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  * The preselect hook for server commands.
  54  *
  55  * The task pointer must contain a pointer to the initialized client data
  56  * structure as it is returned by client_open().
  57  *
  58  * This function checks the state of the connection and adds the file descriptor
  59  * of the connection to the read or write fd set of s accordingly.
  60  */
  61 static void client_pre_select(struct sched *s, void *context)
  62 {
  63         int ret;
  64         struct client_task *ct = context;
  65
  66         if (ct->scc.fd < 0)
  67                 return;
  68         switch (ct->status) {
  69         case CL_CONNECTED:
  70         case CL_SENT_AUTH:
  71         case CL_SENT_CH_RESPONSE:
  72                 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
  73                 return;
  74
  75         case CL_RECEIVED_WELCOME:
  76         case CL_RECEIVED_PROCEED:
  77         case CL_RECEIVED_CHALLENGE:
  78                 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
  79                 return;
  80
  81         case CL_SENDING:
  82                 if (ct->btrn[1]) {
  83                         ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
  84                         if (ret < 0)
  85                                 sched_min_delay(s);
  86                         else if (ret > 0)
  87                                 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
  88                 }
  89                 /* fallthrough */
  90         case CL_EXECUTING:
  91                 if (ct->btrn[0]) {
  92                         ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
  93                         if (ret < 0)
  94                                 sched_min_delay(s);
  95                         else if (ret > 0)
  96                                 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
  97                 }
  98                 return;
  99         }
 100 }
 101
 102 static int send_sb(struct client_task *ct, int channel, void *buf, size_t numbytes,
 103                 enum sb_designator band, bool dont_free)
 104 {
 105         int ret, fd = ct->scc.fd;
 106         struct iovec iov[2];
 107
 108         if (!ct->sbc[channel]) {
 109                 struct sb_buffer sbb;
 110                 sb_transformation trafo = ct->status < CL_RECEIVED_PROCEED?
 111                         NULL : sc_trafo;
 112                 sbb = (typeof(sbb))SBB_INIT(band, buf, numbytes);
 113                 ct->sbc[channel] = sb_new_send(&sbb, dont_free, trafo, ct->scc.send);
 114         }
 115         ret = sb_get_send_buffers(ct->sbc[channel], iov);
 116         ret = xwritev(fd, iov, ret);
 117         if (ret < 0) {
 118                 sb_free(ct->sbc[channel]);
 119                 ct->sbc[channel] = NULL;
 120                 return ret;
 121         }
 122         if (sb_sent(ct->sbc[channel], ret)) {
 123                 ct->sbc[channel] = NULL;
 124                 return 1;
 125         }
 126         return 0;
 127 }
 128
 129 static int recv_sb(struct client_task *ct, fd_set *rfds,
 130                 struct sb_buffer *result)
 131 {
 132         int ret;
 133         size_t n;
 134         sb_transformation trafo;
 135         void *trafo_context;
 136         struct iovec iov;
 137
 138         if (!FD_ISSET(ct->scc.fd, rfds))
 139                 return 0;
 140         if (ct->status < CL_SENT_CH_RESPONSE)
 141                 trafo = trafo_context = NULL;
 142         else {
 143                 trafo = sc_trafo;
 144                 trafo_context = ct->scc.recv;
 145         }
 146         if (!ct->sbc[0])
 147                 ct->sbc[0] = sb_new_recv(0, trafo, trafo_context);
 148 again:
 149         sb_get_recv_buffer(ct->sbc[0], &iov);
 150         ret = read_nonblock(ct->scc.fd, iov.iov_base, iov.iov_len, rfds, &n);
 151         if (ret < 0) {
 152                 sb_free(ct->sbc[0]);
 153                 ct->sbc[0] = NULL;
 154                 return ret;
 155         }
 156         if (n == 0)
 157                 return 0;
 158         ret = sb_received(ct->sbc[0], n, result);
 159         if (ret < 0)
 160                 return ret;
 161         if (ret == 0)
 162                 goto again;
 163         ct->sbc[0] = NULL;
 164         return 1;
 165 }
 166
 167
 168 static char **parse_features(char *buf)
 169 {
 170         int i;
 171         const char id[] = "\nFeatures: ";
 172         char *p, *q, **features;
 173
 174         p = strstr(buf, id);
 175         if (!p)
 176                 return NULL;
 177         p += strlen(id);
 178         q = strchr(p, '\n');
 179         if (!q)
 180                 return NULL;
 181         *q = '\0';
 182         create_argv(p, ",", &features);
