1 /* 2 * iSCSI Initiator over TCP/IP Data-Path 3 * 4 * Copyright (C) 2004 Dmitry Yusupov 5 * Copyright (C) 2004 Alex Aizman 6 * Copyright (C) 2005 - 2006 Mike Christie 7 * Copyright (C) 2006 Red Hat, Inc. All rights reserved. 8 * maintained by open-iscsi@googlegroups.com 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published 12 * by the Free Software Foundation; either version 2 of the License, or 13 * (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, but 16 * WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 18 * General Public License for more details. 19 * 20 * See the file COPYING included with this distribution for more details. 21 * 22 * Credits: 23 * Christoph Hellwig 24 * FUJITA Tomonori 25 * Arne Redlich 26 * Zhenyu Wang 27 */ 28 29 #include <linux/types.h> 30 #include <linux/inet.h> 31 #include <linux/slab.h> 32 #include <linux/file.h> 33 #include <linux/blkdev.h> 34 #include <linux/crypto.h> 35 #include <linux/delay.h> 36 #include <linux/kfifo.h> 37 #include <linux/scatterlist.h> 38 #include <linux/module.h> 39 #include <net/tcp.h> 40 #include <scsi/scsi_cmnd.h> 41 #include <scsi/scsi_device.h> 42 #include <scsi/scsi_host.h> 43 #include <scsi/scsi.h> 44 #include <scsi/scsi_transport_iscsi.h> 45 46 #include "iscsi_tcp.h" 47 48 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, " 49 "Dmitry Yusupov <dmitry_yus@yahoo.com>, " 50 "Alex Aizman <itn780@yahoo.com>"); 51 MODULE_DESCRIPTION("iSCSI/TCP data-path"); 52 MODULE_LICENSE("GPL"); 53 54 static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport; 55 static struct scsi_host_template iscsi_sw_tcp_sht; 56 static struct iscsi_transport iscsi_sw_tcp_transport; 57 58 static unsigned int iscsi_max_lun = 512; 59 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO); 60 61 static int iscsi_sw_tcp_dbg; 62 module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int, 63 S_IRUGO | S_IWUSR); 64 MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module " 65 "Set to 1 to turn on, and zero to turn off. Default is off."); 66 67 #define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \ 68 do { \ 69 if (iscsi_sw_tcp_dbg) \ 70 iscsi_conn_printk(KERN_INFO, _conn, \ 71 "%s " dbg_fmt, \ 72 __func__, ##arg); \ 73 } while (0); 74 75 76 /** 77 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion 78 * @rd_desc: read descriptor 79 * @skb: socket buffer 80 * @offset: offset in skb 81 * @len: skb->len - offset 82 */ 83 static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 84 unsigned int offset, size_t len) 85 { 86 struct iscsi_conn *conn = rd_desc->arg.data; 87 unsigned int consumed, total_consumed = 0; 88 int status; 89 90 ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset); 91 92 do { 93 status = 0; 94 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status); 95 offset += consumed; 96 total_consumed += consumed; 97 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE); 98 99 ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n", 100 skb->len - offset, status); 101 return total_consumed; 102 } 103 104 /** 105 * iscsi_sw_sk_state_check - check socket state 106 * @sk: socket 107 * 108 * If the socket is in CLOSE or CLOSE_WAIT we should 109 * not close the connection if there is still some 110 * data pending. 