dtls.c, netq.c: consider 32bit time overflow.

Fixes issue: eclipse#125

Signed-off-by: Achim Kraus <[email protected]>

dtls.c

@@ -4702,7 +4702,8 @@ dtls_check_retransmit(dtls_context_t *context, clock_time_t *next) {
   netq_t *node = netq_head(&context->sendqueue);
 
   dtls_ticks(&now);
-  while (node && node->t <= now) {
+  // comparison considering 32bit overflow
+  while (node && DTLS_IS_BEFORE_TIME(node->t, now)) {
     netq_pop_first(&context->sendqueue);
     dtls_retransmit(context, node);
     node = netq_head(&context->sendqueue);

dtls_time.h

@@ -51,6 +51,7 @@
 #endif
 
 typedef uint64_t clock_time_t;
+
 #else /* WITH_CONTIKI || RIOT_VERSION */
 
 #ifdef HAVE_TIME_H
@@ -62,6 +63,7 @@ typedef uint64_t clock_time_t;
 #endif
 
 typedef uint32_t clock_time_t;
+
 #endif /* WITH_CONTIKI || RIOT_VERSION */
 
 typedef clock_time_t dtls_tick_t;
@@ -73,6 +75,11 @@ typedef clock_time_t dtls_tick_t;
 void dtls_clock_init(void);
 void dtls_ticks(dtls_tick_t *t);
 
+// see https://godbolt.org/#z:OYLghAFBqd5QCxAYwPYBMCmBRdBLAF1QCcAaPECAMzwBtMA7AQwFtMQByARg9KtQYEAysib0QXACx8BBAKoBnTAAUAHpwAMvAFYTStJg1AB9U8lJL6yAngGVG6AMKpaAVxYMJG0g4AyeBkwAOXcAI0xiEAA2UgAHVAVCWwZnNw8vOISkgX9AkJZwyJjLTGtkoQImYgJU908ubxKygQqqglzgsIjoi0rq2vSG3raO/MLogEoLVFdiZHYOAFIAJgBmAOQ3LABqRdXHBQJ8VAA6BD3sRY0AQRX1hk3XHb2Do4CCM4ur25u7rBpAtsACpBYwAeQAYhChNggdsIABWDQTb7fAgAT1imH%2B21c7wAHMYCNtNqhkABrIl4NhEvYAIVRN3e2xYTACEAAbqg8OgUQB2Bk3bbC7Zcgw2egk2hkyk2GnE4l7AAi2w09O%2BItFLiYEswUplVPl2wYu1WKrVq0F101aAYh31FMNmCJLKYwDwyGMqCoVCUirN8KgpMdcudBAmAD9kabLqtsNsuCjLRqRYsBSnhczkKbzeqhSL%2BMR4cy8DnVaa6dtSy9tqsNBbK9Xlgzm9t%2BVbNZqAPRd0sAdzotG2qA5ESo0r7VcEqG2xMM6GNu3zndnZbweetK8Xyqr2wAtMDQZDobCN1uq1RA8HZdSwxMIKz3Z7vb7MIrWyaD%2BHTY5XU%2BvT6frthm54kisLYMsmy6dmmSogbBIGxMQ7xUBAKzLNKqCxAmJIgCsCILosCKOAw6GkCSSYdqmfJwb80FplRmaCCSZYNiBhbFsx1YBhoFa7jWdYNvxzbgW2DEgd2vbbAOtBDiOY4TlORCrvO27QZq/oquuUGbiuJo7qWB4guCUIwkCZ5bngl5BtKIa3kS96frOEw/qqwHqVuyDgd5Onngh9E0YhyGCKh6GYdhyy4fhhHEaRyzLORyCUfBgV0bpuzptBWasRZwocRAJasXx3G/oJ9LCRBYmZelkn9oOw6jsQ46oJO7wznODALvpHnCppVa5Z2%2BkBoZh4mSe5m%2BZZ1kQE5341si4k9Z2XkiSJk0rv56WbZqSEoWh8XhbWUXLARuyxWRFEDZtQV7eh0VESRF2Ph6AGvuGV3QcQb6zCabG/DRHBTLQnAIrwngcFopCoJwv4KDMcx6ncPCkAQmiA1M5IgKsqwnNjeP4wTMTAxwkhg2jUOcLwCggN4qMQ4DpBwLASBoCwsR0BE5CUKz7P0JEyDAFwXAJTQtAEBE1MQKE5OhAEVTouTrNsIIYIMLQCv06QWCskY4ia/gX1lKO1Oa5gqilK44vk%2B8mDE5DtB4KExDy84WCcMjBDISw7sM%2BOboKAAangmB9mCWLg8j/CCCIYjsFIMiCIoKjqJruhcPohgmGY%2BiO9TkBTFhNgCCb%2B5gqsVO26UReeBADgDPUPidaMXSROn8SJNX9d6O32QMM3BTdOnTTV60/QuHUejD%2BUfTtAEnQD63wxj2kDeHCMc9jIPUxw7M8x6J7mALDwQMg2TmvQxwqj4lEe5RJI2zAMg2ZCyckUQI45G4IQJC7Gs6fbM4NmHMixIwmLwOmWgJgYyxhoV%2BXA%2BTY0kKsfEGg%2BTLD5AATlWNIYmpNSDg0hhfKmNMUZoymEzKAMBEAgCIC4LmEAqjABNrwRhChlCGFtkIBALUfakB5sAvQ2Jv6LyjsIUQ4h46iKTmocmLABBMDQF/IgxAAASTAFB0kPgwa4ltUBh0YNiXhcjmCKPwMo/REdeDGIUagCo%2BBLG9HsZTRxAR2GBFoFwlqDjaG0AAJLoBALEJg3D6CkD7M7WIPsT4cFBvg8mF8gkhMRn/aShAEDbCvjfO%2BD8n4Ji4K/cBZDoHY1xgTMp2N9CcDwd7JEcTz7OOprTMhjMqEQCQDMAgsRLb0P4XzQRZiSB6FETHCR0gpFKBkZrcJTBIncAZsTWJBDeAXzBJbLpxJvQZOvrfe%2Bj9n75LfoA3mERf6rETIU%2BmUDSAIEwEwLAkQIDROqSAWpSyKYcGIU0y5xSognEkJILBqx4r4gRFg/ECDKkcHLnUwhziIHo0hcsM%2BsKPmkO%2BaQRqiQ7CSCAA%3D
+#define DTLS_OFFSET_TIME (((clock_time_t)~0) >> 1)
+/** Checks if A is before (or equal) B. Considers 32 bit time overflow */
+#define DTLS_IS_BEFORE_TIME(A, B) ((DTLS_OFFSET_TIME + (B)-(A)) >= DTLS_OFFSET_TIME)
+
 /** @} */
 
 #endif /* _DTLS_DTLS_TIME_H_ */

netq.c

@@ -93,7 +93,8 @@ netq_insert_node(netq_t **queue, netq_t *node) {
   assert(node);
 
   p = *queue;
-  while(p && p->t <= node->t) {
+  // comparison considering 32bit overflow
+  while(p && DTLS_IS_BEFORE_TIME(p->t, node->t)) {
     assert(p != node);
     if (p == node)
       return 0;