LXR linux/net/mptcp/protocol.h

   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#include <net/genetlink.h>
  15
  16#define MPTCP_SUPPORTED_VERSION 1
  17
  18/* MPTCP option bits */
  19#define OPTION_MPTCP_MPC_SYN    BIT(0)
  20#define OPTION_MPTCP_MPC_SYNACK BIT(1)
  21#define OPTION_MPTCP_MPC_ACK    BIT(2)
  22#define OPTION_MPTCP_MPJ_SYN    BIT(3)
  23#define OPTION_MPTCP_MPJ_SYNACK BIT(4)
  24#define OPTION_MPTCP_MPJ_ACK    BIT(5)
  25#define OPTION_MPTCP_ADD_ADDR   BIT(6)
  26#define OPTION_MPTCP_RM_ADDR    BIT(7)
  27#define OPTION_MPTCP_FASTCLOSE  BIT(8)
  28#define OPTION_MPTCP_PRIO       BIT(9)
  29#define OPTION_MPTCP_RST        BIT(10)
  30#define OPTION_MPTCP_DSS        BIT(11)
  31#define OPTION_MPTCP_FAIL       BIT(12)
  32
  33#define OPTION_MPTCP_CSUMREQD   BIT(13)
  34
  35#define OPTIONS_MPTCP_MPC       (OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK | \
  36                                 OPTION_MPTCP_MPC_ACK)
  37#define OPTIONS_MPTCP_MPJ       (OPTION_MPTCP_MPJ_SYN | OPTION_MPTCP_MPJ_SYNACK | \
  38                                 OPTION_MPTCP_MPJ_ACK)
  39
  40/* MPTCP option subtypes */
  41#define MPTCPOPT_MP_CAPABLE     0
  42#define MPTCPOPT_MP_JOIN        1
  43#define MPTCPOPT_DSS            2
  44#define MPTCPOPT_ADD_ADDR       3
  45#define MPTCPOPT_RM_ADDR        4
  46#define MPTCPOPT_MP_PRIO        5
  47#define MPTCPOPT_MP_FAIL        6
  48#define MPTCPOPT_MP_FASTCLOSE   7
  49#define MPTCPOPT_RST            8
  50
  51/* MPTCP suboption lengths */
  52#define TCPOLEN_MPTCP_MPC_SYN           4
  53#define TCPOLEN_MPTCP_MPC_SYNACK        12
  54#define TCPOLEN_MPTCP_MPC_ACK           20
  55#define TCPOLEN_MPTCP_MPC_ACK_DATA      22
  56#define TCPOLEN_MPTCP_MPJ_SYN           12
  57#define TCPOLEN_MPTCP_MPJ_SYNACK        16
  58#define TCPOLEN_MPTCP_MPJ_ACK           24
  59#define TCPOLEN_MPTCP_DSS_BASE          4
  60#define TCPOLEN_MPTCP_DSS_ACK32         4
  61#define TCPOLEN_MPTCP_DSS_ACK64         8
  62#define TCPOLEN_MPTCP_DSS_MAP32         10
  63#define TCPOLEN_MPTCP_DSS_MAP64         14
  64#define TCPOLEN_MPTCP_DSS_CHECKSUM      2
  65#define TCPOLEN_MPTCP_ADD_ADDR          16
  66#define TCPOLEN_MPTCP_ADD_ADDR_PORT     18
  67#define TCPOLEN_MPTCP_ADD_ADDR_BASE     8
  68#define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT        10
  69#define TCPOLEN_MPTCP_ADD_ADDR6         28
  70#define TCPOLEN_MPTCP_ADD_ADDR6_PORT    30
  71#define TCPOLEN_MPTCP_ADD_ADDR6_BASE    20
  72#define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT       22
  73#define TCPOLEN_MPTCP_PORT_LEN          2
  74#define TCPOLEN_MPTCP_PORT_ALIGN        2
  75#define TCPOLEN_MPTCP_RM_ADDR_BASE      3
  76#define TCPOLEN_MPTCP_PRIO              3
  77#define TCPOLEN_MPTCP_PRIO_ALIGN        4
  78#define TCPOLEN_MPTCP_FASTCLOSE         12
  79#define TCPOLEN_MPTCP_RST               4
  80#define TCPOLEN_MPTCP_FAIL              12
  81
  82#define TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM (TCPOLEN_MPTCP_DSS_CHECKSUM + TCPOLEN_MPTCP_MPC_ACK_DATA)
  83
  84/* MPTCP MP_JOIN flags */
  85#define MPTCPOPT_BACKUP         BIT(0)
  86#define MPTCPOPT_HMAC_LEN       20
  87#define MPTCPOPT_THMAC_LEN      8
  88
  89/* MPTCP MP_CAPABLE flags */
  90#define MPTCP_VERSION_MASK      (0x0F)
  91#define MPTCP_CAP_CHECKSUM_REQD BIT(7)
  92#define MPTCP_CAP_EXTENSIBILITY BIT(6)
  93#define MPTCP_CAP_DENY_JOIN_ID0 BIT(5)
  94#define MPTCP_CAP_HMAC_SHA256   BIT(0)
  95#define MPTCP_CAP_FLAG_MASK     (0x1F)
  96
  97/* MPTCP DSS flags */
  98#define MPTCP_DSS_DATA_FIN      BIT(4)
  99#define MPTCP_DSS_DSN64         BIT(3)
 100#define MPTCP_DSS_HAS_MAP       BIT(2)
 101#define MPTCP_DSS_ACK64         BIT(1)
 102#define MPTCP_DSS_HAS_ACK       BIT(0)
 103#define MPTCP_DSS_FLAG_MASK     (0x1F)
 104
 105/* MPTCP ADD_ADDR flags */
 106#define MPTCP_ADDR_ECHO         BIT(0)
 107
 108/* MPTCP MP_PRIO flags */
 109#define MPTCP_PRIO_BKUP         BIT(0)
 110
 111/* MPTCP TCPRST flags */
 112#define MPTCP_RST_TRANSIENT     BIT(0)
 113
 114/* MPTCP socket atomic flags */
 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
 121/* MPTCP socket release cb flags */
 122#define MPTCP_PUSH_PENDING      1
 123#define MPTCP_CLEAN_UNA         2
 124#define MPTCP_ERROR_REPORT      3
 125#define MPTCP_RETRANSMIT        4
 126#define MPTCP_FLUSH_JOIN_LIST   5
 127#define MPTCP_CONNECTED         6
 128#define MPTCP_RESET_SCHEDULER   7
 129
 130static inline bool before64(__u64 seq1, __u64 seq2)
 131{
 132        return (__s64)(seq1 - seq2) < 0;
 133}
 134
 135#define after64(seq2, seq1)     before64(seq1, seq2)
 136
 137struct mptcp_options_received {
 138        u64     sndr_key;
 139        u64     rcvr_key;
 140        u64     data_ack;
 141        u64     data_seq;
 142        u32     subflow_seq;
 143        u16     data_len;
 144        __sum16 csum;
 145        u16     suboptions;
 146        u32     token;
