Merge topic branch t/openssl-3 into master
[paraslash.git] / client_common.c
1 /* Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
2
3 /** \file client_common.c Common functions of para_client and para_audiod. */
4
5 #include <netinet/in.h>
6 #include <sys/socket.h>
7 #include <regex.h>
8 #include <sys/types.h>
9 #include <arpa/inet.h>
10 #include <sys/un.h>
11 #include <netdb.h>
12 #include <lopsub.h>
13
14 #include "client.lsg.h"
15 #include "para.h"
16 #include "error.h"
17 #include "list.h"
18 #include "lsu.h"
19 #include "sched.h"
20 #include "crypt.h"
21 #include "net.h"
22 #include "fd.h"
23 #include "sideband.h"
24 #include "string.h"
25 #include "client.h"
26 #include "buffer_tree.h"
27 #include "version.h"
28
29 /** The size of the receiving buffer. */
30 #define CLIENT_BUFSIZE 4000
31
32 /**
33 * Close the connection to para_server and free all resources.
34 *
35 * \param ct Pointer to the client data.
36 *
37 * \sa \ref client_open().
38 */
39 void client_close(struct client_task *ct)
40 {
41 if (!ct)
42 return;
43 free(ct->user);
44 free(ct->key_file);
45 lls_free_parse_result(ct->lpr, CLIENT_CMD_PTR);
46 free(ct->challenge_hash);
47 sb_free(ct->sbc[0]);
48 sb_free(ct->sbc[1]);
49 free(ct);
50 }
51
52 /*
53 * This function asks the scheduler to monitor a file descriptor which
54 * corresponds to an active connection. The descriptor is monitored for either
55 * reading or writing, depending on the state of the connection.
56 *
57 * The context pointer is assumed to refer to a client task structure that was
58 * initialized earlier by client_open().
59 */
60 static void client_pre_monitor(struct sched *s, void *context)
61 {
62 int ret;
63 struct client_task *ct = context;
64
65 if (ct->scc.fd < 0)
66 return;
67 switch (ct->status) {
68 case CL_CONNECTED:
69 case CL_SENT_AUTH:
70 case CL_SENT_CH_RESPONSE:
71 sched_monitor_readfd(ct->scc.fd, s);
72 return;
73
74 case CL_RECEIVED_WELCOME:
75 case CL_RECEIVED_PROCEED:
76 case CL_RECEIVED_CHALLENGE:
77 sched_monitor_writefd(ct->scc.fd, s);
78 return;
79
80 case CL_SENDING:
81 if (ct->btrn[1]) {
82 ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
83 if (ret < 0)
84 sched_min_delay(s);
85 else if (ret > 0)
86 sched_monitor_writefd(ct->scc.fd, s);
87 }
88 __attribute__ ((fallthrough));
89 case CL_EXECUTING:
90 if (ct->btrn[0]) {
91 ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
92 if (ret < 0)
93 sched_min_delay(s);
94 else if (ret > 0)
95 sched_monitor_readfd(ct->scc.fd, s);
96 }
97 return;
98 }
99 }
100
101 static int send_sb(struct client_task *ct, int channel, void *buf, size_t numbytes,
102 enum sb_designator band, bool dont_free)
103 {
104 int ret, fd = ct->scc.fd;
105 struct iovec iov[2];
106
107 if (!ct->sbc[channel]) {
108 struct sb_buffer sbb;
109 sb_transformation trafo = ct->status < CL_RECEIVED_PROCEED?
