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 = ~0; 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 (conn->session->state != ISCSI_STATE_LOGGING_OUT) && 120 !atomic_read(&sk->sk_rmem_alloc)) { 121 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n"); 122 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE); 123 return -ECONNRESET; 124 } 125 return 0; 126 } 127 128 static void iscsi_sw_tcp_data_ready(struct sock *sk) 129 { 130 struct iscsi_conn *conn; 131 struct iscsi_tcp_conn *tcp_conn; 132 read_descriptor_t rd_desc; 133 134 read_lock(&sk->sk_callback_lock); 135 conn = sk->sk_user_data; 136 if (!conn) { 137 read_unlock(&sk->sk_callback_lock); 138 return; 139 } 140 tcp_conn = conn->dd_data; 141 142 /* 143 * Use rd_desc to pass 'conn' to iscsi_tcp_recv. 144 * We set count to 1 because we want the network layer to 145 * hand us all the skbs that are available. iscsi_tcp_recv 146 * handled pdus that cross buffers or pdus that still need data. 147 */ 148 rd_desc.arg.data = conn; 149 rd_desc.count = 1; 150 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv); 151 152 iscsi_sw_sk_state_check(sk); 153 154 /* If we had to (atomically) map a highmem page, 155 * unmap it now. */ 156 iscsi_tcp_segment_unmap(&tcp_conn->in.segment); 157 read_unlock(&sk->sk_callback_lock); 158 } 159 160 static void iscsi_sw_tcp_state_change(struct sock *sk) 161 { 162 struct iscsi_tcp_conn *tcp_conn; 163 struct iscsi_sw_tcp_conn *tcp_sw_conn; 164 struct iscsi_conn *conn; 165 struct iscsi_session *session; 166 void (*old_state_change)(struct sock *); 167 168 read_lock(&sk->sk_callback_lock); 169 conn = sk->sk_user_data; 170 if (!conn) { 171 read_unlock(&sk->sk_callback_lock); 172 return; 173 } 174 session = conn->session; 175 176 iscsi_sw_sk_state_check(sk); 177 178 tcp_conn = conn->dd_data; 179 tcp_sw_conn = tcp_conn->dd_data; 180 old_state_change = tcp_sw_conn->old_state_change; 181 182 read_unlock(&sk->sk_callback_lock); 183 184 old_state_change(sk); 185 } 186 187 /** 188 * iscsi_write_space - Called when more output buffer space is available 189 * @sk: socket space is available for 190 **/ 191 static void iscsi_sw_tcp_write_space(struct sock *sk) 192 { 193 struct iscsi_conn *conn; 194 struct iscsi_tcp_conn *tcp_conn; 195 struct iscsi_sw_tcp_conn *tcp_sw_conn; 196 void (*old_write_space)(struct sock *); 197 198 read_lock_bh(&sk->sk_callback_lock); 199 conn = sk->sk_user_data; 200 if (!conn) { 201 read_unlock_bh(&sk->sk_callback_lock); 202 return; 203 } 204 205 tcp_conn = conn->dd_data; 206 tcp_sw_conn = tcp_conn->dd_data; 207 old_write_space = tcp_sw_conn->old_write_space; 208 read_unlock_bh(&sk->sk_callback_lock); 209 210 old_write_space(sk); 211 212 ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n"); 213 iscsi_conn_queue_work(conn); 214 } 215 216 static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn) 217 { 218 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 219 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 220 struct sock *sk = tcp_sw_conn->sock->sk; 221 222 /* assign new callbacks */ 223 write_lock_bh(&sk->sk_callback_lock); 224 sk->sk_user_data = conn; 225 tcp_sw_conn->old_data_ready = sk->sk_data_ready; 226 tcp_sw_conn->old_state_change = sk->sk_state_change; 227 tcp_sw_conn->old_write_space = sk->sk_write_space; 228 sk->sk_data_ready = iscsi_sw_tcp_data_ready; 229 sk->sk_state_change = iscsi_sw_tcp_state_change; 230 sk->sk_write_space = iscsi_sw_tcp_write_space; 231 write_unlock_bh(&sk->sk_callback_lock); 232 } 233 234 static void 235 iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn) 236 { 237 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 238 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 239 struct sock *sk = tcp_sw_conn->sock->sk; 240 241 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */ 242 