client_common.c

   1 /* Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /** \file client_common.c Common functions of para_client and para_audiod. */
   4
   5 #include <netinet/in.h>
   6 #include <sys/socket.h>
   7 #include <regex.h>
   8 #include <sys/types.h>
   9 #include <arpa/inet.h>
  10 #include <sys/un.h>
  11 #include <netdb.h>
  12 #include <lopsub.h>
  13
  14 #include "client.lsg.h"
  15 #include "para.h"
  16 #include "error.h"
  17 #include "list.h"
  18 #include "lsu.h"
  19 #include "sched.h"
  20 #include "crypt.h"
  21 #include "net.h"
  22 #include "fd.h"
  23 #include "sideband.h"
  24 #include "string.h"
  25 #include "client.h"
  26 #include "buffer_tree.h"
  27 #include "version.h"
  28
  29 /** The size of the receiving buffer. */
  30 #define CLIENT_BUFSIZE 4000
  31
  32 /**
  33  * Close the connection to para_server and free all resources.
  34  *
  35  * \param ct Pointer to the client data.
  36  *
  37  * \sa \ref client_open().
  38  */
  39 void client_close(struct client_task *ct)
  40 {
  41         if (!ct)
  42                 return;
  43         free(ct->user);
  44         free(ct->key_file);
  45         lls_free_parse_result(ct->lpr, CLIENT_CMD_PTR);
  46         free(ct->challenge_hash);
  47         sb_free(ct->sbc[0]);
  48         sb_free(ct->sbc[1]);
  49         free(ct);
  50 }
  51
  52 /*
  53  * This function asks the scheduler to monitor a file descriptor which
  54  * corresponds to an active connection. The descriptor is monitored for either
  55  * reading or writing, depending on the state of the connection.
  56  *
  57  * The context pointer is assumed to refer to a client task structure that was
  58  * initialized earlier by client_open().
  59  */
  60 static void client_pre_select(struct sched *s, void *context)
  61 {
  62         int ret;
  63         struct client_task *ct = context;
  64
  65         if (ct->scc.fd < 0)
  66                 return;
  67         switch (ct->status) {
  68         case CL_CONNECTED:
  69         case CL_SENT_AUTH:
  70         case CL_SENT_CH_RESPONSE:
  71                 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
  72                 return;
  73
  74         case CL_RECEIVED_WELCOME:
  75         case CL_RECEIVED_PROCEED:
  76         case CL_RECEIVED_CHALLENGE:
  77                 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
  78                 return;
  79
  80         case CL_SENDING:
  81                 if (ct->btrn[1]) {
  82                         ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
  83                         if (ret < 0)
  84                                 sched_min_delay(s);
  85                         else if (ret > 0)
  86                                 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
  87                 }
  88                 __attribute__ ((fallthrough));
  89         case CL_EXECUTING:
  90                 if (ct->btrn[0]) {
  91                         ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
  92                         if (ret < 0)
  93                                 sched_min_delay(s);
  94                         else if (ret > 0)
  95                                 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
  96                 }
  97                 return;
  98         }
  99 }
 100
 101 static int send_sb(struct client_task *ct, int channel, void *buf, size_t numbytes,
 102                 enum sb_designator band, bool dont_free)
 103 {
 104         int ret, fd = ct->scc.fd;
 105         struct iovec iov[2];
 106
 107         if (!ct->sbc[channel]) {
 108                 struct sb_buffer sbb;
 109                 sb_transformation trafo = ct->status < CL_RECEIVED_PROCEED?
