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