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backlight: atmel-pwm-bl: refactor gpio_on handling
[linux-2.6.git] / drivers / scsi / iscsi_tcp.c
blob9e2588a6881cb72751ece0f0d2092f2e6e214353
1 /*
2 * iSCSI Initiator over TCP/IP Data-Path
3 *
4 * Copyright (C) 2004 Dmitry Yusupov
5 * Copyright (C) 2004 Alex Aizman
6 * Copyright (C) 2005 - 2006 Mike Christie
7 * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
8 * maintained by open-iscsi@googlegroups.com
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published
12 * by the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * See the file COPYING included with this distribution for more details.
21 *
22 * Credits:
23 * Christoph Hellwig
24 * FUJITA Tomonori
25 * Arne Redlich
26 * Zhenyu Wang
27 */
28
29 #include <linux/types.h>
30 #include <linux/inet.h>
31 #include <linux/slab.h>
32 #include <linux/file.h>
33 #include <linux/blkdev.h>
34 #include <linux/crypto.h>
35 #include <linux/delay.h>
36 #include <linux/kfifo.h>
37 #include <linux/scatterlist.h>
38 #include <linux/module.h>
39 #include <net/tcp.h>
40 #include <scsi/scsi_cmnd.h>
41 #include <scsi/scsi_device.h>
42 #include <scsi/scsi_host.h>
43 #include <scsi/scsi.h>
44 #include <scsi/scsi_transport_iscsi.h>
45
46 #include "iscsi_tcp.h"
47
48 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
49 "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
50 "Alex Aizman <itn780@yahoo.com>");
51 MODULE_DESCRIPTION("iSCSI/TCP data-path");
52 MODULE_LICENSE("GPL");
53
54 static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
55 static struct scsi_host_template iscsi_sw_tcp_sht;
56 static struct iscsi_transport iscsi_sw_tcp_transport;
57
58 static unsigned int iscsi_max_lun = ~0;
59 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
60
61 static int iscsi_sw_tcp_dbg;
62 module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
63 S_IRUGO | S_IWUSR);
64 MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
65 "Set to 1 to turn on, and zero to turn off. Default is off.");
66
67 #define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \
68 do { \
69 if (iscsi_sw_tcp_dbg) \
70 iscsi_conn_printk(KERN_INFO, _conn, \
71 "%s " dbg_fmt, \
72 __func__, ##arg); \
73 } while (0);
74
75
76 /**
77 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
78 * @rd_desc: read descriptor
79 * @skb: socket buffer
80 * @offset: offset in skb
81 * @len: skb->len - offset
82 */
83 static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
84 unsigned int offset, size_t len)
85 {
86 struct iscsi_conn *conn = rd_desc->arg.data;
87 unsigned int consumed, total_consumed = 0;
88 int status;
89
90 ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
91
92 do {
93 status = 0;
94 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
95 offset += consumed;
96 total_consumed += consumed;
97 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
98
99 ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
100 skb->len - offset, status);
101 return total_consumed;
102 }
103
104 /**
105 * iscsi_sw_sk_state_check - check socket state
106 * @sk: socket
107 *
108 * If the socket is in CLOSE or CLOSE_WAIT we should
109 * not close the connection if there is still some
110 * data pending.
111 *
112 * Must be called with sk_callback_lock.
113 */
114 static inline int iscsi_sw_sk_state_check(struct sock *sk)
115 {
116 struct iscsi_conn *conn = sk->sk_user_data;
117
118 if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
119 !atomic_read(&sk->sk_rmem_alloc)) {
120 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
121 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
122 return -ECONNRESET;
123 }
124 return 0;
125 }
126
127 static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag)
128 {
129 struct iscsi_conn *conn;
130 struct iscsi_tcp_conn *tcp_conn;
131 read_descriptor_t rd_desc;
132
133 read_lock(&sk->sk_callback_lock);
134 conn = sk->sk_user_data;
135 if (!conn) {
136 read_unlock(&sk->sk_callback_lock);
137 return;
138 }
139 tcp_conn = conn->dd_data;
140
141 /*
142 * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
143 * We set count to 1 because we want the network layer to
144 * hand us all the skbs that are available. iscsi_tcp_recv
145 * handled pdus that cross buffers or pdus that still need data.
