2 * iSCSI Initiator over TCP/IP Data-Path
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
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.
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.
20 * See the file COPYING included with this distribution for more details.
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>
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>
45 #include "iscsi_tcp.h"
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");
55 #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
57 #define debug_tcp(fmt...)
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;
71 static unsigned int iscsi_max_lun = 512;
72 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
74 static int iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn,
75 struct iscsi_segment *segment);
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
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.
91 * iscsi_tcp_segment_init_sg - init indicated scatterlist entry
92 * @segment: the buffer object
94 * @offset: byte offset into that sg entry
96 * This function sets up the segment so that subsequent
97 * data is copied to the indicated sg entry, at the given
101 iscsi_tcp_segment_init_sg(struct iscsi_segment *segment,
102 struct scatterlist *sg, unsigned int offset)
105 segment->sg_offset = offset;
106 segment->size = min(sg->length - offset,
107 segment->total_size - segment->total_copied);
108 segment->data = NULL;
112 * iscsi_tcp_segment_map - map the current S/G page
113 * @segment: iscsi_segment
114 * @recv: 1 if called from recv path
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
121 iscsi_tcp_segment_map(struct iscsi_segment *segment, int recv)
123 struct scatterlist *sg;
125 if (segment->data != NULL || !segment->sg)
129 BUG_ON(segment->sg_mapped);
130 BUG_ON(sg->length == 0);
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
138 if (page_count(sg_page(sg)) >= 1 && !recv)
141 debug_tcp("iscsi_tcp_segment_map %s %p\n", recv ? "recv" : "xmit",
143 segment->sg_mapped = kmap_atomic(sg_page(sg), KM_SOFTIRQ0);
144 segment->data = segment->sg_mapped + sg->offset + segment->sg_offset;
148 iscsi_tcp_segment_unmap(struct iscsi_segment *segment)
150 debug_tcp("iscsi_tcp_segment_unmap %p\n", segment);
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;
161 * Splice the digest buffer into the buffer
164 iscsi_tcp_segment_splice_digest(struct iscsi_segment *segment, void *digest)
166 segment->data = digest;
167 segment->digest_len = ISCSI_DIGEST_SIZE;
168 segment->total_size += ISCSI_DIGEST_SIZE;
169 segment->size = ISCSI_DIGEST_SIZE;
172 segment->hash = NULL;
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
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.
185 * If the amount of data we received isn't a multiple of 4,
186 * we will transparently receive the pad bytes, too.
188 * This function must be re-entrant.
191 iscsi_tcp_segment_done(struct iscsi_segment *segment, int recv, unsigned copied)
193 static unsigned char padbuf[ISCSI_PAD_LEN];
194 struct scatterlist sg;
197 debug_tcp("copied %u %u size %u %s\n", segment->copied, copied,
198 segment->size, recv ? "recv" : "xmit");
199 if (segment->hash && copied) {
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.
204 iscsi_tcp_segment_unmap(segment);
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);
212 sg_init_one(&sg, segment->data + segment->copied,
214 crypto_hash_update(segment->hash, &sg, copied);
217 segment->copied += copied;
218 if (segment->copied < segment->size) {
219 iscsi_tcp_segment_map(segment, recv);
223 segment->total_copied += segment->copied;
227 /* Unmap the current scatterlist page, if there is one. */
228 iscsi_tcp_segment_unmap(segment);
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),
237 iscsi_tcp_segment_map(segment, recv);
238 BUG_ON(segment->size == 0);
242 /* Do we need to handle padding? */
243 pad = iscsi_padding(segment->total_copied);
245 debug_tcp("consume %d pad bytes\n", pad);
246 segment->total_size += pad;
248 segment->data = padbuf;
253 * Set us up for transferring the data digest. hdr digest
254 * is completely handled in hdr done function.
257 crypto_hash_final(segment->hash, segment->digest);
258 iscsi_tcp_segment_splice_digest(segment,
259 recv ? segment->recv_digest : segment->digest);
267 * iscsi_tcp_xmit_segment - transmit segment
268 * @tcp_conn: the iSCSI TCP connection
269 * @segment: the buffer to transmnit
271 * This function transmits as much of the buffer as
272 * the network layer will accept, and returns the number of
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.
280 iscsi_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
281 struct iscsi_segment *segment)
283 struct socket *sk = tcp_conn->sock;
284 unsigned int copied = 0;
287 while (!iscsi_tcp_segment_done(segment, 0, r)) {
288 struct scatterlist *sg;
289 unsigned int offset, copy;
293 offset = segment->copied;
294 copy = segment->size - offset;
296 if (segment->total_copied + segment->size < segment->total_size)
299 /* Use sendpage if we can; else fall back to sendmsg */
300 if (!segment->data) {
302 offset += segment->sg_offset + sg->offset;
303 r = tcp_conn->sendpage(sk, sg_page(sg), offset, copy,
306 struct msghdr msg = { .msg_flags = flags };
308 .iov_base = segment->data + offset,
312 r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
316 iscsi_tcp_segment_unmap(segment);
317 if (copied || r == -EAGAIN)
327 * iscsi_tcp_segment_recv - copy data to segment
328 * @tcp_conn: the iSCSI TCP connection
329 * @segment: the buffer to copy to
331 * @len: amount of data available
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.
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.
344 iscsi_tcp_segment_recv(struct iscsi_tcp_conn *tcp_conn,
345 struct iscsi_segment *segment, const void *ptr,
348 unsigned int copy = 0, copied = 0;
350 while (!iscsi_tcp_segment_done(segment, 1, copy)) {
352 debug_tcp("iscsi_tcp_segment_recv copied %d bytes\n",
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);
366 iscsi_tcp_dgst_header(struct hash_desc *hash, const void *hdr, size_t hdrlen,
367 unsigned char digest[ISCSI_DIGEST_SIZE])
369 struct scatterlist sg;
371 sg_init_one(&sg, hdr, hdrlen);
372 crypto_hash_digest(hash, &sg, hdrlen, digest);
376 iscsi_tcp_dgst_verify(struct iscsi_tcp_conn *tcp_conn,
377 struct iscsi_segment *segment)
379 if (!segment->digest_len)
382 if (memcmp(segment->recv_digest, segment->digest,
383 segment->digest_len)) {
384 debug_scsi("digest mismatch\n");
392 * Helper function to set up segment buffer
395 __iscsi_segment_init(struct iscsi_segment *segment, size_t size,
396 iscsi_segment_done_fn_t *done, struct hash_desc *hash)
398 memset(segment, 0, sizeof(*segment));
399 segment->total_size = size;
400 segment->done = done;
403 segment->hash = hash;
404 crypto_hash_init(hash);
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)
413 __iscsi_segment_init(segment, size, done, hash);
414 segment->data = data;
415 segment->size = size;
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)
424 struct scatterlist *sg;
427 debug_scsi("iscsi_segment_seek_sg offset %u size %llu\n",
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,
433 if (offset < sg->length) {
434 iscsi_tcp_segment_init_sg(segment, sg, offset);
437 offset -= sg->length;
440 return ISCSI_ERR_DATA_OFFSET;
444 * iscsi_tcp_hdr_recv_prep - prep segment for hdr reception
445 * @tcp_conn: iscsi connection to prep for
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.
