xref: /freebsd/usr.sbin/iscsid/discovery.c (revision 5e3190f700637fcfc1a52daeaa4a031fdd2557c7)
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 #include <sys/types.h>
34 #include <sys/ioctl.h>
35 #include <stdbool.h>
36 #include <string.h>
37 #include <netinet/in.h>
38 
39 #include "iscsid.h"
40 #include "iscsi_proto.h"
41 
42 static struct pdu *
43 logout_receive(struct connection *conn)
44 {
45 	struct pdu *response;
46 	struct iscsi_bhs_logout_response *bhslr;
47 
48 	response = pdu_new(conn);
49 	pdu_receive(response);
50 	if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_LOGOUT_RESPONSE)
51 		log_errx(1, "protocol error: received invalid opcode 0x%x",
52 		    response->pdu_bhs->bhs_opcode);
53 	bhslr = (struct iscsi_bhs_logout_response *)response->pdu_bhs;
54 	if (ntohs(bhslr->bhslr_response) != BHSLR_RESPONSE_CLOSED_SUCCESSFULLY)
55 		log_warnx("received Logout Response with reason %d",
56 		    ntohs(bhslr->bhslr_response));
57 	if (ntohl(bhslr->bhslr_statsn) != conn->conn_statsn + 1) {
58 		log_errx(1, "received Logout PDU with wrong StatSN: "
59 		    "is %u, should be %u", ntohl(bhslr->bhslr_statsn),
60 		    conn->conn_statsn + 1);
61 	}
62 	conn->conn_statsn = ntohl(bhslr->bhslr_statsn);
63 
64 	return (response);
65 }
66 
67 static struct pdu *
68 logout_new_request(struct connection *conn)
69 {
70 	struct pdu *request;
71 	struct iscsi_bhs_logout_request *bhslr;
72 
73 	request = pdu_new(conn);
74 	bhslr = (struct iscsi_bhs_logout_request *)request->pdu_bhs;
75 	bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGOUT_REQUEST |
76 	    ISCSI_BHS_OPCODE_IMMEDIATE;
77 	bhslr->bhslr_reason = BHSLR_REASON_CLOSE_SESSION;
78 	bhslr->bhslr_reason |= 0x80;
79 	bhslr->bhslr_initiator_task_tag = 0; /* XXX */
80 	bhslr->bhslr_cmdsn = 0; /* XXX */
81 	bhslr->bhslr_expstatsn = htonl(conn->conn_statsn + 1);
82 
83 	return (request);
84 }
85 
86 static void
87 kernel_add(const struct iscsid_connection *conn, const char *target)
88 {
89 	struct iscsi_session_add isa;
90 	int error;
91 
92 	memset(&isa, 0, sizeof(isa));
93 	memcpy(&isa.isa_conf, &conn->conn_conf, sizeof(isa.isa_conf));
94 	strlcpy(isa.isa_conf.isc_target, target,
95 	    sizeof(isa.isa_conf.isc_target));
96 	isa.isa_conf.isc_discovery = 0;
97 	error = ioctl(conn->conn_iscsi_fd, ISCSISADD, &isa);
98 	if (error != 0)
99 		log_warn("failed to add %s: ISCSISADD", target);
100 }
101 
102 static void
103 kernel_remove(const struct iscsid_connection *conn)
104 {
105 	struct iscsi_session_remove isr;
106 	int error;
107 
108 	memset(&isr, 0, sizeof(isr));
109 	isr.isr_session_id = conn->conn_session_id;
110 	error = ioctl(conn->conn_iscsi_fd, ISCSISREMOVE, &isr);
111 	if (error != 0)
112 		log_warn("ISCSISREMOVE");
113 }
114 
115 void
116 discovery(struct iscsid_connection *conn)
117 {
118 	struct pdu *request, *response;
119 	struct keys *request_keys, *response_keys;
120 	int i;
121 
122 	log_debugx("beginning discovery session");
123 	request_keys = keys_new();
124 	keys_add(request_keys, "SendTargets", "All");
125 	text_send_request(&conn->conn, request_keys);
126 	keys_delete(request_keys);
127 	request_keys = NULL;
128 
129 	log_debugx("waiting for Text Response");
130 	response_keys = text_read_response(&conn->conn);
131 	for (i = 0; i < KEYS_MAX; i++) {
132 		if (response_keys->keys_names[i] == NULL)
133 			break;
134 
135 		if (strcmp(response_keys->keys_names[i], "TargetName") != 0)
136 			continue;
137 
138 		log_debugx("adding target %s", response_keys->keys_values[i]);
139 		/*
140 		 * XXX: Validate the target name?
141 		 */
142 		kernel_add(conn, response_keys->keys_values[i]);
143 	}
144 	keys_delete(response_keys);
145 
146 	log_debugx("removing temporary discovery session");
147 	kernel_remove(conn);
148 
149 #ifdef ICL_KERNEL_PROXY
150 	if (conn->conn_conf.isc_iser == 1) {
151 		/*
152 		 * If we're going through the proxy, the kernel already
153 		 * sent Logout PDU for us and destroyed the session,
154 		 * so we can't send anything anymore.
155 		 */
156 		log_debugx("discovery session done");
157 		return;
158 	}
159 #endif
160 
161 	log_debugx("discovery done; logging out");
162 	request = logout_new_request(&conn->conn);
163 	pdu_send(request);
164 	pdu_delete(request);
165 	request = NULL;
166 
167 	log_debugx("waiting for Logout Response");
168 	response = logout_receive(&conn->conn);
169 	pdu_delete(response);
170 
171 	log_debugx("discovery session done");
172 }
173