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Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6
[pv_ops_mirror.git] / drivers / scsi / iscsi_tcp.c
blobc9a3abf9e7b6eee62f17d58e4f76f661615ef028
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/list.h>
31 #include <linux/inet.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 <linux/mutex.h>
38 #include <net/tcp.h>
39 #include <scsi/scsi_cmnd.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("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
47 "Alex Aizman <itn780@yahoo.com>");
48 MODULE_DESCRIPTION("iSCSI/TCP data-path");
49 MODULE_LICENSE("GPL");
50 /* #define DEBUG_TCP */
51 #define DEBUG_ASSERT
52
53 #ifdef DEBUG_TCP
54 #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
55 #else
56 #define debug_tcp(fmt...)
57 #endif
58
59 #ifndef DEBUG_ASSERT
60 #ifdef BUG_ON
61 #undef BUG_ON
62 #endif
63 #define BUG_ON(expr)
64 #endif
65
66 static unsigned int iscsi_max_lun = 512;
67 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
68
69 static inline void
70 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
71 {
72 ibuf->sg.page = virt_to_page(vbuf);
73 ibuf->sg.offset = offset_in_page(vbuf);
74 ibuf->sg.length = size;
75 ibuf->sent = 0;
76 ibuf->use_sendmsg = 1;
77 }
78
79 static inline void
80 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
81 {
82 ibuf->sg.page = sg->page;
83 ibuf->sg.offset = sg->offset;
84 ibuf->sg.length = sg->length;
85 /*
86 * Fastpath: sg element fits into single page
87 */
88 if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg->page))
89 ibuf->use_sendmsg = 0;
90 else
91 ibuf->use_sendmsg = 1;
92 ibuf->sent = 0;
93 }
94
95 static inline int
96 iscsi_buf_left(struct iscsi_buf *ibuf)
97 {
98 int rc;
99
100 rc = ibuf->sg.length - ibuf->sent;
101 BUG_ON(rc < 0);
102 return rc;
103 }
104
105 static inline void
106 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
107 u8* crc)
108 {
109 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
110
111 crypto_hash_digest(&tcp_conn->tx_hash, &buf->sg, buf->sg.length, crc);
112 buf->sg.length = tcp_conn->hdr_size;
113 }
114
115 static inline int
116 iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
117 {
118 struct sk_buff *skb = tcp_conn->in.skb;
119
120 tcp_conn->in.zero_copy_hdr = 0;
121
122 if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
123 tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
124 /*
125 * Zero-copy PDU Header: using connection context
126 * to store header pointer.
127 */
128 if (skb_shinfo(skb)->frag_list == NULL &&
129 !skb_shinfo(skb)->nr_frags) {
130 tcp_conn->in.hdr = (struct iscsi_hdr *)
131 ((char*)skb->data + tcp_conn->in.offset);
132 tcp_conn->in.zero_copy_hdr = 1;
133 } else {
134 /* ignoring return code since we checked
135 * in.copy before */
136 skb_copy_bits(skb, tcp_conn->in.offset,
137 &tcp_conn->hdr, tcp_conn->hdr_size);
138 tcp_conn->in.hdr = &tcp_conn->hdr;
139 }
140 tcp_conn->in.offset += tcp_conn->hdr_size;
141 tcp_conn->in.copy -= tcp_conn->hdr_size;
142 } else {
143 int hdr_remains;
144 int copylen;
145
146 /*
147 * PDU header scattered across SKB's,
148 * copying it... This'll happen quite rarely.
149 */
150
151 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
152 tcp_conn->in.hdr_offset = 0;
153
154 hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
155 BUG_ON(hdr_remains <= 0);
156
157 copylen = min(tcp_conn->in.copy, hdr_remains);
158 skb_copy_bits(skb, tcp_conn->in.offset,
159 (char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset,
160 copylen);
161
162 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
163 "in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
164 tcp_conn->in.offset, tcp_conn->in.copy);
165
166 tcp_conn->in.offset += copylen;
167 tcp_conn->in.copy -= copylen;
168 if (copylen < hdr_remains) {
169 tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
170 tcp_conn->in.hdr_offset += copylen;
171 return -EAGAIN;
172 }
173 tcp_conn->in.hdr = &tcp_conn->hdr;
174 tcp_conn->discontiguous_hdr_cnt++;
175 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
176 }
177
178 return 0;
179 }
180
181 /*
182 * must be called with session lock
183 */
184 static void
185 iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
186 {
187 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
188 struct iscsi_r2t_info *r2t;
189 struct scsi_cmnd *sc;
190
191 /* flush ctask's r2t queues */
192 while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
193 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
194 sizeof(void*));
195 debug_scsi("iscsi_tcp_cleanup_ctask pending r2t dropped\n");
196 }
197
198 sc = ctask->sc;
199 if (unlikely(!sc))
200 return;
201
202 tcp_ctask->xmstate = XMSTATE_IDLE;
203 tcp_ctask->r2t = NULL;
204 }
205
206 /**
207 * iscsi_data_rsp - SCSI Data-In Response processing
208 * @conn: iscsi connection
209 * @ctask: scsi command task
210 **/
211 static int
212 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
213 {
214 int rc;
215 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
216 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
217 struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
218 struct iscsi_session *session = conn->session;
219 int datasn = be32_to_cpu(rhdr->datasn);
220
221 rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
222 if (rc)
223 return rc;
224 /*
225 * setup Data-In byte counter (gets decremented..)
226 */
227 ctask->data_count = tcp_conn->in.datalen;
228
229 if (tcp_conn->in.datalen == 0)
230 return 0;
231
232 if (ctask->datasn != datasn)
233 return ISCSI_ERR_DATASN;
234
235 ctask->datasn++;
236
237 tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
238 if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
239 return ISCSI_ERR_DATA_OFFSET;
240
241 if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
242 struct scsi_cmnd *sc = ctask->sc;
243
244 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
245 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
246 int res_count = be32_to_cpu(rhdr->residual_count);
247
248 if (res_count > 0 &&
249 res_count <= sc->request_bufflen) {
250 sc->resid = res_count;
251 sc->result = (DID_OK << 16) | rhdr->cmd_status;
252 } else
253 sc->result = (DID_BAD_TARGET << 16) |
254 rhdr->cmd_status;
255 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
256 sc->resid = be32_to_cpu(rhdr->residual_count);
257 sc->result = (DID_OK << 16) | rhdr->cmd_status;
258 } else
259 sc->result = (DID_OK << 16) | rhdr->cmd_status;
260 }
261
262 conn->datain_pdus_cnt++;
263 return 0;
264 }
265
266 /**
267 * iscsi_solicit_data_init - initialize first Data-Out
268 * @conn: iscsi connection
269 * @ctask: scsi command task
270 * @r2t: R2T info
271 *
272 * Notes:
273 * Initialize first Data-Out within this R2T sequence and finds
274 * proper data_offset within this SCSI command.
275 *
276 * This function is called with connection lock taken.
