/* SPDX-License-Identifier: GPL-2.0 */ /* Multipath TCP * * Copyright (c) 2017 - 2019, Intel Corporation. */ #ifndef __MPTCP_PROTOCOL_H #define __MPTCP_PROTOCOL_H #include #include #include #define MPTCP_SUPPORTED_VERSION 1 /* MPTCP option bits */ #define OPTION_MPTCP_MPC_SYN BIT(0) #define OPTION_MPTCP_MPC_SYNACK BIT(1) #define OPTION_MPTCP_MPC_ACK BIT(2) #define OPTION_MPTCP_MPJ_SYN BIT(3) #define OPTION_MPTCP_MPJ_SYNACK BIT(4) #define OPTION_MPTCP_MPJ_ACK BIT(5) #define OPTION_MPTCP_ADD_ADDR BIT(6) #define OPTION_MPTCP_ADD_ADDR6 BIT(7) #define OPTION_MPTCP_RM_ADDR BIT(8) /* MPTCP option subtypes */ #define MPTCPOPT_MP_CAPABLE 0 #define MPTCPOPT_MP_JOIN 1 #define MPTCPOPT_DSS 2 #define MPTCPOPT_ADD_ADDR 3 #define MPTCPOPT_RM_ADDR 4 #define MPTCPOPT_MP_PRIO 5 #define MPTCPOPT_MP_FAIL 6 #define MPTCPOPT_MP_FASTCLOSE 7 /* MPTCP suboption lengths */ #define TCPOLEN_MPTCP_MPC_SYN 4 #define TCPOLEN_MPTCP_MPC_SYNACK 12 #define TCPOLEN_MPTCP_MPC_ACK 20 #define TCPOLEN_MPTCP_MPC_ACK_DATA 22 #define TCPOLEN_MPTCP_MPJ_SYN 12 #define TCPOLEN_MPTCP_MPJ_SYNACK 16 #define TCPOLEN_MPTCP_MPJ_ACK 24 #define TCPOLEN_MPTCP_DSS_BASE 4 #define TCPOLEN_MPTCP_DSS_ACK32 4 #define TCPOLEN_MPTCP_DSS_ACK64 8 #define TCPOLEN_MPTCP_DSS_MAP32 10 #define TCPOLEN_MPTCP_DSS_MAP64 14 #define TCPOLEN_MPTCP_DSS_CHECKSUM 2 #define TCPOLEN_MPTCP_ADD_ADDR 16 #define TCPOLEN_MPTCP_ADD_ADDR_PORT 18 #define TCPOLEN_MPTCP_ADD_ADDR_BASE 8 #define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT 10 #define TCPOLEN_MPTCP_ADD_ADDR6 28 #define TCPOLEN_MPTCP_ADD_ADDR6_PORT 30 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE 20 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT 22 #define TCPOLEN_MPTCP_PORT_LEN 2 #define TCPOLEN_MPTCP_RM_ADDR_BASE 4 /* MPTCP MP_JOIN flags */ #define MPTCPOPT_BACKUP BIT(0) #define MPTCPOPT_HMAC_LEN 20 #define MPTCPOPT_THMAC_LEN 8 /* MPTCP MP_CAPABLE flags */ #define MPTCP_VERSION_MASK (0x0F) #define MPTCP_CAP_CHECKSUM_REQD BIT(7) #define MPTCP_CAP_EXTENSIBILITY BIT(6) #define MPTCP_CAP_HMAC_SHA256 BIT(0) #define MPTCP_CAP_FLAG_MASK (0x3F) /* MPTCP DSS flags */ #define MPTCP_DSS_DATA_FIN BIT(4) #define MPTCP_DSS_DSN64 BIT(3) #define MPTCP_DSS_HAS_MAP BIT(2) #define MPTCP_DSS_ACK64 BIT(1) #define MPTCP_DSS_HAS_ACK BIT(0) #define MPTCP_DSS_FLAG_MASK (0x1F) /* MPTCP ADD_ADDR flags */ #define MPTCP_ADDR_ECHO BIT(0) #define MPTCP_ADDR_IPVERSION_4 4 #define MPTCP_ADDR_IPVERSION_6 6 /* MPTCP socket flags */ #define MPTCP_DATA_READY 0 #define MPTCP_SEND_SPACE 1 #define MPTCP_WORK_RTX 2 #define MPTCP_WORK_EOF 3 #define MPTCP_FALLBACK_DONE 4 struct mptcp_options_received { u64 sndr_key; u64 rcvr_key; u64 data_ack; u64 data_seq; u32 subflow_seq; u16 data_len; u16 mp_capable : 1, mp_join : 1, dss : 1, add_addr : 1, rm_addr : 1, family : 4, echo : 1, backup : 1; u32 token; u32 nonce; u64 thmac; u8 hmac[20]; u8 join_id; u8 use_map:1, dsn64:1, data_fin:1, use_ack:1, ack64:1, mpc_map:1, __unused:2; u8 addr_id; u8 rm_id; union { struct in_addr addr; #if IS_ENABLED(CONFIG_MPTCP_IPV6) struct in6_addr addr6; #endif }; u64 ahmac; u16 port; }; static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field) { return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) | ((nib & 0xF) << 8) | field); } struct mptcp_addr_info { sa_family_t family; __be16 port; u8 id; union { struct in_addr addr; #if IS_ENABLED(CONFIG_MPTCP_IPV6) struct in6_addr addr6; #endif }; }; enum mptcp_pm_status { MPTCP_PM_ADD_ADDR_RECEIVED, MPTCP_PM_ESTABLISHED, MPTCP_PM_SUBFLOW_ESTABLISHED, }; struct mptcp_pm_data { struct mptcp_addr_info local; struct mptcp_addr_info remote; spinlock_t lock; /*protects the whole PM data */ bool addr_signal; bool server_side; bool work_pending; bool accept_addr; bool accept_subflow; u8 add_addr_signaled; u8 add_addr_accepted; u8 local_addr_used; u8 subflows; u8 add_addr_signal_max; u8 add_addr_accept_max; u8 local_addr_max; u8 subflows_max; u8 status; }; struct mptcp_data_frag { struct list_head list; u64 data_seq; int data_len; int offset; int overhead; struct page *page; }; /* MPTCP connection sock */ struct mptcp_sock { /* inet_connection_sock must be the first member */ struct inet_connection_sock sk; u64 local_key; u64 remote_key; u64 write_seq; u64 ack_seq; atomic64_t snd_una; unsigned long timer_ival; u32 token; unsigned long flags; bool can_ack; spinlock_t join_list_lock; struct work_struct work; struct