1 files changed, 363 insertions, 338 deletions

diff --git a/drivers/builtin_openssl2/ssl/d1_lib.c b/drivers/builtin_openssl2/ssl/d1_lib.c
index 6bde16fa21..011d7b7cbe 100644
--- a/drivers/builtin_openssl2/ssl/d1_lib.c
+++ b/drivers/builtin_openssl2/ssl/d1_lib.c
@@ -1,7 +1,7 @@
 /* ssl/d1_lib.c */
-/* 
+/*
  * DTLS implementation written by Nagendra Modadugu
- * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.  
+ * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
  */
 /* ====================================================================
  * Copyright (c) 1999-2005 The OpenSSL Project.  All rights reserved.
@@ -11,7 +11,7 @@
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer. 
+ *    notice, this list of conditions and the following disclaimer.
  *
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in
@@ -63,216 +63,244 @@
 #include "ssl_locl.h"
 
 #if defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS)
-#include <sys/timeb.h>
+# include <sys/timeb.h>
 #endif
 
 static void get_current_time(struct timeval *t);
-const char dtls1_version_str[]="DTLSv1" OPENSSL_VERSION_PTEXT;
+const char dtls1_version_str[] = "DTLSv1" OPENSSL_VERSION_PTEXT;
 int dtls1_listen(SSL *s, struct sockaddr *client);
 
-SSL3_ENC_METHOD DTLSv1_enc_data={
+SSL3_ENC_METHOD DTLSv1_enc_data = {
     dtls1_enc,
-	tls1_mac,
-	tls1_setup_key_block,
-	tls1_generate_master_secret,
-	tls1_change_cipher_state,
-	tls1_final_finish_mac,
-	TLS1_FINISH_MAC_LENGTH,
-	tls1_cert_verify_mac,
-	TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
-	TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
-	tls1_alert_code,
-	tls1_export_keying_material,
-	};
+    tls1_mac,
+    tls1_setup_key_block,
+    tls1_generate_master_secret,
+    tls1_change_cipher_state,
+    tls1_final_finish_mac,
+    TLS1_FINISH_MAC_LENGTH,
+    tls1_cert_verify_mac,
+    TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
+    TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
+    tls1_alert_code,
+    tls1_export_keying_material,
+};
 
 long dtls1_default_timeout(void)
-	{
-	/* 2 hours, the 24 hours mentioned in the DTLSv1 spec
-	 * is way too long for http, the cache would over fill */
-	return(60*60*2);
-	}
+{
+    /*
+     * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
+     * http, the cache would over fill
+     */
+    return (60 * 60 * 2);
+}
 
