[MPTCP] [MPTCP][PATCH v2 mptcp-next 1/7] mptcp: remove multi addrs on outgoing path

[MPTCP] [MPTCP][PATCH v2 mptcp-next 1/7] mptcp: remove multi addrs on outgoing path

[Geliang Tang]

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This patch changed the member rm_id of struct mptcp_out_options as an
array of the removing address ids, and renamed it to rm_ids. The array
size was definced as a new macro MPTCP_RM_IDS_MAX.

Added a new function named mptcp_get_rm_ids_nr to get the number of
address ids in the ids array.

In mptcp_established_options_rm_addr, invoked mptcp_pm_rm_addr_signal to
get the ids array. According the number of addresses in it, calculated
the padded RM_ADDR suboption length. And saved the ids array in struct
mptcp_out_options's rm_ids member.

In mptcp_write_options, iterated each address id from struct
mptcp_out_options's rm_ids member, set the zero ones as TCPOPT_NOP,
then filled them into the RM_ADDR suboption.

Signed-off-by: Geliang Tang <geliangtang(a)gmail.com>
---
 include/net/mptcp.h  |  4 +++-
 net/mptcp/options.c  | 40 ++++++++++++++++++++++++++++++++--------
 net/mptcp/pm.c       |  3 +--
 net/mptcp/protocol.h | 14 ++++++++++++--
 4 files changed, 48 insertions(+), 13 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index 5694370be3d4..1d33fea674d2 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -34,6 +34,8 @@ struct mptcp_ext {
 	/* one byte hole */
 };
 
+#define MPTCP_RM_IDS_MAX	8
+
 struct mptcp_out_options {
 #if IS_ENABLED(CONFIG_MPTCP)
 	u16 suboptions;
@@ -48,7 +50,7 @@ struct mptcp_out_options {
 	u8 addr_id;
 	u16 port;
 	u64 ahmac;
-	u8 rm_id;
+	u8 rm_ids[MPTCP_RM_IDS_MAX];
 	u8 join_id;
 	u8 backup;
 	u32 nonce;
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index bb874c5d663a..3ce7917327d1 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -671,20 +671,27 @@ static bool mptcp_established_options_rm_addr(struct sock *sk,
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
-	u8 rm_id;
+	u8 rm_ids[MPTCP_RM_IDS_MAX], i, nr, align;
 
 	if (!mptcp_pm_should_rm_signal(msk) ||
-	    !(mptcp_pm_rm_addr_signal(msk, remaining, &rm_id)))
+	    !(mptcp_pm_rm_addr_signal(msk, remaining, rm_ids)))
 		return false;
 
-	if (remaining < TCPOLEN_MPTCP_RM_ADDR_BASE)
+	nr = mptcp_get_rm_ids_nr(rm_ids);
+	if (nr > 1)
+		align = 5;
+	if (nr > 5)
+		align = 9;
+
+	if (remaining < TCPOLEN_MPTCP_RM_ADDR_BASE + align)
 		return false;
 
-	*size = TCPOLEN_MPTCP_RM_ADDR_BASE;
+	*size = TCPOLEN_MPTCP_RM_ADDR_BASE + align;
 	opts->suboptions |= OPTION_MPTCP_RM_ADDR;
-	opts->rm_id = rm_id;
+	memcpy(opts->rm_ids, rm_ids, MPTCP_RM_IDS_MAX);
 
-	pr_debug("rm_id=%d", opts->rm_id);
+	for (i = 0; i < nr; i++)
+		pr_debug("rm_ids[%d]=%d", i, opts->rm_ids[i]);
 
 	return true;
 }
@@ -1212,9 +1219,26 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
 	}
 
 	if (OPTION_MPTCP_RM_ADDR & opts->suboptions) {
+		u8 i, nr;
+
+		nr = mptcp_get_rm_ids_nr(opts->rm_ids);
+		for (i = 0; i < MPTCP_RM_IDS_MAX; i++) {
+			if (!opts->rm_ids[i])
+				opts->rm_ids[i] = TCPOPT_NOP;
+		}
 		*ptr++ = mptcp_option(MPTCPOPT_RM_ADDR,
-				      TCPOLEN_MPTCP_RM_ADDR_BASE,
-				      0, opts->rm_id);
+				      TCPOLEN_MPTCP_RM_ADDR_BASE + nr,
+				      0, opts->rm_ids[0]);
+		if (nr > 1) {
+			put_unaligned_be32(opts->rm_ids[1] << 24 | opts->rm_ids[2] << 16 |
+					   opts->rm_ids[3] << 8 | opts->rm_ids[4], ptr);
+			ptr += 1;
+		}
+		if (nr > 5) {
+			put_unaligned_be32(opts->rm_ids[5] << 24 | opts->rm_ids[6] << 16 |
+					   opts->rm_ids[7] << 8 | TCPOPT_NOP, ptr);
+			ptr += 1;
+		}
 	}
 
 	if (OPTION_MPTCP_PRIO & opts->suboptions) {
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 6fd4b2c1b076..764cd62c59ba 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -258,7 +258,7 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 }
 
 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
-			     u8 *rm_id)
+			     u8 rm_ids[])
 {
 	int ret = false;
 
@@ -271,7 +271,6 @@ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 	if (remaining < TCPOLEN_MPTCP_RM_ADDR_BASE)
 		goto out_unlock;
 
-	*rm_id = msk->pm.rm_id;
 	WRITE_ONCE(msk->pm.addr_signal, 0);
 	ret = true;
 
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index d31edbae8da8..411af3334a25 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -60,7 +60,7 @@
 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE	20
 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT	24
 #define TCPOLEN_MPTCP_PORT_LEN		4
-#define TCPOLEN_MPTCP_RM_ADDR_BASE	4
+#define TCPOLEN_MPTCP_RM_ADDR_BASE	3
 #define TCPOLEN_MPTCP_PRIO		3
 #define TCPOLEN_MPTCP_PRIO_ALIGN	4
 #define TCPOLEN_MPTCP_FASTCLOSE		12
@@ -289,6 +289,16 @@ struct mptcp_sock {
 #define mptcp_for_each_subflow(__msk, __subflow)			\
 	list_for_each_entry(__subflow, &((__msk)->conn_list), node)
 
+static inline u8 mptcp_get_rm_ids_nr(u8 rm_ids[])
+{
+	int i, nr = 0;
+
+	for (i = 0; i < MPTCP_RM_IDS_MAX && rm_ids[i]; i++)
+		nr++;
+
+	return nr;
+}
+
 static inline void msk_owned_by_me(const struct mptcp_sock *msk)
 {
 	sock_owned_by_me((const struct sock *)msk);
@@ -714,7 +724,7 @@ static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 			      struct mptcp_addr_info *saddr, bool *echo, bool *port);
 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
-			     u8 *rm_id);
+			     u8 rm_ids[]);
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
 
 void __init mptcp_pm_nl_init(void);
-- 
2.29.2