 147        u32     nonce;
 148        u16     use_map:1,
 149                dsn64:1,
 150                data_fin:1,
 151                use_ack:1,
 152                ack64:1,
 153                mpc_map:1,
 154                reset_reason:4,
 155                reset_transient:1,
 156                echo:1,
 157                backup:1,
 158                deny_join_id0:1,
 159                __unused:2;
 160        u8      join_id;
 161        u64     thmac;
 162        u8      hmac[MPTCPOPT_HMAC_LEN];
 163        struct mptcp_addr_info addr;
 164        struct mptcp_rm_list rm_list;
 165        u64     ahmac;
 166        u64     fail_seq;
 167};
 168
 169static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
 170{
 171        return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
 172                     ((nib & 0xF) << 8) | field);
 173}
 174
 175enum mptcp_pm_status {
 176        MPTCP_PM_ADD_ADDR_RECEIVED,
 177        MPTCP_PM_ADD_ADDR_SEND_ACK,
 178        MPTCP_PM_RM_ADDR_RECEIVED,
 179        MPTCP_PM_ESTABLISHED,
 180        MPTCP_PM_SUBFLOW_ESTABLISHED,
 181        MPTCP_PM_ALREADY_ESTABLISHED,   /* persistent status, set after ESTABLISHED event */
 182        MPTCP_PM_MPC_ENDPOINT_ACCOUNTED /* persistent status, set after MPC local address is
 183                                         * accounted int id_avail_bitmap
 184                                         */
 185};
 186
 187enum mptcp_pm_type {
 188        MPTCP_PM_TYPE_KERNEL = 0,
 189        MPTCP_PM_TYPE_USERSPACE,
 190
 191        __MPTCP_PM_TYPE_NR,
 192        __MPTCP_PM_TYPE_MAX = __MPTCP_PM_TYPE_NR - 1,
 193};
 194
 195/* Status bits below MPTCP_PM_ALREADY_ESTABLISHED need pm worker actions */
 196#define MPTCP_PM_WORK_MASK ((1 << MPTCP_PM_ALREADY_ESTABLISHED) - 1)
 197
 198enum mptcp_addr_signal_status {
 199        MPTCP_ADD_ADDR_SIGNAL,
 200        MPTCP_ADD_ADDR_ECHO,
 201        MPTCP_RM_ADDR_SIGNAL,
 202};
 203
 204/* max value of mptcp_addr_info.id */
 205#define MPTCP_PM_MAX_ADDR_ID            U8_MAX
 206
 207struct mptcp_pm_data {
 208        struct mptcp_addr_info local;
 209        struct mptcp_addr_info remote;
 210        struct list_head anno_list;
 211        struct list_head userspace_pm_local_addr_list;
 212
 213        spinlock_t      lock;           /*protects the whole PM data */
 214
 215        u8              addr_signal;
 216        bool            server_side;
 217        bool            work_pending;
 218        bool            accept_addr;
 219        bool            accept_subflow;
 220        bool            remote_deny_join_id0;
 221        u8              add_addr_signaled;
 222        u8              add_addr_accepted;
 223        u8              local_addr_used;
 224        u8              pm_type;
 225        u8              subflows;
 226        u8              status;
 227        DECLARE_BITMAP(id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
 228        struct mptcp_rm_list rm_list_tx;
 229        struct mptcp_rm_list rm_list_rx;
 230};
 231
 232struct mptcp_pm_addr_entry {
 233        struct list_head        list;
 234        struct mptcp_addr_info  addr;
 235        u8                      flags;
 236        int                     ifindex;
 237        struct socket           *lsk;
 238};
 239
 240struct mptcp_data_frag {
 241        struct list_head list;
 242        u64 data_seq;
 243        u16 data_len;
 244        u16 offset;
 245        u16 overhead;
 246        u16 already_sent;
 247        struct page *page;
 248};
 249
 250/* MPTCP connection sock */
 251struct mptcp_sock {
 252        /* inet_connection_sock must be the first member */
 253        struct inet_connection_sock sk;
 254        u64             local_key;
 255        u64             remote_key;
 256        u64             write_seq;
 257        u64             snd_nxt;
 258        u64             ack_seq;
 259        atomic64_t      rcv_wnd_sent;
 260        u64             rcv_data_fin_seq;
 261        int             rmem_fwd_alloc;
 262        struct sock     *last_snd;
 263        int             snd_burst;
 264        int             old_wspace;
 265        u64             recovery_snd_nxt;       /* in recovery mode accept up to this seq;
 266                                                 * recovery related fields are under data_lock
 267                                                 * protection
 268                                                 */
 269        u64             snd_una;
 270        u64             wnd_end;
 271        unsigned long   timer_ival;
 272        u32             token;
 273        int             rmem_released;
 274        unsigned long   flags;
 275        unsigned long   cb_flags;
 276        unsigned long   push_pending;
 277        bool            recovery;               /* closing subflow write queue reinjected */
 278        bool            can_ack;
