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 <sys/types.h>
  10 #include <dirent.h>
  11 #include <openssl/rc4.h>
  12
  13 #include "para.h"
  14 #include "error.h"
  15 #include "list.h"
  16 #include "sched.h"
  17 #include "client.cmdline.h"
  18 #include "crypt.h"
  19 #include "rc4.h"
  20 #include "net.h"
  21 #include "fd.h"
  22 #include "string.h"
  23 #include "client.cmdline.h"
  24 #include "client.h"
  25 #include "hash.h"
  26
  27 /**
  28  * Close the connection to para_server and free all resources.
  29  *
  30  * \param ct Pointer to the client data.
  31  *
  32  * \sa client_open.
  33  */
  34 void client_close(struct client_task *ct)
  35 {
  36         if (!ct)
  37                 return;
  38         if (ct->rc4c.fd >= 0)
  39                 close(ct->rc4c.fd);
  40         free(ct->buf);
  41         free(ct->user);
  42         free(ct->config_file);
  43         free(ct->key_file);
  44         client_cmdline_parser_free(&ct->conf);
  45         free(ct);
  46 }
  47
  48 /**
  49  * The preselect hook for server commands.
  50  *
  51  * \param s Pointer to the scheduler.
  52  * \param t Pointer to the task struct for this command.
  53  *
  54  * The task pointer must contain a pointer to the initialized client data
  55  * structure as it is returned by client_open().
  56  *
  57  * This function checks the state of the connection and adds the file descriptor
  58  * of the connection to the read or write fd set of \a s accordingly.
  59  *
  60  * \sa register_task() client_open(), struct sched, struct task.
  61  */
  62 static void client_pre_select(struct sched *s, struct task *t)
  63 {
  64         struct client_task *ct = container_of(t, struct client_task, task);
  65
  66         ct->check_r = 0;
  67         ct->check_w = 0;
  68         if (ct->rc4c.fd < 0)
  69                 return;
  70         switch (ct->status) {
  71         case CL_CONNECTED:
  72         case CL_SENT_AUTH:
  73         case CL_SENT_CH_RESPONSE:
  74         case CL_SENT_COMMAND:
  75                 para_fd_set(ct->rc4c.fd, &s->rfds, &s->max_fileno);
  76                 ct->check_r = 1;
  77                 return;
  78
  79         case CL_RECEIVED_WELCOME:
  80         case CL_RECEIVED_CHALLENGE:
  81         case CL_RECEIVED_PROCEED:
  82                 para_fd_set(ct->rc4c.fd, &s->wfds, &s->max_fileno);
  83                 ct->check_w = 1;
  84                 return;
  85
  86         case CL_RECEIVING:
  87                 if (ct->loaded < CLIENT_BUFSIZE - 1) {
  88                         para_fd_set(ct->rc4c.fd, &s->rfds, &s->max_fileno);
  89                         ct->check_r = 1;
  90                 }
  91                 return;
  92         case CL_SENDING:
  93                 if (!ct->in_loaded) /* stdin task not yet started */
  94                         return;
  95                 if (*ct->in_loaded) {
  96                         PARA_INFO_LOG("loaded: %zd\n", *ct->in_loaded);
  97                         para_fd_set(ct->rc4c.fd, &s->wfds, &s->max_fileno);
  98                         ct->check_w = 1;
  99                 } else {
 100                         if (*ct->in_error) {
 101                                 t->error = *ct->in_error;
 102                                 s->timeout.tv_sec = 0;
 103                                 s->timeout.tv_usec = 1;
 104                         }
 105                 }
 106                 return;
 107         }
 108 }
 109
 110 static ssize_t client_recv_buffer(struct client_task *ct)
 111 {
 112         ssize_t ret;
 113
 114         if (ct->status < CL_SENT_CH_RESPONSE)
 115                 ret = recv_buffer(ct->rc4c.fd, ct->buf + ct->loaded,
 116                         CLIENT_BUFSIZE - ct->loaded);
 117         else
 118                 ret = rc4_recv_buffer(&ct->rc4c, ct->buf + ct->loaded,
 119                         CLIENT_BUFSIZE - ct->loaded);
 120         if (!ret)
 121                 return -E_SERVER_EOF;
 122         if (ret > 0)
 123                 ct->loaded += ret;
 124         return ret;
 125 }
 126
 127 /**
 128  * The post select hook for client commands.
 129  *
 130  * \param s Pointer to the scheduler.
 131  * \param t Pointer to the task struct for this command.
 132  *
 133  * Depending on the current state of the connection and the status of the read
 134  * and write fd sets of \a s, this function performs the necessary steps to
 135  * authenticate the connection, to send the command given by \a t->private_data
 136  * and to receive para_server's output, if any.
