Merge branch 'refs/heads/t/makefile_conventions'
[paraslash.git] / client_common.c
1 /*
2 * Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>
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 ret = sb_received(ct->sbc[0], n, result);
163 if (ret < 0)
164 return ret;
165 if (ret == 0)
166 goto again;
167 ct->sbc[0] = NULL;
168 return 1;
169 }
170
171
172 static char **parse_features(char *buf)
173 {
174 int i;
175 const char id[] = "\nFeatures: ";
176 char *p, *q, **features;
177
178 p = strstr(buf, id);
179 if (!p)
180 return NULL;
181 p += strlen(id);
182 q = strchr(p, '\n');
183 if (!q)
184 return NULL;
185 *q = '\0';
186 create_argv(p, ",", &features);
187 for (i = 0; features[i]; i++)
188 PARA_INFO_LOG("server feature: %s\n", features[i]);
189 return features;
190 }
191
192 static int dispatch_sbb(struct client_task *ct, struct sb_buffer *sbb)
193 {
194 int ret;
195 const char *designator[] = {SB_DESIGNATORS_ARRAY};
196
197 if (!sbb)
198 return 0;
199 if (sbb->band < NUM_SB_DESIGNATORS)
200 PARA_DEBUG_LOG("band: %s\n", designator[sbb->band]);
201
202 switch (sbb->band) {
203 case SBD_AWAITING_DATA:
204 ct->status = CL_SENDING;
205 ret = 1;
206 goto out;
207 case SBD_OUTPUT:
208 if (iov_valid(&sbb->iov))
209 btr_add_output(sbb->iov.iov_base, sbb->iov.iov_len,
210 ct->btrn[0]);
211 ret = 1;
212 goto out;
213 case SBD_DEBUG_LOG:
214 case SBD_INFO_LOG:
215 case SBD_NOTICE_LOG:
216 case SBD_WARNING_LOG:
217 case SBD_ERROR_LOG:
218 case SBD_CRIT_LOG:
219 case SBD_EMERG_LOG:
220 if (iov_valid(&sbb->iov)) {
221 int ll = sbb->band - SBD_DEBUG_LOG;
222 para_log(ll, "remote: %s", (char *)sbb->iov.iov_base);
223 }
224 ret = 1;
225 goto deallocate;
226 case SBD_EXIT__SUCCESS:
227 ret = -E_SERVER_CMD_SUCCESS;
228 goto deallocate;
229 case SBD_EXIT__FAILURE:
230 ret = -E_SERVER_CMD_FAILURE;
231 goto deallocate;
232 default:
233 PARA_ERROR_LOG("invalid band %d\n", sbb->band);
234 ret = -E_BAD_BAND;
235 goto deallocate;
236 }
237 deallocate:
238 free(sbb->iov.iov_base);
239 out:
240 sbb->iov.iov_base = NULL;
241 return ret;
242 }
243
244 static int send_sb_command(struct client_task *ct)
245 {
246 int i;
247 char *command, *p;
248 size_t len = 0;
249
250 if (ct->sbc[1])
251 return send_sb(ct, 0, NULL, 0, 0, false);
252
253 for (i = 0; i < ct->conf.inputs_num; i++)
254 len += strlen(ct->conf.inputs[i]) + 1;
255 p = command = para_malloc(len);
256 for (i = 0; i < ct->conf.inputs_num; i++) {
257 strcpy(p, ct->conf.inputs[i]);
258 p += strlen(ct->conf.inputs[i]) + 1;
259 }
260 PARA_DEBUG_LOG("--> %s\n", command);
261 return send_sb(ct, 0, command, len, SBD_COMMAND, false);
262 }
263
264 /*
265 * The post select hook for client commands.
266 *
267 * Depending on the current state of the connection and the status of the read
268 * and write fd sets of s, this function performs the necessary steps to
269 * authenticate the connection, to send the command given by t->private_data
270 * and to receive para_server's output, if any.
