xref: /spdk/lib/nvmf/mdns_server.c (revision b557c9c838f35ad0595ae4bcf005305f78246828)
1 /*  SPDX-License-Identifier: BSD-3-Clause
2  *  Copyright (c) 2022 Dell Inc, or its subsidiaries.
3  *  Copyright (c) 2024 Samsung Electronics Co., Ltd. All rights reserved.
4  *  All rights reserved.
5  */
6 
7 #include "spdk/stdinc.h"
8 #include "spdk/env.h"
9 #include "spdk/thread.h"
10 #include "nvmf_internal.h"
11 #include "spdk/log.h"
12 #include "spdk/config.h"
13 #include "spdk/nvme.h"
14 #include "spdk/string.h"
15 
16 #ifdef SPDK_CONFIG_AVAHI
17 #include <avahi-client/client.h>
18 #include <avahi-client/publish.h>
19 #include <avahi-client/lookup.h>
20 #include <avahi-common/simple-watch.h>
21 #include <avahi-common/malloc.h>
22 #include <avahi-common/error.h>
23 
24 #define NVMF_MAX_DNS_NAME_LENGTH 255
25 
26 static AvahiSimplePoll *g_avahi_publish_simple_poll = NULL;
27 static AvahiClient *g_avahi_publish_client = NULL;
28 static AvahiEntryGroup *g_avahi_entry_group = NULL;
29 
30 struct mdns_publish_ctx {
31 	struct spdk_poller		*poller;
32 	struct spdk_nvmf_subsystem	*subsystem;
33 	struct spdk_nvmf_tgt		*tgt;
34 };
35 
36 static struct mdns_publish_ctx *g_mdns_publish_ctx = NULL;
37 
38 static void
39 nvmf_avahi_publish_destroy(struct mdns_publish_ctx *ctx)
40 {
41 	if (g_avahi_entry_group) {
42 		avahi_entry_group_free(g_avahi_entry_group);
43 		g_avahi_entry_group = NULL;
44 	}
45 
46 	if (g_avahi_publish_client) {
47 		avahi_client_free(g_avahi_publish_client);
48 		g_avahi_publish_client = NULL;
49 	}
50 
51 	if (g_avahi_publish_simple_poll) {
52 		avahi_simple_poll_free(g_avahi_publish_simple_poll);
53 		g_avahi_publish_simple_poll = NULL;
54 	}
55 
56 	g_mdns_publish_ctx = NULL;
57 	free(ctx);
58 }
59 
60 static int
61 nvmf_avahi_publish_iterate(void *arg)
62 {
63 	struct mdns_publish_ctx *ctx = arg;
64 	int rc;
65 
66 	if (ctx == NULL) {
67 		assert(false);
68 		return SPDK_POLLER_IDLE;
69 	}
70 
71 	rc = avahi_simple_poll_iterate(g_avahi_publish_simple_poll, 0);
72 	if (rc && rc != -EAGAIN) {
73 		SPDK_ERRLOG("avahi publish poll returned error\n");
74 		spdk_poller_unregister(&ctx->poller);
75 		nvmf_avahi_publish_destroy(ctx);
76 		return SPDK_POLLER_BUSY;
77 	}
78 
79 	return SPDK_POLLER_BUSY;
80 }
81 
82 static void
83 nvmf_ctx_stop_mdns_prr(struct mdns_publish_ctx *ctx)
84 {
85 	SPDK_INFOLOG(nvmf, "Stopping avahi publish poller\n");
86 	spdk_poller_unregister(&ctx->poller);
87 	nvmf_avahi_publish_destroy(ctx);
88 }
89 
90 void
91 nvmf_tgt_stop_mdns_prr(struct spdk_nvmf_tgt *tgt)
92 {
93 	if (g_mdns_publish_ctx && g_mdns_publish_ctx->tgt == tgt) {
94 		nvmf_ctx_stop_mdns_prr(g_mdns_publish_ctx);
95 		return;
96 	}
97 }
98 
99 static void
100 avahi_entry_group_add_listeners(AvahiEntryGroup *avahi_entry_group,
101 				struct spdk_nvmf_subsystem *subsystem)
102 {
103 	struct spdk_nvmf_subsystem_listener *listener;
104 	const char *name_base = "spdk";
105 	const char *type_base = "_nvme-disc";
106 	const char *domain = "local";
107 	char *protocol;
108 	char name[NVMF_MAX_DNS_NAME_LENGTH];
109 	char type[NVMF_MAX_DNS_NAME_LENGTH];
110 	char txt_protocol[NVMF_MAX_DNS_NAME_LENGTH];
111 	char txt_nqn[NVMF_MAX_DNS_NAME_LENGTH];
112 	AvahiStringList *txt = NULL;
113 	uint16_t port;
114 	uint16_t id = 0;
115 
116 	TAILQ_FOREACH(listener, &subsystem->listeners, link) {
117 		if (listener->trid->trtype == SPDK_NVME_TRANSPORT_TCP) {
118 			protocol = "tcp";
119 		} else if (listener->trid->trtype == SPDK_NVME_TRANSPORT_RDMA) {
120 			SPDK_ERRLOG("Current SPDK doesn't distinguish RoCE(udp) and iWARP(tcp). Skip adding listener id %d to avahi entry",
121 				    listener->id);
122 			continue;
123 		} else {
124 			SPDK_ERRLOG("mDNS PRR does not support trtype %d", listener->trid->trtype);
125 			continue;
126 		}
127 
128 		snprintf(type, sizeof(type), "%s._%s", type_base, protocol);
129 		snprintf(name, sizeof(name), "%s%d", name_base, id++);
130 		snprintf(txt_protocol, sizeof(txt_protocol), "p=%s", protocol);
131 		snprintf(txt_nqn, sizeof(txt_nqn), "nqn=%s", SPDK_NVMF_DISCOVERY_NQN);
132 		txt = avahi_string_list_add(txt, txt_protocol);
133 		txt = avahi_string_list_add(txt, txt_nqn);
