241 lines
6.4 KiB
C
241 lines
6.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* Multipath TCP
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*
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* Copyright (c) 2017 - 2019, Intel Corporation.
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*/
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#ifndef __MPTCP_PROTOCOL_H
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#define __MPTCP_PROTOCOL_H
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#include <linux/random.h>
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#include <net/tcp.h>
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#include <net/inet_connection_sock.h>
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#define MPTCP_SUPPORTED_VERSION 1
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/* MPTCP option bits */
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#define OPTION_MPTCP_MPC_SYN BIT(0)
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#define OPTION_MPTCP_MPC_SYNACK BIT(1)
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#define OPTION_MPTCP_MPC_ACK BIT(2)
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/* MPTCP option subtypes */
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#define MPTCPOPT_MP_CAPABLE 0
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#define MPTCPOPT_MP_JOIN 1
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#define MPTCPOPT_DSS 2
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#define MPTCPOPT_ADD_ADDR 3
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#define MPTCPOPT_RM_ADDR 4
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#define MPTCPOPT_MP_PRIO 5
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#define MPTCPOPT_MP_FAIL 6
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#define MPTCPOPT_MP_FASTCLOSE 7
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/* MPTCP suboption lengths */
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#define TCPOLEN_MPTCP_MPC_SYN 4
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#define TCPOLEN_MPTCP_MPC_SYNACK 12
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#define TCPOLEN_MPTCP_MPC_ACK 20
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#define TCPOLEN_MPTCP_MPC_ACK_DATA 22
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#define TCPOLEN_MPTCP_DSS_BASE 4
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#define TCPOLEN_MPTCP_DSS_ACK32 4
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#define TCPOLEN_MPTCP_DSS_ACK64 8
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#define TCPOLEN_MPTCP_DSS_MAP32 10
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#define TCPOLEN_MPTCP_DSS_MAP64 14
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#define TCPOLEN_MPTCP_DSS_CHECKSUM 2
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/* MPTCP MP_CAPABLE flags */
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#define MPTCP_VERSION_MASK (0x0F)
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#define MPTCP_CAP_CHECKSUM_REQD BIT(7)
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#define MPTCP_CAP_EXTENSIBILITY BIT(6)
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#define MPTCP_CAP_HMAC_SHA256 BIT(0)
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#define MPTCP_CAP_FLAG_MASK (0x3F)
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/* MPTCP DSS flags */
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#define MPTCP_DSS_DATA_FIN BIT(4)
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#define MPTCP_DSS_DSN64 BIT(3)
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#define MPTCP_DSS_HAS_MAP BIT(2)
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#define MPTCP_DSS_ACK64 BIT(1)
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#define MPTCP_DSS_HAS_ACK BIT(0)
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#define MPTCP_DSS_FLAG_MASK (0x1F)
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/* MPTCP socket flags */
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#define MPTCP_DATA_READY BIT(0)
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#define MPTCP_SEND_SPACE BIT(1)
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/* MPTCP connection sock */
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struct mptcp_sock {
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/* inet_connection_sock must be the first member */
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struct inet_connection_sock sk;
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u64 local_key;
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u64 remote_key;
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u64 write_seq;
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u64 ack_seq;
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u32 token;
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unsigned long flags;
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bool can_ack;
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struct list_head conn_list;
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struct skb_ext *cached_ext; /* for the next sendmsg */
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struct socket *subflow; /* outgoing connect/listener/!mp_capable */
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struct sock *first;
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};
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#define mptcp_for_each_subflow(__msk, __subflow) \
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list_for_each_entry(__subflow, &((__msk)->conn_list), node)
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static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
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{
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return (struct mptcp_sock *)sk;
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}
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struct mptcp_subflow_request_sock {
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struct tcp_request_sock sk;
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u16 mp_capable : 1,
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mp_join : 1,
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backup : 1,
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remote_key_valid : 1;
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u64 local_key;
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u64 remote_key;
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u64 idsn;
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u32 token;
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u32 ssn_offset;
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};
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static inline struct mptcp_subflow_request_sock *
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mptcp_subflow_rsk(const struct request_sock *rsk)
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{
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return (struct mptcp_subflow_request_sock *)rsk;
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}
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/* MPTCP subflow context */
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struct mptcp_subflow_context {
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struct list_head node;/* conn_list of subflows */
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u64 local_key;
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u64 remote_key;
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u64 idsn;
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u64 map_seq;
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u32 snd_isn;
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u32 token;
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u32 rel_write_seq;
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u32 map_subflow_seq;
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u32 ssn_offset;
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u32 map_data_len;
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u32 request_mptcp : 1, /* send MP_CAPABLE */
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mp_capable : 1, /* remote is MPTCP capable */
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fourth_ack : 1, /* send initial DSS */
