[SCSI] libiscsi, iser, tcp: remove recv_lock
[linux-2.6.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 #undef 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 struct scsi_transport_template *iscsi_tcp_scsi_transport;
68 static struct scsi_host_template iscsi_sht;
69 static struct iscsi_transport iscsi_tcp_transport;
70
71 static unsigned int iscsi_max_lun = 512;
72 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
73
74 static int iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn,
75                                    struct iscsi_segment *segment);
76
77 /*
78  * Scatterlist handling: inside the iscsi_segment, we
79  * remember an index into the scatterlist, and set data/size
80  * to the current scatterlist entry. For highmem pages, we
81  * kmap as needed.
82  *
83  * Note that the page is unmapped when we return from
84  * TCP's data_ready handler, so we may end up mapping and
85  * unmapping the same page repeatedly. The whole reason
86  * for this is that we shouldn't keep the page mapped
87  * outside the softirq.
88  */
89
90 /**
91  * iscsi_tcp_segment_init_sg - init indicated scatterlist entry
92  * @segment: the buffer object
93  * @sg: scatterlist
94  * @offset: byte offset into that sg entry
95  *
96  * This function sets up the segment so that subsequent
97  * data is copied to the indicated sg entry, at the given
98  * offset.
99  */
100 static inline void
101 iscsi_tcp_segment_init_sg(struct iscsi_segment *segment,
102                           struct scatterlist *sg, unsigned int offset)
103 {
104         segment->sg = sg;
105         segment->sg_offset = offset;
106         segment->size = min(sg->length - offset,
107                             segment->total_size - segment->total_copied);
108         segment->data = NULL;
109 }
110
111 /**
112  * iscsi_tcp_segment_map - map the current S/G page
113  * @segment: iscsi_segment
114  * @recv: 1 if called from recv path
115  *
116  * We only need to possibly kmap data if scatter lists are being used,
117  * because the iscsi passthrough and internal IO paths will never use high
118  * mem pages.
119  */
120 static inline void
121 iscsi_tcp_segment_map(struct iscsi_segment *segment, int recv)
122 {
123         struct scatterlist *sg;
124
125         if (segment->data != NULL || !segment->sg)
126                 return;
127
128         sg = segment->sg;
129         BUG_ON(segment->sg_mapped);
130         BUG_ON(sg->length == 0);
131
132         /*
133          * If the page count is greater than one it is ok to send
134          * to the network layer's zero copy send path. If not we
135          * have to go the slow sendmsg path. We always map for the
136          * recv path.
137          */
138         if (page_count(sg_page(sg)) >= 1 && !recv)
139                 return;
140
141         debug_tcp("iscsi_tcp_segment_map %s %p\n", recv ? "recv" : "xmit",
142                   segment);
143         segment->sg_mapped = kmap_atomic(sg_page(sg), KM_SOFTIRQ0);
144         segment->data = segment->sg_mapped + sg->offset + segment->sg_offset;
145 }
146
147 static inline void
148 iscsi_tcp_segment_unmap(struct iscsi_segment *segment)
149 {
150         debug_tcp("iscsi_tcp_segment_unmap %p\n", segment);
151
152         if (segment->sg_mapped) {
153                 debug_tcp("iscsi_tcp_segment_unmap valid\n");
154                 kunmap_atomic(segment->sg_mapped, KM_SOFTIRQ0);
155                 segment->sg_mapped = NULL;
156                 segment->data = NULL;
157         }
158 }
159
160 /*
161  * Splice the digest buffer into the buffer
162  */
163 static inline void
164 iscsi_tcp_segment_splice_digest(struct iscsi_segment *segment, void *digest)
165 {
166         segment->data = digest;
167         segment->digest_len = ISCSI_DIGEST_SIZE;
168         segment->total_size += ISCSI_DIGEST_SIZE;
169         segment->size = ISCSI_DIGEST_SIZE;
170         segment->copied = 0;
171         segment->sg = NULL;
172         segment->hash = NULL;
173 }
174
175 /**
176  * iscsi_tcp_segment_done - check whether the segment is complete
177  * @segment: iscsi segment to check
178  * @recv: set to one of this is called from the recv path
179  * @copied: number of bytes copied
180  *
181  * Check if we're done receiving this segment. If the receive
182  * buffer is full but we expect more data, move on to the
183  * next entry in the scatterlist.
184  *
185  * If the amount of data we received isn't a multiple of 4,
186  * we will transparently receive the pad bytes, too.
187  *
188  * This function must be re-entrant.
189  */
190 static inline int
191 iscsi_tcp_segment_done(struct iscsi_segment *segment, int recv, unsigned copied)
192 {
193         static unsigned char padbuf[ISCSI_PAD_LEN];
194         struct scatterlist sg;
195         unsigned int pad;
196
197         debug_tcp("copied %u %u size %u %s\n", segment->copied, copied,
198                   segment->size, recv ? "recv" : "xmit");
199         if (segment->hash && copied) {
200                 /*
201                  * If a segment is kmapd we must unmap it before sending
202                  * to the crypto layer since that will try to kmap it again.
203                  */
204                 iscsi_tcp_segment_unmap(segment);
205
206                 if (!segment->data) {
207                         sg_init_table(&sg, 1);
208                         sg_set_page(&sg, sg_page(segment->sg), copied,
209                                     segment->copied + segment->sg_offset +
210                                                         segment->sg->offset);
211                 } else
212                         sg_init_one(&sg, segment->data + segment->copied,
213                                     copied);
214                 crypto_hash_update(segment->hash, &sg, copied);
215         }
216
217         segment->copied += copied;
218         if (segment->copied < segment->size) {
219                 iscsi_tcp_segment_map(segment, recv);
220                 return 0;
221         }
222
223         segment->total_copied += segment->copied;
224         segment->copied = 0;
225         segment->size = 0;
226
227         /* Unmap the current scatterlist page, if there is one. */
228         iscsi_tcp_segment_unmap(segment);
229
230         /* Do we have more scatterlist entries? */
231         debug_tcp("total copied %u total size %u\n", segment->total_copied,
232                    segment->total_size);
233         if (segment->total_copied < segment->total_size) {
234                 /* Proceed to the next entry in the scatterlist. */
235                 iscsi_tcp_segment_init_sg(segment, sg_next(segment->sg),
236                                           0);
237                 iscsi_tcp_segment_map(segment, recv);
238                 BUG_ON(segment->size == 0);
239                 return 0;
240         }
241
242         /* Do we need to handle padding? */
243         pad = iscsi_padding(segment->total_copied);
244         if (pad != 0) {
245                 debug_tcp("consume %d pad bytes\n", pad);
246                 segment->total_size += pad;
247                 segment->size = pad;
248                 segment->data = padbuf;
249                 return 0;
250         }
251
252         /*
253          * Set us up for transferring the data digest. hdr digest
254          * is completely handled in hdr done function.
255          */
256         if (segment->hash) {
257                 crypto_hash_final(segment->hash, segment->digest);
258                 iscsi_tcp_segment_splice_digest(segment,
259                                  recv ? segment->recv_digest : segment->digest);
260                 return 0;
261         }
262
263         return 1;
264 }
265
266 /**
267  * iscsi_tcp_xmit_segment - transmit segment
268  * @tcp_conn: the iSCSI TCP connection
269  * @segment: the buffer to transmnit
270  *
271  * This function transmits as much of the buffer as
272  * the network layer will accept, and returns the number of
273  * bytes transmitted.
274  *
275  * If CRC hashing is enabled, the function will compute the
276  * hash as it goes. When the entire segment has been transmitted,
277  * it will retrieve the hash value and send it as well.
278  */
279 static int
280 iscsi_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
281                        struct iscsi_segment *segment)
282 {
283         struct socket *sk = tcp_conn->sock;
284         unsigned int copied = 0;
285         int r = 0;
286
287         while (!iscsi_tcp_segment_done(segment, 0, r)) {
288                 struct scatterlist *sg;
289                 unsigned int offset, copy;
290                 int flags = 0;
291
292                 r = 0;
293                 offset = segment->copied;
294                 copy = segment->size - offset;
295
296                 if (segment->total_copied + segment->size < segment->total_size)
297                         flags |= MSG_MORE;
298
299                 /* Use sendpage if we can; else fall back to sendmsg */
300                 if (!segment->data) {
301                         sg = segment->sg;
302                         offset += segment->sg_offset + sg->offset;
303                         r = tcp_conn->sendpage(sk, sg_page(sg), offset, copy,
304                                                flags);
305                 } else {
306                         struct msghdr msg = { .msg_flags = flags };
307                         struct kvec iov = {
308                                 .iov_base = segment->data + offset,
309                                 .iov_len = copy
310                         };
311
312                         r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
313                 }
314
315                 if (r < 0) {
316                         iscsi_tcp_segment_unmap(segment);
317                         if (copied || r == -EAGAIN)
318                                 break;
319                         return r;
320                 }
321                 copied += r;
322         }
323         return copied;
324 }
325
326 /**
327  * iscsi_tcp_segment_recv - copy data to segment
328  * @tcp_conn: the iSCSI TCP connection
329  * @segment: the buffer to copy to
330  * @ptr: data pointer
331  * @len: amount of data available
332  *
333  * This function copies up to @len bytes to the
334  * given buffer, and returns the number of bytes
335  * consumed, which can actually be less than @len.