271 */
272 static int client_post_select(struct sched *s, void *context)
273 {
274 struct client_task *ct = context;
275 int ret = 0;
276 size_t n;
277 char buf[CLIENT_BUFSIZE];
278
279 ret = task_get_notification(ct->task);
280 if (ret < 0)
281 goto out;
282 if (ct->scc.fd < 0)
283 return 0;
284 switch (ct->status) {
285 case CL_CONNECTED: /* receive welcome message */
286 ret = read_nonblock(ct->scc.fd, buf, sizeof(buf), &s->rfds, &n);
287 if (ret < 0 || n == 0)
288 goto out;
289 ct->features = parse_features(buf);
290 ct->status = CL_RECEIVED_WELCOME;
291 return 0;
292 case CL_RECEIVED_WELCOME: /* send auth command */
293 if (!FD_ISSET(ct->scc.fd, &s->wfds))
294 return 0;
295 sprintf(buf, AUTH_REQUEST_MSG "%s sideband,aes_ctr128",
296 ct->user);
297 PARA_INFO_LOG("--> %s\n", buf);
298 ret = write_buffer(ct->scc.fd, buf);
299 if (ret < 0)
300 goto out;
301 ct->status = CL_SENT_AUTH;
302 return 0;
303 case CL_SENT_AUTH:
304 /*
305 * Receive challenge and session keys, decrypt the challenge and
306 * send back the hash of the decrypted challenge.
307 */
308 {
309 /* decrypted challenge/session key buffer */
310 unsigned char crypt_buf[1024];
311 struct sb_buffer sbb;
312
313 ret = recv_sb(ct, &s->rfds, &sbb);
314 if (ret <= 0)
315 goto out;
316 if (sbb.band != SBD_CHALLENGE) {
317 ret = -E_BAD_BAND;
318 free(sbb.iov.iov_base);
319 goto out;
320 }
321 n = sbb.iov.iov_len;
322 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
323 ret = priv_decrypt(ct->key_file, crypt_buf,
324 sbb.iov.iov_base, n);
325 free(sbb.iov.iov_base);
326 if (ret < 0)
327 goto out;
328 ct->challenge_hash = para_malloc(HASH_SIZE);
329 hash_function((char *)crypt_buf, CHALLENGE_SIZE, ct->challenge_hash);
330 ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN);
331 ct->scc.recv = sc_new(crypt_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
332 SESSION_KEY_LEN);
333 hash_to_asc(ct->challenge_hash, buf);
334 PARA_INFO_LOG("--> %s\n", buf);
335 ct->status = CL_RECEIVED_CHALLENGE;
336 return 0;
337 }
338 case CL_RECEIVED_CHALLENGE:
339 ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
340 SBD_CHALLENGE_RESPONSE, false);
341 if (ret != 0)
342 ct->challenge_hash = NULL;
343 if (ret <= 0)
344 goto out;
345 ct->status = CL_SENT_CH_RESPONSE;
346 goto out;
347 case CL_SENT_CH_RESPONSE: /* read server response */
348 {
349 struct sb_buffer sbb;
350 ret = recv_sb(ct, &s->rfds, &sbb);
351 if (ret <= 0)
352 goto out;
353 free(sbb.iov.iov_base);
354 if (sbb.band != SBD_PROCEED)
355 ret = -E_BAD_BAND;
356 else
357 ct->status = CL_RECEIVED_PROCEED;
358 goto out;
359 }
360 case CL_RECEIVED_PROCEED: /* concat args and send command */
361 {
362 if (!FD_ISSET(ct->scc.fd, &s->wfds))
363 return 0;
364 ret = send_sb_command(ct);
365 if (ret <= 0)
366 goto out;
367 ct->status = CL_EXECUTING;
368 return 0;
369 }
370 case CL_SENDING:
371 if (ct->btrn[1]) {
372 char *buf2;
373 size_t sz;
374 ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
375 if (ret == -E_BTR_EOF) {
376 /* empty blob data packet indicates EOF */
377 PARA_INFO_LOG("blob sent\n");
378 ret = send_sb(ct, 1, NULL, 0, SBD_BLOB_DATA, true);
379 if (ret >= 0)
380 ret = -E_BTR_EOF;
381 }
382 if (ret < 0)
383 goto close1;
384 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->wfds)) {
385 sz = btr_next_buffer(ct->btrn[1], &buf2);
386 assert(sz);