 183         for (i = 0; features[i]; i++)
 184                 PARA_INFO_LOG("server feature: %s\n", features[i]);
 185         return features;
 186 }
 187
 188 static int dispatch_sbb(struct client_task *ct, struct sb_buffer *sbb)
 189 {
 190         int ret;
 191         const char *designator[] = {SB_DESIGNATORS_ARRAY};
 192
 193         if (!sbb)
 194                 return 0;
 195         if (sbb->band < NUM_SB_DESIGNATORS)
 196                 PARA_DEBUG_LOG("band: %s\n", designator[sbb->band]);
 197
 198         switch (sbb->band) {
 199         case SBD_AWAITING_DATA:
 200                 ct->status = CL_SENDING;
 201                 ret = 1;
 202                 goto out;
 203         case SBD_OUTPUT:
 204                 if (iov_valid(&sbb->iov))
 205                         btr_add_output(sbb->iov.iov_base, sbb->iov.iov_len,
 206                                 ct->btrn[0]);
 207                 ret = 1;
 208                 goto out;
 209         case SBD_DEBUG_LOG:
 210         case SBD_INFO_LOG:
 211         case SBD_NOTICE_LOG:
 212         case SBD_WARNING_LOG:
 213         case SBD_ERROR_LOG:
 214         case SBD_CRIT_LOG:
 215         case SBD_EMERG_LOG:
 216                 if (iov_valid(&sbb->iov)) {
 217                         int ll = sbb->band - SBD_DEBUG_LOG;
 218                         para_log(ll, "remote: %s", (char *)sbb->iov.iov_base);
 219                 }
 220                 ret = 1;
 221                 goto deallocate;
 222         case SBD_EXIT__SUCCESS:
 223                 ret = -E_SERVER_CMD_SUCCESS;
 224                 goto deallocate;
 225         case SBD_EXIT__FAILURE:
 226                 ret = -E_SERVER_CMD_FAILURE;
 227                 goto deallocate;
 228         default:
 229                 PARA_ERROR_LOG("invalid band %d\n", sbb->band);
 230                 ret = -E_BAD_BAND;
 231                 goto deallocate;
 232         }
 233 deallocate:
 234         free(sbb->iov.iov_base);
 235 out:
 236         sbb->iov.iov_base = NULL;
 237         return ret;
 238 }
 239
 240 static int send_sb_command(struct client_task *ct)
 241 {
 242         int i;
 243         char *command, *p;
 244         size_t len = 0;
 245         unsigned num_inputs = lls_num_inputs(ct->lpr);
 246
 247         if (ct->sbc[1])
 248                 return send_sb(ct, 0, NULL, 0, 0, false);
 249
 250         for (i = 0; i < num_inputs; i++)
 251                 len += strlen(lls_input(i, ct->lpr)) + 1;
 252         p = command = para_malloc(len);
 253         for (i = 0; i < num_inputs; i++) {
 254                 const char *str = lls_input(i, ct->lpr);
 255                 strcpy(p, str);
 256                 p += strlen(str) + 1;
 257         }
 258         PARA_DEBUG_LOG("--> %s\n", command);
 259         return send_sb(ct, 0, command, len, SBD_COMMAND, false);
 260 }
 261
 262 /*
 263  * The post select hook for client commands.
 264  *
 265  * Depending on the current state of the connection and the status of the read
 266  * and write fd sets of s, this function performs the necessary steps to
 267  * authenticate the connection, to send the command given by t->private_data
 268  * and to receive para_server's output, if any.
 269  */
 270 static int client_post_select(struct sched *s, void *context)
 271 {
 272         struct client_task *ct = context;
 273         int ret = 0;
 274         size_t n;
 275         char buf[CLIENT_BUFSIZE];
 276
 277         ret = task_get_notification(ct->task);
 278         if (ret < 0)
 279                 goto out;
 280         if (ct->scc.fd < 0)
 281                 return 0;
 282         switch (ct->status) {
 283         case CL_CONNECTED: /* receive welcome message */
 284                 ret = read_nonblock(ct->scc.fd, buf, sizeof(buf), &s->rfds, &n);
 285                 if (ret < 0 || n == 0)
 286                         goto out;
 287                 ct->features = parse_features(buf);
 288                 ct->status = CL_RECEIVED_WELCOME;
 289                 return 0;
 290         case CL_RECEIVED_WELCOME: /* send auth command */
 291                 if (!FD_ISSET(ct->scc.fd, &s->wfds))
 292                         return 0;
 293                 sprintf(buf, AUTH_REQUEST_MSG "%s sideband,aes_ctr128",
 294                         ct->user);
 295                 PARA_INFO_LOG("--> %s\n", buf);
 296                 ret = write_buffer(ct->scc.fd, buf);
 297                 if (ret < 0)
 298                         goto out;
 299                 ct->status = CL_SENT_AUTH;
 300                 return 0;
 301         case CL_SENT_AUTH:
 302                 /*
 303                  * Receive challenge and session keys, decrypt the challenge and
 304                  * send back the hash of the decrypted challenge.