110 NULL : sc_trafo;
111 sbb = (typeof(sbb))SBB_INIT(band, buf, numbytes);
112 ct->sbc[channel] = sb_new_send(&sbb, dont_free, trafo, ct->scc.send);
113 }
114 ret = sb_get_send_buffers(ct->sbc[channel], iov);
115 ret = xwritev(fd, iov, ret);
116 if (ret < 0) {
117 sb_free(ct->sbc[channel]);
118 ct->sbc[channel] = NULL;
119 return ret;
120 }
121 if (sb_sent(ct->sbc[channel], ret)) {
122 ct->sbc[channel] = NULL;
123 return 1;
124 }
125 return 0;
126 }
127
128 static int recv_sb(struct client_task *ct, struct sb_buffer *result)
129 {
130 int ret;
131 size_t n;
132 sb_transformation trafo;
133 void *trafo_context;
134 struct iovec iov;
135
136 if (ct->status < CL_SENT_CH_RESPONSE)
137 trafo = trafo_context = NULL;
138 else {
139 trafo = sc_trafo;
140 trafo_context = ct->scc.recv;
141 }
142 if (!ct->sbc[0])
143 ct->sbc[0] = sb_new_recv(0, trafo, trafo_context);
144 again:
145 sb_get_recv_buffer(ct->sbc[0], &iov);
146 ret = read_nonblock(ct->scc.fd, iov.iov_base, iov.iov_len, &n);
147 if (ret < 0) {
148 sb_free(ct->sbc[0]);
149 ct->sbc[0] = NULL;
150 return ret;
151 }
152 if (n == 0)
153 return 0;
154 ret = sb_received(ct->sbc[0], n, result);
155 if (ret < 0)
156 return ret;
157 if (ret == 0)
158 goto again;
159 ct->sbc[0] = NULL;
160 return 1;
161 }
162
163
164 static char **parse_features(char *buf)
165 {
166 int i;
167 const char id[] = "\nFeatures: ";
168 char *p, *q, **features;
169
170 p = strstr(buf, id);
171 if (!p)
172 return NULL;
173 p += strlen(id);
174 q = strchr(p, '\n');
175 if (!q)
176 return NULL;
177 *q = '\0';
178 create_argv(p, ",", &features);
179 for (i = 0; features[i]; i++)
180 PARA_INFO_LOG("server feature: %s\n", features[i]);
181 return features;
182 }
183
184 static int dispatch_sbb(struct client_task *ct, struct sb_buffer *sbb)
185 {
186 int ret;
187 const char *designator[] = {SB_DESIGNATORS_ARRAY};
188
189 if (!sbb)
190 return 0;
191 if (sbb->band < NUM_SB_DESIGNATORS)
192 PARA_DEBUG_LOG("band: %s\n", designator[sbb->band]);
193
194 switch (sbb->band) {
195 case SBD_AWAITING_DATA:
196 ct->status = CL_SENDING;
197 ret = 1;
198 goto out;
199 case SBD_OUTPUT:
200 if (iov_valid(&sbb->iov))
201 btr_add_output(sbb->iov.iov_base, sbb->iov.iov_len,
202 ct->btrn[0]);
203 ret = 1;
204 goto out;
205 case SBD_DEBUG_LOG:
206 case SBD_INFO_LOG:
207 case SBD_NOTICE_LOG:
208 case SBD_WARNING_LOG:
209 case SBD_ERROR_LOG:
210 case SBD_CRIT_LOG:
211 case SBD_EMERG_LOG:
212 if (iov_valid(&sbb->iov)) {
213 int ll = sbb->band - SBD_DEBUG_LOG;
214 para_log(ll, "remote: %s", (char *)sbb->iov.iov_base);
215 }
216 ret = 1;
217 goto deallocate;
218 case SBD_EXIT__SUCCESS:
219 ret = -E_SERVER_CMD_SUCCESS;
220 goto deallocate;
221 case SBD_EXIT__FAILURE:
222 ret = -E_SERVER_CMD_FAILURE;
223 goto deallocate;
224 default:
225 PARA_ERROR_LOG("invalid band %d\n", sbb->band);
226 ret = -E_BAD_BAND;
227 goto deallocate;
228 }
229 deallocate:
230 free(sbb->iov.iov_base);
231 out:
232 sbb->iov.iov_base = NULL;
233 return ret;
234 }
235
236 static int send_sb_command(struct client_task *ct)
237 {
238 int i;
239 char *command, *p;
240 size_t len = 0;
241 unsigned num_inputs = lls_num_inputs(ct->lpr);
242
243 if (ct->sbc[1])
244 return send_sb(ct, 0, NULL, 0, 0, false);
245
246 for (i = 0; i < num_inputs; i++)
247 len += strlen(lls_input(i, ct->lpr)) + 1;
248 p = command = alloc(len);
249 for (i = 0; i < num_inputs; i++) {
250 const char *str = lls_input(i, ct->lpr);
251 strcpy(p, str);
252 p += strlen(str) + 1;
253 }
254 PARA_DEBUG_LOG("--> %s\n", command);
255 return send_sb(ct, 0, command, len, SBD_COMMAND, false);
256 }
257
258 /* Find out if the given string is contained in the features vector. */
259 static bool has_feature(const char *feature, struct client_task *ct)
260 {
261 if (!ct->features)
262 return false;
263 for (int i = 0; ct->features[i]; i++)
264 if (strcmp(feature, ct->features[i]) == 0)
265 return i;
266 return false;
267 }
268
269 /*
270 * This function reads or writes to the socket file descriptor which
271 * corresponds to an established connection between the client and the server.