336  *
337  * If hash digest is enabled, the function will update the
338  * hash while copying.
339  * Combining these two operations doesn't buy us a lot (yet),
340  * but in the future we could implement combined copy+crc,
341  * just way we do for network layer checksums.
342  */
343 static int
344 iscsi_tcp_segment_recv(struct iscsi_tcp_conn *tcp_conn,
345                        struct iscsi_segment *segment, const void *ptr,
346                        unsigned int len)
347 {
348         unsigned int copy = 0, copied = 0;
349
350         while (!iscsi_tcp_segment_done(segment, 1, copy)) {
351                 if (copied == len) {
352                         debug_tcp("iscsi_tcp_segment_recv copied %d bytes\n",
353                                   len);
354                         break;
355                 }
356
357                 copy = min(len - copied, segment->size - segment->copied);
358                 debug_tcp("iscsi_tcp_segment_recv copying %d\n", copy);
359                 memcpy(segment->data + segment->copied, ptr + copied, copy);
360                 copied += copy;
361         }
362         return copied;
363 }
364
365 static inline void
366 iscsi_tcp_dgst_header(struct hash_desc *hash, const void *hdr, size_t hdrlen,
367                       unsigned char digest[ISCSI_DIGEST_SIZE])
368 {
369         struct scatterlist sg;
370
371         sg_init_one(&sg, hdr, hdrlen);
372         crypto_hash_digest(hash, &sg, hdrlen, digest);
373 }
374
375 static inline int
376 iscsi_tcp_dgst_verify(struct iscsi_tcp_conn *tcp_conn,
377                       struct iscsi_segment *segment)
378 {
379         if (!segment->digest_len)
380                 return 1;
381
382         if (memcmp(segment->recv_digest, segment->digest,
383                    segment->digest_len)) {
384                 debug_scsi("digest mismatch\n");
385                 return 0;
386         }
387
388         return 1;
389 }
390
391 /*
392  * Helper function to set up segment buffer
393  */
394 static inline void
395 __iscsi_segment_init(struct iscsi_segment *segment, size_t size,
396                      iscsi_segment_done_fn_t *done, struct hash_desc *hash)
397 {
398         memset(segment, 0, sizeof(*segment));
399         segment->total_size = size;
400         segment->done = done;
401
402         if (hash) {
403                 segment->hash = hash;
404                 crypto_hash_init(hash);
405         }
406 }
407
408 static inline void
409 iscsi_segment_init_linear(struct iscsi_segment *segment, void *data,
410                           size_t size, iscsi_segment_done_fn_t *done,
411                           struct hash_desc *hash)
412 {
413         __iscsi_segment_init(segment, size, done, hash);
414         segment->data = data;
415         segment->size = size;
416 }
417
418 static inline int
419 iscsi_segment_seek_sg(struct iscsi_segment *segment,
420                       struct scatterlist *sg_list, unsigned int sg_count,
421                       unsigned int offset, size_t size,
422                       iscsi_segment_done_fn_t *done, struct hash_desc *hash)
423 {
424         struct scatterlist *sg;
425         unsigned int i;
426
427         debug_scsi("iscsi_segment_seek_sg offset %u size %llu\n",
428                   offset, size);
429         __iscsi_segment_init(segment, size, done, hash);
430         for_each_sg(sg_list, sg, sg_count, i) {
431                 debug_scsi("sg %d, len %u offset %u\n", i, sg->length,
432                            sg->offset);
433                 if (offset < sg->length) {
434                         iscsi_tcp_segment_init_sg(segment, sg, offset);
435                         return 0;
436                 }
437                 offset -= sg->length;
438         }
439
440         return ISCSI_ERR_DATA_OFFSET;
441 }
442
443 /**
444  * iscsi_tcp_hdr_recv_prep - prep segment for hdr reception
445  * @tcp_conn: iscsi connection to prep for
446  *
447  * This function always passes NULL for the hash argument, because when this
448  * function is called we do not yet know the final size of the header and want
449  * to delay the digest processing until we know that.
450  */
451 static void
452 iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn)
453 {
454         debug_tcp("iscsi_tcp_hdr_recv_prep(%p%s)\n", tcp_conn,
455                   tcp_conn->iscsi_conn->hdrdgst_en ? ", digest enabled" : "");
456         iscsi_segment_init_linear(&tcp_conn->in.segment,
457                                 tcp_conn->in.hdr_buf, sizeof(struct iscsi_hdr),
458                                 iscsi_tcp_hdr_recv_done, NULL);
459 }
460
461 /*
462  * Handle incoming reply to any other type of command
463  */
464 static int
465 iscsi_tcp_data_recv_done(struct iscsi_tcp_conn *tcp_conn,
466                          struct iscsi_segment *segment)
467 {
468         struct iscsi_conn *conn = tcp_conn->iscsi_conn;
469         int rc = 0;
470
471         if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
472                 return ISCSI_ERR_DATA_DGST;
473
474         rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr,
475                         conn->data, tcp_conn->in.datalen);
476         if (rc)
477                 return rc;
478
479         iscsi_tcp_hdr_recv_prep(tcp_conn);
480         return 0;
481 }
482
483 static void
484 iscsi_tcp_data_recv_prep(struct iscsi_tcp_conn *tcp_conn)
485 {
486         struct iscsi_conn *conn = tcp_conn->iscsi_conn;
487         struct hash_desc *rx_hash = NULL;
488
489         if (conn->datadgst_en)
490                 rx_hash = &tcp_conn->rx_hash;
491
492         iscsi_segment_init_linear(&tcp_conn->in.segment,
493                                 conn->data, tcp_conn->in.datalen,
494                                 iscsi_tcp_data_recv_done, rx_hash);
495 }
496
497 /*
498  * must be called with session lock
499  */
500 static void
501 iscsi_tcp_cleanup_task(struct iscsi_conn *conn, struct iscsi_task *task)
502 {
503         struct iscsi_tcp_task *tcp_task = task->dd_data;
504         struct iscsi_r2t_info *r2t;
505
506         /* nothing to do for mgmt tasks */
507         if (!task->sc)
508                 return;
509
510         /* flush task's r2t queues */
511         while (__kfifo_get(tcp_task->r2tqueue, (void*)&r2t, sizeof(void*))) {
512                 __kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t,
513                             sizeof(void*));
514                 debug_scsi("iscsi_tcp_cleanup_task pending r2t dropped\n");
515         }
516
517         r2t = tcp_task->r2t;
518         if (r2t != NULL) {
519                 __kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t,
520                             sizeof(void*));
521                 tcp_task->r2t = NULL;
522         }
523 }
524
525 /**
526  * iscsi_data_rsp - SCSI Data-In Response processing
527  * @conn: iscsi connection
528  * @task: scsi command task
529  **/
530 static int
531 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_task *task)
532 {
533         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
534         struct iscsi_tcp_task *tcp_task = task->dd_data;
535         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
536         struct iscsi_session *session = conn->session;
537         struct scsi_cmnd *sc = task->sc;
538         int datasn = be32_to_cpu(rhdr->datasn);
539         unsigned total_in_length = scsi_in(sc)->length;
540
541         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
542         if (tcp_conn->in.datalen == 0)
543                 return 0;
544
545         if (tcp_task->exp_datasn != datasn) {
546                 debug_tcp("%s: task->exp_datasn(%d) != rhdr->datasn(%d)\n",
547                           __FUNCTION__, tcp_task->exp_datasn, datasn);
548                 return ISCSI_ERR_DATASN;
549         }
550
551         tcp_task->exp_datasn++;
552
553         tcp_task->data_offset = be32_to_cpu(rhdr->offset);
554         if (tcp_task->data_offset + tcp_conn->in.datalen > total_in_length) {
555                 debug_tcp("%s: data_offset(%d) + data_len(%d) > total_length_in(%d)\n",
556                           __FUNCTION__, tcp_task->data_offset,
557                           tcp_conn->in.datalen, total_in_length);
558                 return ISCSI_ERR_DATA_OFFSET;
559         }
560
561         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
562                 sc->result = (DID_OK << 16) | rhdr->cmd_status;
563                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
564                 if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
565                                    ISCSI_FLAG_DATA_OVERFLOW)) {
566                         int res_count = be32_to_cpu(rhdr->residual_count);
567
568                         if (res_count > 0 &&
569                             (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
570                              res_count <= total_in_length))
571                                 scsi_in(sc)->resid = res_count;
572                         else
573                                 sc->result = (DID_BAD_TARGET << 16) |
574                                         rhdr->cmd_status;
575                 }
576         }
577
578         conn->datain_pdus_cnt++;
579         return 0;
580 }
581
582 /**
583  * iscsi_solicit_data_init - initialize first Data-Out
584  * @conn: iscsi connection
585  * @task: scsi command task
586  * @r2t: R2T info
587  *
588  * Notes:
589  *      Initialize first Data-Out within this R2T sequence and finds
590  *      proper data_offset within this SCSI command.
