login.c revision 275259
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: stable/10/usr.sbin/iscsid/login.c 275259 2014-11-29 16:07:15Z trasz $");
33
34#include <sys/types.h>
35#include <sys/ioctl.h>
36#include <assert.h>
37#include <stdbool.h>
38#include <stdio.h>
39#include <stdlib.h>
40#include <string.h>
41#include <netinet/in.h>
42
43#include "iscsid.h"
44#include "iscsi_proto.h"
45
46static int
47login_nsg(const struct pdu *response)
48{
49	struct iscsi_bhs_login_response *bhslr;
50
51	bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
52
53	return (bhslr->bhslr_flags & 0x03);
54}
55
56static void
57login_set_nsg(struct pdu *request, int nsg)
58{
59	struct iscsi_bhs_login_request *bhslr;
60
61	assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
62	    nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
63	    nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
64
65	bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
66
67	bhslr->bhslr_flags &= 0xFC;
68	bhslr->bhslr_flags |= nsg;
69}
70
71static void
72login_set_csg(struct pdu *request, int csg)
73{
74	struct iscsi_bhs_login_request *bhslr;
75
76	assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
77	    csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
78	    csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
79
80	bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
81
82	bhslr->bhslr_flags &= 0xF3;
83	bhslr->bhslr_flags |= csg << 2;
84}
85
86static const char *
87login_target_error_str(int class, int detail)
88{
89	static char msg[128];
90
91	/*
92	 * RFC 3270, 10.13.5.  Status-Class and Status-Detail
93	 */
94	switch (class) {
95	case 0x01:
96		switch (detail) {
97		case 0x01:
98			return ("Target moved temporarily");
99		case 0x02:
100			return ("Target moved permanently");
101		default:
102			snprintf(msg, sizeof(msg), "unknown redirection; "
103			    "Status-Class 0x%x, Status-Detail 0x%x",
104			    class, detail);
105			return (msg);
106		}
107	case 0x02:
108		switch (detail) {
109		case 0x00:
110			return ("Initiator error");
111		case 0x01:
112			return ("Authentication failure");
113		case 0x02:
114			return ("Authorization failure");
115		case 0x03:
116			return ("Not found");
117		case 0x04:
118			return ("Target removed");
119		case 0x05:
120			return ("Unsupported version");
121		case 0x06:
122			return ("Too many connections");
123		case 0x07:
124			return ("Missing parameter");
125		case 0x08:
126			return ("Can't include in session");
127		case 0x09:
128			return ("Session type not supported");
129		case 0x0a:
130			return ("Session does not exist");
131		case 0x0b:
132			return ("Invalid during login");
133		default:
134			snprintf(msg, sizeof(msg), "unknown initiator error; "
135			    "Status-Class 0x%x, Status-Detail 0x%x",
136			    class, detail);
137			return (msg);
138		}
139	case 0x03:
140		switch (detail) {
141		case 0x00:
142			return ("Target error");
143		case 0x01:
144			return ("Service unavailable");
145		case 0x02:
146			return ("Out of resources");
147		default:
148			snprintf(msg, sizeof(msg), "unknown target error; "
149			    "Status-Class 0x%x, Status-Detail 0x%x",
150			    class, detail);
151			return (msg);
152		}
153	default:
154		snprintf(msg, sizeof(msg), "unknown error; "
155		    "Status-Class 0x%x, Status-Detail 0x%x",
156		    class, detail);
157		return (msg);
158	}
159}
160
161static void
162kernel_modify(const struct connection *conn, const char *target_address)
163{
164	struct iscsi_session_modify ism;
165	int error;
166
167	memset(&ism, 0, sizeof(ism));
168	ism.ism_session_id = conn->conn_session_id;
169	memcpy(&ism.ism_conf, &conn->conn_conf, sizeof(ism.ism_conf));
170	strlcpy(ism.ism_conf.isc_target_addr, target_address,
171	    sizeof(ism.ism_conf.isc_target));
172	error = ioctl(conn->conn_iscsi_fd, ISCSISMODIFY, &ism);
173	if (error != 0) {
174		log_err(1, "failed to redirect to %s: ISCSISMODIFY",
175		    target_address);
176	}
177}
178
179/*
180 * XXX:	The way it works is suboptimal; what should happen is described
181 *	in draft-gilligan-iscsi-fault-tolerance-00.  That, however, would
182 *	be much more complicated: we would need to keep "dependencies"
183 *	for sessions, so that, in case described in draft and using draft
184 *	terminology, we would have three sessions: one for discovery,
185 *	one for initial target portal, and one for redirect portal.
