Change year in copyright message to 2012.
[paraslash.git] / client_common.c
1 /*
2 * Copyright (C) 1997-2012 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 deallocate per-command ressources.
31 *
32 * \param ct The client task.
33 *
34 * This frees all ressources of the current command but keeps the configuration
35 * in \p ct->conf.
36 *
37 * \sa \ref client_close().
38 */
39 void client_disconnect(struct client_task *ct)
40 {
41 if (!ct)
42 return;
43 if (ct->scc.fd >= 0)
44 close(ct->scc.fd);
45 sc_free(ct->scc.recv);
46 ct->scc.recv = NULL;
47 sc_free(ct->scc.send);
48 ct->scc.send = NULL;
49 btr_free_node(ct->btrn);
50 ct->btrn = NULL;
51 }
52
53 /**
54 * Close the connection to para_server and free all resources.
55 *
56 * \param ct Pointer to the client data.
57 *
58 * \sa \ref client_open(), \ref client_disconnect().
59 */
60 void client_close(struct client_task *ct)
61 {
62 if (!ct)
63 return;
64 client_disconnect(ct);
65 free(ct->user);
66 free(ct->config_file);
67 free(ct->key_file);
68 client_cmdline_parser_free(&ct->conf);
69 free(ct);
70 }
71
72 /**
73 * The preselect hook for server commands.
74 *
75 * \param s Pointer to the scheduler.
76 * \param t Pointer to the task struct for this command.
77 *
78 * The task pointer must contain a pointer to the initialized client data
79 * structure as it is returned by client_open().
80 *
81 * This function checks the state of the connection and adds the file descriptor
82 * of the connection to the read or write fd set of \a s accordingly.
83 *
84 * \sa register_task() client_open(), struct sched, struct task.
85 */
86 static void client_pre_select(struct sched *s, struct task *t)
87 {
88 int ret;
89 struct client_task *ct = container_of(t, struct client_task, task);
90 struct btr_node *btrn = ct->btrn;
91
92 if (ct->scc.fd < 0)
93 return;
94 switch (ct->status) {
95 case CL_CONNECTED:
96 case CL_SENT_AUTH:
97 case CL_SENT_CH_RESPONSE:
98 case CL_SENT_COMMAND:
99 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
100 return;
101
102 case CL_RECEIVED_WELCOME:
103 case CL_RECEIVED_PROCEED:
104 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
105 return;
106
107 case CL_RECEIVING:
108 ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
109 if (ret != 0) {
110 if (ret < 0)
111 sched_min_delay(s);
112 else
113 para_fd_set(ct->scc.fd, &s->rfds,
114 &s->max_fileno);
115 }
116 return;
117 case CL_SENDING:
118 ret = btr_node_status(btrn, 0, BTR_NT_LEAF);
119 if (ret != 0) {
120 if (ret < 0)
121 sched_min_delay(s);
122 else
123 para_fd_set(ct->scc.fd, &s->wfds,
124 &s->max_fileno);
125 }
126 return;
127 }
128 }
129
130 static int client_recv_buffer(struct client_task *ct, fd_set *rfds,
131 char *buf, size_t sz, size_t *n)
132 {
133 int ret;
134
135 if (ct->status < CL_SENT_CH_RESPONSE)
136 return read_nonblock(ct->scc.fd, buf, sz, rfds, n);
137
138 *n = 0;
139 ret = sc_recv_buffer(&ct->scc, buf, sz);
140 /*
141 * sc_recv_buffer is used with blocking fds elsewhere, so it
142 * does not use the nonblock-API. Therefore we need to
143 * check for EOF and EAGAIN.
144 */
145 if (ret == 0)
146 return -E_SERVER_EOF;
147 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
148 return 0;
149 if (ret < 0)
150 return ret;
151 *n = ret;
152 return 0;
153 }
154
155 /**
156 * The post select hook for client commands.
157 *
158 * \param s Pointer to the scheduler.
159 * \param t Pointer to the task struct for this command.
