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
  26 /**
  27  * Close the connection to para_server and free all resources.
  28  *
  29  * \param ct Pointer to the client data.
  30  *
  31  * \sa client_open.
  32  */
  33 void client_close(struct client_task *ct)
  34 {
  35         if (!ct)
  36                 return;
  37         if (ct->rc4c.fd >= 0)
  38                 close(ct->rc4c.fd);
  39         free(ct->buf);
  40         free(ct->user);
  41         free(ct->config_file);
  42         free(ct->key_file);
  43         client_cmdline_parser_free(&ct->conf);
  44         free(ct);
  45 }
  46
  47 /**
  48  * The preselect hook for server commands.
  49  *
  50  * \param s Pointer to the scheduler.
  51  * \param t Pointer to the task struct for this command.
  52  *
  53  * The task pointer must contain a pointer to the initialized client data
  54  * structure as it is returned by client_open().
  55  *
  56  * This function checks the state of the connection and adds the file descriptor
  57  * of the connection to the read or write fd set of \a s accordingly.
  58  *
  59  * \sa register_task() client_open(), struct sched, struct task.
  60  */
  61 static void client_pre_select(struct sched *s, struct task *t)
  62 {
  63         struct client_task *ct = container_of(t, struct client_task, task);
  64
  65         ct->check_r = 0;
  66         ct->check_w = 0;
  67         if (ct->rc4c.fd < 0)
  68                 return;
  69         switch (ct->status) {
  70         case CL_CONNECTED:
  71         case CL_SENT_AUTH:
  72         case CL_SENT_CH_RESPONSE:
  73         case CL_SENT_COMMAND:
  74                 para_fd_set(ct->rc4c.fd, &s->rfds, &s->max_fileno);
  75                 ct->check_r = 1;
  76                 return;
  77
  78         case CL_RECEIVED_WELCOME:
  79         case CL_RECEIVED_CHALLENGE:
  80         case CL_RECEIVED_PROCEED:
  81                 para_fd_set(ct->rc4c.fd, &s->wfds, &s->max_fileno);
  82                 ct->check_w = 1;
  83                 return;
  84
  85         case CL_RECEIVING:
  86                 if (ct->loaded < CLIENT_BUFSIZE - 1) {
  87                         para_fd_set(ct->rc4c.fd, &s->rfds, &s->max_fileno);
  88                         ct->check_r = 1;
  89                 }
  90                 return;
  91         case CL_SENDING:
  92                 if (!ct->in_loaded) /* stdin task not yet started */
  93                         return;
  94                 if (*ct->in_loaded) {
  95                         PARA_INFO_LOG("loaded: %zd\n", *ct->in_loaded);
  96                         para_fd_set(ct->rc4c.fd, &s->wfds, &s->max_fileno);
  97                         ct->check_w = 1;
  98                 } else {
  99                         if (*ct->in_error) {
 100                                 t->error = *ct->in_error;
 101                                 s->timeout.tv_sec = 0;
 102                                 s->timeout.tv_usec = 1;
 103                         }
 104                 }
 105                 return;
 106         }
 107 }
 108
 109 static ssize_t client_recv_buffer(struct client_task *ct)
 110 {
 111         ssize_t ret;
 112
 113         if (ct->status < CL_RECEIVED_PROCEED)
 114                 ret = recv_buffer(ct->rc4c.fd, ct->buf + ct->loaded,
 115                         CLIENT_BUFSIZE - ct->loaded);
 116         else
 117                 ret = rc4_recv_buffer(&ct->rc4c, ct->buf + ct->loaded,
 118                         CLIENT_BUFSIZE - ct->loaded);
 119         if (!ret)
 120                 return -E_SERVER_EOF;
 121         if (ret > 0)
 122                 ct->loaded += ret;
 123         return ret;
 124
 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
 144         t->error = 0;
 145         if (ct->rc4c.fd < 0)
 146                 return;
 147         if (!ct->check_r && !ct->check_w)
 148                 return;
 149         if (ct->check_r && !FD_ISSET(ct->rc4c.fd, &s->rfds))
 150                 return;
 151         if (ct->check_w && !FD_ISSET(ct->rc4c.fd, &s->wfds))
 152                 return;
 153         switch (ct->status) {
 154         case CL_CONNECTED: /* receive welcome message */
 155                 t->error = client_recv_buffer(ct);
