lnet/lnet/acceptor.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2011, 2017, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  * Lustre is a trademark of Sun Microsystems, Inc.
  31  */
  32
  33 #define DEBUG_SUBSYSTEM S_LNET
  34
  35 #include <linux/completion.h>
  36 #include <net/sock.h>
  37 #include <lnet/lib-lnet.h>
  38
  39 static int   accept_port    = 988;
  40 static int   accept_backlog = 127;
  41 static int   accept_timeout = 5;
  42
  43 static struct {
  44         int                     pta_shutdown;
  45         struct socket           *pta_sock;
  46         struct completion       pta_signal;
  47         struct net              *pta_ns;
  48         wait_queue_head_t       pta_waitq;
  49         atomic_t                pta_ready;
  50 #ifdef HAVE_SK_DATA_READY_ONE_ARG
  51         void                    (*pta_odata)(struct sock *);
  52 #else
  53         void                    (*pta_odata)(struct sock *, int);
  54 #endif
  55 } lnet_acceptor_state = {
  56         .pta_shutdown = 1
  57 };
  58
  59 int
  60 lnet_acceptor_port(void)
  61 {
  62         return accept_port;
  63 }
  64
  65 static inline int
  66 lnet_accept_magic(__u32 magic, __u32 constant)
  67 {
  68         return (magic == constant ||
  69                 magic == __swab32(constant));
  70 }
  71
  72 EXPORT_SYMBOL(lnet_acceptor_port);
  73
  74 static char *accept_type = "secure";
  75
  76 module_param_named(accept, accept_type, charp, 0444);
  77 MODULE_PARM_DESC(accept, "Accept connections (secure|all|none)");
  78 module_param(accept_port, int, 0444);
  79 MODULE_PARM_DESC(accept_port, "Acceptor's port (same on all nodes)");
  80 module_param(accept_backlog, int, 0444);
  81 MODULE_PARM_DESC(accept_backlog, "Acceptor's listen backlog");
  82 module_param(accept_timeout, int, 0644);
  83 MODULE_PARM_DESC(accept_timeout, "Acceptor's timeout (seconds)");
  84
  85 int
  86 lnet_acceptor_timeout(void)
  87 {
  88         return accept_timeout;
  89 }
  90 EXPORT_SYMBOL(lnet_acceptor_timeout);
  91
  92 void
  93 lnet_connect_console_error (int rc, lnet_nid_t peer_nid,
  94                            __u32 peer_ip, int peer_port)
  95 {
  96         switch (rc) {
  97         /* "normal" errors */
  98         case -ECONNREFUSED:
  99                 CNETERR("Connection to %s at host %pI4h on port %d was "
 100                         "refused: check that Lustre is running on that node.\n",
 101                         libcfs_nid2str(peer_nid), &peer_ip, peer_port);
 102                 break;
 103         case -EHOSTUNREACH:
 104         case -ENETUNREACH:
 105                 CNETERR("Connection to %s at host %pI4h "
 106                         "was unreachable: the network or that node may "
 107                         "be down, or Lustre may be misconfigured.\n",
 108                         libcfs_nid2str(peer_nid), &peer_ip);
 109                 break;
 110         case -ETIMEDOUT:
 111                 CNETERR("Connection to %s at host %pI4h on "
 112                         "port %d took too long: that node may be hung "
 113                         "or experiencing high load.\n",
 114                         libcfs_nid2str(peer_nid), &peer_ip, peer_port);
 115                 break;
 116         case -ECONNRESET:
 117                 LCONSOLE_ERROR_MSG(0x11b, "Connection to %s at host %pI4h"
 118                                    " on port %d was reset: "
 119                                    "is it running a compatible version of "
 120                                    "Lustre and is %s one of its NIDs?\n",
 121                                    libcfs_nid2str(peer_nid), &peer_ip,
 122                                    peer_port, libcfs_nid2str(peer_nid));
 123                 break;
 124         case -EPROTO:
 125                 LCONSOLE_ERROR_MSG(0x11c, "Protocol error connecting to %s at "
 126                                    "host %pI4h on port %d: is it running "
 127                                    "a compatible version of Lustre?\n",
