xref: /openbsd-src/usr.sbin/radiusd/radiusd_radius.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c) 
1 /*	$OpenBSD: radiusd_radius.c,v 1.12 2016/03/21 00:49:36 guenther Exp $	*/
2 
3 /*
4  * Copyright (c) 2013 Internet Initiative Japan Inc.
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/queue.h>
21 #include <sys/socket.h>
22 #include <netinet/in.h>
23 
24 #include <err.h>
25 #include <errno.h>
26 #include <event.h>
27 #include <fcntl.h>
28 #include <stdbool.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <syslog.h>
33 #include <unistd.h>
34 
35 #include <radius.h>
36 
37 #include "radiusd.h"
38 #include "radiusd_module.h"
39 #include "util.h"
40 #include "log.h"
41 
42 struct radius_server {
43 	struct module_radius		*module;
44 	int				 sock;
45 	union {
46 		struct sockaddr_in6	 sin6;
47 		struct sockaddr_in	 sin4;
48 	}				 addr;
49 	union {
50 		struct sockaddr_in6	 sin6;
51 		struct sockaddr_in	 sin4;
52 	}				 local;
53 	struct event			 ev;
54 	u_char				 req_id_seq;
55 };
56 
57 struct module_radius {
58 	struct module_base		*base;
59 	struct radius_server		 server[4];
60 	char				 secret[RADIUSD_SECRET_MAX];
61 	u_int				 nserver;
62 	u_int				 curr_server;
63 	u_int				 req_timeout;
64 	u_int				 max_tries;
65 	u_int				 max_failovers;
66 	u_int				 nfailover;
67 	TAILQ_HEAD(,module_radius_req)	 req;
68 };
69 
70 struct module_radius_req {
71 	struct module_radius		*module;
72 	struct radius_server		*server;
73 	u_int				 q_id;
74 	RADIUS_PACKET			*q_pkt;
75 	u_int				 ntry;
76 	u_int				 nfailover;
77 	u_char				 req_id;
78 	struct event			 ev;
79 	TAILQ_ENTRY(module_radius_req)	 next;
80 };
81 
82 static void	 module_radius_init(struct module_radius *);
83 static void	 module_radius_config_set(void *, const char *, int,
84 		    char * const *);
85 static void	 module_radius_start(void *);
86 static void	 module_radius_stop(void *);
87 static void	 module_radius_access_request(void *, u_int, const u_char *,
88 		    size_t);
89 static int	 radius_server_start(struct radius_server *);
90 static void	 radius_server_stop(struct radius_server *);
91 static void	 radius_server_on_event(int, short, void *);
92 static void	 radius_server_on_fail(struct radius_server *, const char *);
93 static void	 module_radius_req_send(struct module_radius_req *);
94 static int	 module_radius_req_reset_event(struct module_radius_req *);
95 static void	 module_radius_req_on_timeout(int, short, void *);
96 static void	 module_radius_req_on_success(struct module_radius_req *,
97 		    const u_char *, size_t);
98 static void	 module_radius_req_on_failure(struct module_radius_req *);
99 
100 static void	 module_radius_req_free(struct module_radius_req *);
101 static void	 module_radius_req_select_server(struct module_radius_req *);
102 
103 static void	 module_radius_req_reset_msgauth(struct module_radius_req *);
104 static void	 module_radius_log(struct module_radius *, int, const char *, ...);
105 
106 static struct module_handlers module_radius_handlers = {
107 	.config_set = module_radius_config_set,
108 	.start = module_radius_start,
