Merge branch 't/audiod_com_version'
[paraslash.git] / client_common.c
1 /*
2 * Copyright (C) 1997-2014 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 <netinet/in.h>
10 #include <sys/socket.h>
11 #include <regex.h>
12 #include <sys/types.h>
13 #include <arpa/inet.h>
14 #include <sys/un.h>
15 #include <netdb.h>
16
17 #include "para.h"
18 #include "error.h"
19 #include "list.h"
20 #include "sched.h"
21 #include "crypt.h"
22 #include "net.h"
23 #include "fd.h"
24 #include "sideband.h"
25 #include "string.h"
26 #include "client.cmdline.h"
27 #include "client.h"
28 #include "buffer_tree.h"
29 #include "version.h"
30 #include "ggo.h"
31
32 /** The size of the receiving buffer. */
33 #define CLIENT_BUFSIZE 4000
34
35 /**
36 * Close the connection to para_server and free all resources.
37 *
38 * \param ct Pointer to the client data.
39 *
40 * \sa \ref client_open().
41 */
42 void client_close(struct client_task *ct)
43 {
44 if (!ct)
45 return;
46 free(ct->user);
47 free(ct->config_file);
48 free(ct->key_file);
49 client_cmdline_parser_free(&ct->conf);
50 free(ct->challenge_hash);
51 sb_free(ct->sbc[0]);
52 sb_free(ct->sbc[1]);
53 free(ct);
54 }
55
56 /**
57 * The preselect hook for server commands.
58 *
59 * \param s Pointer to the scheduler.
60 * \param t Pointer to the task struct for this command.
61 *
62 * The task pointer must contain a pointer to the initialized client data
63 * structure as it is returned by client_open().
64 *
65 * This function checks the state of the connection and adds the file descriptor
66 * of the connection to the read or write fd set of \a s accordingly.
67 *
68 * \sa register_task() client_open(), struct sched, struct task.
69 */
70 static void client_pre_select(struct sched *s, struct task *t)
71 {
72 int ret;
73 struct client_task *ct = container_of(t, struct client_task, task);
74
75 if (ct->scc.fd < 0)
76 return;
77 switch (ct->status) {
78 case CL_CONNECTED:
79 case CL_SENT_AUTH:
80 case CL_SENT_CH_RESPONSE:
81 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
82 return;
83
84 case CL_RECEIVED_WELCOME:
85 case CL_RECEIVED_PROCEED:
86 case CL_RECEIVED_CHALLENGE:
87 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
88 return;
89
90 case CL_SENDING:
91 if (ct->btrn[1]) {
92 ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
93 if (ret < 0)
94 sched_min_delay(s);
95 else if (ret > 0)
96 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
97 }
98 /* fall though */
99 case CL_EXECUTING:
100 if (ct->btrn[0]) {
101 ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
102 if (ret < 0)
103 sched_min_delay(s);
104 else if (ret > 0)
105 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
106 }
107 return;
108 }
109 }
110
111 static int send_sb(struct client_task *ct, int channel, void *buf, size_t numbytes,
112 enum sb_designator band, bool dont_free)
113 {
114 int ret, fd = ct->scc.fd;
115 struct iovec iov[2];
116
117 if (!ct->sbc[channel]) {
118 struct sb_buffer sbb;
119 sb_transformation trafo = ct->status < CL_RECEIVED_PROCEED?