272 * It depends on the current state of the connection and on the readiness of
273 * the socket file descriptor which type of I/O is going to be performed.
274 * Besides the initial handshake and authentication, the function sends the
275 * server command and receives the output from the server, if any.
276 *
277 * The context pointer refers to a client task structure that was initialized
278 * earlier by client_open().
279 */
280 static int client_post_monitor(struct sched *s, void *context)
281 {
282 struct client_task *ct = context;
283 int ret = 0;
284 size_t n;
285 char buf[CLIENT_BUFSIZE];
286
287 ret = task_get_notification(ct->task);
288 if (ret < 0)
289 goto out;
290 if (ct->scc.fd < 0)
291 return 0;
292 switch (ct->status) {
293 case CL_CONNECTED: /* receive welcome message */
294 ret = read_nonblock(ct->scc.fd, buf, sizeof(buf), &n);
295 if (ret < 0 || n == 0)
296 goto out;
297 ct->features = parse_features(buf);
298 ct->status = CL_RECEIVED_WELCOME;
299 return 0;
300 case CL_RECEIVED_WELCOME: /* send auth command */
301 {
302 /*
303 * Use sha256 iff the server announced the feature. After 0.7.0
304 * we may request and use the feature unconditionally. After
305 * 0.8.0 we no longer need to request the feature.
306 */
307 bool has_sha256;
308 if (!sched_write_ok(ct->scc.fd, s))
309 return 0;
310 has_sha256 = has_feature("sha256", ct);
311 sprintf(buf, AUTH_REQUEST_MSG "%s%s", ct->user, has_sha256?
312 " sha256" : "");
313 PARA_INFO_LOG("--> %s\n", buf);
314 ret = write_buffer(ct->scc.fd, buf);
315 if (ret < 0)
316 goto out;
317 ct->status = CL_SENT_AUTH;
318 return 0;
319 }
320 case CL_SENT_AUTH:
321 /*
322 * Receive challenge and session keys, decrypt the challenge and
323 * send back the hash of the decrypted challenge.
324 */
325 {
326 /* decrypted challenge/session key buffer */
327 unsigned char crypt_buf[1024];
328 struct sb_buffer sbb;
329
330 ret = recv_sb(ct, &sbb);
331 if (ret <= 0)
332 goto out;
333 if (sbb.band != SBD_CHALLENGE) {
334 ret = -E_BAD_BAND;
335 free(sbb.iov.iov_base);
336 goto out;
337 }
338 n = sbb.iov.iov_len;
339 PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
340 ret = apc_priv_decrypt(ct->key_file, crypt_buf,
341 sbb.iov.iov_base, n);
342 free(sbb.iov.iov_base);
343 if (ret < 0)
344 goto out;
345 ct->challenge_hash = alloc(HASH2_SIZE);
346 if (has_feature("sha256", ct)) {
347 hash2_function((char *)crypt_buf, APC_CHALLENGE_SIZE, ct->challenge_hash);
348 hash2_to_asc(ct->challenge_hash, buf);
349 } else {
350 hash_function((char *)crypt_buf, APC_CHALLENGE_SIZE, ct->challenge_hash);
351 hash_to_asc(ct->challenge_hash, buf);
352 }
353 ct->scc.send = sc_new(crypt_buf + APC_CHALLENGE_SIZE, SESSION_KEY_LEN);
354 ct->scc.recv = sc_new(crypt_buf + APC_CHALLENGE_SIZE + SESSION_KEY_LEN,
355 SESSION_KEY_LEN);
356 PARA_INFO_LOG("--> %s\n", buf);
357 ct->status = CL_RECEIVED_CHALLENGE;
358 return 0;
359 }
360 case CL_RECEIVED_CHALLENGE:
361 if (has_feature("sha256", ct))
362 ret = send_sb(ct, 0, ct->challenge_hash, HASH2_SIZE,
363 SBD_CHALLENGE_RESPONSE, false);
364 else
365 ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
