linux/net/mptcp/protocol.h
<<
>>
Prefs
   1/* SPDX-License-Identifier: GPL-2.0 */
   2/* Multipath TCP
   3 *
   4 * Copyright (c) 2017 - 2019, Intel Corporation.
   5 */
   6
   7#ifndef __MPTCP_PROTOCOL_H
   8#define __MPTCP_PROTOCOL_H
   9
  10#include <linux/random.h>
  11#include <net/tcp.h>
  12#include <net/inet_connection_sock.h>
  13#include <uapi/linux/mptcp.h>
  14
  15#define MPTCP_SUPPORTED_VERSION 1
  16
  17/* MPTCP option bits */
  18#define OPTION_MPTCP_MPC_SYN    BIT(0)
  19#define OPTION_MPTCP_MPC_SYNACK BIT(1)
  20#define OPTION_MPTCP_MPC_ACK    BIT(2)
  21#define OPTION_MPTCP_MPJ_SYN    BIT(3)
  22#define OPTION_MPTCP_MPJ_SYNACK BIT(4)
  23#define OPTION_MPTCP_MPJ_ACK    BIT(5)
  24#define OPTION_MPTCP_ADD_ADDR   BIT(6)
  25#define OPTION_MPTCP_RM_ADDR    BIT(7)
  26#define OPTION_MPTCP_FASTCLOSE  BIT(8)
  27#define OPTION_MPTCP_PRIO       BIT(9)
  28#define OPTION_MPTCP_RST        BIT(10)
  29#define OPTION_MPTCP_DSS        BIT(11)
  30#define OPTION_MPTCP_FAIL       BIT(12)
  31
  32#define OPTION_MPTCP_CSUMREQD   BIT(13)
  33
  34#define OPTIONS_MPTCP_MPC       (OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK | \
  35                                 OPTION_MPTCP_MPC_ACK)
  36#define OPTIONS_MPTCP_MPJ       (OPTION_MPTCP_MPJ_SYN | OPTION_MPTCP_MPJ_SYNACK | \
  37                                 OPTION_MPTCP_MPJ_ACK)
  38
  39/* MPTCP option subtypes */
  40#define MPTCPOPT_MP_CAPABLE     0
  41#define MPTCPOPT_MP_JOIN        1
  42#define MPTCPOPT_DSS            2
  43#define MPTCPOPT_ADD_ADDR       3
  44#define MPTCPOPT_RM_ADDR        4
  45#define MPTCPOPT_MP_PRIO        5
  46#define MPTCPOPT_MP_FAIL        6
  47#define MPTCPOPT_MP_FASTCLOSE   7
  48#define MPTCPOPT_RST            8
  49
  50/* MPTCP suboption lengths */
  51#define TCPOLEN_MPTCP_MPC_SYN           4
  52#define TCPOLEN_MPTCP_MPC_SYNACK        12
  53#define TCPOLEN_MPTCP_MPC_ACK           20
  54#define TCPOLEN_MPTCP_MPC_ACK_DATA      22
  55#define TCPOLEN_MPTCP_MPJ_SYN           12
  56#define TCPOLEN_MPTCP_MPJ_SYNACK        16
  57#define TCPOLEN_MPTCP_MPJ_ACK           24
  58#define TCPOLEN_MPTCP_DSS_BASE          4
  59#define TCPOLEN_MPTCP_DSS_ACK32         4
  60#define TCPOLEN_MPTCP_DSS_ACK64         8
  61#define TCPOLEN_MPTCP_DSS_MAP32         10
  62#define TCPOLEN_MPTCP_DSS_MAP64         14
  63#define TCPOLEN_MPTCP_DSS_CHECKSUM      2
  64#define TCPOLEN_MPTCP_ADD_ADDR          16
  65#define TCPOLEN_MPTCP_ADD_ADDR_PORT     18
  66#define TCPOLEN_MPTCP_ADD_ADDR_BASE     8
  67#define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT        10
  68#define TCPOLEN_MPTCP_ADD_ADDR6         28
  69#define TCPOLEN_MPTCP_ADD_ADDR6_PORT    30
  70#define TCPOLEN_MPTCP_ADD_ADDR6_BASE    20
  71#define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT       22
  72#define TCPOLEN_MPTCP_PORT_LEN          2
  73#define TCPOLEN_MPTCP_PORT_ALIGN        2
  74#define TCPOLEN_MPTCP_RM_ADDR_BASE      3
  75#define TCPOLEN_MPTCP_PRIO              3
  76#define TCPOLEN_MPTCP_PRIO_ALIGN        4
  77#define TCPOLEN_MPTCP_FASTCLOSE         12
  78#define TCPOLEN_MPTCP_RST               4
  79#define TCPOLEN_MPTCP_FAIL              12
  80
  81#define TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM (TCPOLEN_MPTCP_DSS_CHECKSUM + TCPOLEN_MPTCP_MPC_ACK_DATA)
  82
  83/* MPTCP MP_JOIN flags */
  84#define MPTCPOPT_BACKUP         BIT(0)
  85#define MPTCPOPT_HMAC_LEN       20
  86#define MPTCPOPT_THMAC_LEN      8
  87
  88/* MPTCP MP_CAPABLE flags */
  89#define MPTCP_VERSION_MASK      (0x0F)
  90#define MPTCP_CAP_CHECKSUM_REQD BIT(7)
  91#define MPTCP_CAP_EXTENSIBILITY BIT(6)
  92#define MPTCP_CAP_DENY_JOIN_ID0 BIT(5)
  93#define MPTCP_CAP_HMAC_SHA256   BIT(0)
  94#define MPTCP_CAP_FLAG_MASK     (0x1F)
  95
  96/* MPTCP DSS flags */
  97#define MPTCP_DSS_DATA_FIN      BIT(4)
  98#define MPTCP_DSS_DSN64         BIT(3)
  99#define MPTCP_DSS_HAS_MAP       BIT(2)
 100#define MPTCP_DSS_ACK64         BIT(1)
 101#define MPTCP_DSS_HAS_ACK       BIT(0)
 102#define MPTCP_DSS_FLAG_MASK     (0x1F)
 103
 104/* MPTCP ADD_ADDR flags */
 105#define MPTCP_ADDR_ECHO         BIT(0)
 106
 107/* MPTCP MP_PRIO flags */
 108#define MPTCP_PRIO_BKUP         BIT(0)
 109
 110/* MPTCP TCPRST flags */
 111#define MPTCP_RST_TRANSIENT     BIT(0)
 112
 113/* MPTCP socket flags */
 114#define MPTCP_DATA_READY        0
 115#define MPTCP_NOSPACE           1
 116#define MPTCP_WORK_RTX          2