120 NULL : sc_trafo;
121 sbb = (typeof(sbb))SBB_INIT(band, buf, numbytes);
122 ct->sbc[channel] = sb_new_send(&sbb, dont_free, trafo, ct->scc.send);
123 }
124 ret = sb_get_send_buffers(ct->sbc[channel], iov);
125 ret = xwritev(fd, iov, ret);
126 if (ret < 0) {
127 sb_free(ct->sbc[channel]);
128 ct->sbc[channel] = NULL;
129 return ret;
130 }
131 if (sb_sent(ct->sbc[channel], ret)) {
132 ct->sbc[channel] = NULL;
133 return 1;
134 }
135 return 0;
136 }
137
138 static int recv_sb(struct client_task *ct, fd_set *rfds,
139 struct sb_buffer *result)
140 {
141 int ret;
142 size_t n;
143 sb_transformation trafo;
144 void *trafo_context;
145 struct iovec iov;
146
147 if (!FD_ISSET(ct->scc.fd, rfds))
148 return 0;
149 if (ct->status < CL_SENT_CH_RESPONSE)
150 trafo = trafo_context = NULL;
151 else {
152 trafo = sc_trafo;
153 trafo_context = ct->scc.recv;
154 }
155 if (!ct->sbc[0])
156 ct->sbc[0] = sb_new_recv(0, trafo, trafo_context);
157 again:
158 sb_get_recv_buffer(ct->sbc[0], &iov);
159 ret = read_nonblock(ct->scc.fd, iov.iov_base, iov.iov_len, rfds, &n);
160 if (ret < 0) {
161 sb_free(ct->sbc[0]);
162 ct->sbc[0] = NULL;
163 return ret;
164 }
165 if (n == 0)
166 return 0;
167 if (!sb_received(ct->sbc[0], n, result))
168 goto again;
169 ct->sbc[0] = NULL;
170 return 1;
171 }
172
173
174 static char **parse_features(char *buf)
175 {
176 int i;
177 const char id[] = "\nFeatures: ";
178 char *p, *q, **features;
179
180 p = strstr(buf, id);
181 if (!p)
182 return NULL;
183 p += strlen(id);
184 q = strchr(p, '\n');
185 if (!q)
186 return NULL;
187 *q = '\0';
188 create_argv(p, ",", &features);
189 for (i = 0; features[i]; i++)
190 PARA_INFO_LOG("server feature: %s\n", features[i]);
191 return features;
192 }
193
194 static int dispatch_sbb(struct client_task *ct, struct sb_buffer *sbb)
195 {
196 int ret;
197 const char *designator[] = {SB_DESIGNATORS_ARRAY};
198
199 if (!sbb)
200 return 0;
201 if (sbb->band < NUM_SB_DESIGNATORS)
202 PARA_DEBUG_LOG("band: %s\n", designator[sbb->band]);
203
204 switch (sbb->band) {
205 case SBD_AWAITING_DATA:
206 ct->status = CL_SENDING;
207 ret = 1;
208 goto out;
209 case SBD_OUTPUT:
210 if (iov_valid(&sbb->iov))
211 btr_add_output(sbb->iov.iov_base, sbb->iov.iov_len,
212 ct->btrn[0]);
213 ret = 1;
214 goto out;
215 case SBD_DEBUG_LOG:
216 case SBD_INFO_LOG:
217 case SBD_NOTICE_LOG:
218 case SBD_WARNING_LOG:
219 case SBD_ERROR_LOG:
220 case SBD_CRIT_LOG:
221 case SBD_EMERG_LOG:
222 if (iov_valid(&sbb->iov)) {
223 int ll = sbb->band - SBD_DEBUG_LOG;
224 para_log(ll, "remote: %s", (char *)sbb->iov.iov_base);
225 }
226 ret = 1;
227 goto deallocate;
228 case SBD_EXIT__SUCCESS:
229 ret = -E_SERVER_CMD_SUCCESS;
230 goto deallocate;
231 case SBD_EXIT__FAILURE:
232 ret = -E_SERVER_CMD_FAILURE;
233 goto deallocate;
234 default:
235 PARA_ERROR_LOG("invalid band %d\n", sbb->band);
236 ret = -E_BAD_BAND;
237 goto deallocate;
238 }
239 deallocate:
240 free(sbb->iov.iov_base);
241 out:
242 sbb->iov.iov_base = NULL;
243 return ret;
244 }
245
246 static bool has_feature(const char *feature, struct client_task *ct)
247 {
248 return find_arg(feature, ct->features) >= 0? true : false;
249 }
250
251 static int send_sb_command(struct client_task *ct)
252 {
253 int i;
254 char *command, *p;
255 size_t len = 0;
256
257 if (ct->sbc[1])
258 return send_sb(ct, 0, NULL, 0, 0, false);
259
260 for (i = 0; i < ct->conf.inputs_num; i++)
261 len += strlen(ct->conf.inputs[i]) + 1;
262 p = command = para_malloc(len);
263 for (i = 0; i < ct->conf.inputs_num; i++) {
264 strcpy(p, ct->conf.inputs[i]);
265 p += strlen(ct->conf.inputs[i]) + 1;
266 }
267 PARA_DEBUG_LOG("--> %s\n", command);
268 return send_sb(ct, 0, command, len, SBD_COMMAND, false);
269 }
270
271 /**
272 * The post select hook for client commands.
273 *
274 * \param s Pointer to the scheduler.
