control.c revision 1.33 
1/*	$OpenBSD: control.c,v 1.33 2022/09/19 20:54:02 tobhe Exp $	*/
2
3/*
4 * Copyright (c) 2010-2013 Reyk Floeter <reyk@openbsd.org>
5 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20#include <sys/queue.h>
21#include <sys/stat.h>
22#include <sys/socket.h>
23#include <sys/un.h>
24#include <sys/tree.h>
25
26#include <errno.h>
27#include <event.h>
28#include <fcntl.h>
29#include <stdlib.h>
30#include <string.h>
31#include <unistd.h>
32#include <signal.h>
33
34#include "iked.h"
35
36#define	CONTROL_BACKLOG	5
37
38struct ctl_connlist ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns);
39
40void
41	 control_accept(int, short, void *);
42struct ctl_conn
43	*control_connbyfd(int);
44void	 control_close(int, struct control_sock *);
45void	 control_dispatch_imsg(int, short, void *);
46void	 control_dispatch_parent(int, short, void *);
47void	 control_imsg_forward(struct imsg *);
48void	 control_run(struct privsep *, struct privsep_proc *, void *);
49int	 control_dispatch_ikev2(int, struct privsep_proc *, struct imsg *);
50int	 control_dispatch_ca(int, struct privsep_proc *, struct imsg *);
51
52static struct privsep_proc procs[] = {
53	{ "parent",	PROC_PARENT, NULL },
54	{ "ikev2",	PROC_IKEV2, control_dispatch_ikev2 },
55	{ "ca",		PROC_CERT, control_dispatch_ca },
56};
57
58pid_t
59control(struct privsep *ps, struct privsep_proc *p)
60{
61	return (proc_run(ps, p, procs, nitems(procs), control_run, NULL));
62}
63
64void
65control_run(struct privsep *ps, struct privsep_proc *p, void *arg)
66{
67	/*
68	 * pledge in the control process:
69	 * stdio - for malloc and basic I/O including events.
70	 * unix - for the control socket.
71	 */
72	if (pledge("stdio unix", NULL) == -1)
73		fatal("pledge");
74}
75
76int
77control_init(struct privsep *ps, struct control_sock *cs)
78{
79	struct iked		*env = ps->ps_env;
80	struct sockaddr_un	 sun;
81	int			 fd;
82	mode_t			 old_umask, mode;
83
84	if (cs->cs_name == NULL)
85		return (0);
86
87	if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0)) == -1) {
88		log_warn("%s: socket", __func__);
89		return (-1);
90	}
91
92	sun.sun_family = AF_UNIX;
93	if (strlcpy(sun.sun_path, cs->cs_name,
94	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
95		log_warn("%s: %s name too long", __func__, cs->cs_name);
96		close(fd);
97		return (-1);
98	}
99
100	if (unlink(cs->cs_name) == -1)
101		if (errno != ENOENT) {
102			log_warn("%s: unlink %s", __func__, cs->cs_name);
103			close(fd);
104			return (-1);
105		}
106
107	if (cs->cs_restricted) {
108		old_umask = umask(S_IXUSR|S_IXGRP|S_IXOTH);
109		mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
110	} else {
111		old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
112		mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
113	}
114
115	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
116		log_warn("%s: bind: %s", __func__, cs->cs_name);
117		close(fd);
118		(void)umask(old_umask);
119		return (-1);
120	}
121	(void)umask(old_umask);
122
123	if (chmod(cs->cs_name, mode) == -1) {
124		log_warn("%s: chmod", __func__);
125		close(fd);
126		(void)unlink(cs->cs_name);
127		return (-1);
128	}
129
130	cs->cs_fd = fd;
131	cs->cs_env = env;
132
133	return (0);
134}
135
136int
137control_listen(struct control_sock *cs)
138{
139	if (cs->cs_name == NULL)
140		return (0);
141
142	if (listen(cs->cs_fd, CONTROL_BACKLOG) == -1) {
143		log_warn("%s: listen", __func__);
144		return (-1);
145	}
146
147	event_set(&cs->cs_ev, cs->cs_fd, EV_READ,
148	    control_accept, cs);
149	event_add(&cs->cs_ev, NULL);
150	evtimer_set(&cs->cs_evt, control_accept, cs);
151
152	return (0);
153}
154
155/* ARGSUSED */
156void
157control_accept(int listenfd, short event, void *arg)
158{
159	struct control_sock	*cs = arg;
160	int			 connfd;
161	socklen_t		 len;
162	struct sockaddr_un	 sun;
163	struct ctl_conn		*c;
164
165	event_add(&cs->cs_ev, NULL);
166	if ((event & EV_TIMEOUT))
167		return;
168
169	len = sizeof(sun);
170	if ((connfd = accept4(listenfd,
171	    (struct sockaddr *)&sun, &len, SOCK_NONBLOCK)) == -1) {
172		/*
173		 * Pause accept if we are out of file descriptors, or
174		 * libevent will haunt us here too.