146 */
147 rd_desc.arg.data = conn;
148 rd_desc.count = 1;
149 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
150
151 iscsi_sw_sk_state_check(sk);
152
153 /* If we had to (atomically) map a highmem page,
154 * unmap it now. */
155 iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
156 read_unlock(&sk->sk_callback_lock);
157 }
158
159 static void iscsi_sw_tcp_state_change(struct sock *sk)
160 {
161 struct iscsi_tcp_conn *tcp_conn;
162 struct iscsi_sw_tcp_conn *tcp_sw_conn;
163 struct iscsi_conn *conn;
164 struct iscsi_session *session;
165 void (*old_state_change)(struct sock *);
166
167 read_lock(&sk->sk_callback_lock);
168 conn = sk->sk_user_data;
169 if (!conn) {
170 read_unlock(&sk->sk_callback_lock);
171 return;
172 }
173 session = conn->session;
174
175 iscsi_sw_sk_state_check(sk);
176
177 tcp_conn = conn->dd_data;
178 tcp_sw_conn = tcp_conn->dd_data;
179 old_state_change = tcp_sw_conn->old_state_change;
180
181 read_unlock(&sk->sk_callback_lock);
182
183 old_state_change(sk);
184 }
185
186 /**
187 * iscsi_write_space - Called when more output buffer space is available
188 * @sk: socket space is available for
189 **/
190 static void iscsi_sw_tcp_write_space(struct sock *sk)
191 {
192 struct iscsi_conn *conn;
193 struct iscsi_tcp_conn *tcp_conn;
194 struct iscsi_sw_tcp_conn *tcp_sw_conn;
195 void (*old_write_space)(struct sock *);
196
197 read_lock_bh(&sk->sk_callback_lock);
198 conn = sk->sk_user_data;
199 if (!conn) {
200 read_unlock_bh(&sk->sk_callback_lock);
201 return;
202 }
203
204 tcp_conn = conn->dd_data;
205 tcp_sw_conn = tcp_conn->dd_data;
206 old_write_space = tcp_sw_conn->old_write_space;
207 read_unlock_bh(&sk->sk_callback_lock);
208
209 old_write_space(sk);
210
211 ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
212 iscsi_conn_queue_work(conn);
213 }
214
215 static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
216 {
217 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
218 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
219 struct sock *sk = tcp_sw_conn->sock->sk;
220
221 /* assign new callbacks */
222 write_lock_bh(&sk->sk_callback_lock);
223 sk->sk_user_data = conn;
224 tcp_sw_conn->old_data_ready = sk->sk_data_ready;
225 tcp_sw_conn->old_state_change = sk->sk_state_change;
226 tcp_sw_conn->old_write_space = sk->sk_write_space;
227 sk->sk_data_ready = iscsi_sw_tcp_data_ready;
228 sk->sk_state_change = iscsi_sw_tcp_state_change;
229 sk->sk_write_space = iscsi_sw_tcp_write_space;
230 write_unlock_bh(&sk->sk_callback_lock);
231 }
232
233 static void
234 iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn)
235 {
236 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
237 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
238 struct sock *sk = tcp_sw_conn->sock->sk;
239
240 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
241 write_lock_bh(&sk->sk_callback_lock);
242 sk->sk_user_data = NULL;
243 sk->sk_data_ready = tcp_sw_conn->old_data_ready;
244 sk->sk_state_change = tcp_sw_conn->old_state_change;
245 sk->sk_write_space = tcp_sw_conn->old_write_space;
246 sk->sk_no_check = 0;
247 write_unlock_bh(&sk->sk_callback_lock);
248 }
249
250 /**
251 * iscsi_sw_tcp_xmit_segment - transmit segment
252 * @tcp_conn: the iSCSI TCP connection
253 * @segment: the buffer to transmnit
254 *
255 * This function transmits as much of the buffer as
256 * the network layer will accept, and returns the number of
257 * bytes transmitted.
