PR: 2756

Submitted by: Robin Seggelmann <seggelmann@fh-muenster.de>

Fix DTLS timeout handling.

diff --git a/ssl/d1_lib.c b/ssl/d1_lib.c
index bceba3c971bc1b8d8ac168a36b35ee339cd7174e..8155a890bd4fbc31916e03d6c85e14383c51c218 100644 (file)
--- a/ssl/d1_lib.c
+++ b/ssl/d1_lib.c
@@ -421,6 +421,7 @@ void dtls1_double_timeout(SSL *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));
@@ -428,30 +429,43 @@ void dtls1_stop_timer(SSL *s)
        dtls1_clear_record_buffer(s);
        }
 
-int dtls1_handle_timeout(SSL *s)
+int dtls1_check_timeout_num(SSL *s)
        {
-       DTLS1_STATE *state;
+       s->d1->timeout.num_alerts++;
 
-       /* if no timer is expired, don't do anything */
-       if (!dtls1_is_timer_expired(s))
+       /* Reduce MTU after 2 unsuccessful retransmissions */
+       if (s->d1->timeout.num_alerts > 2)
                {
-               return 0;
+               s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);               
                }
 
-       dtls1_double_timeout(s);
-       state = s->d1;
-       state->timeout.num_alerts++;
-       if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
+       if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
                {
                /* fail the connection, enough alerts have been sent */
                SSLerr(SSL_F_DTLS1_HANDLE_TIMEOUT,SSL_R_READ_TIMEOUT_EXPIRED);
                return -1;
                }
 
-       state->timeout.read_timeouts++;
-       if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
+       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 (dtls1_check_timeout_num(s) < 0)
+               return -1;
+
+       s->d1->timeout.read_timeouts++;
+       if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
                {
-               state->timeout.read_timeouts = 1;
+               s->d1->timeout.read_timeouts = 1;
                }
 
        if (state->timeout_duration > 2)

diff --git a/ssl/d1_pkt.c b/ssl/d1_pkt.c
index b709ebbfaae3d43d9b248ef1ff0a44a9a9432962..65b1ef28cdeb8bc89caf1215d9108b76f8c2d940 100644 (file)
--- a/ssl/d1_pkt.c
+++ b/ssl/d1_pkt.c
@@ -139,7 +139,6 @@ static int dtls1_process_record(SSL *s);
 #if PQ_64BIT_IS_INTEGER
 static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num);
 #endif
-static void dtls1_clear_timeouts(SSL *s);
 
 /* copy buffered record into SSL structure */
 static int
@@ -640,7 +639,6 @@ again:
                goto again;     /* get another record */
                }
 
-       dtls1_clear_timeouts(s);  /* done waiting */
        return(1);
 
        }
@@ -1109,6 +1107,9 @@ start:
                 */
                if (msg_hdr.type == SSL3_MT_FINISHED)
                        {
+                       if (dtls1_check_timeout_num(s) < 0)
+                               return -1;
+
                        dtls1_retransmit_buffered_messages(s);
                        rr->length = 0;
                        goto start;
@@ -1812,10 +1813,3 @@ bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)
        return _num;
        }
 #endif
-
-
-static void
-dtls1_clear_timeouts(SSL *s)
-       {
-       memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
-       }

diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h
index 4741e30b2b20c85ba7ec526cbbd7c34f5a3bedc3..3d581f1f2fe46715e2704ad30d99d4b98fae0d16 100644 (file)
--- a/ssl/ssl_locl.h
+++ b/ssl/ssl_locl.h
@@ -870,6 +870,7 @@ void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr);
 void dtls1_reset_seq_numbers(SSL *s, int rw);
 long dtls1_default_timeout(void);
 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft);
+int dtls1_check_timeout_num(SSL *s);
 int dtls1_handle_timeout(SSL *s);
 SSL_CIPHER *dtls1_get_cipher(unsigned int u);
 void dtls1_start_timer(SSL *s);