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Linux 3.3-rc1
[zen-stable.git] / drivers / scsi / iscsi_tcp.c
blobdb47158e0dde9d5aee28235930ebbb8e26ea76d4
1 /*
2 * iSCSI Initiator over TCP/IP Data-Path
3 *
4 * Copyright (C) 2004 Dmitry Yusupov
5 * Copyright (C) 2004 Alex Aizman
6 * Copyright (C) 2005 - 2006 Mike Christie
7 * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
8 * maintained by open-iscsi@googlegroups.com
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published
12 * by the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * See the file COPYING included with this distribution for more details.
21 *
22 * Credits:
23 * Christoph Hellwig
24 * FUJITA Tomonori
25 * Arne Redlich
26 * Zhenyu Wang
27 */
28
29 #include <linux/types.h>
30 #include <linux/inet.h>
31 #include <linux/slab.h>
32 #include <linux/file.h>
33 #include <linux/blkdev.h>
34 #include <linux/crypto.h>
35 #include <linux/delay.h>
36 #include <linux/kfifo.h>
37 #include <linux/scatterlist.h>
38 #include <linux/module.h>
39 #include <net/tcp.h>
40 #include <scsi/scsi_cmnd.h>
41 #include <scsi/scsi_device.h>
42 #include <scsi/scsi_host.h>
43 #include <scsi/scsi.h>
44 #include <scsi/scsi_transport_iscsi.h>
45
46 #include "iscsi_tcp.h"
47
48 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
49 "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
50 "Alex Aizman <itn780@yahoo.com>");
51 MODULE_DESCRIPTION("iSCSI/TCP data-path");
52 MODULE_LICENSE("GPL");
53
54 static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
55 static struct scsi_host_template iscsi_sw_tcp_sht;
56 static struct iscsi_transport iscsi_sw_tcp_transport;
57
58 static unsigned int iscsi_max_lun = 512;
59 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
60
61 static int iscsi_sw_tcp_dbg;
62 module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
63 S_IRUGO | S_IWUSR);
64 MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
65 "Set to 1 to turn on, and zero to turn off. Default is off.");
66
67 #define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \
68 do { \
69 if (iscsi_sw_tcp_dbg) \
70 iscsi_conn_printk(KERN_INFO, _conn, \
71 "%s " dbg_fmt, \
72 __func__, ##arg); \
73 } while (0);
74
75
76 /**
77 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
78 * @rd_desc: read descriptor
79 * @skb: socket buffer
80 * @offset: offset in skb
81 * @len: skb->len - offset
82 */
83 static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
84 unsigned int offset, size_t len)
85 {
86 struct iscsi_conn *conn = rd_desc->arg.data;
87 unsigned int consumed, total_consumed = 0;
88 int status;
89
90 ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
91
92 do {
93 status = 0;
94 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
95 offset += consumed;
96 total_consumed += consumed;
97 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
98
99 ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
100 skb->len - offset, status);
101 return total_consumed;
102 }
103
104 /**
105 * iscsi_sw_sk_state_check - check socket state
106 * @sk: socket
107 *
108 * If the socket is in CLOSE or CLOSE_WAIT we should
109 * not close the connection if there is still some
110 * data pending.
111 *
112 * Must be called with sk_callback_lock.
113 */
114 static inline int iscsi_sw_sk_state_check(struct sock *sk)
115 {
116 struct iscsi_conn *conn = sk->sk_user_data;
117
118 if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
119 !atomic_read(&sk->sk_rmem_alloc)) {
120 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
121 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
122 return -ECONNRESET;
123 }
124 return 0;
125 }
126
127 static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag)
128 {
129 struct iscsi_conn *conn;
130 struct iscsi_tcp_conn *tcp_conn;
131 read_descriptor_t rd_desc;
132
133 read_lock(&sk->sk_callback_lock);
134 conn = sk->sk_user_data;
135 if (!conn) {
136 read_unlock(&sk->sk_callback_lock);
137 return;
138 }
139 tcp_conn = conn->dd_data;
140
141 /*
142 * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
143 * We set count to 1 because we want the network layer to
144 * hand us all the skbs that are available. iscsi_tcp_recv
145 * handled pdus that cross buffers or pdus that still need data.
