mptcp: handle local addrs announced by userspace PMs

This change adds an internal function to store/retrieve local
addrs announced by userspace PM implementations to/from its kernel
context. The function addresses the requirements of three scenarios:
1) ADD_ADDR announcements (which require that a local id be
provided), 2) retrieving the local id associated with an address,
and also where one may need to be assigned, and 3) reissuance of
ADD_ADDRs when there's a successful match of addr/id.

The list of all stored local addr entries is held under the
MPTCP sock structure. Memory for these entries is allocated from
the sock option buffer, so the list of addrs is bounded by optmem_max.
The list if not released via REMOVE_ADDR signals is ultimately
freed when the sock is destructed.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 25 deletions

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 98b205c2c101..9d515c3e0b16 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -22,14 +22,6 @@ static struct genl_family mptcp_genl_family;
 
 static int pm_nl_pernet_id;
 
-struct mptcp_pm_addr_entry {
-	struct list_head	list;
-	struct mptcp_addr_info	addr;
-	u8			flags;
-	int			ifindex;
-	struct socket		*lsk;
-};
-
 struct mptcp_pm_add_entry {
 	struct list_head	list;
 	struct mptcp_addr_info	addr;
@@ -66,8 +58,8 @@ pm_nl_get_pernet_from_msk(const struct mptcp_sock *msk)
 	return pm_nl_get_pernet(sock_net((struct sock *)msk));
 }
 
-static bool addresses_equal(const struct mptcp_addr_info *a,
-			    const struct mptcp_addr_info *b, bool use_port)
+bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
+			   const struct mptcp_addr_info *b, bool use_port)
 {
 	bool addr_equals = false;
 
@@ -131,7 +123,7 @@ static bool lookup_subflow_by_saddr(const struct list_head *list,
 		skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 
 		local_address(skc, &cur);
-		if (addresses_equal(&cur, saddr, saddr->port))
+		if (mptcp_addresses_equal(&cur, saddr, saddr->port))
 			return true;
 	}
 
@@ -149,7 +141,7 @@ static bool lookup_subflow_by_daddr(const struct list_head *list,
 		skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 
 		remote_address(skc, &cur);
-		if (addresses_equal(&cur, daddr, daddr->port))
+		if (mptcp_addresses_equal(&cur, daddr, daddr->port))
 			return true;
 	}
 
@@ -269,7 +261,7 @@ mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
 	lockdep_assert_held(&msk->pm.lock);
 
 	list_for_each_entry(entry, &msk->pm.anno_list, list) {
-		if (addresses_equal(&entry->addr, addr, true))
+		if (mptcp_addresses_equal(&entry->addr, addr, true))
 			return entry;
 	}
 
@@ -286,7 +278,7 @@ bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
 
 	spin_lock_bh(&msk->pm.lock);
 	list_for_each_entry(entry, &msk->pm.anno_list, list) {
-		if (addresses_equal(&entry->addr, &saddr, true)) {
+		if (mptcp_addresses_equal(&entry->addr, &saddr, true)) {
 			ret = true;
 			goto out;
 		}
@@ -421,7 +413,7 @@ static bool lookup_address_in_vec(const struct mptcp_addr_info *addrs, unsigned
 	int i;
 
 	for (i = 0; i < nr; i++) {
-		if (addresses_equal(&addrs[i], addr, addr->port))
+		if (mptcp_addresses_equal(&addrs[i], addr, addr->port))
 			return true;
 	}
 
@@ -457,7 +449,7 @@ static unsigned int fill_remote_addresses_vec(struct mptcp_sock *msk, bool fullm
 		mptcp_for_each_subflow(msk, subflow) {
 			ssk = mptcp_subflow_tcp_sock(subflow);
 			remote_address((struct sock_common *)ssk, &addrs[i]);
-			if (deny_id0 && addresses_equal(&addrs[i], &remote, false))
+			if (deny_id0 && mptcp_addresses_equal(&addrs[i], &remote, false))
 				continue;
 
 			if (!lookup_address_in_vec(addrs, i, &addrs[i]) &&
@@ -490,7 +482,7 @@ __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info,
 	struct mptcp_pm_addr_entry *entry;
 
 	list_for_each_entry(entry, &pernet->local_addr_list, list) {
-		if ((!lookup_by_id && addresses_equal(&entry->addr, info, true)) ||
+		if ((!lookup_by_id && mptcp_addresses_equal(&entry->addr, info, true)) ||
 		    (lookup_by_id && entry->addr.id == info->id))
 			return entry;
 	}
@@ -505,7 +497,7 @@ lookup_id_by_addr(const struct pm_nl_pernet *pernet, const struct mptcp_addr_inf
 
 	rcu_read_lock();
 	list_for_each_entry(entry, &pernet->local_addr_list, list) {
-		if (addresses_equal(&entry->addr, addr, entry->addr.port)) {
+		if (mptcp_addresses_equal(&entry->addr, addr, entry->addr.port)) {
 			ret = entry->addr.id;
 			break;
 		}
@@ -739,7 +731,7 @@ static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 		struct mptcp_addr_info local;
 
 		local_address((struct sock_common *)ssk, &local);
-		if (!addresses_equal(&local, addr, addr->port))
+		if (!mptcp_addresses_equal(&local, addr, addr->port))
 			continue;
 
 		if (subflow->backup != bkup)
@@ -909,9 +901,9 @@ static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
 	 * singled addresses
 	 */
 	list_for_each_entry(cur, &pernet->local_addr_list, list) {
-		if (addresses_equal(&cur->addr, &entry->addr,
-				    address_use_port(entry) &&
-				    address_use_port(cur))) {
+		if (mptcp_addresses_equal(&cur->addr, &entry->addr,
+					  address_use_port(entry) &&
+					  address_use_port(cur))) {
 			/* allow replacing the exiting endpoint only if such
 			 * endpoint is an implicit one and the user-space
 			 * did not provide an endpoint id
@@ -1038,14 +1030,14 @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 	 */
 	local_address((struct sock_common *)msk, &msk_local);
 	local_address((struct sock_common *)skc, &skc_local);
-	if (addresses_equal(&msk_local, &skc_local, false))
+	if (mptcp_addresses_equal(&msk_local, &skc_local, false))
 		return 0;
 
 	pernet = pm_nl_get_pernet_from_msk(msk);
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
-		if (addresses_equal(&entry->addr, &skc_local, entry->addr.port)) {
+		if (mptcp_addresses_equal(&entry->addr, &skc_local, entry->addr.port)) {
 			ret = entry->addr.id;
 			break;
 		}
@@ -1416,7 +1408,7 @@ static int mptcp_nl_remove_id_zero_address(struct net *net,
 			goto next;
 
 		local_address((struct sock_common *)msk, &msk_local);
-		if (!addresses_equal(&msk_local, addr, addr->port))
+		if (!mptcp_addresses_equal(&msk_local, addr, addr->port))
 			goto next;
 
 		lock_sock(sk);