From 710a2df59c785c93d92a6f85fc0a5b3cc79c2f97 Mon Sep 17 00:00:00 2001
From: Sascha Hlusiak <contact@saschahlusiak.de>
Date: Tue, 19 May 2009 11:00:27 +0200
Subject: [PATCH 5/5] sit: stateless autoconf for isatap
From each potential router in the PRL, a router solicitation will
be sent periodically. The rs_delay can be speficied when adding the
PRL entry and defaults to 15 minutes.
The RS is sent from every link local adress that's assigned to the
tunnel interface. It's directed to the (guessed) linklocal address
of the router and is sent through the tunnel.
Better: send to ff02::2 encapsuled in unicast directed to router-v4.
Signed-off-by: Sascha Hlusiak <contact@saschahlusiak.de>
---
include/linux/if_tunnel.h | 2 +-
include/net/ipip.h | 7 +++++
net/ipv6/ndisc.c | 1 +
net/ipv6/sit.c | 58 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 67 insertions(+), 1 deletions(-)
@@ -44,7 +44,7 @@ struct ip_tunnel_prl {
__u16 flags;
__u16 __reserved;
__u32 datalen;
- __u32 __reserved2;
+ __u32 rs_delay;
/* data follows */
};
@@ -28,11 +28,18 @@ struct ip_tunnel
unsigned int prl_count; /* # of entries in PRL */
};
+/* ISATAP: default interval between RS in secondy */
+#define IPTUNNEL_RS_DEFAULT_DELAY (900)
+
struct ip_tunnel_prl_entry
{
struct ip_tunnel_prl_entry *next;
__be32 addr;
u16 flags;
+ unsigned long rs_delay;
+ struct timer_list rs_timer;
+ struct ip_tunnel *tunnel;
+ spinlock_t lock;
};
#define IPTUNNEL_XMIT() do { \
@@ -658,6 +658,7 @@ void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
&icmp6h, NULL,
send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0);
}
+EXPORT_SYMBOL(ndisc_send_rs);
static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
@@ -15,6 +15,7 @@
* Roger Venning <r.venning@telstra.com>: 6to4 support
* Nate Thompson <nate@thebog.net>: 6to4 support
* Fred Templin <fred.l.templin@boeing.com>: isatap support
+ * Sascha Hlusiak <mail@saschahlusiak.de>: stateless autoconf for isatap
*/
#include <linux/module.h>
@@ -222,6 +223,44 @@ failed:
return NULL;
}
+static void ipip6_tunnel_rs_timer(unsigned long data)
+{
+ struct ip_tunnel_prl_entry *p = (struct ip_tunnel_prl_entry *) data;
+ struct inet6_dev *ifp;
+ struct inet6_ifaddr *addr;
+
+ spin_lock(&p->lock);
+ ifp = __in6_dev_get(p->tunnel->dev);
+
+ spin_lock(&ifp->lock);
+ for (addr = ifp->addr_list; addr; addr = addr->if_next) {
+ struct in6_addr rtr;
+
+ if (!(ipv6_addr_type(&addr->addr) & IPV6_ADDR_LINKLOCAL))
+ continue;
+
+ /* Send RS to guessed linklocal address of router
+ *
+ * Better: send to ff02::2 encapsuled in unicast directly
+ * to router-v4 instead of guessing the v6 address.
+ *
+ * Cisco/Windows seem to not set the u/l bit correctly,
+ * so we won't guess right.
+ */
+ ipv6_addr_set(&rtr, htonl(0xFE800000), 0, 0, 0);
+ if (!__ipv6_isatap_ifid(rtr.s6_addr + 8,
+ p->addr)) {
+ ndisc_send_rs(p->tunnel->dev, &addr->addr, &rtr);
+ }
+ }
+ spin_unlock(&ifp->lock);
+
+ mod_timer(&p->rs_timer, jiffies + HZ * p->rs_delay);
+ spin_unlock(&p->lock);
+
+ return;
+}
+
static struct ip_tunnel_prl_entry *
__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
{
@@ -280,6 +319,7 @@ static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
continue;
kp[c].addr = prl->addr;
kp[c].flags = prl->flags;
+ kp[c].rs_delay = prl->rs_delay;
c++;
if (kprl.addr != htonl(INADDR_ANY))
break;
@@ -329,11 +369,23 @@ ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
}
p->next = t->prl;
+ p->tunnel = t;
t->prl = p;
t->prl_count++;
+
+ spin_lock_init(&p->lock);
+ setup_timer(&p->rs_timer, ipip6_tunnel_rs_timer, (unsigned long) p);
update:
p->addr = a->addr;
p->flags = a->flags;
+ p->rs_delay = a->rs_delay;
+ if (p->rs_delay == 0)
+ p->rs_delay = IPTUNNEL_RS_DEFAULT_DELAY;
+ spin_lock(&p->lock);
+ del_timer(&p->rs_timer);
+ if (p->flags & PRL_DEFAULT)
+ mod_timer(&p->rs_timer, jiffies + 1);
+ spin_unlock(&p->lock);
out:
write_unlock(&ipip6_lock);
return err;
@@ -352,6 +404,9 @@ ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
if ((*p)->addr == a->addr) {
x = *p;
*p = x->next;
+ spin_lock(&x->lock);
+ del_timer(&x->rs_timer);
+ spin_unlock(&x->lock);
kfree(x);
t->prl_count--;
goto out;
@@ -362,6 +417,9 @@ ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
while (t->prl) {
x = t->prl;
t->prl = t->prl->next;
+ spin_lock(&x->lock);
+ del_timer(&x->rs_timer);
+ spin_unlock(&x->lock);
kfree(x);
t->prl_count--;
}
--
1.6.3