 110                         NULL : sc_trafo;
 111                 sbb = (typeof(sbb))SBB_INIT(band, buf, numbytes);
 112                 ct->sbc[channel] = sb_new_send(&sbb, dont_free, trafo, ct->scc.send);
 113         }
 114         ret = sb_get_send_buffers(ct->sbc[channel], iov);
 115         ret = xwritev(fd, iov, ret);
 116         if (ret < 0) {
 117                 sb_free(ct->sbc[channel]);
 118                 ct->sbc[channel] = NULL;
 119                 return ret;
 120         }
 121         if (sb_sent(ct->sbc[channel], ret)) {
 122                 ct->sbc[channel] = NULL;
 123                 return 1;
 124         }
 125         return 0;
 126 }
 127
 128 static int recv_sb(struct client_task *ct, fd_set *rfds,
 129                 struct sb_buffer *result)
 130 {
 131         int ret;
 132         size_t n;
 133         sb_transformation trafo;
 134         void *trafo_context;
 135         struct iovec iov;
 136
 137         if (!FD_ISSET(ct->scc.fd, rfds))
 138                 return 0;
 139         if (ct->status < CL_SENT_CH_RESPONSE)
 140                 trafo = trafo_context = NULL;
 141         else {
 142                 trafo = sc_trafo;
 143                 trafo_context = ct->scc.recv;
 144         }
 145         if (!ct->sbc[0])
 146                 ct->sbc[0] = sb_new_recv(0, trafo, trafo_context);
 147 again:
 148         sb_get_recv_buffer(ct->sbc[0], &iov);
 149         ret = read_nonblock(ct->scc.fd, iov.iov_base, iov.iov_len, rfds, &n);
 150         if (ret < 0) {
 151                 sb_free(ct->sbc[0]);
 152                 ct->sbc[0] = NULL;
 153                 return ret;
 154         }
 155         if (n == 0)
 156                 return 0;
 157         ret = sb_received(ct->sbc[0], n, result);
 158         if (ret < 0)
 159                 return ret;
 160         if (ret == 0)
 161                 goto again;
 162         ct->sbc[0] = NULL;
 163         return 1;
 164 }
 165
 166
 167 static char **parse_features(char *buf)
 168 {
 169         int i;
 170         const char id[] = "\nFeatures: ";
 171         char *p, *q, **features;
 172
 173         p = strstr(buf, id);
 174         if (!p)
 175                 return NULL;
 176         p += strlen(id);
 177         q = strchr(p, '\n');
 178         if (!q)
 179                 return NULL;
 180         *q = '\0';
 181         create_argv(p, ",", &features);
 182         for (i = 0; features[i]; i++)
 183                 PARA_INFO_LOG("server feature: %s\n", features[i]);
 184         return features;
 185 }
 186
 187 static int dispatch_sbb(struct client_task *ct, struct sb_buffer *sbb)
 188 {
 189         int ret;
 190         const char *designator[] = {SB_DESIGNATORS_ARRAY};
 191
 192         if (!sbb)
 193                 return 0;
 194         if (sbb->band < NUM_SB_DESIGNATORS)
 195                 PARA_DEBUG_LOG("band: %s\n", designator[sbb->band]);
 196
 197         switch (sbb->band) {
 198         case SBD_AWAITING_DATA:
 199                 ct->status = CL_SENDING;
 200                 ret = 1;
 201                 goto out;
 202         case SBD_OUTPUT:
 203                 if (iov_valid(&sbb->iov))
 204                         btr_add_output(sbb->iov.iov_base, sbb->iov.iov_len,
 205                                 ct->btrn[0]);
 206                 ret = 1;
 207                 goto out;
 208         case SBD_DEBUG_LOG:
 209         case SBD_INFO_LOG:
 210         case SBD_NOTICE_LOG:
 211         case SBD_WARNING_LOG:
 212         case SBD_ERROR_LOG:
 213         case SBD_CRIT_LOG:
 214         case SBD_EMERG_LOG:
 215                 if (iov_valid(&sbb->iov)) {
 216                         int ll = sbb->band - SBD_DEBUG_LOG;
 217                         para_log(ll, "remote: %s", (char *)sbb->iov.iov_base);
 218                 }
 219                 ret = 1;
 220                 goto deallocate;
 221         case SBD_EXIT__SUCCESS:
 222                 ret = -E_SERVER_CMD_SUCCESS;
 223                 goto deallocate;
 224         case SBD_EXIT__FAILURE:
 225                 ret = -E_SERVER_CMD_FAILURE;
 226                 goto deallocate;
 227         default:
 228                 PARA_ERROR_LOG("invalid band %d\n", sbb->band);
 229                 ret = -E_BAD_BAND;
 230                 goto deallocate;
 231         }
 232 deallocate:
 233         free(sbb->iov.iov_base);
 234 out:
 235         sbb->iov.iov_base = NULL;
 236         return ret;
 237 }
 238
 239 static int send_sb_command(struct client_task *ct)
 240 {
 241         int i;
 242         char *command, *p;
 243         size_t len = 0;
 244         unsigned num_inputs = lls_num_inputs(ct->lpr);
 245
 246         if (ct->sbc[1])
 247                 return send_sb(ct, 0, NULL, 0, 0, false);
 248
 249         for (i = 0; i < num_inputs; i++)
 250                 len += strlen(lls_input(i, ct->lpr)) + 1;
 251         p = command = alloc(len);
 252         for (i = 0; i < num_inputs; i++) {
 253                 const char *str = lls_input(i, ct->lpr);
 254                 strcpy(p, str);
 255                 p += strlen(str) + 1;
 256         }
 257         PARA_DEBUG_LOG("--> %s\n", command);
 258         return send_sb(ct, 0, command, len, SBD_COMMAND, false);
 259 }
 260
 261 static bool has_feature(const char *feature, struct client_task *ct)
 262 {
 263         return find_arg(feature, ct->features) >= 0? true : false;
 264 }
 265
 266 /*
 267  * This function reads or writes to the socket file descriptor which
 268  * corresponds to an established connection between the client and the server.