134 		port = spdk_strtol(listener->trid->trsvcid, 10);
135 
136 		if (avahi_entry_group_add_service_strlst(avahi_entry_group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC,
137 				0, name, type, domain, NULL, port, txt) < 0) {
138 			SPDK_ERRLOG("Failed to add avahi service name: %s, type: %s, domain: %s, port: %d",
139 				    name, type, domain, port);
140 		}
141 		avahi_string_list_free(txt);
142 		txt = NULL;
143 	}
144 
145 	avahi_entry_group_commit(avahi_entry_group);
146 }
147 
148 static int
149 publish_pull_registration_request(AvahiClient *client, struct mdns_publish_ctx *publish_ctx)
150 {
151 	struct spdk_nvmf_subsystem *subsystem = publish_ctx->subsystem;
152 
153 	if (g_avahi_entry_group != NULL) {
154 		return 0;
155 	}
156 
157 	g_avahi_entry_group = avahi_entry_group_new(client, NULL, NULL);
158 	if (g_avahi_entry_group == NULL) {
159 		SPDK_ERRLOG("avahi_entry_group_new failure: %s\n", avahi_strerror(avahi_client_errno(client)));
160 		return -1;
161 	}
162 
163 	avahi_entry_group_add_listeners(g_avahi_entry_group, subsystem);
164 
165 	return 0;
166 }
167 
168 static void
169 publish_client_new_callback(AvahiClient *client, AvahiClientState avahi_state,
170 			    AVAHI_GCC_UNUSED void *user_data)
171 {
172 	int rc;
173 	struct mdns_publish_ctx *publish_ctx = user_data;
174 
175 	switch (avahi_state) {
176 	case AVAHI_CLIENT_S_RUNNING:
177 		rc = publish_pull_registration_request(client, publish_ctx);
178 		if (rc) {
179 			nvmf_ctx_stop_mdns_prr(publish_ctx);
180 		}
181 		break;
182 	case AVAHI_CLIENT_CONNECTING:
183 		SPDK_INFOLOG(nvmf, "Avahi client waiting for avahi-daemon");
184 		break;
185 	case AVAHI_CLIENT_S_REGISTERING:
186 		SPDK_INFOLOG(nvmf, "Avahi client registering service");
187 		break;
188 	case AVAHI_CLIENT_FAILURE:
189 		SPDK_ERRLOG("Server connection failure: %s\n", avahi_strerror(avahi_client_errno(client)));
190 		nvmf_ctx_stop_mdns_prr(publish_ctx);
191 		break;
192 	case AVAHI_CLIENT_S_COLLISION:
193 		SPDK_ERRLOG("Avahi client name is already used in the mDNS");
194 		nvmf_ctx_stop_mdns_prr(publish_ctx);
195 		break;
196 	default:
197 		SPDK_ERRLOG("Avahi client is in unsupported state");
198 		break;
199 	}
200 }
201 
202 int
203 nvmf_publish_mdns_prr(struct spdk_nvmf_tgt *tgt)
204 {
205 	int error;
206 	struct mdns_publish_ctx *publish_ctx = NULL;
207 	struct spdk_nvmf_subsystem *subsystem = NULL;
208 
209 	if (g_mdns_publish_ctx != NULL) {
210 		if (g_mdns_publish_ctx->tgt == tgt) {
211 			SPDK_ERRLOG("mDNS server is already running on target %s.\n", tgt->name);
212 			return -EEXIST;
213 		}
214 		SPDK_ERRLOG("mDNS server does not support publishing multiple targets simultaneously.");
215 		return -EINVAL;
216 	}
217 
218 	subsystem = spdk_nvmf_tgt_find_subsystem(tgt, SPDK_NVMF_DISCOVERY_NQN);
219 	if (TAILQ_EMPTY(&subsystem->listeners)) {
220 		SPDK_ERRLOG("Discovery subsystem has no listeners.\n");
221 		return -EINVAL;
222 	}
223 
224 	publish_ctx = calloc(1, sizeof(*publish_ctx));
225 	if (publish_ctx == NULL) {
226 		SPDK_ERRLOG("Error creating mDNS publish ctx\n");
227 		return -ENOMEM;
228 	}
229 	publish_ctx->subsystem = subsystem;
230 	publish_ctx->tgt = tgt;
231 	/* Allocate main loop object */
232 	g_avahi_publish_simple_poll = avahi_simple_poll_new();
233 	if (g_avahi_publish_simple_poll == NULL) {
234 		SPDK_ERRLOG("Failed to create poll object for mDNS publish.\n");
235 		nvmf_avahi_publish_destroy(publish_ctx);
236 		return -ENOMEM;
237 	}
238 
239 	assert(g_avahi_publish_client == NULL);
240 
241 	/* Allocate a new client */
242 	g_avahi_publish_client = avahi_client_new(avahi_simple_poll_get(g_avahi_publish_simple_poll),
243 				 0, publish_client_new_callback, publish_ctx, &error);
244 	/* Check whether creating the client object succeeded */
245 	if (g_avahi_publish_client == NULL) {
246 		SPDK_ERRLOG("Failed to create mDNS client Error: %s\n", avahi_strerror(error));
247 		nvmf_avahi_publish_destroy(publish_ctx);
248 		return -ENOMEM;
249 	}
250 
251 	g_mdns_publish_ctx = publish_ctx;
252 	publish_ctx->poller = SPDK_POLLER_REGISTER(nvmf_avahi_publish_iterate, publish_ctx, 100 * 1000);
253 	return 0;
254 }
255 
256 #endif
257