Merge branch 't/misc'
[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 deallocate per-command resources.
37 *
38 * \param ct The client task.
39 *
40 * This frees all resources of the current command but keeps the configuration
41 * in \p ct->conf.
42 *
43 * \sa \ref client_close().
44 */
45 void client_disconnect(struct client_task *ct)
46 {
47 if (!ct)
48 return;
49 if (ct->scc.fd >= 0)
50 close(ct->scc.fd);
51 free_argv(ct->features);
52 ct->features = NULL;
53 sc_free(ct->scc.recv);
54 ct->scc.recv = NULL;
55 sc_free(ct->scc.send);
56 ct->scc.send = NULL;
57 btr_remove_node(&ct->btrn[0]);
58 btr_remove_node(&ct->btrn[1]);
59 }
60
61 /**
62 * Close the connection to para_server and free all resources.
63 *
64 * \param ct Pointer to the client data.
65 *
66 * \sa \ref client_open(), \ref client_disconnect().
67 */
68 void client_close(struct client_task *ct)
69 {
70 if (!ct)
71 return;
72 client_disconnect(ct);
73 free(ct->user);
74 free(ct->config_file);
75 free(ct->key_file);
76 client_cmdline_parser_free(&ct->conf);
77 free(ct->challenge_hash);
78 sb_free(ct->sbc[0]);
79 sb_free(ct->sbc[1]);
80 free(ct);
81 }
82
83 /**
84 * The preselect hook for server commands.
85 *
86 * \param s Pointer to the scheduler.
87 * \param t Pointer to the task struct for this command.
88 *
89 * The task pointer must contain a pointer to the initialized client data
90 * structure as it is returned by client_open().
91 *
92 * This function checks the state of the connection and adds the file descriptor
93 * of the connection to the read or write fd set of \a s accordingly.
94 *
95 * \sa register_task() client_open(), struct sched, struct task.
96 */
97 static void client_pre_select(struct sched *s, struct task *t)
98 {
99 int ret;
100 struct client_task *ct = container_of(t, struct client_task, task);
101
102 if (ct->scc.fd < 0)
103 return;
104 switch (ct->status) {
105 case CL_CONNECTED:
106 case CL_SENT_AUTH:
107 case CL_SENT_CH_RESPONSE:
108 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
109 return;
110
111 case CL_RECEIVED_WELCOME:
112 case CL_RECEIVED_PROCEED:
113 case CL_RECEIVED_CHALLENGE:
114 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
115 return;
116
117 case CL_SENDING:
118 if (ct->btrn[1]) {
119 ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
120 if (ret < 0)
121 sched_min_delay(s);
122 else if (ret > 0)
123 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
124 }
125 /* fall though */
126 case CL_EXECUTING:
127 if (ct->btrn[0]) {
128 ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
129 if (ret < 0)
130 sched_min_delay(s);
131 else if (ret > 0)
132 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
133 }
134 return;
135 }
136 }
137
138 static int send_sb(struct client_task *ct, int channel, void *buf, size_t numbytes,
139 enum sb_designator band, bool dont_free)
140 {
141 int ret, fd = ct->scc.fd;
142 struct iovec iov[2];
143
144 if (!ct->sbc[channel]) {
145 struct sb_buffer sbb;
146 sb_transformation trafo = ct->status < CL_RECEIVED_PROCEED?