 128                                    libcfs_nid2str(peer_nid), &peer_ip,
 129                                    peer_port);
 130                 break;
 131         case -EADDRINUSE:
 132                 LCONSOLE_ERROR_MSG(0x11d, "No privileged ports available to "
 133                                    "connect to %s at host %pI4h on port "
 134                                    "%d\n", libcfs_nid2str(peer_nid),
 135                                    &peer_ip, peer_port);
 136                 break;
 137         default:
 138                 LCONSOLE_ERROR_MSG(0x11e, "Unexpected error %d connecting to %s"
 139                                    " at host %pI4h on port %d\n", rc,
 140                                    libcfs_nid2str(peer_nid),
 141                                    &peer_ip, peer_port);
 142                 break;
 143         }
 144 }
 145 EXPORT_SYMBOL(lnet_connect_console_error);
 146
 147 struct socket *
 148 lnet_connect(lnet_nid_t peer_nid, int interface, __u32 peer_ip,
 149              int peer_port, struct net *ns)
 150 {
 151         struct lnet_acceptor_connreq cr;
 152         struct socket           *sock;
 153         int                     rc;
 154         int                     port;
 155
 156         BUILD_BUG_ON(sizeof(cr) > 16); /* not too big to be on the stack */
 157
 158         for (port = LNET_ACCEPTOR_MAX_RESERVED_PORT;
 159              port >= LNET_ACCEPTOR_MIN_RESERVED_PORT;
 160              --port) {
 161                 /* Iterate through reserved ports. */
 162
 163                 sock = lnet_sock_connect(interface, port,
 164                                          peer_ip, peer_port, ns);
 165                 if (IS_ERR(sock)) {
 166                         rc = PTR_ERR(sock);
 167                         if (rc == -EADDRINUSE || rc == -EADDRNOTAVAIL)
 168                                 continue;
 169                         goto failed;
 170                 }
 171
 172                 BUILD_BUG_ON(LNET_PROTO_ACCEPTOR_VERSION != 1);
 173
 174                 cr.acr_magic   = LNET_PROTO_ACCEPTOR_MAGIC;
 175                 cr.acr_version = LNET_PROTO_ACCEPTOR_VERSION;
 176                 cr.acr_nid     = peer_nid;
 177
 178                 if (the_lnet.ln_testprotocompat) {
 179                         /* single-shot proto check */
 180                         if (test_and_clear_bit(2, &the_lnet.ln_testprotocompat))
 181                                 cr.acr_version++;
 182                         if (test_and_clear_bit(3, &the_lnet.ln_testprotocompat))
 183                                 cr.acr_magic = LNET_PROTO_MAGIC;
 184                 }
 185
 186                 rc = lnet_sock_write(sock, &cr, sizeof(cr),
 187                                        accept_timeout);
 188                 if (rc != 0)
 189                         goto failed_sock;
 190
 191                 return sock;
 192         }
 193
 194         rc = -EADDRINUSE;
 195         goto failed;
 196
 197 failed_sock:
 198         sock_release(sock);
 199 failed:
 200         lnet_connect_console_error(rc, peer_nid, peer_ip, peer_port);
 201         return ERR_PTR(rc);
 202 }
 203 EXPORT_SYMBOL(lnet_connect);
 204
 205 static int
 206 lnet_accept(struct socket *sock, __u32 magic)
 207 {
 208         struct lnet_acceptor_connreq cr;
 209         __u32                   peer_ip;
 210         int                     peer_port;
 211         int                     rc;
 212         int                     flip;
 213         struct lnet_ni *ni;
 214         char                   *str;
 215
 216         LASSERT(sizeof(cr) <= 16);              /* not too big for the stack */
 217
 218         rc = lnet_sock_getaddr(sock, true, &peer_ip, &peer_port);
 219         LASSERT(rc == 0);                       /* we succeeded before */
 220
 221         if (!lnet_accept_magic(magic, LNET_PROTO_ACCEPTOR_MAGIC)) {
 222
 223                 if (lnet_accept_magic(magic, LNET_PROTO_MAGIC)) {
 224                         /* future version compatibility!
