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