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1/* $OpenBSD: control.c,v 1.54 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/socket.h>
22#include <sys/un.h>
23#include <errno.h>
24#include <fcntl.h>
25#include <stdlib.h>
26#include <string.h>
27#include <unistd.h>
28
29#include "ospfd.h"
30#include "ospf.h"
31#include "ospfe.h"
32#include "log.h"
33#include "control.h"
34
35TAILQ_HEAD(ctl_conns, ctl_conn) ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns);
36
37#define CONTROL_BACKLOG 5
38
39struct ctl_conn *control_connbyfd(int);
40struct ctl_conn *control_connbypid(pid_t);
41void control_close(int);
42
43struct {
44 struct event ev;
45 struct event evt;
46 int fd;
47} control_state;
48
49int
50control_check(char *path)
51{
52 struct sockaddr_un sun;
53 int fd;
54
55 bzero(&sun, sizeof(sun));
56 sun.sun_family = AF_UNIX;
57 strlcpy(sun.sun_path, path, sizeof(sun.sun_path));
58
59 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
60 log_warn("control_check: socket check");
61 return (-1);
62 }
63
64 if (connect(fd, (struct sockaddr *)&sun, sizeof(sun)) == 0) {
65 log_warnx("control_check: socket in use");
66 close(fd);
67 return (-1);
68 }
69
70 close(fd);
71
72 return (0);
73}
74
75int
76control_init(char *path)
77{
78 struct sockaddr_un sun;
79 int fd;
80 mode_t old_umask;
81
82 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
83 0)) == -1) {
84 log_warn("control_init: socket");
85 return (-1);
86 }
87
88 bzero(&sun, sizeof(sun));
89 sun.sun_family = AF_UNIX;
90 strlcpy(sun.sun_path, path, sizeof(sun.sun_path));
91
92 if (unlink(path) == -1)
93 if (errno != ENOENT) {
94 log_warn("control_init: unlink %s", path);
95 close(fd);
96 return (-1);
97 }
98
99 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
100 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
101 log_warn("control_init: bind: %s", path);
102 close(fd);
103 umask(old_umask);
104 return (-1);
105 }
106 umask(old_umask);
107
108 if (chmod(path, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) {
109 log_warn("control_init: chmod");
110 close(fd);
111 (void)unlink(path);
112 return (-1);
113 }
114
115 return (fd);
116}
117
118int
119control_listen(int fd)
120{
121 control_state.fd = fd;
122
123 if (listen(control_state.fd, CONTROL_BACKLOG) == -1) {
124 log_warn("control_listen: listen");
125 return (-1);
126 }
127
128 event_set(&control_state.ev, control_state.fd, EV_READ,
129 control_accept, NULL);
130 event_add(&control_state.ev, NULL);
131 evtimer_set(&control_state.evt, control_accept, NULL);
132
133 return (0);
134}
135
136void
137control_cleanup(void)
138{
139 event_del(&control_state.ev);
140 event_del(&control_state.evt);
141}
142
143void
144control_accept(int listenfd, short event, void *bula)
145{
146 int connfd;
147 socklen_t len;
148 struct sockaddr_un sun;
149 struct ctl_conn *c;
150
151 event_add(&control_state.ev, NULL);
152 if ((event & EV_TIMEOUT))
153 return;
154
155 len = sizeof(sun);
156 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len,
157 SOCK_CLOEXEC | SOCK_NONBLOCK)) == -1) {
158 /*
159 * Pause accept if we are out of file descriptors, or
160 * libevent will haunt us here too.
