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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
48MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
49 "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
50 "Alex Aizman <itn780@yahoo.com>");
51MODULE_DESCRIPTION("iSCSI/TCP data-path");
52MODULE_LICENSE("GPL");
53
54static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
55static struct scsi_host_template iscsi_sw_tcp_sht;
56static struct iscsi_transport iscsi_sw_tcp_transport;
57
58static unsigned int iscsi_max_lun = 512;
59module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
60
61static int iscsi_sw_tcp_dbg;
62module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
63 S_IRUGO | S_IWUSR);
64MODULE_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 */
83static 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 */
114static 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
127static 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
159static 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 **/
190static 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
215static 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
233static void
234iscsi_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 */
263static 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 **/
311static 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
350error:
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 */
361static 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
370static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
371{
372 struct iscsi_conn *conn = task->conn;
373 int rc;
374
375 while (iscsi_sw_tcp_xmit_qlen(conn)) {
376 rc = iscsi_sw_tcp_xmit(conn);
377 if (rc == 0)
378 return -EAGAIN;
379 if (rc < 0)
380 return rc;
381 }
382
383 return 0;
384}
385
386/*
387 * This is called when we're done sending the header.
388 * Simply copy the data_segment to the send segment, and return.
389 */
390static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
391 struct iscsi_segment *segment)
392{
393 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
394
395 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
396 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
397 "Header done. Next segment size %u total_size %u\n",
398 tcp_sw_conn->out.segment.size,
399 tcp_sw_conn->out.segment.total_size);
400 return 0;
401}
402
403static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
404 size_t hdrlen)
405{
406 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
407 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
408
409 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
410 "digest enabled" : "digest disabled");
411
412 /* Clear the data segment - needs to be filled in by the
413 * caller using iscsi_tcp_send_data_prep() */
414 memset(&tcp_sw_conn->out.data_segment, 0,
415 sizeof(struct iscsi_segment));
416
417 /* If header digest is enabled, compute the CRC and
418 * place the digest into the same buffer. We make
419 * sure that both iscsi_tcp_task and mtask have
420 * sufficient room.
421 */
422 if (conn->hdrdgst_en) {
423 iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen,
424 hdr + hdrlen);
425 hdrlen += ISCSI_DIGEST_SIZE;
426 }
427
428 /* Remember header pointer for later, when we need
429 * to decide whether there's a payload to go along
430 * with the header. */
431 tcp_sw_conn->out.hdr = hdr;
432
433 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
434 iscsi_sw_tcp_send_hdr_done, NULL);
435}
436
437/*
438 * Prepare the send buffer for the payload data.
439 * Padding and checksumming will all be taken care
440 * of by the iscsi_segment routines.
441 */
442static int
443iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
444 unsigned int count, unsigned int offset,
445 unsigned int len)
446{
447 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
448 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
449 struct hash_desc *tx_hash = NULL;
450 unsigned int hdr_spec_len;
451
452 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
453 conn->datadgst_en ?
454 "digest enabled" : "digest disabled");
455
456 /* Make sure the datalen matches what the caller
457 said he would send. */
458 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
459 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
460
461 if (conn->datadgst_en)
462 tx_hash = &tcp_sw_conn->tx_hash;
463
464 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
465 sg, count, offset, len,
466 NULL, tx_hash);
467}
468
469static void
470iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
471 size_t len)
472{
473 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
474 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
475 struct hash_desc *tx_hash = NULL;
476 unsigned int hdr_spec_len;
477
478 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
479 "digest enabled" : "digest disabled");
480
481 /* Make sure the datalen matches what the caller
482 said he would send. */
483 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
484 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
485
486 if (conn->datadgst_en)
487 tx_hash = &tcp_sw_conn->tx_hash;
488
489 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
490 data, len, NULL, tx_hash);
491}
492
493static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
494 unsigned int offset, unsigned int count)
495{
496 struct iscsi_conn *conn = task->conn;
497 int err = 0;
498
499 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
500
501 if (!count)
502 return 0;
503
504 if (!task->sc)
505 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
506 else {
507 struct scsi_data_buffer *sdb = scsi_out(task->sc);
508
509 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
510 sdb->table.nents, offset,
511 count);
512 }
513
514 if (err) {
515 /* got invalid offset/len */
516 return -EIO;
517 }
518 return 0;
519}
520
521static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