277 **/
278 static void
279 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
280 struct iscsi_r2t_info *r2t)
281 {
282 struct iscsi_data *hdr;
283 struct scsi_cmnd *sc = ctask->sc;
284
285 hdr = &r2t->dtask.hdr;
286 memset(hdr, 0, sizeof(struct iscsi_data));
287 hdr->ttt = r2t->ttt;
288 hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
289 r2t->solicit_datasn++;
290 hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
291 memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
292 hdr->itt = ctask->hdr->itt;
293 hdr->exp_statsn = r2t->exp_statsn;
294 hdr->offset = cpu_to_be32(r2t->data_offset);
295 if (r2t->data_length > conn->max_xmit_dlength) {
296 hton24(hdr->dlength, conn->max_xmit_dlength);
297 r2t->data_count = conn->max_xmit_dlength;
298 hdr->flags = 0;
299 } else {
300 hton24(hdr->dlength, r2t->data_length);
301 r2t->data_count = r2t->data_length;
302 hdr->flags = ISCSI_FLAG_CMD_FINAL;
303 }
304 conn->dataout_pdus_cnt++;
305
306 r2t->sent = 0;
307
308 iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
309 sizeof(struct iscsi_hdr));
310
311 if (sc->use_sg) {
312 int i, sg_count = 0;
313 struct scatterlist *sg = sc->request_buffer;
314
315 r2t->sg = NULL;
316 for (i = 0; i < sc->use_sg; i++, sg += 1) {
317 /* FIXME: prefetch ? */
318 if (sg_count + sg->length > r2t->data_offset) {
319 int page_offset;
320
321 /* sg page found! */
322
323 /* offset within this page */
324 page_offset = r2t->data_offset - sg_count;
325
326 /* fill in this buffer */
327 iscsi_buf_init_sg(&r2t->sendbuf, sg);
328 r2t->sendbuf.sg.offset += page_offset;
329 r2t->sendbuf.sg.length -= page_offset;
330
331 /* xmit logic will continue with next one */
332 r2t->sg = sg + 1;
333 break;
334 }
335 sg_count += sg->length;
336 }
337 BUG_ON(r2t->sg == NULL);
338 } else {
339 iscsi_buf_init_iov(&r2t->sendbuf,
340 (char*)sc->request_buffer + r2t->data_offset,
341 r2t->data_count);
342 r2t->sg = NULL;
343 }
344 }
345
346 /**
347 * iscsi_r2t_rsp - iSCSI R2T Response processing
348 * @conn: iscsi connection
349 * @ctask: scsi command task
350 **/
351 static int
352 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
353 {
354 struct iscsi_r2t_info *r2t;
355 struct iscsi_session *session = conn->session;
356 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
357 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
358 struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
359 int r2tsn = be32_to_cpu(rhdr->r2tsn);
360 int rc;
361
362 if (tcp_conn->in.datalen) {
363 printk(KERN_ERR "iscsi_tcp: invalid R2t with datalen %d\n",
364 tcp_conn->in.datalen);
365 return ISCSI_ERR_DATALEN;
366 }
367
368 if (tcp_ctask->exp_r2tsn && tcp_ctask->exp_r2tsn != r2tsn)
369 return ISCSI_ERR_R2TSN;
370
371 rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
372 if (rc)
373 return rc;
374
375 /* FIXME: use R2TSN to detect missing R2T */
376
377 /* fill-in new R2T associated with the task */
378 spin_lock(&session->lock);
379 if (!ctask->sc || ctask->mtask ||
380 session->state != ISCSI_STATE_LOGGED_IN) {
381 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
382 "recovery...\n", ctask->itt);
383 spin_unlock(&session->lock);
384 return 0;
385 }
386
387 rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
388 BUG_ON(!rc);
389
390 r2t->exp_statsn = rhdr->statsn;
391 r2t->data_length = be32_to_cpu(rhdr->data_length);
392 if (r2t->data_length == 0) {
393 printk(KERN_ERR "iscsi_tcp: invalid R2T with zero data len\n");
394 spin_unlock(&session->lock);
395 return ISCSI_ERR_DATALEN;
396 }
397
398 if (r2t->data_length > session->max_burst)
399 debug_scsi("invalid R2T with data len %u and max burst %u."
400 "Attempting to execute request.\n",
401 r2t->data_length, session->max_burst);
402
403 r2t->data_offset = be32_to_cpu(rhdr->data_offset);
404 if (r2t->data_offset + r2t->data_length > ctask->total_length) {
405 spin_unlock(&session->lock);
406 printk(KERN_ERR "iscsi_tcp: invalid R2T with data len %u at "
407 "offset %u and total length %d\n", r2t->data_length,
408 r2t->data_offset, ctask->total_length);
409 return ISCSI_ERR_DATALEN;
410 }
411
412 r2t->ttt = rhdr->ttt; /* no flip */
413 r2t->solicit_datasn = 0;
414
415 iscsi_solicit_data_init(conn, ctask, r2t);
416
417 tcp_ctask->exp_r2tsn = r2tsn + 1;
418 __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
419 tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
420 list_move_tail(&ctask->running, &conn->xmitqueue);
421
422 scsi_queue_work(session->host, &conn->xmitwork);
423 conn->r2t_pdus_cnt++;
424 spin_unlock(&session->lock);
425
426 return 0;
427 }
428
429 static int
430 iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
431 {
432 int rc = 0, opcode, ahslen;
433 struct iscsi_hdr *hdr;
434 struct iscsi_session *session = conn->session;
435 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
436 uint32_t cdgst, rdgst = 0, itt;
437
438 hdr = tcp_conn->in.hdr;
439
440 /* verify PDU length */
441 tcp_conn->in.datalen = ntoh24(hdr->dlength);
442 if (tcp_conn->in.datalen > conn->max_recv_dlength) {
443 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
444 tcp_conn->in.datalen, conn->max_recv_dlength);
445 return ISCSI_ERR_DATALEN;
446 }
447 tcp_conn->data_copied = 0;
448
449 /* read AHS */
450 ahslen = hdr->hlength << 2;
451 tcp_conn->in.offset += ahslen;
452 tcp_conn->in.copy -= ahslen;
453 if (tcp_conn->in.copy < 0) {
454 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
455 "%d bytes\n", ahslen);
456 return ISCSI_ERR_AHSLEN;
457 }
458
459 /* calculate read padding */
460 tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
461 if (tcp_conn->in.padding) {
462 tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
463 debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
464 }
465
466 if (conn->hdrdgst_en) {
467 struct scatterlist sg;
468
469 sg_init_one(&sg, (u8 *)hdr,
470 sizeof(struct iscsi_hdr) + ahslen);
471 crypto_hash_digest(&tcp_conn->rx_hash, &sg, sg.length,
472 (u8 *)&cdgst);
473 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
474 ahslen);
475 if (cdgst != rdgst) {
476 printk(KERN_ERR "iscsi_tcp: hdrdgst error "
477 "recv 0x%x calc 0x%x\n", rdgst, cdgst);
478 return ISCSI_ERR_HDR_DGST;
479 }
480 }
481
482 opcode = hdr->opcode & ISCSI_OPCODE_MASK;
483 /* verify itt (itt encoding: age+cid+itt) */
484 rc = iscsi_verify_itt(conn, hdr, &itt);
485 if (rc == ISCSI_ERR_NO_SCSI_CMD) {
486 tcp_conn->in.datalen = 0; /* force drop */
487 return 0;
488 } else if (rc)
489 return rc;
490
491 debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
492 opcode, tcp_conn->in.offset, tcp_conn->in.copy,
493 ahslen, tcp_conn->in.datalen);
494
495 switch(opcode) {
496 case ISCSI_OP_SCSI_DATA_IN:
497 tcp_conn->in.ctask = session->cmds[itt];
498 rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
499 if (rc)
500 return rc;
501 /* fall through */
502 case ISCSI_OP_SCSI_CMD_RSP:
503 tcp_conn->in.ctask = session->cmds[itt];
504 if (tcp_conn->in.datalen)
505 goto copy_hdr;
506
507 spin_lock(&session->lock);
508 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
509 spin_unlock(&session->lock);
510 break;
511 case ISCSI_OP_R2T:
512 tcp_conn->in.ctask = session->cmds[itt];
513 if (ahslen)
514 rc = ISCSI_ERR_AHSLEN;
515 else if (tcp_conn->in.ctask->sc->sc_data_direction ==
516 DMA_TO_DEVICE)
517 rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
518 else
519 rc = ISCSI_ERR_PROTO;
520 break;
521 case ISCSI_OP_LOGIN_RSP:
522 case ISCSI_OP_TEXT_RSP:
523 case ISCSI_OP_REJECT:
524 case ISCSI_OP_ASYNC_EVENT:
525 /*
526 * It is possible that we could get a PDU with a buffer larger
527 * than 8K, but there are no targets that currently do this.
528 * For now we fail until we find a vendor that needs it
529 */
530 if (ISCSI_DEF_MAX_RECV_SEG_LEN <
531 tcp_conn->in.datalen) {
532 printk(KERN_ERR "iscsi_tcp: received buffer of len %u "
533 "but conn buffer is only %u (opcode %0x)\n",
534 tcp_conn->in.datalen,
535 ISCSI_DEF_MAX_RECV_SEG_LEN, opcode);
536 rc = ISCSI_ERR_PROTO;
537 break;
538 }
539
540 if (tcp_conn->in.datalen)
541 goto copy_hdr;
542 /* fall through */
543 case ISCSI_OP_LOGOUT_RSP:
544 case ISCSI_OP_NOOP_IN:
545 case ISCSI_OP_SCSI_TMFUNC_RSP:
546 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
547 break;
548 default:
549 rc = ISCSI_ERR_BAD_OPCODE;
550 break;
551 }
552
553 return rc;
554
555 copy_hdr:
556 /*
557 * if we did zero copy for the header but we will need multiple
558 * skbs to complete the command then we have to copy the header
559 * for later use
560 */
561 if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <=
562 (tcp_conn->in.datalen + tcp_conn->in.padding +
563 (conn->datadgst_en ? 4 : 0))) {
564 debug_tcp("Copying header for later use. in.copy %d in.datalen"
565 " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
566 memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
567 sizeof(struct iscsi_hdr));
568 tcp_conn->in.hdr = &tcp_conn->hdr;
569 tcp_conn->in.zero_copy_hdr = 0;
570 }
571 return 0;
572 }
573
574 /**
575 * iscsi_ctask_copy - copy skb bits to the destanation cmd task
576 * @conn: iscsi tcp connection
577 * @ctask: scsi command task
578 * @buf: buffer to copy to
579 * @buf_size: size of buffer
580 * @offset: offset within the buffer
581 *
582 * Notes:
583 * The function calls skb_copy_bits() and updates per-connection and
584 * per-cmd byte counters.
