xref: /freebsd/lib/libiscsiutil/pdu.c (revision 5f4c09dd85bff675e0ca63c55ea3c517e0fddfcc)
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/uio.h>
35 #include <assert.h>
36 #include <errno.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <unistd.h>
40 
41 #include <iscsi_proto.h>
42 #include "libiscsiutil.h"
43 
44 int
45 pdu_ahs_length(const struct pdu *pdu)
46 {
47 
48 	return (pdu->pdu_bhs->bhs_total_ahs_len * 4);
49 }
50 
51 int
52 pdu_data_segment_length(const struct pdu *pdu)
53 {
54 	uint32_t len = 0;
55 
56 	len += pdu->pdu_bhs->bhs_data_segment_len[0];
57 	len <<= 8;
58 	len += pdu->pdu_bhs->bhs_data_segment_len[1];
59 	len <<= 8;
60 	len += pdu->pdu_bhs->bhs_data_segment_len[2];
61 
62 	return (len);
63 }
64 
65 void
66 pdu_set_data_segment_length(struct pdu *pdu, uint32_t len)
67 {
68 
69 	pdu->pdu_bhs->bhs_data_segment_len[2] = len;
70 	pdu->pdu_bhs->bhs_data_segment_len[1] = len >> 8;
71 	pdu->pdu_bhs->bhs_data_segment_len[0] = len >> 16;
72 }
73 
74 struct pdu *
75 pdu_new(struct connection *conn)
76 {
77 	struct pdu *pdu;
78 
79 	pdu = calloc(1, sizeof(*pdu));
80 	if (pdu == NULL)
81 		log_err(1, "calloc");
82 
83 	pdu->pdu_bhs = calloc(1, sizeof(*pdu->pdu_bhs));
84 	if (pdu->pdu_bhs == NULL)
85 		log_err(1, "calloc");
86 
87 	pdu->pdu_connection = conn;
88 
89 	return (pdu);
90 }
91 
92 struct pdu *
93 pdu_new_response(struct pdu *request)
94 {
95 
96 	return (pdu_new(request->pdu_connection));
97 }
98 
99 static size_t
100 pdu_padding(const struct pdu *pdu)
101 {
102 
103 	if ((pdu->pdu_data_len % 4) != 0)
104 		return (4 - (pdu->pdu_data_len % 4));
105 
106 	return (0);
107 }
108 
109 static void
110 pdu_read(const struct connection *conn, char *data, size_t len)
111 {
112 	ssize_t ret;
113 
114 	while (len > 0) {
115 		ret = read(conn->conn_socket, data, len);
116 		if (ret < 0) {
117 			if (conn->conn_ops->timed_out()) {
118 				conn->conn_ops->fail(conn,
119 				    "Login Phase timeout");
120 				log_errx(1, "exiting due to timeout");
121 			}
122 			conn->conn_ops->fail(conn, strerror(errno));
123 			log_err(1, "read");
124 		} else if (ret == 0) {
125 			conn->conn_ops->fail(conn, "connection lost");
126 			log_errx(1, "read: connection lost");
127 		}
128 		len -= ret;
129 		data += ret;
130 	}
131 }
132 
133 void
134 pdu_receive(struct pdu *pdu)
135 {
136 	struct connection *conn;
137 	size_t len, padding;
138 	char dummy[4];
139 
140 	conn = pdu->pdu_connection;
141 	if (conn->conn_use_proxy)
142 		return (conn->conn_ops->pdu_receive_proxy(pdu));
143 
144 	pdu_read(conn, (char *)pdu->pdu_bhs, sizeof(*pdu->pdu_bhs));
145 
146 	len = pdu_ahs_length(pdu);
147 	if (len > 0)
148 		log_errx(1, "protocol error: non-empty AHS");
149 
150 	len = pdu_data_segment_length(pdu);
151 	if (len > 0) {
152 		if (len > (size_t)conn->conn_max_recv_data_segment_length) {
153 			log_errx(1, "protocol error: received PDU "
154 			    "with DataSegmentLength exceeding %d",
155 			    conn->conn_max_recv_data_segment_length);
156 		}
157 
158 		pdu->pdu_data_len = len;
159 		pdu->pdu_data = malloc(len);
160 		if (pdu->pdu_data == NULL)
161 			log_err(1, "malloc");
162 
163 		pdu_read(conn, (char *)pdu->pdu_data, pdu->pdu_data_len);
164 
165 		padding = pdu_padding(pdu);
166 		if (padding != 0) {
167 			assert(padding < sizeof(dummy));
168 			pdu_read(conn, (char *)dummy, padding);
169 		}
170 	}
171 }
172 
173 void
174 pdu_send(struct pdu *pdu)
175 {
176 	struct connection *conn;
177 	ssize_t ret, total_len;
178 	size_t padding;
179 	uint32_t zero = 0;
180 	struct iovec iov[3];
181 	int iovcnt;
182 
183 	conn = pdu->pdu_connection;
184 	if (conn->conn_use_proxy)
185 		return (conn->conn_ops->pdu_send_proxy(pdu));
186 
187 	pdu_set_data_segment_length(pdu, pdu->pdu_data_len);
188 	iov[0].iov_base = pdu->pdu_bhs;
189 	iov[0].iov_len = sizeof(*pdu->pdu_bhs);
190 	total_len = iov[0].iov_len;
191 	iovcnt = 1;
192 
193 	if (pdu->pdu_data_len > 0) {
194 		iov[1].iov_base = pdu->pdu_data;
195 		iov[1].iov_len = pdu->pdu_data_len;
196 		total_len += iov[1].iov_len;
197 		iovcnt = 2;
198 
199 		padding = pdu_padding(pdu);
200 		if (padding > 0) {
201 			assert(padding < sizeof(zero));
202 			iov[2].iov_base = &zero;
203 			iov[2].iov_len = padding;
204 			total_len += iov[2].iov_len;
205 			iovcnt = 3;
206 		}
207 	}
208 
209 	ret = writev(conn->conn_socket, iov, iovcnt);
210 	if (ret < 0) {
211 		if (conn->conn_ops->timed_out())
212 			log_errx(1, "exiting due to timeout");
213 		log_err(1, "writev");
214 	}
215 	if (ret != total_len)
216 		log_errx(1, "short write");
217 }
218 
219 void
220 pdu_delete(struct pdu *pdu)
221 {
222 
223 	free(pdu->pdu_data);
224 	free(pdu->pdu_bhs);
225 	free(pdu);
226 }
227