111 * 112 * Must be called with sk_callback_lock. 113 */ 114 static inline int iscsi_sw_sk_state_check(struct sock *sk) 115 { 116 struct iscsi_conn *conn = sk->sk_user_data; 117 118 if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) && 119 !atomic_read(&sk->sk_rmem_alloc)) { 120 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n"); 121 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE); 122 return -ECONNRESET; 123 } 124 return 0; 125 } 126 127 static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag) 128 { 129 struct iscsi_conn *conn; 130 struct iscsi_tcp_conn *tcp_conn; 131 read_descriptor_t rd_desc; 132 133 read_lock(&sk->sk_callback_lock); 134 conn = sk->sk_user_data; 135 if (!conn) { 136 read_unlock(&sk->sk_callback_lock); 137 return; 138 } 139 tcp_conn = conn->dd_data; 140 141 /* 142 * Use rd_desc to pass 'conn' to iscsi_tcp_recv. 143 * We set count to 1 because we want the network layer to 144 * hand us all the skbs that are available. iscsi_tcp_recv 145 * handled pdus that cross buffers or pdus that still need data. 146 */ 147 rd_desc.arg.data = conn; 148 rd_desc.count = 1; 149 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv); 150 151 iscsi_sw_sk_state_check(sk); 152 153 /* If we had to (atomically) map a highmem page, 154 * unmap it now. */ 155 iscsi_tcp_segment_unmap(&tcp_conn->in.segment); 156 read_unlock(&sk->sk_callback_lock); 157 } 158 159 static void iscsi_sw_tcp_state_change(struct sock *sk) 160 { 161 struct iscsi_tcp_conn *tcp_conn; 162 struct iscsi_sw_tcp_conn *tcp_sw_conn; 163 struct iscsi_conn *conn; 164 struct iscsi_session *session; 165 void (*old_state_change)(struct sock *); 166 167 read_lock(&sk->sk_callback_lock); 168 conn = sk->sk_user_data; 169 if (!conn) { 170 read_unlock(&sk->sk_callback_lock); 171 return; 172 } 173 session = conn->session; 174 175 iscsi_sw_sk_state_check(sk); 176 177 tcp_conn = conn->dd_data; 178 tcp_sw_conn = tcp_conn->dd_data; 179 old_state_change = tcp_sw_conn->old_state_change; 180 181 read_unlock(&sk->sk_callback_lock); 182 183 old_state_change(sk); 184 } 185 186 /** 187 * iscsi_write_space - Called when more output buffer space is available 188 * @sk: socket space is available for 189 **/ 190 static void iscsi_sw_tcp_write_space(struct sock *sk) 191 { 192 struct iscsi_conn *conn; 193 struct iscsi_tcp_conn *tcp_conn; 194 struct iscsi_sw_tcp_conn *tcp_sw_conn; 195 void (*old_write_space)(struct sock *); 196 197 read_lock_bh(&sk->sk_callback_lock); 198 conn = sk->sk_user_data; 199 if (!conn) { 200 read_unlock_bh(&sk->sk_callback_lock); 201 return; 202 } 203 204 tcp_conn = conn->dd_data; 205 tcp_sw_conn = tcp_conn->dd_data; 206 old_write_space = tcp_sw_conn->old_write_space; 207 read_unlock_bh(&sk->sk_callback_lock); 208 209 old_write_space(sk); 210 211 ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n"); 212 iscsi_conn_queue_work(conn); 213 } 214 215 static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn) 216 { 217 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 218 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 219 struct sock *sk = tcp_sw_conn->sock->sk; 220 221 /* assign new callbacks */ 222 write_lock_bh(&sk->sk_callback_lock); 223 sk->sk_user_data = conn; 224 tcp_sw_conn->old_data_ready = sk->sk_data_ready; 225 tcp_sw_conn->old_state_change = sk->sk_state_change; 226 tcp_sw_conn->old_write_space = sk->sk_write_space; 227 sk->sk_data_ready = iscsi_sw_tcp_data_ready; 228 sk->sk_state_change = iscsi_sw_tcp_state_change; 229 sk->sk_write_space = iscsi_sw_tcp_write_space; 230 write_unlock_bh(&sk->sk_callback_lock); 231 } 232 233 static void 234 iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn) 235 { 236 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 237 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 238 struct sock *sk = tcp_sw_conn->sock->sk; 239 240 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */ 241 write_lock_bh(&sk->sk_callback_lock); 242 sk->sk_user_data = NULL; 243 sk->sk_data_ready = tcp_sw_conn->old_data_ready; 244 sk->sk_state_change = tcp_sw_conn->old_state_change; 245 sk->sk_write_space = tcp_sw_conn->old_write_space; 246 sk->sk_no_check = 0; 247 write_unlock_bh(&sk->sk_callback_lock); 248 } 249 250 /** 251 * iscsi_sw_tcp_xmit_segment - transmit segment 252 * @tcp_conn: the iSCSI TCP connection 253 * @segment: the buffer to transmnit 254 * 255 * This function transmits as much of the buffer as 256 * the network layer will accept, and returns the number of 257 * bytes transmitted. 