Merge branch 'maint'
[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 bool has_feature(const char *feature, struct client_task *ct)
245 {
246 return find_arg(feature, ct->features) >= 0? true : false;
247 }
248
249 static int send_sb_command(struct client_task *ct)
250 {
251 int i;
252 char *command, *p;
253 size_t len = 0;
254
255 if (ct->sbc[1])
256 return send_sb(ct, 0, NULL, 0, 0, false);
257
258 for (i = 0; i < ct->conf.inputs_num; i++)
259 len += strlen(ct->conf.inputs[i]) + 1;
260 p = command = para_malloc(len);
261 for (i = 0; i < ct->conf.inputs_num; i++) {
262 strcpy(p, ct->conf.inputs[i]);
263 p += strlen(ct->conf.inputs[i]) + 1;
264 }
265 PARA_DEBUG_LOG("--> %s\n", command);
266 return send_sb(ct, 0, command, len, SBD_COMMAND, false);
267 }
268
269 /*
270 * The post select hook for client commands.
271 *
272 * Depending on the current state of the connection and the status of the read
273 * and write fd sets of s, this function performs the necessary steps to
274 * authenticate the connection, to send the command given by t->private_data
275 * and to receive para_server's output, if any.
276 */
277 static int client_post_select(struct sched *s, void *context)
278 {
279 struct client_task *ct = context;
280 int ret = 0;
281 size_t n;
282 char buf[CLIENT_BUFSIZE];
283
284 ret = task_get_notification(ct->task);
285 if (ret < 0)
286 goto out;
287 if (ct->scc.fd < 0)
288 return 0;
289 switch (ct->status) {
290 case CL_CONNECTED: /* receive welcome message */
291 ret = read_nonblock(ct->scc.fd, buf, sizeof(buf), &s->rfds, &n);
292 if (ret < 0 || n == 0)
293 goto out;
294 ct->features = parse_features(buf);
295 if (!has_feature("sideband", ct)) {
296 PARA_ERROR_LOG("server has no sideband support\n");
297 ret = -E_INCOMPAT_FEAT;
298 goto out;
299 }
300 ct->status = CL_RECEIVED_WELCOME;
301 return 0;
302 case CL_RECEIVED_WELCOME: /* send auth command */
303 if (!FD_ISSET(ct->scc.fd, &s->wfds))
304 return 0;
305 sprintf(buf, AUTH_REQUEST_MSG "%s sideband%s", ct->user,
306 has_feature("aes_ctr128", ct)? ",aes_ctr128" : "");
307 PARA_INFO_LOG("--> %s\n", buf);
308 ret = write_buffer(ct->scc.fd, buf);
309 if (ret < 0)
310 goto out;
311 ct->status = CL_SENT_AUTH;
312 return 0;
313 case CL_SENT_AUTH:
314 /*
315 * Receive challenge and session keys, decrypt the challenge and
316 * send back the hash of the decrypted challenge.
317 */
318 {
319 /* decrypted challenge/session key buffer */
320 unsigned char crypt_buf[1024];
321 struct sb_buffer sbb;
322 bool use_aes;
323
324 ret = recv_sb(ct, &s->rfds, &sbb);
325 if (ret <= 0)
326 goto out;
327 if (sbb.band != SBD_CHALLENGE) {
328 ret = -E_BAD_BAND;
329 free(sbb.iov.iov_base);
330 goto out;
331 }
332 n = sbb.iov.iov_len;
333 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
334 ret = priv_decrypt(ct->key_file, crypt_buf,
335 sbb.iov.iov_base, n);
336 free(sbb.iov.iov_base);
337 if (ret < 0)
338 goto out;
339 ct->challenge_hash = para_malloc(HASH_SIZE);
340 hash_function((char *)crypt_buf, CHALLENGE_SIZE, ct->challenge_hash);
341 use_aes = has_feature("aes_ctr128", ct);
342 ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN, use_aes);
343 ct->scc.recv = sc_new(crypt_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
344 SESSION_KEY_LEN, use_aes);
345 hash_to_asc(ct->challenge_hash, buf);
346 PARA_INFO_LOG("--> %s\n", buf);
347 ct->status = CL_RECEIVED_CHALLENGE;
348 return 0;
349 }
350 case CL_RECEIVED_CHALLENGE:
351 ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
352 SBD_CHALLENGE_RESPONSE, false);
353 if (ret != 0)
354 ct->challenge_hash = NULL;
355 if (ret <= 0)
356 goto out;
357 ct->status = CL_SENT_CH_RESPONSE;
358 goto out;
359 case CL_SENT_CH_RESPONSE: /* read server response */
360 {
361 struct sb_buffer sbb;
362 ret = recv_sb(ct, &s->rfds, &sbb);
363 if (ret <= 0)
364 goto out;
365 free(sbb.iov.iov_base);
366 if (sbb.band != SBD_PROCEED)
367 ret = -E_BAD_BAND;
368 else
369 ct->status = CL_RECEIVED_PROCEED;
370 goto out;
371 }
372 case CL_RECEIVED_PROCEED: /* concat args and send command */