186 *	This would allow us to "backtrack" on connection failure,
187 *	as described in draft.
188 */
189static void
190login_handle_redirection(struct connection *conn, struct pdu *response)
191{
192	struct iscsi_bhs_login_response *bhslr;
193	struct keys *response_keys;
194	const char *target_address;
195
196	bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
197	assert (bhslr->bhslr_status_class == 1);
198
199	response_keys = keys_new();
200	keys_load(response_keys, response);
201
202	target_address = keys_find(response_keys, "TargetAddress");
203	if (target_address == NULL)
204		log_errx(1, "received redirection without TargetAddress");
205	if (target_address[0] == '\0')
206		log_errx(1, "received redirection with empty TargetAddress");
207	if (strlen(target_address) >=
208	    sizeof(conn->conn_conf.isc_target_addr) - 1)
209		log_errx(1, "received TargetAddress is too long");
210
211	log_debugx("received redirection to \"%s\"", target_address);
212	kernel_modify(conn, target_address);
213	keys_delete(response_keys);
214}
215
216static struct pdu *
217login_receive(struct connection *conn)
218{
219	struct pdu *response;
220	struct iscsi_bhs_login_response *bhslr;
221	const char *errorstr;
222	static bool initial = true;
223
224	response = pdu_new(conn);
225	pdu_receive(response);
226	if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_LOGIN_RESPONSE) {
227		log_errx(1, "protocol error: received invalid opcode 0x%x",
228		    response->pdu_bhs->bhs_opcode);
229	}
230	bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
231	/*
232	 * XXX: Implement the C flag some day.
233	 */
234	if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0)
235		log_errx(1, "received Login PDU with unsupported \"C\" flag");
236	if (bhslr->bhslr_version_max != 0x00)
237		log_errx(1, "received Login PDU with unsupported "
238		    "Version-max 0x%x", bhslr->bhslr_version_max);
239	if (bhslr->bhslr_version_active != 0x00)
240		log_errx(1, "received Login PDU with unsupported "
241		    "Version-active 0x%x", bhslr->bhslr_version_active);
242	if (bhslr->bhslr_status_class == 1) {
243		login_handle_redirection(conn, response);
244		log_debugx("redirection handled; exiting");
245		exit(0);
246	}
247	if (bhslr->bhslr_status_class != 0) {
248		errorstr = login_target_error_str(bhslr->bhslr_status_class,
249		    bhslr->bhslr_status_detail);
250		fail(conn, errorstr);
251		log_errx(1, "target returned error: %s", errorstr);
252	}
253	if (initial == false &&
254	    ntohl(bhslr->bhslr_statsn) != conn->conn_statsn + 1) {
255		/*
256		 * It's a warning, not an error, to work around what seems
257		 * to be bug in NetBSD iSCSI target.