258 *
259 * If CRC hashing is enabled, the function will compute the
260 * hash as it goes. When the entire segment has been transmitted,
261 * it will retrieve the hash value and send it as well.
262 */
263 static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
264 struct iscsi_segment *segment)
265 {
266 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
267 struct socket *sk = tcp_sw_conn->sock;
268 unsigned int copied = 0;
269 int r = 0;
270
271 while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
272 struct scatterlist *sg;
273 unsigned int offset, copy;
274 int flags = 0;
275
276 r = 0;
277 offset = segment->copied;
278 copy = segment->size - offset;
279
280 if (segment->total_copied + segment->size < segment->total_size)
281 flags |= MSG_MORE;
282
283 /* Use sendpage if we can; else fall back to sendmsg */
284 if (!segment->data) {
285 sg = segment->sg;
286 offset += segment->sg_offset + sg->offset;
287 r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
288 copy, flags);
289 } else {
290 struct msghdr msg = { .msg_flags = flags };
291 struct kvec iov = {
292 .iov_base = segment->data + offset,
293 .iov_len = copy
294 };
295
296 r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
297 }
298
299 if (r < 0) {
300 iscsi_tcp_segment_unmap(segment);
301 return r;
302 }
303 copied += r;
304 }
305 return copied;
306 }
307
308 /**
309 * iscsi_sw_tcp_xmit - TCP transmit
310 **/
311 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
312 {
313 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
314 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
315 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
316 unsigned int consumed = 0;
317 int rc = 0;
318
319 while (1) {
320 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
321 /*
322 * We may not have been able to send data because the conn
323 * is getting stopped. libiscsi will know so propagate err
324 * for it to do the right thing.
325 */
326 if (rc == -EAGAIN)
327 return rc;
328 else if (rc < 0) {
329 rc = ISCSI_ERR_XMIT_FAILED;
330 goto error;
331 } else if (rc == 0)
332 break;
333
334 consumed += rc;
335
336 if (segment->total_copied >= segment->total_size) {
337 if (segment->done != NULL) {
338 rc = segment->done(tcp_conn, segment);
339 if (rc != 0)
340 goto error;
341 }
342 }
343 }
344
345 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
346
347 conn->txdata_octets += consumed;
348 return consumed;
349
350 error:
351 /* Transmit error. We could initiate error recovery
352 * here. */
353 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
354 iscsi_conn_failure(conn, rc);
355 return -EIO;
356 }
357
358 /**
359 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
360 */
361 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
362 {
363 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
364 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
365 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
366
367 return segment->total_copied - segment->total_size;
368 }
369
370 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
371 {
372 struct iscsi_conn *conn = task->conn;
373 unsigned long pflags = current->flags;
374 int rc = 0;
375
376 current->flags |= PF_MEMALLOC;
377
378 while (iscsi_sw_tcp_xmit_qlen(conn)) {
379 rc = iscsi_sw_tcp_xmit(conn);
380 if (rc == 0) {
381 rc = -EAGAIN;
382 break;
383 }
384 if (rc < 0)
385 break;
386 rc = 0;
387 }
388
389 tsk_restore_flags(current, pflags, PF_MEMALLOC);
390 return rc;
391 }
392
393 /*
394 * This is called when we're done sending the header.
395 * Simply copy the data_segment to the send segment, and return.