373 {
374 if (!FD_ISSET(ct->scc.fd, &s->wfds))
375 return 0;
376 ret = send_sb_command(ct);
377 if (ret <= 0)
378 goto out;
379 ct->status = CL_EXECUTING;
380 return 0;
381 }
382 case CL_SENDING:
383 if (ct->btrn[1]) {
384 char *buf2;
385 size_t sz;
386 ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
387 if (ret == -E_BTR_EOF) {
388 /* empty blob data packet indicates EOF */
389 PARA_INFO_LOG("blob sent\n");
390 ret = send_sb(ct, 1, NULL, 0, SBD_BLOB_DATA, true);
391 if (ret >= 0)
392 ret = -E_BTR_EOF;
393 }
394 if (ret < 0)
395 goto close1;
396 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->wfds)) {
397 sz = btr_next_buffer(ct->btrn[1], &buf2);
398 assert(sz);
399 ret = send_sb(ct, 1, buf2, sz, SBD_BLOB_DATA, true);
400 if (ret < 0)
401 goto close1;
402 if (ret > 0)
403 btr_consume(ct->btrn[1], sz);
404 }
405 }
406 /* fall though */
407 case CL_EXECUTING:
408 if (ct->btrn[0]) {
409 ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
410 if (ret < 0)
411 goto close0;
412 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->rfds)) {
413 struct sb_buffer sbb;
414 ret = recv_sb(ct, &s->rfds, &sbb);
415 if (ret < 0)
416 goto close0;
417 if (ret > 0) {
418 ret = dispatch_sbb(ct, &sbb);
419 if (ret < 0)
420 goto close0;
421 }
422 }
423 }
424 ret = 0;
425 goto out;
426 }
427 close1:
428 PARA_INFO_LOG("channel 1: %s\n", para_strerror(-ret));
429 btr_remove_node(&ct->btrn[1]);
430 if (ct->btrn[0])
431 return 0;
432 goto out;
433 close0:
434 PARA_INFO_LOG("channel 0: %s\n", para_strerror(-ret));
435 btr_remove_node(&ct->btrn[0]);
436 if (ct->btrn[1] && ct->status == CL_SENDING)
437 return 0;
438 out:
439 if (ret >= 0)
440 return 0;
441 btr_remove_node(&ct->btrn[0]);
442 btr_remove_node(&ct->btrn[1]);
443 if (ret != -E_SERVER_CMD_SUCCESS && ret != -E_SERVER_CMD_FAILURE)
444 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
445 if (ct->scc.fd >= 0) {
446 close(ct->scc.fd);
447 ct->scc.fd = -1;
448 }
449 free_argv(ct->features);
450 ct->features = NULL;
451 sc_free(ct->scc.recv);
452 ct->scc.recv = NULL;
453 sc_free(ct->scc.send);
454 ct->scc.send = NULL;
455 return ret;
456 }
457
458 /**
459 * Connect to para_server and register the client task.
460 *
461 * \param ct The initialized client task structure.
462 * \param s The scheduler instance to register the client task to.
463 * \param parent The parent node of the client btr node.
464 * \param child The child node of the client node.
465 *
466 * The client task structure given by \a ct must be allocated and initialized
467 * by \ref client_parse_config() before this function is called.
468 *
469 * \return Standard.
470 */
471 int client_connect(struct client_task *ct, struct sched *s,
472 struct btr_node *parent, struct btr_node *child)
473 {
474 int ret;
475
476 PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
477 ct->conf.server_port_arg);
478 ct->scc.fd = -1;
479 ret = para_connect_simple(IPPROTO_TCP, ct->conf.hostname_arg,
480 ct->conf.server_port_arg);
481 if (ret < 0)
482 return ret;
483 ct->scc.fd = ret;
484 ret = mark_fd_nonblocking(ct->scc.fd);
485 if (ret < 0)
486 goto err_out;
487 ct->status = CL_CONNECTED;
488 ct->btrn[0] = btr_new_node(&(struct btr_node_description)
489 EMBRACE(.name = "client recv", .parent = NULL, .child = child));
490 ct->btrn[1] = btr_new_node(&(struct btr_node_description)
491 EMBRACE(.name = "client send", .parent = parent, .child = NULL));
492
493 ct->task = task_register(&(struct task_info) {
494 .name = "client",
495 .pre_select = client_pre_select,
496 .post_select = client_post_select,
497 .context = ct,
498 }, s);
499 return 1;
500 err_out:
501 close(ct->scc.fd);
502 ct->scc.fd = -1;
503 return ret;
504 }
505
506 __noreturn static void print_help_and_die(struct client_task *ct)
507 {
508 struct ggo_help h = DEFINE_GGO_HELP(client);
509 bool d = ct->conf.detailed_help_given;
510
511 ggo_print_help(&h, d? GPH_STANDARD_FLAGS_DETAILED : GPH_STANDARD_FLAGS);
512 exit(0);
513 }
514
515 /**
516 * Parse a client configuration.
