1/*-
2 * Copyright (c) 2012 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by Edward Tomasz Napierala under sponsorship
6 * from the FreeBSD Foundation.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: releng/11.0/usr.sbin/ctld/login.c 303311 2016-07-25 17:17:59Z np $");
33
34#include <assert.h>
35#include <stdbool.h>
36#include <stdlib.h>
37#include <string.h>
38#include <unistd.h>
39#include <netinet/in.h>
40
41#include "ctld.h"
42#include "iscsi_proto.h"
43
44static void login_send_error(struct pdu *request,
45    char class, char detail);
46
47static void
48login_set_nsg(struct pdu *response, int nsg)
49{
50	struct iscsi_bhs_login_response *bhslr;
51
52	assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
53	    nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
54	    nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
55
56	bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
57
58	bhslr->bhslr_flags &= 0xFC;
59	bhslr->bhslr_flags |= nsg;
60	bhslr->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
61}
62
63static int
64login_csg(const struct pdu *request)
65{
66	struct iscsi_bhs_login_request *bhslr;
67
68	bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
69
70	return ((bhslr->bhslr_flags & 0x0C) >> 2);
71}
72
73static void
74login_set_csg(struct pdu *response, int csg)
75{
76	struct iscsi_bhs_login_response *bhslr;
77
78	assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
79	    csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
80	    csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
81
82	bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
83
84	bhslr->bhslr_flags &= 0xF3;
85	bhslr->bhslr_flags |= csg << 2;
86}
87
88static struct pdu *
89login_receive(struct connection *conn, bool initial)
90{
91	struct pdu *request;
92	struct iscsi_bhs_login_request *bhslr;
93
94	request = pdu_new(conn);
95	pdu_receive(request);
96	if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
97	    ISCSI_BHS_OPCODE_LOGIN_REQUEST) {
98		/*
99		 * The first PDU in session is special - if we receive any PDU
100		 * different than login request, we have to drop the connection
101		 * without sending response ("A target receiving any PDU
102		 * except a Login request before the Login Phase is started MUST
103		 * immediately terminate the connection on which the PDU
104		 * was received.")
105		 */
106		if (initial == false)
107			login_send_error(request, 0x02, 0x0b);
108		log_errx(1, "protocol error: received invalid opcode 0x%x",
109		    request->pdu_bhs->bhs_opcode);
110	}
111	bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
112	/*
113	 * XXX: Implement the C flag some day.
114	 */
115	if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0) {
116		login_send_error(request, 0x03, 0x00);
117		log_errx(1, "received Login PDU with unsupported \"C\" flag");
118	}
119	if (bhslr->bhslr_version_max != 0x00) {
120		login_send_error(request, 0x02, 0x05);
121		log_errx(1, "received Login PDU with unsupported "
122		    "Version-max 0x%x", bhslr->bhslr_version_max);
123	}
124	if (bhslr->bhslr_version_min != 0x00) {
125		login_send_error(request, 0x02, 0x05);
126		log_errx(1, "received Login PDU with unsupported "
127		    "Version-min 0x%x", bhslr->bhslr_version_min);
128	}
129	if (initial == false &&
130	    ISCSI_SNLT(ntohl(bhslr->bhslr_cmdsn), conn->conn_cmdsn)) {
131		login_send_error(request, 0x02, 0x00);
132		log_errx(1, "received Login PDU with decreasing CmdSN: "
133		    "was %u, is %u", conn->conn_cmdsn,
134		    ntohl(bhslr->bhslr_cmdsn));
135	}
136	if (initial == false &&
137	    ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) {
138		login_send_error(request, 0x02, 0x00);
139		log_errx(1, "received Login PDU with wrong ExpStatSN: "
140		    "is %u, should be %u", ntohl(bhslr->bhslr_expstatsn),
141		    conn->conn_statsn);
142	}
143	conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn);
144
145	return (request);
146}
147
148static struct pdu *
149login_new_response(struct pdu *request)
150{
151	struct pdu *response;
152	struct connection *conn;
153	struct iscsi_bhs_login_request *bhslr;
154	struct iscsi_bhs_login_response *bhslr2;
155
156	bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
157	conn = request->pdu_connection;
158