452 iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn)
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);
462 * Handle incoming reply to any other type of command
465 iscsi_tcp_data_recv_done(struct iscsi_tcp_conn *tcp_conn,
466 struct iscsi_segment *segment)
468 struct iscsi_conn *conn = tcp_conn->iscsi_conn;
471 if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
472 return ISCSI_ERR_DATA_DGST;
474 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr,
475 conn->data, tcp_conn->in.datalen);
479 iscsi_tcp_hdr_recv_prep(tcp_conn);
484 iscsi_tcp_data_recv_prep(struct iscsi_tcp_conn *tcp_conn)
486 struct iscsi_conn *conn = tcp_conn->iscsi_conn;
487 struct hash_desc *rx_hash = NULL;
489 if (conn->datadgst_en)
490 rx_hash = &tcp_conn->rx_hash;
492 iscsi_segment_init_linear(&tcp_conn->in.segment,
493 conn->data, tcp_conn->in.datalen,
494 iscsi_tcp_data_recv_done, rx_hash);
498 * must be called with session lock
501 iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
503 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
504 struct iscsi_r2t_info *r2t;
506 /* flush ctask's r2t queues */
507 while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
508 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
510 debug_scsi("iscsi_tcp_cleanup_ctask pending r2t dropped\n");
513 r2t = tcp_ctask->r2t;
515 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
517 tcp_ctask->r2t = NULL;
522 * iscsi_data_rsp - SCSI Data-In Response processing
523 * @conn: iscsi connection
524 * @ctask: scsi command task
527 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
529 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
530 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
531 struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
532 struct iscsi_session *session = conn->session;
533 struct scsi_cmnd *sc = ctask->sc;
534 int datasn = be32_to_cpu(rhdr->datasn);
535 unsigned total_in_length = scsi_in(sc)->length;
537 iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
538 if (tcp_conn->in.datalen == 0)
541 if (tcp_ctask->exp_datasn != datasn) {
542 debug_tcp("%s: ctask->exp_datasn(%d) != rhdr->datasn(%d)\n",
543 __FUNCTION__, tcp_ctask->exp_datasn, datasn);
544 return ISCSI_ERR_DATASN;
547 tcp_ctask->exp_datasn++;
549 tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
550 if (tcp_ctask->data_offset + tcp_conn->in.datalen > total_in_length) {
551 debug_tcp("%s: data_offset(%d) + data_len(%d) > total_length_in(%d)\n",
552 __FUNCTION__, tcp_ctask->data_offset,
553 tcp_conn->in.datalen, total_in_length);
554 return ISCSI_ERR_DATA_OFFSET;
557 if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
558 sc->result = (DID_OK << 16) | rhdr->cmd_status;
559 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
560 if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
561 ISCSI_FLAG_DATA_OVERFLOW)) {
562 int res_count = be32_to_cpu(rhdr->residual_count);
565 (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
566 res_count <= total_in_length))
567 scsi_in(sc)->resid = res_count;
569 sc->result = (DID_BAD_TARGET << 16) |
574 conn->datain_pdus_cnt++;
579 * iscsi_solicit_data_init - initialize first Data-Out
580 * @conn: iscsi connection
581 * @ctask: scsi command task
585 * Initialize first Data-Out within this R2T sequence and finds
586 * proper data_offset within this SCSI command.
588 * This function is called with connection lock taken.
591 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
592 struct iscsi_r2t_info *r2t)
594 struct iscsi_data *hdr;
596 hdr = &r2t->dtask.hdr;
597 memset(hdr, 0, sizeof(struct iscsi_data));
599 hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
600 r2t->solicit_datasn++;
601 hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
602 memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
603 hdr->itt = ctask->hdr->itt;
604 hdr->exp_statsn = r2t->exp_statsn;
605 hdr->offset = cpu_to_be32(r2t->data_offset);
606 if (r2t->data_length > conn->max_xmit_dlength) {
607 hton24(hdr->dlength, conn->max_xmit_dlength);
608 r2t->data_count = conn->max_xmit_dlength;
611 hton24(hdr->dlength, r2t->data_length);
612 r2t->data_count = r2t->data_length;
613 hdr->flags = ISCSI_FLAG_CMD_FINAL;
615 conn->dataout_pdus_cnt++;
621 * iscsi_r2t_rsp - iSCSI R2T Response processing
622 * @conn: iscsi connection
623 * @ctask: scsi command task
626 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
628 struct iscsi_r2t_info *r2t;
629 struct iscsi_session *session = conn->session;
630 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
631 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
632 struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
633 int r2tsn = be32_to_cpu(rhdr->r2tsn);
636 if (tcp_conn->in.datalen) {
637 iscsi_conn_printk(KERN_ERR, conn,
638 "invalid R2t with datalen %d\n",
639 tcp_conn->in.datalen);
640 return ISCSI_ERR_DATALEN;
643 if (tcp_ctask->exp_datasn != r2tsn){
644 debug_tcp("%s: ctask->exp_datasn(%d) != rhdr->r2tsn(%d)\n",
645 __FUNCTION__, tcp_ctask->exp_datasn, r2tsn);
646 return ISCSI_ERR_R2TSN;
649 /* fill-in new R2T associated with the task */
650 iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
652 if (!ctask->sc || session->state != ISCSI_STATE_LOGGED_IN) {
653 iscsi_conn_printk(KERN_INFO, conn,
654 "dropping R2T itt %d in recovery.\n",
659 rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
662 r2t->exp_statsn = rhdr->statsn;
663 r2t->data_length = be32_to_cpu(rhdr->data_length);
664 if (r2t->data_length == 0) {
665 iscsi_conn_printk(KERN_ERR, conn,
666 "invalid R2T with zero data len\n");
667 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
669 return ISCSI_ERR_DATALEN;
672 if (r2t->data_length > session->max_burst)
673 debug_scsi("invalid R2T with data len %u and max burst %u."
