1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2012 The FreeBSD Foundation
5 *
6 * This software was developed by Edward Tomasz Napierala under sponsorship
7 * from the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 */
31
32 #include <sys/time.h>
33 #include <assert.h>
34 #include <stdbool.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <unistd.h>
39 #include <netinet/in.h>
40 #include <cam/ctl/ctl.h>
41 #include <cam/ctl/ctl_io.h>
42 #include <cam/ctl/ctl_ioctl.h>
43
44 #include "ctld.hh"
45 #include "iscsi.hh"
46 #include "iscsi_proto.h"
47
48 #define MAX_DATA_SEGMENT_LENGTH (128 * 1024)
49
50 static void login_send_error(struct pdu *request,
51 char error_class, char detail);
52
53 static void
kernel_limits(const char * offload,int s,int * max_recv_dsl,int * max_send_dsl,int * max_burst_length,int * first_burst_length)54 kernel_limits(const char *offload, int s, int *max_recv_dsl, int *max_send_dsl,
55 int *max_burst_length, int *first_burst_length)
56 {
57 struct ctl_iscsi req;
58 struct ctl_iscsi_limits_params *cilp;
59
60 bzero(&req, sizeof(req));
61
62 req.type = CTL_ISCSI_LIMITS;
63 cilp = (struct ctl_iscsi_limits_params *)&(req.data.limits);
64 strlcpy(cilp->offload, offload, sizeof(cilp->offload));
65 cilp->socket = s;
66
67 if (ioctl(ctl_fd, CTL_ISCSI, &req) == -1) {
68 log_err(1, "error issuing CTL_ISCSI ioctl; "
69 "dropping connection");
70 }
71
72 if (req.status != CTL_ISCSI_OK) {
73 log_errx(1, "error returned from CTL iSCSI limits request: "
74 "%s; dropping connection", req.error_str);
75 }
76
77 if (cilp->max_recv_data_segment_length != 0) {
78 *max_recv_dsl = cilp->max_recv_data_segment_length;
79 *max_send_dsl = cilp->max_recv_data_segment_length;
80 }
81 if (cilp->max_send_data_segment_length != 0)
82 *max_send_dsl = cilp->max_send_data_segment_length;
83 if (cilp->max_burst_length != 0)
84 *max_burst_length = cilp->max_burst_length;
85 if (cilp->first_burst_length != 0)
86 *first_burst_length = cilp->first_burst_length;
87 if (*max_burst_length < *first_burst_length)
88 *first_burst_length = *max_burst_length;
89
90 if (offload[0] != '\0') {
91 log_debugx("Kernel limits for offload \"%s\" are "
92 "MaxRecvDataSegment=%d, max_send_dsl=%d, "
93 "MaxBurstLength=%d, FirstBurstLength=%d",
94 offload, *max_recv_dsl, *max_send_dsl, *max_burst_length,
95 *first_burst_length);
96 } else {
97 log_debugx("Kernel limits are "
98 "MaxRecvDataSegment=%d, max_send_dsl=%d, "
99 "MaxBurstLength=%d, FirstBurstLength=%d",
100 *max_recv_dsl, *max_send_dsl, *max_burst_length,
101 *first_burst_length);
102 }
103 }
104
105 static void
login_set_nsg(struct pdu * response,int nsg)106 login_set_nsg(struct pdu *response, int nsg)
107 {
108 struct iscsi_bhs_login_response *bhslr;
109
110 assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
111 nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
112 nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
113
114 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
115
116 bhslr->bhslr_flags &= 0xFC;
117 bhslr->bhslr_flags |= nsg;
118 bhslr->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
119 }
120
121 static int
login_csg(const struct pdu * request)122 login_csg(const struct pdu *request)
123 {
124 struct iscsi_bhs_login_request *bhslr;
125
126 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
127
128 return ((bhslr->bhslr_flags & 0x0C) >> 2);
129 }
130
131 static void
login_set_csg(struct pdu * response,int csg)132 login_set_csg(struct pdu *response, int csg)
133 {
134 struct iscsi_bhs_login_response *bhslr;
135
136 assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
137 csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
138 csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
139
140 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
141
142 bhslr->bhslr_flags &= 0xF3;
143 bhslr->bhslr_flags |= csg << 2;
144 }
145
146 static struct pdu *
login_receive(struct connection * conn,bool initial)147 login_receive(struct connection *conn, bool initial)
148 {
149 struct pdu *request;
150 struct iscsi_bhs_login_request *bhslr;
151
152 request = pdu_new(conn);
153 pdu_receive(request);
154 if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
155 ISCSI_BHS_OPCODE_LOGIN_REQUEST) {
156 /*
157 * The first PDU in session is special - if we receive any PDU
158 * different than login request, we have to drop the connection
159 * without sending response ("A target receiving any PDU
160 * except a Login request before the Login Phase is started MUST
161 * immediately terminate the connection on which the PDU
162 * was received.")
