mptcp: consolidate in_opt sub-options fields in a bitmask

This makes input options processing more consistent with
output ones and will simplify the next patch.

Also avoid clearing the suboption field after processing
it, since it's not needed.

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

1 files changed, 23 insertions, 17 deletions

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 54b7ffc21861..1de7ce883c37 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -141,6 +141,7 @@ static int subflow_check_req(struct request_sock *req,
 	struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener);
 	struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
 	struct mptcp_options_received mp_opt;
+	bool opt_mp_capable, opt_mp_join;
 
 	pr_debug("subflow_req=%p, listener=%p", subflow_req, listener);
 
@@ -154,16 +155,18 @@ static int subflow_check_req(struct request_sock *req,
 
 	mptcp_get_options(sk_listener, skb, &mp_opt);
 
-	if (mp_opt.mp_capable) {
+	opt_mp_capable = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPC);
+	opt_mp_join = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ);
+	if (opt_mp_capable) {
 		SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVE);
 
-		if (mp_opt.mp_join)
+		if (opt_mp_join)
 			return 0;
-	} else if (mp_opt.mp_join) {
+	} else if (opt_mp_join) {
 		SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINSYNRX);
 	}
 
-	if (mp_opt.mp_capable && listener->request_mptcp) {
+	if (opt_mp_capable && listener->request_mptcp) {
 		int err, retries = MPTCP_TOKEN_MAX_RETRIES;
 
 		subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq;
@@ -194,7 +197,7 @@ again:
 		else
 			SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_TOKENFALLBACKINIT);
 
-	} else if (mp_opt.mp_join && listener->request_mptcp) {
+	} else if (opt_mp_join && listener->request_mptcp) {
 		subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq;
 		subflow_req->mp_join = 1;
 		subflow_req->backup = mp_opt.backup;
@@ -243,15 +246,18 @@ int mptcp_subflow_init_cookie_req(struct request_sock *req,
 	struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener);
 	struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
 	struct mptcp_options_received mp_opt;
+	bool opt_mp_capable, opt_mp_join;
 	int err;
 
 	subflow_init_req(req, sk_listener);
 	mptcp_get_options(sk_listener, skb, &mp_opt);
 
-	if (mp_opt.mp_capable && mp_opt.mp_join)
+	opt_mp_capable = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPC);
+	opt_mp_join = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ);
+	if (opt_mp_capable && opt_mp_join)
 		return -EINVAL;
 
-	if (mp_opt.mp_capable && listener->request_mptcp) {
+	if (opt_mp_capable && listener->request_mptcp) {
 		if (mp_opt.sndr_key == 0)
 			return -EINVAL;
 
@@ -262,7 +268,7 @@ int mptcp_subflow_init_cookie_req(struct request_sock *req,
 
 		subflow_req->mp_capable = 1;
 		subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq - 1;
-	} else if (mp_opt.mp_join && listener->request_mptcp) {
+	} else if (opt_mp_join && listener->request_mptcp) {
 		if (!mptcp_token_join_cookie_init_state(subflow_req, skb))
 			return -EINVAL;
 
@@ -394,7 +400,6 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 
 	subflow->icsk_af_ops->sk_rx_dst_set(sk, skb);
 
-
 	/* be sure no special action on any packet other than syn-ack */
 	if (subflow->conn_finished)
 		return;
@@ -407,7 +412,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 
 	mptcp_get_options(sk, skb, &mp_opt);
 	if (subflow->request_mptcp) {
-		if (!mp_opt.mp_capable) {
+		if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPC)) {
 			MPTCP_INC_STATS(sock_net(sk),
 					MPTCP_MIB_MPCAPABLEACTIVEFALLBACK);
 			mptcp_do_fallback(sk);
@@ -415,7 +420,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 			goto fallback;
 		}
 
-		if (mp_opt.csum_reqd)
+		if (mp_opt.suboptions & OPTION_MPTCP_CSUMREQD)
 			WRITE_ONCE(mptcp_sk(parent)->csum_enabled, true);
 		if (mp_opt.deny_join_id0)
 			WRITE_ONCE(mptcp_sk(parent)->pm.remote_deny_join_id0, true);
@@ -430,7 +435,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 	} else if (subflow->request_join) {
 		u8 hmac[SHA256_DIGEST_SIZE];
 
-		if (!mp_opt.mp_join) {
+		if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ)) {
 			subflow->reset_reason = MPTCP_RST_EMPTCP;
 			goto do_reset;
 		}
@@ -636,10 +641,10 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
 
 	pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn);
 
-	/* After child creation we must look for 'mp_capable' even when options
+	/* After child creation we must look for MPC even when options
 	 * are not parsed
 	 */
-	mp_opt.mp_capable = 0;
+	mp_opt.suboptions = 0;
 
 	/* hopefully temporary handling for MP_JOIN+syncookie */
 	subflow_req = mptcp_subflow_rsk(req);
@@ -659,7 +664,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
 		 * options.
 		 */
 		mptcp_get_options(sk, skb, &mp_opt);
-		if (!mp_opt.mp_capable) {
+		if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPC)) {
 			fallback = true;
 			goto create_child;
 		}
@@ -669,7 +674,8 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
 			fallback = true;
 	} else if (subflow_req->mp_join) {
 		mptcp_get_options(sk, skb, &mp_opt);
-		if (!mp_opt.mp_join || !subflow_hmac_valid(req, &mp_opt) ||
+		if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ) ||
+		    !subflow_hmac_valid(req, &mp_opt) ||
 		    !mptcp_can_accept_new_subflow(subflow_req->msk)) {
 			SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC);
 			fallback = true;
@@ -726,7 +732,7 @@ create_child:
 			/* with OoO packets we can reach here without ingress
 			 * mpc option
 			 */
-			if (mp_opt.mp_capable)
+			if (mp_opt.suboptions & OPTIONS_MPTCP_MPC)
 				mptcp_subflow_fully_established(ctx, &mp_opt);
 		} else if (ctx->mp_join) {
 			struct mptcp_sock *owner;