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 #include <lopsub.h>
17
18 #include "client.lsg.h"
19 #include "para.h"
20 #include "error.h"
21 #include "list.h"
22 #include "sched.h"
23 #include "crypt.h"
24 #include "net.h"
25 #include "fd.h"
26 #include "sideband.h"
27 #include "string.h"
28 #include "client.h"
29 #include "buffer_tree.h"
30 #include "version.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 lls_free_parse_result(ct->lpr, CLIENT_CMD_PTR);
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 /* fallthrough */
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 unsigned num_inputs = lls_num_inputs(ct->lpr);
250
251 if (ct->sbc[1])
252 return send_sb(ct, 0, NULL, 0, 0, false);
253
254 for (i = 0; i < num_inputs; i++)
255 len += strlen(lls_input(i, ct->lpr)) + 1;
256 p = command = para_malloc(len);
257 for (i = 0; i < num_inputs; i++) {
258 const char *str = lls_input(i, ct->lpr);
259 strcpy(p, str);
260 p += strlen(str) + 1;
261 }
262 PARA_DEBUG_LOG("--> %s\n", command);
263 return send_sb(ct, 0, command, len, SBD_COMMAND, false);
264 }
265
266 /*
267 * The post select hook for client commands.
268 *
269 * Depending on the current state of the connection and the status of the read
270 * and write fd sets of s, this function performs the necessary steps to
271 * authenticate the connection, to send the command given by t->private_data
272 * and to receive para_server's output, if any.
273 */
274 static int client_post_select(struct sched *s, void *context)
275 {
276 struct client_task *ct = context;
277 int ret = 0;
278 size_t n;
279 char buf[CLIENT_BUFSIZE];
280
281 ret = task_get_notification(ct->task);
282 if (ret < 0)
283 goto out;
284 if (ct->scc.fd < 0)
285 return 0;
286 switch (ct->status) {
287 case CL_CONNECTED: /* receive welcome message */
288 ret = read_nonblock(ct->scc.fd, buf, sizeof(buf), &s->rfds, &n);
289 if (ret < 0 || n == 0)
290 goto out;
291 ct->features = parse_features(buf);
292 ct->status = CL_RECEIVED_WELCOME;
293 return 0;
294 case CL_RECEIVED_WELCOME: /* send auth command */
295 if (!FD_ISSET(ct->scc.fd, &s->wfds))
296 return 0;
297 sprintf(buf, AUTH_REQUEST_MSG "%s sideband,aes_ctr128",
298 ct->user);
299 PARA_INFO_LOG("--> %s\n", buf);
300 ret = write_buffer(ct->scc.fd, buf);
301 if (ret < 0)
302 goto out;
303 ct->status = CL_SENT_AUTH;
304 return 0;
305 case CL_SENT_AUTH:
306 /*
307 * Receive challenge and session keys, decrypt the challenge and
308 * send back the hash of the decrypted challenge.
