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