 117#define MPTCP_WORK_EOF          3
 118#define MPTCP_FALLBACK_DONE     4
 119#define MPTCP_WORK_CLOSE_SUBFLOW 5
 120#define MPTCP_PUSH_PENDING      6
 121#define MPTCP_CLEAN_UNA         7
 122#define MPTCP_ERROR_REPORT      8
 123#define MPTCP_RETRANSMIT        9
 124#define MPTCP_WORK_SYNC_SETSOCKOPT 10
 125#define MPTCP_CONNECTED         11
 126
 127static inline bool before64(__u64 seq1, __u64 seq2)
 128{
 129        return (__s64)(seq1 - seq2) < 0;
 130}
 131
 132#define after64(seq2, seq1)     before64(seq1, seq2)
 133
 134struct mptcp_options_received {
 135        u64     sndr_key;
 136        u64     rcvr_key;
 137        u64     data_ack;
 138        u64     data_seq;
 139        u32     subflow_seq;
 140        u16     data_len;
 141        __sum16 csum;
 142        u16     suboptions;
 143        u32     token;
 144        u32     nonce;
 145        u16     use_map:1,
 146                dsn64:1,
 147                data_fin:1,
 148                use_ack:1,
 149                ack64:1,
 150                mpc_map:1,
 151                reset_reason:4,
 152                reset_transient:1,
 153                echo:1,
 154                backup:1,
 155                deny_join_id0:1,
 156                __unused:2;
 157        u8      join_id;
 158        u64     thmac;
 159        u8      hmac[MPTCPOPT_HMAC_LEN];
 160        struct mptcp_addr_info addr;
 161        struct mptcp_rm_list rm_list;
 162        u64     ahmac;
 163        u64     fail_seq;
 164};
 165
 166static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
 167{
 168        return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
 169                     ((nib & 0xF) << 8) | field);
 170}
 171
 172enum mptcp_pm_status {
 173        MPTCP_PM_ADD_ADDR_RECEIVED,
 174        MPTCP_PM_ADD_ADDR_SEND_ACK,
 175        MPTCP_PM_RM_ADDR_RECEIVED,
 176        MPTCP_PM_ESTABLISHED,
 177        MPTCP_PM_ALREADY_ESTABLISHED,   /* persistent status, set after ESTABLISHED event */
 178        MPTCP_PM_SUBFLOW_ESTABLISHED,
 179};
 180
 181enum mptcp_addr_signal_status {
 182        MPTCP_ADD_ADDR_SIGNAL,
 183        MPTCP_ADD_ADDR_ECHO,
 184        MPTCP_RM_ADDR_SIGNAL,
 185};
 186
 187struct mptcp_pm_data {
 188        struct mptcp_addr_info local;
 189        struct mptcp_addr_info remote;
 190        struct list_head anno_list;
 191
 192        spinlock_t      lock;           /*protects the whole PM data */
 193
 194        u8              addr_signal;
 195        bool            server_side;
 196        bool            work_pending;
 197        bool            accept_addr;
 198        bool            accept_subflow;
 199        bool            remote_deny_join_id0;
 200        u8              add_addr_signaled;
 201        u8              add_addr_accepted;
 202        u8              local_addr_used;
 203        u8              subflows;
 204        u8              status;
 205        struct mptcp_rm_list rm_list_tx;
 206        struct mptcp_rm_list rm_list_rx;
 207};
 208
 209struct mptcp_data_frag {
 210        struct list_head list;
 211        u64 data_seq;
 212        u16 data_len;
 213        u16 offset;
 214        u16 overhead;
 215        u16 already_sent;
 216        struct page *page;
 217};
 218
 219/* MPTCP connection sock */
 220struct mptcp_sock {
 221        /* inet_connection_sock must be the first member */
 222        struct inet_connection_sock sk;
 223        u64             local_key;
 224        u64             remote_key;
 225        u64             write_seq;
 226        u64             snd_nxt;
 227        u64             ack_seq;
 228        u64             rcv_wnd_sent;
 229        u64             rcv_data_fin_seq;
 230        int             wmem_reserved;
 231        struct sock     *last_snd;
 232        int             snd_burst;
 233        int             old_wspace;
 234        u64             recovery_snd_nxt;       /* in recovery mode accept up to this seq;
 235                                                 * recovery related fields are under data_lock
 236                                                 * protection
 237                                                 */
 238        u64             snd_una;
 239        u64             wnd_end;
 240        unsigned long   timer_ival;
 241        u32             token;
 242        int             rmem_released;
 243        unsigned long   flags;
 244        bool            recovery;               /* closing subflow write queue reinjected */
