src/vol/daemon_com.c

   1 /*
   2  * Copyright 2006-2008, Sine Nomine Associates and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 /*
  11  * localhost interprocess communication for servers
  12  *
  13  * currently handled by a localhost socket
  14  * (yes, this needs to be replaced someday)
  15  */
  16
  17 #ifndef _WIN32
  18 #define FD_SETSIZE 65536
  19 #endif
  20
  21 #include <afsconfig.h>
  22 #include <afs/param.h>
  23
  24 #include <roken.h>
  25 #include <afs/opr.h>
  26
  27 #include <rx/xdr.h>
  28 #include <afs/afsint.h>
  29 #include <afs/errors.h>
  30 #include <rx/rx_queue.h>
  31
  32 #include "nfs.h"
  33 #include "daemon_com.h"
  34 #include "lwp.h"
  35 #include "lock.h"
  36 #include <afs/afssyscalls.h>
  37 #include "ihandle.h"
  38 #include "vnode.h"
  39 #include "volume.h"
  40 #include "partition.h"
  41 #include "common.h"
  42 #include <rx/rx_queue.h>
  43
  44 #ifdef USE_UNIX_SOCKETS
  45 #include <afs/afsutil.h>
  46 #include <sys/un.h>
  47 #endif
  48
  49 int (*V_BreakVolumeCallbacks) (VolumeId);
  50
  51 #define MAXHANDLERS     4       /* Up to 4 clients; must be at least 2, so that
  52                                  * move = dump+restore can run on single server */
  53
  54 #define MAX_BIND_TRIES  5       /* Number of times to retry socket bind */
  55
  56 static int SYNC_ask_internal(SYNC_client_state * state, SYNC_command * com, SYNC_response * res);
  57
  58
  59 /*
  60  * On AIX, connect() and bind() require use of SUN_LEN() macro;
  61  * sizeof(struct sockaddr_un) will not suffice.
  62  */
  63 #if defined(AFS_AIX_ENV) && defined(USE_UNIX_SOCKETS)
  64 #define AFS_SOCKADDR_LEN(sa)  SUN_LEN(sa)
  65 #else
  66 #define AFS_SOCKADDR_LEN(sa)  sizeof(*sa)
  67 #endif
  68
  69
  70 /* daemon com SYNC general interfaces */
  71
  72 /**
  73  * fill in sockaddr structure.
  74  *
  75  * @param[in]  endpoint pointer to sync endpoint object
  76  * @param[out] addr     pointer to sockaddr structure
  77  *
  78  * @post sockaddr structure populated using information from
  79  *       endpoint structure.
  80  */
  81 void
  82 SYNC_getAddr(SYNC_endpoint_t * endpoint, SYNC_sockaddr_t * addr)
  83 {
  84     memset(addr, 0, sizeof(*addr));
  85
  86 #ifdef USE_UNIX_SOCKETS
  87     addr->sun_family = AF_UNIX;
  88     snprintf(addr->sun_path, sizeof(addr->sun_path), "%s/%s",
  89              AFSDIR_SERVER_LOCAL_DIRPATH, endpoint->un);
  90     addr->sun_path[sizeof(addr->sun_path) - 1] = '\0';
  91 #else  /* !USE_UNIX_SOCKETS */
  92 #ifdef STRUCT_SOCKADDR_HAS_SA_LEN
  93     addr->sin_len = sizeof(struct sockaddr_in);
  94 #endif
  95     addr->sin_addr.s_addr = htonl(0x7f000001);
  96     addr->sin_family = AF_INET; /* was localhost->h_addrtype */
  97     addr->sin_port = htons(endpoint->in);       /* XXXX htons not _really_ neccessary */
  98 #endif /* !USE_UNIX_SOCKETS */
  99 }
 100
 101 /**
 102  * get a socket descriptor of the appropriate domain.
 103  *
 104  * @param[in]  endpoint pointer to sync endpoint object
 105  *
 106  * @return socket descriptor
 107  *
 108  * @post socket of domain specified in endpoint structure is created and
 109  *       returned to caller.
