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 !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 unsigned long pflags = current->flags; 374 int rc = 0; 375 376 current->flags |= PF_MEMALLOC; 377 378 while (iscsi_sw_tcp_xmit_qlen(conn)) { 379 rc = iscsi_sw_tcp_xmit(conn); 380 if (rc == 0) { 381 rc = -EAGAIN; 382 break; 383 } 384 if (rc < 0) 385 break; 386 rc = 0; 387 } 388 389 tsk_restore_flags(current, pflags, PF_MEMALLOC); 390 return rc; 391 } 392 393 /* 394 * This is called when we're done sending the header. 395 * Simply copy the data_segment to the send segment, and return. 396 */ 397 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn, 398 struct iscsi_segment *segment) 399 { 400 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 401 402 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment; 403 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn, 404 "Header done. Next segment size %u total_size %u\n", 405 tcp_sw_conn->out.segment.size, 406 tcp_sw_conn->out.segment.total_size); 407 return 0; 408 } 409 410 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr, 411 size_t hdrlen) 412 { 413 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 414 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 415 416 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ? 417 "digest enabled" : "digest disabled"); 418 419 /* Clear the data segment - needs to be filled in by the 420 * caller using iscsi_tcp_send_data_prep() */ 421 memset(&tcp_sw_conn->out.data_segment, 0, 422 sizeof(struct iscsi_segment)); 423 424 /* If header digest is enabled, compute the CRC and 425 * place the digest into the same buffer. We make 426 * sure that both iscsi_tcp_task and mtask have 427 * sufficient room. 428 */ 429 if (conn->hdrdgst_en) { 430 iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen, 431 hdr + hdrlen); 432 hdrlen += ISCSI_DIGEST_SIZE; 433 } 434 435 /* Remember header pointer for later, when we need 436 * to decide whether there's a payload to go along 437 * with the header. */ 438 tcp_sw_conn->out.hdr = hdr; 439 440 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen, 441 iscsi_sw_tcp_send_hdr_done, NULL); 442 } 443 444 /* 445 * Prepare the send buffer for the payload data. 446 * Padding and checksumming will all be taken care 447 * of by the iscsi_segment routines. 448 */ 449 static int 450 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg, 451 unsigned int count, unsigned int offset, 452 unsigned int len) 453 { 454 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 455 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 456 struct hash_desc *tx_hash = NULL; 457 unsigned int hdr_spec_len; 458 459 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len, 460 conn->datadgst_en ? 461 "digest enabled" : "digest disabled"); 462 463 /* Make sure the datalen matches what the caller 464 said he would send. */ 465 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); 466 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); 467 468 if (conn->datadgst_en) 469 tx_hash = &tcp_sw_conn->tx_hash; 470 471 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment, 472 sg, count, offset, len, 473 NULL, tx_hash); 474 } 475 476 static void 477 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data, 478 size_t len) 479 { 480 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 481 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 482 struct hash_desc *tx_hash = NULL; 483 unsigned int hdr_spec_len; 484 485 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ? 