pdu.c revision 288704
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 */ 30 31#include <sys/cdefs.h> 32__FBSDID("$FreeBSD: stable/10/usr.sbin/ctld/pdu.c 288704 2015-10-05 07:42:05Z mav $"); 33 34#include <sys/types.h> 35#include <sys/uio.h> 36#include <assert.h> 37#include <stdlib.h> 38#include <unistd.h> 39 40#include "ctld.h" 41#include "iscsi_proto.h" 42 43#ifdef ICL_KERNEL_PROXY 44#include <sys/ioctl.h> 45#endif 46 47extern bool proxy_mode; 48 49static int 50pdu_ahs_length(const struct pdu *pdu) 51{ 52 53 return (pdu->pdu_bhs->bhs_total_ahs_len * 4); 54} 55 56static int 57pdu_data_segment_length(const struct pdu *pdu) 58{ 59 uint32_t len = 0; 60 61 len += pdu->pdu_bhs->bhs_data_segment_len[0]; 62 len <<= 8; 63 len += pdu->pdu_bhs->bhs_data_segment_len[1]; 64 len <<= 8; 65 len += pdu->pdu_bhs->bhs_data_segment_len[2]; 66 67 return (len); 68} 69 70static void 71pdu_set_data_segment_length(struct pdu *pdu, uint32_t len) 72{ 73 74 pdu->pdu_bhs->bhs_data_segment_len[2] = len; 75 pdu->pdu_bhs->bhs_data_segment_len[1] = len >> 8; 76 pdu->pdu_bhs->bhs_data_segment_len[0] = len >> 16; 77} 78 79struct pdu * 80pdu_new(struct connection *conn) 81{ 82 struct pdu *pdu; 83 84 pdu = calloc(sizeof(*pdu), 1); 85 if (pdu == NULL) 86 log_err(1, "calloc"); 87 88 pdu->pdu_bhs = calloc(sizeof(*pdu->pdu_bhs), 1); 89 if (pdu->pdu_bhs == NULL) 90 log_err(1, "calloc"); 91 92 pdu->pdu_connection = conn; 93 94 return (pdu); 95} 96 97struct pdu * 98pdu_new_response(struct pdu *request) 99{ 100 101 return (pdu_new(request->pdu_connection)); 102} 103 104#ifdef ICL_KERNEL_PROXY 105 106static void 107pdu_receive_proxy(struct pdu *pdu) 108{ 109 size_t len; 110 111 assert(proxy_mode); 112 113 kernel_receive(pdu); 114 115 len = pdu_ahs_length(pdu); 116 if (len > 0) 117 log_errx(1, "protocol error: non-empty AHS"); 118 119 len = pdu_data_segment_length(pdu); 120 assert(len <= MAX_DATA_SEGMENT_LENGTH); 121 pdu->pdu_data_len = len; 122} 123 124static void 125pdu_send_proxy(struct pdu *pdu) 126{ 127 128 assert(proxy_mode); 129 130 pdu_set_data_segment_length(pdu, pdu->pdu_data_len); 131 kernel_send(pdu); 132} 133 134#endif /* ICL_KERNEL_PROXY */ 135 136static size_t 137pdu_padding(const struct pdu *pdu) 138{ 139 140 if ((pdu->pdu_data_len % 4) != 0) 141 return (4 - (pdu->pdu_data_len % 4)); 142 143 return (0); 144} 145 146static void 147pdu_read(int fd, char *data, size_t len) 148{ 149 ssize_t ret; 150 151 while (len > 0) { 152 ret = read(fd, data, len); 153 if (ret < 0) { 154 if (timed_out()) 155 log_errx(1, "exiting due to timeout"); 156 log_err(1, "read"); 157 } else if (ret == 0) 158 log_errx(1, "read: connection lost"); 159 len -= ret; 160 data += ret; 161 } 162} 163 164void 165pdu_receive(struct pdu *pdu) 166{ 167 size_t len, padding; 168 char dummy[4]; 169 170#ifdef ICL_KERNEL_PROXY 171 if (proxy_mode) 172 return (pdu_receive_proxy(pdu)); 173#endif 174 175 assert(proxy_mode == false); 176 177 pdu_read(pdu->pdu_connection->conn_socket, 178 (char *)pdu->pdu_bhs, sizeof(*pdu->pdu_bhs)); 179 180 len = pdu_ahs_length(pdu); 181 if (len > 0) 182 log_errx(1, "protocol error: non-empty AHS"); 183 184 len = pdu_data_segment_length(pdu); 185 if (len > 0) { 186 if (len > MAX_DATA_SEGMENT_LENGTH) { 187 log_errx(1, "protocol error: received PDU " 188 "with DataSegmentLength exceeding %d", 189 MAX_DATA_SEGMENT_LENGTH); 190 } 191 192 pdu->pdu_data_len = len; 193 pdu->pdu_data = malloc(len); 194 if (pdu->pdu_data == NULL) 195 log_err(1, "malloc"); 196 197 pdu_read(pdu->pdu_connection->conn_socket, 198 (char *)pdu->pdu_data, pdu->pdu_data_len); 199 200 padding = pdu_padding(pdu); 201 if (padding != 0) { 202 assert(padding < sizeof(dummy)); 203 pdu_read(pdu->pdu_connection->conn_socket, 204 (char *)dummy, padding); 205 } 206 } 207} 208 209void 210pdu_send(struct pdu *pdu) 211{ 212 ssize_t ret, total_len; 213 size_t padding; 214 uint32_t zero = 0; 215 struct iovec iov[3]; 216 int iovcnt; 217 218#ifdef ICL_KERNEL_PROXY 219 if (proxy_mode) 220 return (pdu_send_proxy(pdu)); 221#endif 222 223 assert(proxy_mode == false); 224 225 pdu_set_data_segment_length(pdu, pdu->pdu_data_len); 226 iov[0].iov_base = pdu->pdu_bhs; 227 iov[0].iov_len = sizeof(*pdu->pdu_bhs); 228 total_len = iov[0].iov_len; 229 iovcnt = 1; 230 231 if (pdu->pdu_data_len > 0) { 232 iov[1].iov_base = pdu->pdu_data; 233 iov[1].iov_len = pdu->pdu_data_len; 234 total_len += iov[1].iov_len; 235 iovcnt = 2; 236 237 padding = pdu_padding(pdu); 238 if (padding > 0) { 239 assert(padding < sizeof(zero)); 240 iov[2].iov_base = &zero; 241 iov[2].iov_len = padding; 242 total_len += iov[2].iov_len; 243 iovcnt = 3; 244 } 245 } 246 247 ret = writev(pdu->pdu_connection->conn_socket, iov, iovcnt); 248 if (ret < 0) { 249 if (timed_out()) 250 log_errx(1, "exiting due to timeout"); 251 log_err(1, "writev"); 252 } 253 if (ret != total_len) 254 log_errx(1, "short write"); 255} 256 257void 258pdu_delete(struct pdu *pdu) 259{ 260 261 free(pdu->pdu_data); 262 free(pdu->pdu_bhs); 263 free(pdu); 264} 265