diff options
| -rw-r--r-- | net/ipv6/addrconf.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 26aedaab3647..3aaea56b5166 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -1407,15 +1407,23 @@ retry: write_unlock_bh(&idev->lock); - /* A temporary address is created only if this calculated Preferred - * Lifetime is greater than REGEN_ADVANCE time units. In particular, - * an implementation must not create a temporary address with a zero - * Preferred Lifetime. + /* From RFC 4941: + * + * A temporary address is created only if this calculated Preferred + * Lifetime is greater than REGEN_ADVANCE time units. In + * particular, an implementation must not create a temporary address + * with a zero Preferred Lifetime. + * + * Clamp the preferred lifetime to a minimum of regen_advance, unless + * that would exceed valid_lft. + * * Use age calculation as in addrconf_verify to avoid unnecessary * temporary addresses being generated. */ age = (now - tmp_tstamp + ADDRCONF_TIMER_FUZZ_MINUS) / HZ; - if (cfg.preferred_lft <= regen_advance + age) { + if (cfg.preferred_lft <= regen_advance + age) + cfg.preferred_lft = regen_advance + age + 1; + if (cfg.preferred_lft > cfg.valid_lft) { in6_ifa_put(ifp); in6_dev_put(idev); ret = -1; |