522{
523 struct iscsi_tcp_task *tcp_task = task->dd_data;
524
525 task->hdr = task->dd_data + sizeof(*tcp_task);
526 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
527 return 0;
528}
529
530static struct iscsi_cls_conn *
531iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
532 uint32_t conn_idx)
533{
534 struct iscsi_conn *conn;
535 struct iscsi_cls_conn *cls_conn;
536 struct iscsi_tcp_conn *tcp_conn;
537 struct iscsi_sw_tcp_conn *tcp_sw_conn;
538
539 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
540 conn_idx);
541 if (!cls_conn)
542 return NULL;
543 conn = cls_conn->dd_data;
544 tcp_conn = conn->dd_data;
545 tcp_sw_conn = tcp_conn->dd_data;
546
547 tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
548 CRYPTO_ALG_ASYNC);
549 tcp_sw_conn->tx_hash.flags = 0;
550 if (IS_ERR(tcp_sw_conn->tx_hash.tfm))
551 goto free_conn;
552
553 tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
554 CRYPTO_ALG_ASYNC);
555 tcp_sw_conn->rx_hash.flags = 0;
556 if (IS_ERR(tcp_sw_conn->rx_hash.tfm))
557 goto free_tx_tfm;
558 tcp_conn->rx_hash = &tcp_sw_conn->rx_hash;
559
560 return cls_conn;
561
562free_tx_tfm:
563 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
564free_conn:
565 iscsi_conn_printk(KERN_ERR, conn,
566 "Could not create connection due to crc32c "
567 "loading error. Make sure the crc32c "
568 "module is built as a module or into the "
569 "kernel\n");
570 iscsi_tcp_conn_teardown(cls_conn);
571 return NULL;
572}
573
574static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
575{
576 struct iscsi_session *session = conn->session;
577 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
578 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
579 struct socket *sock = tcp_sw_conn->sock;
580
581 if (!sock)
582 return;
583
584 sock_hold(sock->sk);
585 iscsi_sw_tcp_conn_restore_callbacks(conn);
586 sock_put(sock->sk);
587
588 spin_lock_bh(&session->lock);
589 tcp_sw_conn->sock = NULL;
590 spin_unlock_bh(&session->lock);
591 sockfd_put(sock);
592}
593
594static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
595{
596 struct iscsi_conn *conn = cls_conn->dd_data;
597 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
598 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
599
600 iscsi_sw_tcp_release_conn(conn);
601
602 if (tcp_sw_conn->tx_hash.tfm)
603 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
604 if (tcp_sw_conn->rx_hash.tfm)
605 crypto_free_hash(tcp_sw_conn->rx_hash.tfm);
606
607 iscsi_tcp_conn_teardown(cls_conn);
608}
609
610static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
611{
612 struct iscsi_conn *conn = cls_conn->dd_data;
613 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
614 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
615 struct socket *sock = tcp_sw_conn->sock;
616
617 /* userspace may have goofed up and not bound us */
618 if (!sock)
619 return;
620
621 sock->sk->sk_err = EIO;
622 wake_up_interruptible(sk_sleep(sock->sk));
623
624 /* stop xmit side */
625 iscsi_suspend_tx(conn);
626
627 /* stop recv side and release socket */
628 iscsi_sw_tcp_release_conn(conn);
629
630 iscsi_conn_stop(cls_conn, flag);
631}
632
633static int
634iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
635 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
636 int is_leading)
637{
638 struct iscsi_session *session = cls_session->dd_data;
639 struct iscsi_conn *conn = cls_conn->dd_data;
640 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
641 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
642 struct sock *sk;
643 struct socket *sock;
644 int err;
645
646 /* lookup for existing socket */
647 sock = sockfd_lookup((int)transport_eph, &err);
648 if (!sock) {
649 iscsi_conn_printk(KERN_ERR, conn,
650 "sockfd_lookup failed %d\n", err);
651 return -EEXIST;
652 }
653
654 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
655 if (err)
656 goto free_socket;
657
658 spin_lock_bh(&session->lock);
659 /* bind iSCSI connection and socket */
660 tcp_sw_conn->sock = sock;
661 spin_unlock_bh(&session->lock);
662
663 /* setup Socket parameters */
664 sk = sock->sk;
665 sk->sk_reuse = SK_CAN_REUSE;
666 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
667 sk->sk_allocation = GFP_ATOMIC;
668
669 iscsi_sw_tcp_conn_set_callbacks(conn);
670 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
671 /*
672 * set receive state machine into initial state
673 */
674 iscsi_tcp_hdr_recv_prep(tcp_conn);
675 return 0;
676
677free_socket:
678 sockfd_put(sock);
679 return err;
680}
681
682static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
683 enum iscsi_param param, char *buf,
684 int buflen)
685{
686 struct iscsi_conn *conn = cls_conn->dd_data;
687 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
688 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
689
690 switch(param) {
691 case ISCSI_PARAM_HDRDGST_EN:
692 iscsi_set_param(cls_conn, param, buf, buflen);
693 break;
694 case ISCSI_PARAM_DATADGST_EN:
695 iscsi_set_param(cls_conn, param, buf, buflen);
696 tcp_sw_conn->sendpage = conn->datadgst_en ?
697 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
698 break;
699 case ISCSI_PARAM_MAX_R2T:
700 return iscsi_tcp_set_max_r2t(conn, buf);
701 default:
702 return iscsi_set_param(cls_conn, param, buf, buflen);
703 }
704
705 return 0;
706}
707
708static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
709 enum iscsi_param param, char *buf)
710{
711 struct iscsi_conn *conn = cls_conn->dd_data;
712 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
713 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
714 struct sockaddr_in6 addr;
715 int rc, len;
716
717 switch(param) {
718 case ISCSI_PARAM_CONN_PORT:
719 case ISCSI_PARAM_CONN_ADDRESS:
720 spin_lock_bh(&conn->session->lock);
721 if (!tcp_sw_conn || !tcp_sw_conn->sock) {
722 spin_unlock_bh(&conn->session->lock);
723 return -ENOTCONN;
724 }
725 rc = kernel_getpeername(tcp_sw_conn->sock,
726 (struct sockaddr *)&addr, &len);