486 "digest enabled" : "digest disabled"); 487 488 /* Make sure the datalen matches what the caller 489 said he would send. */ 490 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); 491 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); 492 493 if (conn->datadgst_en) 494 tx_hash = &tcp_sw_conn->tx_hash; 495 496 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment, 497 data, len, NULL, tx_hash); 498 } 499 500 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task, 501 unsigned int offset, unsigned int count) 502 { 503 struct iscsi_conn *conn = task->conn; 504 int err = 0; 505 506 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len); 507 508 if (!count) 509 return 0; 510 511 if (!task->sc) 512 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count); 513 else { 514 struct scsi_data_buffer *sdb = scsi_out(task->sc); 515 516 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl, 517 sdb->table.nents, offset, 518 count); 519 } 520 521 if (err) { 522 /* got invalid offset/len */ 523 return -EIO; 524 } 525 return 0; 526 } 527 528 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode) 529 { 530 struct iscsi_tcp_task *tcp_task = task->dd_data; 531 532 task->hdr = task->dd_data + sizeof(*tcp_task); 533 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE; 534 return 0; 535 } 536 537 static struct iscsi_cls_conn * 538 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session, 539 uint32_t conn_idx) 540 { 541 struct iscsi_conn *conn; 542 struct iscsi_cls_conn *cls_conn; 543 struct iscsi_tcp_conn *tcp_conn; 544 struct iscsi_sw_tcp_conn *tcp_sw_conn; 545 546 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn), 547 conn_idx); 548 if (!cls_conn) 549 return NULL; 550 conn = cls_conn->dd_data; 551 tcp_conn = conn->dd_data; 552 tcp_sw_conn = tcp_conn->dd_data; 553 554 tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0, 555 CRYPTO_ALG_ASYNC); 556 tcp_sw_conn->tx_hash.flags = 0; 557 if (IS_ERR(tcp_sw_conn->tx_hash.tfm)) 558 goto free_conn; 559 560 tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0, 561 CRYPTO_ALG_ASYNC); 562 tcp_sw_conn->rx_hash.flags = 0; 563 if (IS_ERR(tcp_sw_conn->rx_hash.tfm)) 564 goto free_tx_tfm; 565 tcp_conn->rx_hash = &tcp_sw_conn->rx_hash; 566 567 return cls_conn; 568 569 free_tx_tfm: 570 crypto_free_hash(tcp_sw_conn->tx_hash.tfm); 571 free_conn: 572 iscsi_conn_printk(KERN_ERR, conn, 573 "Could not create connection due to crc32c " 574 "loading error. Make sure the crc32c " 575 "module is built as a module or into the " 576 "kernel\n"); 577 iscsi_tcp_conn_teardown(cls_conn); 578 return NULL; 579 } 580 581 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn) 582 { 583 struct iscsi_session *session = conn->session; 584 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 585 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 586 struct socket *sock = tcp_sw_conn->sock; 587 588 if (!sock) 589 return; 590 591 sock_hold(sock->sk); 592 iscsi_sw_tcp_conn_restore_callbacks(conn); 593 sock_put(sock->sk); 594 595 spin_lock_bh(&session->lock); 596 tcp_sw_conn->sock = NULL; 597 spin_unlock_bh(&session->lock); 598 sockfd_put(sock); 599 } 600 601 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn) 602 { 603 struct iscsi_conn *conn = cls_conn->dd_data; 604 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 605 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 606 607 iscsi_sw_tcp_release_conn(conn); 608 609 if (tcp_sw_conn->tx_hash.tfm) 610 crypto_free_hash(tcp_sw_conn->tx_hash.tfm); 611 if (tcp_sw_conn->rx_hash.tfm) 612 crypto_free_hash(tcp_sw_conn->rx_hash.tfm); 613 614 iscsi_tcp_conn_teardown(cls_conn); 615 } 616 617 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) 618 { 619 struct iscsi_conn *conn = cls_conn->dd_data; 620 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 621 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 622 struct socket *sock = tcp_sw_conn->sock; 623 624 /* userspace may have goofed up and not bound us */ 625 if (!sock) 626 return; 627 628 sock->sk->sk_err = EIO; 629 wake_up_interruptible(sk_sleep(sock->sk)); 630 631 /* stop xmit side */ 632 iscsi_suspend_tx(conn); 633 