net/rds/tcp.c

   1 /*
   2  * Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  *
  32  */
  33 #include <linux/kernel.h>
  34 #include <linux/slab.h>
  35 #include <linux/in.h>
  36 #include <linux/module.h>
  37 #include <net/tcp.h>
  38 #include <net/net_namespace.h>
  39 #include <net/netns/generic.h>
  40 #include <net/addrconf.h>
  41
  42 #include "rds.h"
  43 #include "tcp.h"
  44
  45 /* only for info exporting */
  46 static DEFINE_SPINLOCK(rds_tcp_tc_list_lock);
  47 static LIST_HEAD(rds_tcp_tc_list);
  48
  49 /* rds_tcp_tc_count counts only IPv4 connections.
  50  * rds6_tcp_tc_count counts both IPv4 and IPv6 connections.
  51  */
  52 static unsigned int rds_tcp_tc_count;
  53 #if IS_ENABLED(CONFIG_IPV6)
  54 static unsigned int rds6_tcp_tc_count;
  55 #endif
  56
  57 /* Track rds_tcp_connection structs so they can be cleaned up */
  58 static DEFINE_SPINLOCK(rds_tcp_conn_lock);
  59 static LIST_HEAD(rds_tcp_conn_list);
  60 static atomic_t rds_tcp_unloading = ATOMIC_INIT(0);
  61
  62 static struct kmem_cache *rds_tcp_conn_slab;
  63
  64 static int rds_tcp_skbuf_handler(const struct ctl_table *ctl, int write,
  65                                  void *buffer, size_t *lenp, loff_t *fpos);
  66
  67 static int rds_tcp_min_sndbuf = SOCK_MIN_SNDBUF;
  68 static int rds_tcp_min_rcvbuf = SOCK_MIN_RCVBUF;
  69
  70 static struct ctl_table rds_tcp_sysctl_table[] = {
  71 #define RDS_TCP_SNDBUF  0
  72         {
  73                 .procname       = "rds_tcp_sndbuf",
  74                 /* data is per-net pointer */
  75                 .maxlen         = sizeof(int),
  76                 .mode           = 0644,
  77                 .proc_handler   = rds_tcp_skbuf_handler,
  78                 .extra1         = &rds_tcp_min_sndbuf,
  79         },
  80 #define RDS_TCP_RCVBUF  1
  81         {
  82                 .procname       = "rds_tcp_rcvbuf",
  83                 /* data is per-net pointer */
  84                 .maxlen         = sizeof(int),
  85                 .mode           = 0644,
  86                 .proc_handler   = rds_tcp_skbuf_handler,
  87                 .extra1         = &rds_tcp_min_rcvbuf,
  88         },
  89 };
  90
  91 u32 rds_tcp_write_seq(struct rds_tcp_connection *tc)
  92 {
  93         /* seq# of the last byte of data in tcp send buffer */
  94         return tcp_sk(tc->t_sock->sk)->write_seq;
  95 }
  96
  97 u32 rds_tcp_snd_una(struct rds_tcp_connection *tc)
  98 {
  99         return tcp_sk(tc->t_sock->sk)->snd_una;
 100 }
 101
 102 void rds_tcp_restore_callbacks(struct socket *sock,
 103                                struct rds_tcp_connection *tc)
 104 {
 105         rdsdebug("restoring sock %p callbacks from tc %p\n", sock, tc);
 106         write_lock_bh(&sock->sk->sk_callback_lock);
 107
 108         /* done under the callback_lock to serialize with write_space */
 109         spin_lock(&rds_tcp_tc_list_lock);
 110         list_del_init(&tc->t_list_item);
 111 #if IS_ENABLED(CONFIG_IPV6)
 112         rds6_tcp_tc_count--;
 113 #endif
 114         if (!tc->t_cpath->cp_conn->c_isv6)
 115                 rds_tcp_tc_count--;
 116         spin_unlock(&rds_tcp_tc_list_lock);
 117
 118         tc->t_sock = NULL;
 119
 120         sock->sk->sk_write_space = tc->t_orig_write_space;
 121         sock->sk->sk_data_ready = tc->t_orig_data_ready;
 122         sock->sk->sk_state_change = tc->t_orig_state_change;
 123         sock->sk->sk_user_data = NULL;
 124
 125         write_unlock_bh(&sock->sk->sk_callback_lock);
 126 }
 127
 128 /*
 129  * rds_tcp_reset_callbacks() switches the to the new sock and
 130  * returns the existing tc->t_sock.
