Does anyone know the status of this potential patch? There has been
silence since the initial patch proposal was made over a month ago.
Thanks,
-Kevin
--
Kevin W. Rudd
Linux Change Team
IBM Global Services
1-800-426-7378, T/L 775-4161
On Sat, 13 Dec 2003, Julian Anastasov wrote:
> Date: Sat, 13 Dec 2003 01:38:00 +0200 (EET)
> From: Julian Anastasov <ja@xxxxxx>
> To: David S. Miller <davem@xxxxxxxxxx>
> Cc: niv@xxxxxxxxxx, ak@xxxxxxx, ruddk@xxxxxxxxxx, kuznet@xxxxxxxxxxxxx,
> netdev@xxxxxxxxxxx, chester.f.johnson@xxxxxxxxx
> Subject: Re: PMTU issues due to TOS field manipulation (for DSCP)
>
>
> Hello,
>
> On Fri, 12 Dec 2003, David S. Miller wrote:
>
> > 1) PMTU processing applies PMTU change to all TOS'd instances of
> > a route. This behavior change is sysctl controllable, and
> > on by default.
> >
> > The implementation is to just lookup all 8 possible TOS values.
> >
> > 2) Whether TOS is a routing cache hash key is controlled by another
> > sysctl.
> >
> > When CONFIG_IP_ROUTE_TOS is set this sysctl defaults to on, other-
> > wise it defaults to off.
> >
> > I think #2 should be very safe because fib node fn_tos values are only
> > ever set when that config variable is enabled, and fib rule r_tos values
> > are only compared on lookup when it is enabled as well. However, there
> > could be a few more ifdefs added to the fib rule code to cover all the
> > assignment cases too but let's not worry about that right now.
>
> OK, here is a change that compiles. No fib changes yet (it
> is the next step). I'm not sure what var names are better.
>
> > Comments?
>
> What about ip_rt_redirect? May be we need the same TOS
> matching behavior if TOS is changed somewhere after routing?
>
> diff -Nru a/include/linux/sysctl.h b/include/linux/sysctl.h
> --- a/include/linux/sysctl.h Sat Dec 13 01:16:15 2003
> +++ b/include/linux/sysctl.h Sat Dec 13 01:16:15 2003
> @@ -329,6 +329,8 @@
> NET_IPV4_ROUTE_MIN_PMTU=16,
> NET_IPV4_ROUTE_MIN_ADVMSS=17,
> NET_IPV4_ROUTE_SECRET_INTERVAL=18,
> + NET_IPV4_ROUTE_IGNORE_TOS=19,
> + NET_IPV4_ROUTE_PMTU_MODE=20,
> };
>
> enum
> diff -Nru a/net/ipv4/route.c b/net/ipv4/route.c
> --- a/net/ipv4/route.c Sat Dec 13 01:16:15 2003
> +++ b/net/ipv4/route.c Sat Dec 13 01:16:15 2003
> @@ -124,6 +124,14 @@
> int ip_rt_min_advmss = 256;
> int ip_rt_secret_interval = 10 * 60 * HZ;
> static unsigned long rt_deadline;
> +#ifdef CONFIG_IP_ROUTE_TOS
> +static u8 iptos_rt_mask = IPTOS_RT_MASK;
> +int ip_rt_ignore_tos;
> +#else
> +static u8 iptos_rt_mask;
> +int ip_rt_ignore_tos = 1;
> +#endif
> +int ip_rt_pmtu_mode; /* 1=match by iph->tos, 0=ignore TOS for PMTU */
>
> #define RTprint(a...) printk(KERN_DEBUG a)
>
> @@ -967,13 +975,12 @@
> void ip_rt_redirect(u32 old_gw, u32 daddr, u32 new_gw,
> u32 saddr, u8 tos, struct net_device *dev)
> {
> - int i, k;
> + int i;
> struct in_device *in_dev = in_dev_get(dev);
> struct rtable *rth, **rthp;
> u32 skeys[2] = { saddr, 0 };
> - int ikeys[2] = { dev->ifindex, 0 };
>
> - tos &= IPTOS_RT_MASK;
> + tos &= iptos_rt_mask;
>
> if (!in_dev)
> return;
> @@ -993,10 +1000,7 @@
> }
>
> for (i = 0; i < 2; i++) {
> - for (k = 0; k < 2; k++) {
> - unsigned hash = rt_hash_code(daddr,
> - skeys[i] ^ (ikeys[k] << 5),
> - tos);
> + unsigned hash = rt_hash_code(daddr, skeys[i], tos);
>
> rthp=&rt_hash_table[hash].chain;