674 "Attempting to execute request.\n",
675 r2t->data_length, session->max_burst);
677 r2t->data_offset = be32_to_cpu(rhdr->data_offset);
678 if (r2t->data_offset + r2t->data_length > scsi_out(ctask->sc)->length) {
679 iscsi_conn_printk(KERN_ERR, conn,
680 "invalid R2T with data len %u at offset %u "
681 "and total length %d\n", r2t->data_length,
682 r2t->data_offset, scsi_out(ctask->sc)->length);
683 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
685 return ISCSI_ERR_DATALEN;
688 r2t->ttt = rhdr->ttt; /* no flip */
689 r2t->solicit_datasn = 0;
691 iscsi_solicit_data_init(conn, ctask, r2t);
693 tcp_ctask->exp_datasn = r2tsn + 1;
694 __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
695 conn->r2t_pdus_cnt++;
697 iscsi_requeue_ctask(ctask);
702 * Handle incoming reply to DataIn command
705 iscsi_tcp_process_data_in(struct iscsi_tcp_conn *tcp_conn,
706 struct iscsi_segment *segment)
708 struct iscsi_conn *conn = tcp_conn->iscsi_conn;
709 struct iscsi_hdr *hdr = tcp_conn->in.hdr;
712 if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
713 return ISCSI_ERR_DATA_DGST;
715 /* check for non-exceptional status */
716 if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
717 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
722 iscsi_tcp_hdr_recv_prep(tcp_conn);
727 * iscsi_tcp_hdr_dissect - process PDU header
728 * @conn: iSCSI connection
731 * This function analyzes the header of the PDU received,
732 * and performs several sanity checks. If the PDU is accompanied
733 * by data, the receive buffer is set up to copy the incoming data
734 * to the correct location.
737 iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
739 int rc = 0, opcode, ahslen;
740 struct iscsi_session *session = conn->session;
741 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
742 struct iscsi_cmd_task *ctask;
744 /* verify PDU length */
745 tcp_conn->in.datalen = ntoh24(hdr->dlength);
746 if (tcp_conn->in.datalen > conn->max_recv_dlength) {
747 iscsi_conn_printk(KERN_ERR, conn,
748 "iscsi_tcp: datalen %d > %d\n",
749 tcp_conn->in.datalen, conn->max_recv_dlength);
750 return ISCSI_ERR_DATALEN;
753 /* Additional header segments. So far, we don't
754 * process additional headers.
756 ahslen = hdr->hlength << 2;
758 opcode = hdr->opcode & ISCSI_OPCODE_MASK;
759 /* verify itt (itt encoding: age+cid+itt) */
760 rc = iscsi_verify_itt(conn, hdr->itt);
764 debug_tcp("opcode 0x%x ahslen %d datalen %d\n",
765 opcode, ahslen, tcp_conn->in.datalen);
768 case ISCSI_OP_SCSI_DATA_IN:
769 ctask = iscsi_itt_to_ctask(conn, hdr->itt);
771 return ISCSI_ERR_BAD_ITT;
773 spin_lock(&conn->session->lock);
774 rc = iscsi_data_rsp(conn, ctask);
775 spin_unlock(&conn->session->lock);
778 if (tcp_conn->in.datalen) {
779 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
780 struct hash_desc *rx_hash = NULL;
781 struct scsi_data_buffer *sdb = scsi_in(ctask->sc);
784 * Setup copy of Data-In into the Scsi_Cmnd
786 * We set up the iscsi_segment to point to the next
787 * scatterlist entry to copy to. As we go along,
788 * we move on to the next scatterlist entry and
789 * update the digest per-entry.
791 if (conn->datadgst_en)
792 rx_hash = &tcp_conn->rx_hash;
794 debug_tcp("iscsi_tcp_begin_data_in(%p, offset=%d, "
795 "datalen=%d)\n", tcp_conn,
796 tcp_ctask->data_offset,
797 tcp_conn->in.datalen);
798 return iscsi_segment_seek_sg(&tcp_conn->in.segment,
801 tcp_ctask->data_offset,
802 tcp_conn->in.datalen,
803 iscsi_tcp_process_data_in,
807 case ISCSI_OP_SCSI_CMD_RSP:
808 if (tcp_conn->in.datalen) {
809 iscsi_tcp_data_recv_prep(tcp_conn);
812 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
815 ctask = iscsi_itt_to_ctask(conn, hdr->itt);
817 return ISCSI_ERR_BAD_ITT;
820 rc = ISCSI_ERR_AHSLEN;
821 else if (ctask->sc->sc_data_direction == DMA_TO_DEVICE) {
822 spin_lock(&session->lock);
823 rc = iscsi_r2t_rsp(conn, ctask);
824 spin_unlock(&session->lock);
826 rc = ISCSI_ERR_PROTO;
828 case ISCSI_OP_LOGIN_RSP:
829 case ISCSI_OP_TEXT_RSP:
830 case ISCSI_OP_REJECT:
831 case ISCSI_OP_ASYNC_EVENT:
833 * It is possible that we could get a PDU with a buffer larger
834 * than 8K, but there are no targets that currently do this.
835 * For now we fail until we find a vendor that needs it
837 if (ISCSI_DEF_MAX_RECV_SEG_LEN < tcp_conn->in.datalen) {
838 iscsi_conn_printk(KERN_ERR, conn,
839 "iscsi_tcp: received buffer of "
840 "len %u but conn buffer is only %u "
842 tcp_conn->in.datalen,
843 ISCSI_DEF_MAX_RECV_SEG_LEN, opcode);
844 rc = ISCSI_ERR_PROTO;
848 /* If there's data coming in with the response,
849 * receive it to the connection's buffer.
851 if (tcp_conn->in.datalen) {
852 iscsi_tcp_data_recv_prep(tcp_conn);
856 case ISCSI_OP_LOGOUT_RSP:
857 case ISCSI_OP_NOOP_IN:
858 case ISCSI_OP_SCSI_TMFUNC_RSP:
859 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
862 rc = ISCSI_ERR_BAD_OPCODE;
867 /* Anything that comes with data should have
868 * been handled above. */
869 if (tcp_conn->in.datalen)
870 return ISCSI_ERR_PROTO;
871 iscsi_tcp_hdr_recv_prep(tcp_conn);
878 * iscsi_tcp_hdr_recv_done - process PDU header
880 * This is the callback invoked when the PDU header has
881 * been received. If the header is followed by additional
882 * header segments, we go back for more data.
