diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/network.c | 21 | ||||
| -rw-r--r-- | lib/network.h | 18 |
2 files changed, 39 insertions, 0 deletions
diff --git a/lib/network.c b/lib/network.c index b60ad9a57c..cd62b8b593 100644 --- a/lib/network.c +++ b/lib/network.c @@ -122,3 +122,24 @@ float ntohf(float net) { return htonf(net); } + +uint64_t frr_sequence_next(void) +{ + static uint64_t last_sequence; + struct timespec ts; + + (void)clock_gettime(CLOCK_MONOTONIC, &ts); + if (last_sequence == (uint64_t)ts.tv_sec) { + last_sequence++; + return last_sequence; + } + + last_sequence = ts.tv_sec; + return last_sequence; +} + +uint32_t frr_sequence32_next(void) +{ + /* coverity[Y2K38_SAFETY] */ + return (uint32_t)frr_sequence_next(); +} diff --git a/lib/network.h b/lib/network.h index 10ed917572..c163eab8f7 100644 --- a/lib/network.h +++ b/lib/network.h @@ -82,6 +82,24 @@ extern float ntohf(float); #endif /** + * Generate a sequence number using monotonic clock with a same second call + * protection to help guarantee a unique incremental sequence number that never + * goes back (except when wrapping/overflow). + * + * **NOTE** this function is not thread safe since it uses `static` variable. + * + * This function and `frr_sequence32_next` should be used to initialize + * sequence numbers without directly calling other `time_t` returning + * functions because of `time_t` truncation warnings. + * + * \returns `uint64_t` number based on the monotonic clock. + */ +extern uint64_t frr_sequence_next(void); + +/** Same as `frr_sequence_next` but returns truncated number. */ +extern uint32_t frr_sequence32_next(void); + +/** * Helper function that returns a random long value. The main purpose of * this function is to hide a `random()` call that gets flagged by coverity * scan and put it into one place. |