727 spin_unlock_bh(&conn->session->lock);
728 if (rc)
729 return rc;
730
731 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
732 &addr, param, buf);
733 default:
734 return iscsi_conn_get_param(cls_conn, param, buf);
735 }
736
737 return 0;
738}
739
740static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
741 enum iscsi_host_param param, char *buf)
742{
743 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
744 struct iscsi_session *session = tcp_sw_host->session;
745 struct iscsi_conn *conn;
746 struct iscsi_tcp_conn *tcp_conn;
747 struct iscsi_sw_tcp_conn *tcp_sw_conn;
748 struct sockaddr_in6 addr;
749 int rc, len;
750
751 switch (param) {
752 case ISCSI_HOST_PARAM_IPADDRESS:
753 spin_lock_bh(&session->lock);
754 conn = session->leadconn;
755 if (!conn) {
756 spin_unlock_bh(&session->lock);
757 return -ENOTCONN;
758 }
759 tcp_conn = conn->dd_data;
760
761 tcp_sw_conn = tcp_conn->dd_data;
762 if (!tcp_sw_conn->sock) {
763 spin_unlock_bh(&session->lock);
764 return -ENOTCONN;
765 }
766
767 rc = kernel_getsockname(tcp_sw_conn->sock,
768 (struct sockaddr *)&addr, &len);
769 spin_unlock_bh(&session->lock);
770 if (rc)
771 return rc;
772
773 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
774 &addr, param, buf);
775 default:
776 return iscsi_host_get_param(shost, param, buf);
777 }
778
779 return 0;
780}
781
782static void
783iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
784 struct iscsi_stats *stats)
785{
786 struct iscsi_conn *conn = cls_conn->dd_data;
787 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
788 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
789
790 stats->custom_length = 3;
791 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
792 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
793 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
794 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
795 strcpy(stats->custom[2].desc, "eh_abort_cnt");
796 stats->custom[2].value = conn->eh_abort_cnt;
797
798 iscsi_tcp_conn_get_stats(cls_conn, stats);
799}
800
801static struct iscsi_cls_session *
802iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
803 uint16_t qdepth, uint32_t initial_cmdsn)
804{
805 struct iscsi_cls_session *cls_session;
806 struct iscsi_session *session;
807 struct iscsi_sw_tcp_host *tcp_sw_host;
808 struct Scsi_Host *shost;
809
810 if (ep) {
811 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
812 return NULL;
813 }
814
815 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
816 sizeof(struct iscsi_sw_tcp_host), 1);
817 if (!shost)
818 return NULL;
819 shost->transportt = iscsi_sw_tcp_scsi_transport;
820 shost->cmd_per_lun = qdepth;
821 shost->max_lun = iscsi_max_lun;
822 shost->max_id = 0;
823 shost->max_channel = 0;
824 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
825
826 if (iscsi_host_add(shost, NULL))
827 goto free_host;
828
829 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
830 cmds_max, 0,
831 sizeof(struct iscsi_tcp_task) +
832 sizeof(struct iscsi_sw_tcp_hdrbuf),
833 initial_cmdsn, 0);
834 if (!cls_session)
835 goto remove_host;
836 session = cls_session->dd_data;
837 tcp_sw_host = iscsi_host_priv(shost);
838 tcp_sw_host->session = session;
839
840 shost->can_queue = session->scsi_cmds_max;
841 if (iscsi_tcp_r2tpool_alloc(session))
842 goto remove_session;
843 return cls_session;
844
845remove_session:
846 iscsi_session_teardown(cls_session);
847remove_host:
848 iscsi_host_remove(shost);
849free_host:
850 iscsi_host_free(shost);
851 return NULL;
852}
853
854static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
855{
856 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
857
858 iscsi_tcp_r2tpool_free(cls_session->dd_data);
859 iscsi_session_teardown(cls_session);
860
861 iscsi_host_remove(shost);
862 iscsi_host_free(shost);
863}
864
865static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param)
866{
867 switch (param_type) {
868 case ISCSI_HOST_PARAM:
869 switch (param) {
870 case ISCSI_HOST_PARAM_NETDEV_NAME:
871 case ISCSI_HOST_PARAM_HWADDRESS:
872 case ISCSI_HOST_PARAM_IPADDRESS:
873 case ISCSI_HOST_PARAM_INITIATOR_NAME:
874 return S_IRUGO;
875 default:
876 return 0;
877 }
878 case ISCSI_PARAM:
879 switch (param) {
880 case ISCSI_PARAM_MAX_RECV_DLENGTH:
881 case ISCSI_PARAM_MAX_XMIT_DLENGTH:
882 case ISCSI_PARAM_HDRDGST_EN:
883 case ISCSI_PARAM_DATADGST_EN:
884 case ISCSI_PARAM_CONN_ADDRESS:
885 case ISCSI_PARAM_CONN_PORT:
886 case ISCSI_PARAM_EXP_STATSN:
887 case ISCSI_PARAM_PERSISTENT_ADDRESS:
888 case ISCSI_PARAM_PERSISTENT_PORT:
889 case ISCSI_PARAM_PING_TMO:
890 case ISCSI_PARAM_RECV_TMO:
891 case ISCSI_PARAM_INITIAL_R2T_EN:
892 case ISCSI_PARAM_MAX_R2T:
893 case ISCSI_PARAM_IMM_DATA_EN:
894 case ISCSI_PARAM_FIRST_BURST:
895 case ISCSI_PARAM_MAX_BURST:
896 case ISCSI_PARAM_PDU_INORDER_EN:
897 case ISCSI_PARAM_DATASEQ_INORDER_EN:
898 case ISCSI_PARAM_ERL:
899 case ISCSI_PARAM_TARGET_NAME:
900 case ISCSI_PARAM_TPGT:
901 case ISCSI_PARAM_USERNAME:
902 case ISCSI_PARAM_PASSWORD:
903 case ISCSI_PARAM_USERNAME_IN:
904 case ISCSI_PARAM_PASSWORD_IN:
905 case ISCSI_PARAM_FAST_ABORT:
906 case ISCSI_PARAM_ABORT_TMO:
907 case ISCSI_PARAM_LU_RESET_TMO:
908 case ISCSI_PARAM_TGT_RESET_TMO:
909 case ISCSI_PARAM_IFACE_NAME:
910 case ISCSI_PARAM_INITIATOR_NAME:
911 return S_IRUGO;
912 default:
913 return 0;
914 }
915 }
916
917 return 0;
918}
919
920static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
921{
922 set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
923 return 0;
924}
925
926static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
927{
928 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
929 blk_queue_dma_alignment(sdev->request_queue, 0);
930 return 0;
931}
932
933static struct scsi_host_template iscsi_sw_tcp_sht = {
934 .module = THIS_MODULE,
935 .name = "iSCSI Initiator over TCP/IP",
936 .queuecommand = iscsi_queuecommand,
937 .change_queue_depth = iscsi_change_queue_depth,
938 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
