discovery.c revision 275864 
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: head/usr.sbin/ctld/discovery.c 275864 2014-12-17 15:13:21Z mav $");
33
34#include <assert.h>
35#include <stdint.h>
36#include <stdio.h>
37#include <stdlib.h>
38#include <string.h>
39#include <netinet/in.h>
40#include <netdb.h>
41#include <sys/socket.h>
42
43#include "ctld.h"
44#include "iscsi_proto.h"
45
46static struct pdu *
47text_receive(struct connection *conn)
48{
49	struct pdu *request;
50	struct iscsi_bhs_text_request *bhstr;
51
52	request = pdu_new(conn);
53	pdu_receive(request);
54	if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
55	    ISCSI_BHS_OPCODE_TEXT_REQUEST)
56		log_errx(1, "protocol error: received invalid opcode 0x%x",
57		    request->pdu_bhs->bhs_opcode);
58	bhstr = (struct iscsi_bhs_text_request *)request->pdu_bhs;
59#if 0
60	if ((bhstr->bhstr_flags & ISCSI_BHSTR_FLAGS_FINAL) == 0)
61		log_errx(1, "received Text PDU without the \"F\" flag");
62#endif
63	/*
64	 * XXX: Implement the C flag some day.
65	 */
66	if ((bhstr->bhstr_flags & BHSTR_FLAGS_CONTINUE) != 0)
67		log_errx(1, "received Text PDU with unsupported \"C\" flag");
68	if (ISCSI_SNLT(ntohl(bhstr->bhstr_cmdsn), conn->conn_cmdsn)) {
69		log_errx(1, "received Text PDU with decreasing CmdSN: "
70		    "was %u, is %u", conn->conn_cmdsn, ntohl(bhstr->bhstr_cmdsn));
71	}
72	if (ntohl(bhstr->bhstr_expstatsn) != conn->conn_statsn) {
73		log_errx(1, "received Text PDU with wrong StatSN: "
74		    "is %u, should be %u", ntohl(bhstr->bhstr_expstatsn),
75		    conn->conn_statsn);
76	}
77	conn->conn_cmdsn = ntohl(bhstr->bhstr_cmdsn);
78
79	return (request);
80}
81
82static struct pdu *
83text_new_response(struct pdu *request)
84{
85	struct pdu *response;
86	struct connection *conn;
87	struct iscsi_bhs_text_request *bhstr;
88	struct iscsi_bhs_text_response *bhstr2;
89
90	bhstr = (struct iscsi_bhs_text_request *)request->pdu_bhs;
91	conn = request->pdu_connection;
92
93	response = pdu_new_response(request);
94	bhstr2 = (struct iscsi_bhs_text_response *)response->pdu_bhs;
95	bhstr2->bhstr_opcode = ISCSI_BHS_OPCODE_TEXT_RESPONSE;
96	bhstr2->bhstr_flags = BHSTR_FLAGS_FINAL;
97	bhstr2->bhstr_lun = bhstr->bhstr_lun;
98	bhstr2->bhstr_initiator_task_tag = bhstr->bhstr_initiator_task_tag;
99	bhstr2->bhstr_target_transfer_tag = bhstr->bhstr_target_transfer_tag;
100	bhstr2->bhstr_statsn = htonl(conn->conn_statsn++);
101	bhstr2->bhstr_expcmdsn = htonl(conn->conn_cmdsn);
102	bhstr2->bhstr_maxcmdsn = htonl(conn->conn_cmdsn);
103
104	return (response);
105}
106
107static struct pdu *
108logout_receive(struct connection *conn)
109{
110	struct pdu *request;
111	struct iscsi_bhs_logout_request *bhslr;
112
113	request = pdu_new(conn);
114	pdu_receive(request);
115	if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
116	    ISCSI_BHS_OPCODE_LOGOUT_REQUEST)
117		log_errx(1, "protocol error: received invalid opcode 0x%x",
118		    request->pdu_bhs->bhs_opcode);
119	bhslr = (struct iscsi_bhs_logout_request *)request->pdu_bhs;
120	if ((bhslr->bhslr_reason & 0x7f) != BHSLR_REASON_CLOSE_SESSION)
121		log_debugx("received Logout PDU with invalid reason 0x%x; "
122		    "continuing anyway", bhslr->bhslr_reason & 0x7f);
123	if (ISCSI_SNLT(ntohl(bhslr->bhslr_cmdsn), conn->conn_cmdsn)) {
