linux/net/mptcp/protocol.h
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   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
  30/* MPTCP option subtypes */
  31#define MPTCPOPT_MP_CAPABLE     0
  32#define MPTCPOPT_MP_JOIN        1
  33#define MPTCPOPT_DSS            2
  34#define MPTCPOPT_ADD_ADDR       3
  35#define MPTCPOPT_RM_ADDR        4
  36#define MPTCPOPT_MP_PRIO        5
  37#define MPTCPOPT_MP_FAIL        6
  38#define MPTCPOPT_MP_FASTCLOSE   7
  39#define MPTCPOPT_RST            8
  40
  41/* MPTCP suboption lengths */
  42#define TCPOLEN_MPTCP_MPC_SYN           4
  43#define TCPOLEN_MPTCP_MPC_SYNACK        12
  44#define TCPOLEN_MPTCP_MPC_ACK           20
  45#define TCPOLEN_MPTCP_MPC_ACK_DATA      22
  46#define TCPOLEN_MPTCP_MPJ_SYN           12
  47#define TCPOLEN_MPTCP_MPJ_SYNACK        16
  48#define TCPOLEN_MPTCP_MPJ_ACK           24
  49#define TCPOLEN_MPTCP_DSS_BASE          4
  50#define TCPOLEN_MPTCP_DSS_ACK32         4
  51#define TCPOLEN_MPTCP_DSS_ACK64         8
  52#define TCPOLEN_MPTCP_DSS_MAP32         10
  53#define TCPOLEN_MPTCP_DSS_MAP64         14
  54#define TCPOLEN_MPTCP_DSS_CHECKSUM      2
  55#define TCPOLEN_MPTCP_ADD_ADDR          16
  56#define TCPOLEN_MPTCP_ADD_ADDR_PORT     18
  57#define TCPOLEN_MPTCP_ADD_ADDR_BASE     8
  58#define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT        10
  59#define TCPOLEN_MPTCP_ADD_ADDR6         28
  60#define TCPOLEN_MPTCP_ADD_ADDR6_PORT    30
  61#define TCPOLEN_MPTCP_ADD_ADDR6_BASE    20
  62#define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT       22
  63#define TCPOLEN_MPTCP_PORT_LEN          2
  64#define TCPOLEN_MPTCP_PORT_ALIGN        2
  65#define TCPOLEN_MPTCP_RM_ADDR_BASE      3
  66#define TCPOLEN_MPTCP_PRIO              3
  67#define TCPOLEN_MPTCP_PRIO_ALIGN        4
  68#define TCPOLEN_MPTCP_FASTCLOSE         12
  69#define TCPOLEN_MPTCP_RST               4
  70
  71#define TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM (TCPOLEN_MPTCP_DSS_CHECKSUM + TCPOLEN_MPTCP_MPC_ACK_DATA)
  72
  73/* MPTCP MP_JOIN flags */
  74#define MPTCPOPT_BACKUP         BIT(0)
  75#define MPTCPOPT_HMAC_LEN       20
  76#define MPTCPOPT_THMAC_LEN      8
  77
  78/* MPTCP MP_CAPABLE flags */
  79#define MPTCP_VERSION_MASK      (0x0F)
  80#define MPTCP_CAP_CHECKSUM_REQD BIT(7)
  81#define MPTCP_CAP_EXTENSIBILITY BIT(6)
  82#define MPTCP_CAP_DENY_JOIN_ID0 BIT(5)
  83#define MPTCP_CAP_HMAC_SHA256   BIT(0)
  84#define MPTCP_CAP_FLAG_MASK     (0x1F)
  85
  86/* MPTCP DSS flags */
  87#define MPTCP_DSS_DATA_FIN      BIT(4)
  88#define MPTCP_DSS_DSN64         BIT(3)
  89#define MPTCP_DSS_HAS_MAP       BIT(2)
  90#define MPTCP_DSS_ACK64         BIT(1)
  91#define MPTCP_DSS_HAS_ACK       BIT(0)
  92#define MPTCP_DSS_FLAG_MASK     (0x1F)
  93
  94/* MPTCP ADD_ADDR flags */
  95#define MPTCP_ADDR_ECHO         BIT(0)
  96
  97/* MPTCP MP_PRIO flags */
  98#define MPTCP_PRIO_BKUP         BIT(0)
  99
 100/* MPTCP TCPRST flags */
 101#define MPTCP_RST_TRANSIENT     BIT(0)
 102
 103/* MPTCP socket flags */
 104#define MPTCP_DATA_READY        0
 105#define MPTCP_NOSPACE           1
 106#define MPTCP_WORK_RTX          2
 107#define MPTCP_WORK_EOF          3
 108#define MPTCP_FALLBACK_DONE     4
 109#define MPTCP_WORK_CLOSE_SUBFLOW 5
 110#define MPTCP_PUSH_PENDING      6
 111#define MPTCP_CLEAN_UNA         7
 112#define MPTCP_ERROR_REPORT      8
 113#define MPTCP_RETRANSMIT        9
 114#define MPTCP_WORK_SYNC_SETSOCKOPT 10
 115#define MPTCP_CONNECTED         11
 116
 117static inline bool before64(__u64 seq1, __u64 seq2)
 118{
 119        return (__s64)(seq1 - seq2) < 0;
 120}
 121
 122#define after64(seq2, seq1)     before64(seq1, seq2)
 123
 124struct mptcp_options_received {
 125        u64     sndr_key;
 126        u64     rcvr_key;
 127        u64     data_ack;
 128        u64     data_seq;
 129        u32     subflow_seq;
 130        u16     data_len;
 131        __sum16 csum;
 132        u16     mp_capable : 1,
 133                mp_join : 1,
 134                fastclose : 1,
 135                reset : 1,
 136                dss : 1,
 137                add_addr : 1,
 138                rm_addr : 1,
 139                mp_prio : 1,
 140                echo : 1,
 141                csum_reqd : 1,
 142                backup : 1,
 143                deny_join_id0 : 1;
 144        u32     token;
 145        u32     nonce;
 146        u64     thmac;
 147        u8      hmac[MPTCPOPT_HMAC_LEN];
 148        u8      join_id;
 149        u8      use_map:1,
 150                dsn64:1,
 151                data_fin:1,
 152                use_ack:1,
 153                ack64:1,
 154                mpc_map:1,