258 * 259 * If CRC hashing is enabled, the function will compute the 260 * hash as it goes. When the entire segment has been transmitted, 261 * it will retrieve the hash value and send it as well. 262 */ 263 static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn, 264 struct iscsi_segment *segment) 265 { 266 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 267 struct socket *sk = tcp_sw_conn->sock; 268 unsigned int copied = 0; 269 int r = 0; 270 271 while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) { 272 struct scatterlist *sg; 273 unsigned int offset, copy; 274 int flags = 0; 275 276 r = 0; 277 offset = segment->copied; 278 copy = segment->size - offset; 279 280 if (segment->total_copied + segment->size < segment->total_size) 281 flags |= MSG_MORE; 282 283 /* Use sendpage if we can; else fall back to sendmsg */ 284 if (!segment->data) { 285 sg = segment->sg; 286 offset += segment->sg_offset + sg->offset; 287 r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset, 288 copy, flags); 289 } else { 290 struct msghdr msg = { .msg_flags = flags }; 291 struct kvec iov = { 292 .iov_base = segment->data + offset, 293 .iov_len = copy 294 }; 295 296 r = kernel_sendmsg(sk, &msg, &iov, 1, copy); 297 } 298 299 if (r < 0) { 300 iscsi_tcp_segment_unmap(segment); 301 return r; 302 } 303 copied += r; 304 } 305 return copied; 306 } 307 308 /** 309 * iscsi_sw_tcp_xmit - TCP transmit 310 **/ 311 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn) 312 { 313 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 314 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 315 struct iscsi_segment *segment = &tcp_sw_conn->out.segment; 316 unsigned int consumed = 0; 317 int rc = 0; 318 319 while (1) { 320 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment); 321 /* 322 * We may not have been able to send data because the conn 323 * is getting stopped. libiscsi will know so propagate err 324 * for it to do the right thing. 325 */ 326 if (rc == -EAGAIN) 327 return rc; 328 else if (rc < 0) { 329 rc = ISCSI_ERR_XMIT_FAILED; 330 goto error; 331 } else if (rc == 0) 332 break; 333 334 consumed += rc; 335 336 if (segment->total_copied >= segment->total_size) { 337 if (segment->done != NULL) { 338 rc = segment->done(tcp_conn, segment); 339 if (rc != 0) 340 goto error; 341 } 342 } 343 } 344 345 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed); 346 347 conn->txdata_octets += consumed; 348 return consumed; 349 350 error: 351 /* Transmit error. We could initiate error recovery 352 * here. */ 353 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc); 354 iscsi_conn_failure(conn, rc); 355 return -EIO; 356 } 357 358 /** 359 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit 360 */ 361 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn) 362 { 363 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 364 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 365 struct iscsi_segment *segment = &tcp_sw_conn->out.segment; 366 367 return segment->total_copied - segment->total_size; 368 } 369 370 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task) 371 { 372 struct iscsi_conn *conn = task->conn; 373 int rc; 374 375 while (iscsi_sw_tcp_xmit_qlen(conn)) { 376 rc = iscsi_sw_tcp_xmit(conn); 377 if (rc == 0) 378 return -EAGAIN; 379 if (rc < 0) 380 return rc; 381 } 382 383 return 0; 384 } 385 386 /* 387 * This is called when we're done sending the header. 388 * Simply copy the data_segment to the send segment, and return. 