146 */
147 rd_desc.arg.data = conn;
148 rd_desc.count = 1;
149 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
150
151 iscsi_sw_sk_state_check(sk);
152
153 /* If we had to (atomically) map a highmem page,
154 * unmap it now. */
155 iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
156 read_unlock(&sk->sk_callback_lock);
157 }
158
159 static void iscsi_sw_tcp_state_change(struct sock *sk)
160 {
161 struct iscsi_tcp_conn *tcp_conn;
162 struct iscsi_sw_tcp_conn *tcp_sw_conn;
163 struct iscsi_conn *conn;
164 struct iscsi_session *session;
165 void (*old_state_change)(struct sock *);
166
167 read_lock(&sk->sk_callback_lock);
168 conn = sk->sk_user_data;
169 if (!conn) {
170 read_unlock(&sk->sk_callback_lock);
171 return;
172 }
173 session = conn->session;
174
175 iscsi_sw_sk_state_check(sk);
176
177 tcp_conn = conn->dd_data;
178 tcp_sw_conn = tcp_conn->dd_data;
179 old_state_change = tcp_sw_conn->old_state_change;
180
181 read_unlock(&sk->sk_callback_lock);
182
183 old_state_change(sk);
184 }
185
186 /**
187 * iscsi_write_space - Called when more output buffer space is available
188 * @sk: socket space is available for
189 **/
190 static void iscsi_sw_tcp_write_space(struct sock *sk)
191 {
192 struct iscsi_conn *conn;
193 struct iscsi_tcp_conn *tcp_conn;
194 struct iscsi_sw_tcp_conn *tcp_sw_conn;
195 void (*old_write_space)(struct sock *);
196
197 read_lock_bh(&sk->sk_callback_lock);
198 conn = sk->sk_user_data;
199 if (!conn) {
200 read_unlock_bh(&sk->sk_callback_lock);
201 return;
202 }
203
204 tcp_conn = conn->dd_data;
205 tcp_sw_conn = tcp_conn->dd_data;
206 old_write_space = tcp_sw_conn->old_write_space;
207 read_unlock_bh(&sk->sk_callback_lock);
208
209 old_write_space(sk);
210
211 ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
212 iscsi_conn_queue_work(conn);
213 }
214
215 static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
216 {
217 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
218 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
219 struct sock *sk = tcp_sw_conn->sock->sk;
220
221 /* assign new callbacks */
222 write_lock_bh(&sk->sk_callback_lock);
223 sk->sk_user_data = conn;
224 tcp_sw_conn->old_data_ready = sk->sk_data_ready;
225 tcp_sw_conn->old_state_change = sk->sk_state_change;
226 tcp_sw_conn->old_write_space = sk->sk_write_space;
227 sk->sk_data_ready = iscsi_sw_tcp_data_ready;
228 sk->sk_state_change = iscsi_sw_tcp_state_change;
229 sk->sk_write_space = iscsi_sw_tcp_write_space;
230 write_unlock_bh(&sk->sk_callback_lock);
231 }
232
233 static void
234 iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn)
235 {
236 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
237 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
238 struct sock *sk = tcp_sw_conn->sock->sk;
239
240 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
241 write_lock_bh(&sk->sk_callback_lock);
242 sk->sk_user_data = NULL;
243 sk->sk_data_ready = tcp_sw_conn->old_data_ready;
244 sk->sk_state_change = tcp_sw_conn->old_state_change;
245 sk->sk_write_space = tcp_sw_conn->old_write_space;
246 sk->sk_no_check = 0;
247 write_unlock_bh(&sk->sk_callback_lock);
248 }
249
250 /**
251 * iscsi_sw_tcp_xmit_segment - transmit segment
252 * @tcp_conn: the iSCSI TCP connection
253 * @segment: the buffer to transmnit
254 *
255 * This function transmits as much of the buffer as
256 * the network layer will accept, and returns the number of
257 * bytes transmitted.