585 *
586 * Read counters (in bytes):
587 *
588 * conn->in.offset offset within in progress SKB
589 * conn->in.copy left to copy from in progress SKB
590 * including padding
591 * conn->in.copied copied already from in progress SKB
592 * conn->data_copied copied already from in progress buffer
593 * ctask->sent total bytes sent up to the MidLayer
594 * ctask->data_count left to copy from in progress Data-In
595 * buf_left left to copy from in progress buffer
596 **/
597 static inline int
598 iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
599 void *buf, int buf_size, int offset)
600 {
601 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
602 int buf_left = buf_size - (tcp_conn->data_copied + offset);
603 int size = min(tcp_conn->in.copy, buf_left);
604 int rc;
605
606 size = min(size, ctask->data_count);
607
608 debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
609 size, tcp_conn->in.offset, tcp_conn->in.copied);
610
611 BUG_ON(size <= 0);
612 BUG_ON(tcp_ctask->sent + size > ctask->total_length);
613
614 rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
615 (char*)buf + (offset + tcp_conn->data_copied), size);
616 /* must fit into skb->len */
617 BUG_ON(rc);
618
619 tcp_conn->in.offset += size;
620 tcp_conn->in.copy -= size;
621 tcp_conn->in.copied += size;
622 tcp_conn->data_copied += size;
623 tcp_ctask->sent += size;
624 ctask->data_count -= size;
625
626 BUG_ON(tcp_conn->in.copy < 0);
627 BUG_ON(ctask->data_count < 0);
628
629 if (buf_size != (tcp_conn->data_copied + offset)) {
630 if (!ctask->data_count) {
631 BUG_ON(buf_size - tcp_conn->data_copied < 0);
632 /* done with this PDU */
633 return buf_size - tcp_conn->data_copied;
634 }
635 return -EAGAIN;
636 }
637
638 /* done with this buffer or with both - PDU and buffer */
639 tcp_conn->data_copied = 0;
640 return 0;
641 }
642
643 /**
644 * iscsi_tcp_copy - copy skb bits to the destanation buffer
645 * @conn: iscsi tcp connection
646 *
647 * Notes:
648 * The function calls skb_copy_bits() and updates per-connection
649 * byte counters.
650 **/
651 static inline int
652 iscsi_tcp_copy(struct iscsi_conn *conn, int buf_size)
653 {
654 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
655 int buf_left = buf_size - tcp_conn->data_copied;
656 int size = min(tcp_conn->in.copy, buf_left);
657 int rc;
658
659 debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
660 size, tcp_conn->in.offset, tcp_conn->data_copied);
661 BUG_ON(size <= 0);
662
663 rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
664 (char*)conn->data + tcp_conn->data_copied, size);
665 BUG_ON(rc);
666
667 tcp_conn->in.offset += size;
668 tcp_conn->in.copy -= size;
669 tcp_conn->in.copied += size;
670 tcp_conn->data_copied += size;
671
672 if (buf_size != tcp_conn->data_copied)
673 return -EAGAIN;
674
675 return 0;
676 }
677
678 static inline void
679 partial_sg_digest_update(struct hash_desc *desc, struct scatterlist *sg,
680 int offset, int length)
681 {
682 struct scatterlist temp;
683
684 memcpy(&temp, sg, sizeof(struct scatterlist));
685 temp.offset = offset;
686 temp.length = length;
687 crypto_hash_update(desc, &temp, length);
688 }
689
690 static void
691 iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
692 {
693 struct scatterlist tmp;
694
695 sg_init_one(&tmp, buf, len);
696 crypto_hash_update(&tcp_conn->rx_hash, &tmp, len);
697 }
698
699 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
700 {
701 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
702 struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
703 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
704 struct scsi_cmnd *sc = ctask->sc;
705 struct scatterlist *sg;
706 int i, offset, rc = 0;
707
708 BUG_ON((void*)ctask != sc->SCp.ptr);
709
710 /*
711 * copying Data-In into the Scsi_Cmnd
712 */
713 if (!sc->use_sg) {
714 i = ctask->data_count;
715 rc = iscsi_ctask_copy(tcp_conn, ctask, sc->request_buffer,
716 sc->request_bufflen,
717 tcp_ctask->data_offset);
718 if (rc == -EAGAIN)
719 return rc;
720 if (conn->datadgst_en)
721 iscsi_recv_digest_update(tcp_conn, sc->request_buffer,
722 i);
723 rc = 0;
724 goto done;
725 }
726
727 offset = tcp_ctask->data_offset;
728 sg = sc->request_buffer;
729
730 if (tcp_ctask->data_offset)
731 for (i = 0; i < tcp_ctask->sg_count; i++)
732 offset -= sg[i].length;
733 /* we've passed through partial sg*/
734 if (offset < 0)
735 offset = 0;
736
737 for (i = tcp_ctask->sg_count; i < sc->use_sg; i++) {
738 char *dest;
739
740 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
741 rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
742 sg[i].length, offset);
743 kunmap_atomic(dest, KM_SOFTIRQ0);
744 if (rc == -EAGAIN)
745 /* continue with the next SKB/PDU */
746 return rc;
747 if (!rc) {
748 if (conn->datadgst_en) {
749 if (!offset)
750 crypto_hash_update(
751 &tcp_conn->rx_hash,
752 &sg[i], sg[i].length);
753 else
754 partial_sg_digest_update(
755 &tcp_conn->rx_hash,
756 &sg[i],
757 sg[i].offset + offset,
758 sg[i].length - offset);
759 }
760 offset = 0;
761 tcp_ctask->sg_count++;
762 }
763
764 if (!ctask->data_count) {
765 if (rc && conn->datadgst_en)
766 /*
767 * data-in is complete, but buffer not...
768 */
769 partial_sg_digest_update(&tcp_conn->rx_hash,
770 &sg[i],
771 sg[i].offset,
772 sg[i].length-rc);
773 rc = 0;
774 break;
775 }
776
777 if (!tcp_conn->in.copy)
778 return -EAGAIN;
779 }
780 BUG_ON(ctask->data_count);
781
782 done:
783 /* check for non-exceptional status */
784 if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
785 debug_scsi("done [sc %lx res %d itt 0x%x flags 0x%x]\n",
786 (long)sc, sc->result, ctask->itt,
787 tcp_conn->in.hdr->flags);
788 spin_lock(&conn->session->lock);
789 __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
790 spin_unlock(&conn->session->lock);
791 }
792
793 return rc;
794 }
795
796 static int
797 iscsi_data_recv(struct iscsi_conn *conn)
798 {
799 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
800 int rc = 0, opcode;
801
802 opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
803 switch (opcode) {
804 case ISCSI_OP_SCSI_DATA_IN:
805 rc = iscsi_scsi_data_in(conn);
806 break;
807 case ISCSI_OP_SCSI_CMD_RSP:
808 case ISCSI_OP_TEXT_RSP:
809 case ISCSI_OP_LOGIN_RSP:
810 case ISCSI_OP_ASYNC_EVENT:
811 case ISCSI_OP_REJECT:
812 /*
813 * Collect data segment to the connection's data
814 * placeholder
815 */
816 if (iscsi_tcp_copy(conn, tcp_conn->in.datalen)) {
817 rc = -EAGAIN;
818 goto exit;
819 }
820
821 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, conn->data,
822 tcp_conn->in.datalen);
823 if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
824 iscsi_recv_digest_update(tcp_conn, conn->data,
825 tcp_conn->in.datalen);
826 break;
827 default:
828 BUG_ON(1);
829 }
830 exit:
831 return rc;
832 }
833
834 /**
835 * iscsi_tcp_data_recv - TCP receive in sendfile fashion
836 * @rd_desc: read descriptor
837 * @skb: socket buffer
838 * @offset: offset in skb
839 * @len: skb->len - offset
840 **/
841 static int
842 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
843 unsigned int offset, size_t len)
844 {
845 int rc;
846 struct iscsi_conn *conn = rd_desc->arg.data;
847 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
848 int processed;
849 char pad[ISCSI_PAD_LEN];
850 struct scatterlist sg;
851
852 /*
853 * Save current SKB and its offset in the corresponding
854 * connection context.
855 */
856 tcp_conn->in.copy = skb->len - offset;
857 tcp_conn->in.offset = offset;
858 tcp_conn->in.skb = skb;
859 tcp_conn->in.len = tcp_conn->in.copy;
860 BUG_ON(tcp_conn->in.copy <= 0);
861 debug_tcp("in %d bytes\n", tcp_conn->in.copy);
862
863 more:
864 tcp_conn->in.copied = 0;
865 rc = 0;
866
867 if (unlikely(conn->suspend_rx)) {
868 debug_tcp("conn %d Rx suspended!\n", conn->id);
869 return 0;
870 }
871
872 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
873 tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
874 rc = iscsi_hdr_extract(tcp_conn);
875 if (rc) {
876 if (rc == -EAGAIN)
877 goto nomore;
878 else {
879 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
880 return 0;
881 }
882 }
883
884 /*
885 * Verify and process incoming PDU header.
