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 --- net/mptcp/protocol.h | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'net/mptcp/protocol.h') diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index e8c5ff2b8ace..40e9b05856cd 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -26,6 +26,7 @@ #define OPTION_MPTCP_RM_ADDR BIT(8) #define OPTION_MPTCP_FASTCLOSE BIT(9) #define OPTION_MPTCP_PRIO BIT(10) +#define OPTION_MPTCP_RST BIT(11) /* MPTCP option subtypes */ #define MPTCPOPT_MP_CAPABLE 0 @@ -36,6 +37,7 @@ #define MPTCPOPT_MP_PRIO 5 #define MPTCPOPT_MP_FAIL 6 #define MPTCPOPT_MP_FASTCLOSE 7 +#define MPTCPOPT_RST 8 /* MPTCP suboption lengths */ #define TCPOLEN_MPTCP_MPC_SYN 4 @@ -65,6 +67,7 @@ #define TCPOLEN_MPTCP_PRIO 3 #define TCPOLEN_MPTCP_PRIO_ALIGN 4 #define TCPOLEN_MPTCP_FASTCLOSE 12 +#define TCPOLEN_MPTCP_RST 4 /* MPTCP MP_JOIN flags */ #define MPTCPOPT_BACKUP BIT(0) @@ -94,6 +97,9 @@ /* MPTCP MP_PRIO flags */ #define MPTCP_PRIO_BKUP BIT(0) +/* MPTCP TCPRST flags */ +#define MPTCP_RST_TRANSIENT BIT(0) + /* MPTCP socket flags */ #define MPTCP_DATA_READY 0 #define MPTCP_NOSPACE 1 @@ -123,6 +129,7 @@ struct mptcp_options_received { u16 mp_capable : 1, mp_join : 1, fastclose : 1, + reset : 1, dss : 1, add_addr : 1, rm_addr : 1, @@ -152,6 +159,8 @@ struct mptcp_options_received { }; u64 ahmac; u16 port; + u8 reset_reason:4; + u8 reset_transient:1; }; static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field) @@ -422,6 +431,9 @@ struct mptcp_subflow_context { u8 hmac[MPTCPOPT_HMAC_LEN]; u8 local_id; u8 remote_id; + u8 reset_seen:1; + u8 reset_transient:1; + u8 reset_reason:4; long delegated_status; struct list_head delegated_node; /* link into delegated_action, protected by local BH */ @@ -742,7 +754,7 @@ unsigned int mptcp_pm_get_add_addr_accept_max(struct mptcp_sock *msk); unsigned int mptcp_pm_get_subflows_max(struct mptcp_sock *msk); unsigned int mptcp_pm_get_local_addr_max(struct mptcp_sock *msk); -static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb) +static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb) { return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP); } -- cgit v1.2.3