client_common.c

   1 /*
   2  * Copyright (C) 1997-2011 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file client_common.c Common functions of para_client and para_audiod. */
   8
   9 #include <regex.h>
  10 #include <sys/types.h>
  11
  12 #include "para.h"
  13 #include "error.h"
  14 #include "list.h"
  15 #include "sched.h"
  16 #include "client.cmdline.h"
  17 #include "crypt.h"
  18 #include "net.h"
  19 #include "fd.h"
  20 #include "string.h"
  21 #include "client.cmdline.h"
  22 #include "client.h"
  23 #include "buffer_tree.h"
  24 #include "version.h"
  25
  26 /** The size of the receiving buffer. */
  27 #define CLIENT_BUFSIZE 4000
  28
  29 /**
  30  * Close the connection to para_server and free all resources.
  31  *
  32  * \param ct Pointer to the client data.
  33  *
  34  * \sa client_open.
  35  */
  36 void client_close(struct client_task *ct)
  37 {
  38         if (!ct)
  39                 return;
  40         if (ct->scc.fd >= 0)
  41                 close(ct->scc.fd);
  42         sc_free(ct->scc.recv);
  43         sc_free(ct->scc.send);
  44         free(ct->user);
  45         free(ct->config_file);
  46         free(ct->key_file);
  47         client_cmdline_parser_free(&ct->conf);
  48         free(ct);
  49 }
  50
  51 /**
  52  * The preselect hook for server commands.
  53  *
  54  * \param s Pointer to the scheduler.
  55  * \param t Pointer to the task struct for this command.
  56  *
  57  * The task pointer must contain a pointer to the initialized client data
  58  * structure as it is returned by client_open().
  59  *
  60  * This function checks the state of the connection and adds the file descriptor
  61  * of the connection to the read or write fd set of \a s accordingly.
  62  *
  63  * \sa register_task() client_open(), struct sched, struct task.
  64  */
  65 static void client_pre_select(struct sched *s, struct task *t)
  66 {
  67         int ret;
  68         struct client_task *ct = container_of(t, struct client_task, task);
  69         struct btr_node *btrn = ct->btrn;
  70
  71         if (ct->scc.fd < 0)
  72                 return;
  73         switch (ct->status) {
  74         case CL_CONNECTED:
  75         case CL_SENT_AUTH:
  76         case CL_SENT_CH_RESPONSE:
  77         case CL_SENT_COMMAND:
  78                 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
  79                 return;
  80
  81         case CL_RECEIVED_WELCOME:
  82         case CL_RECEIVED_PROCEED:
  83                 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
  84                 return;
  85
  86         case CL_RECEIVING:
  87                 ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
  88                 if (ret != 0) {
  89                         if (ret < 0)
  90                                 sched_min_delay(s);
  91                         else
  92                                 para_fd_set(ct->scc.fd, &s->rfds,
  93                                         &s->max_fileno);
  94                 }
  95                 return;
  96         case CL_SENDING:
  97                 ret = btr_node_status(btrn, 0, BTR_NT_LEAF);
  98                 if (ret != 0) {
  99                         if (ret < 0)
 100                                 sched_min_delay(s);
 101                         else
 102                                 para_fd_set(ct->scc.fd, &s->wfds,
 103                                         &s->max_fileno);
 104                 }
 105                 return;
 106         }
 107 }
 108
 109 static int client_recv_buffer(struct client_task *ct, fd_set *rfds,
 110                 char *buf, size_t sz, size_t *n)
 111 {
 112         int ret;
 113
 114         if (ct->status < CL_SENT_CH_RESPONSE)
 115                 return read_nonblock(ct->scc.fd, buf, sz, rfds, n);
 116
 117         *n = 0;
 118         ret = sc_recv_buffer(&ct->scc, buf, sz);
 119         /*
 120          * sc_recv_buffer is used with blocking fds elsewhere, so it
 121          * does not use the nonblock-API. Therefore we need to
 122          * check for EOF and EAGAIN.
