From dc87efdb1a5cd46134a9d490480160e303bc6eef Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 1 Apr 2021 16:19:44 -0700 Subject: mptcp: add mptcp reset option support The MPTCP reset option allows to carry a mptcp-specific error code that provides more information on the nature of a connection reset. Reset option data received gets stored in the subflow context so it can be sent to userspace via the 'subflow closed' netlink event. When a subflow is closed, the desired error code that should be sent to the peer is also placed in the subflow context structure. If a reset is sent before subflow establishment could complete, e.g. on HMAC failure during an MP_JOIN operation, the mptcp skb extension is used to store the reset information. Signed-off-by: Florian Westphal Signed-off-by: Mat Martineau Signed-off-by: David S. Miller --- include/net/mptcp.h | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) (limited to 'include/net/mptcp.h') diff --git a/include/net/mptcp.h b/include/net/mptcp.h index cea69c801595..16fe34d139c3 100644 --- a/include/net/mptcp.h +++ b/include/net/mptcp.h @@ -30,8 +30,8 @@ struct mptcp_ext { ack64:1, mpc_map:1, frozen:1, - __unused:1; - /* one byte hole */ + reset_transient:1; + u8 reset_reason:4; }; #define MPTCP_RM_IDS_MAX 8 @@ -58,6 +58,8 @@ struct mptcp_out_options { struct mptcp_rm_list rm_list; u8 join_id; u8 backup; + u8 reset_reason:4; + u8 reset_transient:1; u32 nonce; u64 thmac; u32 token; @@ -156,6 +158,16 @@ void mptcp_seq_show(struct seq_file *seq); int mptcp_subflow_init_cookie_req(struct request_sock *req, const struct sock *sk_listener, struct sk_buff *skb); + +__be32 mptcp_get_reset_option(const struct sk_buff *skb); + +static inline __be32 mptcp_reset_option(const struct sk_buff *skb) +{ + if (skb_ext_exist(skb, SKB_EXT_MPTCP)) + return mptcp_get_reset_option(skb); + + return htonl(0u); +} #else static inline void mptcp_init(void) @@ -236,6 +248,8 @@ static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, { return 0; /* TCP fallback */ } + +static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); } #endif /* CONFIG_MPTCP */ #if IS_ENABLED(CONFIG_MPTCP_IPV6) -- cgit v1.2.3