client_common.c

   1 /*
   2  * Copyright (C) 1997-2014 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 <netinet/in.h>
  10 #include <sys/socket.h>
  11 #include <regex.h>
  12 #include <sys/types.h>
  13 #include <arpa/inet.h>
  14 #include <sys/un.h>
  15 #include <netdb.h>
  16
  17 #include "para.h"
  18 #include "error.h"
  19 #include "list.h"
  20 #include "sched.h"
  21 #include "crypt.h"
  22 #include "net.h"
  23 #include "fd.h"
  24 #include "sideband.h"
  25 #include "string.h"
  26 #include "client.cmdline.h"
  27 #include "client.h"
  28 #include "buffer_tree.h"
  29 #include "version.h"
  30 #include "ggo.h"
  31
  32 /** The size of the receiving buffer. */
  33 #define CLIENT_BUFSIZE 4000
  34
  35 /**
  36  * Close the connection to para_server and free all resources.
  37  *
  38  * \param ct Pointer to the client data.
  39  *
  40  * \sa \ref client_open().
  41  */
  42 void client_close(struct client_task *ct)
  43 {
  44         if (!ct)
  45                 return;
  46         free(ct->user);
  47         free(ct->config_file);
  48         free(ct->key_file);
  49         client_cmdline_parser_free(&ct->conf);
  50         free(ct->challenge_hash);
  51         sb_free(ct->sbc[0]);
  52         sb_free(ct->sbc[1]);
  53         free(ct);
  54 }
  55
  56 /**
  57  * The preselect hook for server commands.
  58  *
  59  * \param s Pointer to the scheduler.
  60  * \param t Pointer to the task struct for this command.
  61  *
  62  * The task pointer must contain a pointer to the initialized client data
  63  * structure as it is returned by client_open().
  64  *
  65  * This function checks the state of the connection and adds the file descriptor
  66  * of the connection to the read or write fd set of \a s accordingly.
  67  *
  68  * \sa register_task() client_open(), struct sched, struct task.
  69  */
  70 static void client_pre_select(struct sched *s, struct task *t)
  71 {
  72         int ret;
  73         struct client_task *ct = container_of(t, struct client_task, task);
  74
  75         if (ct->scc.fd < 0)
  76                 return;
  77         switch (ct->status) {
  78         case CL_CONNECTED:
  79         case CL_SENT_AUTH:
  80         case CL_SENT_CH_RESPONSE:
  81                 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
  82                 return;
  83
  84         case CL_RECEIVED_WELCOME:
  85         case CL_RECEIVED_PROCEED:
  86         case CL_RECEIVED_CHALLENGE:
  87                 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
  88                 return;
  89
  90         case CL_SENDING:
  91                 if (ct->btrn[1]) {
  92                         ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
  93                         if (ret < 0)
  94                                 sched_min_delay(s);
  95                         else if (ret > 0)
  96                                 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
  97                 }
  98                 /* fall though */
  99         case CL_EXECUTING:
 100                 if (ct->btrn[0]) {
 101                         ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
 102                         if (ret < 0)
 103                                 sched_min_delay(s);
 104                         else if (ret > 0)
 105                                 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
 106                 }
 107                 return;
 108         }
 109 }
 110
 111 static int send_sb(struct client_task *ct, int channel, void *buf, size_t numbytes,
 112                 enum sb_designator band, bool dont_free)
 113 {
 114         int ret, fd = ct->scc.fd;
 115         struct iovec iov[2];
 116
 117         if (!ct->sbc[channel]) {
 118                 struct sb_buffer sbb;
 119                 sb_transformation trafo = ct->status < CL_RECEIVED_PROCEED?
