xref: /freebsd/usr.sbin/iscsid/discovery.c (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2012 The FreeBSD Foundation
5  * All rights reserved.
6  *
7  * This software was developed by Edward Tomasz Napierala under sponsorship
8  * from the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/types.h>
37 #include <sys/ioctl.h>
38 #include <stdbool.h>
39 #include <string.h>
40 #include <netinet/in.h>
41 
42 #include "iscsid.h"
43 #include "iscsi_proto.h"
44 
45 static struct pdu *
46 text_receive(struct connection *conn)
47 {
48 	struct pdu *response;
49 	struct iscsi_bhs_text_response *bhstr;
50 
51 	response = pdu_new(conn);
52 	pdu_receive(response);
53 	if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_TEXT_RESPONSE)
54 		log_errx(1, "protocol error: received invalid opcode 0x%x",
55 		    response->pdu_bhs->bhs_opcode);
56 	bhstr = (struct iscsi_bhs_text_response *)response->pdu_bhs;
57 #if 0
58 	if ((bhstr->bhstr_flags & BHSTR_FLAGS_FINAL) == 0)
59 		log_errx(1, "received Text PDU without the \"F\" flag");
60 #endif
61 	/*
62 	 * XXX: Implement the C flag some day.
63 	 */
64 	if ((bhstr->bhstr_flags & BHSTR_FLAGS_CONTINUE) != 0)
65 		log_errx(1, "received Text PDU with unsupported \"C\" flag");
66 	if (ntohl(bhstr->bhstr_statsn) != conn->conn_statsn + 1) {
67 		log_errx(1, "received Text PDU with wrong StatSN: "
68 		    "is %u, should be %u", ntohl(bhstr->bhstr_statsn),
69 		    conn->conn_statsn + 1);
70 	}
71 	conn->conn_statsn = ntohl(bhstr->bhstr_statsn);
72 
73 	return (response);
74 }
75 
76 static struct pdu *
77 text_new_request(struct connection *conn)
78 {
79 	struct pdu *request;
80 	struct iscsi_bhs_text_request *bhstr;
81 
82 	request = pdu_new(conn);
83 	bhstr = (struct iscsi_bhs_text_request *)request->pdu_bhs;
84 	bhstr->bhstr_opcode = ISCSI_BHS_OPCODE_TEXT_REQUEST |
85 	    ISCSI_BHS_OPCODE_IMMEDIATE;
86 	bhstr->bhstr_flags = BHSTR_FLAGS_FINAL;
87 	bhstr->bhstr_initiator_task_tag = 0;
88 	bhstr->bhstr_target_transfer_tag = 0xffffffff;
89 
90 	bhstr->bhstr_initiator_task_tag = 0; /* XXX */
91 	bhstr->bhstr_cmdsn = 0; /* XXX */
92 	bhstr->bhstr_expstatsn = htonl(conn->conn_statsn + 1);
93 
94 	return (request);
95 }
96 
97 static struct pdu *
98 logout_receive(struct connection *conn)
99 {
100 	struct pdu *response;
101 	struct iscsi_bhs_logout_response *bhslr;
102 
103 	response = pdu_new(conn);
104 	pdu_receive(response);
105 	if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_LOGOUT_RESPONSE)
106 		log_errx(1, "protocol error: received invalid opcode 0x%x",
107 		    response->pdu_bhs->bhs_opcode);
108 	bhslr = (struct iscsi_bhs_logout_response *)response->pdu_bhs;
109 	if (ntohs(bhslr->bhslr_response) != BHSLR_RESPONSE_CLOSED_SUCCESSFULLY)
110 		log_warnx("received Logout Response with reason %d",
111 		    ntohs(bhslr->bhslr_response));
112 	if (ntohl(bhslr->bhslr_statsn) != conn->conn_statsn + 1) {
113 		log_errx(1, "received Logout PDU with wrong StatSN: "
114 		    "is %u, should be %u", ntohl(bhslr->bhslr_statsn),
115 		    conn->conn_statsn + 1);
116 	}
117 	conn->conn_statsn = ntohl(bhslr->bhslr_statsn);
118 
119 	return (response);
120 }
121 
122 static struct pdu *
123 logout_new_request(struct connection *conn)
124 {
125 	struct pdu *request;
