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_monitor(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                 sched_monitor_readfd(ct->scc.fd, s);
  72                 return;
  73
  74         case CL_RECEIVED_WELCOME:
  75         case CL_RECEIVED_PROCEED:
  76         case CL_RECEIVED_CHALLENGE:
  77                 sched_monitor_writefd(ct->scc.fd, s);
  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                                 sched_monitor_writefd(ct->scc.fd, s);
  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                                 sched_monitor_readfd(ct->scc.fd, s);
  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, struct sb_buffer *result)
 129 {
 130         int ret;
 131         size_t n;
 132         sb_transformation trafo;
 133         void *trafo_context;
 134         struct iovec iov;
 135
 136         if (ct->status < CL_SENT_CH_RESPONSE)
 137                 trafo = trafo_context = NULL;
 138         else {
 139                 trafo = sc_trafo;
 140                 trafo_context = ct->scc.recv;
 141         }
 142         if (!ct->sbc[0])
 143                 ct->sbc[0] = sb_new_recv(0, trafo, trafo_context);
 144 again:
 145         sb_get_recv_buffer(ct->sbc[0], &iov);
 146         ret = read_nonblock(ct->scc.fd, iov.iov_base, iov.iov_len, &n);
 147         if (ret < 0) {
 148                 sb_free(ct->sbc[0]);
 149                 ct->sbc[0] = NULL;
 150                 return ret;
 151         }
 152         if (n == 0)
 153                 return 0;
 154         ret = sb_received(ct->sbc[0], n, result);
 155         if (ret < 0)
 156                 return ret;
 157         if (ret == 0)
 158                 goto again;
 159         ct->sbc[0] = NULL;
 160         return 1;
 161 }
 162
 163
 164 static char **parse_features(char *buf)
 165 {
 166         int i;
 167         const char id[] = "\nFeatures: ";
 168         char *p, *q, **features;
 169
 170         p = strstr(buf, id);
 171         if (!p)
 172                 return NULL;
 173         p += strlen(id);
 174         q = strchr(p, '\n');
 175         if (!q)
 176                 return NULL;
 177         *q = '\0';
 178         create_argv(p, ",", &features);
 179         for (i = 0; features[i]; i++)
 180                 PARA_INFO_LOG("server feature: %s\n", features[i]);
 181         return features;
 182 }
 183
 184 static int dispatch_sbb(struct client_task *ct, struct sb_buffer *sbb)
 185 {
 186         int ret;
 187         const char *designator[] = {SB_DESIGNATORS_ARRAY};
 188
 189         if (!sbb)
 190                 return 0;
 191         if (sbb->band < NUM_SB_DESIGNATORS)
 192                 PARA_DEBUG_LOG("band: %s\n", designator[sbb->band]);
 193
 194         switch (sbb->band) {
 195         case SBD_AWAITING_DATA:
 196                 ct->status = CL_SENDING;
 197                 ret = 1;
 198                 goto out;
 199         case SBD_OUTPUT:
 200                 if (iov_valid(&sbb->iov))
 201                         btr_add_output(sbb->iov.iov_base, sbb->iov.iov_len,
 202                                 ct->btrn[0]);
 203                 ret = 1;
 204                 goto out;
 205         case SBD_DEBUG_LOG:
 206         case SBD_INFO_LOG:
 207         case SBD_NOTICE_LOG:
 208         case SBD_WARNING_LOG:
 209         case SBD_ERROR_LOG:
 210         case SBD_CRIT_LOG:
 211         case SBD_EMERG_LOG:
 212                 if (iov_valid(&sbb->iov)) {
 213                         int ll = sbb->band - SBD_DEBUG_LOG;
 214                         para_log(ll, "remote: %s", (char *)sbb->iov.iov_base);
 215                 }
 216                 ret = 1;
 217                 goto deallocate;
 218         case SBD_EXIT__SUCCESS:
 219                 ret = -E_SERVER_CMD_SUCCESS;
 220                 goto deallocate;
 221         case SBD_EXIT__FAILURE:
 222                 ret = -E_SERVER_CMD_FAILURE;