109 	.stop = module_radius_stop,
110 	.access_request = module_radius_access_request
111 };
112 
113 #ifndef nitems
114 #define nitems(_x)    (sizeof((_x)) / sizeof((_x)[0]))
115 #endif
116 
117 int
118 main(int argc, char *argv[])
119 {
120 	static struct module_radius module_radius;
121 
122 	module_radius_init(&module_radius);
123 	openlog(NULL, LOG_PID, LOG_DAEMON);
124 
125 	if ((module_radius.base = module_create(
126 	    STDIN_FILENO, &module_radius, &module_radius_handlers)) == NULL)
127 		err(1, "Could not create a module instance");
128 	module_drop_privilege(module_radius.base);
129 	setproctitle("[main]");
130 
131 	module_load(module_radius.base);
132 	log_init(0);
133 	event_init();
134 
135 	if (pledge("stdio inet", NULL) == -1)
136 		err(EXIT_FAILURE, "pledge");
137 
138 	module_start(module_radius.base);
139 	event_loop(0);
140 
141 	exit(EXIT_SUCCESS);
142 }
143 
144 static void
145 module_radius_init(struct module_radius *module)
146 {
147 	memset(module, 0, sizeof(struct module_radius));
148 	TAILQ_INIT(&module->req);
149 }
150 
151 static void
152 module_radius_config_set(void *ctx, const char *paramname, int paramvalc,
153     char * const * paramvalv)
154 {
155 	const char		*errmsg = NULL;
156 	struct addrinfo		*res;
157 	struct module_radius	*module = ctx;
158 
159 	if (strcmp(paramname, "server") == 0) {
160 		SYNTAX_ASSERT(paramvalc == 1,
161 		    "`server' must have just one argument");
162 		SYNTAX_ASSERT(module->nserver < (int)nitems(module->server),
163 		    "number of server reached limit");
164 
165 		if (addrport_parse(paramvalv[0], IPPROTO_UDP, &res) != 0)
166 			SYNTAX_ASSERT(0, "could not parse address and port");
167 		memcpy(&module->server[module->nserver].addr, res->ai_addr,
168 		    res->ai_addrlen);
169 
170 		if (ntohs(module->server[module->nserver].addr.sin4.sin_port)
171 		    == 0)
172 			module->server[module->nserver].addr.sin4.sin_port
173 			    = htons(RADIUS_DEFAULT_PORT);
174 
175 		module->server[module->nserver].sock = -1;
176 		module->nserver++;
177 		freeaddrinfo(res);
178 	} else if (strcmp(paramname, "request-timeout") == 0) {
179 		SYNTAX_ASSERT(paramvalc == 1,
180 		    "`request-timeout' must have just one argument");
181 		module->req_timeout = (int)strtonum(paramvalv[0], 0,
182 		    UINT16_MAX, &errmsg);
183 		if (module->req_timeout == 0 && errmsg != NULL) {
184 			module_send_message(module->base, IMSG_NG,
185 			    "`request-timeout must be 0-%d", UINT16_MAX);
186 			return;
187 		}
188 	} else if (strcmp(paramname, "max-tries") == 0) {
189 		SYNTAX_ASSERT(paramvalc == 1,
190 		    "`max-tries' must have just one argument");
191 		module->max_tries = (int)strtonum(paramvalv[0], 0,
192 		    UINT16_MAX, &errmsg);
193 		if (module->max_tries == 0 && errmsg != NULL) {
194 			module_send_message(module->base, IMSG_NG,
195 			    "`max-tries must be 0-%d", UINT16_MAX);
196 			return;
197 		}
198 
199 	} else if (strcmp(paramname, "max-failovers") == 0) {
200 		SYNTAX_ASSERT(paramvalc == 1,
201 		    "`max-failovers' must have just one argument");
