
	51	dns_resource_record_unref(service->srv_rr);
400f54fb DR	52
400f54fb DR	53	dnssd_txtdata_free_all(service->txt_data_items);
6501dd31 DR	54
	55	free(service->filename);
	56	free(service->name);
	57	free(service->type);
	58	free(service->name_template);
6501dd31 DR	59
	60	return mfree(service);
	61	}
	62
	63	static int dnssd_service_load(Manager manager, const char filename) {
	64	_cleanup_(dnssd_service_freep) DnssdService *service = NULL;
400f54fb	65	_cleanup_(dnssd_txtdata_freep) DnssdTxtData *txt_data = NULL;
6501dd31 DR	66	char *d;
	67	const char *dropin_dirname;
	68	int r;
	69
	70	assert(manager);
	71	assert(filename);
	72
	73	service = new0(DnssdService, 1);
	74	if (!service)
	75	return log_oom();
	76
	77	service->filename = strdup(filename);
	78	if (!service->filename)
	79	return log_oom();
	80
	81	service->name = strdup(basename(filename));
	82	if (!service->name)
	83	return log_oom();
	84
	85	d = endswith(service->name, ".dnssd");
	86	if (!d)
	87	return -EINVAL;
	88
	89	assert(streq(d, ".dnssd"));
	90
	91	*d = '\0';
	92
	93	dropin_dirname = strjoina(service->name, ".dnssd.d");
	94
	95	r = config_parse_many(filename, dnssd_service_dirs, dropin_dirname,
	96	"Service\0",
	97	config_item_perf_lookup, resolved_dnssd_gperf_lookup,
	98	false, service);
	99	if (r < 0)
	100	return r;
	101
	102	if (!service->name_template) {
	103	log_error("%s doesn't define service instance name", service->name);
	104	return -EINVAL;
	105	}
	106
	107	if (!service->type) {
	108	log_error("%s doesn't define service type", service->name);
	109	return -EINVAL;
	110	}
	111
400f54fb DR	112	if (LIST_IS_EMPTY(service->txt_data_items)) {
	113	txt_data = new0(DnssdTxtData, 1);
	114	if (!txt_data)
	115	return log_oom();
	116
	117	r = dns_txt_item_new_empty(&txt_data->txt);
6501dd31 DR	118	if (r < 0)
6501dd31 DR	119	return r;
400f54fb DR	120
	121	LIST_PREPEND(items, service->txt_data_items, txt_data);
	122	txt_data = NULL;
6501dd31 DR	123	}
	124
	125	r = hashmap_ensure_allocated(&manager->dnssd_services, &string_hash_ops);
	126	if (r < 0)
	127	return r;
	128
	129	r = hashmap_put(manager->dnssd_services, service->name, service);
	130	if (r < 0)
	131	return r;
	132
	133	service->manager = manager;
	134
6db6a464 DR	135	r = dnssd_update_rrs(service);
	136	if (r < 0)
	137	return r;
	138
6501dd31 DR	139	service = NULL;
	140
	141	return 0;
	142	}
	143
	144	static int specifier_dnssd_host_name(char specifier, void data, void userdata, char **ret) {
	145	DnssdService s = (DnssdService ) userdata;
	146	char *n;
	147
	148	assert(s);
	149	assert(s->manager);
	150	assert(s->manager->llmnr_hostname);
	151
	152	n = strdup(s->manager->llmnr_hostname);
	153	if (!n)
	154	return -ENOMEM;
	155
	156	*ret = n;
	157	return 0;
	158	}
	159
	160	int dnssd_render_instance_name(DnssdService s, char *ret_name) {
	161	static const Specifier specifier_table[] = {
	162	{ 'b', specifier_boot_id, NULL },
	163	{ 'H', specifier_dnssd_host_name, NULL },
24eb8621	164	{ 'm', specifier_machine_id, NULL },
6501dd31 DR	165	{ 'v', specifier_kernel_release, NULL },
	166	{}
	167	};
	168	_cleanup_free_ char *name = NULL;
	169	int r;
	170
	171	assert(s);
	172	assert(s->name_template);
	173
	174	r = specifier_printf(s->name_template, specifier_table, s, &name);
	175	if (r < 0)
	176	return log_debug_errno(r, "Failed to replace specifiers: %m");
	177
	178	if (!dns_service_name_is_valid(name)) {
	179	log_debug("Service instance name '%s' is invalid.", name);
	180	return -EINVAL;
	181	}
	182
ae2a15bc	183	*ret_name = TAKE_PTR(name);
6501dd31 DR	184
	185	return 0;
	186	}
	187
	188	int dnssd_load(Manager *manager) {
	189	_cleanup_strv_free_ char **files = NULL;
	190	char **f;
	191	int r;
	192
	193	assert(manager);
	194
	195	if (manager->mdns_support != RESOLVE_SUPPORT_YES)
	196	return 0;
	197
	198	r = conf_files_list_strv(&files, ".dnssd", NULL, 0, dnssd_service_dirs);
	199	if (r < 0)
	200	return log_error_errno(r, "Failed to enumerate .dnssd files: %m");
	201
	202	STRV_FOREACH_BACKWARDS(f, files) {
	203	r = dnssd_service_load(manager, *f);
	204	if (r < 0)
	205	log_warning_errno(r, "Failed to load '%s': %m", *f);;
	206	}
	207
	208	return 0;
	209	}
	210
6db6a464 DR	211	int dnssd_update_rrs(DnssdService *s) {
	212	_cleanup_free_ char *n = NULL;
	213	_cleanup_free_ char *service_name = NULL;
	214	_cleanup_free_ char *full_name = NULL;
