Merge branch 'mptcp-addr-adv-fixes'

Mat Martineau says:

====================
mptcp: Fixes for address advertisement

Patches 1 and 2 allow address advertisements to be removed without
affecting current connected subflows, and updates associated self tests.

Patches 3 and 4 correctly track (and allow removal of) addresses that
were implicitly announced as part of subflow creation. Also updates
associated self tests.

Patch 5 makes subflow and address announcement counters work consistently
between the userspace and in-kernel path managers.
====================
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mptcp/pm.c

@@ -87,8 +87,15 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
 	unsigned int subflows_max;
 	int ret = 0;
 
-	if (mptcp_pm_is_userspace(msk))
-		return mptcp_userspace_pm_active(msk);
+	if (mptcp_pm_is_userspace(msk)) {
+		if (mptcp_userspace_pm_active(msk)) {
+			spin_lock_bh(&pm->lock);
+			pm->subflows++;
+			spin_unlock_bh(&pm->lock);
+			return true;
+		}
+		return false;
+	}
 
 	subflows_max = mptcp_pm_get_subflows_max(msk);
 
@@ -181,8 +188,16 @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk, const struct sock *ssk,
 	struct mptcp_pm_data *pm = &msk->pm;
 	bool update_subflows;
 
-	update_subflows = (subflow->request_join || subflow->mp_join) &&
-			  mptcp_pm_is_kernel(msk);
+	update_subflows = subflow->request_join || subflow->mp_join;
+	if (mptcp_pm_is_userspace(msk)) {
+		if (update_subflows) {
+			spin_lock_bh(&pm->lock);
+			pm->subflows--;
+			spin_unlock_bh(&pm->lock);
+		}
+		return;
+	}
+
 	if (!READ_ONCE(pm->work_pending) && !update_subflows)
 		return;
 

net/mptcp/pm_netlink.c

@@ -1558,6 +1558,24 @@ static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
+void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list)
+{
+	struct mptcp_rm_list alist = { .nr = 0 };
+	struct mptcp_pm_addr_entry *entry;
+
+	list_for_each_entry(entry, rm_list, list) {
+		remove_anno_list_by_saddr(msk, &entry->addr);
+		if (alist.nr < MPTCP_RM_IDS_MAX)
+			alist.ids[alist.nr++] = entry->addr.id;
+	}
+
+	if (alist.nr) {
+		spin_lock_bh(&msk->pm.lock);
+		mptcp_pm_remove_addr(msk, &alist);
+		spin_unlock_bh(&msk->pm.lock);
+	}
+}
+
 void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
 					struct list_head *rm_list)
 {

net/mptcp/pm_userspace.c

@@ -69,6 +69,7 @@ static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
 							MPTCP_PM_MAX_ADDR_ID + 1,
 							1);
 		list_add_tail_rcu(&e->list, &msk->pm.userspace_pm_local_addr_list);
+		msk->pm.local_addr_used++;
 		ret = e->addr.id;
 	} else if (match) {
 		ret = entry->addr.id;
@@ -79,6 +80,31 @@ static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
 	return ret;
 }
 
+/* If the subflow is closed from the other peer (not via a
+ * subflow destroy command then), we want to keep the entry
+ * not to assign the same ID to another address and to be
+ * able to send RM_ADDR after the removal of the subflow.
+ */
+static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk,
+						struct mptcp_pm_addr_entry *addr)
+{
+	struct mptcp_pm_addr_entry *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &msk->pm.userspace_pm_local_addr_list, list) {
+		if (mptcp_addresses_equal(&entry->addr, &addr->addr, false)) {
+			/* TODO: a refcount is needed because the entry can
+			 * be used multiple times (e.g. fullmesh mode).
+			 */
+			list_del_rcu(&entry->list);
+			kfree(entry);
+			msk->pm.local_addr_used--;
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
 						   unsigned int id,
 						   u8 *flags, int *ifindex)
@@ -171,6 +197,7 @@ int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info)
 	spin_lock_bh(&msk->pm.lock);
 
 	if (mptcp_pm_alloc_anno_list(msk, &addr_val)) {
+		msk->pm.add_addr_signaled++;
 		mptcp_pm_announce_addr(msk, &addr_val.addr, false);
 		mptcp_pm_nl_addr_send_ack(msk);
 	}
@@ -232,7 +259,7 @@ int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
 
 	list_move(&match->list, &free_list);
 
