summaryrefslogtreecommitdiff
path: root/dtls.c
blob: b44a9213416cd01effa0a54e58785201ada4071c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
/*
 * Copyright (C) 2008 Stig Venaas <venaas@uninett.no>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 */

#include <signal.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#ifdef SYS_SOLARIS9
#include <fcntl.h>
#endif
#include <sys/time.h>
#include <sys/types.h>
#include <sys/select.h>
#include <ctype.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#include <regex.h>
#include <pthread.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include "debug.h"
#include "list.h"
#include "util.h"
#include "radsecproxy.h"
#include "dtls.h"

int udp2bio(int s, struct queue *q, int cnt) {
    unsigned char *buf;
    BIO *rbio;

    if (cnt < 1)
	return 0;
    
    buf = malloc(cnt);
    if (!buf) {
	unsigned char err;
	debug(DBG_ERR, "udp2bio: malloc failed");
	recv(s, &err, 1, 0);
	return 0;
    }

    cnt = recv(s, buf, cnt, 0);
    if (cnt < 1) {
	debug(DBG_WARN, "udp2bio: recv failed");
	free(buf);
	return 0;
    }

    rbio = BIO_new_mem_buf(buf, cnt);
    BIO_set_mem_eof_return(rbio, -1);

    pthread_mutex_lock(&q->mutex);
    if (!list_push(q->entries, rbio)) {
	BIO_free(rbio);
	pthread_mutex_unlock(&q->mutex);
	return 0;
    }
    pthread_cond_signal(&q->cond);
    pthread_mutex_unlock(&q->mutex);
    return 1;
}

BIO *getrbio(SSL *ssl, struct queue *q, int timeout) {
    BIO *rbio;
    struct timeval now;
    struct timespec to;

    pthread_mutex_lock(&q->mutex);
    if (!(rbio = (BIO *)list_shift(q->entries))) {
	if (timeout) {
	    gettimeofday(&now, NULL);
	    memset(&to, 0, sizeof(struct timespec));
	    to.tv_sec = now.tv_sec + timeout;
	    pthread_cond_timedwait(&q->cond, &q->mutex, &to);
	} else
	    pthread_cond_wait(&q->cond, &q->mutex);
	rbio = (BIO *)list_shift(q->entries);
    }
    pthread_mutex_unlock(&q->mutex);
    return rbio;
}

void *udpdtlsserverrd(void *arg) {
    int cnt, s = *(int *)arg;
    unsigned char buf[4];
    struct sockaddr_storage from;
    socklen_t fromlen = sizeof(from);
    struct clsrvconf *conf;
    struct list_node *node;
    struct client *client;
    fd_set readfds;
    pthread_t dtlsserverth;

    for (;;) {
	FD_ZERO(&readfds);
        FD_SET(s, &readfds);
	if (select(s + 1, &readfds, NULL, NULL, NULL) < 1)
	    continue;
	cnt = recvfrom(s, buf, 4, MSG_PEEK | MSG_TRUNC, (struct sockaddr *)&from, &fromlen);
	if (cnt == -1) {
	    debug(DBG_WARN, "udpdtlsserverrd: recv failed");
	    continue;
	}
	conf = find_clconf(RAD_DTLS, (struct sockaddr *)&from, NULL);
	if (!conf) {
	    debug(DBG_WARN, "udpdtlsserverrd: got packet from wrong or unknown DTLS peer %s, ignoring", addr2string((struct sockaddr *)&from, fromlen));
	    recv(s, buf, 4, 0);
	    continue;
	}
	
	node = list_first(conf->clients);
	if (node)
	    client = (struct client *)node->data;
	else {
	    client = addclient(conf);
	    if (!client) {
		recv(s, buf, 4, 0);
		continue;
	    }
	    client->sock = s;
	    memcpy(&client->addr, &from, fromlen);
	    if (pthread_create(&dtlsserverth, NULL, dtlsservernew, (void *)client)) {
		debug(DBG_ERR, "udpdtlsserverrd: pthread_create failed");
		removeclient(client);
		recv(s, buf, 4, 0);
		continue;
	    }
	    pthread_detach(dtlsserverth);
	}
	if (udp2bio(s, client->rbios, cnt))
	    debug(DBG_DBG, "udpdtlsserverrd: got DTLS in UDP from %s", addr2string((struct sockaddr *)&from, fromlen));
    }
}