389 */ 390 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn, 391 struct iscsi_segment *segment) 392 { 393 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 394 395 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment; 396 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn, 397 "Header done. Next segment size %u total_size %u\n", 398 tcp_sw_conn->out.segment.size, 399 tcp_sw_conn->out.segment.total_size); 400 return 0; 401 } 402 403 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr, 404 size_t hdrlen) 405 { 406 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 407 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 408 409 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ? 410 "digest enabled" : "digest disabled"); 411 412 /* Clear the data segment - needs to be filled in by the 413 * caller using iscsi_tcp_send_data_prep() */ 414 memset(&tcp_sw_conn->out.data_segment, 0, 415 sizeof(struct iscsi_segment)); 416 417 /* If header digest is enabled, compute the CRC and 418 * place the digest into the same buffer. We make 419 * sure that both iscsi_tcp_task and mtask have 420 * sufficient room. 421 */ 422 if (conn->hdrdgst_en) { 423 iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen, 424 hdr + hdrlen); 425 hdrlen += ISCSI_DIGEST_SIZE; 426 } 427 428 /* Remember header pointer for later, when we need 429 * to decide whether there's a payload to go along 430 * with the header. */ 431 tcp_sw_conn->out.hdr = hdr; 432 433 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen, 434 iscsi_sw_tcp_send_hdr_done, NULL); 435 } 436 437 /* 438 * Prepare the send buffer for the payload data. 439 * Padding and checksumming will all be taken care 440 * of by the iscsi_segment routines. 441 */ 442 static int 443 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg, 444 unsigned int count, unsigned int offset, 445 unsigned int len) 446 { 447 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 448 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 449 struct hash_desc *tx_hash = NULL; 450 unsigned int hdr_spec_len; 451 452 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len, 453 conn->datadgst_en ? 454 "digest enabled" : "digest disabled"); 455 456 /* Make sure the datalen matches what the caller 457 said he would send. */ 458 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); 459 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); 460 461 if (conn->datadgst_en) 462 tx_hash = &tcp_sw_conn->tx_hash; 463 464 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment, 465 sg, count, offset, len, 466 NULL, tx_hash); 467 } 468 469 static void 470 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data, 471 size_t len) 472 { 473 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 474 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 475 struct hash_desc *tx_hash = NULL; 476 unsigned int hdr_spec_len; 477 478 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ? 479 "digest enabled" : "digest disabled"); 480 481 /* Make sure the datalen matches what the caller 482 said he would send. */ 483 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); 484 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); 485 486 if (conn->datadgst_en) 487 tx_hash = &tcp_sw_conn->tx_hash; 488 489 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment, 490 data, len, NULL, tx_hash); 491 } 492 493 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task, 494 unsigned int offset, unsigned int count) 495 { 496 struct iscsi_conn *conn = task->conn; 497 int err = 0; 498 499 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len); 500 501 if (!count) 502 return 0; 503 504 if (!task->sc) 505 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count); 506 else { 507 struct scsi_data_buffer *sdb = scsi_out(task->sc); 508 509 