From: Matteo Croce <mcroce@redhat.com>
Date: Tue, 12 Sep 2017 17:46:37 +0200
Subject: ipv6: fix net.ipv6.conf.all interface DAD handlers
Patch-mainline: v4.14-rc2
Git-commit: 35e015e1f5773417952fe91ce8790baf9b4237a2
References: bsc#1076830
Currently, writing into
net.ipv6.conf.all.{accept_dad,use_optimistic,optimistic_dad} has no effect.
Fix handling of these flags by:
- using the maximum of global and per-interface values for the
accept_dad flag. That is, if at least one of the two values is
non-zero, enable DAD on the interface. If at least one value is
set to 2, enable DAD and disable IPv6 operation on the interface if
MAC-based link-local address was found
- using the logical OR of global and per-interface values for the
optimistic_dad flag. If at least one of them is set to one, optimistic
duplicate address detection (RFC 4429) is enabled on the interface
- using the logical OR of global and per-interface values for the
use_optimistic flag. If at least one of them is set to one,
optimistic addresses won't be marked as deprecated during source address
selection on the interface.
While at it, as we're modifying the prototype for ipv6_use_optimistic_addr(),
drop inline, and let the compiler decide.
Fixes: 7fd2561e4ebd ("net: ipv6: Add a sysctl to make optimistic addresses useful candidates")
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Kubecek <mkubecek@suse.cz>
---
Documentation/networking/ip-sysctl.txt | 18 ++++++++++++++----
net/ipv6/addrconf.c | 27 ++++++++++++++++++++-------
2 files changed, 34 insertions(+), 11 deletions(-)
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 6ea34ba31f18..42f95963db73 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1669,6 +1669,9 @@ accept_dad - INTEGER
2: Enable DAD, and disable IPv6 operation if MAC-based duplicate
link-local address has been found.
+ DAD operation and mode on a given interface will be selected according
+ to the maximum value of conf/{all,interface}/accept_dad.
+
force_tllao - BOOLEAN
Enable sending the target link-layer address option even when
responding to a unicast neighbor solicitation.
@@ -1716,16 +1719,23 @@ suppress_frag_ndisc - INTEGER
optimistic_dad - BOOLEAN
Whether to perform Optimistic Duplicate Address Detection (RFC 4429).
- 0: disabled (default)
- 1: enabled
+ 0: disabled (default)
+ 1: enabled
+
+ Optimistic Duplicate Address Detection for the interface will be enabled
+ if at least one of conf/{all,interface}/optimistic_dad is set to 1,
+ it will be disabled otherwise.
use_optimistic - BOOLEAN
If enabled, do not classify optimistic addresses as deprecated during
source address selection. Preferred addresses will still be chosen
before optimistic addresses, subject to other ranking in the source
address selection algorithm.
- 0: disabled (default)
- 1: enabled
+ 0: disabled (default)
+ 1: enabled
+
+ This will be enabled if at least one of
+ conf/{all,interface}/use_optimistic is set to 1, disabled otherwise.
stable_secret - IPv6 address
This IPv6 address will be used as a secret to generate IPv6
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index abb4858aed90..f3f477ae2bf0 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1385,10 +1385,18 @@ static inline int ipv6_saddr_preferred(int type)
return 0;
}
-static inline bool ipv6_use_optimistic_addr(struct inet6_dev *idev)
+static bool ipv6_use_optimistic_addr(struct net *net,
+ struct inet6_dev *idev)
{
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
- return idev && idev->cnf.optimistic_dad && idev->cnf.use_optimistic;
+ if (!idev)
+ return false;
+ if (!net->ipv6.devconf_all->optimistic_dad && !idev->cnf.optimistic_dad)
+ return false;
+ if (!net->ipv6.devconf_all->use_optimistic && !idev->cnf.use_optimistic)
+ return false;
+
+ return true;
#else
return false;
#endif
@@ -1458,7 +1466,7 @@ static int ipv6_get_saddr_eval(struct net *net,
/* Rule 3: Avoid deprecated and optimistic addresses */
u8 avoid = IFA_F_DEPRECATED;
- if (!ipv6_use_optimistic_addr(score->ifa->idev))
+ if (!ipv6_use_optimistic_addr(net, score->ifa->idev))
avoid |= IFA_F_OPTIMISTIC;
ret = ipv6_saddr_preferred(score->addr_type) ||
!(score->ifa->flags & avoid);
@@ -2446,7 +2454,8 @@ int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev,
int max_addresses = in6_dev->cnf.max_addresses;
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
- if (in6_dev->cnf.optimistic_dad &&
+ if ((net->ipv6.devconf_all->optimistic_dad ||
+ in6_dev->cnf.optimistic_dad) &&
!net->ipv6.devconf_all->forwarding && sllao)
addr_flags |= IFA_F_OPTIMISTIC;
#endif
@@ -3079,7 +3088,8 @@ void addrconf_add_linklocal(struct inet6_dev *idev,
u32 addr_flags = flags | IFA_F_PERMANENT;
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
- if (idev->cnf.optimistic_dad &&
+ if ((dev_net(idev->dev)->ipv6.devconf_all->optimistic_dad ||
+ idev->cnf.optimistic_dad) &&
!dev_net(idev->dev)->ipv6.devconf_all->forwarding)
addr_flags |= IFA_F_OPTIMISTIC;
#endif
@@ -3838,6 +3848,7 @@ static void addrconf_dad_begin(struct inet6_ifaddr *ifp)
goto out;
if (dev->flags&(IFF_NOARP|IFF_LOOPBACK) ||
+ dev_net(dev)->ipv6.devconf_all->accept_dad < 1 ||
idev->cnf.accept_dad < 1 ||
!(ifp->flags&IFA_F_TENTATIVE) ||
ifp->flags & IFA_F_NODAD) {
@@ -3874,7 +3885,7 @@ static void addrconf_dad_begin(struct inet6_ifaddr *ifp)
*/
if (ifp->flags & IFA_F_OPTIMISTIC) {
ip6_ins_rt(ifp->rt);
- if (ipv6_use_optimistic_addr(idev)) {
+ if (ipv6_use_optimistic_addr(dev_net(dev), idev)) {
/* Because optimistic nodes can use this address,
* notify listeners. If DAD fails, RTM_DELADDR is sent.
*/
@@ -3930,7 +3941,9 @@ static void addrconf_dad_work(struct work_struct *w)
action = DAD_ABORT;
ifp->state = INET6_IFADDR_STATE_POSTDAD;
- if (idev->cnf.accept_dad > 1 && !idev->cnf.disable_ipv6 &&
+ if ((dev_net(idev->dev)->ipv6.devconf_all->accept_dad > 1 ||
+ idev->cnf.accept_dad > 1) &&
+ !idev->cnf.disable_ipv6 &&
!(ifp->flags & IFA_F_STABLE_PRIVACY)) {
struct in6_addr addr;
--
2.16.2