xref: /freebsd/usr.sbin/iscsid/discovery.c (revision 5dae51da3da0cc94d17bd67b308fad304ebec7e0)
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 <stdbool.h>
37 #include <string.h>
38 #include <netinet/in.h>
39 
40 #include "iscsid.h"
41 #include "iscsi_proto.h"
42 
43 static struct pdu *
44 text_receive(struct connection *conn)
45 {
46 	struct pdu *response;
47 	struct iscsi_bhs_text_response *bhstr;
48 
49 	response = pdu_new(conn);
50 	pdu_receive(response);
51 	if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_TEXT_RESPONSE)
52 		log_errx(1, "protocol error: received invalid opcode 0x%x",
53 		    response->pdu_bhs->bhs_opcode);
54 	bhstr = (struct iscsi_bhs_text_response *)response->pdu_bhs;
55 #if 0
56 	if ((bhstr->bhstr_flags & BHSTR_FLAGS_FINAL) == 0)
57 		log_errx(1, "received Text PDU without the \"F\" flag");
58 #endif
59 	/*
60 	 * XXX: Implement the C flag some day.
61 	 */
62 	if ((bhstr->bhstr_flags & BHSTR_FLAGS_CONTINUE) != 0)
63 		log_errx(1, "received Text PDU with unsupported \"C\" flag");
64 	if (ntohl(bhstr->bhstr_statsn) != conn->conn_statsn + 1) {
65 		log_errx(1, "received Text PDU with wrong StatSN: "
66 		    "is %u, should be %u", ntohl(bhstr->bhstr_statsn),
67 		    conn->conn_statsn + 1);
68 	}
69 	conn->conn_statsn = ntohl(bhstr->bhstr_statsn);
70 
71 	return (response);
72 }
73 
74 static struct pdu *
75 text_new_request(struct connection *conn)
76 {
77 	struct pdu *request;
78 	struct iscsi_bhs_text_request *bhstr;
79 
80 	request = pdu_new(conn);
81 	bhstr = (struct iscsi_bhs_text_request *)request->pdu_bhs;
82 	bhstr->bhstr_opcode = ISCSI_BHS_OPCODE_TEXT_REQUEST |
83 	    ISCSI_BHS_OPCODE_IMMEDIATE;
84 	bhstr->bhstr_flags = BHSTR_FLAGS_FINAL;
85 	bhstr->bhstr_initiator_task_tag = 0;
86 	bhstr->bhstr_target_transfer_tag = 0xffffffff;
87 
88 	bhstr->bhstr_initiator_task_tag = 0; /* XXX */
89 	bhstr->bhstr_cmdsn = 0; /* XXX */
90 	bhstr->bhstr_expstatsn = htonl(conn->conn_statsn + 1);
91 
92 	return (request);
93 }
94 
95 static struct pdu *
96 logout_receive(struct connection *conn)
97 {
98 	struct pdu *response;
99 	struct iscsi_bhs_logout_response *bhslr;
100 
101 	response = pdu_new(conn);
102 	pdu_receive(response);
103 	if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_LOGOUT_RESPONSE)
104 		log_errx(1, "protocol error: received invalid opcode 0x%x",
105 		    response->pdu_bhs->bhs_opcode);
106 	bhslr = (struct iscsi_bhs_logout_response *)response->pdu_bhs;
107 	if (ntohs(bhslr->bhslr_response) != BHSLR_RESPONSE_CLOSED_SUCCESSFULLY)
108 		log_warnx("received Logout Response with reason %d",
109 		    ntohs(bhslr->bhslr_response));
110 	if (ntohl(bhslr->bhslr_statsn) != conn->conn_statsn + 1) {
111 		log_errx(1, "received Logout PDU with wrong StatSN: "
112 		    "is %u, should be %u", ntohl(bhslr->bhslr_statsn),
113 		    conn->conn_statsn + 1);
114 	}
115 	conn->conn_statsn = ntohl(bhslr->bhslr_statsn);
116 
117 	return (response);
118 }
119 
120 static struct pdu *
121 logout_new_request(struct connection *conn)
122 {
123 	struct pdu *request;
124 	struct iscsi_bhs_logout_request *bhslr;
125 
126 	request = pdu_new(conn);