 110  */
 111 osi_socket
 112 SYNC_getSock(SYNC_endpoint_t * endpoint)
 113 {
 114     osi_socket sd;
 115     opr_Verify((sd = socket(endpoint->domain, SOCK_STREAM, 0)) >= 0);
 116     return sd;
 117 }
 118
 119 /* daemon com SYNC client interface */
 120
 121 /**
 122  * open a client connection to a sync server
 123  *
 124  * @param[in] state  pointer to sync client handle
 125  *
 126  * @return operation status
 127  *    @retval 1 success
 128  *
 129  * @note at present, this routine aborts rather than returning an error code
 130  */
 131 int
 132 SYNC_connect(SYNC_client_state * state)
 133 {
 134     SYNC_sockaddr_t addr;
 135     /* I can't believe the following is needed for localhost connections!! */
 136     static time_t backoff[] =
 137         { 3, 3, 3, 5, 5, 5, 7, 15, 16, 24, 32, 40, 48, 0 };
 138     time_t *timeout = &backoff[0];
 139
 140     if (state->fd != OSI_NULLSOCKET) {
 141         return 1;
 142     }
 143
 144     SYNC_getAddr(&state->endpoint, &addr);
 145
 146     for (;;) {
 147         state->fd = SYNC_getSock(&state->endpoint);
 148         if (connect(state->fd, (struct sockaddr *)&addr, AFS_SOCKADDR_LEN(&addr)) >= 0)
 149             return 1;
 150         if (!*timeout)
 151             break;
 152         if (!(*timeout & 1))
 153             Log("SYNC_connect: temporary failure on circuit '%s' (will retry)\n",
 154                 state->proto_name);
 155         SYNC_disconnect(state);
 156         sleep(*timeout++);
 157     }
 158     perror("SYNC_connect failed (giving up!)");
 159     return 0;
 160 }
 161
 162 /**
 163  * forcibly disconnect a sync client handle.
 164  *
 165  * @param[in] state  pointer to sync client handle
 166  *
 167  * @retval operation status
 168  *    @retval 0 success
 169  */
 170 int
 171 SYNC_disconnect(SYNC_client_state * state)
 172 {
 173     rk_closesocket(state->fd);
 174     state->fd = OSI_NULLSOCKET;
 175     return 0;
 176 }
 177
 178 /**
 179  * gracefully disconnect a sync client handle.
 180  *
 181  * @param[in] state  pointer to sync client handle
 182  *
 183  * @return operation status
 184  *    @retval SYNC_OK success
 185  */
 186 afs_int32
 187 SYNC_closeChannel(SYNC_client_state * state)
 188 {
 189     SYNC_command com;
 190     SYNC_response res;
 191     SYNC_PROTO_BUF_DECL(ores);
 192
 193     if (state->fd == OSI_NULLSOCKET)
 194         return SYNC_OK;
 195
 196     memset(&com, 0, sizeof(com));
 197     memset(&res, 0, sizeof(res));
 198
 199     res.payload.len = SYNC_PROTO_MAX_LEN;
 200     res.payload.buf = ores;
 201
 202     com.hdr.command = SYNC_COM_CHANNEL_CLOSE;
 203     com.hdr.command_len = sizeof(SYNC_command_hdr);
 204     com.hdr.flags |= SYNC_FLAG_CHANNEL_SHUTDOWN;
 205
 206     /* in case the other end dropped, don't do any retries */
 207     state->retry_limit = 0;
 208     state->hard_timeout = 0;
 209
 210     SYNC_ask(state, &com, &res);
 211     SYNC_disconnect(state);
 212
 213     return SYNC_OK;
 214 }
 215
 216 /**
 217  * forcibly break a client connection, and then create a new connection.
 218  *
 219  * @param[in] state  pointer to sync client handle
 220  *
 221  * @post old connection dropped; new connection established
 222  *
 223  * @return @see SYNC_connect()
 224  */
 225 int
 226 SYNC_reconnect(SYNC_client_state * state)
 227 {
 228     SYNC_disconnect(state);
 229     return SYNC_connect(state);
 230 }
 231
 232 /**
 233  * send a command to a sync server and wait for a response.
