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tracing: Consolidate protection of reader access to the ring buffer
[linux-2.6.git] / drivers / scsi / iscsi_tcp.c
blob517da3fd89d30a24bb2c04c0c4a5d3ce86bbe26a
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/file.h>
32 #include <linux/blkdev.h>
33 #include <linux/crypto.h>
34 #include <linux/delay.h>
35 #include <linux/kfifo.h>
36 #include <linux/scatterlist.h>
37 #include <net/tcp.h>
38 #include <scsi/scsi_cmnd.h>
39 #include <scsi/scsi_device.h>
40 #include <scsi/scsi_host.h>
41 #include <scsi/scsi.h>
42 #include <scsi/scsi_transport_iscsi.h>
43
44 #include "iscsi_tcp.h"
45
46 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
47 "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
48 "Alex Aizman <itn780@yahoo.com>");
49 MODULE_DESCRIPTION("iSCSI/TCP data-path");
50 MODULE_LICENSE("GPL");
51
52 static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
53 static struct scsi_host_template iscsi_sw_tcp_sht;
54 static struct iscsi_transport iscsi_sw_tcp_transport;
55
56 static unsigned int iscsi_max_lun = 512;
57 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
58
59 static int iscsi_sw_tcp_dbg;
60 module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
61 S_IRUGO | S_IWUSR);
62 MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
63 "Set to 1 to turn on, and zero to turn off. Default is off.");
64
65 #define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \
66 do { \
67 if (iscsi_sw_tcp_dbg) \
68 iscsi_conn_printk(KERN_INFO, _conn, \
69 "%s " dbg_fmt, \
70 __func__, ##arg); \
71 } while (0);
72
73
74 /**
75 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
76 * @rd_desc: read descriptor
77 * @skb: socket buffer
78 * @offset: offset in skb
79 * @len: skb->len - offset
80 */
81 static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
82 unsigned int offset, size_t len)
83 {
84 struct iscsi_conn *conn = rd_desc->arg.data;
85 unsigned int consumed, total_consumed = 0;
86 int status;
87
88 ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
89
90 do {
91 status = 0;
92 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
93 offset += consumed;
94 total_consumed += consumed;
95 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
96
97 ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
98 skb->len - offset, status);
99 return total_consumed;
100 }
101
102 /**
103 * iscsi_sw_sk_state_check - check socket state
104 * @sk: socket
105 *
106 * If the socket is in CLOSE or CLOSE_WAIT we should
107 * not close the connection if there is still some
108 * data pending.
109 */
110 static inline int iscsi_sw_sk_state_check(struct sock *sk)
111 {
112 struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
113
114 if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
115 !atomic_read(&sk->sk_rmem_alloc)) {
116 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
117 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
118 return -ECONNRESET;
119 }
120 return 0;
121 }
122
123 static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag)
124 {
125 struct iscsi_conn *conn = sk->sk_user_data;
126 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
127 read_descriptor_t rd_desc;
128
129 read_lock(&sk->sk_callback_lock);
130
131 /*
132 * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
133 * We set count to 1 because we want the network layer to
134 * hand us all the skbs that are available. iscsi_tcp_recv
135 * handled pdus that cross buffers or pdus that still need data.
