xref: /freebsd/contrib/wpa/wpa_supplicant/ctrl_iface_unix.c (revision 6ae1554a5d9b318f8ad53ccc39fa5a961403da73)
1 /*
2  * WPA Supplicant / UNIX domain socket -based control interface
3  * Copyright (c) 2004-2014, Jouni Malinen <j@w1.fi>
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 
9 #include "includes.h"
10 #include <sys/un.h>
11 #include <sys/stat.h>
12 #include <grp.h>
13 #include <stddef.h>
14 #include <unistd.h>
15 #include <fcntl.h>
16 #ifdef ANDROID
17 #include <cutils/sockets.h>
18 #endif /* ANDROID */
19 
20 #include "utils/common.h"
21 #include "utils/eloop.h"
22 #include "utils/list.h"
23 #include "eapol_supp/eapol_supp_sm.h"
24 #include "config.h"
25 #include "wpa_supplicant_i.h"
26 #include "ctrl_iface.h"
27 
28 /* Per-interface ctrl_iface */
29 
30 /**
31  * struct wpa_ctrl_dst - Internal data structure of control interface monitors
32  *
33  * This structure is used to store information about registered control
34  * interface monitors into struct wpa_supplicant. This data is private to
35  * ctrl_iface_unix.c and should not be touched directly from other files.
36  */
37 struct wpa_ctrl_dst {
38 	struct dl_list list;
39 	struct sockaddr_un addr;
40 	socklen_t addrlen;
41 	int debug_level;
42 	int errors;
43 };
44 
45 
46 struct ctrl_iface_priv {
47 	struct wpa_supplicant *wpa_s;
48 	int sock;
49 	struct dl_list ctrl_dst;
50 	int android_control_socket;
51 };
52 
53 
54 struct ctrl_iface_global_priv {
55 	struct wpa_global *global;
56 	int sock;
57 	struct dl_list ctrl_dst;
58 	int android_control_socket;
59 };
60 
61 
62 static void wpa_supplicant_ctrl_iface_send(struct wpa_supplicant *wpa_s,
63 					   const char *ifname, int sock,
64 					   struct dl_list *ctrl_dst,
65 					   int level, const char *buf,
66 					   size_t len,
67 					   struct ctrl_iface_priv *priv,
68 					   struct ctrl_iface_global_priv *gp);
69 static int wpas_ctrl_iface_reinit(struct wpa_supplicant *wpa_s,
70 				  struct ctrl_iface_priv *priv);
71 static int wpas_ctrl_iface_global_reinit(struct wpa_global *global,
72 					 struct ctrl_iface_global_priv *priv);
73 
74 
75 static int wpa_supplicant_ctrl_iface_attach(struct dl_list *ctrl_dst,
76 					    struct sockaddr_un *from,
77 					    socklen_t fromlen, int global)
78 {
79 	struct wpa_ctrl_dst *dst;
80 	char addr_txt[200];
81 
82 	dst = os_zalloc(sizeof(*dst));
83 	if (dst == NULL)
84 		return -1;
85 	os_memcpy(&dst->addr, from, sizeof(struct sockaddr_un));
86 	dst->addrlen = fromlen;
87 	dst->debug_level = MSG_INFO;
88 	dl_list_add(ctrl_dst, &dst->list);
89 	printf_encode(addr_txt, sizeof(addr_txt),
90 		      (u8 *) from->sun_path,
91 		      fromlen - offsetof(struct sockaddr_un, sun_path));
92 	wpa_printf(MSG_DEBUG, "CTRL_IFACE %smonitor attached %s",
93 		   global ? "global " : "", addr_txt);
94 	return 0;
95 }
96 
97 
98 static int wpa_supplicant_ctrl_iface_detach(struct dl_list *ctrl_dst,
99 					    struct sockaddr_un *from,
100 					    socklen_t fromlen)
101 {
102 	struct wpa_ctrl_dst *dst;
103 
104 	dl_list_for_each(dst, ctrl_dst, struct wpa_ctrl_dst, list) {
105 		if (fromlen == dst->addrlen &&
106 		    os_memcmp(from->sun_path, dst->addr.sun_path,
107 			      fromlen - offsetof(struct sockaddr_un, sun_path))
108 		    == 0) {
109 			char addr_txt[200];
110 			printf_encode(addr_txt, sizeof(addr_txt),
111 				      (u8 *) from->sun_path,
112 				      fromlen -
113 				      offsetof(struct sockaddr_un, sun_path));
114 			wpa_printf(MSG_DEBUG, "CTRL_IFACE monitor detached %s",
115 				   addr_txt);
116 			dl_list_del(&dst->list);
117 			os_free(dst);
118 			return 0;
119 		}
120 	}
121 	return -1;
122 }
123 
124 
125 static int wpa_supplicant_ctrl_iface_level(struct ctrl_iface_priv *priv,
126 					   struct sockaddr_un *from,
127 					   socklen_t fromlen,
128 					   char *level)
129 {
130 	struct wpa_ctrl_dst *dst;
131 
132 	wpa_printf(MSG_DEBUG, "CTRL_IFACE LEVEL %s", level);
133 
134 	dl_list_for_each(dst, &priv->ctrl_dst, struct wpa_ctrl_dst, list) {
135 		if (fromlen == dst->addrlen &&
136 		    os_memcmp(from->sun_path, dst->addr.sun_path,
137 			      fromlen - offsetof(struct sockaddr_un, sun_path))
138 		    == 0) {
139 			char addr_txt[200];