 int dtls1_new(SSL *s)
-	{
-	DTLS1_STATE *d1;
-
-	if (!ssl3_new(s)) return(0);
-	if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
-	memset(d1,0, sizeof *d1);
-
-	/* d1->handshake_epoch=0; */
-
-	d1->unprocessed_rcds.q=pqueue_new();
-	d1->processed_rcds.q=pqueue_new();
-	d1->buffered_messages = pqueue_new();
-	d1->sent_messages=pqueue_new();
-	d1->buffered_app_data.q=pqueue_new();
-
-	if ( s->server)
-		{
-		d1->cookie_len = sizeof(s->d1->cookie);
-		}
-
-	if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q 
-        || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
-		{
-        if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
-        if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
-        if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
-		if ( d1->sent_messages) pqueue_free(d1->sent_messages);
-		if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
-		OPENSSL_free(d1);
-		return (0);
-		}
-
-	s->d1=d1;
-	s->method->ssl_clear(s);
-	return(1);
-	}
+{
+    DTLS1_STATE *d1;
+
+    if (!ssl3_new(s))
+        return (0);
+    if ((d1 = OPENSSL_malloc(sizeof *d1)) == NULL)
+        return (0);
+    memset(d1, 0, sizeof *d1);
+
+    /* d1->handshake_epoch=0; */
+
+    d1->unprocessed_rcds.q = pqueue_new();
+    d1->processed_rcds.q = pqueue_new();
+    d1->buffered_messages = pqueue_new();
+    d1->sent_messages = pqueue_new();
+    d1->buffered_app_data.q = pqueue_new();
+
+    if (s->server) {
+        d1->cookie_len = sizeof(s->d1->cookie);
+    }
+
+    d1->link_mtu = 0;
+    d1->mtu = 0;
+
+    if (!d1->unprocessed_rcds.q || !d1->processed_rcds.q
+        || !d1->buffered_messages || !d1->sent_messages
+        || !d1->buffered_app_data.q) {
+        if (d1->unprocessed_rcds.q)
+            pqueue_free(d1->unprocessed_rcds.q);
+        if (d1->processed_rcds.q)
+            pqueue_free(d1->processed_rcds.q);
+        if (d1->buffered_messages)
+            pqueue_free(d1->buffered_messages);
+        if (d1->sent_messages)
+            pqueue_free(d1->sent_messages);
+        if (d1->buffered_app_data.q)
+            pqueue_free(d1->buffered_app_data.q);
+        OPENSSL_free(d1);
+        return (0);
+    }
+
+    s->d1 = d1;
+    s->method->ssl_clear(s);
+    return (1);
+}
 
 static void dtls1_clear_queues(SSL *s)
-	{
+{
     pitem *item = NULL;
     hm_fragment *frag = NULL;
-	DTLS1_RECORD_DATA *rdata;
-
-    while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
-        {
-		rdata = (DTLS1_RECORD_DATA *) item->data;
-		if (rdata->rbuf.buf)
-			{
-			OPENSSL_free(rdata->rbuf.buf);
-			}
+    DTLS1_RECORD_DATA *rdata;
+
+    while ((item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) {
+        rdata = (DTLS1_RECORD_DATA *)item->data;
+        if (rdata->rbuf.buf) {
+            OPENSSL_free(rdata->rbuf.buf);
+        }
         OPENSSL_free(item->data);
         pitem_free(item);
-        }
+    }
 
-    while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
-        {
-		rdata = (DTLS1_RECORD_DATA *) item->data;
-		if (rdata->rbuf.buf)
-			{
-			OPENSSL_free(rdata->rbuf.buf);
-			}
+    while ((item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) {
+        rdata = (DTLS1_RECORD_DATA *)item->data;
+        if (rdata->rbuf.buf) {
+            OPENSSL_free(rdata->rbuf.buf);
+        }
         OPENSSL_free(item->data);
         pitem_free(item);
-        }
+    }
 
-    while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
-        {
+    while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
         frag = (hm_fragment *)item->data;
-        OPENSSL_free(frag->fragment);
-        OPENSSL_free(frag);
+        dtls1_hm_fragment_free(frag);
         pitem_free(item);
-        }
+    }
 
-    while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
-        {
+    while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
         frag = (hm_fragment *)item->data;
-        OPENSSL_free(frag->fragment);
-        OPENSSL_free(frag);
+        dtls1_hm_fragment_free(frag);
         pitem_free(item);
-        }
+    }
 
-	while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
-		{
-		rdata = (DTLS1_RECORD_DATA *) item->data;
-		if (rdata->rbuf.buf)
-			{
-			OPENSSL_free(rdata->rbuf.buf);
-			}
-		OPENSSL_free(item->data);
-		pitem_free(item);
-		}
-	}
+    while ((item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) {
+        rdata = (DTLS1_RECORD_DATA *)item->data;
+        if (rdata->rbuf.buf) {
+            OPENSSL_free(rdata->rbuf.buf);
+        }
+        OPENSSL_free(item->data);
+        pitem_free(item);
+    }
+}
 
 void dtls1_free(SSL *s)
-	{
-	ssl3_free(s);
+{
+    ssl3_free(s);
 