136 */
137 rd_desc.arg.data = conn;
138 rd_desc.count = 1;
139 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
140
141 iscsi_sw_sk_state_check(sk);
142
143 read_unlock(&sk->sk_callback_lock);
144
145 /* If we had to (atomically) map a highmem page,
146 * unmap it now. */
147 iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
148 }
149
150 static void iscsi_sw_tcp_state_change(struct sock *sk)
151 {
152 struct iscsi_tcp_conn *tcp_conn;
153 struct iscsi_sw_tcp_conn *tcp_sw_conn;
154 struct iscsi_conn *conn;
155 struct iscsi_session *session;
156 void (*old_state_change)(struct sock *);
157
158 read_lock(&sk->sk_callback_lock);
159
160 conn = (struct iscsi_conn*)sk->sk_user_data;
161 session = conn->session;
162
163 iscsi_sw_sk_state_check(sk);
164
165 tcp_conn = conn->dd_data;
166 tcp_sw_conn = tcp_conn->dd_data;
167 old_state_change = tcp_sw_conn->old_state_change;
168
169 read_unlock(&sk->sk_callback_lock);
170
171 old_state_change(sk);
172 }
173
174 /**
175 * iscsi_write_space - Called when more output buffer space is available
176 * @sk: socket space is available for
177 **/
178 static void iscsi_sw_tcp_write_space(struct sock *sk)
179 {
180 struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
181 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
182 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
183
184 tcp_sw_conn->old_write_space(sk);
185 ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
186 iscsi_conn_queue_work(conn);
187 }
188
189 static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
190 {
191 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
192 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
193 struct sock *sk = tcp_sw_conn->sock->sk;
194
195 /* assign new callbacks */
196 write_lock_bh(&sk->sk_callback_lock);
197 sk->sk_user_data = conn;
198 tcp_sw_conn->old_data_ready = sk->sk_data_ready;
199 tcp_sw_conn->old_state_change = sk->sk_state_change;
200 tcp_sw_conn->old_write_space = sk->sk_write_space;
201 sk->sk_data_ready = iscsi_sw_tcp_data_ready;
202 sk->sk_state_change = iscsi_sw_tcp_state_change;
203 sk->sk_write_space = iscsi_sw_tcp_write_space;
204 write_unlock_bh(&sk->sk_callback_lock);
205 }
206
207 static void
208 iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_sw_tcp_conn *tcp_sw_conn)
209 {
210 struct sock *sk = tcp_sw_conn->sock->sk;
211
212 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
213 write_lock_bh(&sk->sk_callback_lock);
214 sk->sk_user_data = NULL;
215 sk->sk_data_ready = tcp_sw_conn->old_data_ready;
216 sk->sk_state_change = tcp_sw_conn->old_state_change;
217 sk->sk_write_space = tcp_sw_conn->old_write_space;
218 sk->sk_no_check = 0;
219 write_unlock_bh(&sk->sk_callback_lock);
220 }
221
222 /**
223 * iscsi_sw_tcp_xmit_segment - transmit segment
224 * @tcp_conn: the iSCSI TCP connection
225 * @segment: the buffer to transmnit
226 *
227 * This function transmits as much of the buffer as
228 * the network layer will accept, and returns the number of
229 * bytes transmitted.
230 *
231 * If CRC hashing is enabled, the function will compute the
232 * hash as it goes. When the entire segment has been transmitted,
233 * it will retrieve the hash value and send it as well.
234 */
235 static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
236 struct iscsi_segment *segment)
237 {
238 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
239 struct socket *sk = tcp_sw_conn->sock;
240 unsigned int copied = 0;
241 int r = 0;
242
243 while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
244 struct scatterlist *sg;
245 unsigned int offset, copy;
246 int flags = 0;
247
248 r = 0;
249 offset = segment->copied;
250 copy = segment->size - offset;
251
252 if (segment->total_copied + segment->size < segment->total_size)
253 flags |= MSG_MORE;
254
255 /* Use sendpage if we can; else fall back to sendmsg */
256 if (!segment->data) {
257 sg = segment->sg;
258 offset += segment->sg_offset + sg->offset;
259 r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
260 copy, flags);
261 } else {
262 struct msghdr msg = { .msg_flags = flags };
263 struct kvec iov = {
264 .iov_base = segment->data + offset,
265 .iov_len = copy
266 };
267
268 r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
269 }
270
271 if (r < 0) {
272 iscsi_tcp_segment_unmap(segment);
273 return r;
274 }
275 copied += r;
276 }
277 return copied;
278 }
279
280 /**
281 * iscsi_sw_tcp_xmit - TCP transmit
282 **/
283 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
284 {
285 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
286 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
287 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
288 unsigned int consumed = 0;
289 int rc = 0;
290
291 while (1) {
292 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
293 /*
294 * We may not have been able to send data because the conn
295 * is getting stopped. libiscsi will know so propogate err
296 * for it to do the right thing.