 234  *
 235  * @param[in]  state  pointer to sync client handle
 236  * @param[in]  com    command object
 237  * @param[out] res    response object
 238  *
 239  * @return operation status
 240  *    @retval SYNC_OK success
 241  *    @retval SYNC_COM_ERROR communications error
 242  *    @retval SYNC_BAD_COMMAND server did not recognize command code
 243  *
 244  * @note this routine merely handles error processing; SYNC_ask_internal()
 245  *       handles the low-level details of communicating with the SYNC server.
 246  *
 247  * @see SYNC_ask_internal
 248  */
 249 afs_int32
 250 SYNC_ask(SYNC_client_state * state, SYNC_command * com, SYNC_response * res)
 251 {
 252     int tries;
 253     afs_uint32 now, timeout, code=SYNC_OK;
 254
 255     if (state->fd == OSI_NULLSOCKET) {
 256         SYNC_connect(state);
 257     }
 258
 259     if (state->fd == OSI_NULLSOCKET) {
 260         return SYNC_COM_ERROR;
 261     }
 262
 263 #ifdef AFS_DEMAND_ATTACH_FS
 264     com->hdr.flags |= SYNC_FLAG_DAFS_EXTENSIONS;
 265 #endif
 266
 267     now = FT_ApproxTime();
 268     timeout = now + state->hard_timeout;
 269     for (tries = 0;
 270          (tries <= state->retry_limit) && (now <= timeout);
 271          tries++, now = FT_ApproxTime()) {
 272         code = SYNC_ask_internal(state, com, res);
 273         if (code == SYNC_OK) {
 274             break;
 275         } else if (code == SYNC_BAD_COMMAND) {
 276             Log("SYNC_ask: protocol mismatch on circuit '%s'; make sure "
 277                 "fileserver, volserver, salvageserver and salvager are same "
 278                 "version\n", state->proto_name);
 279             break;
 280         } else if ((code == SYNC_COM_ERROR) && (tries < state->retry_limit)) {
 281             Log("SYNC_ask: protocol communications failure on circuit '%s'; "
 282                 "attempting reconnect to server\n", state->proto_name);
 283             SYNC_reconnect(state);
 284             /* try again */
 285         } else {
 286             /*
 287              * unknown (probably protocol-specific) response code, pass it up to
 288              * the caller, and let them deal with it
 289              */
 290             break;
 291         }
 292     }
 293
 294     if (code == SYNC_COM_ERROR) {
 295         Log("SYNC_ask: too many / too latent fatal protocol errors on circuit "
 296             "'%s'; giving up (tries %d timeout %d)\n",
 297             state->proto_name, tries, timeout);
 298     }
 299
 300     return code;
 301 }
 302
 303 /**
 304  * send a command to a sync server and wait for a response.
 305  *
 306  * @param[in]  state  pointer to sync client handle
 307  * @param[in]  com    command object
 308  * @param[out] res    response object
 309  *
 310  * @return operation status
 311  *    @retval SYNC_OK success
 312  *    @retval SYNC_COM_ERROR communications error
 313  *
 314  * @internal
 315  */
 316 static afs_int32
 317 SYNC_ask_internal(SYNC_client_state * state, SYNC_command * com, SYNC_response * res)
 318 {
 319     int n;
 320     SYNC_PROTO_BUF_DECL(buf);
 321 #ifndef AFS_NT40_ENV
 322     int iovcnt;
 323     struct iovec iov[2];
 324 #endif
 325
 326     if (state->fd == OSI_NULLSOCKET) {
 327         Log("SYNC_ask:  invalid sync file descriptor on circuit '%s'\n",
 328             state->proto_name);
 329         res->hdr.response = SYNC_COM_ERROR;
 330         goto done;
 331     }
 332
 333     if (com->hdr.command_len > SYNC_PROTO_MAX_LEN) {
 334         Log("SYNC_ask:  internal SYNC buffer too small on circuit '%s'; "
 335             "please file a bug\n", state->proto_name);
 336         res->hdr.response = SYNC_COM_ERROR;
 337         goto done;
 338     }
 339
 340     /*
 341      * fill in some common header fields
 342      */
 343     com->hdr.proto_version = state->proto_version;
 344     com->hdr.pkt_seq = ++state->pkt_seq;
 345     com->hdr.com_seq = ++state->com_seq;
 346 #ifdef AFS_NT40_ENV
 347     com->hdr.pid = 0;