-	dtls1_clear_queues(s);
+    dtls1_clear_queues(s);
 
     pqueue_free(s->d1->unprocessed_rcds.q);
     pqueue_free(s->d1->processed_rcds.q);
     pqueue_free(s->d1->buffered_messages);
-	pqueue_free(s->d1->sent_messages);
-	pqueue_free(s->d1->buffered_app_data.q);
+    pqueue_free(s->d1->sent_messages);
+    pqueue_free(s->d1->buffered_app_data.q);
 
-	OPENSSL_free(s->d1);
-	s->d1 = NULL;
-	}
+    OPENSSL_free(s->d1);
+    s->d1 = NULL;
+}
 
 void dtls1_clear(SSL *s)
-	{
+{
     pqueue unprocessed_rcds;
     pqueue processed_rcds;
     pqueue buffered_messages;
-	pqueue sent_messages;
-	pqueue buffered_app_data;
-	unsigned int mtu;
-
-	if (s->d1)
-		{
-		unprocessed_rcds = s->d1->unprocessed_rcds.q;
-		processed_rcds = s->d1->processed_rcds.q;
-		buffered_messages = s->d1->buffered_messages;
-		sent_messages = s->d1->sent_messages;
-		buffered_app_data = s->d1->buffered_app_data.q;
-		mtu = s->d1->mtu;
-
-		dtls1_clear_queues(s);
-
-		memset(s->d1, 0, sizeof(*(s->d1)));
-
-		if (s->server)
-			{
-			s->d1->cookie_len = sizeof(s->d1->cookie);
-			}
-
-		if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
-			{
-			s->d1->mtu = mtu;
-			}
-
-		s->d1->unprocessed_rcds.q = unprocessed_rcds;
-		s->d1->processed_rcds.q = processed_rcds;
-		s->d1->buffered_messages = buffered_messages;
-		s->d1->sent_messages = sent_messages;
-		s->d1->buffered_app_data.q = buffered_app_data;
-		}
-
-	ssl3_clear(s);
-	if (s->options & SSL_OP_CISCO_ANYCONNECT)
-		s->version=DTLS1_BAD_VER;
-	else
-		s->version=DTLS1_VERSION;
-	}
+    pqueue sent_messages;
+    pqueue buffered_app_data;
+    unsigned int mtu;
+    unsigned int link_mtu;
+
+    if (s->d1) {
+        unprocessed_rcds = s->d1->unprocessed_rcds.q;
+        processed_rcds = s->d1->processed_rcds.q;
+        buffered_messages = s->d1->buffered_messages;
+        sent_messages = s->d1->sent_messages;
+        buffered_app_data = s->d1->buffered_app_data.q;
+        mtu = s->d1->mtu;
+        link_mtu = s->d1->link_mtu;
+
+        dtls1_clear_queues(s);
+
+        memset(s->d1, 0, sizeof(*(s->d1)));
+
+        if (s->server) {
+            s->d1->cookie_len = sizeof(s->d1->cookie);
+        }
+
+        if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
+            s->d1->mtu = mtu;
+            s->d1->link_mtu = link_mtu;
+        }
+
+        s->d1->unprocessed_rcds.q = unprocessed_rcds;
+        s->d1->processed_rcds.q = processed_rcds;
+        s->d1->buffered_messages = buffered_messages;
+        s->d1->sent_messages = sent_messages;
+        s->d1->buffered_app_data.q = buffered_app_data;
+    }
+
+    ssl3_clear(s);
+    if (s->options & SSL_OP_CISCO_ANYCONNECT)
+        s->version = DTLS1_BAD_VER;
+    else
+        s->version = DTLS1_VERSION;
+}
 