634 /* stop recv side and release socket */ 635 iscsi_sw_tcp_release_conn(conn); 636 637 iscsi_conn_stop(cls_conn, flag); 638 } 639 640 static int 641 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session, 642 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph, 643 int is_leading) 644 { 645 struct iscsi_session *session = cls_session->dd_data; 646 struct iscsi_conn *conn = cls_conn->dd_data; 647 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 648 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 649 struct sock *sk; 650 struct socket *sock; 651 int err; 652 653 /* lookup for existing socket */ 654 sock = sockfd_lookup((int)transport_eph, &err); 655 if (!sock) { 656 iscsi_conn_printk(KERN_ERR, conn, 657 "sockfd_lookup failed %d\n", err); 658 return -EEXIST; 659 } 660 661 err = iscsi_conn_bind(cls_session, cls_conn, is_leading); 662 if (err) 663 goto free_socket; 664 665 spin_lock_bh(&session->lock); 666 /* bind iSCSI connection and socket */ 667 tcp_sw_conn->sock = sock; 668 spin_unlock_bh(&session->lock); 669 670 /* setup Socket parameters */ 671 sk = sock->sk; 672 sk->sk_reuse = SK_CAN_REUSE; 673 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */ 674 sk->sk_allocation = GFP_ATOMIC; 675 sk_set_memalloc(sk); 676 677 iscsi_sw_tcp_conn_set_callbacks(conn); 678 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage; 679 /* 680 * set receive state machine into initial state 681 */ 682 iscsi_tcp_hdr_recv_prep(tcp_conn); 683 return 0; 684 685 free_socket: 686 sockfd_put(sock); 687 return err; 688 } 689 690 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn, 691 enum iscsi_param param, char *buf, 692 int buflen) 693 { 694 struct iscsi_conn *conn = cls_conn->dd_data; 695 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 696 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 697 698 switch(param) { 699 case ISCSI_PARAM_HDRDGST_EN: 700 iscsi_set_param(cls_conn, param, buf, buflen); 701 break; 702 case ISCSI_PARAM_DATADGST_EN: 703 iscsi_set_param(cls_conn, param, buf, buflen); 704 tcp_sw_conn->sendpage = conn->datadgst_en ? 705 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage; 706 break; 707 case ISCSI_PARAM_MAX_R2T: 708 return iscsi_tcp_set_max_r2t(conn, buf); 709 default: 710 return iscsi_set_param(cls_conn, param, buf, buflen); 711 } 712 713 return 0; 714 } 715 716 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn, 717 enum iscsi_param param, char *buf) 718 { 719 struct iscsi_conn *conn = cls_conn->dd_data; 720 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 721 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 722 struct sockaddr_in6 addr; 723 int rc, len; 724 725 switch(param) { 726 case ISCSI_PARAM_CONN_PORT: 727 case ISCSI_PARAM_CONN_ADDRESS: 728 spin_lock_bh(&conn->session->lock); 729 if (!tcp_sw_conn || !tcp_sw_conn->sock) { 730 spin_unlock_bh(&conn->session->lock); 731 return -ENOTCONN; 732 } 733 rc = kernel_getpeername(tcp_sw_conn->sock, 734 (struct sockaddr *)&addr, &len); 735 spin_unlock_bh(&conn->session->lock); 736 if (rc) 737 return rc; 738 739 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 740 &addr, param, buf); 741 default: 742 return iscsi_conn_get_param(cls_conn, param, buf); 743 } 744 745 return 0; 746 } 747 748 static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost, 749 enum iscsi_host_param param, char *buf) 750 { 751 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost); 752 struct iscsi_session *session = tcp_sw_host->session; 753 struct iscsi_conn *conn; 754 struct iscsi_tcp_conn *tcp_conn; 755 struct iscsi_sw_tcp_conn *tcp_sw_conn; 756 struct sockaddr_in6 addr; 757 int rc, len; 758 759 switch (param) { 760 case ISCSI_HOST_PARAM_IPADDRESS: 761 spin_lock_bh(&session->lock); 762 conn = session->leadconn; 763 if (!conn) { 764 spin_unlock_bh(&session->lock); 765 return -ENOTCONN; 