163 */
164 if (initial == false)
165 login_send_error(request, 0x02, 0x0b);
166 log_errx(1, "protocol error: received invalid opcode 0x%x",
167 request->pdu_bhs->bhs_opcode);
168 }
169 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
170 /*
171 * XXX: Implement the C flag some day.
172 */
173 if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0) {
174 login_send_error(request, 0x03, 0x00);
175 log_errx(1, "received Login PDU with unsupported \"C\" flag");
176 }
177 if (bhslr->bhslr_version_max != 0x00) {
178 login_send_error(request, 0x02, 0x05);
179 log_errx(1, "received Login PDU with unsupported "
180 "Version-max 0x%x", bhslr->bhslr_version_max);
181 }
182 if (bhslr->bhslr_version_min != 0x00) {
183 login_send_error(request, 0x02, 0x05);
184 log_errx(1, "received Login PDU with unsupported "
185 "Version-min 0x%x", bhslr->bhslr_version_min);
186 }
187 if (initial == false &&
188 ISCSI_SNLT(ntohl(bhslr->bhslr_cmdsn), conn->conn_cmdsn)) {
189 login_send_error(request, 0x02, 0x00);
190 log_errx(1, "received Login PDU with decreasing CmdSN: "
191 "was %u, is %u", conn->conn_cmdsn,
192 ntohl(bhslr->bhslr_cmdsn));
193 }
194 if (initial == false &&
195 ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) {
196 login_send_error(request, 0x02, 0x00);
197 log_errx(1, "received Login PDU with wrong ExpStatSN: "
198 "is %u, should be %u", ntohl(bhslr->bhslr_expstatsn),
199 conn->conn_statsn);
200 }
201 conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn);
202
203 return (request);
204 }
205
206 static struct pdu *
login_new_response(struct pdu * request)207 login_new_response(struct pdu *request)
208 {
209 struct pdu *response;
210 struct connection *conn;
211 struct iscsi_bhs_login_request *bhslr;
212 struct iscsi_bhs_login_response *bhslr2;
213
214 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
215 conn = request->pdu_connection;
216
217 response = pdu_new_response(request);
218 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
219 bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_RESPONSE;
220 login_set_csg(response, BHSLR_STAGE_SECURITY_NEGOTIATION);
221 memcpy(bhslr2->bhslr_isid,
222 bhslr->bhslr_isid, sizeof(bhslr2->bhslr_isid));
223 bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag;
224 bhslr2->bhslr_statsn = htonl(conn->conn_statsn++);
225 bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn);
226 bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn);
227
228 return (response);
229 }
230
231 static void
login_send_error(struct pdu * request,char error_class,char detail)232 login_send_error(struct pdu *request, char error_class, char detail)
233 {
234 struct pdu *response;
235 struct iscsi_bhs_login_response *bhslr2;
236
237 log_debugx("sending Login Response PDU with failure class 0x%x/0x%x; "
238 "see next line for reason", error_class, detail);
239 response = login_new_response(request);
240 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
241 bhslr2->bhslr_status_class = error_class;
242 bhslr2->bhslr_status_detail = detail;
243
244 pdu_send(response);
245 pdu_delete(response);
246 }
247
248 static int
login_list_contains(const char * list,const char * what)249 login_list_contains(const char *list, const char *what)
250 {
251 char *tofree, *str, *token;
252
253 tofree = str = checked_strdup(list);
254
255 while ((token = strsep(&str, ",")) != NULL) {
256 if (strcmp(token, what) == 0) {
257 free(tofree);
258 return (1);
259 }
260 }
261 free(tofree);
262 return (0);
263 }
264
265 static int
login_list_prefers(const char * list,const char * choice1,const char * choice2)266 login_list_prefers(const char *list,
267 const char *choice1, const char *choice2)
268 {
269 char *tofree, *str, *token;
270
271 tofree = str = checked_strdup(list);
272
273 while ((token = strsep(&str, ",")) != NULL) {
274 if (strcmp(token, choice1) == 0) {
275 free(tofree);
276 return (1);
277 }
278 if (strcmp(token, choice2) == 0) {
279 free(tofree);
280 return (2);
281 }
282 }
283 free(tofree);
284 return (-1);
285 }
286
287 static struct pdu *
login_receive_chap_a(struct connection * conn)288 login_receive_chap_a(struct connection *conn)
289 {
290 struct pdu *request;
291 struct keys *request_keys;
292 const char *chap_a;
293
294 request = login_receive(conn, false);
295 request_keys = keys_new();
296 keys_load_pdu(request_keys, request);
297
298 chap_a = keys_find(request_keys, "CHAP_A");
299 if (chap_a == NULL) {
300 login_send_error(request, 0x02, 0x07);
301 log_errx(1, "received CHAP Login PDU without CHAP_A");
302 }
303 if (login_list_contains(chap_a, "5") == 0) {
304 login_send_error(request, 0x02, 0x01);
305 log_errx(1, "received CHAP Login PDU with unsupported CHAP_A "
306 "\"%s\"", chap_a);
307 }
308 keys_delete(request_keys);
309
310 return (request);
311 }
312
313 static void
