1 /* $OpenBSD: control.c,v 1.38 2024/11/21 13:38:14 claudio Exp $ */
2
3 /*
4 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <sys/types.h>
20 #include <sys/stat.h>
21 #include <sys/un.h>
22 #include <errno.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <unistd.h>
26
27 #include "ldpd.h"
28 #include "ldpe.h"
29 #include "log.h"
30 #include "control.h"
31
32 TAILQ_HEAD(ctl_conns, ctl_conn) ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns);
33
34 #define CONTROL_BACKLOG 5
35
36 static void control_accept(int, short, void *);
37 static struct ctl_conn *control_connbyfd(int);
38 static struct ctl_conn *control_connbypid(pid_t);
39 static void control_close(int);
40 static void control_dispatch_imsg(int, short, void *);
41
42 static int control_fd;
43
44 int
control_init(char * path)45 control_init(char *path)
46 {
47 struct sockaddr_un sun;
48 int fd;
49 mode_t old_umask;
50
51 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
52 0)) == -1) {
53 log_warn("%s: socket", __func__);
54 return (-1);
55 }
56
57 memset(&sun, 0, sizeof(sun));
58 sun.sun_family = AF_UNIX;
59 strlcpy(sun.sun_path, path, sizeof(sun.sun_path));
60
61 if (unlink(path) == -1)
62 if (errno != ENOENT) {
63 log_warn("%s: unlink %s", __func__, path);
64 close(fd);
65 return (-1);
66 }
67
68 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
69 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
70 log_warn("%s: bind: %s", __func__, path);
71 close(fd);
72 umask(old_umask);
73 return (-1);
74 }
75 umask(old_umask);
76
77 if (chmod(path, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) {
78 log_warn("%s: chmod", __func__);
79 close(fd);
80 (void)unlink(path);
81 return (-1);
82 }
83
84 control_fd = fd;
85
86 return (0);
87 }
88
89 int
control_listen(void)90 control_listen(void)
91 {
92 if (listen(control_fd, CONTROL_BACKLOG) == -1) {
93 log_warn("%s: listen", __func__);
94 return (-1);
95 }
96
97 return (accept_add(control_fd, control_accept, NULL));
98 }
99
100 void
control_cleanup(void)101 control_cleanup(void)
102 {
103 accept_del(control_fd);
104 close(control_fd);
105 }
106
107 static void
control_accept(int listenfd,short event,void * bula)108 control_accept(int listenfd, short event, void *bula)
109 {
110 int connfd;
111 socklen_t len;
112 struct sockaddr_un sun;
113 struct ctl_conn *c;
114
115 len = sizeof(sun);
116 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len,
117 SOCK_NONBLOCK | SOCK_CLOEXEC)) == -1) {
118 /*
119 * Pause accept if we are out of file descriptors, or
120 * libevent will haunt us here too.
121 */
122 if (errno == ENFILE || errno == EMFILE)
123 accept_pause();
124 else if (errno != EWOULDBLOCK && errno != EINTR &&
125 errno != ECONNABORTED)
126 log_warn("%s: accept4", __func__);
127 return;
128 }
129
130 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) {
131 log_warn(__func__);
132 close(connfd);
133 return;
134 }
135
136 if (imsgbuf_init(&c->iev.ibuf, connfd) == -1) {
137 log_warn(__func__);
138 close(connfd);
139 free(c);
140 return;
141 }
142
143 c->iev.handler = control_dispatch_imsg;
144 c->iev.events = EV_READ;
145 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
146 c->iev.handler, &c->iev);
147 event_add(&c->iev.ev, NULL);
148
149 TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
150 }
151
152 static struct ctl_conn *
control_connbyfd(int fd)153 control_connbyfd(int fd)
154 {
155 struct ctl_conn *c;
156
157 TAILQ_FOREACH(c, &ctl_conns, entry) {
158 if (c->iev.ibuf.fd == fd)
159 break;
160 }
161
162 return (c);
163 }
164
165 static struct ctl_conn *
