1 /*-
2 * Copyright (c) 2006-2009 Sam Leffler, Errno Consulting
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer,
10 * without modification.
11 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
13 * redistribution must be conditioned upon including a substantially
14 * similar Disclaimer requirement for further binary redistribution.
15 *
16 * NO WARRANTY
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
22 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
25 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27 * THE POSSIBILITY OF SUCH DAMAGES.
28 */
29
30 /*
31 * Test app to demonstrate how to handle dynamic WDS links:
32 * o monitor 802.11 events for wds discovery events
33 * o create wds vap's in response to wds discovery events
34 * and launch a script to handle adding the vap to the
35 * bridge, etc.
36 * o destroy wds vap's when station leaves
37 */
38 #include <sys/param.h>
39 #include <sys/file.h>
40 #include <sys/socket.h>
41 #include <sys/ioctl.h>
42 #include <sys/sysctl.h>
43 #include <sys/types.h>
44
45 #include <net/if.h>
46 #include "net/if_media.h"
47 #include <net/route.h>
48 #include <net/if_dl.h>
49 #include <netinet/in.h>
50 #include <netinet/if_ether.h>
51 #include "net80211/ieee80211_ioctl.h"
52 #include "net80211/ieee80211_freebsd.h"
53 #include <arpa/inet.h>
54 #include <netdb.h>
55
56 #include <net/if.h>
57 #include <net/if_types.h>
58
59 #include <ctype.h>
60 #include <err.h>
61 #include <errno.h>
62 #include <paths.h>
63 #include <stdarg.h>
64 #include <stdio.h>
65 #include <stdlib.h>
66 #include <string.h>
67 #include <sysexits.h>
68 #include <syslog.h>
69 #include <unistd.h>
70 #include <ifaddrs.h>
71
72 #define IEEE80211_ADDR_EQ(a1,a2) (memcmp(a1,a2,IEEE80211_ADDR_LEN) == 0)
73 #define IEEE80211_ADDR_COPY(dst,src) memcpy(dst,src,IEEE80211_ADDR_LEN)
74
75 struct wds {
76 struct wds *next;
77 uint8_t bssid[IEEE80211_ADDR_LEN]; /* bssid of associated sta */
78 char ifname[IFNAMSIZ]; /* vap interface name */
79 };
80 static struct wds *wds;
81
82 static const char *script = NULL;
83 static char **ifnets;
84 static int nifnets = 0;
85 static int discover_on_join = 0;
86
87 static void scanforvaps(int s);
88 static void handle_rtmsg(struct rt_msghdr *rtm, ssize_t msglen);
89 static void wds_discovery(const char *ifname,
90 const uint8_t bssid[IEEE80211_ADDR_LEN]);
91 static void wds_destroy(const char *ifname);
92 static void wds_leave(const uint8_t bssid[IEEE80211_ADDR_LEN]);
93 static int wds_vap_create(const char *ifname, uint8_t macaddr[ETHER_ADDR_LEN],
94 struct wds *);
95 static int wds_vap_destroy(const char *ifname);
96
97 static void
usage(const char * progname)98 usage(const char *progname)
99 {
100 fprintf(stderr, "usage: %s [-efjtv] [-P pidfile] [-s <set_scriptname>] [ifnet0 ... | any]\n",
101 progname);
102 exit(-1);
103 }
104
105 int
main(int argc,char * argv[])106 main(int argc, char *argv[])
107 {
108 const char *progname = argv[0];
109 const char *pidfile = NULL;
110 int s, c, logmask, bg = 1;
111 char msg[2048];
112 int log_stderr = 0;
113
114 logmask = LOG_UPTO(LOG_INFO);
115 while ((c = getopt(argc, argv, "efjP:s:tv")) != -1)
116 switch (c) {
117 case 'e':
118 log_stderr = LOG_PERROR;
119 break;
120 case 'f':
121 bg = 0;
122 break;
123 case 'j':
124 discover_on_join = 1;
125 break;
126 case 'P':
127 pidfile = optarg;
128 break;
129 case 's':
130 script = optarg;
131 break;
132 case 't':
133 logmask = LOG_UPTO(LOG_ERR);
134 break;
135 case 'v':
136 logmask = LOG_UPTO(LOG_DEBUG);
137 break;
138 case '?':
139 usage(progname);
140 /*NOTREACHED*/
141 }
142 argc -= optind, argv += optind;
143 if (argc == 0) {
144 fprintf(stderr, "%s: no ifnet's specified to monitor\n",
145 progname);
146 usage(progname);
147 }
148 ifnets = argv;
149 nifnets = argc;
150
151 s = socket(PF_ROUTE, SOCK_RAW, 0);
152 if (s < 0)
153 err(EX_OSERR, "socket");
154 /*
155 * Scan for inherited state.
