xref: /freebsd/usr.sbin/iscsid/discovery.c (revision b17b639832e707aab0e9514cf94727498e2d67bd)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2012 The FreeBSD Foundation
5  *
6  * This software was developed by Edward Tomasz Napierala under sponsorship
7  * from the FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/types.h>
36 #include <sys/ioctl.h>
37 #include <stdbool.h>
38 #include <string.h>
39 #include <netinet/in.h>
40 
41 #include "iscsid.h"
42 #include "iscsi_proto.h"
43 
44 static struct pdu *
45 logout_receive(struct connection *conn)
46 {
47 	struct pdu *response;
48 	struct iscsi_bhs_logout_response *bhslr;
49 
50 	response = pdu_new(conn);
51 	pdu_receive(response);
52 	if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_LOGOUT_RESPONSE)
53 		log_errx(1, "protocol error: received invalid opcode 0x%x",
54 		    response->pdu_bhs->bhs_opcode);
55 	bhslr = (struct iscsi_bhs_logout_response *)response->pdu_bhs;
56 	if (ntohs(bhslr->bhslr_response) != BHSLR_RESPONSE_CLOSED_SUCCESSFULLY)
57 		log_warnx("received Logout Response with reason %d",
58 		    ntohs(bhslr->bhslr_response));
59 	if (ntohl(bhslr->bhslr_statsn) != conn->conn_statsn + 1) {
60 		log_errx(1, "received Logout PDU with wrong StatSN: "
61 		    "is %u, should be %u", ntohl(bhslr->bhslr_statsn),
62 		    conn->conn_statsn + 1);
63 	}
64 	conn->conn_statsn = ntohl(bhslr->bhslr_statsn);
65 
66 	return (response);
67 }
68 
69 static struct pdu *
70 logout_new_request(struct connection *conn)
71 {
72 	struct pdu *request;
73 	struct iscsi_bhs_logout_request *bhslr;
74 
75 	request = pdu_new(conn);
76 	bhslr = (struct iscsi_bhs_logout_request *)request->pdu_bhs;
77 	bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGOUT_REQUEST |
78 	    ISCSI_BHS_OPCODE_IMMEDIATE;
79 	bhslr->bhslr_reason = BHSLR_REASON_CLOSE_SESSION;
80 	bhslr->bhslr_reason |= 0x80;
81 	bhslr->bhslr_initiator_task_tag = 0; /* XXX */
82 	bhslr->bhslr_cmdsn = 0; /* XXX */
83 	bhslr->bhslr_expstatsn = htonl(conn->conn_statsn + 1);
84 
85 	return (request);
86 }
87 
88 static void
89 kernel_add(const struct iscsid_connection *conn, const char *target)
90 {
91 	struct iscsi_session_add isa;
92 	int error;
93 
94 	memset(&isa, 0, sizeof(isa));
95 	memcpy(&isa.isa_conf, &conn->conn_conf, sizeof(isa.isa_conf));
96 	strlcpy(isa.isa_conf.isc_target, target,
97 	    sizeof(isa.isa_conf.isc_target));
98 	isa.isa_conf.isc_discovery = 0;
99 	error = ioctl(conn->conn_iscsi_fd, ISCSISADD, &isa);
100 	if (error != 0)
101 		log_warn("failed to add %s: ISCSISADD", target);
102 }
103 
104 static void
105 kernel_remove(const struct iscsid_connection *conn)
106 {
107 	struct iscsi_session_remove isr;
108 	int error;
109 
110 	memset(&isr, 0, sizeof(isr));
111 	isr.isr_session_id = conn->conn_session_id;
112 	error = ioctl(conn->conn_iscsi_fd, ISCSISREMOVE, &isr);
113 	if (error != 0)
114 		log_warn("ISCSISREMOVE");
115 }
116 
117 void
118 discovery(struct iscsid_connection *conn)
119 {
120 	struct pdu *request, *response;
121 	struct keys *request_keys, *response_keys;
122 	int i;
123 
124 	log_debugx("beginning discovery session");
125 	request_keys = keys_new();
126 	keys_add(request_keys, "SendTargets", "All");
127 	text_send_request(&conn->conn, request_keys);
128 	keys_delete(request_keys);
129 	request_keys = NULL;
130 
131 	log_debugx("waiting for Text Response");
132 	response_keys = text_read_response(&conn->conn);
133 	for (i = 0; i < KEYS_MAX; i++) {
134 		if (response_keys->keys_names[i] == NULL)
135 			break;
136 
137 		if (strcmp(response_keys->keys_names[i], "TargetName") != 0)
138 			continue;
139 
140 		log_debugx("adding target %s", response_keys->keys_values[i]);
141 		/*
142 		 * XXX: Validate the target name?
143 		 */
144 		kernel_add(conn, response_keys->keys_values[i]);
145 	}
146 	keys_delete(response_keys);
147 
148 	log_debugx("removing temporary discovery session");
149 	kernel_remove(conn);
150 
151 #ifdef ICL_KERNEL_PROXY
152 	if (conn->conn_conf.isc_iser == 1) {
153 		/*
154 		 * If we're going through the proxy, the kernel already
155 		 * sent Logout PDU for us and destroyed the session,
156 		 * so we can't send anything anymore.
157 		 */
158 		log_debugx("discovery session done");
159 		return;
160 	}
161 #endif
162 
163 	log_debugx("discovery done; logging out");
164 	request = logout_new_request(&conn->conn);
165 	pdu_send(request);
166 	pdu_delete(request);
167 	request = NULL;
168 
169 	log_debugx("waiting for Logout Response");
170 	response = logout_receive(&conn->conn);
171 	pdu_delete(response);
172 
173 	log_debugx("discovery session done");
174 }
175