159	response = pdu_new_response(request);
160	bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
161	bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_RESPONSE;
162	login_set_csg(response, BHSLR_STAGE_SECURITY_NEGOTIATION);
163	memcpy(bhslr2->bhslr_isid,
164	    bhslr->bhslr_isid, sizeof(bhslr2->bhslr_isid));
165	bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag;
166	bhslr2->bhslr_statsn = htonl(conn->conn_statsn++);
167	bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn);
168	bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn);
169
170	return (response);
171}
172
173static void
174login_send_error(struct pdu *request, char class, char detail)
175{
176	struct pdu *response;
177	struct iscsi_bhs_login_response *bhslr2;
178
179	log_debugx("sending Login Response PDU with failure class 0x%x/0x%x; "
180	    "see next line for reason", class, detail);
181	response = login_new_response(request);
182	bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
183	bhslr2->bhslr_status_class = class;
184	bhslr2->bhslr_status_detail = detail;
185
186	pdu_send(response);
187	pdu_delete(response);
188}
189
190static int
191login_list_contains(const char *list, const char *what)
192{
193	char *tofree, *str, *token;
194
195	tofree = str = checked_strdup(list);
196
197	while ((token = strsep(&str, ",")) != NULL) {
198		if (strcmp(token, what) == 0) {
199			free(tofree);
200			return (1);
201		}
202	}
203	free(tofree);
204	return (0);
205}
206
207static int
208login_list_prefers(const char *list,
209    const char *choice1, const char *choice2)
210{
211	char *tofree, *str, *token;
212
213	tofree = str = checked_strdup(list);
214
215	while ((token = strsep(&str, ",")) != NULL) {
216		if (strcmp(token, choice1) == 0) {
217			free(tofree);
218			return (1);
219		}
220		if (strcmp(token, choice2) == 0) {
221			free(tofree);
222			return (2);
223		}
224	}
225	free(tofree);
226	return (-1);
227}
228
229static struct pdu *
230login_receive_chap_a(struct connection *conn)
231{
232	struct pdu *request;
233	struct keys *request_keys;
234	const char *chap_a;
235
236	request = login_receive(conn, false);
237	request_keys = keys_new();
238	keys_load(request_keys, request);
239
240	chap_a = keys_find(request_keys, "CHAP_A");
241	if (chap_a == NULL) {
242		login_send_error(request, 0x02, 0x07);
243		log_errx(1, "received CHAP Login PDU without CHAP_A");
244	}
245	if (login_list_contains(chap_a, "5") == 0) {
246		login_send_error(request, 0x02, 0x01);
247		log_errx(1, "received CHAP Login PDU with unsupported CHAP_A "
248		    "\"%s\"", chap_a);
249	}
250	keys_delete(request_keys);
251
252	return (request);
253}
254
255static void
256login_send_chap_c(struct pdu *request, struct chap *chap)
257{
258	struct pdu *response;
259	struct keys *response_keys;
260	char *chap_c, *chap_i;
261
262	chap_c = chap_get_challenge(chap);
263	chap_i = chap_get_id(chap);
264
265	response = login_new_response(request);
266	response_keys = keys_new();
267	keys_add(response_keys, "CHAP_A", "5");
268	keys_add(response_keys, "CHAP_I", chap_i);
269	keys_add(response_keys, "CHAP_C", chap_c);
270	free(chap_i);
271	free(chap_c);
272	keys_save(response_keys, response);
273	pdu_send(response);
274	pdu_delete(response);
275	keys_delete(response_keys);
276}
277
278static struct pdu *
279login_receive_chap_r(struct connection *conn, struct auth_group *ag,
280    struct chap *chap, const struct auth **authp)
281{
282	struct pdu *request;
283	struct keys *request_keys;
284	const char *chap_n, *chap_r;
285	const struct auth *auth;
286	int error;
287
288	request = login_receive(conn, false);
289	request_keys = keys_new();
290	keys_load(request_keys, request);
291
292	chap_n = keys_find(request_keys, "CHAP_N");
293	if (chap_n == NULL) {
294		login_send_error(request, 0x02, 0x07);
295		log_errx(1, "received CHAP Login PDU without CHAP_N");
296	}
297	chap_r = keys_find(request_keys, "CHAP_R");
298	if (chap_r == NULL) {
299		login_send_error(request, 0x02, 0x07);
300		log_errx(1, "received CHAP Login PDU without CHAP_R");
301	}
302	error = chap_receive(chap, chap_r);
303	if (error != 0) {
304		login_send_error(request, 0x02, 0x07);
305		log_errx(1, "received CHAP Login PDU with malformed CHAP_R");
306	}
307
308	/*
309	 * Verify the response.