 131  *
 132  * The only functions that set tc->t_sock are rds_tcp_set_callbacks
 133  * and rds_tcp_reset_callbacks.  Send and receive trust that
 134  * it is set.  The absence of RDS_CONN_UP bit protects those paths
 135  * from being called while it isn't set.
 136  */
 137 void rds_tcp_reset_callbacks(struct socket *sock,
 138                              struct rds_conn_path *cp)
 139 {
 140         struct rds_tcp_connection *tc = cp->cp_transport_data;
 141         struct socket *osock = tc->t_sock;
 142
 143         if (!osock)
 144                 goto newsock;
 145
 146         /* Need to resolve a duelling SYN between peers.
 147          * We have an outstanding SYN to this peer, which may
 148          * potentially have transitioned to the RDS_CONN_UP state,
 149          * so we must quiesce any send threads before resetting
 150          * cp_transport_data. We quiesce these threads by setting
 151          * cp_state to something other than RDS_CONN_UP, and then
 152          * waiting for any existing threads in rds_send_xmit to
 153          * complete release_in_xmit(). (Subsequent threads entering
 154          * rds_send_xmit() will bail on !rds_conn_up().
 155          *
 156          * However an incoming syn-ack at this point would end up
 157          * marking the conn as RDS_CONN_UP, and would again permit
 158          * rds_send_xmi() threads through, so ideally we would
 159          * synchronize on RDS_CONN_UP after lock_sock(), but cannot
 160          * do that: waiting on !RDS_IN_XMIT after lock_sock() may
 161          * end up deadlocking with tcp_sendmsg(), and the RDS_IN_XMIT
 162          * would not get set. As a result, we set c_state to
 163          * RDS_CONN_RESETTTING, to ensure that rds_tcp_state_change
 164          * cannot mark rds_conn_path_up() in the window before lock_sock()
 165          */
 166         atomic_set(&cp->cp_state, RDS_CONN_RESETTING);
 167         wait_event(cp->cp_waitq, !test_bit(RDS_IN_XMIT, &cp->cp_flags));
 168         /* reset receive side state for rds_tcp_data_recv() for osock  */
 169         cancel_delayed_work_sync(&cp->cp_send_w);
 170         cancel_delayed_work_sync(&cp->cp_recv_w);
 171         lock_sock(osock->sk);
 172         if (tc->t_tinc) {
 173                 rds_inc_put(&tc->t_tinc->ti_inc);
 174                 tc->t_tinc = NULL;
 175         }
 176         tc->t_tinc_hdr_rem = sizeof(struct rds_header);
 177         tc->t_tinc_data_rem = 0;
 178         rds_tcp_restore_callbacks(osock, tc);
 179         release_sock(osock->sk);
 180         sock_release(osock);
 181 newsock:
 182         rds_send_path_reset(cp);
 183         lock_sock(sock->sk);
 184         rds_tcp_set_callbacks(sock, cp);
 185         release_sock(sock->sk);
 186 }
 187
 188 /* Add tc to rds_tcp_tc_list and set tc->t_sock. See comments
 189  * above rds_tcp_reset_callbacks for notes about synchronization
 190  * with data path
 191  */
 192 void rds_tcp_set_callbacks(struct socket *sock, struct rds_conn_path *cp)
 193 {
 194         struct rds_tcp_connection *tc = cp->cp_transport_data;
 195
 196         rdsdebug("setting sock %p callbacks to tc %p\n", sock, tc);