517 *
518 * \param argc Usual argument count.
519 * \param argv Usual argument vector.
520 * \param ct_ptr Filled in by this function.
521 * \param loglevel If not \p NULL, the number of the loglevel is stored here.
522 *
523 * This checks the command line options given by \a argc and \a argv, sets
524 * default values for the user name and the name of the rsa key file and reads
525 * further options from the config file.
526 *
527 * Upon successful return, \a ct_ptr points to a dynamically allocated and
528 * initialized client task struct.
529 *
530 * \return The number of non-option arguments in \a argc/argv on success,
531 * negative on errors.
532 */
533 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
534 int *loglevel)
535 {
536 char *home = para_homedir();
537 int ret;
538 struct client_task *ct = para_calloc(sizeof(struct client_task));
539
540 *ct_ptr = ct;
541 ct->scc.fd = -1;
542 ret = -E_CLIENT_SYNTAX;
543 if (client_cmdline_parser(argc, argv, &ct->conf))
544 goto out;
545 version_handle_flag("client", ct->conf.version_given);
546 if (ct->conf.help_given || ct->conf.detailed_help_given)
547 print_help_and_die(ct);
548
549 ct->config_file = ct->conf.config_file_given?
550 para_strdup(ct->conf.config_file_arg) :
551 make_message("%s/.paraslash/client.conf", home);
552 ret = file_exists(ct->config_file);
553 if (!ret && ct->conf.config_file_given) {
554 ret = -E_NO_CONFIG;
555 goto out;
556 }
557 if (ret) {
558 struct client_cmdline_parser_params params = {
559 .override = 0,
560 .initialize = 0,
561 .check_required = 0,
562 .check_ambiguity = 0,
563 .print_errors = 0
564 };
565 ret = -E_BAD_CONFIG;
566 if (client_cmdline_parser_config_file(ct->config_file,
567 &ct->conf, &params))
568 goto out;
569 }
570 ct->user = ct->conf.user_given?
571 para_strdup(ct->conf.user_arg) : para_logname();
572
573 if (ct->conf.key_file_given)
574 ct->key_file = para_strdup(ct->conf.key_file_arg);
575 else {
576 ct->key_file = make_message("%s/.paraslash/key.%s",
577 home, ct->user);
578 if (!file_exists(ct->key_file)) {
579 free(ct->key_file);
580 ct->key_file = make_message("%s/.ssh/id_rsa", home);
581 }
582 }
583
584 if (loglevel)
585 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
586 PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
587 PARA_INFO_LOG("config_file: %s\n", ct->config_file);
588 PARA_INFO_LOG("key_file: %s\n", ct->key_file);
589 ret = ct->conf.inputs_num;
590 out:
591 free(home);
592 if (ret < 0) {
593 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
594 client_close(ct);
595 *ct_ptr = NULL;
596 }
597 return ret;
598 }
599
600 /**
601 * Parse the client configuration and open a connection to para_server.
602 *
603 * \param argc See \ref client_parse_config.
604 * \param argv See \ref client_parse_config.
605 * \param ct_ptr See \ref client_parse_config.
606 * \param loglevel See \ref client_parse_config.
607 * \param parent See \ref client_connect().
608 * \param child See \ref client_connect().
609 * \param sched See \ref client_connect().
610 *
611 * This function combines client_parse_config() and client_connect(). It is
612 * considered a syntax error if no command was given, i.e. if the number
613 * of non-option arguments is zero.
614 *
615 * \return Standard.
616 */
617 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
618 int *loglevel, struct btr_node *parent, struct btr_node *child,
619 struct sched *sched)
620 {
621 int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
622
623 if (ret < 0)
624 return ret;
625 if (ret == 0) {
626 ret = -E_CLIENT_SYNTAX;
627 goto fail;
628 }
629 ret = client_connect(*ct_ptr, sched, parent, child);
630 if (ret < 0)
631 goto fail;
632 return 1;
633 fail:
634 client_close(*ct_ptr);
635 *ct_ptr = NULL;
636 return ret;
637 }