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                 ret = e->addr.id;
  73         } else if (match) {
  74                 ret = entry->addr.id;
  75         }
  76
  77         spin_unlock_bh(&msk->pm.lock);
  78         return ret;
  79 }
  80
  81 /* If the subflow is closed from the other peer (not via a
  82  * subflow destroy command then), we want to keep the entry
  83  * not to assign the same ID to another address and to be
  84  * able to send RM_ADDR after the removal of the subflow.
  85  */
  86 static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk,
  87                                                 struct mptcp_pm_addr_entry *addr)
  88 {
  89         struct mptcp_pm_addr_entry *entry, *tmp;
  90
  91         list_for_each_entry_safe(entry, tmp, &msk->pm.userspace_pm_local_addr_list, list) {
  92                 if (mptcp_addresses_equal(&entry->addr, &addr->addr, false)) {
  93                         /* TODO: a refcount is needed because the entry can
  94                          * be used multiple times (e.g. fullmesh mode).
  95                          */
  96                         list_del_rcu(&entry->list);
  97                         kfree(entry);
  98                         return 0;
  99                 }
 100         }
 101
 102         return -EINVAL;
 103 }
 104
 105 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
 106                                                    unsigned int id,
 107                                                    u8 *flags, int *ifindex)
 108 {
 109         struct mptcp_pm_addr_entry *entry, *match = NULL;
 110
 111         *flags = 0;
 112         *ifindex = 0;
 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_nl_cmd_announce(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         u32 token_val;
 156
 157         if (!addr || !token) {
 158                 GENL_SET_ERR_MSG(info, "missing required inputs");
 159                 return err;
 160         }
 161
 162         token_val = nla_get_u32(token);
 163
 164         msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
 165         if (!msk) {
 166                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 167                 return err;
 168         }
 169
 170         if (!mptcp_pm_is_userspace(msk)) {
 171                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 172                 goto announce_err;
 173         }
 174
 175         err = mptcp_pm_parse_entry(addr, info, true, &addr_val);
 176         if (err < 0) {
 177                 GENL_SET_ERR_MSG(info, "error parsing local address");
 178                 goto announce_err;
 179         }
 180
 181         if (addr_val.addr.id == 0 || !(addr_val.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
 182                 GENL_SET_ERR_MSG(info, "invalid addr id or flags");
 183                 err = -EINVAL;
 184                 goto announce_err;
 185         }
 186
 187         err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val);
 188         if (err < 0) {
 189                 GENL_SET_ERR_MSG(info, "did not match address and id");
 190                 goto announce_err;
 191         }
 192
 193         lock_sock((struct sock *)msk);
 194         spin_lock_bh(&msk->pm.lock);
 195
 196         if (mptcp_pm_alloc_anno_list(msk, &addr_val)) {
 197                 mptcp_pm_announce_addr(msk, &addr_val.addr, false);
 198                 mptcp_pm_nl_addr_send_ack(msk);
 199         }
 200
 201         spin_unlock_bh(&msk->pm.lock);
 202         release_sock((struct sock *)msk);
 203
 204         err = 0;
 205  announce_err:
 206         sock_put((struct sock *)msk);
 207         return err;
 208 }
 209
 210 int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
 211 {
 212         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 213         struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
 214         struct mptcp_pm_addr_entry *match = NULL;
 215         struct mptcp_pm_addr_entry *entry;
 216         struct mptcp_sock *msk;
 217         LIST_HEAD(free_list);
 218         int err = -EINVAL;
 219         u32 token_val;
 220         u8 id_val;
 221
 222         if (!id || !token) {
 223                 GENL_SET_ERR_MSG(info, "missing required inputs");
 224                 return err;
 225         }
 226
 227         id_val = nla_get_u8(id);
 228         token_val = nla_get_u32(token);
 229
 230         msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
 231         if (!msk) {
 232                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 233                 return err;
 234         }
 235
 236         if (!mptcp_pm_is_userspace(msk)) {
 237                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 238                 goto remove_err;
