Merge branch 't/dia'
[paraslash.git] / client_common.c
1 /*
2 * Copyright (C) 1997-2013 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 "crypt.h"
17 #include "net.h"
18 #include "fd.h"
19 #include "sideband.h"
20 #include "string.h"
21 #include "client.cmdline.h"
22 #include "client.h"
23 #include "buffer_tree.h"
24 #include "version.h"
25 #include "ggo.h"
26
27 /** The size of the receiving buffer. */
28 #define CLIENT_BUFSIZE 4000
29
30 /**
31 * Close the connection to para_server and deallocate per-command resources.
32 *
33 * \param ct The client task.
34 *
35 * This frees all resources of the current command but keeps the configuration
36 * in \p ct->conf.
37 *
38 * \sa \ref client_close().
39 */
40 void client_disconnect(struct client_task *ct)
41 {
42 if (!ct)
43 return;
44 if (ct->scc.fd >= 0)
45 close(ct->scc.fd);
46 free_argv(ct->features);
47 ct->features = NULL;
48 sc_free(ct->scc.recv);
49 ct->scc.recv = NULL;
50 sc_free(ct->scc.send);
51 ct->scc.send = NULL;
52 btr_remove_node(&ct->btrn[0]);
53 btr_remove_node(&ct->btrn[1]);
54 }
55
56 /**
57 * Close the connection to para_server and free all resources.
58 *
59 * \param ct Pointer to the client data.
60 *
61 * \sa \ref client_open(), \ref client_disconnect().
62 */
63 void client_close(struct client_task *ct)
64 {
65 if (!ct)
66 return;
67 client_disconnect(ct);
68 free(ct->user);
69 free(ct->config_file);
70 free(ct->key_file);
71 client_cmdline_parser_free(&ct->conf);
72 free(ct->challenge_hash);
73 sb_free(ct->sbc[0]);
74 sb_free(ct->sbc[1]);
75 free(ct);
76 }
77
78 /**
79 * The preselect hook for server commands.
80 *
81 * \param s Pointer to the scheduler.
82 * \param t Pointer to the task struct for this command.
83 *
84 * The task pointer must contain a pointer to the initialized client data
85 * structure as it is returned by client_open().
86 *
87 * This function checks the state of the connection and adds the file descriptor
88 * of the connection to the read or write fd set of \a s accordingly.
89 *
90 * \sa register_task() client_open(), struct sched, struct task.
91 */
92 static void client_pre_select(struct sched *s, struct task *t)
93 {
94 int ret;
95 struct client_task *ct = container_of(t, struct client_task, task);
96
97 if (ct->scc.fd < 0)
98 return;
99 switch (ct->status) {
100 case CL_CONNECTED:
101 case CL_SENT_AUTH:
102 case CL_SENT_CH_RESPONSE:
103 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
104 return;
105
106 case CL_RECEIVED_WELCOME:
107 case CL_RECEIVED_PROCEED:
108 case CL_RECEIVED_CHALLENGE:
109 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
110 return;
111
112 case CL_SENDING:
113 if (ct->btrn[1]) {
114 ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
115 if (ret < 0)
116 sched_min_delay(s);
117 else if (ret > 0)
118 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
119 }
120 /* fall though */
121 case CL_EXECUTING:
122 if (ct->btrn[0]) {
123 ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
124 if (ret < 0)
125 sched_min_delay(s);
126 else if (ret > 0)
127 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
128 }
129 return;
130 }
131 }
132
133 static int send_sb(struct client_task *ct, int channel, void *buf, size_t numbytes,
134 enum sb_designator band, bool dont_free)
135 {
136 int ret, fd = ct->scc.fd;
137 struct iovec iov[2];
138
139 if (!ct->sbc[channel]) {
140 struct sb_buffer sbb;
141 sb_transformation trafo = ct->status < CL_RECEIVED_PROCEED?