>
> @@ -1008,7 +1012,9 @@
> if (rth->fl.fl4_dst != daddr ||
> rth->fl.fl4_src != skeys[i] ||
> rth->fl.fl4_tos != tos ||
> - rth->fl.oif != ikeys[k] ||
> + (rth->fl.oif &&
> + rth->fl.oif != dev->ifindex) ||
> + rth->rt_dst == rth->rt_gateway ||
> rth->fl.iif != 0) {
> rthp = &rth->u.rt_next;
> continue;
> @@ -1075,7 +1081,6 @@
> rcu_read_unlock();
> do_next:
> ;
> - }
> }
> in_dev_put(in_dev);
> return;
> @@ -1105,8 +1110,7 @@
> } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
> rt->u.dst.expires) {
> unsigned hash = rt_hash_code(rt->fl.fl4_dst,
> - rt->fl.fl4_src ^
> - (rt->fl.oif << 5),
> + rt->fl.fl4_src,
> rt->fl.fl4_tos);
> #if RT_CACHE_DEBUG >= 1
> printk(KERN_DEBUG "ip_rt_advice: redirect to "
> @@ -1237,21 +1241,33 @@
> return 68;
> }
>
> +/* See IPTOS_RT_MASK */
> +static u8 all_tos_values[8] = { 0x00, 0x04, 0x08, 0x0C, 0x10, 0x14, 0x18,
> 0x1C };
> +
> unsigned short ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu)
> {
> - int i;
> + int i, j, ntos;
> unsigned short old_mtu = ntohs(iph->tot_len);
> struct rtable *rth;
> u32 skeys[2] = { iph->saddr, 0, };
> u32 daddr = iph->daddr;
> - u8 tos = iph->tos & IPTOS_RT_MASK;
> + u8 *tos_values, tos = iph->tos & iptos_rt_mask;
> unsigned short est_mtu = 0;
>
> if (ipv4_config.no_pmtu_disc)
> return 0;
>
> + if (ip_rt_pmtu_mode || !iptos_rt_mask) {
> + tos_values = &tos;
> + ntos = 1;
> + } else {
> + tos_values = all_tos_values;
> + ntos = ARRAY_SIZE(all_tos_values);
> + }
> +
> + for (j = 0; j < ntos; j++)
> for (i = 0; i < 2; i++) {
> - unsigned hash = rt_hash_code(daddr, skeys[i], tos);
> + unsigned hash = rt_hash_code(daddr, skeys[i], tos_values[j]);
>
> rcu_read_lock();
> for (rth = rt_hash_table[hash].chain; rth;
> @@ -1259,9 +1275,9 @@
> smp_read_barrier_depends();
> if (rth->fl.fl4_dst == daddr &&
> rth->fl.fl4_src == skeys[i] &&
> + rth->fl.fl4_tos == tos_values[j] &&
> rth->rt_dst == daddr &&
> rth->rt_src == iph->saddr &&
> - rth->fl.fl4_tos == tos &&
> rth->fl.iif == 0 &&
> !(dst_metric_locked(&rth->u.dst, RTAX_MTU))) {
> unsigned short mtu = new_mtu;
> @@ -1503,7 +1519,7 @@
> RT_CACHE_STAT_INC(in_slow_mc);
>
> in_dev_put(in_dev);
> - hash = rt_hash_code(daddr, saddr ^ (dev->ifindex << 5), tos);
> + hash = rt_hash_code(daddr, saddr, tos);
> return rt_intern_hash(hash, rth, (struct rtable**) &skb->dst);
>
> e_nobufs:
> @@ -1554,7 +1570,7 @@
> if (!in_dev)
> goto out;
>
> - hash = rt_hash_code(daddr, saddr ^ (fl.iif << 5), tos);
> + hash = rt_hash_code(daddr, saddr, tos);
>
> /* Check for the most weird martians, which can be not detected
> by fib_lookup.
> @@ -1846,8 +1862,8 @@
> unsigned hash;
> int iif = dev->ifindex;
>
> - tos &= IPTOS_RT_MASK;
> - hash = rt_hash_code(daddr, saddr ^ (iif << 5), tos);
> + tos &= iptos_rt_mask;
> + hash = rt_hash_code(daddr, saddr, tos);
>
> rcu_read_lock();
> for (rth = rt_hash_table[hash].chain; rth; rth = rth->u.rt_next) {
> @@ -1912,11 +1928,11 @@
>
> int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
> {
> - u32 tos = oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK);
> + u32 tos = oldflp->fl4_tos & (iptos_rt_mask | RTO_ONLINK);
> struct flowi fl = { .nl_u = { .ip4_u =
> { .daddr = oldflp->fl4_dst,
> .saddr = oldflp->fl4_src,
> - .tos = tos & IPTOS_RT_MASK,
> + .tos = tos & iptos_rt_mask,
> .scope = ((tos & RTO_ONLINK) ?
