client_common.c

   1 /*
   2  * Copyright (C) 1997-2013 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file client_common.c Common functions of para_client and para_audiod. */
   8
   9 #include <regex.h>
  10 #include <sys/types.h>
  11
  12 #include "para.h"
  13 #include "error.h"
  14 #include "list.h"
  15 #include "sched.h"
  16 #include "crypt.h"
  17 #include "net.h"
  18 #include "fd.h"
  19 #include "sideband.h"
  20 #include "string.h"
  21 #include "client.cmdline.h"
  22 #include "client.h"
  23 #include "buffer_tree.h"
  24 #include "version.h"
  25 #include "ggo.h"
  26
  27 /** The size of the receiving buffer. */
  28 #define CLIENT_BUFSIZE 4000
  29
  30 /**
  31  * Close the connection to para_server and deallocate per-command resources.
  32  *
  33  * \param ct The client task.
  34  *
  35  * This frees all resources of the current command but keeps the configuration
  36  * in \p ct->conf.
  37  *
  38  * \sa \ref client_close().
  39  */
  40 void client_disconnect(struct client_task *ct)
  41 {
  42         if (!ct)
  43                 return;
  44         if (ct->scc.fd >= 0)
  45                 close(ct->scc.fd);
  46         free_argv(ct->features);
  47         ct->features = NULL;
  48         sc_free(ct->scc.recv);
  49         ct->scc.recv = NULL;
  50         sc_free(ct->scc.send);
  51         ct->scc.send = NULL;
  52         btr_remove_node(&ct->btrn[0]);
  53         btr_remove_node(&ct->btrn[1]);
  54 }
  55
  56 /**
  57  * Close the connection to para_server and free all resources.
  58  *
  59  * \param ct Pointer to the client data.
  60  *
  61  * \sa \ref client_open(), \ref client_disconnect().
  62  */
  63 void client_close(struct client_task *ct)
  64 {
  65         if (!ct)
  66                 return;
  67         client_disconnect(ct);
  68         free(ct->user);
  69         free(ct->config_file);
  70         free(ct->key_file);
  71         client_cmdline_parser_free(&ct->conf);
  72         free(ct->challenge_hash);
  73         sb_free(ct->sbc[0]);
  74         sb_free(ct->sbc[1]);
  75         free(ct);
  76 }
  77
  78 /**
  79  * The preselect hook for server commands.
  80  *
  81  * \param s Pointer to the scheduler.
  82  * \param t Pointer to the task struct for this command.
  83  *
  84  * The task pointer must contain a pointer to the initialized client data
  85  * structure as it is returned by client_open().
  86  *
  87  * This function checks the state of the connection and adds the file descriptor
  88  * of the connection to the read or write fd set of \a s accordingly.
  89  *
  90  * \sa register_task() client_open(), struct sched, struct task.
  91  */
  92 static void client_pre_select(struct sched *s, struct task *t)
  93 {
  94         int ret;
  95         struct client_task *ct = container_of(t, struct client_task, task);
  96
  97         if (ct->scc.fd < 0)
  98                 return;
  99         switch (ct->status) {
 100         case CL_CONNECTED:
 101         case CL_SENT_AUTH:
 102         case CL_SENT_CH_RESPONSE:
 103                 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
 104                 return;
 105
 106         case CL_RECEIVED_WELCOME:
 107         case CL_RECEIVED_PROCEED:
 108         case CL_RECEIVED_CHALLENGE:
 109                 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
 110                 return;
 111
 112         case CL_SENDING:
 113                 if (ct->btrn[1]) {
 114                         ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
 115                         if (ret < 0)
 116                                 sched_min_delay(s);
 117                         else if (ret > 0)
 118                                 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
 119                 }
 120                 /* fall though */
 121         case CL_EXECUTING:
 122                 if (ct->btrn[0]) {
 123                         ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
 124                         if (ret < 0)
 125                                 sched_min_delay(s);
 126                         else if (ret > 0)
 127                                 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
 128                 }
 129                 return;
 130         }
 131 }
 132
 133 static int send_sb(struct client_task *ct, int channel, void *buf, size_t numbytes,
 134                 enum sb_designator band, bool dont_free)
 135 {
 136         int ret, fd = ct->scc.fd;
 137         struct iovec iov[2];
 138
 139         if (!ct->sbc[channel]) {
 140                 struct sb_buffer sbb;
 141                 sb_transformation trafo = ct->status < CL_RECEIVED_PROCEED?
