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 <crypto/hash.h> 30 #include <linux/types.h> 31 #include <linux/inet.h> 32 #include <linux/slab.h> 33 #include <linux/file.h> 34 #include <linux/blkdev.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_bh(&sk->sk_callback_lock); 135 conn = sk->sk_user_data; 136 if (!conn) { 137 read_unlock_bh(&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_bh(&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_bh(&sk->sk_callback_lock); 169 conn = sk->sk_user_data; 170 if (!conn) { 171 read_unlock_bh(&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_bh(&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_tx = 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 ahash_request *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 ahash_request *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 struct crypto_ahash *tfm; 547 548 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn), 549 conn_idx); 550 if (!cls_conn) 551 return NULL; 552 conn = cls_conn->dd_data; 553 tcp_conn = conn->dd_data; 554 tcp_sw_conn = tcp_conn->dd_data; 555 556 tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC); 557 if (IS_ERR(tfm)) 558 goto free_conn; 559 560 tcp_sw_conn->tx_hash = ahash_request_alloc(tfm, GFP_KERNEL); 561 if (!tcp_sw_conn->tx_hash) 562 goto free_tfm; 563 ahash_request_set_callback(tcp_sw_conn->tx_hash, 0, NULL, NULL); 564 565 tcp_sw_conn->rx_hash = ahash_request_alloc(tfm, GFP_KERNEL); 566 if (!tcp_sw_conn->rx_hash) 567 goto free_tx_hash; 568 ahash_request_set_callback(tcp_sw_conn->rx_hash, 0, NULL, NULL); 569 570 tcp_conn->rx_hash = tcp_sw_conn->rx_hash; 571 572 return cls_conn; 573 574 free_tx_hash: 575 ahash_request_free(tcp_sw_conn->tx_hash); 576 free_tfm: 577 crypto_free_ahash(tfm); 578 free_conn: 579 iscsi_conn_printk(KERN_ERR, conn, 580 "Could not create connection due to crc32c " 581 "loading error. Make sure the crc32c " 582 "module is built as a module or into the " 583 "kernel\n"); 584 iscsi_tcp_conn_teardown(cls_conn); 585 return NULL; 586 } 587 588 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn) 589 { 590 struct iscsi_session *session = conn->session; 591 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 592 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 593 struct socket *sock = tcp_sw_conn->sock; 594 595 if (!sock) 596 return; 597 598 sock_hold(sock->sk); 599 iscsi_sw_tcp_conn_restore_callbacks(conn); 600 sock_put(sock->sk); 601 602 spin_lock_bh(&session->frwd_lock); 603 tcp_sw_conn->sock = NULL; 604 spin_unlock_bh(&session->frwd_lock); 605 sockfd_put(sock); 606 } 607 608 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn) 609 { 610 struct iscsi_conn *conn = cls_conn->dd_data; 611 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 612 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 613 614 iscsi_sw_tcp_release_conn(conn); 615 616 ahash_request_free(tcp_sw_conn->rx_hash); 617 if (tcp_sw_conn->tx_hash) { 618 struct crypto_ahash *tfm; 619 620 tfm = crypto_ahash_reqtfm(tcp_sw_conn->tx_hash); 621 ahash_request_free(tcp_sw_conn->tx_hash); 622 crypto_free_ahash(tfm); 623 } 624 625 iscsi_tcp_conn_teardown(cls_conn); 626 } 627 628 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) 629 { 630 struct iscsi_conn *conn = cls_conn->dd_data; 631 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 632 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 633 struct socket *sock = tcp_sw_conn->sock; 634 635 /* userspace may have goofed up and not bound us */ 636 if (!sock) 637 return; 638 639 sock->sk->sk_err = EIO; 640 wake_up_interruptible(sk_sleep(sock->sk)); 641 642 /* stop xmit side */ 643 iscsi_suspend_tx(conn); 644 645 /* stop recv side and release socket */ 646 iscsi_sw_tcp_release_conn(conn); 647 648 iscsi_conn_stop(cls_conn, flag); 649 } 650 651 static int 652 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session, 