 120                         NULL : sc_trafo;
 121                 sbb = (typeof(sbb))SBB_INIT(band, buf, numbytes);
 122                 ct->sbc[channel] = sb_new_send(&sbb, dont_free, trafo, ct->scc.send);
 123         }
 124         ret = sb_get_send_buffers(ct->sbc[channel], iov);
 125         ret = xwritev(fd, iov, ret);
 126         if (ret < 0) {
 127                 sb_free(ct->sbc[channel]);
 128                 ct->sbc[channel] = NULL;
 129                 return ret;
 130         }
 131         if (sb_sent(ct->sbc[channel], ret)) {
 132                 ct->sbc[channel] = NULL;
 133                 return 1;
 134         }
 135         return 0;
 136 }
 137
 138 static int recv_sb(struct client_task *ct, fd_set *rfds,
 139                 struct sb_buffer *result)
 140 {
 141         int ret;
 142         size_t n;
 143         sb_transformation trafo;
 144         void *trafo_context;
 145         struct iovec iov;
 146
 147         if (!FD_ISSET(ct->scc.fd, rfds))
 148                 return 0;
 149         if (ct->status < CL_SENT_CH_RESPONSE)
 150                 trafo = trafo_context = NULL;
 151         else {
 152                 trafo = sc_trafo;
 153                 trafo_context = ct->scc.recv;
 154         }
 155         if (!ct->sbc[0])
 156                 ct->sbc[0] = sb_new_recv(0, trafo, trafo_context);
 157 again:
 158         sb_get_recv_buffer(ct->sbc[0], &iov);
 159         ret = read_nonblock(ct->scc.fd, iov.iov_base, iov.iov_len, rfds, &n);
 160         if (ret < 0) {
 161                 sb_free(ct->sbc[0]);
 162                 ct->sbc[0] = NULL;
 163                 return ret;
 164         }
 165         if (n == 0)
 166                 return 0;
 167         if (!sb_received(ct->sbc[0], n, result))
 168                 goto again;
 169         ct->sbc[0] = NULL;
 170         return 1;
 171 }
 172
 173
 174 static char **parse_features(char *buf)
 175 {
 176         int i;
 177         const char id[] = "\nFeatures: ";
 178         char *p, *q, **features;
 179
 180         p = strstr(buf, id);
 181         if (!p)
 182                 return NULL;
 183         p += strlen(id);
 184         q = strchr(p, '\n');
 185         if (!q)
 186                 return NULL;
 187         *q = '\0';
 188         create_argv(p, ",", &features);
 189         for (i = 0; features[i]; i++)
 190                 PARA_INFO_LOG("server feature: %s\n", features[i]);
 191         return features;
 192 }
 193
 194 static int dispatch_sbb(struct client_task *ct, struct sb_buffer *sbb)
 195 {
 196         int ret;
 197         const char *designator[] = {SB_DESIGNATORS_ARRAY};
 198
 199         if (!sbb)
 200                 return 0;
 201         if (sbb->band < NUM_SB_DESIGNATORS)
 202                 PARA_DEBUG_LOG("band: %s\n", designator[sbb->band]);
 203
 204         switch (sbb->band) {
 205         case SBD_AWAITING_DATA:
 206                 ct->status = CL_SENDING;
 207                 ret = 1;
 208                 goto out;
 209         case SBD_OUTPUT:
 210                 if (iov_valid(&sbb->iov))
 211                         btr_add_output(sbb->iov.iov_base, sbb->iov.iov_len,
 212                                 ct->btrn[0]);
 213                 ret = 1;
 214                 goto out;
 215         case SBD_DEBUG_LOG:
 216         case SBD_INFO_LOG:
 217         case SBD_NOTICE_LOG:
 218         case SBD_WARNING_LOG:
 219         case SBD_ERROR_LOG:
 220         case SBD_CRIT_LOG:
 221         case SBD_EMERG_LOG:
 222                 if (iov_valid(&sbb->iov)) {
 223                         int ll = sbb->band - SBD_DEBUG_LOG;
 224                         para_log(ll, "remote: %s", (char *)sbb->iov.iov_base);
 225                 }
 226                 ret = 1;
 227                 goto deallocate;
 228         case SBD_EXIT__SUCCESS:
 229                 ret = -E_SERVER_CMD_SUCCESS;
 230                 goto deallocate;
 231         case SBD_EXIT__FAILURE:
 232                 ret = -E_SERVER_CMD_FAILURE;
 233                 goto deallocate;
 234         default:
 235                 PARA_ERROR_LOG("invalid band %d\n", sbb->band);
 236                 ret = -E_BAD_BAND;
 237                 goto deallocate;
 238         }
 239 deallocate:
 240         free(sbb->iov.iov_base);
 241 out:
 242         sbb->iov.iov_base = NULL;
 243         return ret;
 244 }
 245
 246 static bool has_feature(const char *feature, struct client_task *ct)
 247 {
 248         return find_arg(feature, ct->features) >= 0? true : false;
 249 }
 250
 251 static int send_sb_command(struct client_task *ct)
 252 {
 253         int i;
 254         char *command, *p;
 255         size_t len = 0;
 256
 257         if (ct->sbc[1])
 258                 return send_sb(ct, 0, NULL, 0, 0, false);
 259
 260         for (i = 0; i < ct->conf.inputs_num; i++)
 261                 len += strlen(ct->conf.inputs[i]) + 1;
 262         p = command = para_malloc(len);
 263         for (i = 0; i < ct->conf.inputs_num; i++) {
 264                 strcpy(p, ct->conf.inputs[i]);
 265                 p += strlen(ct->conf.inputs[i]) + 1;
 266         }
 267         PARA_DEBUG_LOG("--> %s\n", command);
 268         return send_sb(ct, 0, command, len, SBD_COMMAND, false);
 269 }
 270
 271 /**
 272  * The post select hook for client commands.
 273  *
 274  * \param s Pointer to the scheduler.
 275  * \param t Pointer to the task struct for this command.
 276  *
 277  * Depending on the current state of the connection and the status of the read
 278  * and write fd sets of \a s, this function performs the necessary steps to
 279  * authenticate the connection, to send the command given by \a t->private_data
 280  * and to receive para_server's output, if any.
 281  *
 282  * \sa struct sched, struct task.
 283  */
 284 static int client_post_select(struct sched *s, struct task *t)
 285 {
 286         struct client_task *ct = container_of(t, struct client_task, task);
 287         int ret = 0;
 288         size_t n;
 289         char buf[CLIENT_BUFSIZE];
 290
 291         ret = task_get_notification(t);
 292         if (ret < 0)
 293                 goto out;
 294         if (ct->scc.fd < 0)
 295                 return 0;
 296         switch (ct->status) {
 297         case CL_CONNECTED: /* receive welcome message */
 298                 ret = read_nonblock(ct->scc.fd, buf, sizeof(buf), &s->rfds, &n);
 299                 if (ret < 0 || n == 0)
 300                         goto out;
 301                 ct->features = parse_features(buf);
 302                 if (!has_feature("sideband", ct)) {
 303                         PARA_ERROR_LOG("server has no sideband support\n");
 304                         ret = -E_INCOMPAT_FEAT;
 305                         goto out;
 306                 }
 307                 ct->status = CL_RECEIVED_WELCOME;
 308                 return 0;
 309         case CL_RECEIVED_WELCOME: /* send auth command */
 310                 if (!FD_ISSET(ct->scc.fd, &s->wfds))
 311                         return 0;
 312                 sprintf(buf, AUTH_REQUEST_MSG "%s sideband%s", ct->user,
 313                         has_feature("aes_ctr128", ct)? ",aes_ctr128" : "");
 314                 PARA_INFO_LOG("--> %s\n", buf);
 315                 ret = write_buffer(ct->scc.fd, buf);
 316                 if (ret < 0)
 317                         goto out;
 318                 ct->status = CL_SENT_AUTH;
 319                 return 0;
 320         case CL_SENT_AUTH:
 321                 /*
 322                  * Receive challenge and session keys, decrypt the challenge and
 323                  * send back the hash of the decrypted challenge.