 142                         NULL : sc_trafo;
 143                 sbb = (typeof(sbb))SBB_INIT(band, buf, numbytes);
 144                 ct->sbc[channel] = sb_new_send(&sbb, dont_free, trafo, ct->scc.send);
 145         }
 146         ret = sb_get_send_buffers(ct->sbc[channel], iov);
 147         ret = xwritev(fd, iov, ret);
 148         if (ret < 0) {
 149                 sb_free(ct->sbc[channel]);
 150                 ct->sbc[channel] = NULL;
 151                 return ret;
 152         }
 153         if (sb_sent(ct->sbc[channel], ret)) {
 154                 ct->sbc[channel] = NULL;
 155                 return 1;
 156         }
 157         return 0;
 158 }
 159
 160 static int recv_sb(struct client_task *ct, fd_set *rfds,
 161                 struct sb_buffer *result)
 162 {
 163         int ret;
 164         size_t n;
 165         sb_transformation trafo;
 166         void *trafo_context;
 167         struct iovec iov;
 168
 169         if (!FD_ISSET(ct->scc.fd, rfds))
 170                 return 0;
 171         if (ct->status < CL_SENT_CH_RESPONSE)
 172                 trafo = trafo_context = NULL;
 173         else {
 174                 trafo = sc_trafo;
 175                 trafo_context = ct->scc.recv;
 176         }
 177         if (!ct->sbc[0])
 178                 ct->sbc[0] = sb_new_recv(0, trafo, trafo_context);
 179 again:
 180         sb_get_recv_buffer(ct->sbc[0], &iov);
 181         ret = read_nonblock(ct->scc.fd, iov.iov_base, iov.iov_len, rfds, &n);
 182         if (ret < 0) {
 183                 sb_free(ct->sbc[0]);
 184                 ct->sbc[0] = NULL;
 185                 return ret;
 186         }
 187         if (n == 0)
 188                 return 0;
 189         if (!sb_received(ct->sbc[0], n, result))
 190                 goto again;
 191         ct->sbc[0] = NULL;
 192         return 1;
 193 }
 194
 195
 196 static char **parse_features(char *buf)
 197 {
 198         int i;
 199         const char id[] = "\nFeatures: ";
 200         char *p, *q, **features;
 201
 202         p = strstr(buf, id);
 203         if (!p)
 204                 return NULL;
 205         p += strlen(id);
 206         q = strchr(p, '\n');
 207         if (!q)
 208                 return NULL;
 209         *q = '\0';
 210         create_argv(p, ",", &features);
 211         for (i = 0; features[i]; i++)
 212                 PARA_INFO_LOG("server feature: %s\n", features[i]);
 213         return features;
 214 }
 215
 216 static int dispatch_sbb(struct client_task *ct, struct sb_buffer *sbb)
 217 {
 218         int ret;
 219         const char *designator[] = {SB_DESIGNATORS_ARRAY};
 220
 221         if (!sbb)
 222                 return 0;
 223         if (sbb->band < NUM_SB_DESIGNATORS)
 224                 PARA_DEBUG_LOG("band: %s\n", designator[sbb->band]);
 225
 226         switch (sbb->band) {
 227         case SBD_AWAITING_DATA:
 228                 ct->status = CL_SENDING;
 229                 ret = 1;
 230                 goto out;
 231         case SBD_OUTPUT:
 232                 if (iov_valid(&sbb->iov))
 233                         btr_add_output(sbb->iov.iov_base, sbb->iov.iov_len,
 234                                 ct->btrn[0]);
 235                 ret = 1;
 236                 goto out;
 237         case SBD_DEBUG_LOG:
 238         case SBD_INFO_LOG:
 239         case SBD_NOTICE_LOG:
 240         case SBD_WARNING_LOG:
 241         case SBD_ERROR_LOG:
 242         case SBD_CRIT_LOG:
 243         case SBD_EMERG_LOG:
 244                 if (iov_valid(&sbb->iov)) {
 245                         int ll = sbb->band - SBD_DEBUG_LOG;
 246                         para_log(ll, "remote: %s", (char *)sbb->iov.iov_base);
 247                 }
 248                 ret = 1;
 249                 goto deallocate;
 250         case SBD_EXIT__SUCCESS:
 251                 ret = -E_SERVER_CMD_SUCCESS;
 252                 goto deallocate;
 253         case SBD_EXIT__FAILURE:
 254                 ret = -E_SERVER_CMD_FAILURE;
 255                 goto deallocate;
 256         default:
 257                 PARA_ERROR_LOG("invalid band %d\n", sbb->band);
 258                 ret = -E_BAD_BAND;
 259                 goto deallocate;
 260         }
 261 deallocate:
 262         free(sbb->iov.iov_base);
 263 out:
 264         sbb->iov.iov_base = NULL;
 265         return ret;
 266 }
 267
 268 static bool has_feature(const char *feature, struct client_task *ct)
 269 {
 270         return find_arg(feature, ct->features) >= 0? true : false;
 271 }
 272
 273 static int send_sb_command(struct client_task *ct)
 274 {
 275         int i;
 276         char *command, *p;
 277         size_t len = 0;
 278
 279         if (ct->sbc[1])
 280                 return send_sb(ct, 0, NULL, 0, 0, false);
 281
 282         for (i = 0; i < ct->conf.inputs_num; i++)
 283                 len += strlen(ct->conf.inputs[i]) + 1;
 284         p = command = para_malloc(len);
 285         for (i = 0; i < ct->conf.inputs_num; i++) {
 286                 strcpy(p, ct->conf.inputs[i]);
 287                 p += strlen(ct->conf.inputs[i]) + 1;
 288         }
 289         PARA_DEBUG_LOG("--> %s\n", command);
 290         return send_sb(ct, 0, command, len, SBD_COMMAND, false);
 291 }
 292
 293 /**
 294  * The post select hook for client commands.
 295  *
 296  * \param s Pointer to the scheduler.
 297  * \param t Pointer to the task struct for this command.
 298  *
 299  * Depending on the current state of the connection and the status of the read
 300  * and write fd sets of \a s, this function performs the necessary steps to
 301  * authenticate the connection, to send the command given by \a t->private_data
 302  * and to receive para_server's output, if any.
 303  *
 304  * \sa struct sched, struct task.
 305  */
 306 static int client_post_select(struct sched *s, struct task *t)
 307 {
 308         struct client_task *ct = container_of(t, struct client_task, task);
 309         int ret = 0;
 310         size_t n;
 311         char buf[CLIENT_BUFSIZE];
 312
 313         ret = task_get_notification(t);
 314         if (ret < 0)
 315                 goto out;
 316         if (ct->scc.fd < 0)
 317                 return 0;
 318         switch (ct->status) {
 319         case CL_CONNECTED: /* receive welcome message */
 320                 ret = read_nonblock(ct->scc.fd, buf, sizeof(buf), &s->rfds, &n);
 321                 if (ret < 0 || n == 0)
 322                         goto out;
 323                 ct->features = parse_features(buf);
 324                 if (!has_feature("sideband", ct)) {
 325                         PARA_ERROR_LOG("server has no sideband support\n");
 326                         ret = -E_INCOMPAT_FEAT;
 327                         goto out;
 328                 }
 329                 ct->status = CL_RECEIVED_WELCOME;
 330                 return 0;
 331         case CL_RECEIVED_WELCOME: /* send auth command */
 332                 if (!FD_ISSET(ct->scc.fd, &s->wfds))
 333                         return 0;
 334                 sprintf(buf, AUTH_REQUEST_MSG "%s sideband%s", ct->user,
 335                         has_feature("aes_ctr128", ct)? ",aes_ctr128" : "");
 336                 PARA_INFO_LOG("--> %s\n", buf);
 337                 ret = write_buffer(ct->scc.fd, buf);
 338                 if (ret < 0)
 339                         goto out;
 340                 ct->status = CL_SENT_AUTH;
 341                 return 0;
 342         case CL_SENT_AUTH:
 343                 /*
 344                  * Receive challenge and session keys, decrypt the challenge and
 345                  * send back the hash of the decrypted challenge.