591  *
592  *      This function is called with connection lock taken.
593  **/
594 static void
595 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_task *task,
596                         struct iscsi_r2t_info *r2t)
597 {
598         struct iscsi_data *hdr;
599
600         hdr = &r2t->dtask.hdr;
601         memset(hdr, 0, sizeof(struct iscsi_data));
602         hdr->ttt = r2t->ttt;
603         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
604         r2t->solicit_datasn++;
605         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
606         memcpy(hdr->lun, task->hdr->lun, sizeof(hdr->lun));
607         hdr->itt = task->hdr->itt;
608         hdr->exp_statsn = r2t->exp_statsn;
609         hdr->offset = cpu_to_be32(r2t->data_offset);
610         if (r2t->data_length > conn->max_xmit_dlength) {
611                 hton24(hdr->dlength, conn->max_xmit_dlength);
612                 r2t->data_count = conn->max_xmit_dlength;
613                 hdr->flags = 0;
614         } else {
615                 hton24(hdr->dlength, r2t->data_length);
616                 r2t->data_count = r2t->data_length;
617                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
618         }
619         conn->dataout_pdus_cnt++;
620
621         r2t->sent = 0;
622 }
623
624 /**
625  * iscsi_r2t_rsp - iSCSI R2T Response processing
626  * @conn: iscsi connection
627  * @task: scsi command task
628  **/
629 static int
630 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task)
631 {
632         struct iscsi_r2t_info *r2t;
633         struct iscsi_session *session = conn->session;
634         struct iscsi_tcp_task *tcp_task = task->dd_data;
635         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
636         struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
637         int r2tsn = be32_to_cpu(rhdr->r2tsn);
638         int rc;
639
640         if (tcp_conn->in.datalen) {
641                 iscsi_conn_printk(KERN_ERR, conn,
642                                   "invalid R2t with datalen %d\n",
643                                   tcp_conn->in.datalen);
644                 return ISCSI_ERR_DATALEN;
645         }
646
647         if (tcp_task->exp_datasn != r2tsn){
648                 debug_tcp("%s: task->exp_datasn(%d) != rhdr->r2tsn(%d)\n",
649                           __FUNCTION__, tcp_task->exp_datasn, r2tsn);
650                 return ISCSI_ERR_R2TSN;
651         }
652
653         /* fill-in new R2T associated with the task */
654         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
655
656         if (!task->sc || session->state != ISCSI_STATE_LOGGED_IN) {
657                 iscsi_conn_printk(KERN_INFO, conn,
658                                   "dropping R2T itt %d in recovery.\n",
659                                   task->itt);
660                 return 0;
661         }
662
663         rc = __kfifo_get(tcp_task->r2tpool.queue, (void*)&r2t, sizeof(void*));
664         BUG_ON(!rc);
665
666         r2t->exp_statsn = rhdr->statsn;
667         r2t->data_length = be32_to_cpu(rhdr->data_length);
668         if (r2t->data_length == 0) {
669                 iscsi_conn_printk(KERN_ERR, conn,
670                                   "invalid R2T with zero data len\n");
671                 __kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t,
672                             sizeof(void*));
673                 return ISCSI_ERR_DATALEN;
674         }
675
676         if (r2t->data_length > session->max_burst)
677                 debug_scsi("invalid R2T with data len %u and max burst %u."
678                            "Attempting to execute request.\n",
679                             r2t->data_length, session->max_burst);
680
681         r2t->data_offset = be32_to_cpu(rhdr->data_offset);
682         if (r2t->data_offset + r2t->data_length > scsi_out(task->sc)->length) {
683                 iscsi_conn_printk(KERN_ERR, conn,
684                                   "invalid R2T with data len %u at offset %u "
685                                   "and total length %d\n", r2t->data_length,
686                                   r2t->data_offset, scsi_out(task->sc)->length);
687                 __kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t,
688                             sizeof(void*));
689                 return ISCSI_ERR_DATALEN;
690         }
691
692         r2t->ttt = rhdr->ttt; /* no flip */
693         r2t->solicit_datasn = 0;
694
695         iscsi_solicit_data_init(conn, task, r2t);
696
697         tcp_task->exp_datasn = r2tsn + 1;
698         __kfifo_put(tcp_task->r2tqueue, (void*)&r2t, sizeof(void*));
699         conn->r2t_pdus_cnt++;
700
701         iscsi_requeue_task(task);
702         return 0;
703 }
704
705 /*
706  * Handle incoming reply to DataIn command
707  */
708 static int
709 iscsi_tcp_process_data_in(struct iscsi_tcp_conn *tcp_conn,
710                           struct iscsi_segment *segment)
711 {
712         struct iscsi_conn *conn = tcp_conn->iscsi_conn;
713         struct iscsi_hdr *hdr = tcp_conn->in.hdr;
714         int rc;
715
716         if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
717                 return ISCSI_ERR_DATA_DGST;
718
719         /* check for non-exceptional status */
720         if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
721                 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
722                 if (rc)
723                         return rc;
724         }
725
726         iscsi_tcp_hdr_recv_prep(tcp_conn);
727         return 0;
728 }
729
730 /**
731  * iscsi_tcp_hdr_dissect - process PDU header
732  * @conn: iSCSI connection
733  * @hdr: PDU header
734  *
735  * This function analyzes the header of the PDU received,
736  * and performs several sanity checks. If the PDU is accompanied
737  * by data, the receive buffer is set up to copy the incoming data
738  * to the correct location.
739  */
740 static int
741 iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
742 {
743         int rc = 0, opcode, ahslen;
744         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
745         struct iscsi_task *task;
746
747         /* verify PDU length */
748         tcp_conn->in.datalen = ntoh24(hdr->dlength);
749         if (tcp_conn->in.datalen > conn->max_recv_dlength) {
750                 iscsi_conn_printk(KERN_ERR, conn,
751                                   "iscsi_tcp: datalen %d > %d\n",
752                                   tcp_conn->in.datalen, conn->max_recv_dlength);
753                 return ISCSI_ERR_DATALEN;
754         }
755
756         /* Additional header segments. So far, we don't
757          * process additional headers.
758          */
759         ahslen = hdr->hlength << 2;
760
761         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
762         /* verify itt (itt encoding: age+cid+itt) */
763         rc = iscsi_verify_itt(conn, hdr->itt);
764         if (rc)
765                 return rc;
766
767         debug_tcp("opcode 0x%x ahslen %d datalen %d\n",
768                   opcode, ahslen, tcp_conn->in.datalen);
769
770         switch(opcode) {
771         case ISCSI_OP_SCSI_DATA_IN:
772                 spin_lock(&conn->session->lock);
773                 task = iscsi_itt_to_ctask(conn, hdr->itt);
774                 if (!task)
775                         rc = ISCSI_ERR_BAD_ITT;
776                 else
777                         rc = iscsi_data_rsp(conn, task);
778                 if (rc) {
779                         spin_unlock(&conn->session->lock);
780                         break;
781                 }
782
783                 if (tcp_conn->in.datalen) {
784                         struct iscsi_tcp_task *tcp_task = task->dd_data;
785                         struct hash_desc *rx_hash = NULL;
786                         struct scsi_data_buffer *sdb = scsi_in(task->sc);
787
788                         /*
789                          * Setup copy of Data-In into the Scsi_Cmnd
790                          * Scatterlist case:
791                          * We set up the iscsi_segment to point to the next
792                          * scatterlist entry to copy to. As we go along,
793                          * we move on to the next scatterlist entry and
794                          * update the digest per-entry.