124		log_errx(1, "received Logout PDU with decreasing CmdSN: "
125		    "was %u, is %u", conn->conn_cmdsn,
126		    ntohl(bhslr->bhslr_cmdsn));
127	}
128	if (ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) {
129		log_errx(1, "received Logout PDU with wrong StatSN: "
130		    "is %u, should be %u", ntohl(bhslr->bhslr_expstatsn),
131		    conn->conn_statsn);
132	}
133	conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn);
134
135	return (request);
136}
137
138static struct pdu *
139logout_new_response(struct pdu *request)
140{
141	struct pdu *response;
142	struct connection *conn;
143	struct iscsi_bhs_logout_request *bhslr;
144	struct iscsi_bhs_logout_response *bhslr2;
145
146	bhslr = (struct iscsi_bhs_logout_request *)request->pdu_bhs;
147	conn = request->pdu_connection;
148
149	response = pdu_new_response(request);
150	bhslr2 = (struct iscsi_bhs_logout_response *)response->pdu_bhs;
151	bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGOUT_RESPONSE;
152	bhslr2->bhslr_flags = 0x80;
153	bhslr2->bhslr_response = BHSLR_RESPONSE_CLOSED_SUCCESSFULLY;
154	bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag;
155	bhslr2->bhslr_statsn = htonl(conn->conn_statsn++);
156	bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn);
157	bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn);
158
159	return (response);
160}
161
162static void
163discovery_add_target(struct keys *response_keys, const struct target *targ)
164{
165	struct portal *portal;
166	char *buf;
167	char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
168	struct addrinfo *ai;
169	int ret;
170
171	keys_add(response_keys, "TargetName", targ->t_name);
172	TAILQ_FOREACH(portal, &targ->t_portal_group->pg_portals, p_next) {
173		ai = portal->p_ai;
174		ret = getnameinfo(ai->ai_addr, ai->ai_addrlen,
175		    hbuf, sizeof(hbuf), sbuf, sizeof(sbuf),
176		    NI_NUMERICHOST | NI_NUMERICSERV);
177		if (ret != 0) {
178			log_warnx("getnameinfo: %s", gai_strerror(ret));
179			continue;
180		}
181		switch (ai->ai_addr->sa_family) {
182		case AF_INET:
183			if (strcmp(hbuf, "0.0.0.0") == 0)
184				continue;
185			ret = asprintf(&buf, "%s:%s,%d", hbuf, sbuf,
186			    targ->t_portal_group->pg_tag);
187			break;
188		case AF_INET6:
189			if (strcmp(hbuf, "::") == 0)
190				continue;
191			ret = asprintf(&buf, "[%s]:%s,%d", hbuf, sbuf,
192			    targ->t_portal_group->pg_tag);
193			break;
194		default:
195			continue;
196		}
197		if (ret <= 0)
198		    log_err(1, "asprintf");
199		keys_add(response_keys, "TargetAddress", buf);
200		free(buf);
201	}
202}
203
204static bool
205discovery_target_filtered_out(const struct connection *conn,
206    const struct target *targ)
207{
208	const struct auth_group *ag;
209	const struct portal_group *pg;
210	const struct auth *auth;
211	int error;
212
213	ag = targ->t_auth_group;
214	pg = conn->conn_portal->p_portal_group;
215
216	assert(pg->pg_discovery_auth_group != PG_FILTER_UNKNOWN);
217
218	if (pg->pg_discovery_filter >= PG_FILTER_PORTAL &&
219	    auth_portal_check(ag, &conn->conn_initiator_sa) != 0) {
220		log_debugx("initiator does not match initiator portals "
221		    "allowed for target \"%s\"; skipping", targ->t_name);
222		return (true);
223	}
224
