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         *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 new_entry;
 137         __be16 msk_sport =  ((struct inet_sock *)
 138                              inet_sk((struct sock *)msk))->inet_sport;
 139
 140         memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
 141         new_entry.addr = *skc;
 142         new_entry.addr.id = 0;
 143         new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
 144
 145         if (new_entry.addr.port == msk_sport)
 146                 new_entry.addr.port = 0;
 147
 148         return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry);
 149 }
 150
 151 int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info)
 152 {
 153         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 154         struct nlattr *addr = info->attrs[MPTCP_PM_ATTR_ADDR];
 155         struct mptcp_pm_addr_entry addr_val;
 156         struct mptcp_sock *msk;
 157         int err = -EINVAL;
 158         u32 token_val;
 159
 160         if (!addr || !token) {
 161                 GENL_SET_ERR_MSG(info, "missing required inputs");
 162                 return err;
 163         }
 164
 165         token_val = nla_get_u32(token);
 166
 167         msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
 168         if (!msk) {
 169                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 170                 return err;
 171         }
 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((struct sock *)msk);
 197         spin_lock_bh(&msk->pm.lock);
 198
 199         if (mptcp_pm_alloc_anno_list(msk, &addr_val)) {
 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((struct sock *)msk);
 207
 208         err = 0;
 209  announce_err:
 210         sock_put((struct sock *)msk);
 211         return err;
 212 }
 213
 214 int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
 215 {
 216         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 217         struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
 218         struct mptcp_pm_addr_entry *match = NULL;
 219         struct mptcp_pm_addr_entry *entry;
 220         struct mptcp_sock *msk;
 221         LIST_HEAD(free_list);
 222         int err = -EINVAL;
 223         u32 token_val;
 224         u8 id_val;
 225
 226         if (!id || !token) {
 227                 GENL_SET_ERR_MSG(info, "missing required inputs");
 228                 return err;
 229         }
 230
 231         id_val = nla_get_u8(id);
 232         token_val = nla_get_u32(token);
 233
 234         msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
 235         if (!msk) {
 236                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 237                 return err;
 238         }
 239
 240         if (!mptcp_pm_is_userspace(msk)) {
 241                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 242                 goto remove_err;
 243         }
 244
 245         lock_sock((struct sock *)msk);
 246
 247         list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
 248                 if (entry->addr.id == id_val) {
 249                         match = entry;
 250                         break;
 251                 }
 252         }
 253
 254         if (!match) {
 255                 GENL_SET_ERR_MSG(info, "address with specified id not found");
 256                 release_sock((struct sock *)msk);
 257                 goto remove_err;
 258         }
 259
 260         list_move(&match->list, &free_list);
 261
 262         mptcp_pm_remove_addrs(msk, &free_list);
 263
 264         release_sock((struct sock *)msk);
 265
 266         list_for_each_entry_safe(match, entry, &free_list, list) {
 267                 sock_kfree_s((struct sock *)msk, match, sizeof(*match));
 268         }
 269
 270         err = 0;
 271  remove_err:
 272         sock_put((struct sock *)msk);
 273         return err;
 274 }
 275
 276 int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
 277 {
 278         struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
 279         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 280         struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 281         struct mptcp_pm_addr_entry local = { 0 };
 282         struct mptcp_addr_info addr_r;
 283         struct mptcp_addr_info addr_l;
 284         struct mptcp_sock *msk;
 285         int err = -EINVAL;
 286         struct sock *sk;
 287         u32 token_val;
 288
 289         if (!laddr || !raddr || !token) {
 290                 GENL_SET_ERR_MSG(info, "missing required inputs");
 291                 return err;
 292         }
 293
 294         token_val = nla_get_u32(token);
 295
 296         msk = mptcp_token_get_sock(genl_info_net(info), token_val);
 297         if (!msk) {
 298                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 299                 return err;
 300         }
 301
 302         if (!mptcp_pm_is_userspace(msk)) {
 303                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 304                 goto create_err;
 305         }
 306
 307         err = mptcp_pm_parse_addr(laddr, info, &addr_l);
 308         if (err < 0) {
 309                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
 310                 goto create_err;
 311         }
 312
 313         if (addr_l.id == 0) {
 314                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "missing local addr id");
 315                 err = -EINVAL;
 316                 goto create_err;
 317         }
 318
 319         err = mptcp_pm_parse_addr(raddr, info, &addr_r);
 320         if (err < 0) {
 321                 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
 322                 goto create_err;
 323         }
 324
 325         sk = (struct sock *)msk;
 326
 327         if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
 328                 GENL_SET_ERR_MSG(info, "families mismatch");
 329                 err = -EINVAL;
 330                 goto create_err;
 331         }
 332
 333         local.addr = addr_l;
 334         err = mptcp_userspace_pm_append_new_local_addr(msk, &local);
 335         if (err < 0) {
 336                 GENL_SET_ERR_MSG(info, "did not match address and id");
 337                 goto create_err;