310	 */
311	assert(ag->ag_type == AG_TYPE_CHAP ||
312	    ag->ag_type == AG_TYPE_CHAP_MUTUAL);
313	auth = auth_find(ag, chap_n);
314	if (auth == NULL) {
315		login_send_error(request, 0x02, 0x01);
316		log_errx(1, "received CHAP Login with invalid user \"%s\"",
317		    chap_n);
318	}
319
320	assert(auth->a_secret != NULL);
321	assert(strlen(auth->a_secret) > 0);
322
323	error = chap_authenticate(chap, auth->a_secret);
324	if (error != 0) {
325		login_send_error(request, 0x02, 0x01);
326		log_errx(1, "CHAP authentication failed for user \"%s\"",
327		    auth->a_user);
328	}
329
330	keys_delete(request_keys);
331
332	*authp = auth;
333	return (request);
334}
335
336static void
337login_send_chap_success(struct pdu *request,
338    const struct auth *auth)
339{
340	struct pdu *response;
341	struct keys *request_keys, *response_keys;
342	struct rchap *rchap;
343	const char *chap_i, *chap_c;
344	char *chap_r;
345	int error;
346
347	response = login_new_response(request);
348	login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
349
350	/*
351	 * Actually, one more thing: mutual authentication.
352	 */
353	request_keys = keys_new();
354	keys_load(request_keys, request);
355	chap_i = keys_find(request_keys, "CHAP_I");
356	chap_c = keys_find(request_keys, "CHAP_C");
357	if (chap_i != NULL || chap_c != NULL) {
358		if (chap_i == NULL) {
359			login_send_error(request, 0x02, 0x07);
360			log_errx(1, "initiator requested target "
361			    "authentication, but didn't send CHAP_I");
362		}
363		if (chap_c == NULL) {
364			login_send_error(request, 0x02, 0x07);
365			log_errx(1, "initiator requested target "
366			    "authentication, but didn't send CHAP_C");
367		}
368		if (auth->a_auth_group->ag_type != AG_TYPE_CHAP_MUTUAL) {
369			login_send_error(request, 0x02, 0x01);
370			log_errx(1, "initiator requests target authentication "
371			    "for user \"%s\", but mutual user/secret "
372			    "is not set", auth->a_user);
373		}
374
375		log_debugx("performing mutual authentication as user \"%s\"",
376		    auth->a_mutual_user);
377
378		rchap = rchap_new(auth->a_mutual_secret);
379		error = rchap_receive(rchap, chap_i, chap_c);
380		if (error != 0) {
381			login_send_error(request, 0x02, 0x07);
382			log_errx(1, "received CHAP Login PDU with malformed "
383			    "CHAP_I or CHAP_C");
384		}
385		chap_r = rchap_get_response(rchap);
386		rchap_delete(rchap);
387		response_keys = keys_new();
388		keys_add(response_keys, "CHAP_N", auth->a_mutual_user);
389		keys_add(response_keys, "CHAP_R", chap_r);
390		free(chap_r);
391		keys_save(response_keys, response);
392		keys_delete(response_keys);
393	} else {
394		log_debugx("initiator did not request target authentication");
395	}
396
397	keys_delete(request_keys);
398	pdu_send(response);
399	pdu_delete(response);
400}
401
402static void
403login_chap(struct connection *conn, struct auth_group *ag)
404{
405	const struct auth *auth;
406	struct chap *chap;
407	struct pdu *request;
408
409	/*
410	 * Receive CHAP_A PDU.