225	if (pg->pg_discovery_filter >= PG_FILTER_PORTAL_NAME &&
226	    auth_name_check(ag, conn->conn_initiator_name) != 0) {
227		log_debugx("initiator does not match initiator names "
228		    "allowed for target \"%s\"; skipping", targ->t_name);
229		return (true);
230	}
231
232	if (pg->pg_discovery_filter >= PG_FILTER_PORTAL_NAME_AUTH &&
233	    ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
234		if (conn->conn_chap == NULL) {
235			assert(pg->pg_discovery_auth_group->ag_type ==
236			    AG_TYPE_NO_AUTHENTICATION);
237
238			log_debugx("initiator didn't authenticate, but target "
239			    "\"%s\" requires CHAP; skipping", targ->t_name);
240			return (true);
241		}
242
243		assert(conn->conn_user != NULL);
244		auth = auth_find(ag, conn->conn_user);
245		if (auth == NULL) {
246			log_debugx("CHAP user \"%s\" doesn't match target "
247			    "\"%s\"; skipping", conn->conn_user, targ->t_name);
248			return (true);
249		}
250
251		error = chap_authenticate(conn->conn_chap, auth->a_secret);
252		if (error != 0) {
253			log_debugx("password for CHAP user \"%s\" doesn't "
254			    "match target \"%s\"; skipping",
255			    conn->conn_user, targ->t_name);
256			return (true);
257		}
258	}
259
260	return (false);
261}
262
263void
264discovery(struct connection *conn)
265{
266	struct pdu *request, *response;
267	struct keys *request_keys, *response_keys;
268	const struct portal_group *pg;
269	const struct target *targ;
270	const char *send_targets;
271
272	pg = conn->conn_portal->p_portal_group;
273
274	log_debugx("beginning discovery session; waiting for Text PDU");
275	request = text_receive(conn);
276	request_keys = keys_new();
277	keys_load(request_keys, request);
278
279	send_targets = keys_find(request_keys, "SendTargets");
280	if (send_targets == NULL)
281		log_errx(1, "received Text PDU without SendTargets");
282
283	response = text_new_response(request);
284	response_keys = keys_new();
285
286	if (strcmp(send_targets, "All") == 0) {
287		TAILQ_FOREACH(targ, &pg->pg_conf->conf_targets, t_next) {
288			if (targ->t_portal_group != pg) {
289				log_debugx("not returning target \"%s\"; "
290				    "belongs to a different portal group",
291				    targ->t_name);
292				continue;
293			}
294			if (discovery_target_filtered_out(conn, targ)) {
295				/* Ignore this target. */
296				continue;
297			}
298			discovery_add_target(response_keys, targ);
299		}
300	} else {
301		targ = target_find(pg->pg_conf, send_targets);
302		if (targ == NULL) {
303			log_debugx("initiator requested information on unknown "
304			    "target \"%s\"; returning nothing", send_targets);
305		} else {
306			if (discovery_target_filtered_out(conn, targ)) {
307				/* Ignore this target. */
308			} else {
309				discovery_add_target(response_keys, targ);
310			}
311		}
312	}
313	keys_save(response_keys, response);
314
315	pdu_send(response);
316	pdu_delete(response);
317	keys_delete(response_keys);
318	pdu_delete(request);
319	keys_delete(request_keys);
320
321	log_debugx("done sending targets; waiting for Logout PDU");
322	request = logout_receive(conn);
323	response = logout_new_response(request);
324
325	pdu_send(response);
326	pdu_delete(response);
327	pdu_delete(request);
328
329	log_debugx("discovery session done");
330}
331