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[SCSI] libiscsi, iscsi_tcp: add device support
[deliverable/linux.git] / drivers / scsi / iscsi_tcp.c
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/file.h>
33 #include <linux/blkdev.h>
34 #include <linux/crypto.h>
35 #include <linux/delay.h>
36 #include <linux/kfifo.h>
37 #include <linux/scatterlist.h>
38 #include <net/tcp.h>
39 #include <scsi/scsi_cmnd.h>
40 #include <scsi/scsi_device.h>
41 #include <scsi/scsi_host.h>
42 #include <scsi/scsi.h>
43 #include <scsi/scsi_transport_iscsi.h>
44
45 #include "iscsi_tcp.h"
46
47 MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
48 "Alex Aizman <itn780@yahoo.com>");
49 MODULE_DESCRIPTION("iSCSI/TCP data-path");
50 MODULE_LICENSE("GPL");
51 /* #define DEBUG_TCP */
52 #define DEBUG_ASSERT
53
54 #ifdef DEBUG_TCP
55 #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
56 #else
57 #define debug_tcp(fmt...)
58 #endif
59
60 #ifndef DEBUG_ASSERT
61 #ifdef BUG_ON
62 #undef BUG_ON
63 #endif
64 #define BUG_ON(expr)
65 #endif
66
67 static unsigned int iscsi_max_lun = 512;
68 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
69
70 static inline void
71 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
72 {
73 sg_init_one(&ibuf->sg, vbuf, size);
74 ibuf->sent = 0;
75 ibuf->use_sendmsg = 1;
76 }
77
78 static inline void
79 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
80 {
81 sg_init_table(&ibuf->sg, 1);
82 sg_set_page(&ibuf->sg, sg_page(sg), sg->length, sg->offset);
83 /*
84 * Fastpath: sg element fits into single page
85 */
86 if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg_page(sg)))
87 ibuf->use_sendmsg = 0;
88 else
89 ibuf->use_sendmsg = 1;
90 ibuf->sent = 0;
91 }
92
93 static inline int
94 iscsi_buf_left(struct iscsi_buf *ibuf)
95 {
96 int rc;
97
98 rc = ibuf->sg.length - ibuf->sent;
99 BUG_ON(rc < 0);
100 return rc;
101 }
102
103 static inline void
104 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
105 u8* crc)
106 {
107 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
108
109 crypto_hash_digest(&tcp_conn->tx_hash, &buf->sg, buf->sg.length, crc);
110 buf->sg.length += sizeof(u32);
111 }
112
113 static inline int
114 iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
115 {
116 struct sk_buff *skb = tcp_conn->in.skb;
117
118 tcp_conn->in.zero_copy_hdr = 0;
119
120 if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
121 tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
122 /*
123 * Zero-copy PDU Header: using connection context
124 * to store header pointer.
125 */
126 if (skb_shinfo(skb)->frag_list == NULL &&
127 !skb_shinfo(skb)->nr_frags) {
128 tcp_conn->in.hdr = (struct iscsi_hdr *)
129 ((char*)skb->data + tcp_conn->in.offset);
130 tcp_conn->in.zero_copy_hdr = 1;
131 } else {
132 /* ignoring return code since we checked
133 * in.copy before */
134 skb_copy_bits(skb, tcp_conn->in.offset,
135 &tcp_conn->hdr, tcp_conn->hdr_size);
136 tcp_conn->in.hdr = &tcp_conn->hdr;
137 }
138 tcp_conn->in.offset += tcp_conn->hdr_size;
139 tcp_conn->in.copy -= tcp_conn->hdr_size;
140 } else {
141 int hdr_remains;
142 int copylen;
143
144 /*
145 * PDU header scattered across SKB's,
146 * copying it... This'll happen quite rarely.
147 */
148
149 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
150 tcp_conn->in.hdr_offset = 0;
151
152 hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
153 BUG_ON(hdr_remains <= 0);
154
155 copylen = min(tcp_conn->in.copy, hdr_remains);
156 skb_copy_bits(skb, tcp_conn->in.offset,
157 (char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset,
158 copylen);
159
160 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
161 "in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
162 tcp_conn->in.offset, tcp_conn->in.copy);
163
164 tcp_conn->in.offset += copylen;
165 tcp_conn->in.copy -= copylen;
166 if (copylen < hdr_remains) {
167 tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
168 tcp_conn->in.hdr_offset += copylen;
169 return -EAGAIN;
170 }
171 tcp_conn->in.hdr = &tcp_conn->hdr;
172 tcp_conn->discontiguous_hdr_cnt++;
173 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
174 }
175
176 return 0;
177 }
178
179 /*
180 * must be called with session lock
181 */
182 static void
183 iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
184 {
185 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
186 struct iscsi_r2t_info *r2t;
187 struct scsi_cmnd *sc;
188
189 /* flush ctask's r2t queues */
190 while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
191 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
192 sizeof(void*));
193 debug_scsi("iscsi_tcp_cleanup_ctask pending r2t dropped\n");
194 }
195
196 sc = ctask->sc;
197 if (unlikely(!sc))
198 return;
199
200 tcp_ctask->xmstate = XMSTATE_IDLE;
201 tcp_ctask->r2t = NULL;
202 }
203
204 /**
205 * iscsi_data_rsp - SCSI Data-In Response processing
206 * @conn: iscsi connection
207 * @ctask: scsi command task
208 **/
209 static int
210 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
211 {
212 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
213 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
214 struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
215 struct iscsi_session *session = conn->session;
216 struct scsi_cmnd *sc = ctask->sc;
217 int datasn = be32_to_cpu(rhdr->datasn);
218
219 iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
220 /*
221 * setup Data-In byte counter (gets decremented..)
222 */
223 ctask->data_count = tcp_conn->in.datalen;
224
225 if (tcp_conn->in.datalen == 0)
226 return 0;
227
228 if (tcp_ctask->exp_datasn != datasn) {
229 debug_tcp("%s: ctask->exp_datasn(%d) != rhdr->datasn(%d)\n",
230 __FUNCTION__, tcp_ctask->exp_datasn, datasn);
231 return ISCSI_ERR_DATASN;
232 }
233
234 tcp_ctask->exp_datasn++;
235
236 tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
237 if (tcp_ctask->data_offset + tcp_conn->in.datalen > scsi_bufflen(sc)) {
238 debug_tcp("%s: data_offset(%d) + data_len(%d) > total_length_in(%d)\n",
239 __FUNCTION__, tcp_ctask->data_offset,
240 tcp_conn->in.datalen, scsi_bufflen(sc));
241 return ISCSI_ERR_DATA_OFFSET;
242 }
243
244 if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
245 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
246 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
247 int res_count = be32_to_cpu(rhdr->residual_count);
248
249 if (res_count > 0 &&
250 res_count <= scsi_bufflen(sc)) {
251 scsi_set_resid(sc, res_count);
252 sc->result = (DID_OK << 16) | rhdr->cmd_status;
253 } else
254 sc->result = (DID_BAD_TARGET << 16) |
255 rhdr->cmd_status;
256 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
257 scsi_set_resid(sc, be32_to_cpu(rhdr->residual_count));
258 sc->result = (DID_OK << 16) | rhdr->cmd_status;
259 } else
260 sc->result = (DID_OK << 16) | rhdr->cmd_status;
261 }
262
263 conn->datain_pdus_cnt++;
264 return 0;
265 }
266
267 /**
268 * iscsi_solicit_data_init - initialize first Data-Out
269 * @conn: iscsi connection
270 * @ctask: scsi command task
271 * @r2t: R2T info
272 *
273 * Notes:
274 * Initialize first Data-Out within this R2T sequence and finds
275 * proper data_offset within this SCSI command.
276 *
277 * This function is called with connection lock taken.
278 **/
279 static void
280 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
281 struct iscsi_r2t_info *r2t)
282 {
283 struct iscsi_data *hdr;
284 struct scsi_cmnd *sc = ctask->sc;
285 int i, sg_count = 0;
286 struct scatterlist *sg;
287
288 hdr = &r2t->dtask.hdr;
289 memset(hdr, 0, sizeof(struct iscsi_data));
290 hdr->ttt = r2t->ttt;
291 hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
292 r2t->solicit_datasn++;
293 hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
294 memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
295 hdr->itt = ctask->hdr->itt;
296 hdr->exp_statsn = r2t->exp_statsn;
297 hdr->offset = cpu_to_be32(r2t->data_offset);
298 if (r2t->data_length > conn->max_xmit_dlength) {
299 hton24(hdr->dlength, conn->max_xmit_dlength);
300 r2t->data_count = conn->max_xmit_dlength;
301 hdr->flags = 0;
302 } else {
303 hton24(hdr->dlength, r2t->data_length);
304 r2t->data_count = r2t->data_length;
305 hdr->flags = ISCSI_FLAG_CMD_FINAL;
306 }
307 conn->dataout_pdus_cnt++;
308
309 r2t->sent = 0;
310
311 iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
312 sizeof(struct iscsi_hdr));
313
314 sg = scsi_sglist(sc);
315 r2t->sg = NULL;
316 for (i = 0; i < scsi_sg_count(sc); 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 }
339
340 /**
341 * iscsi_r2t_rsp - iSCSI R2T Response processing
342 * @conn: iscsi connection
343 * @ctask: scsi command task
344 **/
345 static int
346 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
347 {
348 struct iscsi_r2t_info *r2t;
349 struct iscsi_session *session = conn->session;
350 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
351 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
352 struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
353 int r2tsn = be32_to_cpu(rhdr->r2tsn);
354 int rc;
355
356 if (tcp_conn->in.datalen) {
357 printk(KERN_ERR "iscsi_tcp: invalid R2t with datalen %d\n",
358 tcp_conn->in.datalen);
359 return ISCSI_ERR_DATALEN;
360 }
361
362 if (tcp_ctask->exp_datasn != r2tsn){
363 debug_tcp("%s: ctask->exp_datasn(%d) != rhdr->r2tsn(%d)\n",
364 __FUNCTION__, tcp_ctask->exp_datasn, r2tsn);
365 return ISCSI_ERR_R2TSN;
366 }
367
368 /* fill-in new R2T associated with the task */
369 spin_lock(&session->lock);
370 iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
371
372 if (!ctask->sc || session->state != ISCSI_STATE_LOGGED_IN) {
373 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
374 "recovery...\n", ctask->itt);
375 spin_unlock(&session->lock);
376 return 0;
377 }
378
379 rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
380 BUG_ON(!rc);
381
382 r2t->exp_statsn = rhdr->statsn;
383 r2t->data_length = be32_to_cpu(rhdr->data_length);
384 if (r2t->data_length == 0) {
385 printk(KERN_ERR "iscsi_tcp: invalid R2T with zero data len\n");
386 spin_unlock(&session->lock);
387 return ISCSI_ERR_DATALEN;
388 }
389
390 if (r2t->data_length > session->max_burst)
391 debug_scsi("invalid R2T with data len %u and max burst %u."