write_lock_bh(&sk->sk_callback_lock); 243 sk->sk_user_data = NULL; 244 sk->sk_data_ready = tcp_sw_conn->old_data_ready; 245 sk->sk_state_change = tcp_sw_conn->old_state_change; 246 sk->sk_write_space = tcp_sw_conn->old_write_space; 247 sk->sk_no_check = 0; 248 write_unlock_bh(&sk->sk_callback_lock); 249 } 250 251 /** 252 * iscsi_sw_tcp_xmit_segment - transmit segment 253 * @tcp_conn: the iSCSI TCP connection 254 * @segment: the buffer to transmnit 255 * 256 * This function transmits as much of the buffer as 257 * the network layer will accept, and returns the number of 258 * bytes transmitted. 259 * 260 * If CRC hashing is enabled, the function will compute the 261 * hash as it goes. When the entire segment has been transmitted, 262 * it will retrieve the hash value and send it as well. 263 */ 264 static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn, 265 struct iscsi_segment *segment) 266 { 267 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 268 struct socket *sk = tcp_sw_conn->sock; 269 unsigned int copied = 0; 270 int r = 0; 271 272 while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) { 273 struct scatterlist *sg; 274 unsigned int offset, copy; 275 int flags = 0; 276 277 r = 0; 278 offset = segment->copied; 279 copy = segment->size - offset; 280 281 if (segment->total_copied + segment->size < segment->total_size) 282 flags |= MSG_MORE; 283 284 /* Use sendpage if we can; else fall back to sendmsg */ 285 if (!segment->data) { 286 sg = segment->sg; 287 offset += segment->sg_offset + sg->offset; 288 r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset, 289 copy, flags); 290 } else { 291 struct msghdr msg = { .msg_flags = flags }; 292 struct kvec iov = { 293 .iov_base = segment->data + offset, 294 .iov_len = copy 295 }; 296 297 r = kernel_sendmsg(sk, &msg, &iov, 1, copy); 298 } 299 300 if (r < 0) { 301 iscsi_tcp_segment_unmap(segment); 302 return r; 303 } 304 copied += r; 305 } 306 return copied; 307 } 308 309 /** 310 * iscsi_sw_tcp_xmit - TCP transmit 311 **/ 312 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn) 313 { 314 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 315 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 316 struct iscsi_segment *segment = &tcp_sw_conn->out.segment; 317 unsigned int consumed = 0; 318 int rc = 0; 319 320 while (1) { 321 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment); 322 /* 323 * We may not have been able to send data because the conn 324 * is getting stopped. libiscsi will know so propagate err 325 * for it to do the right thing. 326 */ 327 if (rc == -EAGAIN) 328 return rc; 329 else if (rc < 0) { 330 rc = ISCSI_ERR_XMIT_FAILED; 331 goto error; 332 } else if (rc == 0) 333 break; 334 335 consumed += rc; 336 337 if (segment->total_copied >= segment->total_size) { 338 if (segment->done != NULL) { 339 rc = segment->done(tcp_conn, segment); 340 if (rc != 0) 341 goto error; 342 } 343 } 344 } 345 346 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed); 347 348 conn->txdata_octets += consumed; 349 return consumed; 350 351 error: 352 /* Transmit error. We could initiate error recovery 353 * here. */ 354 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc); 355 iscsi_conn_failure(conn, rc); 356 return -EIO; 357 } 358 359 /** 360 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit 361 */ 362 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn) 363 { 364 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 365 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 366 struct iscsi_segment *segment = &tcp_sw_conn->out.segment; 367 368 return segment->total_copied - segment->total_size; 369 } 370 371 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task) 372 { 373 struct iscsi_conn *conn = task->conn; 374 unsigned long pflags = current->flags; 375 int rc = 0; 376 377 current->flags |= PF_MEMALLOC; 378 379 while (iscsi_sw_tcp_xmit_qlen(conn)) { 380 rc = iscsi_sw_tcp_xmit(conn); 381 if (rc == 0) { 382 rc = -EAGAIN; 383 break; 384 } 385 if (rc < 0) 386 break; 387 rc = 0; 388 } 389 390 tsk_restore_flags(current, pflags, PF_MEMALLOC); 391 return rc; 392 } 393 394 /* 395 * This is called when we're done sending the header. 