iscsi_tcp.c 57.8 KB
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/*
 * iSCSI Initiator over TCP/IP Data-Path
 *
 * Copyright (C) 2004 Dmitry Yusupov
 * Copyright (C) 2004 Alex Aizman
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 * Copyright (C) 2005 - 2006 Mike Christie
 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
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 * maintained by open-iscsi@googlegroups.com
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * See the file COPYING included with this distribution for more details.
 *
 * Credits:
 *	Christoph Hellwig
 *	FUJITA Tomonori
 *	Arne Redlich
 *	Zhenyu Wang
 */

#include <linux/types.h>
#include <linux/list.h>
#include <linux/inet.h>
#include <linux/blkdev.h>
#include <linux/crypto.h>
#include <linux/delay.h>
#include <linux/kfifo.h>
#include <linux/scatterlist.h>
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#include <linux/mutex.h>
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#include <net/tcp.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi.h>
#include <scsi/scsi_transport_iscsi.h>

#include "iscsi_tcp.h"

MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
	      "Alex Aizman <itn780@yahoo.com>");
MODULE_DESCRIPTION("iSCSI/TCP data-path");
MODULE_LICENSE("GPL");
/* #define DEBUG_TCP */
#define DEBUG_ASSERT

#ifdef DEBUG_TCP
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#define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
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#else
#define debug_tcp(fmt...)
#endif

#ifndef DEBUG_ASSERT
#ifdef BUG_ON
#undef BUG_ON
#endif
#define BUG_ON(expr)
#endif

static unsigned int iscsi_max_lun = 512;
module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);

static inline void
iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
{
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	ibuf->sg.page = virt_to_page(vbuf);
	ibuf->sg.offset = offset_in_page(vbuf);
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	ibuf->sg.length = size;
	ibuf->sent = 0;
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	ibuf->use_sendmsg = 1;
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}

static inline void
iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
{
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	ibuf->sg.page = sg->page;
	ibuf->sg.offset = sg->offset;
	ibuf->sg.length = sg->length;
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	/*
	 * Fastpath: sg element fits into single page
	 */
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	if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg->page))
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		ibuf->use_sendmsg = 0;
	else
		ibuf->use_sendmsg = 1;
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	ibuf->sent = 0;
}

static inline int
iscsi_buf_left(struct iscsi_buf *ibuf)
{
	int rc;

	rc = ibuf->sg.length - ibuf->sent;
	BUG_ON(rc < 0);
	return rc;
}

static inline void
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iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
		 u8* crc)
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{
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	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
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	crypto_hash_digest(&tcp_conn->tx_hash, &buf->sg, buf->sg.length, crc);
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	buf->sg.length = tcp_conn->hdr_size;
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}

static inline int
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iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
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{
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	struct sk_buff *skb = tcp_conn->in.skb;
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	tcp_conn->in.zero_copy_hdr = 0;
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	if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
	    tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
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		/*
		 * Zero-copy PDU Header: using connection context
		 * to store header pointer.
		 */
		if (skb_shinfo(skb)->frag_list == NULL &&
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		    !skb_shinfo(skb)->nr_frags) {
			tcp_conn->in.hdr = (struct iscsi_hdr *)
				((char*)skb->data + tcp_conn->in.offset);
			tcp_conn->in.zero_copy_hdr = 1;
		} else {
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			/* ignoring return code since we checked
			 * in.copy before */
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			skb_copy_bits(skb, tcp_conn->in.offset,
				&tcp_conn->hdr, tcp_conn->hdr_size);
			tcp_conn->in.hdr = &tcp_conn->hdr;
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		}
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		tcp_conn->in.offset += tcp_conn->hdr_size;
		tcp_conn->in.copy -= tcp_conn->hdr_size;
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	} else {
		int hdr_remains;
		int copylen;

		/*
		 * PDU header scattered across SKB's,
		 * copying it... This'll happen quite rarely.
		 */

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		if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
			tcp_conn->in.hdr_offset = 0;
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		hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
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		BUG_ON(hdr_remains <= 0);

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		copylen = min(tcp_conn->in.copy, hdr_remains);
		skb_copy_bits(skb, tcp_conn->in.offset,
			(char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset,
			copylen);
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		debug_tcp("PDU gather offset %d bytes %d in.offset %d "
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		       "in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
		       tcp_conn->in.offset, tcp_conn->in.copy);
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		tcp_conn->in.offset += copylen;
		tcp_conn->in.copy -= copylen;
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		if (copylen < hdr_remains)  {
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			tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
			tcp_conn->in.hdr_offset += copylen;
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		        return -EAGAIN;
		}
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		tcp_conn->in.hdr = &tcp_conn->hdr;
		tcp_conn->discontiguous_hdr_cnt++;
	        tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
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	}

	return 0;
}

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/*
 * must be called with session lock
 */
static void
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iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
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{
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	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
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	struct iscsi_r2t_info *r2t;
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	struct scsi_cmnd *sc;
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	/* flush ctask's r2t queues */
	while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
		__kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
			    sizeof(void*));
		debug_scsi("iscsi_tcp_cleanup_ctask pending r2t dropped\n");
	}