297 */
298 if (rc == -EAGAIN)
299 return rc;
300 else if (rc < 0) {
301 rc = ISCSI_ERR_XMIT_FAILED;
302 goto error;
303 } else if (rc == 0)
304 break;
305
306 consumed += rc;
307
308 if (segment->total_copied >= segment->total_size) {
309 if (segment->done != NULL) {
310 rc = segment->done(tcp_conn, segment);
311 if (rc != 0)
312 goto error;
313 }
314 }
315 }
316
317 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
318
319 conn->txdata_octets += consumed;
320 return consumed;
321
322 error:
323 /* Transmit error. We could initiate error recovery
324 * here. */
325 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
326 iscsi_conn_failure(conn, rc);
327 return -EIO;
328 }
329
330 /**
331 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
332 */
333 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
334 {
335 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
336 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
337 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
338
339 return segment->total_copied - segment->total_size;
340 }
341
342 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
343 {
344 struct iscsi_conn *conn = task->conn;
345 int rc;
346
347 while (iscsi_sw_tcp_xmit_qlen(conn)) {
348 rc = iscsi_sw_tcp_xmit(conn);
349 if (rc == 0)
350 return -EAGAIN;
351 if (rc < 0)
352 return rc;
353 }
354
355 return 0;
356 }
357
358 /*
359 * This is called when we're done sending the header.
360 * Simply copy the data_segment to the send segment, and return.
361 */
362 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
363 struct iscsi_segment *segment)
364 {
365 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
366
367 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
368 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
369 "Header done. Next segment size %u total_size %u\n",
370 tcp_sw_conn->out.segment.size,
371 tcp_sw_conn->out.segment.total_size);
372 return 0;
373 }
374
375 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
376 size_t hdrlen)
377 {
378 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
379 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
380
381 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
382 "digest enabled" : "digest disabled");
383
384 /* Clear the data segment - needs to be filled in by the
385 * caller using iscsi_tcp_send_data_prep() */
386 memset(&tcp_sw_conn->out.data_segment, 0,
387 sizeof(struct iscsi_segment));
388
389 /* If header digest is enabled, compute the CRC and
390 * place the digest into the same buffer. We make
391 * sure that both iscsi_tcp_task and mtask have
392 * sufficient room.
393 */
394 if (conn->hdrdgst_en) {
395 iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen,
396 hdr + hdrlen);
397 hdrlen += ISCSI_DIGEST_SIZE;
398 }
399
400 /* Remember header pointer for later, when we need
401 * to decide whether there's a payload to go along
402 * with the header. */
403 tcp_sw_conn->out.hdr = hdr;
404
405 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
406 iscsi_sw_tcp_send_hdr_done, NULL);
407 }
408
409 /*
410 * Prepare the send buffer for the payload data.
411 * Padding and checksumming will all be taken care
412 * of by the iscsi_segment routines.
413 */
414 static int
415 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
416 unsigned int count, unsigned int offset,
417 unsigned int len)
418 {
419 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
420 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
421 struct hash_desc *tx_hash = NULL;
422 unsigned int hdr_spec_len;
423
424 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
425 conn->datadgst_en ?