 223                 goto deallocate;
 224         default:
 225                 PARA_ERROR_LOG("invalid band %d\n", sbb->band);
 226                 ret = -E_BAD_BAND;
 227                 goto deallocate;
 228         }
 229 deallocate:
 230         free(sbb->iov.iov_base);
 231 out:
 232         sbb->iov.iov_base = NULL;
 233         return ret;
 234 }
 235
 236 static int send_sb_command(struct client_task *ct)
 237 {
 238         int i;
 239         char *command, *p;
 240         size_t len = 0;
 241         unsigned num_inputs = lls_num_inputs(ct->lpr);
 242
 243         if (ct->sbc[1])
 244                 return send_sb(ct, 0, NULL, 0, 0, false);
 245
 246         for (i = 0; i < num_inputs; i++)
 247                 len += strlen(lls_input(i, ct->lpr)) + 1;
 248         p = command = alloc(len);
 249         for (i = 0; i < num_inputs; i++) {
 250                 const char *str = lls_input(i, ct->lpr);
 251                 strcpy(p, str);
 252                 p += strlen(str) + 1;
 253         }
 254         PARA_DEBUG_LOG("--> %s\n", command);
 255         return send_sb(ct, 0, command, len, SBD_COMMAND, false);
 256 }
 257
 258 static bool has_feature(const char *feature, struct client_task *ct)
 259 {
 260         return find_arg(feature, ct->features) >= 0? true : false;
 261 }
 262
 263 /*
 264  * This function reads or writes to the socket file descriptor which
 265  * corresponds to an established connection between the client and the server.
 266  * It depends on the current state of the connection and on the readiness of
 267  * the socket file descriptor which type of I/O is going to be performed.
 268  * Besides the initial handshake and authentication, the function sends the
 269  * server command and receives the output from the server, if any.
 270  *
 271  * The context pointer refers to a client task structure that was initialized
 272  * earlier by client_open().
 273  */
 274 static int client_post_monitor(struct sched *s, void *context)
 275 {
 276         struct client_task *ct = context;
 277         int ret = 0;
 278         size_t n;
 279         char buf[CLIENT_BUFSIZE];
 280
 281         ret = task_get_notification(ct->task);
 282         if (ret < 0)
 283                 goto out;
 284         if (ct->scc.fd < 0)
 285                 return 0;
 286         switch (ct->status) {
 287         case CL_CONNECTED: /* receive welcome message */
 288                 ret = read_nonblock(ct->scc.fd, buf, sizeof(buf), &n);
 289                 if (ret < 0 || n == 0)
 290                         goto out;
 291                 ct->features = parse_features(buf);
 292                 ct->status = CL_RECEIVED_WELCOME;
 293                 return 0;
 294         case CL_RECEIVED_WELCOME: /* send auth command */
 295                 {
 296                 /*
 297                  * Use sha256 iff the server announced the feature. After 0.7.0
 298                  * we may request and use the feature unconditionally. After
 299                  * 0.8.0 we no longer need to request the feature.
 300                  */
 301                 bool has_sha256;
 302                 if (!sched_write_ok(ct->scc.fd, s))
 303                         return 0;
 304                 has_sha256 = has_feature("sha256", ct);
 305                 sprintf(buf, AUTH_REQUEST_MSG "%s%s", ct->user, has_sha256?
 306                         " sha256" : "");
 307                 PARA_INFO_LOG("--> %s\n", buf);
 308                 ret = write_buffer(ct->scc.fd, buf);
 309                 if (ret < 0)
 310                         goto out;
 311                 ct->status = CL_SENT_AUTH;
 312                 return 0;
 313                 }
 314         case CL_SENT_AUTH:
 315                 /*
 316                  * Receive challenge and session keys, decrypt the challenge and
 317                  * send back the hash of the decrypted challenge.