392 "Attempting to execute request.\n",
393 r2t->data_length, session->max_burst);
394
395 r2t->data_offset = be32_to_cpu(rhdr->data_offset);
396 if (r2t->data_offset + r2t->data_length > scsi_bufflen(ctask->sc)) {
397 spin_unlock(&session->lock);
398 printk(KERN_ERR "iscsi_tcp: invalid R2T with data len %u at "
399 "offset %u and total length %d\n", r2t->data_length,
400 r2t->data_offset, scsi_bufflen(ctask->sc));
401 return ISCSI_ERR_DATALEN;
402 }
403
404 r2t->ttt = rhdr->ttt; /* no flip */
405 r2t->solicit_datasn = 0;
406
407 iscsi_solicit_data_init(conn, ctask, r2t);
408
409 tcp_ctask->exp_datasn = r2tsn + 1;
410 __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
411 tcp_ctask->xmstate |= XMSTATE_SOL_HDR_INIT;
412 conn->r2t_pdus_cnt++;
413
414 iscsi_requeue_ctask(ctask);
415 spin_unlock(&session->lock);
416
417 return 0;
418 }
419
420 static int
421 iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
422 {
423 int rc = 0, opcode, ahslen;
424 struct iscsi_hdr *hdr;
425 struct iscsi_session *session = conn->session;
426 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
427 uint32_t cdgst, rdgst = 0, itt;
428
429 hdr = tcp_conn->in.hdr;
430
431 /* verify PDU length */
432 tcp_conn->in.datalen = ntoh24(hdr->dlength);
433 if (tcp_conn->in.datalen > conn->max_recv_dlength) {
434 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
435 tcp_conn->in.datalen, conn->max_recv_dlength);
436 return ISCSI_ERR_DATALEN;
437 }
438 tcp_conn->data_copied = 0;
439
440 /* read AHS */
441 ahslen = hdr->hlength << 2;
442 tcp_conn->in.offset += ahslen;
443 tcp_conn->in.copy -= ahslen;
444 if (tcp_conn->in.copy < 0) {
445 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
446 "%d bytes\n", ahslen);
447 return ISCSI_ERR_AHSLEN;
448 }
449
450 /* calculate read padding */
451 tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
452 if (tcp_conn->in.padding) {
453 tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
454 debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
455 }
456
457 if (conn->hdrdgst_en) {
458 struct scatterlist sg;
459
460 sg_init_one(&sg, (u8 *)hdr,
461 sizeof(struct iscsi_hdr) + ahslen);
462 crypto_hash_digest(&tcp_conn->rx_hash, &sg, sg.length,
463 (u8 *)&cdgst);
464 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
465 ahslen);
466 if (cdgst != rdgst) {
467 printk(KERN_ERR "iscsi_tcp: hdrdgst error "
468 "recv 0x%x calc 0x%x\n", rdgst, cdgst);
469 return ISCSI_ERR_HDR_DGST;
470 }
471 }
472
473 opcode = hdr->opcode & ISCSI_OPCODE_MASK;
474 /* verify itt (itt encoding: age+cid+itt) */
475 rc = iscsi_verify_itt(conn, hdr, &itt);
476 if (rc == ISCSI_ERR_NO_SCSI_CMD) {
477 tcp_conn->in.datalen = 0; /* force drop */
478 return 0;
479 } else if (rc)
480 return rc;
481
482 debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
483 opcode, tcp_conn->in.offset, tcp_conn->in.copy,
484 ahslen, tcp_conn->in.datalen);
485
486 switch(opcode) {
487 case ISCSI_OP_SCSI_DATA_IN:
488 tcp_conn->in.ctask = session->cmds[itt];
489 rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
490 if (rc)
491 return rc;
492 /* fall through */
493 case ISCSI_OP_SCSI_CMD_RSP:
494 tcp_conn->in.ctask = session->cmds[itt];
495 if (tcp_conn->in.datalen)
496 goto copy_hdr;
497
498 spin_lock(&session->lock);
499 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
500 spin_unlock(&session->lock);
501 break;
502 case ISCSI_OP_R2T:
503 tcp_conn->in.ctask = session->cmds[itt];
504 if (ahslen)
505 rc = ISCSI_ERR_AHSLEN;
506 else if (tcp_conn->in.ctask->sc->sc_data_direction ==
507 DMA_TO_DEVICE)
508 rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
509 else
510 rc = ISCSI_ERR_PROTO;
511 break;
512 case ISCSI_OP_LOGIN_RSP:
513 case ISCSI_OP_TEXT_RSP:
514 case ISCSI_OP_REJECT:
515 case ISCSI_OP_ASYNC_EVENT:
516 /*
517 * It is possible that we could get a PDU with a buffer larger
518 * than 8K, but there are no targets that currently do this.
519 * For now we fail until we find a vendor that needs it
520 */
521 if (ISCSI_DEF_MAX_RECV_SEG_LEN <
522 tcp_conn->in.datalen) {
523 printk(KERN_ERR "iscsi_tcp: received buffer of len %u "
524 "but conn buffer is only %u (opcode %0x)\n",
525 tcp_conn->in.datalen,
526 ISCSI_DEF_MAX_RECV_SEG_LEN, opcode);
527 rc = ISCSI_ERR_PROTO;
528 break;
529 }
530
531 if (tcp_conn->in.datalen)
532 goto copy_hdr;
533 /* fall through */
534 case ISCSI_OP_LOGOUT_RSP:
535 case ISCSI_OP_NOOP_IN:
536 case ISCSI_OP_SCSI_TMFUNC_RSP:
537 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
538 break;
539 default:
540 rc = ISCSI_ERR_BAD_OPCODE;
541 break;
542 }
543
544 return rc;
545
546 copy_hdr:
547 /*
548 * if we did zero copy for the header but we will need multiple
549 * skbs to complete the command then we have to copy the header
550 * for later use
551 */
552 if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <=
553 (tcp_conn->in.datalen + tcp_conn->in.padding +
554 (conn->datadgst_en ? 4 : 0))) {
555 debug_tcp("Copying header for later use. in.copy %d in.datalen"
556 " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
557 memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
558 sizeof(struct iscsi_hdr));
559 tcp_conn->in.hdr = &tcp_conn->hdr;
560 tcp_conn->in.zero_copy_hdr = 0;
561 }
562 return 0;
563 }
564
565 /**
566 * iscsi_ctask_copy - copy skb bits to the destanation cmd task
567 * @conn: iscsi tcp connection
568 * @ctask: scsi command task
569 * @buf: buffer to copy to
570 * @buf_size: size of buffer
571 * @offset: offset within the buffer
572 *
573 * Notes:
574 * The function calls skb_copy_bits() and updates per-connection and
575 * per-cmd byte counters.