396 */
397 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
398 struct iscsi_segment *segment)
399 {
400 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
401
402 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
403 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
404 "Header done. Next segment size %u total_size %u\n",
405 tcp_sw_conn->out.segment.size,
406 tcp_sw_conn->out.segment.total_size);
407 return 0;
408 }
409
410 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
411 size_t hdrlen)
412 {
413 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
414 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
415
416 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
417 "digest enabled" : "digest disabled");
418
419 /* Clear the data segment - needs to be filled in by the
420 * caller using iscsi_tcp_send_data_prep() */
421 memset(&tcp_sw_conn->out.data_segment, 0,
422 sizeof(struct iscsi_segment));
423
424 /* If header digest is enabled, compute the CRC and
425 * place the digest into the same buffer. We make
426 * sure that both iscsi_tcp_task and mtask have
427 * sufficient room.
428 */
429 if (conn->hdrdgst_en) {
430 iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen,
431 hdr + hdrlen);
432 hdrlen += ISCSI_DIGEST_SIZE;
433 }
434
435 /* Remember header pointer for later, when we need
436 * to decide whether there's a payload to go along
437 * with the header. */
438 tcp_sw_conn->out.hdr = hdr;
439
440 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
441 iscsi_sw_tcp_send_hdr_done, NULL);
442 }
443
444 /*
445 * Prepare the send buffer for the payload data.
446 * Padding and checksumming will all be taken care
447 * of by the iscsi_segment routines.
448 */
449 static int
450 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
451 unsigned int count, unsigned int offset,
452 unsigned int len)
453 {
454 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
455 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
456 struct hash_desc *tx_hash = NULL;
457 unsigned int hdr_spec_len;
458
459 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
460 conn->datadgst_en ?
461 "digest enabled" : "digest disabled");
462
463 /* Make sure the datalen matches what the caller
464 said he would send. */
465 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
466 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
467
468 if (conn->datadgst_en)
469 tx_hash = &tcp_sw_conn->tx_hash;
470
471 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
472 sg, count, offset, len,
473 NULL, tx_hash);
474 }
475
476 static void
477 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
478 size_t len)
479 {
480 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
481 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
482 struct hash_desc *tx_hash = NULL;
483 unsigned int hdr_spec_len;
484
485 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
486 "digest enabled" : "digest disabled");
487
488 /* Make sure the datalen matches what the caller
489 said he would send. */
490 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
491 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
492
493 if (conn->datadgst_en)
494 tx_hash = &tcp_sw_conn->tx_hash;
495
496 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
497 data, len, NULL, tx_hash);
498 }
499
500 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
501 unsigned int offset, unsigned int count)
502 {
503 struct iscsi_conn *conn = task->conn;
504 int err = 0;
505
506 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
507
508 if (!count)
509 return 0;
510
511 if (!task->sc)
512 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
513 else {
514 struct scsi_data_buffer *sdb = scsi_out(task->sc);
515
516 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
517 sdb->table.nents, offset,
518 count);
519 }
520
521 if (err) {
522 /* got invalid offset/len */
523 return -EIO;
524 }
525 return 0;
526 }
527
528 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
529 {
530 struct iscsi_tcp_task *tcp_task = task->dd_data;
531
532 task->hdr = task->dd_data + sizeof(*tcp_task);
533 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
534 return 0;
535 }
536
537 static struct iscsi_cls_conn *
538 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
539 uint32_t conn_idx)
540 {
541 struct iscsi_conn *conn;
542 struct iscsi_cls_conn *cls_conn;
543 struct iscsi_tcp_conn *tcp_conn;
544 struct iscsi_sw_tcp_conn *tcp_sw_conn;
545
546 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
547 conn_idx);