426 "digest enabled" : "digest disabled");
427
428 /* Make sure the datalen matches what the caller
429 said he would send. */
430 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
431 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
432
433 if (conn->datadgst_en)
434 tx_hash = &tcp_sw_conn->tx_hash;
435
436 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
437 sg, count, offset, len,
438 NULL, tx_hash);
439 }
440
441 static void
442 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
443 size_t len)
444 {
445 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
446 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
447 struct hash_desc *tx_hash = NULL;
448 unsigned int hdr_spec_len;
449
450 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
451 "digest enabled" : "digest disabled");
452
453 /* Make sure the datalen matches what the caller
454 said he would send. */
455 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
456 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
457
458 if (conn->datadgst_en)
459 tx_hash = &tcp_sw_conn->tx_hash;
460
461 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
462 data, len, NULL, tx_hash);
463 }
464
465 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
466 unsigned int offset, unsigned int count)
467 {
468 struct iscsi_conn *conn = task->conn;
469 int err = 0;
470
471 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
472
473 if (!count)
474 return 0;
475
476 if (!task->sc)
477 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
478 else {
479 struct scsi_data_buffer *sdb = scsi_out(task->sc);
480
481 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
482 sdb->table.nents, offset,
483 count);
484 }
485
486 if (err) {
487 /* got invalid offset/len */
488 return -EIO;
489 }
490 return 0;
491 }
492
493 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
494 {
495 struct iscsi_tcp_task *tcp_task = task->dd_data;
496
497 task->hdr = task->dd_data + sizeof(*tcp_task);
498 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
499 return 0;
500 }
501
502 static struct iscsi_cls_conn *
503 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
504 uint32_t conn_idx)
505 {
506 struct iscsi_conn *conn;
507 struct iscsi_cls_conn *cls_conn;
508 struct iscsi_tcp_conn *tcp_conn;
509 struct iscsi_sw_tcp_conn *tcp_sw_conn;
510
511 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
512 conn_idx);
513 if (!cls_conn)
514 return NULL;
515 conn = cls_conn->dd_data;
516 tcp_conn = conn->dd_data;
517 tcp_sw_conn = tcp_conn->dd_data;
518
519 tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
520 CRYPTO_ALG_ASYNC);
521 tcp_sw_conn->tx_hash.flags = 0;
522 if (IS_ERR(tcp_sw_conn->tx_hash.tfm))
523 goto free_conn;
524
525 tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
526 CRYPTO_ALG_ASYNC);
527 tcp_sw_conn->rx_hash.flags = 0;
528 if (IS_ERR(tcp_sw_conn->rx_hash.tfm))
529 goto free_tx_tfm;
530 tcp_conn->rx_hash = &tcp_sw_conn->rx_hash;
531
532 return cls_conn;
533
534 free_tx_tfm:
535 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
536 free_conn:
537 iscsi_conn_printk(KERN_ERR, conn,
538 "Could not create connection due to crc32c "
539 "loading error. Make sure the crc32c "
540 "module is built as a module or into the "
541 "kernel\n");
542 iscsi_tcp_conn_teardown(cls_conn);
543 return NULL;
544 }
545
546 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
547 {
548 struct iscsi_session *session = conn->session;
549 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
550 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
551 struct socket *sock = tcp_sw_conn->sock;
552
553 if (!sock)
554 return;
555
556 sock_hold(sock->sk);
557 iscsi_sw_tcp_conn_restore_callbacks(tcp_sw_conn);
558 sock_put(sock->sk);
559
560 spin_lock_bh(&session->lock);
561 tcp_sw_conn->sock = NULL;
562 spin_unlock_bh(&session->lock);
563 sockfd_put(sock);
564 }
565
566 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
567 {
568 struct iscsi_conn *conn = cls_conn->dd_data;
569 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
570 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
571
572 iscsi_sw_tcp_release_conn(conn);
573
574 if (tcp_sw_conn->tx_hash.tfm)
575 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
576 if (tcp_sw_conn->rx_hash.tfm)
577 crypto_free_hash(tcp_sw_conn->rx_hash.tfm);
578
579 iscsi_tcp_conn_teardown(cls_conn);
580 }
581
582 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
583 {
584 struct iscsi_conn *conn = cls_conn->dd_data;
585 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
586 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
587
588 /* userspace may have goofed up and not bound us */
589 if (!tcp_sw_conn->sock)
590 return;
591 /*
592 * Make sure our recv side is stopped.
593 * Older tools called conn stop before ep_disconnect
594 * so IO could still be coming in.