939 .sg_tablesize = 4096,
940 .max_sectors = 0xFFFF,
941 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
942 .eh_abort_handler = iscsi_eh_abort,
943 .eh_device_reset_handler= iscsi_eh_device_reset,
944 .eh_target_reset_handler = iscsi_eh_recover_target,
945 .use_clustering = DISABLE_CLUSTERING,
946 .slave_alloc = iscsi_sw_tcp_slave_alloc,
947 .slave_configure = iscsi_sw_tcp_slave_configure,
948 .target_alloc = iscsi_target_alloc,
949 .proc_name = "iscsi_tcp",
950 .this_id = -1,
951};
952
953static struct iscsi_transport iscsi_sw_tcp_transport = {
954 .owner = THIS_MODULE,
955 .name = "tcp",
956 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
957 | CAP_DATADGST,
958 /* session management */
959 .create_session = iscsi_sw_tcp_session_create,
960 .destroy_session = iscsi_sw_tcp_session_destroy,
961 /* connection management */
962 .create_conn = iscsi_sw_tcp_conn_create,
963 .bind_conn = iscsi_sw_tcp_conn_bind,
964 .destroy_conn = iscsi_sw_tcp_conn_destroy,
965 .attr_is_visible = iscsi_sw_tcp_attr_is_visible,
966 .set_param = iscsi_sw_tcp_conn_set_param,
967 .get_conn_param = iscsi_sw_tcp_conn_get_param,
968 .get_session_param = iscsi_session_get_param,
969 .start_conn = iscsi_conn_start,
970 .stop_conn = iscsi_sw_tcp_conn_stop,
971 /* iscsi host params */
972 .get_host_param = iscsi_sw_tcp_host_get_param,
973 .set_host_param = iscsi_host_set_param,
974 /* IO */
975 .send_pdu = iscsi_conn_send_pdu,
976 .get_stats = iscsi_sw_tcp_conn_get_stats,
977 /* iscsi task/cmd helpers */
978 .init_task = iscsi_tcp_task_init,
979 .xmit_task = iscsi_tcp_task_xmit,
980 .cleanup_task = iscsi_tcp_cleanup_task,
981 /* low level pdu helpers */
982 .xmit_pdu = iscsi_sw_tcp_pdu_xmit,
983 .init_pdu = iscsi_sw_tcp_pdu_init,
984 .alloc_pdu = iscsi_sw_tcp_pdu_alloc,
985 /* recovery */
986 .session_recovery_timedout = iscsi_session_recovery_timedout,
987};
988
989static int __init iscsi_sw_tcp_init(void)
990{
991 if (iscsi_max_lun < 1) {
992 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
993 iscsi_max_lun);
994 return -EINVAL;
995 }
996
997 iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
998 &iscsi_sw_tcp_transport);
999 if (!iscsi_sw_tcp_scsi_transport)
1000 return -ENODEV;
1001
1002 return 0;
1003}
1004
1005static void __exit iscsi_sw_tcp_exit(void)
1006{
1007 iscsi_unregister_transport(&iscsi_sw_tcp_transport);
1008}
1009
1010module_init(iscsi_sw_tcp_init);
1011module_exit(iscsi_sw_tcp_exit);
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/sched/mm.h>
34#include <linux/file.h>
35#include <linux/blkdev.h>
36#include <linux/delay.h>
37#include <linux/kfifo.h>
38#include <linux/scatterlist.h>
39#include <linux/module.h>
40#include <linux/backing-dev.h>
41#include <net/tcp.h>
42#include <scsi/scsi_cmnd.h>
43#include <scsi/scsi_device.h>
44#include <scsi/scsi_host.h>
45#include <scsi/scsi.h>
46#include <scsi/scsi_transport_iscsi.h>
47
48#include "iscsi_tcp.h"
49
50MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
51 "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
52 "Alex Aizman <itn780@yahoo.com>");
53MODULE_DESCRIPTION("iSCSI/TCP data-path");
54MODULE_LICENSE("GPL");
55
56static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
57static struct scsi_host_template iscsi_sw_tcp_sht;
58static struct iscsi_transport iscsi_sw_tcp_transport;
59
60static unsigned int iscsi_max_lun = ~0;
61module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
62
63static int iscsi_sw_tcp_dbg;
64module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
65 S_IRUGO | S_IWUSR);
66MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
67 "Set to 1 to turn on, and zero to turn off. Default is off.");
68
69#define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \
70 do { \
71 if (iscsi_sw_tcp_dbg) \
72 iscsi_conn_printk(KERN_INFO, _conn, \
73 "%s " dbg_fmt, \
74 __func__, ##arg); \
75 } while (0);
76
77
78/**
79 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
80 * @rd_desc: read descriptor
81 * @skb: socket buffer
82 * @offset: offset in skb
83 * @len: skb->len - offset
84 */
85static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
86 unsigned int offset, size_t len)
87{
88 struct iscsi_conn *conn = rd_desc->arg.data;
89 unsigned int consumed, total_consumed = 0;
90 int status;
91
92 ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
93
94 do {
95 status = 0;
96 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
97 offset += consumed;
98 total_consumed += consumed;
99 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
100
101 ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
102 skb->len - offset, status);
103 return total_consumed;
104}
105
106/**
107 * iscsi_sw_sk_state_check - check socket state
108 * @sk: socket
109 *
110 * If the socket is in CLOSE or CLOSE_WAIT we should
111 * not close the connection if there is still some
112 * data pending.
113 *
114 * Must be called with sk_callback_lock.
115 */
116static inline int iscsi_sw_sk_state_check(struct sock *sk)
117{
118 struct iscsi_conn *conn = sk->sk_user_data;
119
120 if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
121 (conn->session->state != ISCSI_STATE_LOGGING_OUT) &&
122 !atomic_read(&sk->sk_rmem_alloc)) {
123 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
124 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
125 return -ECONNRESET;
126 }
127 return 0;
128}
129
130static void iscsi_sw_tcp_data_ready(struct sock *sk)
131{
132 struct iscsi_conn *conn;
133 struct iscsi_tcp_conn *tcp_conn;
134 read_descriptor_t rd_desc;
135
136 read_lock_bh(&sk->sk_callback_lock);
137 conn = sk->sk_user_data;
138 if (!conn) {
139 read_unlock_bh(&sk->sk_callback_lock);
140 return;
141 }
142 tcp_conn = conn->dd_data;
143
144 /*
145 * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
146 * We set count to 1 because we want the network layer to
147 * hand us all the skbs that are available. iscsi_tcp_recv
148 * handled pdus that cross buffers or pdus that still need data.