140 			dst->debug_level = atoi(level);
141 			printf_encode(addr_txt, sizeof(addr_txt),
142 				      (u8 *) from->sun_path, fromlen -
143 				      offsetof(struct sockaddr_un, sun_path));
144 			wpa_printf(MSG_DEBUG, "CTRL_IFACE changed monitor level to %d for %s",
145 				   dst->debug_level, addr_txt);
146 			return 0;
147 		}
148 	}
149 
150 	return -1;
151 }
152 
153 
154 static void wpa_supplicant_ctrl_iface_receive(int sock, void *eloop_ctx,
155 					      void *sock_ctx)
156 {
157 	struct wpa_supplicant *wpa_s = eloop_ctx;
158 	struct ctrl_iface_priv *priv = sock_ctx;
159 	char buf[4096];
160 	int res;
161 	struct sockaddr_un from;
162 	socklen_t fromlen = sizeof(from);
163 	char *reply = NULL, *reply_buf = NULL;
164 	size_t reply_len = 0;
165 	int new_attached = 0;
166 
167 	res = recvfrom(sock, buf, sizeof(buf) - 1, 0,
168 		       (struct sockaddr *) &from, &fromlen);
169 	if (res < 0) {
170 		wpa_printf(MSG_ERROR, "recvfrom(ctrl_iface): %s",
171 			   strerror(errno));
172 		return;
173 	}
174 	buf[res] = '\0';
175 
176 	if (os_strcmp(buf, "ATTACH") == 0) {
177 		if (wpa_supplicant_ctrl_iface_attach(&priv->ctrl_dst, &from,
178 						     fromlen, 0))
179 			reply_len = 1;
180 		else {
181 			new_attached = 1;
182 			reply_len = 2;
183 		}
184 	} else if (os_strcmp(buf, "DETACH") == 0) {
185 		if (wpa_supplicant_ctrl_iface_detach(&priv->ctrl_dst, &from,
186 						     fromlen))
187 			reply_len = 1;
188 		else
189 			reply_len = 2;
190 	} else if (os_strncmp(buf, "LEVEL ", 6) == 0) {
191 		if (wpa_supplicant_ctrl_iface_level(priv, &from, fromlen,
192 						    buf + 6))
193 			reply_len = 1;
194 		else
195 			reply_len = 2;
196 	} else {
197 		reply_buf = wpa_supplicant_ctrl_iface_process(wpa_s, buf,
198 							      &reply_len);
199 		reply = reply_buf;
200 	}
201 
202 	if (!reply && reply_len == 1) {
203 		reply = "FAIL\n";
204 		reply_len = 5;
205 	} else if (!reply && reply_len == 2) {
206 		reply = "OK\n";
207 		reply_len = 3;
208 	}
209 
210 	if (reply) {
211 		if (sendto(sock, reply, reply_len, 0, (struct sockaddr *) &from,
212 			   fromlen) < 0) {
213 			int _errno = errno;
214 			wpa_dbg(wpa_s, MSG_DEBUG,
215 				"ctrl_iface sendto failed: %d - %s",
216 				_errno, strerror(_errno));
217 			if (_errno == ENOBUFS || _errno == EAGAIN) {
218 				/*
219 				 * The socket send buffer could be full. This
220 				 * may happen if client programs are not
221 				 * receiving their pending messages. Close and
222 				 * reopen the socket as a workaround to avoid
223 				 * getting stuck being unable to send any new
224 				 * responses.
225 				 */
226 				sock = wpas_ctrl_iface_reinit(wpa_s, priv);
227 				if (sock < 0) {
228 					wpa_dbg(wpa_s, MSG_DEBUG, "Failed to reinitialize ctrl_iface socket");
229 				}
230 			}
231 			if (new_attached) {
232 				wpa_dbg(wpa_s, MSG_DEBUG, "Failed to send response to ATTACH - detaching");
233 				new_attached = 0;
234 				wpa_supplicant_ctrl_iface_detach(
235 					&priv->ctrl_dst, &from, fromlen);
236 			}
237 		}
238 	}
239 	os_free(reply_buf);
240 
241 	if (new_attached)
242 		eapol_sm_notify_ctrl_attached(wpa_s->eapol);
243 }
244 
245 
246 static char * wpa_supplicant_ctrl_iface_path(struct wpa_supplicant *wpa_s)
247 {
248 	char *buf;
249 	size_t len;
250 	char *pbuf, *dir = NULL;
251 	int res;
252 
253 	if (wpa_s->conf->ctrl_interface == NULL)
254 		return NULL;
255 
256 	pbuf = os_strdup(wpa_s->conf->ctrl_interface);
257 	if (pbuf == NULL)
258 		return NULL;
259 	if (os_strncmp(pbuf, "DIR=", 4) == 0) {
260 		char *gid_str;
261 		dir = pbuf + 4;
262 		gid_str = os_strstr(dir, " GROUP=");
263 		if (gid_str)
264 			*gid_str = '\0';
265 	} else
266 		dir = pbuf;
267 
268 	len = os_strlen(dir) + os_strlen(wpa_s->ifname) + 2;
269 	buf = os_malloc(len);
270 	if (buf == NULL) {
271 		os_free(pbuf);
272 		return NULL;
273 	}
274 
275 	res = os_snprintf(buf, len, "%s/%s", dir, wpa_s->ifname);
276 	if (os_snprintf_error(len, res)) {
277 		os_free(pbuf);
278 		os_free(buf);
279 		return NULL;
280 	}
281 #ifdef __CYGWIN__
282 	{
283 		/* Windows/WinPcap uses interface names that are not suitable
284 		 * as a file name - convert invalid chars to underscores */
285 		char *pos = buf;