576 *
577 * Read counters (in bytes):
578 *
579 * conn->in.offset offset within in progress SKB
580 * conn->in.copy left to copy from in progress SKB
581 * including padding
582 * conn->in.copied copied already from in progress SKB
583 * conn->data_copied copied already from in progress buffer
584 * ctask->sent total bytes sent up to the MidLayer
585 * ctask->data_count left to copy from in progress Data-In
586 * buf_left left to copy from in progress buffer
587 **/
588 static inline int
589 iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
590 void *buf, int buf_size, int offset)
591 {
592 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
593 int buf_left = buf_size - (tcp_conn->data_copied + offset);
594 unsigned size = min(tcp_conn->in.copy, buf_left);
595 int rc;
596
597 size = min(size, ctask->data_count);
598
599 debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
600 size, tcp_conn->in.offset, tcp_conn->in.copied);
601
602 BUG_ON(size <= 0);
603 BUG_ON(tcp_ctask->sent + size > scsi_bufflen(ctask->sc));
604
605 rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
606 (char*)buf + (offset + tcp_conn->data_copied), size);
607 /* must fit into skb->len */
608 BUG_ON(rc);
609
610 tcp_conn->in.offset += size;
611 tcp_conn->in.copy -= size;
612 tcp_conn->in.copied += size;
613 tcp_conn->data_copied += size;
614 tcp_ctask->sent += size;
615 ctask->data_count -= size;
616
617 BUG_ON(tcp_conn->in.copy < 0);
618 BUG_ON(ctask->data_count < 0);
619
620 if (buf_size != (tcp_conn->data_copied + offset)) {
621 if (!ctask->data_count) {
622 BUG_ON(buf_size - tcp_conn->data_copied < 0);
623 /* done with this PDU */
624 return buf_size - tcp_conn->data_copied;
625 }
626 return -EAGAIN;
627 }
628
629 /* done with this buffer or with both - PDU and buffer */
630 tcp_conn->data_copied = 0;
631 return 0;
632 }
633
634 /**
635 * iscsi_tcp_copy - copy skb bits to the destanation buffer
636 * @conn: iscsi tcp connection
637 *
638 * Notes:
639 * The function calls skb_copy_bits() and updates per-connection
640 * byte counters.
641 **/
642 static inline int
643 iscsi_tcp_copy(struct iscsi_conn *conn, int buf_size)
644 {
645 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
646 int buf_left = buf_size - tcp_conn->data_copied;
647 int size = min(tcp_conn->in.copy, buf_left);
648 int rc;
649
650 debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
651 size, tcp_conn->in.offset, tcp_conn->data_copied);
652 BUG_ON(size <= 0);
653
654 rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
655 (char*)conn->data + tcp_conn->data_copied, size);
656 BUG_ON(rc);
657
658 tcp_conn->in.offset += size;
659 tcp_conn->in.copy -= size;
660 tcp_conn->in.copied += size;
661 tcp_conn->data_copied += size;
662
663 if (buf_size != tcp_conn->data_copied)
664 return -EAGAIN;
665
666 return 0;
667 }
668
669 static inline void
670 partial_sg_digest_update(struct hash_desc *desc, struct scatterlist *sg,
671 int offset, int length)
672 {
673 struct scatterlist temp;
674
675 sg_init_table(&temp, 1);
676 sg_set_page(&temp, sg_page(sg), length, offset);
677 crypto_hash_update(desc, &temp, length);
678 }
679
680 static void
681 iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
682 {
683 struct scatterlist tmp;
684
685 sg_init_one(&tmp, buf, len);
686 crypto_hash_update(&tcp_conn->rx_hash, &tmp, len);
687 }
688
689 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
690 {
691 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
692 struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
693 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
694 struct scsi_cmnd *sc = ctask->sc;
695 struct scatterlist *sg;
696 int i, offset, rc = 0;
697
698 BUG_ON((void*)ctask != sc->SCp.ptr);
699
700 offset = tcp_ctask->data_offset;
701 sg = scsi_sglist(sc);
702
703 if (tcp_ctask->data_offset)
704 for (i = 0; i < tcp_ctask->sg_count; i++)
705 offset -= sg[i].length;
706 /* we've passed through partial sg*/
707 if (offset < 0)
708 offset = 0;
709
710 for (i = tcp_ctask->sg_count; i < scsi_sg_count(sc); i++) {
711 char *dest;
712
713 dest = kmap_atomic(sg_page(&sg[i]), KM_SOFTIRQ0);
714 rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
715 sg[i].length, offset);
716 kunmap_atomic(dest, KM_SOFTIRQ0);
717 if (rc == -EAGAIN)
718 /* continue with the next SKB/PDU */
719 return rc;
720 if (!rc) {
721 if (conn->datadgst_en) {
722 if (!offset)
723 crypto_hash_update(
724 &tcp_conn->rx_hash,
725 &sg[i], sg[i].length);
726 else
727 partial_sg_digest_update(
728 &tcp_conn->rx_hash,
729 &sg[i],
730 sg[i].offset + offset,
731 sg[i].length - offset);
732 }
733 offset = 0;
734 tcp_ctask->sg_count++;
735 }
736
737 if (!ctask->data_count) {
738 if (rc && conn->datadgst_en)
739 /*
740 * data-in is complete, but buffer not...
741 */
742 partial_sg_digest_update(&tcp_conn->rx_hash,
743 &sg[i],
744 sg[i].offset,
745 sg[i].length-rc);
746 rc = 0;
747 break;
748 }
749
750 if (!tcp_conn->in.copy)
751 return -EAGAIN;
752 }
753 BUG_ON(ctask->data_count);
754
755 /* check for non-exceptional status */
756 if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
757 debug_scsi("done [sc %lx res %d itt 0x%x flags 0x%x]\n",
758 (long)sc, sc->result, ctask->itt,
759 tcp_conn->in.hdr->flags);
760 spin_lock(&conn->session->lock);
761 __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
762 spin_unlock(&conn->session->lock);
763 }
764
765 return rc;
766 }
767
768 static int
769 iscsi_data_recv(struct iscsi_conn *conn)
770 {
771 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
772 int rc = 0, opcode;
773
774 opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
775 switch (opcode) {
776 case ISCSI_OP_SCSI_DATA_IN:
777 rc = iscsi_scsi_data_in(conn);
778 break;
779 case ISCSI_OP_SCSI_CMD_RSP:
780 case ISCSI_OP_TEXT_RSP:
781 case ISCSI_OP_LOGIN_RSP:
782 case ISCSI_OP_ASYNC_EVENT:
783 case ISCSI_OP_REJECT:
784 /*
785 * Collect data segment to the connection's data
786 * placeholder
787 */
788 if (iscsi_tcp_copy(conn, tcp_conn->in.datalen)) {
789 rc = -EAGAIN;
790 goto exit;
791 }
792
793 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, conn->data,
794 tcp_conn->in.datalen);
795 if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
796 iscsi_recv_digest_update(tcp_conn, conn->data,
797 tcp_conn->in.datalen);
798 break;
799 default:
800 BUG_ON(1);
801 }
802 exit:
803 return rc;
804 }
805
806 /**
807 * iscsi_tcp_data_recv - TCP receive in sendfile fashion
808 * @rd_desc: read descriptor
809 * @skb: socket buffer
810 * @offset: offset in skb
811 * @len: skb->len - offset
812 **/
813 static int
814 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
815 unsigned int offset, size_t len)
816 {
817 int rc;
818 struct iscsi_conn *conn = rd_desc->arg.data;
819 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
820 int processed;
821 char pad[ISCSI_PAD_LEN];
822 struct scatterlist sg;
823
824 /*
825 * Save current SKB and its offset in the corresponding
826 * connection context.
827 */
828 tcp_conn->in.copy = skb->len - offset;
829 tcp_conn->in.offset = offset;
830 tcp_conn->in.skb = skb;
831 tcp_conn->in.len = tcp_conn->in.copy;
832 BUG_ON(tcp_conn->in.copy <= 0);
833 debug_tcp("in %d bytes\n", tcp_conn->in.copy);
834
835 more:
836 tcp_conn->in.copied = 0;
837 rc = 0;
838
839 if (unlikely(conn->suspend_rx)) {
840 debug_tcp("conn %d Rx suspended!\n", conn->id);
841 return 0;
842 }
843
844 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
845 tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
846 rc = iscsi_hdr_extract(tcp_conn);
847 if (rc) {
848 if (rc == -EAGAIN)
849 goto nomore;
850 else {
851 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
852 return 0;
853 }
854 }
855
856 /*
857 * Verify and process incoming PDU header.
858 */
859 rc = iscsi_tcp_hdr_recv(conn);
860 if (!rc && tcp_conn->in.datalen) {
861 if (conn->datadgst_en)
862 crypto_hash_init(&tcp_conn->rx_hash);
863 tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
864 } else if (rc) {
865 iscsi_conn_failure(conn, rc);
866 return 0;
867 }
868 }
869
870 if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV &&
871 tcp_conn->in.copy) {
872 uint32_t recv_digest;
873
874 debug_tcp("extra data_recv offset %d copy %d\n",
875 tcp_conn->in.offset, tcp_conn->in.copy);
876
877 if (!tcp_conn->data_copied) {
878 if (tcp_conn->in.padding) {
879 debug_tcp("padding -> %d\n",
880 tcp_conn->in.padding);
881 memset(pad, 0, tcp_conn->in.padding);
882 sg_init_one(&sg, pad, tcp_conn->in.padding);
883 crypto_hash_update(&tcp_conn->rx_hash,
884 &sg, sg.length);
885 }
886 crypto_hash_final(&tcp_conn->rx_hash,
887 (u8 *) &tcp_conn->in.datadgst);
888 debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
889 }
890
891 rc = iscsi_tcp_copy(conn, sizeof(uint32_t));
892 if (rc) {
893 if (rc == -EAGAIN)
894 goto again;
895 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
896 return 0;
897 }
898
899 memcpy(&recv_digest, conn->data, sizeof(uint32_t));
900 if (recv_digest != tcp_conn->in.datadgst) {
901 debug_tcp("iscsi_tcp: data digest error!"
902 "0x%x != 0x%x\n", recv_digest,
903 tcp_conn->in.datadgst);
904 iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
905 return 0;
906 } else {
907 debug_tcp("iscsi_tcp: data digest match!"