 305                  */
 306                 {
 307                 /* decrypted challenge/session key buffer */
 308                 unsigned char crypt_buf[1024];
 309                 struct sb_buffer sbb;
 310
 311                 ret = recv_sb(ct, &s->rfds, &sbb);
 312                 if (ret <= 0)
 313                         goto out;
 314                 if (sbb.band != SBD_CHALLENGE) {
 315                         ret = -E_BAD_BAND;
 316                         free(sbb.iov.iov_base);
 317                                 goto out;
 318                 }
 319                 n = sbb.iov.iov_len;
 320                 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
 321                 ret = apc_priv_decrypt(ct->key_file, crypt_buf,
 322                         sbb.iov.iov_base, n);
 323                 free(sbb.iov.iov_base);
 324                 if (ret < 0)
 325                         goto out;
 326                 ct->challenge_hash = para_malloc(HASH_SIZE);
 327                 hash_function((char *)crypt_buf, APC_CHALLENGE_SIZE, ct->challenge_hash);
 328                 ct->scc.send = sc_new(crypt_buf + APC_CHALLENGE_SIZE, SESSION_KEY_LEN);
 329                 ct->scc.recv = sc_new(crypt_buf + APC_CHALLENGE_SIZE + SESSION_KEY_LEN,
 330                         SESSION_KEY_LEN);
 331                 hash_to_asc(ct->challenge_hash, buf);
 332                 PARA_INFO_LOG("--> %s\n", buf);
 333                 ct->status = CL_RECEIVED_CHALLENGE;
 334                 return 0;
 335                 }
 336         case CL_RECEIVED_CHALLENGE:
 337                 ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
 338                         SBD_CHALLENGE_RESPONSE, false);
 339                 if (ret != 0)
 340                         ct->challenge_hash = NULL;
 341                 if (ret <= 0)
 342                         goto out;
 343                 ct->status = CL_SENT_CH_RESPONSE;
 344                 goto out;
 345         case CL_SENT_CH_RESPONSE: /* read server response */
 346                 {
 347                 struct sb_buffer sbb;
 348                 ret = recv_sb(ct, &s->rfds, &sbb);
 349                 if (ret <= 0)
 350                         goto out;
 351                 free(sbb.iov.iov_base);
 352                 if (sbb.band != SBD_PROCEED)
 353                         ret = -E_BAD_BAND;
 354                 else
 355                         ct->status = CL_RECEIVED_PROCEED;
 356                 goto out;
 357                 }
 358         case CL_RECEIVED_PROCEED: /* concat args and send command */
 359                 {
 360                 if (!FD_ISSET(ct->scc.fd, &s->wfds))
 361                         return 0;
 362                 ret = send_sb_command(ct);
 363                 if (ret <= 0)
 364                         goto out;
 365                 ct->status = CL_EXECUTING;
 366                 return 0;
 367                 }
 368         case CL_SENDING:
 369                 if (ct->btrn[1]) {
 370                         char *buf2;
 371                         size_t sz;
 372                         ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
 373                         if (ret == -E_BTR_EOF) {
 374                                 /* empty blob data packet indicates EOF */
 375                                 PARA_INFO_LOG("blob sent\n");
 376                                 ret = send_sb(ct, 1, NULL, 0, SBD_BLOB_DATA, true);
 377                                 if (ret >= 0)
 378                                         ret = -E_BTR_EOF;
 379                         }
 380                         if (ret < 0)
 381                                 goto close1;
 382                         if (ret > 0 && FD_ISSET(ct->scc.fd, &s->wfds)) {
 383                                 sz = btr_next_buffer(ct->btrn[1], &buf2);
 384                                 assert(sz);
 385                                 ret = send_sb(ct, 1, buf2, sz, SBD_BLOB_DATA, true);
 386                                 if (ret < 0)
 387                                         goto close1;
 388                                 if (ret > 0)
 389                                         btr_consume(ct->btrn[1], sz);
 390                         }
 391                 }
 392                 /* fall through */
 393         case CL_EXECUTING:
 394                 if (ct->btrn[0]) {
 395                         ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
