1 /* $OpenBSD: control.c,v 1.25 2023/03/08 04:43:13 guenther 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 "igmp.h"
30 #include "dvmrpd.h"
31 #include "dvmrp.h"
32 #include "dvmrpe.h"
33 #include "log.h"
34 #include "control.h"
35
36 TAILQ_HEAD(ctl_conns, ctl_conn) ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns);
37
38 #define CONTROL_BACKLOG 5
39
40 struct ctl_conn *control_connbyfd(int);
41 struct ctl_conn *control_connbypid(pid_t);
42 void control_close(int);
43
44 struct {
45 struct event ev;
46 struct event evt;
47 int fd;
48 } control_state;
49
50 int
control_init(void)51 control_init(void)
52 {
53 struct sockaddr_un sun;
54 int fd;
55 mode_t old_umask;
56
57 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
58 0)) == -1) {
59 log_warn("control_init: socket");
60 return (-1);
61 }
62
63 memset(&sun, 0, sizeof(sun));
64 sun.sun_family = AF_UNIX;
65 strlcpy(sun.sun_path, DVMRPD_SOCKET, sizeof(sun.sun_path));
66
67 if (unlink(DVMRPD_SOCKET) == -1)
68 if (errno != ENOENT) {
69 log_warn("control_init: unlink %s", DVMRPD_SOCKET);
70 close(fd);
71 return (-1);
72 }
73
74 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
75 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
76 log_warn("control_init: bind: %s", DVMRPD_SOCKET);
77 close(fd);
78 umask(old_umask);
79 return (-1);
80 }
81 umask(old_umask);
82
83 if (chmod(DVMRPD_SOCKET, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) {
84 log_warn("control_init: chmod");
85 close(fd);
86 (void)unlink(DVMRPD_SOCKET);
87 return (-1);
88 }
89
90 control_state.fd = fd;
91
92 return (0);
93 }
94
95 int
control_listen(void)96 control_listen(void)
97 {
98 if (listen(control_state.fd, CONTROL_BACKLOG) == -1) {
99 log_warn("control_listen: listen");
100 return (-1);
101 }
102
103 event_set(&control_state.ev, control_state.fd, EV_READ,
104 control_accept, NULL);
105 event_add(&control_state.ev, NULL);
106 evtimer_set(&control_state.evt, control_accept, NULL);
107
108 return (0);
109 }
110
111 void
control_cleanup(void)112 control_cleanup(void)
113 {
114 event_del(&control_state.ev);
115 event_del(&control_state.evt);
116 unlink(DVMRPD_SOCKET);
117 }
118
119 void
control_accept(int listenfd,short event,void * bula)120 control_accept(int listenfd, short event, void *bula)
121 {
122 int connfd;
123 socklen_t len;
124 struct sockaddr_un sun;
125 struct ctl_conn *c;
126
127 event_add(&control_state.ev, NULL);
128 if ((event & EV_TIMEOUT))
129 return;
130
131 len = sizeof(sun);
132 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len,
133 SOCK_NONBLOCK | SOCK_CLOEXEC)) == -1) {
134 /*
135 * Pause accept if we are out of file descriptors, or
136 * libevent will haunt us here too.
