xref: /freebsd/usr.sbin/ctld/discovery.c (revision 8d20be1e22095c27faf8fe8b2f0d089739cc742e)
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  * $FreeBSD$
30  */
31 
32 #include <assert.h>
33 #include <stdint.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <netinet/in.h>
38 
39 #include "ctld.h"
40 #include "iscsi_proto.h"
41 
42 static struct pdu *
43 text_receive(struct connection *conn)
44 {
45 	struct pdu *request;
46 	struct iscsi_bhs_text_request *bhstr;
47 
48 	request = pdu_new(conn);
49 	pdu_receive(request);
50 	if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
51 	    ISCSI_BHS_OPCODE_TEXT_REQUEST)
52 		log_errx(1, "protocol error: received invalid opcode 0x%x",
53 		    request->pdu_bhs->bhs_opcode);
54 	bhstr = (struct iscsi_bhs_text_request *)request->pdu_bhs;
55 #if 0
56 	if ((bhstr->bhstr_flags & ISCSI_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 (request->pdu_data_len == 0)
65 		log_errx(1, "received Text PDU with empty data segment");
66 
67 	if (ntohl(bhstr->bhstr_cmdsn) < conn->conn_cmdsn) {
68 		log_errx(1, "received Text PDU with decreasing CmdSN: "
69 		    "was %d, is %d", conn->conn_cmdsn, ntohl(bhstr->bhstr_cmdsn));
70 	}
71 	if (ntohl(bhstr->bhstr_expstatsn) != conn->conn_statsn) {
72 		log_errx(1, "received Text PDU with wrong StatSN: "
73 		    "is %d, should be %d", ntohl(bhstr->bhstr_expstatsn),
74 		    conn->conn_statsn);
75 	}
76 	conn->conn_cmdsn = ntohl(bhstr->bhstr_cmdsn);
77 
78 	return (request);
79 }
80 
81 static struct pdu *
82 text_new_response(struct pdu *request)
83 {
84 	struct pdu *response;
85 	struct connection *conn;
86 	struct iscsi_bhs_text_request *bhstr;
87 	struct iscsi_bhs_text_response *bhstr2;
88 
89 	bhstr = (struct iscsi_bhs_text_request *)request->pdu_bhs;
90 	conn = request->pdu_connection;
91 
92 	response = pdu_new_response(request);
93 	bhstr2 = (struct iscsi_bhs_text_response *)response->pdu_bhs;
94 	bhstr2->bhstr_opcode = ISCSI_BHS_OPCODE_TEXT_RESPONSE;
95 	bhstr2->bhstr_flags = BHSTR_FLAGS_FINAL;
96 	bhstr2->bhstr_lun = bhstr->bhstr_lun;
97 	bhstr2->bhstr_initiator_task_tag = bhstr->bhstr_initiator_task_tag;
98 	bhstr2->bhstr_target_transfer_tag = bhstr->bhstr_target_transfer_tag;
99 	bhstr2->bhstr_statsn = htonl(conn->conn_statsn++);
100 	bhstr2->bhstr_expcmdsn = htonl(conn->conn_cmdsn);
101 	bhstr2->bhstr_maxcmdsn = htonl(conn->conn_cmdsn);
102 
103 	return (response);
104 }
105 
106 static struct pdu *
107 logout_receive(struct connection *conn)
108 {
109 	struct pdu *request;
110 	struct iscsi_bhs_logout_request *bhslr;
111 
112 	request = pdu_new(conn);
113 	pdu_receive(request);
114 	if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
115 	    ISCSI_BHS_OPCODE_LOGOUT_REQUEST)
116 		log_errx(1, "protocol error: received invalid opcode 0x%x",
117 		    request->pdu_bhs->bhs_opcode);
118 	bhslr = (struct iscsi_bhs_logout_request *)request->pdu_bhs;
119 	if ((bhslr->bhslr_reason & 0x7f) != BHSLR_REASON_CLOSE_SESSION)
120 		log_debugx("received Logout PDU with invalid reason 0x%x; "
121 		    "continuing anyway", bhslr->bhslr_reason & 0x7f);
122 	if (ntohl(bhslr->bhslr_cmdsn) < conn->conn_cmdsn) {
123 		log_errx(1, "received Logout PDU with decreasing CmdSN: "