control_connbypid(pid_t pid)166 control_connbypid(pid_t pid)
167 {
168 struct ctl_conn *c;
169
170 TAILQ_FOREACH(c, &ctl_conns, entry) {
171 if (c->iev.ibuf.pid == pid)
172 break;
173 }
174
175 return (c);
176 }
177
178 static void
control_close(int fd)179 control_close(int fd)
180 {
181 struct ctl_conn *c;
182
183 if ((c = control_connbyfd(fd)) == NULL) {
184 log_warnx("%s: fd %d: not found", __func__, fd);
185 return;
186 }
187
188 imsgbuf_clear(&c->iev.ibuf);
189 TAILQ_REMOVE(&ctl_conns, c, entry);
190
191 event_del(&c->iev.ev);
192 close(c->iev.ibuf.fd);
193 accept_unpause();
194 free(c);
195 }
196
197 static void
control_dispatch_imsg(int fd,short event,void * bula)198 control_dispatch_imsg(int fd, short event, void *bula)
199 {
200 struct ctl_conn *c;
201 struct imsg imsg;
202 ssize_t n;
203 unsigned int ifidx;
204 int verbose;
205
206 if ((c = control_connbyfd(fd)) == NULL) {
207 log_warnx("%s: fd %d: not found", __func__, fd);
208 return;
209 }
210
211 if (event & EV_READ) {
212 if (imsgbuf_read(&c->iev.ibuf) != 1) {
213 control_close(fd);
214 return;
215 }
216 }
217 if (event & EV_WRITE) {
218 if (imsgbuf_write(&c->iev.ibuf) == -1) {
219 control_close(fd);
220 return;
221 }
222 }
223
224 for (;;) {
225 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
226 control_close(fd);
227 return;
228 }
229
230 if (n == 0)
231 break;
232
233 switch (imsg.hdr.type) {
234 case IMSG_CTL_FIB_COUPLE:
235 case IMSG_CTL_FIB_DECOUPLE:
236 case IMSG_CTL_RELOAD:
237 c->iev.ibuf.pid = imsg.hdr.pid;
238 ldpe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0);
239 break;
240 case IMSG_CTL_KROUTE:
241 case IMSG_CTL_KROUTE_ADDR:
242 case IMSG_CTL_IFINFO:
243 c->iev.ibuf.pid = imsg.hdr.pid;
244 ldpe_imsg_compose_parent(imsg.hdr.type,
245 imsg.hdr.pid, imsg.data,
246 imsg.hdr.len - IMSG_HEADER_SIZE);
247 break;
248 case IMSG_CTL_SHOW_INTERFACE:
249 if (imsg.hdr.len == IMSG_HEADER_SIZE +
250 sizeof(ifidx)) {
251 memcpy(&ifidx, imsg.data, sizeof(ifidx));
252 ldpe_iface_ctl(c, ifidx);
253 imsg_compose_event(&c->iev, IMSG_CTL_END, 0,
254 0, -1, NULL, 0);
255 }
256 break;
257 case IMSG_CTL_SHOW_DISCOVERY:
258 ldpe_adj_ctl(c);
259 break;
260 case IMSG_CTL_SHOW_LIB:
261 case IMSG_CTL_SHOW_L2VPN_PW:
262 case IMSG_CTL_SHOW_L2VPN_BINDING:
263 c->iev.ibuf.pid = imsg.hdr.pid;
264 ldpe_imsg_compose_lde(imsg.hdr.type, 0, imsg.hdr.pid,
265 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
266 break;
267 case IMSG_CTL_SHOW_NBR:
268 ldpe_nbr_ctl(c);
269 break;
270 case IMSG_CTL_CLEAR_NBR:
271 if (imsg.hdr.len != IMSG_HEADER_SIZE +
272 sizeof(struct ctl_nbr))
273 break;
274
275 nbr_clear_ctl(imsg.data);
276 break;
277 case IMSG_CTL_LOG_VERBOSE:
278 if (imsg.hdr.len != IMSG_HEADER_SIZE +
279 sizeof(verbose))
280 break;
281
282 /* forward to other processes */
283 ldpe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid,
284 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
285 ldpe_imsg_compose_lde(imsg.hdr.type, 0, imsg.hdr.pid,
286 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
287
288 memcpy(&verbose, imsg.data, sizeof(verbose));
289 log_verbose(verbose);
290 break;
291 default:
292 log_debug("%s: error handling imsg %d", __func__,
293 imsg.hdr.type);
294 break;
295 }
296 imsg_free(&imsg);
297 }
298
299 imsg_event_add(&c->iev);
300 }
301
302 int
control_imsg_relay(struct imsg * imsg)303 control_imsg_relay(struct imsg *imsg)
304 {
305 struct ctl_conn *c;
306
307 if ((c = control_connbypid(imsg->hdr.pid)) == NULL)
308 return (0);
309
310 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid,
311 -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE));
312 }
313