 155                __unused:2;
 156        struct mptcp_addr_info addr;
 157        struct mptcp_rm_list rm_list;
 158        u64     ahmac;
 159        u8      reset_reason:4;
 160        u8      reset_transient:1;
 161};
 162
 163static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
 164{
 165        return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
 166                     ((nib & 0xF) << 8) | field);
 167}
 168
 169enum mptcp_pm_status {
 170        MPTCP_PM_ADD_ADDR_RECEIVED,
 171        MPTCP_PM_ADD_ADDR_SEND_ACK,
 172        MPTCP_PM_RM_ADDR_RECEIVED,
 173        MPTCP_PM_ESTABLISHED,
 174        MPTCP_PM_ALREADY_ESTABLISHED,   /* persistent status, set after ESTABLISHED event */
 175        MPTCP_PM_SUBFLOW_ESTABLISHED,
 176};
 177
 178enum mptcp_addr_signal_status {
 179        MPTCP_ADD_ADDR_SIGNAL,
 180        MPTCP_ADD_ADDR_ECHO,
 181        MPTCP_ADD_ADDR_IPV6,
 182        MPTCP_ADD_ADDR_PORT,
 183        MPTCP_RM_ADDR_SIGNAL,
 184};
 185
 186struct mptcp_pm_data {
 187        struct mptcp_addr_info local;
 188        struct mptcp_addr_info remote;
 189        struct list_head anno_list;
 190
 191        spinlock_t      lock;           /*protects the whole PM data */
 192
 193        u8              addr_signal;
 194        bool            server_side;
 195        bool            work_pending;
 196        bool            accept_addr;
 197        bool            accept_subflow;
 198        bool            remote_deny_join_id0;
 199        u8              add_addr_signaled;
 200        u8              add_addr_accepted;
 201        u8              local_addr_used;
 202        u8              subflows;
 203        u8              status;
 204        struct mptcp_rm_list rm_list_tx;
 205        struct mptcp_rm_list rm_list_rx;
 206};
 207
 208struct mptcp_data_frag {
 209        struct list_head list;
 210        u64 data_seq;
 211        u16 data_len;
 212        u16 offset;
 213        u16 overhead;
 214        u16 already_sent;
 215        struct page *page;
 216};
 217
 218/* MPTCP connection sock */
 219struct mptcp_sock {
 220        /* inet_connection_sock must be the first member */
 221        struct inet_connection_sock sk;
 222        u64             local_key;
 223        u64             remote_key;
 224        u64             write_seq;
 225        u64             snd_nxt;
 226        u64             ack_seq;
 227        u64             rcv_wnd_sent;
 228        u64             rcv_data_fin_seq;
 229        int             wmem_reserved;
 230        struct sock     *last_snd;
 231        int             snd_burst;
 232        int             old_wspace;
 233        u64             snd_una;
 234        u64             wnd_end;
 235        unsigned long   timer_ival;
 236        u32             token;
 237        int             rmem_released;
 238        unsigned long   flags;
 239        bool            can_ack;
 240        bool            fully_established;
 241        bool            rcv_data_fin;
 242        bool            snd_data_fin_enable;
 243        bool            rcv_fastclose;
 244        bool            use_64bit_ack; /* Set when we received a 64-bit DSN */
 245        bool            csum_enabled;
 246        spinlock_t      join_list_lock;
 247        struct work_struct work;
 248        struct sk_buff  *ooo_last_skb;
 249        struct rb_root  out_of_order_queue;
 250        struct sk_buff_head receive_queue;
 251        int             tx_pending_data;
 252        struct list_head conn_list;
 253        struct list_head rtx_queue;
 254        struct mptcp_data_frag *first_pending;
 255        struct list_head join_list;
 256        struct socket   *subflow; /* outgoing connect/listener/!mp_capable */
 257        struct sock     *first;
 258        struct mptcp_pm_data    pm;
 259        struct {
 260                u32     space;  /* bytes copied in last measurement window */
 261                u32     copied; /* bytes copied in this measurement window */
 262                u64     time;   /* start time of measurement window */
 263                u64     rtt_us; /* last maximum rtt of subflows */
 264        } rcvq_space;
 265
 266        u32 setsockopt_seq;
 267        char            ca_name[TCP_CA_NAME_MAX];
 268};
 269
 270#define mptcp_lock_sock(___sk, cb) do {                                 \
 271        struct sock *__sk = (___sk); /* silence macro reuse warning */  \
 272        might_sleep();                                                  \
 273        spin_lock_bh(&__sk->sk_lock.slock);                             \
 274        if (__sk->sk_lock.owned)                                        \
 275                __lock_sock(__sk);                                      \