885 iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn,
886 struct iscsi_segment *segment)
888 struct iscsi_conn *conn = tcp_conn->iscsi_conn;
889 struct iscsi_hdr *hdr;
891 /* Check if there are additional header segments
892 * *prior* to computing the digest, because we
893 * may need to go back to the caller for more.
895 hdr = (struct iscsi_hdr *) tcp_conn->in.hdr_buf;
896 if (segment->copied == sizeof(struct iscsi_hdr) && hdr->hlength) {
897 /* Bump the header length - the caller will
898 * just loop around and get the AHS for us, and
900 unsigned int ahslen = hdr->hlength << 2;
902 /* Make sure we don't overflow */
903 if (sizeof(*hdr) + ahslen > sizeof(tcp_conn->in.hdr_buf))
904 return ISCSI_ERR_AHSLEN;
906 segment->total_size += ahslen;
907 segment->size += ahslen;
911 /* We're done processing the header. See if we're doing
912 * header digests; if so, set up the recv_digest buffer
913 * and go back for more. */
914 if (conn->hdrdgst_en) {
915 if (segment->digest_len == 0) {
916 iscsi_tcp_segment_splice_digest(segment,
917 segment->recv_digest);
920 iscsi_tcp_dgst_header(&tcp_conn->rx_hash, hdr,
921 segment->total_copied - ISCSI_DIGEST_SIZE,
924 if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
925 return ISCSI_ERR_HDR_DGST;
928 tcp_conn->in.hdr = hdr;
929 return iscsi_tcp_hdr_dissect(conn, hdr);
933 * iscsi_tcp_recv - TCP receive in sendfile fashion
934 * @rd_desc: read descriptor
935 * @skb: socket buffer
936 * @offset: offset in skb
937 * @len: skb->len - offset
940 iscsi_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
941 unsigned int offset, size_t len)
943 struct iscsi_conn *conn = rd_desc->arg.data;
944 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
945 struct iscsi_segment *segment = &tcp_conn->in.segment;
946 struct skb_seq_state seq;
947 unsigned int consumed = 0;
950 debug_tcp("in %d bytes\n", skb->len - offset);
952 if (unlikely(conn->suspend_rx)) {
953 debug_tcp("conn %d Rx suspended!\n", conn->id);
957 skb_prepare_seq_read(skb, offset, skb->len, &seq);
962 avail = skb_seq_read(consumed, &ptr, &seq);
964 debug_tcp("no more data avail. Consumed %d\n",
968 BUG_ON(segment->copied >= segment->size);
970 debug_tcp("skb %p ptr=%p avail=%u\n", skb, ptr, avail);
971 rc = iscsi_tcp_segment_recv(tcp_conn, segment, ptr, avail);
975 if (segment->total_copied >= segment->total_size) {
976 debug_tcp("segment done\n");
977 rc = segment->done(tcp_conn, segment);
979 skb_abort_seq_read(&seq);
983 /* The done() functions sets up the
987 skb_abort_seq_read(&seq);
988 conn->rxdata_octets += consumed;
992 debug_tcp("Error receiving PDU, errno=%d\n", rc);
993 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
998 iscsi_tcp_data_ready(struct sock *sk, int flag)
1000 struct iscsi_conn *conn = sk->sk_user_data;
1001 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1002 read_descriptor_t rd_desc;
1004 read_lock(&sk->sk_callback_lock);
1007 * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
1008 * We set count to 1 because we want the network layer to
1009 * hand us all the skbs that are available. iscsi_tcp_recv
1010 * handled pdus that cross buffers or pdus that still need data.
1012 rd_desc.arg.data = conn;
1014 tcp_read_sock(sk, &rd_desc, iscsi_tcp_recv);
1016 read_unlock(&sk->sk_callback_lock);
1018 /* If we had to (atomically) map a highmem page,
1020 iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
1024 iscsi_tcp_state_change(struct sock *sk)
1026 struct iscsi_tcp_conn *tcp_conn;
1027 struct iscsi_conn *conn;
1028 struct iscsi_session *session;
1029 void (*old_state_change)(struct sock *);
1031 read_lock(&sk->sk_callback_lock);
1033 conn = (struct iscsi_conn*)sk->sk_user_data;
1034 session = conn->session;
1036 if ((sk->sk_state == TCP_CLOSE_WAIT ||
1037 sk->sk_state == TCP_CLOSE) &&
1038 !atomic_read(&sk->sk_rmem_alloc)) {
1039 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1040 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1043 tcp_conn = conn->dd_data;
1044 old_state_change = tcp_conn->old_state_change;
1046 read_unlock(&sk->sk_callback_lock);
1048 old_state_change(sk);
1052 * iscsi_write_space - Called when more output buffer space is available
1053 * @sk: socket space is available for
1056 iscsi_write_space(struct sock *sk)
1058 struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1059 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1061 tcp_conn->old_write_space(sk);
1062 debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1063 scsi_queue_work(conn->session->host, &conn->xmitwork);
1067 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1069 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1070 struct sock *sk = tcp_conn->sock->sk;
1072 /* assign new callbacks */
1073 write_lock_bh(&sk->sk_callback_lock);
1074 sk->sk_user_data = conn;
1075 tcp_conn->old_data_ready = sk->sk_data_ready;
1076 tcp_conn->old_state_change = sk->sk_state_change;
1077 tcp_conn->old_write_space = sk->sk_write_space;
1078 sk->sk_data_ready = iscsi_tcp_data_ready;
1079 sk->sk_state_change = iscsi_tcp_state_change;
1080 sk->sk_write_space = iscsi_write_space;
1081 write_unlock_bh(&sk->sk_callback_lock);
1085 iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
1087 struct sock *sk = tcp_conn->sock->sk;
1089 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1090 write_lock_bh(&sk->sk_callback_lock);
1091 sk->sk_user_data = NULL;
1092 sk->sk_data_ready = tcp_conn->old_data_ready;
1093 sk->sk_state_change = tcp_conn->old_state_change;
1094 sk->sk_write_space = tcp_conn->old_write_space;
1095 sk->sk_no_check = 0;
1096 write_unlock_bh(&sk->sk_callback_lock);
1100 * iscsi_xmit - TCP transmit
1103 iscsi_xmit(struct iscsi_conn *conn)
1105 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1106 struct iscsi_segment *segment = &tcp_conn->out.segment;
1107 unsigned int consumed = 0;
1111 rc = iscsi_tcp_xmit_segment(tcp_conn, segment);
1119 if (segment->total_copied >= segment->total_size) {
1120 if (segment->done != NULL) {
1121 rc = segment->done(tcp_conn, segment);
1128 debug_tcp("xmit %d bytes\n", consumed);
1130 conn->txdata_octets += consumed;
1134 /* Transmit error. We could initiate error recovery
1136 debug_tcp("Error sending PDU, errno=%d\n", rc);
1137 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1142 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
1145 iscsi_tcp_xmit_qlen(struct iscsi_conn *conn)
1147 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1148 struct iscsi_segment *segment = &tcp_conn->out.segment;
1150 return segment->total_copied - segment->total_size;
1154 iscsi_tcp_flush(struct iscsi_conn *conn)
1158 while (iscsi_tcp_xmit_qlen(conn)) {
1159 rc = iscsi_xmit(conn);
1170 * This is called when we're done sending the header.
