cache: use proper avl lookup for entries
[project/mdnsd.git] / service.c
1 /*
2 * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU Lesser General Public License version 2.1
6 * as published by the Free Software Foundation
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 */
13
14 #include <sys/types.h>
15 #include <netinet/in.h>
16 #include <arpa/nameser.h>
17 #include <sys/socket.h>
18 #include <netinet/in.h>
19 #include <arpa/inet.h>
20
21 #include <resolv.h>
22 #include <glob.h>
23 #include <stdio.h>
24 #include <time.h>
25
26 #include <uci.h>
27 #include <uci_blob.h>
28
29 #include <libubox/avl.h>
30 #include <libubox/uloop.h>
31 #include <libubox/avl-cmp.h>
32 #include <libubox/blobmsg_json.h>
33
34 #include "dns.h"
35 #include "service.h"
36 #include "util.h"
37
38 enum {
39 SERVICE_PORT,
40 SERVICE_TXT,
41 __SERVICE_MAX,
42 };
43
44 struct service {
45 struct avl_node avl;
46
47 time_t t;
48
49 char *service;
50 char *daemon;
51 char *txt;
52 int txt_len;
53 int port;
54 int active;
55 };
56
57 static const struct blobmsg_policy service_policy[__SERVICE_MAX] = {
58 [SERVICE_PORT] = { .name = "port", .type = BLOBMSG_TYPE_INT32 },
59 [SERVICE_TXT] = { .name = "txt", .type = BLOBMSG_TYPE_ARRAY },
60 };
61
62 static const struct uci_blob_param_list service_attr_list = {
63 .n_params = __SERVICE_MAX,
64 .params = service_policy,
65 };
66
67 static struct blob_buf b;
68 static struct avl_tree services;
69 char *hostname = NULL;
70 static char *sdudp = "_services._dns-sd._udp.local";
71 static char *sdtcp = "_services._dns-sd._tcp.local";
72
73 char*
74 service_name(char *domain)
75 {
76 static char buffer[256];
77
78 snprintf(buffer, sizeof(buffer), "%s.%s", hostname, domain);
79
80 return buffer;
81 }
82
83 static void
84 service_send_ptr(struct uloop_fd *u, struct service *s)
85 {
86 unsigned char buffer[MAX_NAME_LEN];
87 char *host = service_name(s->service);
88 int len = dn_comp(host, buffer, MAX_NAME_LEN, NULL, NULL);
89
90 if (len < 1)
91 return;
92
93 dns_add_answer(TYPE_PTR, buffer, len);
94 }
95
96 static void
97 service_send_ptr_c(struct uloop_fd *u, char *host)
98 {
99 unsigned char buffer[MAX_NAME_LEN];
100 int len = dn_comp(host, buffer, MAX_NAME_LEN, NULL, NULL);
101
102 if (len < 1)
103 return;
104
105 dns_add_answer(TYPE_PTR, buffer, len);
106 }
107
108 static void
109 service_send_a(struct uloop_fd *u)
110 {
111 unsigned char buffer[MAX_NAME_LEN];
112 char *host = service_name("local");
113 int len = dn_comp(host, buffer, MAX_NAME_LEN, NULL, NULL);
114 struct in_addr in;
115
116 if (!inet_aton(iface_ip, &in)) {
117 fprintf(stderr, "%s is not valid\n", iface_ip);
118 return;
119 }
120
121 if (len < 1)
122 return;
123
124 dns_add_answer(TYPE_A, (uint8_t *) &in.s_addr, 4);
125 }
126
127 static void
128 service_send_srv(struct uloop_fd *u, struct service *s)
129 {
130 unsigned char buffer[MAX_NAME_LEN];
131 struct dns_srv_data *sd;
132 char *host = service_name("local");
133 int len = dn_comp(host, buffer, MAX_NAME_LEN, NULL, NULL);
134
135 if (len < 1)
136 return;
137
138 sd = malloc(len + sizeof(struct dns_srv_data));
139 if (!sd)
140 return;
141
142 memset(sd, 0, sizeof(struct dns_srv_data));
143 sd->port = cpu_to_be16(s->port);
144 memcpy(&sd[1], buffer, len);
145 host = service_name(s->service);
146 dns_add_answer(TYPE_SRV, (uint8_t *) sd, len + sizeof(struct dns_srv_data));
147 free(sd);
148 }
149
150 #define TOUT_LOOKUP 60
151
152 static int
153 service_timeout(struct service *s)
154 {
155 time_t t = time(NULL);
156
157 if (t - s->t <= TOUT_LOOKUP)
158 return 0;
159
160 s->t = t;
161
162 return 1;
163 }
164
165 void
