pdu.c revision 265526 
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: stable/10/usr.sbin/iscsid/pdu.c 265526 2014-05-07 07:56:36Z trasz $
30 */
31
32#include <sys/types.h>
33#include <sys/uio.h>
34#include <assert.h>
35#include <stdint.h>
36#include <stdio.h>
37#include <stdlib.h>
38#include <unistd.h>
39
40#include "iscsid.h"
41#include "iscsi_proto.h"
42
43#ifdef ICL_KERNEL_PROXY
44#include <sys/ioctl.h>
45#endif
46
47static int
48pdu_ahs_length(const struct pdu *pdu)
49{
50
51	return (pdu->pdu_bhs->bhs_total_ahs_len * 4);
52}
53
54static int
55pdu_data_segment_length(const struct pdu *pdu)
56{
57	uint32_t len = 0;
58
59	len += pdu->pdu_bhs->bhs_data_segment_len[0];
60	len <<= 8;
61	len += pdu->pdu_bhs->bhs_data_segment_len[1];
62	len <<= 8;
63	len += pdu->pdu_bhs->bhs_data_segment_len[2];
64
65	return (len);
66}
67
68static void
69pdu_set_data_segment_length(struct pdu *pdu, uint32_t len)
70{
71
72	pdu->pdu_bhs->bhs_data_segment_len[2] = len;
73	pdu->pdu_bhs->bhs_data_segment_len[1] = len >> 8;
74	pdu->pdu_bhs->bhs_data_segment_len[0] = len >> 16;
75}
76
77struct pdu *
78pdu_new(struct connection *conn)
79{
80	struct pdu *pdu;
81
82	pdu = calloc(sizeof(*pdu), 1);
83	if (pdu == NULL)
84		log_err(1, "calloc");
85
86	pdu->pdu_bhs = calloc(sizeof(*pdu->pdu_bhs), 1);
87	if (pdu->pdu_bhs == NULL)
88		log_err(1, "calloc");
89
90	pdu->pdu_connection = conn;
91
92	return (pdu);
93}
94
95struct pdu *
96pdu_new_response(struct pdu *request)
97{
98
99	return (pdu_new(request->pdu_connection));
100}
101
102#ifdef ICL_KERNEL_PROXY
103
104static void
105pdu_receive_proxy(struct pdu *pdu)
106{
107	struct iscsi_daemon_receive *idr;
108	size_t len;
109	int error;
110
111	assert(pdu->pdu_connection->conn_conf.isc_iser != 0);
112
113	pdu->pdu_data = malloc(ISCSI_MAX_DATA_SEGMENT_LENGTH);
114	if (pdu->pdu_data == NULL)
115		log_err(1, "malloc");
116
117	idr = calloc(1, sizeof(*idr));
118	if (idr == NULL)
119		log_err(1, "calloc");
120
121	idr->idr_session_id = pdu->pdu_connection->conn_session_id;
122	idr->idr_bhs = pdu->pdu_bhs;
123	idr->idr_data_segment_len = ISCSI_MAX_DATA_SEGMENT_LENGTH;
124	idr->idr_data_segment = pdu->pdu_data;
125
126	error = ioctl(pdu->pdu_connection->conn_iscsi_fd, ISCSIDRECEIVE, idr);
127	if (error != 0)
128		log_err(1, "ISCSIDRECEIVE");
129
130	len = pdu_ahs_length(pdu);
131	if (len > 0)
132		log_errx(1, "protocol error: non-empty AHS");
133
134	len = pdu_data_segment_length(pdu);
135	assert(len <= ISCSI_MAX_DATA_SEGMENT_LENGTH);
136	pdu->pdu_data_len = len;
137
138	free(idr);
139}
140
141static void
142pdu_send_proxy(struct pdu *pdu)
143{
144	struct iscsi_daemon_send *ids;
145	int error;
146
147	assert(pdu->pdu_connection->conn_conf.isc_iser != 0);
148
149	pdu_set_data_segment_length(pdu, pdu->pdu_data_len);
150
151	ids = calloc(1, sizeof(*ids));
152	if (ids == NULL)
153		log_err(1, "calloc");
154
155	ids->ids_session_id = pdu->pdu_connection->conn_session_id;
156	ids->ids_bhs = pdu->pdu_bhs;
157	ids->ids_data_segment_len = pdu->pdu_data_len;
158	ids->ids_data_segment = pdu->pdu_data;
159
160	error = ioctl(pdu->pdu_connection->conn_iscsi_fd, ISCSIDSEND, ids);
161	if (error != 0)