411	 */
412	log_debugx("beginning CHAP authentication; waiting for CHAP_A");
413	request = login_receive_chap_a(conn);
414
415	/*
416	 * Generate the challenge.
417	 */
418	chap = chap_new();
419
420	/*
421	 * Send the challenge.
422	 */
423	log_debugx("sending CHAP_C, binary challenge size is %zd bytes",
424	    sizeof(chap->chap_challenge));
425	login_send_chap_c(request, chap);
426	pdu_delete(request);
427
428	/*
429	 * Receive CHAP_N/CHAP_R PDU and authenticate.
430	 */
431	log_debugx("waiting for CHAP_N/CHAP_R");
432	request = login_receive_chap_r(conn, ag, chap, &auth);
433
434	/*
435	 * Yay, authentication succeeded!
436	 */
437	log_debugx("authentication succeeded for user \"%s\"; "
438	    "transitioning to Negotiation Phase", auth->a_user);
439	login_send_chap_success(request, auth);
440	pdu_delete(request);
441
442	/*
443	 * Leave username and CHAP information for discovery().
444	 */
445	conn->conn_user = auth->a_user;
446	conn->conn_chap = chap;
447}
448
449static void
450login_negotiate_key(struct pdu *request, const char *name,
451    const char *value, bool skipped_security, struct keys *response_keys)
452{
453	int which;
454	size_t tmp;
455	struct connection *conn;
456
457	conn = request->pdu_connection;
458
459	if (strcmp(name, "InitiatorName") == 0) {
460		if (!skipped_security)
461			log_errx(1, "initiator resent InitiatorName");
462	} else if (strcmp(name, "SessionType") == 0) {
463		if (!skipped_security)
464			log_errx(1, "initiator resent SessionType");
465	} else if (strcmp(name, "TargetName") == 0) {
466		if (!skipped_security)
467			log_errx(1, "initiator resent TargetName");
468	} else if (strcmp(name, "InitiatorAlias") == 0) {
469		if (conn->conn_initiator_alias != NULL)
470			free(conn->conn_initiator_alias);
471		conn->conn_initiator_alias = checked_strdup(value);
472	} else if (strcmp(value, "Irrelevant") == 0) {
473		/* Ignore. */
474	} else if (strcmp(name, "HeaderDigest") == 0) {
475		/*
476		 * We don't handle digests for discovery sessions.
477		 */
478		if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
479			log_debugx("discovery session; digests disabled");
480			keys_add(response_keys, name, "None");
481			return;
482		}
483
484		which = login_list_prefers(value, "CRC32C", "None");
485		switch (which) {
486		case 1:
487			log_debugx("initiator prefers CRC32C "
488			    "for header digest; we'll use it");
489			conn->conn_header_digest = CONN_DIGEST_CRC32C;
490			keys_add(response_keys, name, "CRC32C");
491			break;
492		case 2:
493			log_debugx("initiator prefers not to do "
494			    "header digest; we'll comply");
495			keys_add(response_keys, name, "None");
496			break;
497		default:
498			log_warnx("initiator sent unrecognized "
499			    "HeaderDigest value \"%s\"; will use None", value);
500			keys_add(response_keys, name, "None");
501			break;
502		}
503	} else if (strcmp(name, "DataDigest") == 0) {
504		if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
505			log_debugx("discovery session; digests disabled");
506			keys_add(response_keys, name, "None");
507			return;
508		}
509
510		which = login_list_prefers(value, "CRC32C", "None");
511		switch (which) {
512		case 1:
513			log_debugx("initiator prefers CRC32C "
514			    "for data digest; we'll use it");
515			conn->conn_data_digest = CONN_DIGEST_CRC32C;
516			keys_add(response_keys, name, "CRC32C");
517			break;
518		case 2:
519			log_debugx("initiator prefers not to do "
520			    "data digest; we'll comply");
521			keys_add(response_keys, name, "None");
522			break;
523		default:
524			log_warnx("initiator sent unrecognized "
525			    "DataDigest value \"%s\"; will use None", value);
526			keys_add(response_keys, name, "None");
527			break;
528		}
529	} else if (strcmp(name, "MaxConnections") == 0) {
530		keys_add(response_keys, name, "1");
531	} else if (strcmp(name, "InitialR2T") == 0) {
532		keys_add(response_keys, name, "Yes");
533	} else if (strcmp(name, "ImmediateData") == 0) {
534		if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
535			log_debugx("discovery session; ImmediateData irrelevant");
536			keys_add(response_keys, name, "Irrelevant");
537		} else {
538			if (strcmp(value, "Yes") == 0) {
539				conn->conn_immediate_data = true;