275 * \param t Pointer to the task struct for this command.
276 *
277 * Depending on the current state of the connection and the status of the read
278 * and write fd sets of \a s, this function performs the necessary steps to
279 * authenticate the connection, to send the command given by \a t->private_data
280 * and to receive para_server's output, if any.
281 *
282 * \sa struct sched, struct task.
283 */
284 static int client_post_select(struct sched *s, struct task *t)
285 {
286 struct client_task *ct = container_of(t, struct client_task, task);
287 int ret = 0;
288 size_t n;
289 char buf[CLIENT_BUFSIZE];
290
291 ret = task_get_notification(t);
292 if (ret < 0)
293 goto out;
294 if (ct->scc.fd < 0)
295 return 0;
296 switch (ct->status) {
297 case CL_CONNECTED: /* receive welcome message */
298 ret = read_nonblock(ct->scc.fd, buf, sizeof(buf), &s->rfds, &n);
299 if (ret < 0 || n == 0)
300 goto out;
301 ct->features = parse_features(buf);
302 if (!has_feature("sideband", ct)) {
303 PARA_ERROR_LOG("server has no sideband support\n");
304 ret = -E_INCOMPAT_FEAT;
305 goto out;
306 }
307 ct->status = CL_RECEIVED_WELCOME;
308 return 0;
309 case CL_RECEIVED_WELCOME: /* send auth command */
310 if (!FD_ISSET(ct->scc.fd, &s->wfds))
311 return 0;
312 sprintf(buf, AUTH_REQUEST_MSG "%s sideband%s", ct->user,
313 has_feature("aes_ctr128", ct)? ",aes_ctr128" : "");
314 PARA_INFO_LOG("--> %s\n", buf);
315 ret = write_buffer(ct->scc.fd, buf);
316 if (ret < 0)
317 goto out;
318 ct->status = CL_SENT_AUTH;
319 return 0;
320 case CL_SENT_AUTH:
321 /*
322 * Receive challenge and session keys, decrypt the challenge and
323 * send back the hash of the decrypted challenge.
324 */
325 {
326 /* decrypted challenge/session key buffer */
327 unsigned char crypt_buf[1024];
328 struct sb_buffer sbb;
329 bool use_aes;
330
331 ret = recv_sb(ct, &s->rfds, &sbb);
332 if (ret <= 0)
333 goto out;
334 if (sbb.band != SBD_CHALLENGE) {
335 ret = -E_BAD_BAND;
336 free(sbb.iov.iov_base);
337 goto out;
338 }
339 n = sbb.iov.iov_len;
340 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
341 ret = priv_decrypt(ct->key_file, crypt_buf,
342 sbb.iov.iov_base, n);
343 free(sbb.iov.iov_base);
344 if (ret < 0)
345 goto out;
346 ct->challenge_hash = para_malloc(HASH_SIZE);
347 hash_function((char *)crypt_buf, CHALLENGE_SIZE, ct->challenge_hash);
348 use_aes = has_feature("aes_ctr128", ct);
349 ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN, use_aes);
350 ct->scc.recv = sc_new(crypt_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
351 SESSION_KEY_LEN, use_aes);
352 hash_to_asc(ct->challenge_hash, buf);
353 PARA_INFO_LOG("--> %s\n", buf);
354 ct->status = CL_RECEIVED_CHALLENGE;
355 return 0;
356 }
357 case CL_RECEIVED_CHALLENGE:
358 ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
359 SBD_CHALLENGE_RESPONSE, false);
360 if (ret != 0)
361 ct->challenge_hash = NULL;
362 if (ret <= 0)
363 goto out;
364 ct->status = CL_SENT_CH_RESPONSE;
365 goto out;
366 case CL_SENT_CH_RESPONSE: /* read server response */
367 {
368 struct sb_buffer sbb;
369 ret = recv_sb(ct, &s->rfds, &sbb);
370 if (ret <= 0)
371 goto out;
372 free(sbb.iov.iov_base);
373 if (sbb.band != SBD_PROCEED)
374 ret = -E_BAD_BAND;
375 else
376 ct->status = CL_RECEIVED_PROCEED;
377 goto out;
378 }
379 case CL_RECEIVED_PROCEED: /* concat args and send command */
380 {
381 if (!FD_ISSET(ct->scc.fd, &s->wfds))
382 return 0;
383 ret = send_sb_command(ct);
384 if (ret <= 0)
385 goto out;
386 ct->status = CL_EXECUTING;
387 return 0;
388 }
389 case CL_SENDING:
390 if (ct->btrn[1]) {
391 char *buf2;
392 size_t sz;
393 ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
394 if (ret == -E_BTR_EOF) {