258		 */
259		log_warnx("received Login PDU with wrong StatSN: "
260		    "is %d, should be %d", ntohl(bhslr->bhslr_statsn),
261		    conn->conn_statsn + 1);
262	}
263	conn->conn_tsih = ntohs(bhslr->bhslr_tsih);
264	conn->conn_statsn = ntohl(bhslr->bhslr_statsn);
265
266	initial = false;
267
268	return (response);
269}
270
271static struct pdu *
272login_new_request(struct connection *conn, int csg)
273{
274	struct pdu *request;
275	struct iscsi_bhs_login_request *bhslr;
276	int nsg;
277
278	request = pdu_new(conn);
279	bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
280	bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_REQUEST |
281	    ISCSI_BHS_OPCODE_IMMEDIATE;
282
283	bhslr->bhslr_flags = BHSLR_FLAGS_TRANSIT;
284	switch (csg) {
285	case BHSLR_STAGE_SECURITY_NEGOTIATION:
286		nsg = BHSLR_STAGE_OPERATIONAL_NEGOTIATION;
287		break;
288	case BHSLR_STAGE_OPERATIONAL_NEGOTIATION:
289		nsg = BHSLR_STAGE_FULL_FEATURE_PHASE;
290		break;
291	default:
292		assert(!"invalid csg");
293		log_errx(1, "invalid csg %d", csg);
294	}
295	login_set_csg(request, csg);
296	login_set_nsg(request, nsg);
297
298	memcpy(bhslr->bhslr_isid, &conn->conn_isid, sizeof(bhslr->bhslr_isid));
299	bhslr->bhslr_tsih = htons(conn->conn_tsih);
300	bhslr->bhslr_initiator_task_tag = 0;
301	bhslr->bhslr_cmdsn = 0;
302	bhslr->bhslr_expstatsn = htonl(conn->conn_statsn + 1);
303
304	return (request);
305}
306
307static int
308login_list_prefers(const char *list,
309    const char *choice1, const char *choice2)
310{
311	char *tofree, *str, *token;
312
313	tofree = str = checked_strdup(list);
314
315	while ((token = strsep(&str, ",")) != NULL) {
316		if (strcmp(token, choice1) == 0) {
317			free(tofree);
318			return (1);
319		}
320		if (strcmp(token, choice2) == 0) {
321			free(tofree);
322			return (2);
323		}
324	}
325	free(tofree);
326	return (-1);
327}
328
329static void
330login_negotiate_key(struct connection *conn, const char *name,
331    const char *value)
332{
333	int which, tmp;
334
335	if (strcmp(name, "TargetAlias") == 0) {
336		strlcpy(conn->conn_target_alias, value,
337		    sizeof(conn->conn_target_alias));
338	} else if (strcmp(value, "Irrelevant") == 0) {
339		/* Ignore. */
340	} else if (strcmp(name, "HeaderDigest") == 0) {
341		which = login_list_prefers(value, "CRC32C", "None");
342		switch (which) {
343		case 1:
344			log_debugx("target prefers CRC32C "
345			    "for header digest; we'll use it");
346			conn->conn_header_digest = CONN_DIGEST_CRC32C;
347			break;
348		case 2:
349			log_debugx("target prefers not to do "
350			    "header digest; we'll comply");
351			break;
352		default:
353			log_warnx("target sent unrecognized "
354			    "HeaderDigest value \"%s\"; will use None", value);
355			break;
356		}
357	} else if (strcmp(name, "DataDigest") == 0) {
358		which = login_list_prefers(value, "CRC32C", "None");
359		switch (which) {
360		case 1:
361			log_debugx("target prefers CRC32C "
362			    "for data digest; we'll use it");
363			conn->conn_data_digest = CONN_DIGEST_CRC32C;
364			break;
365		case 2:
366			log_debugx("target prefers not to do "
367			    "data digest; we'll comply");
368			break;
369		default:
370			log_warnx("target sent unrecognized "
371			    "DataDigest value \"%s\"; will use None", value);
372			break;
373		}
374	} else if (strcmp(name, "MaxConnections") == 0) {
375		/* Ignore. */
376	} else if (strcmp(name, "InitialR2T") == 0) {
377		if (strcmp(value, "Yes") == 0)
378			conn->conn_initial_r2t = true;
379		else
380			conn->conn_initial_r2t = false;
