net/mptcp/pm_userspace.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Multipath TCP
   3  *
   4  * Copyright (c) 2022, Intel Corporation.
   5  */
   6
   7 #include "protocol.h"
   8 #include "mib.h"
   9
  10 void mptcp_free_local_addr_list(struct mptcp_sock *msk)
  11 {
  12         struct mptcp_pm_addr_entry *entry, *tmp;
  13         struct sock *sk = (struct sock *)msk;
  14         LIST_HEAD(free_list);
  15
  16         if (!mptcp_pm_is_userspace(msk))
  17                 return;
  18
  19         spin_lock_bh(&msk->pm.lock);
  20         list_splice_init(&msk->pm.userspace_pm_local_addr_list, &free_list);
  21         spin_unlock_bh(&msk->pm.lock);
  22
  23         list_for_each_entry_safe(entry, tmp, &free_list, list) {
  24                 sock_kfree_s(sk, entry, sizeof(*entry));
  25         }
  26 }
  27
  28 static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
  29                                                     struct mptcp_pm_addr_entry *entry,
  30                                                     bool needs_id)
  31 {
  32         DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
  33         struct mptcp_pm_addr_entry *match = NULL;
  34         struct sock *sk = (struct sock *)msk;
  35         struct mptcp_pm_addr_entry *e;
  36         bool addr_match = false;
  37         bool id_match = false;
  38         int ret = -EINVAL;
  39
  40         bitmap_zero(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
  41
  42         spin_lock_bh(&msk->pm.lock);
  43         list_for_each_entry(e, &msk->pm.userspace_pm_local_addr_list, list) {
  44                 addr_match = mptcp_addresses_equal(&e->addr, &entry->addr, true);
  45                 if (addr_match && entry->addr.id == 0 && needs_id)
  46                         entry->addr.id = e->addr.id;
  47                 id_match = (e->addr.id == entry->addr.id);
  48                 if (addr_match && id_match) {
  49                         match = e;
  50                         break;
  51                 } else if (addr_match || id_match) {
  52                         break;
  53                 }
  54                 __set_bit(e->addr.id, id_bitmap);
  55         }
  56
  57         if (!match && !addr_match && !id_match) {
  58                 /* Memory for the entry is allocated from the
  59                  * sock option buffer.
  60                  */
  61                 e = sock_kmalloc(sk, sizeof(*e), GFP_ATOMIC);
  62                 if (!e) {
  63                         spin_unlock_bh(&msk->pm.lock);
  64                         return -ENOMEM;
  65                 }
  66
  67                 *e = *entry;
  68                 if (!e->addr.id && needs_id)
  69                         e->addr.id = find_next_zero_bit(id_bitmap,
  70                                                         MPTCP_PM_MAX_ADDR_ID + 1,
  71                                                         1);
  72                 list_add_tail_rcu(&e->list, &msk->pm.userspace_pm_local_addr_list);
  73                 msk->pm.local_addr_used++;
  74                 ret = e->addr.id;
  75         } else if (match) {
  76                 ret = entry->addr.id;
  77         }
  78
  79         spin_unlock_bh(&msk->pm.lock);
  80         return ret;
  81 }
  82
  83 /* If the subflow is closed from the other peer (not via a
  84  * subflow destroy command then), we want to keep the entry
  85  * not to assign the same ID to another address and to be
  86  * able to send RM_ADDR after the removal of the subflow.
  87  */
  88 static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk,
  89                                                 struct mptcp_pm_addr_entry *addr)
  90 {
  91         struct mptcp_pm_addr_entry *entry, *tmp;
  92
  93         list_for_each_entry_safe(entry, tmp, &msk->pm.userspace_pm_local_addr_list, list) {
  94                 if (mptcp_addresses_equal(&entry->addr, &addr->addr, false)) {
  95                         /* TODO: a refcount is needed because the entry can
  96                          * be used multiple times (e.g. fullmesh mode).