 245        bool            can_ack;
 246        bool            fully_established;
 247        bool            rcv_data_fin;
 248        bool            snd_data_fin_enable;
 249        bool            rcv_fastclose;
 250        bool            use_64bit_ack; /* Set when we received a 64-bit DSN */
 251        bool            csum_enabled;
 252        spinlock_t      join_list_lock;
 253        struct work_struct work;
 254        struct sk_buff  *ooo_last_skb;
 255        struct rb_root  out_of_order_queue;
 256        struct sk_buff_head receive_queue;
 257        int             tx_pending_data;
 258        struct list_head conn_list;
 259        struct list_head rtx_queue;
 260        struct mptcp_data_frag *first_pending;
 261        struct list_head join_list;
 262        struct socket   *subflow; /* outgoing connect/listener/!mp_capable */
 263        struct sock     *first;
 264        struct mptcp_pm_data    pm;
 265        struct {
 266                u32     space;  /* bytes copied in last measurement window */
 267                u32     copied; /* bytes copied in this measurement window */
 268                u64     time;   /* start time of measurement window */
 269                u64     rtt_us; /* last maximum rtt of subflows */
 270        } rcvq_space;
 271
 272        u32 setsockopt_seq;
 273        char            ca_name[TCP_CA_NAME_MAX];
 274};
 275
 276#define mptcp_lock_sock(___sk, cb) do {                                 \
 277        struct sock *__sk = (___sk); /* silence macro reuse warning */  \
 278        might_sleep();                                                  \
 279        spin_lock_bh(&__sk->sk_lock.slock);                             \
 280        if (__sk->sk_lock.owned)                                        \
 281                __lock_sock(__sk);                                      \
 282        cb;                                                             \
 283        __sk->sk_lock.owned = 1;                                        \
 284        spin_unlock(&__sk->sk_lock.slock);                              \
 285        mutex_acquire(&__sk->sk_lock.dep_map, 0, 0, _RET_IP_);          \
 286        local_bh_enable();                                              \
 287} while (0)
 288
 289#define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
 290#define mptcp_data_unlock(sk) spin_unlock_bh(&(sk)->sk_lock.slock)
 291
 292#define mptcp_for_each_subflow(__msk, __subflow)                        \
 293        list_for_each_entry(__subflow, &((__msk)->conn_list), node)
 294
 295static inline void msk_owned_by_me(const struct mptcp_sock *msk)
 296{
 297        sock_owned_by_me((const struct sock *)msk);
 298}
 299
 300static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
 301{
 302        return (struct mptcp_sock *)sk;
 303}
 304
 305/* the msk socket don't use the backlog, also account for the bulk
 306 * free memory
 307 */
 308static inline int __mptcp_rmem(const struct sock *sk)
 309{
 310        return atomic_read(&sk->sk_rmem_alloc) - READ_ONCE(mptcp_sk(sk)->rmem_released);
 311}
 312
 313static inline int __mptcp_space(const struct sock *sk)
 314{
 315        return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - __mptcp_rmem(sk));
 316}
 317
 318static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
 319{
 320        const struct mptcp_sock *msk = mptcp_sk(sk);
 321
 322        return READ_ONCE(msk->first_pending);
 323}
 324
 325static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
 326{
 327        struct mptcp_sock *msk = mptcp_sk(sk);
 328        struct mptcp_data_frag *cur;
 329
 330        cur = msk->first_pending;
 331        return list_is_last(&cur->list, &msk->rtx_queue) ? NULL :
 332                                                     list_next_entry(cur, list);
 333}
 334
 335static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
 336{
 337        struct mptcp_sock *msk = mptcp_sk(sk);
 338
 339        if (!msk->first_pending)
 340                return NULL;
 341
 342        if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
 343                return NULL;
 344
 345        return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
 346}
 347
 348static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
 349{
 350        struct mptcp_sock *msk = mptcp_sk(sk);
 351
 352        if (msk->snd_una == READ_ONCE(msk->snd_nxt))