381	} else if (strcmp(name, "ImmediateData") == 0) {
382		if (strcmp(value, "Yes") == 0)
383			conn->conn_immediate_data = true;
384		else
385			conn->conn_immediate_data = false;
386	} else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
387		tmp = strtoul(value, NULL, 10);
388		if (tmp <= 0)
389			log_errx(1, "received invalid "
390			    "MaxRecvDataSegmentLength");
391		conn->conn_max_data_segment_length = tmp;
392	} else if (strcmp(name, "MaxBurstLength") == 0) {
393		if (conn->conn_immediate_data) {
394			tmp = strtoul(value, NULL, 10);
395			if (tmp <= 0)
396				log_errx(1, "received invalid MaxBurstLength");
397			conn->conn_max_burst_length = tmp;
398		}
399	} else if (strcmp(name, "FirstBurstLength") == 0) {
400		tmp = strtoul(value, NULL, 10);
401		if (tmp <= 0)
402			log_errx(1, "received invalid FirstBurstLength");
403		conn->conn_first_burst_length = tmp;
404	} else if (strcmp(name, "DefaultTime2Wait") == 0) {
405		/* Ignore */
406	} else if (strcmp(name, "DefaultTime2Retain") == 0) {
407		/* Ignore */
408	} else if (strcmp(name, "MaxOutstandingR2T") == 0) {
409		/* Ignore */
410	} else if (strcmp(name, "DataPDUInOrder") == 0) {
411		/* Ignore */
412	} else if (strcmp(name, "DataSequenceInOrder") == 0) {
413		/* Ignore */
414	} else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
415		/* Ignore */
416	} else if (strcmp(name, "OFMarker") == 0) {
417		/* Ignore */
418	} else if (strcmp(name, "IFMarker") == 0) {
419		/* Ignore */
420	} else if (strcmp(name, "TargetPortalGroupTag") == 0) {
421		/* Ignore */
422	} else {
423		log_debugx("unknown key \"%s\"; ignoring",  name);
424	}
425}
426
427static void
428login_negotiate(struct connection *conn)
429{
430	struct pdu *request, *response;
431	struct keys *request_keys, *response_keys;
432	struct iscsi_bhs_login_response *bhslr;
433	int i, nrequests = 0;
434
435	log_debugx("beginning operational parameter negotiation");
436	request = login_new_request(conn, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
437	request_keys = keys_new();
438
439	/*
440	 * The following keys are irrelevant for discovery sessions.
441	 */
442	if (conn->conn_conf.isc_discovery == 0) {
443		if (conn->conn_conf.isc_header_digest != 0)
444			keys_add(request_keys, "HeaderDigest", "CRC32C");
445		else
446			keys_add(request_keys, "HeaderDigest", "None");
447		if (conn->conn_conf.isc_data_digest != 0)
448			keys_add(request_keys, "DataDigest", "CRC32C");
449		else
450			keys_add(request_keys, "DataDigest", "None");
451
452		keys_add(request_keys, "ImmediateData", "Yes");
453		keys_add_int(request_keys, "MaxBurstLength",
454		    ISCSI_MAX_DATA_SEGMENT_LENGTH);
455		keys_add_int(request_keys, "FirstBurstLength",
456		    ISCSI_MAX_DATA_SEGMENT_LENGTH);
457		keys_add(request_keys, "InitialR2T", "Yes");
458	} else {
459		keys_add(request_keys, "HeaderDigest", "None");
460		keys_add(request_keys, "DataDigest", "None");
461	}
462
463	keys_add_int(request_keys, "MaxRecvDataSegmentLength",
464	    ISCSI_MAX_DATA_SEGMENT_LENGTH);
465	keys_add(request_keys, "DefaultTime2Wait", "0");
466	keys_add(request_keys, "DefaultTime2Retain", "0");
467	keys_add(request_keys, "ErrorRecoveryLevel", "0");
468	keys_add(request_keys, "MaxOutstandingR2T", "1");
469	keys_save(request_keys, request);
470	keys_delete(request_keys);
471	request_keys = NULL;
472	pdu_send(request);
473	pdu_delete(request);
474	request = NULL;
475
476	response = login_receive(conn);
477	response_keys = keys_new();
478	keys_load(response_keys, response);
479	for (i = 0; i < KEYS_MAX; i++) {