766 } 767 tcp_conn = conn->dd_data; 768 769 tcp_sw_conn = tcp_conn->dd_data; 770 if (!tcp_sw_conn->sock) { 771 spin_unlock_bh(&session->lock); 772 return -ENOTCONN; 773 } 774 775 rc = kernel_getsockname(tcp_sw_conn->sock, 776 (struct sockaddr *)&addr, &len); 777 spin_unlock_bh(&session->lock); 778 if (rc) 779 return rc; 780 781 return iscsi_conn_get_addr_param((struct sockaddr_storage *) 782 &addr, param, buf); 783 default: 784 return iscsi_host_get_param(shost, param, buf); 785 } 786 787 return 0; 788 } 789 790 static void 791 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn, 792 struct iscsi_stats *stats) 793 { 794 struct iscsi_conn *conn = cls_conn->dd_data; 795 struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 796 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; 797 798 stats->custom_length = 3; 799 strcpy(stats->custom[0].desc, "tx_sendpage_failures"); 800 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt; 801 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr"); 802 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt; 803 strcpy(stats->custom[2].desc, "eh_abort_cnt"); 804 stats->custom[2].value = conn->eh_abort_cnt; 805 806 iscsi_tcp_conn_get_stats(cls_conn, stats); 807 } 808 809 static struct iscsi_cls_session * 810 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max, 811 uint16_t qdepth, uint32_t initial_cmdsn) 812 { 813 struct iscsi_cls_session *cls_session; 814 struct iscsi_session *session; 815 struct iscsi_sw_tcp_host *tcp_sw_host; 816 struct Scsi_Host *shost; 817 818 if (ep) { 819 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep); 820 return NULL; 821 } 822 823 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht, 824 sizeof(struct iscsi_sw_tcp_host), 1); 825 if (!shost) 826 return NULL; 827 shost->transportt = iscsi_sw_tcp_scsi_transport; 828 shost->cmd_per_lun = qdepth; 829 shost->max_lun = iscsi_max_lun; 830 shost->max_id = 0; 831 shost->max_channel = 0; 832 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE; 833 834 if (iscsi_host_add(shost, NULL)) 835 goto free_host; 836 837 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost, 838 cmds_max, 0, 839 sizeof(struct iscsi_tcp_task) + 840 sizeof(struct iscsi_sw_tcp_hdrbuf), 841 initial_cmdsn, 0); 842 if (!cls_session) 843 goto remove_host; 844 session = cls_session->dd_data; 845 tcp_sw_host = iscsi_host_priv(shost); 846 tcp_sw_host->session = session; 847 848 shost->can_queue = session->scsi_cmds_max; 849 if (iscsi_tcp_r2tpool_alloc(session)) 850 goto remove_session; 851 return cls_session; 852 853 remove_session: 854 iscsi_session_teardown(cls_session); 855 remove_host: 856 iscsi_host_remove(shost); 857 free_host: 858 iscsi_host_free(shost); 859 return NULL; 860 } 861 862 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session) 863 { 864 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session); 865 866 iscsi_tcp_r2tpool_free(cls_session->dd_data); 867 iscsi_session_teardown(cls_session); 868 869 iscsi_host_remove(shost); 870 iscsi_host_free(shost); 871 } 872 873 static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param) 874 { 875 switch (param_type) { 876 case ISCSI_HOST_PARAM: 877 switch (param) { 878 case ISCSI_HOST_PARAM_NETDEV_NAME: 879 case ISCSI_HOST_PARAM_HWADDRESS: 880 case ISCSI_HOST_PARAM_IPADDRESS: 881 case ISCSI_HOST_PARAM_INITIATOR_NAME: 882 return S_IRUGO; 883 default: 884 return 0; 885 } 886 case ISCSI_PARAM: 887 switch (param) { 888 case ISCSI_PARAM_MAX_RECV_DLENGTH: 889 case ISCSI_PARAM_MAX_XMIT_DLENGTH: 890 case ISCSI_PARAM_HDRDGST_EN: 891 case ISCSI_PARAM_DATADGST_EN: 892 case ISCSI_PARAM_CONN_ADDRESS: 893 case ISCSI_PARAM_CONN_PORT: 894 case ISCSI_PARAM_EXP_STATSN: 895 case ISCSI_PARAM_PERSISTENT_ADDRESS: 896 case ISCSI_PARAM_PERSISTENT_PORT: 897 case ISCSI_PARAM_PING_TMO: 898 case ISCSI_PARAM_RECV_TMO: 899 case