395 /* empty blob data packet indicates EOF */
396 PARA_INFO_LOG("blob sent\n");
397 ret = send_sb(ct, 1, NULL, 0, SBD_BLOB_DATA, true);
398 if (ret >= 0)
399 ret = -E_BTR_EOF;
400 }
401 if (ret < 0)
402 goto close1;
403 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->wfds)) {
404 sz = btr_next_buffer(ct->btrn[1], &buf2);
405 assert(sz);
406 ret = send_sb(ct, 1, buf2, sz, SBD_BLOB_DATA, true);
407 if (ret < 0)
408 goto close1;
409 if (ret > 0)
410 btr_consume(ct->btrn[1], sz);
411 }
412 }
413 /* fall though */
414 case CL_EXECUTING:
415 if (ct->btrn[0]) {
416 ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
417 if (ret < 0)
418 goto close0;
419 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->rfds)) {
420 struct sb_buffer sbb;
421 ret = recv_sb(ct, &s->rfds, &sbb);
422 if (ret < 0)
423 goto close0;
424 if (ret > 0) {
425 ret = dispatch_sbb(ct, &sbb);
426 if (ret < 0)
427 goto close0;
428 }
429 }
430 }
431 ret = 0;
432 goto out;
433 }
434 close1:
435 PARA_INFO_LOG("channel 1: %s\n", para_strerror(-ret));
436 btr_remove_node(&ct->btrn[1]);
437 if (ct->btrn[0])
438 return 0;
439 goto out;
440 close0:
441 PARA_INFO_LOG("channel 0: %s\n", para_strerror(-ret));
442 btr_remove_node(&ct->btrn[0]);
443 if (ct->btrn[1] && ct->status == CL_SENDING)
444 return 0;
445 out:
446 if (ret >= 0)
447 return 0;
448 btr_remove_node(&ct->btrn[0]);
449 btr_remove_node(&ct->btrn[1]);
450 if (ret != -E_SERVER_CMD_SUCCESS && ret != -E_SERVER_CMD_FAILURE)
451 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
452 if (ct->scc.fd >= 0) {
453 close(ct->scc.fd);
454 ct->scc.fd = -1;
455 }
456 free_argv(ct->features);
457 ct->features = NULL;
458 sc_free(ct->scc.recv);
459 ct->scc.recv = NULL;
460 sc_free(ct->scc.send);
461 ct->scc.send = NULL;
462 return ret;
463 }
464
465 /**
466 * Connect to para_server and register the client task.
467 *
468 * \param ct The initialized client task structure.
469 * \param s The scheduler instance to register the client task to.
470 * \param parent The parent node of the client btr node.
471 * \param child The child node of the client node.
472 *
473 * The client task structure given by \a ct must be allocated and initialized
474 * by \ref client_parse_config() before this function is called.
475 *
476 * \return Standard.
477 */
478 int client_connect(struct client_task *ct, struct sched *s,
479 struct btr_node *parent, struct btr_node *child)
480 {
481 int ret;
482
483 PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
484 ct->conf.server_port_arg);
485 ct->scc.fd = -1;
486 ret = para_connect_simple(IPPROTO_TCP, ct->conf.hostname_arg,
487 ct->conf.server_port_arg);
488 if (ret < 0)
489 return ret;
490 ct->scc.fd = ret;
491 ret = mark_fd_nonblocking(ct->scc.fd);
492 if (ret < 0)
493 goto err_out;
494 ct->status = CL_CONNECTED;
495 ct->btrn[0] = btr_new_node(&(struct btr_node_description)
496 EMBRACE(.name = "client recv", .parent = NULL, .child = child));
497 ct->btrn[1] = btr_new_node(&(struct btr_node_description)
498 EMBRACE(.name = "client send", .parent = parent, .child = NULL));
499 ct->task.pre_select = client_pre_select;
500 ct->task.post_select = client_post_select;
501 ct->task.error = 0;
502 sprintf(ct->task.status, "client");
503 register_task(s, &ct->task);
504 return 1;
505 err_out:
506 close(ct->scc.fd);
507 ct->scc.fd = -1;
508 return ret;
509 }
510
511 __noreturn static void print_help_and_die(struct client_task *ct)
512 {
513 struct ggo_help h = DEFINE_GGO_HELP(client);
514 bool d = ct->conf.detailed_help_given;
515
516 ggo_print_help(&h, d? GPH_STANDARD_FLAGS_DETAILED : GPH_STANDARD_FLAGS);
517 exit(0);
518 }
519
520 /**
521 * Parse a client configuration.