202 		module->max_failovers = (int)strtonum(paramvalv[0], 0,
203 		    UINT16_MAX, &errmsg);
204 		if (module->max_failovers == 0 && errmsg != NULL) {
205 			module_send_message(module->base, IMSG_NG,
206 			    "`max-failovers' must be 0-%d", UINT16_MAX);
207 			return;
208 		}
209 	} else if (strcmp(paramname, "secret") == 0) {
210 		SYNTAX_ASSERT(paramvalc == 1,
211 		    "`secret' must have just one argument");
212 		if (strlcpy(module->secret, paramvalv[0],
213 		    sizeof(module->secret)) >= sizeof(module->secret)) {
214 			module_send_message(module->base, IMSG_NG,
215 			    "`secret' length must be 0-%lu",
216 			    (u_long) sizeof(module->secret) - 1);
217 			return;
218 		}
219 	} else {
220 		module_send_message(module->base, IMSG_NG,
221 		    "Unknown config parameter name `%s'", paramname);
222 		return;
223 	}
224 	module_send_message(module->base, IMSG_OK, NULL);
225 
226 	return;
227 syntax_error:
228 	module_send_message(module->base, IMSG_NG, "%s", errmsg);
229 }
230 
231 static void
232 module_radius_start(void *ctx)
233 {
234 	u_int			 i;
235 	struct module_radius	*module = ctx;
236 
237 	if (module->nserver <= 0) {
238 		module_send_message(module->base, IMSG_NG,
239 			"module `radius' needs one `server' at least");
240 		return;
241 	}
242 
243 	for (i = 0; i < module->nserver; i++) {
244 		module->server[i].module = module;
245 		if (radius_server_start(&module->server[i]) != 0) {
246 			module_send_message(module->base, IMSG_NG,
247 				"module `radius' failed to start one of "
248 				"the servers");
249 			return;
250 		}
251 	}
252 	module_send_message(module->base, IMSG_OK, NULL);
253 
254 	if (module->secret[0] != '\0')
255 		module_notify_secret(module->base, module->secret);
256 }
257 
258 static void
259 module_radius_stop(void *ctx)
260 {
261 	u_int				 i;
262 	struct module_radius_req	*req, *treq;
263 	struct module_radius		*module = ctx;
264 
265 	TAILQ_FOREACH_SAFE(req, &module->req, next, treq) {
266 		module_radius_req_on_failure(req);
267 		TAILQ_REMOVE(&module->req, req, next);
268 	}
269 
270 	for (i = 0; i < module->nserver; i++)
271 		radius_server_stop(&module->server[i]);
272 }
273 
274 static void
275 module_radius_access_request(void *ctx, u_int q_id, const u_char *pkt,
276     size_t pktlen)
277 {
278 	struct module_radius		*module = ctx;
279 	struct module_radius_req	*req;
280 	u_char				 attrbuf[256];
281 	ssize_t				 attrlen;
282 
283 	req = calloc(1, sizeof(struct module_radius_req));
284 	if (req == NULL) {
285 		module_radius_log(module, LOG_WARNING,
286 		    "%s: Out of memory: %m", __func__);
287 		goto on_fail;
288 	}
289 
290 	req->ntry = 0;
291 	req->module = module;
292 	req->q_id = q_id;
293 	if ((req->q_pkt = radius_convert_packet(pkt, pktlen)) == NULL) {
294 		module_radius_log(module, LOG_WARNING,
295 		    "%s: radius_convert_packet() failed: %m", __func__);
296 		goto on_fail;
297 	}
298 	evtimer_set(&req->ev, module_radius_req_on_timeout, req);
299 	TAILQ_INSERT_TAIL(&req->module->req, req, next);
300 
301 	/*
302 	 * radiusd decrypt User-Password attribute.  crypt it again with our
303 	 * secret.