258 *
259 * If CRC hashing is enabled, the function will compute the
260 * hash as it goes. When the entire segment has been transmitted,
261 * it will retrieve the hash value and send it as well.
262 */
263 static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
264 struct iscsi_segment *segment)
265 {
266 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
267 struct socket *sk = tcp_sw_conn->sock;
268 unsigned int copied = 0;
269 int r = 0;
270
271 while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
272 struct scatterlist *sg;
273 unsigned int offset, copy;
274 int flags = 0;
275
276 r = 0;
277 offset = segment->copied;
278 copy = segment->size - offset;
279
280 if (segment->total_copied + segment->size < segment->total_size)
281 flags |= MSG_MORE;
282
283 /* Use sendpage if we can; else fall back to sendmsg */
284 if (!segment->data) {
285 sg = segment->sg;
286 offset += segment->sg_offset + sg->offset;
287 r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
288 copy, flags);
289 } else {
290 struct msghdr msg = { .msg_flags = flags };
291 struct kvec iov = {
292 .iov_base = segment->data + offset,
293 .iov_len = copy
294 };
295
296 r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
297 }
298
299 if (r < 0) {
300 iscsi_tcp_segment_unmap(segment);
301 return r;
302 }
303 copied += r;
304 }
305 return copied;
306 }
307
308 /**
309 * iscsi_sw_tcp_xmit - TCP transmit
310 **/
311 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
312 {
313 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
314 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
315 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
316 unsigned int consumed = 0;
317 int rc = 0;
318
319 while (1) {
320 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
321 /*
322 * We may not have been able to send data because the conn
323 * is getting stopped. libiscsi will know so propagate err
324 * for it to do the right thing.
325 */
326 if (rc == -EAGAIN)
327 return rc;
328 else if (rc < 0) {
329 rc = ISCSI_ERR_XMIT_FAILED;
330 goto error;
331 } else if (rc == 0)
332 break;
333
334 consumed += rc;
335
336 if (segment->total_copied >= segment->total_size) {
337 if (segment->done != NULL) {
338 rc = segment->done(tcp_conn, segment);
339 if (rc != 0)
340 goto error;
341 }
342 }
343 }
344
345 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
346
347 conn->txdata_octets += consumed;
348 return consumed;
349
350 error:
351 /* Transmit error. We could initiate error recovery
352 * here. */
353 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
354 iscsi_conn_failure(conn, rc);
355 return -EIO;
356 }
357
358 /**
359 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
360 */
361 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
362 {
363 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
364 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
365 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
366
367 return segment->total_copied - segment->total_size;
368 }
369
370 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
371 {
372 struct iscsi_conn *conn = task->conn;
373 int rc;
374
375 while (iscsi_sw_tcp_xmit_qlen(conn)) {
376 rc = iscsi_sw_tcp_xmit(conn);
377 if (rc == 0)
378 return -EAGAIN;
379 if (rc < 0)
380 return rc;
381 }
382
383 return 0;
384 }
385
386 /*
387 * This is called when we're done sending the header.
388 * Simply copy the data_segment to the send segment, and return.
389 */
390 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
391 struct iscsi_segment *segment)
392 {
393 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
394
395 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
396 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
397 "Header done. Next segment size %u total_size %u\n",
398 tcp_sw_conn->out.segment.size,
399 tcp_sw_conn->out.segment.total_size);
400 return 0;
401 }
402
403 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
404 size_t hdrlen)
405 {
406 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
407 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
408
409 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
410 "digest enabled" : "digest disabled");
411
412 /* Clear the data segment - needs to be filled in by the
413 * caller using iscsi_tcp_send_data_prep() */
414 memset(&tcp_sw_conn->out.data_segment, 0,
415 sizeof(struct iscsi_segment));
416
417 /* If header digest is enabled, compute the CRC and
418 * place the digest into the same buffer. We make
419 * sure that both iscsi_tcp_task and mtask have
420 * sufficient room.