login_send_chap_c(struct pdu * request,struct chap * chap)314 login_send_chap_c(struct pdu *request, struct chap *chap)
315 {
316 struct pdu *response;
317 struct keys *response_keys;
318 char *chap_c, *chap_i;
319
320 chap_c = chap_get_challenge(chap);
321 chap_i = chap_get_id(chap);
322
323 response = login_new_response(request);
324 response_keys = keys_new();
325 keys_add(response_keys, "CHAP_A", "5");
326 keys_add(response_keys, "CHAP_I", chap_i);
327 keys_add(response_keys, "CHAP_C", chap_c);
328 free(chap_i);
329 free(chap_c);
330 keys_save_pdu(response_keys, response);
331 pdu_send(response);
332 pdu_delete(response);
333 keys_delete(response_keys);
334 }
335
336 static struct pdu *
login_receive_chap_r(struct connection * conn,struct auth_group * ag,struct chap * chap,const struct auth ** authp,std::string & user)337 login_receive_chap_r(struct connection *conn, struct auth_group *ag,
338 struct chap *chap, const struct auth **authp, std::string &user)
339 {
340 struct pdu *request;
341 struct keys *request_keys;
342 const char *chap_n, *chap_r;
343 const struct auth *auth;
344 int error;
345
346 request = login_receive(conn, false);
347 request_keys = keys_new();
348 keys_load_pdu(request_keys, request);
349
350 chap_n = keys_find(request_keys, "CHAP_N");
351 if (chap_n == NULL) {
352 login_send_error(request, 0x02, 0x07);
353 log_errx(1, "received CHAP Login PDU without CHAP_N");
354 }
355 chap_r = keys_find(request_keys, "CHAP_R");
356 if (chap_r == NULL) {
357 login_send_error(request, 0x02, 0x07);
358 log_errx(1, "received CHAP Login PDU without CHAP_R");
359 }
360 error = chap_receive(chap, chap_r);
361 if (error != 0) {
362 login_send_error(request, 0x02, 0x07);
363 log_errx(1, "received CHAP Login PDU with malformed CHAP_R");
364 }
365
366 /*
367 * Verify the response.
368 */
369 assert(ag->type() == auth_type::CHAP ||
370 ag->type() == auth_type::CHAP_MUTUAL);
371 auth = ag->find_auth(chap_n);
372 if (auth == NULL) {
373 login_send_error(request, 0x02, 0x01);
374 log_errx(1, "received CHAP Login with invalid user \"%s\"",
375 chap_n);
376 }
377
378 error = chap_authenticate(chap, auth->secret());
379 if (error != 0) {
380 login_send_error(request, 0x02, 0x01);
381 log_errx(1, "CHAP authentication failed for user \"%s\"",
382 chap_n);
383 }
384 user = chap_n;
385
386 keys_delete(request_keys);
387
388 *authp = auth;
389 return (request);
390 }
391
392 static void
login_send_chap_success(struct pdu * request,const struct auth * auth,const std::string & user)393 login_send_chap_success(struct pdu *request,
394 const struct auth *auth, const std::string &user)
395 {
396 struct pdu *response;
397 struct keys *request_keys, *response_keys;
398 struct rchap *rchap;
399 const char *chap_i, *chap_c;
400 char *chap_r;
401 int error;
402
403 response = login_new_response(request);
404 login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
405
406 /*
407 * Actually, one more thing: mutual authentication.
408 */
409 request_keys = keys_new();
410 keys_load_pdu(request_keys, request);
411 chap_i = keys_find(request_keys, "CHAP_I");
412 chap_c = keys_find(request_keys, "CHAP_C");
413 if (chap_i != NULL || chap_c != NULL) {
414 if (chap_i == NULL) {
415 login_send_error(request, 0x02, 0x07);
416 log_errx(1, "initiator requested target "
417 "authentication, but didn't send CHAP_I");
418 }
419 if (chap_c == NULL) {
420 login_send_error(request, 0x02, 0x07);
421 log_errx(1, "initiator requested target "
422 "authentication, but didn't send CHAP_C");
423 }
424 if (!auth->mutual()) {
425 login_send_error(request, 0x02, 0x01);
426 log_errx(1, "initiator requests target authentication "
427 "for user \"%s\", but mutual user/secret "
428 "is not set", user.c_str());
429 }
430
431 log_debugx("performing mutual authentication as user \"%s\"",
432 auth->mutual_user());
433
434 rchap = rchap_new(auth->mutual_secret());
435 error = rchap_receive(rchap, chap_i, chap_c);
436 if (error != 0) {
437 login_send_error(request, 0x02, 0x07);
438 log_errx(1, "received CHAP Login PDU with malformed "
439 "CHAP_I or CHAP_C");
440 }
441 chap_r = rchap_get_response(rchap);
442 rchap_delete(rchap);
443 response_keys = keys_new();
444 keys_add(response_keys, "CHAP_N", auth->mutual_user());
445 keys_add(response_keys, "CHAP_R", chap_r);
446 free(chap_r);
447 keys_save_pdu(response_keys, response);
448 keys_delete(response_keys);
449 } else {
450 log_debugx("initiator did not request target authentication");
451 }
452
453 keys_delete(request_keys);
454 pdu_send(response);
455 pdu_delete(response);
456 }
457
458 void
login_chap(struct auth_group * ag)459 iscsi_connection::login_chap(struct auth_group *ag)
460 {
461 std::string user;
462 const struct auth *auth;
463 struct chap *chap;
464 struct pdu *request;
465
466 /*
467 * Receive CHAP_A PDU.