160 *
161 * Depending on the current state of the connection and the status of the read
162 * and write fd sets of \a s, this function performs the necessary steps to
163 * authenticate the connection, to send the command given by \a t->private_data
164 * and to receive para_server's output, if any.
165 *
166 * \sa struct sched, struct task.
167 */
168 static void client_post_select(struct sched *s, struct task *t)
169 {
170 struct client_task *ct = container_of(t, struct client_task, task);
171 struct btr_node *btrn = ct->btrn;
172 int ret = 0;
173 size_t n;
174 char buf[CLIENT_BUFSIZE];
175
176 t->error = 0;
177 if (ct->scc.fd < 0)
178 return;
179 switch (ct->status) {
180 case CL_CONNECTED: /* receive welcome message */
181 ret = client_recv_buffer(ct, &s->rfds, buf, sizeof(buf), &n);
182 if (ret < 0 || n == 0)
183 goto out;
184 ct->status = CL_RECEIVED_WELCOME;
185 return;
186 case CL_RECEIVED_WELCOME: /* send auth command */
187 sprintf(buf, AUTH_REQUEST_MSG "%s", ct->user);
188 PARA_INFO_LOG("--> %s\n", buf);
189 if (!FD_ISSET(ct->scc.fd, &s->wfds))
190 return;
191 ret = send_buffer(ct->scc.fd, buf);
192 if (ret < 0)
193 goto out;
194 ct->status = CL_SENT_AUTH;
195 return;
196 case CL_SENT_AUTH:
197 /*
198 * Receive challenge and session keys, decrypt the challenge and
199 * send back the hash of the decrypted challenge.
200 */
201 {
202 /* decrypted challenge/session key buffer */
203 unsigned char crypt_buf[1024];
204 /* the SHA1 of the decrypted challenge */
205 unsigned char challenge_hash[HASH_SIZE];
206
207 ret = client_recv_buffer(ct, &s->rfds, buf, sizeof(buf), &n);
208 if (ret < 0 || n == 0)
209 goto out;
210 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
211 ret = priv_decrypt(ct->key_file, crypt_buf,
212 (unsigned char *)buf, n);
213 if (ret < 0)
214 goto out;
215 hash_function((char *)crypt_buf, CHALLENGE_SIZE, challenge_hash);
216 ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN);
217 ct->scc.recv = sc_new(crypt_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
218 SESSION_KEY_LEN);
219 hash_to_asc(challenge_hash, buf);
220 PARA_INFO_LOG("--> %s\n", buf);
221 ret = send_bin_buffer(ct->scc.fd, (char *)challenge_hash,
222 HASH_SIZE);
223 if (ret < 0)
224 goto out;
225 ct->status = CL_SENT_CH_RESPONSE;
226 return;
227 }
228 case CL_SENT_CH_RESPONSE: /* read server response */
229 {
230 ret = client_recv_buffer(ct, &s->rfds, buf, sizeof(buf), &n);
231 if (ret < 0 || n == 0)
232 goto out;
233 /* check if server has sent "Proceed" message */
234 ret = -E_CLIENT_AUTH;
235 if (n < PROCEED_MSG_LEN)
236 goto out;
237 if (!strstr(buf, PROCEED_MSG))
238 goto out;
239 ct->status = CL_RECEIVED_PROCEED;
240 return;
241 }
242 case CL_RECEIVED_PROCEED: /* concat args and send command */
243 {
244 int i;
245 char *command = NULL;
246 if (!FD_ISSET(ct->scc.fd, &s->wfds))
247 return;
248 for (i = 0; i < ct->conf.inputs_num; i++) {
249 char *tmp = command;
250 command = make_message("%s\n%s", command?