 225                          * When LNET unifies protocols over all LNDs, the first
 226                          * thing sent will be a version query.  I send back
 227                          * LNET_PROTO_ACCEPTOR_MAGIC to tell her I'm "old" */
 228
 229                         memset(&cr, 0, sizeof(cr));
 230                         cr.acr_magic = LNET_PROTO_ACCEPTOR_MAGIC;
 231                         cr.acr_version = LNET_PROTO_ACCEPTOR_VERSION;
 232                         rc = lnet_sock_write(sock, &cr, sizeof(cr),
 233                                                accept_timeout);
 234
 235                         if (rc != 0)
 236                                 CERROR("Error sending magic+version in response to LNET magic from %pI4h: %d\n",
 237                                        &peer_ip, rc);
 238                         return -EPROTO;
 239                 }
 240
 241                 if (lnet_accept_magic(magic, LNET_PROTO_TCP_MAGIC))
 242                         str = "'old' socknal/tcpnal";
 243                 else
 244                         str = "unrecognised";
 245
 246                 LCONSOLE_ERROR_MSG(0x11f, "Refusing connection from %pI4h"
 247                                    " magic %08x: %s acceptor protocol\n",
 248                                    &peer_ip, magic, str);
 249                 return -EPROTO;
 250         }
 251
 252         flip = (magic != LNET_PROTO_ACCEPTOR_MAGIC);
 253
 254         rc = lnet_sock_read(sock, &cr.acr_version,
 255                               sizeof(cr.acr_version),
 256                               accept_timeout);
 257         if (rc != 0) {
 258                 CERROR("Error %d reading connection request version from "
 259                        "%pI4h\n", rc, &peer_ip);
 260                 return -EIO;
 261         }
 262
 263         if (flip)
 264                 __swab32s(&cr.acr_version);
 265
 266         if (cr.acr_version != LNET_PROTO_ACCEPTOR_VERSION) {
 267                 /* future version compatibility!
 268                  * An acceptor-specific protocol rev will first send a version
 269                  * query.  I send back my current version to tell her I'm
 270                  * "old". */
 271                 int peer_version = cr.acr_version;
 272
 273                 memset(&cr, 0, sizeof(cr));
 274                 cr.acr_magic = LNET_PROTO_ACCEPTOR_MAGIC;
 275                 cr.acr_version = LNET_PROTO_ACCEPTOR_VERSION;
 276
 277                 rc = lnet_sock_write(sock, &cr, sizeof(cr),
 278                                        accept_timeout);
 279
 280                 if (rc != 0)
 281                         CERROR("Error sending magic+version in response to version %d from %pI4h: %d\n",
 282                                peer_version, &peer_ip, rc);
 283                 return -EPROTO;
 284         }
 285
 286         rc = lnet_sock_read(sock, &cr.acr_nid,
 287                               sizeof(cr) -
 288                               offsetof(struct lnet_acceptor_connreq, acr_nid),
 289                               accept_timeout);
 290         if (rc != 0) {
 291                 CERROR("Error %d reading connection request from "
 292                        "%pI4h\n", rc, &peer_ip);
 293                 return -EIO;
 294         }
 295
 296         if (flip)
 297                 __swab64s(&cr.acr_nid);
 298
 299         ni = lnet_nid2ni_addref(cr.acr_nid);
 300         if (ni == NULL ||               /* no matching net */
 301             ni->ni_nid != cr.acr_nid) { /* right NET, wrong NID! */
 302                 if (ni != NULL)
 303                         lnet_ni_decref(ni);
 304                 LCONSOLE_ERROR_MSG(0x120, "Refusing connection from %pI4h "
 305                                    "for %s: No matching NI\n",
 306                                    &peer_ip, libcfs_nid2str(cr.acr_nid));
 307                 return -EPERM;
 308         }
 309
 310         if (ni->ni_net->net_lnd->lnd_accept == NULL) {
 311                 /* This catches a request for the loopback LND */
 312                 lnet_ni_decref(ni);
 313                 LCONSOLE_ERROR_MSG(0x121, "Refusing connection from %pI4h "
 314                                   "for %s: NI doesn not accept IP connections\n",
 315                                   &peer_ip, libcfs_nid2str(cr.acr_nid));