 276        cb;                                                             \
 277        __sk->sk_lock.owned = 1;                                        \
 278        spin_unlock(&__sk->sk_lock.slock);                              \
 279        mutex_acquire(&__sk->sk_lock.dep_map, 0, 0, _RET_IP_);          \
 280        local_bh_enable();                                              \
 281} while (0)
 282
 283#define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
 284#define mptcp_data_unlock(sk) spin_unlock_bh(&(sk)->sk_lock.slock)
 285
 286#define mptcp_for_each_subflow(__msk, __subflow)                        \
 287        list_for_each_entry(__subflow, &((__msk)->conn_list), node)
 288
 289static inline void msk_owned_by_me(const struct mptcp_sock *msk)
 290{
 291        sock_owned_by_me((const struct sock *)msk);
 292}
 293
 294static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
 295{
 296        return (struct mptcp_sock *)sk;
 297}
 298
 299/* the msk socket don't use the backlog, also account for the bulk
 300 * free memory
 301 */
 302static inline int __mptcp_rmem(const struct sock *sk)
 303{
 304        return atomic_read(&sk->sk_rmem_alloc) - READ_ONCE(mptcp_sk(sk)->rmem_released);
 305}
 306
 307static inline int __mptcp_space(const struct sock *sk)
 308{
 309        return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - __mptcp_rmem(sk));
 310}
 311
 312static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
 313{
 314        const struct mptcp_sock *msk = mptcp_sk(sk);
 315
 316        return READ_ONCE(msk->first_pending);
 317}
 318
 319static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
 320{
 321        struct mptcp_sock *msk = mptcp_sk(sk);
 322        struct mptcp_data_frag *cur;
 323
 324        cur = msk->first_pending;
 325        return list_is_last(&cur->list, &msk->rtx_queue) ? NULL :
 326                                                     list_next_entry(cur, list);
 327}
 328
 329static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
 330{
 331        struct mptcp_sock *msk = mptcp_sk(sk);
 332
 333        if (!msk->first_pending)
 334                return NULL;
 335
 336        if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
 337                return NULL;
 338
 339        return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
 340}
 341
 342static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
 343{
 344        struct mptcp_sock *msk = mptcp_sk(sk);
 345
 346        if (msk->snd_una == READ_ONCE(msk->snd_nxt))
 347                return NULL;
 348
 349        return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
 350}
 351
 352struct csum_pseudo_header {
 353        __be64 data_seq;
 354        __be32 subflow_seq;
 355        __be16 data_len;
 356        __sum16 csum;
 357};
 358
 359struct mptcp_subflow_request_sock {
 360        struct  tcp_request_sock sk;
 361        u16     mp_capable : 1,
 362                mp_join : 1,
 363                backup : 1,
 364                csum_reqd : 1,
 365                allow_join_id0 : 1;
 366        u8      local_id;
 367        u8      remote_id;
 368        u64     local_key;
 369        u64     idsn;
 370        u32     token;
 371        u32     ssn_offset;
 372        u64     thmac;
 373        u32     local_nonce;
 374        u32     remote_nonce;
 375        struct mptcp_sock       *msk;
 376        struct hlist_nulls_node token_node;
 377};
 378
 379static inline struct mptcp_subflow_request_sock *
 380mptcp_subflow_rsk(const struct request_sock *rsk)
 381{
 382        return (struct mptcp_subflow_request_sock *)rsk;
 383}
 384
 385enum mptcp_data_avail {
 386        MPTCP_SUBFLOW_NODATA,
 387        MPTCP_SUBFLOW_DATA_AVAIL,
 388};
 389
 390struct mptcp_delegated_action {
 391        struct napi_struct napi;
 392        struct list_head head;
 393};
 394
 395DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
 396
 397#define MPTCP_DELEGATE_SEND             0
 398
 399/* MPTCP subflow context */
 400struct mptcp_subflow_context {
 401        struct  list_head node;/* conn_list of subflows */
 402        u64     local_key;
 403        u64     remote_key;
 404        u64     idsn;
 405        u64     map_seq;
 406        u32     snd_isn;
 407        u32     token;
 408        u32     rel_write_seq;
 409        u32     map_subflow_seq;
 410        u32     ssn_offset;
 411        u32     map_data_len;
 412        __wsum  map_data_csum;
 413        u32     map_csum_len;
 414        u32     request_mptcp : 1,  /* send MP_CAPABLE */
 415                request_join : 1,   /* send MP_JOIN */
 416                request_bkup : 1,