175		 */
176		if (errno == ENFILE || errno == EMFILE) {
177			struct timeval evtpause = { 1, 0 };
178
179			event_del(&cs->cs_ev);
180			evtimer_add(&cs->cs_evt, &evtpause);
181		} else if (errno != EWOULDBLOCK && errno != EINTR &&
182		    errno != ECONNABORTED)
183			log_warn("%s: accept", __func__);
184		return;
185	}
186
187	if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) {
188		log_warn("%s", __func__);
189		close(connfd);
190		return;
191	}
192
193	imsg_init(&c->iev.ibuf, connfd);
194	c->iev.handler = control_dispatch_imsg;
195	c->iev.events = EV_READ;
196	c->iev.data = cs;
197	event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
198	    c->iev.handler, c->iev.data);
199	event_add(&c->iev.ev, NULL);
200
201	TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
202}
203
204struct ctl_conn *
205control_connbyfd(int fd)
206{
207	struct ctl_conn	*c;
208
209	TAILQ_FOREACH(c, &ctl_conns, entry) {
210		if (c->iev.ibuf.fd == fd)
211			break;
212	}
213
214	return (c);
215}
216
217void
218control_close(int fd, struct control_sock *cs)
219{
220	struct ctl_conn	*c;
221
222	if ((c = control_connbyfd(fd)) == NULL) {
223		log_warn("%s: fd %d: not found", __func__, fd);
224		return;
225	}
226
227	msgbuf_clear(&c->iev.ibuf.w);
228	TAILQ_REMOVE(&ctl_conns, c, entry);
229
230	event_del(&c->iev.ev);
231	close(c->iev.ibuf.fd);
232
233	/* Some file descriptors are available again. */
234	if (evtimer_pending(&cs->cs_evt, NULL)) {
235		evtimer_del(&cs->cs_evt);
236		event_add(&cs->cs_ev, NULL);
237	}
238
239	free(c);
240}
241
242/* ARGSUSED */
243void
244control_dispatch_imsg(int fd, short event, void *arg)
245{
246	struct control_sock	*cs = arg;
247	struct iked		*env = cs->cs_env;
248	struct ctl_conn		*c;
249	struct imsg		 imsg;
250	int			 n, v;
251
252	if ((c = control_connbyfd(fd)) == NULL) {
253		log_warn("%s: fd %d: not found", __func__, fd);
254		return;
255	}
256
257	if (event & EV_READ) {
258		if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) ||
259		    n == 0) {
260			control_close(fd, cs);
261			return;
262		}
263	}
264	if (event & EV_WRITE) {
265		if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) {
266			control_close(fd, cs);
267			return;
268		}
269	}
270
271	for (;;) {
272		if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
273			control_close(fd, cs);
274			return;
275		}
276
277		if (n == 0)
278			break;
279
280		control_imsg_forward(&imsg);
281
282		switch (imsg.hdr.type) {
283		case IMSG_CTL_NOTIFY:
284			if (c->flags & CTL_CONN_NOTIFY) {
285				log_debug("%s: "
286				    "client requested notify more than once",
287				    __func__);
288				imsg_compose_event(&c->iev, IMSG_CTL_FAIL,
289				    0, 0, -1, NULL, 0);
290				break;
291			}
292			c->flags |= CTL_CONN_NOTIFY;
293			break;
294		case IMSG_CTL_VERBOSE:
295			IMSG_SIZE_CHECK(&imsg, &v);
296
297			memcpy(&v, imsg.data, sizeof(v));
298			log_setverbose(v);
299
300			proc_forward_imsg(&env->sc_ps, &imsg, PROC_PARENT, -1);
301			break;
302		case IMSG_CTL_RELOAD:
303		case IMSG_CTL_RESET:
304		case IMSG_CTL_COUPLE:
305		case IMSG_CTL_DECOUPLE:
306		case IMSG_CTL_ACTIVE:
307		case IMSG_CTL_PASSIVE:
308			proc_forward_imsg(&env->sc_ps, &imsg, PROC_PARENT, -1);
309			break;
310		case IMSG_CTL_RESET_ID:
311			proc_forward_imsg(&env->sc_ps, &imsg, PROC_IKEV2, -1);
312			break;
313		case IMSG_CTL_SHOW_SA:
314		case IMSG_CTL_SHOW_STATS:
315			proc_forward_imsg(&env->sc_ps, &imsg, PROC_IKEV2, -1);
316			c->flags |= CTL_CONN_NOTIFY;
317			break;
318		case IMSG_CTL_SHOW_CERTSTORE:
319			proc_forward_imsg(&env->sc_ps, &imsg, PROC_CERT, -1);
320			c->flags |= CTL_CONN_NOTIFY;
321			break;
322		default:
323			log_debug("%s: error handling imsg %d",
324			    __func__, imsg.hdr.type);
325			break;
326		}
327		imsg_free(&imsg);
328	}
329
330	imsg_event_add(&c->iev);
331}
332
333void
334control_imsg_forward(struct imsg *imsg)
335{
336	struct ctl_conn *c;
337
338	TAILQ_FOREACH(c, &ctl_conns, entry)
339		if (c->flags & CTL_CONN_NOTIFY)
340			imsg_compose_event(&c->iev, imsg->hdr.type,
341			    0, imsg->hdr.pid, -1, imsg->data,
342			    imsg->hdr.len - IMSG_HEADER_SIZE);
343}
344
345int
346control_dispatch_ikev2(int fd, struct privsep_proc *p, struct imsg *imsg)
347{
348	switch (imsg->hdr.type) {
349	case IMSG_CTL_SHOW_SA:
350	case IMSG_CTL_SHOW_STATS:
351		control_imsg_forward(imsg);
352		return (0);
353	default:
354		break;
355	}
356
357	return (-1);
358}
359
360int
361control_dispatch_ca(int fd, struct privsep_proc *p, struct imsg *imsg)
362{
363	switch (imsg->hdr.type) {
364	case IMSG_CTL_SHOW_CERTSTORE:
365		control_imsg_forward(imsg);
366		return (0);
367	default:
368		break;
369	}
370
371	return (-1);
372}
373