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl, 510 sdb->table.nents, offset, 511 count); 512 } 513 514 if (err) { 515 /* got invalid offset/len */ 516 return -EIO; 517 } 518 return 0; 519 } 520 521 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode) 522 { 523 struct iscsi_tcp_task *tcp_task = task->dd_data; 524 525 task->hdr = task->dd_data + sizeof(*tcp_task); 526 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE; 527 return 0; 528 } 529 530 static struct iscsi_cls_conn * 531 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session, 532 uint32_t conn_idx) 533 { 534 struct iscsi_conn *conn; 535 struct iscsi_cls_conn *cls_conn; 536 struct iscsi_tcp_conn *tcp_conn; 537 struct iscsi_sw_tcp_conn *tcp_sw_conn; 538 539 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn), 540 conn_idx); 541 if (!cls_conn) 542 return NULL; 543 conn = cls_conn->dd_data; 544 tcp_conn = conn->dd_data; 545 tcp_sw_conn = tcp_conn->dd_data; 546 547 tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0, 548 CRYPTO_ALG_ASYNC); 549 tcp_sw_conn->tx_hash.flags = 0; 550 if (IS_ERR(tcp_sw_conn->tx_hash.tfm)) 551 goto free_conn; 552 553 tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0, 554 CRYPTO_ALG_ASYNC); 555 tcp_sw_conn->rx_hash.flags = 0; 556 if (IS_ERR(tcp_sw_conn->rx_hash.tfm)) 557 goto free_tx_tfm; 558 tcp_conn->rx_hash = &tcp_sw_conn->rx_hash; 559 560 return cls_conn; 561 562 free_tx_tfm: 563 crypto_free_hash(tcp_sw_conn->tx_hash.tfm); 564 free_conn: 565 iscsi_conn_printk(KERN_ERR, conn, 566 "Could not create connection due to crc32c " 567 "loading error. Make sure the crc32c " 568 "module is built as a module or into the " 569 "kernel\n"); 570 iscsi_tcp_conn_teardown(cls_conn); 571 return NULL; 572 } 573 574 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn) 575 { 576 struct iscsi_session *session = conn->session; 577 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 578 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 579 struct socket *sock = tcp_sw_conn->sock; 580 581 if (!sock) 582 return; 583 584 sock_hold(sock->sk); 585 iscsi_sw_tcp_conn_restore_callbacks(conn); 586 sock_put(sock->sk); 587 588 spin_lock_bh(&session->lock); 589 tcp_sw_conn->sock = NULL; 590 spin_unlock_bh(&session->lock); 591 sockfd_put(sock); 592 } 593 594 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn) 595 { 596 struct iscsi_conn *conn = cls_conn->dd_data; 597 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 598 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 599 600 iscsi_sw_tcp_release_conn(conn); 601 602 if (tcp_sw_conn->tx_hash.tfm) 603 crypto_free_hash(tcp_sw_conn->tx_hash.tfm); 604 if (tcp_sw_conn->rx_hash.tfm) 605 crypto_free_hash(tcp_sw_conn->rx_hash.tfm); 606 607 iscsi_tcp_conn_teardown(cls_conn); 608 } 609 610 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) 611 { 612 struct iscsi_conn *conn = cls_conn->dd_data; 613 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 614 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 615 struct socket *sock = tcp_sw_conn->sock; 616 617 /* userspace may have goofed up and not bound us */ 618 if (!sock) 619 return; 620 621 sock->sk->sk_err = EIO; 622 wake_up_interruptible(sk_sleep(sock->sk)); 623 624 /* stop xmit side */ 625 iscsi_suspend_tx(conn); 626 627 /* stop recv side and release socket */ 628 iscsi_sw_tcp_release_conn(conn); 629 630 iscsi_conn_stop(cls_conn, flag); 631 } 632 633 static int 634 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session, 635 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph, 636 int is_leading) 637 { 638 struct iscsi_session *session = cls_session->dd_data; 639 struct iscsi_conn *conn = cls_conn->dd_data; 640 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 641 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 