 123          */
 124         if (ret == 0)
 125                 return -E_SERVER_EOF;
 126         if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
 127                 return 0;
 128         if (ret < 0)
 129                 return ret;
 130         *n = ret;
 131         return 0;
 132 }
 133
 134 /**
 135  * The post select hook for client commands.
 136  *
 137  * \param s Pointer to the scheduler.
 138  * \param t Pointer to the task struct for this command.
 139  *
 140  * Depending on the current state of the connection and the status of the read
 141  * and write fd sets of \a s, this function performs the necessary steps to
 142  * authenticate the connection, to send the command given by \a t->private_data
 143  * and to receive para_server's output, if any.
 144  *
 145  * \sa struct sched, struct task.
 146  */
 147 static void client_post_select(struct sched *s, struct task *t)
 148 {
 149         struct client_task *ct = container_of(t, struct client_task, task);
 150         struct btr_node *btrn = ct->btrn;
 151         int ret = 0;
 152         size_t n;
 153         char buf[CLIENT_BUFSIZE];
 154
 155         t->error = 0;
 156         if (ct->scc.fd < 0)
 157                 return;
 158         switch (ct->status) {
 159         case CL_CONNECTED: /* receive welcome message */
 160                 ret = client_recv_buffer(ct, &s->rfds, buf, sizeof(buf), &n);
 161                 if (ret < 0 || n == 0)
 162                         goto out;
 163                 ct->status = CL_RECEIVED_WELCOME;
 164                 return;
 165         case CL_RECEIVED_WELCOME: /* send auth command */
 166                 sprintf(buf, AUTH_REQUEST_MSG "%s", ct->user);
 167                 PARA_INFO_LOG("--> %s\n", buf);
 168                 if (!FD_ISSET(ct->scc.fd, &s->wfds))
 169                         return;
 170                 ret = send_buffer(ct->scc.fd, buf);
 171                 if (ret < 0)
 172                         goto out;
 173                 ct->status = CL_SENT_AUTH;
 174                 return;
 175         case CL_SENT_AUTH:
 176                 /*
 177                  * Receive challenge and session keys, decrypt the challenge and
 178                  * send back the hash of the decrypted challenge.
 179                  */
 180                 {
 181                 /* decrypted challenge/session key buffer */
 182                 unsigned char crypt_buf[1024];
 183                 /* the SHA1 of the decrypted challenge */
 184                 unsigned char challenge_hash[HASH_SIZE];
 185
 186                 ret = client_recv_buffer(ct, &s->rfds, buf, sizeof(buf), &n);
 187                 if (ret < 0 || n == 0)
 188                         goto out;
 189                 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
 190                 ret = priv_decrypt(ct->key_file, crypt_buf,
 191                         (unsigned char *)buf, n);
 192                 if (ret < 0)
 193                         goto out;
 194                 hash_function((char *)crypt_buf, CHALLENGE_SIZE, challenge_hash);
 195                 ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN);
 196                 ct->scc.recv = sc_new(crypt_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
 197                         SESSION_KEY_LEN);
 198                 hash_to_asc(challenge_hash, buf);
 199                 PARA_INFO_LOG("--> %s\n", buf);
 200                 ret = send_bin_buffer(ct->scc.fd, (char *)challenge_hash,
 201                         HASH_SIZE);
 202                 if (ret < 0)
 203                         goto out;
 204                 ct->status = CL_SENT_CH_RESPONSE;
 205                 return;
 206                 }
 207         case CL_SENT_CH_RESPONSE: /* read server response */
 208                 {
 209                 ret = client_recv_buffer(ct, &s->rfds, buf, sizeof(buf), &n);
 210                 if (ret < 0 || n == 0)
 211                         goto out;
 212                 /* check if server has sent "Proceed" message */
 213                 ret = -E_CLIENT_AUTH;
 214                 if (n < PROCEED_MSG_LEN)
 215                         goto out;
 216                 if (!strstr(buf, PROCEED_MSG))
 217                         goto out;
 218                 ct->status = CL_RECEIVED_PROCEED;
 219                 return;
 220                 }
 221         case CL_RECEIVED_PROCEED: /* concat args and send command */
 222                 {
 223                 int i;
 224                 char *command = NULL;
 225                 if (!FD_ISSET(ct->scc.fd, &s->wfds))
 226                         return;
 227                 for (i = 0; i < ct->conf.inputs_num; i++) {
 228                         char *tmp = command;
 229                         command = make_message("%s\n%s", command?
