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>
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