396 * Simply copy the data_segment to the send segment, and return. 397 */ 398 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn, 399 struct iscsi_segment *segment) 400 { 401 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 402 403 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment; 404 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn, 405 "Header done. Next segment size %u total_size %u\n", 406 tcp_sw_conn->out.segment.size, 407 tcp_sw_conn->out.segment.total_size); 408 return 0; 409 } 410 411 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr, 412 size_t hdrlen) 413 { 414 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 415 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 416 417 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ? 418 "digest enabled" : "digest disabled"); 419 420 /* Clear the data segment - needs to be filled in by the 421 * caller using iscsi_tcp_send_data_prep() */ 422 memset(&tcp_sw_conn->out.data_segment, 0, 423 sizeof(struct iscsi_segment)); 424 425 /* If header digest is enabled, compute the CRC and 426 * place the digest into the same buffer. We make 427 * sure that both iscsi_tcp_task and mtask have 428 * sufficient room. 429 */ 430 if (conn->hdrdgst_en) { 431 iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen, 432 hdr + hdrlen); 433 hdrlen += ISCSI_DIGEST_SIZE; 434 } 435 436 /* Remember header pointer for later, when we need 437 * to decide whether there's a payload to go along 438 * with the header. */ 439 tcp_sw_conn->out.hdr = hdr; 440 441 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen, 442 iscsi_sw_tcp_send_hdr_done, NULL); 443 } 444 445 /* 446 * Prepare the send buffer for the payload data. 447 * Padding and checksumming will all be taken care 448 * of by the iscsi_segment routines. 449 */ 450 static int 451 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg, 452 unsigned int count, unsigned int offset, 453 unsigned int len) 454 { 455 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 456 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 457 struct hash_desc *tx_hash = NULL; 458 unsigned int hdr_spec_len; 459 460 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len, 461 conn->datadgst_en ? 462 "digest enabled" : "digest disabled"); 463 464 /* Make sure the datalen matches what the caller 465 said he would send. */ 466 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); 467 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); 468 469 if (conn->datadgst_en) 470 tx_hash = &tcp_sw_conn->tx_hash; 471 472 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment, 473 sg, count, offset, len, 474 NULL, tx_hash); 475 } 476 477 static void 478 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data, 479 size_t len) 480 { 481 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 482 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 483 struct hash_desc *tx_hash = NULL; 484 unsigned int hdr_spec_len; 485 486 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ? 