149 */
150 rd_desc.arg.data = conn;
151 rd_desc.count = 1;
152 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
153
154 iscsi_sw_sk_state_check(sk);
155
156 /* If we had to (atomically) map a highmem page,
157 * unmap it now. */
158 iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
159 read_unlock_bh(&sk->sk_callback_lock);
160}
161
162static void iscsi_sw_tcp_state_change(struct sock *sk)
163{
164 struct iscsi_tcp_conn *tcp_conn;
165 struct iscsi_sw_tcp_conn *tcp_sw_conn;
166 struct iscsi_conn *conn;
167 void (*old_state_change)(struct sock *);
168
169 read_lock_bh(&sk->sk_callback_lock);
170 conn = sk->sk_user_data;
171 if (!conn) {
172 read_unlock_bh(&sk->sk_callback_lock);
173 return;
174 }
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 **/
191static 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
216static 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
234static void
235iscsi_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 */
264static 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 * @conn: iscsi connection
312 **/
313static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
314{
315 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
316 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
317 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
318 unsigned int consumed = 0;
319 int rc = 0;
320
321 while (1) {
322 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
323 /*
324 * We may not have been able to send data because the conn
325 * is getting stopped. libiscsi will know so propagate err
326 * for it to do the right thing.
327 */
328 if (rc == -EAGAIN)
329 return rc;
330 else if (rc < 0) {
331 rc = ISCSI_ERR_XMIT_FAILED;
332 goto error;
333 } else if (rc == 0)
334 break;
335
336 consumed += rc;
337
338 if (segment->total_copied >= segment->total_size) {
339 if (segment->done != NULL) {
340 rc = segment->done(tcp_conn, segment);
341 if (rc != 0)
342 goto error;
343 }
344 }
345 }
346
347 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
348
349 conn->txdata_octets += consumed;
350 return consumed;
351
352error:
353 /* Transmit error. We could initiate error recovery
354 * here. */
355 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
356 iscsi_conn_failure(conn, rc);
357 return -EIO;
358}
359
360/**
361 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
362 * @conn: iscsi connection
363 */
364static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
365{
366 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
367 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
368 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
369
370 return segment->total_copied - segment->total_size;
371}
372
373static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
374{
375 struct iscsi_conn *conn = task->conn;
376 unsigned int noreclaim_flag;
377 int rc = 0;
378
379 noreclaim_flag = memalloc_noreclaim_save();
380
381 while (iscsi_sw_tcp_xmit_qlen(conn)) {
382 rc = iscsi_sw_tcp_xmit(conn);
383 if (rc == 0) {
384 rc = -EAGAIN;
385 break;
386 }
387 if (rc < 0)
388 break;
389 rc = 0;
390 }
391
392 memalloc_noreclaim_restore(noreclaim_flag);
393 return rc;
394}
395
396/*
397 * This is called when we're done sending the header.
398 * Simply copy the data_segment to the send segment, and return.
399 */
400static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
401 struct iscsi_segment *segment)
402{
403 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
404
405 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
406 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
407 "Header done. Next segment size %u total_size %u\n",
408 tcp_sw_conn->out.segment.size,
409 tcp_sw_conn->out.segment.total_size);
410 return 0;
411}
412
413static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
414 size_t hdrlen)
415{
416 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
417 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
418
419 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
420 "digest enabled" : "digest disabled");
421
422 /* Clear the data segment - needs to be filled in by the
423 * caller using iscsi_tcp_send_data_prep() */
424 memset(&tcp_sw_conn->out.data_segment, 0,
425 sizeof(struct iscsi_segment));
426
427 /* If header digest is enabled, compute the CRC and
428 * place the digest into the same buffer. We make
429 * sure that both iscsi_tcp_task and mtask have
430 * sufficient room.
431 */
432 if (conn->hdrdgst_en) {
433 iscsi_tcp_dgst_header(tcp_sw_conn->tx_hash, hdr, hdrlen,
434 hdr + hdrlen);
435 hdrlen += ISCSI_DIGEST_SIZE;
436 }
437
438 /* Remember header pointer for later, when we need
439 * to decide whether there's a payload to go along
440 * with the header. */
441 tcp_sw_conn->out.hdr = hdr;
442
443 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
444 iscsi_sw_tcp_send_hdr_done, NULL);
445}
446
447/*
448 * Prepare the send buffer for the payload data.
449 * Padding and checksumming will all be taken care
450 * of by the iscsi_segment routines.
451 */
452static int
453iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
454 unsigned int count, unsigned int offset,
455 unsigned int len)
456{
457 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
458 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
459 struct ahash_request *tx_hash = NULL;
460 unsigned int hdr_spec_len;
461
462 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
463 conn->datadgst_en ?