 230                                 command : "", ct->conf.inputs[i]);
 231                         free(tmp);
 232                 }
 233                 command = para_strcat(command, EOC_MSG "\n");
 234                 PARA_DEBUG_LOG("--> %s\n", command);
 235                 ret = sc_send_buffer(&ct->scc, command);
 236                 free(command);
 237                 if (ret < 0)
 238                         goto out;
 239                 ct->status = CL_SENT_COMMAND;
 240                 return;
 241                 }
 242         case CL_SENT_COMMAND:
 243                 {
 244                 char *buf2;
 245                 /* can not use "buf" here because we need a malloced buffer */
 246                 buf2 = para_malloc(CLIENT_BUFSIZE);
 247                 ret = client_recv_buffer(ct, &s->rfds, buf2, CLIENT_BUFSIZE, &n);
 248                 if (n > 0) {
 249                         if (strstr(buf2, AWAITING_DATA_MSG)) {
 250                                 free(buf2);
 251                                 ct->status = CL_SENDING;
 252                                 return;
 253                         }
 254                         ct->status = CL_RECEIVING;
 255                         btr_add_output(buf2, n, btrn);
 256                 } else
 257                         free(buf2);
 258                 goto out;
 259                 }
 260         case CL_SENDING:
 261                 {
 262                 char *buf2;
 263                 size_t sz;
 264                 ret = btr_node_status(btrn, 0, BTR_NT_LEAF);
 265                 if (ret < 0)
 266                         goto out;
 267                 if (ret == 0)
 268                         return;
 269                 if (!FD_ISSET(ct->scc.fd, &s->wfds))
 270                         return;
 271                 sz = btr_next_buffer(btrn, &buf2);
 272                 ret = sc_send_bin_buffer(&ct->scc, buf2, sz);
 273                 if (ret < 0)
 274                         goto out;
 275                 btr_consume(btrn, sz);
 276                 return;
 277                 }
 278         case CL_RECEIVING:
 279                 {
 280                 char *buf2;
 281                 ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
 282                 if (ret < 0)
 283                         goto out;
 284                 if (ret == 0)
 285                         return;
 286                 /*
 287                  * The FD_ISSET() is not strictly necessary, but is allows us
 288                  * to skip the malloc below if there is nothing to read anyway.
 289                  */
 290                 if (!FD_ISSET(ct->scc.fd, &s->rfds))
 291                         return;
 292                 buf2 = para_malloc(CLIENT_BUFSIZE);
 293                 ret = client_recv_buffer(ct, &s->rfds, buf2, CLIENT_BUFSIZE, &n);
 294                 if (n > 0) {
 295                         buf2 = para_realloc(buf2, n);
 296                         btr_add_output(buf2, n, btrn);
 297                 } else
 298                         free(buf2);
 299                 goto out;
 300                 }
 301         }
 302 out:
 303         t->error = ret;
 304         if (ret < 0) {
 305                 if (ret != -E_SERVER_EOF && ret != -E_BTR_EOF)
 306                         PARA_ERROR_LOG("%s\n", para_strerror(-t->error));
 307                 btr_remove_node(btrn);
 308         }
 309 }
 310
 311 /* connect to para_server and register the client task */
 312 static int client_connect(struct client_task *ct)
 313 {
 314         int ret;
 315
 316         ct->scc.fd = -1;
 317         ret = para_connect_simple(IPPROTO_TCP, ct->conf.hostname_arg,
 318                                                ct->conf.server_port_arg);
 319         if (ret < 0)
 320                 return ret;
 321         ct->scc.fd = ret;
 322         ct->status = CL_CONNECTED;
 323         ret = mark_fd_nonblocking(ct->scc.fd);
 324         if (ret < 0)
 325                 goto err_out;
 326         ct->task.pre_select = client_pre_select;
 327         ct->task.post_select = client_post_select;
 328         sprintf(ct->task.status, "client");
 329         register_task(&ct->task);
 330         return 1;
 331 err_out:
 332         close(ct->scc.fd);
 333         ct->scc.fd = -1;
 334         return ret;
 335 }
 336
 337 /**
 338  * Open connection to para_server.