 346                  */
 347                 {
 348                 /* decrypted challenge/session key buffer */
 349                 unsigned char crypt_buf[1024];
 350                 struct sb_buffer sbb;
 351                 bool use_aes;
 352
 353                 ret = recv_sb(ct, &s->rfds, &sbb);
 354                 if (ret <= 0)
 355                         goto out;
 356                 if (sbb.band != SBD_CHALLENGE) {
 357                         ret = -E_BAD_BAND;
 358                         free(sbb.iov.iov_base);
 359                                 goto out;
 360                 }
 361                 n = sbb.iov.iov_len;
 362                 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
 363                 ret = priv_decrypt(ct->key_file, crypt_buf,
 364                         sbb.iov.iov_base, n);
 365                 free(sbb.iov.iov_base);
 366                 if (ret < 0)
 367                         goto out;
 368                 ct->challenge_hash = para_malloc(HASH_SIZE);
 369                 hash_function((char *)crypt_buf, CHALLENGE_SIZE, ct->challenge_hash);
 370                 use_aes = has_feature("aes_ctr128", ct);
 371                 ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN, use_aes);
 372                 ct->scc.recv = sc_new(crypt_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
 373                         SESSION_KEY_LEN, use_aes);
 374                 hash_to_asc(ct->challenge_hash, buf);
 375                 PARA_INFO_LOG("--> %s\n", buf);
 376                 ct->status = CL_RECEIVED_CHALLENGE;
 377                 return 0;
 378                 }
 379         case CL_RECEIVED_CHALLENGE:
 380                 ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
 381                         SBD_CHALLENGE_RESPONSE, false);
 382                 if (ret != 0)
 383                         ct->challenge_hash = NULL;
 384                 if (ret <= 0)
 385                         goto out;
 386                 ct->status = CL_SENT_CH_RESPONSE;
 387                 goto out;
 388         case CL_SENT_CH_RESPONSE: /* read server response */
 389                 {
 390                 struct sb_buffer sbb;
 391                 ret = recv_sb(ct, &s->rfds, &sbb);
 392                 if (ret <= 0)
 393                         goto out;
 394                 free(sbb.iov.iov_base);
 395                 if (sbb.band != SBD_PROCEED)
 396                         ret = -E_BAD_BAND;
 397                 else
 398                         ct->status = CL_RECEIVED_PROCEED;
 399                 goto out;
 400                 }
 401         case CL_RECEIVED_PROCEED: /* concat args and send command */
 402                 {
 403                 if (!FD_ISSET(ct->scc.fd, &s->wfds))
 404                         return 0;
 405                 ret = send_sb_command(ct);
 406                 if (ret <= 0)
 407                         goto out;
 408                 ct->status = CL_EXECUTING;
 409                 return 0;
 410                 }
 411         case CL_SENDING:
 412                 if (ct->btrn[1]) {
 413                         char *buf2;
 414                         size_t sz;
 415                         ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
 416                         if (ret == -E_BTR_EOF) {
 417                                 /* empty blob data packet indicates EOF */
 418                                 PARA_INFO_LOG("blob sent\n");
 419                                 ret = send_sb(ct, 1, NULL, 0, SBD_BLOB_DATA, true);
 420                                 if (ret >= 0)
 421                                         ret = -E_BTR_EOF;
 422                         }
 423                         if (ret < 0)
 424                                 goto close1;
 425                         if (ret > 0 && FD_ISSET(ct->scc.fd, &s->wfds)) {
 426                                 sz = btr_next_buffer(ct->btrn[1], &buf2);
 427                                 assert(sz);
 428                                 ret = send_sb(ct, 1, buf2, sz, SBD_BLOB_DATA, true);
 429                                 if (ret < 0)
 430                                         goto close1;
 431                                 if (ret > 0)
 432                                         btr_consume(ct->btrn[1], sz);