642 struct sock *sk; 643 struct socket *sock; 644 int err; 645 646 /* lookup for existing socket */ 647 sock = sockfd_lookup((int)transport_eph, &err); 648 if (!sock) { 649 iscsi_conn_printk(KERN_ERR, conn, 650 "sockfd_lookup failed %d\n", err); 651 return -EEXIST; 652 } 653 654 err = iscsi_conn_bind(cls_session, cls_conn, is_leading); 655 if (err) 656 goto free_socket; 657 658 spin_lock_bh(&session->lock); 659 /* bind iSCSI connection and socket */ 660 tcp_sw_conn->sock = sock; 661 spin_unlock_bh(&session->lock); 662 663 /* setup Socket parameters */ 664 sk = sock->sk; 665 sk->sk_reuse = 1; 666 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */ 667 sk->sk_allocation = GFP_ATOMIC; 668 669 iscsi_sw_tcp_conn_set_callbacks(conn); 670 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage; 671 /* 672 * set receive state machine into initial state 673 */ 674 iscsi_tcp_hdr_recv_prep(tcp_conn); 675 return 0; 676 677 free_socket: 678 sockfd_put(sock); 679 return err; 680 } 681 682 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn, 683 enum iscsi_param param, char *buf, 684 int buflen) 685 { 686 struct iscsi_conn *conn = cls_conn->dd_data; 687 struct iscsi_session *session = conn->session; 688 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 689 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 690 int value; 691 692 switch(param) { 693 case ISCSI_PARAM_HDRDGST_EN: 694 iscsi_set_param(cls_conn, param, buf, buflen); 695 break; 696 case ISCSI_PARAM_DATADGST_EN: 697 iscsi_set_param(cls_conn, param, buf, buflen); 698 tcp_sw_conn->sendpage = conn->datadgst_en ? 699 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage; 700 break; 701 case ISCSI_PARAM_MAX_R2T: 702 sscanf(buf, "%d", &value); 703 if (value <= 0 || !is_power_of_2(value)) 704 return -EINVAL; 705 if (session->max_r2t == value) 706 break; 707 iscsi_tcp_r2tpool_free(session); 708 iscsi_set_param(cls_conn, param, buf, buflen); 709 if (iscsi_tcp_r2tpool_alloc(session)) 710 return -ENOMEM; 711 break; 712 default: 713 return iscsi_set_param(cls_conn, param, buf, buflen); 714 } 715 716 return 0; 717 } 718 719 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn, 720 enum iscsi_param param, char *buf) 721 { 722 struct iscsi_conn *conn = cls_conn->dd_data; 723 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 724 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 725 struct sockaddr_in6 addr; 726 int rc, len; 727 728 switch(param) { 729 case ISCSI_PARAM_CONN_PORT: 730 case ISCSI_PARAM_CONN_ADDRESS: 731 spin_lock_bh(&conn->session->lock); 732 if (!tcp_sw_conn || !tcp_sw_conn->sock) { 733 spin_unlock_bh(&conn->session->lock); 734 return -ENOTCONN; 735 } 736 rc = kernel_getpeername(tcp_sw_conn->sock, 737 (struct sockaddr *)&addr, &len); 738 spin_unlock_bh(&conn->session->lock); 739 if (rc) 740 return rc; 741 742 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 743 &addr, param, buf); 744 default: 745 return iscsi_conn_get_param(cls_conn, param, buf); 746 } 747 748 return 0; 749 } 750 751 static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost, 752 enum iscsi_host_param param, char *buf) 753 { 754 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost); 755 struct iscsi_session *session = tcp_sw_host->session; 756 struct iscsi_conn *conn; 757 struct iscsi_tcp_conn *tcp_conn; 758 struct iscsi_sw_tcp_conn *tcp_sw_conn; 759 struct sockaddr_in6 addr; 760 int rc, len; 761 762 switch (param) { 763 case ISCSI_HOST_PARAM_IPADDRESS: 764 spin_lock_bh(&session->lock); 765 conn = session->leadconn; 766 if (!conn) { 767 spin_unlock_bh(&session->lock); 768 return -ENOTCONN; 769 } 770 tcp_conn = conn->dd_data; 771 772 tcp_sw_conn = tcp_conn->dd_data; 773 if (!tcp_sw_conn->sock) { 774 spin_unlock_bh(&session->lock); 775 