 197         write_lock_bh(&sock->sk->sk_callback_lock);
 198
 199         /* done under the callback_lock to serialize with write_space */
 200         spin_lock(&rds_tcp_tc_list_lock);
 201         list_add_tail(&tc->t_list_item, &rds_tcp_tc_list);
 202 #if IS_ENABLED(CONFIG_IPV6)
 203         rds6_tcp_tc_count++;
 204 #endif
 205         if (!tc->t_cpath->cp_conn->c_isv6)
 206                 rds_tcp_tc_count++;
 207         spin_unlock(&rds_tcp_tc_list_lock);
 208
 209         /* accepted sockets need our listen data ready undone */
 210         if (sock->sk->sk_data_ready == rds_tcp_listen_data_ready)
 211                 sock->sk->sk_data_ready = sock->sk->sk_user_data;
 212
 213         tc->t_sock = sock;
 214         tc->t_cpath = cp;
 215         tc->t_orig_data_ready = sock->sk->sk_data_ready;
 216         tc->t_orig_write_space = sock->sk->sk_write_space;
 217         tc->t_orig_state_change = sock->sk->sk_state_change;
 218
 219         sock->sk->sk_user_data = cp;
 220         sock->sk->sk_data_ready = rds_tcp_data_ready;
 221         sock->sk->sk_write_space = rds_tcp_write_space;
 222         sock->sk->sk_state_change = rds_tcp_state_change;
 223
 224         write_unlock_bh(&sock->sk->sk_callback_lock);
 225 }
 226
 227 /* Handle RDS_INFO_TCP_SOCKETS socket option.  It only returns IPv4
 228  * connections for backward compatibility.
 229  */
 230 static void rds_tcp_tc_info(struct socket *rds_sock, unsigned int len,
 231                             struct rds_info_iterator *iter,
 232                             struct rds_info_lengths *lens)
 233 {
 234         struct rds_info_tcp_socket tsinfo;
 235         struct rds_tcp_connection *tc;
 236         unsigned long flags;
 237
 238         spin_lock_irqsave(&rds_tcp_tc_list_lock, flags);
 239
 240         if (len / sizeof(tsinfo) < rds_tcp_tc_count)
 241                 goto out;
 242
 243         list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) {
 244                 struct inet_sock *inet = inet_sk(tc->t_sock->sk);
 245
 246                 if (tc->t_cpath->cp_conn->c_isv6)
 247                         continue;
 248
 249                 tsinfo.local_addr = inet->inet_saddr;
 250                 tsinfo.local_port = inet->inet_sport;
 251                 tsinfo.peer_addr = inet->inet_daddr;
 252                 tsinfo.peer_port = inet->inet_dport;
 253
 254                 tsinfo.hdr_rem = tc->t_tinc_hdr_rem;
 255                 tsinfo.data_rem = tc->t_tinc_data_rem;
 256                 tsinfo.last_sent_nxt = tc->t_last_sent_nxt;
 257                 tsinfo.last_expected_una = tc->t_last_expected_una;
 258                 tsinfo.last_seen_una = tc->t_last_seen_una;
 259                 tsinfo.tos = tc->t_cpath->cp_conn->c_tos;
 260
 261                 rds_info_copy(iter, &tsinfo, sizeof(tsinfo));
 262         }
 263
 264 out:
 265         lens->nr = rds_tcp_tc_count;
 266         lens->each = sizeof(tsinfo);
 267
 268         spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
 269 }
 270
 271 #if IS_ENABLED(CONFIG_IPV6)
 272 /* Handle RDS6_INFO_TCP_SOCKETS socket option. It returns both IPv4 and
 273  * IPv6 connections. IPv4 connection address is returned in an IPv4 mapped
 274  * address.