 433                         }
 434                 }
 435                 /* fall though */
 436         case CL_EXECUTING:
 437                 if (ct->btrn[0]) {
 438                         ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
 439                         if (ret < 0)
 440                                 goto close0;
 441                         if (ret > 0 && FD_ISSET(ct->scc.fd, &s->rfds)) {
 442                                 struct sb_buffer sbb;
 443                                 ret = recv_sb(ct, &s->rfds, &sbb);
 444                                 if (ret < 0)
 445                                         goto close0;
 446                                 if (ret > 0) {
 447                                         ret = dispatch_sbb(ct, &sbb);
 448                                         if (ret < 0)
 449                                                 goto close0;
 450                                 }
 451                         }
 452                 }
 453                 ret = 0;
 454                 goto out;
 455         }
 456 close1:
 457         PARA_INFO_LOG("channel 1: %s\n", para_strerror(-ret));
 458         btr_remove_node(&ct->btrn[1]);
 459         if (ct->btrn[0])
 460                 return 0;
 461         goto out;
 462 close0:
 463         PARA_INFO_LOG("channel 0: %s\n", para_strerror(-ret));
 464         btr_remove_node(&ct->btrn[0]);
 465         if (ct->btrn[1] && ct->status == CL_SENDING)
 466                 return 0;
 467 out:
 468         if (ret >= 0)
 469                 return 0;
 470         btr_remove_node(&ct->btrn[0]);
 471         btr_remove_node(&ct->btrn[1]);
 472         if (ret != -E_SERVER_CMD_SUCCESS && ret != -E_SERVER_CMD_FAILURE)
 473                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 474         return ret;
 475 }
 476
 477 /**
 478  * Connect to para_server and register the client task.
 479  *
 480  * \param ct The initialized client task structure.
 481  * \param s The scheduler instance to register the client task to.
 482  * \param parent The parent node of the client btr node.
 483  * \param child The child node of the client node.
 484  *
 485  * The client task structure given by \a ct  must be allocated and initialized
 486  * by \ref client_parse_config() before this function is called.
 487  *
 488  * \return Standard.
 489  */
 490 int client_connect(struct client_task *ct, struct sched *s,
 491                 struct btr_node *parent, struct btr_node *child)
 492 {
 493         int ret;
 494
 495         PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
 496                 ct->conf.server_port_arg);
 497         ct->scc.fd = -1;
 498         ret = para_connect_simple(IPPROTO_TCP, ct->conf.hostname_arg,
 499                                                ct->conf.server_port_arg);
 500         if (ret < 0)
 501                 return ret;
 502         ct->scc.fd = ret;
 503         ret = mark_fd_nonblocking(ct->scc.fd);
 504         if (ret < 0)
 505                 goto err_out;
 506         ct->status = CL_CONNECTED;
 507         ct->btrn[0] = btr_new_node(&(struct btr_node_description)
 508                 EMBRACE(.name = "client recv", .parent = NULL, .child = child));
 509         ct->btrn[1] = btr_new_node(&(struct btr_node_description)
 510                 EMBRACE(.name = "client send", .parent = parent, .child = NULL));
 511         ct->task.pre_select = client_pre_select;
 512         ct->task.post_select = client_post_select;
 513         ct->task.error = 0;
 514         sprintf(ct->task.status, "client");
 515         register_task(s, &ct->task);
 516         return 1;
 517 err_out:
 518         close(ct->scc.fd);
 519         ct->scc.fd = -1;
 520         return ret;
 521 }
 522
 523 __noreturn static void print_help_and_die(struct client_task *ct)
 524 {
 525         struct ggo_help h = DEFINE_GGO_HELP(client);
 526         bool d = ct->conf.detailed_help_given;
 527
 528         ggo_print_help(&h, d? GPH_STANDARD_FLAGS_DETAILED : GPH_STANDARD_FLAGS);
 529         exit(0);
 530 }
 531
 532 /**
 533  * Parse a client configuration.
 534  *
 535  * \param argc Usual argument count.
 536  * \param argv Usual argument vector.
 537  * \param ct_ptr Filled in by this function.
 538  * \param loglevel If not \p NULL, the number of the loglevel is stored here.