 417                mp_capable : 1,     /* remote is MPTCP capable */
 418                mp_join : 1,        /* remote is JOINing */
 419                fully_established : 1,      /* path validated */
 420                pm_notified : 1,    /* PM hook called for established status */
 421                conn_finished : 1,
 422                map_valid : 1,
 423                map_csum_reqd : 1,
 424                map_data_fin : 1,
 425                mpc_map : 1,
 426                backup : 1,
 427                send_mp_prio : 1,
 428                rx_eof : 1,
 429                can_ack : 1,        /* only after processing the remote a key */
 430                disposable : 1;     /* ctx can be free at ulp release time */
 431        enum mptcp_data_avail data_avail;
 432        u32     remote_nonce;
 433        u64     thmac;
 434        u32     local_nonce;
 435        u32     remote_token;
 436        u8      hmac[MPTCPOPT_HMAC_LEN];
 437        u8      local_id;
 438        u8      remote_id;
 439        u8      reset_seen:1;
 440        u8      reset_transient:1;
 441        u8      reset_reason:4;
 442
 443        long    delegated_status;
 444        struct  list_head delegated_node;   /* link into delegated_action, protected by local BH */
 445
 446        u32 setsockopt_seq;
 447
 448        struct  sock *tcp_sock;     /* tcp sk backpointer */
 449        struct  sock *conn;         /* parent mptcp_sock */
 450        const   struct inet_connection_sock_af_ops *icsk_af_ops;
 451        void    (*tcp_data_ready)(struct sock *sk);
 452        void    (*tcp_state_change)(struct sock *sk);
 453        void    (*tcp_write_space)(struct sock *sk);
 454        void    (*tcp_error_report)(struct sock *sk);
 455
 456        struct  rcu_head rcu;
 457};
 458
 459static inline struct mptcp_subflow_context *
 460mptcp_subflow_ctx(const struct sock *sk)
 461{
 462        struct inet_connection_sock *icsk = inet_csk(sk);
 463
 464        /* Use RCU on icsk_ulp_data only for sock diag code */
 465        return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
 466}
 467
 468static inline struct sock *
 469mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
 470{
 471        return subflow->tcp_sock;
 472}
 473
 474static inline u64
 475mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
 476{
 477        return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
 478                      subflow->ssn_offset -
 479                      subflow->map_subflow_seq;
 480}
 481
 482static inline u64
 483mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
 484{
 485        return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
 486}
 487
 488static inline void mptcp_add_pending_subflow(struct mptcp_sock *msk,
 489                                             struct mptcp_subflow_context *subflow)
 490{
 491        sock_hold(mptcp_subflow_tcp_sock(subflow));
 492        spin_lock_bh(&msk->join_list_lock);
 493        list_add_tail(&subflow->node, &msk->join_list);
 494        spin_unlock_bh(&msk->join_list_lock);
 495}
 496
 497void mptcp_subflow_process_delegated(struct sock *ssk);
 498
 499static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow)
 500{
 501        struct mptcp_delegated_action *delegated;
 502        bool schedule;
 503
 504        /* The implied barrier pairs with mptcp_subflow_delegated_done(), and
 505         * ensures the below list check sees list updates done prior to status
 506         * bit changes
 507         */
 508        if (!test_and_set_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status)) {
 509                /* still on delegated list from previous scheduling */
 510                if (!list_empty(&subflow->delegated_node))
 511                        return;
 512
 513                /* the caller held the subflow bh socket lock */
 514                lockdep_assert_in_softirq();
 515
 516                delegated = this_cpu_ptr(&mptcp_delegated_actions);
 517                schedule = list_empty(&delegated->head);
 518                list_add_tail(&subflow->delegated_node, &delegated->head);
 519                sock_hold(mptcp_subflow_tcp_sock(subflow));
 520                if (schedule)
 521                        napi_schedule(&delegated->napi);
 522        }
 523}
 524
 525static inline struct mptcp_subflow_context *
 526mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated)
 527{
 528        struct mptcp_subflow_context *ret;
 529
 530        if (list_empty(&delegated->head))
 531                return NULL;
 532
 533        ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node);
 534        list_del_init(&ret->delegated_node);