480		if (response_keys->keys_names[i] == NULL)
481			break;
482
483		login_negotiate_key(conn,
484		    response_keys->keys_names[i], response_keys->keys_values[i]);
485	}
486
487	keys_delete(response_keys);
488	response_keys = NULL;
489
490	for (;;) {
491		bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
492		if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0)
493			break;
494
495		nrequests++;
496		if (nrequests > 5) {
497			log_warnx("received login response "
498			    "without the \"T\" flag too many times; giving up");
499			break;
500		}
501
502		log_debugx("received login response "
503		    "without the \"T\" flag; sending another request");
504
505		pdu_delete(response);
506
507		request = login_new_request(conn,
508		    BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
509		pdu_send(request);
510		pdu_delete(request);
511
512		response = login_receive(conn);
513	}
514
515	if (login_nsg(response) != BHSLR_STAGE_FULL_FEATURE_PHASE)
516		log_warnx("received final login response with wrong NSG 0x%x",
517		    login_nsg(response));
518	pdu_delete(response);
519
520	log_debugx("operational parameter negotiation done; "
521	    "transitioning to Full Feature phase");
522}
523
524static void
525login_send_chap_a(struct connection *conn)
526{
527	struct pdu *request;
528	struct keys *request_keys;
529
530	request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
531	request_keys = keys_new();
532	keys_add(request_keys, "CHAP_A", "5");
533	keys_save(request_keys, request);
534	keys_delete(request_keys);
535	pdu_send(request);
536	pdu_delete(request);
537}
538
539static void
540login_send_chap_r(struct pdu *response)
541{
542	struct connection *conn;
543	struct pdu *request;
544	struct keys *request_keys, *response_keys;
545	struct rchap *rchap;
546	const char *chap_a, *chap_c, *chap_i;
547	char *chap_r;
548	int error;
549        char *mutual_chap_c, *mutual_chap_i;
550
551	/*
552	 * As in the rest of the initiator, 'request' means
553	 * 'initiator -> target', and 'response' means 'target -> initiator',
554	 *
555	 * So, here the 'response' from the target is the packet that contains
556	 * CHAP challenge; our CHAP response goes into 'request'.
557	 */
558
559	conn = response->pdu_connection;
560
561	response_keys = keys_new();
562	keys_load(response_keys, response);
563
564	/*
565	 * First, compute the response.
566	 */
567	chap_a = keys_find(response_keys, "CHAP_A");
568	if (chap_a == NULL)
569		log_errx(1, "received CHAP packet without CHAP_A");
570	chap_c = keys_find(response_keys, "CHAP_C");
571	if (chap_c == NULL)
572		log_errx(1, "received CHAP packet without CHAP_C");
573	chap_i = keys_find(response_keys, "CHAP_I");
574	if (chap_i == NULL)
575		log_errx(1, "received CHAP packet without CHAP_I");
576
577	if (strcmp(chap_a, "5") != 0) {
578		log_errx(1, "received CHAP packet "
579		    "with unsupported CHAP_A \"%s\"", chap_a);
580	}
581
582	rchap = rchap_new(conn->conn_conf.isc_secret);
583	error = rchap_receive(rchap, chap_i, chap_c);
584	if (error != 0) {
585		log_errx(1, "received CHAP packet "
586		    "with malformed CHAP_I or CHAP_C");
587	}
588	chap_r = rchap_get_response(rchap);
589	rchap_delete(rchap);
590
591	keys_delete(response_keys);
592
593	request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
594	request_keys = keys_new();
595	keys_add(request_keys, "CHAP_N", conn->conn_conf.isc_user);
596	keys_add(request_keys, "CHAP_R", chap_r);
597	free(chap_r);
598
599	/*
600	 * If we want mutual authentication, we're expected to send
601	 * our CHAP_I/CHAP_C now.