304 	 */
305 	attrlen = sizeof(attrbuf);
306 	if (module->secret[0] != '\0' &&
307 	    radius_get_raw_attr(req->q_pkt, RADIUS_TYPE_USER_PASSWORD,
308 		    attrbuf, &attrlen) == 0) {
309 		attrbuf[attrlen] = '\0';
310 		radius_del_attr_all(req->q_pkt, RADIUS_TYPE_USER_PASSWORD);
311 		radius_put_user_password_attr(req->q_pkt, attrbuf,
312 		    module->secret);
313 	}
314 
315 	/* select current server */
316 	module_radius_req_select_server(req);
317 
318 	module_radius_req_send(req);
319 
320 	return;
321 
322 on_fail:
323 	free(req);
324 	module_accsreq_aborted(module->base, q_id);
325 }
326 
327 /*
328  * radius_server
329  */
330 static int
331 radius_server_start(struct radius_server *server)
332 {
333 	socklen_t	 locallen;
334 	char		 buf0[NI_MAXHOST + NI_MAXSERV + 32];
335 	char		 buf1[NI_MAXHOST + NI_MAXSERV + 32];
336 
337 	if ((server->sock = socket(AF_INET, SOCK_DGRAM | SOCK_NONBLOCK, 0))
338 	    < 0) {
339 		module_radius_log(server->module, LOG_WARNING,
340 		    "%s: socket() failed", __func__);
341 		goto on_error;
342 	}
343 	if (connect(server->sock, (struct sockaddr *)&server->addr,
344 		server->addr.sin4.sin_len) != 0) {
345 		module_radius_log(server->module, LOG_WARNING,
346 		    "%s: connect to %s failed", __func__,
347 		    addrport_tostring((struct sockaddr *)&server->addr,
348 			server->addr.sin4.sin_len, buf1, sizeof(buf1)));
349 		goto on_error;
350 	}
351 	locallen = sizeof(server->local);
352 	if (getsockname(server->sock, (struct sockaddr *)&server->local,
353 	    &locallen) != 0) {
354 		module_radius_log(server->module, LOG_WARNING,
355 		    "%s: getsockanme() failed", __func__);
356 		goto on_error;
357 	}
358 	module_radius_log(server->module, LOG_INFO,
359 	    "Use %s to send requests for %s",
360 	    addrport_tostring((struct sockaddr *)&server->local,
361 		    locallen, buf0, sizeof(buf0)),
362 	    addrport_tostring((struct sockaddr *)&server->addr,
363 		    server->addr.sin4.sin_len, buf1, sizeof(buf1)));
364 
365 	event_set(&server->ev, server->sock, EV_READ | EV_PERSIST,
366 	    radius_server_on_event, server);
367 	if (event_add(&server->ev, NULL)) {
368 		module_radius_log(server->module, LOG_WARNING,
369 		    "%s: event_add() failed", __func__);
370 		goto on_error;
371 	}
372 
373 	return (0);
374 on_error:
375 	if (server->sock >= 0)
376 		close(server->sock);
377 	server->sock = -1;
378 	return (-1);
379 }
380 
381 static void
382 radius_server_stop(struct radius_server *server)
383 {
384 	event_del(&server->ev);
385 	if (server->sock >= 0)
386 		close(server->sock);
387 	server->sock = -1;
388 }
389 
390 static void
391 radius_server_on_event(int fd, short evmask, void *ctx)
392 {
393 	int				 sz, res_id;
394 	u_char				 pkt[65535];
395 	char				 buf[NI_MAXHOST + NI_MAXSERV + 32];
396 	struct radius_server		*server = ctx;
397 	RADIUS_PACKET			*radpkt = NULL;
398 	struct module_radius_req	*req;
399 	struct sockaddr			*peer;
400 
401 	peer = (struct sockaddr *)&server->addr;
402 	if ((sz = recv(server->sock, pkt, sizeof(pkt), 0)) == -1) {
403 		if (errno == EAGAIN)
404 			return;
405 		module_radius_log(server->module, LOG_WARNING,
406 		    "server=%s recv() failed: %m",
407 		    addrport_tostring(peer, peer->sa_len, buf, sizeof(buf)));
408 		return;
409 	}
410 	if ((radpkt = radius_convert_packet(pkt, sz)) == NULL) {
411 		module_radius_log(server->module, LOG_WARNING,
412 		    "server=%s could not convert the received message to a "
