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, 30 insertions, 44 deletions

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 79b68ae9ef4d..0d33c020062f 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -81,11 +81,11 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 		 * is if both hosts in their SYNs set A=0."
 		 */
 		if (flags & MPTCP_CAP_CHECKSUM_REQD)
-			mp_opt->csum_reqd = 1;
+			mp_opt->suboptions |= OPTION_MPTCP_CSUMREQD;
 
 		mp_opt->deny_join_id0 = !!(flags & MPTCP_CAP_DENY_JOIN_ID0);
 
-		mp_opt->mp_capable = 1;
+		mp_opt->suboptions |= OPTIONS_MPTCP_MPC;
 		if (opsize >= TCPOLEN_MPTCP_MPC_SYNACK) {
 			mp_opt->sndr_key = get_unaligned_be64(ptr);
 			ptr += 8;
@@ -100,7 +100,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 			 * equivalent to those in a DSS option and can be used
 			 * interchangeably."
 			 */
-			mp_opt->dss = 1;
+			mp_opt->suboptions |= OPTION_MPTCP_DSS;
 			mp_opt->use_map = 1;
 			mp_opt->mpc_map = 1;
 			mp_opt->data_len = get_unaligned_be16(ptr);
@@ -108,7 +108,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 		}
 		if (opsize == TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM) {
 			mp_opt->csum = (__force __sum16)get_unaligned_be16(ptr);
-			mp_opt->csum_reqd = 1;
+			mp_opt->suboptions |= OPTION_MPTCP_CSUMREQD;
 			ptr += 2;
 		}
 		pr_debug("MP_CAPABLE version=%x, flags=%x, optlen=%d sndr=%llu, rcvr=%llu len=%d csum=%u",
@@ -117,7 +117,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 		break;
 
 	case MPTCPOPT_MP_JOIN:
-		mp_opt->mp_join = 1;
+		mp_opt->suboptions |= OPTIONS_MPTCP_MPJ;
 		if (opsize == TCPOLEN_MPTCP_MPJ_SYN) {
 			mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP;
 			mp_opt->join_id = *ptr++;
@@ -143,7 +143,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 			memcpy(mp_opt->hmac, ptr, MPTCPOPT_HMAC_LEN);
 			pr_debug("MP_JOIN hmac");
 		} else {
-			mp_opt->mp_join = 0;
+			mp_opt->suboptions &= ~OPTIONS_MPTCP_MPJ;
 		}
 		break;
 
@@ -191,8 +191,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 		    opsize != expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM)
 			break;
 
-		mp_opt->dss = 1;
-
+		mp_opt->suboptions |= OPTION_MPTCP_DSS;
 		if (mp_opt->use_ack) {
 			if (mp_opt->ack64) {
 				mp_opt->data_ack = get_unaligned_be64(ptr);
@@ -221,14 +220,15 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 			ptr += 2;
 
 			if (opsize == expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM) {
-				mp_opt->csum_reqd = 1;
+				mp_opt->suboptions |= OPTION_MPTCP_CSUMREQD;
 				mp_opt->csum = (__force __sum16)get_unaligned_be16(ptr);
 				ptr += 2;
 			}
 
 			pr_debug("data_seq=%llu subflow_seq=%u data_len=%u csum=%d:%u",
 				 mp_opt->data_seq, mp_opt->subflow_seq,
-				 mp_opt->data_len, mp_opt->csum_reqd, mp_opt->csum);
+				 mp_opt->data_len, !!(mp_opt->suboptions & OPTION_MPTCP_CSUMREQD),
+				 mp_opt->csum);
 		}
 
 		break;
@@ -259,7 +259,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 				break;
 		}
 
-		mp_opt->add_addr = 1;
+		mp_opt->suboptions |= OPTION_MPTCP_ADD_ADDR;
 		mp_opt->addr.id = *ptr++;
 		mp_opt->addr.port = 0;
 		mp_opt->ahmac = 0;
@@ -299,7 +299,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 
 		ptr++;
 
-		mp_opt->rm_addr = 1;
+		mp_opt->suboptions |= OPTION_MPTCP_RM_ADDR;
 		mp_opt->rm_list.nr = opsize - TCPOLEN_MPTCP_RM_ADDR_BASE;
 		for (i = 0; i < mp_opt->rm_list.nr; i++)
 			mp_opt->rm_list.ids[i] = *ptr++;
@@ -310,7 +310,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 		if (opsize != TCPOLEN_MPTCP_PRIO)
 			break;
 
-		mp_opt->mp_prio = 1;
+		mp_opt->suboptions |= OPTION_MPTCP_PRIO;
 		mp_opt->backup = *ptr++ & MPTCP_PRIO_BKUP;
 		pr_debug("MP_PRIO: prio=%d", mp_opt->backup);
 		break;
@@ -322,7 +322,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 		ptr += 2;
 		mp_opt->rcvr_key = get_unaligned_be64(ptr);
 		ptr += 8;
-		mp_opt->fastclose = 1;
+		mp_opt->suboptions |= OPTION_MPTCP_FASTCLOSE;
 		break;
 
 	case MPTCPOPT_RST:
@@ -331,7 +331,8 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 
 		if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST))
 			break;
-		mp_opt->reset = 1;
+
+		mp_opt->suboptions |= OPTION_MPTCP_RST;
 		flags = *ptr++;
 		mp_opt->reset_transient = flags & MPTCP_RST_TRANSIENT;
 		mp_opt->reset_reason = *ptr;
@@ -342,7 +343,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 			break;
 
 		ptr += 2;
-		mp_opt->mp_fail = 1;
+		mp_opt->suboptions |= OPTION_MPTCP_FAIL;
 		mp_opt->fail_seq = get_unaligned_be64(ptr);
 		pr_debug("MP_FAIL: data_seq=%llu", mp_opt->fail_seq);
 		break;
@@ -361,16 +362,7 @@ void mptcp_get_options(const struct sock *sk,
 	int length;
 