127 	bhslr = (struct iscsi_bhs_logout_request *)request->pdu_bhs;
128 	bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGOUT_REQUEST |
129 	    ISCSI_BHS_OPCODE_IMMEDIATE;
130 	bhslr->bhslr_reason = BHSLR_REASON_CLOSE_SESSION;
131 	bhslr->bhslr_reason |= 0x80;
132 	bhslr->bhslr_initiator_task_tag = 0; /* XXX */
133 	bhslr->bhslr_cmdsn = 0; /* XXX */
134 	bhslr->bhslr_expstatsn = htonl(conn->conn_statsn + 1);
135 
136 	return (request);
137 }
138 
139 static void
140 kernel_add(const struct connection *conn, const char *target)
141 {
142 	struct iscsi_session_add isa;
143 	int error;
144 
145 	memset(&isa, 0, sizeof(isa));
146 	memcpy(&isa.isa_conf, &conn->conn_conf, sizeof(isa.isa_conf));
147 	strlcpy(isa.isa_conf.isc_target, target,
148 	    sizeof(isa.isa_conf.isc_target));
149 	isa.isa_conf.isc_discovery = 0;
150 	error = ioctl(conn->conn_iscsi_fd, ISCSISADD, &isa);
151 	if (error != 0)
152 		log_warn("failed to add %s: ISCSISADD", target);
153 }
154 
155 static void
156 kernel_remove(const struct connection *conn)
157 {
158 	struct iscsi_session_remove isr;
159 	int error;
160 
161 	memset(&isr, 0, sizeof(isr));
162 	isr.isr_session_id = conn->conn_session_id;
163 	error = ioctl(conn->conn_iscsi_fd, ISCSISREMOVE, &isr);
164 	if (error != 0)
165 		log_warn("ISCSISREMOVE");
166 }
167 
168 void
169 discovery(struct connection *conn)
170 {
171 	struct pdu *request, *response;
172 	struct keys *request_keys, *response_keys;
173 	int i;
174 
175 	log_debugx("beginning discovery session");
176 	request = text_new_request(conn);
177 	request_keys = keys_new();
178 	keys_add(request_keys, "SendTargets", "All");
179 	keys_save(request_keys, request);
180 	keys_delete(request_keys);
181 	request_keys = NULL;
182 	pdu_send(request);
183 	pdu_delete(request);
184 	request = NULL;
185 
186 	log_debugx("waiting for Text Response");
187 	response = text_receive(conn);
188 	response_keys = keys_new();
189 	keys_load(response_keys, response);
190 	for (i = 0; i < KEYS_MAX; i++) {
191 		if (response_keys->keys_names[i] == NULL)
192 			break;
193 
194 		if (strcmp(response_keys->keys_names[i], "TargetName") != 0)
195 			continue;
196 
197 		log_debugx("adding target %s", response_keys->keys_values[i]);
198 		/*
199 		 * XXX: Validate the target name?
200 		 */
201 		kernel_add(conn, response_keys->keys_values[i]);
202 	}
203 	keys_delete(response_keys);
204 	pdu_delete(response);
205 
206 	log_debugx("removing temporary discovery session");
207 	kernel_remove(conn);
208 
209 #ifdef ICL_KERNEL_PROXY
210 	if (conn->conn_conf.isc_iser == 1) {
211 		/*
212 		 * If we're going through the proxy, the kernel already
213 		 * sent Logout PDU for us and destroyed the session,
214 		 * so we can't send anything anymore.
215 		 */
216 		log_debugx("discovery session done");
217 		return;
218 	}
219 #endif
220 
221 	log_debugx("discovery done; logging out");
222 	request = logout_new_request(conn);
223 	pdu_send(request);
224 	pdu_delete(request);
225 	request = NULL;
226 
227 	log_debugx("waiting for Logout Response");
228 	response = logout_receive(conn);
229 	pdu_delete(response);
230 
231 	log_debugx("discovery session done");
232 }
233