void *dtlsserverwr(void *arg) {
    int cnt;
    unsigned long error;
    struct client *client = (struct client *)arg;
    struct queue *replyq;
    struct reply *reply;
    
    debug(DBG_DBG, "dtlsserverwr: starting for %s", client->conf->host);
    replyq = client->replyq;
    for (;;) {
	pthread_mutex_lock(&replyq->mutex);
	while (!list_first(replyq->entries)) {
	    if (client->ssl) {	    
		debug(DBG_DBG, "dtlsserverwr: waiting for signal");
		pthread_cond_wait(&replyq->cond, &replyq->mutex);
		debug(DBG_DBG, "dtlsserverwr: got signal");
	    }
	    if (!client->ssl) {
		/* ssl might have changed while waiting */
		pthread_mutex_unlock(&replyq->mutex);
		debug(DBG_DBG, "dtlsserverwr: exiting as requested");
		ERR_remove_state(0);
		pthread_exit(NULL);
	    }
	}
	reply = (struct reply *)list_shift(replyq->entries);
	pthread_mutex_unlock(&replyq->mutex);
	cnt = SSL_write(client->ssl, reply->buf, RADLEN(reply->buf));
	if (cnt > 0)
	    debug(DBG_DBG, "dtlsserverwr: sent %d bytes, Radius packet of length %d",
		  cnt, RADLEN(reply->buf));
	else
	    while ((error = ERR_get_error()))
		debug(DBG_ERR, "dtlsserverwr: SSL: %s", ERR_error_string(error, NULL));
	free(reply->buf);
	free(reply);
    }
}

int dtlsread(SSL *ssl, struct queue *q, unsigned char *buf, int num) {
    int len, cnt;

    for (len = 0; len < num; len += cnt) {
	cnt = SSL_read(ssl, buf + len, num - len);
	if (cnt <= 0)
	    switch (cnt = SSL_get_error(ssl, cnt)) {
	    case SSL_ERROR_WANT_READ:
		BIO_free(ssl->rbio);		
		ssl->rbio = getrbio(ssl, q, 0);
		if (!ssl->rbio)
		    return -1;
		cnt = 0;
		continue;
	    case SSL_ERROR_WANT_WRITE:
		cnt = 0;
		continue;
	    case SSL_ERROR_ZERO_RETURN:
		/* remote end sent close_notify, send one back */
		SSL_shutdown(ssl);
		return -1;
	    default:
		return -1;
	    }
    }
    return num;
}

unsigned char *raddtlsget(SSL *ssl, struct queue *rbios) {
    int cnt, len;
    unsigned char buf[4], *rad;

    for (;;) {
        cnt = dtlsread(ssl, rbios, buf, 4);
        if (cnt < 1) {
            debug(DBG_DBG, "raddtlsget: connection lost");
            return NULL;
        }

	len = RADLEN(buf);
	rad = malloc(len);
	if (!rad) {
	    debug(DBG_ERR, "raddtlsget: malloc failed");
	    continue;
	}
	memcpy(rad, buf, 4);
	
	cnt = dtlsread(ssl, rbios, rad + 4, len - 4);
        if (cnt < 1) {
            debug(DBG_DBG, "raddtlsget: connection lost");
            free(rad);
            return NULL;
        }
        
        if (len >= 20)
            break;
	
        free(rad);
        debug(DBG_WARN, "raddtlsget: packet smaller than minimum radius size");
    }
    
    debug(DBG_DBG, "raddtlsget: got %d bytes", len);
    return rad;
}

void dtlsserverrd(struct client *client) {
    struct request rq;
    pthread_t dtlsserverwrth;
    
    debug(DBG_DBG, "dtlsserverrd: starting for %s", client->conf->host);

    if (pthread_create(&dtlsserverwrth, NULL, dtlsserverwr, (void *)client)) {
	debug(DBG_ERR, "dtlsserverrd: pthread_create failed");
	return;
    }

    for (;;) {
	memset(&rq, 0, sizeof(struct request));
	rq.buf = raddtlsget(client->ssl, client->rbios);
	if (!rq.buf) {
	    debug(DBG_ERR, "dtlsserverrd: connection from %s lost", client->conf->host);
	    break;
	}
	debug(DBG_DBG, "dtlsserverrd: got Radius message from %s", client->conf->host);
	rq.from = client;
	if (!radsrv(&rq)) {
	    debug(DBG_ERR, "dtlsserverrd: message authentication/validation failed, closing connection from %s", client->conf->host);
	    break;
	}
    }
    