421 */
422 if (conn->hdrdgst_en) {
423 iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen,
424 hdr + hdrlen);
425 hdrlen += ISCSI_DIGEST_SIZE;
426 }
427
428 /* Remember header pointer for later, when we need
429 * to decide whether there's a payload to go along
430 * with the header. */
431 tcp_sw_conn->out.hdr = hdr;
432
433 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
434 iscsi_sw_tcp_send_hdr_done, NULL);
435 }
436
437 /*
438 * Prepare the send buffer for the payload data.
439 * Padding and checksumming will all be taken care
440 * of by the iscsi_segment routines.
441 */
442 static int
443 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
444 unsigned int count, unsigned int offset,
445 unsigned int len)
446 {
447 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
448 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
449 struct hash_desc *tx_hash = NULL;
450 unsigned int hdr_spec_len;
451
452 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
453 conn->datadgst_en ?
454 "digest enabled" : "digest disabled");
455
456 /* Make sure the datalen matches what the caller
457 said he would send. */
458 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
459 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
460
461 if (conn->datadgst_en)
462 tx_hash = &tcp_sw_conn->tx_hash;
463
464 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
465 sg, count, offset, len,
466 NULL, tx_hash);
467 }
468
469 static void
470 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
471 size_t len)
472 {
473 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
474 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
475 struct hash_desc *tx_hash = NULL;
476 unsigned int hdr_spec_len;
477
478 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
479 "digest enabled" : "digest disabled");
480
481 /* Make sure the datalen matches what the caller
482 said he would send. */
483 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
484 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
485
486 if (conn->datadgst_en)
487 tx_hash = &tcp_sw_conn->tx_hash;
488
489 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
490 data, len, NULL, tx_hash);
491 }
492
493 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
494 unsigned int offset, unsigned int count)
495 {
496 struct iscsi_conn *conn = task->conn;
497 int err = 0;
498
499 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
500
501 if (!count)
502 return 0;
503
504 if (!task->sc)
505 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
506 else {
507 struct scsi_data_buffer *sdb = scsi_out(task->sc);
508
509 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
510 sdb->table.nents, offset,
511 count);
512 }
513
514 if (err) {
515 /* got invalid offset/len */
516 return -EIO;
517 }
518 return 0;
519 }
520
521 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
522 {
523 struct iscsi_tcp_task *tcp_task = task->dd_data;
524
525 task->hdr = task->dd_data + sizeof(*tcp_task);
526 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
527 return 0;
528 }
529
530 static struct iscsi_cls_conn *
531 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
532 uint32_t conn_idx)
533 {
534 struct iscsi_conn *conn;
535 struct iscsi_cls_conn *cls_conn;
536 struct iscsi_tcp_conn *tcp_conn;
537 struct iscsi_sw_tcp_conn *tcp_sw_conn;
538
539 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
540 conn_idx);
541 if (!cls_conn)
542 return NULL;
543 conn = cls_conn->dd_data;
544 tcp_conn = conn->dd_data;
545 tcp_sw_conn = tcp_conn->dd_data;
546
547 tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
548 CRYPTO_ALG_ASYNC);
549 tcp_sw_conn->tx_hash.flags = 0;
550 if (IS_ERR(tcp_sw_conn->tx_hash.tfm))
551 goto free_conn;
552
553 tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
554 CRYPTO_ALG_ASYNC);
555 tcp_sw_conn->rx_hash.flags = 0;
556 if (IS_ERR(tcp_sw_conn->rx_hash.tfm))
557 goto free_tx_tfm;
558 tcp_conn->rx_hash = &tcp_sw_conn->rx_hash;
559
560 return cls_conn;