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	sc = ctask->sc;
	if (unlikely(!sc))
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		return;
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	tcp_ctask->xmstate = XMSTATE_IDLE;
	tcp_ctask->r2t = NULL;
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}

/**
 * iscsi_data_rsp - SCSI Data-In Response processing
 * @conn: iscsi connection
 * @ctask: scsi command task
 **/
static int
iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
	int rc;
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	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
	struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
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	struct iscsi_session *session = conn->session;
	int datasn = be32_to_cpu(rhdr->datasn);

	rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
	if (rc)
		return rc;
	/*
	 * setup Data-In byte counter (gets decremented..)
	 */
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	ctask->data_count = tcp_conn->in.datalen;
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	if (tcp_conn->in.datalen == 0)
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		return 0;

	if (ctask->datasn != datasn)
		return ISCSI_ERR_DATASN;

	ctask->datasn++;

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	tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
	if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
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		return ISCSI_ERR_DATA_OFFSET;

	if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
		struct scsi_cmnd *sc = ctask->sc;

		conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
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		if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
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			int res_count = be32_to_cpu(rhdr->residual_count);

			if (res_count > 0 &&
			    res_count <= sc->request_bufflen) {
				sc->resid = res_count;
				sc->result = (DID_OK << 16) | rhdr->cmd_status;
			} else
				sc->result = (DID_BAD_TARGET << 16) |
					rhdr->cmd_status;
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		} else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
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			sc->resid = be32_to_cpu(rhdr->residual_count);
			sc->result = (DID_OK << 16) | rhdr->cmd_status;
		} else
			sc->result = (DID_OK << 16) | rhdr->cmd_status;
	}

	conn->datain_pdus_cnt++;
	return 0;
}

/**
 * iscsi_solicit_data_init - initialize first Data-Out
 * @conn: iscsi connection
 * @ctask: scsi command task
 * @r2t: R2T info
 *
 * Notes:
 *	Initialize first Data-Out within this R2T sequence and finds
 *	proper data_offset within this SCSI command.
 *
 *	This function is called with connection lock taken.
 **/
static void
iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
			struct iscsi_r2t_info *r2t)
{
	struct iscsi_data *hdr;
	struct scsi_cmnd *sc = ctask->sc;

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	hdr = &r2t->dtask.hdr;
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	memset(hdr, 0, sizeof(struct iscsi_data));
	hdr->ttt = r2t->ttt;
	hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
	r2t->solicit_datasn++;
	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
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	memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
	hdr->itt = ctask->hdr->itt;
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	hdr->exp_statsn = r2t->exp_statsn;
	hdr->offset = cpu_to_be32(r2t->data_offset);
	if (r2t->data_length > conn->max_xmit_dlength) {
		hton24(hdr->dlength, conn->max_xmit_dlength);
		r2t->data_count = conn->max_xmit_dlength;
		hdr->flags = 0;
	} else {
		hton24(hdr->dlength, r2t->data_length);
		r2t->data_count = r2t->data_length;
		hdr->flags = ISCSI_FLAG_CMD_FINAL;
	}
	conn->dataout_pdus_cnt++;

	r2t->sent = 0;

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	iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
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			   sizeof(struct iscsi_hdr));
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	if (sc->use_sg) {
		int i, sg_count = 0;
		struct scatterlist *sg = sc->request_buffer;

		r2t->sg = NULL;
		for (i = 0; i < sc->use_sg; i++, sg += 1) {
			/* FIXME: prefetch ? */
			if (sg_count + sg->length > r2t->data_offset) {
				int page_offset;

				/* sg page found! */

				/* offset within this page */
				page_offset = r2t->data_offset - sg_count;

				/* fill in this buffer */
				iscsi_buf_init_sg(&r2t->sendbuf, sg);
				r2t->sendbuf.sg.offset += page_offset;
				r2t->sendbuf.sg.length -= page_offset;

				/* xmit logic will continue with next one */
				r2t->sg = sg + 1;
				break;
			}
			sg_count += sg->length;
		}
		BUG_ON(r2t->sg == NULL);
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	} else {
		iscsi_buf_init_iov(&r2t->sendbuf,
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			    (char*)sc->request_buffer + r2t->data_offset,
			    r2t->data_count);
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		r2t->sg = NULL;
	}
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}