 338         }
 339
 340         lock_sock(sk);
 341
 342         err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
 343
 344         release_sock(sk);
 345
 346         spin_lock_bh(&msk->pm.lock);
 347         if (err)
 348                 mptcp_userspace_pm_delete_local_addr(msk, &local);
 349         else
 350                 msk->pm.subflows++;
 351         spin_unlock_bh(&msk->pm.lock);
 352
 353  create_err:
 354         sock_put((struct sock *)msk);
 355         return err;
 356 }
 357
 358 static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
 359                                       const struct mptcp_addr_info *local,
 360                                       const struct mptcp_addr_info *remote)
 361 {
 362         struct mptcp_subflow_context *subflow;
 363
 364         if (local->family != remote->family)
 365                 return NULL;
 366
 367         mptcp_for_each_subflow(msk, subflow) {
 368                 const struct inet_sock *issk;
 369                 struct sock *ssk;
 370
 371                 ssk = mptcp_subflow_tcp_sock(subflow);
 372
 373                 if (local->family != ssk->sk_family)
 374                         continue;
 375
 376                 issk = inet_sk(ssk);
 377
 378                 switch (ssk->sk_family) {
 379                 case AF_INET:
 380                         if (issk->inet_saddr != local->addr.s_addr ||
 381                             issk->inet_daddr != remote->addr.s_addr)
 382                                 continue;
 383                         break;
 384 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 385                 case AF_INET6: {
 386                         const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
 387
 388                         if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
 389                             !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
 390                                 continue;
 391                         break;
 392                 }
 393 #endif
 394                 default:
 395                         continue;
 396                 }
 397
 398                 if (issk->inet_sport == local->port &&
 399                     issk->inet_dport == remote->port)
 400                         return ssk;
 401         }
 402
 403         return NULL;
 404 }
 405
 406 int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
 407 {
 408         struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
 409         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 410         struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 411         struct mptcp_addr_info addr_l;
 412         struct mptcp_addr_info addr_r;
 413         struct mptcp_sock *msk;
 414         struct sock *sk, *ssk;
 415         int err = -EINVAL;
 416         u32 token_val;
 417
 418         if (!laddr || !raddr || !token) {
 419                 GENL_SET_ERR_MSG(info, "missing required inputs");
 420                 return err;
 421         }
 422
 423         token_val = nla_get_u32(token);
 424
 425         msk = mptcp_token_get_sock(genl_info_net(info), token_val);
 426         if (!msk) {
 427                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 428                 return err;
 429         }
 430
 431         if (!mptcp_pm_is_userspace(msk)) {
 432                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 433                 goto destroy_err;
 434         }
 435
 436         err = mptcp_pm_parse_addr(laddr, info, &addr_l);
 437         if (err < 0) {
 438                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
 439                 goto destroy_err;
 440         }
 441
 442         err = mptcp_pm_parse_addr(raddr, info, &addr_r);
 443         if (err < 0) {
 444                 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
 445                 goto destroy_err;
 446         }
 447
 448         if (addr_l.family != addr_r.family) {
 449                 GENL_SET_ERR_MSG(info, "address families do not match");
 450                 err = -EINVAL;
 451                 goto destroy_err;
 452         }
 453
 454         if (!addr_l.port || !addr_r.port) {
 455                 GENL_SET_ERR_MSG(info, "missing local or remote port");
 456                 err = -EINVAL;
 457                 goto destroy_err;
 458         }
 459
 460         sk = (struct sock *)msk;
 461         lock_sock(sk);
 462         ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
 463         if (ssk) {
 464                 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
 465                 struct mptcp_pm_addr_entry entry = { .addr = addr_l };
 466
 467                 spin_lock_bh(&msk->pm.lock);
 468                 mptcp_userspace_pm_delete_local_addr(msk, &entry);
 469                 spin_unlock_bh(&msk->pm.lock);
 470                 mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
 471                 mptcp_close_ssk(sk, ssk, subflow);
 472                 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
 473                 err = 0;
 474         } else {
 475                 err = -ESRCH;
 476         }
 477         release_sock(sk);
 478
 479 destroy_err:
 480         sock_put((struct sock *)msk);
 481         return err;
 482 }
 483
 484 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
 485                                  struct mptcp_pm_addr_entry *loc,
 486                                  struct mptcp_pm_addr_entry *rem, u8 bkup)
 487 {
 488         struct mptcp_sock *msk;
 489         int ret = -EINVAL;
 490         u32 token_val;
 491
 492         token_val = nla_get_u32(token);
 493
 494         msk = mptcp_token_get_sock(net, token_val);
 495         if (!msk)
 496                 return ret;
 497
 498         if (!mptcp_pm_is_userspace(msk))
 499                 goto set_flags_err;
 500
 501         if (loc->addr.family == AF_UNSPEC ||
 502             rem->addr.family == AF_UNSPEC)
 503                 goto set_flags_err;
 504
 505         lock_sock((struct sock *)msk);
 506         ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
 507         release_sock((struct sock *)msk);
 508
 509 set_flags_err:
 510         sock_put((struct sock *)msk);
 511         return ret;
 512 }