309 */
310 {
311 /* decrypted challenge/session key buffer */
312 unsigned char crypt_buf[1024];
313 struct sb_buffer sbb;
314
315 ret = recv_sb(ct, &s->rfds, &sbb);
316 if (ret <= 0)
317 goto out;
318 if (sbb.band != SBD_CHALLENGE) {
319 ret = -E_BAD_BAND;
320 free(sbb.iov.iov_base);
321 goto out;
322 }
323 n = sbb.iov.iov_len;
324 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
325 ret = priv_decrypt(ct->key_file, crypt_buf,
326 sbb.iov.iov_base, n);
327 free(sbb.iov.iov_base);
328 if (ret < 0)
329 goto out;
330 ct->challenge_hash = para_malloc(HASH_SIZE);
331 hash_function((char *)crypt_buf, CHALLENGE_SIZE, ct->challenge_hash);
332 ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN);
333 ct->scc.recv = sc_new(crypt_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
334 SESSION_KEY_LEN);
335 hash_to_asc(ct->challenge_hash, buf);
336 PARA_INFO_LOG("--> %s\n", buf);
337 ct->status = CL_RECEIVED_CHALLENGE;
338 return 0;
339 }
340 case CL_RECEIVED_CHALLENGE:
341 ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
342 SBD_CHALLENGE_RESPONSE, false);
343 if (ret != 0)
344 ct->challenge_hash = NULL;
345 if (ret <= 0)
346 goto out;
347 ct->status = CL_SENT_CH_RESPONSE;
348 goto out;
349 case CL_SENT_CH_RESPONSE: /* read server response */
350 {
351 struct sb_buffer sbb;
352 ret = recv_sb(ct, &s->rfds, &sbb);
353 if (ret <= 0)
354 goto out;
355 free(sbb.iov.iov_base);
356 if (sbb.band != SBD_PROCEED)
357 ret = -E_BAD_BAND;
358 else
359 ct->status = CL_RECEIVED_PROCEED;
360 goto out;
361 }
362 case CL_RECEIVED_PROCEED: /* concat args and send command */
363 {
364 if (!FD_ISSET(ct->scc.fd, &s->wfds))
365 return 0;
366 ret = send_sb_command(ct);
367 if (ret <= 0)
368 goto out;
369 ct->status = CL_EXECUTING;
370 return 0;
371 }
372 case CL_SENDING:
373 if (ct->btrn[1]) {
374 char *buf2;
375 size_t sz;
376 ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
377 if (ret == -E_BTR_EOF) {
378 /* empty blob data packet indicates EOF */
379 PARA_INFO_LOG("blob sent\n");
380 ret = send_sb(ct, 1, NULL, 0, SBD_BLOB_DATA, true);
381 if (ret >= 0)
382 ret = -E_BTR_EOF;
383 }
384 if (ret < 0)
385 goto close1;
386 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->wfds)) {
387 sz = btr_next_buffer(ct->btrn[1], &buf2);
388 assert(sz);
389 ret = send_sb(ct, 1, buf2, sz, SBD_BLOB_DATA, true);
390 if (ret < 0)
391 goto close1;
392 if (ret > 0)
393 btr_consume(ct->btrn[1], sz);
394 }
395 }
396 /* fall through */
397 case CL_EXECUTING:
398 if (ct->btrn[0]) {
399 ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
400 if (ret < 0)
401 goto close0;
402 if (ret > 0 && FD_ISSET(ct->scc.fd, &s->rfds)) {
403 struct sb_buffer sbb;
404 ret = recv_sb(ct, &s->rfds, &sbb);
405 if (ret < 0)
406 goto close0;
407 if (ret > 0) {
408 ret = dispatch_sbb(ct, &sbb);
409 if (ret < 0)
410 goto close0;
411 }
412 }
413 }
414 ret = 0;
415 goto out;
416 }
417 close1:
418 PARA_INFO_LOG("channel 1: %s\n", para_strerror(-ret));
419 btr_remove_node(&ct->btrn[1]);
420 if (ct->btrn[0])
421 return 0;
422 goto out;
423 close0:
424 PARA_INFO_LOG("channel 0: %s\n", para_strerror(-ret));
425 btr_remove_node(&ct->btrn[0]);
426 if (ct->btrn[1] && ct->status == CL_SENDING)
427 return 0;
428 out:
429 if (ret >= 0)
430 return 0;
431 btr_remove_node(&ct->btrn[0]);
432 btr_remove_node(&ct->btrn[1]);
433 if (ret != -E_SERVER_CMD_SUCCESS && ret != -E_SERVER_CMD_FAILURE)
434 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
435 if (ct->scc.fd >= 0) {
436 close(ct->scc.fd);
437 ct->scc.fd = -1;
438 }
439 free_argv(ct->features);
440 ct->features = NULL;
441 sc_free(ct->scc.recv);
442 ct->scc.recv = NULL;
443 sc_free(ct->scc.send);
444 ct->scc.send = NULL;
445 return ret;
446 }
447
448 /**
449 * Connect to para_server and register the client task.
450 *
451 * \param ct The initialized client task structure.