 324                  */
 325                 {
 326                 /* decrypted challenge/session key buffer */
 327                 unsigned char crypt_buf[1024];
 328                 struct sb_buffer sbb;
 329                 bool use_aes;
 330
 331                 ret = recv_sb(ct, &s->rfds, &sbb);
 332                 if (ret <= 0)
 333                         goto out;
 334                 if (sbb.band != SBD_CHALLENGE) {
 335                         ret = -E_BAD_BAND;
 336                         free(sbb.iov.iov_base);
 337                                 goto out;
 338                 }
 339                 n = sbb.iov.iov_len;
 340                 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
 341                 ret = priv_decrypt(ct->key_file, crypt_buf,
 342                         sbb.iov.iov_base, n);
 343                 free(sbb.iov.iov_base);
 344                 if (ret < 0)
 345                         goto out;
 346                 ct->challenge_hash = para_malloc(HASH_SIZE);
 347                 hash_function((char *)crypt_buf, CHALLENGE_SIZE, ct->challenge_hash);
 348                 use_aes = has_feature("aes_ctr128", ct);
 349                 ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN, use_aes);
 350                 ct->scc.recv = sc_new(crypt_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
 351                         SESSION_KEY_LEN, use_aes);
 352                 hash_to_asc(ct->challenge_hash, buf);
 353                 PARA_INFO_LOG("--> %s\n", buf);
 354                 ct->status = CL_RECEIVED_CHALLENGE;
 355                 return 0;
 356                 }
 357         case CL_RECEIVED_CHALLENGE:
 358                 ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
 359                         SBD_CHALLENGE_RESPONSE, false);
 360                 if (ret != 0)
 361                         ct->challenge_hash = NULL;
 362                 if (ret <= 0)
 363                         goto out;
 364                 ct->status = CL_SENT_CH_RESPONSE;
 365                 goto out;
 366         case CL_SENT_CH_RESPONSE: /* read server response */
 367                 {
 368                 struct sb_buffer sbb;
 369                 ret = recv_sb(ct, &s->rfds, &sbb);
 370                 if (ret <= 0)
 371                         goto out;
 372                 free(sbb.iov.iov_base);
 373                 if (sbb.band != SBD_PROCEED)
 374                         ret = -E_BAD_BAND;
 375                 else
 376                         ct->status = CL_RECEIVED_PROCEED;
 377                 goto out;
 378                 }
 379         case CL_RECEIVED_PROCEED: /* concat args and send command */
 380                 {
 381                 if (!FD_ISSET(ct->scc.fd, &s->wfds))
 382                         return 0;
 383                 ret = send_sb_command(ct);
 384                 if (ret <= 0)
 385                         goto out;
 386                 ct->status = CL_EXECUTING;
 387                 return 0;
 388                 }
 389         case CL_SENDING:
 390                 if (ct->btrn[1]) {
 391                         char *buf2;
 392                         size_t sz;
 393                         ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
 394                         if (ret == -E_BTR_EOF) {
 395                                 /* empty blob data packet indicates EOF */
 396                                 PARA_INFO_LOG("blob sent\n");
 397                                 ret = send_sb(ct, 1, NULL, 0, SBD_BLOB_DATA, true);
 398                                 if (ret >= 0)
 399                                         ret = -E_BTR_EOF;
 400                         }
 401                         if (ret < 0)
 402                                 goto close1;
 403                         if (ret > 0 && FD_ISSET(ct->scc.fd, &s->wfds)) {
 404                                 sz = btr_next_buffer(ct->btrn[1], &buf2);
 405                                 assert(sz);
 406                                 ret = send_sb(ct, 1, buf2, sz, SBD_BLOB_DATA, true);
 407                                 if (ret < 0)
 408                                         goto close1;
 409                                 if (ret > 0)
 410                                         btr_consume(ct->btrn[1], sz);
 411                         }
 412                 }
 413                 /* fall though */
 414         case CL_EXECUTING:
 415                 if (ct->btrn[0]) {
 416                         ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
 417                         if (ret < 0)