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conn_finished : 1,
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map_valid : 1,
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mpc_map : 1,
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data_avail : 1,
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rx_eof : 1,
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can_ack : 1; /* only after processing the remote a key */
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struct sock *tcp_sock; /* tcp sk backpointer */
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struct sock *conn; /* parent mptcp_sock */
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const struct inet_connection_sock_af_ops *icsk_af_ops;
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void (*tcp_data_ready)(struct sock *sk);
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void (*tcp_state_change)(struct sock *sk);
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void (*tcp_write_space)(struct sock *sk);
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struct rcu_head rcu;
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};
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static inline struct mptcp_subflow_context *
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mptcp_subflow_ctx(const struct sock *sk)
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{
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struct inet_connection_sock *icsk = inet_csk(sk);
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/* Use RCU on icsk_ulp_data only for sock diag code */
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return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
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}
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static inline struct sock *
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mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
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{
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return subflow->tcp_sock;
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}
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static inline u64
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mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
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{
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return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
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subflow->ssn_offset -
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subflow->map_subflow_seq;
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}
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static inline u64
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mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
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{
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return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
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}
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int mptcp_is_enabled(struct net *net);
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bool mptcp_subflow_data_available(struct sock *sk);
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void mptcp_subflow_init(void);
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int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
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static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
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struct mptcp_subflow_context *ctx)
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{
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sk->sk_data_ready = ctx->tcp_data_ready;
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sk->sk_state_change = ctx->tcp_state_change;
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sk->sk_write_space = ctx->tcp_write_space;
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inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
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}
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extern const struct inet_connection_sock_af_ops ipv4_specific;
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#if IS_ENABLED(CONFIG_MPTCP_IPV6)
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extern const struct inet_connection_sock_af_ops ipv6_specific;
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#endif
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void mptcp_proto_init(void);
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#if IS_ENABLED(CONFIG_MPTCP_IPV6)
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int mptcp_proto_v6_init(void);
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#endif
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struct mptcp_read_arg {
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struct msghdr *msg;
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};
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int mptcp_read_actor(read_descriptor_t *desc, struct sk_buff *skb,
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unsigned int offset, size_t len);
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void mptcp_get_options(const struct sk_buff *skb,
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struct tcp_options_received *opt_rx);
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void mptcp_finish_connect(struct sock *sk);
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int mptcp_token_new_request(struct request_sock *req);
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void mptcp_token_destroy_request(u32 token);
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int mptcp_token_new_connect(struct sock *sk);
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int mptcp_token_new_accept(u32 token);
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void mptcp_token_update_accept(struct sock *sk, struct sock *conn);
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void mptcp_token_destroy(u32 token);
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void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
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static inline void mptcp_crypto_key_gen_sha(u64 *key, u32 *token, u64 *idsn)
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{
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/* we might consider a faster version that computes the key as a
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* hash of some information available in the MPTCP socket. Use
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* random data at the moment, as it's probably the safest option
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* in case multiple sockets are opened in different namespaces at
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* the same time.
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*/
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get_random_bytes(key, sizeof(u64));
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mptcp_crypto_key_sha(*key, token, idsn);
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}
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void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
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void *hash_out);
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static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
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{
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return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
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}
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static inline bool before64(__u64 seq1, __u64 seq2)
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{
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return (__s64)(seq1 - seq2) < 0;
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}
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#define after64(seq2, seq1) before64(seq1, seq2)
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#endif /* __MPTCP_PROTOCOL_H */
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