886 */
887 rc = iscsi_tcp_hdr_recv(conn);
888 if (!rc && tcp_conn->in.datalen) {
889 if (conn->datadgst_en)
890 crypto_hash_init(&tcp_conn->rx_hash);
891 tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
892 } else if (rc) {
893 iscsi_conn_failure(conn, rc);
894 return 0;
895 }
896 }
897
898 if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
899 uint32_t recv_digest;
900
901 debug_tcp("extra data_recv offset %d copy %d\n",
902 tcp_conn->in.offset, tcp_conn->in.copy);
903 rc = iscsi_tcp_copy(conn, sizeof(uint32_t));
904 if (rc) {
905 if (rc == -EAGAIN)
906 goto again;
907 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
908 return 0;
909 }
910
911 memcpy(&recv_digest, conn->data, sizeof(uint32_t));
912 if (recv_digest != tcp_conn->in.datadgst) {
913 debug_tcp("iscsi_tcp: data digest error!"
914 "0x%x != 0x%x\n", recv_digest,
915 tcp_conn->in.datadgst);
916 iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
917 return 0;
918 } else {
919 debug_tcp("iscsi_tcp: data digest match!"
920 "0x%x == 0x%x\n", recv_digest,
921 tcp_conn->in.datadgst);
922 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
923 }
924 }
925
926 if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
927 tcp_conn->in.copy) {
928
929 debug_tcp("data_recv offset %d copy %d\n",
930 tcp_conn->in.offset, tcp_conn->in.copy);
931
932 rc = iscsi_data_recv(conn);
933 if (rc) {
934 if (rc == -EAGAIN)
935 goto again;
936 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
937 return 0;
938 }
939 tcp_conn->in.copy -= tcp_conn->in.padding;
940 tcp_conn->in.offset += tcp_conn->in.padding;
941 if (conn->datadgst_en) {
942 if (tcp_conn->in.padding) {
943 debug_tcp("padding -> %d\n",
944 tcp_conn->in.padding);
945 memset(pad, 0, tcp_conn->in.padding);
946 sg_init_one(&sg, pad, tcp_conn->in.padding);
947 crypto_hash_update(&tcp_conn->rx_hash,
948 &sg, sg.length);
949 }
950 crypto_hash_final(&tcp_conn->rx_hash,
951 (u8 *) &tcp_conn->in.datadgst);
952 debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
953 tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
954 tcp_conn->data_copied = 0;
955 } else
956 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
957 }
958
959 debug_tcp("f, processed %d from out of %d padding %d\n",
960 tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
961 BUG_ON(tcp_conn->in.offset - offset > len);
962
963 if (tcp_conn->in.offset - offset != len) {
964 debug_tcp("continue to process %d bytes\n",
965 (int)len - (tcp_conn->in.offset - offset));
966 goto more;
967 }
968
969 nomore:
970 processed = tcp_conn->in.offset - offset;
971 BUG_ON(processed == 0);
972 return processed;
973
974 again:
975 processed = tcp_conn->in.offset - offset;
976 debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
977 processed, (int)len, (int)rd_desc->count);
978 BUG_ON(processed == 0);
979 BUG_ON(processed > len);
980
981 conn->rxdata_octets += processed;
982 return processed;
983 }
984
985 static void
986 iscsi_tcp_data_ready(struct sock *sk, int flag)
987 {
988 struct iscsi_conn *conn = sk->sk_user_data;
989 read_descriptor_t rd_desc;
990
991 read_lock(&sk->sk_callback_lock);
992
993 /*
994 * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
995 * We set count to 1 because we want the network layer to
996 * hand us all the skbs that are available. iscsi_tcp_data_recv
997 * handled pdus that cross buffers or pdus that still need data.
998 */
999 rd_desc.arg.data = conn;
1000 rd_desc.count = 1;
1001 tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
1002
1003 read_unlock(&sk->sk_callback_lock);
1004 }
1005
1006 static void
1007 iscsi_tcp_state_change(struct sock *sk)
1008 {
1009 struct iscsi_tcp_conn *tcp_conn;
1010 struct iscsi_conn *conn;
1011 struct iscsi_session *session;
1012 void (*old_state_change)(struct sock *);
1013
1014 read_lock(&sk->sk_callback_lock);
1015
1016 conn = (struct iscsi_conn*)sk->sk_user_data;
1017 session = conn->session;
1018
1019 if ((sk->sk_state == TCP_CLOSE_WAIT ||
1020 sk->sk_state == TCP_CLOSE) &&
1021 !atomic_read(&sk->sk_rmem_alloc)) {
1022 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1023 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1024 }
1025
1026 tcp_conn = conn->dd_data;
1027 old_state_change = tcp_conn->old_state_change;
1028
1029 read_unlock(&sk->sk_callback_lock);
1030
1031 old_state_change(sk);
1032 }
1033
1034 /**
1035 * iscsi_write_space - Called when more output buffer space is available
1036 * @sk: socket space is available for
1037 **/
1038 static void
1039 iscsi_write_space(struct sock *sk)
1040 {
1041 struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1042 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1043
1044 tcp_conn->old_write_space(sk);
1045 debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1046 scsi_queue_work(conn->session->host, &conn->xmitwork);
1047 }
1048
1049 static void
1050 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1051 {
1052 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1053 struct sock *sk = tcp_conn->sock->sk;
1054
1055 /* assign new callbacks */
1056 write_lock_bh(&sk->sk_callback_lock);
1057 sk->sk_user_data = conn;
1058 tcp_conn->old_data_ready = sk->sk_data_ready;
1059 tcp_conn->old_state_change = sk->sk_state_change;
1060 tcp_conn->old_write_space = sk->sk_write_space;
1061 sk->sk_data_ready = iscsi_tcp_data_ready;
1062 sk->sk_state_change = iscsi_tcp_state_change;
1063 sk->sk_write_space = iscsi_write_space;
1064 write_unlock_bh(&sk->sk_callback_lock);
1065 }
1066
1067 static void
1068 iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
1069 {
1070 struct sock *sk = tcp_conn->sock->sk;
1071
1072 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1073 write_lock_bh(&sk->sk_callback_lock);
1074 sk->sk_user_data = NULL;
1075 sk->sk_data_ready = tcp_conn->old_data_ready;
1076 sk->sk_state_change = tcp_conn->old_state_change;
1077 sk->sk_write_space = tcp_conn->old_write_space;
1078 sk->sk_no_check = 0;
1079 write_unlock_bh(&sk->sk_callback_lock);
1080 }
1081
1082 /**
1083 * iscsi_send - generic send routine
1084 * @sk: kernel's socket
1085 * @buf: buffer to write from
1086 * @size: actual size to write
1087 * @flags: socket's flags
1088 */
1089 static inline int
1090 iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1091 {
1092 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1093 struct socket *sk = tcp_conn->sock;
1094 int offset = buf->sg.offset + buf->sent, res;
1095
1096 /*
1097 * if we got use_sg=0 or are sending something we kmallocd
1098 * then we did not have to do kmap (kmap returns page_address)
1099 *
1100 * if we got use_sg > 0, but had to drop down, we do not
1101 * set clustering so this should only happen for that
1102 * slab case.
1103 */
1104 if (buf->use_sendmsg)
1105 res = sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
1106 else
1107 res = tcp_conn->sendpage(sk, buf->sg.page, offset, size, flags);
1108
1109 if (res >= 0) {
1110 conn->txdata_octets += res;
1111 buf->sent += res;
1112 return res;
1113 }
1114
1115 tcp_conn->sendpage_failures_cnt++;
1116 if (res == -EAGAIN)
1117 res = -ENOBUFS;
1118 else
1119 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1120 return res;
1121 }
1122
1123 /**
1124 * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1125 * @conn: iscsi connection
1126 * @buf: buffer to write from
1127 * @datalen: lenght of data to be sent after the header
1128 *
1129 * Notes:
1130 * (Tx, Fast Path)
1131 **/
1132 static inline int
1133 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1134 {
1135 int flags = 0; /* MSG_DONTWAIT; */
1136 int res, size;
1137
1138 size = buf->sg.length - buf->sent;
1139 BUG_ON(buf->sent + size > buf->sg.length);
1140 if (buf->sent + size != buf->sg.length || datalen)
1141 flags |= MSG_MORE;
1142
1143 res = iscsi_send(conn, buf, size, flags);
1144 debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1145 if (res >= 0) {
1146 if (size != res)
1147 return -EAGAIN;
1148 return 0;
1149 }
1150
1151 return res;
1152 }
1153
1154 /**
1155 * iscsi_sendpage - send one page of iSCSI Data-Out.