  97                          */
  98                         list_del_rcu(&entry->list);
  99                         kfree(entry);
 100                         msk->pm.local_addr_used--;
 101                         return 0;
 102                 }
 103         }
 104
 105         return -EINVAL;
 106 }
 107
 108 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
 109                                                    unsigned int id,
 110                                                    u8 *flags, int *ifindex)
 111 {
 112         struct mptcp_pm_addr_entry *entry, *match = NULL;
 113
 114         *flags = 0;
 115         *ifindex = 0;
 116
 117         spin_lock_bh(&msk->pm.lock);
 118         list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
 119                 if (id == entry->addr.id) {
 120                         match = entry;
 121                         break;
 122                 }
 123         }
 124         spin_unlock_bh(&msk->pm.lock);
 125         if (match) {
 126                 *flags = match->flags;
 127                 *ifindex = match->ifindex;
 128         }
 129
 130         return 0;
 131 }
 132
 133 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
 134                                     struct mptcp_addr_info *skc)
 135 {
 136         struct mptcp_pm_addr_entry *entry = NULL, *e, new_entry;
 137         __be16 msk_sport =  ((struct inet_sock *)
 138                              inet_sk((struct sock *)msk))->inet_sport;
 139
 140         spin_lock_bh(&msk->pm.lock);
 141         list_for_each_entry(e, &msk->pm.userspace_pm_local_addr_list, list) {
 142                 if (mptcp_addresses_equal(&e->addr, skc, false)) {
 143                         entry = e;
 144                         break;
 145                 }
 146         }
 147         spin_unlock_bh(&msk->pm.lock);
 148         if (entry)
 149                 return entry->addr.id;
 150
 151         memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
 152         new_entry.addr = *skc;
 153         new_entry.addr.id = 0;
 154         new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
 155
 156         if (new_entry.addr.port == msk_sport)
 157                 new_entry.addr.port = 0;
 158
 159         return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry, true);
 160 }
 161
 162 int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info)
 163 {
 164         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 165         struct nlattr *addr = info->attrs[MPTCP_PM_ATTR_ADDR];
 166         struct mptcp_pm_addr_entry addr_val;
 167         struct mptcp_sock *msk;
 168         int err = -EINVAL;
 169         u32 token_val;
 170
 171         if (!addr || !token) {
 172                 GENL_SET_ERR_MSG(info, "missing required inputs");
 173                 return err;
 174         }
 175
 176         token_val = nla_get_u32(token);
 177
 178         msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
 179         if (!msk) {
 180                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 181                 return err;
 182         }
 183
 184         if (!mptcp_pm_is_userspace(msk)) {
 185                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 186                 goto announce_err;
 187         }
 188
 189         err = mptcp_pm_parse_entry(addr, info, true, &addr_val);
 190         if (err < 0) {
 191                 GENL_SET_ERR_MSG(info, "error parsing local address");
 192                 goto announce_err;
 193         }
 194
 195         if (addr_val.addr.id == 0 || !(addr_val.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
 196                 GENL_SET_ERR_MSG(info, "invalid addr id or flags");
 197                 err = -EINVAL;
 198                 goto announce_err;
 199         }
 200
 201         err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val, false);
 202         if (err < 0) {
 203                 GENL_SET_ERR_MSG(info, "did not match address and id");
 204                 goto announce_err;
 205         }
 206
 207         lock_sock((struct sock *)msk);
 208         spin_lock_bh(&msk->pm.lock);
 209
 210         if (mptcp_pm_alloc_anno_list(msk, &addr_val)) {
 211                 msk->pm.add_addr_signaled++;
 212                 mptcp_pm_announce_addr(msk, &addr_val.addr, false);
 213                 mptcp_pm_nl_addr_send_ack(msk);
 214         }
 215
 216         spin_unlock_bh(&msk->pm.lock);
 217         release_sock((struct sock *)msk);
 218
 219         err = 0;
 220  announce_err:
 221         sock_put((struct sock *)msk);
 222         return err;
 223 }
 224
 225 static int mptcp_userspace_pm_remove_id_zero_address(struct mptcp_sock *msk,
 226                                                      struct genl_info *info)
 227 {
 228         struct mptcp_rm_list list = { .nr = 0 };
 229         struct mptcp_subflow_context *subflow;
 230         struct sock *sk = (struct sock *)msk;
 231         bool has_id_0 = false;
 232         int err = -EINVAL;
 233
 234         lock_sock(sk);
 235         mptcp_for_each_subflow(msk, subflow) {
 236                 if (READ_ONCE(subflow->local_id) == 0) {
 237                         has_id_0 = true;
 238                         break;
 239                 }
 240         }
 241         if (!has_id_0) {
 242                 GENL_SET_ERR_MSG(info, "address with id 0 not found");
 243                 goto remove_err;
 244         }
 245
 246         list.ids[list.nr++] = 0;
 247
 248         spin_lock_bh(&msk->pm.lock);
 249         mptcp_pm_remove_addr(msk, &list);
 250         spin_unlock_bh(&msk->pm.lock);
 251
 252         err = 0;