return -ENOTCONN; 776 } 777 778 rc = kernel_getsockname(tcp_sw_conn->sock, 779 (struct sockaddr *)&addr, &len); 780 spin_unlock_bh(&session->lock); 781 if (rc) 782 return rc; 783 784 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 785 &addr, param, buf); 786 default: 787 return iscsi_host_get_param(shost, param, buf); 788 } 789 790 return 0; 791 } 792 793 static void 794 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn, 795 struct iscsi_stats *stats) 796 { 797 struct iscsi_conn *conn = cls_conn->dd_data; 798 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 799 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 800 801 stats->custom_length = 3; 802 strcpy(stats->custom[0].desc, "tx_sendpage_failures"); 803 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt; 804 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr"); 805 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt; 806 strcpy(stats->custom[2].desc, "eh_abort_cnt"); 807 stats->custom[2].value = conn->eh_abort_cnt; 808 809 iscsi_tcp_conn_get_stats(cls_conn, stats); 810 } 811 812 static struct iscsi_cls_session * 813 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max, 814 uint16_t qdepth, uint32_t initial_cmdsn) 815 { 816 struct iscsi_cls_session *cls_session; 817 struct iscsi_session *session; 818 struct iscsi_sw_tcp_host *tcp_sw_host; 819 struct Scsi_Host *shost; 820 821 if (ep) { 822 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep); 823 return NULL; 824 } 825 826 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht, 827 sizeof(struct iscsi_sw_tcp_host), 1); 828 if (!shost) 829 return NULL; 830 shost->transportt = iscsi_sw_tcp_scsi_transport; 831 shost->cmd_per_lun = qdepth; 832 shost->max_lun = iscsi_max_lun; 833 shost->max_id = 0; 834 shost->max_channel = 0; 835 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE; 836 837 if (iscsi_host_add(shost, NULL)) 838 goto free_host; 839 840 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost, 841 cmds_max, 0, 842 sizeof(struct iscsi_tcp_task) + 843 sizeof(struct iscsi_sw_tcp_hdrbuf), 844 initial_cmdsn, 0); 845 if (!cls_session) 846 goto remove_host; 847 session = cls_session->dd_data; 848 tcp_sw_host = iscsi_host_priv(shost); 849 tcp_sw_host->session = session; 850 851 shost->can_queue = session->scsi_cmds_max; 852 if (iscsi_tcp_r2tpool_alloc(session)) 853 goto remove_session; 854 return cls_session; 855 856 remove_session: 857 iscsi_session_teardown(cls_session); 858 remove_host: 859 iscsi_host_remove(shost); 860 free_host: 861 iscsi_host_free(shost); 862 return NULL; 863 } 864 865 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session) 866 { 867 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session); 868 869 iscsi_tcp_r2tpool_free(cls_session->dd_data); 870 iscsi_session_teardown(cls_session); 871 872 iscsi_host_remove(shost); 873 iscsi_host_free(shost); 874 } 875 876 static mode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param) 877 { 878 switch (param_type) { 879 case ISCSI_HOST_PARAM: 880 switch (param) { 881 case ISCSI_HOST_PARAM_NETDEV_NAME: 882 case ISCSI_HOST_PARAM_HWADDRESS: 883 case ISCSI_HOST_PARAM_IPADDRESS: 884 case ISCSI_HOST_PARAM_INITIATOR_NAME: 885 return S_IRUGO; 886 default: 887 return 0; 888 } 889 case ISCSI_PARAM: 890 switch (param) { 891 case ISCSI_PARAM_MAX_RECV_DLENGTH: 892 case ISCSI_PARAM_MAX_XMIT_DLENGTH: 893 case ISCSI_PARAM_HDRDGST_EN: 894 case ISCSI_PARAM_DATADGST_EN: 895 case ISCSI_PARAM_CONN_ADDRESS: 896 case ISCSI_PARAM_CONN_PORT: 897 case ISCSI_PARAM_EXP_STATSN: 898 case ISCSI_PARAM_PERSISTENT_ADDRESS: 899 case ISCSI_PARAM_PERSISTENT_PORT: 900 case ISCSI_PARAM_PING_TMO: 901 case ISCSI_PARAM_RECV_TMO: 902 case ISCSI_PARAM_INITIAL_R2T_EN: 903 case ISCSI_PARAM_MAX_R2T: 904 case ISCSI_PARAM_IMM_DATA_EN: 