mirror of
https://github.com/torvalds/linux.git
synced 2024-11-22 20:22:09 +00:00
8ab183deb2
With MPTCP v1, passive connections can fallback to TCP after the subflow becomes established: syn + MP_CAPABLE -> <- syn, ack + MP_CAPABLE ack, seq = 3 -> // OoO packet is accepted because in-sequence // passive socket is created, is in ESTABLISHED // status and tentatively as MP_CAPABLE ack, seq = 2 -> // no MP_CAPABLE opt, subflow should fallback to TCP We can't use the 'subflow' socket fallback, as we don't have it available for passive connection. Instead, when the fallback is detected, replace the mptcp socket with the underlying TCP subflow. Beyond covering the above scenario, it makes a TCP fallback socket as efficient as plain TCP ones. Co-developed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Christoph Paasch <cpaasch@apple.com> Signed-off-by: David S. Miller <davem@davemloft.net>
241 lines
6.4 KiB
C
241 lines
6.4 KiB
C
/* 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 */
|