 348     com->hdr.tid = 0;
 349 #else
 350     com->hdr.pid = getpid();
 351 #ifdef AFS_PTHREAD_ENV
 352     com->hdr.tid = afs_pointer_to_int(pthread_self());
 353 #else
 354     {
 355         PROCESS handle = LWP_ThreadId();
 356         com->hdr.tid = (handle) ? handle->index : 0;
 357     }
 358 #endif /* !AFS_PTHREAD_ENV */
 359 #endif /* !AFS_NT40_ENV */
 360
 361     memcpy(buf, &com->hdr, sizeof(com->hdr));
 362     if (com->payload.len) {
 363         memcpy(buf + sizeof(com->hdr), com->payload.buf,
 364                com->hdr.command_len - sizeof(com->hdr));
 365     }
 366
 367 #ifdef AFS_NT40_ENV
 368     n = send(state->fd, buf, com->hdr.command_len, 0);
 369     if (n != com->hdr.command_len) {
 370         Log("SYNC_ask:  write failed on circuit '%s'\n", state->proto_name);
 371         res->hdr.response = SYNC_COM_ERROR;
 372         goto done;
 373     }
 374
 375     if (com->hdr.command == SYNC_COM_CHANNEL_CLOSE) {
 376         /* short circuit close channel requests */
 377         res->hdr.response = SYNC_OK;
 378         goto done;
 379     }
 380
 381     n = recv(state->fd, buf, SYNC_PROTO_MAX_LEN, 0);
 382     if (n == 0 || (n < 0 && WSAEINTR != WSAGetLastError())) {
 383         Log("SYNC_ask:  No response on circuit '%s'\n", state->proto_name);
 384         res->hdr.response = SYNC_COM_ERROR;
 385         goto done;
 386     }
 387 #else /* !AFS_NT40_ENV */
 388     n = write(state->fd, buf, com->hdr.command_len);
 389     if (com->hdr.command_len != n) {
 390         Log("SYNC_ask: write failed on circuit '%s'\n", state->proto_name);
 391         res->hdr.response = SYNC_COM_ERROR;
 392         goto done;
 393     }
 394
 395     if (com->hdr.command == SYNC_COM_CHANNEL_CLOSE) {
 396         /* short circuit close channel requests */
 397         res->hdr.response = SYNC_OK;
 398         goto done;
 399     }
 400
 401     /* receive the response */
 402     iov[0].iov_base = (char *)&res->hdr;
 403     iov[0].iov_len = sizeof(res->hdr);
 404     if (res->payload.len) {
 405         iov[1].iov_base = (char *)res->payload.buf;
 406         iov[1].iov_len = res->payload.len;
 407         iovcnt = 2;
 408     } else {
 409         iovcnt = 1;
 410     }
 411     n = readv(state->fd, iov, iovcnt);
 412     if (n == 0 || (n < 0 && errno != EINTR)) {
 413         Log("SYNC_ask: No response on circuit '%s'\n", state->proto_name);
 414         res->hdr.response = SYNC_COM_ERROR;
 415         goto done;
 416     }
 417 #endif /* !AFS_NT40_ENV */
 418
 419     res->recv_len = n;
 420
 421     if (n < sizeof(res->hdr)) {
 422         Log("SYNC_ask:  response too short on circuit '%s'\n",
 423             state->proto_name);
 424         res->hdr.response = SYNC_COM_ERROR;
 425         goto done;
 426     }
 427 #ifdef AFS_NT40_ENV
 428     memcpy(&res->hdr, buf, sizeof(res->hdr));
 429 #endif
 430
 431     if ((n - sizeof(res->hdr)) > res->payload.len) {
 432         Log("SYNC_ask:  response too long on circuit '%s'\n",
 433             state->proto_name);
 434         res->hdr.response = SYNC_COM_ERROR;
 435         goto done;
 436     }
 437 #ifdef AFS_NT40_ENV
 438     memcpy(res->payload.buf, buf + sizeof(res->hdr), n - sizeof(res->hdr));
 439 #endif
 440
 441     if (res->hdr.response_len != n) {
 442         Log("SYNC_ask:  length field in response inconsistent "
 443             "on circuit '%s' command %ld, %d != %lu\n", state->proto_name,
 444             afs_printable_int32_ld(com->hdr.command),
 445             n,
 446             afs_printable_uint32_lu(res->hdr.response_len));
 447         res->hdr.response = SYNC_COM_ERROR;
 448         goto done;
 449     }
 450     if (res->hdr.response == SYNC_DENIED) {
 451         Log("SYNC_ask: negative response on circuit '%s'\n", state->proto_name);
 452     }
 453
 454   done:
 455     return res->hdr.response;
 456 }
 457
 458
 459 /*
 460  * daemon com SYNC server-side interfaces
 461  */
 462
 463 /**
 464  * receive a command structure off a sync socket.