251 command : "", ct->conf.inputs[i]);
252 free(tmp);
253 }
254 command = para_strcat(command, EOC_MSG "\n");
255 PARA_DEBUG_LOG("--> %s\n", command);
256 ret = sc_send_buffer(&ct->scc, command);
257 free(command);
258 if (ret < 0)
259 goto out;
260 ct->status = CL_SENT_COMMAND;
261 return;
262 }
263 case CL_SENT_COMMAND:
264 {
265 char *buf2;
266 /* can not use "buf" here because we need a malloced buffer */
267 buf2 = para_malloc(CLIENT_BUFSIZE);
268 ret = client_recv_buffer(ct, &s->rfds, buf2, CLIENT_BUFSIZE, &n);
269 if (n > 0) {
270 if (strstr(buf2, AWAITING_DATA_MSG)) {
271 free(buf2);
272 ct->status = CL_SENDING;
273 return;
274 }
275 ct->status = CL_RECEIVING;
276 btr_add_output(buf2, n, btrn);
277 } else
278 free(buf2);
279 goto out;
280 }
281 case CL_SENDING:
282 {
283 char *buf2;
284 size_t sz;
285 ret = btr_node_status(btrn, 0, BTR_NT_LEAF);
286 if (ret < 0)
287 goto out;
288 if (ret == 0)
289 return;
290 if (!FD_ISSET(ct->scc.fd, &s->wfds))
291 return;
292 sz = btr_next_buffer(btrn, &buf2);
293 ret = sc_send_bin_buffer(&ct->scc, buf2, sz);
294 if (ret < 0)
295 goto out;
296 btr_consume(btrn, sz);
297 return;
298 }
299 case CL_RECEIVING:
300 {
301 char *buf2;
302 ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
303 if (ret < 0)
304 goto out;
305 if (ret == 0)
306 return;
307 /*
308 * The FD_ISSET() is not strictly necessary, but is allows us
309 * to skip the malloc below if there is nothing to read anyway.
310 */
311 if (!FD_ISSET(ct->scc.fd, &s->rfds))
312 return;
313 buf2 = para_malloc(CLIENT_BUFSIZE);
314 ret = client_recv_buffer(ct, &s->rfds, buf2, CLIENT_BUFSIZE, &n);
315 if (n > 0) {
316 buf2 = para_realloc(buf2, n);
317 btr_add_output(buf2, n, btrn);
318 } else
319 free(buf2);
320 goto out;
321 }
322 }
323 out:
324 t->error = ret;
325 if (ret < 0) {
326 if (ret != -E_SERVER_EOF && ret != -E_BTR_EOF)
327 PARA_ERROR_LOG("%s\n", para_strerror(-t->error));
328 btr_remove_node(btrn);
329 }
330 }
331
332 /**
333 * Connect to para_server and register the client task.
334 *
335 * \param ct The initialized client task structure.
336 * \param s The scheduler instance to register the client task to.
337 * \param parent The parent node of the client btr node.
338 * \param child The child node of the client node.
339 *
340 * The client task structure given by \a ct must be allocated and initialized
341 * by \ref client_parse_config() before this function is called.
342 *
343 * \return Standard.
344 */
345 int client_connect(struct client_task *ct, struct sched *s,
346 struct btr_node *parent, struct btr_node *child)
347 {
348 int ret;
349
350 PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
351 ct->conf.server_port_arg);
352 ct->scc.fd = -1;
353 ret = para_connect_simple(IPPROTO_TCP, ct->conf.hostname_arg,
354 ct->conf.server_port_arg);
355 if (ret < 0)
356 return ret;
357 ct->scc.fd = ret;
358 ret = mark_fd_nonblocking(ct->scc.fd);
359 if (ret < 0)
360 goto err_out;
361 ct->status = CL_CONNECTED;
362 ct->btrn = btr_new_node(&(struct btr_node_description)
363 EMBRACE(.name = "client", .parent = parent, .child = child));
364 ct->task.pre_select = client_pre_select;
365 ct->task.post_select = client_post_select;
366 ct->task.error = 0;
367 sprintf(ct->task.status, "client");
368 register_task(s, &ct->task);
369 return 1;
370 err_out:
371 close(ct->scc.fd);
372 ct->scc.fd = -1;
373 return ret;
374 }
375
376 /**
377 * Parse a client configuration.
