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_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.addr)) {
 197                 msk->pm.add_addr_signaled++;
 198                 mptcp_pm_announce_addr(msk, &addr_val.addr, false);
 199                 mptcp_pm_nl_addr_send_ack(msk);
 200         }
 201
 202         spin_unlock_bh(&msk->pm.lock);
 203         release_sock((struct sock *)msk);
 204
 205         err = 0;
 206  announce_err:
 207         sock_put((struct sock *)msk);
 208         return err;
 209 }
 210
 211 int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
 212 {
 213         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 214         struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
 215         struct mptcp_pm_addr_entry *match = NULL;
 216         struct mptcp_pm_addr_entry *entry;
 217         struct mptcp_sock *msk;
 218         LIST_HEAD(free_list);
 219         int err = -EINVAL;
 220         u32 token_val;
 221         u8 id_val;
 222
 223         if (!id || !token) {
 224                 GENL_SET_ERR_MSG(info, "missing required inputs");
 225                 return err;
 226         }
 227
 228         id_val = nla_get_u8(id);
 229         token_val = nla_get_u32(token);
 230
 231         msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
 232         if (!msk) {
 233                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 234                 return err;
 235         }
 236
 237         if (!mptcp_pm_is_userspace(msk)) {
 238                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 239                 goto remove_err;
 240         }
 241
 242         lock_sock((struct sock *)msk);
 243
 244         list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
 245                 if (entry->addr.id == id_val) {
 246                         match = entry;
 247                         break;
 248                 }
 249         }
 250
 251         if (!match) {
 252                 GENL_SET_ERR_MSG(info, "address with specified id not found");
 253                 release_sock((struct sock *)msk);
 254                 goto remove_err;
 255         }
 256
 257         list_move(&match->list, &free_list);
 258
 259         mptcp_pm_remove_addrs(msk, &free_list);
 260
 261         release_sock((struct sock *)msk);
 262
 263         list_for_each_entry_safe(match, entry, &free_list, list) {
 264                 sock_kfree_s((struct sock *)msk, match, sizeof(*match));
 265         }
 266
 267         err = 0;
 268  remove_err:
 269         sock_put((struct sock *)msk);
 270         return err;
 271 }
 272
 273 int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
 274 {
 275         struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
 276         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 277         struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 278         struct mptcp_pm_addr_entry local = { 0 };
 279         struct mptcp_addr_info addr_r;
 280         struct mptcp_addr_info addr_l;
 281         struct mptcp_sock *msk;
 282         int err = -EINVAL;
 283         struct sock *sk;
 284         u32 token_val;
 285
 286         if (!laddr || !raddr || !token) {
 287                 GENL_SET_ERR_MSG(info, "missing required inputs");
 288                 return err;
 289         }
 290
 291         token_val = nla_get_u32(token);
 292
 293         msk = mptcp_token_get_sock(genl_info_net(info), token_val);
 294         if (!msk) {
 295                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 296                 return err;
 297         }
 298
 299         if (!mptcp_pm_is_userspace(msk)) {
 300                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 301                 goto create_err;
 302         }
 303
 304         err = mptcp_pm_parse_addr(laddr, info, &addr_l);
 305         if (err < 0) {
 306                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
 307                 goto create_err;
 308         }
 309
 310         if (addr_l.id == 0) {
 311                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "missing local addr id");
 312                 err = -EINVAL;
 313                 goto create_err;
 314         }
 315
 316         err = mptcp_pm_parse_addr(raddr, info, &addr_r);
 317         if (err < 0) {
 318                 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
 319                 goto create_err;
 320         }
 321
 322         sk = (struct sock *)msk;
 323
 324         if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
 325                 GENL_SET_ERR_MSG(info, "families mismatch");
 326                 err = -EINVAL;
 327                 goto create_err;
 328         }
 329
 330         local.addr = addr_l;
 331         err = mptcp_userspace_pm_append_new_local_addr(msk, &local);
 332         if (err < 0) {
 333                 GENL_SET_ERR_MSG(info, "did not match address and id");
 334                 goto create_err;
 335         }
 336
 337         lock_sock(sk);
 338
 339         err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
 340
 341         release_sock(sk);
 342
 343         spin_lock_bh(&msk->pm.lock);
 344         if (err)
 345                 mptcp_userspace_pm_delete_local_addr(msk, &local);
 346         else
 347                 msk->pm.subflows++;
 348         spin_unlock_bh(&msk->pm.lock);
 349
 350  create_err:
 351         sock_put((struct sock *)msk);
 352         return err;
 353 }
 354
 355 static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
 356                                       const struct mptcp_addr_info *local,