 465  *
 466  * @param[in]  state  pointer to server-side state object
 467  * @param[in]  fd     file descriptor on which to perform i/o
 468  * @param[out] com    sync command object to be populated
 469  *
 470  * @return operation status
 471  *    @retval SYNC_OK command received
 472  *    @retval SYNC_COM_ERROR there was a socket communications error
 473  */
 474 afs_int32
 475 SYNC_getCom(SYNC_server_state_t * state,
 476             osi_socket fd,
 477             SYNC_command * com)
 478 {
 479     int n;
 480     afs_int32 code = SYNC_OK;
 481 #ifdef AFS_NT40_ENV
 482     SYNC_PROTO_BUF_DECL(buf);
 483 #else
 484     struct iovec iov[2];
 485     int iovcnt;
 486 #endif
 487
 488 #ifdef AFS_NT40_ENV
 489     n = recv(fd, buf, SYNC_PROTO_MAX_LEN, 0);
 490
 491     if (n == 0 || (n < 0 && WSAEINTR != WSAGetLastError())) {
 492         Log("SYNC_getCom:  error receiving command\n");
 493         code = SYNC_COM_ERROR;
 494         goto done;
 495     }
 496 #else /* !AFS_NT40_ENV */
 497     iov[0].iov_base = (char *)&com->hdr;
 498     iov[0].iov_len = sizeof(com->hdr);
 499     if (com->payload.len) {
 500         iov[1].iov_base = (char *)com->payload.buf;
 501         iov[1].iov_len = com->payload.len;
 502         iovcnt = 2;
 503     } else {
 504         iovcnt = 1;
 505     }
 506
 507     n = readv(fd, iov, iovcnt);
 508     if (n == 0 || (n < 0 && errno != EINTR)) {
 509         Log("SYNC_getCom:  error receiving command\n");
 510         code = SYNC_COM_ERROR;
 511         goto done;
 512     }
 513 #endif /* !AFS_NT40_ENV */
 514
 515     com->recv_len = n;
 516
 517     if (n < sizeof(com->hdr)) {
 518         Log("SYNC_getCom:  command too short\n");
 519         code = SYNC_COM_ERROR;
 520         goto done;
 521     }
 522 #ifdef AFS_NT40_ENV
 523     memcpy(&com->hdr, buf, sizeof(com->hdr));
 524 #endif
 525
 526     if ((n - sizeof(com->hdr)) > com->payload.len) {
 527         Log("SYNC_getCom:  command too long\n");
 528         code = SYNC_COM_ERROR;
 529         goto done;
 530     }
 531 #ifdef AFS_NT40_ENV
 532     memcpy(com->payload.buf, buf + sizeof(com->hdr), n - sizeof(com->hdr));
 533 #endif
 534
 535  done:
 536     return code;
 537 }
 538
 539 /**
 540  * write a response structure to a sync socket.