908 "0x%x == 0x%x\n", recv_digest,
909 tcp_conn->in.datadgst);
910 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
911 }
912 }
913
914 if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
915 tcp_conn->in.copy) {
916 debug_tcp("data_recv offset %d copy %d\n",
917 tcp_conn->in.offset, tcp_conn->in.copy);
918
919 rc = iscsi_data_recv(conn);
920 if (rc) {
921 if (rc == -EAGAIN)
922 goto again;
923 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
924 return 0;
925 }
926
927 if (tcp_conn->in.padding)
928 tcp_conn->in_progress = IN_PROGRESS_PAD_RECV;
929 else if (conn->datadgst_en)
930 tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
931 else
932 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
933 tcp_conn->data_copied = 0;
934 }
935
936 if (tcp_conn->in_progress == IN_PROGRESS_PAD_RECV &&
937 tcp_conn->in.copy) {
938 int copylen = min(tcp_conn->in.padding - tcp_conn->data_copied,
939 tcp_conn->in.copy);
940
941 tcp_conn->in.copy -= copylen;
942 tcp_conn->in.offset += copylen;
943 tcp_conn->data_copied += copylen;
944
945 if (tcp_conn->data_copied != tcp_conn->in.padding)
946 tcp_conn->in_progress = IN_PROGRESS_PAD_RECV;
947 else if (conn->datadgst_en)
948 tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
949 else
950 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
951 tcp_conn->data_copied = 0;
952 }
953
954 debug_tcp("f, processed %d from out of %d padding %d\n",
955 tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
956 BUG_ON(tcp_conn->in.offset - offset > len);
957
958 if (tcp_conn->in.offset - offset != len) {
959 debug_tcp("continue to process %d bytes\n",
960 (int)len - (tcp_conn->in.offset - offset));
961 goto more;
962 }
963
964 nomore:
965 processed = tcp_conn->in.offset - offset;
966 BUG_ON(processed == 0);
967 return processed;
968
969 again:
970 processed = tcp_conn->in.offset - offset;
971 debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
972 processed, (int)len, (int)rd_desc->count);
973 BUG_ON(processed == 0);
974 BUG_ON(processed > len);
975
976 conn->rxdata_octets += processed;
977 return processed;
978 }
979
980 static void
981 iscsi_tcp_data_ready(struct sock *sk, int flag)
982 {
983 struct iscsi_conn *conn = sk->sk_user_data;
984 read_descriptor_t rd_desc;
985
986 read_lock(&sk->sk_callback_lock);
987
988 /*
989 * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
990 * We set count to 1 because we want the network layer to
991 * hand us all the skbs that are available. iscsi_tcp_data_recv
992 * handled pdus that cross buffers or pdus that still need data.
993 */
994 rd_desc.arg.data = conn;
995 rd_desc.count = 1;
996 tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
997
998 read_unlock(&sk->sk_callback_lock);
999 }
1000
1001 static void
1002 iscsi_tcp_state_change(struct sock *sk)
1003 {
1004 struct iscsi_tcp_conn *tcp_conn;
1005 struct iscsi_conn *conn;
1006 struct iscsi_session *session;
1007 void (*old_state_change)(struct sock *);
1008
1009 read_lock(&sk->sk_callback_lock);
1010
1011 conn = (struct iscsi_conn*)sk->sk_user_data;
1012 session = conn->session;
1013
1014 if ((sk->sk_state == TCP_CLOSE_WAIT ||
1015 sk->sk_state == TCP_CLOSE) &&
1016 !atomic_read(&sk->sk_rmem_alloc)) {
1017 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1018 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1019 }
1020
1021 tcp_conn = conn->dd_data;
1022 old_state_change = tcp_conn->old_state_change;
1023
1024 read_unlock(&sk->sk_callback_lock);
1025
1026 old_state_change(sk);
1027 }
1028
1029 /**
1030 * iscsi_write_space - Called when more output buffer space is available
1031 * @sk: socket space is available for
1032 **/
1033 static void
1034 iscsi_write_space(struct sock *sk)
1035 {
1036 struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1037 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1038
1039 tcp_conn->old_write_space(sk);
1040 debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1041 scsi_queue_work(conn->session->host, &conn->xmitwork);
1042 }
1043
1044 static void
1045 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1046 {
1047 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1048 struct sock *sk = tcp_conn->sock->sk;
1049
1050 /* assign new callbacks */
1051 write_lock_bh(&sk->sk_callback_lock);
1052 sk->sk_user_data = conn;
1053 tcp_conn->old_data_ready = sk->sk_data_ready;
1054 tcp_conn->old_state_change = sk->sk_state_change;
1055 tcp_conn->old_write_space = sk->sk_write_space;
1056 sk->sk_data_ready = iscsi_tcp_data_ready;
1057 sk->sk_state_change = iscsi_tcp_state_change;
1058 sk->sk_write_space = iscsi_write_space;
1059 write_unlock_bh(&sk->sk_callback_lock);
1060 }
1061
1062 static void
1063 iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
1064 {
1065 struct sock *sk = tcp_conn->sock->sk;
1066
1067 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1068 write_lock_bh(&sk->sk_callback_lock);
1069 sk->sk_user_data = NULL;
1070 sk->sk_data_ready = tcp_conn->old_data_ready;
1071 sk->sk_state_change = tcp_conn->old_state_change;
1072 sk->sk_write_space = tcp_conn->old_write_space;
1073 sk->sk_no_check = 0;
1074 write_unlock_bh(&sk->sk_callback_lock);
1075 }
1076
1077 /**
1078 * iscsi_send - generic send routine
1079 * @sk: kernel's socket
1080 * @buf: buffer to write from
1081 * @size: actual size to write
1082 * @flags: socket's flags
1083 */
1084 static inline int
1085 iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1086 {
1087 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1088 struct socket *sk = tcp_conn->sock;
1089 int offset = buf->sg.offset + buf->sent, res;
1090
1091 /*
1092 * if we got use_sg=0 or are sending something we kmallocd
1093 * then we did not have to do kmap (kmap returns page_address)
1094 *
1095 * if we got use_sg > 0, but had to drop down, we do not
1096 * set clustering so this should only happen for that
1097 * slab case.
1098 */
1099 if (buf->use_sendmsg)
1100 res = sock_no_sendpage(sk, sg_page(&buf->sg), offset, size, flags);
1101 else
1102 res = tcp_conn->sendpage(sk, sg_page(&buf->sg), offset, size, flags);
1103
1104 if (res >= 0) {
1105 conn->txdata_octets += res;
1106 buf->sent += res;
1107 return res;
1108 }
1109
1110 tcp_conn->sendpage_failures_cnt++;
1111 if (res == -EAGAIN)
1112 res = -ENOBUFS;
1113 else
1114 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1115 return res;
1116 }
1117
1118 /**
1119 * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1120 * @conn: iscsi connection
1121 * @buf: buffer to write from
1122 * @datalen: lenght of data to be sent after the header
1123 *
1124 * Notes:
1125 * (Tx, Fast Path)
1126 **/
1127 static inline int
1128 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1129 {
1130 int flags = 0; /* MSG_DONTWAIT; */
1131 int res, size;
1132
1133 size = buf->sg.length - buf->sent;
1134 BUG_ON(buf->sent + size > buf->sg.length);
1135 if (buf->sent + size != buf->sg.length || datalen)
1136 flags |= MSG_MORE;
1137
1138 res = iscsi_send(conn, buf, size, flags);
1139 debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1140 if (res >= 0) {
1141 if (size != res)
1142 return -EAGAIN;
1143 return 0;
1144 }
1145
1146 return res;
1147 }
1148
1149 /**
1150 * iscsi_sendpage - send one page of iSCSI Data-Out.
1151 * @conn: iscsi connection
1152 * @buf: buffer to write from
1153 * @count: remaining data
1154 * @sent: number of bytes sent
1155 *
1156 * Notes:
1157 * (Tx, Fast Path)
1158 **/
1159 static inline int
1160 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1161 int *count, int *sent)
1162 {
1163 int flags = 0; /* MSG_DONTWAIT; */
1164 int res, size;
1165
1166 size = buf->sg.length - buf->sent;
1167 BUG_ON(buf->sent + size > buf->sg.length);
1168 if (size > *count)
1169 size = *count;
1170 if (buf->sent + size != buf->sg.length || *count != size)
1171 flags |= MSG_MORE;
1172
1173 res = iscsi_send(conn, buf, size, flags);
1174 debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1175 size, buf->sent, *count, *sent, res);
1176 if (res >= 0) {
1177 *count -= res;
1178 *sent += res;
1179 if (size != res)
1180 return -EAGAIN;
1181 return 0;
1182 }
1183
1184 return res;
1185 }
1186
1187 static inline void
1188 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1189 struct iscsi_tcp_cmd_task *tcp_ctask)
1190 {
1191 crypto_hash_init(&tcp_conn->tx_hash);
1192 tcp_ctask->digest_count = 4;
1193 }
1194
1195 /**
1196 * iscsi_solicit_data_cont - initialize next Data-Out
1197 * @conn: iscsi connection
1198 * @ctask: scsi command task
1199 * @r2t: R2T info
1200 * @left: bytes left to transfer
1201 *
1202 * Notes:
1203 * Initialize next Data-Out within this R2T sequence and continue
1204 * to process next Scatter-Gather element(if any) of this SCSI command.
1205 *
1206 * Called under connection lock.
