Hello! While looking over the old remaining bugs reported against iproute in Debian I came across http://bugs.debian.org/394780 which has also been reported as http://bugzilla.kernel.org/show_bug.cgi?id=7398 (please see the old comments here).
As there seems to be a question remaining which still hasn't been answered (read: shot down), I thought I'd try to give this a push a last time. The bugs last comment was from Pierre asking about a patch he provided: > I am sorry, I didn't mean to break anything... What about a sysctl option, to > give the user the possibility to disable the hack? See attached patch. I can't > really see any drawback to that. Please review and consider re-opening the > bug. The patch (which probably doesn't even apply anymore) is available from http://andrea.via.ecp.fr/mc-src-strict.patch but also quoted below for your convenience... It would be nice to have some comments on this so we can put this issue to rest without leaving any loose ends. (Btw, I'm a bit surprised by the comment about backwards compatability before proper functionality. If this hack has been in the kernel for 11 years, isn't it soon time to say that the applications has been given enough time to fix their problems and remove it? I thought thats how it usually worked around here.... I guess I was wrong.) diff -urNp linux-2.6.18/Documentation/filesystems/proc.txt linux-2.6.18/Documentation/filesystems/proc.txt --- linux-2.6.18/Documentation/filesystems/proc.txt 2006-09-19 20:42:06.000000000 -0700 +++ linux-2.6.18/Documentation/filesystems/proc.txt 2006-10-26 05:13:15.000000000 -0700 @@ -1758,6 +1758,15 @@ max_delay, min_delay Delays for flushing the routing cache. +mc_src_strict +------------- + +There is a hack in the kernel router which provides compatibility for old +multicast applications such as vic, vat and friends. Unfortunately, this +hack also breaks normal behavior of preferred source address selection +(iproute2 "src" field) with multicast and limited broadcast. Enabling this +option disables this hack and restores normal (strict) behavior. + redirect_load, redirect_number ------------------------------ diff -urNp linux-2.6.18/include/linux/sysctl.h linux-2.6.18/include/linux/sysctl.h --- linux-2.6.18/include/linux/sysctl.h 2006-09-19 20:42:06.000000000 -0700 +++ linux-2.6.18/include/linux/sysctl.h 2006-10-26 04:25:00.000000000 -0700 @@ -433,6 +433,7 @@ enum { NET_IPV4_ROUTE_MIN_ADVMSS=17, NET_IPV4_ROUTE_SECRET_INTERVAL=18, NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS=19, + NET_IPV4_ROUTE_MC_SRC_STRICT=20, }; enum diff -urNp linux-2.6.18/net/ipv4/route.c linux-2.6.18/net/ipv4/route.c --- linux-2.6.18/net/ipv4/route.c 2006-09-19 20:42:06.000000000 -0700 +++ linux-2.6.18/net/ipv4/route.c 2006-10-26 05:11:00.000000000 -0700 @@ -132,6 +132,7 @@ static int ip_rt_mtu_expires = 10 * 60 static int ip_rt_min_pmtu = 512 + 20 + 20; static int ip_rt_min_advmss = 256; static int ip_rt_secret_interval = 10 * 60 * HZ; +static int ip_rt_mc_src_strict = 0; static unsigned long rt_deadline; #define RTprint(a...) printk(KERN_DEBUG a) @@ -2416,7 +2417,7 @@ static int ip_route_output_slow(struct r of another iface. --ANK */ - if (oldflp->oif == 0 + if (!ip_rt_mc_src_strict && oldflp->oif == 0 && (MULTICAST(oldflp->fl4_dst) || oldflp->fl4_dst == 0xFFFFFFFF)) { /* Special hack: user can direct multicasts and limited broadcast via necessary interface @@ -2431,6 +2432,12 @@ static int ip_route_output_slow(struct r cannot know, that ttl is zero, so that packet will not leave this host and route is valid). Luckily, this hack is good workaround. + + Unfortunately, it also breaks normal behavior of + source address preference, so I added a sysctl option + to let the user disable this hack and restore normal + behavior. By default, the hack is still enabled (old + compatibility behavior). -- PY */ fl.oif = dev_out->ifindex; @@ -3057,6 +3064,15 @@ ctl_table ipv4_route_table[] = { .proc_handler = &proc_dointvec_jiffies, .strategy = &sysctl_jiffies, }, + { + .ctl_name = NET_IPV4_ROUTE_MC_SRC_STRICT, + .procname = "mc_src_strict", + .data = &ip_rt_mc_src_strict, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &ipv4_doint_and_flush, + .strategy = &ipv4_doint_and_flush_strategy, + }, { .ctl_name = 0 } }; #endif -- Regards, Andreas Henriksson -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
