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 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                         spin_unlock_bh(&msk->pm.lock);
  63                         return -ENOMEM;
  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         spin_unlock_bh(&msk->pm.lock);
  79         return ret;
  80 }
  81
  82 /* If the subflow is closed from the other peer (not via a
  83  * subflow destroy command then), we want to keep the entry
  84  * not to assign the same ID to another address and to be
  85  * able to send RM_ADDR after the removal of the subflow.
  86  */
  87 static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk,
  88                                                 struct mptcp_pm_addr_entry *addr)
  89 {
  90         struct mptcp_pm_addr_entry *entry, *tmp;
  91
  92         list_for_each_entry_safe(entry, tmp, &msk->pm.userspace_pm_local_addr_list, list) {
  93                 if (mptcp_addresses_equal(&entry->addr, &addr->addr, false)) {
  94                         /* TODO: a refcount is needed because the entry can
  95                          * be used multiple times (e.g. fullmesh mode).
  96                          */
  97                         list_del_rcu(&entry->list);
  98                         kfree(entry);
  99                         msk->pm.local_addr_used--;
 100                         return 0;
 101                 }
 102         }
 103
 104         return -EINVAL;
 105 }
 106
 107 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
 108                                                    unsigned int id,
 109                                                    u8 *flags, int *ifindex)
 110 {
 111         struct mptcp_pm_addr_entry *entry, *match = NULL;
 112
 113         *flags = 0;
 114         *ifindex = 0;
 115
 116         spin_lock_bh(&msk->pm.lock);
 117         list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
 118                 if (id == entry->addr.id) {
 119                         match = entry;
 120                         break;
 121                 }
 122         }
 123         spin_unlock_bh(&msk->pm.lock);
 124         if (match) {
 125                 *flags = match->flags;
 126                 *ifindex = match->ifindex;
 127         }
 128
 129         return 0;
 130 }
 131
 132 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
 133                                     struct mptcp_addr_info *skc)
 134 {
 135         struct mptcp_pm_addr_entry new_entry;
 136         __be16 msk_sport =  ((struct inet_sock *)
 137                              inet_sk((struct sock *)msk))->inet_sport;
 138
 139         memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
 140         new_entry.addr = *skc;
 141         new_entry.addr.id = 0;
 142         new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
 143
 144         if (new_entry.addr.port == msk_sport)
 145                 new_entry.addr.port = 0;
 146
 147         return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry);
 148 }
 149
 150 int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info)
 151 {
 152         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 153         struct nlattr *addr = info->attrs[MPTCP_PM_ATTR_ADDR];
 154         struct mptcp_pm_addr_entry addr_val;
 155         struct mptcp_sock *msk;
 156         int err = -EINVAL;
 157         u32 token_val;
 158
 159         if (!addr || !token) {
 160                 GENL_SET_ERR_MSG(info, "missing required inputs");
 161                 return err;
 162         }
 163
 164         token_val = nla_get_u32(token);
 165
 166         msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
 167         if (!msk) {
 168                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 169                 return err;
 170         }
 171
 172         if (!mptcp_pm_is_userspace(msk)) {
 173                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 174                 goto announce_err;
 175         }
 176
 177         err = mptcp_pm_parse_entry(addr, info, true, &addr_val);
 178         if (err < 0) {
 179                 GENL_SET_ERR_MSG(info, "error parsing local address");
 180                 goto announce_err;
 181         }
 182
 183         if (addr_val.addr.id == 0 || !(addr_val.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
 184                 GENL_SET_ERR_MSG(info, "invalid addr id or flags");
 185                 err = -EINVAL;
 186                 goto announce_err;
 187         }
 188
 189         err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val);
 190         if (err < 0) {
 191                 GENL_SET_ERR_MSG(info, "did not match address and id");
 192                 goto announce_err;
 193         }
 194
 195         lock_sock((struct sock *)msk);
 196         spin_lock_bh(&msk->pm.lock);
 197
 198         if (mptcp_pm_alloc_anno_list(msk, &addr_val)) {
 199                 msk->pm.add_addr_signaled++;
 200                 mptcp_pm_announce_addr(msk, &addr_val.addr, false);
 201                 mptcp_pm_nl_addr_send_ack(msk);
 202         }
 203
 204         spin_unlock_bh(&msk->pm.lock);
 205         release_sock((struct sock *)msk);
 206
 207         err = 0;
 208  announce_err:
 209         sock_put((struct sock *)msk);
 210         return err;
 211 }
 212