/**
 * iscsi_r2t_rsp - iSCSI R2T Response processing
 * @conn: iscsi connection
 * @ctask: scsi command task
 **/
static int
iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
	struct iscsi_r2t_info *r2t;
	struct iscsi_session *session = conn->session;
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	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
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	int r2tsn = be32_to_cpu(rhdr->r2tsn);
	int rc;

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	if (tcp_conn->in.datalen) {
		printk(KERN_ERR "iscsi_tcp: invalid R2t with datalen %d\n",
		       tcp_conn->in.datalen);
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		return ISCSI_ERR_DATALEN;
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	}
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	if (tcp_ctask->exp_r2tsn && tcp_ctask->exp_r2tsn != r2tsn)
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		return ISCSI_ERR_R2TSN;

	rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
	if (rc)
		return rc;

	/* FIXME: use R2TSN to detect missing R2T */

	/* fill-in new R2T associated with the task */
	spin_lock(&session->lock);
	if (!ctask->sc || ctask->mtask ||
	     session->state != ISCSI_STATE_LOGGED_IN) {
		printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
		       "recovery...\n", ctask->itt);
		spin_unlock(&session->lock);
		return 0;
	}
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	rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
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	BUG_ON(!rc);

	r2t->exp_statsn = rhdr->statsn;
	r2t->data_length = be32_to_cpu(rhdr->data_length);
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	if (r2t->data_length == 0) {
		printk(KERN_ERR "iscsi_tcp: invalid R2T with zero data len\n");
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		spin_unlock(&session->lock);
		return ISCSI_ERR_DATALEN;
	}

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	if (r2t->data_length > session->max_burst)
		debug_scsi("invalid R2T with data len %u and max burst %u."
			   "Attempting to execute request.\n",
			    r2t->data_length, session->max_burst);

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	r2t->data_offset = be32_to_cpu(rhdr->data_offset);
	if (r2t->data_offset + r2t->data_length > ctask->total_length) {
		spin_unlock(&session->lock);
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		printk(KERN_ERR "iscsi_tcp: invalid R2T with data len %u at "
		       "offset %u and total length %d\n", r2t->data_length,
		       r2t->data_offset, ctask->total_length);
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		return ISCSI_ERR_DATALEN;
	}

	r2t->ttt = rhdr->ttt; /* no flip */
	r2t->solicit_datasn = 0;

	iscsi_solicit_data_init(conn, ctask, r2t);

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	tcp_ctask->exp_r2tsn = r2tsn + 1;
	__kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
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	tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
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	list_move_tail(&ctask->running, &conn->xmitqueue);
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	scsi_queue_work(session->host, &conn->xmitwork);
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	conn->r2t_pdus_cnt++;
	spin_unlock(&session->lock);

	return 0;
}

static int
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iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
431
{
432
	int rc = 0, opcode, ahslen;
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	struct iscsi_hdr *hdr;
	struct iscsi_session *session = conn->session;
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	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	uint32_t cdgst, rdgst = 0, itt;
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	hdr = tcp_conn->in.hdr;
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	/* verify PDU length */
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	tcp_conn->in.datalen = ntoh24(hdr->dlength);
	if (tcp_conn->in.datalen > conn->max_recv_dlength) {
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		printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
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		       tcp_conn->in.datalen, conn->max_recv_dlength);
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		return ISCSI_ERR_DATALEN;
	}
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	tcp_conn->data_copied = 0;
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	/* read AHS */
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	ahslen = hdr->hlength << 2;
	tcp_conn->in.offset += ahslen;
	tcp_conn->in.copy -= ahslen;
	if (tcp_conn->in.copy < 0) {
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		printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
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		       "%d bytes\n", ahslen);
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		return ISCSI_ERR_AHSLEN;
	}

	/* calculate read padding */
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	tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
	if (tcp_conn->in.padding) {
		tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
		debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
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	}

	if (conn->hdrdgst_en) {
		struct scatterlist sg;

		sg_init_one(&sg, (u8 *)hdr,
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			    sizeof(struct iscsi_hdr) + ahslen);
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		crypto_hash_digest(&tcp_conn->rx_hash, &sg, sg.length,
				   (u8 *)&cdgst);
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		rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
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				     ahslen);
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		if (cdgst != rdgst) {
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			printk(KERN_ERR "iscsi_tcp: hdrdgst error "
			       "recv 0x%x calc 0x%x\n", rdgst, cdgst);
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			return ISCSI_ERR_HDR_DGST;
		}
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	}