 535        return ret;
 536}
 537
 538static inline bool mptcp_subflow_has_delegated_action(const struct mptcp_subflow_context *subflow)
 539{
 540        return test_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status);
 541}
 542
 543static inline void mptcp_subflow_delegated_done(struct mptcp_subflow_context *subflow)
 544{
 545        /* pairs with mptcp_subflow_delegate, ensures delegate_node is updated before
 546         * touching the status bit
 547         */
 548        smp_wmb();
 549        clear_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status);
 550}
 551
 552int mptcp_is_enabled(struct net *net);
 553unsigned int mptcp_get_add_addr_timeout(struct net *net);
 554int mptcp_is_checksum_enabled(struct net *net);
 555int mptcp_allow_join_id0(struct net *net);
 556void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
 557                                     struct mptcp_options_received *mp_opt);
 558bool mptcp_subflow_data_available(struct sock *sk);
 559void __init mptcp_subflow_init(void);
 560void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
 561void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
 562                     struct mptcp_subflow_context *subflow);
 563void mptcp_subflow_reset(struct sock *ssk);
 564void mptcp_sock_graft(struct sock *sk, struct socket *parent);
 565struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk);
 566
 567/* called with sk socket lock held */
 568int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
 569                            const struct mptcp_addr_info *remote,
 570                            u8 flags, int ifindex);
 571int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
 572void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
 573                         struct sockaddr_storage *addr,
 574                         unsigned short family);
 575
 576static inline bool mptcp_subflow_active(struct mptcp_subflow_context *subflow)
 577{
 578        struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 579
 580        /* can't send if JOIN hasn't completed yet (i.e. is usable for mptcp) */
 581        if (subflow->request_join && !subflow->fully_established)
 582                return false;
 583
 584        /* only send if our side has not closed yet */
 585        return ((1 << ssk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT));
 586}
 587
 588static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
 589                                              struct mptcp_subflow_context *ctx)
 590{
 591        sk->sk_data_ready = ctx->tcp_data_ready;
 592        sk->sk_state_change = ctx->tcp_state_change;
 593        sk->sk_write_space = ctx->tcp_write_space;
 594        sk->sk_error_report = ctx->tcp_error_report;
 595
 596        inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
 597}
 598
 599void __init mptcp_proto_init(void);
 600#if IS_ENABLED(CONFIG_MPTCP_IPV6)
 601int __init mptcp_proto_v6_init(void);
 602#endif
 603
 604struct sock *mptcp_sk_clone(const struct sock *sk,
 605                            const struct mptcp_options_received *mp_opt,
 606                            struct request_sock *req);
 607void mptcp_get_options(const struct sock *sk,
 608                       const struct sk_buff *skb,
 609                       struct mptcp_options_received *mp_opt);
 610
 611void mptcp_finish_connect(struct sock *sk);
 612void __mptcp_set_connected(struct sock *sk);
 613static inline bool mptcp_is_fully_established(struct sock *sk)
 614{
 615        return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
 616               READ_ONCE(mptcp_sk(sk)->fully_established);
 617}
 618void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
 619void mptcp_data_ready(struct sock *sk, struct sock *ssk);
 620bool mptcp_finish_join(struct sock *sk);
 621bool mptcp_schedule_work(struct sock *sk);
 622int mptcp_setsockopt(struct sock *sk, int level, int optname,
 623                     sockptr_t optval, unsigned int optlen);
 624int mptcp_getsockopt(struct sock *sk, int level, int optname,
 625                     char __user *optval, int __user *option);
 626
 627u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq);
 628static inline u64 mptcp_expand_seq(u64 old_seq, u64 cur_seq, bool use_64bit)
 629{
 630        if (use_64bit)
 631                return cur_seq;
 632
 633        return __mptcp_expand_seq(old_seq, cur_seq);
 634}
 635void __mptcp_check_push(struct sock *sk, struct sock *ssk);
 636void __mptcp_data_acked(struct sock *sk);
 637void __mptcp_error_report(struct sock *sk);
 638void mptcp_subflow_eof(struct sock *sk);
 639bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