561
562 free_tx_tfm:
563 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
564 free_conn:
565 iscsi_conn_printk(KERN_ERR, conn,
566 "Could not create connection due to crc32c "
567 "loading error. Make sure the crc32c "
568 "module is built as a module or into the "
569 "kernel\n");
570 iscsi_tcp_conn_teardown(cls_conn);
571 return NULL;
572 }
573
574 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
575 {
576 struct iscsi_session *session = conn->session;
577 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
578 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
579 struct socket *sock = tcp_sw_conn->sock;
580
581 if (!sock)
582 return;
583
584 sock_hold(sock->sk);
585 iscsi_sw_tcp_conn_restore_callbacks(conn);
586 sock_put(sock->sk);
587
588 spin_lock_bh(&session->lock);
589 tcp_sw_conn->sock = NULL;
590 spin_unlock_bh(&session->lock);
591 sockfd_put(sock);
592 }
593
594 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
595 {
596 struct iscsi_conn *conn = cls_conn->dd_data;
597 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
598 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
599
600 iscsi_sw_tcp_release_conn(conn);
601
602 if (tcp_sw_conn->tx_hash.tfm)
603 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
604 if (tcp_sw_conn->rx_hash.tfm)
605 crypto_free_hash(tcp_sw_conn->rx_hash.tfm);
606
607 iscsi_tcp_conn_teardown(cls_conn);
608 }
609
610 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
611 {
612 struct iscsi_conn *conn = cls_conn->dd_data;
613 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
614 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
615 struct socket *sock = tcp_sw_conn->sock;
616
617 /* userspace may have goofed up and not bound us */
618 if (!sock)
619 return;
620
621 sock->sk->sk_err = EIO;
622 wake_up_interruptible(sk_sleep(sock->sk));
623
624 /* stop xmit side */
625 iscsi_suspend_tx(conn);
626
627 /* stop recv side and release socket */
628 iscsi_sw_tcp_release_conn(conn);
629
630 iscsi_conn_stop(cls_conn, flag);
631 }
632
633 static int
634 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
635 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
636 int is_leading)
637 {
638 struct iscsi_session *session = cls_session->dd_data;
639 struct iscsi_conn *conn = cls_conn->dd_data;
640 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
641 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
642 struct sock *sk;
643 struct socket *sock;
644 int err;
645
646 /* lookup for existing socket */
647 sock = sockfd_lookup((int)transport_eph, &err);
648 if (!sock) {
649 iscsi_conn_printk(KERN_ERR, conn,
650 "sockfd_lookup failed %d\n", err);
651 return -EEXIST;
652 }
653
654 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
655 if (err)
656 goto free_socket;
657
658 spin_lock_bh(&session->lock);
659 /* bind iSCSI connection and socket */
660 tcp_sw_conn->sock = sock;
661 spin_unlock_bh(&session->lock);
662
663 /* setup Socket parameters */
664 sk = sock->sk;
665 sk->sk_reuse = 1;
666 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
667 sk->sk_allocation = GFP_ATOMIC;
668
669 iscsi_sw_tcp_conn_set_callbacks(conn);
670 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
671 /*
672 * set receive state machine into initial state
673 */
674 iscsi_tcp_hdr_recv_prep(tcp_conn);
675 return 0;
676
677 free_socket:
678 sockfd_put(sock);
679 return err;
680 }
681
682 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
683 enum iscsi_param param, char *buf,
684 int buflen)
685 {
686 struct iscsi_conn *conn = cls_conn->dd_data;
687 struct iscsi_session *session = conn->session;
688 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
689 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
690 int value;
691
692 switch(param) {
693 case ISCSI_PARAM_HDRDGST_EN:
694 iscsi_set_param(cls_conn, param, buf, buflen);
695 break;
696 case ISCSI_PARAM_DATADGST_EN:
697 iscsi_set_param(cls_conn, param, buf, buflen);
698 tcp_sw_conn->sendpage = conn->datadgst_en ?