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	opcode = hdr->opcode & ISCSI_OPCODE_MASK;
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	/* verify itt (itt encoding: age+cid+itt) */
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	rc = iscsi_verify_itt(conn, hdr, &itt);
	if (rc == ISCSI_ERR_NO_SCSI_CMD) {
		tcp_conn->in.datalen = 0; /* force drop */
		return 0;
	} else if (rc)
		return rc;
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	debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
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		  opcode, tcp_conn->in.offset, tcp_conn->in.copy,
		  ahslen, tcp_conn->in.datalen);
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	switch(opcode) {
	case ISCSI_OP_SCSI_DATA_IN:
		tcp_conn->in.ctask = session->cmds[itt];
		rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
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		if (rc)
			return rc;
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		/* fall through */
	case ISCSI_OP_SCSI_CMD_RSP:
		tcp_conn->in.ctask = session->cmds[itt];
		if (tcp_conn->in.datalen)
			goto copy_hdr;
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		spin_lock(&session->lock);
		rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
		spin_unlock(&session->lock);
		break;
	case ISCSI_OP_R2T:
		tcp_conn->in.ctask = session->cmds[itt];
		if (ahslen)
			rc = ISCSI_ERR_AHSLEN;
		else if (tcp_conn->in.ctask->sc->sc_data_direction ==
								DMA_TO_DEVICE)
			rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
		else
			rc = ISCSI_ERR_PROTO;
		break;
	case ISCSI_OP_LOGIN_RSP:
	case ISCSI_OP_TEXT_RSP:
	case ISCSI_OP_REJECT:
	case ISCSI_OP_ASYNC_EVENT:
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		/*
		 * It is possible that we could get a PDU with a buffer larger
		 * than 8K, but there are no targets that currently do this.
		 * For now we fail until we find a vendor that needs it
		 */
		if (DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH <
		    tcp_conn->in.datalen) {
			printk(KERN_ERR "iscsi_tcp: received buffer of len %u "
			      "but conn buffer is only %u (opcode %0x)\n",
			      tcp_conn->in.datalen,
			      DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, opcode);
			rc = ISCSI_ERR_PROTO;
			break;
		}

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		if (tcp_conn->in.datalen)
			goto copy_hdr;
	/* fall through */
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	case ISCSI_OP_LOGOUT_RSP:
	case ISCSI_OP_NOOP_IN:
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	case ISCSI_OP_SCSI_TMFUNC_RSP:
		rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
		break;
	default:
		rc = ISCSI_ERR_BAD_OPCODE;
		break;
	}
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	return rc;
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copy_hdr:
	/*
	 * if we did zero copy for the header but we will need multiple
	 * skbs to complete the command then we have to copy the header
	 * for later use
	 */
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	if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <=
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	   (tcp_conn->in.datalen + tcp_conn->in.padding +
	    (conn->datadgst_en ? 4 : 0))) {
		debug_tcp("Copying header for later use. in.copy %d in.datalen"
			  " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
		memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
		       sizeof(struct iscsi_hdr));
		tcp_conn->in.hdr = &tcp_conn->hdr;
		tcp_conn->in.zero_copy_hdr = 0;
	}
	return 0;
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}

/**
 * iscsi_ctask_copy - copy skb bits to the destanation cmd task
576
 * @conn: iscsi tcp connection
577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597
 * @ctask: scsi command task
 * @buf: buffer to copy to
 * @buf_size: size of buffer
 * @offset: offset within the buffer
 *
 * Notes:
 *	The function calls skb_copy_bits() and updates per-connection and
 *	per-cmd byte counters.
 *
 *	Read counters (in bytes):
 *
 *	conn->in.offset		offset within in progress SKB
 *	conn->in.copy		left to copy from in progress SKB
 *				including padding
 *	conn->in.copied		copied already from in progress SKB
 *	conn->data_copied	copied already from in progress buffer
 *	ctask->sent		total bytes sent up to the MidLayer
 *	ctask->data_count	left to copy from in progress Data-In
 *	buf_left		left to copy from in progress buffer
 **/
static inline int
598
iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
599 600
		void *buf, int buf_size, int offset)
{
601 602 603
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
	int buf_left = buf_size - (tcp_conn->data_copied + offset);
	int size = min(tcp_conn->in.copy, buf_left);
604 605 606 607 608
	int rc;

	size = min(size, ctask->data_count);

	debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
609
	       size, tcp_conn->in.offset, tcp_conn->in.copied);
610 611

	BUG_ON(size <= 0);
612
	BUG_ON(tcp_ctask->sent + size > ctask->total_length);
613

614 615
	rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
			   (char*)buf + (offset + tcp_conn->data_copied), size);
616 617 618
	/* must fit into skb->len */
	BUG_ON(rc);

619 620 621 622 623
	tcp_conn->in.offset += size;
	tcp_conn->in.copy -= size;
	tcp_conn->in.copied += size;
	tcp_conn->data_copied += size;
	tcp_ctask->sent += size;
624 625
	ctask->data_count -= size;

626
	BUG_ON(tcp_conn->in.copy < 0);
627 628
	BUG_ON(ctask->data_count < 0);

629
	if (buf_size != (tcp_conn->data_copied + offset)) {
630
		if (!ctask->data_count) {
631
			BUG_ON(buf_size - tcp_conn->data_copied < 0);
632
			/* done with this PDU */
633
			return buf_size - tcp_conn->data_copied;
634 635 636 637 638
		}
		return -EAGAIN;
	}