452 * \param s The scheduler instance to register the client task to.
453 * \param parent The parent node of the client btr node.
454 * \param child The child node of the client node.
455 *
456 * The client task structure given by \a ct must be allocated and initialized
457 * by \ref client_parse_config() before this function is called.
458 *
459 * \return Standard.
460 */
461 int client_connect(struct client_task *ct, struct sched *s,
462 struct btr_node *parent, struct btr_node *child)
463 {
464 int ret;
465 const char *host = CLIENT_OPT_STRING_VAL(HOSTNAME, ct->lpr);
466 uint32_t port = CLIENT_OPT_UINT32_VAL(SERVER_PORT, ct->lpr);
467
468 PARA_NOTICE_LOG("connecting %s:%u\n", host, port);
469 ct->scc.fd = -1;
470 ret = para_connect_simple(IPPROTO_TCP, host, port);
471 if (ret < 0)
472 return ret;
473 ct->scc.fd = ret;
474 ret = mark_fd_nonblocking(ct->scc.fd);
475 if (ret < 0)
476 goto err_out;
477 ct->status = CL_CONNECTED;
478 ct->btrn[0] = btr_new_node(&(struct btr_node_description)
479 EMBRACE(.name = "client recv", .parent = NULL, .child = child));
480 ct->btrn[1] = btr_new_node(&(struct btr_node_description)
481 EMBRACE(.name = "client send", .parent = parent, .child = NULL));
482
483 ct->task = task_register(&(struct task_info) {
484 .name = "client",
485 .pre_select = client_pre_select,
486 .post_select = client_post_select,
487 .context = ct,
488 }, s);
489 return 1;
490 err_out:
491 close(ct->scc.fd);
492 ct->scc.fd = -1;
493 return ret;
494 }
495
496 static void handle_help_flag(struct lls_parse_result *lpr)
497 {
498 char *help;
499
500 if (CLIENT_OPT_GIVEN(DETAILED_HELP, lpr))
501 help = lls_long_help(CLIENT_CMD_PTR);
502 else if (CLIENT_OPT_GIVEN(HELP, lpr))
503 help = lls_short_help(CLIENT_CMD_PTR);
504 else
505 return;
506 printf("%s\n", help);
507 free(help);
508 exit(EXIT_SUCCESS);
509 }
510
511 /**
512 * Parse a client configuration.
513 *
514 * \param argc Usual argument count.
515 * \param argv Usual argument vector.
516 * \param ct_ptr Filled in by this function.
517 * \param loglevel If not \p NULL, the number of the loglevel is stored here.
518 *
519 * This checks the command line options given by \a argc and \a argv, sets
520 * default values for the user name and the name of the rsa key file and reads
521 * further options from the config file.
522 *
523 * Upon successful return, \a ct_ptr points to a dynamically allocated and
524 * initialized client task struct.
525 *
526 * \return The number of non-option arguments in \a argc/argv on success,
527 * negative on errors.