522 *
523 * \param argc Usual argument count.
524 * \param argv Usual argument vector.
525 * \param ct_ptr Filled in by this function.
526 * \param loglevel If not \p NULL, the number of the loglevel is stored here.
527 *
528 * This checks the command line options given by \a argc and \a argv, sets
529 * default values for the user name and the name of the rsa key file and reads
530 * further options from the config file.
531 *
532 * Upon successful return, \a ct_ptr points to a dynamically allocated and
533 * initialized client task struct.
534 *
535 * \return The number of non-option arguments in \a argc/argv on success,
536 * negative on errors.
537 */
538 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
539 int *loglevel)
540 {
541 char *home = para_homedir();
542 int ret;
543 struct client_task *ct = para_calloc(sizeof(struct client_task));
544
545 *ct_ptr = ct;
546 ct->scc.fd = -1;
547 ret = -E_CLIENT_SYNTAX;
548 if (client_cmdline_parser(argc, argv, &ct->conf))
549 goto out;
550 version_handle_flag("client", ct->conf.version_given);
551 if (ct->conf.help_given || ct->conf.detailed_help_given)
552 print_help_and_die(ct);
553
554 ct->config_file = ct->conf.config_file_given?
555 para_strdup(ct->conf.config_file_arg) :
556 make_message("%s/.paraslash/client.conf", home);
557 ret = file_exists(ct->config_file);
558 if (!ret && ct->conf.config_file_given) {
559 ret = -E_NO_CONFIG;
560 goto out;
561 }
562 if (ret) {
563 struct client_cmdline_parser_params params = {
564 .override = 0,
565 .initialize = 0,
566 .check_required = 0,
567 .check_ambiguity = 0,
568 .print_errors = 0
569 };
570 ret = -E_BAD_CONFIG;
571 if (client_cmdline_parser_config_file(ct->config_file,
572 &ct->conf, &params))
573 goto out;
574 }
575 ct->user = ct->conf.user_given?
576 para_strdup(ct->conf.user_arg) : para_logname();
577
578 if (ct->conf.key_file_given)
579 ct->key_file = para_strdup(ct->conf.key_file_arg);
580 else {
581 ct->key_file = make_message("%s/.paraslash/key.%s",
582 home, ct->user);
583 if (!file_exists(ct->key_file)) {
584 free(ct->key_file);
585 ct->key_file = make_message("%s/.ssh/id_rsa", home);
586 }
587 }
588
589 if (loglevel)
590 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
591 PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
592 PARA_INFO_LOG("config_file: %s\n", ct->config_file);
593 PARA_INFO_LOG("key_file: %s\n", ct->key_file);
594 ret = ct->conf.inputs_num;
595 out:
596 free(home);
597 if (ret < 0) {
598 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
599 client_close(ct);
600 *ct_ptr = NULL;
601 }
602 return ret;
603 }
604
605 /**
606 * Parse the client configuration and open a connection to para_server.
607 *
608 * \param argc See \ref client_parse_config.
609 * \param argv See \ref client_parse_config.
610 * \param ct_ptr See \ref client_parse_config.
611 * \param loglevel See \ref client_parse_config.
612 * \param parent See \ref client_connect().
613 * \param child See \ref client_connect().
614 * \param sched See \ref client_connect().
615 *
616 * This function combines client_parse_config() and client_connect(). It is
617 * considered a syntax error if no command was given, i.e. if the number
618 * of non-option arguments is zero.
619 *
620 * \return Standard.
621 */
622 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
623 int *loglevel, struct btr_node *parent, struct btr_node *child,
624 struct sched *sched)
625 {
626 int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
627
628 if (ret < 0)
629 return ret;
630 if (ret == 0) {
631 ret = -E_CLIENT_SYNTAX;
632 goto fail;
633 }
634 ret = client_connect(*ct_ptr, sched, parent, child);
635 if (ret < 0)
636 goto fail;
637 return 1;
638 fail:
639 client_close(*ct_ptr);
640 *ct_ptr = NULL;
641 return ret;
642 }