147 NULL : sc_trafo;
148 sbb = (typeof(sbb))SBB_INIT(band, buf, numbytes);
149 ct->sbc[channel] = sb_new_send(&sbb, dont_free, trafo, ct->scc.send);
150 }
151 ret = sb_get_send_buffers(ct->sbc[channel], iov);
152 ret = xwritev(fd, iov, ret);
153 if (ret < 0) {
154 sb_free(ct->sbc[channel]);
155 ct->sbc[channel] = NULL;
156 return ret;
157 }
158 if (sb_sent(ct->sbc[channel], ret)) {
159 ct->sbc[channel] = NULL;
160 return 1;
161 }
162 return 0;
163 }
164
165 static int recv_sb(struct client_task *ct, fd_set *rfds,
166 struct sb_buffer *result)
167 {
168 int ret;
169 size_t n;
170 sb_transformation trafo;
171 void *trafo_context;
172 struct iovec iov;
173
174 if (!FD_ISSET(ct->scc.fd, rfds))
175 return 0;
176 if (ct->status < CL_SENT_CH_RESPONSE)
177 trafo = trafo_context = NULL;
178 else {
179 trafo = sc_trafo;
180 trafo_context = ct->scc.recv;
181 }
182 if (!ct->sbc[0])
183 ct->sbc[0] = sb_new_recv(0, trafo, trafo_context);
184 again:
185 sb_get_recv_buffer(ct->sbc[0], &iov);
186 ret = read_nonblock(ct->scc.fd, iov.iov_base, iov.iov_len, rfds, &n);
187 if (ret < 0) {
188 sb_free(ct->sbc[0]);
189 ct->sbc[0] = NULL;
190 return ret;
191 }
192 if (n == 0)
193 return 0;
194 if (!sb_received(ct->sbc[0], n, result))
195 goto again;
196 ct->sbc[0] = NULL;
197 return 1;
198 }
199
200
201 static char **parse_features(char *buf)
202 {
203 int i;
204 const char id[] = "\nFeatures: ";
205 char *p, *q, **features;
206
207 p = strstr(buf, id);
208 if (!p)
209 return NULL;
210 p += strlen(id);
211 q = strchr(p, '\n');
212 if (!q)
213 return NULL;
214 *q = '\0';
215 create_argv(p, ",", &features);
216 for (i = 0; features[i]; i++)
217 PARA_INFO_LOG("server feature: %s\n", features[i]);
218 return features;
219 }
220
221 static int dispatch_sbb(struct client_task *ct, struct sb_buffer *sbb)
222 {
223 int ret;
224 const char *designator[] = {SB_DESIGNATORS_ARRAY};
225
226 if (!sbb)
227 return 0;
228 if (sbb->band < NUM_SB_DESIGNATORS)
229 PARA_DEBUG_LOG("band: %s\n", designator[sbb->band]);
230
231 switch (sbb->band) {
232 case SBD_AWAITING_DATA:
233 ct->status = CL_SENDING;
234 ret = 1;
235 goto out;
236 case SBD_OUTPUT:
237 if (iov_valid(&sbb->iov))
238 btr_add_output(sbb->iov.iov_base, sbb->iov.iov_len,
239 ct->btrn[0]);
240 ret = 1;
241 goto out;
242 case SBD_DEBUG_LOG:
243 case SBD_INFO_LOG:
244 case SBD_NOTICE_LOG:
245 case SBD_WARNING_LOG:
246 case SBD_ERROR_LOG:
247 case SBD_CRIT_LOG:
248 case SBD_EMERG_LOG:
249 if (iov_valid(&sbb->iov)) {
250 int ll = sbb->band - SBD_DEBUG_LOG;
251 para_log(ll, "remote: %s", (char *)sbb->iov.iov_base);
252 }
253 ret = 1;
254 goto deallocate;
255 case SBD_EXIT__SUCCESS:
256 ret = -E_SERVER_CMD_SUCCESS;
257 goto deallocate;
258 case SBD_EXIT__FAILURE:
259 ret = -E_SERVER_CMD_FAILURE;
260 goto deallocate;
261 default:
262 PARA_ERROR_LOG("invalid band %d\n", sbb->band);
263 ret = -E_BAD_BAND;
264 goto deallocate;
265 }
266 deallocate:
267 free(sbb->iov.iov_base);
268 out:
269 sbb->iov.iov_base = NULL;
270 return ret;
271 }
272
273 static bool has_feature(const char *feature, struct client_task *ct)
274 {
275 return find_arg(feature, ct->features) >= 0? true : false;
276 }
277
278 static int send_sb_command(struct client_task *ct)
279 {
280 int i;
281 char *command, *p;
282 size_t len = 0;
283
284 if (ct->sbc[1])
285 return send_sb(ct, 0, NULL, 0, 0, false);
286
287 for (i = 0; i < ct->conf.inputs_num; i++)
288 len += strlen(ct->conf.inputs[i]) + 1;
289 p = command = para_malloc(len);
290 for (i = 0; i < ct->conf.inputs_num; i++) {
291 strcpy(p, ct->conf.inputs[i]);
292 p += strlen(ct->conf.inputs[i]) + 1;
293 }
294 PARA_DEBUG_LOG("--> %s\n", command);
295 return send_sb(ct, 0, command, len, SBD_COMMAND, false);
296 }
297
298 /**
299 * The post select hook for client commands.
