xref: /freebsd/usr.sbin/iscsid/discovery.c (revision 9268022b74279434ed6300244e3f977e56a8ceb5)
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("$FreeBSD$");
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 
46 static struct pdu *
47 text_receive(struct connection *conn)
48 {
49 	struct pdu *response;
50 	struct iscsi_bhs_text_response *bhstr;
51 
52 	response = pdu_new(conn);
53 	pdu_receive(response);
54 	if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_TEXT_RESPONSE)
55 		log_errx(1, "protocol error: received invalid opcode 0x%x",
56 		    response->pdu_bhs->bhs_opcode);
57 	bhstr = (struct iscsi_bhs_text_response *)response->pdu_bhs;
58 #if 0
59 	if ((bhstr->bhstr_flags & BHSTR_FLAGS_FINAL) == 0)
60 		log_errx(1, "received Text PDU without the \"F\" flag");
61 #endif
62 	/*
63 	 * XXX: Implement the C flag some day.
64 	 */
65 	if ((bhstr->bhstr_flags & BHSTR_FLAGS_CONTINUE) != 0)
66 		log_errx(1, "received Text PDU with unsupported \"C\" flag");
67 	if (ntohl(bhstr->bhstr_statsn) != conn->conn_statsn + 1) {
68 		log_errx(1, "received Text PDU with wrong StatSN: "
69 		    "is %d, should be %d", ntohl(bhstr->bhstr_statsn),
70 		    conn->conn_statsn + 1);
71 	}
72 	conn->conn_statsn = ntohl(bhstr->bhstr_statsn);
73 
74 	return (response);
75 }
76 
77 static struct pdu *
78 text_new_request(struct connection *conn)
79 {
80 	struct pdu *request;
81 	struct iscsi_bhs_text_request *bhstr;
82 
83 	request = pdu_new(conn);
84 	bhstr = (struct iscsi_bhs_text_request *)request->pdu_bhs;
85 	bhstr->bhstr_opcode = ISCSI_BHS_OPCODE_TEXT_REQUEST |
86 	    ISCSI_BHS_OPCODE_IMMEDIATE;
87 	bhstr->bhstr_flags = BHSTR_FLAGS_FINAL;
88 	bhstr->bhstr_initiator_task_tag = 0;
89 	bhstr->bhstr_target_transfer_tag = 0xffffffff;
90 
91 	bhstr->bhstr_initiator_task_tag = 0; /* XXX */
92 	bhstr->bhstr_cmdsn = 0; /* XXX */
93 	bhstr->bhstr_expstatsn = htonl(conn->conn_statsn + 1);
94 
95 	return (request);
96 }
97 
98 static struct pdu *
99 logout_receive(struct connection *conn)
100 {
101 	struct pdu *response;
102 	struct iscsi_bhs_logout_response *bhslr;
103 
104 	response = pdu_new(conn);
105 	pdu_receive(response);
106 	if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_LOGOUT_RESPONSE)
107 		log_errx(1, "protocol error: received invalid opcode 0x%x",
108 		    response->pdu_bhs->bhs_opcode);
109 	bhslr = (struct iscsi_bhs_logout_response *)response->pdu_bhs;
110 	if (ntohs(bhslr->bhslr_response) != BHSLR_RESPONSE_CLOSED_SUCCESSFULLY)
111 		log_warnx("received Logout Response with reason %d",
112 		    ntohs(bhslr->bhslr_response));
113 	if (ntohl(bhslr->bhslr_statsn) != conn->conn_statsn + 1) {
114 		log_errx(1, "received Logout PDU with wrong StatSN: "
115 		    "is %d, should be %d", ntohl(bhslr->bhslr_statsn),
116 		    conn->conn_statsn + 1);
117 	}
118 	conn->conn_statsn = ntohl(bhslr->bhslr_statsn);
119 
120 	return (response);
121 }
122 
123 static struct pdu *
124 logout_new_request(struct connection *conn)
125 {
126 	struct pdu *request;
127 	struct iscsi_bhs_logout_request *bhslr;
128 
129 	request = pdu_new(conn);
130 	bhslr = (struct iscsi_bhs_logout_request *)request->pdu_bhs;
131 	bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGOUT_REQUEST |
132 	    ISCSI_BHS_OPCODE_IMMEDIATE;
133 	bhslr->bhslr_reason = BHSLR_REASON_CLOSE_SESSION;
134 	bhslr->bhslr_reason |= 0x80;
135 	bhslr->bhslr_initiator_task_tag = 0; /* XXX */
136 	bhslr->bhslr_cmdsn = 0; /* XXX */
137 	bhslr->bhslr_expstatsn = htonl(conn->conn_statsn + 1);
138 
139 	return (request);
140 }
141 
142 static void
143 kernel_add(const struct connection *conn, const char *target)
144 {
145 	struct iscsi_session_add isa;
146 	int error;
147 
148 	memset(&isa, 0, sizeof(isa));
149 	memcpy(&isa.isa_conf, &conn->conn_conf, sizeof(isa.isa_conf));
150 	strlcpy(isa.isa_conf.isc_target, target,
151 	    sizeof(isa.isa_conf.isc_target));
152 	isa.isa_conf.isc_discovery = 0;
153 	error = ioctl(conn->conn_iscsi_fd, ISCSISADD, &isa);
154 	if (error != 0)
155 		log_warn("failed to add %s: ISCSISADD", target);
156 }
157 
158 static void
159 kernel_remove(const struct connection *conn)
160 {
161 	struct iscsi_session_remove isr;
162 	int error;
163 
164 	memset(&isr, 0, sizeof(isr));
165 	isr.isr_session_id = conn->conn_session_id;
166 	error = ioctl(conn->conn_iscsi_fd, ISCSISREMOVE, &isr);
167 	if (error != 0)
168 		log_warn("ISCSISREMOVE");
169 }
170 
171 void
172 discovery(struct connection *conn)
173 {
174 	struct pdu *request, *response;
175 	struct keys *request_keys, *response_keys;
176 	int i;
177 
178 	log_debugx("beginning discovery session");
179 	request = text_new_request(conn);
180 	request_keys = keys_new();
181 	keys_add(request_keys, "SendTargets", "All");
182 	keys_save(request_keys, request);
183 	keys_delete(request_keys);
184 	request_keys = NULL;
185 	pdu_send(request);
186 	pdu_delete(request);
187 	request = NULL;
188 
189 	log_debugx("waiting for Text Response");
190 	response = text_receive(conn);
191 	response_keys = keys_new();
192 	keys_load(response_keys, response);
193 	for (i = 0; i < KEYS_MAX; i++) {
194 		if (response_keys->keys_names[i] == NULL)
195 			break;
196 
197 		if (strcmp(response_keys->keys_names[i], "TargetName") != 0)
198 			continue;
199 
200 		log_debugx("adding target %s", response_keys->keys_values[i]);
201 		/*
202 		 * XXX: Validate the target name?
203 		 */
204 		kernel_add(conn, response_keys->keys_values[i]);
205 	}
206 	keys_delete(response_keys);
207 	pdu_delete(response);
208 
209 	log_debugx("removing temporary discovery session");
210 	kernel_remove(conn);
211 
212 	log_debugx("discovery done; logging out");
213 	request = logout_new_request(conn);
214 	pdu_send(request);
215 	pdu_delete(request);
216 	request = NULL;
217 
218 	log_debugx("waiting for Logout Response");
219 	response = logout_receive(conn);
220 	pdu_delete(response);
221 
222 	log_debugx("discovery session done");
223 }
224