 253
 254 remove_err:
 255         release_sock(sk);
 256         return err;
 257 }
 258
 259 int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
 260 {
 261         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 262         struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
 263         struct mptcp_pm_addr_entry *match = NULL;
 264         struct mptcp_pm_addr_entry *entry;
 265         struct mptcp_sock *msk;
 266         LIST_HEAD(free_list);
 267         int err = -EINVAL;
 268         u32 token_val;
 269         u8 id_val;
 270
 271         if (!id || !token) {
 272                 GENL_SET_ERR_MSG(info, "missing required inputs");
 273                 return err;
 274         }
 275
 276         id_val = nla_get_u8(id);
 277         token_val = nla_get_u32(token);
 278
 279         msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
 280         if (!msk) {
 281                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 282                 return err;
 283         }
 284
 285         if (!mptcp_pm_is_userspace(msk)) {
 286                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 287                 goto remove_err;
 288         }
 289
 290         if (id_val == 0) {
 291                 err = mptcp_userspace_pm_remove_id_zero_address(msk, info);
 292                 goto remove_err;
 293         }
 294
 295         lock_sock((struct sock *)msk);
 296
 297         list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
 298                 if (entry->addr.id == id_val) {
 299                         match = entry;
 300                         break;
 301                 }
 302         }
 303
 304         if (!match) {
 305                 GENL_SET_ERR_MSG(info, "address with specified id not found");
 306                 release_sock((struct sock *)msk);
 307                 goto remove_err;
 308         }
 309
 310         list_move(&match->list, &free_list);
 311
 312         mptcp_pm_remove_addrs(msk, &free_list);
 313
 314         release_sock((struct sock *)msk);
 315
 316         list_for_each_entry_safe(match, entry, &free_list, list) {
 317                 sock_kfree_s((struct sock *)msk, match, sizeof(*match));
 318         }
 319
 320         err = 0;
 321  remove_err:
 322         sock_put((struct sock *)msk);
 323         return err;
 324 }
 325
 326 int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
 327 {
 328         struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
 329         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 330         struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 331         struct mptcp_pm_addr_entry local = { 0 };
 332         struct mptcp_addr_info addr_r;
 333         struct mptcp_addr_info addr_l;
 334         struct mptcp_sock *msk;
 335         int err = -EINVAL;
 336         struct sock *sk;
 337         u32 token_val;
 338
 339         if (!laddr || !raddr || !token) {
 340                 GENL_SET_ERR_MSG(info, "missing required inputs");
 341                 return err;
 342         }
 343
 344         token_val = nla_get_u32(token);
 345
 346         msk = mptcp_token_get_sock(genl_info_net(info), token_val);
 347         if (!msk) {
 348                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 349                 return err;
 350         }
 351
 352         if (!mptcp_pm_is_userspace(msk)) {
 353                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 354                 goto create_err;
 355         }
 356
 357         err = mptcp_pm_parse_addr(laddr, info, &addr_l);
 358         if (err < 0) {
 359                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
 360                 goto create_err;
 361         }
 362
 363         err = mptcp_pm_parse_addr(raddr, info, &addr_r);
 364         if (err < 0) {
 365                 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
 366                 goto create_err;
 367         }
 368
 369         sk = &msk->sk.icsk_inet.sk;
 370
 371         if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
 372                 GENL_SET_ERR_MSG(info, "families mismatch");
 373                 err = -EINVAL;
 374                 goto create_err;
 375         }
 376
 377         local.addr = addr_l;
 378         err = mptcp_userspace_pm_append_new_local_addr(msk, &local, false);
 379         if (err < 0) {
 380                 GENL_SET_ERR_MSG(info, "did not match address and id");
 381                 goto create_err;
 382         }
 383
 384         lock_sock(sk);
 385
 386         err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
 387
 388         release_sock(sk);
 389
 390         spin_lock_bh(&msk->pm.lock);
 391         if (err)
 392                 mptcp_userspace_pm_delete_local_addr(msk, &local);
 393         else
 394                 msk->pm.subflows++;
 395         spin_unlock_bh(&msk->pm.lock);
 396
 397  create_err:
 398         sock_put((struct sock *)msk);
 399         return err;
 400 }
 401
 402 static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
 403                                       const struct mptcp_addr_info *local,
 404                                       const struct mptcp_addr_info *remote)
 405 {
 406         struct mptcp_subflow_context *subflow;
 407
 408         if (local->family != remote->family)
 409                 return NULL;
 410
 411         mptcp_for_each_subflow(msk, subflow) {
 412                 const struct inet_sock *issk;
 413                 struct sock *ssk;
 414
 415                 ssk = mptcp_subflow_tcp_sock(subflow);
 416
 417                 if (local->family != ssk->sk_family)