1171 * Simply copy the data_segment to the send segment, and return.
1174 iscsi_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
1175 struct iscsi_segment *segment)
1177 tcp_conn->out.segment = tcp_conn->out.data_segment;
1178 debug_tcp("Header done. Next segment size %u total_size %u\n",
1179 tcp_conn->out.segment.size, tcp_conn->out.segment.total_size);
1184 iscsi_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr, size_t hdrlen)
1186 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1188 debug_tcp("%s(%p%s)\n", __FUNCTION__, tcp_conn,
1189 conn->hdrdgst_en? ", digest enabled" : "");
1191 /* Clear the data segment - needs to be filled in by the
1192 * caller using iscsi_tcp_send_data_prep() */
1193 memset(&tcp_conn->out.data_segment, 0, sizeof(struct iscsi_segment));
1195 /* If header digest is enabled, compute the CRC and
1196 * place the digest into the same buffer. We make
1197 * sure that both iscsi_tcp_ctask and mtask have
1200 if (conn->hdrdgst_en) {
1201 iscsi_tcp_dgst_header(&tcp_conn->tx_hash, hdr, hdrlen,
1203 hdrlen += ISCSI_DIGEST_SIZE;
1206 /* Remember header pointer for later, when we need
1207 * to decide whether there's a payload to go along
1208 * with the header. */
1209 tcp_conn->out.hdr = hdr;
1211 iscsi_segment_init_linear(&tcp_conn->out.segment, hdr, hdrlen,
1212 iscsi_tcp_send_hdr_done, NULL);
1216 * Prepare the send buffer for the payload data.
1217 * Padding and checksumming will all be taken care
1218 * of by the iscsi_segment routines.
1221 iscsi_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
1222 unsigned int count, unsigned int offset,
1225 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1226 struct hash_desc *tx_hash = NULL;
1227 unsigned int hdr_spec_len;
1229 debug_tcp("%s(%p, offset=%d, datalen=%d%s)\n", __FUNCTION__,
1230 tcp_conn, offset, len,
1231 conn->datadgst_en? ", digest enabled" : "");
1233 /* Make sure the datalen matches what the caller
1234 said he would send. */
1235 hdr_spec_len = ntoh24(tcp_conn->out.hdr->dlength);
1236 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
1238 if (conn->datadgst_en)
1239 tx_hash = &tcp_conn->tx_hash;
1241 return iscsi_segment_seek_sg(&tcp_conn->out.data_segment,
1242 sg, count, offset, len,
1247 iscsi_tcp_send_linear_data_prepare(struct iscsi_conn *conn, void *data,
1250 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1251 struct hash_desc *tx_hash = NULL;
1252 unsigned int hdr_spec_len;
1254 debug_tcp("%s(%p, datalen=%d%s)\n", __FUNCTION__, tcp_conn, len,
1255 conn->datadgst_en? ", digest enabled" : "");
1257 /* Make sure the datalen matches what the caller
1258 said he would send. */
1259 hdr_spec_len = ntoh24(tcp_conn->out.hdr->dlength);
1260 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
1262 if (conn->datadgst_en)
1263 tx_hash = &tcp_conn->tx_hash;
1265 iscsi_segment_init_linear(&tcp_conn->out.data_segment,
1266 data, len, NULL, tx_hash);
1270 * iscsi_solicit_data_cont - initialize next Data-Out
1271 * @conn: iscsi connection
1272 * @ctask: scsi command task
1274 * @left: bytes left to transfer
1277 * Initialize next Data-Out within this R2T sequence and continue
1278 * to process next Scatter-Gather element(if any) of this SCSI command.
1280 * Called under connection lock.
