Re: [net-next] ipv6: Enable netlink notification for tentative addresses.
From: Brian Haley <hidden>
Date: 2010-08-26 19:57:54
On 08/26/2010 02:50 PM, Ben Greear wrote:
On 08/25/2010 09:24 PM, David Miller wrote:quoted
From: Ben Greear<redacted> Date: Wed, 25 Aug 2010 11:26:17 -0700quoted
By default, netlink messages are not sent when an IPv6 address is added if it is in tentative state. This makes it harder for user-space applications to know the current state of the IPv6 addresses. This patch adds an ipv6 sysctl that will allow tentative address notifications to be sent. The sysctl is off by default. Signed-off-by: Ben Greear<redacted>It's inconsistent to send two NEWADDR events for the same add. I would advise that we unconditionally do the NEWADDR once, when the tentative state address is added, and completely elide the one we current send when it leaves tentative state.
But then we get a message for an address that can't be used because it hasn't passed DAD, I'm not so sure that is a good thing, especially if we don't get notified when it passes DAD.
quoted hunk ↗ jump to hunk
@@ -697,9 +698,10 @@ ipv6_add_addr(struct inet6_dev *idev, const structin6_addr *addr, int pfxlen, out2: rcu_read_unlock_bh(); - if (likely(err == 0)) + if (likely(err == 0)) { atomic_notifier_call_chain(&inet6addr_chain, NETDEV_UP, ifa); - else { + inet6_ifa_notify(RTM_NEWADDR, ifa); + } else { kfree(ifa); ifa = ERR_PTR(err); }
This will generate two messages in some cases, for example, when lo is configured, or a SIT tunnel is added, see add_addr() in addrconf.c. -Brian