 275  */
 276 static void rds6_tcp_tc_info(struct socket *sock, unsigned int len,
 277                              struct rds_info_iterator *iter,
 278                              struct rds_info_lengths *lens)
 279 {
 280         struct rds6_info_tcp_socket tsinfo6;
 281         struct rds_tcp_connection *tc;
 282         unsigned long flags;
 283
 284         spin_lock_irqsave(&rds_tcp_tc_list_lock, flags);
 285
 286         if (len / sizeof(tsinfo6) < rds6_tcp_tc_count)
 287                 goto out;
 288
 289         list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) {
 290                 struct sock *sk = tc->t_sock->sk;
 291                 struct inet_sock *inet = inet_sk(sk);
 292
 293                 tsinfo6.local_addr = sk->sk_v6_rcv_saddr;
 294                 tsinfo6.local_port = inet->inet_sport;
 295                 tsinfo6.peer_addr = sk->sk_v6_daddr;
 296                 tsinfo6.peer_port = inet->inet_dport;
 297
 298                 tsinfo6.hdr_rem = tc->t_tinc_hdr_rem;
 299                 tsinfo6.data_rem = tc->t_tinc_data_rem;
 300                 tsinfo6.last_sent_nxt = tc->t_last_sent_nxt;
 301                 tsinfo6.last_expected_una = tc->t_last_expected_una;
 302                 tsinfo6.last_seen_una = tc->t_last_seen_una;
 303
 304                 rds_info_copy(iter, &tsinfo6, sizeof(tsinfo6));
 305         }
 306
 307 out:
 308         lens->nr = rds6_tcp_tc_count;
 309         lens->each = sizeof(tsinfo6);
 310
 311         spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
 312 }
 313 #endif
 314
 315 int rds_tcp_laddr_check(struct net *net, const struct in6_addr *addr,
 316                         __u32 scope_id)
 317 {
 318         struct net_device *dev = NULL;
 319 #if IS_ENABLED(CONFIG_IPV6)
 320         int ret;
 321 #endif
 322
 323         if (ipv6_addr_v4mapped(addr)) {
 324                 if (inet_addr_type(net, addr->s6_addr32[3]) == RTN_LOCAL)
 325                         return 0;
 326                 return -EADDRNOTAVAIL;
 327         }
 328
 329         /* If the scope_id is specified, check only those addresses
 330          * hosted on the specified interface.
 331          */
 332         if (scope_id != 0) {
 333                 rcu_read_lock();
 334                 dev = dev_get_by_index_rcu(net, scope_id);
 335                 /* scope_id is not valid... */
 336                 if (!dev) {
 337                         rcu_read_unlock();
 338                         return -EADDRNOTAVAIL;
 339                 }
 340                 rcu_read_unlock();
 341         }
 342 #if IS_ENABLED(CONFIG_IPV6)
 343         ret = ipv6_chk_addr(net, addr, dev, 0);
 344         if (ret)
 345                 return 0;
 346 #endif
 347         return -EADDRNOTAVAIL;
 348 }
 349
 350 static void rds_tcp_conn_free(void *arg)
 351 {
 352         struct rds_tcp_connection *tc = arg;
 353         unsigned long flags;
 354
 355         rdsdebug("freeing tc %p\n", tc);
 356
 357         spin_lock_irqsave(&rds_tcp_conn_lock, flags);
 358         if (!tc->t_tcp_node_detached)
 359                 list_del(&tc->t_tcp_node);
 360         spin_unlock_irqrestore(&rds_tcp_conn_lock, flags);
 361
 362         kmem_cache_free(rds_tcp_conn_slab, tc);
 363 }
 364
 365 static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp)
 366 {
 367         struct rds_tcp_connection *tc;
 368         int i, j;
 369         int ret = 0;
 370
 371         for (i = 0; i < RDS_MPATH_WORKERS; i++) {
 372                 tc = kmem_cache_alloc(rds_tcp_conn_slab, gfp);
