control.c revision 1.30 
1/*	$OpenBSD: control.c,v 1.30 2020/10/09 08:59:15 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;
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 *);
50
51static struct privsep_proc procs[] = {
52	{ "parent",	PROC_PARENT, NULL },
53	{ "ikev2",	PROC_IKEV2, control_dispatch_ikev2 },
54};
55
56pid_t
57control(struct privsep *ps, struct privsep_proc *p)
58{
59	return (proc_run(ps, p, procs, nitems(procs), control_run, NULL));
60}
61
62void
63control_run(struct privsep *ps, struct privsep_proc *p, void *arg)
64{
65	/*
66	 * pledge in the control process:
67	 * stdio - for malloc and basic I/O including events.
68	 * unix - for the control socket.
69	 */
70	if (pledge("stdio unix", NULL) == -1)
71		fatal("pledge");
72}
73
74int
75control_init(struct privsep *ps, struct control_sock *cs)
76{
77	struct iked		*env = ps->ps_env;
78	struct sockaddr_un	 sun;
79	int			 fd;
80	mode_t			 old_umask, mode;
81
82	if (cs->cs_name == NULL)
83		return (0);
84
85	if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0)) == -1) {
86		log_warn("%s: socket", __func__);
87		return (-1);
88	}
89
90	sun.sun_family = AF_UNIX;
91	if (strlcpy(sun.sun_path, cs->cs_name,
92	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
93		log_warn("%s: %s name too long", __func__, cs->cs_name);
94		close(fd);
95		return (-1);
96	}
97
98	if (unlink(cs->cs_name) == -1)
99		if (errno != ENOENT) {
100			log_warn("%s: unlink %s", __func__, cs->cs_name);
101			close(fd);
102			return (-1);
103		}
104
105	if (cs->cs_restricted) {
106		old_umask = umask(S_IXUSR|S_IXGRP|S_IXOTH);
107		mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
108	} else {
109		old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
110		mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
111	}
112
113	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
114		log_warn("%s: bind: %s", __func__, cs->cs_name);
115		close(fd);
116		(void)umask(old_umask);
117		return (-1);
118	}
119	(void)umask(old_umask);
120
121	if (chmod(cs->cs_name, mode) == -1) {
122		log_warn("%s: chmod", __func__);
123		close(fd);
124		(void)unlink(cs->cs_name);
125		return (-1);
126	}
127
128	cs->cs_fd = fd;
129	cs->cs_env = env;
130
131	return (0);
132}
133
134int
135control_listen(struct control_sock *cs)
136{
137	if (cs->cs_name == NULL)
138		return (0);
139
140	if (listen(cs->cs_fd, CONTROL_BACKLOG) == -1) {
141		log_warn("%s: listen", __func__);
142		return (-1);
143	}
144
145	event_set(&cs->cs_ev, cs->cs_fd, EV_READ,
146	    control_accept, cs);
147	event_add(&cs->cs_ev, NULL);
148	evtimer_set(&cs->cs_evt, control_accept, cs);
149
150	return (0);
151}
152
153/* ARGSUSED */
154void
155control_accept(int listenfd, short event, void *arg)
156{
157	struct control_sock	*cs = arg;
158	int			 connfd;
159	socklen_t		 len;
160	struct sockaddr_un	 sun;
161	struct ctl_conn		*c;
162
163	event_add(&cs->cs_ev, NULL);
164	if ((event & EV_TIMEOUT))
165		return;
166
167	len = sizeof(sun);
168	if ((connfd = accept4(listenfd,
169	    (struct sockaddr *)&sun, &len, SOCK_NONBLOCK)) == -1) {
170		/*
171		 * Pause accept if we are out of file descriptors, or
172		 * libevent will haunt us here too.