 137  *
 138  * \sa struct sched, struct task.
 139  */
 140 static void client_post_select(struct sched *s, struct task *t)
 141 {
 142         struct client_task *ct = container_of(t, struct client_task, task);
 143         unsigned char crypt_buf[1024];
 144
 145         t->error = 0;
 146         if (ct->rc4c.fd < 0)
 147                 return;
 148         if (!ct->check_r && !ct->check_w)
 149                 return;
 150         if (ct->check_r && !FD_ISSET(ct->rc4c.fd, &s->rfds))
 151                 return;
 152         if (ct->check_w && !FD_ISSET(ct->rc4c.fd, &s->wfds))
 153                 return;
 154         switch (ct->status) {
 155         case CL_CONNECTED: /* receive welcome message */
 156                 t->error = client_recv_buffer(ct);
 157                 if (t->error < 0)
 158                         goto err;
 159                 ct->status = CL_RECEIVED_WELCOME;
 160                 return;
 161         case CL_RECEIVED_WELCOME: /* send auth command */
 162                 sprintf(ct->buf, AUTH_REQUEST_MSG "%s", ct->user);
 163                 PARA_INFO_LOG("--> %s\n", ct->buf);
 164                 t->error = send_buffer(ct->rc4c.fd, ct->buf);
 165                 if (t->error < 0)
 166                         goto err;
 167                 ct->status = CL_SENT_AUTH;
 168                 return;
 169         case CL_SENT_AUTH: /* receive challenge and rc4 keys */
 170                 ct->loaded = 0;
 171                 t->error = client_recv_buffer(ct);
 172                 if (t->error < 0)
 173                         goto err;
 174                 PARA_INFO_LOG("<-- [challenge] (%d bytes)\n", t->error);
 175                 /* decrypt challenge/rc4 buffer  */
 176                 t->error = para_decrypt_buffer(ct->key_file, crypt_buf,
 177                         (unsigned char *)ct->buf, t->error);
 178                 if (t->error < 0)
 179                         goto err;
 180                 ct->status = CL_RECEIVED_CHALLENGE;
 181                 RC4_set_key(&ct->rc4c.send_key, RC4_KEY_LEN,
 182                         crypt_buf + CHALLENGE_SIZE);
 183                 RC4_set_key(&ct->rc4c.recv_key, RC4_KEY_LEN,
 184                         crypt_buf + CHALLENGE_SIZE + RC4_KEY_LEN);
 185                 return;
 186         case CL_RECEIVED_CHALLENGE:
 187                 {
 188                 unsigned char challenge_sha1[HASH_SIZE];
 189                 /* send sha1 of decrypted challenge */
 190                 sha1_hash((char *)crypt_buf, CHALLENGE_SIZE, challenge_sha1);
 191                 hash_to_asc(challenge_sha1, ct->buf);
 192                 PARA_INFO_LOG("--> %s\n", ct->buf);
 193                 t->error = send_bin_buffer(ct->rc4c.fd, (char *)challenge_sha1,
 194                         HASH_SIZE);
 195                 if (t->error < 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                 ct->loaded = 0;
 204                 t->error = client_recv_buffer(ct);
 205                 if (t->error < 0)
 206                         goto err;
 207                 bytes_received = t->error;
 208                 /* check if server has sent "Proceed" message */
 209                 t->error = -E_CLIENT_AUTH;
 210                 if (bytes_received < PROCEED_MSG_LEN)
 211                         goto err;
 212                 if (!strstr(ct->buf, PROCEED_MSG))
 213                         goto err;
 214                 ct->status = CL_RECEIVED_PROCEED;
 215                 t->error = 0;
 216                 return;
 217                 }
 218         case CL_RECEIVED_PROCEED: /* concat args and send command */
 219                 {
 220                 int i;
 221                 char *command = NULL;
 222                 for (i = 0; i < ct->conf.inputs_num; i++) {
 223                         char *tmp = command;
 224                         command = make_message("%s\n%s", command?