548 if (!cls_conn)
549 return NULL;
550 conn = cls_conn->dd_data;
551 tcp_conn = conn->dd_data;
552 tcp_sw_conn = tcp_conn->dd_data;
553
554 tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
555 CRYPTO_ALG_ASYNC);
556 tcp_sw_conn->tx_hash.flags = 0;
557 if (IS_ERR(tcp_sw_conn->tx_hash.tfm))
558 goto free_conn;
559
560 tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
561 CRYPTO_ALG_ASYNC);
562 tcp_sw_conn->rx_hash.flags = 0;
563 if (IS_ERR(tcp_sw_conn->rx_hash.tfm))
564 goto free_tx_tfm;
565 tcp_conn->rx_hash = &tcp_sw_conn->rx_hash;
566
567 return cls_conn;
568
569 free_tx_tfm:
570 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
571 free_conn:
572 iscsi_conn_printk(KERN_ERR, conn,
573 "Could not create connection due to crc32c "
574 "loading error. Make sure the crc32c "
575 "module is built as a module or into the "
576 "kernel\n");
577 iscsi_tcp_conn_teardown(cls_conn);
578 return NULL;
579 }
580
581 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
582 {
583 struct iscsi_session *session = conn->session;
584 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
585 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
586 struct socket *sock = tcp_sw_conn->sock;
587
588 if (!sock)
589 return;
590
591 sock_hold(sock->sk);
592 iscsi_sw_tcp_conn_restore_callbacks(conn);
593 sock_put(sock->sk);
594
595 spin_lock_bh(&session->lock);
596 tcp_sw_conn->sock = NULL;
597 spin_unlock_bh(&session->lock);
598 sockfd_put(sock);
599 }
600
601 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
602 {
603 struct iscsi_conn *conn = cls_conn->dd_data;
604 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
605 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
606
607 iscsi_sw_tcp_release_conn(conn);
608
609 if (tcp_sw_conn->tx_hash.tfm)
610 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
611 if (tcp_sw_conn->rx_hash.tfm)
612 crypto_free_hash(tcp_sw_conn->rx_hash.tfm);
613
614 iscsi_tcp_conn_teardown(cls_conn);
615 }
616
617 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
618 {
619 struct iscsi_conn *conn = cls_conn->dd_data;
620 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
621 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
622 struct socket *sock = tcp_sw_conn->sock;
623
624 /* userspace may have goofed up and not bound us */
625 if (!sock)
626 return;
627
628 sock->sk->sk_err = EIO;
629 wake_up_interruptible(sk_sleep(sock->sk));
630
631 /* stop xmit side */
632 iscsi_suspend_tx(conn);
633
634 /* stop recv side and release socket */
635 iscsi_sw_tcp_release_conn(conn);
636
637 iscsi_conn_stop(cls_conn, flag);
638 }
639
640 static int
641 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
642 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
643 int is_leading)
644 {
645 struct iscsi_session *session = cls_session->dd_data;
646 struct iscsi_conn *conn = cls_conn->dd_data;
647 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
648 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
649 struct sock *sk;
650 struct socket *sock;
651 int err;
652
653 /* lookup for existing socket */
654 sock = sockfd_lookup((int)transport_eph, &err);
655 if (!sock) {
656 iscsi_conn_printk(KERN_ERR, conn,
657 "sockfd_lookup failed %d\n", err);
658 return -EEXIST;
659 }
660
661 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
662 if (err)
663 goto free_socket;
664
665 spin_lock_bh(&session->lock);
666 /* bind iSCSI connection and socket */
667 tcp_sw_conn->sock = sock;
668 spin_unlock_bh(&session->lock);
669
670 /* setup Socket parameters */
671 sk = sock->sk;
672 sk->sk_reuse = SK_CAN_REUSE;
673 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
674 sk->sk_allocation = GFP_ATOMIC;
675 sk_set_memalloc(sk);
676
677 iscsi_sw_tcp_conn_set_callbacks(conn);
678 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
679 /*
680 * set receive state machine into initial state
681 */
682 iscsi_tcp_hdr_recv_prep(tcp_conn);
683 return 0;
684
685 free_socket:
686 sockfd_put(sock);
687 return err;
688 }
689
690 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
691 enum iscsi_param param, char *buf,
692 int buflen)
693 {
694 struct iscsi_conn *conn = cls_conn->dd_data;
695 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
696 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
697
698 switch(param) {
699 case ISCSI_PARAM_HDRDGST_EN:
700 iscsi_set_param(cls_conn, param, buf, buflen);
701 break;
702 case ISCSI_PARAM_DATADGST_EN:
703 iscsi_set_param(cls_conn, param, buf, buflen);
704 tcp_sw_conn->sendpage = conn->datadgst_en ?