1207 **/
1208 static void
1209 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1210 struct iscsi_r2t_info *r2t, int left)
1211 {
1212 struct iscsi_data *hdr;
1213 int new_offset;
1214
1215 hdr = &r2t->dtask.hdr;
1216 memset(hdr, 0, sizeof(struct iscsi_data));
1217 hdr->ttt = r2t->ttt;
1218 hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1219 r2t->solicit_datasn++;
1220 hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1221 memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1222 hdr->itt = ctask->hdr->itt;
1223 hdr->exp_statsn = r2t->exp_statsn;
1224 new_offset = r2t->data_offset + r2t->sent;
1225 hdr->offset = cpu_to_be32(new_offset);
1226 if (left > conn->max_xmit_dlength) {
1227 hton24(hdr->dlength, conn->max_xmit_dlength);
1228 r2t->data_count = conn->max_xmit_dlength;
1229 } else {
1230 hton24(hdr->dlength, left);
1231 r2t->data_count = left;
1232 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1233 }
1234 conn->dataout_pdus_cnt++;
1235
1236 iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
1237 sizeof(struct iscsi_hdr));
1238
1239 if (iscsi_buf_left(&r2t->sendbuf))
1240 return;
1241
1242 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1243 r2t->sg += 1;
1244 }
1245
1246 static void iscsi_set_padding(struct iscsi_tcp_cmd_task *tcp_ctask,
1247 unsigned long len)
1248 {
1249 tcp_ctask->pad_count = len & (ISCSI_PAD_LEN - 1);
1250 if (!tcp_ctask->pad_count)
1251 return;
1252
1253 tcp_ctask->pad_count = ISCSI_PAD_LEN - tcp_ctask->pad_count;
1254 debug_scsi("write padding %d bytes\n", tcp_ctask->pad_count);
1255 tcp_ctask->xmstate |= XMSTATE_W_PAD;
1256 }
1257
1258 /**
1259 * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1260 * @conn: iscsi connection
1261 * @ctask: scsi command task
1262 * @sc: scsi command
1263 **/
1264 static void
1265 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1266 {
1267 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1268
1269 BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1270 tcp_ctask->xmstate = XMSTATE_CMD_HDR_INIT;
1271 }
1272
1273 /**
1274 * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1275 * @conn: iscsi connection
1276 * @mtask: task management task
1277 *
1278 * Notes:
1279 * The function can return -EAGAIN in which case caller must
1280 * call it again later, or recover. '0' return code means successful
1281 * xmit.
1282 *
1283 * Management xmit state machine consists of these states:
1284 * XMSTATE_IMM_HDR_INIT - calculate digest of PDU Header
1285 * XMSTATE_IMM_HDR - PDU Header xmit in progress
1286 * XMSTATE_IMM_DATA - PDU Data xmit in progress
1287 * XMSTATE_IDLE - management PDU is done
1288 **/
1289 static int
1290 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1291 {
1292 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1293 int rc;
1294
1295 debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1296 conn->id, tcp_mtask->xmstate, mtask->itt);
1297
1298 if (tcp_mtask->xmstate & XMSTATE_IMM_HDR_INIT) {
1299 iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
1300 sizeof(struct iscsi_hdr));
1301
1302 if (mtask->data_count) {
1303 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1304 iscsi_buf_init_iov(&tcp_mtask->sendbuf,
1305 (char*)mtask->data,
1306 mtask->data_count);
1307 }
1308
1309 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1310 conn->stop_stage != STOP_CONN_RECOVER &&
1311 conn->hdrdgst_en)
1312 iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
1313 (u8*)tcp_mtask->hdrext);
1314
1315 tcp_mtask->sent = 0;
1316 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR_INIT;
1317 tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1318 }
1319
1320 if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1321 rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
1322 mtask->data_count);
1323 if (rc)
1324 return rc;
1325 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1326 }
1327
1328 if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1329 BUG_ON(!mtask->data_count);
1330 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1331 /* FIXME: implement.
1332 * Virtual buffer could be spreaded across multiple pages...
1333 */
1334 do {
1335 int rc;
1336
1337 rc = iscsi_sendpage(conn, &tcp_mtask->sendbuf,
1338 &mtask->data_count, &tcp_mtask->sent);
1339 if (rc) {
1340 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1341 return rc;
1342 }
1343 } while (mtask->data_count);
1344 }
1345
1346 BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
1347 if (mtask->hdr->itt == RESERVED_ITT) {
1348 struct iscsi_session *session = conn->session;
1349
1350 spin_lock_bh(&session->lock);
1351 list_del(&conn->mtask->running);
1352 __kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
1353 sizeof(void*));
1354 spin_unlock_bh(&session->lock);
1355 }
1356 return 0;
1357 }
1358
1359 static int
1360 iscsi_send_cmd_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1361 {
1362 struct scsi_cmnd *sc = ctask->sc;
1363 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1364 int rc = 0;
1365
1366 if (tcp_ctask->xmstate & XMSTATE_CMD_HDR_INIT) {
1367 tcp_ctask->sent = 0;
1368 tcp_ctask->sg_count = 0;
1369 tcp_ctask->exp_datasn = 0;
1370
1371 if (sc->sc_data_direction == DMA_TO_DEVICE) {
1372 struct scatterlist *sg = scsi_sglist(sc);
1373
1374 iscsi_buf_init_sg(&tcp_ctask->sendbuf, sg);
1375 tcp_ctask->sg = sg + 1;
1376 tcp_ctask->bad_sg = sg + scsi_sg_count(sc);
1377
1378 debug_scsi("cmd [itt 0x%x total %d imm_data %d "
1379 "unsol count %d, unsol offset %d]\n",
1380 ctask->itt, scsi_bufflen(sc),
1381 ctask->imm_count, ctask->unsol_count,
1382 ctask->unsol_offset);
1383 }
1384
1385 iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
1386 sizeof(struct iscsi_hdr));
1387
1388 if (conn->hdrdgst_en)
1389 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1390 (u8*)tcp_ctask->hdrext);
1391 tcp_ctask->xmstate &= ~XMSTATE_CMD_HDR_INIT;
1392 tcp_ctask->xmstate |= XMSTATE_CMD_HDR_XMIT;
1393 }
1394
1395 if (tcp_ctask->xmstate & XMSTATE_CMD_HDR_XMIT) {
1396 rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
1397 if (rc)
1398 return rc;
1399 tcp_ctask->xmstate &= ~XMSTATE_CMD_HDR_XMIT;
1400
1401 if (sc->sc_data_direction != DMA_TO_DEVICE)
1402 return 0;
1403
1404 if (ctask->imm_count) {
1405 tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1406 iscsi_set_padding(tcp_ctask, ctask->imm_count);
1407
1408 if (ctask->conn->datadgst_en) {
1409 iscsi_data_digest_init(ctask->conn->dd_data,
1410 tcp_ctask);
1411 tcp_ctask->immdigest = 0;
1412 }
1413 }
1414
1415 if (ctask->unsol_count)
1416 tcp_ctask->xmstate |=
1417 XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
1418 }
1419 return rc;
1420 }
1421
1422 static int
1423 iscsi_send_padding(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1424 {
1425 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1426 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1427 int sent = 0, rc;
1428
1429 if (tcp_ctask->xmstate & XMSTATE_W_PAD) {
1430 iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
1431 tcp_ctask->pad_count);
1432 if (conn->datadgst_en)
1433 crypto_hash_update(&tcp_conn->tx_hash,
1434 &tcp_ctask->sendbuf.sg,
1435 tcp_ctask->sendbuf.sg.length);
1436 } else if (!(tcp_ctask->xmstate & XMSTATE_W_RESEND_PAD))
1437 return 0;
1438
1439 tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
1440 tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_PAD;
1441 debug_scsi("sending %d pad bytes for itt 0x%x\n",
1442 tcp_ctask->pad_count, ctask->itt);
1443 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
1444 &sent);
1445 if (rc) {
1446 debug_scsi("padding send failed %d\n", rc);
1447 tcp_ctask->xmstate |= XMSTATE_W_RESEND_PAD;
1448 }
1449 return rc;
1450 }
1451
1452 static int
1453 iscsi_send_digest(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1454 struct iscsi_buf *buf, uint32_t *digest)
1455 {
1456 struct iscsi_tcp_cmd_task *tcp_ctask;
1457 struct iscsi_tcp_conn *tcp_conn;
1458 int rc, sent = 0;
1459
1460 if (!conn->datadgst_en)
1461 return 0;
1462
1463 tcp_ctask = ctask->dd_data;
1464 tcp_conn = conn->dd_data;
1465
1466 if (!(tcp_ctask->xmstate & XMSTATE_W_RESEND_DATA_DIGEST)) {
