Hi,
When adding an IPv6 address to a given interface, I'm allowed to
add that address multiple time, e.g.:
[root@abulafia root]# ip addr add 3ffe:4242:4242::1 dev eth0
[root@abulafia root]# ip addr add 3ffe:4242:4242::1 dev eth0
[root@abulafia root]# ip addr add 3ffe:4242:4242::1 dev eth0
[root@abulafia root]# ip addr show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 100
link/ether 00:48:54:1b:25:30 brd ff:ff:ff:ff:ff:ff
inet6 3ffe:4242:4242::1/128 scope global
inet6 3ffe:4242:4242::1/128 scope global
inet6 3ffe:4242:4242::1/128 scope global
inet6 fe80::248:54ff:fe1b:2530/10 scope link
Apparently, this is not a stability problem, because I'm allowed to
delete 3 times that address before receving a "not found" error,
but there's no reason to allow multiple instances of the same address
on the same interface, so this is a bug nonetheless.
Bug is confirmed on:
- 2.4.20
- 2.5.66
- latest -usagi
Following is a patch attempting to fix this bug.
It's for 2.4.20 but sould apply cleanly on 2.5 too.
Credits:
Chad N. Tindel - discovered the bug and showed it to me
Peter Bieringer - confirmed it's a bug
Mauro Tortonesi - suggested sending a patch to this list.
Regards,
Simone Piunno
--- net/ipv6/addrconf.c.orig 2003-03-25 21:33:55.000000000 +0100
+++ net/ipv6/addrconf.c 2003-03-30 13:48:23.000000000 +0200
@@ -89,6 +89,8 @@
static struct inet6_ifaddr *inet6_addr_lst[IN6_ADDR_HSIZE];
static rwlock_t addrconf_hash_lock = RW_LOCK_UNLOCKED;
+static spinlock_t addrconf_add_lock = SPIN_LOCK_UNLOCKED;
+
/* Protects inet6 devices */
rwlock_t addrconf_lock = RW_LOCK_UNLOCKED;
@@ -621,6 +623,24 @@
return ifp != NULL;
}
+static struct inet6_ifaddr *
+ipv6_addr_already_present(struct in6_addr *addr, struct net_device *dev)
+{
+ struct inet6_ifaddr *ifp;
+ u8 hash = ipv6_addr_hash(addr);
+
+ read_lock_bh(&addrconf_hash_lock);
+ for (ifp = inet6_addr_lst[hash]; ifp; ifp = ifp->lst_next) {
+ if (ipv6_addr_cmp(&ifp->addr, addr) == 0 && ifp->idev->dev == dev) {
+ read_unlock_bh(&addrconf_hash_lock);
+ return ifp;
+ }
+ }
+ read_unlock_bh(&addrconf_hash_lock);
+ return NULL;
+}
+
+
struct inet6_ifaddr * ipv6_get_ifaddr(struct in6_addr *addr, struct net_device *dev)
{
struct inet6_ifaddr * ifp;
@@ -908,7 +928,7 @@
return;
ok:
-
+ spin_lock_bh(&addrconf_add_lock);
ifp = ipv6_get_ifaddr(&addr, dev);
if (ifp == NULL && valid_lft) {
@@ -920,12 +940,14 @@
addr_type&IPV6_ADDR_SCOPE_MASK, 0);
if (ifp == NULL) {
+ spin_unlock_bh(&addrconf_add_lock);
in6_dev_put(in6_dev);
return;
}
addrconf_dad_start(ifp);
}
+ spin_unlock_bh(&addrconf_add_lock);
if (ifp && valid_lft == 0) {
ipv6_del_addr(ifp);
@@ -1033,11 +1055,19 @@
scope = ipv6_addr_scope(pfx);
+ spin_lock_bh(&addrconf_add_lock);
+ if (ipv6_addr_already_present(pfx, dev)) {
+ spin_unlock_bh(&addrconf_add_lock);
+ return -EEXIST;
+ }
+
if ((ifp = ipv6_add_addr(idev, pfx, plen, scope, IFA_F_PERMANENT)) != NULL) {
+ spin_unlock_bh(&addrconf_add_lock);
addrconf_dad_start(ifp);
in6_ifa_put(ifp);
return 0;
}
+ spin_unlock_bh(&addrconf_add_lock);
return -ENOBUFS;
}
-- Simone Piunno -- http://members.ferrara.linux.it/pioppo .------- Adde parvum parvo magnus acervus erit -------. Ferrara Linux Users Group - http://www.ferrara.linux.it Deep Space 6, IPv6 on Linux - http://www.deepspace6.net GNU Mailman, Mailing List Manager - http://www.list.org `-------------------------------------------------------' - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Mon Mar 31 2003 - 22:00:35 EST