464 "digest enabled" : "digest disabled");
465
466 /* Make sure the datalen matches what the caller
467 said he would send. */
468 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
469 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
470
471 if (conn->datadgst_en)
472 tx_hash = tcp_sw_conn->tx_hash;
473
474 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
475 sg, count, offset, len,
476 NULL, tx_hash);
477}
478
479static void
480iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
481 size_t len)
482{
483 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
484 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
485 struct ahash_request *tx_hash = NULL;
486 unsigned int hdr_spec_len;
487
488 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
489 "digest enabled" : "digest disabled");
490
491 /* Make sure the datalen matches what the caller
492 said he would send. */
493 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
494 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
495
496 if (conn->datadgst_en)
497 tx_hash = tcp_sw_conn->tx_hash;
498
499 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
500 data, len, NULL, tx_hash);
501}
502
503static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
504 unsigned int offset, unsigned int count)
505{
506 struct iscsi_conn *conn = task->conn;
507 int err = 0;
508
509 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
510
511 if (!count)
512 return 0;
513
514 if (!task->sc)
515 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
516 else {
517 struct scsi_data_buffer *sdb = scsi_out(task->sc);
518
519 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
520 sdb->table.nents, offset,
521 count);
522 }
523
524 if (err) {
525 /* got invalid offset/len */
526 return -EIO;
527 }
528 return 0;
529}
530
531static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
532{
533 struct iscsi_tcp_task *tcp_task = task->dd_data;
534
535 task->hdr = task->dd_data + sizeof(*tcp_task);
536 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
537 return 0;
538}
539
540static struct iscsi_cls_conn *
541iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
542 uint32_t conn_idx)
543{
544 struct iscsi_conn *conn;
545 struct iscsi_cls_conn *cls_conn;
546 struct iscsi_tcp_conn *tcp_conn;
547 struct iscsi_sw_tcp_conn *tcp_sw_conn;
548 struct crypto_ahash *tfm;
549
550 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
551 conn_idx);
552 if (!cls_conn)
553 return NULL;
554 conn = cls_conn->dd_data;
555 tcp_conn = conn->dd_data;
556 tcp_sw_conn = tcp_conn->dd_data;
557
558 tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
559 if (IS_ERR(tfm))
560 goto free_conn;
561
562 tcp_sw_conn->tx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
563 if (!tcp_sw_conn->tx_hash)
564 goto free_tfm;
565 ahash_request_set_callback(tcp_sw_conn->tx_hash, 0, NULL, NULL);
566
567 tcp_sw_conn->rx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
568 if (!tcp_sw_conn->rx_hash)
569 goto free_tx_hash;
570 ahash_request_set_callback(tcp_sw_conn->rx_hash, 0, NULL, NULL);
571
572 tcp_conn->rx_hash = tcp_sw_conn->rx_hash;
573
574 return cls_conn;
575
576free_tx_hash:
577 ahash_request_free(tcp_sw_conn->tx_hash);
578free_tfm:
579 crypto_free_ahash(tfm);
580free_conn:
581 iscsi_conn_printk(KERN_ERR, conn,
582 "Could not create connection due to crc32c "
583 "loading error. Make sure the crc32c "
584 "module is built as a module or into the "
585 "kernel\n");
586 iscsi_tcp_conn_teardown(cls_conn);
587 return NULL;
588}
589
590static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
591{
592 struct iscsi_session *session = conn->session;
593 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
594 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
595 struct socket *sock = tcp_sw_conn->sock;
596
597 if (!sock)
598 return;
599
600 sock_hold(sock->sk);
601 iscsi_sw_tcp_conn_restore_callbacks(conn);
602 sock_put(sock->sk);
603
604 spin_lock_bh(&session->frwd_lock);
605 tcp_sw_conn->sock = NULL;
606 spin_unlock_bh(&session->frwd_lock);
607 sockfd_put(sock);
608}
609
610static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
611{
612 struct iscsi_conn *conn = cls_conn->dd_data;
613 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
614 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
615
616 iscsi_sw_tcp_release_conn(conn);
617
618 ahash_request_free(tcp_sw_conn->rx_hash);
619 if (tcp_sw_conn->tx_hash) {
620 struct crypto_ahash *tfm;
621
622 tfm = crypto_ahash_reqtfm(tcp_sw_conn->tx_hash);
623 ahash_request_free(tcp_sw_conn->tx_hash);
624 crypto_free_ahash(tfm);
625 }
626
627 iscsi_tcp_conn_teardown(cls_conn);
628}
629
630static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
631{
632 struct iscsi_conn *conn = cls_conn->dd_data;
633 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
634 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
635 struct socket *sock = tcp_sw_conn->sock;
636
637 /* userspace may have goofed up and not bound us */
638 if (!sock)
639 return;
640
641 sock->sk->sk_err = EIO;
642 wake_up_interruptible(sk_sleep(sock->sk));
643
644 /* stop xmit side */
645 iscsi_suspend_tx(conn);
646
647 /* stop recv side and release socket */
648 iscsi_sw_tcp_release_conn(conn);
649
650 iscsi_conn_stop(cls_conn, flag);
651}
652
653static int
654iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
655 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
656 int is_leading)
657{
658 struct iscsi_session *session = cls_session->dd_data;
659 struct iscsi_conn *conn = cls_conn->dd_data;
660 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
661 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
662 struct sock *sk;
663 struct socket *sock;
664 int err;
665
666 /* lookup for existing socket */
667 sock = sockfd_lookup((int)transport_eph, &err);
668 if (!sock) {
669 iscsi_conn_printk(KERN_ERR, conn,
670 "sockfd_lookup failed %d\n", err);
671 return -EEXIST;
672 }
673
674 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
675 if (err)
676 goto free_socket;
677
678 spin_lock_bh(&session->frwd_lock);
679 /* bind iSCSI connection and socket */
680 tcp_sw_conn->sock = sock;
681 spin_unlock_bh(&session->frwd_lock);
682
683 /* setup Socket parameters */
684 sk = sock->sk;
685 sk->sk_reuse = SK_CAN_REUSE;
686 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
687 sk->sk_allocation = GFP_ATOMIC;
688 sk_set_memalloc(sk);
689
690 iscsi_sw_tcp_conn_set_callbacks(conn);
691 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
692 /*
693 * set receive state machine into initial state
694 */
695 iscsi_tcp_hdr_recv_prep(tcp_conn);
696 return 0;
697
698free_socket:
699 sockfd_put(sock);
700 return err;
701}
702
703static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
704 enum iscsi_param param, char *buf,
705 int buflen)
706{
707 struct iscsi_conn *conn = cls_conn->dd_data;
708 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
709 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
710
711 switch(param) {
712 case ISCSI_PARAM_HDRDGST_EN:
713 iscsi_set_param(cls_conn, param, buf, buflen);
714 break;
715 case ISCSI_PARAM_DATADGST_EN:
716 iscsi_set_param(cls_conn, param, buf, buflen);
717 tcp_sw_conn->sendpage = conn->datadgst_en ?
