diff mbox series

[v10,mptcp-next,4/9] mptcp: add port number check for MP_JOIN

Message ID 59e26e34527116be45a5231a96b9d2f8b6c8b99c.1610598621.git.geliangtang@gmail.com
State Accepted, archived
Commit 551edb8d92ab125c7e2e6b179b03a82344a61f8e
Delegated to: Matthieu Baerts
Headers show
Series ADD_ADDR: ports support | expand

Commit Message

Geliang Tang Jan. 14, 2021, 5:25 a.m. UTC 
This patch adds two new helpers, subflow_use_different_sport and
subflow_use_different_dport, to check whether the subflow's source or
destination port number is different from the msk's port number. When
receiving the MP_JOIN's SYN/SYNACK/ACK, we do these port number checks
and print out the different port numbers.

And furthermore, when receiving the MP_JOIN's SYN/ACK, we also use a new
helper mptcp_pm_sport_in_anno_list to check whether this port number is
announced. If it isn't, we need to abort this connection.

This patch alse populates the local address's port field in local_address.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 net/mptcp/pm_netlink.c | 23 ++++++++++++++++++++++-
 net/mptcp/protocol.h   |  1 +
 net/mptcp/subflow.c    | 38 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 61 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 2164b016585a..e6a8ca4694c0 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -97,8 +97,8 @@  static bool address_zero(const struct mptcp_addr_info *addr)
 static void local_address(const struct sock_common *skc,
 			  struct mptcp_addr_info *addr)
 {
-	addr->port = 0;
 	addr->family = skc->skc_family;
+	addr->port = htons(skc->skc_num);
 	if (addr->family == AF_INET)
 		addr->addr.s_addr = skc->skc_rcv_saddr;
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
@@ -251,6 +251,27 @@  lookup_anno_list_by_saddr(struct mptcp_sock *msk,
 	return NULL;
 }
 
+bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
+{
+	struct mptcp_pm_add_entry *entry;
+	struct mptcp_addr_info saddr;
+	bool ret = false;
+
+	local_address((struct sock_common *)sk, &saddr);
+
+	spin_lock_bh(&msk->pm.lock);
+	list_for_each_entry(entry, &msk->pm.anno_list, list) {
+		if (addresses_equal(&entry->addr, &saddr, true)) {
+			ret = true;
+			goto out;
+		}
+	}
+
+out:
+	spin_unlock_bh(&msk->pm.lock);
+	return ret;
+}
+
 static void mptcp_pm_add_timer(struct timer_list *timer)
 {
 	struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 486eebf8c7c9..93afa4c1dd76 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -582,6 +582,7 @@  int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 				 struct mptcp_addr_info *addr,
 				 u8 bkup);
 void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
+bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
 struct mptcp_pm_add_entry *
 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 		       struct mptcp_addr_info *addr);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index fee38bb9d80a..e3cb06938b91 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -117,6 +117,11 @@  static int __subflow_init_req(struct request_sock *req, const struct sock *sk_li
 	return 0;
 }
 
+static bool subflow_use_different_sport(struct mptcp_sock *msk, const struct sock *sk)
+{
+	return inet_sk(sk)->inet_sport != inet_sk((struct sock *)msk)->inet_sport;
+}
+
 /* Init mptcp request socket.
  *
  * Returns an error code if a JOIN has failed and a TCP reset
@@ -189,6 +194,20 @@  static int subflow_init_req(struct request_sock *req,
 		if (!subflow_req->msk)
 			return -EPERM;
 
+		if (subflow_use_different_sport(subflow_req->msk, sk_listener)) {
+			pr_debug("syn inet_sport=%d %d",
+				 ntohs(inet_sk(sk_listener)->inet_sport),
+				 ntohs(inet_sk((struct sock *)subflow_req->msk)->inet_sport));
+			if (!mptcp_pm_sport_in_anno_list(subflow_req->msk, sk_listener)) {
+				sock_put((struct sock *)subflow_req->msk);
+				mptcp_token_destroy_request(req);
+				tcp_request_sock_ops.destructor(req);
+				subflow_req->msk = NULL;
+				subflow_req->mp_join = 0;
+				return -EPERM;
+			}
+		}
+
 		subflow_req_create_thmac(subflow_req);
 
 		if (unlikely(req->syncookie)) {
@@ -333,6 +352,11 @@  void mptcp_subflow_reset(struct sock *ssk)
 	sock_put(sk);
 }
 
+static bool subflow_use_different_dport(struct mptcp_sock *msk, const struct sock *sk)
+{
+	return inet_sk(sk)->inet_dport != inet_sk((struct sock *)msk)->inet_dport;
+}
+
 static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
@@ -399,6 +423,12 @@  static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 
 		subflow->mp_join = 1;
 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX);
+
+		if (subflow_use_different_dport(mptcp_sk(parent), sk)) {
+			pr_debug("synack inet_dport=%d %d",
+				 ntohs(inet_sk(sk)->inet_dport),
+				 ntohs(inet_sk(parent)->inet_dport));
+		}
 	} else if (mptcp_check_fallback(sk)) {
 fallback:
 		mptcp_rcv_space_init(mptcp_sk(parent), sk);
@@ -661,6 +691,14 @@  static struct sock *subflow_syn_recv_sock(const struct sock *sk,
 
 			SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKRX);
 			tcp_rsk(req)->drop_req = true;
+
+			if (subflow_use_different_sport(owner, sk)) {
+				pr_debug("ack inet_sport=%d %d",
+					 ntohs(inet_sk(sk)->inet_sport),
+					 ntohs(inet_sk((struct sock *)owner)->inet_sport));
+				if (!mptcp_pm_sport_in_anno_list(owner, sk))
+					goto out;
+			}
 		}
 	}