156 */
157 scanforvaps(s);
158
159 /* XXX what directory to work in? */
160 if (bg && daemon(0, 0) < 0)
161 err(EX_OSERR, "daemon");
162
163 openlog("wlanwds", log_stderr | LOG_PID | LOG_CONS, LOG_DAEMON);
164 setlogmask(logmask);
165
166 for (;;) {
167 ssize_t n = read(s, msg, sizeof(msg));
168 handle_rtmsg((struct rt_msghdr *)msg, n);
169 }
170 return 0;
171 }
172
173 static const char *
ether_sprintf(const uint8_t mac[IEEE80211_ADDR_LEN])174 ether_sprintf(const uint8_t mac[IEEE80211_ADDR_LEN])
175 {
176 static char buf[32];
177
178 snprintf(buf, sizeof(buf), "%02x:%02x:%02x:%02x:%02x:%02x",
179 mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
180 return buf;
181 }
182
183 /*
184 * Fetch a vap's parent ifnet name.
185 */
186 static int
getparent(const char * ifname,char parent[IFNAMSIZ+1])187 getparent(const char *ifname, char parent[IFNAMSIZ+1])
188 {
189 char oid[256];
190 size_t parentlen;
191
192 /* fetch parent interface name */
193 snprintf(oid, sizeof(oid), "net.wlan.%s.%%parent", ifname+4);
194 parentlen = IFNAMSIZ;
195 if (sysctlbyname(oid, parent, &parentlen, NULL, 0) < 0)
196 return -1;
197 parent[parentlen] = '\0';
198 return 0;
199 }
200
201 /*
202 * Check if the specified ifnet is one we're supposed to monitor.
203 * The ifnet is assumed to be a vap; we find it's parent and check
204 * it against the set of ifnet's specified on the command line.
205 *
206 * TODO: extend this to also optionally allow the specific DWDS
207 * VAP to be monitored, instead of assuming all VAPs on a parent
208 * physical interface are being monitored by this instance of
209 * wlanwds.
210 */
211 static int
checkifnet(const char * ifname,int complain)212 checkifnet(const char *ifname, int complain)
213 {
214 char parent[256];
215 int i;
216
217 if (getparent(ifname, parent) < 0) {
218 if (complain)
219 syslog(LOG_ERR,
220 "%s: no pointer to parent interface: %m", ifname);
221 return 0;
222 }
223
224 for (i = 0; i < nifnets; i++)
225 if (strcasecmp(ifnets[i], "any") == 0 ||
226 strcmp(ifnets[i], parent) == 0)
227 return 1;
228 syslog(LOG_DEBUG, "%s: parent %s not being monitored", ifname, parent);
229 return 0;
230 }
231
232 /*
233 * Return 1 if the specified ifnet is a WDS vap.
234 */
235 static int
iswdsvap(int s,const char * ifname)236 iswdsvap(int s, const char *ifname)
237 {
238 struct ifmediareq ifmr;
239
240 memset(&ifmr, 0, sizeof(ifmr));
241 strncpy(ifmr.ifm_name, ifname, sizeof(ifmr.ifm_name));
242 if (ioctl(s, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0)
243 err(-1, "%s: cannot get media", ifname);
244 return (ifmr.ifm_current & IFM_IEEE80211_WDS) != 0;
245 }
246
247 /*
248 * Fetch the bssid for an ifnet. The caller is assumed
249 * to have already verified this is possible.
250 */
251 static void
getbssid(int s,const char * ifname,uint8_t bssid[IEEE80211_ADDR_LEN])252 getbssid(int s, const char *ifname, uint8_t bssid[IEEE80211_ADDR_LEN])
253 {
254 struct ieee80211req ireq;
255
256 memset(&ireq, 0, sizeof(ireq));
257 strncpy(ireq.i_name, ifname, sizeof(ireq.i_name));
258 ireq.i_type = IEEE80211_IOC_BSSID;
259 ireq.i_data = bssid;
260 ireq.i_len = IEEE80211_ADDR_LEN;
261 if (ioctl(s, SIOCG80211, &ireq) < 0)
262 err(-1, "%s: cannot fetch bssid", ifname);
263 }
264
265 /*
266 * Fetch the mac address configured for a given ifnet.
