net: Remove networking headers from para.h.
[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 <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", ct->user);
340 PARA_INFO_LOG("--> %s\n", buf);
341 ret = write_buffer(ct->scc.fd, buf);
342 if (ret < 0)
343 goto out;
344 ct->status = CL_SENT_AUTH;
345 return 0;
346 case CL_SENT_AUTH:
347 /*
348 * Receive challenge and session keys, decrypt the challenge and
349 * send back the hash of the decrypted challenge.
350 */
351 {
352 /* decrypted challenge/session key buffer */
353 unsigned char crypt_buf[1024];
354 struct sb_buffer sbb;
355
356 ret = recv_sb(ct, &s->rfds, &sbb);
357 if (ret <= 0)
358 goto out;
359 if (sbb.band != SBD_CHALLENGE) {
360 ret = -E_BAD_BAND;
361 free(sbb.iov.iov_base);
362 goto out;
363 }
364 n = sbb.iov.iov_len;
365 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
366 ret = priv_decrypt(ct->key_file, crypt_buf,
367 sbb.iov.iov_base, n);
368 free(sbb.iov.iov_base);
369 if (ret < 0)
370 goto out;
371 ct->challenge_hash = para_malloc(HASH_SIZE);
372 hash_function((char *)crypt_buf, CHALLENGE_SIZE, ct->challenge_hash);
373 ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN);
374 ct->scc.recv = sc_new(crypt_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
375 SESSION_KEY_LEN);
376 hash_to_asc(ct->challenge_hash, buf);
377 PARA_INFO_LOG("--> %s\n", buf);
378 ct->status = CL_RECEIVED_CHALLENGE;
379 return 0;
380 }
381 case CL_RECEIVED_CHALLENGE:
382 ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
383 SBD_CHALLENGE_RESPONSE, false);
384 if (ret != 0)
385 ct->challenge_hash = NULL;
386 if (ret <= 0)
387 goto out;
388 ct->status = CL_SENT_CH_RESPONSE;
389 goto out;
390 case CL_SENT_CH_RESPONSE: /* read server response */
391 {
392 struct sb_buffer sbb;
393 ret = recv_sb(ct, &s->rfds, &sbb);
394 if (ret <= 0)
395 goto out;
396 free(sbb.iov.iov_base);
397 if (sbb.band != SBD_PROCEED)
398 ret = -E_BAD_BAND;
399 else
400 ct->status = CL_RECEIVED_PROCEED;
401 goto out;
402 }
403 case CL_RECEIVED_PROCEED: /* concat args and send command */
404 {
405 if (!FD_ISSET(ct->scc.fd, &s->wfds))
406 return 0;
407 ret = send_sb_command(ct);
408 if (ret <= 0)
409 goto out;
410 ct->status = CL_EXECUTING;
411 return 0;
412 }
413 case CL_SENDING:
414 if (ct->btrn[1]) {
415 char *buf2;
416 size_t sz;
417 ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
418 if (ret == -E_BTR_EOF) {
419 /* empty blob data packet indicates EOF */
420 PARA_INFO_LOG("blob sent\n");
421 ret = send_sb(ct, 1, NULL, 0, SBD_BLOB_DATA, true);
422 if (ret >= 0)
423 ret = -E_BTR_EOF;
424 }
425 if (ret < 0)
426 goto close1;
427 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->wfds)) {
428 sz = btr_next_buffer(ct->btrn[1], &buf2);
429 assert(sz);
430 ret = send_sb(ct, 1, buf2, sz, SBD_BLOB_DATA, true);
431 if (ret < 0)
432 goto close1;
433 if (ret > 0)
434 btr_consume(ct->btrn[1], sz);
435 }
436 }
437 /* fall though */
438 case CL_EXECUTING:
439 if (ct->btrn[0]) {
440 ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
441 if (ret < 0)
442 goto close0;
443 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->rfds)) {
444 struct sb_buffer sbb;
445 ret = recv_sb(ct, &s->rfds, &sbb);
446 if (ret < 0)
447 goto close0;
448 if (ret > 0) {
449 ret = dispatch_sbb(ct, &sbb);
450 if (ret < 0)
451 goto close0;
452 }
453 }
454 }
455 ret = 0;
456 goto out;
457 }
458 close1:
459 PARA_INFO_LOG("channel 1: %s\n", para_strerror(-ret));
460 btr_remove_node(&ct->btrn[1]);
461 if (ct->btrn[0])
462 return 0;
463 goto out;
464 close0:
465 PARA_INFO_LOG("channel 0: %s\n", para_strerror(-ret));
466 btr_remove_node(&ct->btrn[0]);
467 if (ct->btrn[1] && ct->status == CL_SENDING)
468 return 0;
469 out:
470 if (ret >= 0)
471 return 0;
472 btr_remove_node(&ct->btrn[0]);
473 btr_remove_node(&ct->btrn[1]);
474 if (ret != -E_SERVER_CMD_SUCCESS && ret != -E_SERVER_CMD_FAILURE)
475 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
476 return ret;
477 }
478
479 /**
480 * Connect to para_server and register the client task.
481 *
482 * \param ct The initialized client task structure.
483 * \param s The scheduler instance to register the client task to.
484 * \param parent The parent node of the client btr node.
485 * \param child The child node of the client node.
486 *
487 * The client task structure given by \a ct must be allocated and initialized
488 * by \ref client_parse_config() before this function is called.
489 *
490 * \return Standard.