 279        bool            fully_established;
 280        bool            rcv_data_fin;
 281        bool            snd_data_fin_enable;
 282        bool            rcv_fastclose;
 283        bool            use_64bit_ack; /* Set when we received a 64-bit DSN */
 284        bool            csum_enabled;
 285        bool            allow_infinite_fallback;
 286        u8              recvmsg_inq:1,
 287                        cork:1,
 288                        nodelay:1;
 289        struct work_struct work;
 290        struct sk_buff  *ooo_last_skb;
 291        struct rb_root  out_of_order_queue;
 292        struct sk_buff_head receive_queue;
 293        struct list_head conn_list;
 294        struct list_head rtx_queue;
 295        struct mptcp_data_frag *first_pending;
 296        struct list_head join_list;
 297        struct socket   *subflow; /* outgoing connect/listener/!mp_capable */
 298        struct sock     *first;
 299        struct mptcp_pm_data    pm;
 300        struct {
 301                u32     space;  /* bytes copied in last measurement window */
 302                u32     copied; /* bytes copied in this measurement window */
 303                u64     time;   /* start time of measurement window */
 304                u64     rtt_us; /* last maximum rtt of subflows */
 305        } rcvq_space;
 306
 307        u32 setsockopt_seq;
 308        char            ca_name[TCP_CA_NAME_MAX];
 309        struct mptcp_sock       *dl_next;
 310};
 311
 312#define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
 313#define mptcp_data_unlock(sk) spin_unlock_bh(&(sk)->sk_lock.slock)
 314
 315#define mptcp_for_each_subflow(__msk, __subflow)                        \
 316        list_for_each_entry(__subflow, &((__msk)->conn_list), node)
 317
 318static inline void msk_owned_by_me(const struct mptcp_sock *msk)
 319{
 320        sock_owned_by_me((const struct sock *)msk);
 321}
 322
 323static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
 324{
 325        return (struct mptcp_sock *)sk;
 326}
 327
 328/* the msk socket don't use the backlog, also account for the bulk
 329 * free memory
 330 */
 331static inline int __mptcp_rmem(const struct sock *sk)
 332{
 333        return atomic_read(&sk->sk_rmem_alloc) - READ_ONCE(mptcp_sk(sk)->rmem_released);
 334}
 335
 336static inline int __mptcp_space(const struct sock *sk)
 337{
 338        return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - __mptcp_rmem(sk));
 339}
 340
 341static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
 342{
 343        const struct mptcp_sock *msk = mptcp_sk(sk);
 344
 345        return READ_ONCE(msk->first_pending);
 346}
 347
 348static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
 349{
 350        struct mptcp_sock *msk = mptcp_sk(sk);
 351        struct mptcp_data_frag *cur;
 352
 353        cur = msk->first_pending;
 354        return list_is_last(&cur->list, &msk->rtx_queue) ? NULL :
 355                                                     list_next_entry(cur, list);
 356}
 357
 358static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
 359{
 360        struct mptcp_sock *msk = mptcp_sk(sk);
 361
 362        if (!msk->first_pending)
 363                return NULL;
 364
 365        if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
 366                return NULL;
 367
 368        return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
 369}
 370
 371static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
 372{
 373        struct mptcp_sock *msk = mptcp_sk(sk);
 374
 375        if (msk->snd_una == READ_ONCE(msk->snd_nxt))
 376                return NULL;
 377
 378        return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
 379}
 380
 381struct csum_pseudo_header {
 382        __be64 data_seq;
 383        __be32 subflow_seq;
 384        __be16 data_len;
 385        __sum16 csum;
 386};
 387
 388struct mptcp_subflow_request_sock {
 389        struct  tcp_request_sock sk;
 390        u16     mp_capable : 1,
 391                mp_join : 1,
 392                backup : 1,
 393                csum_reqd : 1,
 394                allow_join_id0 : 1;
 395        u8      local_id;
 396        u8      remote_id;
 397        u64     local_key;
 398        u64     idsn;
 399        u32     token;
 400        u32     ssn_offset;
 401        u64     thmac;
 402        u32     local_nonce;
 403        u32     remote_nonce;
 404        struct mptcp_sock       *msk;
 405        struct hlist_nulls_node token_node;
 406};
 407
 408static inline struct mptcp_subflow_request_sock *
 409mptcp_subflow_rsk(const struct request_sock *rsk)
 410{
 411        return (struct mptcp_subflow_request_sock *)rsk;
 412}
 413
 414enum mptcp_data_avail {
 415        MPTCP_SUBFLOW_NODATA,
 416        MPTCP_SUBFLOW_DATA_AVAIL,
 417};
 418
 419struct mptcp_delegated_action {
 420        struct napi_struct napi;
 421        struct list_head head;