 213 int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
 214 {
 215         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 216         struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
 217         struct mptcp_pm_addr_entry *match = NULL;
 218         struct mptcp_pm_addr_entry *entry;
 219         struct mptcp_sock *msk;
 220         LIST_HEAD(free_list);
 221         int err = -EINVAL;
 222         u32 token_val;
 223         u8 id_val;
 224
 225         if (!id || !token) {
 226                 GENL_SET_ERR_MSG(info, "missing required inputs");
 227                 return err;
 228         }
 229
 230         id_val = nla_get_u8(id);
 231         token_val = nla_get_u32(token);
 232
 233         msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
 234         if (!msk) {
 235                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 236                 return err;
 237         }
 238
 239         if (!mptcp_pm_is_userspace(msk)) {
 240                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 241                 goto remove_err;
 242         }
 243
 244         lock_sock((struct sock *)msk);
 245
 246         list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
 247                 if (entry->addr.id == id_val) {
 248                         match = entry;
 249                         break;
 250                 }
 251         }
 252
 253         if (!match) {
 254                 GENL_SET_ERR_MSG(info, "address with specified id not found");
 255                 release_sock((struct sock *)msk);
 256                 goto remove_err;
 257         }
 258
 259         list_move(&match->list, &free_list);
 260
 261         mptcp_pm_remove_addrs(msk, &free_list);
 262
 263         release_sock((struct sock *)msk);
 264
 265         list_for_each_entry_safe(match, entry, &free_list, list) {
 266                 sock_kfree_s((struct sock *)msk, match, sizeof(*match));
 267         }
 268
 269         err = 0;
 270  remove_err:
 271         sock_put((struct sock *)msk);
 272         return err;
 273 }
 274
 275 int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
 276 {
 277         struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
 278         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 279         struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 280         struct mptcp_pm_addr_entry local = { 0 };
 281         struct mptcp_addr_info addr_r;
 282         struct mptcp_addr_info addr_l;
 283         struct mptcp_sock *msk;
 284         int err = -EINVAL;
 285         struct sock *sk;
 286         u32 token_val;
 287
 288         if (!laddr || !raddr || !token) {
 289                 GENL_SET_ERR_MSG(info, "missing required inputs");
 290                 return err;
 291         }
 292
 293         token_val = nla_get_u32(token);
 294
 295         msk = mptcp_token_get_sock(genl_info_net(info), token_val);
 296         if (!msk) {
 297                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 298                 return err;
 299         }
 300
 301         if (!mptcp_pm_is_userspace(msk)) {
 302                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 303                 goto create_err;
 304         }
 305
 306         err = mptcp_pm_parse_addr(laddr, info, &addr_l);
 307         if (err < 0) {
 308                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
 309                 goto create_err;
 310         }
 311
 312         if (addr_l.id == 0) {
 313                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "missing local addr id");
 314                 err = -EINVAL;
 315                 goto create_err;
 316         }
 317
 318         err = mptcp_pm_parse_addr(raddr, info, &addr_r);
 319         if (err < 0) {
 320                 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
 321                 goto create_err;
 322         }
 323
 324         sk = &msk->sk.icsk_inet.sk;
 325
 326         if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
 327                 GENL_SET_ERR_MSG(info, "families mismatch");
 328                 err = -EINVAL;
 329                 goto create_err;
 330         }
 331
 332         local.addr = addr_l;
 333         err = mptcp_userspace_pm_append_new_local_addr(msk, &local);
 334         if (err < 0) {
 335                 GENL_SET_ERR_MSG(info, "did not match address and id");
 336                 goto create_err;
 337         }
 338
 339         lock_sock(sk);
 340
 341         err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
 342
 343         release_sock(sk);
 344
 345         spin_lock_bh(&msk->pm.lock);
 346         if (err)
 347                 mptcp_userspace_pm_delete_local_addr(msk, &local);
 348         else
 349                 msk->pm.subflows++;
 350         spin_unlock_bh(&msk->pm.lock);
 351
 352  create_err:
 353         sock_put((struct sock *)msk);
 354         return err;
 355 }
 356
 357 static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
 358                                       const struct mptcp_addr_info *local,
 359                                       const struct mptcp_addr_info *remote)
 360 {
 361         struct mptcp_subflow_context *subflow;
 362
 363         if (local->family != remote->family)
 364                 return NULL;
 365
 366         mptcp_for_each_subflow(msk, subflow) {