    /* stop writer by setting ssl to NULL and give signal in case waiting for data */
    client->ssl = NULL;

    pthread_mutex_lock(&client->replyq->mutex);
    pthread_cond_signal(&client->replyq->cond);
    pthread_mutex_unlock(&client->replyq->mutex);
    debug(DBG_DBG, "dtlsserverrd: waiting for writer to end");
    pthread_join(dtlsserverwrth, NULL);
    removeclientrqs(client);
    debug(DBG_DBG, "dtlsserverrd: reader for %s exiting", client->conf->host);
}

/* accept if acc == 1, else connect */
SSL *dtlsacccon(uint8_t acc, SSL_CTX *ctx, int s, struct sockaddr *addr, struct queue *rbios) {
    SSL *ssl;
    int i, res;
    unsigned long error;
    BIO *mem0bio, *wbio;
    
    ssl = SSL_new(ctx);
    if (!ssl)
	return NULL;
    
    mem0bio = BIO_new(BIO_s_mem());
    BIO_set_mem_eof_return(mem0bio, -1);
    wbio = BIO_new_dgram(s, BIO_NOCLOSE);
    BIO_dgram_set_peer(wbio, addr);
    SSL_set_bio(ssl, mem0bio, wbio);

    for (i = 0; i < 5; i++) {
        res = acc ? SSL_accept(ssl) : SSL_connect(ssl);
        if (res > 0)
            return ssl;
        if (res == 0)
            break;
        if (SSL_get_error(ssl, res) == SSL_ERROR_WANT_READ) {
            BIO_free(ssl->rbio);
            ssl->rbio = getrbio(ssl, rbios, 5);
            if (!ssl->rbio)
                break;
        }
        while ((error = ERR_get_error()))
            debug(DBG_ERR, "dtls%st: DTLS: %s", acc ? "accep" : "connec", ERR_error_string(error, NULL));
    }

    SSL_free(ssl);
    return NULL;
}

void *dtlsservernew(void *arg) {
    struct client *client = (struct client *)arg;
    X509 *cert = NULL;

    client->ssl = dtlsacccon(1, client->conf->ssl_ctx, client->sock, (struct sockaddr *)&client->addr, client->rbios);
    if (!client->ssl)
	goto exit;
    cert = verifytlscert(client->ssl);
    if (!cert)
	goto exit;
    if (verifyconfcert(cert, client->conf)) {
	X509_free(cert);
	dtlsserverrd(client);
	removeclient(client);
    } else
	debug(DBG_WARN, "dtlsservernew: ignoring request, certificate validation failed");
    if (cert)
	X509_free(cert);

 exit:
    SSL_free(client->ssl);
    ERR_remove_state(0);
    pthread_exit(NULL);
}

int dtlsconnect(struct server *server, struct timeval *when, int timeout, char *text) {
    struct timeval now;
    time_t elapsed;
    X509 *cert;
    
    debug(DBG_DBG, "dtlsconnect: called from %s", text);
    pthread_mutex_lock(&server->lock);
    if (when && memcmp(&server->lastconnecttry, when, sizeof(struct timeval))) {
	/* already reconnected, nothing to do */
	debug(DBG_DBG, "dtlsconnect(%s): seems already reconnected", text);
	pthread_mutex_unlock(&server->lock);
	return 1;
    }

    for (;;) {
	gettimeofday(&now, NULL);
	elapsed = now.tv_sec - server->lastconnecttry.tv_sec;

	if (timeout && server->lastconnecttry.tv_sec && elapsed > timeout) {
	    debug(DBG_DBG, "dtlsconnect: timeout");
	    SSL_free(server->ssl);
	    server->ssl = NULL;
	    pthread_mutex_unlock(&server->lock);
	    return 0;
	}