 541  *
 542  * @param[in] state  handle to server-side state object
 543  * @param[in] fd     file descriptor on which to perform i/o
 544  * @param[in] res    handle to response packet
 545  *
 546  * @return operation status
 547  *    @retval SYNC_OK
 548  *    @retval SYNC_COM_ERROR
 549  */
 550 afs_int32
 551 SYNC_putRes(SYNC_server_state_t * state,
 552             osi_socket fd,
 553             SYNC_response * res)
 554 {
 555     int n;
 556     afs_int32 code = SYNC_OK;
 557     SYNC_PROTO_BUF_DECL(buf);
 558
 559     if (res->hdr.response_len > (sizeof(res->hdr) + res->payload.len)) {
 560         Log("SYNC_putRes:  response_len field in response header inconsistent\n");
 561         code = SYNC_COM_ERROR;
 562         goto done;
 563     }
 564
 565     if (res->hdr.response_len > SYNC_PROTO_MAX_LEN) {
 566         Log("SYNC_putRes:  internal SYNC buffer too small; please file a bug\n");
 567         code = SYNC_COM_ERROR;
 568         goto done;
 569     }
 570
 571 #ifdef AFS_DEMAND_ATTACH_FS
 572     res->hdr.flags |= SYNC_FLAG_DAFS_EXTENSIONS;
 573 #endif
 574     res->hdr.proto_version = state->proto_version;
 575     res->hdr.pkt_seq = ++state->pkt_seq;
 576     res->hdr.res_seq = ++state->res_seq;
 577
 578     memcpy(buf, &res->hdr, sizeof(res->hdr));
 579     if (res->payload.len) {
 580         memcpy(buf + sizeof(res->hdr), res->payload.buf,
 581                res->hdr.response_len - sizeof(res->hdr));
 582     }
 583
 584 #ifdef AFS_NT40_ENV
 585     n = send(fd, buf, res->hdr.response_len, 0);
 586 #else /* !AFS_NT40_ENV */
 587     n = write(fd, buf, res->hdr.response_len);
 588 #endif /* !AFS_NT40_ENV */
 589
 590     if (res->hdr.response_len != n) {
 591         Log("SYNC_putRes: write failed\n");
 592         res->hdr.response = SYNC_COM_ERROR;
 593         goto done;
 594     }
 595
 596  done:
 597     return code;
 598 }
 599
 600 /* return 0 for legal (null-terminated) string,
 601  * 1 for illegal (unterminated) string */
 602 int
 603 SYNC_verifyProtocolString(char * buf, size_t len)
 604 {
 605     size_t s_len;
 606
 607     s_len = strnlen(buf, len);
 608
 609     return (s_len == len) ? 1 : 0;
 610 }
 611
 612 /**
 613  * clean up old sockets.
 614  *
 615  * @param[in]  state  server state object
 616  *
 617  * @post unix domain sockets are cleaned up
 618  */
 619 void
 620 SYNC_cleanupSock(SYNC_server_state_t * state)
 621 {
 622 #ifdef USE_UNIX_SOCKETS
 623     remove(state->addr.sun_path);
 624 #endif
 625 }
 626
 627 /**
 628  * bind socket and set it to listen state.
 629  *
 630  * @param[in] state  server state object
 631  *
 632  * @return operation status
 633  *    @retval 0 success
 634  *    @retval nonzero failure
 635  *
 636  * @post socket bound and set to listen state
 637  */
 638 int
 639 SYNC_bindSock(SYNC_server_state_t * state)
 640 {
 641     int code;
 642     int on = 1;
 643     int numTries;
 644
 645     /* Reuseaddr needed because system inexplicably leaves crud lying around */
 646     code =
 647         setsockopt(state->fd, SOL_SOCKET, SO_REUSEADDR, (char *)&on,
 648                    sizeof(on));
 649     if (code)
 650         Log("SYNC_bindSock: setsockopt failed with (%d)\n", errno);
 651
 652     for (numTries = 0; numTries < state->bind_retry_limit; numTries++) {
 653         code = bind(state->fd,
 654                     (struct sockaddr *)&state->addr,
 655                     AFS_SOCKADDR_LEN(&state->addr));
 656         if (code == 0)
 657             break;
 658         Log("SYNC_bindSock: bind failed with (%d), will sleep and retry\n",
 659             errno);
 660         sleep(5);
 661     }
 662     listen(state->fd, state->listen_depth);
 663
 664     return code;
 665 }