378 *
379 * \param argc Usual argument count.
380 * \param argv Usual argument vector.
381 * \param ct_ptr Filled in by this function.
382 * \param loglevel If not \p NULL, the number of the loglevel is stored here.
383 *
384 * This checks the command line options given by \a argc and \a argv, sets
385 * default values for the user name and the name of the rsa key file and reads
386 * further options from the config file.
387 *
388 * Upon successful return, \a ct_ptr points to a dynamically allocated and
389 * initialized client task struct.
390 *
391 * \return The number of non-option arguments in \a argc/argv on success,
392 * negative on errors.
393 */
394 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
395 int *loglevel)
396 {
397 char *home = para_homedir();
398 int ret;
399 struct client_task *ct = para_calloc(sizeof(struct client_task));
400
401 *ct_ptr = ct;
402 ct->scc.fd = -1;
403 ret = -E_CLIENT_SYNTAX;
404 if (client_cmdline_parser(argc, argv, &ct->conf))
405 goto out;
406 HANDLE_VERSION_FLAG("client", ct->conf);
407
408 ct->config_file = ct->conf.config_file_given?
409 para_strdup(ct->conf.config_file_arg) :
410 make_message("%s/.paraslash/client.conf", home);
411 ret = file_exists(ct->config_file);
412 if (!ret && ct->conf.config_file_given) {
413 ret = -E_NO_CONFIG;
414 goto out;
415 }
416 if (ret) {
417 struct client_cmdline_parser_params params = {
418 .override = 0,
419 .initialize = 0,
420 .check_required = 0,
421 .check_ambiguity = 0,
422 .print_errors = 0
423 };
424 ret = -E_BAD_CONFIG;
425 if (client_cmdline_parser_config_file(ct->config_file,
426 &ct->conf, &params))
427 goto out;
428 }
429 ct->user = ct->conf.user_given?
430 para_strdup(ct->conf.user_arg) : para_logname();
431
432 if (ct->conf.key_file_given)
433 ct->key_file = para_strdup(ct->conf.key_file_arg);
434 else {
435 ct->key_file = make_message("%s/.paraslash/key.%s",
436 home, ct->user);
437 if (!file_exists(ct->key_file)) {
438 free(ct->key_file);
439 ct->key_file = make_message("%s/.ssh/id_rsa", home);
440 }
441 }
442
443 if (loglevel)
444 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
445 PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
446 PARA_INFO_LOG("config_file: %s\n", ct->config_file);
447 PARA_INFO_LOG("key_file: %s\n", ct->key_file);
448 ret = ct->conf.inputs_num;
449 out:
450 free(home);
451 if (ret < 0) {
452 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
453 client_close(ct);
454 *ct_ptr = NULL;
455 }
456 return ret;
457 }
458
459 /**
460 * Parse the client configuration and open a connection to para_server.
461 *
462 * \param argc See \ref client_parse_config.
463 * \param argv See \ref client_parse_config.
464 * \param ct_ptr See \ref client_parse_config.
465 * \param loglevel See \ref client_parse_config.
466 * \param parent See \ref client_connect().
467 * \param child See \ref client_connect().
468 * \param sched See \ref client_connect().
469 *
470 * This function combines client_parse_config() and client_connect(). It is
471 * considered a syntax error if no command was given, i.e. if the number
472 * of non-option arguments is zero.
473 *
474 * \return Standard.
475 */
476 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
477 int *loglevel, struct btr_node *parent, struct btr_node *child,
478 struct sched *sched)
479 {
480 int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
481
482 if (ret < 0)
483 return ret;
484 if (ret == 0) {
485 ret = -E_CLIENT_SYNTAX;
486 goto fail;
487 }
488 ret = client_connect(*ct_ptr, sched, parent, child);
489 if (ret < 0)
490 goto fail;
491 return 1;
492 fail:
493 client_close(*ct_ptr);
494 *ct_ptr = NULL;
495 return ret;
496 }