 539  *
 540  * This checks the command line options given by \a argc and \a argv, sets
 541  * default values for the user name and the name of the rsa key file and reads
 542  * further options from the config file.
 543  *
 544  * Upon successful return, \a ct_ptr points to a dynamically allocated and
 545  * initialized client task struct.
 546  *
 547  * \return The number of non-option arguments in \a argc/argv on success,
 548  * negative on errors.
 549  */
 550 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
 551                 int *loglevel)
 552 {
 553         char *home = para_homedir();
 554         int ret;
 555         struct client_task *ct = para_calloc(sizeof(struct client_task));
 556
 557         *ct_ptr = ct;
 558         ct->scc.fd = -1;
 559         ret = -E_CLIENT_SYNTAX;
 560         if (client_cmdline_parser(argc, argv, &ct->conf))
 561                 goto out;
 562         version_handle_flag("client", ct->conf.version_given);
 563         if (ct->conf.help_given || ct->conf.detailed_help_given)
 564                 print_help_and_die(ct);
 565
 566         ct->config_file = ct->conf.config_file_given?
 567                 para_strdup(ct->conf.config_file_arg) :
 568                 make_message("%s/.paraslash/client.conf", home);
 569         ret = file_exists(ct->config_file);
 570         if (!ret && ct->conf.config_file_given) {
 571                 ret = -E_NO_CONFIG;
 572                 goto out;
 573         }
 574         if (ret) {
 575                 struct client_cmdline_parser_params params = {
 576                         .override = 0,
 577                         .initialize = 0,
 578                         .check_required = 0,
 579                         .check_ambiguity = 0,
 580                         .print_errors = 0
 581                 };
 582                 ret = -E_BAD_CONFIG;
 583                 if (client_cmdline_parser_config_file(ct->config_file,
 584                         &ct->conf, &params))
 585                         goto out;
 586         }
 587         ct->user = ct->conf.user_given?
 588                 para_strdup(ct->conf.user_arg) : para_logname();
 589
 590         if (ct->conf.key_file_given)
 591                 ct->key_file = para_strdup(ct->conf.key_file_arg);
 592         else {
 593                 ct->key_file = make_message("%s/.paraslash/key.%s",
 594                         home, ct->user);
 595                 if (!file_exists(ct->key_file)) {
 596                         free(ct->key_file);
 597                         ct->key_file = make_message("%s/.ssh/id_rsa", home);
 598                 }
 599         }
 600
 601         if (loglevel)
 602                 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
 603         PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
 604         PARA_INFO_LOG("config_file: %s\n", ct->config_file);
 605         PARA_INFO_LOG("key_file: %s\n", ct->key_file);
 606         ret = ct->conf.inputs_num;
 607 out:
 608         free(home);
 609         if (ret < 0) {
 610                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 611                 client_close(ct);
 612                 *ct_ptr = NULL;
 613         }
 614         return ret;
 615 }
 616
 617 /**
 618  * Parse the client configuration and open a connection to para_server.
 619  *
 620  * \param argc See \ref client_parse_config.
 621  * \param argv See \ref client_parse_config.
 622  * \param ct_ptr See \ref client_parse_config.
 623  * \param loglevel See \ref client_parse_config.
 624  * \param parent See \ref client_connect().
 625  * \param child See \ref client_connect().
 626  * \param sched See \ref client_connect().
 627  *
 628  * This function combines client_parse_config() and client_connect(). It is
 629  * considered a syntax error if no command was given, i.e. if the number
 630  * of non-option arguments is zero.
 631  *
 632  * \return Standard.
 633  */
 634 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
 635                 int *loglevel, struct btr_node *parent, struct btr_node *child,
 636                 struct sched *sched)
 637 {
 638         int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
 639
 640         if (ret < 0)
 641                 return ret;
 642         if (ret == 0) {
 643                 ret = -E_CLIENT_SYNTAX;
 644                 goto fail;
 645         }
 646         ret = client_connect(*ct_ptr, sched, parent, child);
 647         if (ret < 0)
 648                 goto fail;
 649         return 1;
 650 fail:
 651         client_close(*ct_ptr);
 652         *ct_ptr = NULL;
 653         return ret;
 654 }