540				keys_add(response_keys, name, "Yes");
541			} else {
542				conn->conn_immediate_data = false;
543				keys_add(response_keys, name, "No");
544			}
545		}
546	} else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
547		tmp = strtoul(value, NULL, 10);
548		if (tmp <= 0) {
549			login_send_error(request, 0x02, 0x00);
550			log_errx(1, "received invalid "
551			    "MaxRecvDataSegmentLength");
552		}
553		if (tmp > conn->conn_data_segment_limit) {
554			log_debugx("capping MaxRecvDataSegmentLength "
555			    "from %zd to %zd", tmp, conn->conn_data_segment_limit);
556			tmp = conn->conn_data_segment_limit;
557		}
558		conn->conn_max_data_segment_length = tmp;
559		keys_add_int(response_keys, name, conn->conn_data_segment_limit);
560	} else if (strcmp(name, "MaxBurstLength") == 0) {
561		tmp = strtoul(value, NULL, 10);
562		if (tmp <= 0) {
563			login_send_error(request, 0x02, 0x00);
564			log_errx(1, "received invalid MaxBurstLength");
565		}
566		if (tmp > MAX_BURST_LENGTH) {
567			log_debugx("capping MaxBurstLength from %zd to %d",
568			    tmp, MAX_BURST_LENGTH);
569			tmp = MAX_BURST_LENGTH;
570		}
571		conn->conn_max_burst_length = tmp;
572		keys_add_int(response_keys, name, tmp);
573	} else if (strcmp(name, "FirstBurstLength") == 0) {
574		tmp = strtoul(value, NULL, 10);
575		if (tmp <= 0) {
576			login_send_error(request, 0x02, 0x00);
577			log_errx(1, "received invalid FirstBurstLength");
578		}
579		if (tmp > FIRST_BURST_LENGTH) {
580			log_debugx("capping FirstBurstLength from %zd to %d",
581			    tmp, FIRST_BURST_LENGTH);
582			tmp = FIRST_BURST_LENGTH;
583		}
584		conn->conn_first_burst_length = tmp;
585		keys_add_int(response_keys, name, tmp);
586	} else if (strcmp(name, "DefaultTime2Wait") == 0) {
587		keys_add(response_keys, name, value);
588	} else if (strcmp(name, "DefaultTime2Retain") == 0) {
589		keys_add(response_keys, name, "0");
590	} else if (strcmp(name, "MaxOutstandingR2T") == 0) {
591		keys_add(response_keys, name, "1");
592	} else if (strcmp(name, "DataPDUInOrder") == 0) {
593		keys_add(response_keys, name, "Yes");
594	} else if (strcmp(name, "DataSequenceInOrder") == 0) {
595		keys_add(response_keys, name, "Yes");
596	} else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
597		keys_add(response_keys, name, "0");
598	} else if (strcmp(name, "OFMarker") == 0) {
599		keys_add(response_keys, name, "No");
600	} else if (strcmp(name, "IFMarker") == 0) {
601		keys_add(response_keys, name, "No");
602	} else if (strcmp(name, "iSCSIProtocolLevel") == 0) {
603		tmp = strtoul(value, NULL, 10);
604		if (tmp > 2)
605			tmp = 2;
606		keys_add_int(response_keys, name, tmp);
607	} else {
608		log_debugx("unknown key \"%s\"; responding "
609		    "with NotUnderstood", name);
610		keys_add(response_keys, name, "NotUnderstood");
611	}
612}
613
614static void
615login_redirect(struct pdu *request, const char *target_address)
616{
617	struct pdu *response;
618	struct iscsi_bhs_login_response *bhslr2;
619	struct keys *response_keys;
620
621	response = login_new_response(request);
622	login_set_csg(response, login_csg(request));
623	bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
624	bhslr2->bhslr_status_class = 0x01;
625	bhslr2->bhslr_status_detail = 0x01;
626
627	response_keys = keys_new();
628	keys_add(response_keys, "TargetAddress", target_address);
629
630	keys_save(response_keys, response);
631	pdu_send(response);
632	pdu_delete(response);
633	keys_delete(response_keys);
634}
635
636static bool
637login_portal_redirect(struct connection *conn, struct pdu *request)
638{
639	const struct portal_group *pg;
640
641	pg = conn->conn_portal->p_portal_group;
642	if (pg->pg_redirection == NULL)
643		return (false);
644
645	log_debugx("portal-group \"%s\" configured to redirect to %s",
646	    pg->pg_name, pg->pg_redirection);
647	login_redirect(request, pg->pg_redirection);
648
649	return (true);
650}
651
652static bool
653login_target_redirect(struct connection *conn, struct pdu *request)
654{
655	const char *target_address;
656
657	assert(conn->conn_portal->p_portal_group->pg_redirection == NULL);
658
659	if (conn->conn_target == NULL)
660		return (false);
661
662	target_address = conn->conn_target->t_redirection;