1467 crypto_hash_final(&tcp_conn->tx_hash, (u8*)digest);
1468 iscsi_buf_init_iov(buf, (char*)digest, 4);
1469 }
1470 tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_DATA_DIGEST;
1471
1472 rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
1473 if (!rc)
1474 debug_scsi("sent digest 0x%x for itt 0x%x\n", *digest,
1475 ctask->itt);
1476 else {
1477 debug_scsi("sending digest 0x%x failed for itt 0x%x!\n",
1478 *digest, ctask->itt);
1479 tcp_ctask->xmstate |= XMSTATE_W_RESEND_DATA_DIGEST;
1480 }
1481 return rc;
1482 }
1483
1484 static int
1485 iscsi_send_data(struct iscsi_cmd_task *ctask, struct iscsi_buf *sendbuf,
1486 struct scatterlist **sg, int *sent, int *count,
1487 struct iscsi_buf *digestbuf, uint32_t *digest)
1488 {
1489 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1490 struct iscsi_conn *conn = ctask->conn;
1491 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1492 int rc, buf_sent, offset;
1493
1494 while (*count) {
1495 buf_sent = 0;
1496 offset = sendbuf->sent;
1497
1498 rc = iscsi_sendpage(conn, sendbuf, count, &buf_sent);
1499 *sent = *sent + buf_sent;
1500 if (buf_sent && conn->datadgst_en)
1501 partial_sg_digest_update(&tcp_conn->tx_hash,
1502 &sendbuf->sg, sendbuf->sg.offset + offset,
1503 buf_sent);
1504 if (!iscsi_buf_left(sendbuf) && *sg != tcp_ctask->bad_sg) {
1505 iscsi_buf_init_sg(sendbuf, *sg);
1506 *sg = *sg + 1;
1507 }
1508
1509 if (rc)
1510 return rc;
1511 }
1512
1513 rc = iscsi_send_padding(conn, ctask);
1514 if (rc)
1515 return rc;
1516
1517 return iscsi_send_digest(conn, ctask, digestbuf, digest);
1518 }
1519
1520 static int
1521 iscsi_send_unsol_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1522 {
1523 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1524 struct iscsi_data_task *dtask;
1525 int rc;
1526
1527 tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1528 if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1529 dtask = &tcp_ctask->unsol_dtask;
1530
1531 iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr);
1532 iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
1533 sizeof(struct iscsi_hdr));
1534 if (conn->hdrdgst_en)
1535 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1536 (u8*)dtask->hdrext);
1537
1538 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1539 iscsi_set_padding(tcp_ctask, ctask->data_count);
1540 }
1541
1542 rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count);
1543 if (rc) {
1544 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1545 tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1546 return rc;
1547 }
1548
1549 if (conn->datadgst_en) {
1550 dtask = &tcp_ctask->unsol_dtask;
1551 iscsi_data_digest_init(ctask->conn->dd_data, tcp_ctask);
1552 dtask->digest = 0;
1553 }
1554
1555 debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1556 ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1557 return 0;
1558 }
1559
1560 static int
1561 iscsi_send_unsol_pdu(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1562 {
1563 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1564 int rc;
1565
1566 if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
1567 BUG_ON(!ctask->unsol_count);
1568 tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
1569 send_hdr:
1570 rc = iscsi_send_unsol_hdr(conn, ctask);
1571 if (rc)
1572 return rc;
1573 }
1574
1575 if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
1576 struct iscsi_data_task *dtask = &tcp_ctask->unsol_dtask;
1577 int start = tcp_ctask->sent;
1578
1579 rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
1580 &tcp_ctask->sent, &ctask->data_count,
1581 &dtask->digestbuf, &dtask->digest);
1582 ctask->unsol_count -= tcp_ctask->sent - start;
1583 if (rc)
1584 return rc;
1585 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1586 /*
1587 * Done with the Data-Out. Next, check if we need
1588 * to send another unsolicited Data-Out.
1589 */
1590 if (ctask->unsol_count) {
1591 debug_scsi("sending more uns\n");
1592 tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
1593 goto send_hdr;
1594 }
1595 }
1596 return 0;
1597 }
1598
1599 static int iscsi_send_sol_pdu(struct iscsi_conn *conn,
1600 struct iscsi_cmd_task *ctask)
1601 {
1602 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1603 struct iscsi_session *session = conn->session;
1604 struct iscsi_r2t_info *r2t;
1605 struct iscsi_data_task *dtask;
1606 int left, rc;
1607
1608 if (tcp_ctask->xmstate & XMSTATE_SOL_HDR_INIT) {
1609 if (!tcp_ctask->r2t) {
1610 spin_lock_bh(&session->lock);
1611 __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1612 sizeof(void*));
1613 spin_unlock_bh(&session->lock);
1614 }
1615 send_hdr:
1616 r2t = tcp_ctask->r2t;
1617 dtask = &r2t->dtask;
1618
1619 if (conn->hdrdgst_en)
1620 iscsi_hdr_digest(conn, &r2t->headbuf,
1621 (u8*)dtask->hdrext);
1622 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR_INIT;
1623 tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1624 }
1625
1626 if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
1627 r2t = tcp_ctask->r2t;
1628 dtask = &r2t->dtask;
1629
1630 rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
1631 if (rc)
1632 return rc;
1633 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1634 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1635
1636 if (conn->datadgst_en) {
1637 iscsi_data_digest_init(conn->dd_data, tcp_ctask);
1638 dtask->digest = 0;
1639 }
1640
1641 iscsi_set_padding(tcp_ctask, r2t->data_count);
1642 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
1643 r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
1644 r2t->sent);
1645 }
1646
1647 if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
1648 r2t = tcp_ctask->r2t;
1649 dtask = &r2t->dtask;
1650
1651 rc = iscsi_send_data(ctask, &r2t->sendbuf, &r2t->sg,
1652 &r2t->sent, &r2t->data_count,
1653 &dtask->digestbuf, &dtask->digest);
1654 if (rc)
1655 return rc;
1656 tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1657
1658 /*
1659 * Done with this Data-Out. Next, check if we have
1660 * to send another Data-Out for this R2T.
1661 */
1662 BUG_ON(r2t->data_length - r2t->sent < 0);
1663 left = r2t->data_length - r2t->sent;
1664 if (left) {
1665 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1666 goto send_hdr;
1667 }
1668
1669 /*
1670 * Done with this R2T. Check if there are more
1671 * outstanding R2Ts ready to be processed.
1672 */
1673 spin_lock_bh(&session->lock);
1674 tcp_ctask->r2t = NULL;
1675 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
1676 sizeof(void*));
1677 if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t,
1678 sizeof(void*))) {
1679 tcp_ctask->r2t = r2t;
1680 spin_unlock_bh(&session->lock);
1681 goto send_hdr;
1682 }
1683 spin_unlock_bh(&session->lock);
1684 }
1685 return 0;
1686 }
1687
1688 /**
1689 * iscsi_tcp_ctask_xmit - xmit normal PDU task
1690 * @conn: iscsi connection
1691 * @ctask: iscsi command task
1692 *
1693 * Notes:
1694 * The function can return -EAGAIN in which case caller must
1695 * call it again later, or recover. '0' return code means successful
1696 * xmit.
1697 * The function is devided to logical helpers (above) for the different
1698 * xmit stages.
1699 *
1700 *iscsi_send_cmd_hdr()
1701 * XMSTATE_CMD_HDR_INIT - prepare Header and Data buffers Calculate
1702 * Header Digest
1703 * XMSTATE_CMD_HDR_XMIT - Transmit header in progress
1704 *
1705 *iscsi_send_padding
1706 * XMSTATE_W_PAD - Prepare and send pading
1707 * XMSTATE_W_RESEND_PAD - retry send pading
1708 *
1709 *iscsi_send_digest
1710 * XMSTATE_W_RESEND_DATA_DIGEST - Finalize and send Data Digest
1711 * XMSTATE_W_RESEND_DATA_DIGEST - retry sending digest
1712 *
1713 *iscsi_send_unsol_hdr
1714 * XMSTATE_UNS_INIT - prepare un-solicit data header and digest
1715 * XMSTATE_UNS_HDR - send un-solicit header
1716 *
1717 *iscsi_send_unsol_pdu
1718 * XMSTATE_UNS_DATA - send un-solicit data in progress
1719 *
1720 *iscsi_send_sol_pdu
1721 * XMSTATE_SOL_HDR_INIT - solicit data header and digest initialize
1722 * XMSTATE_SOL_HDR - send solicit header
1723 * XMSTATE_SOL_DATA - send solicit data
1724 *
1725 *iscsi_tcp_ctask_xmit
1726 * XMSTATE_IMM_DATA - xmit managment data (??)