 367                 const struct inet_sock *issk;
 368                 struct sock *ssk;
 369
 370                 ssk = mptcp_subflow_tcp_sock(subflow);
 371
 372                 if (local->family != ssk->sk_family)
 373                         continue;
 374
 375                 issk = inet_sk(ssk);
 376
 377                 switch (ssk->sk_family) {
 378                 case AF_INET:
 379                         if (issk->inet_saddr != local->addr.s_addr ||
 380                             issk->inet_daddr != remote->addr.s_addr)
 381                                 continue;
 382                         break;
 383 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 384                 case AF_INET6: {
 385                         const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
 386
 387                         if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
 388                             !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
 389                                 continue;
 390                         break;
 391                 }
 392 #endif
 393                 default:
 394                         continue;
 395                 }
 396
 397                 if (issk->inet_sport == local->port &&
 398                     issk->inet_dport == remote->port)
 399                         return ssk;
 400         }
 401
 402         return NULL;
 403 }
 404
 405 int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
 406 {
 407         struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
 408         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 409         struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 410         struct mptcp_addr_info addr_l;
 411         struct mptcp_addr_info addr_r;
 412         struct mptcp_sock *msk;
 413         struct sock *sk, *ssk;
 414         int err = -EINVAL;
 415         u32 token_val;
 416
 417         if (!laddr || !raddr || !token) {
 418                 GENL_SET_ERR_MSG(info, "missing required inputs");
 419                 return err;
 420         }
 421
 422         token_val = nla_get_u32(token);
 423
 424         msk = mptcp_token_get_sock(genl_info_net(info), token_val);
 425         if (!msk) {
 426                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 427                 return err;
 428         }
 429
 430         if (!mptcp_pm_is_userspace(msk)) {
 431                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 432                 goto destroy_err;
 433         }
 434
 435         err = mptcp_pm_parse_addr(laddr, info, &addr_l);
 436         if (err < 0) {
 437                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
 438                 goto destroy_err;
 439         }
 440
 441         err = mptcp_pm_parse_addr(raddr, info, &addr_r);
 442         if (err < 0) {
 443                 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
 444                 goto destroy_err;
 445         }
 446
 447         if (addr_l.family != addr_r.family) {
 448                 GENL_SET_ERR_MSG(info, "address families do not match");
 449                 err = -EINVAL;
 450                 goto destroy_err;
 451         }
 452
 453         if (!addr_l.port || !addr_r.port) {
 454                 GENL_SET_ERR_MSG(info, "missing local or remote port");
 455                 err = -EINVAL;
 456                 goto destroy_err;
 457         }
 458
 459         sk = &msk->sk.icsk_inet.sk;
 460         lock_sock(sk);
 461         ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
 462         if (ssk) {
 463                 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
 464                 struct mptcp_pm_addr_entry entry = { .addr = addr_l };
 465
 466                 spin_lock_bh(&msk->pm.lock);
 467                 mptcp_userspace_pm_delete_local_addr(msk, &entry);
 468                 spin_unlock_bh(&msk->pm.lock);
 469                 mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
 470                 mptcp_close_ssk(sk, ssk, subflow);
 471                 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
 472                 err = 0;
 473         } else {
 474                 err = -ESRCH;
 475         }
 476         release_sock(sk);
 477
 478 destroy_err:
 479         sock_put((struct sock *)msk);
 480         return err;
 481 }
 482
 483 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
 484                                  struct mptcp_pm_addr_entry *loc,
 485                                  struct mptcp_pm_addr_entry *rem, u8 bkup)
 486 {
 487         struct mptcp_sock *msk;
 488         int ret = -EINVAL;
 489         u32 token_val;
 490
 491         token_val = nla_get_u32(token);
 492
 493         msk = mptcp_token_get_sock(net, token_val);
 494         if (!msk)
 495                 return ret;
 496
 497         if (!mptcp_pm_is_userspace(msk))
 498                 goto set_flags_err;
 499
 500         if (loc->addr.family == AF_UNSPEC ||
 501             rem->addr.family == AF_UNSPEC)
 502                 goto set_flags_err;
 503
 504         lock_sock((struct sock *)msk);
 505         ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
 506         release_sock((struct sock *)msk);
 507
 508 set_flags_err:
 509         sock_put((struct sock *)msk);
 510         return ret;
 511 }