795                          */
796                         if (conn->datadgst_en)
797                                 rx_hash = &tcp_conn->rx_hash;
798
799                         debug_tcp("iscsi_tcp_begin_data_in(%p, offset=%d, "
800                                   "datalen=%d)\n", tcp_conn,
801                                   tcp_task->data_offset,
802                                   tcp_conn->in.datalen);
803                         rc = iscsi_segment_seek_sg(&tcp_conn->in.segment,
804                                                    sdb->table.sgl,
805                                                    sdb->table.nents,
806                                                    tcp_task->data_offset,
807                                                    tcp_conn->in.datalen,
808                                                    iscsi_tcp_process_data_in,
809                                                    rx_hash);
810                         spin_unlock(&conn->session->lock);
811                         return rc;
812                 }
813                 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
814                 spin_unlock(&conn->session->lock);
815                 break;
816         case ISCSI_OP_SCSI_CMD_RSP:
817                 if (tcp_conn->in.datalen) {
818                         iscsi_tcp_data_recv_prep(tcp_conn);
819                         return 0;
820                 }
821                 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
822                 break;
823         case ISCSI_OP_R2T:
824                 spin_lock(&conn->session->lock);
825                 task = iscsi_itt_to_ctask(conn, hdr->itt);
826                 if (!task)
827                         rc = ISCSI_ERR_BAD_ITT;
828                 else if (ahslen)
829                         rc = ISCSI_ERR_AHSLEN;
830                 else if (task->sc->sc_data_direction == DMA_TO_DEVICE)
831                         rc = iscsi_r2t_rsp(conn, task);
832                 else
833                         rc = ISCSI_ERR_PROTO;
834                 spin_unlock(&conn->session->lock);
835                 break;
836         case ISCSI_OP_LOGIN_RSP:
837         case ISCSI_OP_TEXT_RSP:
838         case ISCSI_OP_REJECT:
839         case ISCSI_OP_ASYNC_EVENT:
840                 /*
841                  * It is possible that we could get a PDU with a buffer larger
842                  * than 8K, but there are no targets that currently do this.
843                  * For now we fail until we find a vendor that needs it
844                  */
845                 if (ISCSI_DEF_MAX_RECV_SEG_LEN < tcp_conn->in.datalen) {
846                         iscsi_conn_printk(KERN_ERR, conn,
847                                           "iscsi_tcp: received buffer of "
848                                           "len %u but conn buffer is only %u "
849                                           "(opcode %0x)\n",
850                                           tcp_conn->in.datalen,
851                                           ISCSI_DEF_MAX_RECV_SEG_LEN, opcode);
852                         rc = ISCSI_ERR_PROTO;
853                         break;
854                 }
855
856                 /* If there's data coming in with the response,
857                  * receive it to the connection's buffer.
858                  */
859                 if (tcp_conn->in.datalen) {
860                         iscsi_tcp_data_recv_prep(tcp_conn);
861                         return 0;
862                 }
863         /* fall through */
864         case ISCSI_OP_LOGOUT_RSP:
865         case ISCSI_OP_NOOP_IN:
866         case ISCSI_OP_SCSI_TMFUNC_RSP:
867                 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
868                 break;
869         default:
870                 rc = ISCSI_ERR_BAD_OPCODE;
871                 break;
872         }
873
874         if (rc == 0) {
875                 /* Anything that comes with data should have
876                  * been handled above. */
877                 if (tcp_conn->in.datalen)
878                         return ISCSI_ERR_PROTO;
879                 iscsi_tcp_hdr_recv_prep(tcp_conn);
880         }
881
882         return rc;
883 }
884
885 /**
886  * iscsi_tcp_hdr_recv_done - process PDU header
887  *
888  * This is the callback invoked when the PDU header has
889  * been received. If the header is followed by additional
890  * header segments, we go back for more data.
891  */
892 static int
893 iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn,
894                         struct iscsi_segment *segment)
895 {
896         struct iscsi_conn *conn = tcp_conn->iscsi_conn;
897         struct iscsi_hdr *hdr;
898
899         /* Check if there are additional header segments
900          * *prior* to computing the digest, because we
901          * may need to go back to the caller for more.
902          */
903         hdr = (struct iscsi_hdr *) tcp_conn->in.hdr_buf;
904         if (segment->copied == sizeof(struct iscsi_hdr) && hdr->hlength) {
905                 /* Bump the header length - the caller will
906                  * just loop around and get the AHS for us, and
907                  * call again. */
908                 unsigned int ahslen = hdr->hlength << 2;
909
910                 /* Make sure we don't overflow */
911                 if (sizeof(*hdr) + ahslen > sizeof(tcp_conn->in.hdr_buf))
912                         return ISCSI_ERR_AHSLEN;
913
914                 segment->total_size += ahslen;
915                 segment->size += ahslen;
916                 return 0;
917         }
918
919         /* We're done processing the header. See if we're doing
920          * header digests; if so, set up the recv_digest buffer
921          * and go back for more. */
922         if (conn->hdrdgst_en) {
923                 if (segment->digest_len == 0) {
924                         iscsi_tcp_segment_splice_digest(segment,
925                                                         segment->recv_digest);
926                         return 0;
927                 }
928                 iscsi_tcp_dgst_header(&tcp_conn->rx_hash, hdr,
929                                       segment->total_copied - ISCSI_DIGEST_SIZE,
930                                       segment->digest);
931
932                 if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
933                         return ISCSI_ERR_HDR_DGST;
934         }
935
936         tcp_conn->in.hdr = hdr;
937         return iscsi_tcp_hdr_dissect(conn, hdr);
938 }
939
940 /**
941  * iscsi_tcp_recv - TCP receive in sendfile fashion
942  * @rd_desc: read descriptor
943  * @skb: socket buffer
944  * @offset: offset in skb
945  * @len: skb->len - offset
946  **/
947 static int
948 iscsi_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
949                unsigned int offset, size_t len)
950 {
951         struct iscsi_conn *conn = rd_desc->arg.data;
952         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
953         struct iscsi_segment *segment = &tcp_conn->in.segment;
954         struct skb_seq_state seq;
955         unsigned int consumed = 0;
956         int rc = 0;
957
958         debug_tcp("in %d bytes\n", skb->len - offset);
959
960         if (unlikely(conn->suspend_rx)) {
961                 debug_tcp("conn %d Rx suspended!\n", conn->id);
962                 return 0;
963         }
964
965         skb_prepare_seq_read(skb, offset, skb->len, &seq);
966         while (1) {
967                 unsigned int avail;
968                 const u8 *ptr;
969
970                 avail = skb_seq_read(consumed, &ptr, &seq);
971                 if (avail == 0) {
972                         debug_tcp("no more data avail. Consumed %d\n",
973                                   consumed);
974                         break;
975                 }
976                 BUG_ON(segment->copied >= segment->size);
977
978                 debug_tcp("skb %p ptr=%p avail=%u\n", skb, ptr, avail);
979                 rc = iscsi_tcp_segment_recv(tcp_conn, segment, ptr, avail);
980                 BUG_ON(rc == 0);
981                 consumed += rc;
982
983                 if (segment->total_copied >= segment->total_size) {
984                         debug_tcp("segment done\n");
985                         rc = segment->done(tcp_conn, segment);
986                         if (rc != 0) {
987                                 skb_abort_seq_read(&seq);
988                                 goto error;
989                         }
990
991                         /* The done() functions sets up the
992                          * next segment. */
993                 }
994         }
995         skb_abort_seq_read(&seq);
996         conn->rxdata_octets += consumed;
997         return consumed;
998
999 error:
1000         debug_tcp("Error receiving PDU, errno=%d\n", rc);
1001         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1002         return 0;
1003 }
1004
1005 static void
1006 iscsi_tcp_data_ready(struct sock *sk, int flag)
1007 {
1008         struct iscsi_conn *conn = sk->sk_user_data;
1009         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1010         read_descriptor_t rd_desc;
1011
1012         read_lock(&sk->sk_callback_lock);
1013
1014         /*
1015          * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
1016          * We set count to 1 because we want the network layer to
1017          * hand us all the skbs that are available. iscsi_tcp_recv
1018          * handled pdus that cross buffers or pdus that still need data.