1727 **/
1728 static int
1729 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1730 {
1731 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1732 int rc = 0;
1733
1734 debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1735 conn->id, tcp_ctask->xmstate, ctask->itt);
1736
1737 rc = iscsi_send_cmd_hdr(conn, ctask);
1738 if (rc)
1739 return rc;
1740 if (ctask->sc->sc_data_direction != DMA_TO_DEVICE)
1741 return 0;
1742
1743 if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1744 rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
1745 &tcp_ctask->sent, &ctask->imm_count,
1746 &tcp_ctask->immbuf, &tcp_ctask->immdigest);
1747 if (rc)
1748 return rc;
1749 tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1750 }
1751
1752 rc = iscsi_send_unsol_pdu(conn, ctask);
1753 if (rc)
1754 return rc;
1755
1756 rc = iscsi_send_sol_pdu(conn, ctask);
1757 if (rc)
1758 return rc;
1759
1760 return rc;
1761 }
1762
1763 static struct iscsi_cls_conn *
1764 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1765 {
1766 struct iscsi_conn *conn;
1767 struct iscsi_cls_conn *cls_conn;
1768 struct iscsi_tcp_conn *tcp_conn;
1769
1770 cls_conn = iscsi_conn_setup(cls_session, conn_idx);
1771 if (!cls_conn)
1772 return NULL;
1773 conn = cls_conn->dd_data;
1774 /*
1775 * due to strange issues with iser these are not set
1776 * in iscsi_conn_setup
1777 */
1778 conn->max_recv_dlength = ISCSI_DEF_MAX_RECV_SEG_LEN;
1779
1780 tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
1781 if (!tcp_conn)
1782 goto tcp_conn_alloc_fail;
1783
1784 conn->dd_data = tcp_conn;
1785 tcp_conn->iscsi_conn = conn;
1786 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1787 /* initial operational parameters */
1788 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1789
1790 tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1791 CRYPTO_ALG_ASYNC);
1792 tcp_conn->tx_hash.flags = 0;
1793 if (IS_ERR(tcp_conn->tx_hash.tfm)) {
1794 printk(KERN_ERR "Could not create connection due to crc32c "
1795 "loading error %ld. Make sure the crc32c module is "
1796 "built as a module or into the kernel\n",
1797 PTR_ERR(tcp_conn->tx_hash.tfm));
1798 goto free_tcp_conn;
1799 }
1800
1801 tcp_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1802 CRYPTO_ALG_ASYNC);
1803 tcp_conn->rx_hash.flags = 0;
1804 if (IS_ERR(tcp_conn->rx_hash.tfm)) {
1805 printk(KERN_ERR "Could not create connection due to crc32c "
1806 "loading error %ld. Make sure the crc32c module is "
1807 "built as a module or into the kernel\n",
1808 PTR_ERR(tcp_conn->rx_hash.tfm));
1809 goto free_tx_tfm;
1810 }
1811
1812 return cls_conn;
1813
1814 free_tx_tfm:
1815 crypto_free_hash(tcp_conn->tx_hash.tfm);
1816 free_tcp_conn:
1817 kfree(tcp_conn);
1818 tcp_conn_alloc_fail:
1819 iscsi_conn_teardown(cls_conn);
1820 return NULL;
1821 }
1822
1823 static void
1824 iscsi_tcp_release_conn(struct iscsi_conn *conn)
1825 {
1826 struct iscsi_session *session = conn->session;
1827 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1828 struct socket *sock = tcp_conn->sock;
1829
1830 if (!sock)
1831 return;
1832
1833 sock_hold(sock->sk);
1834 iscsi_conn_restore_callbacks(tcp_conn);
1835 sock_put(sock->sk);
1836
1837 spin_lock_bh(&session->lock);
1838 tcp_conn->sock = NULL;
1839 conn->recv_lock = NULL;
1840 spin_unlock_bh(&session->lock);
1841 sockfd_put(sock);
1842 }
1843
1844 static void
1845 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1846 {
1847 struct iscsi_conn *conn = cls_conn->dd_data;
1848 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1849
1850 iscsi_tcp_release_conn(conn);
1851 iscsi_conn_teardown(cls_conn);
1852
1853 if (tcp_conn->tx_hash.tfm)
1854 crypto_free_hash(tcp_conn->tx_hash.tfm);
1855 if (tcp_conn->rx_hash.tfm)
1856 crypto_free_hash(tcp_conn->rx_hash.tfm);
1857
1858 kfree(tcp_conn);
1859 }
1860
1861 static void
1862 iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1863 {
1864 struct iscsi_conn *conn = cls_conn->dd_data;
1865 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1866
1867 iscsi_conn_stop(cls_conn, flag);
1868 iscsi_tcp_release_conn(conn);
1869 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1870 }
1871
1872 static int iscsi_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
1873 char *buf, int *port,
1874 int (*getname)(struct socket *, struct sockaddr *,
1875 int *addrlen))
1876 {
1877 struct sockaddr_storage *addr;
1878 struct sockaddr_in6 *sin6;
1879 struct sockaddr_in *sin;
1880 int rc = 0, len;
1881
1882 addr = kmalloc(sizeof(*addr), GFP_KERNEL);
1883 if (!addr)
1884 return -ENOMEM;
1885
1886 if (getname(sock, (struct sockaddr *) addr, &len)) {
1887 rc = -ENODEV;
1888 goto free_addr;
1889 }
1890
1891 switch (addr->ss_family) {
1892 case AF_INET:
1893 sin = (struct sockaddr_in *)addr;
1894 spin_lock_bh(&conn->session->lock);
1895 sprintf(buf, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr));
1896 *port = be16_to_cpu(sin->sin_port);
1897 spin_unlock_bh(&conn->session->lock);
1898 break;
1899 case AF_INET6:
1900 sin6 = (struct sockaddr_in6 *)addr;
1901 spin_lock_bh(&conn->session->lock);
1902 sprintf(buf, NIP6_FMT, NIP6(sin6->sin6_addr));
1903 *port = be16_to_cpu(sin6->sin6_port);
1904 spin_unlock_bh(&conn->session->lock);
1905 break;
1906 }
1907 free_addr:
1908 kfree(addr);
1909 return rc;
1910 }
1911
1912 static int
1913 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1914 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1915 int is_leading)
1916 {
1917 struct iscsi_conn *conn = cls_conn->dd_data;
1918 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1919 struct sock *sk;
1920 struct socket *sock;
1921 int err;
1922
1923 /* lookup for existing socket */
1924 sock = sockfd_lookup((int)transport_eph, &err);
1925 if (!sock) {
1926 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
1927 return -EEXIST;
1928 }
1929 /*
1930 * copy these values now because if we drop the session
1931 * userspace may still want to query the values since we will
1932 * be using them for the reconnect
1933 */
1934 err = iscsi_tcp_get_addr(conn, sock, conn->portal_address,
1935 &conn->portal_port, kernel_getpeername);
1936 if (err)
1937 goto free_socket;
1938
1939 err = iscsi_tcp_get_addr(conn, sock, conn->local_address,
1940 &conn->local_port, kernel_getsockname);
1941 if (err)
1942 goto free_socket;
1943
1944 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
1945 if (err)
1946 goto free_socket;
1947
1948 /* bind iSCSI connection and socket */
1949 tcp_conn->sock = sock;
1950
1951 /* setup Socket parameters */
1952 sk = sock->sk;
1953 sk->sk_reuse = 1;
1954 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
1955 sk->sk_allocation = GFP_ATOMIC;
1956
1957 /* FIXME: disable Nagle's algorithm */
1958
1959 /*
1960 * Intercept TCP callbacks for sendfile like receive
1961 * processing.
1962 */
1963 conn->recv_lock = &sk->sk_callback_lock;
1964 iscsi_conn_set_callbacks(conn);
1965 tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
1966 /*
1967 * set receive state machine into initial state
1968 */
1969 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1970 return 0;
1971
1972 free_socket:
1973 sockfd_put(sock);
1974 return err;
1975 }
1976
1977 /* called with host lock */
1978 static void
1979 iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1980 {
1981 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1982 tcp_mtask->xmstate = XMSTATE_IMM_HDR_INIT;
1983 }
1984
1985 static int
1986 iscsi_r2tpool_alloc(struct iscsi_session *session)
1987 {
1988 int i;
1989 int cmd_i;
1990
1991 /*
1992 * initialize per-task: R2T pool and xmit queue
1993 */
1994 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1995 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1996 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1997
1998 /*
1999 * pre-allocated x4 as much r2ts to handle race when
2000 * target acks DataOut faster than we data_xmit() queues
2001 * could replenish r2tqueue.
2002 */
2003
2004 /* R2T pool */
2005 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
2006 (void***)&tcp_ctask->r2ts,
2007 sizeof(struct iscsi_r2t_info))) {
2008 goto r2t_alloc_fail;
2009 }
2010
2011 /* R2T xmit queue */
2012 tcp_ctask->r2tqueue = kfifo_alloc(
2013 session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
2014 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
2015 iscsi_pool_free(&tcp_ctask->r2tpool,
2016 (void**)tcp_ctask->r2ts);
2017 goto r2t_alloc_fail;
2018 }
2019 }
2020
2021 return 0;
2022
2023 r2t_alloc_fail:
2024 for (i = 0; i < cmd_i; i++) {
2025 struct iscsi_cmd_task *ctask = session->cmds[i];
2026 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2027
2028 kfifo_free(tcp_ctask->r2tqueue);
2029 iscsi_pool_free(&tcp_ctask->r2tpool,
2030 (void**)tcp_ctask->r2ts);
2031 }
2032 return -ENOMEM;
2033 }
2034
2035 static void
2036 iscsi_r2tpool_free(struct iscsi_session *session)
2037 {
2038 int i;
2039
2040 for (i = 0; i < session->cmds_max; i++) {
2041 struct iscsi_cmd_task *ctask = session->cmds[i];
2042 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2043
2044 kfifo_free(tcp_ctask->r2tqueue);
2045 iscsi_pool_free(&tcp_ctask->r2tpool,
2046 (void**)tcp_ctask->r2ts);
2047 }
2048 }
2049
2050 static int
2051 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
2052 char *buf, int buflen)
2053 {
2054 struct iscsi_conn *conn = cls_conn->dd_data;
2055 struct iscsi_session *session = conn->session;
2056 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2057 int value;
2058
2059 switch(param) {
2060 case ISCSI_PARAM_HDRDGST_EN:
2061 iscsi_set_param(cls_conn, param, buf, buflen);
2062 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
2063 if (conn->hdrdgst_en)
2064 tcp_conn->hdr_size += sizeof(__u32);
2065 break;
2066 case ISCSI_PARAM_DATADGST_EN:
2067 iscsi_set_param(cls_conn, param, buf, buflen);
2068 tcp_conn->sendpage = conn->datadgst_en ?