267 * (Note - the current link level address, NOT hwaddr.)
268 *
269 * This is currently, sigh, O(n) because there's no current kernel
270 * API that will do it for a single interface.
271 *
272 * Return 0 if successful, -1 if failure.
273 */
274 static int
getlladdr(const char * ifname,uint8_t macaddr[ETHER_ADDR_LEN])275 getlladdr(const char *ifname, uint8_t macaddr[ETHER_ADDR_LEN])
276 {
277 struct ifaddrs *ifap, *ifa;
278 struct sockaddr_dl *sdl;
279
280 if (getifaddrs(&ifap) < 0) {
281 warn("%s: getifaddrs", __func__);
282 return (-1);
283 }
284
285 /* Look for a matching interface */
286 for (ifa = ifap; ifa != NULL; ifa++) {
287 if (strcmp(ifname, ifa->ifa_name) != 0)
288 continue;
289
290 /* Found it - check if there's an ifa_addr */
291 if (ifa->ifa_addr == NULL) {
292 syslog(LOG_CRIT, "%s: ifname %s; ifa_addr is NULL\n",
293 __func__, ifname);
294 goto err;
295 }
296
297 /* Check address family */
298 sdl = (struct sockaddr_dl *) ifa->ifa_addr;
299 if (sdl->sdl_type != IFT_ETHER) {
300 syslog(LOG_CRIT, "%s: %s: unknown aftype (%d)\n",
301 __func__,
302 ifname,
303 sdl->sdl_type);
304 goto err;
305 }
306 if (sdl->sdl_alen != ETHER_ADDR_LEN) {
307 syslog(LOG_CRIT, "%s: %s: aflen too short (%d)\n",
308 __func__,
309 ifname,
310 sdl->sdl_alen);
311 goto err;
312 }
313
314 /* Ok, found it */
315 memcpy(macaddr, (void *) LLADDR(sdl), ETHER_ADDR_LEN);
316 goto ok;
317 }
318 syslog(LOG_CRIT, "%s: couldn't find ifname %s\n", __func__, ifname);
319 /* FALLTHROUGH */
320 err:
321 freeifaddrs(ifap);
322 return (-1);
323
324 ok:
325 freeifaddrs(ifap);
326 return (0);
327 }
328
329 /*
330 * Scan the system for WDS vaps associated with the ifnet's we're
331 * supposed to monitor. Any vaps are added to our internal table
332 * so we can find them (and destroy them) on station leave.
333 */
334 static void
scanforvaps(int s)335 scanforvaps(int s)
336 {
337 char ifname[IFNAMSIZ+1];
338 uint8_t bssid[IEEE80211_ADDR_LEN];
339 int i;
340
341 /* XXX brutal; should just walk sysctl tree */
342 for (i = 0; i < 128; i++) {
343 snprintf(ifname, sizeof(ifname), "wlan%d", i);
344 if (checkifnet(ifname, 0) && iswdsvap(s, ifname)) {
345 struct wds *p = malloc(sizeof(struct wds));
346 if (p == NULL)
347 err(-1, "%s: malloc failed", __func__);
348 strlcpy(p->ifname, ifname, IFNAMSIZ);
349 getbssid(s, ifname, p->bssid);
350 p->next = wds;
351 wds = p;
352
353 syslog(LOG_INFO, "[%s] discover wds vap %s",
354 ether_sprintf(bssid), ifname);
355 }
356 }
357 }
358
359 /*
360 * Process a routing socket message. We handle messages related
361 * to dynamic WDS:
362 * o on WDS discovery (rx of a 4-address frame with DWDS enabled)
363 * we create a WDS vap for the specified mac address
364 * o on station leave we destroy any associated WDS vap
365 * o on ifnet destroy we update state if this is manual destroy of
366 * a WDS vap in our table
367 * o if the -j option is supplied on the command line we create
368 * WDS vaps on station join/rejoin, this is useful for some setups
369 * where a WDS vap is required for 4-address traffic to flow
370 */
371 static void
handle_rtmsg(struct rt_msghdr * rtm,ssize_t msglen)372 handle_rtmsg(struct rt_msghdr *rtm, ssize_t msglen)
373 {
374 struct if_announcemsghdr *ifan;
375
376 (void) msglen; /* UNUSED */
377
378 if (rtm->rtm_version != RTM_VERSION) {