 269  * It depends on the current state of the connection and on the readiness of
 270  * the socket file descriptor which type of I/O is going to be performed.
 271  * Besides the initial handshake and authentication, the function sends the
 272  * server command and receives the output from the server, if any.
 273  *
 274  * The context pointer refers to a client task structure that was initialized
 275  * earlier by client_open().
 276  */
 277 static int client_post_select(struct sched *s, void *context)
 278 {
 279         struct client_task *ct = context;
 280         int ret = 0;
 281         size_t n;
 282         char buf[CLIENT_BUFSIZE];
 283
 284         ret = task_get_notification(ct->task);
 285         if (ret < 0)
 286                 goto out;
 287         if (ct->scc.fd < 0)
 288                 return 0;
 289         switch (ct->status) {
 290         case CL_CONNECTED: /* receive welcome message */
 291                 ret = read_nonblock(ct->scc.fd, buf, sizeof(buf), &s->rfds, &n);
 292                 if (ret < 0 || n == 0)
 293                         goto out;
 294                 ct->features = parse_features(buf);
 295                 ct->status = CL_RECEIVED_WELCOME;
 296                 return 0;
 297         case CL_RECEIVED_WELCOME: /* send auth command */
 298                 {
 299                 /*
 300                  * Use sha256 iff the server announced the feature. After 0.7.0
 301                  * we may request and use the feature unconditionally. After
 302                  * 0.8.0 we no longer need to request the feature.
 303                  */
 304                 bool has_sha256;
 305                 if (!FD_ISSET(ct->scc.fd, &s->wfds))
 306                         return 0;
 307                 has_sha256 = has_feature("sha256", ct);
 308                 sprintf(buf, AUTH_REQUEST_MSG "%s%s", ct->user, has_sha256?
 309                         " sha256" : "");
 310                 PARA_INFO_LOG("--> %s\n", buf);
 311                 ret = write_buffer(ct->scc.fd, buf);
 312                 if (ret < 0)
 313                         goto out;
 314                 ct->status = CL_SENT_AUTH;
 315                 return 0;
 316                 }
 317         case CL_SENT_AUTH:
 318                 /*
 319                  * Receive challenge and session keys, decrypt the challenge and
 320                  * send back the hash of the decrypted challenge.