142 NULL : sc_trafo;
143 sbb = (typeof(sbb))SBB_INIT(band, buf, numbytes);
144 ct->sbc[channel] = sb_new_send(&sbb, dont_free, trafo, ct->scc.send);
145 }
146 ret = sb_get_send_buffers(ct->sbc[channel], iov);
147 ret = xwritev(fd, iov, ret);
148 if (ret < 0) {
149 sb_free(ct->sbc[channel]);
150 ct->sbc[channel] = NULL;
151 return ret;
152 }
153 if (sb_sent(ct->sbc[channel], ret)) {
154 ct->sbc[channel] = NULL;
155 return 1;
156 }
157 return 0;
158 }
159
160 static int recv_sb(struct client_task *ct, fd_set *rfds,
161 struct sb_buffer *result)
162 {
163 int ret;
164 size_t n;
165 sb_transformation trafo;
166 void *trafo_context;
167 struct iovec iov;
168
169 if (!FD_ISSET(ct->scc.fd, rfds))
170 return 0;
171 if (ct->status < CL_SENT_CH_RESPONSE)
172 trafo = trafo_context = NULL;
173 else {
174 trafo = sc_trafo;
175 trafo_context = ct->scc.recv;
176 }
177 if (!ct->sbc[0])
178 ct->sbc[0] = sb_new_recv(0, trafo, trafo_context);
179 again:
180 sb_get_recv_buffer(ct->sbc[0], &iov);
181 ret = read_nonblock(ct->scc.fd, iov.iov_base, iov.iov_len, rfds, &n);
182 if (ret < 0) {
183 sb_free(ct->sbc[0]);
184 ct->sbc[0] = NULL;
185 return ret;
186 }
187 if (n == 0)
188 return 0;
189 if (!sb_received(ct->sbc[0], n, result))
190 goto again;
191 ct->sbc[0] = NULL;
192 return 1;
193 }
194
195
196 static char **parse_features(char *buf)
197 {
198 int i;
199 const char id[] = "\nFeatures: ";
200 char *p, *q, **features;
201
202 p = strstr(buf, id);
203 if (!p)
204 return NULL;
205 p += strlen(id);
206 q = strchr(p, '\n');
207 if (!q)
208 return NULL;
209 *q = '\0';
210 create_argv(p, ",", &features);
211 for (i = 0; features[i]; i++)
212 PARA_INFO_LOG("server feature: %s\n", features[i]);
213 return features;
214 }
215
216 static int dispatch_sbb(struct client_task *ct, struct sb_buffer *sbb)
217 {
218 int ret;
219 const char *designator[] = {SB_DESIGNATORS_ARRAY};
220
221 if (!sbb)
222 return 0;
223 if (sbb->band < NUM_SB_DESIGNATORS)
224 PARA_DEBUG_LOG("band: %s\n", designator[sbb->band]);
225
226 switch (sbb->band) {
227 case SBD_AWAITING_DATA:
228 ct->status = CL_SENDING;
229 ret = 1;
230 goto out;
231 case SBD_OUTPUT:
232 if (iov_valid(&sbb->iov))
233 btr_add_output(sbb->iov.iov_base, sbb->iov.iov_len,
234 ct->btrn[0]);
235 ret = 1;
236 goto out;
237 case SBD_DEBUG_LOG:
238 case SBD_INFO_LOG:
239 case SBD_NOTICE_LOG:
240 case SBD_WARNING_LOG:
241 case SBD_ERROR_LOG:
242 case SBD_CRIT_LOG:
243 case SBD_EMERG_LOG:
244 if (iov_valid(&sbb->iov)) {
245 int ll = sbb->band - SBD_DEBUG_LOG;
246 para_log(ll, "remote: %s", (char *)sbb->iov.iov_base);
247 }
248 ret = 1;
249 goto deallocate;
250 case SBD_EXIT__SUCCESS:
251 ret = -E_SERVER_CMD_SUCCESS;
252 goto deallocate;
253 case SBD_EXIT__FAILURE:
254 ret = -E_SERVER_CMD_FAILURE;
255 goto deallocate;
256 default:
257 PARA_ERROR_LOG("invalid band %d\n", sbb->band);
258 ret = -E_BAD_BAND;
259 goto deallocate;
260 }
261 deallocate:
262 free(sbb->iov.iov_base);
263 out:
264 sbb->iov.iov_base = NULL;
265 return ret;
266 }
267
268 static bool has_feature(const char *feature, struct client_task *ct)
269 {
270 return find_arg(feature, ct->features) >= 0? true : false;
271 }
272
273 static int send_sb_command(struct client_task *ct)
274 {
275 int i;
276 char *command, *p;
277 size_t len = 0;
278
279 if (ct->sbc[1])
280 return send_sb(ct, 0, NULL, 0, 0, false);
281
282 for (i = 0; i < ct->conf.inputs_num; i++)
283 len += strlen(ct->conf.inputs[i]) + 1;
284 p = command = para_malloc(len);
285 for (i = 0; i < ct->conf.inputs_num; i++) {
286 strcpy(p, ct->conf.inputs[i]);
287 p += strlen(ct->conf.inputs[i]) + 1;
288 }
289 PARA_DEBUG_LOG("--> %s\n", command);
290 return send_sb(ct, 0, command, len, SBD_COMMAND, false);
291 }
292
293 /**
294 * The post select hook for client commands.
