netdev - [PATCH 2/2] inet6: Set default traffic class

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-Id: <1249841569-23706-3-git-send-email-gerrit@erg.abdn.ac.uk>
Date:	Sun,  9 Aug 2009 20:12:49 +0200
From:	Gerrit Renker <gerrit@....abdn.ac.uk>
To:	davem@...emloft.net
Cc:	netdev@...r.kernel.org, Gerrit Renker <gerrit@....abdn.ac.uk>
Subject: [PATCH 2/2] inet6: Set default traffic class

This patch addresses:
 * assigning -1 to np->tclass as it is currently done is not very meaningful,
   since it turns into 0xff;
 * RFC 3542, 6.5 allows -1 for clearing the sticky IPV6_TCLASS option
   and specifies -1 to mean "use kernel default":
   - RFC 2460, 7. requires that the default traffic class must be zero for
     all 8 bits,
   - this is consistent with RFC 2474, 4.1 which recommends a default PHB of 0,
     in combination with a value of the ECN field of "non-ECT" (RFC 3168, 5.).

This patch changes the meaning of -1 from assigning 255 to mean the RFC 2460
default, which at the same time allows to satisfy clearing the sticky TCLASS
option as per RFC 3542, 6.5.

(When passing -1 as ancillary data, the fallback remains np->tclass, which
 has either been set via socket options, or contains the default value.)

Signed-off-by: Gerrit Renker <gerrit@....abdn.ac.uk>
---
 net/ipv6/ipv6_sockglue.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -315,6 +315,9 @@ static int do_ipv6_setsockopt(struct soc
 			goto e_inval;
 		if (val < -1 || val > 0xff)
 			goto e_inval;
+		/* RFC 3542, 6.5: default traffic class of 0x0 */
+		if (val == -1)
+			val = 0;
 		np->tclass = val;
 		retv = 0;
 		break;
--
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