487 "digest enabled" : "digest disabled"); 488 489 /* Make sure the datalen matches what the caller 490 said he would send. */ 491 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); 492 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); 493 494 if (conn->datadgst_en) 495 tx_hash = &tcp_sw_conn->tx_hash; 496 497 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment, 498 data, len, NULL, tx_hash); 499 } 500 501 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task, 502 unsigned int offset, unsigned int count) 503 { 504 struct iscsi_conn *conn = task->conn; 505 int err = 0; 506 507 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len); 508 509 if (!count) 510 return 0; 511 512 if (!task->sc) 513 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count); 514 else { 515 struct scsi_data_buffer *sdb = scsi_out(task->sc); 516 517 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl, 518 sdb->table.nents, offset, 519 count); 520 } 521 522 if (err) { 523 /* got invalid offset/len */ 524 return -EIO; 525 } 526 return 0; 527 } 528 529 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode) 530 { 531 struct iscsi_tcp_task *tcp_task = task->dd_data; 532 533 task->hdr = task->dd_data + sizeof(*tcp_task); 534 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE; 535 return 0; 536 } 537 538 static struct iscsi_cls_conn * 539 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session, 540 uint32_t conn_idx) 541 { 542 struct iscsi_conn *conn; 543 struct iscsi_cls_conn *cls_conn; 544 struct iscsi_tcp_conn *tcp_conn; 545 struct iscsi_sw_tcp_conn *tcp_sw_conn; 546 547 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn), 548 conn_idx); 549 if (!cls_conn) 550 return NULL; 551 conn = cls_conn->dd_data; 552 tcp_conn = conn->dd_data; 553 tcp_sw_conn = tcp_conn->dd_data; 554 555 tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0, 556 CRYPTO_ALG_ASYNC); 557 tcp_sw_conn->tx_hash.flags = 0; 558 if (IS_ERR(tcp_sw_conn->tx_hash.tfm)) 559 goto free_conn; 560 561 tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0, 562 CRYPTO_ALG_ASYNC); 563 tcp_sw_conn->rx_hash.flags = 0; 564 if (IS_ERR(tcp_sw_conn->rx_hash.tfm)) 565 goto free_tx_tfm; 566 tcp_conn->rx_hash = &tcp_sw_conn->rx_hash; 567 568 return cls_conn; 569 570 free_tx_tfm: 571 crypto_free_hash(tcp_sw_conn->tx_hash.tfm); 572 free_conn: 573 iscsi_conn_printk(KERN_ERR, conn, 574 "Could not create connection due to crc32c " 575 "loading error. Make sure the crc32c " 576 "module is built as a module or into the " 577 "kernel\n"); 578 iscsi_tcp_conn_teardown(cls_conn); 579 return NULL; 580 } 581 582 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn) 583 { 584 struct iscsi_session *session = conn->session; 585 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 586 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 587 struct socket *sock = tcp_sw_conn->sock; 588 589 if (!sock) 590 return; 591 592 sock_hold(sock->sk); 593 iscsi_sw_tcp_conn_restore_callbacks(conn); 594 sock_put(sock->sk); 595 596 spin_lock_bh(&session->frwd_lock); 597 tcp_sw_conn->sock = NULL; 598 spin_unlock_bh(&session->frwd_lock); 599 sockfd_put(sock); 600 } 601 602 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn) 603 { 604 struct iscsi_conn *conn = cls_conn->dd_data; 605 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 606 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 607 608 iscsi_sw_tcp_release_conn(conn); 609 610 if (tcp_sw_conn->tx_hash.tfm) 611 crypto_free_hash(tcp_sw_conn->tx_hash.tfm); 612 if (tcp_sw_conn->rx_hash.tfm) 613 crypto_free_hash(tcp_sw_conn->rx_hash.tfm); 614 615 iscsi_tcp_conn_teardown(cls_conn); 616 } 617 618 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) 619 { 620 struct iscsi_conn *conn = cls_conn->dd_data; 621 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 622 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 623 struct socket *sock = tcp_sw_conn->sock; 624 625 /* userspace may have goofed up and not bound us */ 626 if (!sock) 627 return; 628 629 sock->sk->sk_err = EIO; 630 wake_up_interruptible(sk_sleep(sock->sk)); 631 632 /* stop xmit side */ 633 iscsi_suspend_tx(conn); 634 635 /* stop recv side and release socket */ 636 iscsi_sw_tcp_release_conn(conn); 637 638 iscsi_conn_stop(cls_conn, flag); 639 } 640 641 