468 */
469 log_debugx("beginning CHAP authentication; waiting for CHAP_A");
470 request = login_receive_chap_a(&conn);
471
472 /*
473 * Generate the challenge.
474 */
475 chap = chap_new();
476
477 /*
478 * Send the challenge.
479 */
480 log_debugx("sending CHAP_C, binary challenge size is %zd bytes",
481 sizeof(chap->chap_challenge));
482 login_send_chap_c(request, chap);
483 pdu_delete(request);
484
485 /*
486 * Receive CHAP_N/CHAP_R PDU and authenticate.
487 */
488 log_debugx("waiting for CHAP_N/CHAP_R");
489 request = login_receive_chap_r(&conn, ag, chap, &auth, user);
490
491 /*
492 * Yay, authentication succeeded!
493 */
494 log_debugx("authentication succeeded for user \"%s\"; "
495 "transitioning to operational parameter negotiation", user.c_str());
496 login_send_chap_success(request, auth, user);
497 pdu_delete(request);
498
499 /*
500 * Leave username and CHAP information for discovery().
501 */
502 conn_user = user;
503 conn_chap = chap;
504 }
505
506 void
login_negotiate_key(struct pdu * request,const char * name,const char * value,bool skipped_security,struct keys * response_keys)507 iscsi_connection::login_negotiate_key(struct pdu *request, const char *name,
508 const char *value, bool skipped_security, struct keys *response_keys)
509 {
510 int which;
511 size_t tmp;
512
513 assert(request->pdu_connection == &conn);
514
515 if (strcmp(name, "InitiatorName") == 0) {
516 if (!skipped_security)
517 log_errx(1, "initiator resent InitiatorName");
518 } else if (strcmp(name, "SessionType") == 0) {
519 if (!skipped_security)
520 log_errx(1, "initiator resent SessionType");
521 } else if (strcmp(name, "TargetName") == 0) {
522 if (!skipped_security)
523 log_errx(1, "initiator resent TargetName");
524 } else if (strcmp(name, "InitiatorAlias") == 0) {
525 conn_initiator_alias = value;
526 } else if (strcmp(value, "Irrelevant") == 0) {
527 /* Ignore. */
528 } else if (strcmp(name, "HeaderDigest") == 0) {
529 /*
530 * We don't handle digests for discovery sessions.
531 */
532 if (conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
533 log_debugx("discovery session; digests disabled");
534 keys_add(response_keys, name, "None");
535 return;
536 }
537
538 which = login_list_prefers(value, "CRC32C", "None");
539 switch (which) {
540 case 1:
541 log_debugx("initiator prefers CRC32C "
542 "for header digest; we'll use it");
543 conn.conn_header_digest = CONN_DIGEST_CRC32C;
544 keys_add(response_keys, name, "CRC32C");
545 break;
546 case 2:
547 log_debugx("initiator prefers not to do "
548 "header digest; we'll comply");
549 keys_add(response_keys, name, "None");
550 break;
551 default:
552 log_warnx("initiator sent unrecognized "
553 "HeaderDigest value \"%s\"; will use None", value);
554 keys_add(response_keys, name, "None");
555 break;
556 }
557 } else if (strcmp(name, "DataDigest") == 0) {
558 if (conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
559 log_debugx("discovery session; digests disabled");
560 keys_add(response_keys, name, "None");
561 return;
562 }
563
564 which = login_list_prefers(value, "CRC32C", "None");
565 switch (which) {
566 case 1:
567 log_debugx("initiator prefers CRC32C "
568 "for data digest; we'll use it");
569 conn.conn_data_digest = CONN_DIGEST_CRC32C;
570 keys_add(response_keys, name, "CRC32C");
571 break;
572 case 2:
573 log_debugx("initiator prefers not to do "
574 "data digest; we'll comply");
575 keys_add(response_keys, name, "None");
576 break;
577 default:
578 log_warnx("initiator sent unrecognized "
579 "DataDigest value \"%s\"; will use None", value);
580 keys_add(response_keys, name, "None");
581 break;
582 }
583 } else if (strcmp(name, "MaxConnections") == 0) {
584 keys_add(response_keys, name, "1");
585 } else if (strcmp(name, "InitialR2T") == 0) {
586 keys_add(response_keys, name, "Yes");
587 } else if (strcmp(name, "ImmediateData") == 0) {
588 if (conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
589 log_debugx("discovery session; ImmediateData irrelevant");
590 keys_add(response_keys, name, "Irrelevant");
591 } else {
592 if (strcmp(value, "Yes") == 0) {
593 conn.conn_immediate_data = true;
594 keys_add(response_keys, name, "Yes");
595 } else {
596 conn.conn_immediate_data = false;
597 keys_add(response_keys, name, "No");
598 }
599 }
600 } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
601 tmp = strtoul(value, NULL, 10);
602 if (tmp <= 0) {
603 login_send_error(request, 0x02, 0x00);
604 log_errx(1, "received invalid "
605 "MaxRecvDataSegmentLength");
606 }
607
608 /*
609 * MaxRecvDataSegmentLength is a direction-specific parameter.