 422};
 423
 424DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
 425
 426#define MPTCP_DELEGATE_SEND             0
 427#define MPTCP_DELEGATE_ACK              1
 428
 429/* MPTCP subflow context */
 430struct mptcp_subflow_context {
 431        struct  list_head node;/* conn_list of subflows */
 432
 433        struct_group(reset,
 434
 435        unsigned long avg_pacing_rate; /* protected by msk socket lock */
 436        u64     local_key;
 437        u64     remote_key;
 438        u64     idsn;
 439        u64     map_seq;
 440        u32     snd_isn;
 441        u32     token;
 442        u32     rel_write_seq;
 443        u32     map_subflow_seq;
 444        u32     ssn_offset;
 445        u32     map_data_len;
 446        __wsum  map_data_csum;
 447        u32     map_csum_len;
 448        u32     request_mptcp : 1,  /* send MP_CAPABLE */
 449                request_join : 1,   /* send MP_JOIN */
 450                request_bkup : 1,
 451                mp_capable : 1,     /* remote is MPTCP capable */
 452                mp_join : 1,        /* remote is JOINing */
 453                fully_established : 1,      /* path validated */
 454                pm_notified : 1,    /* PM hook called for established status */
 455                conn_finished : 1,
 456                map_valid : 1,
 457                map_csum_reqd : 1,
 458                map_data_fin : 1,
 459                mpc_map : 1,
 460                backup : 1,
 461                send_mp_prio : 1,
 462                send_mp_fail : 1,
 463                send_fastclose : 1,
 464                send_infinite_map : 1,
 465                rx_eof : 1,
 466                can_ack : 1,        /* only after processing the remote a key */
 467                disposable : 1,     /* ctx can be free at ulp release time */
 468                stale : 1,          /* unable to snd/rcv data, do not use for xmit */
 469                local_id_valid : 1, /* local_id is correctly initialized */
 470                valid_csum_seen : 1;        /* at least one csum validated */
 471        enum mptcp_data_avail data_avail;
 472        u32     remote_nonce;
 473        u64     thmac;
 474        u32     local_nonce;
 475        u32     remote_token;
 476        u8      hmac[MPTCPOPT_HMAC_LEN];
 477        u8      local_id;
 478        u8      remote_id;
 479        u8      reset_seen:1;
 480        u8      reset_transient:1;
 481        u8      reset_reason:4;
 482        u8      stale_count;
 483
 484        long    delegated_status;
 485        unsigned long   fail_tout;
 486
 487        );
 488
 489        struct  list_head delegated_node;   /* link into delegated_action, protected by local BH */
 490
 491        u32     setsockopt_seq;
 492        u32     stale_rcv_tstamp;
 493
 494        struct  sock *tcp_sock;     /* tcp sk backpointer */
 495        struct  sock *conn;         /* parent mptcp_sock */
 496        const   struct inet_connection_sock_af_ops *icsk_af_ops;
 497        void    (*tcp_state_change)(struct sock *sk);
 498        void    (*tcp_error_report)(struct sock *sk);
 499
 500        struct  rcu_head rcu;
 501};
 502
 503static inline struct mptcp_subflow_context *
 504mptcp_subflow_ctx(const struct sock *sk)
 505{
 506        struct inet_connection_sock *icsk = inet_csk(sk);
 507
 508        /* Use RCU on icsk_ulp_data only for sock diag code */
 509        return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
 510}
 511
 512static inline struct sock *
 513mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
 514{
 515        return subflow->tcp_sock;
 516}
 517
 518static inline void
 519mptcp_subflow_ctx_reset(struct mptcp_subflow_context *subflow)
 520{
 521        memset(&subflow->reset, 0, sizeof(subflow->reset));
 522        subflow->request_mptcp = 1;
 523}
 524
 525static inline u64
 526mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
 527{
 528        return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
 529                      subflow->ssn_offset -
 530                      subflow->map_subflow_seq;
 531}
 532
 533static inline u64
 534mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
 535{
 536        return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
 537}
 538
 539void mptcp_subflow_process_delegated(struct sock *ssk);
 540
 541static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow, int action)
 542{
 543        struct mptcp_delegated_action *delegated;
 544        bool schedule;
 545
 546        /* the caller held the subflow bh socket lock */
 547        lockdep_assert_in_softirq();
 548
 549        /* The implied barrier pairs with mptcp_subflow_delegated_done(), and
 550         * ensures the below list check sees list updates done prior to status
 551         * bit changes
 552         */
 553        if (!test_and_set_bit(action, &subflow->delegated_status)) {