 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
-	{
-	int ret=0;
-
-	switch (cmd)
-		{
-	case DTLS_CTRL_GET_TIMEOUT:
-		if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
-			{
-			ret = 1;
-			}
-		break;
-	case DTLS_CTRL_HANDLE_TIMEOUT:
-		ret = dtls1_handle_timeout(s);
-		break;
-	case DTLS_CTRL_LISTEN:
-		ret = dtls1_listen(s, parg);
-		break;
-
-	default:
-		ret = ssl3_ctrl(s, cmd, larg, parg);
-		break;
-		}
-	return(ret);
-	}
+{
+    int ret = 0;
+
+    switch (cmd) {
+    case DTLS_CTRL_GET_TIMEOUT:
+        if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
+            ret = 1;
+        }
+        break;
+    case DTLS_CTRL_HANDLE_TIMEOUT:
+        ret = dtls1_handle_timeout(s);
+        break;
+    case DTLS_CTRL_LISTEN:
+        ret = dtls1_listen(s, parg);
+        break;
+    case SSL_CTRL_CHECK_PROTO_VERSION:
+        /*
+         * For library-internal use; checks that the current protocol is the
+         * highest enabled version (according to s->ctx->method, as version
+         * negotiation may have changed s->method).
+         */
+#if DTLS_MAX_VERSION != DTLS1_VERSION
+# error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
+#endif
+        /*
+         * Just one protocol version is supported so far; fail closed if the
+         * version is not as expected.
+         */
+        return s->version == DTLS_MAX_VERSION;
+    case DTLS_CTRL_SET_LINK_MTU:
+        if (larg < (long)dtls1_link_min_mtu())
+            return 0;
+        s->d1->link_mtu = larg;
+        return 1;
+    case DTLS_CTRL_GET_LINK_MIN_MTU:
+        return (long)dtls1_link_min_mtu();
+    case SSL_CTRL_SET_MTU:
+        /*
+         *  We may not have a BIO set yet so can't call dtls1_min_mtu()
+         *  We'll have to make do with dtls1_link_min_mtu() and max overhead
+         */
+        if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
+            return 0;
+        s->d1->mtu = larg;
+        return larg;
+    default:
+        ret = ssl3_ctrl(s, cmd, larg, parg);
+        break;
+    }
+    return (ret);
+}
 
 /*
  * As it's impossible to use stream ciphers in "datagram" mode, this
@@ -282,205 +310,202 @@ long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
  * available, but if new ones emerge, they will have to be added...
  */
 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
-	{
-	const SSL_CIPHER *ciph = ssl3_get_cipher(u);
+{
+    const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 
-	if (ciph != NULL)
-		{
-		if (ciph->algorithm_enc == SSL_RC4)
-			return NULL;
-		}
+    if (ciph != NULL) {
+        if (ciph->algorithm_enc == SSL_RC4)
+            return NULL;
+    }
 
-	return ciph;
-	}
+    return ciph;
+}
 
 void dtls1_start_timer(SSL *s)
-	{
+{
 #ifndef OPENSSL_NO_SCTP
-	/* Disable timer for SCTP */
-	if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
-		{
-		memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
-		return;
-		}
+    /* Disable timer for SCTP */
+    if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
+        memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
+        return;
+    }
 #endif
 