 225                                 command : "", ct->conf.inputs[i]);
 226                         free(tmp);
 227                 }
 228                 command = para_strcat(command, EOC_MSG "\n");
 229                 PARA_DEBUG_LOG("--> %s\n", command);
 230                 t->error = rc4_send_buffer(&ct->rc4c, command);
 231                 free(command);
 232                 if (t->error < 0)
 233                         goto err;
 234                 ct->status = CL_SENT_COMMAND;
 235                 return;
 236                 }
 237         case CL_SENT_COMMAND:
 238                 ct->loaded = 0;
 239                 t->error = client_recv_buffer(ct);
 240                 if (t->error < 0)
 241                         goto err;
 242                 if (strstr(ct->buf, AWAITING_DATA_MSG))
 243                         ct->status = CL_SENDING;
 244                 else
 245                         ct->status = CL_RECEIVING;
 246                 return;
 247         case CL_SENDING:
 248                 PARA_INFO_LOG("loaded: %zd\n", *ct->in_loaded);
 249                 t->error = rc4_send_bin_buffer(&ct->rc4c, ct->inbuf,
 250                         *ct->in_loaded);
 251                 if (t->error < 0)
 252                         goto err;
 253                 *ct->in_loaded = 0;
 254                 return;
 255         case CL_RECEIVING:
 256                 t->error = client_recv_buffer(ct);
 257                 if (t->error < 0)
 258                         goto err;
 259                 return;
 260         }
 261 err:
 262         if (t->error != -E_SERVER_EOF)
 263                 PARA_ERROR_LOG("%s\n", para_strerror(-t->error));
 264 }
 265
 266 /* connect to para_server and register the client task */
 267 static int client_connect(struct client_task *ct)
 268 {
 269         int ret;
 270
 271         ct->rc4c.fd = -1;
 272         ret = makesock(AF_UNSPEC, IPPROTO_TCP, 0, ct->conf.hostname_arg,
 273                 ct->conf.server_port_arg);
 274         if (ret < 0)
 275                 return ret;
 276         ct->rc4c.fd = ret;
 277         ct->status = CL_CONNECTED;
 278         ret = mark_fd_nonblocking(ct->rc4c.fd);
 279         if (ret < 0)
 280                 goto err_out;
 281         ct->task.pre_select = client_pre_select;
 282         ct->task.post_select = client_post_select;
 283         sprintf(ct->task.status, "client");
 284         register_task(&ct->task);
 285         return 1;
 286 err_out:
 287         close(ct->rc4c.fd);
 288         ct->rc4c.fd = -1;
 289         return ret;
 290 }
 291
 292 /**
 293  * Open connection to para_server.
 294  *
 295  * \param argc Usual argument count.
 296  * \param argv Usual argument vector.
 297  * \param ct_ptr Points to dynamically allocated and initialized client task
 298  * struct upon successful return.
 299  * \param loglevel If not \p NULL, the number of the loglevel is stored here.
 300  *
 301  * Check the command line options given by \a argc and argv, set default values
 302  * for user name and rsa key file, read further option from the config file.
 303  * Finally, establish a connection to para_server.
 304  *
 305  * \return Standard.
 306  */
 307 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
 308                 int *loglevel)
 309 {
 310         char *home = para_homedir();
 311         int ret;
 312         struct client_task *ct = para_calloc(sizeof(struct client_task));
 313
 314         ct->buf = para_malloc(CLIENT_BUFSIZE);
 315         *ct_ptr = ct;
 316         ct->rc4c.fd = -1;
 317         ret = -E_CLIENT_SYNTAX;
 318         if (client_cmdline_parser(argc, argv, &ct->conf))
 319                 goto out;
 320         HANDLE_VERSION_FLAG("client", ct->conf);
 321         ret = -E_CLIENT_SYNTAX;
 322         if (!ct->conf.inputs_num)
 323                 goto out;
 324         ct->user = ct->conf.user_given?
 325                 para_strdup(ct->conf.user_arg) : para_logname();
 326
 327         ct->key_file = ct->conf.key_file_given?
 328                 para_strdup(ct->conf.key_file_arg) :
 329                 make_message("%s/.paraslash/key.%s", home, ct->user);
 330
 331         ct->config_file = ct->conf.config_file_given?
 332                 para_strdup(ct->conf.config_file_arg) :
 333                 make_message("%s/.paraslash/client.conf", home);
 334         ret = file_exists(ct->config_file);
 335         if (!ret && ct->conf.config_file_given) {
 336                 ret = -E_NO_CONFIG;
 337                 goto out;
 338         }
 339         if (ret) {
 340                 struct client_cmdline_parser_params params = {
 341                         .override = 0,
 342                         .initialize = 0,
 343                         .check_required = 0,
 344                         .check_ambiguity = 0,
 345                         .print_errors = 0
 346                 };
 347                 ret = -E_BAD_CONFIG;
 348                 if (client_cmdline_parser_config_file(ct->config_file,
 349                         &ct->conf, &params))
 350                         goto out;
 351         }
 352         if (loglevel)
 353                 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
 354         PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
 355         PARA_INFO_LOG("config_file: %s\n", ct->config_file);
 356         PARA_INFO_LOG("key_file: %s\n", ct->key_file);
 357         PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
 358                 ct->conf.server_port_arg);
 359         ret = client_connect(ct);
 360 out:
 361         free(home);
 362         if (ret < 0) {
 363                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 364                 client_close(ct);
 365                 *ct_ptr = NULL;
 366         }
 367         return ret;
 368 }