 554                /* still on delegated list from previous scheduling */
 555                if (!list_empty(&subflow->delegated_node))
 556                        return;
 557
 558                delegated = this_cpu_ptr(&mptcp_delegated_actions);
 559                schedule = list_empty(&delegated->head);
 560                list_add_tail(&subflow->delegated_node, &delegated->head);
 561                sock_hold(mptcp_subflow_tcp_sock(subflow));
 562                if (schedule)
 563                        napi_schedule(&delegated->napi);
 564        }
 565}
 566
 567static inline struct mptcp_subflow_context *
 568mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated)
 569{
 570        struct mptcp_subflow_context *ret;
 571
 572        if (list_empty(&delegated->head))
 573                return NULL;
 574
 575        ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node);
 576        list_del_init(&ret->delegated_node);
 577        return ret;
 578}
 579
 580static inline bool mptcp_subflow_has_delegated_action(const struct mptcp_subflow_context *subflow)
 581{
 582        return !!READ_ONCE(subflow->delegated_status);
 583}
 584
 585static inline void mptcp_subflow_delegated_done(struct mptcp_subflow_context *subflow, int action)
 586{
 587        /* pairs with mptcp_subflow_delegate, ensures delegate_node is updated before
 588         * touching the status bit
 589         */
 590        smp_wmb();
 591        clear_bit(action, &subflow->delegated_status);
 592}
 593
 594int mptcp_is_enabled(const struct net *net);
 595unsigned int mptcp_get_add_addr_timeout(const struct net *net);
 596int mptcp_is_checksum_enabled(const struct net *net);
 597int mptcp_allow_join_id0(const struct net *net);
 598unsigned int mptcp_stale_loss_cnt(const struct net *net);
 599int mptcp_get_pm_type(const struct net *net);
 600void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
 601                                     struct mptcp_options_received *mp_opt);
 602bool __mptcp_retransmit_pending_data(struct sock *sk);
 603void mptcp_check_and_set_pending(struct sock *sk);
 604void __mptcp_push_pending(struct sock *sk, unsigned int flags);
 605bool mptcp_subflow_data_available(struct sock *sk);
 606void __init mptcp_subflow_init(void);
 607void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
 608void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
 609                     struct mptcp_subflow_context *subflow);
 610void __mptcp_subflow_send_ack(struct sock *ssk);
 611void mptcp_subflow_send_ack(struct sock *ssk);
 612void mptcp_subflow_reset(struct sock *ssk);
 613void mptcp_subflow_queue_clean(struct sock *ssk);
 614void mptcp_sock_graft(struct sock *sk, struct socket *parent);
 615struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk);
 616
 617bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
 618                           const struct mptcp_addr_info *b, bool use_port);
 619
 620/* called with sk socket lock held */
 621int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
 622                            const struct mptcp_addr_info *remote);
 623int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
 624void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
 625                         struct sockaddr_storage *addr,
 626                         unsigned short family);
 627
 628static inline bool __mptcp_subflow_active(struct mptcp_subflow_context *subflow)
 629{
 630        struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 631
 632        /* can't send if JOIN hasn't completed yet (i.e. is usable for mptcp) */
 633        if (subflow->request_join && !subflow->fully_established)
 634                return false;
 635
 636        /* only send if our side has not closed yet */
 637        return ((1 << ssk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT));
 638}
 639
 640void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow);
 641
 642bool mptcp_subflow_active(struct mptcp_subflow_context *subflow);
 643
 644static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
 645                                              struct mptcp_subflow_context *ctx)
 646{
 647        sk->sk_data_ready = sock_def_readable;
 648        sk->sk_state_change = ctx->tcp_state_change;
 649        sk->sk_write_space = sk_stream_write_space;
 650        sk->sk_error_report = ctx->tcp_error_report;
 651
 652        inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
 653}
 654
 655void __init mptcp_proto_init(void);
 656#if IS_ENABLED(CONFIG_MPTCP_IPV6)
 657int __init mptcp_proto_v6_init(void);
 658#endif
 659
 660struct sock *mptcp_sk_clone(const struct sock *sk,
 661                            const struct mptcp_options_received *mp_opt,
 662                            struct request_sock *req);
 663void mptcp_get_options(const struct sk_buff *skb,
 664                       struct mptcp_options_received *mp_opt);
 665