1283 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1284 struct iscsi_r2t_info *r2t)
1286 struct iscsi_data *hdr;
1287 int new_offset, left;
1289 BUG_ON(r2t->data_length - r2t->sent < 0);
1290 left = r2t->data_length - r2t->sent;
1294 hdr = &r2t->dtask.hdr;
1295 memset(hdr, 0, sizeof(struct iscsi_data));
1296 hdr->ttt = r2t->ttt;
1297 hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1298 r2t->solicit_datasn++;
1299 hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1300 memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1301 hdr->itt = ctask->hdr->itt;
1302 hdr->exp_statsn = r2t->exp_statsn;
1303 new_offset = r2t->data_offset + r2t->sent;
1304 hdr->offset = cpu_to_be32(new_offset);
1305 if (left > conn->max_xmit_dlength) {
1306 hton24(hdr->dlength, conn->max_xmit_dlength);
1307 r2t->data_count = conn->max_xmit_dlength;
1309 hton24(hdr->dlength, left);
1310 r2t->data_count = left;
1311 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1314 conn->dataout_pdus_cnt++;
1319 * iscsi_tcp_ctask - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1320 * @conn: iscsi connection
1321 * @ctask: scsi command task
1325 iscsi_tcp_ctask_init(struct iscsi_cmd_task *ctask)
1327 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1328 struct iscsi_conn *conn = ctask->conn;
1329 struct scsi_cmnd *sc = ctask->sc;
1332 BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1333 tcp_ctask->sent = 0;
1334 tcp_ctask->exp_datasn = 0;
1336 /* Prepare PDU, optionally w/ immediate data */
1337 debug_scsi("ctask deq [cid %d itt 0x%x imm %d unsol %d]\n",
1338 conn->id, ctask->itt, ctask->imm_count,
1339 ctask->unsol_count);
1340 iscsi_tcp_send_hdr_prep(conn, ctask->hdr, ctask->hdr_len);
1342 if (!ctask->imm_count)
1345 /* If we have immediate data, attach a payload */
1346 err = iscsi_tcp_send_data_prep(conn, scsi_out(sc)->table.sgl,
1347 scsi_out(sc)->table.nents,
1348 0, ctask->imm_count);
1351 tcp_ctask->sent += ctask->imm_count;
1352 ctask->imm_count = 0;
1357 * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1358 * @conn: iscsi connection
1359 * @mtask: task management task
1362 * The function can return -EAGAIN in which case caller must
1363 * call it again later, or recover. '0' return code means successful
1367 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1371 /* Flush any pending data first. */
1372 rc = iscsi_tcp_flush(conn);
1376 if (mtask->hdr->itt == RESERVED_ITT) {
1377 struct iscsi_session *session = conn->session;
1379 spin_lock_bh(&session->lock);
1380 iscsi_free_mgmt_task(conn, mtask);
1381 spin_unlock_bh(&session->lock);
1388 * iscsi_tcp_ctask_xmit - xmit normal PDU task
1389 * @conn: iscsi connection
1390 * @ctask: iscsi command task
1392 * We're expected to return 0 when everything was transmitted succesfully,
1393 * -EAGAIN if there's still data in the queue, or != 0 for any other kind
1397 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1399 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1400 struct scsi_cmnd *sc = ctask->sc;
1401 struct scsi_data_buffer *sdb = scsi_out(sc);
1405 /* Flush any pending data first. */
1406 rc = iscsi_tcp_flush(conn);
1410 /* Are we done already? */
1411 if (sc->sc_data_direction != DMA_TO_DEVICE)
1414 if (ctask->unsol_count != 0) {
1415 struct iscsi_data *hdr = &tcp_ctask->unsol_dtask.hdr;
1417 /* Prepare a header for the unsolicited PDU.
1418 * The amount of data we want to send will be
1419 * in ctask->data_count.
1420 * FIXME: return the data count instead.
1422 iscsi_prep_unsolicit_data_pdu(ctask, hdr);
1424 debug_tcp("unsol dout [itt 0x%x doff %d dlen %d]\n",
1425 ctask->itt, tcp_ctask->sent, ctask->data_count);
1427 iscsi_tcp_send_hdr_prep(conn, hdr, sizeof(*hdr));
1428 rc = iscsi_tcp_send_data_prep(conn, sdb->table.sgl,
1429 sdb->table.nents, tcp_ctask->sent,
1433 tcp_ctask->sent += ctask->data_count;
1434 ctask->unsol_count -= ctask->data_count;
1437 struct iscsi_session *session = conn->session;
1438 struct iscsi_r2t_info *r2t;
1440 /* All unsolicited PDUs sent. Check for solicited PDUs.
1442 spin_lock_bh(&session->lock);
1443 r2t = tcp_ctask->r2t;
1445 /* Continue with this R2T? */
1446 if (!iscsi_solicit_data_cont(conn, ctask, r2t)) {
1447 debug_scsi(" done with r2t %p\n", r2t);
1449 __kfifo_put(tcp_ctask->r2tpool.queue,
1450 (void*)&r2t, sizeof(void*));
1451 tcp_ctask->r2t = r2t = NULL;
1456 __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1458 r2t = tcp_ctask->r2t;
1460 spin_unlock_bh(&session->lock);
1462 /* Waiting for more R2Ts to arrive. */
1464 debug_tcp("no R2Ts yet\n");
1468 debug_scsi("sol dout %p [dsn %d itt 0x%x doff %d dlen %d]\n",
1469 r2t, r2t->solicit_datasn - 1, ctask->itt,
1470 r2t->data_offset + r2t->sent, r2t->data_count);
1472 iscsi_tcp_send_hdr_prep(conn, &r2t->dtask.hdr,
1473 sizeof(struct iscsi_hdr));
1475 rc = iscsi_tcp_send_data_prep(conn, sdb->table.sgl,
1477 r2t->data_offset + r2t->sent,
1481 tcp_ctask->sent += r2t->data_count;
1482 r2t->sent += r2t->data_count;
1487 iscsi_conn_failure(conn, rc);
1491 static struct iscsi_cls_conn *
1492 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1494 struct iscsi_conn *conn;
1495 struct iscsi_cls_conn *cls_conn;
1496 struct iscsi_tcp_conn *tcp_conn;
1498 cls_conn = iscsi_conn_setup(cls_session, sizeof(*tcp_conn), conn_idx);
1501 conn = cls_conn->dd_data;
1503 * due to strange issues with iser these are not set
1504 * in iscsi_conn_setup
1506 conn->max_recv_dlength = ISCSI_DEF_MAX_RECV_SEG_LEN;
1508 tcp_conn = conn->dd_data;
1509 tcp_conn->iscsi_conn = conn;
1511 tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1513 tcp_conn->tx_hash.flags = 0;
1514 if (IS_ERR(tcp_conn->tx_hash.tfm))
1517 tcp_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
1519 tcp_conn->rx_hash.flags = 0;
1520 if (IS_ERR(tcp_conn->rx_hash.tfm))
1526 crypto_free_hash(tcp_conn->tx_hash.tfm);