137 */
138 if (errno == ENFILE || errno == EMFILE) {
139 struct timeval evtpause = { 1, 0 };
140
141 event_del(&control_state.ev);
142 evtimer_add(&control_state.evt, &evtpause);
143 } else if (errno != EWOULDBLOCK && errno != EINTR &&
144 errno != ECONNABORTED)
145 log_warn("control_accept: accept");
146 return;
147 }
148
149 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) {
150 log_warn("control_accept");
151 close(connfd);
152 return;
153 }
154
155 imsg_init(&c->iev.ibuf, connfd);
156 c->iev.handler = control_dispatch_imsg;
157 c->iev.events = EV_READ;
158 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
159 c->iev.handler, &c->iev);
160 event_add(&c->iev.ev, NULL);
161
162 TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
163 }
164
165 struct ctl_conn *
control_connbyfd(int fd)166 control_connbyfd(int fd)
167 {
168 struct ctl_conn *c;
169
170 TAILQ_FOREACH(c, &ctl_conns, entry) {
171 if (c->iev.ibuf.fd == fd)
172 break;
173 }
174
175 return (c);
176 }
177
178 struct ctl_conn *
control_connbypid(pid_t pid)179 control_connbypid(pid_t pid)
180 {
181 struct ctl_conn *c;
182
183 TAILQ_FOREACH(c, &ctl_conns, entry) {
184 if (c->iev.ibuf.pid == pid)
185 break;
186 }
187
188 return (c);
189 }
190
191 void
control_close(int fd)192 control_close(int fd)
193 {
194 struct ctl_conn *c;
195
196 if ((c = control_connbyfd(fd)) == NULL) {
197 log_warn("control_close: fd %d: not found", fd);
198 return;
199 }
200
201 msgbuf_clear(&c->iev.ibuf.w);
202 TAILQ_REMOVE(&ctl_conns, c, entry);
203
204 event_del(&c->iev.ev);
205 close(c->iev.ibuf.fd);
206
207 /* Some file descriptors are available again. */
208 if (evtimer_pending(&control_state.evt, NULL)) {
209 evtimer_del(&control_state.evt);
210 event_add(&control_state.ev, NULL);
211 }
212
213 free(c);
214 }
215
216 void
control_dispatch_imsg(int fd,short event,void * bula)217 control_dispatch_imsg(int fd, short event, void *bula)
218 {
219 struct ctl_conn *c;
220 struct imsg imsg;
221 int n;
222 unsigned int ifidx;
223 int verbose;
224
225 if ((c = control_connbyfd(fd)) == NULL) {
226 log_warn("control_dispatch_imsg: fd %d: not found", fd);
227 return;
228 }
229
230 if (event & EV_READ) {
231 if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) ||
232 n == 0) {
233 control_close(fd);
234 return;
235 }
236 }
237 if (event & EV_WRITE) {
238 if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) {
239 control_close(fd);
240 return;
241 }
242 }
243
244 for (;;) {
245 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
246 control_close(fd);
247 return;
248 }
249
250 if (n == 0)
251 break;
252
253 switch (imsg.hdr.type) {
254 case IMSG_CTL_MFC_COUPLE:
255 case IMSG_CTL_MFC_DECOUPLE:
256 case IMSG_CTL_RELOAD:
257 dvmrpe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0);
258 break;
259 case IMSG_CTL_SHOW_IFACE:
260 if (imsg.hdr.len == IMSG_HEADER_SIZE +
261 sizeof(ifidx)) {
262 memcpy(&ifidx, imsg.data, sizeof(ifidx));
263 dvmrpe_iface_ctl(c, ifidx);
264 imsg_compose_event(&c->iev, IMSG_CTL_END, 0,
265 0, -1, NULL, 0);
266 }
267 break;
268 case IMSG_CTL_SHOW_IGMP:
269 if (imsg.hdr.len == IMSG_HEADER_SIZE +
270 sizeof(ifidx)) {
271 memcpy(&ifidx, imsg.data, sizeof(ifidx));
272 dvmrpe_iface_igmp_ctl(c, ifidx);
273 imsg_compose_event(&c->iev, IMSG_CTL_END, 0,
274 0, -1, NULL, 0);
275 }
276 break;
277 case IMSG_CTL_SHOW_NBR:
278 dvmrpe_nbr_ctl(c);
279 break;
280 case IMSG_CTL_SHOW_RIB:
281 case IMSG_CTL_SHOW_MFC:
282 case IMSG_CTL_SHOW_SUM:
283 c->iev.ibuf.pid = imsg.hdr.pid;
284 dvmrpe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid,
285 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
286 break;
287 case IMSG_CTL_LOG_VERBOSE:
288 if (imsg.hdr.len != IMSG_HEADER_SIZE +
289 sizeof(verbose))
290 break;
291
292 /* forward to other processes */
293 dvmrpe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid,
294 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
295 dvmrpe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid,
296 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
297
298 memcpy(&verbose, imsg.data, sizeof(verbose));
299 log_verbose(verbose);
300 break;
301 default:
302 log_debug("control_dispatch_imsg: "
303 "error handling imsg %d", imsg.hdr.type);
304 break;
305 }
306 imsg_free(&imsg);
307 }
308
309 imsg_event_add(&c->iev);
310 }
311
312 int
control_imsg_relay(struct imsg * imsg)313 control_imsg_relay(struct imsg *imsg)
314 {
315 struct ctl_conn *c;
316
317 if ((c = control_connbypid(imsg->hdr.pid)) == NULL)
318 return (0);
319
320 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid,
321 -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE));
322 }
323