 318                  */
 319                 {
 320                 /* decrypted challenge/session key buffer */
 321                 unsigned char crypt_buf[1024];
 322                 struct sb_buffer sbb;
 323
 324                 ret = recv_sb(ct, &sbb);
 325                 if (ret <= 0)
 326                         goto out;
 327                 if (sbb.band != SBD_CHALLENGE) {
 328                         ret = -E_BAD_BAND;
 329                         free(sbb.iov.iov_base);
 330                                 goto out;
 331                 }
 332                 n = sbb.iov.iov_len;
 333                 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
 334                 ret = apc_priv_decrypt(ct->key_file, crypt_buf,
 335                         sbb.iov.iov_base, n);
 336                 free(sbb.iov.iov_base);
 337                 if (ret < 0)
 338                         goto out;
 339                 ct->challenge_hash = alloc(HASH2_SIZE);
 340                 if (has_feature("sha256", ct)) {
 341                         hash2_function((char *)crypt_buf, APC_CHALLENGE_SIZE, ct->challenge_hash);
 342                         hash2_to_asc(ct->challenge_hash, buf);
 343                 } else {
 344                         hash_function((char *)crypt_buf, APC_CHALLENGE_SIZE, ct->challenge_hash);
 345                         hash_to_asc(ct->challenge_hash, buf);
 346                 }
 347                 ct->scc.send = sc_new(crypt_buf + APC_CHALLENGE_SIZE, SESSION_KEY_LEN);
 348                 ct->scc.recv = sc_new(crypt_buf + APC_CHALLENGE_SIZE + SESSION_KEY_LEN,
 349                         SESSION_KEY_LEN);
 350                 PARA_INFO_LOG("--> %s\n", buf);
 351                 ct->status = CL_RECEIVED_CHALLENGE;
 352                 return 0;
 353                 }
 354         case CL_RECEIVED_CHALLENGE:
 355                 if (has_feature("sha256", ct))
 356                         ret = send_sb(ct, 0, ct->challenge_hash, HASH2_SIZE,
 357                                 SBD_CHALLENGE_RESPONSE, false);
 358                 else
 359                         ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
 360                                 SBD_CHALLENGE_RESPONSE, false);
 361                 if (ret != 0)
 362                         ct->challenge_hash = NULL;
 363                 if (ret <= 0)
 364                         goto out;
 365                 ct->status = CL_SENT_CH_RESPONSE;
 366                 goto out;
 367         case CL_SENT_CH_RESPONSE: /* read server response */
 368                 {
 369                 struct sb_buffer sbb;
 370                 ret = recv_sb(ct, &sbb);
 371                 if (ret <= 0)
 372                         goto out;
 373                 free(sbb.iov.iov_base);
 374                 if (sbb.band != SBD_PROCEED)
 375                         ret = -E_BAD_BAND;
 376                 else
 377                         ct->status = CL_RECEIVED_PROCEED;
 378                 goto out;
 379                 }
 380         case CL_RECEIVED_PROCEED: /* concat args and send command */
 381                 {
 382                 if (!sched_write_ok(ct->scc.fd, s))
 383                         return 0;
 384                 ret = send_sb_command(ct);
 385                 if (ret <= 0)
 386                         goto out;
 387                 ct->status = CL_EXECUTING;
 388                 return 0;
 389                 }
 390         case CL_SENDING:
 391                 if (ct->btrn[1]) {
 392                         char *buf2;
 393                         size_t sz;
 394                         ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
 395                         if (ret == -E_BTR_EOF) {
 396                                 /* empty blob data packet indicates EOF */
 397                                 PARA_INFO_LOG("blob sent\n");
 398                                 ret = send_sb(ct, 1, NULL, 0, SBD_BLOB_DATA, true);
 399                                 if (ret >= 0)
 400                                         ret = -E_BTR_EOF;
 401                         }
 402                         if (ret < 0)