1528 iscsi_conn_printk(KERN_ERR, conn,
1529 "Could not create connection due to crc32c "
1530 "loading error. Make sure the crc32c "
1531 "module is built as a module or into the "
1533 iscsi_conn_teardown(cls_conn);
1538 iscsi_tcp_release_conn(struct iscsi_conn *conn)
1540 struct iscsi_session *session = conn->session;
1541 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1542 struct socket *sock = tcp_conn->sock;
1547 sock_hold(sock->sk);
1548 iscsi_conn_restore_callbacks(tcp_conn);
1551 spin_lock_bh(&session->lock);
1552 tcp_conn->sock = NULL;
1553 conn->recv_lock = NULL;
1554 spin_unlock_bh(&session->lock);
1559 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1561 struct iscsi_conn *conn = cls_conn->dd_data;
1562 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1564 iscsi_tcp_release_conn(conn);
1566 if (tcp_conn->tx_hash.tfm)
1567 crypto_free_hash(tcp_conn->tx_hash.tfm);
1568 if (tcp_conn->rx_hash.tfm)
1569 crypto_free_hash(tcp_conn->rx_hash.tfm);
1571 iscsi_conn_teardown(cls_conn);
1575 iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1577 struct iscsi_conn *conn = cls_conn->dd_data;
1579 iscsi_conn_stop(cls_conn, flag);
1580 iscsi_tcp_release_conn(conn);
1583 static int iscsi_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
1584 char *buf, int *port,
1585 int (*getname)(struct socket *, struct sockaddr *,
1588 struct sockaddr_storage *addr;
1589 struct sockaddr_in6 *sin6;
1590 struct sockaddr_in *sin;
1593 addr = kmalloc(sizeof(*addr), GFP_KERNEL);
1597 if (getname(sock, (struct sockaddr *) addr, &len)) {
1602 switch (addr->ss_family) {
1604 sin = (struct sockaddr_in *)addr;
1605 spin_lock_bh(&conn->session->lock);
1606 sprintf(buf, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr));
1607 *port = be16_to_cpu(sin->sin_port);
1608 spin_unlock_bh(&conn->session->lock);
1611 sin6 = (struct sockaddr_in6 *)addr;
1612 spin_lock_bh(&conn->session->lock);
1613 sprintf(buf, NIP6_FMT, NIP6(sin6->sin6_addr));
1614 *port = be16_to_cpu(sin6->sin6_port);
1615 spin_unlock_bh(&conn->session->lock);
1624 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1625 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1628 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1629 struct iscsi_host *ihost = shost_priv(shost);
1630 struct iscsi_conn *conn = cls_conn->dd_data;
1631 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1633 struct socket *sock;
1636 /* lookup for existing socket */
1637 sock = sockfd_lookup((int)transport_eph, &err);
1639 iscsi_conn_printk(KERN_ERR, conn,
1640 "sockfd_lookup failed %d\n", err);
1644 * copy these values now because if we drop the session
1645 * userspace may still want to query the values since we will
1646 * be using them for the reconnect
1648 err = iscsi_tcp_get_addr(conn, sock, conn->portal_address,
1649 &conn->portal_port, kernel_getpeername);
1653 err = iscsi_tcp_get_addr(conn, sock, ihost->local_address,
1654 &ihost->local_port, kernel_getsockname);
1658 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
1662 /* bind iSCSI connection and socket */
1663 tcp_conn->sock = sock;
1665 /* setup Socket parameters */
1668 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
1669 sk->sk_allocation = GFP_ATOMIC;
1671 /* FIXME: disable Nagle's algorithm */
1674 * Intercept TCP callbacks for sendfile like receive
1677 conn->recv_lock = &sk->sk_callback_lock;
1678 iscsi_conn_set_callbacks(conn);
1679 tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
1681 * set receive state machine into initial state
1683 iscsi_tcp_hdr_recv_prep(tcp_conn);
1691 /* called with host lock */
1693 iscsi_tcp_mtask_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1695 debug_scsi("mtask deq [cid %d itt 0x%x]\n", conn->id, mtask->itt);
1697 /* Prepare PDU, optionally w/ immediate data */
1698 iscsi_tcp_send_hdr_prep(conn, mtask->hdr, sizeof(*mtask->hdr));
1700 /* If we have immediate data, attach a payload */
1701 if (mtask->data_count)
1702 iscsi_tcp_send_linear_data_prepare(conn, mtask->data,
1707 iscsi_r2tpool_alloc(struct iscsi_session *session)
1713 * initialize per-task: R2T pool and xmit queue
1715 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1716 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1717 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1720 * pre-allocated x4 as much r2ts to handle race when
1721 * target acks DataOut faster than we data_xmit() queues
1722 * could replenish r2tqueue.
1726 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4, NULL,
1727 sizeof(struct iscsi_r2t_info))) {
1728 goto r2t_alloc_fail;
1731 /* R2T xmit queue */
1732 tcp_ctask->r2tqueue = kfifo_alloc(
1733 session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
1734 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
1735 iscsi_pool_free(&tcp_ctask->r2tpool);
1736 goto r2t_alloc_fail;
1743 for (i = 0; i < cmd_i; i++) {
1744 struct iscsi_cmd_task *ctask = session->cmds[i];
1745 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1747 kfifo_free(tcp_ctask->r2tqueue);
1748 iscsi_pool_free(&tcp_ctask->r2tpool);
1754 iscsi_r2tpool_free(struct iscsi_session *session)
1758 for (i = 0; i < session->cmds_max; i++) {
1759 struct iscsi_cmd_task *ctask = session->cmds[i];
1760 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1762 kfifo_free(tcp_ctask->r2tqueue);
1763 iscsi_pool_free(&tcp_ctask->r2tpool);
1768 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
1769 char *buf, int buflen)
1771 struct iscsi_conn *conn = cls_conn->dd_data;
1772 struct iscsi_session *session = conn->session;
1773 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1777 case ISCSI_PARAM_HDRDGST_EN:
1778 iscsi_set_param(cls_conn, param, buf, buflen);
1780 case ISCSI_PARAM_DATADGST_EN:
1781 iscsi_set_param(cls_conn, param, buf, buflen);
1782 tcp_conn->sendpage = conn->datadgst_en ?