595 */
596 write_lock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
597 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
598 write_unlock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
599
600 iscsi_conn_stop(cls_conn, flag);
601 iscsi_sw_tcp_release_conn(conn);
602 }
603
604 static int iscsi_sw_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
605 char *buf, int *port,
606 int (*getname)(struct socket *,
607 struct sockaddr *,
608 int *addrlen))
609 {
610 struct sockaddr_storage *addr;
611 struct sockaddr_in6 *sin6;
612 struct sockaddr_in *sin;
613 int rc = 0, len;
614
615 addr = kmalloc(sizeof(*addr), GFP_KERNEL);
616 if (!addr)
617 return -ENOMEM;
618
619 if (getname(sock, (struct sockaddr *) addr, &len)) {
620 rc = -ENODEV;
621 goto free_addr;
622 }
623
624 switch (addr->ss_family) {
625 case AF_INET:
626 sin = (struct sockaddr_in *)addr;
627 spin_lock_bh(&conn->session->lock);
628 sprintf(buf, "%pI4", &sin->sin_addr.s_addr);
629 *port = be16_to_cpu(sin->sin_port);
630 spin_unlock_bh(&conn->session->lock);
631 break;
632 case AF_INET6:
633 sin6 = (struct sockaddr_in6 *)addr;
634 spin_lock_bh(&conn->session->lock);
635 sprintf(buf, "%pI6", &sin6->sin6_addr);
636 *port = be16_to_cpu(sin6->sin6_port);
637 spin_unlock_bh(&conn->session->lock);
638 break;
639 }
640 free_addr:
641 kfree(addr);
642 return rc;
643 }
644
645 static int
646 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
647 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
648 int is_leading)
649 {
650 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
651 struct iscsi_host *ihost = shost_priv(shost);
652 struct iscsi_conn *conn = cls_conn->dd_data;
653 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
654 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
655 struct sock *sk;
656 struct socket *sock;
657 int err;
658
659 /* lookup for existing socket */
660 sock = sockfd_lookup((int)transport_eph, &err);
661 if (!sock) {
662 iscsi_conn_printk(KERN_ERR, conn,
663 "sockfd_lookup failed %d\n", err);
664 return -EEXIST;
665 }
666 /*
667 * copy these values now because if we drop the session
668 * userspace may still want to query the values since we will
669 * be using them for the reconnect
670 */
671 err = iscsi_sw_tcp_get_addr(conn, sock, conn->portal_address,
672 &conn->portal_port, kernel_getpeername);
673 if (err)
674 goto free_socket;
675
676 err = iscsi_sw_tcp_get_addr(conn, sock, ihost->local_address,
677 &ihost->local_port, kernel_getsockname);
678 if (err)
679 goto free_socket;
680
681 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
682 if (err)
683 goto free_socket;
684
685 /* bind iSCSI connection and socket */
686 tcp_sw_conn->sock = sock;
687
688 /* setup Socket parameters */
689 sk = sock->sk;
690 sk->sk_reuse = 1;
691 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
692 sk->sk_allocation = GFP_ATOMIC;
693
694 iscsi_sw_tcp_conn_set_callbacks(conn);
695 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
696 /*
697 * set receive state machine into initial state
698 */
699 iscsi_tcp_hdr_recv_prep(tcp_conn);
700 return 0;
701
702 free_socket:
703 sockfd_put(sock);
704 return err;
705 }
706
707 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
708 enum iscsi_param param, char *buf,
709 int buflen)
710 {
711 struct iscsi_conn *conn = cls_conn->dd_data;
712 struct iscsi_session *session = conn->session;
713 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
714 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
715 int value;
716
717 switch(param) {
718 case ISCSI_PARAM_HDRDGST_EN:
719 iscsi_set_param(cls_conn, param, buf, buflen);
720 break;
721 case ISCSI_PARAM_DATADGST_EN:
722 iscsi_set_param(cls_conn, param, buf, buflen);
723 tcp_sw_conn->sendpage = conn->datadgst_en ?