	/* done with this buffer or with both - PDU and buffer */
639
	tcp_conn->data_copied = 0;
640 641 642 643 644
	return 0;
}

/**
 * iscsi_tcp_copy - copy skb bits to the destanation buffer
645
 * @conn: iscsi tcp connection
646 647 648 649 650 651
 *
 * Notes:
 *	The function calls skb_copy_bits() and updates per-connection
 *	byte counters.
 **/
static inline int
652
iscsi_tcp_copy(struct iscsi_conn *conn, int buf_size)
653
{
654
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
655 656
	int buf_left = buf_size - tcp_conn->data_copied;
	int size = min(tcp_conn->in.copy, buf_left);
657 658 659
	int rc;

	debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
660
	       size, tcp_conn->in.offset, tcp_conn->data_copied);
661 662
	BUG_ON(size <= 0);

663
	rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
664
			   (char*)conn->data + tcp_conn->data_copied, size);
665 666
	BUG_ON(rc);

667 668 669 670
	tcp_conn->in.offset += size;
	tcp_conn->in.copy -= size;
	tcp_conn->in.copied += size;
	tcp_conn->data_copied += size;
671

672
	if (buf_size != tcp_conn->data_copied)
673 674 675 676 677 678
		return -EAGAIN;

	return 0;
}

static inline void
679
partial_sg_digest_update(struct hash_desc *desc, struct scatterlist *sg,
680
			 int offset, int length)
681 682 683 684 685 686
{
	struct scatterlist temp;

	memcpy(&temp, sg, sizeof(struct scatterlist));
	temp.offset = offset;
	temp.length = length;
687
	crypto_hash_update(desc, &temp, length);
688 689
}

690
static void
691
iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
692 693 694 695
{
	struct scatterlist tmp;

	sg_init_one(&tmp, buf, len);
696
	crypto_hash_update(&tcp_conn->rx_hash, &tmp, len);
697 698
}

699 700
static int iscsi_scsi_data_in(struct iscsi_conn *conn)
{
701 702 703
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
704
	struct scsi_cmnd *sc = ctask->sc;
705
	struct scatterlist *sg;
706 707 708 709 710 711 712 713 714
	int i, offset, rc = 0;

	BUG_ON((void*)ctask != sc->SCp.ptr);

	/*
	 * copying Data-In into the Scsi_Cmnd
	 */
	if (!sc->use_sg) {
		i = ctask->data_count;
715 716 717
		rc = iscsi_ctask_copy(tcp_conn, ctask, sc->request_buffer,
				      sc->request_bufflen,
				      tcp_ctask->data_offset);
718 719
		if (rc == -EAGAIN)
			return rc;
720
		if (conn->datadgst_en)
721 722
			iscsi_recv_digest_update(tcp_conn, sc->request_buffer,
						 i);
723 724 725 726
		rc = 0;
		goto done;
	}

727
	offset = tcp_ctask->data_offset;
728 729
	sg = sc->request_buffer;

730 731
	if (tcp_ctask->data_offset)
		for (i = 0; i < tcp_ctask->sg_count; i++)
732 733 734 735 736
			offset -= sg[i].length;
	/* we've passed through partial sg*/
	if (offset < 0)
		offset = 0;

737
	for (i = tcp_ctask->sg_count; i < sc->use_sg; i++) {
738 739 740
		char *dest;

		dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
741
		rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
742 743 744 745 746 747 748 749
				      sg[i].length, offset);
		kunmap_atomic(dest, KM_SOFTIRQ0);
		if (rc == -EAGAIN)
			/* continue with the next SKB/PDU */
			return rc;
		if (!rc) {
			if (conn->datadgst_en) {
				if (!offset)
750
					crypto_hash_update(
751
							&tcp_conn->rx_hash,
752
							&sg[i], sg[i].length);
753
				else
754
					partial_sg_digest_update(
755
							&tcp_conn->rx_hash,
756
							&sg[i],
757 758 759 760
							sg[i].offset + offset,
							sg[i].length - offset);
			}
			offset = 0;
761
			tcp_ctask->sg_count++;
762 763 764 765 766 767 768
		}

		if (!ctask->data_count) {
			if (rc && conn->datadgst_en)
				/*
				 * data-in is complete, but buffer not...
				 */
769 770 771 772
				partial_sg_digest_update(&tcp_conn->rx_hash,
							 &sg[i],
							 sg[i].offset,
							 sg[i].length-rc);
773 774 775 776
			rc = 0;
			break;
		}