1156 * @conn: iscsi connection
1157 * @buf: buffer to write from
1158 * @count: remaining data
1159 * @sent: number of bytes sent
1160 *
1161 * Notes:
1162 * (Tx, Fast Path)
1163 **/
1164 static inline int
1165 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1166 int *count, int *sent)
1167 {
1168 int flags = 0; /* MSG_DONTWAIT; */
1169 int res, size;
1170
1171 size = buf->sg.length - buf->sent;
1172 BUG_ON(buf->sent + size > buf->sg.length);
1173 if (size > *count)
1174 size = *count;
1175 if (buf->sent + size != buf->sg.length || *count != size)
1176 flags |= MSG_MORE;
1177
1178 res = iscsi_send(conn, buf, size, flags);
1179 debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1180 size, buf->sent, *count, *sent, res);
1181 if (res >= 0) {
1182 *count -= res;
1183 *sent += res;
1184 if (size != res)
1185 return -EAGAIN;
1186 return 0;
1187 }
1188
1189 return res;
1190 }
1191
1192 static inline void
1193 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1194 struct iscsi_tcp_cmd_task *tcp_ctask)
1195 {
1196 crypto_hash_init(&tcp_conn->tx_hash);
1197 tcp_ctask->digest_count = 4;
1198 }
1199
1200 /**
1201 * iscsi_solicit_data_cont - initialize next Data-Out
1202 * @conn: iscsi connection
1203 * @ctask: scsi command task
1204 * @r2t: R2T info
1205 * @left: bytes left to transfer
1206 *
1207 * Notes:
1208 * Initialize next Data-Out within this R2T sequence and continue
1209 * to process next Scatter-Gather element(if any) of this SCSI command.
1210 *
1211 * Called under connection lock.
1212 **/
1213 static void
1214 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1215 struct iscsi_r2t_info *r2t, int left)
1216 {
1217 struct iscsi_data *hdr;
1218 struct scsi_cmnd *sc = ctask->sc;
1219 int new_offset;
1220
1221 hdr = &r2t->dtask.hdr;
1222 memset(hdr, 0, sizeof(struct iscsi_data));
1223 hdr->ttt = r2t->ttt;
1224 hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1225 r2t->solicit_datasn++;
1226 hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1227 memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1228 hdr->itt = ctask->hdr->itt;
1229 hdr->exp_statsn = r2t->exp_statsn;
1230 new_offset = r2t->data_offset + r2t->sent;
1231 hdr->offset = cpu_to_be32(new_offset);
1232 if (left > conn->max_xmit_dlength) {
1233 hton24(hdr->dlength, conn->max_xmit_dlength);
1234 r2t->data_count = conn->max_xmit_dlength;
1235 } else {
1236 hton24(hdr->dlength, left);
1237 r2t->data_count = left;
1238 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1239 }
1240 conn->dataout_pdus_cnt++;
1241
1242 iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
1243 sizeof(struct iscsi_hdr));
1244
1245 if (iscsi_buf_left(&r2t->sendbuf))
1246 return;
1247
1248 if (sc->use_sg) {
1249 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1250 r2t->sg += 1;
1251 } else {
1252 iscsi_buf_init_iov(&r2t->sendbuf,
1253 (char*)sc->request_buffer + new_offset,
1254 r2t->data_count);
1255 r2t->sg = NULL;
1256 }
1257 }
1258
1259 static void iscsi_set_padding(struct iscsi_tcp_cmd_task *tcp_ctask,
1260 unsigned long len)
1261 {
1262 tcp_ctask->pad_count = len & (ISCSI_PAD_LEN - 1);
1263 if (!tcp_ctask->pad_count)
1264 return;
1265
1266 tcp_ctask->pad_count = ISCSI_PAD_LEN - tcp_ctask->pad_count;
1267 debug_scsi("write padding %d bytes\n", tcp_ctask->pad_count);
1268 tcp_ctask->xmstate |= XMSTATE_W_PAD;
1269 }
1270
1271 /**
1272 * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1273 * @conn: iscsi connection
1274 * @ctask: scsi command task
1275 * @sc: scsi command
1276 **/
1277 static void
1278 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1279 {
1280 struct scsi_cmnd *sc = ctask->sc;
1281 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1282
1283 BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1284
1285 tcp_ctask->sent = 0;
1286 tcp_ctask->sg_count = 0;
1287
1288 if (sc->sc_data_direction == DMA_TO_DEVICE) {
1289 tcp_ctask->xmstate = XMSTATE_W_HDR;
1290 tcp_ctask->exp_r2tsn = 0;
1291 BUG_ON(ctask->total_length == 0);
1292
1293 if (sc->use_sg) {
1294 struct scatterlist *sg = sc->request_buffer;
1295
1296 iscsi_buf_init_sg(&tcp_ctask->sendbuf, sg);
1297 tcp_ctask->sg = sg + 1;
1298 tcp_ctask->bad_sg = sg + sc->use_sg;
1299 } else {
1300 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1301 sc->request_buffer,
1302 sc->request_bufflen);
1303 tcp_ctask->sg = NULL;
1304 tcp_ctask->bad_sg = NULL;
1305 }
1306 debug_scsi("cmd [itt 0x%x total %d imm_data %d "
1307 "unsol count %d, unsol offset %d]\n",
1308 ctask->itt, ctask->total_length, ctask->imm_count,
1309 ctask->unsol_count, ctask->unsol_offset);
1310 } else
1311 tcp_ctask->xmstate = XMSTATE_R_HDR;
1312
1313 iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
1314 sizeof(struct iscsi_hdr));
1315 }
1316
1317 /**
1318 * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1319 * @conn: iscsi connection
1320 * @mtask: task management task
1321 *
1322 * Notes:
1323 * The function can return -EAGAIN in which case caller must
1324 * call it again later, or recover. '0' return code means successful
1325 * xmit.
1326 *
1327 * Management xmit state machine consists of two states:
1328 * IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1329 * IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1330 **/
1331 static int
1332 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1333 {
1334 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1335 int rc;
1336
1337 debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1338 conn->id, tcp_mtask->xmstate, mtask->itt);
1339
1340 if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1341 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1342 if (mtask->data_count)
1343 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1344 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1345 conn->stop_stage != STOP_CONN_RECOVER &&
1346 conn->hdrdgst_en)
1347 iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
1348 (u8*)tcp_mtask->hdrext);
1349 rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
1350 mtask->data_count);
1351 if (rc) {
1352 tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1353 if (mtask->data_count)
1354 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1355 return rc;
1356 }
1357 }
1358
1359 if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1360 BUG_ON(!mtask->data_count);
1361 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1362 /* FIXME: implement.
1363 * Virtual buffer could be spreaded across multiple pages...