295 *
296 * \param s Pointer to the scheduler.
297 * \param t Pointer to the task struct for this command.
298 *
299 * Depending on the current state of the connection and the status of the read
300 * and write fd sets of \a s, this function performs the necessary steps to
301 * authenticate the connection, to send the command given by \a t->private_data
302 * and to receive para_server's output, if any.
303 *
304 * \sa struct sched, struct task.
305 */
306 static int client_post_select(struct sched *s, struct task *t)
307 {
308 struct client_task *ct = container_of(t, struct client_task, task);
309 int ret = 0;
310 size_t n;
311 char buf[CLIENT_BUFSIZE];
312
313 ret = task_get_notification(t);
314 if (ret < 0)
315 goto out;
316 if (ct->scc.fd < 0)
317 return 0;
318 switch (ct->status) {
319 case CL_CONNECTED: /* receive welcome message */
320 ret = read_nonblock(ct->scc.fd, buf, sizeof(buf), &s->rfds, &n);
321 if (ret < 0 || n == 0)
322 goto out;
323 ct->features = parse_features(buf);
324 if (!has_feature("sideband", ct)) {
325 PARA_ERROR_LOG("server has no sideband support\n");
326 ret = -E_INCOMPAT_FEAT;
327 goto out;
328 }
329 ct->status = CL_RECEIVED_WELCOME;
330 return 0;
331 case CL_RECEIVED_WELCOME: /* send auth command */
332 if (!FD_ISSET(ct->scc.fd, &s->wfds))
333 return 0;
334 sprintf(buf, AUTH_REQUEST_MSG "%s sideband", ct->user);
335 PARA_INFO_LOG("--> %s\n", buf);
336 ret = write_buffer(ct->scc.fd, buf);
337 if (ret < 0)
338 goto out;
339 ct->status = CL_SENT_AUTH;
340 return 0;
341 case CL_SENT_AUTH:
342 /*
343 * Receive challenge and session keys, decrypt the challenge and
344 * send back the hash of the decrypted challenge.
345 */
346 {
347 /* decrypted challenge/session key buffer */
348 unsigned char crypt_buf[1024];
349 struct sb_buffer sbb;
350
351 ret = recv_sb(ct, &s->rfds, &sbb);
352 if (ret <= 0)
353 goto out;
354 if (sbb.band != SBD_CHALLENGE) {
355 ret = -E_BAD_BAND;
356 free(sbb.iov.iov_base);
357 goto out;
358 }
359 n = sbb.iov.iov_len;
360 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
361 ret = priv_decrypt(ct->key_file, crypt_buf,
362 sbb.iov.iov_base, n);
363 free(sbb.iov.iov_base);
364 if (ret < 0)
365 goto out;
366 ct->challenge_hash = para_malloc(HASH_SIZE);
367 hash_function((char *)crypt_buf, CHALLENGE_SIZE, ct->challenge_hash);
368 ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN);
369 ct->scc.recv = sc_new(crypt_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
370 SESSION_KEY_LEN);
371 hash_to_asc(ct->challenge_hash, buf);
372 PARA_INFO_LOG("--> %s\n", buf);
373 ct->status = CL_RECEIVED_CHALLENGE;
374 return 0;
375 }
376 case CL_RECEIVED_CHALLENGE:
377 ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
378 SBD_CHALLENGE_RESPONSE, false);
379 if (ret != 0)
380 ct->challenge_hash = NULL;
381 if (ret <= 0)
382 goto out;
383 ct->status = CL_SENT_CH_RESPONSE;
384 goto out;
385 case CL_SENT_CH_RESPONSE: /* read server response */
386 {
387 struct sb_buffer sbb;
388 ret = recv_sb(ct, &s->rfds, &sbb);
389 if (ret <= 0)
390 goto out;
391 free(sbb.iov.iov_base);
392 if (sbb.band != SBD_PROCEED)
393 ret = -E_BAD_BAND;
394 else
395 ct->status = CL_RECEIVED_PROCEED;
396 goto out;
397 }
398 case CL_RECEIVED_PROCEED: /* concat args and send command */
399 {
400 if (!FD_ISSET(ct->scc.fd, &s->wfds))
401 return 0;
402 ret = send_sb_command(ct);
403 if (ret <= 0)
404 goto out;
405 ct->status = CL_EXECUTING;
406 return 0;
407 }
408 case CL_SENDING:
409 if (ct->btrn[1]) {
410 char *buf2;
411 size_t sz;