699 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
700 break;
701 case ISCSI_PARAM_MAX_R2T:
702 sscanf(buf, "%d", &value);
703 if (value <= 0 || !is_power_of_2(value))
704 return -EINVAL;
705 if (session->max_r2t == value)
706 break;
707 iscsi_tcp_r2tpool_free(session);
708 iscsi_set_param(cls_conn, param, buf, buflen);
709 if (iscsi_tcp_r2tpool_alloc(session))
710 return -ENOMEM;
711 break;
712 default:
713 return iscsi_set_param(cls_conn, param, buf, buflen);
714 }
715
716 return 0;
717 }
718
719 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
720 enum iscsi_param param, char *buf)
721 {
722 struct iscsi_conn *conn = cls_conn->dd_data;
723 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
724 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
725 struct sockaddr_in6 addr;
726 int rc, len;
727
728 switch(param) {
729 case ISCSI_PARAM_CONN_PORT:
730 case ISCSI_PARAM_CONN_ADDRESS:
731 spin_lock_bh(&conn->session->lock);
732 if (!tcp_sw_conn || !tcp_sw_conn->sock) {
733 spin_unlock_bh(&conn->session->lock);
734 return -ENOTCONN;
735 }
736 rc = kernel_getpeername(tcp_sw_conn->sock,
737 (struct sockaddr *)&addr, &len);
738 spin_unlock_bh(&conn->session->lock);
739 if (rc)
740 return rc;
741
742 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
743 &addr, param, buf);
744 default:
745 return iscsi_conn_get_param(cls_conn, param, buf);
746 }
747
748 return 0;
749 }
750
751 static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
752 enum iscsi_host_param param, char *buf)
753 {
754 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
755 struct iscsi_session *session = tcp_sw_host->session;
756 struct iscsi_conn *conn;
757 struct iscsi_tcp_conn *tcp_conn;
758 struct iscsi_sw_tcp_conn *tcp_sw_conn;
759 struct sockaddr_in6 addr;
760 int rc, len;
761
762 switch (param) {
763 case ISCSI_HOST_PARAM_IPADDRESS:
764 spin_lock_bh(&session->lock);
765 conn = session->leadconn;
766 if (!conn) {
767 spin_unlock_bh(&session->lock);
768 return -ENOTCONN;
769 }
770 tcp_conn = conn->dd_data;
771
772 tcp_sw_conn = tcp_conn->dd_data;
773 if (!tcp_sw_conn->sock) {
774 spin_unlock_bh(&session->lock);
775 return -ENOTCONN;
776 }
777
778 rc = kernel_getsockname(tcp_sw_conn->sock,
779 (struct sockaddr *)&addr, &len);
780 spin_unlock_bh(&session->lock);
781 if (rc)
782 return rc;
783
784 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
785 &addr, param, buf);
786 default:
787 return iscsi_host_get_param(shost, param, buf);
788 }
789
790 return 0;
791 }
792
793 static void
794 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
795 struct iscsi_stats *stats)
796 {
797 struct iscsi_conn *conn = cls_conn->dd_data;
798 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
799 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
800
801 stats->custom_length = 3;
802 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
803 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
804 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
805 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
806 strcpy(stats->custom[2].desc, "eh_abort_cnt");
807 stats->custom[2].value = conn->eh_abort_cnt;
808
809 iscsi_tcp_conn_get_stats(cls_conn, stats);
810 }