	if (server->connectionok) {
	    server->connectionok = 0;
	    sleep(2);
	} else if (elapsed < 1)
	    sleep(2);
	else if (elapsed < 60) {
	    debug(DBG_INFO, "dtlsconnect: sleeping %lds", elapsed);
	    sleep(elapsed);
	} else if (elapsed < 100000) {
	    debug(DBG_INFO, "dtlsconnect: sleeping %ds", 60);
	    sleep(60);
	} else
	    server->lastconnecttry.tv_sec = now.tv_sec;  /* no sleep at startup */
	debug(DBG_WARN, "dtlsconnect: trying to open DTLS connection to %s port %s", server->conf->host, server->conf->port);

	SSL_free(server->ssl);
	server->ssl = dtlsacccon(0, server->conf->ssl_ctx, server->sock, server->conf->addrinfo->ai_addr, server->rbios);
	if (!server->ssl)
	    continue;
	debug(DBG_DBG, "dtlsconnect: DTLS: ok");
	
	cert = verifytlscert(server->ssl);
	if (!cert)
	    continue;
	
	if (verifyconfcert(cert, server->conf))
	    break;
	X509_free(cert);
    }
    X509_free(cert);
    debug(DBG_WARN, "dtlsconnect: DTLS connection to %s port %s up", server->conf->host, server->conf->port);
    gettimeofday(&server->lastconnecttry, NULL);
    pthread_mutex_unlock(&server->lock);
    return 1;
}

int clientradputdtls(struct server *server, unsigned char *rad) {
    int cnt;
    size_t len;
    unsigned long error;
    struct clsrvconf *conf = server->conf;
    
    len = RADLEN(rad);
    while ((cnt = SSL_write(server->ssl, rad, len)) <= 0) {
	while ((error = ERR_get_error()))
	    debug(DBG_ERR, "clientradputdtls: DTLS: %s", ERR_error_string(error, NULL));
    }
    debug(DBG_DBG, "clientradputdtls: Sent %d bytes, Radius packet of length %d to DTLS peer %s", cnt, len, conf->host);
    return 1;
}

/* reads UDP containing DTLS and passes it on to dtlsclientrd */
void *udpdtlsclientrd(void *arg) {
    int cnt, s = *(int *)arg;
    unsigned char buf[4];
    struct sockaddr_storage from;
    socklen_t fromlen = sizeof(from);
    struct clsrvconf *conf;
    fd_set readfds;
    
    for (;;) {
	FD_ZERO(&readfds);
        FD_SET(s, &readfds);
	if (select(s + 1, &readfds, NULL, NULL, NULL) < 1)
	    continue;
	cnt = recvfrom(s, buf, 4, MSG_PEEK | MSG_TRUNC, (struct sockaddr *)&from, &fromlen);
	if (cnt == -1) {
	    debug(DBG_WARN, "udpdtlsclientrd: recv failed");
	    continue;
	}
	
	conf = find_srvconf(RAD_DTLS, (struct sockaddr *)&from, NULL);
	if (!conf) {
	    debug(DBG_WARN, "udpdtlsclientrd: got packet from wrong or unknown DTLS peer %s, ignoring", addr2string((struct sockaddr *)&from, fromlen));
	    recv(s, buf, 4, 0);
	    continue;
	}
	if (udp2bio(s, conf->servers->rbios, cnt))
	    debug(DBG_DBG, "radudpget: got DTLS in UDP from %s", addr2string((struct sockaddr *)&from, fromlen));
    }
}

void *dtlsclientrd(void *arg) {
    struct server *server = (struct server *)arg;
    unsigned char *buf;
    struct timeval lastconnecttry;
    
    for (;;) {
	/* yes, lastconnecttry is really necessary */
	lastconnecttry = server->lastconnecttry;
	buf = raddtlsget(server->ssl, server->rbios);
	if (!buf) {
	    dtlsconnect(server, &lastconnecttry, 0, "dtlsclientrd");
	    continue;
	}

	if (!replyh(server, buf))
	    free(buf);
    }
}