static int 642 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session, 643 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph, 644 int is_leading) 645 { 646 struct iscsi_session *session = cls_session->dd_data; 647 struct iscsi_conn *conn = cls_conn->dd_data; 648 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 649 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 650 struct sock *sk; 651 struct socket *sock; 652 int err; 653 654 /* lookup for existing socket */ 655 sock = sockfd_lookup((int)transport_eph, &err); 656 if (!sock) { 657 iscsi_conn_printk(KERN_ERR, conn, 658 "sockfd_lookup failed %d\n", err); 659 return -EEXIST; 660 } 661 662 err = iscsi_conn_bind(cls_session, cls_conn, is_leading); 663 if (err) 664 goto free_socket; 665 666 spin_lock_bh(&session->frwd_lock); 667 /* bind iSCSI connection and socket */ 668 tcp_sw_conn->sock = sock; 669 spin_unlock_bh(&session->frwd_lock); 670 671 /* setup Socket parameters */ 672 sk = sock->sk; 673 sk->sk_reuse = SK_CAN_REUSE; 674 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */ 675 sk->sk_allocation = GFP_ATOMIC; 676 sk_set_memalloc(sk); 677 678 iscsi_sw_tcp_conn_set_callbacks(conn); 679 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage; 680 /* 681 * set receive state machine into initial state 682 */ 683 iscsi_tcp_hdr_recv_prep(tcp_conn); 684 return 0; 685 686 free_socket: 687 sockfd_put(sock); 688 return err; 689 } 690 691 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn, 692 enum iscsi_param param, char *buf, 693 int buflen) 694 { 695 struct iscsi_conn *conn = cls_conn->dd_data; 696 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 697 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 698 699 switch(param) { 700 case ISCSI_PARAM_HDRDGST_EN: 701 iscsi_set_param(cls_conn, param, buf, buflen); 702 break; 703 case ISCSI_PARAM_DATADGST_EN: 704 iscsi_set_param(cls_conn, param, buf, buflen); 705 tcp_sw_conn->sendpage = conn->datadgst_en ? 706 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage; 707 break; 708 case ISCSI_PARAM_MAX_R2T: 709 return iscsi_tcp_set_max_r2t(conn, buf); 710 default: 711 return iscsi_set_param(cls_conn, param, buf, buflen); 712 } 713 714 return 0; 715 } 716 717 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn, 718 enum iscsi_param param, char *buf) 719 { 720 struct iscsi_conn *conn = cls_conn->dd_data; 721 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 722 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 723 struct sockaddr_in6 addr; 724 int rc, len; 725 726 switch(param) { 727 case ISCSI_PARAM_CONN_PORT: 728 case ISCSI_PARAM_CONN_ADDRESS: 729 spin_lock_bh(&conn->session->frwd_lock); 730 if (!tcp_sw_conn || !tcp_sw_conn->sock) { 731 spin_unlock_bh(&conn->session->frwd_lock); 732 return -ENOTCONN; 733 } 734 rc = kernel_getpeername(tcp_sw_conn->sock, 735 (struct sockaddr *)&addr, &len); 736 spin_unlock_bh(&conn->session->frwd_lock); 737 if (rc) 738 return rc; 739 740 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 741 &addr, param, buf); 742 default: 743 return iscsi_conn_get_param(cls_conn, param, buf); 744 } 745 746 return 0; 747 } 748 749 static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost, 750 enum iscsi_host_param param, char *buf) 751 { 752 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost); 753 struct iscsi_session *session = tcp_sw_host->session; 754 struct iscsi_conn *conn; 755 struct iscsi_tcp_conn *tcp_conn; 756 struct iscsi_sw_tcp_conn *tcp_sw_conn; 757 struct sockaddr_in6 addr; 758 int rc, len; 759 760 switch (param) { 761 case ISCSI_HOST_PARAM_IPADDRESS: 762 if (!session) 763 return -ENOTCONN; 764 765 spin_lock_bh(&session->frwd_lock); 766 conn = session->leadconn; 767 if (!conn) { 768 spin_unlock_bh(&session->frwd_lock); 769 return -ENOTCONN; 770 } 771 tcp_conn = conn->dd_data; 772 