-	mptcp_pm_remove_addrs_and_subflows(msk, &free_list);
+	mptcp_pm_remove_addrs(msk, &free_list);
 
 	release_sock((struct sock *)msk);
 
@@ -251,6 +278,7 @@ int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
 	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
+	struct mptcp_pm_addr_entry local = { 0 };
 	struct mptcp_addr_info addr_r;
 	struct mptcp_addr_info addr_l;
 	struct mptcp_sock *msk;
@@ -302,12 +330,26 @@ int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
 		goto create_err;
 	}
 
+	local.addr = addr_l;
+	err = mptcp_userspace_pm_append_new_local_addr(msk, &local);
+	if (err < 0) {
+		GENL_SET_ERR_MSG(info, "did not match address and id");
+		goto create_err;
+	}
+
 	lock_sock(sk);
 
 	err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
 
 	release_sock(sk);
 
+	spin_lock_bh(&msk->pm.lock);
+	if (err)
+		mptcp_userspace_pm_delete_local_addr(msk, &local);
+	else
+		msk->pm.subflows++;
+	spin_unlock_bh(&msk->pm.lock);
+
  create_err:
 	sock_put((struct sock *)msk);
 	return err;
@@ -420,7 +462,11 @@ int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
 	ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
 	if (ssk) {
 		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
+		struct mptcp_pm_addr_entry entry = { .addr = addr_l };
 
+		spin_lock_bh(&msk->pm.lock);
+		mptcp_userspace_pm_delete_local_addr(msk, &entry);
+		spin_unlock_bh(&msk->pm.lock);
 		mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
 		mptcp_close_ssk(sk, ssk, subflow);
 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);

net/mptcp/protocol.h

@@ -832,6 +832,7 @@ int mptcp_pm_announce_addr(struct mptcp_sock *msk,
 			   bool echo);
 int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
+void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list);
 void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
 					struct list_head *rm_list);
 

tools/testing/selftests/net/mptcp/mptcp_join.sh

@@ -862,7 +862,15 @@ do_transfer()
 				     sed -n 's/.*\(token:\)\([[:digit:]]*\).*$/\2/p;q')
 				ip netns exec ${listener_ns} ./pm_nl_ctl ann $addr token $tk id $id
 				sleep 1
+				sp=$(grep "type:10" "$evts_ns1" |
+				     sed -n 's/.*\(sport:\)\([[:digit:]]*\).*$/\2/p;q')
+				da=$(grep "type:10" "$evts_ns1" |
+				     sed -n 's/.*\(daddr6:\)\([0-9a-f:.]*\).*$/\2/p;q')
+				dp=$(grep "type:10" "$evts_ns1" |
+				     sed -n 's/.*\(dport:\)\([[:digit:]]*\).*$/\2/p;q')
 				ip netns exec ${listener_ns} ./pm_nl_ctl rem token $tk id $id
+				ip netns exec ${listener_ns} ./pm_nl_ctl dsf lip "::ffff:$addr" \
+							lport $sp rip $da rport $dp token $tk
 			fi
 
 			counter=$((counter + 1))
@@ -928,6 +936,7 @@ do_transfer()
 				sleep 1
 				sp=$(grep "type:10" "$evts_ns2" |
 				     sed -n 's/.*\(sport:\)\([[:digit:]]*\).*$/\2/p;q')
+				ip netns exec ${connector_ns} ./pm_nl_ctl rem token $tk id $id
 				ip netns exec ${connector_ns} ./pm_nl_ctl dsf lip $addr lport $sp \
 									rip $da rport $dp token $tk
 			fi
@@ -3142,7 +3151,7 @@ userspace_tests()
 		pm_nl_set_limits $ns1 0 1
 		run_tests $ns1 $ns2 10.0.1.1 0 0 userspace_1 slow
 		chk_join_nr 1 1 1
-		chk_rm_nr 0 1
+		chk_rm_nr 1 1
 		kill_events_pids
 	fi
 }