 373                 if (!tc) {
 374                         ret = -ENOMEM;
 375                         goto fail;
 376                 }
 377                 mutex_init(&tc->t_conn_path_lock);
 378                 tc->t_sock = NULL;
 379                 tc->t_tinc = NULL;
 380                 tc->t_tinc_hdr_rem = sizeof(struct rds_header);
 381                 tc->t_tinc_data_rem = 0;
 382
 383                 conn->c_path[i].cp_transport_data = tc;
 384                 tc->t_cpath = &conn->c_path[i];
 385                 tc->t_tcp_node_detached = true;
 386
 387                 rdsdebug("rds_conn_path [%d] tc %p\n", i,
 388                          conn->c_path[i].cp_transport_data);
 389         }
 390         spin_lock_irq(&rds_tcp_conn_lock);
 391         for (i = 0; i < RDS_MPATH_WORKERS; i++) {
 392                 tc = conn->c_path[i].cp_transport_data;
 393                 tc->t_tcp_node_detached = false;
 394                 list_add_tail(&tc->t_tcp_node, &rds_tcp_conn_list);
 395         }
 396         spin_unlock_irq(&rds_tcp_conn_lock);
 397 fail:
 398         if (ret) {
 399                 for (j = 0; j < i; j++)
 400                         rds_tcp_conn_free(conn->c_path[j].cp_transport_data);
 401         }
 402         return ret;
 403 }
 404
 405 static bool list_has_conn(struct list_head *list, struct rds_connection *conn)
 406 {
 407         struct rds_tcp_connection *tc, *_tc;
 408
 409         list_for_each_entry_safe(tc, _tc, list, t_tcp_node) {
 410                 if (tc->t_cpath->cp_conn == conn)
 411                         return true;
 412         }
 413         return false;
 414 }
 415
 416 static void rds_tcp_set_unloading(void)
 417 {
 418         atomic_set(&rds_tcp_unloading, 1);
 419 }
 420
 421 static bool rds_tcp_is_unloading(struct rds_connection *conn)
 422 {
 423         return atomic_read(&rds_tcp_unloading) != 0;
 424 }
 425
 426 static void rds_tcp_destroy_conns(void)
 427 {
 428         struct rds_tcp_connection *tc, *_tc;
 429         LIST_HEAD(tmp_list);
 430
 431         /* avoid calling conn_destroy with irqs off */
 432         spin_lock_irq(&rds_tcp_conn_lock);
 433         list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
 434                 if (!list_has_conn(&tmp_list, tc->t_cpath->cp_conn))
 435                         list_move_tail(&tc->t_tcp_node, &tmp_list);
 436         }
 437         spin_unlock_irq(&rds_tcp_conn_lock);
 438
 439         list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node)
 440                 rds_conn_destroy(tc->t_cpath->cp_conn);
 441 }
 442
 443 static void rds_tcp_exit(void);
 444
 445 static u8 rds_tcp_get_tos_map(u8 tos)
 446 {
 447         /* all user tos mapped to default 0 for TCP transport */
 448         return 0;
 449 }
 450
 451 struct rds_transport rds_tcp_transport = {
 452         .laddr_check            = rds_tcp_laddr_check,
 453         .xmit_path_prepare      = rds_tcp_xmit_path_prepare,
 454         .xmit_path_complete     = rds_tcp_xmit_path_complete,
 455         .xmit                   = rds_tcp_xmit,
 456         .recv_path              = rds_tcp_recv_path,
 457         .conn_alloc             = rds_tcp_conn_alloc,
 458         .conn_free              = rds_tcp_conn_free,
 459         .conn_path_connect      = rds_tcp_conn_path_connect,
 460         .conn_path_shutdown     = rds_tcp_conn_path_shutdown,
 461         .inc_copy_to_user       = rds_tcp_inc_copy_to_user,
 462         .inc_free               = rds_tcp_inc_free,
