client_common.c

   1 /*
   2  * Copyright (C) 1997-2009 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 #include <dirent.h>
  12 #include <openssl/rc4.h>
  13
  14 #include "para.h"
  15 #include "error.h"
  16 #include "list.h"
  17 #include "sched.h"
  18 #include "client.cmdline.h"
  19 #include "crypt.h"
  20 #include "rc4.h"
  21 #include "net.h"
  22 #include "fd.h"
  23 #include "string.h"
  24 #include "client.cmdline.h"
  25 #include "client.h"
  26 #include "hash.h"
  27 #include "buffer_tree.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 client_open.
  38  */
  39 void client_close(struct client_task *ct)
  40 {
  41         if (!ct)
  42                 return;
  43         if (ct->rc4c.fd >= 0)
  44                 close(ct->rc4c.fd);
  45         free(ct->user);
  46         free(ct->config_file);
  47         free(ct->key_file);
  48         client_cmdline_parser_free(&ct->conf);
  49         free(ct);
  50 }
  51
  52 /**
  53  * The preselect hook for server commands.
  54  *
  55  * \param s Pointer to the scheduler.
  56  * \param t Pointer to the task struct for this command.
  57  *
  58  * The task pointer must contain a pointer to the initialized client data
  59  * structure as it is returned by client_open().
  60  *
  61  * This function checks the state of the connection and adds the file descriptor
  62  * of the connection to the read or write fd set of \a s accordingly.
  63  *
  64  * \sa register_task() client_open(), struct sched, struct task.
  65  */
  66 static void client_pre_select(struct sched *s, struct task *t)
  67 {
  68         int ret;
  69         struct client_task *ct = container_of(t, struct client_task, task);
  70         struct btr_node *btrn = ct->btrn;
  71
  72         if (ct->rc4c.fd < 0)
  73                 return;
  74         switch (ct->status) {
  75         case CL_CONNECTED:
  76         case CL_SENT_AUTH:
  77         case CL_SENT_CH_RESPONSE:
  78         case CL_SENT_COMMAND:
  79                 para_fd_set(ct->rc4c.fd, &s->rfds, &s->max_fileno);
  80                 return;
  81
  82         case CL_RECEIVED_WELCOME:
  83         case CL_RECEIVED_PROCEED:
  84                 para_fd_set(ct->rc4c.fd, &s->wfds, &s->max_fileno);
  85                 return;
  86
  87         case CL_RECEIVING:
  88                 ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
  89                 if (ret != 0) {
  90                         if (ret < 0)
  91                                 sched_min_delay(s);
  92                         else
  93                                 para_fd_set(ct->rc4c.fd, &s->rfds,
  94                                         &s->max_fileno);
  95                 }
  96                 return;
  97         case CL_SENDING:
  98                 ret = btr_node_status(btrn, 0, BTR_NT_LEAF);
  99                 if (ret != 0) {
 100                         if (ret < 0)
 101                                 sched_min_delay(s);
 102                         else
 103                                 para_fd_set(ct->rc4c.fd, &s->wfds,
 104                                         &s->max_fileno);
 105                 }
 106                 return;
 107         }
 108 }
 109
 110 static ssize_t client_recv_buffer(struct client_task *ct, char *buf, size_t len)
 111 {
 112         ssize_t ret;
 113
 114         if (ct->status < CL_SENT_CH_RESPONSE)
 115                 ret = recv_buffer(ct->rc4c.fd, buf, len);
 116         else
 117                 ret = rc4_recv_buffer(&ct->rc4c, buf, len);
 118         if (ret == 0)
 119                 return -E_SERVER_EOF;
 120         return ret;
 121 }
 122
 123 /**
 124  * The post select hook for client commands.
 125  *
 126  * \param s Pointer to the scheduler.
 127  * \param t Pointer to the task struct for this command.
 128  *
 129  * Depending on the current state of the connection and the status of the read
 130  * and write fd sets of \a s, this function performs the necessary steps to
 131  * authenticate the connection, to send the command given by \a t->private_data
 132  * and to receive para_server's output, if any.
 133  *
 134  * \sa struct sched, struct task.
 135  */
 136 static void client_post_select(struct sched *s, struct task *t)
 137 {
 138         struct client_task *ct = container_of(t, struct client_task, task);
 139         struct btr_node *btrn = ct->btrn;
 140         int ret = 0;
 141         char buf[CLIENT_BUFSIZE];
 142
 143         t->error = 0;
 144         if (ct->rc4c.fd < 0)
 145                 return;
 146         switch (ct->status) {
 147         case CL_CONNECTED: /* receive welcome message */
 148                 if (!FD_ISSET(ct->rc4c.fd, &s->rfds))
 149                         return;
 150                 ret = client_recv_buffer(ct, buf, sizeof(buf));
 151                 if (ret < 0)
 152                         goto err;
 153                 ct->status = CL_RECEIVED_WELCOME;
 154                 return;
 155         case CL_RECEIVED_WELCOME: /* send auth command */
 156                 sprintf(buf, AUTH_REQUEST_MSG "%s", ct->user);
 157                 PARA_INFO_LOG("--> %s\n", buf);
 158                 if (!FD_ISSET(ct->rc4c.fd, &s->wfds))
 159                         return;
 160                 ret = send_buffer(ct->rc4c.fd, buf);
 161                 if (ret < 0)
 162                         goto err;
 163                 ct->status = CL_SENT_AUTH;
 164                 return;
 165         case CL_SENT_AUTH:
 166                 /*
 167                  * Receive challenge and rc4 keys, decrypt the challenge and
 168                  * send back the hash of the decrypted challenge.
