control.c revision 1.19 
1/*	$OpenBSD: control.c,v 1.19 2015/10/22 15:55:18 reyk 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 <net/if.h>
27
28#include <errno.h>
29#include <event.h>
30#include <fcntl.h>
31#include <stdlib.h>
32#include <string.h>
33#include <unistd.h>
34#include <signal.h>
35
36#include "iked.h"
37
38#define	CONTROL_BACKLOG	5
39
40struct ctl_connlist ctl_conns;
41
42void
43	 control_accept(int, short, void *);
44struct ctl_conn
45	*control_connbyfd(int);
46void	 control_close(int, struct control_sock *);
47void	 control_dispatch_imsg(int, short, void *);
48void	 control_dispatch_parent(int, short, void *);
49void	 control_imsg_forward(struct imsg *);
50void	 control_run(struct privsep *, struct privsep_proc *, void *);
51
52static struct privsep_proc procs[] = {
53	{ "parent",	PROC_PARENT, NULL }
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	 * cpath - for unlinking the control socket.
69	 * unix - for the control socket.
70	 */
71	if (pledge("stdio cpath unix", NULL) == -1)
72		fatal("pledge");
73}
74
75int
76control_init(struct privsep *ps, struct control_sock *cs)
77{
78	struct iked		*env = ps->ps_env;
79	struct sockaddr_un	 sun;
80	int			 fd;
81	mode_t			 old_umask, mode;
82
83	if (cs->cs_name == NULL)
84		return (0);
85
86	if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
87		log_warn("%s: socket", __func__);
88		return (-1);
89	}
90
91	sun.sun_family = AF_UNIX;
92	if (strlcpy(sun.sun_path, cs->cs_name,
93	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
94		log_warn("%s: %s name too long", __func__, cs->cs_name);
95		close(fd);
96		return (-1);
97	}
98
99	if (unlink(cs->cs_name) == -1)
100		if (errno != ENOENT) {
101			log_warn("%s: unlink %s", __func__, cs->cs_name);
102			close(fd);
103			return (-1);
104		}
105
106	if (cs->cs_restricted) {
107		old_umask = umask(S_IXUSR|S_IXGRP|S_IXOTH);
108		mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
109	} else {
110		old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
111		mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
112	}
113
114	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
115		log_warn("%s: bind: %s", __func__, cs->cs_name);
116		close(fd);
117		(void)umask(old_umask);
118		return (-1);
119	}
120	(void)umask(old_umask);
121
122	if (chmod(cs->cs_name, mode) == -1) {
123		log_warn("%s: chmod", __func__);
124		close(fd);
125		(void)unlink(cs->cs_name);
126		return (-1);
127	}
128
129	socket_set_blockmode(fd, BM_NONBLOCK);
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
155void
156control_cleanup(struct control_sock *cs)
157{
158	if (cs->cs_name == NULL)
159		return;
160	event_del(&cs->cs_ev);
161	event_del(&cs->cs_evt);
162	(void)unlink(cs->cs_name);
163}
164
165/* ARGSUSED */
166void
167control_accept(int listenfd, short event, void *arg)
168{
169	struct control_sock	*cs = arg;
170	int			 connfd;
171	socklen_t		 len;
172	struct sockaddr_un	 sun;
173	struct ctl_conn		*c;
174
175	event_add(&cs->cs_ev, NULL);
176	if ((event & EV_TIMEOUT))
177		return;
178
179	len = sizeof(sun);
180	if ((connfd = accept(listenfd,
181	    (struct sockaddr *)&sun, &len)) == -1) {
182		/*
183		 * Pause accept if we are out of file descriptors, or
184		 * libevent will haunt us here too.