379 syslog(LOG_ERR, "routing message version %d not understood",
380 rtm->rtm_version);
381 return;
382 }
383 switch (rtm->rtm_type) {
384 case RTM_IFANNOUNCE:
385 ifan = (struct if_announcemsghdr *)rtm;
386 switch (ifan->ifan_what) {
387 case IFAN_ARRIVAL:
388 syslog(LOG_DEBUG,
389 "RTM_IFANNOUNCE: if# %d, what: arrival",
390 ifan->ifan_index);
391 break;
392 case IFAN_DEPARTURE:
393 syslog(LOG_DEBUG,
394 "RTM_IFANNOUNCE: if# %d, what: departure",
395 ifan->ifan_index);
396 /* NB: ok to call w/ unmonitored ifnets */
397 wds_destroy(ifan->ifan_name);
398 break;
399 }
400 break;
401 case RTM_IEEE80211:
402 #define V(type) ((struct type *)(&ifan[1]))
403 ifan = (struct if_announcemsghdr *)rtm;
404 switch (ifan->ifan_what) {
405 case RTM_IEEE80211_DISASSOC:
406 if (!discover_on_join)
407 break;
408 /* fall thru... */
409 case RTM_IEEE80211_LEAVE:
410 if (!checkifnet(ifan->ifan_name, 1))
411 break;
412 syslog(LOG_INFO, "[%s] station leave",
413 ether_sprintf(V(ieee80211_leave_event)->iev_addr));
414 wds_leave(V(ieee80211_leave_event)->iev_addr);
415 break;
416 case RTM_IEEE80211_JOIN:
417 case RTM_IEEE80211_REJOIN:
418 case RTM_IEEE80211_ASSOC:
419 case RTM_IEEE80211_REASSOC:
420 if (!discover_on_join)
421 break;
422 /* fall thru... */
423 case RTM_IEEE80211_WDS:
424 syslog(LOG_INFO, "[%s] wds discovery",
425 ether_sprintf(V(ieee80211_wds_event)->iev_addr));
426 if (!checkifnet(ifan->ifan_name, 1))
427 break;
428 wds_discovery(ifan->ifan_name,
429 V(ieee80211_wds_event)->iev_addr);
430 break;
431 }
432 break;
433 #undef V
434 }
435 }
436
437 /*
438 * Handle WDS discovery; create a WDS vap for the specified bssid.
439 * If a vap already exists then do nothing (can happen when a flood
440 * of 4-address frames causes multiple events to be queued before
441 * we create a vap).
442 */
443 static void
wds_discovery(const char * ifname,const uint8_t bssid[IEEE80211_ADDR_LEN])444 wds_discovery(const char *ifname, const uint8_t bssid[IEEE80211_ADDR_LEN])
445 {
446 struct wds *p;
447 char parent[256];
448 char cmd[1024];
449 uint8_t macaddr[ETHER_ADDR_LEN];
450 int status;
451
452 for (p = wds; p != NULL; p = p->next)
453 if (IEEE80211_ADDR_EQ(p->bssid, bssid)) {
454 syslog(LOG_INFO, "[%s] wds vap already created (%s)",
455 ether_sprintf(bssid), ifname);
456 return;
457 }
458 if (getparent(ifname, parent) < 0) {
459 syslog(LOG_ERR, "%s: no pointer to parent interface: %m",
460 ifname);
461 return;
462 }
463
464 if (getlladdr(ifname, macaddr) < 0) {
465 syslog(LOG_ERR, "%s: couldn't get lladdr for parent interface: %m",
466 ifname);
467 return;
468 }
469
470 p = malloc(sizeof(struct wds));
471 if (p == NULL) {
472 syslog(LOG_ERR, "%s: malloc failed: %m", __func__);
473 return;
474 }
475 IEEE80211_ADDR_COPY(p->bssid, bssid);
476 if (wds_vap_create(parent, macaddr, p) < 0) {
477 free(p);
478 return;
479 }
480 /*
481 * Add to table and launch setup script.
482 */
483 p->next = wds;
484 wds = p;
485 syslog(LOG_INFO, "[%s] create wds vap %s, parent %s (%s)",
486 ether_sprintf(bssid),
487 p->ifname,
488 ifname,
489 parent);
490 if (script != NULL) {
491 snprintf(cmd, sizeof(cmd), "%s %s", script, p->ifname);
492 status = system(cmd);
493 if (status)
494 syslog(LOG_ERR, "vap setup script %s exited with "
495 "status %d", script, status);
496 }
497 }
498
499 /*
500 * Destroy a WDS vap (if known).