173		 */
174		if (errno == ENFILE || errno == EMFILE) {
175			struct timeval evtpause = { 1, 0 };
176
177			event_del(&cs->cs_ev);
178			evtimer_add(&cs->cs_evt, &evtpause);
179		} else if (errno != EWOULDBLOCK && errno != EINTR &&
180		    errno != ECONNABORTED)
181			log_warn("%s: accept", __func__);
182		return;
183	}
184
185	if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) {
186		log_warn("%s", __func__);
187		close(connfd);
188		return;
189	}
190
191	imsg_init(&c->iev.ibuf, connfd);
192	c->iev.handler = control_dispatch_imsg;
193	c->iev.events = EV_READ;
194	c->iev.data = cs;
195	event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
196	    c->iev.handler, c->iev.data);
197	event_add(&c->iev.ev, NULL);
198
199	TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
200}
201
202struct ctl_conn *
203control_connbyfd(int fd)
204{
205	struct ctl_conn	*c;
206
207	TAILQ_FOREACH(c, &ctl_conns, entry) {
208		if (c->iev.ibuf.fd == fd)
209			break;
210	}
211
212	return (c);
213}
214
215void
216control_close(int fd, struct control_sock *cs)
217{
218	struct ctl_conn	*c;
219
220	if ((c = control_connbyfd(fd)) == NULL) {
221		log_warn("%s: fd %d: not found", __func__, fd);
222		return;
223	}
224
225	msgbuf_clear(&c->iev.ibuf.w);
226	TAILQ_REMOVE(&ctl_conns, c, entry);
227
228	event_del(&c->iev.ev);
229	close(c->iev.ibuf.fd);
230
231	/* Some file descriptors are available again. */
232	if (evtimer_pending(&cs->cs_evt, NULL)) {
233		evtimer_del(&cs->cs_evt);
234		event_add(&cs->cs_ev, NULL);
235	}
236
237	free(c);
238}
239
240/* ARGSUSED */
241void
242control_dispatch_imsg(int fd, short event, void *arg)
243{
244	struct control_sock	*cs = arg;
245	struct iked		*env = cs->cs_env;
246	struct ctl_conn		*c;
247	struct imsg		 imsg;
248	int			 n, v;
249
250	if ((c = control_connbyfd(fd)) == NULL) {
251		log_warn("%s: fd %d: not found", __func__, fd);
252		return;
253	}
254
255	if (event & EV_READ) {
256		if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) ||
257		    n == 0) {
258			control_close(fd, cs);
259			return;
260		}
261	}
262	if (event & EV_WRITE) {
263		if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) {
264			control_close(fd, cs);
265			return;
266		}
267	}
268
269	for (;;) {
270		if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
271			control_close(fd, cs);
272			return;
273		}
274
275		if (n == 0)
276			break;
277
278		control_imsg_forward(&imsg);
279
280		switch (imsg.hdr.type) {
281		case IMSG_CTL_NOTIFY:
282			if (c->flags & CTL_CONN_NOTIFY) {
283				log_debug("%s: "
284				    "client requested notify more than once",
285				    __func__);
286				imsg_compose_event(&c->iev, IMSG_CTL_FAIL,
287				    0, 0, -1, NULL, 0);
288				break;
289			}
290			c->flags |= CTL_CONN_NOTIFY;
291			break;
292		case IMSG_CTL_VERBOSE:
293			IMSG_SIZE_CHECK(&imsg, &v);
294
295			memcpy(&v, imsg.data, sizeof(v));
296			log_setverbose(v);
297
298			proc_forward_imsg(&env->sc_ps, &imsg, PROC_PARENT, -1);
299			break;
300		case IMSG_CTL_RELOAD:
301		case IMSG_CTL_RESET:
302		case IMSG_CTL_COUPLE:
303		case IMSG_CTL_DECOUPLE:
304		case IMSG_CTL_ACTIVE:
305		case IMSG_CTL_PASSIVE:
306			proc_forward_imsg(&env->sc_ps, &imsg, PROC_PARENT, -1);
307			break;
308		case IMSG_CTL_RESET_ID:
309			proc_forward_imsg(&env->sc_ps, &imsg, PROC_IKEV2, -1);
310			break;
311		case IMSG_CTL_SHOW_SA:
312			proc_forward_imsg(&env->sc_ps, &imsg, PROC_IKEV2, -1);
313			c->flags |= CTL_CONN_NOTIFY;
314			break;
315		default:
316			log_debug("%s: error handling imsg %d",
317			    __func__, imsg.hdr.type);
318			break;
319		}
320		imsg_free(&imsg);
321	}
322
323	imsg_event_add(&c->iev);
324}
325
326void
327control_imsg_forward(struct imsg *imsg)
328{
329	struct ctl_conn *c;
330
331	TAILQ_FOREACH(c, &ctl_conns, entry)
332		if (c->flags & CTL_CONN_NOTIFY)
333			imsg_compose_event(&c->iev, imsg->hdr.type,
334			    0, imsg->hdr.pid, -1, imsg->data,
335			    imsg->hdr.len - IMSG_HEADER_SIZE);
336}
337
338int
339control_dispatch_ikev2(int fd, struct privsep_proc *p, struct imsg *imsg)
340{
341	switch (imsg->hdr.type) {
342	case IMSG_CTL_SHOW_SA:
343		control_imsg_forward(imsg);
344		return (0);
345	default:
346		break;
347	}
348
349	return (-1);
350}
351