705 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
706 break;
707 case ISCSI_PARAM_MAX_R2T:
708 return iscsi_tcp_set_max_r2t(conn, buf);
709 default:
710 return iscsi_set_param(cls_conn, param, buf, buflen);
711 }
712
713 return 0;
714 }
715
716 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
717 enum iscsi_param param, char *buf)
718 {
719 struct iscsi_conn *conn = cls_conn->dd_data;
720 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
721 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
722 struct sockaddr_in6 addr;
723 int rc, len;
724
725 switch(param) {
726 case ISCSI_PARAM_CONN_PORT:
727 case ISCSI_PARAM_CONN_ADDRESS:
728 spin_lock_bh(&conn->session->lock);
729 if (!tcp_sw_conn || !tcp_sw_conn->sock) {
730 spin_unlock_bh(&conn->session->lock);
731 return -ENOTCONN;
732 }
733 rc = kernel_getpeername(tcp_sw_conn->sock,
734 (struct sockaddr *)&addr, &len);
735 spin_unlock_bh(&conn->session->lock);
736 if (rc)
737 return rc;
738
739 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
740 &addr, param, buf);
741 default:
742 return iscsi_conn_get_param(cls_conn, param, buf);
743 }
744
745 return 0;
746 }
747
748 static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
749 enum iscsi_host_param param, char *buf)
750 {
751 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
752 struct iscsi_session *session = tcp_sw_host->session;
753 struct iscsi_conn *conn;
754 struct iscsi_tcp_conn *tcp_conn;
755 struct iscsi_sw_tcp_conn *tcp_sw_conn;
756 struct sockaddr_in6 addr;
757 int rc, len;
758
759 switch (param) {
760 case ISCSI_HOST_PARAM_IPADDRESS:
761 spin_lock_bh(&session->lock);
762 conn = session->leadconn;
763 if (!conn) {
764 spin_unlock_bh(&session->lock);
765 return -ENOTCONN;
766 }
767 tcp_conn = conn->dd_data;
768
769 tcp_sw_conn = tcp_conn->dd_data;
770 if (!tcp_sw_conn->sock) {
771 spin_unlock_bh(&session->lock);
772 return -ENOTCONN;
773 }
774
775 rc = kernel_getsockname(tcp_sw_conn->sock,
776 (struct sockaddr *)&addr, &len);
777 spin_unlock_bh(&session->lock);
778 if (rc)
779 return rc;
780
781 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
782 &addr, param, buf);
783 default:
784 return iscsi_host_get_param(shost, param, buf);
785 }
786
787 return 0;
788 }
789
790 static void
791 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
792 struct iscsi_stats *stats)
793 {
794 struct iscsi_conn *conn = cls_conn->dd_data;
795 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
796 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
797
798 stats->custom_length = 3;
799 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
800 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
801 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
802 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
803 strcpy(stats->custom[2].desc, "eh_abort_cnt");
804 stats->custom[2].value = conn->eh_abort_cnt;
805
806 iscsi_tcp_conn_get_stats(cls_conn, stats);
807 }
808
809 static struct iscsi_cls_session *
810 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
811 uint16_t qdepth, uint32_t initial_cmdsn)
812 {
813 struct iscsi_cls_session *cls_session;