162		log_err(1, "ISCSIDSEND");
163
164	free(ids);
165}
166
167#endif /* ICL_KERNEL_PROXY */
168
169static size_t
170pdu_padding(const struct pdu *pdu)
171{
172
173	if ((pdu->pdu_data_len % 4) != 0)
174		return (4 - (pdu->pdu_data_len % 4));
175
176	return (0);
177}
178
179static void
180pdu_read(int fd, char *data, size_t len)
181{
182	ssize_t ret;
183
184	while (len > 0) {
185		ret = read(fd, data, len);
186		if (ret < 0) {
187			if (timed_out())
188				log_errx(1, "exiting due to timeout");
189			log_err(1, "read");
190		} else if (ret == 0)
191			log_errx(1, "read: connection lost");
192		len -= ret;
193		data += ret;
194	}
195}
196
197void
198pdu_receive(struct pdu *pdu)
199{
200	size_t len, padding;
201	char dummy[4];
202
203#ifdef ICL_KERNEL_PROXY
204	if (pdu->pdu_connection->conn_conf.isc_iser != 0)
205		return (pdu_receive_proxy(pdu));
206#endif
207
208	assert(pdu->pdu_connection->conn_conf.isc_iser == 0);
209
210	pdu_read(pdu->pdu_connection->conn_socket,
211	    (char *)pdu->pdu_bhs, sizeof(*pdu->pdu_bhs));
212
213	len = pdu_ahs_length(pdu);
214	if (len > 0)
215		log_errx(1, "protocol error: non-empty AHS");
216
217	len = pdu_data_segment_length(pdu);
218	if (len > 0) {
219		if (len > ISCSI_MAX_DATA_SEGMENT_LENGTH) {
220			log_errx(1, "protocol error: received PDU "
221			    "with DataSegmentLength exceeding %d",
222			    ISCSI_MAX_DATA_SEGMENT_LENGTH);
223		}
224
225		pdu->pdu_data_len = len;
226		pdu->pdu_data = malloc(len);
227		if (pdu->pdu_data == NULL)
228			log_err(1, "malloc");
229
230		pdu_read(pdu->pdu_connection->conn_socket,
231		    (char *)pdu->pdu_data, pdu->pdu_data_len);
232
233		padding = pdu_padding(pdu);
234		if (padding != 0) {
235			assert(padding < sizeof(dummy));
236			pdu_read(pdu->pdu_connection->conn_socket,
237			    (char *)dummy, padding);
238		}
239	}
240}
241
242void
243pdu_send(struct pdu *pdu)
244{
245	ssize_t ret, total_len;
246	size_t padding;
247	uint32_t zero = 0;
248	struct iovec iov[3];
249	int iovcnt;
250
251#ifdef ICL_KERNEL_PROXY
252	if (pdu->pdu_connection->conn_conf.isc_iser != 0)
253		return (pdu_send_proxy(pdu));
254#endif
255
256	assert(pdu->pdu_connection->conn_conf.isc_iser == 0);
257
258	pdu_set_data_segment_length(pdu, pdu->pdu_data_len);
259	iov[0].iov_base = pdu->pdu_bhs;
260	iov[0].iov_len = sizeof(*pdu->pdu_bhs);
261	total_len = iov[0].iov_len;
262	iovcnt = 1;
263
264	if (pdu->pdu_data_len > 0) {
265		iov[1].iov_base = pdu->pdu_data;
266		iov[1].iov_len = pdu->pdu_data_len;
267		total_len += iov[1].iov_len;
268		iovcnt = 2;
269
270		padding = pdu_padding(pdu);
271		if (padding > 0) {
272			assert(padding < sizeof(zero));
273			iov[2].iov_base = &zero;
274			iov[2].iov_len = padding;
275			total_len += iov[2].iov_len;
276			iovcnt = 3;
277		}
278	}
279
280	ret = writev(pdu->pdu_connection->conn_socket, iov, iovcnt);
281	if (ret < 0) {
282		if (timed_out())
283			log_errx(1, "exiting due to timeout");
284		log_err(1, "writev");
285	}
286	if (ret != total_len)
287		log_errx(1, "short write");
288}
289
290void
291pdu_delete(struct pdu *pdu)
292{
293
294	free(pdu->pdu_data);
295	free(pdu->pdu_bhs);
296	free(pdu);
297}
298