> RT_SCOPE_LINK :
> RT_SCOPE_UNIVERSE),
> @@ -2190,7 +2206,7 @@
>
> rth->rt_flags = flags;
>
> - hash = rt_hash_code(oldflp->fl4_dst, oldflp->fl4_src ^ (oldflp->oif <<
> 5), tos);
> + hash = rt_hash_code(oldflp->fl4_dst, oldflp->fl4_src, tos);
> err = rt_intern_hash(hash, rth, rp);
> done:
> if (free_res)
> @@ -2213,8 +2229,9 @@
> {
> unsigned hash;
> struct rtable *rth;
> + u8 tos = flp->fl4_tos & (iptos_rt_mask | RTO_ONLINK);
>
> - hash = rt_hash_code(flp->fl4_dst, flp->fl4_src ^ (flp->oif << 5),
> flp->fl4_tos);
> + hash = rt_hash_code(flp->fl4_dst, flp->fl4_src, tos);
>
> rcu_read_lock();
> for (rth = rt_hash_table[hash].chain; rth; rth = rth->u.rt_next) {
> @@ -2226,8 +2243,7 @@
> #ifdef CONFIG_IP_ROUTE_FWMARK
> rth->fl.fl4_fwmark == flp->fl4_fwmark &&
> #endif
> - !((rth->fl.fl4_tos ^ flp->fl4_tos) &
> - (IPTOS_RT_MASK | RTO_ONLINK))) {
> + rth->fl.fl4_tos == tos) {
> rth->u.dst.lastuse = jiffies;
> dst_hold(&rth->u.dst);
> rth->u.dst.__use++;
> @@ -2479,6 +2495,26 @@
> }
>
> #ifdef CONFIG_SYSCTL
> +
> +static int ipv4_sysctl_doint_strategy(ctl_table *table, int *name,
> + int nlen, void *oldval,
> + size_t *oldlenp, void *newval,
> + size_t newlen, void **context)
> +{
> + int val;
> +
> + if (!newval || !newlen)
> + return 0;
> + if (newlen != sizeof(int))
> + return -EINVAL;
> + if (get_user(val, (int *)newval))
> + return -EFAULT;
> + if (val == *(int *) table->data)
> + return 0;
> + *(int *) table->data = val;
> + return 1;
> +}
> +
> static int flush_delay;
>
> static int ipv4_sysctl_rtcache_flush(ctl_table *ctl, int write,
> @@ -2508,6 +2544,53 @@
> return 0;
> }
>
> +#ifdef CONFIG_IP_ROUTE_TOS
> +
> +static void do_ignore_tos(void)
> +{
> + iptos_rt_mask = ip_rt_ignore_tos? 0 : IPTOS_RT_MASK;
> + rt_cache_flush(0);
> +}
> +
> +#endif
> +
> +static int ip_rt_ignore_tos_handler(ctl_table *ctl, int write,
> + struct file *filp, void *buffer,
> + size_t *lenp)
> +{
> + if (write) {
> +#ifdef CONFIG_IP_ROUTE_TOS
> + int old = ip_rt_ignore_tos;
> + int ret = proc_dointvec(ctl, write, filp, buffer, lenp);
> +
> + if (ret)
> + return ret;
> + if (old != ip_rt_ignore_tos) do_ignore_tos();
> + return 0;
> +#else
> + return -EINVAL;
> +#endif
> + }
> + return proc_dointvec(ctl, write, filp, buffer, lenp);
> +}
> +static int ipv4_sysctl_ignore_tos_strategy(ctl_table *table, int *name,
> + int nlen, void *oldval,
> + size_t *oldlenp, void *newval,
> + size_t newlen, void **context)
> +{
> +#ifdef CONFIG_IP_ROUTE_TOS
> + int ret = ipv4_sysctl_doint_strategy(table, name, nlen, oldval, oldlenp,
> + newval, newlen, context);
> +
> + if (1 != ret)
> + return ret;
> + do_ignore_tos();
> + return 0;
> +#else
> + return (newval || newlen) ? -EINVAL : 0;
> +#endif
> +}
> +
> ctl_table ipv4_route_table[] = {
> {
> .ctl_name = NET_IPV4_ROUTE_FLUSH,
> @@ -2660,6 +2743,23 @@
> .mode = 0644,
> .proc_handler = &proc_dointvec_jiffies,
> .strategy = &sysctl_jiffies,
> + },
> + {
> + .ctl_name = NET_IPV4_ROUTE_IGNORE_TOS,
> + .procname = "ignore_tos",
> + .data = &ip_rt_ignore_tos,
> + .maxlen = sizeof(int),
> + .mode = 0644,
> + .proc_handler = &ip_rt_ignore_tos_handler,
> + .strategy = &ipv4_sysctl_ignore_tos_strategy,
> + },
> + {
> + .ctl_name = NET_IPV4_ROUTE_PMTU_MODE,
> + .procname = "pmtu_mode",
> + .data = &ip_rt_pmtu_mode,
> + .maxlen = sizeof(int),
> + .mode = 0644,
> + .proc_handler = &proc_dointvec,
> },
> { .ctl_name = 0 }
> };
>
> Regards
>
> --
> Julian Anastasov <ja@xxxxxx>
>
>
|