286 		while (*pos) {
287 			if (*pos == '\\')
288 				*pos = '_';
289 			pos++;
290 		}
291 	}
292 #endif /* __CYGWIN__ */
293 	os_free(pbuf);
294 	return buf;
295 }
296 
297 
298 static void wpa_supplicant_ctrl_iface_msg_cb(void *ctx, int level, int global,
299 					     const char *txt, size_t len)
300 {
301 	struct wpa_supplicant *wpa_s = ctx;
302 
303 	if (wpa_s == NULL)
304 		return;
305 
306 	if (global != 2 && wpa_s->global->ctrl_iface) {
307 		struct ctrl_iface_global_priv *priv = wpa_s->global->ctrl_iface;
308 		if (!dl_list_empty(&priv->ctrl_dst)) {
309 			wpa_supplicant_ctrl_iface_send(wpa_s, global ? NULL :
310 						       wpa_s->ifname,
311 						       priv->sock,
312 						       &priv->ctrl_dst,
313 						       level, txt, len, NULL,
314 						       priv);
315 		}
316 	}
317 
318 	if (wpa_s->ctrl_iface == NULL)
319 		return;
320 	wpa_supplicant_ctrl_iface_send(wpa_s, NULL, wpa_s->ctrl_iface->sock,
321 				       &wpa_s->ctrl_iface->ctrl_dst,
322 				       level, txt, len, wpa_s->ctrl_iface,
323 				       NULL);
324 }
325 
326 
327 static int wpas_ctrl_iface_open_sock(struct wpa_supplicant *wpa_s,
328 				     struct ctrl_iface_priv *priv)
329 {
330 	struct sockaddr_un addr;
331 	char *fname = NULL;
332 	gid_t gid = 0;
333 	int gid_set = 0;
334 	char *buf, *dir = NULL, *gid_str = NULL;
335 	struct group *grp;
336 	char *endp;
337 	int flags;
338 
339 	buf = os_strdup(wpa_s->conf->ctrl_interface);
340 	if (buf == NULL)
341 		goto fail;
342 #ifdef ANDROID
343 	os_snprintf(addr.sun_path, sizeof(addr.sun_path), "wpa_%s",
344 		    wpa_s->conf->ctrl_interface);
345 	priv->sock = android_get_control_socket(addr.sun_path);
346 	if (priv->sock >= 0) {
347 		priv->android_control_socket = 1;
348 		goto havesock;
349 	}
350 #endif /* ANDROID */
351 	if (os_strncmp(buf, "DIR=", 4) == 0) {
352 		dir = buf + 4;
353 		gid_str = os_strstr(dir, " GROUP=");
354 		if (gid_str) {
355 			*gid_str = '\0';
356 			gid_str += 7;
357 		}
358 	} else {
359 		dir = buf;
360 		gid_str = wpa_s->conf->ctrl_interface_group;
361 	}
362 
363 	if (mkdir(dir, S_IRWXU | S_IRWXG) < 0) {
364 		if (errno == EEXIST) {
365 			wpa_printf(MSG_DEBUG, "Using existing control "
366 				   "interface directory.");
367 		} else {
368 			wpa_printf(MSG_ERROR, "mkdir[ctrl_interface=%s]: %s",
369 				   dir, strerror(errno));
370 			goto fail;
371 		}
372 	}
373 
374 #ifdef ANDROID
375 	/*
376 	 * wpa_supplicant is started from /init.*.rc on Android and that seems
377 	 * to be using umask 0077 which would leave the control interface
378 	 * directory without group access. This breaks things since Wi-Fi
379 	 * framework assumes that this directory can be accessed by other
380 	 * applications in the wifi group. Fix this by adding group access even
381 	 * if umask value would prevent this.
382 	 */
383 	if (chmod(dir, S_IRWXU | S_IRWXG) < 0) {
384 		wpa_printf(MSG_ERROR, "CTRL: Could not chmod directory: %s",
385 			   strerror(errno));
386 		/* Try to continue anyway */
387 	}
388 #endif /* ANDROID */
389 
390 	if (gid_str) {
391 		grp = getgrnam(gid_str);
392 		if (grp) {
393 			gid = grp->gr_gid;
394 			gid_set = 1;
395 			wpa_printf(MSG_DEBUG, "ctrl_interface_group=%d"
396 				   " (from group name '%s')",
397 				   (int) gid, gid_str);
398 		} else {
399 			/* Group name not found - try to parse this as gid */
400 			gid = strtol(gid_str, &endp, 10);
401 			if (*gid_str == '\0' || *endp != '\0') {
402 				wpa_printf(MSG_ERROR, "CTRL: Invalid group "
403 					   "'%s'", gid_str);
404 				goto fail;
405 			}
406 			gid_set = 1;
407 			wpa_printf(MSG_DEBUG, "ctrl_interface_group=%d",
408 				   (int) gid);
409 		}
410 	}
411 
412 	if (gid_set && chown(dir, -1, gid) < 0) {
413 		wpa_printf(MSG_ERROR, "chown[ctrl_interface=%s,gid=%d]: %s",
414 			   dir, (int) gid, strerror(errno));
415 		goto fail;
416 	}
417 
418 	/* Make sure the group can enter and read the directory */
419 	if (gid_set &&
420 	    chmod(dir, S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP) < 0) {
421 		wpa_printf(MSG_ERROR, "CTRL: chmod[ctrl_interface]: %s",
422 			   strerror(errno));
423 		goto fail;
424 	}
425 
426 	if (os_strlen(dir) + 1 + os_strlen(wpa_s->ifname) >=