412 ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
413 if (ret == -E_BTR_EOF) {
414 /* empty blob data packet indicates EOF */
415 PARA_INFO_LOG("blob sent\n");
416 ret = send_sb(ct, 1, NULL, 0, SBD_BLOB_DATA, true);
417 if (ret >= 0)
418 ret = -E_BTR_EOF;
419 }
420 if (ret < 0)
421 goto close1;
422 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->wfds)) {
423 sz = btr_next_buffer(ct->btrn[1], &buf2);
424 assert(sz);
425 ret = send_sb(ct, 1, buf2, sz, SBD_BLOB_DATA, true);
426 if (ret < 0)
427 goto close1;
428 if (ret > 0)
429 btr_consume(ct->btrn[1], sz);
430 }
431 }
432 /* fall though */
433 case CL_EXECUTING:
434 if (ct->btrn[0]) {
435 ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
436 if (ret < 0)
437 goto close0;
438 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->rfds)) {
439 struct sb_buffer sbb;
440 ret = recv_sb(ct, &s->rfds, &sbb);
441 if (ret < 0)
442 goto close0;
443 if (ret > 0) {
444 ret = dispatch_sbb(ct, &sbb);
445 if (ret < 0)
446 goto close0;
447 }
448 }
449 }
450 ret = 0;
451 goto out;
452 }
453 close1:
454 PARA_INFO_LOG("channel 1: %s\n", para_strerror(-ret));
455 btr_remove_node(&ct->btrn[1]);
456 if (ct->btrn[0])
457 return 0;
458 goto out;
459 close0:
460 PARA_INFO_LOG("channel 0: %s\n", para_strerror(-ret));
461 btr_remove_node(&ct->btrn[0]);
462 if (ct->btrn[1] && ct->status == CL_SENDING)
463 return 0;
464 out:
465 if (ret >= 0)
466 return 0;
467 btr_remove_node(&ct->btrn[0]);
468 btr_remove_node(&ct->btrn[1]);
469 if (ret != -E_SERVER_CMD_SUCCESS && ret != -E_SERVER_CMD_FAILURE)
470 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
471 return ret;
472 }
473
474 /**
475 * Connect to para_server and register the client task.
476 *
477 * \param ct The initialized client task structure.
478 * \param s The scheduler instance to register the client task to.
479 * \param parent The parent node of the client btr node.
480 * \param child The child node of the client node.
481 *
482 * The client task structure given by \a ct must be allocated and initialized
483 * by \ref client_parse_config() before this function is called.
484 *
485 * \return Standard.
486 */
487 int client_connect(struct client_task *ct, struct sched *s,
488 struct btr_node *parent, struct btr_node *child)
489 {
490 int ret;
491
492 PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
493 ct->conf.server_port_arg);
494 ct->scc.fd = -1;
495 ret = para_connect_simple(IPPROTO_TCP, ct->conf.hostname_arg,
496 ct->conf.server_port_arg);
497 if (ret < 0)
498 return ret;
499 ct->scc.fd = ret;
500 ret = mark_fd_nonblocking(ct->scc.fd);
501 if (ret < 0)
502 goto err_out;
503 ct->status = CL_CONNECTED;
504 ct->btrn[0] = btr_new_node(&(struct btr_node_description)
505 EMBRACE(.name = "client recv", .parent = NULL, .child = child));
506 ct->btrn[1] = btr_new_node(&(struct btr_node_description)
507 EMBRACE(.name = "client send", .parent = parent, .child = NULL));
508 ct->task.pre_select = client_pre_select;
509 ct->task.post_select = client_post_select;
510 ct->task.error = 0;
511 sprintf(ct->task.status, "client");
512 register_task(s, &ct->task);
513 return 1;
514 err_out:
515 close(ct->scc.fd);
516 ct->scc.fd = -1;
517 return ret;
518 }
519
520 __noreturn static void print_help_and_die(struct client_task *ct)
521 {
522 struct ggo_help h = DEFINE_GGO_HELP(client);
523 bool d = ct->conf.detailed_help_given;
524
525 ggo_print_help(&h, d? GPH_STANDARD_FLAGS_DETAILED : GPH_STANDARD_FLAGS);
526 exit(0);
527 }
528
529 /**
530 * Parse a client configuration.