2069 sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2070 break;
2071 case ISCSI_PARAM_MAX_R2T:
2072 sscanf(buf, "%d", &value);
2073 if (session->max_r2t == roundup_pow_of_two(value))
2074 break;
2075 iscsi_r2tpool_free(session);
2076 iscsi_set_param(cls_conn, param, buf, buflen);
2077 if (session->max_r2t & (session->max_r2t - 1))
2078 session->max_r2t = roundup_pow_of_two(session->max_r2t);
2079 if (iscsi_r2tpool_alloc(session))
2080 return -ENOMEM;
2081 break;
2082 default:
2083 return iscsi_set_param(cls_conn, param, buf, buflen);
2084 }
2085
2086 return 0;
2087 }
2088
2089 static int
2090 iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
2091 enum iscsi_param param, char *buf)
2092 {
2093 struct iscsi_conn *conn = cls_conn->dd_data;
2094 int len;
2095
2096 switch(param) {
2097 case ISCSI_PARAM_CONN_PORT:
2098 spin_lock_bh(&conn->session->lock);
2099 len = sprintf(buf, "%hu\n", conn->portal_port);
2100 spin_unlock_bh(&conn->session->lock);
2101 break;
2102 case ISCSI_PARAM_CONN_ADDRESS:
2103 spin_lock_bh(&conn->session->lock);
2104 len = sprintf(buf, "%s\n", conn->portal_address);
2105 spin_unlock_bh(&conn->session->lock);
2106 break;
2107 default:
2108 return iscsi_conn_get_param(cls_conn, param, buf);
2109 }
2110
2111 return len;
2112 }
2113
2114 static int
2115 iscsi_tcp_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2116 char *buf)
2117 {
2118 struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2119 int len;
2120
2121 switch (param) {
2122 case ISCSI_HOST_PARAM_IPADDRESS:
2123 spin_lock_bh(&session->lock);
2124 if (!session->leadconn)
2125 len = -ENODEV;
2126 else
2127 len = sprintf(buf, "%s\n",
2128 session->leadconn->local_address);
2129 spin_unlock_bh(&session->lock);
2130 break;
2131 default:
2132 return iscsi_host_get_param(shost, param, buf);
2133 }
2134 return len;
2135 }
2136
2137 static void
2138 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2139 {
2140 struct iscsi_conn *conn = cls_conn->dd_data;
2141 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2142
2143 stats->txdata_octets = conn->txdata_octets;
2144 stats->rxdata_octets = conn->rxdata_octets;
2145 stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
2146 stats->dataout_pdus = conn->dataout_pdus_cnt;
2147 stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
2148 stats->datain_pdus = conn->datain_pdus_cnt;
2149 stats->r2t_pdus = conn->r2t_pdus_cnt;
2150 stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
2151 stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
2152 stats->custom_length = 3;
2153 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2154 stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2155 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2156 stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2157 strcpy(stats->custom[2].desc, "eh_abort_cnt");
2158 stats->custom[2].value = conn->eh_abort_cnt;
2159 }
2160
2161 static struct iscsi_cls_session *
2162 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
2163 struct scsi_transport_template *scsit,
2164 uint16_t cmds_max, uint16_t qdepth,
2165 uint32_t initial_cmdsn, uint32_t *hostno)
2166 {
2167 struct iscsi_cls_session *cls_session;
2168 struct iscsi_session *session;
2169 uint32_t hn;
2170 int cmd_i;
2171
2172 cls_session = iscsi_session_setup(iscsit, scsit, cmds_max, qdepth,
2173 sizeof(struct iscsi_tcp_cmd_task),
2174 sizeof(struct iscsi_tcp_mgmt_task),
2175 initial_cmdsn, &hn);
2176 if (!cls_session)
2177 return NULL;
2178 *hostno = hn;
2179
2180 session = class_to_transport_session(cls_session);
2181 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2182 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2183 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2184
2185 ctask->hdr = &tcp_ctask->hdr;
2186 }
2187
2188 for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
2189 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
2190 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2191
2192 mtask->hdr = &tcp_mtask->hdr;
2193 }
2194
2195 if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
2196 goto r2tpool_alloc_fail;
2197
2198 return cls_session;
2199
2200 r2tpool_alloc_fail:
2201 iscsi_session_teardown(cls_session);
2202 return NULL;
2203 }
2204
2205 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
2206 {
2207 iscsi_r2tpool_free(class_to_transport_session(cls_session));
2208 iscsi_session_teardown(cls_session);
2209 }
2210
2211 static int iscsi_tcp_slave_configure(struct scsi_device *sdev)
2212 {
2213 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
2214 blk_queue_dma_alignment(sdev->request_queue, 0);
2215 return 0;
2216 }
2217
2218 static struct scsi_host_template iscsi_sht = {
2219 .module = THIS_MODULE,
2220 .name = "iSCSI Initiator over TCP/IP",
2221 .queuecommand = iscsi_queuecommand,
2222 .change_queue_depth = iscsi_change_queue_depth,
2223 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
2224 .sg_tablesize = ISCSI_SG_TABLESIZE,
2225 .max_sectors = 0xFFFF,
2226 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
2227 .eh_abort_handler = iscsi_eh_abort,
2228 .eh_device_reset_handler= iscsi_eh_device_reset,
2229 .eh_host_reset_handler = iscsi_eh_host_reset,
2230 .use_clustering = DISABLE_CLUSTERING,
2231 .slave_configure = iscsi_tcp_slave_configure,
2232 .proc_name = "iscsi_tcp",
2233 .this_id = -1,
2234 };
2235
2236 static struct iscsi_transport iscsi_tcp_transport = {
2237 .owner = THIS_MODULE,
2238 .name = "tcp",
2239 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
2240 | CAP_DATADGST,
2241 .param_mask = ISCSI_MAX_RECV_DLENGTH |
2242 ISCSI_MAX_XMIT_DLENGTH |
2243 ISCSI_HDRDGST_EN |
2244 ISCSI_DATADGST_EN |
2245 ISCSI_INITIAL_R2T_EN |
2246 ISCSI_MAX_R2T |
2247 ISCSI_IMM_DATA_EN |
2248 ISCSI_FIRST_BURST |
2249 ISCSI_MAX_BURST |
2250 ISCSI_PDU_INORDER_EN |
2251 ISCSI_DATASEQ_INORDER_EN |
2252 ISCSI_ERL |
2253 ISCSI_CONN_PORT |
2254 ISCSI_CONN_ADDRESS |
2255 ISCSI_EXP_STATSN |
2256 ISCSI_PERSISTENT_PORT |
2257 ISCSI_PERSISTENT_ADDRESS |
2258 ISCSI_TARGET_NAME | ISCSI_TPGT |
2259 ISCSI_USERNAME | ISCSI_PASSWORD |
2260 ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
2261 ISCSI_FAST_ABORT,
2262 .host_param_mask = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
2263 ISCSI_HOST_INITIATOR_NAME |
2264 ISCSI_HOST_NETDEV_NAME,
2265 .host_template = &iscsi_sht,
2266 .conndata_size = sizeof(struct iscsi_conn),
2267 .max_conn = 1,
2268 .max_cmd_len = ISCSI_TCP_MAX_CMD_LEN,
2269 /* session management */
2270 .create_session = iscsi_tcp_session_create,
2271 .destroy_session = iscsi_tcp_session_destroy,
2272 /* connection management */
2273 .create_conn = iscsi_tcp_conn_create,
2274 .bind_conn = iscsi_tcp_conn_bind,
2275 .destroy_conn = iscsi_tcp_conn_destroy,
2276 .set_param = iscsi_conn_set_param,
2277 .get_conn_param = iscsi_tcp_conn_get_param,
2278 .get_session_param = iscsi_session_get_param,
2279 .start_conn = iscsi_conn_start,
2280 .stop_conn = iscsi_tcp_conn_stop,
2281 /* iscsi host params */
2282 .get_host_param = iscsi_tcp_host_get_param,
2283 .set_host_param = iscsi_host_set_param,
2284 /* IO */
2285 .send_pdu = iscsi_conn_send_pdu,
2286 .get_stats = iscsi_conn_get_stats,
2287 .init_cmd_task = iscsi_tcp_cmd_init,
2288 .init_mgmt_task = iscsi_tcp_mgmt_init,
2289 .xmit_cmd_task = iscsi_tcp_ctask_xmit,
2290 .xmit_mgmt_task = iscsi_tcp_mtask_xmit,
2291 .cleanup_cmd_task = iscsi_tcp_cleanup_ctask,
2292 /* recovery */
2293 .session_recovery_timedout = iscsi_session_recovery_timedout,
2294 };
2295
2296 static int __init
2297 iscsi_tcp_init(void)
2298 {
2299 if (iscsi_max_lun < 1) {
2300 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2301 iscsi_max_lun);
2302 return -EINVAL;
2303 }
2304 iscsi_tcp_transport.max_lun = iscsi_max_lun;
2305
2306 if (!iscsi_register_transport(&iscsi_tcp_transport))
2307 return -ENODEV;
2308
2309 return 0;
2310 }
2311
2312 static void __exit
2313 iscsi_tcp_exit(void)
2314 {
2315 iscsi_unregister_transport(&iscsi_tcp_transport);
2316 }
2317
2318 module_init(iscsi_tcp_init);
2319 module_exit(iscsi_tcp_exit);
Linux kernel - Deliverables
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