718 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
719 break;
720 case ISCSI_PARAM_MAX_R2T:
721 return iscsi_tcp_set_max_r2t(conn, buf);
722 default:
723 return iscsi_set_param(cls_conn, param, buf, buflen);
724 }
725
726 return 0;
727}
728
729static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
730 enum iscsi_param param, char *buf)
731{
732 struct iscsi_conn *conn = cls_conn->dd_data;
733 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
734 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
735 struct sockaddr_in6 addr;
736 int rc;
737
738 switch(param) {
739 case ISCSI_PARAM_CONN_PORT:
740 case ISCSI_PARAM_CONN_ADDRESS:
741 case ISCSI_PARAM_LOCAL_PORT:
742 spin_lock_bh(&conn->session->frwd_lock);
743 if (!tcp_sw_conn || !tcp_sw_conn->sock) {
744 spin_unlock_bh(&conn->session->frwd_lock);
745 return -ENOTCONN;
746 }
747 if (param == ISCSI_PARAM_LOCAL_PORT)
748 rc = kernel_getsockname(tcp_sw_conn->sock,
749 (struct sockaddr *)&addr);
750 else
751 rc = kernel_getpeername(tcp_sw_conn->sock,
752 (struct sockaddr *)&addr);
753 spin_unlock_bh(&conn->session->frwd_lock);
754 if (rc < 0)
755 return rc;
756
757 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
758 &addr, param, buf);
759 default:
760 return iscsi_conn_get_param(cls_conn, param, buf);
761 }
762
763 return 0;
764}
765
766static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
767 enum iscsi_host_param param, char *buf)
768{
769 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
770 struct iscsi_session *session = tcp_sw_host->session;
771 struct iscsi_conn *conn;
772 struct iscsi_tcp_conn *tcp_conn;
773 struct iscsi_sw_tcp_conn *tcp_sw_conn;
774 struct sockaddr_in6 addr;
775 int rc;
776
777 switch (param) {
778 case ISCSI_HOST_PARAM_IPADDRESS:
779 if (!session)
780 return -ENOTCONN;
781
782 spin_lock_bh(&session->frwd_lock);
783 conn = session->leadconn;
784 if (!conn) {
785 spin_unlock_bh(&session->frwd_lock);
786 return -ENOTCONN;
787 }
788 tcp_conn = conn->dd_data;
789
790 tcp_sw_conn = tcp_conn->dd_data;
791 if (!tcp_sw_conn->sock) {
792 spin_unlock_bh(&session->frwd_lock);
793 return -ENOTCONN;
794 }
795
796 rc = kernel_getsockname(tcp_sw_conn->sock,
797 (struct sockaddr *)&addr);
798 spin_unlock_bh(&session->frwd_lock);
799 if (rc < 0)
800 return rc;
801
802 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
803 &addr, param, buf);
804 default:
805 return iscsi_host_get_param(shost, param, buf);
806 }
807
808 return 0;
809}
810
811static void
812iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
813 struct iscsi_stats *stats)
814{
815 struct iscsi_conn *conn = cls_conn->dd_data;
816 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
817 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
818
819 stats->custom_length = 3;
820 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
821 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
822 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
823 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
824 strcpy(stats->custom[2].desc, "eh_abort_cnt");
825 stats->custom[2].value = conn->eh_abort_cnt;
826
827 iscsi_tcp_conn_get_stats(cls_conn, stats);
828}
829
830static struct iscsi_cls_session *
831iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
832 uint16_t qdepth, uint32_t initial_cmdsn)
833{
834 struct iscsi_cls_session *cls_session;
835 struct iscsi_session *session;
836 struct iscsi_sw_tcp_host *tcp_sw_host;
837 struct Scsi_Host *shost;
838
839 if (ep) {
840 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
841 return NULL;
842 }
843
844 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
845 sizeof(struct iscsi_sw_tcp_host), 1);
846 if (!shost)
847 return NULL;
848 shost->transportt = iscsi_sw_tcp_scsi_transport;
849 shost->cmd_per_lun = qdepth;
850 shost->max_lun = iscsi_max_lun;
851 shost->max_id = 0;
852 shost->max_channel = 0;
853 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
854
855 if (iscsi_host_add(shost, NULL))
856 goto free_host;
857
858 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
859 cmds_max, 0,
860 sizeof(struct iscsi_tcp_task) +
861 sizeof(struct iscsi_sw_tcp_hdrbuf),
862 initial_cmdsn, 0);
863 if (!cls_session)
864 goto remove_host;
865 session = cls_session->dd_data;
866 tcp_sw_host = iscsi_host_priv(shost);
867 tcp_sw_host->session = session;
868
869 shost->can_queue = session->scsi_cmds_max;
870 if (iscsi_tcp_r2tpool_alloc(session))
871 goto remove_session;
872 return cls_session;
873
874remove_session:
875 iscsi_session_teardown(cls_session);
876remove_host:
877 iscsi_host_remove(shost);
878free_host:
879 iscsi_host_free(shost);
880 return NULL;
881}
882
883static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
884{
885 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
886
887 iscsi_tcp_r2tpool_free(cls_session->dd_data);
888 iscsi_session_teardown(cls_session);
889
890 iscsi_host_remove(shost);
891 iscsi_host_free(shost);
892}
893
894static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param)
