| Message ID | 4A24B920.2010605@cosmosbay.com |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Eric Dumazet <dada1@cosmosbay.com> Date: Tue, 02 Jun 2009 07:31:12 +0200 > David Miller a écrit : >> From: Nicolas Dichtel <nicolas.dichtel@dev.6wind.com> >> Date: Mon, 01 Jun 2009 17:13:43 +0200 >> >>> RFC indicates that a router must drop the packet if this field is 0. >> >> It only must do this when executing the forwarding function. It's an >> egress check, not an ingress one. >> >> I'm not applying this patch, it can even break some applications >> out there that use a TTL of zero intentionally to keep traffic >> only on a local subnet. > > I wonder if we then should allow setting ttl to zero. I had to patch > my kernel to allow ping to do this... > > I'll check RFC when time permits. Eric, notice how I mentioned in my other reply to this thread "multicast" applications, which use mc_ttl which we allow to be set to zero. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index e2d1f87..efe2797 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -558,7 +558,7 @@ static int do_ip_setsockopt(struct sock *sk, int level, case IP_TTL: if (optlen<1) goto e_inval; - if (val != -1 && (val < 1 || val>255)) + if (val != -1 && (val < 0 || val>255)) goto e_inval; inet->uc_ttl = val; break;