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1/* $OpenBSD: control.c,v 1.34 2024/11/21 13:38:15 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 "ripd.h"
30#include "rip.h"
31#include "ripe.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_init(char *path)
51{
52 struct sockaddr_un sun;
53 int fd;
54 mode_t old_umask;
55
56 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
57 0)) == -1) {
58 log_warn("control_init: socket");
59 return (-1);
60 }
61
62 bzero(&sun, sizeof(sun));
63 sun.sun_family = AF_UNIX;
64 strlcpy(sun.sun_path, path, sizeof(sun.sun_path));
65
66 if (unlink(path) == -1)
67 if (errno != ENOENT) {
68 log_warn("control_init: unlink %s", path);
69 close(fd);
70 return (-1);
71 }
72
73 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
74 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
75 log_warn("control_init: bind: %s", path);
76 close(fd);
77 umask(old_umask);
78 return (-1);
79 }
80 umask(old_umask);
81
82 if (chmod(path, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) {
83 log_warn("control_init: chmod");
84 close(fd);
85 (void)unlink(path);
86 return (-1);
87 }
88
89 control_state.fd = fd;
90
91 return (0);
92}
93
94int
95control_listen(void)
96{
97 if (listen(control_state.fd, CONTROL_BACKLOG) == -1) {
98 log_warn("control_listen: listen");
99 return (-1);
100 }
101
102 event_set(&control_state.ev, control_state.fd, EV_READ,
103 control_accept, NULL);
104 event_add(&control_state.ev, NULL);
105 evtimer_set(&control_state.evt, control_accept, NULL);
106
107 return (0);
108}
109
110void
111control_accept(int listenfd, short event, void *bula)
112{
113 int connfd;
114 socklen_t len;
115 struct sockaddr_un sun;
116 struct ctl_conn *c;
117
118 event_add(&control_state.ev, NULL);
119 if ((event & EV_TIMEOUT))
120 return;
121
122 len = sizeof(sun);
123 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len,
124 SOCK_CLOEXEC | SOCK_NONBLOCK)) == -1) {
125 /*
126 * Pause accept if we are out of file descriptors, or
127 * libevent will haunt us here too.
128 */
129 if (errno == ENFILE || errno == EMFILE) {
130 struct timeval evtpause = { 1, 0 };
131
132 event_del(&control_state.ev);
133 evtimer_add(&control_state.evt, &evtpause);
134 } else if (errno != EWOULDBLOCK && errno != EINTR &&
135 errno != ECONNABORTED)
136 log_warn("control_accept: accept");
137 return;
138 }
139
140 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) {
141 log_warn("control_accept");
142 close(connfd);
143 return;
144 }
145
146 if (imsgbuf_init(&c->iev.ibuf, connfd) == -1) {
147 log_warn("control_accept");
148 close(connfd);
149 free(c);
150 return;
151 }
152 c->iev.handler = control_dispatch_imsg;
153 c->iev.events = EV_READ;
154 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
155 c->iev.handler, &c->iev);
156 event_add(&c->iev.ev, NULL);
157
158 TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
159}
160
161struct ctl_conn *
162control_connbyfd(int fd)
163{
164 struct ctl_conn *c;
165
166 TAILQ_FOREACH(c, &ctl_conns, entry) {
167 if (c->iev.ibuf.fd == fd)
168 break;
169 }
170
171 return (c);
172}
173
174struct ctl_conn *
175control_connbypid(pid_t pid)
176{
177 struct ctl_conn *c;
178
179 TAILQ_FOREACH(c, &ctl_conns, entry) {
180 if (c->iev.ibuf.pid == pid)
181 break;
182 }
183
184 return (c);
185}
186
187void
188control_close(int fd)
189{
190 struct ctl_conn *c;
191
192 if ((c = control_connbyfd(fd)) == NULL) {
193 log_warn("control_close: fd %d: not found", fd);
194 return;
195 }
196
197 imsgbuf_clear(&c->iev.ibuf);
198 TAILQ_REMOVE(&ctl_conns, c, entry);
199
200 event_del(&c->iev.ev);
201 close(c->iev.ibuf.fd);
202
203 /* Some file descriptors are available again. */
204 if (evtimer_pending(&control_state.evt, NULL)) {
205 evtimer_del(&control_state.evt);
206 event_add(&control_state.ev, NULL);
207 }
208
209 free(c);
210}
211
212void
213control_dispatch_imsg(int fd, short event, void *bula)
214{
215 struct ctl_conn *c;
216 struct imsg imsg;
217 ssize_t n;
218 unsigned int ifidx;
219 int verbose;
220
221 if ((c = control_connbyfd(fd)) == NULL) {
222 log_warn("control_dispatch_imsg: fd %d: not found", fd);
223 return;
224 }
225
226 if (event & EV_READ) {
227 if (imsgbuf_read(&c->iev.ibuf) != 1) {
228 control_close(fd);
229 return;
230 }
231 }
232 if (event & EV_WRITE) {
233 if (imsgbuf_write(&c->iev.ibuf) == -1) {
234 control_close(fd);
235 return;
236 }
237 }
238
239 for (;;) {
240 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
241 control_close(fd);
242 return;
243 }
244
245 if (n == 0)
246 break;
247
248 switch (imsg.hdr.type) {
249 case IMSG_CTL_SHOW_INTERFACE:
250 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(ifidx))
251 return;
252
253 memcpy(&ifidx, imsg.data, sizeof(ifidx));
254 ripe_iface_ctl(c, ifidx);
255 imsg_compose(&c->iev.ibuf, IMSG_CTL_END, 0, 0,
256 -1, NULL, 0);
257
258 break;
259 case IMSG_CTL_SHOW_RIB:
260 c->iev.ibuf.pid = imsg.hdr.pid;
261 ripe_imsg_compose_rde(imsg.hdr.type, 0,
262 imsg.hdr.pid, imsg.data, imsg.hdr.len -
263 IMSG_HEADER_SIZE);
264 break;
265 case IMSG_CTL_SHOW_NBR:
266 ripe_nbr_ctl(c);
267 break;
268 case IMSG_CTL_KROUTE_ADDR:
269 case IMSG_CTL_KROUTE:
270 case IMSG_CTL_IFINFO:
271 c->iev.ibuf.pid = imsg.hdr.pid;
272 ripe_imsg_compose_parent(imsg.hdr.type,
273 imsg.hdr.pid, imsg.data,
274 imsg.hdr.len - IMSG_HEADER_SIZE);
275 break;
276 case IMSG_CTL_FIB_COUPLE:
277 case IMSG_CTL_FIB_DECOUPLE:
278 case IMSG_CTL_RELOAD:
279 c->iev.ibuf.pid = imsg.hdr.pid;
280 ripe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0);
281 break;
282 case IMSG_CTL_LOG_VERBOSE:
283 if (imsg.hdr.len != IMSG_HEADER_SIZE +
284 sizeof(verbose))
285 break;
286
287 /* forward to other processes */
288 ripe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid,
289 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
290 ripe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid,
291 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
292
293 memcpy(&verbose, imsg.data, sizeof(verbose));
294 log_verbose(verbose);
295 break;
296 default:
297 log_debug("control_dispatch_imsg: "
298 "error handling imsg %d", imsg.hdr.type);
299 break;
300 }
301 imsg_free(&imsg);
302 }
303
304 imsg_event_add(&c->iev);
305}
306
307int
308control_imsg_relay(struct imsg *imsg)
309{
310 struct ctl_conn *c;
311
312 if ((c = control_connbypid(imsg->hdr.pid)) == NULL)
313 return (0);
314
315 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid,
316 -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE));
317}