Merge pull request #12708 from donaldsharp/no_notification

[mirror_frr.git] / lib / network.h

diff --git a/lib/network.h b/lib/network.h
index a00c5a0a6574ce6122c868c6ba2a773ea1037c6e..c163eab8f76e0f3b32142976212b95e070c6a499 100644 (file)
--- a/lib/network.h
+++ b/lib/network.h
@@ -22,6 +22,13 @@
 #ifndef _ZEBRA_NETWORK_H
 #define _ZEBRA_NETWORK_H
 
+#ifdef HAVE_SYS_ENDIAN_H
+#include <sys/endian.h>
+#endif
+#ifdef HAVE_ENDIAN_H
+#include <endian.h>
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -45,6 +52,71 @@ extern int set_cloexec(int fd);
 extern float htonf(float);
 extern float ntohf(float);
 
+/* force type for be64toh/htobe64 to be uint64_t, *without* a direct cast
+ *
+ * this is a workaround for false-positive printfrr warnings from FRR's
+ * frr-format GCC plugin that would be triggered from
+ * { printfrr("%"PRIu64, (uint64_t)be64toh(...)); }
+ *
+ * the key element here is that "(uint64_t)expr" causes the warning, while
+ * "({ uint64_t x = expr; x; })" does not.  (The cast is the trigger, a
+ * variable of the same type works correctly.)
+ */
+
+/* zap system definitions... */
+#ifdef be64toh
+#undef be64toh
+#endif
+#ifdef htobe64
+#undef htobe64
+#endif
+
+#if BYTE_ORDER == LITTLE_ENDIAN
+#define be64toh(x)     ({ uint64_t r = __builtin_bswap64(x); r; })
+#define htobe64(x)     ({ uint64_t r = __builtin_bswap64(x); r; })
+#elif BYTE_ORDER == BIG_ENDIAN
+#define be64toh(x)     ({ uint64_t r = (x); r; })
+#define htobe64(x)     ({ uint64_t r = (x); r; })
+#else
+#error nobody expects the endianish inquisition. check OS endian.h headers.
+#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.
+ *
+ * The main usage of this function should be for generating jitter or weak
+ * random values for simple purposes.
+ *
+ * See 'man 3 random' for more information.
+ *
+ * \returns random long integer.
+ */
+static inline long frr_weak_random(void)
+{
+       /* coverity[dont_call] */
+       return random();
+}
+
 #ifdef __cplusplus
 }
 #endif