366 SBD_CHALLENGE_RESPONSE, false);
367 if (ret != 0)
368 ct->challenge_hash = NULL;
369 if (ret <= 0)
370 goto out;
371 ct->status = CL_SENT_CH_RESPONSE;
372 goto out;
373 case CL_SENT_CH_RESPONSE: /* read server response */
374 {
375 struct sb_buffer sbb;
376 ret = recv_sb(ct, &sbb);
377 if (ret <= 0)
378 goto out;
379 free(sbb.iov.iov_base);
380 if (sbb.band != SBD_PROCEED)
381 ret = -E_BAD_BAND;
382 else
383 ct->status = CL_RECEIVED_PROCEED;
384 goto out;
385 }
386 case CL_RECEIVED_PROCEED: /* concat args and send command */
387 {
388 if (!sched_write_ok(ct->scc.fd, s))
389 return 0;
390 ret = send_sb_command(ct);
391 if (ret <= 0)
392 goto out;
393 ct->status = CL_EXECUTING;
394 return 0;
395 }
396 case CL_SENDING:
397 if (ct->btrn[1]) {
398 char *buf2;
399 size_t sz;
400 ret = btr_node_status(ct->btrn[1], 0, BTR_NT_LEAF);
401 if (ret == -E_BTR_EOF) {
402 /* empty blob data packet indicates EOF */
403 PARA_INFO_LOG("blob sent\n");
404 ret = send_sb(ct, 1, NULL, 0, SBD_BLOB_DATA, true);
405 if (ret >= 0)
406 ret = -E_BTR_EOF;
407 }
408 if (ret < 0)
409 goto close1;
410 if (ret > 0 && sched_write_ok(ct->scc.fd, s)) {
411 sz = btr_next_buffer(ct->btrn[1], &buf2);
412 assert(sz);
413 ret = send_sb(ct, 1, buf2, sz, SBD_BLOB_DATA, true);
414 if (ret < 0)
415 goto close1;
416 if (ret > 0)
417 btr_consume(ct->btrn[1], sz);
418 }
419 }
420 __attribute__ ((fallthrough));
421 case CL_EXECUTING:
422 if (ct->btrn[0]) {
423 ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
424 if (ret < 0)
425 goto close0;
426 if (ret > 0 && sched_read_ok(ct->scc.fd, s)) {
427 struct sb_buffer sbb;
428 ret = recv_sb(ct, &sbb);
429 if (ret < 0)
430 goto close0;
431 if (ret > 0) {
432 ret = dispatch_sbb(ct, &sbb);
433 if (ret < 0)
434 goto close0;
435 }
436 }
437 }
438 ret = 0;
439 goto out;
440 }
441 close1:
442 PARA_INFO_LOG("channel 1: %s\n", para_strerror(-ret));
443 btr_remove_node(&ct->btrn[1]);
444 if (ct->btrn[0])
445 return 0;
446 goto out;
447 close0:
448 PARA_INFO_LOG("channel 0: %s\n", para_strerror(-ret));
449 btr_remove_node(&ct->btrn[0]);
450 if (ct->btrn[1] && ct->status == CL_SENDING)
451 return 0;
452 out:
453 if (ret >= 0)
454 return 0;
455 btr_remove_node(&ct->btrn[0]);
456 btr_remove_node(&ct->btrn[1]);
457 PARA_NOTICE_LOG("closing connection (%s)\n", para_strerror(-ret));
458 if (ct->scc.fd >= 0) {
459 close(ct->scc.fd);
460 ct->scc.fd = -1;
461 }
462 free_argv(ct->features);
463 ct->features = NULL;
464 sc_free(ct->scc.recv);
465 ct->scc.recv = NULL;
466 sc_free(ct->scc.send);
467 ct->scc.send = NULL;
468 return ret;
469 }
470
471 /**
472 * Connect to para_server and register the client task.
473 *
474 * \param ct The initialized client task structure.
475 * \param s The scheduler instance to register the client task to.
476 * \param parent The parent node of the client btr node.
477 * \param child The child node of the client node.
478 *
479 * The client task structure given by \a ct must be allocated and initialized
480 * by \ref client_parse_config() before this function is called.
481 *
482 * \return Standard.