 418                                 goto close0;
 419                         if (ret > 0 && FD_ISSET(ct->scc.fd, &s->rfds)) {
 420                                 struct sb_buffer sbb;
 421                                 ret = recv_sb(ct, &s->rfds, &sbb);
 422                                 if (ret < 0)
 423                                         goto close0;
 424                                 if (ret > 0) {
 425                                         ret = dispatch_sbb(ct, &sbb);
 426                                         if (ret < 0)
 427                                                 goto close0;
 428                                 }
 429                         }
 430                 }
 431                 ret = 0;
 432                 goto out;
 433         }
 434 close1:
 435         PARA_INFO_LOG("channel 1: %s\n", para_strerror(-ret));
 436         btr_remove_node(&ct->btrn[1]);
 437         if (ct->btrn[0])
 438                 return 0;
 439         goto out;
 440 close0:
 441         PARA_INFO_LOG("channel 0: %s\n", para_strerror(-ret));
 442         btr_remove_node(&ct->btrn[0]);
 443         if (ct->btrn[1] && ct->status == CL_SENDING)
 444                 return 0;
 445 out:
 446         if (ret >= 0)
 447                 return 0;
 448         btr_remove_node(&ct->btrn[0]);
 449         btr_remove_node(&ct->btrn[1]);
 450         if (ret != -E_SERVER_CMD_SUCCESS && ret != -E_SERVER_CMD_FAILURE)
 451                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 452         if (ct->scc.fd >= 0) {
 453                 close(ct->scc.fd);
 454                 ct->scc.fd = -1;
 455         }
 456         free_argv(ct->features);
 457         ct->features = NULL;
 458         sc_free(ct->scc.recv);
 459         ct->scc.recv = NULL;
 460         sc_free(ct->scc.send);
 461         ct->scc.send = NULL;
 462         return ret;
 463 }
 464
 465 /**
 466  * Connect to para_server and register the client task.
 467  *
 468  * \param ct The initialized client task structure.
 469  * \param s The scheduler instance to register the client task to.
 470  * \param parent The parent node of the client btr node.
 471  * \param child The child node of the client node.
 472  *
 473  * The client task structure given by \a ct  must be allocated and initialized
 474  * by \ref client_parse_config() before this function is called.
 475  *
 476  * \return Standard.
 477  */
 478 int client_connect(struct client_task *ct, struct sched *s,
 479                 struct btr_node *parent, struct btr_node *child)
 480 {
 481         int ret;
 482
 483         PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
 484                 ct->conf.server_port_arg);
 485         ct->scc.fd = -1;
 486         ret = para_connect_simple(IPPROTO_TCP, ct->conf.hostname_arg,
 487                                                ct->conf.server_port_arg);
 488         if (ret < 0)
 489                 return ret;
 490         ct->scc.fd = ret;
 491         ret = mark_fd_nonblocking(ct->scc.fd);
 492         if (ret < 0)
 493                 goto err_out;
 494         ct->status = CL_CONNECTED;
 495         ct->btrn[0] = btr_new_node(&(struct btr_node_description)
 496                 EMBRACE(.name = "client recv", .parent = NULL, .child = child));
 497         ct->btrn[1] = btr_new_node(&(struct btr_node_description)
 498                 EMBRACE(.name = "client send", .parent = parent, .child = NULL));
 499         ct->task.pre_select = client_pre_select;
 500         ct->task.post_select = client_post_select;
 501         ct->task.error = 0;
 502         sprintf(ct->task.status, "client");
 503         register_task(s, &ct->task);
 504         return 1;
 505 err_out:
 506         close(ct->scc.fd);
 507         ct->scc.fd = -1;
 508         return ret;
 509 }
 510
 511 __noreturn static void print_help_and_die(struct client_task *ct)
 512 {
 513         struct ggo_help h = DEFINE_GGO_HELP(client);
 514         bool d = ct->conf.detailed_help_given;
 515
 516         ggo_print_help(&h, d? GPH_STANDARD_FLAGS_DETAILED : GPH_STANDARD_FLAGS);
 517         exit(0);
 518 }
 519
 520 /**
 521  * Parse a client configuration.
 522  *
 523  * \param argc Usual argument count.
 524  * \param argv Usual argument vector.
 525  * \param ct_ptr Filled in by this function.
 526  * \param loglevel If not \p NULL, the number of the loglevel is stored here.
 527  *
 528  * This checks the command line options given by \a argc and \a argv, sets
 529  * default values for the user name and the name of the rsa key file and reads
 530  * further options from the config file.