814 struct iscsi_session *session;
815 struct iscsi_sw_tcp_host *tcp_sw_host;
816 struct Scsi_Host *shost;
817
818 if (ep) {
819 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
820 return NULL;
821 }
822
823 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
824 sizeof(struct iscsi_sw_tcp_host), 1);
825 if (!shost)
826 return NULL;
827 shost->transportt = iscsi_sw_tcp_scsi_transport;
828 shost->cmd_per_lun = qdepth;
829 shost->max_lun = iscsi_max_lun;
830 shost->max_id = 0;
831 shost->max_channel = 0;
832 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
833
834 if (iscsi_host_add(shost, NULL))
835 goto free_host;
836
837 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
838 cmds_max, 0,
839 sizeof(struct iscsi_tcp_task) +
840 sizeof(struct iscsi_sw_tcp_hdrbuf),
841 initial_cmdsn, 0);
842 if (!cls_session)
843 goto remove_host;
844 session = cls_session->dd_data;
845 tcp_sw_host = iscsi_host_priv(shost);
846 tcp_sw_host->session = session;
847
848 shost->can_queue = session->scsi_cmds_max;
849 if (iscsi_tcp_r2tpool_alloc(session))
850 goto remove_session;
851 return cls_session;
852
853 remove_session:
854 iscsi_session_teardown(cls_session);
855 remove_host:
856 iscsi_host_remove(shost);
857 free_host:
858 iscsi_host_free(shost);
859 return NULL;
860 }
861
862 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
863 {
864 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
865
866 iscsi_tcp_r2tpool_free(cls_session->dd_data);
867 iscsi_session_teardown(cls_session);
868
869 iscsi_host_remove(shost);
870 iscsi_host_free(shost);
871 }
872
873 static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param)
874 {
875 switch (param_type) {
876 case ISCSI_HOST_PARAM:
877 switch (param) {
878 case ISCSI_HOST_PARAM_NETDEV_NAME:
879 case ISCSI_HOST_PARAM_HWADDRESS:
880 case ISCSI_HOST_PARAM_IPADDRESS:
881 case ISCSI_HOST_PARAM_INITIATOR_NAME:
882 return S_IRUGO;
883 default:
884 return 0;
885 }
886 case ISCSI_PARAM:
887 switch (param) {
888 case ISCSI_PARAM_MAX_RECV_DLENGTH:
889 case ISCSI_PARAM_MAX_XMIT_DLENGTH:
890 case ISCSI_PARAM_HDRDGST_EN:
891 case ISCSI_PARAM_DATADGST_EN:
892 case ISCSI_PARAM_CONN_ADDRESS:
893 case ISCSI_PARAM_CONN_PORT:
894 case ISCSI_PARAM_EXP_STATSN:
895 case ISCSI_PARAM_PERSISTENT_ADDRESS:
896 case ISCSI_PARAM_PERSISTENT_PORT:
897 case ISCSI_PARAM_PING_TMO:
898 case ISCSI_PARAM_RECV_TMO:
899 case ISCSI_PARAM_INITIAL_R2T_EN:
900 case ISCSI_PARAM_MAX_R2T:
901 case ISCSI_PARAM_IMM_DATA_EN:
902 case ISCSI_PARAM_FIRST_BURST:
903 case ISCSI_PARAM_MAX_BURST:
904 case ISCSI_PARAM_PDU_INORDER_EN:
905 case ISCSI_PARAM_DATASEQ_INORDER_EN:
906 case ISCSI_PARAM_ERL:
907 case ISCSI_PARAM_TARGET_NAME:
908 case ISCSI_PARAM_TPGT:
909 case ISCSI_PARAM_USERNAME:
910 case ISCSI_PARAM_PASSWORD:
911 case ISCSI_PARAM_USERNAME_IN:
912 case ISCSI_PARAM_PASSWORD_IN:
913 case ISCSI_PARAM_FAST_ABORT:
914 case ISCSI_PARAM_ABORT_TMO:
915 case ISCSI_PARAM_LU_RESET_TMO:
916 case ISCSI_PARAM_TGT_RESET_TMO:
917 case ISCSI_PARAM_IFACE_NAME:
918 case ISCSI_PARAM_INITIATOR_NAME:
919 return S_IRUGO;
920 default:
921 return 0;
922 }
923 }
924