 316                 return -EPERM;
 317         }
 318
 319         CDEBUG(D_NET, "Accept %s from %pI4h\n",
 320                libcfs_nid2str(cr.acr_nid), &peer_ip);
 321
 322         rc = ni->ni_net->net_lnd->lnd_accept(ni, sock);
 323
 324         lnet_ni_decref(ni);
 325         return rc;
 326 }
 327
 328 #ifdef HAVE_SK_DATA_READY_ONE_ARG
 329 static void lnet_acceptor_ready(struct sock *sk)
 330 #else
 331 static void lnet_acceptor_ready(struct sock *sk, int len)
 332 #endif
 333 {
 334         /* Ensure pta_odata has actually been set before calling it */
 335         rmb();
 336 #ifdef HAVE_SK_DATA_READY_ONE_ARG
 337         lnet_acceptor_state.pta_odata(sk);
 338 #else
 339         lnet_acceptor_state.pta_odata(sk, 0);
 340 #endif
 341
 342         atomic_set(&lnet_acceptor_state.pta_ready, 1);
 343         wake_up(&lnet_acceptor_state.pta_waitq);
 344 }
 345
 346 static int
 347 lnet_acceptor(void *arg)
 348 {
 349         struct socket  *newsock;
 350         int            rc;
 351         __u32          magic;
 352         __u32          peer_ip;
 353         int            peer_port;
 354         int            secure = (int)((uintptr_t)arg);
 355
 356         LASSERT(lnet_acceptor_state.pta_sock == NULL);
 357
 358         lnet_acceptor_state.pta_sock =
 359                 lnet_sock_listen(accept_port, accept_backlog,
 360                                  lnet_acceptor_state.pta_ns);
 361         if (IS_ERR(lnet_acceptor_state.pta_sock)) {
 362                 rc = PTR_ERR(lnet_acceptor_state.pta_sock);
 363                 if (rc == -EADDRINUSE)
 364                         LCONSOLE_ERROR_MSG(0x122, "Can't start acceptor on port"
 365                                            " %d: port already in use\n",
 366                                            accept_port);
 367                 else
 368                         LCONSOLE_ERROR_MSG(0x123, "Can't start acceptor on port "
 369                                            "%d: unexpected error %d\n",
 370                                            accept_port, rc);
 371
 372                 lnet_acceptor_state.pta_sock = NULL;
 373         } else {
 374                 rc = 0;
 375                 LCONSOLE(0, "Accept %s, port %d\n", accept_type, accept_port);
 376                 init_waitqueue_head(&lnet_acceptor_state.pta_waitq);
 377                 lnet_acceptor_state.pta_odata =
 378                         lnet_acceptor_state.pta_sock->sk->sk_data_ready;
 379                 /* ensure pta_odata gets set before there is any chance of
 380                  * lnet_accept_ready() trying to read it.
 381                  */
 382                 wmb();
 383                 lnet_acceptor_state.pta_sock->sk->sk_data_ready =
 384                         lnet_acceptor_ready;
 385                 atomic_set(&lnet_acceptor_state.pta_ready, 1);
 386         }
 387
 388         /* set init status and unblock parent */
 389         lnet_acceptor_state.pta_shutdown = rc;
 390         complete(&lnet_acceptor_state.pta_signal);
 391
 392         if (rc != 0)
 393                 return rc;
 394
 395         while (!lnet_acceptor_state.pta_shutdown) {
 396
 397                 wait_event_idle(lnet_acceptor_state.pta_waitq,
 398                                 lnet_acceptor_state.pta_shutdown ||
 399                                 atomic_read(&lnet_acceptor_state.pta_ready));
 400                 if (!atomic_read(&lnet_acceptor_state.pta_ready))
 401                         continue;
 402                 atomic_set(&lnet_acceptor_state.pta_ready, 0);
 403                 rc = kernel_accept(lnet_acceptor_state.pta_sock, &newsock,
 404                                    SOCK_NONBLOCK);
 405                 if (rc != 0) {
 406                         if (rc != -EAGAIN) {
 407                                 CWARN("Accept error %d: pausing...\n", rc);
 408                                 schedule_timeout_uninterruptible(
 409                                         cfs_time_seconds(1));
 410                         }
 411                         continue;
 412                 }
 413
 414                 /* make sure we call lnet_sock_accept() again, until it fails */
 415                 atomic_set(&lnet_acceptor_state.pta_ready, 1);
 416
 417                 rc = lnet_sock_getaddr(newsock, true, &peer_ip, &peer_port);