773 tcp_sw_conn = tcp_conn->dd_data; 774 if (!tcp_sw_conn->sock) { 775 spin_unlock_bh(&session->frwd_lock); 776 return -ENOTCONN; 777 } 778 779 rc = kernel_getsockname(tcp_sw_conn->sock, 780 (struct sockaddr *)&addr, &len); 781 spin_unlock_bh(&session->frwd_lock); 782 if (rc) 783 return rc; 784 785 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 786 &addr, param, buf); 787 default: 788 return iscsi_host_get_param(shost, param, buf); 789 } 790 791 return 0; 792 } 793 794 static void 795 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn, 796 struct iscsi_stats *stats) 797 { 798 struct iscsi_conn *conn = cls_conn->dd_data; 799 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 800 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 801 802 stats->custom_length = 3; 803 strcpy(stats->custom[0].desc, "tx_sendpage_failures"); 804 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt; 805 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr"); 806 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt; 807 strcpy(stats->custom[2].desc, "eh_abort_cnt"); 808 stats->custom[2].value = conn->eh_abort_cnt; 809 810 iscsi_tcp_conn_get_stats(cls_conn, stats); 811 } 812 813 static struct iscsi_cls_session * 814 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max, 815 uint16_t qdepth, uint32_t initial_cmdsn) 816 { 817 struct iscsi_cls_session *cls_session; 818 struct iscsi_session *session; 819 struct iscsi_sw_tcp_host *tcp_sw_host; 820 struct Scsi_Host *shost; 821 822 if (ep) { 823 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep); 824 return NULL; 825 } 826 827 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht, 828 sizeof(struct iscsi_sw_tcp_host), 1); 829 if (!shost) 830 return NULL; 831 shost->transportt = iscsi_sw_tcp_scsi_transport; 832 shost->cmd_per_lun = qdepth; 833 shost->max_lun = iscsi_max_lun; 834 shost->max_id = 0; 835 shost->max_channel = 0; 836 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE; 837 838 if (iscsi_host_add(shost, NULL)) 839 goto free_host; 840 841 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost, 842 cmds_max, 0, 843 sizeof(struct iscsi_tcp_task) + 844 sizeof(struct iscsi_sw_tcp_hdrbuf), 845 initial_cmdsn, 0); 846 if (!cls_session) 847 goto remove_host; 848 session = cls_session->dd_data; 849 tcp_sw_host = iscsi_host_priv(shost); 850 tcp_sw_host->session = session; 851 852 shost->can_queue = session->scsi_cmds_max; 853 if (iscsi_tcp_r2tpool_alloc(session)) 854 goto remove_session; 855 return cls_session; 856 857 remove_session: 858 iscsi_session_teardown(cls_session); 859 remove_host: 860 iscsi_host_remove(shost); 861 free_host: 862 iscsi_host_free(shost); 863 return NULL; 864 } 865 866 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session) 867 { 868 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session); 869 870 iscsi_tcp_r2tpool_free(cls_session->dd_data); 871 iscsi_session_teardown(cls_session); 872 873 iscsi_host_remove(shost); 874 iscsi_host_free(shost); 875 } 876 877 static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param) 878 { 879 switch (param_type) { 880 case ISCSI_HOST_PARAM: 881 switch (param) { 882 case ISCSI_HOST_PARAM_NETDEV_NAME: 883 case ISCSI_HOST_PARAM_HWADDRESS: 884 case ISCSI_HOST_PARAM_IPADDRESS: 885 case ISCSI_HOST_PARAM_INITIATOR_NAME: 886 return S_IRUGO; 887 default: 888 return 0; 889 } 890 case ISCSI_PARAM: 891 switch (param) { 892 case ISCSI_PARAM_MAX_RECV_DLENGTH: 893 case ISCSI_PARAM_MAX_XMIT_DLENGTH: 894 case ISCSI_PARAM_HDRDGST_EN: 895 case ISCSI_PARAM_DATADGST_EN: 896 case ISCSI_PARAM_CONN_ADDRESS: 897 case ISCSI_PARAM_CONN_PORT: 898 case ISCSI_PARAM_EXP_STATSN: 899 case ISCSI_PARAM_PERSISTENT_ADDRESS: 900 case ISCSI_PARAM_PERSISTENT_PORT: 901 case ISCSI_PARAM_PING_TMO: 902 case ISCSI_PARAM_RECV_TMO: 903 case ISCSI_PARAM_INITIAL_R2T_EN: 904 