xref: /spdk/lib/nvmf/mdns_server.c (revision 7ff7ec0ed88d5acad07010b6c577326debc22f7c)
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 	SPDK_ERRLOG("Failed to stop mDNS PRR. It is not running on target %s.\n", tgt->name);
99 }
100 
101 static int
102 publish_pull_registration_request(AvahiClient *client, struct mdns_publish_ctx *publish_ctx)
103 {
104 	struct spdk_nvmf_subsystem *subsystem = publish_ctx->subsystem;
105 	struct spdk_nvmf_subsystem_listener *listener;
106 	const char *name_base = "spdk";
107 	const char *type_base = "_nvme-disc";
108 	const char *domain = "local";
109 	char *protocol;
110 	char name[NVMF_MAX_DNS_NAME_LENGTH];
111 	char type[NVMF_MAX_DNS_NAME_LENGTH];
112 	char txt_protocol[NVMF_MAX_DNS_NAME_LENGTH];
113 	char txt_nqn[NVMF_MAX_DNS_NAME_LENGTH];
114 	AvahiStringList *txt = NULL;
115 	uint16_t port;
116 	uint16_t id = 0;
117 
118 	if (g_avahi_entry_group != NULL) {
119 		return 0;
120 	}
121 
122 	g_avahi_entry_group = avahi_entry_group_new(client, NULL, NULL);
123 	if (g_avahi_entry_group == NULL) {
124 		SPDK_ERRLOG("avahi_entry_group_new failure: %s\n", avahi_strerror(avahi_client_errno(client)));
125 		return -1;
126 	}
127 
128 	TAILQ_FOREACH(listener, &subsystem->listeners, link) {
129 		if (listener->trid->trtype == SPDK_NVME_TRANSPORT_TCP) {
130 			protocol = "tcp";
131 		} else if (listener->trid->trtype == SPDK_NVME_TRANSPORT_RDMA) {
132 			SPDK_ERRLOG("Current SPDK doesn't distinguish RoCE(udp) and iWARP(tcp). Skip adding listener id %d to avahi entry",
133 				    listener->id);
134 			continue;
135 		} else {
136 			SPDK_ERRLOG("mDNS PRR does not support trtype %d", listener->trid->trtype);
137 			continue;
138 		}
139 
140 		snprintf(type, sizeof(type), "%s._%s", type_base, protocol);
141 		snprintf(name, sizeof(name), "%s%d", name_base, id++);
142 		snprintf(txt_protocol, sizeof(txt_protocol), "p=%s", protocol);
143 		snprintf(txt_nqn, sizeof(txt_nqn), "nqn=%s", SPDK_NVMF_DISCOVERY_NQN);
144 		txt = avahi_string_list_add(txt, txt_protocol);
145 		txt = avahi_string_list_add(txt, txt_nqn);
146 		port = spdk_strtol(listener->trid->trsvcid, 10);
147 
148 		if (avahi_entry_group_add_service_strlst(g_avahi_entry_group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC,
149 				0, name, type, domain, NULL, port, txt) < 0) {
150 			SPDK_ERRLOG("Failed to add avahi service name: %s, type: %s, domain: %s, port: %d, error: %s\n",
151 				    name, type, domain, port, avahi_strerror(avahi_client_errno(client)));
152 			continue;
153 		}
154 	}
155 
156 	avahi_entry_group_commit(g_avahi_entry_group);
157 
158 	return 0;
159 }
160 
161 static void
162 publish_client_new_callback(AvahiClient *client, AvahiClientState avahi_state,
163 			    AVAHI_GCC_UNUSED void *user_data)
164 {
165 	int rc;
166 	struct mdns_publish_ctx *publish_ctx = user_data;
167 
168 	switch (avahi_state) {
169 	case AVAHI_CLIENT_S_RUNNING:
170 		rc = publish_pull_registration_request(client, publish_ctx);
171 		if (rc) {
172 			nvmf_ctx_stop_mdns_prr(publish_ctx);
173 		}
174 		break;
175 	case AVAHI_CLIENT_CONNECTING:
176 		SPDK_INFOLOG(nvmf, "Avahi client waiting for avahi-daemon");
177 		break;
178 	case AVAHI_CLIENT_S_REGISTERING:
179 		SPDK_INFOLOG(nvmf, "Avahi client registering service");
180 		break;
181 	case AVAHI_CLIENT_FAILURE:
182 		SPDK_ERRLOG("Server connection failure: %s\n", avahi_strerror(avahi_client_errno(client)));
183 		nvmf_ctx_stop_mdns_prr(publish_ctx);
184 		break;
185 	case AVAHI_CLIENT_S_COLLISION:
186 		SPDK_ERRLOG("Avahi client name is already used in the mDNS");
187 		nvmf_ctx_stop_mdns_prr(publish_ctx);
188 		break;
189 	default:
190 		SPDK_ERRLOG("Avahi client is in unsupported state");
191 		break;
192 	}
193 }
194 
195 int
196 nvmf_publish_mdns_prr(struct spdk_nvmf_tgt *tgt)
197 {
198 	int error;
199 	struct mdns_publish_ctx *publish_ctx = NULL;
200 	struct spdk_nvmf_subsystem *subsystem = NULL;
201 
202 	if (g_mdns_publish_ctx != NULL) {
203 		if (g_mdns_publish_ctx->tgt == tgt) {
204 			SPDK_ERRLOG("mDNS server is already running on target %s.\n", tgt->name);
205 			return -EEXIST;
206 		}
207 		SPDK_ERRLOG("mDNS server does not support publishing multiple targets simultaneously.");
208 		return -EINVAL;
209 	}
210 
211 	subsystem = spdk_nvmf_tgt_find_subsystem(tgt, SPDK_NVMF_DISCOVERY_NQN);
212 	if (TAILQ_EMPTY(&subsystem->listeners)) {
213 		SPDK_ERRLOG("Discovery subsystem has no listeners.\n");
214 		return -EINVAL;
215 	}
216 
217 	publish_ctx = calloc(1, sizeof(*publish_ctx));
218 	if (publish_ctx == NULL) {
219 		SPDK_ERRLOG("Error creating mDNS publish ctx\n");
220 		return -ENOMEM;
221 	}
222 	publish_ctx->subsystem = subsystem;
223 	publish_ctx->tgt = tgt;
224 	/* Allocate main loop object */
225 	g_avahi_publish_simple_poll = avahi_simple_poll_new();
226 	if (g_avahi_publish_simple_poll == NULL) {
227 		SPDK_ERRLOG("Failed to create poll object for mDNS publish.\n");
228 		nvmf_avahi_publish_destroy(publish_ctx);
229 		return -ENOMEM;
230 	}
231 
232 	assert(g_avahi_publish_client == NULL);
233 
234 	/* Allocate a new client */
235 	g_avahi_publish_client = avahi_client_new(avahi_simple_poll_get(g_avahi_publish_simple_poll),
236 				 0, publish_client_new_callback, publish_ctx, &error);
237 	/* Check whether creating the client object succeeded */
238 	if (g_avahi_publish_client == NULL) {
239 		SPDK_ERRLOG("Failed to create mDNS client Error: %s\n", avahi_strerror(error));
240 		nvmf_avahi_publish_destroy(publish_ctx);
241 		return -ENOMEM;
242 	}
243 
244 	g_mdns_publish_ctx = publish_ctx;
245 	publish_ctx->poller = SPDK_POLLER_REGISTER(nvmf_avahi_publish_iterate, publish_ctx, 100 * 1000);
246 	return 0;
247 }
248 
249 #endif
250