724 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
725 break;
726 case ISCSI_PARAM_MAX_R2T:
727 sscanf(buf, "%d", &value);
728 if (value <= 0 || !is_power_of_2(value))
729 return -EINVAL;
730 if (session->max_r2t == value)
731 break;
732 iscsi_tcp_r2tpool_free(session);
733 iscsi_set_param(cls_conn, param, buf, buflen);
734 if (iscsi_tcp_r2tpool_alloc(session))
735 return -ENOMEM;
736 break;
737 default:
738 return iscsi_set_param(cls_conn, param, buf, buflen);
739 }
740
741 return 0;
742 }
743
744 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
745 enum iscsi_param param, char *buf)
746 {
747 struct iscsi_conn *conn = cls_conn->dd_data;
748 int len;
749
750 switch(param) {
751 case ISCSI_PARAM_CONN_PORT:
752 spin_lock_bh(&conn->session->lock);
753 len = sprintf(buf, "%hu\n", conn->portal_port);
754 spin_unlock_bh(&conn->session->lock);
755 break;
756 case ISCSI_PARAM_CONN_ADDRESS:
757 spin_lock_bh(&conn->session->lock);
758 len = sprintf(buf, "%s\n", conn->portal_address);
759 spin_unlock_bh(&conn->session->lock);
760 break;
761 default:
762 return iscsi_conn_get_param(cls_conn, param, buf);
763 }
764
765 return len;
766 }
767
768 static void
769 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
770 struct iscsi_stats *stats)
771 {
772 struct iscsi_conn *conn = cls_conn->dd_data;
773 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
774 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
775
776 stats->custom_length = 3;
777 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
778 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
779 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
780 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
781 strcpy(stats->custom[2].desc, "eh_abort_cnt");
782 stats->custom[2].value = conn->eh_abort_cnt;
783
784 iscsi_tcp_conn_get_stats(cls_conn, stats);
785 }
786
787 static struct iscsi_cls_session *
788 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
789 uint16_t qdepth, uint32_t initial_cmdsn)
790 {
791 struct iscsi_cls_session *cls_session;
792 struct iscsi_session *session;
793 struct Scsi_Host *shost;
794
795 if (ep) {
796 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
797 return NULL;
798 }
799
800 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht, 0, 1);
801 if (!shost)
802 return NULL;
803 shost->transportt = iscsi_sw_tcp_scsi_transport;
804 shost->cmd_per_lun = qdepth;
805 shost->max_lun = iscsi_max_lun;
806 shost->max_id = 0;
807 shost->max_channel = 0;
808 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
809
810 if (iscsi_host_add(shost, NULL))
811 goto free_host;
812
813 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
814 cmds_max, 0,
815 sizeof(struct iscsi_tcp_task) +
816 sizeof(struct iscsi_sw_tcp_hdrbuf),
817 initial_cmdsn, 0);
818 if (!cls_session)
819 goto remove_host;
820 session = cls_session->dd_data;
821
822 shost->can_queue = session->scsi_cmds_max;
823 if (iscsi_tcp_r2tpool_alloc(session))
824 goto remove_session;
825 return cls_session;
826
827 remove_session:
828 iscsi_session_teardown(cls_session);
829 remove_host:
830 iscsi_host_remove(shost);
831 free_host:
832 iscsi_host_free(shost);
833 return NULL;
834 }
835
836 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
837 {
838 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
839
840 iscsi_tcp_r2tpool_free(cls_session->dd_data);
841 iscsi_session_teardown(cls_session);
842
843 iscsi_host_remove(shost);
844 iscsi_host_free(shost);
845 }
846
847 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
848 {
849 set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
850 return 0;
851 }
852
853 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
854 {
