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-rw-r--r--net/mptcp/protocol.h240
1 files changed, 240 insertions, 0 deletions
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
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+++ 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 */