 418                         continue;
 419
 420                 issk = inet_sk(ssk);
 421
 422                 switch (ssk->sk_family) {
 423                 case AF_INET:
 424                         if (issk->inet_saddr != local->addr.s_addr ||
 425                             issk->inet_daddr != remote->addr.s_addr)
 426                                 continue;
 427                         break;
 428 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 429                 case AF_INET6: {
 430                         const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
 431
 432                         if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
 433                             !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
 434                                 continue;
 435                         break;
 436                 }
 437 #endif
 438                 default:
 439                         continue;
 440                 }
 441
 442                 if (issk->inet_sport == local->port &&
 443                     issk->inet_dport == remote->port)
 444                         return ssk;
 445         }
 446
 447         return NULL;
 448 }
 449
 450 int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
 451 {
 452         struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
 453         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 454         struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 455         struct mptcp_addr_info addr_l;
 456         struct mptcp_addr_info addr_r;
 457         struct mptcp_sock *msk;
 458         struct sock *sk, *ssk;
 459         int err = -EINVAL;
 460         u32 token_val;
 461
 462         if (!laddr || !raddr || !token) {
 463                 GENL_SET_ERR_MSG(info, "missing required inputs");
 464                 return err;
 465         }
 466
 467         token_val = nla_get_u32(token);
 468
 469         msk = mptcp_token_get_sock(genl_info_net(info), token_val);
 470         if (!msk) {
 471                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 472                 return err;
 473         }
 474
 475         if (!mptcp_pm_is_userspace(msk)) {
 476                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 477                 goto destroy_err;
 478         }
 479
 480         err = mptcp_pm_parse_addr(laddr, info, &addr_l);
 481         if (err < 0) {
 482                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
 483                 goto destroy_err;
 484         }
 485
 486         err = mptcp_pm_parse_addr(raddr, info, &addr_r);
 487         if (err < 0) {
 488                 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
 489                 goto destroy_err;
 490         }
 491
 492 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 493         if (addr_l.family == AF_INET && ipv6_addr_v4mapped(&addr_r.addr6)) {
 494                 ipv6_addr_set_v4mapped(addr_l.addr.s_addr, &addr_l.addr6);
 495                 addr_l.family = AF_INET6;
 496         }
 497         if (addr_r.family == AF_INET && ipv6_addr_v4mapped(&addr_l.addr6)) {
 498                 ipv6_addr_set_v4mapped(addr_r.addr.s_addr, &addr_r.addr6);
 499                 addr_r.family = AF_INET6;
 500         }
 501 #endif
 502         if (addr_l.family != addr_r.family) {
 503                 GENL_SET_ERR_MSG(info, "address families do not match");
 504                 err = -EINVAL;
 505                 goto destroy_err;
 506         }
 507
 508         if (!addr_l.port || !addr_r.port) {
 509                 GENL_SET_ERR_MSG(info, "missing local or remote port");
 510                 err = -EINVAL;
 511                 goto destroy_err;
 512         }
 513
 514         sk = &msk->sk.icsk_inet.sk;
 515         lock_sock(sk);
 516         ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
 517         if (ssk) {
 518                 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
 519                 struct mptcp_pm_addr_entry entry = { .addr = addr_l };
 520
 521                 spin_lock_bh(&msk->pm.lock);
 522                 mptcp_userspace_pm_delete_local_addr(msk, &entry);
 523                 spin_unlock_bh(&msk->pm.lock);
 524                 mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
 525                 mptcp_close_ssk(sk, ssk, subflow);
 526                 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
 527                 err = 0;
 528         } else {
 529                 err = -ESRCH;
 530         }
 531         release_sock(sk);
 532
 533 destroy_err:
 534         sock_put((struct sock *)msk);
 535         return err;
 536 }
 537
 538 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
 539                                  struct mptcp_pm_addr_entry *loc,
 540                                  struct mptcp_pm_addr_entry *rem, u8 bkup)
 541 {
 542         struct mptcp_sock *msk;
 543         int ret = -EINVAL;
 544         u32 token_val;
 545
 546         token_val = nla_get_u32(token);
 547
 548         msk = mptcp_token_get_sock(net, token_val);
 549         if (!msk)
 550                 return ret;
 551
 552         if (!mptcp_pm_is_userspace(msk))
 553                 goto set_flags_err;
 554
 555         if (loc->addr.family == AF_UNSPEC ||
 556             rem->addr.family == AF_UNSPEC)
 557                 goto set_flags_err;
 558
 559         lock_sock((struct sock *)msk);
 560         ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
 561         release_sock((struct sock *)msk);
 562
 563 set_flags_err:
 564         sock_put((struct sock *)msk);
 565         return ret;
 566 }