diff options
Diffstat (limited to 'sys/netinet6/ip6_id.c')
| -rw-r--r-- | sys/netinet6/ip6_id.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/sys/netinet6/ip6_id.c b/sys/netinet6/ip6_id.c index f41df2a2e5a9..1d6c2c7d9668 100644 --- a/sys/netinet6/ip6_id.c +++ b/sys/netinet6/ip6_id.c @@ -89,6 +89,7 @@ __FBSDID("$FreeBSD$"); #include <sys/types.h> #include <sys/param.h> #include <sys/kernel.h> +#include <sys/random.h> #include <sys/socket.h> #include <sys/libkern.h> @@ -258,5 +259,15 @@ u_int32_t ip6_randomflowlabel(void) { + /* + * It's ok to emit zero flow labels early, before random is available + * (seeded). RFC 6437: + * + * "A Flow Label of zero is used to indicate packets that have not been + * labeled." + */ + if (__predict_false(!is_random_seeded())) + return (0); + return randomid(&randomtab_20) & 0xfffff; } |