811
812 static struct iscsi_cls_session *
813 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
814 uint16_t qdepth, uint32_t initial_cmdsn)
815 {
816 struct iscsi_cls_session *cls_session;
817 struct iscsi_session *session;
818 struct iscsi_sw_tcp_host *tcp_sw_host;
819 struct Scsi_Host *shost;
820
821 if (ep) {
822 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
823 return NULL;
824 }
825
826 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
827 sizeof(struct iscsi_sw_tcp_host), 1);
828 if (!shost)
829 return NULL;
830 shost->transportt = iscsi_sw_tcp_scsi_transport;
831 shost->cmd_per_lun = qdepth;
832 shost->max_lun = iscsi_max_lun;
833 shost->max_id = 0;
834 shost->max_channel = 0;
835 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
836
837 if (iscsi_host_add(shost, NULL))
838 goto free_host;
839
840 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
841 cmds_max, 0,
842 sizeof(struct iscsi_tcp_task) +
843 sizeof(struct iscsi_sw_tcp_hdrbuf),
844 initial_cmdsn, 0);
845 if (!cls_session)
846 goto remove_host;
847 session = cls_session->dd_data;
848 tcp_sw_host = iscsi_host_priv(shost);
849 tcp_sw_host->session = session;
850
851 shost->can_queue = session->scsi_cmds_max;
852 if (iscsi_tcp_r2tpool_alloc(session))
853 goto remove_session;
854 return cls_session;
855
856 remove_session:
857 iscsi_session_teardown(cls_session);
858 remove_host:
859 iscsi_host_remove(shost);
860 free_host:
861 iscsi_host_free(shost);
862 return NULL;
863 }
864
865 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
866 {
867 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
868
869 iscsi_tcp_r2tpool_free(cls_session->dd_data);
870 iscsi_session_teardown(cls_session);
871
872 iscsi_host_remove(shost);
873 iscsi_host_free(shost);
874 }
875
876 static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param)
877 {
878 switch (param_type) {
879 case ISCSI_HOST_PARAM:
880 switch (param) {
881 case ISCSI_HOST_PARAM_NETDEV_NAME:
882 case ISCSI_HOST_PARAM_HWADDRESS:
883 case ISCSI_HOST_PARAM_IPADDRESS:
884 case ISCSI_HOST_PARAM_INITIATOR_NAME:
885 return S_IRUGO;
886 default:
887 return 0;
888 }
889 case ISCSI_PARAM:
890 switch (param) {
891 case ISCSI_PARAM_MAX_RECV_DLENGTH:
892 case ISCSI_PARAM_MAX_XMIT_DLENGTH:
893 case ISCSI_PARAM_HDRDGST_EN:
894 case ISCSI_PARAM_DATADGST_EN:
895 case ISCSI_PARAM_CONN_ADDRESS:
896 case ISCSI_PARAM_CONN_PORT:
897 case ISCSI_PARAM_EXP_STATSN:
898 case ISCSI_PARAM_PERSISTENT_ADDRESS:
899 case ISCSI_PARAM_PERSISTENT_PORT:
900 case ISCSI_PARAM_PING_TMO:
901 case ISCSI_PARAM_RECV_TMO:
902 case ISCSI_PARAM_INITIAL_R2T_EN:
903 case ISCSI_PARAM_MAX_R2T:
904 case ISCSI_PARAM_IMM_DATA_EN:
905 case ISCSI_PARAM_FIRST_BURST:
906 case ISCSI_PARAM_MAX_BURST:
907 case ISCSI_PARAM_PDU_INORDER_EN:
908 case ISCSI_PARAM_DATASEQ_INORDER_EN:
909 case ISCSI_PARAM_ERL:
910 case ISCSI_PARAM_TARGET_NAME:
911 case ISCSI_PARAM_TPGT:
912 case ISCSI_PARAM_USERNAME:
913 case ISCSI_PARAM_PASSWORD:
914 case ISCSI_PARAM_USERNAME_IN:
915 case ISCSI_PARAM_PASSWORD_IN:
916 case ISCSI_PARAM_FAST_ABORT:
917 case ISCSI_PARAM_ABORT_TMO:
918 case ISCSI_PARAM_LU_RESET_TMO:
919 case ISCSI_PARAM_TGT_RESET_TMO:
920 case ISCSI_PARAM_IFACE_NAME:
921 case ISCSI_PARAM_INITIATOR_NAME:
922 return S_IRUGO;
923 default:
924 return 0;
925 }
926 }
927
928 return 0;
929 }
930
931 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
932 {
933 set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
934 return 0;
935 }
936
937 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
938 {
939 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
940 blk_queue_dma_alignment(sdev->request_queue, 0);
941 return 0;
942 }
943
944 static struct scsi_host_template iscsi_sw_tcp_sht = {
945 .module = THIS_MODULE,
946 .name = "iSCSI Initiator over TCP/IP",
947 .queuecommand = iscsi_queuecommand,
948 .change_queue_depth = iscsi_change_queue_depth,
949 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
950 .sg_tablesize = 4096,
951 .max_sectors = 0xFFFF,
952 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
953 .eh_abort_handler = iscsi_eh_abort,
954 .eh_device_reset_handler= iscsi_eh_device_reset,
955 .eh_target_reset_handler = iscsi_eh_recover_target,
956 .use_clustering = DISABLE_CLUSTERING,
957 .slave_alloc = iscsi_sw_tcp_slave_alloc,
958 .slave_configure = iscsi_sw_tcp_slave_configure,
959 .target_alloc = iscsi_target_alloc,
960 .proc_name = "iscsi_tcp",
961 .this_id = -1,
962 };
963
964 static struct iscsi_transport iscsi_sw_tcp_transport = {
965 .owner = THIS_MODULE,
966 .name = "tcp",
967 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
968 | CAP_DATADGST,
969 /* session management */
970 .create_session = iscsi_sw_tcp_session_create,
971 .destroy_session = iscsi_sw_tcp_session_destroy,
972 /* connection management */
973 .create_conn = iscsi_sw_tcp_conn_create,
974 .bind_conn = iscsi_sw_tcp_conn_bind,
975 .destroy_conn = iscsi_sw_tcp_conn_destroy,
976 .attr_is_visible = iscsi_sw_tcp_attr_is_visible,
977 .set_param = iscsi_sw_tcp_conn_set_param,
978 .get_conn_param = iscsi_sw_tcp_conn_get_param,
979 .get_session_param = iscsi_session_get_param,
980 .start_conn = iscsi_conn_start,
981 .stop_conn = iscsi_sw_tcp_conn_stop,
982 /* iscsi host params */
983 .get_host_param = iscsi_sw_tcp_host_get_param,
984 .set_host_param = iscsi_host_set_param,
985 /* IO */
986 .send_pdu = iscsi_conn_send_pdu,
987 .get_stats = iscsi_sw_tcp_conn_get_stats,
988 /* iscsi task/cmd helpers */
989 .init_task = iscsi_tcp_task_init,
990 .xmit_task = iscsi_tcp_task_xmit,
991 .cleanup_task = iscsi_tcp_cleanup_task,
992 /* low level pdu helpers */
993 .xmit_pdu = iscsi_sw_tcp_pdu_xmit,
994 .init_pdu = iscsi_sw_tcp_pdu_init,
995 .alloc_pdu = iscsi_sw_tcp_pdu_alloc,
996 /* recovery */
997 .session_recovery_timedout = iscsi_session_recovery_timedout,
998 };
999
1000 static int __init iscsi_sw_tcp_init(void)
1001 {
1002 if (iscsi_max_lun < 1) {
1003 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
1004 iscsi_max_lun);
1005 return -EINVAL;
1006 }
1007
1008 iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
1009 &iscsi_sw_tcp_transport);
1010 if (!iscsi_sw_tcp_scsi_transport)
1011 return -ENODEV;
1012
1013 return 0;
1014 }
1015
1016 static void __exit iscsi_sw_tcp_exit(void)
1017 {
1018 iscsi_unregister_transport(&iscsi_sw_tcp_transport);
1019 }
1020
1021 module_init(iscsi_sw_tcp_init);
1022 module_exit(iscsi_sw_tcp_exit);