 169                  */
 170                 {
 171                 /* decrypted challenge/rc4 buffer */
 172                 unsigned char crypt_buf[1024];
 173                 /* the SHA1 of the decrypted challenge */
 174                 unsigned char challenge_sha1[HASH_SIZE];
 175
 176                 if (!FD_ISSET(ct->rc4c.fd, &s->rfds))
 177                         return;
 178                 ret = client_recv_buffer(ct, buf, sizeof(buf));
 179                 if (ret < 0)
 180                         goto err;
 181                 PARA_INFO_LOG("<-- [challenge] (%d bytes)\n", ret);
 182                 ret = para_decrypt_buffer(ct->key_file, crypt_buf,
 183                         (unsigned char *)buf, ret);
 184                 if (ret < 0)
 185                         goto err;
 186                 sha1_hash((char *)crypt_buf, CHALLENGE_SIZE, challenge_sha1);
 187                 RC4_set_key(&ct->rc4c.send_key, RC4_KEY_LEN,
 188                         crypt_buf + CHALLENGE_SIZE);
 189                 RC4_set_key(&ct->rc4c.recv_key, RC4_KEY_LEN,
 190                         crypt_buf + CHALLENGE_SIZE + RC4_KEY_LEN);
 191                 hash_to_asc(challenge_sha1, buf);
 192                 PARA_INFO_LOG("--> %s\n", buf);
 193                 ret = send_bin_buffer(ct->rc4c.fd, (char *)challenge_sha1,
 194                         HASH_SIZE);
 195                 if (ret < 0)
 196                         goto err;
 197                 ct->status = CL_SENT_CH_RESPONSE;
 198                 return;
 199                 }
 200         case CL_SENT_CH_RESPONSE: /* read server response */
 201                 {
 202                 size_t bytes_received;
 203                 if (!FD_ISSET(ct->rc4c.fd, &s->rfds))
 204                         return;
 205                 ret = client_recv_buffer(ct, buf, sizeof(buf));
 206                 if (ret < 0)
 207                         goto err;
 208                 bytes_received = ret;
 209                 /* check if server has sent "Proceed" message */
 210                 ret = -E_CLIENT_AUTH;
 211                 if (bytes_received < PROCEED_MSG_LEN)
 212                         goto err;
 213                 if (!strstr(buf, PROCEED_MSG))
 214                         goto err;
 215                 ct->status = CL_RECEIVED_PROCEED;
 216                 return;
 217                 }
 218         case CL_RECEIVED_PROCEED: /* concat args and send command */
 219                 {
 220                 int i;
 221                 char *command = NULL;
 222                 if (!FD_ISSET(ct->rc4c.fd, &s->wfds))
 223                         return;
 224                 for (i = 0; i < ct->conf.inputs_num; i++) {
 225                         char *tmp = command;
 226                         command = make_message("%s\n%s", command?
 227                                 command : "", ct->conf.inputs[i]);
 228                         free(tmp);
 229                 }
 230                 command = para_strcat(command, EOC_MSG "\n");
 231                 PARA_DEBUG_LOG("--> %s\n", command);
 232                 ret = rc4_send_buffer(&ct->rc4c, command);
 233                 free(command);
 234                 if (ret < 0)
 235                         goto err;
 236                 ct->status = CL_SENT_COMMAND;
 237                 return;
 238                 }
 239         case CL_SENT_COMMAND:
 240                 {
 241                 char *buf2;
 242                 if (!FD_ISSET(ct->rc4c.fd, &s->rfds))
 243                         return;
 244                 /* can not use "buf" here because we need a malloced buffer */
 245                 buf2 = para_malloc(CLIENT_BUFSIZE);
 246                 ret = client_recv_buffer(ct, buf2, CLIENT_BUFSIZE);
 247                 if (ret < 0) {
 248                         free(buf2);
 249                         goto err;
 250                 }
 251                 if (strstr(buf2, AWAITING_DATA_MSG)) {
 252                         free(buf2);
 253                         ct->status = CL_SENDING;
 254                         return;
 255                 }
 256                 ct->status = CL_RECEIVING;
 257                 btr_add_output(buf2, ret, btrn);
 258                 return;
 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 err;
 267                 if (ret == 0)
 268                         return;
 269                 if (!FD_ISSET(ct->rc4c.fd, &s->wfds))
 270                         return;
 271                 sz = btr_next_buffer(btrn, &buf2);
 272                 ret = rc4_send_bin_buffer(&ct->rc4c, buf2, sz);
 273                 if (ret < 0)
 274                         goto err;
 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 err;
 284                 if (ret == 0)
 285                         return;
 286                 if (!FD_ISSET(ct->rc4c.fd, &s->rfds))
 287                         return;
 288                 buf2 = para_malloc(CLIENT_BUFSIZE);
 289                 ret = client_recv_buffer(ct, buf2, CLIENT_BUFSIZE);
 290                 if (ret < 0) {