400f54fb	215	DnssdTxtData *txt_data;
6db6a464 DR	216	int r;
	217
	218	assert(s);
400f54fb	219	assert(s->txt_data_items);
6db6a464 DR	220	assert(s->manager);
	221
	222	s->ptr_rr = dns_resource_record_unref(s->ptr_rr);
	223	s->srv_rr = dns_resource_record_unref(s->srv_rr);
400f54fb DR	224	LIST_FOREACH(items, txt_data, s->txt_data_items)
400f54fb DR	225	txt_data->rr = dns_resource_record_unref(txt_data->rr);
6db6a464 DR	226
	227	r = dnssd_render_instance_name(s, &n);
	228	if (r < 0)
	229	return r;
	230
	231	r = dns_name_concat(s->type, "local", &service_name);
	232	if (r < 0)
	233	return r;
	234	r = dns_name_concat(n, service_name, &full_name);
	235	if (r < 0)
	236	return r;
	237
400f54fb DR	238	LIST_FOREACH(items, txt_data, s->txt_data_items) {
	239	txt_data->rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_TXT,
	240	full_name);
	241	if (!txt_data->rr)
	242	goto oom;
6db6a464	243
400f54fb DR	244	txt_data->rr->ttl = MDNS_DEFAULT_TTL;
	245	txt_data->rr->txt.items = dns_txt_item_copy(txt_data->txt);
	246	if (!txt_data->rr->txt.items)
	247	goto oom;
	248	}
6db6a464 DR	249
	250	s->ptr_rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_PTR,
	251	service_name);
	252	if (!s->ptr_rr)
	253	goto oom;
	254
	255	s->ptr_rr->ttl = MDNS_DEFAULT_TTL;
	256	s->ptr_rr->ptr.name = strdup(full_name);
	257	if (!s->ptr_rr->ptr.name)
	258	goto oom;
	259
	260	s->srv_rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_SRV,
	261	full_name);
	262	if (!s->srv_rr)
	263	goto oom;
	264
	265	s->srv_rr->ttl = MDNS_DEFAULT_TTL;
	266	s->srv_rr->srv.priority = s->priority;
	267	s->srv_rr->srv.weight = s->weight;
	268	s->srv_rr->srv.port = s->port;
	269	s->srv_rr->srv.name = strdup(s->manager->mdns_hostname);
	270	if (!s->srv_rr->srv.name)
	271	goto oom;
	272
	273	return 0;
	274
	275	oom:
400f54fb DR	276	LIST_FOREACH(items, txt_data, s->txt_data_items)
400f54fb DR	277	txt_data->rr = dns_resource_record_unref(txt_data->rr);
6db6a464 DR	278	s->ptr_rr = dns_resource_record_unref(s->ptr_rr);
	279	s->srv_rr = dns_resource_record_unref(s->srv_rr);
	280	return -ENOMEM;
	281	}
	282
6501dd31 DR	283	int dnssd_txt_item_new_from_string(const char key, const char value, DnsTxtItem **ret_item) {
	284	size_t length;
	285	DnsTxtItem *i;
	286
	287	length = strlen(key);
	288
	289	if (!isempty(value))
	290	length += strlen(value) + 1; /* length of value plus '=' */
	291
	292	i = malloc0(offsetof(DnsTxtItem, data) + length + 1); /* for safety reasons we add an extra NUL byte */
	293	if (!i)
	294	return -ENOMEM;
	295
	296	memcpy(i->data, key, strlen(key));
	297	if (!isempty(value)) {
	298	memcpy(i->data + strlen(key), "=", 1);
	299	memcpy(i->data + strlen(key) + 1, value, strlen(value));
	300	}
	301	i->length = length;
	302
ae2a15bc	303	*ret_item = TAKE_PTR(i);
6501dd31 DR	304
	305	return 0;
	306	}
	307
	308	int dnssd_txt_item_new_from_data(const char key, const void data, const size_t size, DnsTxtItem **ret_item) {
	309	size_t length;
	310	DnsTxtItem *i;
	311
	312	length = strlen(key);
	313
	314	if (size > 0)
	315	length += size + 1; /* size of date plus '=' */
	316
	317	i = malloc0(offsetof(DnsTxtItem, data) + length + 1); /* for safety reasons we add an extra NUL byte */
	318	if (!i)
	319	return -ENOMEM;
	320
	321	memcpy(i->data, key, strlen(key));
	322	if (size > 0) {
	323	memcpy(i->data + strlen(key), "=", 1);
	324	memcpy(i->data + strlen(key) + 1, data, size);
	325	}
	326	i->length = length;
	327
ae2a15bc	328	*ret_item = TAKE_PTR(i);
6501dd31 DR	329
	330	return 0;
	331	}
c3036641 DR	332
	333	void dnssd_signal_conflict(Manager manager, const char name) {
	334	Iterator i;
	335	DnssdService *s;
	336	int r;
	337
	338	HASHMAP_FOREACH(s, manager->dnssd_services, i) {
	339	if (s->withdrawn)
	340	continue;
	341
	342	if (dns_name_equal(dns_resource_key_name(s->srv_rr->key), name)) {
	343	_cleanup_free_ char *path = NULL;
	344
	345	s->withdrawn = true;
	346
	347	r = sd_bus_path_encode("/org/freedesktop/resolve1/dnssd", s->name, &path);
	348	if (r < 0) {
	349	log_error_errno(r, "Can't get D-BUS object path: %m");
	350	return;
	351	}
	352
	353	r = sd_bus_emit_signal(manager->bus,
	354	path,
	355	"org.freedesktop.resolve1.DnssdService",
	356	"Conflicted",
	357	NULL);
	358	if (r < 0) {
	359	log_error_errno(r, "Cannot emit signal: %m");
	360	return;
	361	}
	362
	363	break;
	364	}
	365	}
	366	}