 339  *
 340  * \param argc Usual argument count.
 341  * \param argv Usual argument vector.
 342  * \param ct_ptr Points to dynamically allocated and initialized client task
 343  * struct upon successful return.
 344  * \param loglevel If not \p NULL, the number of the loglevel is stored here.
 345  * \param parent Add the new buffer tree node as a child of this node.
 346  * \param child Add the new buffer tree node as a parent of this node.
 347  *
 348  * Check the command line options given by \a argc and argv, set default values
 349  * for user name and rsa key file, read further option from the config file.
 350  * Finally, establish a connection to para_server.
 351  *
 352  * \return Standard.
 353  */
 354 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
 355                 int *loglevel, struct btr_node *parent, struct btr_node *child)
 356 {
 357         char *home = para_homedir();
 358         int ret;
 359         struct client_task *ct = para_calloc(sizeof(struct client_task));
 360
 361         ct->btrn = btr_new_node(&(struct btr_node_description)
 362                 EMBRACE(.name = "client", .parent = parent, .child = child));
 363         *ct_ptr = ct;
 364         ct->scc.fd = -1;
 365         ret = -E_CLIENT_SYNTAX;
 366         if (client_cmdline_parser(argc, argv, &ct->conf))
 367                 goto out;
 368         HANDLE_VERSION_FLAG("client", ct->conf);
 369         ret = -E_CLIENT_SYNTAX;
 370         if (!ct->conf.inputs_num)
 371                 goto out;
 372
 373         ct->config_file = ct->conf.config_file_given?
 374                 para_strdup(ct->conf.config_file_arg) :
 375                 make_message("%s/.paraslash/client.conf", home);
 376         ret = file_exists(ct->config_file);
 377         if (!ret && ct->conf.config_file_given) {
 378                 ret = -E_NO_CONFIG;
 379                 goto out;
 380         }
 381         if (ret) {
 382                 struct client_cmdline_parser_params params = {
 383                         .override = 0,
 384                         .initialize = 0,
 385                         .check_required = 0,
 386                         .check_ambiguity = 0,
 387                         .print_errors = 0
 388                 };
 389                 ret = -E_BAD_CONFIG;
 390                 if (client_cmdline_parser_config_file(ct->config_file,
 391                         &ct->conf, &params))
 392                         goto out;
 393         }
 394         ct->user = ct->conf.user_given?
 395                 para_strdup(ct->conf.user_arg) : para_logname();
 396
 397         if (ct->conf.key_file_given)
 398                 ct->key_file = para_strdup(ct->conf.key_file_arg);
 399         else {
 400                 ct->key_file = make_message("%s/.paraslash/key.%s",
 401                         home, ct->user);
 402                 if (!file_exists(ct->key_file)) {
 403                         free(ct->key_file);
 404                         ct->key_file = make_message("%s/.ssh/id_rsa", home);
 405                 }
 406         }
 407
 408         if (loglevel)
 409                 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
 410         PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
 411         PARA_INFO_LOG("config_file: %s\n", ct->config_file);
 412         PARA_INFO_LOG("key_file: %s\n", ct->key_file);
 413         PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
 414                 ct->conf.server_port_arg);
 415         ret = client_connect(ct);
 416 out:
 417         free(home);
 418         if (ret < 0) {
 419                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 420                 btr_remove_node(ct->btrn);
 421                 btr_free_node(ct->btrn);
 422                 client_close(ct);
 423                 *ct_ptr = NULL;
 424         }
 425         return ret;
 426 }