124 		    "was %d, is %d", conn->conn_cmdsn,
125 		    ntohl(bhslr->bhslr_cmdsn));
126 	}
127 	if (ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) {
128 		log_errx(1, "received Logout PDU with wrong StatSN: "
129 		    "is %d, should be %d", ntohl(bhslr->bhslr_expstatsn),
130 		    conn->conn_statsn);
131 	}
132 	conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn);
133 
134 	return (request);
135 }
136 
137 static struct pdu *
138 logout_new_response(struct pdu *request)
139 {
140 	struct pdu *response;
141 	struct connection *conn;
142 	struct iscsi_bhs_logout_request *bhslr;
143 	struct iscsi_bhs_logout_response *bhslr2;
144 
145 	bhslr = (struct iscsi_bhs_logout_request *)request->pdu_bhs;
146 	conn = request->pdu_connection;
147 
148 	response = pdu_new_response(request);
149 	bhslr2 = (struct iscsi_bhs_logout_response *)response->pdu_bhs;
150 	bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGOUT_RESPONSE;
151 	bhslr2->bhslr_flags = 0x80;
152 	bhslr2->bhslr_response = BHSLR_RESPONSE_CLOSED_SUCCESSFULLY;
153 	bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag;
154 	bhslr2->bhslr_statsn = htonl(conn->conn_statsn++);
155 	bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn);
156 	bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn);
157 
158 	return (response);
159 }
160 
161 void
162 discovery(struct connection *conn)
163 {
164 	struct pdu *request, *response;
165 	struct keys *request_keys, *response_keys;
166 	struct target *targ;
167 	const char *send_targets;
168 
169 	log_debugx("beginning discovery session; waiting for Text PDU");
170 	request = text_receive(conn);
171 	request_keys = keys_new();
172 	keys_load(request_keys, request);
173 
174 	send_targets = keys_find(request_keys, "SendTargets");
175 	if (send_targets == NULL)
176 		log_errx(1, "received Text PDU without SendTargets");
177 
178 	response = text_new_response(request);
179 	response_keys = keys_new();
180 
181 	if (strcmp(send_targets, "All") == 0) {
182 		TAILQ_FOREACH(targ,
183 		    &conn->conn_portal->p_portal_group->pg_conf->conf_targets,
184 		    t_next) {
185 			if (targ->t_portal_group !=
186 			    conn->conn_portal->p_portal_group) {
187 				log_debugx("not returning target \"%s\"; "
188 				    "belongs to a different portal group",
189 				    targ->t_iqn);
190 				continue;
191 			}
192 			keys_add(response_keys, "TargetName", targ->t_iqn);
193 		}
194 	} else {
195 		targ = target_find(conn->conn_portal->p_portal_group->pg_conf,
196 		    send_targets);
197 		if (targ == NULL) {
198 			log_debugx("initiator requested information on unknown "
199 			    "target \"%s\"; returning nothing", send_targets);
200 		} else {
201 			keys_add(response_keys, "TargetName", targ->t_iqn);
202 		}
203 	}
204 	keys_save(response_keys, response);
205 
206 	pdu_send(response);
207 	pdu_delete(response);
208 	keys_delete(response_keys);
209 	pdu_delete(request);
210 	keys_delete(request_keys);
211 
212 	log_debugx("done sending targets; waiting for Logout PDU");
213 	request = logout_receive(conn);
214 	response = logout_new_response(request);
215 
216 	pdu_send(response);
217 	pdu_delete(response);
218 	pdu_delete(request);
219 
220 	log_debugx("discovery session done");
221 }
222