387 ret = send_sb(ct, 1, buf2, sz, SBD_BLOB_DATA, true);
388 if (ret < 0)
389 goto close1;
390 if (ret > 0)
391 btr_consume(ct->btrn[1], sz);
392 }
393 }
394 /* fall through */
395 case CL_EXECUTING:
396 if (ct->btrn[0]) {
397 ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
398 if (ret < 0)
399 goto close0;
400 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->rfds)) {
401 struct sb_buffer sbb;
402 ret = recv_sb(ct, &s->rfds, &sbb);
403 if (ret < 0)
404 goto close0;
405 if (ret > 0) {
406 ret = dispatch_sbb(ct, &sbb);
407 if (ret < 0)
408 goto close0;
409 }
410 }
411 }
412 ret = 0;
413 goto out;
414 }
415 close1:
416 PARA_INFO_LOG("channel 1: %s\n", para_strerror(-ret));
417 btr_remove_node(&ct->btrn[1]);
418 if (ct->btrn[0])
419 return 0;
420 goto out;
421 close0:
422 PARA_INFO_LOG("channel 0: %s\n", para_strerror(-ret));
423 btr_remove_node(&ct->btrn[0]);
424 if (ct->btrn[1] && ct->status == CL_SENDING)
425 return 0;
426 out:
427 if (ret >= 0)
428 return 0;
429 btr_remove_node(&ct->btrn[0]);
430 btr_remove_node(&ct->btrn[1]);
431 if (ret != -E_SERVER_CMD_SUCCESS && ret != -E_SERVER_CMD_FAILURE)
432 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
433 if (ct->scc.fd >= 0) {
434 close(ct->scc.fd);
435 ct->scc.fd = -1;
436 }
437 free_argv(ct->features);
438 ct->features = NULL;
439 sc_free(ct->scc.recv);
440 ct->scc.recv = NULL;
441 sc_free(ct->scc.send);
442 ct->scc.send = NULL;
443 return ret;
444 }
445
446 /**
447 * Connect to para_server and register the client task.
448 *
449 * \param ct The initialized client task structure.
450 * \param s The scheduler instance to register the client task to.
451 * \param parent The parent node of the client btr node.
452 * \param child The child node of the client node.
453 *
454 * The client task structure given by \a ct must be allocated and initialized
455 * by \ref client_parse_config() before this function is called.
456 *
457 * \return Standard.
458 */
459 int client_connect(struct client_task *ct, struct sched *s,
460 struct btr_node *parent, struct btr_node *child)
461 {
462 int ret;
463
464 PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
465 ct->conf.server_port_arg);
466 ct->scc.fd = -1;
467 ret = para_connect_simple(IPPROTO_TCP, ct->conf.hostname_arg,
468 ct->conf.server_port_arg);
469 if (ret < 0)
470 return ret;
471 ct->scc.fd = ret;
472 ret = mark_fd_nonblocking(ct->scc.fd);
473 if (ret < 0)
474 goto err_out;
475 ct->status = CL_CONNECTED;
476 ct->btrn[0] = btr_new_node(&(struct btr_node_description)
477 EMBRACE(.name = "client recv", .parent = NULL, .child = child));
478 ct->btrn[1] = btr_new_node(&(struct btr_node_description)
479 EMBRACE(.name = "client send", .parent = parent, .child = NULL));
480
481 ct->task = task_register(&(struct task_info) {
482 .name = "client",
483 .pre_select = client_pre_select,
484 .post_select = client_post_select,
485 .context = ct,
486 }, s);
487 return 1;
488 err_out:
489 close(ct->scc.fd);
490 ct->scc.fd = -1;
491 return ret;
492 }
493
494 __noreturn static void print_help_and_die(struct client_task *ct)
495 {
496 struct ggo_help h = DEFINE_GGO_HELP(client);
497 bool d = ct->conf.detailed_help_given;
498
499 ggo_print_help(&h, d? GPH_STANDARD_FLAGS_DETAILED : GPH_STANDARD_FLAGS);
500 exit(0);
501 }
502
503 /**
504 * Parse a client configuration.