166 service_reply_a(struct uloop_fd *u, int type)
167 {
168 if (type != TYPE_A)
169 return;
170
171 dns_init_answer();
172 service_send_a(u);
173 dns_send_answer(u, service_name("local"));
174 }
175
176 void
177 service_reply(struct uloop_fd *u, char *match)
178 {
179 struct service *s;
180
181 avl_for_each_element(&services, s, avl) {
182 char *host = service_name(s->service);
183 char *service = strstr(host, "._");
184
185 if (!s->active || !service || !service_timeout(s))
186 continue;
187
188 service++;
189
190 if (match && strcmp(match, s->service))
191 continue;
192
193 dns_init_answer();
194 service_send_ptr(u, s);
195 dns_send_answer(u, service);
196
197 dns_init_answer();
198 service_send_srv(u, s);
199 if (s->txt && s->txt_len)
200 dns_add_answer(TYPE_TXT, (uint8_t *) s->txt, s->txt_len);
201 dns_send_answer(u, host);
202 }
203
204 if (match)
205 return;
206
207 dns_init_answer();
208 service_send_a(u);
209 dns_send_answer(u, service_name("local"));
210 }
211
212 void
213 service_announce_services(struct uloop_fd *u, char *service)
214 {
215 struct service *s;
216 int tcp = 1;
217
218 if (!strcmp(service, sdudp))
219 tcp = 0;
220 else if (strcmp(service, sdtcp))
221 return;
222
223 avl_for_each_element(&services, s, avl) {
224 if (!strstr(s->service, "._tcp") && tcp)
225 continue;
226 if (!strstr(s->service, "._udp") && !tcp)
227 continue;
228 s->t = 0;
229 dns_init_answer();
230 service_send_ptr_c(u, s->service);
231 if (tcp)
232 dns_send_answer(u, sdtcp);
233 else
234 dns_send_answer(u, sdudp);
235 service_reply(u, s->service);
236 }
237 }
238
239 void
240 service_announce(struct uloop_fd *u)
241 {
242 service_announce_services(u, sdudp);
243 service_announce_services(u, sdtcp);
244 }
245
246 static void
247 service_load(char *path)
248 {
249 struct blob_attr *txt, *cur, *_tb[__SERVICE_MAX];
250 int rem, i;
251 glob_t gl;
252
253 if (glob(path, GLOB_NOESCAPE | GLOB_MARK, NULL, &gl))
254 return;
255
256 for (i = 0; i < gl.gl_pathc; i++) {
257 blob_buf_init(&b, 0);
258
259 if (!blobmsg_add_json_from_file(&b, gl.gl_pathv[i]))
260 continue;
261 blob_for_each_attr(cur, b.head, rem) {
262 struct service *s;
263 char *d_service, *d_txt, *d_daemon;
264 int rem2;
265
266 blobmsg_parse(service_policy, ARRAY_SIZE(service_policy),
267 _tb, blobmsg_data(cur), blobmsg_data_len(cur));
268 if (!_tb[SERVICE_PORT] || !_tb[SERVICE_TXT])
269 continue;
270
271 s = calloc_a(sizeof(*s),
272 &d_daemon, strlen(gl.gl_pathv[i]) + 1,
273 &d_service, strlen(blobmsg_name(cur)) + 1,
274 &d_txt, blobmsg_data_len(_tb[SERVICE_TXT]));
275 if (!s)
276 continue;
277
278 s->port = blobmsg_get_u32(_tb[SERVICE_PORT]);
279 s->service = d_service;
280 s->daemon = d_daemon;
281 strcpy(s->service, blobmsg_name(cur));
282 strcpy(s->daemon, gl.gl_pathv[i]);
283 s->avl.key = s->service;
284 s->active = 1;
285 s->t = 0;
286 avl_insert(&services, &s->avl);
287
288 blobmsg_for_each_attr(txt, _tb[SERVICE_TXT], rem2)
289 s->txt_len += 1 + strlen(blobmsg_get_string(txt));
290
291 if (!s->txt_len)
292 continue;
293
294 d_txt = s->txt = malloc(s->txt_len);
295 if (!s->txt)
296 continue;
297
298 blobmsg_for_each_attr(txt, _tb[SERVICE_TXT], rem2) {
299 int len = strlen(blobmsg_get_string(txt));
300 if (!len)
301 continue;
302 if (len > 0xff)
303 len = 0xff;
304 *d_txt = len;
305 d_txt++;
306 memcpy(d_txt, blobmsg_get_string(txt), len);
307 d_txt += len;
308 }
309 }
310 }
311 }
312
313 void
314 service_init(void)
315 {
316 if (!hostname)
317 hostname = get_hostname();
318 avl_init(&services, avl_strcmp, true, NULL);
319 service_load("/tmp/run/mdnsd/*");
320 }
321
322 void
323 service_cleanup(void)
324 {
325 }