-	/* If timer is not set, initialize duration with 1 second */
-	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
-		{
-		s->d1->timeout_duration = 1;
-		}
-	
-	/* Set timeout to current time */
-	get_current_time(&(s->d1->next_timeout));
-
-	/* Add duration to current time */
-	s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
-	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
-	}
-
-struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
-	{
-	struct timeval timenow;
-
-	/* If no timeout is set, just return NULL */
-	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
-		{
-		return NULL;
-		}
-
-	/* Get current time */
-	get_current_time(&timenow);
-
-	/* If timer already expired, set remaining time to 0 */
-	if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
-		(s->d1->next_timeout.tv_sec == timenow.tv_sec &&
-		 s->d1->next_timeout.tv_usec <= timenow.tv_usec))
-		{
-		memset(timeleft, 0, sizeof(struct timeval));
-		return timeleft;
-		}
-
-	/* Calculate time left until timer expires */
-	memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
-	timeleft->tv_sec -= timenow.tv_sec;
-	timeleft->tv_usec -= timenow.tv_usec;
-	if (timeleft->tv_usec < 0)
-		{
-		timeleft->tv_sec--;
-		timeleft->tv_usec += 1000000;
-		}
-
-	/* If remaining time is less than 15 ms, set it to 0
-	 * to prevent issues because of small devergences with
-	 * socket timeouts.
-	 */
-	if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
-		{
-		memset(timeleft, 0, sizeof(struct timeval));
-		}
-	
-
-	return timeleft;
-	}
+    /* If timer is not set, initialize duration with 1 second */
+    if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
+        s->d1->timeout_duration = 1;
+    }
+
+    /* Set timeout to current time */
+    get_current_time(&(s->d1->next_timeout));
+
+    /* Add duration to current time */
+    s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
+    BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
+             &(s->d1->next_timeout));
+}
+
+struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
+{
+    struct timeval timenow;
+
+    /* If no timeout is set, just return NULL */
+    if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
+        return NULL;
+    }
+
+    /* Get current time */
+    get_current_time(&timenow);
+
+    /* If timer already expired, set remaining time to 0 */
+    if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
+        (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
+         s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
+        memset(timeleft, 0, sizeof(struct timeval));
+        return timeleft;
+    }
+
+    /* Calculate time left until timer expires */
+    memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
+    timeleft->tv_sec -= timenow.tv_sec;
+    timeleft->tv_usec -= timenow.tv_usec;
+    if (timeleft->tv_usec < 0) {
+        timeleft->tv_sec--;
+        timeleft->tv_usec += 1000000;
+    }
+
+    /*
+     * If remaining time is less than 15 ms, set it to 0 to prevent issues
+     * because of small devergences with socket timeouts.
+     */
+    if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
+        memset(timeleft, 0, sizeof(struct timeval));
+    }
+
+    return timeleft;
+}
 
 int dtls1_is_timer_expired(SSL *s)
-	{
-	struct timeval timeleft;
+{
+    struct timeval timeleft;
 
-	/* Get time left until timeout, return false if no timer running */
-	if (dtls1_get_timeout(s, &timeleft) == NULL)
-		{
-		return 0;
-		}
+    /* Get time left until timeout, return false if no timer running */
+    if (dtls1_get_timeout(s, &timeleft) == NULL) {
+        return 0;
+    }
 
-	/* Return false if timer is not expired yet */
-	if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
-		{
-		return 0;
-		}
+    /* Return false if timer is not expired yet */
+    if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
+        return 0;
+    }
 
-	/* Timer expired, so return true */	
-	return 1;
-	}
+    /* Timer expired, so return true */
+    return 1;
+}
 
 void dtls1_double_timeout(SSL *s)
-	{
-	s->d1->timeout_duration *= 2;
-	if (s->d1->timeout_duration > 60)
-		s->d1->timeout_duration = 60;
-	dtls1_start_timer(s);
-	}
+{
+    s->d1->timeout_duration *= 2;
+    if (s->d1->timeout_duration > 60)
+        s->d1->timeout_duration = 60;
+    dtls1_start_timer(s);
+}
 
 void dtls1_stop_timer(SSL *s)
-	{
-	/* Reset everything */
-	memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
-	memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
-	s->d1->timeout_duration = 1;
-	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
-	/* Clear retransmission buffer */
-	dtls1_clear_record_buffer(s);
-	}
+{
+    /* Reset everything */
+    memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
+    memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
+    s->d1->timeout_duration = 1;
+    BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
+             &(s->d1->next_timeout));
+    /* Clear retransmission buffer */
+    dtls1_clear_record_buffer(s);
+}
 