 156                 if (t->error > 0)
 157                         ct->status = CL_RECEIVED_WELCOME;
 158                 return;
 159         case CL_RECEIVED_WELCOME: /* send auth command */
 160                 sprintf(ct->buf, "auth rc4 %s", ct->user);
 161                 PARA_INFO_LOG("--> %s\n", ct->buf);
 162                 t->error = send_buffer(ct->rc4c.fd, ct->buf);
 163                 if (t->error >= 0)
 164                         ct->status = CL_SENT_AUTH;
 165                 return;
 166         case CL_SENT_AUTH: /* receive challenge number */
 167                 ct->loaded = 0;
 168                 t->error = client_recv_buffer(ct);
 169                 if (t->error < 0)
 170                         return;
 171                 if (t->error != 64) {
 172                         t->error = -E_INVALID_CHALLENGE;
 173                         PARA_ERROR_LOG("received the following: %s\n", ct->buf);
 174                         return;
 175                 }
 176                 PARA_INFO_LOG("<-- [challenge]\n");
 177                 /* decrypt challenge number */
 178                 t->error = para_decrypt_challenge(ct->key_file, &ct->challenge_nr,
 179                         (unsigned char *) ct->buf, 64);
 180                 if (t->error > 0)
 181                         ct->status = CL_RECEIVED_CHALLENGE;
 182                 return;
 183         case CL_RECEIVED_CHALLENGE: /* send decrypted challenge */
 184                 PARA_INFO_LOG("--> %lu\n", ct->challenge_nr);
 185                 t->error = send_va_buffer(ct->rc4c.fd, "%s%lu", CHALLENGE_RESPONSE_MSG,
 186                         ct->challenge_nr);
 187                 if (t->error > 0)
 188                         ct->status = CL_SENT_CH_RESPONSE;
 189                 return;
 190         case CL_SENT_CH_RESPONSE: /* read server response */
 191                 {
 192                 size_t bytes_received;
 193                 unsigned char rc4_buf[2 * RC4_KEY_LEN] = "";
 194                 ct->loaded = 0;
 195                 t->error = client_recv_buffer(ct);
 196                 if (t->error < 0)
 197                         return;
 198                 bytes_received = t->error;
 199                 PARA_DEBUG_LOG("++++ server info ++++\n%s\n++++ end of server "
 200                         "info ++++\n", ct->buf);
 201                 /* check if server has sent "Proceed" message and the rc4 keys */
 202                 t->error = -E_CLIENT_AUTH;
 203                 if (bytes_received < PROCEED_MSG_LEN + 2 * RC4_KEY_LEN)
 204                         return;
 205                 if (!strstr(ct->buf, PROCEED_MSG))
 206                         return;
 207                 PARA_INFO_LOG("decrypting session key\n");
 208                 t->error = para_decrypt_buffer(ct->key_file, rc4_buf,
 209                         (unsigned char *)ct->buf + PROCEED_MSG_LEN + 1,
 210                         bytes_received - PROCEED_MSG_LEN - 1);
 211                 if (t->error < 0)
 212                         return;
 213                 RC4_set_key(&ct->rc4c.send_key, RC4_KEY_LEN, rc4_buf);
 214                 RC4_set_key(&ct->rc4c.recv_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
 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                 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                         ct->status = CL_SENT_COMMAND;
 234                 return;
 235                 }
 236         case CL_SENT_COMMAND:
 237                 ct->loaded = 0;
 238                 t->error = client_recv_buffer(ct);
 239                 if (t->error < 0)
 240                         return;
 241                 if (strstr(ct->buf, AWAITING_DATA_MSG))
 242                         ct->status = CL_SENDING;
 243                 else
 244                         ct->status = CL_RECEIVING;
 245                 return;
 246         case CL_SENDING: /* FIXME: might block */
 247                 PARA_INFO_LOG("loaded: %zd\n", *ct->in_loaded);
 248                 t->error = rc4_send_bin_buffer(&ct->rc4c, ct->inbuf, *ct->in_loaded);
 249                 if (t->error < 0)
 250                         return;
 251                 *ct->in_loaded = 0;
 252                 return;
 253         case CL_RECEIVING:
 254                 t->error = client_recv_buffer(ct);
 255                 return;
 256         }
 257 }
 258
 259 /* connect to para_server and register the client task */
 260 static int client_connect(struct client_task *ct)
 261 {
 262         int ret;
 263
 264         ct->rc4c.fd = -1;
 265         ret = makesock(AF_UNSPEC, IPPROTO_TCP, 0, ct->conf.hostname_arg,
 266                 ct->conf.server_port_arg);
 267         if (ret < 0)
 268                 return ret;
 269         ct->rc4c.fd = ret;
 270         ct->status = CL_CONNECTED;
 271         ret = mark_fd_nonblocking(ct->rc4c.fd);
 272         if (ret < 0)
 273                 goto err_out;
 274         ct->task.pre_select = client_pre_select;
 275         ct->task.post_select = client_post_select;
 276         sprintf(ct->task.status, "client");
 277         register_task(&ct->task);
 278         return 1;
 279 err_out:
 280         close(ct->rc4c.fd);
 281         ct->rc4c.fd = -1;
 282         return ret;
 283 }
 284
 285 /**
 286  * Open connection to para_server.
 287  *
 288  * \param argc Usual argument count.
 289  * \param argv Usual argument vector.
 290  * \param ct_ptr Points to dynamically allocated and initialized client task
 291  * struct upon successful return.
 292  * \param loglevel If not \p NULL, the number of the loglevel is stored here.
 293  *
 294  * Check the command line options given by \a argc and argv, set default values
 295  * for user name and rsa key file, read further option from the config file.
 296  * Finally, establish a connection to para_server.
 297  *
 298  * \return Standard.
 299  */
 300 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
 301                 int *loglevel)
 302 {
 303         char *home = para_homedir();
 304         int ret;
 305         struct client_task *ct = para_calloc(sizeof(struct client_task));
 306
 307         ct->buf = para_malloc(CLIENT_BUFSIZE);
 308         *ct_ptr = ct;
 309         ct->rc4c.fd = -1;
 310         ret = -E_CLIENT_SYNTAX;
 311         if (client_cmdline_parser(argc, argv, &ct->conf))
 312                 goto out;
 313         HANDLE_VERSION_FLAG("client", ct->conf);
 314         ret = -E_CLIENT_SYNTAX;
 315         if (!ct->conf.inputs_num)
 316                 goto out;
 317         ct->user = ct->conf.user_given?
 318                 para_strdup(ct->conf.user_arg) : para_logname();
 319
 320         ct->key_file = ct->conf.key_file_given?
 321                 para_strdup(ct->conf.key_file_arg) :
 322                 make_message("%s/.paraslash/key.%s", home, ct->user);
 323
 324         ct->config_file = ct->conf.config_file_given?
 325                 para_strdup(ct->conf.config_file_arg) :
 326                 make_message("%s/.paraslash/client.conf", home);
 327         ret = file_exists(ct->config_file);
 328         if (!ret && ct->conf.config_file_given) {
 329                 ret = -E_NO_CONFIG;
 330                 goto out;
 331         }
 332         if (ret) {
 333                 struct client_cmdline_parser_params params = {
 334                         .override = 0,
 335                         .initialize = 0,
 336                         .check_required = 0,
 337                         .check_ambiguity = 0,
 338                         .print_errors = 0
 339                 };
 340                 ret = -E_BAD_CONFIG;
 341                 if (client_cmdline_parser_config_file(ct->config_file,
 342                         &ct->conf, &params))
 343                         goto out;
 344         }
 345         if (loglevel)
 346                 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
 347         PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
 348         PARA_INFO_LOG("config_file: %s\n", ct->config_file);
 349         PARA_INFO_LOG("key_file: %s\n", ct->key_file);
 350         PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
 351                 ct->conf.server_port_arg);
 352         ret = client_connect(ct);
 353 out:
 354         free(home);
 355         if (ret < 0) {
 356                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 357                 client_close(ct);
 358                 *ct_ptr = NULL;
 359         }
 360         return ret;
 361 }