427 	    sizeof(addr.sun_path)) {
428 		wpa_printf(MSG_ERROR, "ctrl_iface path limit exceeded");
429 		goto fail;
430 	}
431 
432 	priv->sock = socket(PF_UNIX, SOCK_DGRAM, 0);
433 	if (priv->sock < 0) {
434 		wpa_printf(MSG_ERROR, "socket(PF_UNIX): %s", strerror(errno));
435 		goto fail;
436 	}
437 
438 	os_memset(&addr, 0, sizeof(addr));
439 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
440 	addr.sun_len = sizeof(addr);
441 #endif /* __FreeBSD__ */
442 	addr.sun_family = AF_UNIX;
443 	fname = wpa_supplicant_ctrl_iface_path(wpa_s);
444 	if (fname == NULL)
445 		goto fail;
446 	os_strlcpy(addr.sun_path, fname, sizeof(addr.sun_path));
447 	if (bind(priv->sock, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
448 		wpa_printf(MSG_DEBUG, "ctrl_iface bind(PF_UNIX) failed: %s",
449 			   strerror(errno));
450 		if (connect(priv->sock, (struct sockaddr *) &addr,
451 			    sizeof(addr)) < 0) {
452 			wpa_printf(MSG_DEBUG, "ctrl_iface exists, but does not"
453 				   " allow connections - assuming it was left"
454 				   "over from forced program termination");
455 			if (unlink(fname) < 0) {
456 				wpa_printf(MSG_ERROR,
457 					   "Could not unlink existing ctrl_iface socket '%s': %s",
458 					   fname, strerror(errno));
459 				goto fail;
460 			}
461 			if (bind(priv->sock, (struct sockaddr *) &addr,
462 				 sizeof(addr)) < 0) {
463 				wpa_printf(MSG_ERROR, "supp-ctrl-iface-init: bind(PF_UNIX): %s",
464 					   strerror(errno));
465 				goto fail;
466 			}
467 			wpa_printf(MSG_DEBUG, "Successfully replaced leftover "
468 				   "ctrl_iface socket '%s'", fname);
469 		} else {
470 			wpa_printf(MSG_INFO, "ctrl_iface exists and seems to "
471 				   "be in use - cannot override it");
472 			wpa_printf(MSG_INFO, "Delete '%s' manually if it is "
473 				   "not used anymore", fname);
474 			os_free(fname);
475 			fname = NULL;
476 			goto fail;
477 		}
478 	}
479 
480 	if (gid_set && chown(fname, -1, gid) < 0) {
481 		wpa_printf(MSG_ERROR, "chown[ctrl_interface=%s,gid=%d]: %s",
482 			   fname, (int) gid, strerror(errno));
483 		goto fail;
484 	}
485 
486 	if (chmod(fname, S_IRWXU | S_IRWXG) < 0) {
487 		wpa_printf(MSG_ERROR, "chmod[ctrl_interface=%s]: %s",
488 			   fname, strerror(errno));
489 		goto fail;
490 	}
491 	os_free(fname);
492 
493 #ifdef ANDROID
494 havesock:
495 #endif /* ANDROID */
496 
497 	/*
498 	 * Make socket non-blocking so that we don't hang forever if
499 	 * target dies unexpectedly.
500 	 */
501 	flags = fcntl(priv->sock, F_GETFL);
502 	if (flags >= 0) {
503 		flags |= O_NONBLOCK;
504 		if (fcntl(priv->sock, F_SETFL, flags) < 0) {
505 			wpa_printf(MSG_INFO, "fcntl(ctrl, O_NONBLOCK): %s",
506 				   strerror(errno));
507 			/* Not fatal, continue on.*/
508 		}
509 	}
510 
511 	eloop_register_read_sock(priv->sock, wpa_supplicant_ctrl_iface_receive,
512 				 wpa_s, priv);
513 	wpa_msg_register_cb(wpa_supplicant_ctrl_iface_msg_cb);
514 
515 	os_free(buf);
516 	return 0;
517 
518 fail:
519 	if (priv->sock >= 0) {
520 		close(priv->sock);
521 		priv->sock = -1;
522 	}
523 	if (fname) {
524 		unlink(fname);
525 		os_free(fname);
526 	}
527 	os_free(buf);
528 	return -1;
529 }
530 
531 
532 struct ctrl_iface_priv *
533 wpa_supplicant_ctrl_iface_init(struct wpa_supplicant *wpa_s)
534 {
535 	struct ctrl_iface_priv *priv;
536 
537 	priv = os_zalloc(sizeof(*priv));
538 	if (priv == NULL)
539 		return NULL;
540 	dl_list_init(&priv->ctrl_dst);
541 	priv->wpa_s = wpa_s;
542 	priv->sock = -1;
543 
544 	if (wpa_s->conf->ctrl_interface == NULL)
545 		return priv;
546 
547 	if (wpas_ctrl_iface_open_sock(wpa_s, priv) < 0) {
548 		os_free(priv);
549 		return NULL;
550 	}
551 
552 	return priv;
553 }
554 
555 
556 static int wpas_ctrl_iface_reinit(struct wpa_supplicant *wpa_s,
557 				  struct ctrl_iface_priv *priv)
558 {
559 	int res;
560 
561 	if (priv->sock <= 0)
562 		return -1;
563 
564 	/*
565 	 * On Android, the control socket being used may be the socket
566 	 * that is created when wpa_supplicant is started as a /init.*.rc
567 	 * service. Such a socket is maintained as a key-value pair in
568 	 * Android's environment. Closing this control socket would leave us
569 	 * in a bad state with an invalid socket descriptor.
