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