Merge branch 'refs/heads/t/ubsan'
[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_select(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 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
72 return;
73
74 case CL_RECEIVED_WELCOME:
75 case CL_RECEIVED_PROCEED:
76 case CL_RECEIVED_CHALLENGE:
77 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
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 para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
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 para_fd_set(ct->scc.fd, &s->rfds, &s->max_fileno);
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, fd_set *rfds,
129 struct sb_buffer *result)
130 {
131 int ret;
132 size_t n;
133 sb_transformation trafo;
134 void *trafo_context;
135 struct iovec iov;
136
137 if (!FD_ISSET(ct->scc.fd, rfds))
138 return 0;
139 if (ct->status < CL_SENT_CH_RESPONSE)
140 trafo = trafo_context = NULL;
141 else {
142 trafo = sc_trafo;
143 trafo_context = ct->scc.recv;
144 }
145 if (!ct->sbc[0])
146 ct->sbc[0] = sb_new_recv(0, trafo, trafo_context);
147 again:
148 sb_get_recv_buffer(ct->sbc[0], &iov);
149 ret = read_nonblock(ct->scc.fd, iov.iov_base, iov.iov_len, rfds, &n);
150 if (ret < 0) {
151 sb_free(ct->sbc[0]);
152 ct->sbc[0] = NULL;
153 return ret;
154 }
155 if (n == 0)
156 return 0;
157 ret = sb_received(ct->sbc[0], n, result);
158 if (ret < 0)
159 return ret;
160 if (ret == 0)
161 goto again;
162 ct->sbc[0] = NULL;
163 return 1;
164 }
165
166
167 static char **parse_features(char *buf)
168 {
169 int i;
170 const char id[] = "\nFeatures: ";
171 char *p, *q, **features;
172
173 p = strstr(buf, id);
174 if (!p)
175 return NULL;
176 p += strlen(id);
177 q = strchr(p, '\n');
178 if (!q)
179 return NULL;
180 *q = '\0';
181 create_argv(p, ",", &features);
182 for (i = 0; features[i]; i++)
183 PARA_INFO_LOG("server feature: %s\n", features[i]);
184 return features;
185 }
186
187 static int dispatch_sbb(struct client_task *ct, struct sb_buffer *sbb)
188 {
189 int ret;
190 const char *designator[] = {SB_DESIGNATORS_ARRAY};
191
192 if (!sbb)
193 return 0;
194 if (sbb->band < NUM_SB_DESIGNATORS)
195 PARA_DEBUG_LOG("band: %s\n", designator[sbb->band]);
196
197 switch (sbb->band) {
198 case SBD_AWAITING_DATA:
199 ct->status = CL_SENDING;
200 ret = 1;
201 goto out;
202 case SBD_OUTPUT:
203 if (iov_valid(&sbb->iov))
204 btr_add_output(sbb->iov.iov_base, sbb->iov.iov_len,
205 ct->btrn[0]);
206 ret = 1;
207 goto out;
208 case SBD_DEBUG_LOG:
209 case SBD_INFO_LOG:
210 case SBD_NOTICE_LOG:
211 case SBD_WARNING_LOG:
212 case SBD_ERROR_LOG:
213 case SBD_CRIT_LOG:
214 case SBD_EMERG_LOG:
215 if (iov_valid(&sbb->iov)) {
216 int ll = sbb->band - SBD_DEBUG_LOG;
217 para_log(ll, "remote: %s", (char *)sbb->iov.iov_base);
218 }
219 ret = 1;
220 goto deallocate;
221 case SBD_EXIT__SUCCESS:
222 ret = -E_SERVER_CMD_SUCCESS;
223 goto deallocate;
224 case SBD_EXIT__FAILURE:
225 ret = -E_SERVER_CMD_FAILURE;
226 goto deallocate;
227 default:
228 PARA_ERROR_LOG("invalid band %d\n", sbb->band);
229 ret = -E_BAD_BAND;
230 goto deallocate;
231 }
232 deallocate:
233 free(sbb->iov.iov_base);
234 out:
235 sbb->iov.iov_base = NULL;
236 return ret;
237 }
238
239 static int send_sb_command(struct client_task *ct)
240 {
241 int i;
242 char *command, *p;
243 size_t len = 0;
244 unsigned num_inputs = lls_num_inputs(ct->lpr);
245
246 if (ct->sbc[1])
247 return send_sb(ct, 0, NULL, 0, 0, false);
248
249 for (i = 0; i < num_inputs; i++)
250 len += strlen(lls_input(i, ct->lpr)) + 1;
251 p = command = para_malloc(len);
252 for (i = 0; i < num_inputs; i++) {
253 const char *str = lls_input(i, ct->lpr);
254 strcpy(p, str);
255 p += strlen(str) + 1;
256 }
257 PARA_DEBUG_LOG("--> %s\n", command);
258 return send_sb(ct, 0, command, len, SBD_COMMAND, false);
259 }
260
261 /*
262 * This function reads or writes to the socket file descriptor which
263 * corresponds to an established connection between the client and the server.
264 * It depends on the current state of the connection and on the readiness of
265 * the socket file descriptor which type of I/O is going to be performed.
266 * Besides the initial handshake and authentication, the function sends the
267 * server command and receives the output from the server, if any.
268 *
269 * The context pointer refers to a client task structure that was initialized
270 * earlier by client_open().