 396                         if (ret < 0)
 397                                 goto close0;
 398                         if (ret > 0 && FD_ISSET(ct->scc.fd, &s->rfds)) {
 399                                 struct sb_buffer sbb;
 400                                 ret = recv_sb(ct, &s->rfds, &sbb);
 401                                 if (ret < 0)
 402                                         goto close0;
 403                                 if (ret > 0) {
 404                                         ret = dispatch_sbb(ct, &sbb);
 405                                         if (ret < 0)
 406                                                 goto close0;
 407                                 }
 408                         }
 409                 }
 410                 ret = 0;
 411                 goto out;
 412         }
 413 close1:
 414         PARA_INFO_LOG("channel 1: %s\n", para_strerror(-ret));
 415         btr_remove_node(&ct->btrn[1]);
 416         if (ct->btrn[0])
 417                 return 0;
 418         goto out;
 419 close0:
 420         PARA_INFO_LOG("channel 0: %s\n", para_strerror(-ret));
 421         btr_remove_node(&ct->btrn[0]);
 422         if (ct->btrn[1] && ct->status == CL_SENDING)
 423                 return 0;
 424 out:
 425         if (ret >= 0)
 426                 return 0;
 427         btr_remove_node(&ct->btrn[0]);
 428         btr_remove_node(&ct->btrn[1]);
 429         if (ret != -E_SERVER_CMD_SUCCESS && ret != -E_SERVER_CMD_FAILURE)
 430                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 431         if (ct->scc.fd >= 0) {
 432                 close(ct->scc.fd);
 433                 ct->scc.fd = -1;
 434         }
 435         free_argv(ct->features);
 436         ct->features = NULL;
 437         sc_free(ct->scc.recv);
 438         ct->scc.recv = NULL;
 439         sc_free(ct->scc.send);
 440         ct->scc.send = NULL;
 441         return ret;
 442 }
 443
 444 /**
 445  * Connect to para_server and register the client task.
 446  *
 447  * \param ct The initialized client task structure.
 448  * \param s The scheduler instance to register the client task to.
 449  * \param parent The parent node of the client btr node.
 450  * \param child The child node of the client node.
 451  *
 452  * The client task structure given by \a ct  must be allocated and initialized
 453  * by \ref client_parse_config() before this function is called.
 454  *
 455  * \return Standard.
 456  */
 457 int client_connect(struct client_task *ct, struct sched *s,
 458                 struct btr_node *parent, struct btr_node *child)
 459 {
 460         int ret;
 461         const char *host = CLIENT_OPT_STRING_VAL(HOSTNAME, ct->lpr);
 462         uint32_t port = CLIENT_OPT_UINT32_VAL(SERVER_PORT, ct->lpr);
 463
 464         PARA_NOTICE_LOG("connecting %s:%u\n", host, port);
 465         ct->scc.fd = -1;
 466         ret = para_connect_simple(IPPROTO_TCP, host, port);
 467         if (ret < 0)
 468                 return ret;
 469         ct->scc.fd = ret;
 470         ret = mark_fd_nonblocking(ct->scc.fd);
 471         if (ret < 0)
 472                 goto err_out;
 473         ct->status = CL_CONNECTED;
 474         ct->btrn[0] = btr_new_node(&(struct btr_node_description)
 475                 EMBRACE(.name = "client recv", .parent = NULL, .child = child));
 476         ct->btrn[1] = btr_new_node(&(struct btr_node_description)
 477                 EMBRACE(.name = "client send", .parent = parent, .child = NULL));
 478
 479         ct->task = task_register(&(struct task_info) {
 480                 .name = "client",
 481                 .pre_select = client_pre_select,
 482                 .post_select = client_post_select,
 483                 .context = ct,
 484         }, s);
 485         return 1;
 486 err_out:
 487         close(ct->scc.fd);
 488         ct->scc.fd = -1;
 489         return ret;
 490 }
 491
 492 static void handle_help_flag(struct lls_parse_result *lpr)
 493 {
 494         char *help;
 495
 496         if (CLIENT_OPT_GIVEN(DETAILED_HELP, lpr))
 497                 help = lls_long_help(CLIENT_CMD_PTR);
 498         else if (CLIENT_OPT_GIVEN(HELP, lpr))
 499                 help = lls_short_help(CLIENT_CMD_PTR);
 500         else
 501                 return;
 502         printf("%s\n", help);
 503         free(help);
 504         exit(EXIT_SUCCESS);
 505 }
 506
 507 /**
 508  * Parse a client configuration.