855 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
856 blk_queue_dma_alignment(sdev->request_queue, 0);
857 return 0;
858 }
859
860 static struct scsi_host_template iscsi_sw_tcp_sht = {
861 .module = THIS_MODULE,
862 .name = "iSCSI Initiator over TCP/IP",
863 .queuecommand = iscsi_queuecommand,
864 .change_queue_depth = iscsi_change_queue_depth,
865 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
866 .sg_tablesize = 4096,
867 .max_sectors = 0xFFFF,
868 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
869 .eh_abort_handler = iscsi_eh_abort,
870 .eh_device_reset_handler= iscsi_eh_device_reset,
871 .eh_target_reset_handler= iscsi_eh_target_reset,
872 .use_clustering = DISABLE_CLUSTERING,
873 .slave_alloc = iscsi_sw_tcp_slave_alloc,
874 .slave_configure = iscsi_sw_tcp_slave_configure,
875 .target_alloc = iscsi_target_alloc,
876 .proc_name = "iscsi_tcp",
877 .this_id = -1,
878 };
879
880 static struct iscsi_transport iscsi_sw_tcp_transport = {
881 .owner = THIS_MODULE,
882 .name = "tcp",
883 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
884 | CAP_DATADGST,
885 .param_mask = ISCSI_MAX_RECV_DLENGTH |
886 ISCSI_MAX_XMIT_DLENGTH |
887 ISCSI_HDRDGST_EN |
888 ISCSI_DATADGST_EN |
889 ISCSI_INITIAL_R2T_EN |
890 ISCSI_MAX_R2T |
891 ISCSI_IMM_DATA_EN |
892 ISCSI_FIRST_BURST |
893 ISCSI_MAX_BURST |
894 ISCSI_PDU_INORDER_EN |
895 ISCSI_DATASEQ_INORDER_EN |
896 ISCSI_ERL |
897 ISCSI_CONN_PORT |
898 ISCSI_CONN_ADDRESS |
899 ISCSI_EXP_STATSN |
900 ISCSI_PERSISTENT_PORT |
901 ISCSI_PERSISTENT_ADDRESS |
902 ISCSI_TARGET_NAME | ISCSI_TPGT |
903 ISCSI_USERNAME | ISCSI_PASSWORD |
904 ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
905 ISCSI_FAST_ABORT | ISCSI_ABORT_TMO |
906 ISCSI_LU_RESET_TMO | ISCSI_TGT_RESET_TMO |
907 ISCSI_PING_TMO | ISCSI_RECV_TMO |
908 ISCSI_IFACE_NAME | ISCSI_INITIATOR_NAME,
909 .host_param_mask = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
910 ISCSI_HOST_INITIATOR_NAME |
911 ISCSI_HOST_NETDEV_NAME,
912 /* session management */
913 .create_session = iscsi_sw_tcp_session_create,
914 .destroy_session = iscsi_sw_tcp_session_destroy,
915 /* connection management */
916 .create_conn = iscsi_sw_tcp_conn_create,
917 .bind_conn = iscsi_sw_tcp_conn_bind,
918 .destroy_conn = iscsi_sw_tcp_conn_destroy,
919 .set_param = iscsi_sw_tcp_conn_set_param,
920 .get_conn_param = iscsi_sw_tcp_conn_get_param,
921 .get_session_param = iscsi_session_get_param,
922 .start_conn = iscsi_conn_start,
923 .stop_conn = iscsi_sw_tcp_conn_stop,
924 /* iscsi host params */
925 .get_host_param = iscsi_host_get_param,
926 .set_host_param = iscsi_host_set_param,
927 /* IO */
928 .send_pdu = iscsi_conn_send_pdu,
929 .get_stats = iscsi_sw_tcp_conn_get_stats,
930 /* iscsi task/cmd helpers */
931 .init_task = iscsi_tcp_task_init,
932 .xmit_task = iscsi_tcp_task_xmit,
933 .cleanup_task = iscsi_tcp_cleanup_task,
934 /* low level pdu helpers */
935 .xmit_pdu = iscsi_sw_tcp_pdu_xmit,
936 .init_pdu = iscsi_sw_tcp_pdu_init,
937 .alloc_pdu = iscsi_sw_tcp_pdu_alloc,
938 /* recovery */
939 .session_recovery_timedout = iscsi_session_recovery_timedout,
940 };
941
942 static int __init iscsi_sw_tcp_init(void)
943 {
944 if (iscsi_max_lun < 1) {
945 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
946 iscsi_max_lun);
947 return -EINVAL;
948 }
949
950 iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
951 &iscsi_sw_tcp_transport);
952 if (!iscsi_sw_tcp_scsi_transport)
953 return -ENODEV;
954
955 return 0;
956 }
957
958 static void __exit iscsi_sw_tcp_exit(void)
959 {
960 iscsi_unregister_transport(&iscsi_sw_tcp_transport);
961 }
962
963 module_init(iscsi_sw_tcp_init);
964 module_exit(iscsi_sw_tcp_exit);
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