diff options
Diffstat (limited to 'net/mptcp/protocol.h')
| -rw-r--r-- | net/mptcp/protocol.h | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h new file mode 100644 index 000000000000..8a99a2930284 --- /dev/null +++ b/net/mptcp/protocol.h @@ -0,0 +1,240 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Multipath TCP + * + * Copyright (c) 2017 - 2019, Intel Corporation. + */ + +#ifndef __MPTCP_PROTOCOL_H +#define __MPTCP_PROTOCOL_H + +#include <linux/random.h> +#include <net/tcp.h> +#include <net/inet_connection_sock.h> + +#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) + +/* 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_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 + +/* 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 socket flags */ +#define MPTCP_DATA_READY BIT(0) +#define MPTCP_SEND_SPACE BIT(1) + +/* 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; + u32 token; + unsigned long flags; + bool can_ack; + struct list_head conn_list; + struct skb_ext *cached_ext; /* for the next sendmsg */ + struct socket *subflow; /* outgoing connect/listener/!mp_capable */ + struct sock *first; +}; + +#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; +} + +struct mptcp_subflow_request_sock { + struct tcp_request_sock sk; + u16 mp_capable : 1, + mp_join : 1, + backup : 1, + remote_key_valid : 1; + u64 local_key; + u64 remote_key; + u64 idsn; + u32 token; + u32 ssn_offset; +}; + +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 */ + mp_capable : 1, /* remote is MPTCP capable */ + fourth_ack : 1, /* send initial DSS */ + conn_finished : 1, + map_valid : 1, + mpc_map : 1, + data_avail : 1, + rx_eof : 1, + can_ack : 1; /* only after processing the remote a key */ + + 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 mptcp_subflow_init(void); +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; +} + +extern const struct inet_connection_sock_af_ops ipv4_specific; +#if IS_ENABLED(CONFIG_MPTCP_IPV6) +extern const struct inet_connection_sock_af_ops ipv6_specific; +#endif + +void mptcp_proto_init(void); +#if IS_ENABLED(CONFIG_MPTCP_IPV6) +int mptcp_proto_v6_init(void); +#endif + +struct mptcp_read_arg { + struct msghdr *msg; +}; + +int mptcp_read_actor(read_descriptor_t *desc, struct sk_buff *skb, + unsigned int offset, size_t len); + +void mptcp_get_options(const struct sk_buff *skb, + struct tcp_options_received *opt_rx); + +void mptcp_finish_connect(struct sock *sk); + +int mptcp_token_new_request(struct request_sock *req); +void mptcp_token_destroy_request(u32 token); +int mptcp_token_new_connect(struct sock *sk); +int mptcp_token_new_accept(u32 token); +void mptcp_token_update_accept(struct sock *sk, struct sock *conn); +void mptcp_token_destroy(u32 token); + +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, u32 nonce1, u32 nonce2, + void *hash_out); + +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) + +#endif /* __MPTCP_PROTOCOL_H */ |