777
		if (!tcp_conn->in.copy)
778 779 780 781 782 783
			return -EAGAIN;
	}
	BUG_ON(ctask->data_count);

done:
	/* check for non-exceptional status */
784
	if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
785 786 787
		debug_scsi("done [sc %lx res %d itt 0x%x flags 0x%x]\n",
			   (long)sc, sc->result, ctask->itt,
			   tcp_conn->in.hdr->flags);
788 789 790
		spin_lock(&conn->session->lock);
		__iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
		spin_unlock(&conn->session->lock);
791 792 793 794 795 796 797 798
	}

	return rc;
}

static int
iscsi_data_recv(struct iscsi_conn *conn)
{
799 800
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	int rc = 0, opcode;
801

802 803
	opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
	switch (opcode) {
804 805 806
	case ISCSI_OP_SCSI_DATA_IN:
		rc = iscsi_scsi_data_in(conn);
		break;
807
	case ISCSI_OP_SCSI_CMD_RSP:
808 809
	case ISCSI_OP_TEXT_RSP:
	case ISCSI_OP_LOGIN_RSP:
810 811
	case ISCSI_OP_ASYNC_EVENT:
	case ISCSI_OP_REJECT:
812 813 814 815
		/*
		 * Collect data segment to the connection's data
		 * placeholder
		 */
816
		if (iscsi_tcp_copy(conn, tcp_conn->in.datalen)) {
817 818 819 820
			rc = -EAGAIN;
			goto exit;
		}

821
		rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, conn->data,
822 823
					tcp_conn->in.datalen);
		if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
824
			iscsi_recv_digest_update(tcp_conn, conn->data,
825 826
			  			tcp_conn->in.datalen);
		break;
827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846
	default:
		BUG_ON(1);
	}
exit:
	return rc;
}

/**
 * iscsi_tcp_data_recv - TCP receive in sendfile fashion
 * @rd_desc: read descriptor
 * @skb: socket buffer
 * @offset: offset in skb
 * @len: skb->len - offset
 **/
static int
iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
		unsigned int offset, size_t len)
{
	int rc;
	struct iscsi_conn *conn = rd_desc->arg.data;
847
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
848 849 850 851 852 853 854 855
	int processed;
	char pad[ISCSI_PAD_LEN];
	struct scatterlist sg;

	/*
	 * Save current SKB and its offset in the corresponding
	 * connection context.
	 */
856 857 858 859 860 861
	tcp_conn->in.copy = skb->len - offset;
	tcp_conn->in.offset = offset;
	tcp_conn->in.skb = skb;
	tcp_conn->in.len = tcp_conn->in.copy;
	BUG_ON(tcp_conn->in.copy <= 0);
	debug_tcp("in %d bytes\n", tcp_conn->in.copy);
862 863

more:
864
	tcp_conn->in.copied = 0;
865 866 867 868 869 870 871
	rc = 0;

	if (unlikely(conn->suspend_rx)) {
		debug_tcp("conn %d Rx suspended!\n", conn->id);
		return 0;
	}

872 873 874
	if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
	    tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
		rc = iscsi_hdr_extract(tcp_conn);
875 876 877 878
		if (rc) {
		       if (rc == -EAGAIN)
				goto nomore;
		       else {
879
				iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
880 881 882 883 884 885 886
				return 0;
		       }
		}

		/*
		 * Verify and process incoming PDU header.
		 */
887 888
		rc = iscsi_tcp_hdr_recv(conn);
		if (!rc && tcp_conn->in.datalen) {
889
			if (conn->datadgst_en)
890
				crypto_hash_init(&tcp_conn->rx_hash);
891
			tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
892
		} else if (rc) {
893
			iscsi_conn_failure(conn, rc);
894 895 896 897
			return 0;
		}
	}

898
	if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
899
		uint32_t recv_digest;
900

901
		debug_tcp("extra data_recv offset %d copy %d\n",
902
			  tcp_conn->in.offset, tcp_conn->in.copy);
903 904 905 906 907 908 909 910 911
		rc = iscsi_tcp_copy(conn, sizeof(uint32_t));
		if (rc) {
			if (rc == -EAGAIN)
				goto again;
			iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
			return 0;
		}

		memcpy(&recv_digest, conn->data, sizeof(uint32_t));
912
		if (recv_digest != tcp_conn->in.datadgst) {
913 914
			debug_tcp("iscsi_tcp: data digest error!"
				  "0x%x != 0x%x\n", recv_digest,
915
				  tcp_conn->in.datadgst);
916 917 918 919 920
			iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
			return 0;
		} else {
			debug_tcp("iscsi_tcp: data digest match!"
				  "0x%x == 0x%x\n", recv_digest,
921 922
				  tcp_conn->in.datadgst);
			tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
923 924 925
		}
	}

