mptcp: Exclude MPTCP options with IPv6 ADD_ADDR2

This guarantees that ADD_ADDR2 fits in the TCP options in case of IPv6 address advertisement and no port field. In this implementation, only MPTCP DSS option and MP_PRIO option are excluded. Plain TCP options are not affected. Signed-off-by: Fabrizio Demaria <fabrizio.demaria@intel.com>
multipath-tcp · Nov 25, 2015 · 4b7f599 · 4b7f599
1 parent d80199c
commit 4b7f599
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Showing 2 changed files with 10 additions and 7 deletions.
diff --git a/net/mptcp/mptcp_fullmesh.c b/net/mptcp/mptcp_fullmesh.c
@@ -1555,8 +1555,7 @@ static void full_mesh_addr_signal(struct sock *sk, unsigned *size,
 	    ((mpcb->mptcp_ver == 0 &&
 	    MAX_TCP_OPTION_SPACE - *size >= MPTCP_SUB_LEN_ADD_ADDR4_ALIGN) ||
 	    (mpcb->mptcp_ver >= 1 &&
-	    MAX_TCP_OPTION_SPACE - *size >=
-	    MPTCP_SUB_LEN_ADD_ADDR4_ALIGN_VER1))) {
+	    MAX_TCP_OPTION_SPACE - *size >= MPTCP_SUB_LEN_ADD_ADDR4_ALIGN_VER1))) {
 		int ind = mptcp_find_free_index(~unannouncedv4);
 
 		opts->options |= OPTION_MPTCP;
@@ -1597,8 +1596,7 @@ static void full_mesh_addr_signal(struct sock *sk, unsigned *size,
 	    ((mpcb->mptcp_ver == 0 &&
 	    MAX_TCP_OPTION_SPACE - *size >= MPTCP_SUB_LEN_ADD_ADDR6_ALIGN) ||
 	    (mpcb->mptcp_ver >= 1 &&
-	    MAX_TCP_OPTION_SPACE - *size >=
-	    MPTCP_SUB_LEN_ADD_ADDR6_ALIGN_VER1))) {
+	    MAX_TCP_OPTION_SPACE - *size >= MPTCP_SUB_LEN_ADD_ADDR6_ALIGN_VER1))) {
 		int ind = mptcp_find_free_index(~unannouncedv6);
 
 		opts->options |= OPTION_MPTCP;

diff --git a/net/mptcp/mptcp_output.c b/net/mptcp/mptcp_output.c
@@ -960,12 +960,20 @@ void mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 		if (skb)
 			tp->mptcp->include_mpc = 0;
 	}
+
 	if (unlikely(tp->mptcp->pre_established)) {
 		opts->options |= OPTION_MPTCP;
 		opts->mptcp_options |= OPTION_MP_JOIN | OPTION_TYPE_ACK;
 		*size += MPTCP_SUB_LEN_JOIN_ACK_ALIGN;
 	}
 
+	if (unlikely(mpcb->addr_signal) && mpcb->pm_ops->addr_signal) {
+		mpcb->pm_ops->addr_signal(sk, size, opts, skb);
+		if (opts->add_addr_v6)
+			/* Skip subsequent options */
+			return;
+	}
+
 	if (!tp->mptcp->include_mpc && !tp->mptcp->pre_established) {
 		opts->options |= OPTION_MPTCP;
 		opts->mptcp_options |= OPTION_DATA_ACK;
@@ -985,9 +993,6 @@ void mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 		*size += MPTCP_SUB_LEN_DSS_ALIGN;
 	}
 
-	if (unlikely(mpcb->addr_signal) && mpcb->pm_ops->addr_signal)
-		mpcb->pm_ops->addr_signal(sk, size, opts, skb);
-
 	if (unlikely(tp->mptcp->send_mp_prio) &&
 	    MAX_TCP_OPTION_SPACE - *size >= MPTCP_SUB_LEN_PRIO_ALIGN) {
 		opts->options |= OPTION_MPTCP;