 463         .stats_info_copy        = rds_tcp_stats_info_copy,
 464         .exit                   = rds_tcp_exit,
 465         .get_tos_map            = rds_tcp_get_tos_map,
 466         .t_owner                = THIS_MODULE,
 467         .t_name                 = "tcp",
 468         .t_type                 = RDS_TRANS_TCP,
 469         .t_prefer_loopback      = 1,
 470         .t_mp_capable           = 1,
 471         .t_unloading            = rds_tcp_is_unloading,
 472 };
 473
 474 static unsigned int rds_tcp_netid;
 475
 476 /* per-network namespace private data for this module */
 477 struct rds_tcp_net {
 478         struct socket *rds_tcp_listen_sock;
 479         struct work_struct rds_tcp_accept_w;
 480         struct ctl_table_header *rds_tcp_sysctl;
 481         struct ctl_table *ctl_table;
 482         int sndbuf_size;
 483         int rcvbuf_size;
 484 };
 485
 486 /* All module specific customizations to the RDS-TCP socket should be done in
 487  * rds_tcp_tune() and applied after socket creation.
 488  */
 489 bool rds_tcp_tune(struct socket *sock)
 490 {
 491         struct sock *sk = sock->sk;
 492         struct net *net = sock_net(sk);
 493         struct rds_tcp_net *rtn;
 494
 495         tcp_sock_set_nodelay(sock->sk);
 496         lock_sock(sk);
 497         /* TCP timer functions might access net namespace even after
 498          * a process which created this net namespace terminated.
 499          */
 500         if (!sk->sk_net_refcnt) {
 501                 if (!maybe_get_net(net)) {
 502                         release_sock(sk);
 503                         return false;
 504                 }
 505                 /* Update ns_tracker to current stack trace and refcounted tracker */
 506                 __netns_tracker_free(net, &sk->ns_tracker, false);
 507
 508                 sk->sk_net_refcnt = 1;
 509                 netns_tracker_alloc(net, &sk->ns_tracker, GFP_KERNEL);
 510                 sock_inuse_add(net, 1);
 511         }
 512         rtn = net_generic(net, rds_tcp_netid);
 513         if (rtn->sndbuf_size > 0) {
 514                 sk->sk_sndbuf = rtn->sndbuf_size;
 515                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
 516         }
 517         if (rtn->rcvbuf_size > 0) {
 518                 sk->sk_rcvbuf = rtn->rcvbuf_size;
 519                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
 520         }
 521         release_sock(sk);
 522         return true;
 523 }
 524
 525 static void rds_tcp_accept_worker(struct work_struct *work)
 526 {
 527         struct rds_tcp_net *rtn = container_of(work,
 528                                                struct rds_tcp_net,
 529                                                rds_tcp_accept_w);
 530
 531         while (rds_tcp_accept_one(rtn->rds_tcp_listen_sock) == 0)
 532                 cond_resched();
 533 }
 534
 535 void rds_tcp_accept_work(struct sock *sk)
 536 {
 537         struct net *net = sock_net(sk);
 538         struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
 539
 540         queue_work(rds_wq, &rtn->rds_tcp_accept_w);
 541 }
 542
 543 static __net_init int rds_tcp_init_net(struct net *net)
 544 {
 545         struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
 546         struct ctl_table *tbl;
 547         int err = 0;
 548
 549         memset(rtn, 0, sizeof(*rtn));
 550
 551         /* {snd, rcv}buf_size default to 0, which implies we let the
 552          * stack pick the value, and permit auto-tuning of buffer size.