 666void mptcp_finish_connect(struct sock *sk);
 667void __mptcp_set_connected(struct sock *sk);
 668void mptcp_reset_timeout(struct mptcp_sock *msk, unsigned long fail_tout);
 669static inline bool mptcp_is_fully_established(struct sock *sk)
 670{
 671        return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
 672               READ_ONCE(mptcp_sk(sk)->fully_established);
 673}
 674void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
 675void mptcp_data_ready(struct sock *sk, struct sock *ssk);
 676bool mptcp_finish_join(struct sock *sk);
 677bool mptcp_schedule_work(struct sock *sk);
 678int mptcp_setsockopt(struct sock *sk, int level, int optname,
 679                     sockptr_t optval, unsigned int optlen);
 680int mptcp_getsockopt(struct sock *sk, int level, int optname,
 681                     char __user *optval, int __user *option);
 682
 683u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq);
 684static inline u64 mptcp_expand_seq(u64 old_seq, u64 cur_seq, bool use_64bit)
 685{
 686        if (use_64bit)
 687                return cur_seq;
 688
 689        return __mptcp_expand_seq(old_seq, cur_seq);
 690}
 691void __mptcp_check_push(struct sock *sk, struct sock *ssk);
 692void __mptcp_data_acked(struct sock *sk);
 693void __mptcp_error_report(struct sock *sk);
 694void mptcp_subflow_eof(struct sock *sk);
 695bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
 696static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
 697{
 698        return READ_ONCE(msk->snd_data_fin_enable) &&
 699               READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
 700}
 701
 702static inline bool mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
 703{
 704        if ((sk->sk_userlocks & SOCK_SNDBUF_LOCK) || ssk->sk_sndbuf <= READ_ONCE(sk->sk_sndbuf))
 705                return false;
 706
 707        WRITE_ONCE(sk->sk_sndbuf, ssk->sk_sndbuf);
 708        return true;
 709}
 710
 711static inline void mptcp_write_space(struct sock *sk)
 712{
 713        if (sk_stream_is_writeable(sk)) {
 714                /* pairs with memory barrier in mptcp_poll */
 715                smp_mb();
 716                if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags))
 717                        sk_stream_write_space(sk);
 718        }
 719}
 720
 721void mptcp_destroy_common(struct mptcp_sock *msk);
 722
 723#define MPTCP_TOKEN_MAX_RETRIES 4
 724
 725void __init mptcp_token_init(void);
 726static inline void mptcp_token_init_request(struct request_sock *req)
 727{
 728        mptcp_subflow_rsk(req)->token_node.pprev = NULL;
 729}
 730
 731int mptcp_token_new_request(struct request_sock *req);
 732void mptcp_token_destroy_request(struct request_sock *req);
 733int mptcp_token_new_connect(struct sock *sk);
 734void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
 735                        struct mptcp_sock *msk);
 736bool mptcp_token_exists(u32 token);
 737struct mptcp_sock *mptcp_token_get_sock(struct net *net, u32 token);
 738struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
 739                                         long *s_num);
 740void mptcp_token_destroy(struct mptcp_sock *msk);
 741
 742void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
 743
 744void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
 745__sum16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum);
 746
 747void __init mptcp_pm_init(void);
 748void mptcp_pm_data_init(struct mptcp_sock *msk);
 749void mptcp_pm_data_reset(struct mptcp_sock *msk);
 750int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
 751                        struct mptcp_addr_info *addr);
 752int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
 753                         bool require_family,
 754                         struct mptcp_pm_addr_entry *entry);
 755void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
 756void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
 757void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);
 758void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk, gfp_t gfp);
 759bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
 760void mptcp_pm_connection_closed(struct mptcp_sock *msk);
 761void mptcp_pm_subflow_established(struct mptcp_sock *msk);
 762bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
 763void mptcp_pm_subflow_check_next(struct mptcp_sock *msk, const struct sock *ssk,
 764                                 const struct mptcp_subflow_context *subflow);
 765void mptcp_pm_add_addr_received(const struct sock *ssk,
 766                                const struct mptcp_addr_info *addr);
 767void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
 768                              const struct mptcp_addr_info *addr);
 769void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
 770void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk);