300 *
301 * \param s Pointer to the scheduler.
302 * \param t Pointer to the task struct for this command.
303 *
304 * Depending on the current state of the connection and the status of the read
305 * and write fd sets of \a s, this function performs the necessary steps to
306 * authenticate the connection, to send the command given by \a t->private_data
307 * and to receive para_server's output, if any.
308 *
309 * \sa struct sched, struct task.
310 */
311 static int client_post_select(struct sched *s, struct task *t)
312 {
313 struct client_task *ct = container_of(t, struct client_task, task);
314 int ret = 0;
315 size_t n;
316 char buf[CLIENT_BUFSIZE];
317
318 ret = task_get_notification(t);
319 if (ret < 0)
320 goto out;
321 if (ct->scc.fd < 0)
322 return 0;
323 switch (ct->status) {
324 case CL_CONNECTED: /* receive welcome message */
325 ret = read_nonblock(ct->scc.fd, buf, sizeof(buf), &s->rfds, &n);
326 if (ret < 0 || n == 0)
327 goto out;
328 ct->features = parse_features(buf);
329 if (!has_feature("sideband", ct)) {
330 PARA_ERROR_LOG("server has no sideband support\n");
331 ret = -E_INCOMPAT_FEAT;
332 goto out;
333 }
334 ct->status = CL_RECEIVED_WELCOME;
335 return 0;
336 case CL_RECEIVED_WELCOME: /* send auth command */
337 if (!FD_ISSET(ct->scc.fd, &s->wfds))
338 return 0;
339 sprintf(buf, AUTH_REQUEST_MSG "%s sideband%s", ct->user,
340 has_feature("aes_ctr128", ct)? ",aes_ctr128" : "");
341 PARA_INFO_LOG("--> %s\n", buf);
342 ret = write_buffer(ct->scc.fd, buf);
343 if (ret < 0)
344 goto out;
345 ct->status = CL_SENT_AUTH;
346 return 0;
347 case CL_SENT_AUTH:
348 /*
349 * Receive challenge and session keys, decrypt the challenge and
350 * send back the hash of the decrypted challenge.
351 */
352 {
353 /* decrypted challenge/session key buffer */
354 unsigned char crypt_buf[1024];
355 struct sb_buffer sbb;
356 bool use_aes;
357
358 ret = recv_sb(ct, &s->rfds, &sbb);
359 if (ret <= 0)
360 goto out;
361 if (sbb.band != SBD_CHALLENGE) {
362 ret = -E_BAD_BAND;
363 free(sbb.iov.iov_base);
364 goto out;
365 }
366 n = sbb.iov.iov_len;
367 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
368 ret = priv_decrypt(ct->key_file, crypt_buf,
369 sbb.iov.iov_base, n);
370 free(sbb.iov.iov_base);
371 if (ret < 0)
372 goto out;
373 ct->challenge_hash = para_malloc(HASH_SIZE);
374 hash_function((char *)crypt_buf, CHALLENGE_SIZE, ct->challenge_hash);
375 use_aes = has_feature("aes_ctr128", ct);
376 ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN, use_aes);
377 ct->scc.recv = sc_new(crypt_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
378 SESSION_KEY_LEN, use_aes);
379 hash_to_asc(ct->challenge_hash, buf);
380 PARA_INFO_LOG("--> %s\n", buf);
381 ct->status = CL_RECEIVED_CHALLENGE;
382 return 0;
383 }
384 case CL_RECEIVED_CHALLENGE:
385 ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
386 SBD_CHALLENGE_RESPONSE, false);
387 if (ret != 0)
388 ct->challenge_hash = NULL;
389 if (ret <= 0)
390 goto out;
391 ct->status = CL_SENT_CH_RESPONSE;
392 goto out;
393 case CL_SENT_CH_RESPONSE: /* read server response */
394 {
395 struct sb_buffer sbb;
396 ret = recv_sb(ct, &s->rfds, &sbb);
397 if (ret <= 0)
398 goto out;
399 free(sbb.iov.iov_base);
400 if (sbb.band != SBD_PROCEED)
401 ret = -E_BAD_BAND;
402 else
403 ct->status = CL_RECEIVED_PROCEED;
404 goto out;
405 }
406 case CL_RECEIVED_PROCEED: /* concat args and send command */
407 {
408 if (!FD_ISSET(ct->scc.fd, &s->wfds))
409 return 0;
410 ret = send_sb_command(ct);
411 if (ret <= 0)
412 goto out;
413 ct->status = CL_EXECUTING;
414 return 0;
415 }
416 case CL_SENDING:
417 if (ct->btrn[1]) {
418 char *buf2;
419 size_t sz;
420 ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
421 if (ret == -E_BTR_EOF) {
422 /* empty blob data packet indicates EOF */
423 PARA_INFO_LOG("blob sent\n");
424 ret = send_sb(ct, 1, NULL, 0, SBD_BLOB_DATA, true);
425 if (ret >= 0)
426 ret = -E_BTR_EOF;
427 }
428 if (ret < 0)
429 goto close1;
430 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->wfds)) {
431 sz = btr_next_buffer(ct->btrn[1], &buf2);
432 assert(sz);
433 ret = send_sb(ct, 1, buf2, sz, SBD_BLOB_DATA, true);
434 if (ret < 0)
435 goto close1;
436 if (ret > 0)
437 btr_consume(ct->btrn[1], sz);
438 }
439 }
440 /* fall though */
441 case CL_EXECUTING:
442 if (ct->btrn[0]) {
443 ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
444 if (ret < 0)
445 goto close0;
446 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->rfds)) {
447 struct sb_buffer sbb;
448 ret = recv_sb(ct, &s->rfds, &sbb);
449 if (ret < 0)
450 goto close0;
451 if (ret > 0) {
452 ret = dispatch_sbb(ct, &sbb);
453 if (ret < 0)
454 goto close0;
455 }
456 }
457 }
458 ret = 0;
459 goto out;
460 }
461 close1:
462 PARA_INFO_LOG("channel 1: %s\n", para_strerror(-ret));
463 btr_remove_node(&ct->btrn[1]);
464 if (ct->btrn[0])
465 return 0;
466 goto out;
467 close0:
468 PARA_INFO_LOG("channel 0: %s\n", para_strerror(-ret));
469 btr_remove_node(&ct->btrn[0]);
470 if (ct->btrn[1] && ct->status == CL_SENDING)
471 return 0;
472 out:
473 if (ret >= 0)
474 return 0;
475 btr_remove_node(&ct->btrn[0]);
476 btr_remove_node(&ct->btrn[1]);
477 if (ret != -E_SERVER_CMD_SUCCESS && ret != -E_SERVER_CMD_FAILURE)
478 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
479 return ret;
480 }
481
482 /**
483 * Connect to para_server and register the client task.
484 *
485 * \param ct The initialized client task structure.
486 * \param s The scheduler instance to register the client task to.
487 * \param parent The parent node of the client btr node.
488 * \param child The child node of the client node.
489 *
490 * The client task structure given by \a ct must be allocated and initialized
491 * by \ref client_parse_config() before this function is called.
492 *
493 * \return Standard.
494 */
495 int client_connect(struct client_task *ct, struct sched *s,
496 struct btr_node *parent, struct btr_node *child)
497 {
498 int ret;
499
500 PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
501 ct->conf.server_port_arg);
502 ct->scc.fd = -1;
503 ret = para_connect_simple(IPPROTO_TCP, ct->conf.hostname_arg,
504 ct->conf.server_port_arg);
505 if (ret < 0)
506 return ret;
507 ct->scc.fd = ret;
508 ret = mark_fd_nonblocking(ct->scc.fd);
509 if (ret < 0)
510 goto err_out;
511 ct->status = CL_CONNECTED;
512 ct->btrn[0] = btr_new_node(&(struct btr_node_description)
513 EMBRACE(.name = "client recv", .parent = NULL, .child = child));
514 ct->btrn[1] = btr_new_node(&(struct btr_node_description)
515 EMBRACE(.name = "client send", .parent = parent, .child = NULL));
516 ct->task.pre_select = client_pre_select;
517 ct->task.post_select = client_post_select;
518 ct->task.error = 0;
519 sprintf(ct->task.status, "client");
520 register_task(s, &ct->task);
521 return 1;
522 err_out:
523 close(ct->scc.fd);
524 ct->scc.fd = -1;
525 return ret;
526 }
527
528 __noreturn static void print_help_and_die(struct client_task *ct)
529 {
530 struct ggo_help h = DEFINE_GGO_HELP(client);
531 bool d = ct->conf.detailed_help_given;
532
533 ggo_print_help(&h, d? GPH_STANDARD_FLAGS_DETAILED : GPH_STANDARD_FLAGS);
534 exit(0);
535 }
536
537 /**
538 * Parse a client configuration.