483 */
484 int client_connect(struct client_task *ct, struct sched *s,
485 struct btr_node *parent, struct btr_node *child)
486 {
487 int ret;
488 const char *host = CLIENT_OPT_STRING_VAL(HOSTNAME, ct->lpr);
489 uint32_t port = CLIENT_OPT_UINT32_VAL(SERVER_PORT, ct->lpr);
490
491 PARA_NOTICE_LOG("connecting %s:%u\n", host, port);
492 ct->scc.fd = -1;
493 ret = para_connect(IPPROTO_TCP, host, port);
494 if (ret < 0)
495 return ret;
496 ct->scc.fd = ret;
497 ret = mark_fd_nonblocking(ct->scc.fd);
498 if (ret < 0)
499 goto err_out;
500 ct->status = CL_CONNECTED;
501 ct->btrn[0] = btr_new_node(&(struct btr_node_description)
502 EMBRACE(.name = "client recv", .parent = NULL, .child = child));
503 ct->btrn[1] = btr_new_node(&(struct btr_node_description)
504 EMBRACE(.name = "client send", .parent = parent, .child = NULL));
505
506 ct->task = task_register(&(struct task_info) {
507 .name = "client",
508 .pre_monitor = client_pre_monitor,
509 .post_monitor = client_post_monitor,
510 .context = ct,
511 }, s);
512 return 1;
513 err_out:
514 close(ct->scc.fd);
515 ct->scc.fd = -1;
516 return ret;
517 }
518
519 static void handle_help_flag(struct lls_parse_result *lpr)
520 {
521 char *help;
522
523 if (CLIENT_OPT_GIVEN(DETAILED_HELP, lpr))
524 help = lls_long_help(CLIENT_CMD_PTR);
525 else if (CLIENT_OPT_GIVEN(HELP, lpr))
526 help = lls_short_help(CLIENT_CMD_PTR);
527 else
528 return;
529 printf("%s\n", help);
530 free(help);
531 exit(EXIT_SUCCESS);
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 const struct lls_command *cmd = CLIENT_CMD_PTR;
556 struct lls_parse_result *lpr;
557 int ret, ll;
558 struct client_task *ct;
559 char *kf = NULL, *user, *errctx, *home = para_homedir();
560
561 ret = lls(lls_parse(argc, argv, cmd, &lpr, &errctx));
562 if (ret < 0)
563 goto out;
564 version_handle_flag("client", CLIENT_OPT_GIVEN(VERSION, lpr));
565 handle_help_flag(lpr);
566
567 ret = lsu_merge_config_file_options(CLIENT_OPT_STRING_VAL(CONFIG_FILE, lpr),
568 "client.conf", &lpr, cmd, client_suite, 0U /* default flags */);
569 if (ret < 0)
570 goto out;
571 /* success */
572 ll = CLIENT_OPT_UINT32_VAL(LOGLEVEL, lpr);
573 if (loglevel)
574 *loglevel = ll;
575 user = CLIENT_OPT_GIVEN(USER, lpr)?
576 para_strdup(CLIENT_OPT_STRING_VAL(USER, lpr)) : para_logname();
577
578 if (CLIENT_OPT_GIVEN(KEY_FILE, lpr))
579 kf = para_strdup(CLIENT_OPT_STRING_VAL(KEY_FILE, lpr));
580 else {
581 kf = make_message("%s/.paraslash/key.%s", home, user);
582 if (!file_exists(kf)) {
583 free(kf);
584 kf = make_message("%s/.ssh/id_rsa", home);
585 }
586 }
587 PARA_INFO_LOG("user: %s\n", user);
588 PARA_INFO_LOG("key file: %s\n", kf);
589 PARA_INFO_LOG("loglevel: %d\n", ll);
590 ct = zalloc(sizeof(*ct));
591 ct->scc.fd = -1;
592 ct->lpr = lpr;
593 ct->key_file = kf;
594 ct->user = user;
595 *ct_ptr = ct;
596 ret = lls_num_inputs(lpr);
597 out:
598 free(home);
599 if (ret < 0) {
600 if (errctx)
601 PARA_ERROR_LOG("%s\n", errctx);
602 free(errctx);
603 lls_free_parse_result(lpr, cmd);
604 free(kf);
605 *ct_ptr = NULL;
606 }
607 return ret;
608 }
609
610 /**
611 * Parse the client configuration and open a connection to para_server.
612 *
613 * \param argc See \ref client_parse_config.
614 * \param argv See \ref client_parse_config.
615 * \param ct_ptr See \ref client_parse_config.
616 * \param loglevel See \ref client_parse_config.
617 * \param parent See \ref client_connect().
618 * \param child See \ref client_connect().
619 * \param sched See \ref client_connect().
620 *
621 * This function combines client_parse_config() and client_connect(). It is
622 * considered a syntax error if no command was given, i.e. if the number
623 * of non-option arguments is zero.
624 *
625 * \return Standard.
626 */
627 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
628 int *loglevel, struct btr_node *parent, struct btr_node *child,
629 struct sched *sched)
630 {
631 int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
632
633 if (ret < 0)
634 return ret;
635 if (ret == 0) {
636 ret = -E_CLIENT_SYNTAX;
637 goto fail;
638 }
639 ret = client_connect(*ct_ptr, sched, parent, child);
640 if (ret < 0)
641 goto fail;
642 return 1;
643 fail:
644 client_close(*ct_ptr);
645 *ct_ptr = NULL;
646 return ret;
647 }