 403                                 goto close1;
 404                         if (ret > 0 && sched_write_ok(ct->scc.fd, s)) {
 405                                 sz = btr_next_buffer(ct->btrn[1], &buf2);
 406                                 assert(sz);
 407                                 ret = send_sb(ct, 1, buf2, sz, SBD_BLOB_DATA, true);
 408                                 if (ret < 0)
 409                                         goto close1;
 410                                 if (ret > 0)
 411                                         btr_consume(ct->btrn[1], sz);
 412                         }
 413                 }
 414                 __attribute__ ((fallthrough));
 415         case CL_EXECUTING:
 416                 if (ct->btrn[0]) {
 417                         ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
 418                         if (ret < 0)
 419                                 goto close0;
 420                         if (ret > 0 && sched_read_ok(ct->scc.fd, s)) {
 421                                 struct sb_buffer sbb;
 422                                 ret = recv_sb(ct, &sbb);
 423                                 if (ret < 0)
 424                                         goto close0;
 425                                 if (ret > 0) {
 426                                         ret = dispatch_sbb(ct, &sbb);
 427                                         if (ret < 0)
 428                                                 goto close0;
 429                                 }
 430                         }
 431                 }
 432                 ret = 0;
 433                 goto out;
 434         }
 435 close1:
 436         PARA_INFO_LOG("channel 1: %s\n", para_strerror(-ret));
 437         btr_remove_node(&ct->btrn[1]);
 438         if (ct->btrn[0])
 439                 return 0;
 440         goto out;
 441 close0:
 442         PARA_INFO_LOG("channel 0: %s\n", para_strerror(-ret));
 443         btr_remove_node(&ct->btrn[0]);
 444         if (ct->btrn[1] && ct->status == CL_SENDING)
 445                 return 0;
 446 out:
 447         if (ret >= 0)
 448                 return 0;
 449         btr_remove_node(&ct->btrn[0]);
 450         btr_remove_node(&ct->btrn[1]);
 451         PARA_NOTICE_LOG("closing connection (%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         const char *host = CLIENT_OPT_STRING_VAL(HOSTNAME, ct->lpr);
 483         uint32_t port = CLIENT_OPT_UINT32_VAL(SERVER_PORT, ct->lpr);
 484
 485         PARA_NOTICE_LOG("connecting %s:%u\n", host, port);
 486         ct->scc.fd = -1;
 487         ret = para_connect_simple(IPPROTO_TCP, host, port);
 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
 500         ct->task = task_register(&(struct task_info) {
 501                 .name = "client",
 502                 .pre_monitor = client_pre_monitor,
 503                 .post_monitor = client_post_monitor,
 504                 .context = ct,
 505         }, s);
 506         return 1;
 507 err_out:
 508         close(ct->scc.fd);
 509         ct->scc.fd = -1;
 510         return ret;
 511 }
 512
 513 static void handle_help_flag(struct lls_parse_result *lpr)
 514 {
 515         char *help;
 516
 517         if (CLIENT_OPT_GIVEN(DETAILED_HELP, lpr))
 518                 help = lls_long_help(CLIENT_CMD_PTR);
 519         else if (CLIENT_OPT_GIVEN(HELP, lpr))
 520                 help = lls_short_help(CLIENT_CMD_PTR);
 521         else
 522                 return;
 523         printf("%s\n", help);
 524         free(help);
 525         exit(EXIT_SUCCESS);
 526 }
 527
 528 /**
 529  * Parse a client configuration.
 530  *
 531  * \param argc Usual argument count.
 532  * \param argv Usual argument vector.
 533  * \param ct_ptr Filled in by this function.
 534  * \param loglevel If not \p NULL, the number of the loglevel is stored here.
 535  *
 536  * This checks the command line options given by \a argc and \a argv, sets
 537  * default values for the user name and the name of the rsa key file and reads
 538  * further options from the config file.
 539  *
 540  * Upon successful return, \a ct_ptr points to a dynamically allocated and
 541  * initialized client task struct.