602	 */
603	if (conn->conn_conf.isc_mutual_user[0] != '\0') {
604		log_debugx("requesting mutual authentication; "
605		    "binary challenge size is %zd bytes",
606		    sizeof(conn->conn_mutual_chap->chap_challenge));
607
608		assert(conn->conn_mutual_chap == NULL);
609		conn->conn_mutual_chap = chap_new();
610		mutual_chap_i = chap_get_id(conn->conn_mutual_chap);
611		mutual_chap_c = chap_get_challenge(conn->conn_mutual_chap);
612		keys_add(request_keys, "CHAP_I", mutual_chap_i);
613		keys_add(request_keys, "CHAP_C", mutual_chap_c);
614		free(mutual_chap_i);
615		free(mutual_chap_c);
616	}
617
618	keys_save(request_keys, request);
619	keys_delete(request_keys);
620	pdu_send(request);
621	pdu_delete(request);
622}
623
624static void
625login_verify_mutual(const struct pdu *response)
626{
627	struct connection *conn;
628	struct keys *response_keys;
629	const char *chap_n, *chap_r;
630	int error;
631
632	conn = response->pdu_connection;
633
634	response_keys = keys_new();
635	keys_load(response_keys, response);
636
637        chap_n = keys_find(response_keys, "CHAP_N");
638        if (chap_n == NULL)
639                log_errx(1, "received CHAP Response PDU without CHAP_N");
640        chap_r = keys_find(response_keys, "CHAP_R");
641        if (chap_r == NULL)
642                log_errx(1, "received CHAP Response PDU without CHAP_R");
643
644	error = chap_receive(conn->conn_mutual_chap, chap_r);
645	if (error != 0)
646                log_errx(1, "received CHAP Response PDU with invalid CHAP_R");
647
648	if (strcmp(chap_n, conn->conn_conf.isc_mutual_user) != 0) {
649		fail(conn, "Mutual CHAP failed");
650		log_errx(1, "mutual CHAP authentication failed: wrong user");
651	}
652
653	error = chap_authenticate(conn->conn_mutual_chap,
654	    conn->conn_conf.isc_mutual_secret);
655	if (error != 0) {
656		fail(conn, "Mutual CHAP failed");
657                log_errx(1, "mutual CHAP authentication failed: wrong secret");
658	}
659
660	keys_delete(response_keys);
661	chap_delete(conn->conn_mutual_chap);
662	conn->conn_mutual_chap = NULL;
663
664	log_debugx("mutual CHAP authentication succeeded");
665}
666
667static void
668login_chap(struct connection *conn)
669{
670	struct pdu *response;
671
672	log_debugx("beginning CHAP authentication; sending CHAP_A");
673	login_send_chap_a(conn);
674
675	log_debugx("waiting for CHAP_A/CHAP_C/CHAP_I");
676	response = login_receive(conn);
677
678	log_debugx("sending CHAP_N/CHAP_R");
679	login_send_chap_r(response);
680	pdu_delete(response);
681
682	/*
683	 * XXX: Make sure this is not susceptible to MITM.
684	 */
685
686	log_debugx("waiting for CHAP result");
687	response = login_receive(conn);
688	if (conn->conn_conf.isc_mutual_user[0] != '\0')
689		login_verify_mutual(response);
690	pdu_delete(response);
691
692	log_debugx("CHAP authentication done");
693}
694
695void
696login(struct connection *conn)
697{
698	struct pdu *request, *response;
699	struct keys *request_keys, *response_keys;
700	struct iscsi_bhs_login_response *bhslr2;
701	const char *auth_method;
702	int i;
703
704	log_debugx("beginning Login phase; sending Login PDU");
705	request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
706	request_keys = keys_new();
707	if (conn->conn_conf.isc_mutual_user[0] != '\0') {
708		keys_add(request_keys, "AuthMethod", "CHAP");
709	} else if (conn->conn_conf.isc_user[0] != '\0') {
710		/*
711		 * Give target a chance to skip authentication if it
712		 * doesn't feel like it.