570 	 */
571 	if (priv->android_control_socket)
572 		return priv->sock;
573 
574 	eloop_unregister_read_sock(priv->sock);
575 	close(priv->sock);
576 	priv->sock = -1;
577 	res = wpas_ctrl_iface_open_sock(wpa_s, priv);
578 	if (res < 0)
579 		return -1;
580 	return priv->sock;
581 }
582 
583 
584 void wpa_supplicant_ctrl_iface_deinit(struct ctrl_iface_priv *priv)
585 {
586 	struct wpa_ctrl_dst *dst, *prev;
587 
588 	if (priv->sock > -1) {
589 		char *fname;
590 		char *buf, *dir = NULL;
591 		eloop_unregister_read_sock(priv->sock);
592 		if (!dl_list_empty(&priv->ctrl_dst)) {
593 			/*
594 			 * Wait before closing the control socket if
595 			 * there are any attached monitors in order to allow
596 			 * them to receive any pending messages.
597 			 */
598 			wpa_printf(MSG_DEBUG, "CTRL_IFACE wait for attached "
599 				   "monitors to receive messages");
600 			os_sleep(0, 100000);
601 		}
602 		close(priv->sock);
603 		priv->sock = -1;
604 		fname = wpa_supplicant_ctrl_iface_path(priv->wpa_s);
605 		if (fname) {
606 			unlink(fname);
607 			os_free(fname);
608 		}
609 
610 		if (priv->wpa_s->conf->ctrl_interface == NULL)
611 			goto free_dst;
612 		buf = os_strdup(priv->wpa_s->conf->ctrl_interface);
613 		if (buf == NULL)
614 			goto free_dst;
615 		if (os_strncmp(buf, "DIR=", 4) == 0) {
616 			char *gid_str;
617 			dir = buf + 4;
618 			gid_str = os_strstr(dir, " GROUP=");
619 			if (gid_str)
620 				*gid_str = '\0';
621 		} else
622 			dir = buf;
623 
624 		if (rmdir(dir) < 0) {
625 			if (errno == ENOTEMPTY) {
626 				wpa_printf(MSG_DEBUG, "Control interface "
627 					   "directory not empty - leaving it "
628 					   "behind");
629 			} else {
630 				wpa_printf(MSG_ERROR,
631 					   "rmdir[ctrl_interface=%s]: %s",
632 					   dir, strerror(errno));
633 			}
634 		}
635 		os_free(buf);
636 	}
637 
638 free_dst:
639 	dl_list_for_each_safe(dst, prev, &priv->ctrl_dst, struct wpa_ctrl_dst,
640 			      list)
641 		os_free(dst);
642 	os_free(priv);
643 }
644 
645 
646 /**
647  * wpa_supplicant_ctrl_iface_send - Send a control interface packet to monitors
648  * @ifname: Interface name for global control socket or %NULL
649  * @sock: Local socket fd
650  * @ctrl_dst: List of attached listeners
651  * @level: Priority level of the message
652  * @buf: Message data
653  * @len: Message length
654  *
655  * Send a packet to all monitor programs attached to the control interface.
656  */
657 static void wpa_supplicant_ctrl_iface_send(struct wpa_supplicant *wpa_s,
658 					   const char *ifname, int sock,
659 					   struct dl_list *ctrl_dst,
660 					   int level, const char *buf,
661 					   size_t len,
662 					   struct ctrl_iface_priv *priv,
663 					   struct ctrl_iface_global_priv *gp)
664 {
665 	struct wpa_ctrl_dst *dst, *next;
666 	char levelstr[10];
667 	int idx, res;
668 	struct msghdr msg;
669 	struct iovec io[5];
670 
671 	if (sock < 0 || dl_list_empty(ctrl_dst))
672 		return;
673 
674 	res = os_snprintf(levelstr, sizeof(levelstr), "<%d>", level);
675 	if (os_snprintf_error(sizeof(levelstr), res))
676 		return;
677 	idx = 0;
678 	if (ifname) {
679 		io[idx].iov_base = "IFNAME=";
680 		io[idx].iov_len = 7;
681 		idx++;
682 		io[idx].iov_base = (char *) ifname;
683 		io[idx].iov_len = os_strlen(ifname);
684 		idx++;
685 		io[idx].iov_base = " ";
686 		io[idx].iov_len = 1;
687 		idx++;
688 	}
689 	io[idx].iov_base = levelstr;
690 	io[idx].iov_len = os_strlen(levelstr);
691 	idx++;
692 	io[idx].iov_base = (char *) buf;
693 	io[idx].iov_len = len;
694 	idx++;
695 	os_memset(&msg, 0, sizeof(msg));
696 	msg.msg_iov = io;
697 	msg.msg_iovlen = idx;
698 
699 	dl_list_for_each_safe(dst, next, ctrl_dst, struct wpa_ctrl_dst, list) {
700 		int _errno;
701 		char addr_txt[200];
702 
703 		if (level < dst->debug_level)
704 			continue;
705 
706 		printf_encode(addr_txt, sizeof(addr_txt),
707 			      (u8 *) dst->addr.sun_path, dst->addrlen -
708 			      offsetof(struct sockaddr_un, sun_path));
709 		msg.msg_name = (void *) &dst->addr;
710 		msg.msg_namelen = dst->addrlen;
711 		if (sendmsg(sock, &msg, MSG_DONTWAIT) >= 0) {
712 			wpa_printf(MSG_DEBUG, "CTRL_IFACE monitor sent successfully to %s",
713 				   addr_txt);
714 			dst->errors = 0;
715 			continue;
716 		}
717 
718 		_errno = errno;
719 		wpa_printf(MSG_DEBUG, "CTRL_IFACE monitor[%s]: %d - %s",
720 			   addr_txt, errno, strerror(errno));
721 		dst->errors++;
722 
723 		if (dst->errors > 10 || _errno == ENOENT || _errno == EPERM) {
724 			wpa_printf(MSG_INFO, "CTRL_IFACE: Detach monitor %s that cannot receive messages",
725 				addr_txt);
726 			wpa_supplicant_ctrl_iface_detach(ctrl_dst, &dst->addr,
727 							 dst->addrlen);
728 		}
729 
730 		if (_errno == ENOBUFS || _errno == EAGAIN) {
731 			/*
732 			 * The socket send buffer could be full. This may happen
733 			 * if client programs are not receiving their pending
734 			 * messages. Close and reopen the socket as a workaround
735 			 * to avoid getting stuck being unable to send any new
736 			 * responses.