663	if (target_address == NULL)
664		return (false);
665
666	log_debugx("target \"%s\" configured to redirect to %s",
667	  conn->conn_target->t_name, target_address);
668	login_redirect(request, target_address);
669
670	return (true);
671}
672
673static void
674login_negotiate(struct connection *conn, struct pdu *request)
675{
676	struct pdu *response;
677	struct iscsi_bhs_login_response *bhslr2;
678	struct keys *request_keys, *response_keys;
679	int i;
680	bool redirected, skipped_security;
681
682	if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
683		/*
684		 * Query the kernel for MaxDataSegmentLength it can handle.
685		 * In case of offload, it depends on hardware capabilities.
686		 */
687		assert(conn->conn_target != NULL);
688		kernel_limits(conn->conn_portal->p_portal_group->pg_offload,
689		    &conn->conn_data_segment_limit);
690	} else {
691		conn->conn_data_segment_limit = MAX_DATA_SEGMENT_LENGTH;
692	}
693
694	if (request == NULL) {
695		log_debugx("beginning operational parameter negotiation; "
696		    "waiting for Login PDU");
697		request = login_receive(conn, false);
698		skipped_security = false;
699	} else
700		skipped_security = true;
701
702	/*
703	 * RFC 3720, 10.13.5.  Status-Class and Status-Detail, says
704	 * the redirection SHOULD be accepted by the initiator before
705	 * authentication, but MUST be be accepted afterwards; that's
706	 * why we're doing it here and not earlier.
707	 */
708	redirected = login_target_redirect(conn, request);
709	if (redirected) {
710		log_debugx("initiator redirected; exiting");
711		exit(0);
712	}
713
714	request_keys = keys_new();
715	keys_load(request_keys, request);
716
717	response = login_new_response(request);
718	bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
719	bhslr2->bhslr_tsih = htons(0xbadd);
720	login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
721	login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE);
722	response_keys = keys_new();
723
724	if (skipped_security &&
725	    conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
726		if (conn->conn_target->t_alias != NULL)
727			keys_add(response_keys,
728			    "TargetAlias", conn->conn_target->t_alias);
729		keys_add_int(response_keys, "TargetPortalGroupTag",
730		    conn->conn_portal->p_portal_group->pg_tag);
731	}
732
733	for (i = 0; i < KEYS_MAX; i++) {
734		if (request_keys->keys_names[i] == NULL)
735			break;
736
737		login_negotiate_key(request, request_keys->keys_names[i],
738		    request_keys->keys_values[i], skipped_security,
739		    response_keys);
740	}
741
742	log_debugx("operational parameter negotiation done; "
743	    "transitioning to Full Feature Phase");
744
745	keys_save(response_keys, response);
746	pdu_send(response);
747	pdu_delete(response);
748	keys_delete(response_keys);
749	pdu_delete(request);
750	keys_delete(request_keys);
751}
752
753static void
754login_wait_transition(struct connection *conn)
755{
756	struct pdu *request, *response;
757	struct iscsi_bhs_login_request *bhslr;
758
759	log_debugx("waiting for state transition request");
760	request = login_receive(conn, false);
761	bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
762	if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0) {
763		login_send_error(request, 0x02, 0x00);
764		log_errx(1, "got no \"T\" flag after answering AuthMethod");
765	}
766
767	log_debugx("got state transition request");
768	response = login_new_response(request);
769	pdu_delete(request);
770	login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
771	pdu_send(response);
772	pdu_delete(response);
773
774	login_negotiate(conn, NULL);
775}
776
777void
778login(struct connection *conn)
779{
780	struct pdu *request, *response;
781	struct iscsi_bhs_login_request *bhslr;
782	struct keys *request_keys, *response_keys;
783	struct auth_group *ag;
784	struct portal_group *pg;
785	const char *initiator_name, *initiator_alias, *session_type,
786	    *target_name, *auth_method;
787	bool redirected, fail, trans;
788
789	/*
790	 * Handle the initial Login Request - figure out required authentication
791	 * method and either transition to the next phase, if no authentication
792	 * is required, or call appropriate authentication code.