1364 */
1365 do {
1366 int rc;
1367
1368 rc = iscsi_sendpage(conn, &tcp_mtask->sendbuf,
1369 &mtask->data_count, &tcp_mtask->sent);
1370 if (rc) {
1371 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1372 return rc;
1373 }
1374 } while (mtask->data_count);
1375 }
1376
1377 BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
1378 if (mtask->hdr->itt == RESERVED_ITT) {
1379 struct iscsi_session *session = conn->session;
1380
1381 spin_lock_bh(&session->lock);
1382 list_del(&conn->mtask->running);
1383 __kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
1384 sizeof(void*));
1385 spin_unlock_bh(&session->lock);
1386 }
1387 return 0;
1388 }
1389
1390 static inline int
1391 iscsi_send_read_hdr(struct iscsi_conn *conn,
1392 struct iscsi_tcp_cmd_task *tcp_ctask)
1393 {
1394 int rc;
1395
1396 tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
1397 if (conn->hdrdgst_en)
1398 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1399 (u8*)tcp_ctask->hdrext);
1400 rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0);
1401 if (!rc) {
1402 BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
1403 return 0; /* wait for Data-In */
1404 }
1405 tcp_ctask->xmstate |= XMSTATE_R_HDR;
1406 return rc;
1407 }
1408
1409 static inline int
1410 iscsi_send_write_hdr(struct iscsi_conn *conn,
1411 struct iscsi_cmd_task *ctask)
1412 {
1413 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1414 int rc;
1415
1416 tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
1417 if (conn->hdrdgst_en)
1418 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1419 (u8*)tcp_ctask->hdrext);
1420 rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
1421 if (rc) {
1422 tcp_ctask->xmstate |= XMSTATE_W_HDR;
1423 return rc;
1424 }
1425
1426 if (ctask->imm_count) {
1427 tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1428 iscsi_set_padding(tcp_ctask, ctask->imm_count);
1429
1430 if (ctask->conn->datadgst_en) {
1431 iscsi_data_digest_init(ctask->conn->dd_data, tcp_ctask);
1432 tcp_ctask->immdigest = 0;
1433 }
1434 }
1435
1436 if (ctask->unsol_count)
1437 tcp_ctask->xmstate |= XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
1438 return 0;
1439 }
1440
1441 static int
1442 iscsi_send_padding(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1443 {
1444 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1445 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1446 int sent = 0, rc;
1447
1448 if (tcp_ctask->xmstate & XMSTATE_W_PAD) {
1449 iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
1450 tcp_ctask->pad_count);
1451 if (conn->datadgst_en)
1452 crypto_hash_update(&tcp_conn->tx_hash,
1453 &tcp_ctask->sendbuf.sg,
1454 tcp_ctask->sendbuf.sg.length);
1455 } else if (!(tcp_ctask->xmstate & XMSTATE_W_RESEND_PAD))
1456 return 0;
1457
1458 tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
1459 tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_PAD;
1460 debug_scsi("sending %d pad bytes for itt 0x%x\n",
1461 tcp_ctask->pad_count, ctask->itt);
1462 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
1463 &sent);
1464 if (rc) {
1465 debug_scsi("padding send failed %d\n", rc);
1466 tcp_ctask->xmstate |= XMSTATE_W_RESEND_PAD;
1467 }
1468 return rc;
1469 }
1470
1471 static int
1472 iscsi_send_digest(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1473 struct iscsi_buf *buf, uint32_t *digest)
1474 {
1475 struct iscsi_tcp_cmd_task *tcp_ctask;
1476 struct iscsi_tcp_conn *tcp_conn;
1477 int rc, sent = 0;
1478
1479 if (!conn->datadgst_en)
1480 return 0;
1481
1482 tcp_ctask = ctask->dd_data;
1483 tcp_conn = conn->dd_data;
1484
1485 if (!(tcp_ctask->xmstate & XMSTATE_W_RESEND_DATA_DIGEST)) {
1486 crypto_hash_final(&tcp_conn->tx_hash, (u8*)digest);
1487 iscsi_buf_init_iov(buf, (char*)digest, 4);
1488 }
1489 tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_DATA_DIGEST;
1490
1491 rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
1492 if (!rc)
1493 debug_scsi("sent digest 0x%x for itt 0x%x\n", *digest,
1494 ctask->itt);
1495 else {
1496 debug_scsi("sending digest 0x%x failed for itt 0x%x!\n",
1497 *digest, ctask->itt);
1498 tcp_ctask->xmstate |= XMSTATE_W_RESEND_DATA_DIGEST;
1499 }
1500 return rc;
1501 }
1502
1503 static int
1504 iscsi_send_data(struct iscsi_cmd_task *ctask, struct iscsi_buf *sendbuf,
1505 struct scatterlist **sg, int *sent, int *count,
1506 struct iscsi_buf *digestbuf, uint32_t *digest)
1507 {
1508 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1509 struct iscsi_conn *conn = ctask->conn;
1510 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1511 int rc, buf_sent, offset;
1512
1513 while (*count) {
1514 buf_sent = 0;
1515 offset = sendbuf->sent;
1516
1517 rc = iscsi_sendpage(conn, sendbuf, count, &buf_sent);
1518 *sent = *sent + buf_sent;
1519 if (buf_sent && conn->datadgst_en)
1520 partial_sg_digest_update(&tcp_conn->tx_hash,
1521 &sendbuf->sg, sendbuf->sg.offset + offset,
1522 buf_sent);
1523 if (!iscsi_buf_left(sendbuf) && *sg != tcp_ctask->bad_sg) {
1524 iscsi_buf_init_sg(sendbuf, *sg);
1525 *sg = *sg + 1;
1526 }
1527
1528 if (rc)
1529 return rc;
1530 }
1531
1532 rc = iscsi_send_padding(conn, ctask);
1533 if (rc)
1534 return rc;
1535
1536 return iscsi_send_digest(conn, ctask, digestbuf, digest);
1537 }
1538
1539 static int
1540 iscsi_send_unsol_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1541 {
1542 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1543 struct iscsi_data_task *dtask;
1544 int rc;
1545
1546 tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1547 if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1548 dtask = &tcp_ctask->unsol_dtask;
1549
1550 iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr);
1551 iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
1552 sizeof(struct iscsi_hdr));
1553 if (conn->hdrdgst_en)
1554 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1555 (u8*)dtask->hdrext);
1556
1557 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1558 iscsi_set_padding(tcp_ctask, ctask->data_count);
1559 }
1560
1561 rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count);
1562 if (rc) {
1563 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1564 tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1565 return rc;
1566 }
1567
1568 if (conn->datadgst_en) {
1569 dtask = &tcp_ctask->unsol_dtask;
1570 iscsi_data_digest_init(ctask->conn->dd_data, tcp_ctask);
1571 dtask->digest = 0;
1572 }
1573
1574 debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1575 ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1576 return 0;
1577 }
1578
1579 static int
1580 iscsi_send_unsol_pdu(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1581 {
1582 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1583 int rc;
1584
1585 if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
1586 BUG_ON(!ctask->unsol_count);
1587 tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
1588 send_hdr:
1589 rc = iscsi_send_unsol_hdr(conn, ctask);
1590 if (rc)
1591 return rc;
1592 }
1593
1594 if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
1595 struct iscsi_data_task *dtask = &tcp_ctask->unsol_dtask;
1596 int start = tcp_ctask->sent;
1597
1598 rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
1599 &tcp_ctask->sent, &ctask->data_count,
1600 &dtask->digestbuf, &dtask->digest);
1601 ctask->unsol_count -= tcp_ctask->sent - start;
1602 if (rc)
1603 return rc;
1604 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1605 /*
1606 * Done with the Data-Out. Next, check if we need
1607 * to send another unsolicited Data-Out.
1608 */
1609 if (ctask->unsol_count) {
1610 debug_scsi("sending more uns\n");
1611 tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
1612 goto send_hdr;
1613 }
1614 }
1615 return 0;
1616 }
1617
1618 static int iscsi_send_sol_pdu(struct iscsi_conn *conn,
1619 struct iscsi_cmd_task *ctask)
1620 {
1621 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1622 struct iscsi_session *session = conn->session;
1623 struct iscsi_r2t_info *r2t;
1624 struct iscsi_data_task *dtask;
1625 int left, rc;
1626
1627 if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
1628 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1629 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1630 if (!tcp_ctask->r2t) {
1631 spin_lock_bh(&session->lock);
1632 __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1633 sizeof(void*));
1634 spin_unlock_bh(&session->lock);
1635 }
1636 send_hdr:
1637 r2t = tcp_ctask->r2t;
1638 dtask = &r2t->dtask;
1639
1640 if (conn->hdrdgst_en)
1641 iscsi_hdr_digest(conn, &r2t->headbuf,
1642 (u8*)dtask->hdrext);
1643 rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
1644 if (rc) {
1645 tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1646 tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1647 return rc;
1648 }
1649
1650 if (conn->datadgst_en) {
1651 iscsi_data_digest_init(conn->dd_data, tcp_ctask);
1652 dtask->digest = 0;
1653 }
1654
1655 iscsi_set_padding(tcp_ctask, r2t->data_count);
1656 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
1657 r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
1658 r2t->sent);
1659 }
1660
1661 if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
1662 r2t = tcp_ctask->r2t;
1663 dtask = &r2t->dtask;
1664
1665 rc = iscsi_send_data(ctask, &r2t->sendbuf, &r2t->sg,
1666 &r2t->sent, &r2t->data_count,
1667 &dtask->digestbuf, &dtask->digest);
1668 if (rc)
1669 return rc;
1670 tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1671
1672 /*
1673 * Done with this Data-Out. Next, check if we have
1674 * to send another Data-Out for this R2T.
1675 */
1676 BUG_ON(r2t->data_length - r2t->sent < 0);
1677 left = r2t->data_length - r2t->sent;
1678 if (left) {
1679 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1680 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1681 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1682 goto send_hdr;
1683 }
1684
1685 /*
1686 * Done with this R2T. Check if there are more
1687 * outstanding R2Ts ready to be processed.
