[RFC PATCH v2 17/45] mptcp: Add MPTCP to skb extensions

[Mat Martineau]

Add enum value for MPTCP and update config dependencies

Signed-off-by: Mat Martineau <mathew.j.martin...@linux.intel.com>
---
 include/linux/skbuff.h |  3 +++
 include/net/mptcp.h    | 16 ++++++++++++++++
 net/core/skbuff.c      |  7 +++++++
 net/mptcp/Kconfig      |  1 +
 4 files changed, 27 insertions(+)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index e7a7abd62026..5a9b26ff44e9 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -4068,6 +4068,9 @@ enum skb_ext_id {
 #endif
 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
        TC_SKB_EXT,
+#endif
+#if IS_ENABLED(CONFIG_MPTCP)
+       SKB_EXT_MPTCP,
 #endif
        SKB_EXT_NUM, /* must be last */
 };
diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index 1a3ed7734bb4..6921b7fb6f0d 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -8,6 +8,22 @@
 #ifndef __NET_MPTCP_H
 #define __NET_MPTCP_H
 
+/* MPTCP sk_buff extension data */
+struct mptcp_ext {
+       u64             data_ack;
+       u64             data_seq;
+       u32             subflow_seq;
+       u16             data_len;
+       __sum16         checksum;
+       u8              use_map:1,
+                       dsn64:1,
+                       use_checksum:1,
+                       data_fin:1,
+                       use_ack:1,
+                       ack64:1,
+                       __unused:2;
+};
+
 struct mptcp_out_options {
 #if IS_ENABLED(CONFIG_MPTCP)
        u16 suboptions;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 01d65206f4fb..20094629e103 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -68,6 +68,7 @@
 #include <net/ip6_checksum.h>
 #include <net/xfrm.h>
 #include <net/mpls.h>
+#include <net/mptcp.h>
 
 #include <linux/uaccess.h>
 #include <trace/events/skb.h>
@@ -4109,6 +4110,9 @@ static const u8 skb_ext_type_len[] = {
 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
        [TC_SKB_EXT] = SKB_EXT_CHUNKSIZEOF(struct tc_skb_ext),
 #endif
+#if IS_ENABLED(CONFIG_MPTCP)
+       [SKB_EXT_MPTCP] = SKB_EXT_CHUNKSIZEOF(struct mptcp_ext),
+#endif
 };
 
 static __always_inline unsigned int skb_ext_total_length(void)
@@ -4122,6 +4126,9 @@ static __always_inline unsigned int 
skb_ext_total_length(void)
 #endif
 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
                skb_ext_type_len[TC_SKB_EXT] +
+#endif
+#if IS_ENABLED(CONFIG_MPTCP)
+               skb_ext_type_len[SKB_EXT_MPTCP] +
 #endif
                0;
 }
diff --git a/net/mptcp/Kconfig b/net/mptcp/Kconfig
index d87dfdc210cc..f21190a4f7e9 100644
--- a/net/mptcp/Kconfig
+++ b/net/mptcp/Kconfig
@@ -2,6 +2,7 @@
 config MPTCP
        bool "Multipath TCP"
        depends on INET
+       select SKB_EXTENSIONS
        help
          Multipath TCP (MPTCP) connections send and receive data over multiple
          subflows in order to utilize multiple network paths. Each subflow
-- 
2.23.0