 	/* initialize option status */
-	mp_opt->mp_capable = 0;
-	mp_opt->mp_join = 0;
-	mp_opt->add_addr = 0;
-	mp_opt->fastclose = 0;
-	mp_opt->rm_addr = 0;
-	mp_opt->dss = 0;
-	mp_opt->mp_prio = 0;
-	mp_opt->reset = 0;
-	mp_opt->csum_reqd = 0;
-	mp_opt->mp_fail = 0;
+	mp_opt->suboptions = 0;
 
 	length = (th->doff * 4) - sizeof(struct tcphdr);
 	ptr = (const unsigned char *)(th + 1);
@@ -924,7 +916,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk,
 		 */
 		if (TCP_SKB_CB(skb)->seq == subflow->ssn_offset + 1 &&
 		    TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq &&
-		    subflow->mp_join && mp_opt->mp_join &&
+		    subflow->mp_join && (mp_opt->suboptions & OPTIONS_MPTCP_MPJ) &&
 		    READ_ONCE(msk->pm.server_side))
 			tcp_send_ack(ssk);
 		goto fully_established;
@@ -941,8 +933,8 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk,
 		return subflow->mp_capable;
 	}
 
-	if ((mp_opt->dss && mp_opt->use_ack) ||
-	    (mp_opt->add_addr && !mp_opt->echo)) {
+	if (((mp_opt->suboptions & OPTION_MPTCP_DSS) && mp_opt->use_ack) ||
+	    ((mp_opt->suboptions & OPTION_MPTCP_ADD_ADDR) && !mp_opt->echo)) {
 		/* subflows are fully established as soon as we get any
 		 * additional ack, including ADD_ADDR.
 		 */
@@ -955,7 +947,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk,
 	 * then fallback to TCP. Fallback scenarios requires a reset for
 	 * MP_JOIN subflows.
 	 */
-	if (!mp_opt->mp_capable) {
+	if (!(mp_opt->suboptions & OPTIONS_MPTCP_MPC)) {
 		if (subflow->mp_join)
 			goto reset;
 		subflow->mp_capable = 0;
@@ -1119,13 +1111,13 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 	if (!check_fully_established(msk, sk, subflow, skb, &mp_opt))
 		return sk->sk_state != TCP_CLOSE;
 
-	if (mp_opt.fastclose &&
+	if ((mp_opt.suboptions & OPTION_MPTCP_FASTCLOSE) &&
 	    msk->local_key == mp_opt.rcvr_key) {
 		WRITE_ONCE(msk->rcv_fastclose, true);
 		mptcp_schedule_work((struct sock *)msk);
 	}
 
-	if (mp_opt.add_addr && add_addr_hmac_valid(msk, &mp_opt)) {
+	if ((mp_opt.suboptions & OPTION_MPTCP_ADD_ADDR) && add_addr_hmac_valid(msk, &mp_opt)) {
 		if (!mp_opt.echo) {
 			mptcp_pm_add_addr_received(msk, &mp_opt.addr);
 			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ADDADDR);
@@ -1137,34 +1129,28 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 
 		if (mp_opt.addr.port)
 			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_PORTADD);
-
-		mp_opt.add_addr = 0;
 	}
 
-	if (mp_opt.rm_addr) {
+	if (mp_opt.suboptions & OPTION_MPTCP_RM_ADDR)
 		mptcp_pm_rm_addr_received(msk, &mp_opt.rm_list);
-		mp_opt.rm_addr = 0;
-	}
 
-	if (mp_opt.mp_prio) {
+	if (mp_opt.suboptions & OPTION_MPTCP_PRIO) {
 		mptcp_pm_mp_prio_received(sk, mp_opt.backup);
 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPPRIORX);
-		mp_opt.mp_prio = 0;
 	}
 
-	if (mp_opt.mp_fail) {
+	if (mp_opt.suboptions & OPTION_MPTCP_FAIL) {
 		mptcp_pm_mp_fail_received(sk, mp_opt.fail_seq);
 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILRX);
-		mp_opt.mp_fail = 0;
 	}
 
-	if (mp_opt.reset) {
+	if (mp_opt.suboptions & OPTION_MPTCP_RST) {
 		subflow->reset_seen = 1;
 		subflow->reset_reason = mp_opt.reset_reason;
 		subflow->reset_transient = mp_opt.reset_transient;
 	}
 
-	if (!mp_opt.dss)
+	if (!(mp_opt.suboptions & OPTION_MPTCP_DSS))
 		return true;
 
 	/* we can't wait for recvmsg() to update the ack_seq, otherwise
@@ -1213,7 +1199,7 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 		}
 		mpext->data_len = mp_opt.data_len;
 		mpext->use_map = 1;
-		mpext->csum_reqd = mp_opt.csum_reqd;
+		mpext->csum_reqd = !!(mp_opt.suboptions & OPTION_MPTCP_CSUMREQD);
 
 		if (mpext->csum_reqd)
 			mpext->csum = mp_opt.csum;