 321                  */
 322                 {
 323                 /* decrypted challenge/session key buffer */
 324                 unsigned char crypt_buf[1024];
 325                 struct sb_buffer sbb;
 326
 327                 ret = recv_sb(ct, &s->rfds, &sbb);
 328                 if (ret <= 0)
 329                         goto out;
 330                 if (sbb.band != SBD_CHALLENGE) {
 331                         ret = -E_BAD_BAND;
 332                         free(sbb.iov.iov_base);
 333                                 goto out;
 334                 }
 335                 n = sbb.iov.iov_len;
 336                 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
 337                 ret = apc_priv_decrypt(ct->key_file, crypt_buf,
 338                         sbb.iov.iov_base, n);
 339                 free(sbb.iov.iov_base);
 340                 if (ret < 0)
 341                         goto out;
 342                 ct->challenge_hash = alloc(HASH2_SIZE);
 343                 if (has_feature("sha256", ct)) {
 344                         hash2_function((char *)crypt_buf, APC_CHALLENGE_SIZE, ct->challenge_hash);
 345                         hash2_to_asc(ct->challenge_hash, buf);
 346                 } else {
 347                         hash_function((char *)crypt_buf, APC_CHALLENGE_SIZE, ct->challenge_hash);
 348                         hash_to_asc(ct->challenge_hash, buf);
 349                 }
 350                 ct->scc.send = sc_new(crypt_buf + APC_CHALLENGE_SIZE, SESSION_KEY_LEN);
 351                 ct->scc.recv = sc_new(crypt_buf + APC_CHALLENGE_SIZE + SESSION_KEY_LEN,
 352                         SESSION_KEY_LEN);
 353                 PARA_INFO_LOG("--> %s\n", buf);
 354                 ct->status = CL_RECEIVED_CHALLENGE;
 355                 return 0;
 356                 }
 357         case CL_RECEIVED_CHALLENGE:
 358                 if (has_feature("sha256", ct))
 359                         ret = send_sb(ct, 0, ct->challenge_hash, HASH2_SIZE,
 360                                 SBD_CHALLENGE_RESPONSE, false);
 361                 else
 362                         ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
 363                                 SBD_CHALLENGE_RESPONSE, false);
 364                 if (ret != 0)
 365                         ct->challenge_hash = NULL;
 366                 if (ret <= 0)
 367                         goto out;
 368                 ct->status = CL_SENT_CH_RESPONSE;
 369                 goto out;
 370         case CL_SENT_CH_RESPONSE: /* read server response */
 371                 {
 372                 struct sb_buffer sbb;
 373                 ret = recv_sb(ct, &s->rfds, &sbb);
 374                 if (ret <= 0)
 375                         goto out;
 376                 free(sbb.iov.iov_base);
 377                 if (sbb.band != SBD_PROCEED)
 378                         ret = -E_BAD_BAND;
 379                 else
 380                         ct->status = CL_RECEIVED_PROCEED;
 381                 goto out;
 382                 }
 383         case CL_RECEIVED_PROCEED: /* concat args and send command */
 384                 {
 385                 if (!FD_ISSET(ct->scc.fd, &s->wfds))
 386                         return 0;
 387                 ret = send_sb_command(ct);
 388                 if (ret <= 0)
 389                         goto out;
 390                 ct->status = CL_EXECUTING;
 391                 return 0;
 392                 }
 393         case CL_SENDING:
 394                 if (ct->btrn[1]) {
 395                         char *buf2;
 396                         size_t sz;
 397                         ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
 398                         if (ret == -E_BTR_EOF) {
 399                                 /* empty blob data packet indicates EOF */
 400                                 PARA_INFO_LOG("blob sent\n");
 401                                 ret = send_sb(ct, 1, NULL, 0, SBD_BLOB_DATA, true);
 402                                 if (ret >= 0)
 403                                         ret = -E_BTR_EOF;
 404                         }
 405                         if (ret < 0)
 406                                 goto close1;
 407                         if (ret > 0 && FD_ISSET(ct->scc.fd, &s->wfds)) {
 408                                 sz = btr_next_buffer(ct->btrn[1], &buf2);
 409                                 assert(sz);
 410                                 ret = send_sb(ct, 1, buf2, sz, SBD_BLOB_DATA, true);
 411                                 if (ret < 0)
 412                                         goto close1;
 413                                 if (ret > 0)
 414                                         btr_consume(ct->btrn[1], sz);
 415                         }
 416                 }