 542  *
 543  * \return The number of non-option arguments in \a argc/argv on success,
 544  * negative on errors.
 545  */
 546 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
 547                 int *loglevel)
 548 {
 549         const struct lls_command *cmd = CLIENT_CMD_PTR;
 550         struct lls_parse_result *lpr;
 551         int ret, ll;
 552         struct client_task *ct;
 553         char *kf = NULL, *user, *errctx, *home = para_homedir();
 554
 555         ret = lls(lls_parse(argc, argv, cmd, &lpr, &errctx));
 556         if (ret < 0)
 557                 goto out;
 558         version_handle_flag("client", CLIENT_OPT_GIVEN(VERSION, lpr));
 559         handle_help_flag(lpr);
 560
 561         ret = lsu_merge_config_file_options(CLIENT_OPT_STRING_VAL(CONFIG_FILE, lpr),
 562                 "client.conf", &lpr, cmd, client_suite, 0U /* default flags */);
 563         if (ret < 0)
 564                 goto out;
 565         /* success */
 566         ll = CLIENT_OPT_UINT32_VAL(LOGLEVEL, lpr);
 567         if (loglevel)
 568                 *loglevel = ll;
 569         user = CLIENT_OPT_GIVEN(USER, lpr)?
 570                 para_strdup(CLIENT_OPT_STRING_VAL(USER, lpr)) : para_logname();
 571
 572         if (CLIENT_OPT_GIVEN(KEY_FILE, lpr))
 573                 kf = para_strdup(CLIENT_OPT_STRING_VAL(KEY_FILE, lpr));
 574         else {
 575                 kf = make_message("%s/.paraslash/key.%s", home, user);
 576                 if (!file_exists(kf)) {
 577                         free(kf);
 578                         kf = make_message("%s/.ssh/id_rsa", home);
 579                 }
 580         }
 581         PARA_INFO_LOG("user: %s\n", user);
 582         PARA_INFO_LOG("key file: %s\n", kf);
 583         PARA_INFO_LOG("loglevel: %d\n", ll);
 584         ct = zalloc(sizeof(*ct));
 585         ct->scc.fd = -1;
 586         ct->lpr = lpr;
 587         ct->key_file = kf;
 588         ct->user = user;
 589         *ct_ptr = ct;
 590         ret = lls_num_inputs(lpr);
 591 out:
 592         free(home);
 593         if (ret < 0) {
 594                 if (errctx)
 595                         PARA_ERROR_LOG("%s\n", errctx);
 596                 free(errctx);
 597                 lls_free_parse_result(lpr, cmd);
 598                 free(kf);
 599                 *ct_ptr = NULL;
 600         }
 601         return ret;
 602 }
 603
 604 /**
 605  * Parse the client configuration and open a connection to para_server.
 606  *
 607  * \param argc See \ref client_parse_config.
 608  * \param argv See \ref client_parse_config.
 609  * \param ct_ptr See \ref client_parse_config.
 610  * \param loglevel See \ref client_parse_config.
 611  * \param parent See \ref client_connect().
 612  * \param child See \ref client_connect().
 613  * \param sched See \ref client_connect().
 614  *
 615  * This function combines client_parse_config() and client_connect(). It is
 616  * considered a syntax error if no command was given, i.e. if the number
 617  * of non-option arguments is zero.
 618  *
 619  * \return Standard.
 620  */
 621 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
 622                 int *loglevel, struct btr_node *parent, struct btr_node *child,
 623                 struct sched *sched)
 624 {
 625         int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
 626
 627         if (ret < 0)
 628                 return ret;
 629         if (ret == 0) {
 630                 ret = -E_CLIENT_SYNTAX;
 631                 goto fail;
 632         }
 633         ret = client_connect(*ct_ptr, sched, parent, child);
 634         if (ret < 0)
 635                 goto fail;
 636         return 1;
 637 fail:
 638         client_close(*ct_ptr);
 639         *ct_ptr = NULL;
 640         return ret;
 641 }