531 *
532 * \param argc Usual argument count.
533 * \param argv Usual argument vector.
534 * \param ct_ptr Filled in by this function.
535 * \param loglevel If not \p NULL, the number of the loglevel is stored here.
536 *
537 * This checks the command line options given by \a argc and \a argv, sets
538 * default values for the user name and the name of the rsa key file and reads
539 * further options from the config file.
540 *
541 * Upon successful return, \a ct_ptr points to a dynamically allocated and
542 * initialized client task struct.
543 *
544 * \return The number of non-option arguments in \a argc/argv on success,
545 * negative on errors.
546 */
547 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
548 int *loglevel)
549 {
550 char *home = para_homedir();
551 int ret;
552 struct client_task *ct = para_calloc(sizeof(struct client_task));
553
554 *ct_ptr = ct;
555 ct->scc.fd = -1;
556 ret = -E_CLIENT_SYNTAX;
557 if (client_cmdline_parser(argc, argv, &ct->conf))
558 goto out;
559 version_handle_flag("client", ct->conf.version_given);
560 if (ct->conf.help_given || ct->conf.detailed_help_given)
561 print_help_and_die(ct);
562
563 ct->config_file = ct->conf.config_file_given?
564 para_strdup(ct->conf.config_file_arg) :
565 make_message("%s/.paraslash/client.conf", home);
566 ret = file_exists(ct->config_file);
567 if (!ret && ct->conf.config_file_given) {
568 ret = -E_NO_CONFIG;
569 goto out;
570 }
571 if (ret) {
572 struct client_cmdline_parser_params params = {
573 .override = 0,
574 .initialize = 0,
575 .check_required = 0,
576 .check_ambiguity = 0,
577 .print_errors = 0
578 };
579 ret = -E_BAD_CONFIG;
580 if (client_cmdline_parser_config_file(ct->config_file,
581 &ct->conf, &params))
582 goto out;
583 }
584 ct->user = ct->conf.user_given?
585 para_strdup(ct->conf.user_arg) : para_logname();
586
587 if (ct->conf.key_file_given)
588 ct->key_file = para_strdup(ct->conf.key_file_arg);
589 else {
590 ct->key_file = make_message("%s/.paraslash/key.%s",
591 home, ct->user);
592 if (!file_exists(ct->key_file)) {
593 free(ct->key_file);
594 ct->key_file = make_message("%s/.ssh/id_rsa", home);
595 }
596 }
597
598 if (loglevel)
599 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
600 PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
601 PARA_INFO_LOG("config_file: %s\n", ct->config_file);
602 PARA_INFO_LOG("key_file: %s\n", ct->key_file);
603 ret = ct->conf.inputs_num;
604 out:
605 free(home);
606 if (ret < 0) {
607 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
608 client_close(ct);
609 *ct_ptr = NULL;
610 }
611 return ret;
612 }
613
614 /**
615 * Parse the client configuration and open a connection to para_server.
616 *
617 * \param argc See \ref client_parse_config.
618 * \param argv See \ref client_parse_config.
619 * \param ct_ptr See \ref client_parse_config.
620 * \param loglevel See \ref client_parse_config.
621 * \param parent See \ref client_connect().
622 * \param child See \ref client_connect().
623 * \param sched See \ref client_connect().
624 *
625 * This function combines client_parse_config() and client_connect(). It is
626 * considered a syntax error if no command was given, i.e. if the number
627 * of non-option arguments is zero.
628 *
629 * \return Standard.
630 */
631 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
632 int *loglevel, struct btr_node *parent, struct btr_node *child,
633 struct sched *sched)
634 {
635 int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
636
637 if (ret < 0)
638 return ret;
639 if (ret == 0) {
640 ret = -E_CLIENT_SYNTAX;
641 goto fail;
642 }
643 ret = client_connect(*ct_ptr, sched, parent, child);
644 if (ret < 0)
645 goto fail;
646 return 1;
647 fail:
648 client_close(*ct_ptr);
649 *ct_ptr = NULL;
650 return ret;
651 }