1688 */
1689 spin_lock_bh(&session->lock);
1690 tcp_ctask->r2t = NULL;
1691 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
1692 sizeof(void*));
1693 if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t,
1694 sizeof(void*))) {
1695 tcp_ctask->r2t = r2t;
1696 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1697 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1698 spin_unlock_bh(&session->lock);
1699 goto send_hdr;
1700 }
1701 spin_unlock_bh(&session->lock);
1702 }
1703 return 0;
1704 }
1705
1706 static int
1707 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1708 {
1709 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1710 int rc = 0;
1711
1712 debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1713 conn->id, tcp_ctask->xmstate, ctask->itt);
1714
1715 /*
1716 * serialize with TMF AbortTask
1717 */
1718 if (ctask->mtask)
1719 return rc;
1720
1721 if (tcp_ctask->xmstate & XMSTATE_R_HDR)
1722 return iscsi_send_read_hdr(conn, tcp_ctask);
1723
1724 if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
1725 rc = iscsi_send_write_hdr(conn, ctask);
1726 if (rc)
1727 return rc;
1728 }
1729
1730 if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1731 rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
1732 &tcp_ctask->sent, &ctask->imm_count,
1733 &tcp_ctask->immbuf, &tcp_ctask->immdigest);
1734 if (rc)
1735 return rc;
1736 tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1737 }
1738
1739 rc = iscsi_send_unsol_pdu(conn, ctask);
1740 if (rc)
1741 return rc;
1742
1743 rc = iscsi_send_sol_pdu(conn, ctask);
1744 if (rc)
1745 return rc;
1746
1747 return rc;
1748 }
1749
1750 static struct iscsi_cls_conn *
1751 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1752 {
1753 struct iscsi_conn *conn;
1754 struct iscsi_cls_conn *cls_conn;
1755 struct iscsi_tcp_conn *tcp_conn;
1756
1757 cls_conn = iscsi_conn_setup(cls_session, conn_idx);
1758 if (!cls_conn)
1759 return NULL;
1760 conn = cls_conn->dd_data;
1761 /*
1762 * due to strange issues with iser these are not set
1763 * in iscsi_conn_setup
1764 */
1765 conn->max_recv_dlength = ISCSI_DEF_MAX_RECV_SEG_LEN;
1766
1767 tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
1768 if (!tcp_conn)
1769 goto tcp_conn_alloc_fail;
1770
1771 conn->dd_data = tcp_conn;
1772 tcp_conn->iscsi_conn = conn;
1773 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1774 /* initial operational parameters */
1775 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1776
1777 tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1778 CRYPTO_ALG_ASYNC);
1779 tcp_conn->tx_hash.flags = 0;
1780 if (IS_ERR(tcp_conn->tx_hash.tfm)) {
1781 printk(KERN_ERR "Could not create connection due to crc32c "
1782 "loading error %ld. Make sure the crc32c module is "
1783 "built as a module or into the kernel\n",
1784 PTR_ERR(tcp_conn->tx_hash.tfm));
1785 goto free_tcp_conn;
1786 }
1787
1788 tcp_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1789 CRYPTO_ALG_ASYNC);
1790 tcp_conn->rx_hash.flags = 0;
1791 if (IS_ERR(tcp_conn->rx_hash.tfm)) {
1792 printk(KERN_ERR "Could not create connection due to crc32c "
1793 "loading error %ld. Make sure the crc32c module is "
1794 "built as a module or into the kernel\n",
1795 PTR_ERR(tcp_conn->rx_hash.tfm));
1796 goto free_tx_tfm;
1797 }
1798
1799 return cls_conn;
1800
1801 free_tx_tfm:
1802 crypto_free_hash(tcp_conn->tx_hash.tfm);
1803 free_tcp_conn:
1804 kfree(tcp_conn);
1805 tcp_conn_alloc_fail:
1806 iscsi_conn_teardown(cls_conn);
1807 return NULL;
1808 }
1809
1810 static void
1811 iscsi_tcp_release_conn(struct iscsi_conn *conn)
1812 {
1813 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1814
1815 if (!tcp_conn->sock)
1816 return;
1817
1818 sock_hold(tcp_conn->sock->sk);
1819 iscsi_conn_restore_callbacks(tcp_conn);
1820 sock_put(tcp_conn->sock->sk);
1821
1822 sock_release(tcp_conn->sock);
1823 tcp_conn->sock = NULL;
1824 conn->recv_lock = NULL;
1825 }
1826
1827 static void
1828 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1829 {
1830 struct iscsi_conn *conn = cls_conn->dd_data;
1831 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1832
1833 iscsi_tcp_release_conn(conn);
1834 iscsi_conn_teardown(cls_conn);
1835
1836 if (tcp_conn->tx_hash.tfm)
1837 crypto_free_hash(tcp_conn->tx_hash.tfm);
1838 if (tcp_conn->rx_hash.tfm)
1839 crypto_free_hash(tcp_conn->rx_hash.tfm);
1840
1841 kfree(tcp_conn);
1842 }
1843
1844 static void
1845 iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1846 {
1847 struct iscsi_conn *conn = cls_conn->dd_data;
1848 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1849
1850 iscsi_conn_stop(cls_conn, flag);
1851 iscsi_tcp_release_conn(conn);
1852 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1853 }
1854
1855 static int
1856 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1857 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1858 int is_leading)
1859 {
1860 struct iscsi_conn *conn = cls_conn->dd_data;
1861 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1862 struct sock *sk;
1863 struct socket *sock;
1864 int err;
1865
1866 /* lookup for existing socket */
1867 sock = sockfd_lookup((int)transport_eph, &err);
1868 if (!sock) {
1869 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
1870 return -EEXIST;
1871 }
1872
1873 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
1874 if (err)
1875 return err;
1876
1877 /* bind iSCSI connection and socket */
1878 tcp_conn->sock = sock;
1879
1880 /* setup Socket parameters */
1881 sk = sock->sk;
1882 sk->sk_reuse = 1;
1883 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
1884 sk->sk_allocation = GFP_ATOMIC;
1885
1886 /* FIXME: disable Nagle's algorithm */
1887
1888 /*
1889 * Intercept TCP callbacks for sendfile like receive
1890 * processing.
1891 */
1892 conn->recv_lock = &sk->sk_callback_lock;
1893 iscsi_conn_set_callbacks(conn);
1894 tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
1895 /*
1896 * set receive state machine into initial state
1897 */
1898 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1899
1900 return 0;
1901 }
1902
1903 /* called with host lock */
1904 static void
1905 iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask,
1906 char *data, uint32_t data_size)
1907 {
1908 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1909
1910 iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
1911 sizeof(struct iscsi_hdr));
1912 tcp_mtask->xmstate = XMSTATE_IMM_HDR;
1913 tcp_mtask->sent = 0;
1914
1915 if (mtask->data_count)
1916 iscsi_buf_init_iov(&tcp_mtask->sendbuf, (char*)mtask->data,
1917 mtask->data_count);
1918 }
1919
1920 static int
1921 iscsi_r2tpool_alloc(struct iscsi_session *session)
1922 {
1923 int i;
1924 int cmd_i;
1925
1926 /*
1927 * initialize per-task: R2T pool and xmit queue
1928 */
1929 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1930 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1931 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1932
1933 /*
1934 * pre-allocated x4 as much r2ts to handle race when
1935 * target acks DataOut faster than we data_xmit() queues
1936 * could replenish r2tqueue.
1937 */
1938
1939 /* R2T pool */
1940 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
1941 (void***)&tcp_ctask->r2ts,
1942 sizeof(struct iscsi_r2t_info))) {
1943 goto r2t_alloc_fail;
1944 }
1945
1946 /* R2T xmit queue */
1947 tcp_ctask->r2tqueue = kfifo_alloc(
1948 session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
1949 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
1950 iscsi_pool_free(&tcp_ctask->r2tpool,
1951 (void**)tcp_ctask->r2ts);
1952 goto r2t_alloc_fail;
1953 }
1954 }
1955
1956 return 0;
1957
1958 r2t_alloc_fail:
1959 for (i = 0; i < cmd_i; i++) {
1960 struct iscsi_cmd_task *ctask = session->cmds[i];
1961 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1962
1963 kfifo_free(tcp_ctask->r2tqueue);
1964 iscsi_pool_free(&tcp_ctask->r2tpool,
1965 (void**)tcp_ctask->r2ts);
1966 }
1967 return -ENOMEM;
1968 }
1969
1970 static void
1971 iscsi_r2tpool_free(struct iscsi_session *session)
1972 {
1973 int i;
1974
1975 for (i = 0; i < session->cmds_max; i++) {
1976 struct iscsi_cmd_task *ctask = session->cmds[i];
1977 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1978
1979 kfifo_free(tcp_ctask->r2tqueue);
1980 iscsi_pool_free(&tcp_ctask->r2tpool,
1981 (void**)tcp_ctask->r2ts);
1982 }
1983 }
1984
1985 static int
1986 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
1987 char *buf, int buflen)
1988 {
1989 struct iscsi_conn *conn = cls_conn->dd_data;
1990 struct iscsi_session *session = conn->session;
1991 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1992 int value;
1993
1994 switch(param) {
1995 case ISCSI_PARAM_HDRDGST_EN:
1996 iscsi_set_param(cls_conn, param, buf, buflen);
1997 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1998 if (conn->hdrdgst_en)
1999 tcp_conn->hdr_size += sizeof(__u32);
2000 break;
2001 case ISCSI_PARAM_DATADGST_EN:
2002 iscsi_set_param(cls_conn, param, buf, buflen);
2003 tcp_conn->sendpage = conn->datadgst_en ?