 418                 if (rc != 0) {
 419                         CERROR("Can't determine new connection's address\n");
 420                         goto failed;
 421                 }
 422
 423                 if (secure && peer_port > LNET_ACCEPTOR_MAX_RESERVED_PORT) {
 424                         CERROR("Refusing connection from %pI4h: "
 425                                "insecure port %d\n", &peer_ip, peer_port);
 426                         goto failed;
 427                 }
 428
 429                 rc = lnet_sock_read(newsock, &magic, sizeof(magic),
 430                                       accept_timeout);
 431                 if (rc != 0) {
 432                         CERROR("Error %d reading connection request from "
 433                                "%pI4h\n", rc, &peer_ip);
 434                         goto failed;
 435                 }
 436
 437                 rc = lnet_accept(newsock, magic);
 438                 if (rc != 0)
 439                         goto failed;
 440
 441                 continue;
 442
 443 failed:
 444                 sock_release(newsock);
 445         }
 446
 447         lnet_acceptor_state.pta_sock->sk->sk_data_ready =
 448                 lnet_acceptor_state.pta_odata;
 449         sock_release(lnet_acceptor_state.pta_sock);
 450         lnet_acceptor_state.pta_sock = NULL;
 451
 452         CDEBUG(D_NET, "Acceptor stopping\n");
 453
 454         /* unblock lnet_acceptor_stop() */
 455         complete(&lnet_acceptor_state.pta_signal);
 456         return 0;
 457 }
 458
 459 static inline int
 460 accept2secure(const char *acc, long *sec)
 461 {
 462         if (!strcmp(acc, "secure")) {
 463                 *sec = 1;
 464                 return 1;
 465         } else if (!strcmp(acc, "all")) {
 466                 *sec = 0;
 467                 return 1;
 468         } else if (!strcmp(acc, "none")) {
 469                 return 0;
 470         } else {
 471                 LCONSOLE_ERROR_MSG(0x124, "Can't parse 'accept=\"%s\"'\n",
 472                                    acc);
 473                 return -EINVAL;
 474         }
 475 }
 476
 477 int
 478 lnet_acceptor_start(void)
 479 {
 480         struct task_struct *task;
 481         int  rc;
 482         long rc2;
 483         long secure;
 484
 485         /* if acceptor is already running return immediately */
 486         if (!lnet_acceptor_state.pta_shutdown)
 487                 return 0;
 488
 489         LASSERT(lnet_acceptor_state.pta_sock == NULL);
 490
 491         init_completion(&lnet_acceptor_state.pta_signal);
 492         rc = accept2secure(accept_type, &secure);
 493         if (rc <= 0)
 494                 return rc;
 495
 496         if (lnet_count_acceptor_nets() == 0)  /* not required */
 497                 return 0;
 498         if (current->nsproxy && current->nsproxy->net_ns)
 499                 lnet_acceptor_state.pta_ns = current->nsproxy->net_ns;
 500         else
 501                 lnet_acceptor_state.pta_ns = &init_net;
 502         task = kthread_run(lnet_acceptor, (void *)(uintptr_t)secure,
 503                            "acceptor_%03ld", secure);
 504         if (IS_ERR(task)) {
 505                 rc2 = PTR_ERR(task);
 506                 CERROR("Can't start acceptor thread: %ld\n", rc2);
 507                 return -ESRCH;
 508         }
 509
 510         /* wait for acceptor to startup */
 511         wait_for_completion(&lnet_acceptor_state.pta_signal);
 512
 513         if (!lnet_acceptor_state.pta_shutdown) {
 514                 /* started OK */
 515                 LASSERT(lnet_acceptor_state.pta_sock != NULL);
 516                 return 0;
 517         }
 518
 519         LASSERT(lnet_acceptor_state.pta_sock == NULL);
 520
 521         return -ENETDOWN;
 522 }
 523
 524 void
 525 lnet_acceptor_stop(void)
 526 {
 527         if (lnet_acceptor_state.pta_shutdown) /* not running */
 528                 return;
 529
 530         /* If still required, return immediately */
 531         if (the_lnet.ln_refcount && lnet_count_acceptor_nets() > 0)
 532                 return;
 533
 534         lnet_acceptor_state.pta_shutdown = 1;
 535         wake_up(&lnet_acceptor_state.pta_waitq);
 536
 537         /* block until acceptor signals exit */
 538         wait_for_completion(&lnet_acceptor_state.pta_signal);
 539 }