185		 */
186		if (errno == ENFILE || errno == EMFILE) {
187			struct timeval evtpause = { 1, 0 };
188
189			event_del(&cs->cs_ev);
190			evtimer_add(&cs->cs_evt, &evtpause);
191		} else if (errno != EWOULDBLOCK && errno != EINTR &&
192		    errno != ECONNABORTED)
193			log_warn("%s: accept", __func__);
194		return;
195	}
196
197	socket_set_blockmode(connfd, BM_NONBLOCK);
198
199	if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) {
200		log_warn("%s", __func__);
201		close(connfd);
202		return;
203	}
204
205	imsg_init(&c->iev.ibuf, connfd);
206	c->iev.handler = control_dispatch_imsg;
207	c->iev.events = EV_READ;
208	c->iev.data = cs;
209	event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
210	    c->iev.handler, c->iev.data);
211	event_add(&c->iev.ev, NULL);
212
213	TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
214}
215
216struct ctl_conn *
217control_connbyfd(int fd)
218{
219	struct ctl_conn	*c;
220
221	for (c = TAILQ_FIRST(&ctl_conns); c != NULL && c->iev.ibuf.fd != fd;
222	    c = TAILQ_NEXT(c, entry))
223		;	/* nothing */
224
225	return (c);
226}
227
228void
229control_close(int fd, struct control_sock *cs)
230{
231	struct ctl_conn	*c;
232
233	if ((c = control_connbyfd(fd)) == NULL) {
234		log_warn("%s: fd %d: not found", __func__, fd);
235		return;
236	}
237
238	msgbuf_clear(&c->iev.ibuf.w);
239	TAILQ_REMOVE(&ctl_conns, c, entry);
240
241	event_del(&c->iev.ev);
242	close(c->iev.ibuf.fd);
243
244	/* Some file descriptors are available again. */
245	if (evtimer_pending(&cs->cs_evt, NULL)) {
246		evtimer_del(&cs->cs_evt);
247		event_add(&cs->cs_ev, NULL);
248	}
249
250	free(c);
251}
252
253/* ARGSUSED */
254void
255control_dispatch_imsg(int fd, short event, void *arg)
256{
257	struct control_sock	*cs = arg;
258	struct iked		*env = cs->cs_env;
259	struct ctl_conn		*c;
260	struct imsg		 imsg;
261	int			 n, v;
262
263	if ((c = control_connbyfd(fd)) == NULL) {
264		log_warn("%s: fd %d: not found", __func__, fd);
265		return;
266	}
267
268	if (event & EV_READ) {
269		if ((n = imsg_read(&c->iev.ibuf)) == -1 || n == 0) {
270			control_close(fd, cs);
271			return;
272		}
273	}
274	if (event & EV_WRITE) {
275		if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) {
276			control_close(fd, cs);
277			return;
278		}
279	}
280
281	for (;;) {
282		if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
283			control_close(fd, cs);
284			return;
285		}
286
287		if (n == 0)
288			break;
289
290		control_imsg_forward(&imsg);
291
292		switch (imsg.hdr.type) {
293		case IMSG_CTL_NOTIFY:
294			if (c->flags & CTL_CONN_NOTIFY) {
295				log_debug("%s: "
296				    "client requested notify more than once",
297				    __func__);
298				imsg_compose_event(&c->iev, IMSG_CTL_FAIL,
299				    0, 0, -1, NULL, 0);
300				break;
301			}
302			c->flags |= CTL_CONN_NOTIFY;
303			break;
304		case IMSG_CTL_VERBOSE:
305			IMSG_SIZE_CHECK(&imsg, &v);
306
307			memcpy(&v, imsg.data, sizeof(v));
308			log_verbose(v);
309
310			proc_forward_imsg(&env->sc_ps, &imsg, PROC_PARENT, -1);
311			proc_forward_imsg(&env->sc_ps, &imsg, PROC_IKEV2, -1);
312			break;
313		case IMSG_CTL_RELOAD:
314		case IMSG_CTL_RESET:
315		case IMSG_CTL_COUPLE:
316		case IMSG_CTL_DECOUPLE:
317		case IMSG_CTL_ACTIVE:
318		case IMSG_CTL_PASSIVE:
319			proc_forward_imsg(&env->sc_ps, &imsg, PROC_PARENT, -1);
320			break;
321		default:
322			log_debug("%s: error handling imsg %d",
323			    __func__, imsg.hdr.type);
324			break;
325		}
326		imsg_free(&imsg);
327	}
328
329	imsg_event_add(&c->iev);
330}
331
332void
333control_imsg_forward(struct imsg *imsg)
334{
335	struct ctl_conn *c;
336
337	TAILQ_FOREACH(c, &ctl_conns, entry)
338		if (c->flags & CTL_CONN_NOTIFY)
339			imsg_compose_event(&c->iev, imsg->hdr.type,
340			    0, imsg->hdr.pid, -1, imsg->data,
341			    imsg->hdr.len - IMSG_HEADER_SIZE);
342}
343