 353                return NULL;
 354
 355        return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
 356}
 357
 358struct csum_pseudo_header {
 359        __be64 data_seq;
 360        __be32 subflow_seq;
 361        __be16 data_len;
 362        __sum16 csum;
 363};
 364
 365struct mptcp_subflow_request_sock {
 366        struct  tcp_request_sock sk;
 367        u16     mp_capable : 1,
 368                mp_join : 1,
 369                backup : 1,
 370                csum_reqd : 1,
 371                allow_join_id0 : 1;
 372        u8      local_id;
 373        u8      remote_id;
 374        u64     local_key;
 375        u64     idsn;
 376        u32     token;
 377        u32     ssn_offset;
 378        u64     thmac;
 379        u32     local_nonce;
 380        u32     remote_nonce;
 381        struct mptcp_sock       *msk;
 382        struct hlist_nulls_node token_node;
 383};
 384
 385static inline struct mptcp_subflow_request_sock *
 386mptcp_subflow_rsk(const struct request_sock *rsk)
 387{
 388        return (struct mptcp_subflow_request_sock *)rsk;
 389}
 390
 391enum mptcp_data_avail {
 392        MPTCP_SUBFLOW_NODATA,
 393        MPTCP_SUBFLOW_DATA_AVAIL,
 394};
 395
 396struct mptcp_delegated_action {
 397        struct napi_struct napi;
 398        struct list_head head;
 399};
 400
 401DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
 402
 403#define MPTCP_DELEGATE_SEND             0
 404
 405/* MPTCP subflow context */
 406struct mptcp_subflow_context {
 407        struct  list_head node;/* conn_list of subflows */
 408        u64     local_key;
 409        u64     remote_key;
 410        u64     idsn;
 411        u64     map_seq;
 412        u32     snd_isn;
 413        u32     token;
 414        u32     rel_write_seq;
 415        u32     map_subflow_seq;
 416        u32     ssn_offset;
 417        u32     map_data_len;
 418        __wsum  map_data_csum;
 419        u32     map_csum_len;
 420        u32     request_mptcp : 1,  /* send MP_CAPABLE */
 421                request_join : 1,   /* send MP_JOIN */
 422                request_bkup : 1,
 423                mp_capable : 1,     /* remote is MPTCP capable */
 424                mp_join : 1,        /* remote is JOINing */
 425                fully_established : 1,      /* path validated */
 426                pm_notified : 1,    /* PM hook called for established status */
 427                conn_finished : 1,
 428                map_valid : 1,
 429                map_csum_reqd : 1,
 430                map_data_fin : 1,
 431                mpc_map : 1,
 432                backup : 1,
 433                send_mp_prio : 1,
 434                send_mp_fail : 1,
 435                rx_eof : 1,
 436                can_ack : 1,        /* only after processing the remote a key */
 437                disposable : 1,     /* ctx can be free at ulp release time */
 438                stale : 1;          /* unable to snd/rcv data, do not use for xmit */
 439        enum mptcp_data_avail data_avail;
 440        u32     remote_nonce;
 441        u64     thmac;
 442        u32     local_nonce;
 443        u32     remote_token;
 444        u8      hmac[MPTCPOPT_HMAC_LEN];
 445        u8      local_id;
 446        u8      remote_id;
 447        u8      reset_seen:1;
 448        u8      reset_transient:1;
 449        u8      reset_reason:4;
 450        u8      stale_count;
 451
 452        long    delegated_status;
 453        struct  list_head delegated_node;   /* link into delegated_action, protected by local BH */
 454
 455        u32     setsockopt_seq;
 456        u32     stale_rcv_tstamp;
 457
 458        struct  sock *tcp_sock;     /* tcp sk backpointer */
 459        struct  sock *conn;         /* parent mptcp_sock */
 460        const   struct inet_connection_sock_af_ops *icsk_af_ops;
 461        void    (*tcp_data_ready)(struct sock *sk);
 462        void    (*tcp_state_change)(struct sock *sk);
 463        void    (*tcp_write_space)(struct sock *sk);
 464        void    (*tcp_error_report)(struct sock *sk);
 465
 466        struct  rcu_head rcu;
 467};
 468
 469static inline struct mptcp_subflow_context *
 470mptcp_subflow_ctx(const struct sock *sk)
 471{
 472        struct inet_connection_sock *icsk = inet_csk(sk);
 473
 474        /* Use RCU on icsk_ulp_data only for sock diag code */
 475        return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
 476}
 477
