netdev - Re: Fw: [Bugme-new] [Bug 7665] New: getsockopt(IPV6_*CAST

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <457DD3EB.9030201@hp.com>
Date:	Mon, 11 Dec 2006 16:55:55 -0500
From:	Brian Haley <brian.haley@...com>
To:	rdenis@...phalempin.com
Cc:	Andrew Morton <akpm@...l.org>, netdev@...r.kernel.org
Subject: Re: Fw: [Bugme-new] [Bug 7665] New: getsockopt(IPV6_*CAST_HOPS) returns
 -1

Andrew Morton wrote:
> Where fd is a socket (datagram or raw) with IPv6 protocol family,
> getsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, ...) succeeds, but the returned 
> hop limit is -1. connect()'ing the socket first does not solve the problem.

An IPv6 socket's hoplimit value is not set at creation time, instead, 
the hoplimit in an outgoing packet is set dynamically at transmit time 
to one of the following (in this order):

1. Hoplimit route metric (if set)
2. Outgoing interface value (/proc/sys/net/ipv6/conf/ethX/hop_limit)
3. Global IPv6 value (/proc/sys/net/ipv6/conf/all/hop_limit)

A setsockopt() value *will* override this.

Some *nixes have a different behavior and do set it at socket() creation 
time.

-Brian
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html