413 		    "RADIUS packet object: %m",
414 		    addrport_tostring(peer, peer->sa_len, buf, sizeof(buf)));
415 		return;
416 	}
417 	res_id = radius_get_id(radpkt);
418 	TAILQ_FOREACH(req, &server->module->req, next) {
419 		if (req->server == server && req->req_id == res_id)
420 			break;
421 	}
422 	if (req == NULL) {
423 		module_radius_log(server->module, LOG_WARNING,
424 		    "server=%s Received radius message has unknown id=%d",
425 		    addrport_tostring(peer, peer->sa_len, buf, sizeof(buf)),
426 		    res_id);
427 		goto out;
428 	}
429 	radius_set_request_packet(radpkt, req->q_pkt);
430 
431 	if (server->module->secret[0] != '\0') {
432 		if (radius_check_response_authenticator(radpkt,
433 		    server->module->secret) != 0) {
434 			module_radius_log(server->module, LOG_WARNING,
435 			    "server=%s Received radius message(id=%d) has bad "
436 			    "authenticator",
437 			    addrport_tostring(peer, peer->sa_len, buf,
438 			    sizeof(buf)), res_id);
439 			goto out;
440 		}
441 		if (radius_has_attr(radpkt,
442 		    RADIUS_TYPE_MESSAGE_AUTHENTICATOR) &&
443 		    radius_check_message_authenticator(radpkt,
444 			    server->module->secret) != 0) {
445 			module_radius_log(server->module, LOG_WARNING,
446 			    "server=%s Received radius message(id=%d) has bad "
447 			    "message authenticator",
448 			    addrport_tostring(peer, peer->sa_len, buf,
449 			    sizeof(buf)), res_id);
450 			goto out;
451 		}
452 	}
453 
454 	module_radius_log(server->module, LOG_INFO,
455 	    "q=%u received a response from server %s", req->q_id,
456 	    addrport_tostring(peer, peer->sa_len, buf, sizeof(buf)));
457 
458 	module_radius_req_on_success(req, radius_get_data(radpkt),
459 	    radius_get_length(radpkt));
460 out:
461 	if (radpkt != NULL)
462 		radius_delete_packet(radpkt);
463 }
464 
465 static void
466 radius_server_on_fail(struct radius_server *server, const char *failmsg)
467 {
468 	char		 buf0[NI_MAXHOST + NI_MAXSERV + 32];
469 	char		 buf1[NI_MAXHOST + NI_MAXSERV + 32];
470 	struct sockaddr	*caddr, *naddr;
471 
472 	caddr = (struct sockaddr *)&server->addr;
473 	if (server->module->nserver <= 1) {
474 		module_radius_log(server->module, LOG_WARNING,
475 		    "Server %s failed: %s",
476 		    addrport_tostring(caddr, caddr->sa_len, buf0, sizeof(buf0)),
477 		    failmsg);
478 		return;
479 	}
480 	server->module->curr_server++;
481 	server->module->curr_server %= server->module->nserver;
482 	naddr = (struct sockaddr *)
483 	    &server->module->server[server->module->curr_server].addr;
484 
485 	module_radius_log(server->module, LOG_WARNING,
486 	    "Server %s failed: %s  Fail over to %s",
487 	    addrport_tostring(caddr, caddr->sa_len, buf0, sizeof(buf0)),
488 	    failmsg,
489 	    addrport_tostring(naddr, naddr->sa_len, buf1, sizeof(buf1)));
490 }
491 
492 /* module_radius_req */
493 
494 static void
495 module_radius_req_send(struct module_radius_req *req)
496 {
497 	int		 sz;
498 	struct sockaddr	*peer;
499 	char		 msg[BUFSIZ];
500 
501 	peer = (struct sockaddr *)&req->server->addr;
502 	if ((sz = send(req->server->sock, radius_get_data(req->q_pkt),
503 	    radius_get_length(req->q_pkt), 0)) < 0) {
504 		module_radius_log(req->module, LOG_WARNING,
505 		    "Sending RADIUS query q=%u to %s failed: %m",
506 		    req->q_id,
507 		    addrport_tostring(peer, peer->sa_len, msg, sizeof(msg)));
508 		/* retry anyway */
509 	}