925 return 0;
926 }
927
928 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
929 {
930 set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
931 return 0;
932 }
933
934 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
935 {
936 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
937 blk_queue_dma_alignment(sdev->request_queue, 0);
938 return 0;
939 }
940
941 static struct scsi_host_template iscsi_sw_tcp_sht = {
942 .module = THIS_MODULE,
943 .name = "iSCSI Initiator over TCP/IP",
944 .queuecommand = iscsi_queuecommand,
945 .change_queue_depth = iscsi_change_queue_depth,
946 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
947 .sg_tablesize = 4096,
948 .max_sectors = 0xFFFF,
949 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
950 .eh_abort_handler = iscsi_eh_abort,
951 .eh_device_reset_handler= iscsi_eh_device_reset,
952 .eh_target_reset_handler = iscsi_eh_recover_target,
953 .use_clustering = DISABLE_CLUSTERING,
954 .slave_alloc = iscsi_sw_tcp_slave_alloc,
955 .slave_configure = iscsi_sw_tcp_slave_configure,
956 .target_alloc = iscsi_target_alloc,
957 .proc_name = "iscsi_tcp",
958 .this_id = -1,
959 };
960
961 static struct iscsi_transport iscsi_sw_tcp_transport = {
962 .owner = THIS_MODULE,
963 .name = "tcp",
964 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
965 | CAP_DATADGST,
966 /* session management */
967 .create_session = iscsi_sw_tcp_session_create,
968 .destroy_session = iscsi_sw_tcp_session_destroy,
969 /* connection management */
970 .create_conn = iscsi_sw_tcp_conn_create,
971 .bind_conn = iscsi_sw_tcp_conn_bind,
972 .destroy_conn = iscsi_sw_tcp_conn_destroy,
973 .attr_is_visible = iscsi_sw_tcp_attr_is_visible,
974 .set_param = iscsi_sw_tcp_conn_set_param,
975 .get_conn_param = iscsi_sw_tcp_conn_get_param,
976 .get_session_param = iscsi_session_get_param,
977 .start_conn = iscsi_conn_start,
978 .stop_conn = iscsi_sw_tcp_conn_stop,
979 /* iscsi host params */
980 .get_host_param = iscsi_sw_tcp_host_get_param,
981 .set_host_param = iscsi_host_set_param,
982 /* IO */
983 .send_pdu = iscsi_conn_send_pdu,
984 .get_stats = iscsi_sw_tcp_conn_get_stats,
985 /* iscsi task/cmd helpers */
986 .init_task = iscsi_tcp_task_init,
987 .xmit_task = iscsi_tcp_task_xmit,
988 .cleanup_task = iscsi_tcp_cleanup_task,
989 /* low level pdu helpers */
990 .xmit_pdu = iscsi_sw_tcp_pdu_xmit,
991 .init_pdu = iscsi_sw_tcp_pdu_init,
992 .alloc_pdu = iscsi_sw_tcp_pdu_alloc,
993 /* recovery */
994 .session_recovery_timedout = iscsi_session_recovery_timedout,
995 };
996
997 static int __init iscsi_sw_tcp_init(void)
998 {
999 if (iscsi_max_lun < 1) {
1000 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
1001 iscsi_max_lun);
1002 return -EINVAL;
1003 }
1004
1005 iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
1006 &iscsi_sw_tcp_transport);
1007 if (!iscsi_sw_tcp_scsi_transport)
1008 return -ENODEV;
1009
1010 return 0;
1011 }
1012
1013 static void __exit iscsi_sw_tcp_exit(void)
1014 {
1015 iscsi_unregister_transport(&iscsi_sw_tcp_transport);
1016 }
1017
1018 module_init(iscsi_sw_tcp_init);
1019 module_exit(iscsi_sw_tcp_exit);
Linus' kernel tree