 771void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
 772                               const struct mptcp_rm_list *rm_list);
 773void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
 774void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
 775int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 776                                 struct mptcp_addr_info *addr,
 777                                 struct mptcp_addr_info *rem,
 778                                 u8 bkup);
 779bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 780                              const struct mptcp_pm_addr_entry *entry);
 781void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
 782bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
 783struct mptcp_pm_add_entry *
 784mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 785                       const struct mptcp_addr_info *addr, bool check_id);
 786struct mptcp_pm_add_entry *
 787mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
 788                                const struct mptcp_addr_info *addr);
 789int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
 790                                         unsigned int id,
 791                                         u8 *flags, int *ifindex);
 792int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
 793                                                   unsigned int id,
 794                                                   u8 *flags, int *ifindex);
 795int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
 796                                 struct mptcp_pm_addr_entry *loc,
 797                                 struct mptcp_pm_addr_entry *rem, u8 bkup);
 798int mptcp_pm_announce_addr(struct mptcp_sock *msk,
 799                           const struct mptcp_addr_info *addr,
 800                           bool echo);
 801int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
 802int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
 803void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
 804                                        struct list_head *rm_list);
 805
 806int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
 807                                             struct mptcp_pm_addr_entry *entry);
 808void mptcp_free_local_addr_list(struct mptcp_sock *msk);
 809int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info);
 810int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info);
 811int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info);
 812int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info);
 813
 814void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
 815                 const struct sock *ssk, gfp_t gfp);
 816void mptcp_event_addr_announced(const struct sock *ssk, const struct mptcp_addr_info *info);
 817void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id);
 818bool mptcp_userspace_pm_active(const struct mptcp_sock *msk);
 819
 820static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
 821{
 822        return READ_ONCE(msk->pm.addr_signal) &
 823                (BIT(MPTCP_ADD_ADDR_SIGNAL) | BIT(MPTCP_ADD_ADDR_ECHO));
 824}
 825
 826static inline bool mptcp_pm_should_add_signal_addr(struct mptcp_sock *msk)
 827{
 828        return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
 829}
 830
 831static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
 832{
 833        return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
 834}
 835
 836static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
 837{
 838        return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
 839}
 840
 841static inline bool mptcp_pm_is_userspace(const struct mptcp_sock *msk)
 842{
 843        return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_USERSPACE;
 844}
 845
 846static inline bool mptcp_pm_is_kernel(const struct mptcp_sock *msk)
 847{
 848        return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_KERNEL;
 849}
 850
 851static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
 852{
 853        u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
 854
 855        if (family == AF_INET6)
 856                len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
 857        if (!echo)
 858                len += MPTCPOPT_THMAC_LEN;
 859        /* account for 2 trailing 'nop' options */
 860        if (port)
 861                len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
 862
 863        return len;
 864}
 865
 866static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
 867{
 868        if (rm_list->nr == 0 || rm_list->nr > MPTCP_RM_IDS_MAX)
 869                return -EINVAL;
 870
 871        return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1;
 872}
 873
 874bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 875                              unsigned int opt_size, unsigned int remaining,