 553          */
 554         if (net == &init_net) {
 555                 tbl = rds_tcp_sysctl_table;
 556         } else {
 557                 tbl = kmemdup(rds_tcp_sysctl_table,
 558                               sizeof(rds_tcp_sysctl_table), GFP_KERNEL);
 559                 if (!tbl) {
 560                         pr_warn("could not set allocate sysctl table\n");
 561                         return -ENOMEM;
 562                 }
 563                 rtn->ctl_table = tbl;
 564         }
 565         tbl[RDS_TCP_SNDBUF].data = &rtn->sndbuf_size;
 566         tbl[RDS_TCP_RCVBUF].data = &rtn->rcvbuf_size;
 567         rtn->rds_tcp_sysctl = register_net_sysctl_sz(net, "net/rds/tcp", tbl,
 568                                                      ARRAY_SIZE(rds_tcp_sysctl_table));
 569         if (!rtn->rds_tcp_sysctl) {
 570                 pr_warn("could not register sysctl\n");
 571                 err = -ENOMEM;
 572                 goto fail;
 573         }
 574
 575 #if IS_ENABLED(CONFIG_IPV6)
 576         rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net, true);
 577 #else
 578         rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net, false);
 579 #endif
 580         if (!rtn->rds_tcp_listen_sock) {
 581                 pr_warn("could not set up IPv6 listen sock\n");
 582
 583 #if IS_ENABLED(CONFIG_IPV6)
 584                 /* Try IPv4 as some systems disable IPv6 */
 585                 rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net, false);
 586                 if (!rtn->rds_tcp_listen_sock) {
 587 #endif
 588                         unregister_net_sysctl_table(rtn->rds_tcp_sysctl);
 589                         rtn->rds_tcp_sysctl = NULL;
 590                         err = -EAFNOSUPPORT;
 591                         goto fail;
 592 #if IS_ENABLED(CONFIG_IPV6)
 593                 }
 594 #endif
 595         }
 596         INIT_WORK(&rtn->rds_tcp_accept_w, rds_tcp_accept_worker);
 597         return 0;
 598
 599 fail:
 600         if (net != &init_net)
 601                 kfree(tbl);
 602         return err;
 603 }
 604
 605 static void rds_tcp_kill_sock(struct net *net)
 606 {
 607         struct rds_tcp_connection *tc, *_tc;
 608         LIST_HEAD(tmp_list);
 609         struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
 610         struct socket *lsock = rtn->rds_tcp_listen_sock;
 611
 612         rtn->rds_tcp_listen_sock = NULL;
 613         rds_tcp_listen_stop(lsock, &rtn->rds_tcp_accept_w);
 614         spin_lock_irq(&rds_tcp_conn_lock);
 615         list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
 616                 struct net *c_net = read_pnet(&tc->t_cpath->cp_conn->c_net);
 617
 618                 if (net != c_net)
 619                         continue;
 620                 if (!list_has_conn(&tmp_list, tc->t_cpath->cp_conn)) {
 621                         list_move_tail(&tc->t_tcp_node, &tmp_list);
 622                 } else {
 623                         list_del(&tc->t_tcp_node);
 624                         tc->t_tcp_node_detached = true;
 625                 }
 626         }
 627         spin_unlock_irq(&rds_tcp_conn_lock);
 628         list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node)
 629                 rds_conn_destroy(tc->t_cpath->cp_conn);
 630 }
 631
 632 static void __net_exit rds_tcp_exit_net(struct net *net)
 633 {
 634         struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
 635
 636         rds_tcp_kill_sock(net);
 637
 638         if (rtn->rds_tcp_sysctl)
 639                 unregister_net_sysctl_table(rtn->rds_tcp_sysctl);
 640
 641         if (net != &init_net)
 642                 kfree(rtn->ctl_table);
 643 }
 644
 645 static struct pernet_operations rds_tcp_net_ops = {
 646         .init = rds_tcp_init_net,
 647         .exit = rds_tcp_exit_net,
 648         .id = &rds_tcp_netid,
 649         .size = sizeof(struct rds_tcp_net),
 650 };
 651
 652 void *rds_tcp_listen_sock_def_readable(struct net *net)
 653 {
 654         struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
 655         struct socket *lsock = rtn->rds_tcp_listen_sock;
 656
 657         if (!lsock)
 658                 return NULL;
 659
 660         return lsock->sk->sk_user_data;
 661 }
 662
 663 /* when sysctl is used to modify some kernel socket parameters,this
 664  * function  resets the RDS connections in that netns  so that we can
 665  * restart with new parameters.  The assumption is that such reset
 666  * events are few and far-between.