case ISCSI_PARAM_MAX_R2T: 905 case ISCSI_PARAM_IMM_DATA_EN: 906 case ISCSI_PARAM_FIRST_BURST: 907 case ISCSI_PARAM_MAX_BURST: 908 case ISCSI_PARAM_PDU_INORDER_EN: 909 case ISCSI_PARAM_DATASEQ_INORDER_EN: 910 case ISCSI_PARAM_ERL: 911 case ISCSI_PARAM_TARGET_NAME: 912 case ISCSI_PARAM_TPGT: 913 case ISCSI_PARAM_USERNAME: 914 case ISCSI_PARAM_PASSWORD: 915 case ISCSI_PARAM_USERNAME_IN: 916 case ISCSI_PARAM_PASSWORD_IN: 917 case ISCSI_PARAM_FAST_ABORT: 918 case ISCSI_PARAM_ABORT_TMO: 919 case ISCSI_PARAM_LU_RESET_TMO: 920 case ISCSI_PARAM_TGT_RESET_TMO: 921 case ISCSI_PARAM_IFACE_NAME: 922 case ISCSI_PARAM_INITIATOR_NAME: 923 return S_IRUGO; 924 default: 925 return 0; 926 } 927 } 928 929 return 0; 930 } 931 932 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev) 933 { 934 set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags); 935 return 0; 936 } 937 938 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev) 939 { 940 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY); 941 blk_queue_dma_alignment(sdev->request_queue, 0); 942 return 0; 943 } 944 945 static struct scsi_host_template iscsi_sw_tcp_sht = { 946 .module = THIS_MODULE, 947 .name = "iSCSI Initiator over TCP/IP", 948 .queuecommand = iscsi_queuecommand, 949 .change_queue_depth = iscsi_change_queue_depth, 950 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1, 951 .sg_tablesize = 4096, 952 .max_sectors = 0xFFFF, 953 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN, 954 .eh_abort_handler = iscsi_eh_abort, 955 .eh_device_reset_handler= iscsi_eh_device_reset, 956 .eh_target_reset_handler = iscsi_eh_recover_target, 957 .use_clustering = DISABLE_CLUSTERING, 958 .slave_alloc = iscsi_sw_tcp_slave_alloc, 959 .slave_configure = iscsi_sw_tcp_slave_configure, 960 .target_alloc = iscsi_target_alloc, 961 .proc_name = "iscsi_tcp", 962 .this_id = -1, 963 }; 964 965 static struct iscsi_transport iscsi_sw_tcp_transport = { 966 .owner = THIS_MODULE, 967 .name = "tcp", 968 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST 969 | CAP_DATADGST, 970 /* session management */ 971 .create_session = iscsi_sw_tcp_session_create, 972 .destroy_session = iscsi_sw_tcp_session_destroy, 973 /* connection management */ 974 .create_conn = iscsi_sw_tcp_conn_create, 975 .bind_conn = iscsi_sw_tcp_conn_bind, 976 .destroy_conn = iscsi_sw_tcp_conn_destroy, 977 .attr_is_visible = iscsi_sw_tcp_attr_is_visible, 978 .set_param = iscsi_sw_tcp_conn_set_param, 979 .get_conn_param = iscsi_sw_tcp_conn_get_param, 980 .get_session_param = iscsi_session_get_param, 981 .start_conn = iscsi_conn_start, 982 .stop_conn = iscsi_sw_tcp_conn_stop, 983 /* iscsi host params */ 984 .get_host_param = iscsi_sw_tcp_host_get_param, 985 .set_host_param = iscsi_host_set_param, 986 /* IO */ 987 .send_pdu = iscsi_conn_send_pdu, 988 .get_stats = iscsi_sw_tcp_conn_get_stats, 989 /* iscsi task/cmd helpers */ 990 .init_task = iscsi_tcp_task_init, 991 .xmit_task = iscsi_tcp_task_xmit, 992 .cleanup_task = iscsi_tcp_cleanup_task, 993 /* low level pdu helpers */ 994 .xmit_pdu = iscsi_sw_tcp_pdu_xmit, 995 .init_pdu = iscsi_sw_tcp_pdu_init, 996 .alloc_pdu = iscsi_sw_tcp_pdu_alloc, 997 /* recovery */ 998 .session_recovery_timedout = iscsi_session_recovery_timedout, 999 }; 1000 1001 static int __init iscsi_sw_tcp_init(void) 1002 { 1003 if (iscsi_max_lun < 1) { 1004 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n", 1005 iscsi_max_lun); 1006 return -EINVAL; 1007 } 1008 1009 iscsi_sw_tcp_scsi_transport = iscsi_register_transport( 1010 &iscsi_sw_tcp_transport); 1011 if (!iscsi_sw_tcp_scsi_transport) 1012 return -ENODEV; 1013 1014 return 0; 1015 } 1016 1017 static void __exit iscsi_sw_tcp_exit(void) 1018 { 1019 iscsi_unregister_transport(&iscsi_sw_tcp_transport); 1020 } 1021 1022 module_init(iscsi_sw_tcp_init); 1023 module_exit(iscsi_sw_tcp_exit); 1024