653 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph, 654 int is_leading) 655 { 656 struct iscsi_session *session = cls_session->dd_data; 657 struct iscsi_conn *conn = cls_conn->dd_data; 658 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 659 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 660 struct sock *sk; 661 struct socket *sock; 662 int err; 663 664 /* lookup for existing socket */ 665 sock = sockfd_lookup((int)transport_eph, &err); 666 if (!sock) { 667 iscsi_conn_printk(KERN_ERR, conn, 668 "sockfd_lookup failed %d\n", err); 669 return -EEXIST; 670 } 671 672 err = iscsi_conn_bind(cls_session, cls_conn, is_leading); 673 if (err) 674 goto free_socket; 675 676 spin_lock_bh(&session->frwd_lock); 677 /* bind iSCSI connection and socket */ 678 tcp_sw_conn->sock = sock; 679 spin_unlock_bh(&session->frwd_lock); 680 681 /* setup Socket parameters */ 682 sk = sock->sk; 683 sk->sk_reuse = SK_CAN_REUSE; 684 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */ 685 sk->sk_allocation = GFP_ATOMIC; 686 sk_set_memalloc(sk); 687 688 iscsi_sw_tcp_conn_set_callbacks(conn); 689 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage; 690 /* 691 * set receive state machine into initial state 692 */ 693 iscsi_tcp_hdr_recv_prep(tcp_conn); 694 return 0; 695 696 free_socket: 697 sockfd_put(sock); 698 return err; 699 } 700 701 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn, 702 enum iscsi_param param, char *buf, 703 int buflen) 704 { 705 struct iscsi_conn *conn = cls_conn->dd_data; 706 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 707 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 708 709 switch(param) { 710 case ISCSI_PARAM_HDRDGST_EN: 711 iscsi_set_param(cls_conn, param, buf, buflen); 712 break; 713 case ISCSI_PARAM_DATADGST_EN: 714 iscsi_set_param(cls_conn, param, buf, buflen); 715 tcp_sw_conn->sendpage = conn->datadgst_en ? 716 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage; 717 break; 718 case ISCSI_PARAM_MAX_R2T: 719 return iscsi_tcp_set_max_r2t(conn, buf); 720 default: 721 return iscsi_set_param(cls_conn, param, buf, buflen); 722 } 723 724 return 0; 725 } 726 727 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn, 728 enum iscsi_param param, char *buf) 729 { 730 struct iscsi_conn *conn = cls_conn->dd_data; 731 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 732 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 733 struct sockaddr_in6 addr; 734 int rc, len; 735 736 switch(param) { 737 case ISCSI_PARAM_CONN_PORT: 738 case ISCSI_PARAM_CONN_ADDRESS: 739 case ISCSI_PARAM_LOCAL_PORT: 740 spin_lock_bh(&conn->session->frwd_lock); 741 if (!tcp_sw_conn || !tcp_sw_conn->sock) { 742 spin_unlock_bh(&conn->session->frwd_lock); 743 return -ENOTCONN; 744 } 745 if (param == ISCSI_PARAM_LOCAL_PORT) 746 rc = kernel_getsockname(tcp_sw_conn->sock, 747 (struct sockaddr *)&addr, &len); 748 else 749 rc = kernel_getpeername(tcp_sw_conn->sock, 750 (struct sockaddr *)&addr, &len); 751 spin_unlock_bh(&conn->session->frwd_lock); 752 if (rc) 753 return rc; 754 755 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 756 &addr, param, buf); 757 default: 758 return iscsi_conn_get_param(cls_conn, param, buf); 759 } 760 761 return 0; 762 } 763 764 static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost, 765 enum iscsi_host_param param, char *buf) 766 { 767 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost); 768 struct iscsi_session *session = tcp_sw_host->session; 769 struct iscsi_conn *conn; 770 struct iscsi_tcp_conn *tcp_conn; 771 struct iscsi_sw_tcp_conn *tcp_sw_conn; 772 struct sockaddr_in6 addr; 773 int rc, len; 774 775 switch (param) { 776 case ISCSI_HOST_PARAM_IPADDRESS: 777 if (!session) 778 return -ENOTCONN; 779 780 spin_lock_bh(&session->frwd_lock); 781 conn = session->leadconn; 782 if (!conn) { 783 spin_unlock_bh(&session->frwd_lock); 784 return -ENOTCONN; 