 667  */
 668 static void rds_tcp_sysctl_reset(struct net *net)
 669 {
 670         struct rds_tcp_connection *tc, *_tc;
 671
 672         spin_lock_irq(&rds_tcp_conn_lock);
 673         list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
 674                 struct net *c_net = read_pnet(&tc->t_cpath->cp_conn->c_net);
 675
 676                 if (net != c_net || !tc->t_sock)
 677                         continue;
 678
 679                 /* reconnect with new parameters */
 680                 rds_conn_path_drop(tc->t_cpath, false);
 681         }
 682         spin_unlock_irq(&rds_tcp_conn_lock);
 683 }
 684
 685 static int rds_tcp_skbuf_handler(const struct ctl_table *ctl, int write,
 686                                  void *buffer, size_t *lenp, loff_t *fpos)
 687 {
 688         struct net *net = current->nsproxy->net_ns;
 689         int err;
 690
 691         err = proc_dointvec_minmax(ctl, write, buffer, lenp, fpos);
 692         if (err < 0) {
 693                 pr_warn("Invalid input. Must be >= %d\n",
 694                         *(int *)(ctl->extra1));
 695                 return err;
 696         }
 697         if (write)
 698                 rds_tcp_sysctl_reset(net);
 699         return 0;
 700 }
 701
 702 static void rds_tcp_exit(void)
 703 {
 704         rds_tcp_set_unloading();
 705         synchronize_rcu();
 706         rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
 707 #if IS_ENABLED(CONFIG_IPV6)
 708         rds_info_deregister_func(RDS6_INFO_TCP_SOCKETS, rds6_tcp_tc_info);
 709 #endif
 710         unregister_pernet_device(&rds_tcp_net_ops);
 711         rds_tcp_destroy_conns();
 712         rds_trans_unregister(&rds_tcp_transport);
 713         rds_tcp_recv_exit();
 714         kmem_cache_destroy(rds_tcp_conn_slab);
 715 }
 716 module_exit(rds_tcp_exit);
 717
 718 static int __init rds_tcp_init(void)
 719 {
 720         int ret;
 721
 722         rds_tcp_conn_slab = KMEM_CACHE(rds_tcp_connection, 0);
 723         if (!rds_tcp_conn_slab) {
 724                 ret = -ENOMEM;
 725                 goto out;
 726         }
 727
 728         ret = rds_tcp_recv_init();
 729         if (ret)
 730                 goto out_slab;
 731
 732         ret = register_pernet_device(&rds_tcp_net_ops);
 733         if (ret)
 734                 goto out_recv;
 735
 736         rds_trans_register(&rds_tcp_transport);
 737
 738         rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
 739 #if IS_ENABLED(CONFIG_IPV6)
 740         rds_info_register_func(RDS6_INFO_TCP_SOCKETS, rds6_tcp_tc_info);
 741 #endif
 742
 743         goto out;
 744 out_recv:
 745         rds_tcp_recv_exit();
 746 out_slab:
 747         kmem_cache_destroy(rds_tcp_conn_slab);
 748 out:
 749         return ret;
 750 }
 751 module_init(rds_tcp_init);
 752
 753 MODULE_AUTHOR("Oracle Corporation <[email protected]>");
 754 MODULE_DESCRIPTION("RDS: TCP transport");
 755 MODULE_LICENSE("Dual BSD/GPL");