737 			 */
738 			if (priv)
739 				sock = wpas_ctrl_iface_reinit(wpa_s, priv);
740 			else if (gp)
741 				sock = wpas_ctrl_iface_global_reinit(
742 					wpa_s->global, gp);
743 			else
744 				break;
745 			if (sock < 0) {
746 				wpa_dbg(wpa_s, MSG_DEBUG,
747 					"Failed to reinitialize ctrl_iface socket");
748 				break;
749 			}
750 		}
751 	}
752 }
753 
754 
755 void wpa_supplicant_ctrl_iface_wait(struct ctrl_iface_priv *priv)
756 {
757 	char buf[256];
758 	int res;
759 	struct sockaddr_un from;
760 	socklen_t fromlen = sizeof(from);
761 
762 	for (;;) {
763 		wpa_printf(MSG_DEBUG, "CTRL_IFACE - %s - wait for monitor to "
764 			   "attach", priv->wpa_s->ifname);
765 		eloop_wait_for_read_sock(priv->sock);
766 
767 		res = recvfrom(priv->sock, buf, sizeof(buf) - 1, 0,
768 			       (struct sockaddr *) &from, &fromlen);
769 		if (res < 0) {
770 			wpa_printf(MSG_ERROR, "recvfrom(ctrl_iface): %s",
771 				   strerror(errno));
772 			continue;
773 		}
774 		buf[res] = '\0';
775 
776 		if (os_strcmp(buf, "ATTACH") == 0) {
777 			/* handle ATTACH signal of first monitor interface */
778 			if (!wpa_supplicant_ctrl_iface_attach(&priv->ctrl_dst,
779 							      &from, fromlen,
780 							      0)) {
781 				if (sendto(priv->sock, "OK\n", 3, 0,
782 					   (struct sockaddr *) &from, fromlen) <
783 				    0) {
784 					wpa_printf(MSG_DEBUG, "ctrl_iface sendto failed: %s",
785 						   strerror(errno));
786 				}
787 				/* OK to continue */
788 				return;
789 			} else {
790 				if (sendto(priv->sock, "FAIL\n", 5, 0,
791 					   (struct sockaddr *) &from, fromlen) <
792 				    0) {
793 					wpa_printf(MSG_DEBUG, "ctrl_iface sendto failed: %s",
794 						   strerror(errno));
795 				}
796 			}
797 		} else {
798 			/* return FAIL for all other signals */
799 			if (sendto(priv->sock, "FAIL\n", 5, 0,
800 				   (struct sockaddr *) &from, fromlen) < 0) {
801 				wpa_printf(MSG_DEBUG,
802 					   "ctrl_iface sendto failed: %s",
803 					   strerror(errno));
804 			}
805 		}
806 	}
807 }
808 
809 
810 /* Global ctrl_iface */
811 
812 static void wpa_supplicant_global_ctrl_iface_receive(int sock, void *eloop_ctx,
813 						     void *sock_ctx)
814 {
815 	struct wpa_global *global = eloop_ctx;
816 	struct ctrl_iface_global_priv *priv = sock_ctx;
817 	char buf[4096];
818 	int res;
819 	struct sockaddr_un from;
820 	socklen_t fromlen = sizeof(from);
821 	char *reply = NULL, *reply_buf = NULL;
822 	size_t reply_len;
823 
824 	res = recvfrom(sock, buf, sizeof(buf) - 1, 0,
825 		       (struct sockaddr *) &from, &fromlen);
826 	if (res < 0) {
827 		wpa_printf(MSG_ERROR, "recvfrom(ctrl_iface): %s",
828 			   strerror(errno));
829 		return;
830 	}
831 	buf[res] = '\0';
832 
833 	if (os_strcmp(buf, "ATTACH") == 0) {
834 		if (wpa_supplicant_ctrl_iface_attach(&priv->ctrl_dst, &from,
835 						     fromlen, 1))
836 			reply_len = 1;
837 		else
838 			reply_len = 2;
839 	} else if (os_strcmp(buf, "DETACH") == 0) {
840 		if (wpa_supplicant_ctrl_iface_detach(&priv->ctrl_dst, &from,
841 						     fromlen))
842 			reply_len = 1;
843 		else
844 			reply_len = 2;
845 	} else {
846 		reply_buf = wpa_supplicant_global_ctrl_iface_process(
847 			global, buf, &reply_len);
848 		reply = reply_buf;
849 	}
850 
851 	if (!reply && reply_len == 1) {
852 		reply = "FAIL\n";
853 		reply_len = 5;
854 	} else if (!reply && reply_len == 2) {
855 		reply = "OK\n";
856 		reply_len = 3;
857 	}
858 
859 	if (reply) {
860 		if (sendto(sock, reply, reply_len, 0, (struct sockaddr *) &from,
861 			   fromlen) < 0) {
862 			wpa_printf(MSG_DEBUG, "ctrl_iface sendto failed: %s",
863 				strerror(errno));
864 		}
865 	}
866 	os_free(reply_buf);
867 }
868 
869 
870 static int wpas_global_ctrl_iface_open_sock(struct wpa_global *global,
871 					    struct ctrl_iface_global_priv *priv)