1783 sock_no_sendpage : tcp_conn->sock->ops->sendpage;
1785 case ISCSI_PARAM_MAX_R2T:
1786 sscanf(buf, "%d", &value);
1787 if (value <= 0 || !is_power_of_2(value))
1789 if (session->max_r2t == value)
1791 iscsi_r2tpool_free(session);
1792 iscsi_set_param(cls_conn, param, buf, buflen);
1793 if (iscsi_r2tpool_alloc(session))
1797 return iscsi_set_param(cls_conn, param, buf, buflen);
1804 iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
1805 enum iscsi_param param, char *buf)
1807 struct iscsi_conn *conn = cls_conn->dd_data;
1811 case ISCSI_PARAM_CONN_PORT:
1812 spin_lock_bh(&conn->session->lock);
1813 len = sprintf(buf, "%hu\n", conn->portal_port);
1814 spin_unlock_bh(&conn->session->lock);
1816 case ISCSI_PARAM_CONN_ADDRESS:
1817 spin_lock_bh(&conn->session->lock);
1818 len = sprintf(buf, "%s\n", conn->portal_address);
1819 spin_unlock_bh(&conn->session->lock);
1822 return iscsi_conn_get_param(cls_conn, param, buf);
1829 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
1831 struct iscsi_conn *conn = cls_conn->dd_data;
1832 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1834 stats->txdata_octets = conn->txdata_octets;
1835 stats->rxdata_octets = conn->rxdata_octets;
1836 stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
1837 stats->dataout_pdus = conn->dataout_pdus_cnt;
1838 stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
1839 stats->datain_pdus = conn->datain_pdus_cnt;
1840 stats->r2t_pdus = conn->r2t_pdus_cnt;
1841 stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
1842 stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
1843 stats->custom_length = 3;
1844 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
1845 stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
1846 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
1847 stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
1848 strcpy(stats->custom[2].desc, "eh_abort_cnt");
1849 stats->custom[2].value = conn->eh_abort_cnt;
1852 static struct iscsi_cls_session *
1853 iscsi_tcp_session_create(struct Scsi_Host *shost, uint16_t cmds_max,
1854 uint16_t qdepth, uint32_t initial_cmdsn,
1857 struct iscsi_cls_session *cls_session;
1858 struct iscsi_session *session;
1862 printk(KERN_ERR "iscsi_tcp: invalid shost %d.\n",
1867 shost = iscsi_host_alloc(&iscsi_sht, 0, qdepth);
1870 shost->transportt = iscsi_tcp_scsi_transport;
1871 shost->max_lun = iscsi_max_lun;
1873 shost->max_channel = 0;
1874 shost->max_cmd_len = 16;
1875 shost->can_queue = cmds_max;
1877 if (iscsi_host_add(shost, NULL))
1879 *hostno = shost->host_no;
1881 cls_session = iscsi_session_setup(&iscsi_tcp_transport, shost, cmds_max,
1882 sizeof(struct iscsi_tcp_cmd_task),
1883 sizeof(struct iscsi_tcp_mgmt_task),
1887 session = cls_session->dd_data;
1889 shost->can_queue = session->cmds_max;
1890 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1891 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1892 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1894 ctask->hdr = &tcp_ctask->hdr.cmd_hdr;
1895 ctask->hdr_max = sizeof(tcp_ctask->hdr) - ISCSI_DIGEST_SIZE;
1898 for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1899 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1900 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1902 mtask->hdr = (struct iscsi_hdr *) &tcp_mtask->hdr;
1905 if (iscsi_r2tpool_alloc(session))
1906 goto remove_session;
1910 iscsi_session_teardown(cls_session);
1912 iscsi_host_remove(shost);
1914 iscsi_host_free(shost);
1918 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
1920 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1922 iscsi_r2tpool_free(cls_session->dd_data);
1924 iscsi_host_remove(shost);
1925 iscsi_host_free(shost);
1928 static int iscsi_tcp_slave_configure(struct scsi_device *sdev)
1930 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
1931 blk_queue_dma_alignment(sdev->request_queue, 0);
1935 static struct scsi_host_template iscsi_sht = {
1936 .module = THIS_MODULE,
1937 .name = "iSCSI Initiator over TCP/IP",
1938 .queuecommand = iscsi_queuecommand,
1939 .change_queue_depth = iscsi_change_queue_depth,
1940 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
1941 .sg_tablesize = 4096,
1942 .max_sectors = 0xFFFF,
1943 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
1944 .eh_abort_handler = iscsi_eh_abort,
1945 .eh_device_reset_handler= iscsi_eh_device_reset,
1946 .eh_host_reset_handler = iscsi_eh_host_reset,
1947 .use_clustering = DISABLE_CLUSTERING,
1948 .slave_configure = iscsi_tcp_slave_configure,
1949 .proc_name = "iscsi_tcp",
1953 static struct iscsi_transport iscsi_tcp_transport = {
1954 .owner = THIS_MODULE,
1956 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
1958 .param_mask = ISCSI_MAX_RECV_DLENGTH |
1959 ISCSI_MAX_XMIT_DLENGTH |
1962 ISCSI_INITIAL_R2T_EN |
1967 ISCSI_PDU_INORDER_EN |
1968 ISCSI_DATASEQ_INORDER_EN |
1971 ISCSI_CONN_ADDRESS |
1973 ISCSI_PERSISTENT_PORT |
1974 ISCSI_PERSISTENT_ADDRESS |
1975 ISCSI_TARGET_NAME | ISCSI_TPGT |
1976 ISCSI_USERNAME | ISCSI_PASSWORD |
1977 ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
1978 ISCSI_FAST_ABORT | ISCSI_ABORT_TMO |
1979 ISCSI_LU_RESET_TMO |
1980 ISCSI_PING_TMO | ISCSI_RECV_TMO,
1981 .host_param_mask = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
1982 ISCSI_HOST_INITIATOR_NAME |
1983 ISCSI_HOST_NETDEV_NAME,
1984 /* session management */
1985 .create_session = iscsi_tcp_session_create,
1986 .destroy_session = iscsi_tcp_session_destroy,
1987 /* connection management */
1988 .create_conn = iscsi_tcp_conn_create,
1989 .bind_conn = iscsi_tcp_conn_bind,
1990 .destroy_conn = iscsi_tcp_conn_destroy,
1991 .set_param = iscsi_conn_set_param,
1992 .get_conn_param = iscsi_tcp_conn_get_param,
1993 .get_session_param = iscsi_session_get_param,
1994 .start_conn = iscsi_conn_start,
1995 .stop_conn = iscsi_tcp_conn_stop,
1996 /* iscsi host params */
1997 .get_host_param = iscsi_host_get_param,
1998 .set_host_param = iscsi_host_set_param,
2000 .send_pdu = iscsi_conn_send_pdu,
2001 .get_stats = iscsi_conn_get_stats,
2002 .init_cmd_task = iscsi_tcp_ctask_init,
2003 .init_mgmt_task = iscsi_tcp_mtask_init,
2004 .xmit_cmd_task = iscsi_tcp_ctask_xmit,
2005 .xmit_mgmt_task = iscsi_tcp_mtask_xmit,
2006 .cleanup_cmd_task = iscsi_tcp_cleanup_ctask,
2008 .session_recovery_timedout = iscsi_session_recovery_timedout,
2012 iscsi_tcp_init(void)
2014 if (iscsi_max_lun < 1) {
2015 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2020 iscsi_tcp_scsi_transport = iscsi_register_transport(
2021 &iscsi_tcp_transport);
2022 if (!iscsi_tcp_scsi_transport)
2029 iscsi_tcp_exit(void)
2031 iscsi_unregister_transport(&iscsi_tcp_transport);
2034 module_init(iscsi_tcp_init);
2035 module_exit(iscsi_tcp_exit);