610 * We'll limit our _send_ to what the initiator can handle but
611 * our MaxRecvDataSegmentLength is not influenced by the
612 * initiator in any way.
613 */
614 if ((int)tmp > conn_max_send_data_segment_limit) {
615 log_debugx("capping MaxRecvDataSegmentLength "
616 "from %zd to %d", tmp,
617 conn_max_send_data_segment_limit);
618 tmp = conn_max_send_data_segment_limit;
619 }
620 conn.conn_max_send_data_segment_length = tmp;
621 } else if (strcmp(name, "MaxBurstLength") == 0) {
622 tmp = strtoul(value, NULL, 10);
623 if (tmp <= 0) {
624 login_send_error(request, 0x02, 0x00);
625 log_errx(1, "received invalid MaxBurstLength");
626 }
627 if ((int)tmp > conn_max_burst_limit) {
628 log_debugx("capping MaxBurstLength from %zd to %d",
629 tmp, conn_max_burst_limit);
630 tmp = conn_max_burst_limit;
631 }
632 conn.conn_max_burst_length = tmp;
633 keys_add_int(response_keys, name, tmp);
634 } else if (strcmp(name, "FirstBurstLength") == 0) {
635 tmp = strtoul(value, NULL, 10);
636 if (tmp <= 0) {
637 login_send_error(request, 0x02, 0x00);
638 log_errx(1, "received invalid FirstBurstLength");
639 }
640 if ((int)tmp > conn_first_burst_limit) {
641 log_debugx("capping FirstBurstLength from %zd to %d",
642 tmp, conn_first_burst_limit);
643 tmp = conn_first_burst_limit;
644 }
645 conn.conn_first_burst_length = tmp;
646 keys_add_int(response_keys, name, tmp);
647 } else if (strcmp(name, "DefaultTime2Wait") == 0) {
648 keys_add(response_keys, name, value);
649 } else if (strcmp(name, "DefaultTime2Retain") == 0) {
650 keys_add(response_keys, name, "0");
651 } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
652 keys_add(response_keys, name, "1");
653 } else if (strcmp(name, "DataPDUInOrder") == 0) {
654 keys_add(response_keys, name, "Yes");
655 } else if (strcmp(name, "DataSequenceInOrder") == 0) {
656 keys_add(response_keys, name, "Yes");
657 } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
658 keys_add(response_keys, name, "0");
659 } else if (strcmp(name, "OFMarker") == 0) {
660 keys_add(response_keys, name, "No");
661 } else if (strcmp(name, "IFMarker") == 0) {
662 keys_add(response_keys, name, "No");
663 } else if (strcmp(name, "iSCSIProtocolLevel") == 0) {
664 tmp = strtoul(value, NULL, 10);
665 if (tmp > 2)
666 tmp = 2;
667 keys_add_int(response_keys, name, tmp);
668 } else {
669 log_debugx("unknown key \"%s\"; responding "
670 "with NotUnderstood", name);
671 keys_add(response_keys, name, "NotUnderstood");
672 }
673 }
674
675 static void
login_redirect(struct pdu * request,const char * target_address)676 login_redirect(struct pdu *request, const char *target_address)
677 {
678 struct pdu *response;
679 struct iscsi_bhs_login_response *bhslr2;
680 struct keys *response_keys;
681
682 response = login_new_response(request);
683 login_set_csg(response, login_csg(request));
684 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
685 bhslr2->bhslr_status_class = 0x01;
686 bhslr2->bhslr_status_detail = 0x01;
687
688 response_keys = keys_new();
689 keys_add(response_keys, "TargetAddress", target_address);
690
691 keys_save_pdu(response_keys, response);
692 pdu_send(response);
693 pdu_delete(response);
694 keys_delete(response_keys);
695 }
696
697 bool
login_portal_redirect(struct pdu * request)698 iscsi_connection::login_portal_redirect(struct pdu *request)
699 {
700 const struct portal_group *pg;
701
702 pg = conn_portal->portal_group();
703 if (!pg->is_redirecting())
704 return (false);
705
706 log_debugx("portal-group \"%s\" configured to redirect to %s",
707 pg->name(), pg->redirection());
708 login_redirect(request, pg->redirection());
709
710 return (true);
711 }
712
713 bool
login_target_redirect(struct pdu * request)714 iscsi_connection::login_target_redirect(struct pdu *request)
715 {
716 const char *target_address;
717
718 assert(!conn_portal->portal_group()->is_redirecting());
719
720 if (conn_target == NULL)
721 return (false);
722
723 if (!conn_target->has_redirection())
724 return (false);
725
726 target_address = conn_target->redirection();
727 log_debugx("target \"%s\" configured to redirect to %s",
728 conn_target->name(), target_address);
729 login_redirect(request, target_address);
730
731 return (true);
732 }
733
734 void
login_negotiate(struct pdu * request)735 iscsi_connection::login_negotiate(struct pdu *request)
736 {
737 struct portal_group *pg = conn_portal->portal_group();
738 struct pdu *response;
739 struct iscsi_bhs_login_response *bhslr2;
740 struct keys *request_keys, *response_keys;
741 int i;
742 bool redirected, skipped_security;
743
744 if (conn_session_type == CONN_SESSION_TYPE_NORMAL) {
745 /*
746 * Query the kernel for various size limits. In case of
747 * offload, it depends on hardware capabilities.