785 } 786 tcp_conn = conn->dd_data; 787 788 tcp_sw_conn = tcp_conn->dd_data; 789 if (!tcp_sw_conn->sock) { 790 spin_unlock_bh(&session->frwd_lock); 791 return -ENOTCONN; 792 } 793 794 rc = kernel_getsockname(tcp_sw_conn->sock, 795 (struct sockaddr *)&addr, &len); 796 spin_unlock_bh(&session->frwd_lock); 797 if (rc) 798 return rc; 799 800 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 801 &addr, param, buf); 802 default: 803 return iscsi_host_get_param(shost, param, buf); 804 } 805 806 return 0; 807 } 808 809 static void 810 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn, 811 struct iscsi_stats *stats) 812 { 813 struct iscsi_conn *conn = cls_conn->dd_data; 814 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 815 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 816 817 stats->custom_length = 3; 818 strcpy(stats->custom[0].desc, "tx_sendpage_failures"); 819 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt; 820 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr"); 821 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt; 822 strcpy(stats->custom[2].desc, "eh_abort_cnt"); 823 stats->custom[2].value = conn->eh_abort_cnt; 824 825 iscsi_tcp_conn_get_stats(cls_conn, stats); 826 } 827 828 static struct iscsi_cls_session * 829 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max, 830 uint16_t qdepth, uint32_t initial_cmdsn) 831 { 832 struct iscsi_cls_session *cls_session; 833 struct iscsi_session *session; 834 struct iscsi_sw_tcp_host *tcp_sw_host; 835 struct Scsi_Host *shost; 836 837 if (ep) { 838 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep); 839 return NULL; 840 } 841 842 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht, 843 sizeof(struct iscsi_sw_tcp_host), 1); 844 if (!shost) 845 return NULL; 846 shost->transportt = iscsi_sw_tcp_scsi_transport; 847 shost->cmd_per_lun = qdepth; 848 shost->max_lun = iscsi_max_lun; 849 shost->max_id = 0; 850 shost->max_channel = 0; 851 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE; 852 853 if (iscsi_host_add(shost, NULL)) 854 goto free_host; 855 856 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost, 857 cmds_max, 0, 858 sizeof(struct iscsi_tcp_task) + 859 sizeof(struct iscsi_sw_tcp_hdrbuf), 860 initial_cmdsn, 0); 861 if (!cls_session) 862 goto remove_host; 863 session = cls_session->dd_data; 864 tcp_sw_host = iscsi_host_priv(shost); 865 tcp_sw_host->session = session; 866 867 shost->can_queue = session->scsi_cmds_max; 868 if (iscsi_tcp_r2tpool_alloc(session)) 869 goto remove_session; 870 return cls_session; 871 872 remove_session: 873 iscsi_session_teardown(cls_session); 874 remove_host: 875 iscsi_host_remove(shost); 876 free_host: 877 iscsi_host_free(shost); 878 return NULL; 879 } 880 881 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session) 882 { 883 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session); 884 885 iscsi_tcp_r2tpool_free(cls_session->dd_data); 886 iscsi_session_teardown(cls_session); 887 888 iscsi_host_remove(shost); 889 iscsi_host_free(shost); 890 } 891 892 static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param) 893 { 894 switch (param_type) { 895 case ISCSI_HOST_PARAM: 896 switch (param) { 897 case ISCSI_HOST_PARAM_NETDEV_NAME: 898 case ISCSI_HOST_PARAM_HWADDRESS: 899 case ISCSI_HOST_PARAM_IPADDRESS: 900 case ISCSI_HOST_PARAM_INITIATOR_NAME: 901 return S_IRUGO; 902 default: 903 return 0; 904 } 905 case ISCSI_PARAM: 906 switch (param) { 907 case ISCSI_PARAM_MAX_RECV_DLENGTH: 908 case ISCSI_PARAM_MAX_XMIT_DLENGTH: 909 case ISCSI_PARAM_HDRDGST_EN: 910 case ISCSI_PARAM_DATADGST_EN: 911 case ISCSI_PARAM_CONN_ADDRESS: 912 case ISCSI_PARAM_CONN_PORT: 913 case ISCSI_PARAM_LOCAL_PORT: 914 case ISCSI_PARAM_EXP_STATSN: 915 case ISCSI_PARAM_PERSISTENT_ADDRESS: 916 case ISCSI_PARAM_PERSISTENT_PORT: 917 case ISCSI_PARAM_PING_TMO: 918 case ISCSI_PARAM_RECV_TMO: 919 case ISCSI_PARAM_INITIAL_R2T_EN: 