From 1ef3103b7a9ac37bd2967ae57c5f0bc6e697bb7f Mon Sep 17 00:00:00 2001 From: Will Mortensen Date: Sun, 18 Oct 2015 20:50:56 -0700 Subject: [PATCH] Don't overflow router lifetime When a prefix lifetime was greater than UINT16_MAX, we would advertise a shorter router lifetime (even potentially 0). Saturate instead. --- src/router.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/src/router.c b/src/router.c index 526f9c2..74d8a09 100644 --- a/src/router.c +++ b/src/router.c @@ -292,10 +292,13 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add minvalid > 1000LL * TIME_LEFT(addr->valid, now)) minvalid = 1000LL * TIME_LEFT(addr->valid, now); + uint32_t this_lifetime = TIME_LEFT(addr->valid, now); + if (this_lifetime > UINT16_MAX) + this_lifetime = UINT16_MAX; if (((addr->addr.s6_addr[0] & 0xfe) != 0xfc || iface->default_router) && adv.h.nd_ra_router_lifetime - && ntohs(adv.h.nd_ra_router_lifetime) < TIME_LEFT(addr->valid, now)) - adv.h.nd_ra_router_lifetime = htons(TIME_LEFT(addr->valid, now)); + && ntohs(adv.h.nd_ra_router_lifetime) < this_lifetime) + adv.h.nd_ra_router_lifetime = htons(this_lifetime); odhcpd_bmemcpy(&p->nd_opt_pi_prefix, &addr->addr, (iface->ra_advrouter) ? 128 : addr->prefix); -- 2.25.1