793	 */
794	log_debugx("beginning Login Phase; waiting for Login PDU");
795	request = login_receive(conn, true);
796	bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
797	if (bhslr->bhslr_tsih != 0) {
798		login_send_error(request, 0x02, 0x0a);
799		log_errx(1, "received Login PDU with non-zero TSIH");
800	}
801
802	pg = conn->conn_portal->p_portal_group;
803
804	memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid,
805	    sizeof(conn->conn_initiator_isid));
806
807	/*
808	 * XXX: Implement the C flag some day.
809	 */
810	request_keys = keys_new();
811	keys_load(request_keys, request);
812
813	assert(conn->conn_initiator_name == NULL);
814	initiator_name = keys_find(request_keys, "InitiatorName");
815	if (initiator_name == NULL) {
816		login_send_error(request, 0x02, 0x07);
817		log_errx(1, "received Login PDU without InitiatorName");
818	}
819	if (valid_iscsi_name(initiator_name) == false) {
820		login_send_error(request, 0x02, 0x00);
821		log_errx(1, "received Login PDU with invalid InitiatorName");
822	}
823	conn->conn_initiator_name = checked_strdup(initiator_name);
824	log_set_peer_name(conn->conn_initiator_name);
825	setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name);
826
827	redirected = login_portal_redirect(conn, request);
828	if (redirected) {
829		log_debugx("initiator redirected; exiting");
830		exit(0);
831	}
832
833	initiator_alias = keys_find(request_keys, "InitiatorAlias");
834	if (initiator_alias != NULL)
835		conn->conn_initiator_alias = checked_strdup(initiator_alias);
836
837	assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE);
838	session_type = keys_find(request_keys, "SessionType");
839	if (session_type != NULL) {
840		if (strcmp(session_type, "Normal") == 0) {
841			conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
842		} else if (strcmp(session_type, "Discovery") == 0) {
843			conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY;
844		} else {
845			login_send_error(request, 0x02, 0x00);
846			log_errx(1, "received Login PDU with invalid "
847			    "SessionType \"%s\"", session_type);
848		}
849	} else
850		conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
851
852	assert(conn->conn_target == NULL);
853	if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
854		target_name = keys_find(request_keys, "TargetName");
855		if (target_name == NULL) {
856			login_send_error(request, 0x02, 0x07);
857			log_errx(1, "received Login PDU without TargetName");
858		}
859
860		conn->conn_port = port_find_in_pg(pg, target_name);
861		if (conn->conn_port == NULL) {
862			login_send_error(request, 0x02, 0x03);
863			log_errx(1, "requested target \"%s\" not found",
864			    target_name);
865		}
866		conn->conn_target = conn->conn_port->p_target;
867	}
868
869	/*
870	 * At this point we know what kind of authentication we need.
