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-rw-r--r--net/ipv4/arp.c95
1 files changed, 58 insertions, 37 deletions
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 05eb42f347e8..4f7237661afb 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -125,6 +125,7 @@ static int arp_constructor(struct neighbour *neigh);
static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb);
static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb);
static void parp_redo(struct sk_buff *skb);
+static int arp_is_multicast(const void *pkey);
static const struct neigh_ops arp_generic_ops = {
.family = AF_INET,
@@ -156,6 +157,7 @@ struct neigh_table arp_tbl = {
.key_eq = arp_key_eq,
.constructor = arp_constructor,
.proxy_redo = parp_redo,
+ .is_multicast = arp_is_multicast,
.id = "arp_cache",
.parms = {
.tbl = &arp_tbl,
@@ -166,6 +168,7 @@ struct neigh_table arp_tbl = {
[NEIGH_VAR_RETRANS_TIME] = 1 * HZ,
[NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ,
[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,
@@ -291,7 +294,7 @@ static int arp_constructor(struct neighbour *neigh)
static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb)
{
dst_link_failure(skb);
- kfree_skb(skb);
+ kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_FAILED);
}
/* Create and send an arp packet. */
@@ -426,6 +429,26 @@ static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip)
return !inet_confirm_addr(net, in_dev, sip, tip, scope);
}
+static int arp_accept(struct in_device *in_dev, __be32 sip)
+{
+ struct net *net = dev_net(in_dev->dev);
+ int scope = RT_SCOPE_LINK;
+
+ switch (IN_DEV_ARP_ACCEPT(in_dev)) {
+ case 0: /* Don't create new entries from garp */
+ return 0;
+ case 1: /* Create new entries from garp */
+ return 1;
+ case 2: /* Create a neighbor in the arp table only if sip
+ * is in the same subnet as an address configured
+ * on the interface that received the garp message
+ */
+ return !!inet_confirm_addr(net, in_dev, sip, 0, scope);
+ default:
+ return 0;
+ }
+}
+
static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
{
struct rtable *rt;
@@ -865,12 +888,12 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb)
n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
addr_type = -1;
- if (n || IN_DEV_ARP_ACCEPT(in_dev)) {
+ if (n || arp_accept(in_dev, sip)) {
is_garp = arp_is_garp(net, dev, &addr_type, arp->ar_op,
sip, tip, sha, tha);
}
- if (IN_DEV_ARP_ACCEPT(in_dev)) {
+ if (arp_accept(in_dev, sip)) {
/* Unsolicited ARP is not accepted by default.
It is possible, that this option should be enabled for some
devices (strip is candidate)
@@ -928,6 +951,10 @@ static void parp_redo(struct sk_buff *skb)
arp_process(dev_net(skb->dev), NULL, skb);
}
+static int arp_is_multicast(const void *pkey)
+{
+ return ipv4_is_multicast(*((__be32 *)pkey));
+}
/*
* Receive an arp request from the device layer.
@@ -1102,7 +1129,7 @@ static int arp_req_get(struct arpreq *r, struct net_device *dev)
r->arp_flags = arp_state_to_flags(neigh);
read_unlock_bh(&neigh->lock);
r->arp_ha.sa_family = dev->type;
- strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
+ strscpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
err = 0;
}
neigh_release(neigh);
@@ -1110,13 +1137,18 @@ static int arp_req_get(struct arpreq *r, struct net_device *dev)
return err;
}
-static int arp_invalidate(struct net_device *dev, __be32 ip)
+int arp_invalidate(struct net_device *dev, __be32 ip, bool force)
{
struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev);
int err = -ENXIO;
struct neigh_table *tbl = &arp_tbl;
if (neigh) {
+ if ((neigh->nud_state & NUD_VALID) && !force) {
+ neigh_release(neigh);
+ return 0;
+ }
+
if (neigh->nud_state & ~NUD_NOARP)
err = neigh_update(neigh, NULL, NUD_FAILED,
NEIGH_UPDATE_F_OVERRIDE|
@@ -1163,7 +1195,7 @@ static int arp_req_delete(struct net *net, struct arpreq *r,
if (!dev)
return -EINVAL;
}
- return arp_invalidate(dev, ip);
+ return arp_invalidate(dev, ip, true);
}
/*
@@ -1181,7 +1213,7 @@ int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg)
case SIOCSARP:
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
- /* fall through */
+ fallthrough;
case SIOCGARP:
err = copy_from_user(&r, arg, sizeof(struct arpreq));
if (err)
@@ -1241,6 +1273,8 @@ static int arp_netdev_event(struct notifier_block *this, unsigned long event,
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct netdev_notifier_change_info *change_info;
+ struct in_device *in_dev;
+ bool evict_nocarrier;
switch (event) {
case NETDEV_CHANGEADDR:
@@ -1251,7 +1285,14 @@ static int arp_netdev_event(struct notifier_block *this, unsigned long event,
change_info = ptr;
if (change_info->flags_changed & IFF_NOARP)
neigh_changeaddr(&arp_tbl, dev);
- if (!netif_carrier_ok(dev))
+
+ in_dev = __in_dev_get_rtnl(dev);
+ if (!in_dev)
+ evict_nocarrier = true;
+ else
+ evict_nocarrier = IN_DEV_ARP_EVICT_NOCARRIER(in_dev);
+
+ if (evict_nocarrier && !netif_carrier_ok(dev))
neigh_carrier_down(&arp_tbl, dev);
break;
default:
@@ -1284,24 +1325,9 @@ static struct packet_type arp_packet_type __read_mostly = {
.func = arp_rcv,
};
-static int arp_proc_init(void);
-
-void __init arp_init(void)
-{
- neigh_table_init(NEIGH_ARP_TABLE, &arp_tbl);
-
- dev_add_pack(&arp_packet_type);
- arp_proc_init();
-#ifdef CONFIG_SYSCTL
- neigh_sysctl_register(NULL, &arp_tbl.parms, NULL);
-#endif
- register_netdevice_notifier(&arp_netdev_notifier);
-}
-
#ifdef CONFIG_PROC_FS
#if IS_ENABLED(CONFIG_AX25)
-/* ------------------------------------------------------------------------ */
/*
* ax25 -> ASCII conversion
*/
@@ -1407,16 +1433,13 @@ static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP);
}
-/* ------------------------------------------------------------------------ */
-
static const struct seq_operations arp_seq_ops = {
.start = arp_seq_start,
.next = neigh_seq_next,
.stop = neigh_seq_stop,
.show = arp_seq_show,
};
-
-/* ------------------------------------------------------------------------ */
+#endif /* CONFIG_PROC_FS */
static int __net_init arp_net_init(struct net *net)
{
@@ -1436,16 +1459,14 @@ static struct pernet_operations arp_net_ops = {
.exit = arp_net_exit,
};
-static int __init arp_proc_init(void)
+void __init arp_init(void)
{
- return register_pernet_subsys(&arp_net_ops);
-}
-
-#else /* CONFIG_PROC_FS */
+ neigh_table_init(NEIGH_ARP_TABLE, &arp_tbl);
-static int __init arp_proc_init(void)
-{
- return 0;
+ dev_add_pack(&arp_packet_type);
+ register_pernet_subsys(&arp_net_ops);
+#ifdef CONFIG_SYSCTL
+ neigh_sysctl_register(NULL, &arp_tbl.parms, NULL);
+#endif
+ register_netdevice_notifier(&arp_netdev_notifier);
}
-
-#endif /* CONFIG_PROC_FS */
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.