161 */
162 if (errno == ENFILE || errno == EMFILE) {
163 struct timeval evtpause = { 1, 0 };
164
165 event_del(&control_state.ev);
166 evtimer_add(&control_state.evt, &evtpause);
167 } else if (errno != EWOULDBLOCK && errno != EINTR &&
168 errno != ECONNABORTED)
169 log_warn("control_accept: accept");
170 return;
171 }
172
173 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) {
174 log_warn("control_accept");
175 close(connfd);
176 return;
177 }
178
179 if (imsgbuf_init(&c->iev.ibuf, connfd) == -1) {
180 log_warn("imsgbuf_init");
181 close(connfd);
182 free(c);
183 return;
184 }
185 c->iev.handler = control_dispatch_imsg;
186 c->iev.events = EV_READ;
187 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
188 c->iev.handler, &c->iev);
189 event_add(&c->iev.ev, NULL);
190
191 TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
192}
193
194struct ctl_conn *
195control_connbyfd(int fd)
196{
197 struct ctl_conn *c;
198
199 TAILQ_FOREACH(c, &ctl_conns, entry) {
200 if (c->iev.ibuf.fd == fd)
201 break;
202 }
203
204 return (c);
205}
206
207struct ctl_conn *
208control_connbypid(pid_t pid)
209{
210 struct ctl_conn *c;
211
212 TAILQ_FOREACH(c, &ctl_conns, entry) {
213 if (c->iev.ibuf.pid == pid)
214 break;
215 }
216
217 return (c);
218}
219
220void
221control_close(int fd)
222{
223 struct ctl_conn *c;
224
225 if ((c = control_connbyfd(fd)) == NULL) {
226 log_warn("control_close: fd %d: not found", fd);
227 return;
228 }
229
230 imsgbuf_clear(&c->iev.ibuf);
231 TAILQ_REMOVE(&ctl_conns, c, entry);
232
233 event_del(&c->iev.ev);
234 close(c->iev.ibuf.fd);
235
236 /* Some file descriptors are available again. */
237 if (evtimer_pending(&control_state.evt, NULL)) {
238 evtimer_del(&control_state.evt);
239 event_add(&control_state.ev, NULL);
240 }
241
242 free(c);
243}
244
245void
246control_dispatch_imsg(int fd, short event, void *bula)
247{
248 struct ctl_conn *c;
249 struct imsg imsg;
250 ssize_t n;
251 unsigned int ifidx;
252 int verbose;
253
254 if ((c = control_connbyfd(fd)) == NULL) {
255 log_warn("control_dispatch_imsg: fd %d: not found", fd);
256 return;
257 }
258
259 if (event & EV_READ) {
260 if (imsgbuf_read(&c->iev.ibuf) != 1) {
261 control_close(fd);
262 return;
263 }
264 }
265 if (event & EV_WRITE) {
266 if (imsgbuf_write(&c->iev.ibuf) == -1) {
267 control_close(fd);
268 return;
269 }
270 }
271
272 for (;;) {
273 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
274 control_close(fd);
275 return;
276 }
277
278 if (n == 0)
279 break;
280
281 switch (imsg.hdr.type) {
282 case IMSG_CTL_FIB_COUPLE:
283 case IMSG_CTL_FIB_DECOUPLE:
284 ospfe_fib_update(imsg.hdr.type);
285 /* FALLTHROUGH */
286 case IMSG_CTL_FIB_RELOAD:
287 case IMSG_CTL_RELOAD:
288 c->iev.ibuf.pid = imsg.hdr.pid;
289 ospfe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0);
290 break;
291 case IMSG_CTL_KROUTE:
292 case IMSG_CTL_KROUTE_ADDR:
293 case IMSG_CTL_IFINFO:
294 c->iev.ibuf.pid = imsg.hdr.pid;
295 ospfe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid,
296 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
297 break;
298 case IMSG_CTL_SHOW_INTERFACE:
299 if (imsg.hdr.len == IMSG_HEADER_SIZE +
300 sizeof(ifidx)) {
301 memcpy(&ifidx, imsg.data, sizeof(ifidx));
302 ospfe_iface_ctl(c, ifidx);
303 imsg_compose_event(&c->iev, IMSG_CTL_END, 0,
304 0, -1, NULL, 0);
305 }
306 break;
307 case IMSG_CTL_SHOW_DATABASE:
308 case IMSG_CTL_SHOW_DB_EXT:
309 case IMSG_CTL_SHOW_DB_NET:
310 case IMSG_CTL_SHOW_DB_RTR:
311 case IMSG_CTL_SHOW_DB_SELF:
312 case IMSG_CTL_SHOW_DB_SUM:
313 case IMSG_CTL_SHOW_DB_ASBR:
314 case IMSG_CTL_SHOW_DB_OPAQ:
315 case IMSG_CTL_SHOW_RIB:
316 case IMSG_CTL_SHOW_SUM:
317 c->iev.ibuf.pid = imsg.hdr.pid;
318 ospfe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid,
319 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
320 break;
321 case IMSG_CTL_SHOW_NBR:
322 ospfe_nbr_ctl(c);
323 break;
324 case IMSG_CTL_LOG_VERBOSE:
325 if (imsg.hdr.len != IMSG_HEADER_SIZE +
326 sizeof(verbose))
327 break;
328
329 /* forward to other processes */
330 ospfe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid,
331 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
332 ospfe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid,
333 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
334
335 memcpy(&verbose, imsg.data, sizeof(verbose));
336 log_setverbose(verbose);
337 break;
338 default:
339 log_debug("control_dispatch_imsg: "
340 "error handling imsg %d", imsg.hdr.type);
341 break;
342 }
343 imsg_free(&imsg);
344 }
345
346 imsg_event_add(&c->iev);
347}
348
349int
350control_imsg_relay(struct imsg *imsg)
351{
352 struct ctl_conn *c;
353
354 if ((c = control_connbypid(imsg->hdr.pid)) == NULL)
355 return (0);
356
357 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid,
358 -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE));
359}