491 */
492 int client_connect(struct client_task *ct, struct sched *s,
493 struct btr_node *parent, struct btr_node *child)
494 {
495 int ret;
496
497 PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
498 ct->conf.server_port_arg);
499 ct->scc.fd = -1;
500 ret = para_connect_simple(IPPROTO_TCP, ct->conf.hostname_arg,
501 ct->conf.server_port_arg);
502 if (ret < 0)
503 return ret;
504 ct->scc.fd = ret;
505 ret = mark_fd_nonblocking(ct->scc.fd);
506 if (ret < 0)
507 goto err_out;
508 ct->status = CL_CONNECTED;
509 ct->btrn[0] = btr_new_node(&(struct btr_node_description)
510 EMBRACE(.name = "client recv", .parent = NULL, .child = child));
511 ct->btrn[1] = btr_new_node(&(struct btr_node_description)
512 EMBRACE(.name = "client send", .parent = parent, .child = NULL));
513 ct->task.pre_select = client_pre_select;
514 ct->task.post_select = client_post_select;
515 ct->task.error = 0;
516 sprintf(ct->task.status, "client");
517 register_task(s, &ct->task);
518 return 1;
519 err_out:
520 close(ct->scc.fd);
521 ct->scc.fd = -1;
522 return ret;
523 }
524
525 __noreturn static void print_help_and_die(struct client_task *ct)
526 {
527 struct ggo_help h = DEFINE_GGO_HELP(client);
528 bool d = ct->conf.detailed_help_given;
529
530 ggo_print_help(&h, d? GPH_STANDARD_FLAGS_DETAILED : GPH_STANDARD_FLAGS);
531 exit(0);
532 }
533
534 /**
535 * Parse a client configuration.
536 *
537 * \param argc Usual argument count.
538 * \param argv Usual argument vector.
539 * \param ct_ptr Filled in by this function.
540 * \param loglevel If not \p NULL, the number of the loglevel is stored here.
541 *
542 * This checks the command line options given by \a argc and \a argv, sets
543 * default values for the user name and the name of the rsa key file and reads
544 * further options from the config file.
545 *
546 * Upon successful return, \a ct_ptr points to a dynamically allocated and
547 * initialized client task struct.
548 *
549 * \return The number of non-option arguments in \a argc/argv on success,
550 * negative on errors.
551 */
552 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
553 int *loglevel)
554 {
555 char *home = para_homedir();
556 int ret;
557 struct client_task *ct = para_calloc(sizeof(struct client_task));
558
559 *ct_ptr = ct;
560 ct->scc.fd = -1;
561 ret = -E_CLIENT_SYNTAX;
562 if (client_cmdline_parser(argc, argv, &ct->conf))
563 goto out;
564 version_handle_flag("client", ct->conf.version_given);
565 if (ct->conf.help_given || ct->conf.detailed_help_given)
566 print_help_and_die(ct);
567
568 ct->config_file = ct->conf.config_file_given?
569 para_strdup(ct->conf.config_file_arg) :
570 make_message("%s/.paraslash/client.conf", home);
571 ret = file_exists(ct->config_file);
572 if (!ret && ct->conf.config_file_given) {
573 ret = -E_NO_CONFIG;
574 goto out;
575 }
576 if (ret) {
577 struct client_cmdline_parser_params params = {
578 .override = 0,
579 .initialize = 0,
580 .check_required = 0,
581 .check_ambiguity = 0,
582 .print_errors = 0
583 };
584 ret = -E_BAD_CONFIG;
585 if (client_cmdline_parser_config_file(ct->config_file,
586 &ct->conf, &params))
587 goto out;
588 }
589 ct->user = ct->conf.user_given?
590 para_strdup(ct->conf.user_arg) : para_logname();
591
592 if (ct->conf.key_file_given)
593 ct->key_file = para_strdup(ct->conf.key_file_arg);
594 else {
595 ct->key_file = make_message("%s/.paraslash/key.%s",
596 home, ct->user);
597 if (!file_exists(ct->key_file)) {
598 free(ct->key_file);
599 ct->key_file = make_message("%s/.ssh/id_rsa", home);
600 }
601 }
602
603 if (loglevel)
604 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
605 PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
606 PARA_INFO_LOG("config_file: %s\n", ct->config_file);
607 PARA_INFO_LOG("key_file: %s\n", ct->key_file);
608 ret = ct->conf.inputs_num;
609 out:
610 free(home);
611 if (ret < 0) {
612 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
613 client_close(ct);
614 *ct_ptr = NULL;
615 }
616 return ret;
617 }
618
619 /**
620 * Parse the client configuration and open a connection to para_server.
621 *
622 * \param argc See \ref client_parse_config.
623 * \param argv See \ref client_parse_config.
624 * \param ct_ptr See \ref client_parse_config.
625 * \param loglevel See \ref client_parse_config.
626 * \param parent See \ref client_connect().
627 * \param child See \ref client_connect().
628 * \param sched See \ref client_connect().
629 *
630 * This function combines client_parse_config() and client_connect(). It is
631 * considered a syntax error if no command was given, i.e. if the number
632 * of non-option arguments is zero.
633 *
634 * \return Standard.
635 */
636 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
637 int *loglevel, struct btr_node *parent, struct btr_node *child,
638 struct sched *sched)
639 {
640 int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
641
642 if (ret < 0)
643 return ret;
644 if (ret == 0) {
645 ret = -E_CLIENT_SYNTAX;
646 goto fail;
647 }
648 ret = client_connect(*ct_ptr, sched, parent, child);
649 if (ret < 0)
650 goto fail;
651 return 1;
652 fail:
653 client_close(*ct_ptr);
654 *ct_ptr = NULL;
655 return ret;
656 }