 291                         free(buf2);
 292                         goto err;
 293                 }
 294                 buf2 = para_realloc(buf2, ret);
 295                 btr_add_output(buf2, ret, btrn);
 296                 return;
 297                 }
 298         }
 299 err:
 300         t->error = ret;
 301         if (ret < 0) {
 302                 if (ret != -E_SERVER_EOF && ret != -E_BTR_EOF)
 303                         PARA_ERROR_LOG("%s\n", para_strerror(-t->error));
 304                 btr_remove_node(btrn);
 305         }
 306 }
 307
 308 /* connect to para_server and register the client task */
 309 static int client_connect(struct client_task *ct)
 310 {
 311         int ret;
 312
 313         ct->rc4c.fd = -1;
 314         ret = makesock(AF_UNSPEC, IPPROTO_TCP, 0, ct->conf.hostname_arg,
 315                 ct->conf.server_port_arg);
 316         if (ret < 0)
 317                 return ret;
 318         ct->rc4c.fd = ret;
 319         ct->status = CL_CONNECTED;
 320         ret = mark_fd_nonblocking(ct->rc4c.fd);
 321         if (ret < 0)
 322                 goto err_out;
 323         ct->task.pre_select = client_pre_select;
 324         ct->task.post_select = client_post_select;
 325         sprintf(ct->task.status, "client");
 326         register_task(&ct->task);
 327         return 1;
 328 err_out:
 329         close(ct->rc4c.fd);
 330         ct->rc4c.fd = -1;
 331         return ret;
 332 }
 333
 334 /**
 335  * Open connection to para_server.
 336  *
 337  * \param argc Usual argument count.
 338  * \param argv Usual argument vector.
 339  * \param ct_ptr Points to dynamically allocated and initialized client task
 340  * struct upon successful return.
 341  * \param loglevel If not \p NULL, the number of the loglevel is stored here.
 342  * \param parent Add the new buffer tree node as a child of this node.
 343  * \param child Add the new buffer tree node as a parent of this node.
 344  *
 345  * Check the command line options given by \a argc and argv, set default values
 346  * for user name and rsa key file, read further option from the config file.
 347  * Finally, establish a connection to para_server.
 348  *
 349  * \return Standard.
 350  */
 351 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
 352                 int *loglevel, struct btr_node *parent, struct btr_node *child)
 353 {
 354         char *home = para_homedir();
 355         int ret;
 356         struct client_task *ct = para_calloc(sizeof(struct client_task));
 357
 358         ct->btrn = btr_new_node(&(struct btr_node_description)
 359                 EMBRACE(.name = "client", .parent = parent, .child = child));
 360         *ct_ptr = ct;
 361         ct->rc4c.fd = -1;
 362         ret = -E_CLIENT_SYNTAX;
 363         if (client_cmdline_parser(argc, argv, &ct->conf))
 364                 goto out;
 365         HANDLE_VERSION_FLAG("client", ct->conf);
 366         ret = -E_CLIENT_SYNTAX;
 367         if (!ct->conf.inputs_num)
 368                 goto out;
 369         ct->user = ct->conf.user_given?
 370                 para_strdup(ct->conf.user_arg) : para_logname();
 371
 372         ct->key_file = ct->conf.key_file_given?
 373                 para_strdup(ct->conf.key_file_arg) :
 374                 make_message("%s/.paraslash/key.%s", home, ct->user);
 375
 376         ct->config_file = ct->conf.config_file_given?
 377                 para_strdup(ct->conf.config_file_arg) :
 378                 make_message("%s/.paraslash/client.conf", home);
 379         ret = file_exists(ct->config_file);
 380         if (!ret && ct->conf.config_file_given) {
 381                 ret = -E_NO_CONFIG;
 382                 goto out;
 383         }
 384         if (ret) {
 385                 struct client_cmdline_parser_params params = {
 386                         .override = 0,
 387                         .initialize = 0,
 388                         .check_required = 0,
 389                         .check_ambiguity = 0,
 390                         .print_errors = 0
 391                 };
 392                 ret = -E_BAD_CONFIG;
 393                 if (client_cmdline_parser_config_file(ct->config_file,
 394                         &ct->conf, &params))
 395                         goto out;
 396         }
 397         if (loglevel)
 398                 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
 399         PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
 400         PARA_INFO_LOG("config_file: %s\n", ct->config_file);
 401         PARA_INFO_LOG("key_file: %s\n", ct->key_file);
 402         PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
 403                 ct->conf.server_port_arg);
 404         ret = client_connect(ct);
 405 out:
 406         free(home);
 407         if (ret < 0) {
 408                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 409                 btr_remove_node(ct->btrn);
 410                 btr_free_node(ct->btrn);
 411                 client_close(ct);
 412                 *ct_ptr = NULL;
 413         }
 414         return ret;
 415 }