 531  *
 532  * Upon successful return, \a ct_ptr points to a dynamically allocated and
 533  * initialized client task struct.
 534  *
 535  * \return The number of non-option arguments in \a argc/argv on success,
 536  * negative on errors.
 537  */
 538 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
 539                 int *loglevel)
 540 {
 541         char *home = para_homedir();
 542         int ret;
 543         struct client_task *ct = para_calloc(sizeof(struct client_task));
 544
 545         *ct_ptr = ct;
 546         ct->scc.fd = -1;
 547         ret = -E_CLIENT_SYNTAX;
 548         if (client_cmdline_parser(argc, argv, &ct->conf))
 549                 goto out;
 550         version_handle_flag("client", ct->conf.version_given);
 551         if (ct->conf.help_given || ct->conf.detailed_help_given)
 552                 print_help_and_die(ct);
 553
 554         ct->config_file = ct->conf.config_file_given?
 555                 para_strdup(ct->conf.config_file_arg) :
 556                 make_message("%s/.paraslash/client.conf", home);
 557         ret = file_exists(ct->config_file);
 558         if (!ret && ct->conf.config_file_given) {
 559                 ret = -E_NO_CONFIG;
 560                 goto out;
 561         }
 562         if (ret) {
 563                 struct client_cmdline_parser_params params = {
 564                         .override = 0,
 565                         .initialize = 0,
 566                         .check_required = 0,
 567                         .check_ambiguity = 0,
 568                         .print_errors = 0
 569                 };
 570                 ret = -E_BAD_CONFIG;
 571                 if (client_cmdline_parser_config_file(ct->config_file,
 572                         &ct->conf, &params))
 573                         goto out;
 574         }
 575         ct->user = ct->conf.user_given?
 576                 para_strdup(ct->conf.user_arg) : para_logname();
 577
 578         if (ct->conf.key_file_given)
 579                 ct->key_file = para_strdup(ct->conf.key_file_arg);
 580         else {
 581                 ct->key_file = make_message("%s/.paraslash/key.%s",
 582                         home, ct->user);
 583                 if (!file_exists(ct->key_file)) {
 584                         free(ct->key_file);
 585                         ct->key_file = make_message("%s/.ssh/id_rsa", home);
 586                 }
 587         }
 588
 589         if (loglevel)
 590                 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
 591         PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
 592         PARA_INFO_LOG("config_file: %s\n", ct->config_file);
 593         PARA_INFO_LOG("key_file: %s\n", ct->key_file);
 594         ret = ct->conf.inputs_num;
 595 out:
 596         free(home);
 597         if (ret < 0) {
 598                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 599                 client_close(ct);
 600                 *ct_ptr = NULL;
 601         }
 602         return ret;
 603 }
 604
 605 /**
 606  * Parse the client configuration and open a connection to para_server.
 607  *
 608  * \param argc See \ref client_parse_config.
 609  * \param argv See \ref client_parse_config.
 610  * \param ct_ptr See \ref client_parse_config.
 611  * \param loglevel See \ref client_parse_config.
 612  * \param parent See \ref client_connect().
 613  * \param child See \ref client_connect().
 614  * \param sched See \ref client_connect().
 615  *
 616  * This function combines client_parse_config() and client_connect(). It is
 617  * considered a syntax error if no command was given, i.e. if the number
 618  * of non-option arguments is zero.
 619  *
 620  * \return Standard.
 621  */
 622 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
 623                 int *loglevel, struct btr_node *parent, struct btr_node *child,
 624                 struct sched *sched)
 625 {
 626         int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
 627
 628         if (ret < 0)
 629                 return ret;
 630         if (ret == 0) {
 631                 ret = -E_CLIENT_SYNTAX;
 632                 goto fail;
 633         }
 634         ret = client_connect(*ct_ptr, sched, parent, child);
 635         if (ret < 0)
 636                 goto fail;
 637         return 1;
 638 fail:
 639         client_close(*ct_ptr);
 640         *ct_ptr = NULL;
 641         return ret;
 642 }