 478static inline struct sock *
 479mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
 480{
 481        return subflow->tcp_sock;
 482}
 483
 484static inline u64
 485mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
 486{
 487        return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
 488                      subflow->ssn_offset -
 489                      subflow->map_subflow_seq;
 490}
 491
 492static inline u64
 493mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
 494{
 495        return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
 496}
 497
 498static inline void mptcp_add_pending_subflow(struct mptcp_sock *msk,
 499                                             struct mptcp_subflow_context *subflow)
 500{
 501        sock_hold(mptcp_subflow_tcp_sock(subflow));
 502        spin_lock_bh(&msk->join_list_lock);
 503        list_add_tail(&subflow->node, &msk->join_list);
 504        spin_unlock_bh(&msk->join_list_lock);
 505}
 506
 507void mptcp_subflow_process_delegated(struct sock *ssk);
 508
 509static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow)
 510{
 511        struct mptcp_delegated_action *delegated;
 512        bool schedule;
 513
 514        /* The implied barrier pairs with mptcp_subflow_delegated_done(), and
 515         * ensures the below list check sees list updates done prior to status
 516         * bit changes
 517         */
 518        if (!test_and_set_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status)) {
 519                /* still on delegated list from previous scheduling */
 520                if (!list_empty(&subflow->delegated_node))
 521                        return;
 522
 523                /* the caller held the subflow bh socket lock */
 524                lockdep_assert_in_softirq();
 525
 526                delegated = this_cpu_ptr(&mptcp_delegated_actions);
 527                schedule = list_empty(&delegated->head);
 528                list_add_tail(&subflow->delegated_node, &delegated->head);
 529                sock_hold(mptcp_subflow_tcp_sock(subflow));
 530                if (schedule)
 531                        napi_schedule(&delegated->napi);
 532        }
 533}
 534
 535static inline struct mptcp_subflow_context *
 536mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated)
 537{
 538        struct mptcp_subflow_context *ret;
 539
 540        if (list_empty(&delegated->head))
 541                return NULL;
 542
 543        ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node);
 544        list_del_init(&ret->delegated_node);
 545        return ret;
 546}
 547
 548static inline bool mptcp_subflow_has_delegated_action(const struct mptcp_subflow_context *subflow)
 549{
 550        return test_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status);
 551}
 552
 553static inline void mptcp_subflow_delegated_done(struct mptcp_subflow_context *subflow)
 554{
 555        /* pairs with mptcp_subflow_delegate, ensures delegate_node is updated before
 556         * touching the status bit
 557         */
 558        smp_wmb();
 559        clear_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status);
 560}
 561
 562int mptcp_is_enabled(const struct net *net);
 563unsigned int mptcp_get_add_addr_timeout(const struct net *net);
 564int mptcp_is_checksum_enabled(const struct net *net);
 565int mptcp_allow_join_id0(const struct net *net);
 566unsigned int mptcp_stale_loss_cnt(const struct net *net);
 567void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
 568                                     struct mptcp_options_received *mp_opt);
 569bool __mptcp_retransmit_pending_data(struct sock *sk);
 570void __mptcp_push_pending(struct sock *sk, unsigned int flags);
 571bool mptcp_subflow_data_available(struct sock *sk);
 572void __init mptcp_subflow_init(void);
 573void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
 574void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
 575                     struct mptcp_subflow_context *subflow);
 576void mptcp_subflow_send_ack(struct sock *ssk);
 577void mptcp_subflow_reset(struct sock *ssk);
 578void mptcp_sock_graft(struct sock *sk, struct socket *parent);
 579struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk);
 580
 581/* called with sk socket lock held */
 582int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
 583                            const struct mptcp_addr_info *remote);