 357                                       const struct mptcp_addr_info *remote)
 358 {
 359         struct mptcp_subflow_context *subflow;
 360
 361         if (local->family != remote->family)
 362                 return NULL;
 363
 364         mptcp_for_each_subflow(msk, subflow) {
 365                 const struct inet_sock *issk;
 366                 struct sock *ssk;
 367
 368                 ssk = mptcp_subflow_tcp_sock(subflow);
 369
 370                 if (local->family != ssk->sk_family)
 371                         continue;
 372
 373                 issk = inet_sk(ssk);
 374
 375                 switch (ssk->sk_family) {
 376                 case AF_INET:
 377                         if (issk->inet_saddr != local->addr.s_addr ||
 378                             issk->inet_daddr != remote->addr.s_addr)
 379                                 continue;
 380                         break;
 381 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 382                 case AF_INET6: {
 383                         const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
 384
 385                         if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
 386                             !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
 387                                 continue;
 388                         break;
 389                 }
 390 #endif
 391                 default:
 392                         continue;
 393                 }
 394
 395                 if (issk->inet_sport == local->port &&
 396                     issk->inet_dport == remote->port)
 397                         return ssk;
 398         }
 399
 400         return NULL;
 401 }
 402
 403 int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
 404 {
 405         struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
 406         struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 407         struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 408         struct mptcp_addr_info addr_l;
 409         struct mptcp_addr_info addr_r;
 410         struct mptcp_sock *msk;
 411         struct sock *sk, *ssk;
 412         int err = -EINVAL;
 413         u32 token_val;
 414
 415         if (!laddr || !raddr || !token) {
 416                 GENL_SET_ERR_MSG(info, "missing required inputs");
 417                 return err;
 418         }
 419
 420         token_val = nla_get_u32(token);
 421
 422         msk = mptcp_token_get_sock(genl_info_net(info), token_val);
 423         if (!msk) {
 424                 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
 425                 return err;
 426         }
 427
 428         if (!mptcp_pm_is_userspace(msk)) {
 429                 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
 430                 goto destroy_err;
 431         }
 432
 433         err = mptcp_pm_parse_addr(laddr, info, &addr_l);
 434         if (err < 0) {
 435                 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
 436                 goto destroy_err;
 437         }
 438
 439         err = mptcp_pm_parse_addr(raddr, info, &addr_r);
 440         if (err < 0) {
 441                 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
 442                 goto destroy_err;
 443         }
 444
 445         if (addr_l.family != addr_r.family) {
 446                 GENL_SET_ERR_MSG(info, "address families do not match");
 447                 err = -EINVAL;
 448                 goto destroy_err;
 449         }
 450
 451         if (!addr_l.port || !addr_r.port) {
 452                 GENL_SET_ERR_MSG(info, "missing local or remote port");
 453                 err = -EINVAL;
 454                 goto destroy_err;
 455         }
 456
 457         sk = (struct sock *)msk;
 458         lock_sock(sk);
 459         ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
 460         if (ssk) {
 461                 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
 462                 struct mptcp_pm_addr_entry entry = { .addr = addr_l };
 463
 464                 spin_lock_bh(&msk->pm.lock);
 465                 mptcp_userspace_pm_delete_local_addr(msk, &entry);
 466                 spin_unlock_bh(&msk->pm.lock);
 467                 mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
 468                 mptcp_close_ssk(sk, ssk, subflow);
 469                 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
 470                 err = 0;
 471         } else {
 472                 err = -ESRCH;
 473         }
 474         release_sock(sk);
 475
 476 destroy_err:
 477         sock_put((struct sock *)msk);
 478         return err;
 479 }
 480
 481 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
 482                                  struct mptcp_pm_addr_entry *loc,
 483                                  struct mptcp_pm_addr_entry *rem, u8 bkup)
 484 {
 485         struct mptcp_sock *msk;
 486         int ret = -EINVAL;
 487         u32 token_val;
 488
 489         token_val = nla_get_u32(token);
 490
 491         msk = mptcp_token_get_sock(net, token_val);
 492         if (!msk)
 493                 return ret;
 494
 495         if (!mptcp_pm_is_userspace(msk))
 496                 goto set_flags_err;
 497
 498         if (loc->addr.family == AF_UNSPEC ||
 499             rem->addr.family == AF_UNSPEC)
 500                 goto set_flags_err;
 501
 502         lock_sock((struct sock *)msk);
 503         ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
 504         release_sock((struct sock *)msk);
 505
 506 set_flags_err:
 507         sock_put((struct sock *)msk);
 508         return ret;
 509 }