 640void __mptcp_flush_join_list(struct mptcp_sock *msk);
 641static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
 642{
 643        return READ_ONCE(msk->snd_data_fin_enable) &&
 644               READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
 645}
 646
 647static inline bool mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
 648{
 649        if ((sk->sk_userlocks & SOCK_SNDBUF_LOCK) || ssk->sk_sndbuf <= READ_ONCE(sk->sk_sndbuf))
 650                return false;
 651
 652        WRITE_ONCE(sk->sk_sndbuf, ssk->sk_sndbuf);
 653        return true;
 654}
 655
 656static inline void mptcp_write_space(struct sock *sk)
 657{
 658        if (sk_stream_is_writeable(sk)) {
 659                /* pairs with memory barrier in mptcp_poll */
 660                smp_mb();
 661                if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags))
 662                        sk_stream_write_space(sk);
 663        }
 664}
 665
 666void mptcp_destroy_common(struct mptcp_sock *msk);
 667
 668#define MPTCP_TOKEN_MAX_RETRIES 4
 669
 670void __init mptcp_token_init(void);
 671static inline void mptcp_token_init_request(struct request_sock *req)
 672{
 673        mptcp_subflow_rsk(req)->token_node.pprev = NULL;
 674}
 675
 676int mptcp_token_new_request(struct request_sock *req);
 677void mptcp_token_destroy_request(struct request_sock *req);
 678int mptcp_token_new_connect(struct sock *sk);
 679void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
 680                        struct mptcp_sock *msk);
 681bool mptcp_token_exists(u32 token);
 682struct mptcp_sock *mptcp_token_get_sock(u32 token);
 683struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
 684                                         long *s_num);
 685void mptcp_token_destroy(struct mptcp_sock *msk);
 686
 687void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
 688
 689void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
 690
 691void __init mptcp_pm_init(void);
 692void mptcp_pm_data_init(struct mptcp_sock *msk);
 693void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);
 694void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk, gfp_t gfp);
 695bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
 696void mptcp_pm_connection_closed(struct mptcp_sock *msk);
 697void mptcp_pm_subflow_established(struct mptcp_sock *msk);
 698void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
 699void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
 700                                const struct mptcp_addr_info *addr);
 701void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
 702                              struct mptcp_addr_info *addr);
 703void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
 704void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk);
 705void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
 706                               const struct mptcp_rm_list *rm_list);
 707void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
 708int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 709                                 struct mptcp_addr_info *addr,
 710                                 u8 bkup);
 711void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
 712bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
 713struct mptcp_pm_add_entry *
 714mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 715                       struct mptcp_addr_info *addr, bool check_id);
 716struct mptcp_pm_add_entry *
 717mptcp_lookup_anno_list_by_saddr(struct mptcp_sock *msk,
 718                                struct mptcp_addr_info *addr);
 719
 720int mptcp_pm_announce_addr(struct mptcp_sock *msk,
 721                           const struct mptcp_addr_info *addr,
 722                           bool echo);
 723int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
 724int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
 725
 726void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
 727                 const struct sock *ssk, gfp_t gfp);
 728void mptcp_event_addr_announced(const struct mptcp_sock *msk, const struct mptcp_addr_info *info);
 729void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id);
 730
 731static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
 732{
 733        return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
 734}
 735
 736static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
 737{
 738        return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
 739}
 740
 741static inline bool mptcp_pm_should_add_signal_ipv6(struct mptcp_sock *msk)
 742{
 743        return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_IPV6);