 584int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
 585void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
 586                         struct sockaddr_storage *addr,
 587                         unsigned short family);
 588
 589static inline bool __mptcp_subflow_active(struct mptcp_subflow_context *subflow)
 590{
 591        struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 592
 593        /* can't send if JOIN hasn't completed yet (i.e. is usable for mptcp) */
 594        if (subflow->request_join && !subflow->fully_established)
 595                return false;
 596
 597        /* only send if our side has not closed yet */
 598        return ((1 << ssk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT));
 599}
 600
 601void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow);
 602
 603bool mptcp_subflow_active(struct mptcp_subflow_context *subflow);
 604
 605static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
 606                                              struct mptcp_subflow_context *ctx)
 607{
 608        sk->sk_data_ready = ctx->tcp_data_ready;
 609        sk->sk_state_change = ctx->tcp_state_change;
 610        sk->sk_write_space = ctx->tcp_write_space;
 611        sk->sk_error_report = ctx->tcp_error_report;
 612
 613        inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
 614}
 615
 616static inline bool mptcp_has_another_subflow(struct sock *ssk)
 617{
 618        struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk), *tmp;
 619        struct mptcp_sock *msk = mptcp_sk(subflow->conn);
 620
 621        mptcp_for_each_subflow(msk, tmp) {
 622                if (tmp != subflow)
 623                        return true;
 624        }
 625
 626        return false;
 627}
 628
 629void __init mptcp_proto_init(void);
 630#if IS_ENABLED(CONFIG_MPTCP_IPV6)
 631int __init mptcp_proto_v6_init(void);
 632#endif
 633
 634struct sock *mptcp_sk_clone(const struct sock *sk,
 635                            const struct mptcp_options_received *mp_opt,
 636                            struct request_sock *req);
 637void mptcp_get_options(const struct sock *sk,
 638                       const struct sk_buff *skb,
 639                       struct mptcp_options_received *mp_opt);
 640
 641void mptcp_finish_connect(struct sock *sk);
 642void __mptcp_set_connected(struct sock *sk);
 643static inline bool mptcp_is_fully_established(struct sock *sk)
 644{
 645        return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
 646               READ_ONCE(mptcp_sk(sk)->fully_established);
 647}
 648void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
 649void mptcp_data_ready(struct sock *sk, struct sock *ssk);
 650bool mptcp_finish_join(struct sock *sk);
 651bool mptcp_schedule_work(struct sock *sk);
 652int mptcp_setsockopt(struct sock *sk, int level, int optname,
 653                     sockptr_t optval, unsigned int optlen);
 654int mptcp_getsockopt(struct sock *sk, int level, int optname,
 655                     char __user *optval, int __user *option);
 656
 657u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq);
 658static inline u64 mptcp_expand_seq(u64 old_seq, u64 cur_seq, bool use_64bit)
 659{
 660        if (use_64bit)
 661                return cur_seq;
 662
 663        return __mptcp_expand_seq(old_seq, cur_seq);
 664}
 665void __mptcp_check_push(struct sock *sk, struct sock *ssk);
 666void __mptcp_data_acked(struct sock *sk);
 667void __mptcp_error_report(struct sock *sk);
 668void mptcp_subflow_eof(struct sock *sk);
 669bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
 670void __mptcp_flush_join_list(struct mptcp_sock *msk);
 671static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
 672{
 673        return READ_ONCE(msk->snd_data_fin_enable) &&
 674               READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
 675}
 676
 677static inline bool mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
 678{
 679        if ((sk->sk_userlocks & SOCK_SNDBUF_LOCK) || ssk->sk_sndbuf <= READ_ONCE(sk->sk_sndbuf))
 680                return false;
 681
 682        WRITE_ONCE(sk->sk_sndbuf, ssk->sk_sndbuf);
 683        return true;
 684}
 685
 686static inline void mptcp_write_space(struct sock *sk)
 687{
 688        if (sk_stream_is_writeable(sk)) {
 689                /* pairs with memory barrier in mptcp_poll */
 690                smp_mb();
 691                if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags))