1019          */
1020         rd_desc.arg.data = conn;
1021         rd_desc.count = 1;
1022         tcp_read_sock(sk, &rd_desc, iscsi_tcp_recv);
1023
1024         read_unlock(&sk->sk_callback_lock);
1025
1026         /* If we had to (atomically) map a highmem page,
1027          * unmap it now. */
1028         iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
1029 }
1030
1031 static void
1032 iscsi_tcp_state_change(struct sock *sk)
1033 {
1034         struct iscsi_tcp_conn *tcp_conn;
1035         struct iscsi_conn *conn;
1036         struct iscsi_session *session;
1037         void (*old_state_change)(struct sock *);
1038
1039         read_lock(&sk->sk_callback_lock);
1040
1041         conn = (struct iscsi_conn*)sk->sk_user_data;
1042         session = conn->session;
1043
1044         if ((sk->sk_state == TCP_CLOSE_WAIT ||
1045              sk->sk_state == TCP_CLOSE) &&
1046             !atomic_read(&sk->sk_rmem_alloc)) {
1047                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1048                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1049         }
1050
1051         tcp_conn = conn->dd_data;
1052         old_state_change = tcp_conn->old_state_change;
1053
1054         read_unlock(&sk->sk_callback_lock);
1055
1056         old_state_change(sk);
1057 }
1058
1059 /**
1060  * iscsi_write_space - Called when more output buffer space is available
1061  * @sk: socket space is available for
1062  **/
1063 static void
1064 iscsi_write_space(struct sock *sk)
1065 {
1066         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1067         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1068
1069         tcp_conn->old_write_space(sk);
1070         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1071         scsi_queue_work(conn->session->host, &conn->xmitwork);
1072 }
1073
1074 static void
1075 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1076 {
1077         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1078         struct sock *sk = tcp_conn->sock->sk;
1079
1080         /* assign new callbacks */
1081         write_lock_bh(&sk->sk_callback_lock);
1082         sk->sk_user_data = conn;
1083         tcp_conn->old_data_ready = sk->sk_data_ready;
1084         tcp_conn->old_state_change = sk->sk_state_change;
1085         tcp_conn->old_write_space = sk->sk_write_space;
1086         sk->sk_data_ready = iscsi_tcp_data_ready;
1087         sk->sk_state_change = iscsi_tcp_state_change;
1088         sk->sk_write_space = iscsi_write_space;
1089         write_unlock_bh(&sk->sk_callback_lock);
1090 }
1091
1092 static void
1093 iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
1094 {
1095         struct sock *sk = tcp_conn->sock->sk;
1096
1097         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1098         write_lock_bh(&sk->sk_callback_lock);
1099         sk->sk_user_data    = NULL;
1100         sk->sk_data_ready   = tcp_conn->old_data_ready;
1101         sk->sk_state_change = tcp_conn->old_state_change;
1102         sk->sk_write_space  = tcp_conn->old_write_space;
1103         sk->sk_no_check  = 0;
1104         write_unlock_bh(&sk->sk_callback_lock);
1105 }
1106
1107 /**
1108  * iscsi_xmit - TCP transmit
1109  **/
1110 static int
1111 iscsi_xmit(struct iscsi_conn *conn)
1112 {
1113         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1114         struct iscsi_segment *segment = &tcp_conn->out.segment;
1115         unsigned int consumed = 0;
1116         int rc = 0;
1117
1118         while (1) {
1119                 rc = iscsi_tcp_xmit_segment(tcp_conn, segment);
1120                 if (rc < 0)
1121                         goto error;
1122                 if (rc == 0)
1123                         break;
1124
1125                 consumed += rc;
1126
1127                 if (segment->total_copied >= segment->total_size) {
1128                         if (segment->done != NULL) {
1129                                 rc = segment->done(tcp_conn, segment);
1130                                 if (rc < 0)
1131                                         goto error;
1132                         }
1133                 }
1134         }
1135
1136         debug_tcp("xmit %d bytes\n", consumed);
1137
1138         conn->txdata_octets += consumed;
1139         return consumed;
1140
1141 error:
1142         /* Transmit error. We could initiate error recovery
1143          * here. */
1144         debug_tcp("Error sending PDU, errno=%d\n", rc);
1145         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1146         return rc;
1147 }
1148
1149 /**
1150  * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
1151  */
1152 static inline int
1153 iscsi_tcp_xmit_qlen(struct iscsi_conn *conn)
1154 {
1155         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1156         struct iscsi_segment *segment = &tcp_conn->out.segment;
1157
1158         return segment->total_copied - segment->total_size;
1159 }
1160
1161 static inline int
1162 iscsi_tcp_flush(struct iscsi_conn *conn)
1163 {
1164         int rc;
1165
1166         while (iscsi_tcp_xmit_qlen(conn)) {
1167                 rc = iscsi_xmit(conn);
1168                 if (rc == 0)
1169                         return -EAGAIN;
1170                 if (rc < 0)
1171                         return rc;
1172         }
1173
1174         return 0;
1175 }
1176
1177 /*
1178  * This is called when we're done sending the header.
1179  * Simply copy the data_segment to the send segment, and return.
1180  */
1181 static int
1182 iscsi_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
1183                         struct iscsi_segment *segment)
1184 {
1185         tcp_conn->out.segment = tcp_conn->out.data_segment;
1186         debug_tcp("Header done. Next segment size %u total_size %u\n",
1187                   tcp_conn->out.segment.size, tcp_conn->out.segment.total_size);
1188         return 0;
1189 }
1190
1191 static void
1192 iscsi_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr, size_t hdrlen)
1193 {
1194         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1195
1196         debug_tcp("%s(%p%s)\n", __FUNCTION__, tcp_conn,
1197                         conn->hdrdgst_en? ", digest enabled" : "");
1198
1199         /* Clear the data segment - needs to be filled in by the
1200          * caller using iscsi_tcp_send_data_prep() */
1201         memset(&tcp_conn->out.data_segment, 0, sizeof(struct iscsi_segment));
1202
1203         /* If header digest is enabled, compute the CRC and
1204          * place the digest into the same buffer. We make
1205          * sure that both iscsi_tcp_task and mtask have
1206          * sufficient room.
1207          */
1208         if (conn->hdrdgst_en) {
1209                 iscsi_tcp_dgst_header(&tcp_conn->tx_hash, hdr, hdrlen,
1210                                       hdr + hdrlen);
1211                 hdrlen += ISCSI_DIGEST_SIZE;
1212         }
1213
1214         /* Remember header pointer for later, when we need
1215          * to decide whether there's a payload to go along
1216          * with the header. */
1217         tcp_conn->out.hdr = hdr;
1218
1219         iscsi_segment_init_linear(&tcp_conn->out.segment, hdr, hdrlen,
1220                                 iscsi_tcp_send_hdr_done, NULL);
1221 }
1222
1223 /*
1224  * Prepare the send buffer for the payload data.
1225  * Padding and checksumming will all be taken care
1226  * of by the iscsi_segment routines.
1227  */
1228 static int
1229 iscsi_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
1230                          unsigned int count, unsigned int offset,
1231                          unsigned int len)
1232 {
1233         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1234         struct hash_desc *tx_hash = NULL;
1235         unsigned int hdr_spec_len;
1236
1237         debug_tcp("%s(%p, offset=%d, datalen=%d%s)\n", __FUNCTION__,
1238                         tcp_conn, offset, len,
1239                         conn->datadgst_en? ", digest enabled" : "");
1240
1241         /* Make sure the datalen matches what the caller
1242            said he would send. */
1243         hdr_spec_len = ntoh24(tcp_conn->out.hdr->dlength);
1244         WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
1245
1246         if (conn->datadgst_en)
1247                 tx_hash = &tcp_conn->tx_hash;
1248
1249         return iscsi_segment_seek_sg(&tcp_conn->out.data_segment,
1250                                    sg, count, offset, len,
1251                                    NULL, tx_hash);
1252 }
1253
1254 static void
1255 iscsi_tcp_send_linear_data_prepare(struct iscsi_conn *conn, void *data,
1256                                    size_t len)
1257 {
1258         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1259         struct hash_desc *tx_hash = NULL;
1260         unsigned int hdr_spec_len;
1261
1262         debug_tcp("%s(%p, datalen=%d%s)\n", __FUNCTION__, tcp_conn, len,
1263                   conn->datadgst_en? ", digest enabled" : "");
1264
1265         /* Make sure the datalen matches what the caller
1266            said he would send. */
1267         hdr_spec_len = ntoh24(tcp_conn->out.hdr->dlength);
1268         WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
1269
1270         if (conn->datadgst_en)
1271                 tx_hash = &tcp_conn->tx_hash;
1272
1273         iscsi_segment_init_linear(&tcp_conn->out.data_segment,
1274                                 data, len, NULL, tx_hash);
1275 }
1276
1277 /**
1278  * iscsi_solicit_data_cont - initialize next Data-Out
1279  * @conn: iscsi connection
1280  * @task: scsi command task
1281  * @r2t: R2T info
1282  * @left: bytes left to transfer
1283  *
1284  * Notes:
1285  *      Initialize next Data-Out within this R2T sequence and continue
1286  *      to process next Scatter-Gather element(if any) of this SCSI command.
1287  *
1288  *      Called under connection lock.
