1 /* $OpenBSD: control.c,v 1.28 2023/03/08 04:43:14 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 "ripd.h"
30 #include "rip.h"
31 #include "ripe.h"
32 #include "log.h"
33 #include "control.h"
34
35 TAILQ_HEAD(ctl_conns, ctl_conn) ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns);
36
37 #define CONTROL_BACKLOG 5
38
39 struct ctl_conn *control_connbyfd(int);
40 struct ctl_conn *control_connbypid(pid_t);
41 void control_close(int);
42
43 struct {
44 struct event ev;
45 struct event evt;
46 int fd;
47 } control_state;
48
49 int
control_init(char * path)50 control_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
94 int
control_listen(void)95 control_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
110 void
control_accept(int listenfd,short event,void * bula)111 control_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 imsg_init(&c->iev.ibuf, connfd);
147 c->iev.handler = control_dispatch_imsg;
148 c->iev.events = EV_READ;
149 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
150 c->iev.handler, &c->iev);
151 event_add(&c->iev.ev, NULL);
152
153 TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
154 }
155
156 struct ctl_conn *
control_connbyfd(int fd)157 control_connbyfd(int fd)
158 {
159 struct ctl_conn *c;
160
161 TAILQ_FOREACH(c, &ctl_conns, entry) {
162 if (c->iev.ibuf.fd == fd)
163 break;
164 }
165
166 return (c);
167 }
168
169 struct ctl_conn *
control_connbypid(pid_t pid)170 control_connbypid(pid_t pid)
171 {
172 struct ctl_conn *c;
173
174 TAILQ_FOREACH(c, &ctl_conns, entry) {
175 if (c->iev.ibuf.pid == pid)
176 break;
177 }
178
179 return (c);
180 }
181
182 void
control_close(int fd)183 control_close(int fd)
184 {
185 struct ctl_conn *c;
186
187 if ((c = control_connbyfd(fd)) == NULL) {
188 log_warn("control_close: fd %d: not found", fd);
189 return;
190 }
191
192 msgbuf_clear(&c->iev.ibuf.w);
193 TAILQ_REMOVE(&ctl_conns, c, entry);
194
195 event_del(&c->iev.ev);
196 close(c->iev.ibuf.fd);
197
198 /* Some file descriptors are available again. */
199 if (evtimer_pending(&control_state.evt, NULL)) {
200 evtimer_del(&control_state.evt);
201 event_add(&control_state.ev, NULL);
202 }
203
204 free(c);
205 }
206
207 void
control_dispatch_imsg(int fd,short event,void * bula)208 control_dispatch_imsg(int fd, short event, void *bula)
209 {
210 struct ctl_conn *c;
211 struct imsg imsg;
212 ssize_t n;
213 unsigned int ifidx;
214 int verbose;
215
216 if ((c = control_connbyfd(fd)) == NULL) {
217 log_warn("control_dispatch_imsg: fd %d: not found", fd);
218 return;
219 }
220
221 if (event & EV_READ) {
222 if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) ||
223 n == 0) {
224 control_close(fd);
225 return;
226 }
227 }
228 if (event & EV_WRITE) {
229 if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) {
230 control_close(fd);
231 return;
232 }
233 }
234
235 for (;;) {
236 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
237 control_close(fd);
238 return;
239 }
240
241 if (n == 0)
242 break;
243
244 switch (imsg.hdr.type) {
245 case IMSG_CTL_SHOW_INTERFACE:
246 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(ifidx))
247 return;
248
249 memcpy(&ifidx, imsg.data, sizeof(ifidx));
250 ripe_iface_ctl(c, ifidx);
251 imsg_compose(&c->iev.ibuf, IMSG_CTL_END, 0, 0,
252 -1, NULL, 0);
253
254 break;
255 case IMSG_CTL_SHOW_RIB:
256 c->iev.ibuf.pid = imsg.hdr.pid;
257 ripe_imsg_compose_rde(imsg.hdr.type, 0,
258 imsg.hdr.pid, imsg.data, imsg.hdr.len -
259 IMSG_HEADER_SIZE);
260 break;
261 case IMSG_CTL_SHOW_NBR:
262 ripe_nbr_ctl(c);
263 break;
264 case IMSG_CTL_KROUTE_ADDR:
265 case IMSG_CTL_KROUTE:
266 case IMSG_CTL_IFINFO:
267 c->iev.ibuf.pid = imsg.hdr.pid;
268 ripe_imsg_compose_parent(imsg.hdr.type,
269 imsg.hdr.pid, imsg.data,
270 imsg.hdr.len - IMSG_HEADER_SIZE);
271 break;
272 case IMSG_CTL_FIB_COUPLE:
273 case IMSG_CTL_FIB_DECOUPLE:
274 case IMSG_CTL_RELOAD:
275 c->iev.ibuf.pid = imsg.hdr.pid;
276 ripe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0);
277 break;
278 case IMSG_CTL_LOG_VERBOSE:
279 if (imsg.hdr.len != IMSG_HEADER_SIZE +
280 sizeof(verbose))
281 break;
282
283 /* forward to other processes */
284 ripe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid,
285 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
286 ripe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid,
287 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
288
289 memcpy(&verbose, imsg.data, sizeof(verbose));
290 log_verbose(verbose);
291 break;
292 default:
293 log_debug("control_dispatch_imsg: "
294 "error handling imsg %d", imsg.hdr.type);
295 break;
296 }
297 imsg_free(&imsg);
298 }
299
300 imsg_event_add(&c->iev);
301 }
302
303 int
control_imsg_relay(struct imsg * imsg)304 control_imsg_relay(struct imsg *imsg)
305 {
306 struct ctl_conn *c;
307
308 if ((c = control_connbypid(imsg->hdr.pid)) == NULL)
309 return (0);
310
311 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid,
312 -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE));
313 }
314