 692                        sk_stream_write_space(sk);
 693        }
 694}
 695
 696void mptcp_destroy_common(struct mptcp_sock *msk);
 697
 698#define MPTCP_TOKEN_MAX_RETRIES 4
 699
 700void __init mptcp_token_init(void);
 701static inline void mptcp_token_init_request(struct request_sock *req)
 702{
 703        mptcp_subflow_rsk(req)->token_node.pprev = NULL;
 704}
 705
 706int mptcp_token_new_request(struct request_sock *req);
 707void mptcp_token_destroy_request(struct request_sock *req);
 708int mptcp_token_new_connect(struct sock *sk);
 709void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
 710                        struct mptcp_sock *msk);
 711bool mptcp_token_exists(u32 token);
 712struct mptcp_sock *mptcp_token_get_sock(struct net *net, u32 token);
 713struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
 714                                         long *s_num);
 715void mptcp_token_destroy(struct mptcp_sock *msk);
 716
 717void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
 718
 719void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
 720
 721void __init mptcp_pm_init(void);
 722void mptcp_pm_data_init(struct mptcp_sock *msk);
 723void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
 724void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
 725void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);
 726void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk, gfp_t gfp);
 727bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
 728void mptcp_pm_connection_closed(struct mptcp_sock *msk);
 729void mptcp_pm_subflow_established(struct mptcp_sock *msk);
 730void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
 731void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
 732                                const struct mptcp_addr_info *addr);
 733void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
 734                              struct mptcp_addr_info *addr);
 735void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
 736void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk);
 737void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
 738                               const struct mptcp_rm_list *rm_list);
 739void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
 740int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 741                                 struct mptcp_addr_info *addr,
 742                                 u8 bkup);
 743void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
 744void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
 745bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
 746struct mptcp_pm_add_entry *
 747mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 748                       struct mptcp_addr_info *addr, bool check_id);
 749struct mptcp_pm_add_entry *
 750mptcp_lookup_anno_list_by_saddr(struct mptcp_sock *msk,
 751                                struct mptcp_addr_info *addr);
 752int mptcp_pm_get_flags_and_ifindex_by_id(struct net *net, unsigned int id,
 753                                         u8 *flags, int *ifindex);
 754
 755int mptcp_pm_announce_addr(struct mptcp_sock *msk,
 756                           const struct mptcp_addr_info *addr,
 757                           bool echo);
 758int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
 759int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
 760
 761void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
 762                 const struct sock *ssk, gfp_t gfp);
 763void mptcp_event_addr_announced(const struct mptcp_sock *msk, const struct mptcp_addr_info *info);
 764void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id);
 765
 766static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
 767{
 768        return READ_ONCE(msk->pm.addr_signal) &
 769                (BIT(MPTCP_ADD_ADDR_SIGNAL) | BIT(MPTCP_ADD_ADDR_ECHO));
 770}
 771
 772static inline bool mptcp_pm_should_add_signal_addr(struct mptcp_sock *msk)
 773{
 774        return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
 775}
 776
 777static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
 778{
 779        return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
 780}
 781
 782static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
 783{
 784        return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
 785}
 786
 787static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