 417                 __attribute__ ((fallthrough));
 418         case CL_EXECUTING:
 419                 if (ct->btrn[0]) {
 420                         ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
 421                         if (ret < 0)
 422                                 goto close0;
 423                         if (ret > 0 && FD_ISSET(ct->scc.fd, &s->rfds)) {
 424                                 struct sb_buffer sbb;
 425                                 ret = recv_sb(ct, &s->rfds, &sbb);
 426                                 if (ret < 0)
 427                                         goto close0;
 428                                 if (ret > 0) {
 429                                         ret = dispatch_sbb(ct, &sbb);
 430                                         if (ret < 0)
 431                                                 goto close0;
 432                                 }
 433                         }
 434                 }
 435                 ret = 0;
 436                 goto out;
 437         }
 438 close1:
 439         PARA_INFO_LOG("channel 1: %s\n", para_strerror(-ret));
 440         btr_remove_node(&ct->btrn[1]);
 441         if (ct->btrn[0])
 442                 return 0;
 443         goto out;
 444 close0:
 445         PARA_INFO_LOG("channel 0: %s\n", para_strerror(-ret));
 446         btr_remove_node(&ct->btrn[0]);
 447         if (ct->btrn[1] && ct->status == CL_SENDING)
 448                 return 0;
 449 out:
 450         if (ret >= 0)
 451                 return 0;
 452         btr_remove_node(&ct->btrn[0]);
 453         btr_remove_node(&ct->btrn[1]);
 454         PARA_NOTICE_LOG("closing connection (%s)\n", para_strerror(-ret));
 455         if (ct->scc.fd >= 0) {
 456                 close(ct->scc.fd);
 457                 ct->scc.fd = -1;
 458         }
 459         free_argv(ct->features);
 460         ct->features = NULL;
 461         sc_free(ct->scc.recv);
 462         ct->scc.recv = NULL;
 463         sc_free(ct->scc.send);
 464         ct->scc.send = NULL;
 465         return ret;
 466 }
 467
 468 /**
 469  * Connect to para_server and register the client task.
 470  *
 471  * \param ct The initialized client task structure.
 472  * \param s The scheduler instance to register the client task to.
 473  * \param parent The parent node of the client btr node.
 474  * \param child The child node of the client node.
 475  *
 476  * The client task structure given by \a ct  must be allocated and initialized
 477  * by \ref client_parse_config() before this function is called.
 478  *
 479  * \return Standard.
 480  */
 481 int client_connect(struct client_task *ct, struct sched *s,
 482                 struct btr_node *parent, struct btr_node *child)
 483 {
 484         int ret;
 485         const char *host = CLIENT_OPT_STRING_VAL(HOSTNAME, ct->lpr);
 486         uint32_t port = CLIENT_OPT_UINT32_VAL(SERVER_PORT, ct->lpr);
 487
 488         PARA_NOTICE_LOG("connecting %s:%u\n", host, port);
 489         ct->scc.fd = -1;
 490         ret = para_connect_simple(IPPROTO_TCP, host, port);
 491         if (ret < 0)
 492                 return ret;
 493         ct->scc.fd = ret;
 494         ret = mark_fd_nonblocking(ct->scc.fd);
 495         if (ret < 0)
 496                 goto err_out;
 497         ct->status = CL_CONNECTED;
 498         ct->btrn[0] = btr_new_node(&(struct btr_node_description)
 499                 EMBRACE(.name = "client recv", .parent = NULL, .child = child));
 500         ct->btrn[1] = btr_new_node(&(struct btr_node_description)
 501                 EMBRACE(.name = "client send", .parent = parent, .child = NULL));
 502
 503         ct->task = task_register(&(struct task_info) {
 504                 .name = "client",
 505                 .pre_select = client_pre_select,
 506                 .post_select = client_post_select,
 507                 .context = ct,
 508         }, s);
 509         return 1;
 510 err_out:
 511         close(ct->scc.fd);
 512         ct->scc.fd = -1;
 513         return ret;
 514 }
 515
 516 static void handle_help_flag(struct lls_parse_result *lpr)
 517 {
 518         char *help;
 519
 520         if (CLIENT_OPT_GIVEN(DETAILED_HELP, lpr))
 521                 help = lls_long_help(CLIENT_CMD_PTR);
 522         else if (CLIENT_OPT_GIVEN(HELP, lpr))
 523                 help = lls_short_help(CLIENT_CMD_PTR);
 524         else
 525                 return;
 526         printf("%s\n", help);
 527         free(help);
 528         exit(EXIT_SUCCESS);
 529 }
 530
 531 /**
 532  * Parse a client configuration.
 533  *
 534  * \param argc Usual argument count.
 535  * \param argv Usual argument vector.
 536  * \param ct_ptr Filled in by this function.
 537  * \param loglevel If not \p NULL, the number of the loglevel is stored here.