 509  *
 510  * \param argc Usual argument count.
 511  * \param argv Usual argument vector.
 512  * \param ct_ptr Filled in by this function.
 513  * \param loglevel If not \p NULL, the number of the loglevel is stored here.
 514  *
 515  * This checks the command line options given by \a argc and \a argv, sets
 516  * default values for the user name and the name of the rsa key file and reads
 517  * further options from the config file.
 518  *
 519  * Upon successful return, \a ct_ptr points to a dynamically allocated and
 520  * initialized client task struct.
 521  *
 522  * \return The number of non-option arguments in \a argc/argv on success,
 523  * negative on errors.
 524  */
 525 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
 526                 int *loglevel)
 527 {
 528         const struct lls_command *cmd = CLIENT_CMD_PTR;
 529         struct lls_parse_result *lpr;
 530         int ret, ll;
 531         struct client_task *ct;
 532         char *kf = NULL, *user, *errctx, *home = para_homedir();
 533
 534         ret = lls(lls_parse(argc, argv, cmd, &lpr, &errctx));
 535         if (ret < 0)
 536                 goto out;
 537         version_handle_flag("client", CLIENT_OPT_GIVEN(VERSION, lpr));
 538         handle_help_flag(lpr);
 539
 540         ret = lsu_merge_config_file_options(CLIENT_OPT_STRING_VAL(CONFIG_FILE, lpr),
 541                 "client.conf", &lpr, cmd, client_suite, 0U /* default flags */);
 542         if (ret < 0)
 543                 goto out;
 544         /* success */
 545         ll = CLIENT_OPT_UINT32_VAL(LOGLEVEL, lpr);
 546         if (loglevel)
 547                 *loglevel = ll;
 548         user = CLIENT_OPT_GIVEN(USER, lpr)?
 549                 para_strdup(CLIENT_OPT_STRING_VAL(USER, lpr)) : para_logname();
 550
 551         if (CLIENT_OPT_GIVEN(KEY_FILE, lpr))
 552                 kf = para_strdup(CLIENT_OPT_STRING_VAL(KEY_FILE, lpr));
 553         else {
 554                 kf = make_message("%s/.paraslash/key.%s", home, user);
 555                 if (!file_exists(kf)) {
 556                         free(kf);
 557                         kf = make_message("%s/.ssh/id_rsa", home);
 558                 }
 559         }
 560         PARA_INFO_LOG("user: %s\n", user);
 561         PARA_INFO_LOG("key file: %s\n", kf);
 562         PARA_INFO_LOG("loglevel: %d\n", ll);
 563         ct = para_calloc(sizeof(*ct));
 564         ct->scc.fd = -1;
 565         ct->lpr = lpr;
 566         ct->key_file = kf;
 567         ct->user = user;
 568         *ct_ptr = ct;
 569         ret = lls_num_inputs(lpr);
 570 out:
 571         free(home);
 572         if (ret < 0) {
 573                 if (errctx)
 574                         PARA_ERROR_LOG("%s\n", errctx);
 575                 free(errctx);
 576                 lls_free_parse_result(lpr, cmd);
 577                 free(kf);
 578                 *ct_ptr = NULL;
 579         }
 580         return ret;
 581 }
 582
 583 /**
 584  * Parse the client configuration and open a connection to para_server.
 585  *
 586  * \param argc See \ref client_parse_config.
 587  * \param argv See \ref client_parse_config.
 588  * \param ct_ptr See \ref client_parse_config.
 589  * \param loglevel See \ref client_parse_config.
 590  * \param parent See \ref client_connect().
 591  * \param child See \ref client_connect().
 592  * \param sched See \ref client_connect().
 593  *
 594  * This function combines client_parse_config() and client_connect(). It is
 595  * considered a syntax error if no command was given, i.e. if the number
 596  * of non-option arguments is zero.
 597  *
 598  * \return Standard.
 599  */
 600 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
 601                 int *loglevel, struct btr_node *parent, struct btr_node *child,
 602                 struct sched *sched)
 603 {
 604         int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
 605
 606         if (ret < 0)
 607                 return ret;
 608         if (ret == 0) {
 609                 ret = -E_CLIENT_SYNTAX;
 610                 goto fail;
 611         }
 612         ret = client_connect(*ct_ptr, sched, parent, child);
 613         if (ret < 0)
 614                 goto fail;
 615         return 1;
 616 fail:
 617         client_close(*ct_ptr);
 618         *ct_ptr = NULL;
 619         return ret;
 620 }