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-rw-r--r--net/ipv6/ndisc.c108
1 files changed, 88 insertions, 20 deletions
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index f03b597e4121..3a553494ff16 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -128,6 +128,7 @@ struct neigh_table nd_tbl = {
[NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
[NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
+ [NEIGH_VAR_INTERVAL_PROBE_TIME_MS] = 5 * HZ,
[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
[NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
[NEIGH_VAR_PROXY_QLEN] = 64,
@@ -466,9 +467,8 @@ static void ip6_nd_hdr(struct sk_buff *skb,
hdr->daddr = *daddr;
}
-static void ndisc_send_skb(struct sk_buff *skb,
- const struct in6_addr *daddr,
- const struct in6_addr *saddr)
+void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
+ const struct in6_addr *saddr)
{
struct dst_entry *dst = skb_dst(skb);
struct net *net = dev_net(skb->dev);
@@ -515,6 +515,7 @@ static void ndisc_send_skb(struct sk_buff *skb,
rcu_read_unlock();
}
+EXPORT_SYMBOL(ndisc_send_skb);
void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
const struct in6_addr *solicited_addr,
@@ -598,22 +599,16 @@ static void ndisc_send_unsol_na(struct net_device *dev)
in6_dev_put(idev);
}
-void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
- const struct in6_addr *daddr, const struct in6_addr *saddr,
- u64 nonce)
+struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
+ const struct in6_addr *saddr, u64 nonce)
{
- struct sk_buff *skb;
- struct in6_addr addr_buf;
int inc_opt = dev->addr_len;
- int optlen = 0;
+ struct sk_buff *skb;
struct nd_msg *msg;
+ int optlen = 0;
- if (!saddr) {
- if (ipv6_get_lladdr(dev, &addr_buf,
- (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
- return;
- saddr = &addr_buf;
- }
+ if (!saddr)
+ return NULL;
if (ipv6_addr_any(saddr))
inc_opt = false;
@@ -625,7 +620,7 @@ void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
if (!skb)
- return;
+ return NULL;
msg = skb_put(skb, sizeof(*msg));
*msg = (struct nd_msg) {
@@ -647,7 +642,28 @@ void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
memcpy(opt + 2, &nonce, 6);
}
- ndisc_send_skb(skb, daddr, saddr);
+ return skb;
+}
+EXPORT_SYMBOL(ndisc_ns_create);
+
+void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
+ const struct in6_addr *daddr, const struct in6_addr *saddr,
+ u64 nonce)
+{
+ struct in6_addr addr_buf;
+ struct sk_buff *skb;
+
+ if (!saddr) {
+ if (ipv6_get_lladdr(dev, &addr_buf,
+ (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC)))
+ return;
+ saddr = &addr_buf;
+ }
+
+ skb = ndisc_ns_create(dev, solicit, saddr, nonce);
+
+ if (skb)
+ ndisc_send_skb(skb, daddr, saddr);
}
void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
@@ -951,6 +967,25 @@ out:
in6_dev_put(idev);
}
+static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
+{
+ struct inet6_dev *idev = __in6_dev_get(dev);
+
+ switch (idev->cnf.accept_untracked_na) {
+ case 0: /* Don't accept untracked na (absent in neighbor cache) */
+ return 0;
+ case 1: /* Create new entries from na if currently untracked */
+ return 1;
+ case 2: /* Create new entries from untracked na only if saddr is in the
+ * same subnet as an address configured on the interface that
+ * received the na
+ */
+ return !!ipv6_chk_prefix(saddr, dev);
+ default:
+ return 0;
+ }
+}
+
static void ndisc_recv_na(struct sk_buff *skb)
{
struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
@@ -964,6 +999,7 @@ static void ndisc_recv_na(struct sk_buff *skb)
struct inet6_dev *idev = __in6_dev_get(dev);
struct inet6_ifaddr *ifp;
struct neighbour *neigh;
+ u8 new_state;
if (skb->len < sizeof(struct nd_msg)) {
ND_PRINTK(2, warn, "NA: packet too short\n");
@@ -984,6 +1020,7 @@ static void ndisc_recv_na(struct sk_buff *skb)
/* 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.
+ * drop_unsolicited_na takes precedence over accept_untracked_na
*/
if (!msg->icmph.icmp6_solicited && idev &&
idev->cnf.drop_unsolicited_na)
@@ -1024,9 +1061,33 @@ static void ndisc_recv_na(struct sk_buff *skb)
in6_ifa_put(ifp);
return;
}
+
neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
- if (neigh) {
+ /* RFC 9131 updates original Neighbour Discovery RFC 4861.
+ * NAs with Target LL Address option without a corresponding
+ * entry in the neighbour cache can now create a STALE neighbour
+ * cache entry on routers.
+ *
+ * entry accept fwding solicited behaviour
+ * ------- ------ ------ --------- ----------------------
+ * present X X 0 Set state to STALE
+ * present X X 1 Set state to REACHABLE
+ * absent 0 X X Do nothing
+ * absent 1 0 X Do nothing
+ * absent 1 1 X Add a new STALE entry
+ *
+ * Note that we don't do a (daddr == all-routers-mcast) check.
+ */
+ new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE;
+ if (!neigh && lladdr && idev && idev->cnf.forwarding) {
+ if (accept_untracked_na(dev, saddr)) {
+ neigh = neigh_create(&nd_tbl, &msg->target, dev);
+ new_state = NUD_STALE;
+ }
+ }
+
+ if (neigh && !IS_ERR(neigh)) {
u8 old_flags = neigh->flags;
struct net *net = dev_net(dev);
@@ -1046,7 +1107,7 @@ static void ndisc_recv_na(struct sk_buff *skb)
}
ndisc_update(dev, neigh, lladdr,
- msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
+ new_state,
NEIGH_UPDATE_F_WEAK_OVERRIDE|
(msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
@@ -1317,6 +1378,9 @@ static void ndisc_router_discovery(struct sk_buff *skb)
if (!rt && lifetime) {
ND_PRINTK(3, info, "RA: adding default router\n");
+ if (neigh)
+ neigh_release(neigh);
+
rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
skb->dev, pref, defrtr_usr_metric);
if (!rt) {
@@ -1337,8 +1401,12 @@ static void ndisc_router_discovery(struct sk_buff *skb)
return;
}
neigh->flags |= NTF_ROUTER;
- } else if (rt) {
+ } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) {
+ struct nl_info nlinfo = {
+ .nl_net = net,
+ };
rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
+ inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE);
}
if (rt)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.