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 = apc_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, APC_CHALLENGE_SIZE, ct->challenge_hash);
330 ct->scc.send = sc_new(crypt_buf + APC_CHALLENGE_SIZE, SESSION_KEY_LEN);
331 ct->scc.recv = sc_new(crypt_buf + APC_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 __attribute__ ((fallthrough));
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 const char *host = CLIENT_OPT_STRING_VAL(HOSTNAME, ct->lpr);
464 uint32_t port = CLIENT_OPT_UINT32_VAL(SERVER_PORT, ct->lpr);
465
466 PARA_NOTICE_LOG("connecting %s:%u\n", host, port);
467 ct->scc.fd = -1;
468 ret = para_connect_simple(IPPROTO_TCP, host, port);
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 static void handle_help_flag(struct lls_parse_result *lpr)
495 {
496 char *help;
497
498 if (CLIENT_OPT_GIVEN(DETAILED_HELP, lpr))
499 help = lls_long_help(CLIENT_CMD_PTR);
500 else if (CLIENT_OPT_GIVEN(HELP, lpr))
501 help = lls_short_help(CLIENT_CMD_PTR);
502 else
503 return;
504 printf("%s\n", help);
505 free(help);
506 exit(EXIT_SUCCESS);
507 }
508
509 /**
510 * Parse a client configuration.
511 *
512 * \param argc Usual argument count.
513 * \param argv Usual argument vector.
514 * \param ct_ptr Filled in by this function.
515 * \param loglevel If not \p NULL, the number of the loglevel is stored here.
516 *
517 * This checks the command line options given by \a argc and \a argv, sets
518 * default values for the user name and the name of the rsa key file and reads
519 * further options from the config file.
520 *
521 * Upon successful return, \a ct_ptr points to a dynamically allocated and
522 * initialized client task struct.
523 *
524 * \return The number of non-option arguments in \a argc/argv on success,
525 * negative on errors.
526 */
527 int client_parse_config(int argc, char *argv[], struct client_task **ct_ptr,
528 int *loglevel)
529 {
530 const struct lls_command *cmd = CLIENT_CMD_PTR;
531 struct lls_parse_result *lpr;
532 int ret, ll;
533 struct client_task *ct;
534 char *kf = NULL, *user, *errctx, *home = para_homedir();
535
536 ret = lls(lls_parse(argc, argv, cmd, &lpr, &errctx));
537 if (ret < 0)
538 goto out;
539 version_handle_flag("client", CLIENT_OPT_GIVEN(VERSION, lpr));
540 handle_help_flag(lpr);
541
542 ret = lsu_merge_config_file_options(CLIENT_OPT_STRING_VAL(CONFIG_FILE, lpr),
543 "client.conf", &lpr, cmd, client_suite, 0U /* default flags */);
544 if (ret < 0)
545 goto out;
546 /* success */
547 ll = CLIENT_OPT_UINT32_VAL(LOGLEVEL, lpr);
548 if (loglevel)
549 *loglevel = ll;
550 user = CLIENT_OPT_GIVEN(USER, lpr)?
551 para_strdup(CLIENT_OPT_STRING_VAL(USER, lpr)) : para_logname();
552
553 if (CLIENT_OPT_GIVEN(KEY_FILE, lpr))
554 kf = para_strdup(CLIENT_OPT_STRING_VAL(KEY_FILE, lpr));
555 else {
556 kf = make_message("%s/.paraslash/key.%s", home, user);
557 if (!file_exists(kf)) {
558 free(kf);
559 kf = make_message("%s/.ssh/id_rsa", home);
560 }
561 }
562 PARA_INFO_LOG("user: %s\n", user);
563 PARA_INFO_LOG("key file: %s\n", kf);
564 PARA_INFO_LOG("loglevel: %d\n", ll);
565 ct = para_calloc(sizeof(*ct));
566 ct->scc.fd = -1;
567 ct->lpr = lpr;
568 ct->key_file = kf;
569 ct->user = user;
570 *ct_ptr = ct;
571 ret = lls_num_inputs(lpr);
572 out:
573 free(home);
574 if (ret < 0) {
575 if (errctx)
576 PARA_ERROR_LOG("%s\n", errctx);
577 free(errctx);
578 lls_free_parse_result(lpr, cmd);
579 free(kf);
580 *ct_ptr = NULL;
581 }
582 return ret;
583 }
584
585 /**
586 * Parse the client configuration and open a connection to para_server.
587 *
588 * \param argc See \ref client_parse_config.
589 * \param argv See \ref client_parse_config.
590 * \param ct_ptr See \ref client_parse_config.
591 * \param loglevel See \ref client_parse_config.
592 * \param parent See \ref client_connect().
593 * \param child See \ref client_connect().
594 * \param sched See \ref client_connect().
595 *
596 * This function combines client_parse_config() and client_connect(). It is
597 * considered a syntax error if no command was given, i.e. if the number
598 * of non-option arguments is zero.
599 *
600 * \return Standard.
601 */
602 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
603 int *loglevel, struct btr_node *parent, struct btr_node *child,
604 struct sched *sched)
605 {
606 int ret = client_parse_config(argc, argv, ct_ptr, loglevel);
607
608 if (ret < 0)
609 return ret;
610 if (ret == 0) {
611 ret = -E_CLIENT_SYNTAX;
612 goto fail;
613 }
614 ret = client_connect(*ct_ptr, sched, parent, child);
615 if (ret < 0)
616 goto fail;
617 return 1;
618 fail:
619 client_close(*ct_ptr);
620 *ct_ptr = NULL;
621 return ret;
622 }