872 {
873 	struct sockaddr_un addr;
874 	const char *ctrl = global->params.ctrl_interface;
875 	int flags;
876 
877 	wpa_printf(MSG_DEBUG, "Global control interface '%s'", ctrl);
878 
879 #ifdef ANDROID
880 	if (os_strncmp(ctrl, "@android:", 9) == 0) {
881 		priv->sock = android_get_control_socket(ctrl + 9);
882 		if (priv->sock < 0) {
883 			wpa_printf(MSG_ERROR, "Failed to open Android control "
884 				   "socket '%s'", ctrl + 9);
885 			goto fail;
886 		}
887 		wpa_printf(MSG_DEBUG, "Using Android control socket '%s'",
888 			   ctrl + 9);
889 		priv->android_control_socket = 1;
890 		goto havesock;
891 	}
892 
893 	if (os_strncmp(ctrl, "@abstract:", 10) != 0) {
894 		/*
895 		 * Backwards compatibility - try to open an Android control
896 		 * socket and if that fails, assume this was a UNIX domain
897 		 * socket instead.
898 		 */
899 		priv->sock = android_get_control_socket(ctrl);
900 		if (priv->sock >= 0) {
901 			wpa_printf(MSG_DEBUG,
902 				   "Using Android control socket '%s'",
903 				   ctrl);
904 			priv->android_control_socket = 1;
905 			goto havesock;
906 		}
907 	}
908 #endif /* ANDROID */
909 
910 	priv->sock = socket(PF_UNIX, SOCK_DGRAM, 0);
911 	if (priv->sock < 0) {
912 		wpa_printf(MSG_ERROR, "socket(PF_UNIX): %s", strerror(errno));
913 		goto fail;
914 	}
915 
916 	os_memset(&addr, 0, sizeof(addr));
917 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
918 	addr.sun_len = sizeof(addr);
919 #endif /* __FreeBSD__ */
920 	addr.sun_family = AF_UNIX;
921 
922 	if (os_strncmp(ctrl, "@abstract:", 10) == 0) {
923 		addr.sun_path[0] = '\0';
924 		os_strlcpy(addr.sun_path + 1, ctrl + 10,
925 			   sizeof(addr.sun_path) - 1);
926 		if (bind(priv->sock, (struct sockaddr *) &addr, sizeof(addr)) <
927 		    0) {
928 			wpa_printf(MSG_ERROR, "supp-global-ctrl-iface-init: "
929 				   "bind(PF_UNIX;%s) failed: %s",
930 				   ctrl, strerror(errno));
931 			goto fail;
932 		}
933 		wpa_printf(MSG_DEBUG, "Using Abstract control socket '%s'",
934 			   ctrl + 10);
935 		goto havesock;
936 	}
937 
938 	os_strlcpy(addr.sun_path, ctrl, sizeof(addr.sun_path));
939 	if (bind(priv->sock, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
940 		wpa_printf(MSG_INFO, "supp-global-ctrl-iface-init(%s) (will try fixup): bind(PF_UNIX): %s",
941 			   ctrl, strerror(errno));
942 		if (connect(priv->sock, (struct sockaddr *) &addr,
943 			    sizeof(addr)) < 0) {
944 			wpa_printf(MSG_DEBUG, "ctrl_iface exists, but does not"
945 				   " allow connections - assuming it was left"
946 				   "over from forced program termination");
947 			if (unlink(ctrl) < 0) {
948 				wpa_printf(MSG_ERROR,
949 					   "Could not unlink existing ctrl_iface socket '%s': %s",
950 					   ctrl, strerror(errno));
951 				goto fail;
952 			}
953 			if (bind(priv->sock, (struct sockaddr *) &addr,
954 				 sizeof(addr)) < 0) {
955 				wpa_printf(MSG_ERROR, "supp-glb-iface-init: bind(PF_UNIX;%s): %s",
956 					   ctrl, strerror(errno));
957 				goto fail;
958 			}
959 			wpa_printf(MSG_DEBUG, "Successfully replaced leftover "
960 				   "ctrl_iface socket '%s'",
961 				   ctrl);
962 		} else {
963 			wpa_printf(MSG_INFO, "ctrl_iface exists and seems to "
964 				   "be in use - cannot override it");
965 			wpa_printf(MSG_INFO, "Delete '%s' manually if it is "
966 				   "not used anymore",
967 				   ctrl);
968 			goto fail;
969 		}
970 	}
971 
972 	wpa_printf(MSG_DEBUG, "Using UNIX control socket '%s'", ctrl);
973 
974 	if (global->params.ctrl_interface_group) {
975 		char *gid_str = global->params.ctrl_interface_group;
976 		gid_t gid = 0;
977 		struct group *grp;
978 		char *endp;
979 
980 		grp = getgrnam(gid_str);
981 		if (grp) {
982 			gid = grp->gr_gid;
983 			wpa_printf(MSG_DEBUG, "ctrl_interface_group=%d"
984 				   " (from group name '%s')",