list_head conn_list; struct list_head rtx_queue; struct list_head join_list; struct skb_ext *cached_ext; /* for the next sendmsg */ struct socket *subflow; /* outgoing connect/listener/!mp_capable */ struct sock *first; struct mptcp_pm_data pm; struct { u32 space; /* bytes copied in last measurement window */ u32 copied; /* bytes copied in this measurement window */ u64 time; /* start time of measurement window */ u64 rtt_us; /* last maximum rtt of subflows */ } rcvq_space; }; #define mptcp_for_each_subflow(__msk, __subflow) \ list_for_each_entry(__subflow, &((__msk)->conn_list), node) static inline struct mptcp_sock *mptcp_sk(const struct sock *sk) { return (struct mptcp_sock *)sk; } static inline struct mptcp_data_frag *mptcp_rtx_tail(const struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); if (list_empty(&msk->rtx_queue)) return NULL; return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list); } static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list); } struct mptcp_subflow_request_sock { struct tcp_request_sock sk; u16 mp_capable : 1, mp_join : 1, backup : 1; u8 local_id; u8 remote_id; u64 local_key; u64 idsn; u32 token; u32 ssn_offset; u64 thmac; u32 local_nonce; u32 remote_nonce; struct mptcp_sock *msk; struct hlist_nulls_node token_node; }; static inline struct mptcp_subflow_request_sock * mptcp_subflow_rsk(const struct request_sock *rsk) { return (struct mptcp_subflow_request_sock *)rsk; } /* MPTCP subflow context */ struct mptcp_subflow_context { struct list_head node;/* conn_list of subflows */ u64 local_key; u64 remote_key; u64 idsn; u64 map_seq; u32 snd_isn; u32 token; u32 rel_write_seq; u32 map_subflow_seq; u32 ssn_offset; u32 map_data_len; u32 request_mptcp : 1, /* send MP_CAPABLE */ request_join : 1, /* send MP_JOIN */ request_bkup : 1, mp_capable : 1, /* remote is MPTCP capable */ mp_join : 1, /* remote is JOINing */ fully_established : 1, /* path validated */ pm_notified : 1, /* PM hook called for established status */ conn_finished : 1, map_valid : 1, mpc_map : 1, backup : 1, data_avail : 1, rx_eof : 1, data_fin_tx_enable : 1, use_64bit_ack : 1, /* Set when we received a 64-bit DSN */ can_ack : 1; /* only after processing the remote a key */ u64 data_fin_tx_seq; u32 remote_nonce; u64 thmac; u32 local_nonce; u32 remote_token; u8 hmac[MPTCPOPT_HMAC_LEN]; u8 local_id; u8 remote_id; struct sock *tcp_sock; /* tcp sk backpointer */ struct sock *conn; /* parent mptcp_sock */ const struct inet_connection_sock_af_ops *icsk_af_ops; void (*tcp_data_ready)(struct sock *sk); void (*tcp_state_change)(struct sock *sk); void (*tcp_write_space)(struct sock *sk); struct rcu_head rcu; }; static inline struct mptcp_subflow_context * mptcp_subflow_ctx(const struct sock *sk) { struct inet_connection_sock *icsk = inet_csk(sk); /* Use RCU on icsk_ulp_data only for sock diag code */ return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data; } static inline struct sock * mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow) { return subflow->tcp_sock; } static inline u64 mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow) { return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq - subflow->ssn_offset - subflow->map_subflow_seq; } static inline u64 mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow) { return subflow->map_seq + mptcp_subflow_get_map_offset(subflow); } int mptcp_is_enabled(struct net *net); bool mptcp_subflow_data_available(struct sock *sk); void __init mptcp_subflow_init(void); /* called with sk socket lock held */ int __mptcp_subflow_connect(struct sock *sk, int ifindex, const struct mptcp_addr_info *loc, const struct mptcp_addr_info *remote); int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock); static inline void mptcp_subflow_tcp_fallback(struct sock *sk, struct mptcp_subflow_context *ctx) { sk->sk_data_ready = ctx->tcp_data_ready; sk->sk_state_change = ctx->tcp_state_change; sk->sk_write_space = ctx->tcp_write_space; inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops; } void __init mptcp_proto_init(void); #if IS_ENABLED(CONFIG_MPTCP_IPV6) int __init mptcp_proto_v6_init(void); #endif struct sock *mptcp_sk_clone(const struct sock *sk, const struct mptcp_options_received *mp_opt, struct request_sock *req); void mptcp_get_options(const struct sk_buff *skb, struct mptcp_options_received *mp_opt); void