748 */
749 assert(conn_target != NULL);
750 conn_max_recv_data_segment_limit = (1 << 24) - 1;
751 conn_max_send_data_segment_limit = (1 << 24) - 1;
752 conn_max_burst_limit = (1 << 24) - 1;
753 conn_first_burst_limit = (1 << 24) - 1;
754 kernel_limits(pg->offload(),
755 conn_fd,
756 &conn_max_recv_data_segment_limit,
757 &conn_max_send_data_segment_limit,
758 &conn_max_burst_limit,
759 &conn_first_burst_limit);
760
761 /* We expect legal, usable values at this point. */
762 assert(conn_max_recv_data_segment_limit >= 512);
763 assert(conn_max_recv_data_segment_limit < (1 << 24));
764 assert(conn_max_send_data_segment_limit >= 512);
765 assert(conn_max_send_data_segment_limit < (1 << 24));
766 assert(conn_max_burst_limit >= 512);
767 assert(conn_max_burst_limit < (1 << 24));
768 assert(conn_first_burst_limit >= 512);
769 assert(conn_first_burst_limit < (1 << 24));
770 assert(conn_first_burst_limit <= conn_max_burst_limit);
771
772 /*
773 * Limit default send length in case it won't be negotiated.
774 * We can't do it for other limits, since they may affect both
775 * sender and receiver operation, and we must obey defaults.
776 */
777 if (conn_max_send_data_segment_limit <
778 conn.conn_max_send_data_segment_length) {
779 conn.conn_max_send_data_segment_length =
780 conn_max_send_data_segment_limit;
781 }
782 } else {
783 conn_max_recv_data_segment_limit = MAX_DATA_SEGMENT_LENGTH;
784 conn_max_send_data_segment_limit = MAX_DATA_SEGMENT_LENGTH;
785 }
786
787 if (request == NULL) {
788 log_debugx("beginning operational parameter negotiation; "
789 "waiting for Login PDU");
790 request = login_receive(&conn, false);
791 skipped_security = false;
792 } else
793 skipped_security = true;
794
795 /*
796 * RFC 3720, 10.13.5. Status-Class and Status-Detail, says
797 * the redirection SHOULD be accepted by the initiator before
798 * authentication, but MUST be accepted afterwards; that's
799 * why we're doing it here and not earlier.
800 */
801 redirected = login_target_redirect(request);
802 if (redirected) {
803 log_debugx("initiator redirected; exiting");
804 exit(0);
805 }
806
807 request_keys = keys_new();
808 keys_load_pdu(request_keys, request);
809
810 response = login_new_response(request);
811 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
812 bhslr2->bhslr_tsih = htons(0xbadd);
813 login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
814 login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE);
815 response_keys = keys_new();
816
817 if (skipped_security &&
818 conn_session_type == CONN_SESSION_TYPE_NORMAL) {
819 if (conn_target->has_alias())
820 keys_add(response_keys,
821 "TargetAlias", conn_target->alias());
822 keys_add_int(response_keys, "TargetPortalGroupTag",
823 pg->tag());
824 }
825
826 for (i = 0; i < KEYS_MAX; i++) {
827 if (request_keys->keys_names[i] == NULL)
828 break;
829
830 login_negotiate_key(request, request_keys->keys_names[i],
831 request_keys->keys_values[i], skipped_security,
832 response_keys);
833 }
834
835 /*
836 * We'd started with usable values at our end. But a bad initiator
837 * could have presented a large FirstBurstLength and then a smaller
838 * MaxBurstLength (in that order) and because we process the key/value
839 * pairs in the order they are in the request we might have ended up
840 * with illegal values here.