 239         }
 240
 241         lock_sock((struct sock *)msk);
 242
 243         list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
 244                 if (entry->addr.id == id_val) {
 245                         match = entry;
 246                         break;
 247                 }
 248         }
 249
 250         if (!match) {
 251                 GENL_SET_ERR_MSG(info, "address with specified id not found");
 252                 release_sock((struct sock *)msk);
 253                 goto remove_err;
 254         }
 255
 256         list_move(&match->list, &free_list);
 257
 258         mptcp_pm_remove_addrs(msk, &free_list);
 259
 260         release_sock((struct sock *)msk);
 261
 262         list_for_each_entry_safe(match, entry, &free_list, list) {
 263                 sock_kfree_s((struct sock *)msk, match, sizeof(*match));
 264         }
 265
 266         err = 0;
 267  remove_err:
 268         sock_put((struct sock *)msk);
 269         return err;
 270 }
 271
 272 int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
 273 {
 274         struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
 275         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 276         struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 277         struct mptcp_pm_addr_entry local = { 0 };
 278         struct mptcp_addr_info addr_r;
 279         struct mptcp_addr_info addr_l;
 280         struct mptcp_sock *msk;
 281         int err = -EINVAL;
 282         struct sock *sk;
 283         u32 token_val;
 284
 285         if (!laddr || !raddr || !token) {
 286                 GENL_SET_ERR_MSG(info, "missing required inputs");
 287                 return err;
 288         }
 289
 290         token_val = nla_get_u32(token);
 291
 292         msk = mptcp_token_get_sock(genl_info_net(info), token_val);
 293         if (!msk) {
 294                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 295                 return err;
 296         }
 297
 298         if (!mptcp_pm_is_userspace(msk)) {
 299                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 300                 goto create_err;
 301         }
 302
 303         err = mptcp_pm_parse_addr(laddr, info, &addr_l);
 304         if (err < 0) {
 305                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
 306                 goto create_err;
 307         }
 308
 309         if (addr_l.id == 0) {
 310                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "missing local addr id");
 311                 err = -EINVAL;
 312                 goto create_err;
 313         }
 314
 315         err = mptcp_pm_parse_addr(raddr, info, &addr_r);
 316         if (err < 0) {
 317                 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
 318                 goto create_err;
 319         }
 320
 321         sk = &msk->sk.icsk_inet.sk;
 322
 323         if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
 324                 GENL_SET_ERR_MSG(info, "families mismatch");
 325                 err = -EINVAL;
 326                 goto create_err;
 327         }
 328
 329         local.addr = addr_l;
 330         err = mptcp_userspace_pm_append_new_local_addr(msk, &local);
 331         if (err < 0) {
 332                 GENL_SET_ERR_MSG(info, "did not match address and id");
 333                 goto create_err;
 334         }
 335
 336         lock_sock(sk);
 337
 338         err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
 339
 340         release_sock(sk);
 341
 342         spin_lock_bh(&msk->pm.lock);
 343         if (err)
 344                 mptcp_userspace_pm_delete_local_addr(msk, &local);
 345         spin_unlock_bh(&msk->pm.lock);
 346
 347  create_err:
 348         sock_put((struct sock *)msk);
 349         return err;
 350 }
 351
 352 static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
 353                                       const struct mptcp_addr_info *local,
 354                                       const struct mptcp_addr_info *remote)
 355 {
 356         struct mptcp_subflow_context *subflow;
 357
 358         if (local->family != remote->family)
 359                 return NULL;
 360
 361         mptcp_for_each_subflow(msk, subflow) {
 362                 const struct inet_sock *issk;
 363                 struct sock *ssk;
 364
 365                 ssk = mptcp_subflow_tcp_sock(subflow);
 366
 367                 if (local->family != ssk->sk_family)
 368                         continue;
 369
 370                 issk = inet_sk(ssk);
 371
 372                 switch (ssk->sk_family) {
 373                 case AF_INET:
 374                         if (issk->inet_saddr != local->addr.s_addr ||
 375                             issk->inet_daddr != remote->addr.s_addr)