mptcp_finish_connect(struct sock *sk); void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk); void mptcp_data_ready(struct sock *sk, struct sock *ssk); bool mptcp_finish_join(struct sock *sk); void mptcp_data_acked(struct sock *sk); void mptcp_subflow_eof(struct sock *sk); void __init mptcp_token_init(void); static inline void mptcp_token_init_request(struct request_sock *req) { mptcp_subflow_rsk(req)->token_node.pprev = NULL; } int mptcp_token_new_request(struct request_sock *req); void mptcp_token_destroy_request(struct request_sock *req); int mptcp_token_new_connect(struct sock *sk); void mptcp_token_accept(struct mptcp_subflow_request_sock *r, struct mptcp_sock *msk); struct mptcp_sock *mptcp_token_get_sock(u32 token); struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot, long *s_num); void mptcp_token_destroy(struct mptcp_sock *msk); void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn); static inline void mptcp_crypto_key_gen_sha(u64 *key, u32 *token, u64 *idsn) { /* we might consider a faster version that computes the key as a * hash of some information available in the MPTCP socket. Use * random data at the moment, as it's probably the safest option * in case multiple sockets are opened in different namespaces at * the same time. */ get_random_bytes(key, sizeof(u64)); mptcp_crypto_key_sha(*key, token, idsn); } void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac); void __init mptcp_pm_init(void); void mptcp_pm_data_init(struct mptcp_sock *msk); void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side); void mptcp_pm_fully_established(struct mptcp_sock *msk); bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk); void mptcp_pm_connection_closed(struct mptcp_sock *msk); void mptcp_pm_subflow_established(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow); void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id); void mptcp_pm_add_addr_received(struct mptcp_sock *msk, const struct mptcp_addr_info *addr); int mptcp_pm_announce_addr(struct mptcp_sock *msk, const struct mptcp_addr_info *addr); int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id); int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 remote_id); static inline bool mptcp_pm_should_signal(struct mptcp_sock *msk) { return READ_ONCE(msk->pm.addr_signal); } static inline unsigned int mptcp_add_addr_len(int family) { if (family == AF_INET) return TCPOLEN_MPTCP_ADD_ADDR; return TCPOLEN_MPTCP_ADD_ADDR6; } bool mptcp_pm_addr_signal(struct mptcp_sock *msk, unsigned int remaining, struct mptcp_addr_info *saddr); int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc); void __init mptcp_pm_nl_init(void); void mptcp_pm_nl_data_init(struct mptcp_sock *msk); void mptcp_pm_nl_fully_established(struct mptcp_sock *msk); void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk); void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk); int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc); static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb) { return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP); } static inline bool before64(__u64 seq1, __u64 seq2) { return (__s64)(seq1 - seq2) < 0; } #define after64(seq2, seq1) before64(seq1, seq2) void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops); static inline bool __mptcp_check_fallback(struct mptcp_sock *msk) { return test_bit(MPTCP_FALLBACK_DONE, &msk->flags); } static inline bool mptcp_check_fallback(struct sock *sk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); struct mptcp_sock *msk = mptcp_sk(subflow->conn); return __mptcp_check_fallback(msk); } static inline void __mptcp_do_fallback(struct mptcp_sock *msk) { if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) { pr_debug("TCP fallback already done (msk=%p)", msk); return; } set_bit(MPTCP_FALLBACK_DONE, &msk->flags); } static inline void mptcp_do_fallback(struct sock *sk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); struct mptcp_sock *msk = mptcp_sk(subflow->conn); __mptcp_do_fallback(msk); } #define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a) static inline bool subflow_simultaneous_connect(struct sock *sk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); struct sock *parent = subflow->conn; return sk->sk_state == TCP_ESTABLISHED && !mptcp_sk(parent)->pm.server_side && !subflow->conn_finished; } #endif /* __MPTCP_PROTOCOL_H */