 788{
 789        u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
 790
 791        if (family == AF_INET6)
 792                len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
 793        if (!echo)
 794                len += MPTCPOPT_THMAC_LEN;
 795        /* account for 2 trailing 'nop' options */
 796        if (port)
 797                len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
 798
 799        return len;
 800}
 801
 802static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
 803{
 804        if (rm_list->nr == 0 || rm_list->nr > MPTCP_RM_IDS_MAX)
 805                return -EINVAL;
 806
 807        return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1;
 808}
 809
 810bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, struct sk_buff *skb,
 811                              unsigned int opt_size, unsigned int remaining,
 812                              struct mptcp_addr_info *addr, bool *echo,
 813                              bool *port, bool *drop_other_suboptions);
 814bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 815                             struct mptcp_rm_list *rm_list);
 816int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
 817
 818void __init mptcp_pm_nl_init(void);
 819void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
 820void mptcp_pm_nl_work(struct mptcp_sock *msk);
 821void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
 822                                     const struct mptcp_rm_list *rm_list);
 823int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
 824unsigned int mptcp_pm_get_add_addr_signal_max(struct mptcp_sock *msk);
 825unsigned int mptcp_pm_get_add_addr_accept_max(struct mptcp_sock *msk);
 826unsigned int mptcp_pm_get_subflows_max(struct mptcp_sock *msk);
 827unsigned int mptcp_pm_get_local_addr_max(struct mptcp_sock *msk);
 828
 829void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk);
 830void mptcp_sockopt_sync_all(struct mptcp_sock *msk);
 831
 832static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb)
 833{
 834        return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
 835}
 836
 837void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
 838
 839static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
 840{
 841        return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
 842}
 843
 844static inline bool mptcp_check_fallback(const struct sock *sk)
 845{
 846        struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 847        struct mptcp_sock *msk = mptcp_sk(subflow->conn);
 848
 849        return __mptcp_check_fallback(msk);
 850}
 851
 852static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
 853{
 854        if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
 855                pr_debug("TCP fallback already done (msk=%p)", msk);
 856                return;
 857        }
 858        set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
 859}
 860
 861static inline void mptcp_do_fallback(struct sock *sk)
 862{
 863        struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 864        struct mptcp_sock *msk = mptcp_sk(subflow->conn);
 865
 866        __mptcp_do_fallback(msk);
 867}
 868
 869#define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
 870
 871static inline bool subflow_simultaneous_connect(struct sock *sk)
 872{
 873        struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 874        struct sock *parent = subflow->conn;
 875
 876        return sk->sk_state == TCP_ESTABLISHED &&
 877               !mptcp_sk(parent)->pm.server_side &&
 878               !subflow->conn_finished;
 879}
 880
 881#ifdef CONFIG_SYN_COOKIES
 882void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
 883                                       struct sk_buff *skb);
 884bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
 885                                        struct sk_buff *skb);
 886void __init mptcp_join_cookie_init(void);
 887#else
 888static inline void
 889subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
 890                                  struct sk_buff *skb) {}
 891static inline bool
 892mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
 893                                   struct sk_buff *skb)
 894{
 895        return false;
 896}
 897
 898static inline void mptcp_join_cookie_init(void) {}
 899#endif
 900
 901#endif /* __MPTCP_PROTOCOL_H */
 902