895{
896 switch (param_type) {
897 case ISCSI_HOST_PARAM:
898 switch (param) {
899 case ISCSI_HOST_PARAM_NETDEV_NAME:
900 case ISCSI_HOST_PARAM_HWADDRESS:
901 case ISCSI_HOST_PARAM_IPADDRESS:
902 case ISCSI_HOST_PARAM_INITIATOR_NAME:
903 return S_IRUGO;
904 default:
905 return 0;
906 }
907 case ISCSI_PARAM:
908 switch (param) {
909 case ISCSI_PARAM_MAX_RECV_DLENGTH:
910 case ISCSI_PARAM_MAX_XMIT_DLENGTH:
911 case ISCSI_PARAM_HDRDGST_EN:
912 case ISCSI_PARAM_DATADGST_EN:
913 case ISCSI_PARAM_CONN_ADDRESS:
914 case ISCSI_PARAM_CONN_PORT:
915 case ISCSI_PARAM_LOCAL_PORT:
916 case ISCSI_PARAM_EXP_STATSN:
917 case ISCSI_PARAM_PERSISTENT_ADDRESS:
918 case ISCSI_PARAM_PERSISTENT_PORT:
919 case ISCSI_PARAM_PING_TMO:
920 case ISCSI_PARAM_RECV_TMO:
921 case ISCSI_PARAM_INITIAL_R2T_EN:
922 case ISCSI_PARAM_MAX_R2T:
923 case ISCSI_PARAM_IMM_DATA_EN:
924 case ISCSI_PARAM_FIRST_BURST:
925 case ISCSI_PARAM_MAX_BURST:
926 case ISCSI_PARAM_PDU_INORDER_EN:
927 case ISCSI_PARAM_DATASEQ_INORDER_EN:
928 case ISCSI_PARAM_ERL:
929 case ISCSI_PARAM_TARGET_NAME:
930 case ISCSI_PARAM_TPGT:
931 case ISCSI_PARAM_USERNAME:
932 case ISCSI_PARAM_PASSWORD:
933 case ISCSI_PARAM_USERNAME_IN:
934 case ISCSI_PARAM_PASSWORD_IN:
935 case ISCSI_PARAM_FAST_ABORT:
936 case ISCSI_PARAM_ABORT_TMO:
937 case ISCSI_PARAM_LU_RESET_TMO:
938 case ISCSI_PARAM_TGT_RESET_TMO:
939 case ISCSI_PARAM_IFACE_NAME:
940 case ISCSI_PARAM_INITIATOR_NAME:
941 return S_IRUGO;
942 default:
943 return 0;
944 }
945 }
946
947 return 0;
948}
949
950static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
951{
952 blk_queue_flag_set(QUEUE_FLAG_BIDI, sdev->request_queue);
953 return 0;
954}
955
956static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
957{
958 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(sdev->host);
959 struct iscsi_session *session = tcp_sw_host->session;
960 struct iscsi_conn *conn = session->leadconn;
961
962 if (conn->datadgst_en)
963 sdev->request_queue->backing_dev_info->capabilities
964 |= BDI_CAP_STABLE_WRITES;
965 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
966 blk_queue_dma_alignment(sdev->request_queue, 0);
967 return 0;
968}
969
970static struct scsi_host_template iscsi_sw_tcp_sht = {
971 .module = THIS_MODULE,
972 .name = "iSCSI Initiator over TCP/IP",
973 .queuecommand = iscsi_queuecommand,
974 .change_queue_depth = scsi_change_queue_depth,
975 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
976 .sg_tablesize = 4096,
977 .max_sectors = 0xFFFF,
978 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
979 .eh_timed_out = iscsi_eh_cmd_timed_out,
980 .eh_abort_handler = iscsi_eh_abort,
981 .eh_device_reset_handler= iscsi_eh_device_reset,
982 .eh_target_reset_handler = iscsi_eh_recover_target,
983 .use_clustering = DISABLE_CLUSTERING,
984 .slave_alloc = iscsi_sw_tcp_slave_alloc,
985 .slave_configure = iscsi_sw_tcp_slave_configure,
986 .target_alloc = iscsi_target_alloc,
987 .proc_name = "iscsi_tcp",
988 .this_id = -1,
989 .track_queue_depth = 1,
990};
991
992static struct iscsi_transport iscsi_sw_tcp_transport = {
993 .owner = THIS_MODULE,
994 .name = "tcp",
995 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
996 | CAP_DATADGST,
997 /* session management */
998 .create_session = iscsi_sw_tcp_session_create,
999 .destroy_session = iscsi_sw_tcp_session_destroy,
1000 /* connection management */
1001 .create_conn = iscsi_sw_tcp_conn_create,
1002 .bind_conn = iscsi_sw_tcp_conn_bind,
1003 .destroy_conn = iscsi_sw_tcp_conn_destroy,
1004 .attr_is_visible = iscsi_sw_tcp_attr_is_visible,
1005 .set_param = iscsi_sw_tcp_conn_set_param,
1006 .get_conn_param = iscsi_sw_tcp_conn_get_param,
1007 .get_session_param = iscsi_session_get_param,
1008 .start_conn = iscsi_conn_start,
1009 .stop_conn = iscsi_sw_tcp_conn_stop,
1010 /* iscsi host params */
1011 .get_host_param = iscsi_sw_tcp_host_get_param,
1012 .set_host_param = iscsi_host_set_param,
1013 /* IO */
1014 .send_pdu = iscsi_conn_send_pdu,
1015 .get_stats = iscsi_sw_tcp_conn_get_stats,
1016 /* iscsi task/cmd helpers */
1017 .init_task = iscsi_tcp_task_init,
1018 .xmit_task = iscsi_tcp_task_xmit,
1019 .cleanup_task = iscsi_tcp_cleanup_task,
1020 /* low level pdu helpers */
1021 .xmit_pdu = iscsi_sw_tcp_pdu_xmit,
1022 .init_pdu = iscsi_sw_tcp_pdu_init,
1023 .alloc_pdu = iscsi_sw_tcp_pdu_alloc,
1024 /* recovery */
1025 .session_recovery_timedout = iscsi_session_recovery_timedout,
1026};
1027
1028static int __init iscsi_sw_tcp_init(void)
1029{
1030 if (iscsi_max_lun < 1) {
1031 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
1032 iscsi_max_lun);
1033 return -EINVAL;
1034 }
1035
1036 iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
1037 &iscsi_sw_tcp_transport);
1038 if (!iscsi_sw_tcp_scsi_transport)
1039 return -ENODEV;
1040
1041 return 0;
1042}
1043
1044static void __exit iscsi_sw_tcp_exit(void)
1045{
1046 iscsi_unregister_transport(&iscsi_sw_tcp_transport);
1047}
1048
1049module_init(iscsi_sw_tcp_init);
1050module_exit(iscsi_sw_tcp_exit);