 538  *
 539  * This checks the command line options given by \a argc and \a argv, sets
 540  * default values for the user name and the name of the rsa key file and reads
 541  * further options from the config file.
 542  *
 543  * Upon successful return, \a ct_ptr points to a dynamically allocated and
 544  * initialized client task struct.
 545  *
 546  * \return The number of non-option arguments in \a argc/argv on success,
 547  * negative on errors.
 548  */
 549 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
 550                 int *loglevel)
 551 {
 552         const struct lls_command *cmd = CLIENT_CMD_PTR;
 553         struct lls_parse_result *lpr;
 554         int ret, ll;
 555         struct client_task *ct;
 556         char *kf = NULL, *user, *errctx, *home = para_homedir();
 557
 558         ret = lls(lls_parse(argc, argv, cmd, &lpr, &errctx));
 559         if (ret < 0)
 560                 goto out;
 561         version_handle_flag("client", CLIENT_OPT_GIVEN(VERSION, lpr));
 562         handle_help_flag(lpr);
 563
 564         ret = lsu_merge_config_file_options(CLIENT_OPT_STRING_VAL(CONFIG_FILE, lpr),
 565                 "client.conf", &lpr, cmd, client_suite, 0U /* default flags */);
 566         if (ret < 0)
 567                 goto out;
 568         /* success */
 569         ll = CLIENT_OPT_UINT32_VAL(LOGLEVEL, lpr);
 570         if (loglevel)
 571                 *loglevel = ll;
 572         user = CLIENT_OPT_GIVEN(USER, lpr)?
 573                 para_strdup(CLIENT_OPT_STRING_VAL(USER, lpr)) : para_logname();
 574
 575         if (CLIENT_OPT_GIVEN(KEY_FILE, lpr))
 576                 kf = para_strdup(CLIENT_OPT_STRING_VAL(KEY_FILE, lpr));
 577         else {
 578                 kf = make_message("%s/.paraslash/key.%s", home, user);
 579                 if (!file_exists(kf)) {
 580                         free(kf);
 581                         kf = make_message("%s/.ssh/id_rsa", home);
 582                 }
 583         }
 584         PARA_INFO_LOG("user: %s\n", user);
 585         PARA_INFO_LOG("key file: %s\n", kf);
 586         PARA_INFO_LOG("loglevel: %d\n", ll);
 587         ct = zalloc(sizeof(*ct));
 588         ct->scc.fd = -1;
 589         ct->lpr = lpr;
 590         ct->key_file = kf;
 591         ct->user = user;
 592         *ct_ptr = ct;
 593         ret = lls_num_inputs(lpr);
 594 out:
 595         free(home);
 596         if (ret < 0) {
 597                 if (errctx)
 598                         PARA_ERROR_LOG("%s\n", errctx);
 599                 free(errctx);
 600                 lls_free_parse_result(lpr, cmd);
 601                 free(kf);
 602                 *ct_ptr = NULL;
 603         }
 604         return ret;
 605 }
 606
 607 /**
 608  * Parse the client configuration and open a connection to para_server.
 609  *
 610  * \param argc See \ref client_parse_config.
 611  * \param argv See \ref client_parse_config.
 612  * \param ct_ptr See \ref client_parse_config.
 613  * \param loglevel See \ref client_parse_config.
 614  * \param parent See \ref client_connect().
 615  * \param child See \ref client_connect().
 616  * \param sched See \ref client_connect().
 617  *
 618  * This function combines client_parse_config() and client_connect(). It is
 619  * considered a syntax error if no command was given, i.e. if the number
 620  * of non-option arguments is zero.
 621  *
 622  * \return Standard.
 623  */
 624 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
 625                 int *loglevel, struct btr_node *parent, struct btr_node *child,
 626                 struct sched *sched)
 627 {
 628         int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
 629
 630         if (ret < 0)
 631                 return ret;
 632         if (ret == 0) {
 633                 ret = -E_CLIENT_SYNTAX;
 634                 goto fail;
 635         }
 636         ret = client_connect(*ct_ptr, sched, parent, child);
 637         if (ret < 0)
 638                 goto fail;
 639         return 1;
 640 fail:
 641         client_close(*ct_ptr);
 642         *ct_ptr = NULL;
 643         return ret;
 644 }