985 				   (int) gid, gid_str);
986 		} else {
987 			/* Group name not found - try to parse this as gid */
988 			gid = strtol(gid_str, &endp, 10);
989 			if (*gid_str == '\0' || *endp != '\0') {
990 				wpa_printf(MSG_ERROR, "CTRL: Invalid group "
991 					   "'%s'", gid_str);
992 				goto fail;
993 			}
994 			wpa_printf(MSG_DEBUG, "ctrl_interface_group=%d",
995 				   (int) gid);
996 		}
997 		if (chown(ctrl, -1, gid) < 0) {
998 			wpa_printf(MSG_ERROR,
999 				   "chown[global_ctrl_interface=%s,gid=%d]: %s",
1000 				   ctrl, (int) gid, strerror(errno));
1001 			goto fail;
1002 		}
1003 
1004 		if (chmod(ctrl, S_IRWXU | S_IRWXG) < 0) {
1005 			wpa_printf(MSG_ERROR,
1006 				   "chmod[global_ctrl_interface=%s]: %s",
1007 				   ctrl, strerror(errno));
1008 			goto fail;
1009 		}
1010 	} else {
1011 		if (chmod(ctrl, S_IRWXU) < 0) {
1012 			wpa_printf(MSG_DEBUG,
1013 				   "chmod[global_ctrl_interface=%s](S_IRWXU): %s",
1014 				   ctrl, strerror(errno));
1015 			/* continue anyway since group change was not required
1016 			 */
1017 		}
1018 	}
1019 
1020 havesock:
1021 
1022 	/*
1023 	 * Make socket non-blocking so that we don't hang forever if
1024 	 * target dies unexpectedly.
1025 	 */
1026 	flags = fcntl(priv->sock, F_GETFL);
1027 	if (flags >= 0) {
1028 		flags |= O_NONBLOCK;
1029 		if (fcntl(priv->sock, F_SETFL, flags) < 0) {
1030 			wpa_printf(MSG_INFO, "fcntl(ctrl, O_NONBLOCK): %s",
1031 				   strerror(errno));
1032 			/* Not fatal, continue on.*/
1033 		}
1034 	}
1035 
1036 	eloop_register_read_sock(priv->sock,
1037 				 wpa_supplicant_global_ctrl_iface_receive,
1038 				 global, priv);
1039 
1040 	return 0;
1041 
1042 fail:
1043 	if (priv->sock >= 0) {
1044 		close(priv->sock);
1045 		priv->sock = -1;
1046 	}
1047 	return -1;
1048 }
1049 
1050 
1051 struct ctrl_iface_global_priv *
1052 wpa_supplicant_global_ctrl_iface_init(struct wpa_global *global)
1053 {
1054 	struct ctrl_iface_global_priv *priv;
1055 
1056 	priv = os_zalloc(sizeof(*priv));
1057 	if (priv == NULL)
1058 		return NULL;
1059 	dl_list_init(&priv->ctrl_dst);
1060 	priv->global = global;
1061 	priv->sock = -1;
1062 
1063 	if (global->params.ctrl_interface == NULL)
1064 		return priv;
1065 
1066 	if (wpas_global_ctrl_iface_open_sock(global, priv) < 0) {
1067 		os_free(priv);
1068 		return NULL;
1069 	}
1070 
1071 	wpa_msg_register_cb(wpa_supplicant_ctrl_iface_msg_cb);
1072 
1073 	return priv;
1074 }
1075 
1076 
1077 static int wpas_ctrl_iface_global_reinit(struct wpa_global *global,
1078 					 struct ctrl_iface_global_priv *priv)
1079 {
1080 	int res;
1081 
1082 	if (priv->sock <= 0)
1083 		return -1;
1084 
1085 	/*
1086 	 * On Android, the control socket being used may be the socket
1087 	 * that is created when wpa_supplicant is started as a /init.*.rc
1088 	 * service. Such a socket is maintained as a key-value pair in
1089 	 * Android's environment. Closing this control socket would leave us
1090 	 * in a bad state with an invalid socket descriptor.
1091 	 */
1092 	if (priv->android_control_socket)
1093 		return priv->sock;
1094 
1095 	eloop_unregister_read_sock(priv->sock);
1096 	close(priv->sock);
1097 	priv->sock = -1;
1098 	res = wpas_global_ctrl_iface_open_sock(global, priv);
1099 	if (res < 0)
1100 		return -1;
1101 	return priv->sock;
1102 }
1103 
1104 
1105 void
1106 wpa_supplicant_global_ctrl_iface_deinit(struct ctrl_iface_global_priv *priv)
1107 {
1108 	struct wpa_ctrl_dst *dst, *prev;
1109 
1110 	if (priv->sock >= 0) {
1111 		eloop_unregister_read_sock(priv->sock);
1112 		close(priv->sock);
1113 	}
1114 	if (priv->global->params.ctrl_interface)
1115 		unlink(priv->global->params.ctrl_interface);
1116 	dl_list_for_each_safe(dst, prev, &priv->ctrl_dst, struct wpa_ctrl_dst,
1117 			      list)
1118 		os_free(dst);
1119 	os_free(priv);
1120 }
1121