control.c revision 1.24 
1/*	$OpenBSD: control.c,v 1.24 2017/01/09 14:49:21 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 | SOCK_NONBLOCK, 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	cs->cs_fd = fd;
130	cs->cs_env = env;
131
132	return (0);
133}
134
135int
136control_listen(struct control_sock *cs)
137{
138	if (cs->cs_name == NULL)
139		return (0);
140
141	if (listen(cs->cs_fd, CONTROL_BACKLOG) == -1) {
142		log_warn("%s: listen", __func__);
143		return (-1);
144	}
145
146	event_set(&cs->cs_ev, cs->cs_fd, EV_READ,
147	    control_accept, cs);
148	event_add(&cs->cs_ev, NULL);
149	evtimer_set(&cs->cs_evt, control_accept, cs);
150
151	return (0);
152}
153
154void
155control_cleanup(struct control_sock *cs)
156{
157	if (cs->cs_name == NULL)
158		return;
159	event_del(&cs->cs_ev);
160	event_del(&cs->cs_evt);
161	(void)unlink(cs->cs_name);
162}
163
164/* ARGSUSED */
165void
166control_accept(int listenfd, short event, void *arg)
167{
168	struct control_sock	*cs = arg;
169	int			 connfd;
170	socklen_t		 len;
171	struct sockaddr_un	 sun;
172	struct ctl_conn		*c;
173
174	event_add(&cs->cs_ev, NULL);
175	if ((event & EV_TIMEOUT))
176		return;
177
178	len = sizeof(sun);
179	if ((connfd = accept4(listenfd,
180	    (struct sockaddr *)&sun, &len, SOCK_NONBLOCK)) == -1) {
181		/*
182		 * Pause accept if we are out of file descriptors, or
183		 * libevent will haunt us here too.
184		 */
185		if (errno == ENFILE || errno == EMFILE) {
186			struct timeval evtpause = { 1, 0 };
187
188			event_del(&cs->cs_ev);
189			evtimer_add(&cs->cs_evt, &evtpause);
190		} else if (errno != EWOULDBLOCK && errno != EINTR &&
191		    errno != ECONNABORTED)
192			log_warn("%s: accept", __func__);
193		return;
194	}
195
196	if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) {
197		log_warn("%s", __func__);
198		close(connfd);
199		return;
200	}
201
202	imsg_init(&c->iev.ibuf, connfd);
203	c->iev.handler = control_dispatch_imsg;
204	c->iev.events = EV_READ;
205	c->iev.data = cs;
206	event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
207	    c->iev.handler, c->iev.data);
208	event_add(&c->iev.ev, NULL);
209
210	TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
211}
212
213struct ctl_conn *
214control_connbyfd(int fd)
215{
216	struct ctl_conn	*c;
217
218	TAILQ_FOREACH(c, &ctl_conns, entry) {
219		if (c->iev.ibuf.fd == fd)
220			break;
221	}
222
223	return (c);
224}
225
226void
227control_close(int fd, struct control_sock *cs)
228{
229	struct ctl_conn	*c;
230
231	if ((c = control_connbyfd(fd)) == NULL) {
232		log_warn("%s: fd %d: not found", __func__, fd);
233		return;
234	}
235
236	msgbuf_clear(&c->iev.ibuf.w);
237	TAILQ_REMOVE(&ctl_conns, c, entry);
238
239	event_del(&c->iev.ev);
240	close(c->iev.ibuf.fd);
241
242	/* Some file descriptors are available again. */
243	if (evtimer_pending(&cs->cs_evt, NULL)) {
244		evtimer_del(&cs->cs_evt);
245		event_add(&cs->cs_ev, NULL);
246	}
247
248	free(c);
249}
250
251/* ARGSUSED */
252void
253control_dispatch_imsg(int fd, short event, void *arg)
254{
255	struct control_sock	*cs = arg;
256	struct iked		*env = cs->cs_env;
257	struct ctl_conn		*c;
258	struct imsg		 imsg;
259	int			 n, v;
260
261	if ((c = control_connbyfd(fd)) == NULL) {
262		log_warn("%s: fd %d: not found", __func__, fd);
263		return;
264	}
265
266	if (event & EV_READ) {
267		if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) ||
268		    n == 0) {
269			control_close(fd, cs);
270			return;
271		}
272	}
273	if (event & EV_WRITE) {
274		if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) {
275			control_close(fd, cs);
276			return;
277		}
278	}
279
280	for (;;) {
281		if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
282			control_close(fd, cs);
283			return;
284		}
285
286		if (n == 0)
287			break;
288
289		control_imsg_forward(&imsg);
290
291		switch (imsg.hdr.type) {
292		case IMSG_CTL_NOTIFY:
293			if (c->flags & CTL_CONN_NOTIFY) {
294				log_debug("%s: "
295				    "client requested notify more than once",
296				    __func__);
297				imsg_compose_event(&c->iev, IMSG_CTL_FAIL,
298				    0, 0, -1, NULL, 0);
299				break;
300			}
301			c->flags |= CTL_CONN_NOTIFY;
302			break;
303		case IMSG_CTL_VERBOSE:
304			IMSG_SIZE_CHECK(&imsg, &v);
305
306			memcpy(&v, imsg.data, sizeof(v));
307			log_setverbose(v);
308
309			proc_forward_imsg(&env->sc_ps, &imsg, PROC_PARENT, -1);
310			break;
311		case IMSG_CTL_RELOAD:
312		case IMSG_CTL_RESET:
313		case IMSG_CTL_COUPLE:
314		case IMSG_CTL_DECOUPLE:
315		case IMSG_CTL_ACTIVE:
316		case IMSG_CTL_PASSIVE:
317			proc_forward_imsg(&env->sc_ps, &imsg, PROC_PARENT, -1);
318			break;
319		default:
320			log_debug("%s: error handling imsg %d",
321			    __func__, imsg.hdr.type);
322			break;
323		}
324		imsg_free(&imsg);
325	}
326
327	imsg_event_add(&c->iev);
328}
329
330void
331control_imsg_forward(struct imsg *imsg)
332{
333	struct ctl_conn *c;
334
335	TAILQ_FOREACH(c, &ctl_conns, entry)
336		if (c->flags & CTL_CONN_NOTIFY)
337			imsg_compose_event(&c->iev, imsg->hdr.type,
338			    0, imsg->hdr.pid, -1, imsg->data,
339			    imsg->hdr.len - IMSG_HEADER_SIZE);
340}
341