539 *
540 * \param argc Usual argument count.
541 * \param argv Usual argument vector.
542 * \param ct_ptr Filled in by this function.
543 * \param loglevel If not \p NULL, the number of the loglevel is stored here.
544 *
545 * This checks the command line options given by \a argc and \a argv, sets
546 * default values for the user name and the name of the rsa key file and reads
547 * further options from the config file.
548 *
549 * Upon successful return, \a ct_ptr points to a dynamically allocated and
550 * initialized client task struct.
551 *
552 * \return The number of non-option arguments in \a argc/argv on success,
553 * negative on errors.
554 */
555 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
556 int *loglevel)
557 {
558 char *home = para_homedir();
559 int ret;
560 struct client_task *ct = para_calloc(sizeof(struct client_task));
561
562 *ct_ptr = ct;
563 ct->scc.fd = -1;
564 ret = -E_CLIENT_SYNTAX;
565 if (client_cmdline_parser(argc, argv, &ct->conf))
566 goto out;
567 version_handle_flag("client", ct->conf.version_given);
568 if (ct->conf.help_given || ct->conf.detailed_help_given)
569 print_help_and_die(ct);
570
571 ct->config_file = ct->conf.config_file_given?
572 para_strdup(ct->conf.config_file_arg) :
573 make_message("%s/.paraslash/client.conf", home);
574 ret = file_exists(ct->config_file);
575 if (!ret && ct->conf.config_file_given) {
576 ret = -E_NO_CONFIG;
577 goto out;
578 }
579 if (ret) {
580 struct client_cmdline_parser_params params = {
581 .override = 0,
582 .initialize = 0,
583 .check_required = 0,
584 .check_ambiguity = 0,
585 .print_errors = 0
586 };
587 ret = -E_BAD_CONFIG;
588 if (client_cmdline_parser_config_file(ct->config_file,
589 &ct->conf, &params))
590 goto out;
591 }
592 ct->user = ct->conf.user_given?
593 para_strdup(ct->conf.user_arg) : para_logname();
594
595 if (ct->conf.key_file_given)
596 ct->key_file = para_strdup(ct->conf.key_file_arg);
597 else {
598 ct->key_file = make_message("%s/.paraslash/key.%s",
599 home, ct->user);
600 if (!file_exists(ct->key_file)) {
601 free(ct->key_file);
602 ct->key_file = make_message("%s/.ssh/id_rsa", home);
603 }
604 }
605
606 if (loglevel)
607 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
608 PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
609 PARA_INFO_LOG("config_file: %s\n", ct->config_file);
610 PARA_INFO_LOG("key_file: %s\n", ct->key_file);
611 ret = ct->conf.inputs_num;
612 out:
613 free(home);
614 if (ret < 0) {
615 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
616 client_close(ct);
617 *ct_ptr = NULL;
618 }
619 return ret;
620 }
621
622 /**
623 * Parse the client configuration and open a connection to para_server.
624 *
625 * \param argc See \ref client_parse_config.
626 * \param argv See \ref client_parse_config.
627 * \param ct_ptr See \ref client_parse_config.
628 * \param loglevel See \ref client_parse_config.
629 * \param parent See \ref client_connect().
630 * \param child See \ref client_connect().
631 * \param sched See \ref client_connect().
632 *
633 * This function combines client_parse_config() and client_connect(). It is
634 * considered a syntax error if no command was given, i.e. if the number
635 * of non-option arguments is zero.
636 *
637 * \return Standard.
638 */
639 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
640 int *loglevel, struct btr_node *parent, struct btr_node *child,
641 struct sched *sched)
642 {
643 int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
644
645 if (ret < 0)
646 return ret;
647 if (ret == 0) {
648 ret = -E_CLIENT_SYNTAX;
649 goto fail;
650 }
651 ret = client_connect(*ct_ptr, sched, parent, child);
652 if (ret < 0)
653 goto fail;
654 return 1;
655 fail:
656 client_close(*ct_ptr);
657 *ct_ptr = NULL;
658 return ret;
659 }