713		 *
714		 * None is first, CHAP second; this is to work around
715		 * what seems to be LIO (Linux target) bug: otherwise,
716		 * if target is configured with no authentication,
717		 * and we are configured to authenticate, the target
718		 * will erroneously respond with AuthMethod=CHAP
719		 * instead of AuthMethod=None, and will subsequently
720		 * fail the connection.  This usually happens with
721		 * Discovery sessions, which default to no authentication.
722		 */
723		keys_add(request_keys, "AuthMethod", "None,CHAP");
724	} else {
725		keys_add(request_keys, "AuthMethod", "None");
726	}
727	keys_add(request_keys, "InitiatorName",
728	    conn->conn_conf.isc_initiator);
729	if (conn->conn_conf.isc_initiator_alias[0] != '\0') {
730		keys_add(request_keys, "InitiatorAlias",
731		    conn->conn_conf.isc_initiator_alias);
732	}
733	if (conn->conn_conf.isc_discovery == 0) {
734		keys_add(request_keys, "SessionType", "Normal");
735		keys_add(request_keys,
736		    "TargetName", conn->conn_conf.isc_target);
737	} else {
738		keys_add(request_keys, "SessionType", "Discovery");
739	}
740	keys_save(request_keys, request);
741	keys_delete(request_keys);
742	pdu_send(request);
743	pdu_delete(request);
744
745	response = login_receive(conn);
746
747	response_keys = keys_new();
748	keys_load(response_keys, response);
749
750	for (i = 0; i < KEYS_MAX; i++) {
751		if (response_keys->keys_names[i] == NULL)
752			break;
753
754		/*
755		 * Not interested in AuthMethod at this point; we only need
756		 * to parse things such as TargetAlias.
757		 *
758		 * XXX: This is somewhat ugly.  We should have a way to apply
759		 *      all the keys to the session and use that by default
760		 *      instead of discarding them.
761		 */
762		if (strcmp(response_keys->keys_names[i], "AuthMethod") == 0)
763			continue;
764
765		login_negotiate_key(conn,
766		    response_keys->keys_names[i], response_keys->keys_values[i]);
767	}
768
769	bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
770	if ((bhslr2->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0 &&
771	    login_nsg(response) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
772		if (conn->conn_conf.isc_mutual_user[0] != '\0') {
773			log_errx(1, "target requested transition "
774			    "to operational parameter negotiation, "
775			    "but we require mutual CHAP");
776		}
777
778		log_debugx("target requested transition "
779		    "to operational parameter negotiation");
780		keys_delete(response_keys);
781		pdu_delete(response);
782		login_negotiate(conn);
783		return;
784	}
785
786	auth_method = keys_find(response_keys, "AuthMethod");
787	if (auth_method == NULL)
788		log_errx(1, "received response without AuthMethod");
789	if (strcmp(auth_method, "None") == 0) {
790		if (conn->conn_conf.isc_mutual_user[0] != '\0') {
791			log_errx(1, "target does not require authantication, "
792			    "but we require mutual CHAP");
793		}
794
795		log_debugx("target does not require authentication");
796		keys_delete(response_keys);
797		pdu_delete(response);
798		login_negotiate(conn);
799		return;
800	}
801
802	if (strcmp(auth_method, "CHAP") != 0) {
803		fail(conn, "Unsupported AuthMethod");
804		log_errx(1, "received response "
805		    "with unsupported AuthMethod \"%s\"", auth_method);
806	}
807
808	if (conn->conn_conf.isc_user[0] == '\0' ||
809	    conn->conn_conf.isc_secret[0] == '\0') {
810		fail(conn, "Authentication required");
811		log_errx(1, "target requests CHAP authentication, but we don't "
812		    "have user and secret");
813	}
814
815	keys_delete(response_keys);
816	response_keys = NULL;
817	pdu_delete(response);
818	response = NULL;
819
820	login_chap(conn);
821	login_negotiate(conn);
822}
823