920 case ISCSI_PARAM_MAX_R2T: 921 case ISCSI_PARAM_IMM_DATA_EN: 922 case ISCSI_PARAM_FIRST_BURST: 923 case ISCSI_PARAM_MAX_BURST: 924 case ISCSI_PARAM_PDU_INORDER_EN: 925 case ISCSI_PARAM_DATASEQ_INORDER_EN: 926 case ISCSI_PARAM_ERL: 927 case ISCSI_PARAM_TARGET_NAME: 928 case ISCSI_PARAM_TPGT: 929 case ISCSI_PARAM_USERNAME: 930 case ISCSI_PARAM_PASSWORD: 931 case ISCSI_PARAM_USERNAME_IN: 932 case ISCSI_PARAM_PASSWORD_IN: 933 case ISCSI_PARAM_FAST_ABORT: 934 case ISCSI_PARAM_ABORT_TMO: 935 case ISCSI_PARAM_LU_RESET_TMO: 936 case ISCSI_PARAM_TGT_RESET_TMO: 937 case ISCSI_PARAM_IFACE_NAME: 938 case ISCSI_PARAM_INITIATOR_NAME: 939 return S_IRUGO; 940 default: 941 return 0; 942 } 943 } 944 945 return 0; 946 } 947 948 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev) 949 { 950 set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags); 951 return 0; 952 } 953 954 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev) 955 { 956 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY); 957 blk_queue_dma_alignment(sdev->request_queue, 0); 958 return 0; 959 } 960 961 static struct scsi_host_template iscsi_sw_tcp_sht = { 962 .module = THIS_MODULE, 963 .name = "iSCSI Initiator over TCP/IP", 964 .queuecommand = iscsi_queuecommand, 965 .change_queue_depth = scsi_change_queue_depth, 966 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1, 967 .sg_tablesize = 4096, 968 .max_sectors = 0xFFFF, 969 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN, 970 .eh_abort_handler = iscsi_eh_abort, 971 .eh_device_reset_handler= iscsi_eh_device_reset, 972 .eh_target_reset_handler = iscsi_eh_recover_target, 973 .use_clustering = DISABLE_CLUSTERING, 974 .slave_alloc = iscsi_sw_tcp_slave_alloc, 975 .slave_configure = iscsi_sw_tcp_slave_configure, 976 .target_alloc = iscsi_target_alloc, 977 .proc_name = "iscsi_tcp", 978 .this_id = -1, 979 .track_queue_depth = 1, 980 }; 981 982 static struct iscsi_transport iscsi_sw_tcp_transport = { 983 .owner = THIS_MODULE, 984 .name = "tcp", 985 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST 986 | CAP_DATADGST, 987 /* session management */ 988 .create_session = iscsi_sw_tcp_session_create, 989 .destroy_session = iscsi_sw_tcp_session_destroy, 990 /* connection management */ 991 .create_conn = iscsi_sw_tcp_conn_create, 992 .bind_conn = iscsi_sw_tcp_conn_bind, 993 .destroy_conn = iscsi_sw_tcp_conn_destroy, 994 .attr_is_visible = iscsi_sw_tcp_attr_is_visible, 995 .set_param = iscsi_sw_tcp_conn_set_param, 996 .get_conn_param = iscsi_sw_tcp_conn_get_param, 997 .get_session_param = iscsi_session_get_param, 998 .start_conn = iscsi_conn_start, 999 .stop_conn = iscsi_sw_tcp_conn_stop, 1000 /* iscsi host params */ 1001 .get_host_param = iscsi_sw_tcp_host_get_param, 1002 .set_host_param = iscsi_host_set_param, 1003 /* IO */ 1004 .send_pdu = iscsi_conn_send_pdu, 1005 .get_stats = iscsi_sw_tcp_conn_get_stats, 1006 /* iscsi task/cmd helpers */ 1007 .init_task = iscsi_tcp_task_init, 1008 .xmit_task = iscsi_tcp_task_xmit, 1009 .cleanup_task = iscsi_tcp_cleanup_task, 1010 /* low level pdu helpers */ 1011 .xmit_pdu = iscsi_sw_tcp_pdu_xmit, 1012 .init_pdu = iscsi_sw_tcp_pdu_init, 1013 .alloc_pdu = iscsi_sw_tcp_pdu_alloc, 1014 /* recovery */ 1015 .session_recovery_timedout = iscsi_session_recovery_timedout, 1016 }; 1017 1018 static int __init iscsi_sw_tcp_init(void) 1019 { 1020 if (iscsi_max_lun < 1) { 1021 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n", 1022 iscsi_max_lun); 1023 return -EINVAL; 1024 } 1025 1026 iscsi_sw_tcp_scsi_transport = iscsi_register_transport( 1027 &iscsi_sw_tcp_transport); 1028 if (!iscsi_sw_tcp_scsi_transport) 1029 return -ENODEV; 1030 1031 return 0; 1032 } 1033 1034 static void __exit iscsi_sw_tcp_exit(void) 1035 { 1036 iscsi_unregister_transport(&iscsi_sw_tcp_transport); 1037 } 1038 1039 module_init(iscsi_sw_tcp_init); 1040 module_exit(iscsi_sw_tcp_exit); 1041