528 */
529 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
530 int *loglevel)
531 {
532 const struct lls_command *cmd = CLIENT_CMD_PTR;
533 void *map;
534 size_t sz;
535 struct lls_parse_result *lpr;
536 int ret, ll;
537 struct client_task *ct;
538 char *cf = NULL, *kf = NULL, *user, *errctx, *home = para_homedir();
539
540 ret = lls(lls_parse(argc, argv, cmd, &lpr, &errctx));
541 if (ret < 0)
542 goto out;
543 ll = CLIENT_OPT_UINT32_VAL(LOGLEVEL, lpr);
544 version_handle_flag("client", CLIENT_OPT_GIVEN(VERSION, lpr));
545 handle_help_flag(lpr);
546
547 if (CLIENT_OPT_GIVEN(CONFIG_FILE, lpr))
548 cf = para_strdup(CLIENT_OPT_STRING_VAL(CONFIG_FILE, lpr));
549 else
550 cf = make_message("%s/.paraslash/client.conf", home);
551 ret = mmap_full_file(cf, O_RDONLY, &map, &sz, NULL);
552 if (ret < 0) {
553 if (ret != -E_EMPTY && ret != -ERRNO_TO_PARA_ERROR(ENOENT))
554 goto out;
555 if (ret == -ERRNO_TO_PARA_ERROR(ENOENT) &&
556 CLIENT_OPT_GIVEN(CONFIG_FILE, lpr))
557 goto out;
558 } else {
559 int cf_argc;
560 char **cf_argv;
561 struct lls_parse_result *cf_lpr, *merged_lpr;
562 ret = lls(lls_convert_config(map, sz, NULL, &cf_argv, &errctx));
563 para_munmap(map, sz);
564 if (ret < 0)
565 goto out;
566 cf_argc = ret;
567 ret = lls(lls_parse(cf_argc, cf_argv, cmd, &cf_lpr, &errctx));
568 lls_free_argv(cf_argv);
569 if (ret < 0)
570 goto out;
571 ret = lls(lls_merge(lpr, cf_lpr, cmd, &merged_lpr,
572 &errctx));
573 lls_free_parse_result(cf_lpr, cmd);
574 if (ret < 0)
575 goto out;
576 lls_free_parse_result(lpr, cmd);
577 lpr = merged_lpr;
578 }
579 /* success */
580 user = CLIENT_OPT_GIVEN(USER, lpr)?
581 para_strdup(CLIENT_OPT_STRING_VAL(USER, lpr)) : para_logname();
582
583 if (CLIENT_OPT_GIVEN(KEY_FILE, lpr))
584 kf = para_strdup(CLIENT_OPT_STRING_VAL(KEY_FILE, lpr));
585 else {
586 kf = make_message("%s/.paraslash/key.%s", home, user);
587 if (!file_exists(kf)) {
588 free(kf);
589 kf = make_message("%s/.ssh/id_rsa", home);
590 }
591 }
592 PARA_INFO_LOG("user: %s\n", user);
593 PARA_INFO_LOG("config file: %s\n", cf);
594 PARA_INFO_LOG("key file: %s\n", kf);
595 PARA_INFO_LOG("loglevel: %d\n", ll);
596 ct = para_calloc(sizeof(*ct));
597 ct->scc.fd = -1;
598 ct->lpr = lpr;
599 ct->key_file = kf;
600 ct->config_file = cf;
601 ct->user = user;
602 *ct_ptr = ct;
603 if (loglevel)
604 *loglevel = ll;
605 ret = lls_num_inputs(lpr);
606 out:
607 free(home);
608 if (ret < 0) {
609 if (errctx)
610 PARA_ERROR_LOG("%s\n", errctx);
611 free(errctx);
612 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
613 lls_free_parse_result(lpr, cmd);
614 free(cf);
615 free(kf);
616 *ct_ptr = NULL;
617 }
618 return ret;
619 }
620
621 /**
622 * Parse the client configuration and open a connection to para_server.
623 *
624 * \param argc See \ref client_parse_config.
625 * \param argv See \ref client_parse_config.
626 * \param ct_ptr See \ref client_parse_config.
627 * \param loglevel See \ref client_parse_config.
628 * \param parent See \ref client_connect().
629 * \param child See \ref client_connect().
630 * \param sched See \ref client_connect().
631 *
632 * This function combines client_parse_config() and client_connect(). It is
633 * considered a syntax error if no command was given, i.e. if the number
634 * of non-option arguments is zero.
635 *
636 * \return Standard.
637 */
638 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
639 int *loglevel, struct btr_node *parent, struct btr_node *child,
640 struct sched *sched)
641 {
642 int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
643
644 if (ret < 0)
645 return ret;
646 if (ret == 0) {
647 ret = -E_CLIENT_SYNTAX;
648 goto fail;
649 }
650 ret = client_connect(*ct_ptr, sched, parent, child);
651 if (ret < 0)
652 goto fail;
653 return 1;
654 fail:
655 client_close(*ct_ptr);
656 *ct_ptr = NULL;
657 return ret;
658 }