xref: /freebsd/lib/libiscsiutil/pdu.c (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
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/types.h>
33 #include <sys/uio.h>
34 #include <assert.h>
35 #include <errno.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <unistd.h>
39 
40 #include <iscsi_proto.h>
41 #include "libiscsiutil.h"
42 
43 int
44 pdu_ahs_length(const struct pdu *pdu)
45 {
46 
47 	return (pdu->pdu_bhs->bhs_total_ahs_len * 4);
48 }
49 
50 int
51 pdu_data_segment_length(const struct pdu *pdu)
52 {
53 	uint32_t len = 0;
54 
55 	len += pdu->pdu_bhs->bhs_data_segment_len[0];
56 	len <<= 8;
57 	len += pdu->pdu_bhs->bhs_data_segment_len[1];
58 	len <<= 8;
59 	len += pdu->pdu_bhs->bhs_data_segment_len[2];
60 
61 	return (len);
62 }
63 
64 void
65 pdu_set_data_segment_length(struct pdu *pdu, uint32_t len)
66 {
67 
68 	pdu->pdu_bhs->bhs_data_segment_len[2] = len;
69 	pdu->pdu_bhs->bhs_data_segment_len[1] = len >> 8;
70 	pdu->pdu_bhs->bhs_data_segment_len[0] = len >> 16;
71 }
72 
73 struct pdu *
74 pdu_new(struct connection *conn)
75 {
76 	struct pdu *pdu;
77 
78 	pdu = calloc(1, sizeof(*pdu));
79 	if (pdu == NULL)
80 		log_err(1, "calloc");
81 
82 	pdu->pdu_bhs = calloc(1, sizeof(*pdu->pdu_bhs));
83 	if (pdu->pdu_bhs == NULL)
84 		log_err(1, "calloc");
85 
86 	pdu->pdu_connection = conn;
87 
88 	return (pdu);
89 }
90 
91 struct pdu *
92 pdu_new_response(struct pdu *request)
93 {
94 
95 	return (pdu_new(request->pdu_connection));
96 }
97 
98 static size_t
99 pdu_padding(const struct pdu *pdu)
100 {
101 
102 	if ((pdu->pdu_data_len % 4) != 0)
103 		return (4 - (pdu->pdu_data_len % 4));
104 
105 	return (0);
106 }
107 
108 static void
109 pdu_read(const struct connection *conn, char *data, size_t len)
110 {
111 	ssize_t ret;
112 
113 	while (len > 0) {
114 		ret = read(conn->conn_socket, data, len);
115 		if (ret < 0) {
116 			if (conn->conn_ops->timed_out()) {
117 				conn->conn_ops->fail(conn,
118 				    "Login Phase timeout");
119 				log_errx(1, "exiting due to timeout");
120 			}
121 			conn->conn_ops->fail(conn, strerror(errno));
122 			log_err(1, "read");
123 		} else if (ret == 0) {
124 			conn->conn_ops->fail(conn, "connection lost");
125 			log_errx(1, "read: connection lost");
126 		}
127 		len -= ret;
128 		data += ret;
129 	}
130 }
131 
132 void
133 pdu_receive(struct pdu *pdu)
134 {
135 	struct connection *conn;
136 	size_t len, padding;
137 	char dummy[4];
138 
139 	conn = pdu->pdu_connection;
140 	if (conn->conn_use_proxy)
141 		return (conn->conn_ops->pdu_receive_proxy(pdu));
142 
143 	pdu_read(conn, (char *)pdu->pdu_bhs, sizeof(*pdu->pdu_bhs));
144 
145 	len = pdu_ahs_length(pdu);
146 	if (len > 0)
147 		log_errx(1, "protocol error: non-empty AHS");
148 
149 	len = pdu_data_segment_length(pdu);
150 	if (len > 0) {
151 		if (len > (size_t)conn->conn_max_recv_data_segment_length) {
152 			log_errx(1, "protocol error: received PDU "
153 			    "with DataSegmentLength exceeding %d",
154 			    conn->conn_max_recv_data_segment_length);
155 		}
156 
157 		pdu->pdu_data_len = len;
158 		pdu->pdu_data = malloc(len);
159 		if (pdu->pdu_data == NULL)
160 			log_err(1, "malloc");
161 
162 		pdu_read(conn, (char *)pdu->pdu_data, pdu->pdu_data_len);
163 
164 		padding = pdu_padding(pdu);
165 		if (padding != 0) {
166 			assert(padding < sizeof(dummy));
167 			pdu_read(conn, (char *)dummy, padding);
168 		}
169 	}
170 }
171 
172 void
173 pdu_send(struct pdu *pdu)
174 {
175 	struct connection *conn;
176 	ssize_t ret, total_len;
177 	size_t padding;
178 	uint32_t zero = 0;
179 	struct iovec iov[3];
180 	int iovcnt;
181 
182 	conn = pdu->pdu_connection;
183 	if (conn->conn_use_proxy)
184 		return (conn->conn_ops->pdu_send_proxy(pdu));
185 
186 	pdu_set_data_segment_length(pdu, pdu->pdu_data_len);
187 	iov[0].iov_base = pdu->pdu_bhs;
188 	iov[0].iov_len = sizeof(*pdu->pdu_bhs);
189 	total_len = iov[0].iov_len;
190 	iovcnt = 1;
191 
192 	if (pdu->pdu_data_len > 0) {
193 		iov[1].iov_base = pdu->pdu_data;
194 		iov[1].iov_len = pdu->pdu_data_len;
195 		total_len += iov[1].iov_len;
196 		iovcnt = 2;
197 
198 		padding = pdu_padding(pdu);
199 		if (padding > 0) {
200 			assert(padding < sizeof(zero));
201 			iov[2].iov_base = &zero;
202 			iov[2].iov_len = padding;
203 			total_len += iov[2].iov_len;
204 			iovcnt = 3;
205 		}
206 	}
207 
208 	ret = writev(conn->conn_socket, iov, iovcnt);
209 	if (ret < 0) {
210 		if (conn->conn_ops->timed_out())
211 			log_errx(1, "exiting due to timeout");
212 		log_err(1, "writev");
213 	}
214 	if (ret != total_len)
215 		log_errx(1, "short write");
216 }
217 
218 void
219 pdu_delete(struct pdu *pdu)
220 {
221 
222 	free(pdu->pdu_data);
223 	free(pdu->pdu_bhs);
224 	free(pdu);
225 }
226