xref: /freebsd/lib/libiscsiutil/pdu.c (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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/uio.h>
37 #include <assert.h>
38 #include <errno.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 
43 #include <iscsi_proto.h>
44 #include "libiscsiutil.h"
45 
46 int
47 pdu_ahs_length(const struct pdu *pdu)
48 {
49 
50 	return (pdu->pdu_bhs->bhs_total_ahs_len * 4);
51 }
52 
53 int
54 pdu_data_segment_length(const struct pdu *pdu)
55 {
56 	uint32_t len = 0;
57 
58 	len += pdu->pdu_bhs->bhs_data_segment_len[0];
59 	len <<= 8;
60 	len += pdu->pdu_bhs->bhs_data_segment_len[1];
61 	len <<= 8;
62 	len += pdu->pdu_bhs->bhs_data_segment_len[2];
63 
64 	return (len);
65 }
66 
67 void
68 pdu_set_data_segment_length(struct pdu *pdu, uint32_t len)
69 {
70 
71 	pdu->pdu_bhs->bhs_data_segment_len[2] = len;
72 	pdu->pdu_bhs->bhs_data_segment_len[1] = len >> 8;
73 	pdu->pdu_bhs->bhs_data_segment_len[0] = len >> 16;
74 }
75 
76 struct pdu *
77 pdu_new(struct connection *conn)
78 {
79 	struct pdu *pdu;
80 
81 	pdu = calloc(1, sizeof(*pdu));
82 	if (pdu == NULL)
83 		log_err(1, "calloc");
84 
85 	pdu->pdu_bhs = calloc(1, sizeof(*pdu->pdu_bhs));
86 	if (pdu->pdu_bhs == NULL)
87 		log_err(1, "calloc");
88 
89 	pdu->pdu_connection = conn;
90 
91 	return (pdu);
92 }
93 
94 struct pdu *
95 pdu_new_response(struct pdu *request)
96 {
97 
98 	return (pdu_new(request->pdu_connection));
99 }
100 
101 static size_t
102 pdu_padding(const struct pdu *pdu)
103 {
104 
105 	if ((pdu->pdu_data_len % 4) != 0)
106 		return (4 - (pdu->pdu_data_len % 4));
107 
108 	return (0);
109 }
110 
111 static void
112 pdu_read(const struct connection *conn, char *data, size_t len)
113 {
114 	ssize_t ret;
115 
116 	while (len > 0) {
117 		ret = read(conn->conn_socket, data, len);
118 		if (ret < 0) {
119 			if (conn->conn_ops->timed_out()) {
120 				conn->conn_ops->fail(conn,
121 				    "Login Phase timeout");
122 				log_errx(1, "exiting due to timeout");
123 			}
124 			conn->conn_ops->fail(conn, strerror(errno));
125 			log_err(1, "read");
126 		} else if (ret == 0) {
127 			conn->conn_ops->fail(conn, "connection lost");
128 			log_errx(1, "read: connection lost");
129 		}
130 		len -= ret;
131 		data += ret;
132 	}
133 }
134 
135 void
136 pdu_receive(struct pdu *pdu)
137 {
138 	struct connection *conn;
139 	size_t len, padding;
140 	char dummy[4];
141 
142 	conn = pdu->pdu_connection;
143 	if (conn->conn_use_proxy)
144 		return (conn->conn_ops->pdu_receive_proxy(pdu));
145 
146 	pdu_read(conn, (char *)pdu->pdu_bhs, sizeof(*pdu->pdu_bhs));
147 
148 	len = pdu_ahs_length(pdu);
149 	if (len > 0)
150 		log_errx(1, "protocol error: non-empty AHS");
151 
152 	len = pdu_data_segment_length(pdu);
153 	if (len > 0) {
154 		if (len > (size_t)conn->conn_max_recv_data_segment_length) {
155 			log_errx(1, "protocol error: received PDU "
156 			    "with DataSegmentLength exceeding %d",
157 			    conn->conn_max_recv_data_segment_length);
158 		}
159 
160 		pdu->pdu_data_len = len;
161 		pdu->pdu_data = malloc(len);
162 		if (pdu->pdu_data == NULL)
163 			log_err(1, "malloc");
164 
165 		pdu_read(conn, (char *)pdu->pdu_data, pdu->pdu_data_len);
166 
167 		padding = pdu_padding(pdu);
168 		if (padding != 0) {
169 			assert(padding < sizeof(dummy));
170 			pdu_read(conn, (char *)dummy, padding);
171 		}
172 	}
173 }
174 
175 void
176 pdu_send(struct pdu *pdu)
177 {
178 	struct connection *conn;
179 	ssize_t ret, total_len;
180 	size_t padding;
181 	uint32_t zero = 0;
182 	struct iovec iov[3];
183 	int iovcnt;
184 
185 	conn = pdu->pdu_connection;
186 	if (conn->conn_use_proxy)
187 		return (conn->conn_ops->pdu_send_proxy(pdu));
188 
189 	pdu_set_data_segment_length(pdu, pdu->pdu_data_len);
190 	iov[0].iov_base = pdu->pdu_bhs;
191 	iov[0].iov_len = sizeof(*pdu->pdu_bhs);
192 	total_len = iov[0].iov_len;
193 	iovcnt = 1;
194 
195 	if (pdu->pdu_data_len > 0) {
196 		iov[1].iov_base = pdu->pdu_data;
197 		iov[1].iov_len = pdu->pdu_data_len;
198 		total_len += iov[1].iov_len;
199 		iovcnt = 2;
200 
201 		padding = pdu_padding(pdu);
202 		if (padding > 0) {
203 			assert(padding < sizeof(zero));
204 			iov[2].iov_base = &zero;
205 			iov[2].iov_len = padding;
206 			total_len += iov[2].iov_len;
207 			iovcnt = 3;
208 		}
209 	}
210 
211 	ret = writev(conn->conn_socket, iov, iovcnt);
212 	if (ret < 0) {
213 		if (conn->conn_ops->timed_out())
214 			log_errx(1, "exiting due to timeout");
215 		log_err(1, "writev");
216 	}
217 	if (ret != total_len)
218 		log_errx(1, "short write");
219 }
220 
221 void
222 pdu_delete(struct pdu *pdu)
223 {
224 
225 	free(pdu->pdu_data);
226 	free(pdu->pdu_bhs);
227 	free(pdu);
228 }
229