871	 */
872	if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
873		ag = conn->conn_port->p_auth_group;
874		if (ag == NULL)
875			ag = conn->conn_target->t_auth_group;
876		if (ag->ag_name != NULL) {
877			log_debugx("initiator requests to connect "
878			    "to target \"%s\"; auth-group \"%s\"",
879			    conn->conn_target->t_name,
880			    ag->ag_name);
881		} else {
882			log_debugx("initiator requests to connect "
883			    "to target \"%s\"", conn->conn_target->t_name);
884		}
885	} else {
886		assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY);
887		ag = pg->pg_discovery_auth_group;
888		if (ag->ag_name != NULL) {
889			log_debugx("initiator requests "
890			    "discovery session; auth-group \"%s\"", ag->ag_name);
891		} else {
892			log_debugx("initiator requests discovery session");
893		}
894	}
895
896	if (ag->ag_type == AG_TYPE_DENY) {
897		login_send_error(request, 0x02, 0x01);
898		log_errx(1, "auth-type is \"deny\"");
899	}
900
901	if (ag->ag_type == AG_TYPE_UNKNOWN) {
902		/*
903		 * This can happen with empty auth-group.
904		 */
905		login_send_error(request, 0x02, 0x01);
906		log_errx(1, "auth-type not set, denying access");
907	}
908
909	/*
910	 * Enforce initiator-name and initiator-portal.
911	 */
912	if (auth_name_check(ag, initiator_name) != 0) {
913		login_send_error(request, 0x02, 0x02);
914		log_errx(1, "initiator does not match allowed initiator names");
915	}
916
917	if (auth_portal_check(ag, &conn->conn_initiator_sa) != 0) {
918		login_send_error(request, 0x02, 0x02);
919		log_errx(1, "initiator does not match allowed "
920		    "initiator portals");
921	}
922
923	/*
924	 * Let's see if the initiator intends to do any kind of authentication
925	 * at all.
926	 */
927	if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
928		if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
929			login_send_error(request, 0x02, 0x01);
930			log_errx(1, "initiator skipped the authentication, "
931			    "but authentication is required");
932		}
933
934		keys_delete(request_keys);
935
936		log_debugx("initiator skipped the authentication, "
937		    "and we don't need it; proceeding with negotiation");
938		login_negotiate(conn, request);
939		return;
940	}
941
942	fail = false;
943	response = login_new_response(request);
944	response_keys = keys_new();
945	trans = (bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0;
946	auth_method = keys_find(request_keys, "AuthMethod");
947	if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) {
948		log_debugx("authentication not required");
949		if (auth_method == NULL ||
950		    login_list_contains(auth_method, "None")) {
951			keys_add(response_keys, "AuthMethod", "None");
952		} else {
953			log_warnx("initiator requests "
954			    "AuthMethod \"%s\" instead of \"None\"",
955			    auth_method);
956			keys_add(response_keys, "AuthMethod", "Reject");
957		}
958		if (trans)
959			login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
960	} else {
961		log_debugx("CHAP authentication required");
962		if (auth_method == NULL ||
963		    login_list_contains(auth_method, "CHAP")) {
964			keys_add(response_keys, "AuthMethod", "CHAP");
965		} else {
966			log_warnx("initiator requests unsupported "
967			    "AuthMethod \"%s\" instead of \"CHAP\"",
968			    auth_method);
969			keys_add(response_keys, "AuthMethod", "Reject");
970			fail = true;
971		}
972	}
973	if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
974		if (conn->conn_target->t_alias != NULL)
975			keys_add(response_keys,
976			    "TargetAlias", conn->conn_target->t_alias);
977		keys_add_int(response_keys,
978		    "TargetPortalGroupTag", pg->pg_tag);
979	}
980	keys_save(response_keys, response);
981
982	pdu_send(response);
983	pdu_delete(response);
984	keys_delete(response_keys);
985	pdu_delete(request);
986	keys_delete(request_keys);
987
988	if (fail) {
989		log_debugx("sent reject for AuthMethod; exiting");
990		exit(1);
991	}
992
993	if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
994		login_chap(conn, ag);
995		login_negotiate(conn, NULL);
996	} else if (trans) {
997		login_negotiate(conn, NULL);
998	} else {
999		login_wait_transition(conn);
1000	}
1001}
1002