926 927
	if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
	   tcp_conn->in.copy) {
928 929

		debug_tcp("data_recv offset %d copy %d\n",
930
		       tcp_conn->in.offset, tcp_conn->in.copy);
931 932 933

		rc = iscsi_data_recv(conn);
		if (rc) {
934
			if (rc == -EAGAIN)
935
				goto again;
936
			iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
937 938
			return 0;
		}
939 940
		tcp_conn->in.copy -= tcp_conn->in.padding;
		tcp_conn->in.offset += tcp_conn->in.padding;
941
		if (conn->datadgst_en) {
942 943 944 945 946
			if (tcp_conn->in.padding) {
				debug_tcp("padding -> %d\n",
					  tcp_conn->in.padding);
				memset(pad, 0, tcp_conn->in.padding);
				sg_init_one(&sg, pad, tcp_conn->in.padding);
947
				crypto_hash_update(&tcp_conn->rx_hash,
948
						   &sg, sg.length);
949
			}
950 951
			crypto_hash_final(&tcp_conn->rx_hash,
					  (u8 *) &tcp_conn->in.datadgst);
952 953
			debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
			tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
954
			tcp_conn->data_copied = 0;
955
		} else
956
			tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
957 958 959
	}

	debug_tcp("f, processed %d from out of %d padding %d\n",
960 961
	       tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
	BUG_ON(tcp_conn->in.offset - offset > len);
962

963
	if (tcp_conn->in.offset - offset != len) {
964
		debug_tcp("continue to process %d bytes\n",
965
		       (int)len - (tcp_conn->in.offset - offset));
966 967 968 969
		goto more;
	}

nomore:
970
	processed = tcp_conn->in.offset - offset;
971 972 973 974
	BUG_ON(processed == 0);
	return processed;

again:
975
	processed = tcp_conn->in.offset - offset;
976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992
	debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
	          processed, (int)len, (int)rd_desc->count);
	BUG_ON(processed == 0);
	BUG_ON(processed > len);

	conn->rxdata_octets += processed;
	return processed;
}

static void
iscsi_tcp_data_ready(struct sock *sk, int flag)
{
	struct iscsi_conn *conn = sk->sk_user_data;
	read_descriptor_t rd_desc;

	read_lock(&sk->sk_callback_lock);

993 994 995 996 997 998
	/*
	 * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
	 * We set count to 1 because we want the network layer to
	 * hand us all the skbs that are available. iscsi_tcp_data_recv
	 * handled pdus that cross buffers or pdus that still need data.
	 */
999
	rd_desc.arg.data = conn;
1000
	rd_desc.count = 1;
1001 1002 1003 1004 1005 1006 1007 1008
	tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);

	read_unlock(&sk->sk_callback_lock);
}

static void
iscsi_tcp_state_change(struct sock *sk)
{
1009
	struct iscsi_tcp_conn *tcp_conn;
1010 1011 1012 1013 1014 1015 1016 1017 1018
	struct iscsi_conn *conn;
	struct iscsi_session *session;
	void (*old_state_change)(struct sock *);

	read_lock(&sk->sk_callback_lock);

	conn = (struct iscsi_conn*)sk->sk_user_data;
	session = conn->session;

M
Mike Christie 已提交
1019 1020 1021
	if ((sk->sk_state == TCP_CLOSE_WAIT ||
	     sk->sk_state == TCP_CLOSE) &&
	    !atomic_read(&sk->sk_rmem_alloc)) {
1022 1023 1024 1025
		debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
	}

1026 1027
	tcp_conn = conn->dd_data;
	old_state_change = tcp_conn->old_state_change;
1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041

	read_unlock(&sk->sk_callback_lock);

	old_state_change(sk);
}

/**
 * iscsi_write_space - Called when more output buffer space is available
 * @sk: socket space is available for
 **/
static void
iscsi_write_space(struct sock *sk)
{
	struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1042 1043 1044
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;

	tcp_conn->old_write_space(sk);
1045
	debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1046
	scsi_queue_work(conn->session->host, &conn->xmitwork);
1047 1048 1049 1050 1051
}

static void
iscsi_conn_set_callbacks(struct iscsi_conn *conn)
{
1052 1053
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct sock *sk = tcp_conn->sock->sk;
1054 1055 1056 1057

	/* assign new callbacks */
	write_lock_bh(&sk->sk_callback_lock);
	sk->sk_user_data = conn;
1058 1059 1060
	tcp_conn->old_data_ready = sk->sk_data_ready;
	tcp_conn->old_state_change = sk->sk_state_change;
	tcp_conn->old_write_space = sk->sk_write_space;
1061 1062 1063 1064 1065 1066 1067
	sk->sk_data_ready = iscsi_tcp_data_ready;
	sk->sk_state_change = iscsi_tcp_state_change;
	sk->sk_write_space = iscsi_write_space;
	write_unlock_bh(&sk->sk_callback_lock);
}

static void
1068
iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
1069
{
1070
	struct sock *sk = tcp_conn->sock->sk;
1071 1072 1073 1074