1289  **/
1290 static int
1291 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_task *task,
1292                         struct iscsi_r2t_info *r2t)
1293 {
1294         struct iscsi_data *hdr;
1295         int new_offset, left;
1296
1297         BUG_ON(r2t->data_length - r2t->sent < 0);
1298         left = r2t->data_length - r2t->sent;
1299         if (left == 0)
1300                 return 0;
1301
1302         hdr = &r2t->dtask.hdr;
1303         memset(hdr, 0, sizeof(struct iscsi_data));
1304         hdr->ttt = r2t->ttt;
1305         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1306         r2t->solicit_datasn++;
1307         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1308         memcpy(hdr->lun, task->hdr->lun, sizeof(hdr->lun));
1309         hdr->itt = task->hdr->itt;
1310         hdr->exp_statsn = r2t->exp_statsn;
1311         new_offset = r2t->data_offset + r2t->sent;
1312         hdr->offset = cpu_to_be32(new_offset);
1313         if (left > conn->max_xmit_dlength) {
1314                 hton24(hdr->dlength, conn->max_xmit_dlength);
1315                 r2t->data_count = conn->max_xmit_dlength;
1316         } else {
1317                 hton24(hdr->dlength, left);
1318                 r2t->data_count = left;
1319                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1320         }
1321
1322         conn->dataout_pdus_cnt++;
1323         return 1;
1324 }
1325
1326 /**
1327  * iscsi_tcp_task - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1328  * @conn: iscsi connection
1329  * @task: scsi command task
1330  * @sc: scsi command
1331  **/
1332 static int
1333 iscsi_tcp_task_init(struct iscsi_task *task)
1334 {
1335         struct iscsi_tcp_task *tcp_task = task->dd_data;
1336         struct iscsi_conn *conn = task->conn;
1337         struct scsi_cmnd *sc = task->sc;
1338         int err;
1339
1340         if (!sc) {
1341                 /*
1342                  * mgmt tasks do not have a scatterlist since they come
1343                  * in from the iscsi interface.
1344                  */
1345                 debug_scsi("mtask deq [cid %d itt 0x%x]\n", conn->id,
1346                            task->itt);
1347
1348                 /* Prepare PDU, optionally w/ immediate data */
1349                 iscsi_tcp_send_hdr_prep(conn, task->hdr, sizeof(*task->hdr));
1350
1351                 /* If we have immediate data, attach a payload */
1352                 if (task->data_count)
1353                         iscsi_tcp_send_linear_data_prepare(conn, task->data,
1354                                                            task->data_count);
1355                 return 0;
1356         }
1357
1358         BUG_ON(__kfifo_len(tcp_task->r2tqueue));
1359         tcp_task->sent = 0;
1360         tcp_task->exp_datasn = 0;
1361
1362         /* Prepare PDU, optionally w/ immediate data */
1363         debug_scsi("task deq [cid %d itt 0x%x imm %d unsol %d]\n",
1364                     conn->id, task->itt, task->imm_count,
1365                     task->unsol_count);
1366         iscsi_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
1367
1368         if (!task->imm_count)
1369                 return 0;
1370
1371         /* If we have immediate data, attach a payload */
1372         err = iscsi_tcp_send_data_prep(conn, scsi_out(sc)->table.sgl,
1373                                        scsi_out(sc)->table.nents,
1374                                        0, task->imm_count);
1375         if (err)
1376                 return err;
1377         tcp_task->sent += task->imm_count;
1378         task->imm_count = 0;
1379         return 0;
1380 }
1381
1382 /*
1383  * iscsi_tcp_task_xmit - xmit normal PDU task
1384  * @task: iscsi command task
1385  *
1386  * We're expected to return 0 when everything was transmitted succesfully,
1387  * -EAGAIN if there's still data in the queue, or != 0 for any other kind
1388  * of error.
1389  */
1390 static int
1391 iscsi_tcp_task_xmit(struct iscsi_task *task)
1392 {
1393         struct iscsi_conn *conn = task->conn;
1394         struct iscsi_tcp_task *tcp_task = task->dd_data;
1395         struct scsi_cmnd *sc = task->sc;
1396         struct scsi_data_buffer *sdb;
1397         int rc = 0;
1398
1399 flush:
1400         /* Flush any pending data first. */
1401         rc = iscsi_tcp_flush(conn);
1402         if (rc < 0)
1403                 return rc;
1404
1405         /* mgmt command */
1406         if (!sc) {
1407                 if (task->hdr->itt == RESERVED_ITT)
1408                         iscsi_put_task(task);
1409                 return 0;
1410         }
1411
1412         /* Are we done already? */
1413         if (sc->sc_data_direction != DMA_TO_DEVICE)
1414                 return 0;
1415
1416         sdb = scsi_out(sc);
1417         if (task->unsol_count != 0) {
1418                 struct iscsi_data *hdr = &tcp_task->unsol_dtask.hdr;
1419
1420                 /* Prepare a header for the unsolicited PDU.
1421                  * The amount of data we want to send will be
1422                  * in task->data_count.
1423                  * FIXME: return the data count instead.
1424                  */
1425                 iscsi_prep_unsolicit_data_pdu(task, hdr);
1426
1427                 debug_tcp("unsol dout [itt 0x%x doff %d dlen %d]\n",
1428                                 task->itt, tcp_task->sent, task->data_count);
1429
1430                 iscsi_tcp_send_hdr_prep(conn, hdr, sizeof(*hdr));
1431                 rc = iscsi_tcp_send_data_prep(conn, sdb->table.sgl,
1432                                               sdb->table.nents, tcp_task->sent,
1433                                               task->data_count);
1434                 if (rc)
1435                         goto fail;
1436                 tcp_task->sent += task->data_count;
1437                 task->unsol_count -= task->data_count;
1438                 goto flush;
1439         } else {
1440                 struct iscsi_session *session = conn->session;
1441                 struct iscsi_r2t_info *r2t;
1442
1443                 /* All unsolicited PDUs sent. Check for solicited PDUs.
1444                  */
1445                 spin_lock_bh(&session->lock);
1446                 r2t = tcp_task->r2t;
1447                 if (r2t != NULL) {
1448                         /* Continue with this R2T? */
1449                         if (!iscsi_solicit_data_cont(conn, task, r2t)) {
1450                                 debug_scsi("  done with r2t %p\n", r2t);
1451
1452                                 __kfifo_put(tcp_task->r2tpool.queue,
1453                                             (void*)&r2t, sizeof(void*));
1454                                 tcp_task->r2t = r2t = NULL;
1455                         }
1456                 }
1457
1458                 if (r2t == NULL) {
1459                         __kfifo_get(tcp_task->r2tqueue, (void*)&tcp_task->r2t,
1460                                     sizeof(void*));
1461                         r2t = tcp_task->r2t;
1462                 }
1463                 spin_unlock_bh(&session->lock);
1464
1465                 /* Waiting for more R2Ts to arrive. */
1466                 if (r2t == NULL) {
1467                         debug_tcp("no R2Ts yet\n");
1468                         return 0;
1469                 }
1470
1471                 debug_scsi("sol dout %p [dsn %d itt 0x%x doff %d dlen %d]\n",
1472                         r2t, r2t->solicit_datasn - 1, task->itt,
1473                         r2t->data_offset + r2t->sent, r2t->data_count);
1474
1475                 iscsi_tcp_send_hdr_prep(conn, &r2t->dtask.hdr,
1476                                         sizeof(struct iscsi_hdr));
1477
1478                 rc = iscsi_tcp_send_data_prep(conn, sdb->table.sgl,
1479                                               sdb->table.nents,
1480                                               r2t->data_offset + r2t->sent,
1481                                               r2t->data_count);
1482                 if (rc)
1483                         goto fail;
1484                 tcp_task->sent += r2t->data_count;
1485                 r2t->sent += r2t->data_count;
1486                 goto flush;
1487         }
1488         return 0;
1489 fail:
1490         iscsi_conn_failure(conn, rc);
1491         return -EIO;
1492 }
1493
1494 static struct iscsi_cls_conn *
1495 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1496 {
1497         struct iscsi_conn *conn;
1498         struct iscsi_cls_conn *cls_conn;
1499         struct iscsi_tcp_conn *tcp_conn;
1500
1501         cls_conn = iscsi_conn_setup(cls_session, sizeof(*tcp_conn), conn_idx);
1502         if (!cls_conn)
1503                 return NULL;
1504         conn = cls_conn->dd_data;
1505         /*
1506          * due to strange issues with iser these are not set
1507          * in iscsi_conn_setup
1508          */
1509         conn->max_recv_dlength = ISCSI_DEF_MAX_RECV_SEG_LEN;
1510
1511         tcp_conn = conn->dd_data;
1512         tcp_conn->iscsi_conn = conn;
1513
1514         tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1515                                                   CRYPTO_ALG_ASYNC);
1516         tcp_conn->tx_hash.flags = 0;
1517         if (IS_ERR(tcp_conn->tx_hash.tfm))
1518                 goto free_conn;
1519
1520         tcp_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1521                                                   CRYPTO_ALG_ASYNC);
1522         tcp_conn->rx_hash.flags = 0;
1523         if (IS_ERR(tcp_conn->rx_hash.tfm))
1524                 goto free_tx_tfm;
1525
1526         return cls_conn;
1527
1528 free_tx_tfm:
1529         crypto_free_hash(tcp_conn->tx_hash.tfm);
1530 free_conn:
1531         iscsi_conn_printk(KERN_ERR, conn,
1532                           "Could not create connection due to crc32c "
1533                           "loading error. Make sure the crc32c "
1534                           "module is built as a module or into the "
1535                           "kernel\n");
1536         iscsi_conn_teardown(cls_conn);
1537         return NULL;
1538 }
1539
1540 static void
1541 iscsi_tcp_release_conn(struct iscsi_conn *conn)
1542 {
1543         struct iscsi_session *session = conn->session;
1544         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1545         struct socket *sock = tcp_conn->sock;
1546
1547         if (!sock)
1548                 return;
1549
1550         sock_hold(sock->sk);
1551         iscsi_conn_restore_callbacks(tcp_conn);
1552         sock_put(sock->sk);
1553
1554         spin_lock_bh(&session->lock);
1555         tcp_conn->sock = NULL;
1556         spin_unlock_bh(&session->lock);
1557         sockfd_put(sock);
1558 }
1559
1560 static void
1561 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1562 {
1563         struct iscsi_conn *conn = cls_conn->dd_data;
1564         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1565
1566         iscsi_tcp_release_conn(conn);
1567
1568         if (tcp_conn->tx_hash.tfm)
1569                 crypto_free_hash(tcp_conn->tx_hash.tfm);
1570         if (tcp_conn->rx_hash.tfm)
1571                 crypto_free_hash(tcp_conn->rx_hash.tfm);
1572
1573         iscsi_conn_teardown(cls_conn);
1574 }
1575
1576 static void
1577 iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1578 {
1579         struct iscsi_conn *conn = cls_conn->dd_data;
1580         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1581
1582         /* userspace may have goofed up and not bound us */
1583         if (!tcp_conn->sock)
1584                 return;
1585         /*
1586          * Make sure our recv side is stopped.
