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-rw-r--r--net/ipv4/devinet.c78
1 files changed, 78 insertions, 0 deletions
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 036652c..6d85800d 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -51,6 +51,7 @@
#include <linux/inetdevice.h>
#include <linux/igmp.h>
#include <linux/slab.h>
+#include <linux/hash.h>
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif
@@ -92,6 +93,71 @@ static const struct nla_policy ifa_ipv4_policy[IFA_MAX+1] = {
[IFA_LABEL] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
};
+/* inet_addr_hash's shifting is dependent upon this IN4_ADDR_HSIZE
+ * value. So if you change this define, make appropriate changes to
+ * inet_addr_hash as well.
+ */
+#define IN4_ADDR_HSIZE 256
+static struct hlist_head inet_addr_lst[IN4_ADDR_HSIZE];
+static DEFINE_SPINLOCK(inet_addr_hash_lock);
+
+static inline unsigned int inet_addr_hash(struct net *net, __be32 addr)
+{
+ u32 val = (__force u32) addr ^ hash_ptr(net, 8);
+
+ return ((val ^ (val >> 8) ^ (val >> 16) ^ (val >> 24)) &
+ (IN4_ADDR_HSIZE - 1));
+}
+
+static void inet_hash_insert(struct net *net, struct in_ifaddr *ifa)
+{
+ unsigned int hash = inet_addr_hash(net, ifa->ifa_local);
+
+ spin_lock(&inet_addr_hash_lock);
+ hlist_add_head_rcu(&ifa->hash, &inet_addr_lst[hash]);
+ spin_unlock(&inet_addr_hash_lock);
+}
+
+static void inet_hash_remove(struct in_ifaddr *ifa)
+{
+ spin_lock(&inet_addr_hash_lock);
+ hlist_del_init_rcu(&ifa->hash);
+ spin_unlock(&inet_addr_hash_lock);
+}
+
+/**
+ * __ip_dev_find - find the first device with a given source address.
+ * @net: the net namespace
+ * @addr: the source address
+ * @devref: if true, take a reference on the found device
+ *
+ * If a caller uses devref=false, it should be protected by RCU, or RTNL
+ */
+struct net_device *__ip_dev_find(struct net *net, __be32 addr, bool devref)
+{
+ unsigned int hash = inet_addr_hash(net, addr);
+ struct net_device *result = NULL;
+ struct in_ifaddr *ifa;
+ struct hlist_node *node;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(ifa, node, &inet_addr_lst[hash], hash) {
+ struct net_device *dev = ifa->ifa_dev->dev;
+
+ if (!net_eq(dev_net(dev), net))
+ continue;
+ if (ifa->ifa_local == addr) {
+ result = dev;
+ break;
+ }
+ }
+ if (result && devref)
+ dev_hold(result);
+ rcu_read_unlock();
+ return result;
+}
+EXPORT_SYMBOL(__ip_dev_find);
+
static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32);
static BLOCKING_NOTIFIER_HEAD(inetaddr_chain);
@@ -265,6 +331,7 @@ static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
}
if (!do_promote) {
+ inet_hash_remove(ifa);
*ifap1 = ifa->ifa_next;
rtmsg_ifa(RTM_DELADDR, ifa, nlh, pid);
@@ -281,6 +348,7 @@ static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
/* 2. Unlink it */
*ifap = ifa1->ifa_next;
+ inet_hash_remove(ifa1);
/* 3. Announce address deletion */
@@ -368,6 +436,8 @@ static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh,
ifa->ifa_next = *ifap;
*ifap = ifa;
+ inet_hash_insert(dev_net(in_dev->dev), ifa);
+
/* Send message first, then call notifier.
Notifier will trigger FIB update, so that
listeners of netlink will know about new ifaddr */
@@ -521,6 +591,7 @@ static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh)
if (tb[IFA_ADDRESS] == NULL)
tb[IFA_ADDRESS] = tb[IFA_LOCAL];
+ INIT_HLIST_NODE(&ifa->hash);
ifa->ifa_prefixlen = ifm->ifa_prefixlen;
ifa->ifa_mask = inet_make_mask(ifm->ifa_prefixlen);
ifa->ifa_flags = ifm->ifa_flags;
@@ -728,6 +799,7 @@ int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
if (!ifa) {
ret = -ENOBUFS;
ifa = inet_alloc_ifa();
+ INIT_HLIST_NODE(&ifa->hash);
if (!ifa)
break;
if (colon)
@@ -1084,6 +1156,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
struct in_ifaddr *ifa = inet_alloc_ifa();
if (ifa) {
+ INIT_HLIST_NODE(&ifa->hash);
ifa->ifa_local =
ifa->ifa_address = htonl(INADDR_LOOPBACK);
ifa->ifa_prefixlen = 8;
@@ -1720,6 +1793,11 @@ static struct rtnl_af_ops inet_af_ops = {
void __init devinet_init(void)
{
+ int i;
+
+ for (i = 0; i < IN4_ADDR_HSIZE; i++)
+ INIT_HLIST_HEAD(&inet_addr_lst[i]);
+
register_pernet_subsys(&devinet_ops);
register_gifconf(PF_INET, inet_gifconf);
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