2004 sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2005 break;
2006 case ISCSI_PARAM_MAX_R2T:
2007 sscanf(buf, "%d", &value);
2008 if (session->max_r2t == roundup_pow_of_two(value))
2009 break;
2010 iscsi_r2tpool_free(session);
2011 iscsi_set_param(cls_conn, param, buf, buflen);
2012 if (session->max_r2t & (session->max_r2t - 1))
2013 session->max_r2t = roundup_pow_of_two(session->max_r2t);
2014 if (iscsi_r2tpool_alloc(session))
2015 return -ENOMEM;
2016 break;
2017 default:
2018 return iscsi_set_param(cls_conn, param, buf, buflen);
2019 }
2020
2021 return 0;
2022 }
2023
2024 static int
2025 iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
2026 enum iscsi_param param, char *buf)
2027 {
2028 struct iscsi_conn *conn = cls_conn->dd_data;
2029 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2030 struct inet_sock *inet;
2031 struct ipv6_pinfo *np;
2032 struct sock *sk;
2033 int len;
2034
2035 switch(param) {
2036 case ISCSI_PARAM_CONN_PORT:
2037 mutex_lock(&conn->xmitmutex);
2038 if (!tcp_conn->sock) {
2039 mutex_unlock(&conn->xmitmutex);
2040 return -EINVAL;
2041 }
2042
2043 inet = inet_sk(tcp_conn->sock->sk);
2044 len = sprintf(buf, "%hu\n", be16_to_cpu(inet->dport));
2045 mutex_unlock(&conn->xmitmutex);
2046 break;
2047 case ISCSI_PARAM_CONN_ADDRESS:
2048 mutex_lock(&conn->xmitmutex);
2049 if (!tcp_conn->sock) {
2050 mutex_unlock(&conn->xmitmutex);
2051 return -EINVAL;
2052 }
2053
2054 sk = tcp_conn->sock->sk;
2055 if (sk->sk_family == PF_INET) {
2056 inet = inet_sk(sk);
2057 len = sprintf(buf, NIPQUAD_FMT "\n",
2058 NIPQUAD(inet->daddr));
2059 } else {
2060 np = inet6_sk(sk);
2061 len = sprintf(buf, NIP6_FMT "\n", NIP6(np->daddr));
2062 }
2063 mutex_unlock(&conn->xmitmutex);
2064 break;
2065 default:
2066 return iscsi_conn_get_param(cls_conn, param, buf);
2067 }
2068
2069 return len;
2070 }
2071
2072 static void
2073 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2074 {
2075 struct iscsi_conn *conn = cls_conn->dd_data;
2076 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2077
2078 stats->txdata_octets = conn->txdata_octets;
2079 stats->rxdata_octets = conn->rxdata_octets;
2080 stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
2081 stats->dataout_pdus = conn->dataout_pdus_cnt;
2082 stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
2083 stats->datain_pdus = conn->datain_pdus_cnt;
2084 stats->r2t_pdus = conn->r2t_pdus_cnt;
2085 stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
2086 stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
2087 stats->custom_length = 3;
2088 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2089 stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2090 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2091 stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2092 strcpy(stats->custom[2].desc, "eh_abort_cnt");
2093 stats->custom[2].value = conn->eh_abort_cnt;
2094 }
2095
2096 static struct iscsi_cls_session *
2097 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
2098 struct scsi_transport_template *scsit,
2099 uint32_t initial_cmdsn, uint32_t *hostno)
2100 {
2101 struct iscsi_cls_session *cls_session;
2102 struct iscsi_session *session;
2103 uint32_t hn;
2104 int cmd_i;
2105
2106 cls_session = iscsi_session_setup(iscsit, scsit,
2107 sizeof(struct iscsi_tcp_cmd_task),
2108 sizeof(struct iscsi_tcp_mgmt_task),
2109 initial_cmdsn, &hn);
2110 if (!cls_session)
2111 return NULL;
2112 *hostno = hn;
2113
2114 session = class_to_transport_session(cls_session);
2115 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2116 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2117 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2118
2119 ctask->hdr = &tcp_ctask->hdr;
2120 }
2121
2122 for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
2123 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
2124 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2125
2126 mtask->hdr = &tcp_mtask->hdr;
2127 }
2128
2129 if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
2130 goto r2tpool_alloc_fail;
2131
2132 return cls_session;
2133
2134 r2tpool_alloc_fail:
2135 iscsi_session_teardown(cls_session);
2136 return NULL;
2137 }
2138
2139 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
2140 {
2141 iscsi_r2tpool_free(class_to_transport_session(cls_session));
2142 iscsi_session_teardown(cls_session);
2143 }
2144
2145 static struct scsi_host_template iscsi_sht = {
2146 .name = "iSCSI Initiator over TCP/IP",
2147 .queuecommand = iscsi_queuecommand,
2148 .change_queue_depth = iscsi_change_queue_depth,
2149 .can_queue = ISCSI_XMIT_CMDS_MAX - 1,
2150 .sg_tablesize = ISCSI_SG_TABLESIZE,
2151 .max_sectors = 0xFFFF,
2152 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
2153 .eh_abort_handler = iscsi_eh_abort,
2154 .eh_host_reset_handler = iscsi_eh_host_reset,
2155 .use_clustering = DISABLE_CLUSTERING,
2156 .proc_name = "iscsi_tcp",
2157 .this_id = -1,
2158 };
2159
2160 static struct iscsi_transport iscsi_tcp_transport = {
2161 .owner = THIS_MODULE,
2162 .name = "tcp",
2163 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
2164 | CAP_DATADGST,
2165 .param_mask = ISCSI_MAX_RECV_DLENGTH |
2166 ISCSI_MAX_XMIT_DLENGTH |
2167 ISCSI_HDRDGST_EN |
2168 ISCSI_DATADGST_EN |
2169 ISCSI_INITIAL_R2T_EN |
2170 ISCSI_MAX_R2T |
2171 ISCSI_IMM_DATA_EN |
2172 ISCSI_FIRST_BURST |
2173 ISCSI_MAX_BURST |
2174 ISCSI_PDU_INORDER_EN |
2175 ISCSI_DATASEQ_INORDER_EN |
2176 ISCSI_ERL |
2177 ISCSI_CONN_PORT |
2178 ISCSI_CONN_ADDRESS |
2179 ISCSI_EXP_STATSN |
2180 ISCSI_PERSISTENT_PORT |
2181 ISCSI_PERSISTENT_ADDRESS |
2182 ISCSI_TARGET_NAME |
2183 ISCSI_TPGT,
2184 .host_template = &iscsi_sht,
2185 .conndata_size = sizeof(struct iscsi_conn),
2186 .max_conn = 1,
2187 .max_cmd_len = ISCSI_TCP_MAX_CMD_LEN,
2188 /* session management */
2189 .create_session = iscsi_tcp_session_create,
2190 .destroy_session = iscsi_tcp_session_destroy,
2191 /* connection management */
2192 .create_conn = iscsi_tcp_conn_create,
2193 .bind_conn = iscsi_tcp_conn_bind,
2194 .destroy_conn = iscsi_tcp_conn_destroy,
2195 .set_param = iscsi_conn_set_param,
2196 .get_conn_param = iscsi_tcp_conn_get_param,
2197 .get_session_param = iscsi_session_get_param,
2198 .start_conn = iscsi_conn_start,
2199 .stop_conn = iscsi_tcp_conn_stop,
2200 /* IO */
2201 .send_pdu = iscsi_conn_send_pdu,
2202 .get_stats = iscsi_conn_get_stats,
2203 .init_cmd_task = iscsi_tcp_cmd_init,
2204 .init_mgmt_task = iscsi_tcp_mgmt_init,
2205 .xmit_cmd_task = iscsi_tcp_ctask_xmit,
2206 .xmit_mgmt_task = iscsi_tcp_mtask_xmit,
2207 .cleanup_cmd_task = iscsi_tcp_cleanup_ctask,
2208 /* recovery */
2209 .session_recovery_timedout = iscsi_session_recovery_timedout,
2210 };
2211
2212 static int __init
2213 iscsi_tcp_init(void)
2214 {
2215 if (iscsi_max_lun < 1) {
2216 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2217 iscsi_max_lun);
2218 return -EINVAL;
2219 }
2220 iscsi_tcp_transport.max_lun = iscsi_max_lun;
2221
2222 if (!iscsi_register_transport(&iscsi_tcp_transport))
2223 return -ENODEV;
2224
2225 return 0;
2226 }
2227
2228 static void __exit
2229 iscsi_tcp_exit(void)
2230 {
2231 iscsi_unregister_transport(&iscsi_tcp_transport);
2232 }
2233
2234 module_init(iscsi_tcp_init);
2235 module_exit(iscsi_tcp_exit);
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