 876                              struct mptcp_addr_info *addr, bool *echo,
 877                              bool *drop_other_suboptions);
 878bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 879                             struct mptcp_rm_list *rm_list);
 880int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
 881int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
 882
 883void __init mptcp_pm_nl_init(void);
 884void mptcp_pm_nl_work(struct mptcp_sock *msk);
 885void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
 886                                     const struct mptcp_rm_list *rm_list);
 887int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
 888unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk);
 889unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk);
 890unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk);
 891unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk);
 892
 893/* called under PM lock */
 894static inline void __mptcp_pm_close_subflow(struct mptcp_sock *msk)
 895{
 896        if (--msk->pm.subflows < mptcp_pm_get_subflows_max(msk))
 897                WRITE_ONCE(msk->pm.accept_subflow, true);
 898}
 899
 900static inline void mptcp_pm_close_subflow(struct mptcp_sock *msk)
 901{
 902        spin_lock_bh(&msk->pm.lock);
 903        __mptcp_pm_close_subflow(msk);
 904        spin_unlock_bh(&msk->pm.lock);
 905}
 906
 907void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk);
 908void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk);
 909
 910static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb)
 911{
 912        return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
 913}
 914
 915void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
 916
 917static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
 918{
 919        return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
 920}
 921
 922static inline bool mptcp_check_fallback(const struct sock *sk)
 923{
 924        struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 925        struct mptcp_sock *msk = mptcp_sk(subflow->conn);
 926
 927        return __mptcp_check_fallback(msk);
 928}
 929
 930static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
 931{
 932        if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
 933                pr_debug("TCP fallback already done (msk=%p)", msk);
 934                return;
 935        }
 936        set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
 937}
 938
 939static inline void mptcp_do_fallback(struct sock *ssk)
 940{
 941        struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
 942        struct sock *sk = subflow->conn;
 943        struct mptcp_sock *msk;
 944
 945        msk = mptcp_sk(sk);
 946        __mptcp_do_fallback(msk);
 947        if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) {
 948                gfp_t saved_allocation = ssk->sk_allocation;
 949
 950                /* we are in a atomic (BH) scope, override ssk default for data
 951                 * fin allocation
 952                 */
 953                ssk->sk_allocation = GFP_ATOMIC;
 954                ssk->sk_shutdown |= SEND_SHUTDOWN;
 955                tcp_shutdown(ssk, SEND_SHUTDOWN);
 956                ssk->sk_allocation = saved_allocation;
 957        }
 958}
 959
 960#define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
 961
 962static inline bool mptcp_check_infinite_map(struct sk_buff *skb)
 963{
 964        struct mptcp_ext *mpext;
 965
 966        mpext = skb ? mptcp_get_ext(skb) : NULL;
 967        if (mpext && mpext->infinite_map)
 968                return true;
 969
 970        return false;
 971}
 972
 973static inline bool is_active_ssk(struct mptcp_subflow_context *subflow)
 974{
 975        return (subflow->request_mptcp || subflow->request_join);
 976}
 977
 978static inline bool subflow_simultaneous_connect(struct sock *sk)
 979{
 980        struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 981
 982        return sk->sk_state == TCP_ESTABLISHED &&
 983               is_active_ssk(subflow) &&
 984               !subflow->conn_finished;
 985}
 986
 987#ifdef CONFIG_SYN_COOKIES
 988void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
 989                                       struct sk_buff *skb);
 990bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
 991                                        struct sk_buff *skb);
 992void __init mptcp_join_cookie_init(void);
 993#else
 994static inline void
 995subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
 996                                  struct sk_buff *skb) {}
 997static inline bool
 998mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
 999                                   struct sk_buff *skb)
1000{

1001        return false;
1002}
1003
1004static inline void mptcp_join_cookie_init(void) {}
1005#endif
1006
1007#endif /* __MPTCP_PROTOCOL_H */
1008