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authorJohannes Berg <johannes.berg@intel.com>2016-02-04 13:31:20 +0100
committerMoyster <oysterized@gmail.com>2017-11-18 19:27:10 +0100
commita69a6d3b998143407295884c2dba110e3f7cceaf (patch)
tree286005fd8b3d9948118de5aee7183700f2543e25 /net/ipv6
parent1212bd2498a4852c104f6cf7557f7c1ac4c2f75c (diff)
ipv6: add option to drop unsolicited neighbor advertisements
In certain 802.11 wireless deployments, there will be NA proxies that use knowledge of the network to correctly answer requests. To prevent unsolicitd advertisements on the shared medium from being a problem, on such deployments wireless needs to drop them. Enable this by providing an option called "drop_unsolicited_na". Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: danielhk <daniel_hk>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/addrconf.c8
-rw-r--r--net/ipv6/ndisc.c9
2 files changed, 17 insertions, 0 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 358218595..1e489c4ec 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4356,6 +4356,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
array[DEVCONF_NDISC_NOTIFY] = cnf->ndisc_notify;
array[DEVCONF_USE_OIF_ADDRS_ONLY] = cnf->use_oif_addrs_only;
array[DEVCONF_DROP_UNICAST_IN_L2_MULTICAST] = cnf->drop_unicast_in_l2_multicast;
+ array[DEVCONF_DROP_UNSOLICITED_NA] = cnf->drop_unsolicited_na;
}
static inline size_t inet6_ifla6_size(void)
@@ -5218,6 +5219,13 @@ static struct addrconf_sysctl_table
.mode = 0644,
.proc_handler = proc_dointvec,
},
+ {
+ .procname = "drop_unsolicited_na",
+ .data = &ipv6_devconf.drop_unsolicited_na,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
{
/* sentinel */
}
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 4513f5935..d3690db1f 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -859,6 +859,7 @@ static void ndisc_recv_na(struct sk_buff *skb)
offsetof(struct nd_msg, opt));
struct ndisc_options ndopts;
struct net_device *dev = skb->dev;
+ struct inet6_dev *idev = __in6_dev_get(dev);
struct inet6_ifaddr *ifp;
struct neighbour *neigh;
@@ -878,6 +879,14 @@ static void ndisc_recv_na(struct sk_buff *skb)
return;
}
+ /* For some 802.11 wireless deployments (and possibly other networks),
+ * there will be a NA proxy and unsolicitd packets are attacks
+ * and thus should not be accepted.
+ */
+ if (!msg->icmph.icmp6_solicited && idev &&
+ idev->cnf.drop_unsolicited_na)
+ return;
+
if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
ND_PRINTK(2, warn, "NS: invalid ND option\n");
return;