 744}
 745
 746static inline bool mptcp_pm_should_add_signal_port(struct mptcp_sock *msk)
 747{
 748        return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_PORT);
 749}
 750
 751static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
 752{
 753        return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
 754}
 755
 756static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
 757{
 758        u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
 759
 760        if (family == AF_INET6)
 761                len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
 762        if (!echo)
 763                len += MPTCPOPT_THMAC_LEN;
 764        /* account for 2 trailing 'nop' options */
 765        if (port)
 766                len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
 767
 768        return len;
 769}
 770
 771static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
 772{
 773        if (rm_list->nr == 0 || rm_list->nr > MPTCP_RM_IDS_MAX)
 774                return -EINVAL;
 775
 776        return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1;
 777}
 778
 779bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 780                              struct mptcp_addr_info *saddr, bool *echo, bool *port);
 781bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 782                             struct mptcp_rm_list *rm_list);
 783int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
 784
 785void __init mptcp_pm_nl_init(void);
 786void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
 787void mptcp_pm_nl_work(struct mptcp_sock *msk);
 788void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
 789                                     const struct mptcp_rm_list *rm_list);
 790int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
 791unsigned int mptcp_pm_get_add_addr_signal_max(struct mptcp_sock *msk);
 792unsigned int mptcp_pm_get_add_addr_accept_max(struct mptcp_sock *msk);
 793unsigned int mptcp_pm_get_subflows_max(struct mptcp_sock *msk);
 794unsigned int mptcp_pm_get_local_addr_max(struct mptcp_sock *msk);
 795
 796void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk);
 797void mptcp_sockopt_sync_all(struct mptcp_sock *msk);
 798
 799static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb)
 800{
 801        return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
 802}
 803
 804void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
 805
 806static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
 807{
 808        return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
 809}
 810
 811static inline bool mptcp_check_fallback(const struct sock *sk)
 812{
 813        struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 814        struct mptcp_sock *msk = mptcp_sk(subflow->conn);
 815
 816        return __mptcp_check_fallback(msk);
 817}
 818
 819static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
 820{
 821        if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
 822                pr_debug("TCP fallback already done (msk=%p)", msk);
 823                return;
 824        }
 825        set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
 826}
 827
 828static inline void mptcp_do_fallback(struct sock *sk)
 829{
 830        struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 831        struct mptcp_sock *msk = mptcp_sk(subflow->conn);
 832
 833        __mptcp_do_fallback(msk);
 834}
 835
 836#define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
 837
 838static inline bool subflow_simultaneous_connect(struct sock *sk)
 839{
 840        struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 841        struct sock *parent = subflow->conn;
 842
 843        return sk->sk_state == TCP_ESTABLISHED &&
 844               !mptcp_sk(parent)->pm.server_side &&
 845               !subflow->conn_finished;
 846}
 847
 848#ifdef CONFIG_SYN_COOKIES
 849void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
 850                                       struct sk_buff *skb);
 851bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
 852                                        struct sk_buff *skb);
 853void __init mptcp_join_cookie_init(void);
 854#else
 855static inline void
 856subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
 857                                  struct sk_buff *skb) {}
 858static inline bool
 859mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
 860                                   struct sk_buff *skb)
 861{
 862        return false;
 863}
 864
 865static inline void mptcp_join_cookie_init(void) {}
 866#endif
 867
 868#endif /* __MPTCP_PROTOCOL_H */
 869