501 */
502 static void
wds_destroy(const char * ifname)503 wds_destroy(const char *ifname)
504 {
505 struct wds *p, **pp;
506
507 for (pp = &wds; (p = *pp) != NULL; pp = &p->next)
508 if (strncmp(p->ifname, ifname, IFNAMSIZ) == 0)
509 break;
510 if (p != NULL) {
511 *pp = p->next;
512 /* NB: vap already destroyed */
513 free(p);
514 return;
515 }
516 }
517
518 /*
519 * Handle a station leave event; destroy any associated WDS vap.
520 */
521 static void
wds_leave(const uint8_t bssid[IEEE80211_ADDR_LEN])522 wds_leave(const uint8_t bssid[IEEE80211_ADDR_LEN])
523 {
524 struct wds *p, **pp;
525
526 for (pp = &wds; (p = *pp) != NULL; pp = &p->next)
527 if (IEEE80211_ADDR_EQ(p->bssid, bssid))
528 break;
529 if (p != NULL) {
530 *pp = p->next;
531 if (wds_vap_destroy(p->ifname) >= 0)
532 syslog(LOG_INFO, "[%s] wds vap %s destroyed",
533 ether_sprintf(bssid), p->ifname);
534 free(p);
535 }
536 }
537
538 static int
wds_vap_create(const char * parent,uint8_t macaddr[ETHER_ADDR_LEN],struct wds * p)539 wds_vap_create(const char *parent, uint8_t macaddr[ETHER_ADDR_LEN],
540 struct wds *p)
541 {
542 struct ieee80211_clone_params cp;
543 struct ifreq ifr;
544 int s, status;
545 char bssid_str[32], macaddr_str[32];
546
547 memset(&cp, 0, sizeof(cp));
548
549 /* Parent interface */
550 strncpy(cp.icp_parent, parent, IFNAMSIZ);
551
552 /* WDS interface */
553 cp.icp_opmode = IEEE80211_M_WDS;
554
555 /* BSSID for the current node */
556 IEEE80211_ADDR_COPY(cp.icp_bssid, p->bssid);
557
558 /*
559 * Set the MAC address to match the actual interface
560 * that we received the discovery event from.
561 * That way we can run WDS on any VAP rather than
562 * only the first VAP and then correctly set the
563 * MAC address.
564 */
565 cp.icp_flags |= IEEE80211_CLONE_MACADDR;
566 IEEE80211_ADDR_COPY(cp.icp_macaddr, macaddr);
567
568 memset(&ifr, 0, sizeof(ifr));
569 strncpy(ifr.ifr_name, "wlan", IFNAMSIZ);
570 ifr.ifr_data = (void *) &cp;
571
572 status = -1;
573 s = socket(AF_INET, SOCK_DGRAM, 0);
574 if (s >= 0) {
575 if (ioctl(s, SIOCIFCREATE2, &ifr) >= 0) {
576 strlcpy(p->ifname, ifr.ifr_name, IFNAMSIZ);
577 status = 0;
578 } else {
579 syslog(LOG_ERR, "SIOCIFCREATE2("
580 "mode %u flags 0x%x parent %s bssid %s macaddr %s): %m",
581 cp.icp_opmode, cp.icp_flags, parent,
582 ether_ntoa_r((void *) cp.icp_bssid, bssid_str),
583 ether_ntoa_r((void *) cp.icp_macaddr, macaddr_str));
584 }
585 close(s);
586 } else
587 syslog(LOG_ERR, "socket(SOCK_DRAGM): %m");
588 return status;
589 }
590
591 static int
wds_vap_destroy(const char * ifname)592 wds_vap_destroy(const char *ifname)
593 {
594 struct ieee80211req ifr;
595 int s, status;
596
597 s = socket(AF_INET, SOCK_DGRAM, 0);
598 if (s < 0) {
599 syslog(LOG_ERR, "socket(SOCK_DRAGM): %m");
600 return -1;
601 }
602 memset(&ifr, 0, sizeof(ifr));
603 strncpy(ifr.i_name, ifname, IFNAMSIZ);
604 if (ioctl(s, SIOCIFDESTROY, &ifr) < 0) {
605 syslog(LOG_ERR, "ioctl(SIOCIFDESTROY): %m");
606 status = -1;
607 } else
608 status = 0;
609 close(s);
610 return status;
611 }
612