905 case ISCSI_PARAM_FIRST_BURST: 906 case ISCSI_PARAM_MAX_BURST: 907 case ISCSI_PARAM_PDU_INORDER_EN: 908 case ISCSI_PARAM_DATASEQ_INORDER_EN: 909 case ISCSI_PARAM_ERL: 910 case ISCSI_PARAM_TARGET_NAME: 911 case ISCSI_PARAM_TPGT: 912 case ISCSI_PARAM_USERNAME: 913 case ISCSI_PARAM_PASSWORD: 914 case ISCSI_PARAM_USERNAME_IN: 915 case ISCSI_PARAM_PASSWORD_IN: 916 case ISCSI_PARAM_FAST_ABORT: 917 case ISCSI_PARAM_ABORT_TMO: 918 case ISCSI_PARAM_LU_RESET_TMO: 919 case ISCSI_PARAM_TGT_RESET_TMO: 920 case ISCSI_PARAM_IFACE_NAME: 921 case ISCSI_PARAM_INITIATOR_NAME: 922 return S_IRUGO; 923 default: 924 return 0; 925 } 926 } 927 928 return 0; 929 } 930 931 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev) 932 { 933 set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags); 934 return 0; 935 } 936 937 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev) 938 { 939 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY); 940 blk_queue_dma_alignment(sdev->request_queue, 0); 941 return 0; 942 } 943 944 static struct scsi_host_template iscsi_sw_tcp_sht = { 945 .module = THIS_MODULE, 946 .name = "iSCSI Initiator over TCP/IP", 947 .queuecommand = iscsi_queuecommand, 948 .change_queue_depth = iscsi_change_queue_depth, 949 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1, 950 .sg_tablesize = 4096, 951 .max_sectors = 0xFFFF, 952 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN, 953 .eh_abort_handler = iscsi_eh_abort, 954 .eh_device_reset_handler= iscsi_eh_device_reset, 955 .eh_target_reset_handler = iscsi_eh_recover_target, 956 .use_clustering = DISABLE_CLUSTERING, 957 .slave_alloc = iscsi_sw_tcp_slave_alloc, 958 .slave_configure = iscsi_sw_tcp_slave_configure, 959 .target_alloc = iscsi_target_alloc, 960 .proc_name = "iscsi_tcp", 961 .this_id = -1, 962 }; 963 964 static struct iscsi_transport iscsi_sw_tcp_transport = { 965 .owner = THIS_MODULE, 966 .name = "tcp", 967 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST 968 | CAP_DATADGST, 969 /* session management */ 970 .create_session = iscsi_sw_tcp_session_create, 971 .destroy_session = iscsi_sw_tcp_session_destroy, 972 /* connection management */ 973 .create_conn = iscsi_sw_tcp_conn_create, 974 .bind_conn = iscsi_sw_tcp_conn_bind, 975 .destroy_conn = iscsi_sw_tcp_conn_destroy, 976 .attr_is_visible = iscsi_sw_tcp_attr_is_visible, 977 .set_param = iscsi_sw_tcp_conn_set_param, 978 .get_conn_param = iscsi_sw_tcp_conn_get_param, 979 .get_session_param = iscsi_session_get_param, 980 .start_conn = iscsi_conn_start, 981 .stop_conn = iscsi_sw_tcp_conn_stop, 982 /* iscsi host params */ 983 .get_host_param = iscsi_sw_tcp_host_get_param, 984 .set_host_param = iscsi_host_set_param, 985 /* IO */ 986 .send_pdu = iscsi_conn_send_pdu, 987 .get_stats = iscsi_sw_tcp_conn_get_stats, 988 /* iscsi task/cmd helpers */ 989 .init_task = iscsi_tcp_task_init, 990 .xmit_task = iscsi_tcp_task_xmit, 991 .cleanup_task = iscsi_tcp_cleanup_task, 992 /* low level pdu helpers */ 993 .xmit_pdu = iscsi_sw_tcp_pdu_xmit, 994 .init_pdu = iscsi_sw_tcp_pdu_init, 995 .alloc_pdu = iscsi_sw_tcp_pdu_alloc, 996 /* recovery */ 997 .session_recovery_timedout = iscsi_session_recovery_timedout, 998 }; 999 1000 static int __init iscsi_sw_tcp_init(void) 1001 { 1002 if (iscsi_max_lun < 1) { 1003 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n", 1004 iscsi_max_lun); 1005 return -EINVAL; 1006 } 1007 1008 iscsi_sw_tcp_scsi_transport = iscsi_register_transport( 1009 &iscsi_sw_tcp_transport); 1010 if (!iscsi_sw_tcp_scsi_transport) 1011 return -ENODEV; 1012 1013 return 0; 1014 } 1015 1016 static void __exit iscsi_sw_tcp_exit(void) 1017 { 1018 iscsi_unregister_transport(&iscsi_sw_tcp_transport); 1019 } 1020 1021 module_init(iscsi_sw_tcp_init); 1022 module_exit(iscsi_sw_tcp_exit); 1023