 376                                 continue;
 377                         break;
 378 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 379                 case AF_INET6: {
 380                         const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
 381
 382                         if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
 383                             !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
 384                                 continue;
 385                         break;
 386                 }
 387 #endif
 388                 default:
 389                         continue;
 390                 }
 391
 392                 if (issk->inet_sport == local->port &&
 393                     issk->inet_dport == remote->port)
 394                         return ssk;
 395         }
 396
 397         return NULL;
 398 }
 399
 400 int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
 401 {
 402         struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
 403         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 404         struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 405         struct mptcp_addr_info addr_l;
 406         struct mptcp_addr_info addr_r;
 407         struct mptcp_sock *msk;
 408         struct sock *sk, *ssk;
 409         int err = -EINVAL;
 410         u32 token_val;
 411
 412         if (!laddr || !raddr || !token) {
 413                 GENL_SET_ERR_MSG(info, "missing required inputs");
 414                 return err;
 415         }
 416
 417         token_val = nla_get_u32(token);
 418
 419         msk = mptcp_token_get_sock(genl_info_net(info), token_val);
 420         if (!msk) {
 421                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 422                 return err;
 423         }
 424
 425         if (!mptcp_pm_is_userspace(msk)) {
 426                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 427                 goto destroy_err;
 428         }
 429
 430         err = mptcp_pm_parse_addr(laddr, info, &addr_l);
 431         if (err < 0) {
 432                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
 433                 goto destroy_err;
 434         }
 435
 436         err = mptcp_pm_parse_addr(raddr, info, &addr_r);
 437         if (err < 0) {
 438                 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
 439                 goto destroy_err;
 440         }
 441
 442         if (addr_l.family != addr_r.family) {
 443                 GENL_SET_ERR_MSG(info, "address families do not match");
 444                 err = -EINVAL;
 445                 goto destroy_err;
 446         }
 447
 448         if (!addr_l.port || !addr_r.port) {
 449                 GENL_SET_ERR_MSG(info, "missing local or remote port");
 450                 err = -EINVAL;
 451                 goto destroy_err;
 452         }
 453
 454         sk = &msk->sk.icsk_inet.sk;
 455         lock_sock(sk);
 456         ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
 457         if (ssk) {
 458                 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
 459                 struct mptcp_pm_addr_entry entry = { .addr = addr_l };
 460
 461                 spin_lock_bh(&msk->pm.lock);
 462                 mptcp_userspace_pm_delete_local_addr(msk, &entry);
 463                 spin_unlock_bh(&msk->pm.lock);
 464                 mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
 465                 mptcp_close_ssk(sk, ssk, subflow);
 466                 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
 467                 err = 0;
 468         } else {
 469                 err = -ESRCH;
 470         }
 471         release_sock(sk);
 472
 473 destroy_err:
 474         sock_put((struct sock *)msk);
 475         return err;
 476 }
 477
 478 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
 479                                  struct mptcp_pm_addr_entry *loc,
 480                                  struct mptcp_pm_addr_entry *rem, u8 bkup)
 481 {
 482         struct mptcp_sock *msk;
 483         int ret = -EINVAL;
 484         u32 token_val;
 485
 486         token_val = nla_get_u32(token);
 487
 488         msk = mptcp_token_get_sock(net, token_val);
 489         if (!msk)
 490                 return ret;
 491
 492         if (!mptcp_pm_is_userspace(msk))
 493                 goto set_flags_err;
 494
 495         if (loc->addr.family == AF_UNSPEC ||
 496             rem->addr.family == AF_UNSPEC)
 497                 goto set_flags_err;
 498
 499         lock_sock((struct sock *)msk);
 500         ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
 501         release_sock((struct sock *)msk);
 502
 503 set_flags_err:
 504         sock_put((struct sock *)msk);
 505         return ret;
 506 }