841 */
842 if (conn_session_type == CONN_SESSION_TYPE_NORMAL &&
843 conn.conn_first_burst_length > conn.conn_max_burst_length) {
844 log_errx(1, "initiator sent FirstBurstLength > MaxBurstLength");
845 }
846
847 conn.conn_max_recv_data_segment_length =
848 conn_max_recv_data_segment_limit;
849 keys_add_int(response_keys, "MaxRecvDataSegmentLength",
850 conn.conn_max_recv_data_segment_length);
851
852 log_debugx("operational parameter negotiation done; "
853 "transitioning to Full Feature Phase");
854
855 keys_save_pdu(response_keys, response);
856 pdu_send(response);
857 pdu_delete(response);
858 keys_delete(response_keys);
859 pdu_delete(request);
860 keys_delete(request_keys);
861 }
862
863 void
login_wait_transition()864 iscsi_connection::login_wait_transition()
865 {
866 struct pdu *request, *response;
867 struct iscsi_bhs_login_request *bhslr;
868
869 log_debugx("waiting for state transition request");
870 request = login_receive(&conn, false);
871 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
872 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0) {
873 login_send_error(request, 0x02, 0x00);
874 log_errx(1, "got no \"T\" flag after answering AuthMethod");
875 }
876
877 log_debugx("got state transition request");
878 response = login_new_response(request);
879 pdu_delete(request);
880 login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
881 pdu_send(response);
882 pdu_delete(response);
883
884 login_negotiate(nullptr);
885 }
886
887 void
login()888 iscsi_connection::login()
889 {
890 struct pdu *request, *response;
891 struct iscsi_bhs_login_request *bhslr;
892 struct keys *request_keys, *response_keys;
893 struct auth_group *ag;
894 struct portal_group *pg;
895 const char *initiator_name, *initiator_alias, *session_type,
896 *target_name, *auth_method;
897 bool redirected, fail, trans;
898
899 /*
900 * Handle the initial Login Request - figure out required authentication
901 * method and either transition to the next phase, if no authentication
902 * is required, or call appropriate authentication code.
903 */
904 log_debugx("beginning Login Phase; waiting for Login PDU");
905 request = login_receive(&conn, true);
906 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
907 if (bhslr->bhslr_tsih != 0) {
908 login_send_error(request, 0x02, 0x0a);
909 log_errx(1, "received Login PDU with non-zero TSIH");
910 }
911
912 pg = conn_portal->portal_group();
913
914 memcpy(conn_initiator_isid, bhslr->bhslr_isid,
915 sizeof(conn_initiator_isid));
916
917 /*
918 * XXX: Implement the C flag some day.
919 */
920 request_keys = keys_new();
921 keys_load_pdu(request_keys, request);
922
923 assert(conn_initiator_name.empty());
924 initiator_name = keys_find(request_keys, "InitiatorName");
925 if (initiator_name == NULL) {
926 login_send_error(request, 0x02, 0x07);
927 log_errx(1, "received Login PDU without InitiatorName");
928 }
929 if (valid_iscsi_name(initiator_name, log_warnx) == false) {
930 login_send_error(request, 0x02, 0x00);
931 log_errx(1, "received Login PDU with invalid InitiatorName");
932 }
933 conn_initiator_name = initiator_name;
934 log_set_peer_name(conn_initiator_name.c_str());
935 setproctitle("%s (%s)", conn_initiator_addr.c_str(),
936 conn_initiator_name.c_str());
937
938 redirected = login_portal_redirect(request);
939 if (redirected) {
940 log_debugx("initiator redirected; exiting");
941 exit(0);
942 }
943
944 initiator_alias = keys_find(request_keys, "InitiatorAlias");
945 if (initiator_alias != NULL)
946 conn_initiator_alias = initiator_alias;
947
948 assert(conn_session_type == CONN_SESSION_TYPE_NONE);
949 session_type = keys_find(request_keys, "SessionType");
950 if (session_type != NULL) {
951 if (strcmp(session_type, "Normal") == 0) {
952 conn_session_type = CONN_SESSION_TYPE_NORMAL;
953 } else if (strcmp(session_type, "Discovery") == 0) {
954 conn_session_type = CONN_SESSION_TYPE_DISCOVERY;
955 } else {
956 login_send_error(request, 0x02, 0x00);
957 log_errx(1, "received Login PDU with invalid "
958 "SessionType \"%s\"", session_type);
959 }
960 } else
961 conn_session_type = CONN_SESSION_TYPE_NORMAL;
962
963 assert(conn_target == NULL);
964 if (conn_session_type == CONN_SESSION_TYPE_NORMAL) {
965 target_name = keys_find(request_keys, "TargetName");
966 if (target_name == NULL) {
967 login_send_error(request, 0x02, 0x07);
968 log_errx(1, "received Login PDU without TargetName");
969 }
970
971 conn_port = pg->find_port(target_name);
972 if (conn_port == NULL) {
973 login_send_error(request, 0x02, 0x03);
974 log_errx(1, "requested target \"%s\" not found",
975 target_name);
976 }
977 conn_target = conn_port->target();
978 }
979
980 /*
981 * At this point we know what kind of authentication we need.