1587          * Older tools called conn stop before ep_disconnect
1588          * so IO could still be coming in.
1589          */
1590         write_lock_bh(&tcp_conn->sock->sk->sk_callback_lock);
1591         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1592         write_unlock_bh(&tcp_conn->sock->sk->sk_callback_lock);
1593
1594         iscsi_conn_stop(cls_conn, flag);
1595         iscsi_tcp_release_conn(conn);
1596 }
1597
1598 static int iscsi_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
1599                               char *buf, int *port,
1600                               int (*getname)(struct socket *, struct sockaddr *,
1601                                         int *addrlen))
1602 {
1603         struct sockaddr_storage *addr;
1604         struct sockaddr_in6 *sin6;
1605         struct sockaddr_in *sin;
1606         int rc = 0, len;
1607
1608         addr = kmalloc(sizeof(*addr), GFP_KERNEL);
1609         if (!addr)
1610                 return -ENOMEM;
1611
1612         if (getname(sock, (struct sockaddr *) addr, &len)) {
1613                 rc = -ENODEV;
1614                 goto free_addr;
1615         }
1616
1617         switch (addr->ss_family) {
1618         case AF_INET:
1619                 sin = (struct sockaddr_in *)addr;
1620                 spin_lock_bh(&conn->session->lock);
1621                 sprintf(buf, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr));
1622                 *port = be16_to_cpu(sin->sin_port);
1623                 spin_unlock_bh(&conn->session->lock);
1624                 break;
1625         case AF_INET6:
1626                 sin6 = (struct sockaddr_in6 *)addr;
1627                 spin_lock_bh(&conn->session->lock);
1628                 sprintf(buf, NIP6_FMT, NIP6(sin6->sin6_addr));
1629                 *port = be16_to_cpu(sin6->sin6_port);
1630                 spin_unlock_bh(&conn->session->lock);
1631                 break;
1632         }
1633 free_addr:
1634         kfree(addr);
1635         return rc;
1636 }
1637
1638 static int
1639 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1640                     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1641                     int is_leading)
1642 {
1643         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1644         struct iscsi_host *ihost = shost_priv(shost);
1645         struct iscsi_conn *conn = cls_conn->dd_data;
1646         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1647         struct sock *sk;
1648         struct socket *sock;
1649         int err;
1650
1651         /* lookup for existing socket */
1652         sock = sockfd_lookup((int)transport_eph, &err);
1653         if (!sock) {
1654                 iscsi_conn_printk(KERN_ERR, conn,
1655                                   "sockfd_lookup failed %d\n", err);
1656                 return -EEXIST;
1657         }
1658         /*
1659          * copy these values now because if we drop the session
1660          * userspace may still want to query the values since we will
1661          * be using them for the reconnect
1662          */
1663         err = iscsi_tcp_get_addr(conn, sock, conn->portal_address,
1664                                  &conn->portal_port, kernel_getpeername);
1665         if (err)
1666                 goto free_socket;
1667
1668         err = iscsi_tcp_get_addr(conn, sock, ihost->local_address,
1669                                 &ihost->local_port, kernel_getsockname);
1670         if (err)
1671                 goto free_socket;
1672
1673         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
1674         if (err)
1675                 goto free_socket;
1676
1677         /* bind iSCSI connection and socket */
1678         tcp_conn->sock = sock;
1679
1680         /* setup Socket parameters */
1681         sk = sock->sk;
1682         sk->sk_reuse = 1;
1683         sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
1684         sk->sk_allocation = GFP_ATOMIC;
1685
1686         iscsi_conn_set_callbacks(conn);
1687         tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
1688         /*
1689          * set receive state machine into initial state
1690          */
1691         iscsi_tcp_hdr_recv_prep(tcp_conn);
1692         return 0;
1693
1694 free_socket:
1695         sockfd_put(sock);
1696         return err;
1697 }
1698
1699 static int
1700 iscsi_r2tpool_alloc(struct iscsi_session *session)
1701 {
1702         int i;
1703         int cmd_i;
1704
1705         /*
1706          * initialize per-task: R2T pool and xmit queue
1707          */
1708         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1709                 struct iscsi_task *task = session->cmds[cmd_i];
1710                 struct iscsi_tcp_task *tcp_task = task->dd_data;
1711
1712                 /*
1713                  * pre-allocated x4 as much r2ts to handle race when
1714                  * target acks DataOut faster than we data_xmit() queues
1715                  * could replenish r2tqueue.
1716                  */
1717
1718                 /* R2T pool */
1719                 if (iscsi_pool_init(&tcp_task->r2tpool, session->max_r2t * 4, NULL,
1720                                     sizeof(struct iscsi_r2t_info))) {
1721                         goto r2t_alloc_fail;
1722                 }
1723
1724                 /* R2T xmit queue */
1725                 tcp_task->r2tqueue = kfifo_alloc(
1726                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
1727                 if (tcp_task->r2tqueue == ERR_PTR(-ENOMEM)) {
1728                         iscsi_pool_free(&tcp_task->r2tpool);
1729                         goto r2t_alloc_fail;
1730                 }
1731         }
1732
1733         return 0;
1734
1735 r2t_alloc_fail:
1736         for (i = 0; i < cmd_i; i++) {
1737                 struct iscsi_task *task = session->cmds[i];
1738                 struct iscsi_tcp_task *tcp_task = task->dd_data;
1739
1740                 kfifo_free(tcp_task->r2tqueue);
1741                 iscsi_pool_free(&tcp_task->r2tpool);
1742         }
1743         return -ENOMEM;
1744 }
1745
1746 static void
1747 iscsi_r2tpool_free(struct iscsi_session *session)
1748 {
1749         int i;
1750
1751         for (i = 0; i < session->cmds_max; i++) {
1752                 struct iscsi_task *task = session->cmds[i];
1753                 struct iscsi_tcp_task *tcp_task = task->dd_data;
1754
1755                 kfifo_free(tcp_task->r2tqueue);
1756                 iscsi_pool_free(&tcp_task->r2tpool);
1757         }
1758 }
1759
1760 static int
1761 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
1762                      char *buf, int buflen)
1763 {
1764         struct iscsi_conn *conn = cls_conn->dd_data;
1765         struct iscsi_session *session = conn->session;
1766         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1767         int value;
1768
1769         switch(param) {
1770         case ISCSI_PARAM_HDRDGST_EN:
1771                 iscsi_set_param(cls_conn, param, buf, buflen);
1772                 break;
1773         case ISCSI_PARAM_DATADGST_EN:
1774                 iscsi_set_param(cls_conn, param, buf, buflen);
1775                 tcp_conn->sendpage = conn->datadgst_en ?