505 *
506 * \param argc Usual argument count.
507 * \param argv Usual argument vector.
508 * \param ct_ptr Filled in by this function.
509 * \param loglevel If not \p NULL, the number of the loglevel is stored here.
510 *
511 * This checks the command line options given by \a argc and \a argv, sets
512 * default values for the user name and the name of the rsa key file and reads
513 * further options from the config file.
514 *
515 * Upon successful return, \a ct_ptr points to a dynamically allocated and
516 * initialized client task struct.
517 *
518 * \return The number of non-option arguments in \a argc/argv on success,
519 * negative on errors.
520 */
521 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
522 int *loglevel)
523 {
524 char *home = para_homedir();
525 int ret;
526 struct client_task *ct = para_calloc(sizeof(struct client_task));
527
528 *ct_ptr = ct;
529 ct->scc.fd = -1;
530 ret = -E_CLIENT_SYNTAX;
531 if (client_cmdline_parser(argc, argv, &ct->conf))
532 goto out;
533 version_handle_flag("client", ct->conf.version_given);
534 if (ct->conf.help_given || ct->conf.detailed_help_given)
535 print_help_and_die(ct);
536
537 ct->config_file = ct->conf.config_file_given?
538 para_strdup(ct->conf.config_file_arg) :
539 make_message("%s/.paraslash/client.conf", home);
540 ret = file_exists(ct->config_file);
541 if (!ret && ct->conf.config_file_given) {
542 ret = -E_NO_CONFIG;
543 goto out;
544 }
545 if (ret) {
546 struct client_cmdline_parser_params params = {
547 .override = 0,
548 .initialize = 0,
549 .check_required = 0,
550 .check_ambiguity = 0,
551 .print_errors = 0
552 };
553 ret = -E_BAD_CONFIG;
554 if (client_cmdline_parser_config_file(ct->config_file,
555 &ct->conf, &params))
556 goto out;
557 }
558 ct->user = ct->conf.user_given?
559 para_strdup(ct->conf.user_arg) : para_logname();
560
561 if (ct->conf.key_file_given)
562 ct->key_file = para_strdup(ct->conf.key_file_arg);
563 else {
564 ct->key_file = make_message("%s/.paraslash/key.%s",
565 home, ct->user);
566 if (!file_exists(ct->key_file)) {
567 free(ct->key_file);
568 ct->key_file = make_message("%s/.ssh/id_rsa", home);
569 }
570 }
571
572 if (loglevel)
573 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
574 PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
575 PARA_INFO_LOG("config_file: %s\n", ct->config_file);
576 PARA_INFO_LOG("key_file: %s\n", ct->key_file);
577 ret = ct->conf.inputs_num;
578 out:
579 free(home);
580 if (ret < 0) {
581 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
582 client_close(ct);
583 *ct_ptr = NULL;
584 }
585 return ret;
586 }
587
588 /**
589 * Parse the client configuration and open a connection to para_server.
590 *
591 * \param argc See \ref client_parse_config.
592 * \param argv See \ref client_parse_config.
593 * \param ct_ptr See \ref client_parse_config.
594 * \param loglevel See \ref client_parse_config.
595 * \param parent See \ref client_connect().
596 * \param child See \ref client_connect().
597 * \param sched See \ref client_connect().
598 *
599 * This function combines client_parse_config() and client_connect(). It is
600 * considered a syntax error if no command was given, i.e. if the number
601 * of non-option arguments is zero.
602 *
603 * \return Standard.
604 */
605 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
606 int *loglevel, struct btr_node *parent, struct btr_node *child,
607 struct sched *sched)
608 {
609 int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
610
611 if (ret < 0)
612 return ret;
613 if (ret == 0) {
614 ret = -E_CLIENT_SYNTAX;
615 goto fail;
616 }
617 ret = client_connect(*ct_ptr, sched, parent, child);
618 if (ret < 0)
619 goto fail;
620 return 1;
621 fail:
622 client_close(*ct_ptr);
623 *ct_ptr = NULL;
624 return ret;
625 }