982 */
983 if (conn_session_type == CONN_SESSION_TYPE_NORMAL) {
984 ag = conn_port->auth_group();
985 if (ag == nullptr)
986 ag = conn_target->auth_group();
987 if (conn_port->auth_group() == nullptr &&
988 conn_target->private_auth()) {
989 log_debugx("initiator requests to connect "
990 "to target \"%s\"", conn_target->name());
991 } else {
992 log_debugx("initiator requests to connect "
993 "to target \"%s\"; %s",
994 conn_target->name(), ag->label());
995 }
996 } else {
997 assert(conn_session_type == CONN_SESSION_TYPE_DISCOVERY);
998 ag = pg->discovery_auth_group();
999 log_debugx("initiator requests discovery session; %s",
1000 ag->label());
1001 }
1002
1003 if (ag->type() == auth_type::DENY) {
1004 login_send_error(request, 0x02, 0x01);
1005 log_errx(1, "auth-type is \"deny\"");
1006 }
1007
1008 if (ag->type() == auth_type::UNKNOWN) {
1009 /*
1010 * This can happen with empty auth-group.
1011 */
1012 login_send_error(request, 0x02, 0x01);
1013 log_errx(1, "auth-type not set, denying access");
1014 }
1015
1016 /*
1017 * Enforce initiator-name and initiator-portal.
1018 */
1019 if (!ag->initiator_permitted(initiator_name)) {
1020 login_send_error(request, 0x02, 0x02);
1021 log_errx(1, "initiator does not match allowed initiator names");
1022 }
1023
1024 if (!ag->initiator_permitted(conn_initiator_sa)) {
1025 login_send_error(request, 0x02, 0x02);
1026 log_errx(1, "initiator does not match allowed "
1027 "initiator portals");
1028 }
1029
1030 /*
1031 * Let's see if the initiator intends to do any kind of authentication
1032 * at all.
1033 */
1034 if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
1035 if (ag->type() != auth_type::NO_AUTHENTICATION) {
1036 login_send_error(request, 0x02, 0x01);
1037 log_errx(1, "initiator skipped the authentication, "
1038 "but authentication is required");
1039 }
1040
1041 keys_delete(request_keys);
1042
1043 log_debugx("initiator skipped the authentication, "
1044 "and we don't need it; proceeding with negotiation");
1045 login_negotiate(request);
1046 return;
1047 }
1048
1049 fail = false;
1050 response = login_new_response(request);
1051 response_keys = keys_new();
1052 trans = (bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0;
1053 auth_method = keys_find(request_keys, "AuthMethod");
1054 if (ag->type() == auth_type::NO_AUTHENTICATION) {
1055 log_debugx("authentication not required");
1056 if (auth_method == NULL ||
1057 login_list_contains(auth_method, "None")) {
1058 keys_add(response_keys, "AuthMethod", "None");
1059 } else {
1060 log_warnx("initiator requests "
1061 "AuthMethod \"%s\" instead of \"None\"",
1062 auth_method);
1063 keys_add(response_keys, "AuthMethod", "Reject");
1064 }
1065 if (trans)
1066 login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
1067 } else {
1068 log_debugx("CHAP authentication required");
1069 if (auth_method == NULL ||
1070 login_list_contains(auth_method, "CHAP")) {
1071 keys_add(response_keys, "AuthMethod", "CHAP");
1072 } else {
1073 log_warnx("initiator requests unsupported "
1074 "AuthMethod \"%s\" instead of \"CHAP\"",
1075 auth_method);
1076 keys_add(response_keys, "AuthMethod", "Reject");
1077 fail = true;
1078 }
1079 }
1080 if (conn_session_type == CONN_SESSION_TYPE_NORMAL) {
1081 if (conn_target->has_alias())
1082 keys_add(response_keys,
1083 "TargetAlias", conn_target->alias());
1084 keys_add_int(response_keys,
1085 "TargetPortalGroupTag", pg->tag());
1086 }
1087 keys_save_pdu(response_keys, response);
1088
1089 pdu_send(response);
1090 pdu_delete(response);
1091 keys_delete(response_keys);
1092 pdu_delete(request);
1093 keys_delete(request_keys);
1094
1095 if (fail) {
1096 log_debugx("sent reject for AuthMethod; exiting");
1097 exit(1);
1098 }
1099
1100 if (ag->type() != auth_type::NO_AUTHENTICATION) {
1101 login_chap(ag);
1102 login_negotiate(nullptr);
1103 } else if (trans) {
1104 login_negotiate(nullptr);
1105 } else {
1106 login_wait_transition();
1107 }
1108 }
1109