1776                         sock_no_sendpage : tcp_conn->sock->ops->sendpage;
1777                 break;
1778         case ISCSI_PARAM_MAX_R2T:
1779                 sscanf(buf, "%d", &value);
1780                 if (value <= 0 || !is_power_of_2(value))
1781                         return -EINVAL;
1782                 if (session->max_r2t == value)
1783                         break;
1784                 iscsi_r2tpool_free(session);
1785                 iscsi_set_param(cls_conn, param, buf, buflen);
1786                 if (iscsi_r2tpool_alloc(session))
1787                         return -ENOMEM;
1788                 break;
1789         default:
1790                 return iscsi_set_param(cls_conn, param, buf, buflen);
1791         }
1792
1793         return 0;
1794 }
1795
1796 static int
1797 iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
1798                          enum iscsi_param param, char *buf)
1799 {
1800         struct iscsi_conn *conn = cls_conn->dd_data;
1801         int len;
1802
1803         switch(param) {
1804         case ISCSI_PARAM_CONN_PORT:
1805                 spin_lock_bh(&conn->session->lock);
1806                 len = sprintf(buf, "%hu\n", conn->portal_port);
1807                 spin_unlock_bh(&conn->session->lock);
1808                 break;
1809         case ISCSI_PARAM_CONN_ADDRESS:
1810                 spin_lock_bh(&conn->session->lock);
1811                 len = sprintf(buf, "%s\n", conn->portal_address);
1812                 spin_unlock_bh(&conn->session->lock);
1813                 break;
1814         default:
1815                 return iscsi_conn_get_param(cls_conn, param, buf);
1816         }
1817
1818         return len;
1819 }
1820
1821 static void
1822 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
1823 {
1824         struct iscsi_conn *conn = cls_conn->dd_data;
1825         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1826
1827         stats->txdata_octets = conn->txdata_octets;
1828         stats->rxdata_octets = conn->rxdata_octets;
1829         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
1830         stats->dataout_pdus = conn->dataout_pdus_cnt;
1831         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
1832         stats->datain_pdus = conn->datain_pdus_cnt;
1833         stats->r2t_pdus = conn->r2t_pdus_cnt;
1834         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
1835         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
1836         stats->custom_length = 3;
1837         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
1838         stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
1839         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
1840         stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
1841         strcpy(stats->custom[2].desc, "eh_abort_cnt");
1842         stats->custom[2].value = conn->eh_abort_cnt;
1843 }
1844
1845 static struct iscsi_cls_session *
1846 iscsi_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
1847                          uint16_t qdepth, uint32_t initial_cmdsn,
1848                          uint32_t *hostno)
1849 {
1850         struct iscsi_cls_session *cls_session;
1851         struct iscsi_session *session;
1852         struct Scsi_Host *shost;
1853         int cmd_i;
1854
1855         if (ep) {
1856                 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
1857                 return NULL;
1858         }
1859
1860         shost = iscsi_host_alloc(&iscsi_sht, 0, qdepth);
1861         if (!shost)
1862                 return NULL;
1863         shost->transportt = iscsi_tcp_scsi_transport;
1864         shost->max_lun = iscsi_max_lun;
1865         shost->max_id = 0;
1866         shost->max_channel = 0;
1867         shost->max_cmd_len = 16;
1868         shost->can_queue = cmds_max;
1869
1870         if (iscsi_host_add(shost, NULL))
1871                 goto free_host;
1872         *hostno = shost->host_no;
1873
1874         cls_session = iscsi_session_setup(&iscsi_tcp_transport, shost, cmds_max,
1875                                           sizeof(struct iscsi_tcp_task),
1876                                           initial_cmdsn, 0);
1877         if (!cls_session)
1878                 goto remove_host;
1879         session = cls_session->dd_data;
1880
1881         shost->can_queue = session->scsi_cmds_max;
1882         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1883                 struct iscsi_task *task = session->cmds[cmd_i];
1884                 struct iscsi_tcp_task *tcp_task = task->dd_data;
1885
1886                 task->hdr = &tcp_task->hdr.cmd_hdr;
1887                 task->hdr_max = sizeof(tcp_task->hdr) - ISCSI_DIGEST_SIZE;
1888         }
1889
1890         if (iscsi_r2tpool_alloc(session))
1891                 goto remove_session;
1892         return cls_session;
1893
1894 remove_session:
1895         iscsi_session_teardown(cls_session);
1896 remove_host:
1897         iscsi_host_remove(shost);
1898 free_host:
1899         iscsi_host_free(shost);
1900         return NULL;
1901 }
1902
1903 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
1904 {
1905         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1906
1907         iscsi_r2tpool_free(cls_session->dd_data);
1908
1909         iscsi_host_remove(shost);
1910         iscsi_host_free(shost);
1911 }
1912
1913 static int iscsi_tcp_slave_configure(struct scsi_device *sdev)
1914 {
1915         blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
1916         blk_queue_dma_alignment(sdev->request_queue, 0);
1917         return 0;
1918 }
1919
1920 static struct scsi_host_template iscsi_sht = {
1921         .module                 = THIS_MODULE,
1922         .name                   = "iSCSI Initiator over TCP/IP",
1923         .queuecommand           = iscsi_queuecommand,
1924         .change_queue_depth     = iscsi_change_queue_depth,
1925         .can_queue              = ISCSI_DEF_XMIT_CMDS_MAX - 1,
1926         .sg_tablesize           = 4096,
1927         .max_sectors            = 0xFFFF,
1928         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
1929         .eh_abort_handler       = iscsi_eh_abort,
1930         .eh_device_reset_handler= iscsi_eh_device_reset,
1931         .eh_host_reset_handler  = iscsi_eh_host_reset,
1932         .use_clustering         = DISABLE_CLUSTERING,
1933         .slave_configure        = iscsi_tcp_slave_configure,
1934         .proc_name              = "iscsi_tcp",
1935         .this_id                = -1,
1936 };
1937
1938 static struct iscsi_transport iscsi_tcp_transport = {
1939         .owner                  = THIS_MODULE,
1940         .name                   = "tcp",
1941         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
1942                                   | CAP_DATADGST,
1943         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
1944                                   ISCSI_MAX_XMIT_DLENGTH |
1945                                   ISCSI_HDRDGST_EN |
1946                                   ISCSI_DATADGST_EN |
1947                                   ISCSI_INITIAL_R2T_EN |
1948                                   ISCSI_MAX_R2T |
1949                                   ISCSI_IMM_DATA_EN |
1950                                   ISCSI_FIRST_BURST |
1951                                   ISCSI_MAX_BURST |
1952                                   ISCSI_PDU_INORDER_EN |
1953                                   ISCSI_DATASEQ_INORDER_EN |
1954                                   ISCSI_ERL |
1955                                   ISCSI_CONN_PORT |
1956                                   ISCSI_CONN_ADDRESS |
1957                                   ISCSI_EXP_STATSN |
1958                                   ISCSI_PERSISTENT_PORT |
1959                                   ISCSI_PERSISTENT_ADDRESS |
1960                                   ISCSI_TARGET_NAME | ISCSI_TPGT |
1961                                   ISCSI_USERNAME | ISCSI_PASSWORD |
1962                                   ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
1963                                   ISCSI_FAST_ABORT | ISCSI_ABORT_TMO |
1964                                   ISCSI_LU_RESET_TMO |
1965                                   ISCSI_PING_TMO | ISCSI_RECV_TMO |
1966                                   ISCSI_IFACE_NAME | ISCSI_INITIATOR_NAME,
1967         .host_param_mask        = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
1968                                   ISCSI_HOST_INITIATOR_NAME |
1969                                   ISCSI_HOST_NETDEV_NAME,
1970         /* session management */
1971         .create_session         = iscsi_tcp_session_create,
1972         .destroy_session        = iscsi_tcp_session_destroy,
1973         /* connection management */
1974         .create_conn            = iscsi_tcp_conn_create,
1975         .bind_conn              = iscsi_tcp_conn_bind,
1976         .destroy_conn           = iscsi_tcp_conn_destroy,
1977         .set_param              = iscsi_conn_set_param,
1978         .get_conn_param         = iscsi_tcp_conn_get_param,
1979         .get_session_param      = iscsi_session_get_param,
1980         .start_conn             = iscsi_conn_start,
1981         .stop_conn              = iscsi_tcp_conn_stop,
1982         /* iscsi host params */
1983         .get_host_param         = iscsi_host_get_param,
1984         .set_host_param         = iscsi_host_set_param,
1985         /* IO */
1986         .send_pdu               = iscsi_conn_send_pdu,
1987         .get_stats              = iscsi_conn_get_stats,
1988         .init_task              = iscsi_tcp_task_init,
1989         .xmit_task              = iscsi_tcp_task_xmit,
1990         .cleanup_task           = iscsi_tcp_cleanup_task,
1991         /* recovery */
1992         .session_recovery_timedout = iscsi_session_recovery_timedout,
1993 };
1994
1995 static int __init
1996 iscsi_tcp_init(void)
1997 {
1998         if (iscsi_max_lun < 1) {
1999                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2000                        iscsi_max_lun);
2001                 return -EINVAL;
2002         }
2003
2004         iscsi_tcp_scsi_transport = iscsi_register_transport(
2005                                                         &iscsi_tcp_transport);
2006         if (!iscsi_tcp_scsi_transport)
2007                 return -ENODEV;
2008
2009         return 0;
2010 }
2011
2012 static void __exit
2013 iscsi_tcp_exit(void)
2014 {
2015         iscsi_unregister_transport(&iscsi_tcp_transport);
2016 }
2017
2018 module_init(iscsi_tcp_init);
2019 module_exit(iscsi_tcp_exit);