ISCSI_PARAM_INITIAL_R2T_EN: 900 case ISCSI_PARAM_MAX_R2T: 901 case ISCSI_PARAM_IMM_DATA_EN: 902 case ISCSI_PARAM_FIRST_BURST: 903 case ISCSI_PARAM_MAX_BURST: 904 case ISCSI_PARAM_PDU_INORDER_EN: 905 case ISCSI_PARAM_DATASEQ_INORDER_EN: 906 case ISCSI_PARAM_ERL: 907 case ISCSI_PARAM_TARGET_NAME: 908 case ISCSI_PARAM_TPGT: 909 case ISCSI_PARAM_USERNAME: 910 case ISCSI_PARAM_PASSWORD: 911 case ISCSI_PARAM_USERNAME_IN: 912 case ISCSI_PARAM_PASSWORD_IN: 913 case ISCSI_PARAM_FAST_ABORT: 914 case ISCSI_PARAM_ABORT_TMO: 915 case ISCSI_PARAM_LU_RESET_TMO: 916 case ISCSI_PARAM_TGT_RESET_TMO: 917 case ISCSI_PARAM_IFACE_NAME: 918 case ISCSI_PARAM_INITIATOR_NAME: 919 return S_IRUGO; 920 default: 921 return 0; 922 } 923 } 924 925 return 0; 926 } 927 928 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev) 929 { 930 set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags); 931 return 0; 932 } 933 934 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev) 935 { 936 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY); 937 blk_queue_dma_alignment(sdev->request_queue, 0); 938 return 0; 939 } 940 941 static struct scsi_host_template iscsi_sw_tcp_sht = { 942 .module = THIS_MODULE, 943 .name = "iSCSI Initiator over TCP/IP", 944 .queuecommand = iscsi_queuecommand, 945 .change_queue_depth = iscsi_change_queue_depth, 946 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1, 947 .sg_tablesize = 4096, 948 .max_sectors = 0xFFFF, 949 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN, 950 .eh_abort_handler = iscsi_eh_abort, 951 .eh_device_reset_handler= iscsi_eh_device_reset, 952 .eh_target_reset_handler = iscsi_eh_recover_target, 953 .use_clustering = DISABLE_CLUSTERING, 954 .slave_alloc = iscsi_sw_tcp_slave_alloc, 955 .slave_configure = iscsi_sw_tcp_slave_configure, 956 .target_alloc = iscsi_target_alloc, 957 .proc_name = "iscsi_tcp", 958 .this_id = -1, 959 }; 960 961 static struct iscsi_transport iscsi_sw_tcp_transport = { 962 .owner = THIS_MODULE, 963 .name = "tcp", 964 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST 965 | CAP_DATADGST, 966 /* session management */ 967 .create_session = iscsi_sw_tcp_session_create, 968 .destroy_session = iscsi_sw_tcp_session_destroy, 969 /* connection management */ 970 .create_conn = iscsi_sw_tcp_conn_create, 971 .bind_conn = iscsi_sw_tcp_conn_bind, 972 .destroy_conn = iscsi_sw_tcp_conn_destroy, 973 .attr_is_visible = iscsi_sw_tcp_attr_is_visible, 974 .set_param = iscsi_sw_tcp_conn_set_param, 975 .get_conn_param = iscsi_sw_tcp_conn_get_param, 976 .get_session_param = iscsi_session_get_param, 977 .start_conn = iscsi_conn_start, 978 .stop_conn = iscsi_sw_tcp_conn_stop, 979 /* iscsi host params */ 980 .get_host_param = iscsi_sw_tcp_host_get_param, 981 .set_host_param = iscsi_host_set_param, 982 /* IO */ 983 .send_pdu = iscsi_conn_send_pdu, 984 .get_stats = iscsi_sw_tcp_conn_get_stats, 985 /* iscsi task/cmd helpers */ 986 .init_task = iscsi_tcp_task_init, 987 .xmit_task = iscsi_tcp_task_xmit, 988 .cleanup_task = iscsi_tcp_cleanup_task, 989 /* low level pdu helpers */ 990 .xmit_pdu = iscsi_sw_tcp_pdu_xmit, 991 .init_pdu = iscsi_sw_tcp_pdu_init, 992 .alloc_pdu = iscsi_sw_tcp_pdu_alloc, 993 /* recovery */ 994 .session_recovery_timedout = iscsi_session_recovery_timedout, 995 }; 996 997 static int __init iscsi_sw_tcp_init(void) 998 { 999 if (iscsi_max_lun < 1) { 1000 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n", 1001 iscsi_max_lun); 1002 return -EINVAL; 1003 } 1004 1005 iscsi_sw_tcp_scsi_transport = iscsi_register_transport( 1006 &iscsi_sw_tcp_transport); 1007 if (!iscsi_sw_tcp_scsi_transport) 1008 return -ENODEV; 1009 1010 return 0; 1011 } 1012 1013 static void __exit iscsi_sw_tcp_exit(void) 1014 { 1015 iscsi_unregister_transport(&iscsi_sw_tcp_transport); 1016 } 1017 1018 module_init(iscsi_sw_tcp_init); 1019 module_exit(iscsi_sw_tcp_exit); 1020