510 	module_radius_log(req->module, LOG_INFO,
511 	    "Send RADIUS query q=%u id=%d to %s successfully",
512 	    req->q_id, req->req_id,
513 	    addrport_tostring(peer, peer->sa_len, msg, sizeof(msg)));
514 	if (module_radius_req_reset_event(req) != -1)
515 		req->ntry++;
516 }
517 
518 static int
519 module_radius_req_reset_event(struct module_radius_req *req)
520 {
521 	struct timeval	 tv;
522 	static int	 timeouts[] = { 2, 4, 8 };
523 
524 	tv.tv_usec = 0;
525 	if (req->module->req_timeout != 0)
526 		tv.tv_sec = req->module->req_timeout;
527 	else {
528 		if (req->ntry < nitems(timeouts))
529 			tv.tv_sec = timeouts[req->ntry];
530 		else
531 			tv.tv_sec = timeouts[nitems(timeouts) - 1];
532 	}
533 	if (evtimer_add(&req->ev, &tv) != 0) {
534 		module_radius_log(req->module, LOG_WARNING,
535 		    "Cannot proccess the request for q=%u: "
536 		    "evtimer_add() failed: %m", req->q_id);
537 		module_radius_req_on_failure(req);
538 		return (-1);
539 	}
540 	return (0);
541 }
542 
543 static void
544 module_radius_req_on_timeout(int fd, short evmask, void *ctx)
545 {
546 	struct module_radius_req	*req = ctx;
547 	char				 msg[BUFSIZ];
548 
549 
550 	if (req->module->max_tries <= req->ntry) {
551 		snprintf(msg, sizeof(msg), "q=%u didn't response RADIUS query "
552 		    "%d time%s", req->q_id, req->ntry,
553 		    (req->ntry > 0)? "s" : "");
554 		radius_server_on_fail(req->server, msg);
555 		if (++req->nfailover >= req->module->max_failovers) {
556 			module_radius_log(req->module,
557 			    LOG_WARNING, "RADIUS query q=%u time out",
558 			    req->q_id);
559 			module_radius_req_on_failure(req);
560 			return;
561 		}
562 		/* select the next server */
563 		module_radius_req_select_server(req);
564 	}
565 	module_radius_req_send(req);
566 }
567 
568 static void
569 module_radius_req_on_success(struct module_radius_req *req,
570     const u_char *pkt, size_t pktlen)
571 {
572 	module_accsreq_answer(req->module->base, req->q_id, 1, pkt, pktlen);
573 	module_radius_req_free(req);
574 }
575 
576 static void
577 module_radius_req_on_failure(struct module_radius_req *req)
578 {
579 	module_accsreq_aborted(req->module->base, req->q_id);
580 	module_radius_req_free(req);
581 }
582 
583 
584 static void
585 module_radius_req_free(struct module_radius_req *req)
586 {
587 	evtimer_del(&req->ev);
588 	TAILQ_REMOVE(&req->module->req, req, next);
589 	if (req->q_pkt != NULL)
590 		radius_delete_packet(req->q_pkt);
591 	free(req);
592 }
593 
594 static void
595 module_radius_req_select_server(struct module_radius_req *req)
596 {
597 	req->server = &req->module->server[req->module->curr_server];
598 	req->ntry = 0;
599 	req->req_id = req->server->req_id_seq++;
600 	radius_set_id(req->q_pkt, req->req_id);
601 	module_radius_req_reset_msgauth(req);
602 }
603 
604 static void
605 module_radius_req_reset_msgauth(struct module_radius_req *req)
606 {
607 	if (radius_has_attr(req->q_pkt, RADIUS_TYPE_MESSAGE_AUTHENTICATOR))
608 		radius_del_attr_all(req->q_pkt,
609 		    RADIUS_TYPE_MESSAGE_AUTHENTICATOR);
610 	if (req->module->secret[0] != '\0')
611 		radius_put_message_authenticator(req->q_pkt,
612 		    req->module->secret);
613 }
614 
615 static void
616 module_radius_log(struct module_radius *module, int pri, const char *fmt, ...)
617 {
618 	char		fmt0[BUFSIZ];
619 	va_list		va;
620 
621 	snprintf(fmt0, sizeof(fmt0), "radius: %s", fmt);
622 	va_start(va, fmt);
623 	vlog(pri, fmt0, va);
624 	va_end(va);
625 }
626