 int dtls1_check_timeout_num(SSL *s)
-	{
-	s->d1->timeout.num_alerts++;
-
-	/* Reduce MTU after 2 unsuccessful retransmissions */
-	if (s->d1->timeout.num_alerts > 2)
-		{
-		s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);		
-		}
-
-	if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
-		{
-		/* fail the connection, enough alerts have been sent */
-		SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
-		return -1;
-		}
-
-	return 0;
-	}
+{
+    unsigned int mtu;
+
+    s->d1->timeout.num_alerts++;
+
+    /* Reduce MTU after 2 unsuccessful retransmissions */
+    if (s->d1->timeout.num_alerts > 2
+        && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
+        mtu =
+            BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0,
+                     NULL);
+        if (mtu < s->d1->mtu)
+            s->d1->mtu = mtu;
+    }
+
+    if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
+        /* fail the connection, enough alerts have been sent */
+        SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);
+        return -1;
+    }
+
+    return 0;
+}
 
 int dtls1_handle_timeout(SSL *s)
-	{
-	/* if no timer is expired, don't do anything */
-	if (!dtls1_is_timer_expired(s))
-		{
-		return 0;
-		}
-
-	dtls1_double_timeout(s);
+{
+    /* if no timer is expired, don't do anything */
+    if (!dtls1_is_timer_expired(s)) {
+        return 0;
+    }
 
-	if (dtls1_check_timeout_num(s) < 0)
-		return -1;
+    dtls1_double_timeout(s);
 
-	s->d1->timeout.read_timeouts++;
-	if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
-		{
-		s->d1->timeout.read_timeouts = 1;
-		}
+    if (dtls1_check_timeout_num(s) < 0)
+        return -1;
 
+    s->d1->timeout.read_timeouts++;
+    if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
+        s->d1->timeout.read_timeouts = 1;
+    }
 #ifndef OPENSSL_NO_HEARTBEATS
-	if (s->tlsext_hb_pending)
-		{
-		s->tlsext_hb_pending = 0;
-		return dtls1_heartbeat(s);
-		}
+    if (s->tlsext_hb_pending) {
+        s->tlsext_hb_pending = 0;
+        return dtls1_heartbeat(s);
+    }
 #endif
 
-	dtls1_start_timer(s);
-	return dtls1_retransmit_buffered_messages(s);
-	}
+    dtls1_start_timer(s);
+    return dtls1_retransmit_buffered_messages(s);
+}
 
 static void get_current_time(struct timeval *t)
 {
 #ifdef OPENSSL_SYS_WIN32
-	struct _timeb tb;
-	_ftime(&tb);
-	t->tv_sec = (long)tb.time;
-	t->tv_usec = (long)tb.millitm * 1000;
+    struct _timeb tb;
+    _ftime(&tb);
+    t->tv_sec = (long)tb.time;
+    t->tv_usec = (long)tb.millitm * 1000;
 #elif defined(OPENSSL_SYS_VMS)
-	struct timeb tb;
-	ftime(&tb);
-	t->tv_sec = (long)tb.time;
-	t->tv_usec = (long)tb.millitm * 1000;
+    struct timeb tb;
+    ftime(&tb);
+    t->tv_sec = (long)tb.time;
+    t->tv_usec = (long)tb.millitm * 1000;
 #else
-	gettimeofday(t, NULL);
+    gettimeofday(t, NULL);
 #endif
 }
 
 int dtls1_listen(SSL *s, struct sockaddr *client)
-	{
-	int ret;
-
-	SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
-	s->d1->listen = 1;
-
-	ret = SSL_accept(s);
-	if (ret <= 0) return ret;
-	
-	(void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
-	return 1;
-	}
+{
+    int ret;
+
+    /* Ensure there is no state left over from a previous invocation */
+    SSL_clear(s);
+
+    SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
+    s->d1->listen = 1;
+
+    ret = SSL_accept(s);
+    if (ret <= 0)
+        return ret;
+
+    (void)BIO_dgram_get_peer(SSL_get_rbio(s), client);
+    return 1;
+}