126 	struct iscsi_bhs_logout_request *bhslr;
127 
128 	request = pdu_new(conn);
129 	bhslr = (struct iscsi_bhs_logout_request *)request->pdu_bhs;
130 	bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGOUT_REQUEST |
131 	    ISCSI_BHS_OPCODE_IMMEDIATE;
132 	bhslr->bhslr_reason = BHSLR_REASON_CLOSE_SESSION;
133 	bhslr->bhslr_reason |= 0x80;
134 	bhslr->bhslr_initiator_task_tag = 0; /* XXX */
135 	bhslr->bhslr_cmdsn = 0; /* XXX */
136 	bhslr->bhslr_expstatsn = htonl(conn->conn_statsn + 1);
137 
138 	return (request);
139 }
140 
141 static void
142 kernel_add(const struct connection *conn, const char *target)
143 {
144 	struct iscsi_session_add isa;
145 	int error;
146 
147 	memset(&isa, 0, sizeof(isa));
148 	memcpy(&isa.isa_conf, &conn->conn_conf, sizeof(isa.isa_conf));
149 	strlcpy(isa.isa_conf.isc_target, target,
150 	    sizeof(isa.isa_conf.isc_target));
151 	isa.isa_conf.isc_discovery = 0;
152 	error = ioctl(conn->conn_iscsi_fd, ISCSISADD, &isa);
153 	if (error != 0)
154 		log_warn("failed to add %s: ISCSISADD", target);
155 }
156 
157 static void
158 kernel_remove(const struct connection *conn)
159 {
160 	struct iscsi_session_remove isr;
161 	int error;
162 
163 	memset(&isr, 0, sizeof(isr));
164 	isr.isr_session_id = conn->conn_session_id;
165 	error = ioctl(conn->conn_iscsi_fd, ISCSISREMOVE, &isr);
166 	if (error != 0)
167 		log_warn("ISCSISREMOVE");
168 }
169 
170 void
171 discovery(struct connection *conn)
172 {
173 	struct pdu *request, *response;
174 	struct keys *request_keys, *response_keys;
175 	int i;
176 
177 	log_debugx("beginning discovery session");
178 	request = text_new_request(conn);
179 	request_keys = keys_new();
180 	keys_add(request_keys, "SendTargets", "All");
181 	keys_save(request_keys, request);
182 	keys_delete(request_keys);
183 	request_keys = NULL;
184 	pdu_send(request);
185 	pdu_delete(request);
186 	request = NULL;
187 
188 	log_debugx("waiting for Text Response");
189 	response = text_receive(conn);
190 	response_keys = keys_new();
191 	keys_load(response_keys, response);
192 	for (i = 0; i < KEYS_MAX; i++) {
193 		if (response_keys->keys_names[i] == NULL)
194 			break;
195 
196 		if (strcmp(response_keys->keys_names[i], "TargetName") != 0)
197 			continue;
198 
199 		log_debugx("adding target %s", response_keys->keys_values[i]);
200 		/*
201 		 * XXX: Validate the target name?
202 		 */
203 		kernel_add(conn, response_keys->keys_values[i]);
204 	}
205 	keys_delete(response_keys);
206 	pdu_delete(response);
207 
208 	log_debugx("removing temporary discovery session");
209 	kernel_remove(conn);
210 
211 #ifdef ICL_KERNEL_PROXY
212 	if (conn->conn_conf.isc_iser == 1) {
213 		/*
214 		 * If we're going through the proxy, the kernel already
215 		 * sent Logout PDU for us and destroyed the session,
216 		 * so we can't send anything anymore.
217 		 */
218 		log_debugx("discovery session done");
219 		return;
220 	}
221 #endif
222 
223 	log_debugx("discovery done; logging out");
224 	request = logout_new_request(conn);
225 	pdu_send(request);
226 	pdu_delete(request);
227 	request = NULL;
228 
229 	log_debugx("waiting for Logout Response");
230 	response = logout_receive(conn);
231 	pdu_delete(response);
232 
233 	log_debugx("discovery session done");
234 }
235