	/* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
	write_lock_bh(&sk->sk_callback_lock);
	sk->sk_user_data    = NULL;
1075 1076 1077
	sk->sk_data_ready   = tcp_conn->old_data_ready;
	sk->sk_state_change = tcp_conn->old_state_change;
	sk->sk_write_space  = tcp_conn->old_write_space;
1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089
	sk->sk_no_check	 = 0;
	write_unlock_bh(&sk->sk_callback_lock);
}

/**
 * iscsi_send - generic send routine
 * @sk: kernel's socket
 * @buf: buffer to write from
 * @size: actual size to write
 * @flags: socket's flags
 */
static inline int
1090
iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1091
{
1092 1093
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct socket *sk = tcp_conn->sock;
1094
	int offset = buf->sg.offset + buf->sent, res;
1095

1096 1097 1098 1099 1100 1101 1102 1103 1104
	/*
	 * if we got use_sg=0 or are sending something we kmallocd
	 * then we did not have to do kmap (kmap returns page_address)
	 *
	 * if we got use_sg > 0, but had to drop down, we do not
	 * set clustering so this should only happen for that
	 * slab case.
	 */
	if (buf->use_sendmsg)
1105
		res = sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
1106
	else
1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120
		res = tcp_conn->sendpage(sk, buf->sg.page, offset, size, flags);

	if (res >= 0) {
		conn->txdata_octets += res;
		buf->sent += res;
		return res;
	}

	tcp_conn->sendpage_failures_cnt++;
	if (res == -EAGAIN)
		res = -ENOBUFS;
	else
		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
	return res;
1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142
}

/**
 * iscsi_sendhdr - send PDU Header via tcp_sendpage()
 * @conn: iscsi connection
 * @buf: buffer to write from
 * @datalen: lenght of data to be sent after the header
 *
 * Notes:
 *	(Tx, Fast Path)
 **/
static inline int
iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
{
	int flags = 0; /* MSG_DONTWAIT; */
	int res, size;

	size = buf->sg.length - buf->sent;
	BUG_ON(buf->sent + size > buf->sg.length);
	if (buf->sent + size != buf->sg.length || datalen)
		flags |= MSG_MORE;

1143
	res = iscsi_send(conn, buf, size, flags);
1144 1145 1146 1147 1148
	debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
	if (res >= 0) {
		if (size != res)
			return -EAGAIN;
		return 0;
1149
	}
1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174

	return res;
}

/**
 * iscsi_sendpage - send one page of iSCSI Data-Out.
 * @conn: iscsi connection
 * @buf: buffer to write from
 * @count: remaining data
 * @sent: number of bytes sent
 *
 * Notes:
 *	(Tx, Fast Path)
 **/
static inline int
iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
	       int *count, int *sent)
{
	int flags = 0; /* MSG_DONTWAIT; */
	int res, size;

	size = buf->sg.length - buf->sent;
	BUG_ON(buf->sent + size > buf->sg.length);
	if (size > *count)
		size = *count;
M
Mike Christie 已提交
1175
	if (buf->sent + size != buf->sg.length || *count != size)
1176 1177
		flags |= MSG_MORE;

1178
	res = iscsi_send(conn, buf, size, flags);
1179 1180 1181 1182 1183 1184 1185 1186
	debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
		  size, buf->sent, *count, *sent, res);
	if (res >= 0) {
		*count -= res;
		*sent += res;
		if (size != res)
			return -EAGAIN;
		return 0;
1187
	}
1188 1189 1190 1191 1192

	return res;
}

static inline void
1193
iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1194
		      struct iscsi_tcp_cmd_task *tcp_ctask)
1195
{
1196
	crypto_hash_init(&tcp_conn->tx_hash);
1197
	tcp_ctask->digest_count = 4;
1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220
}

/**
 * iscsi_solicit_data_cont - initialize next Data-Out
 * @conn: iscsi connection
 * @ctask: scsi command task
 * @r2t: R2T info
 * @left: bytes left to transfer
 *
 * Notes:
 *	Initialize next Data-Out within this R2T sequence and continue
 *	to process next Scatter-Gather element(if any) of this SCSI command.
 *
 *	Called under connection lock.
 **/
static void
iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
			struct iscsi_r2t_info *r2t, int left)
{
	struct iscsi_data *hdr;
	struct scsi_cmnd *sc = ctask->sc;
	int new_offset;

1221
	hdr = &r2t->dtask.hdr;
1222 1223 1224 1225 1226
	memset(hdr, 0, sizeof(struct iscsi_data));
	hdr->ttt = r2t->ttt;
	hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
	r2t->solicit_datasn++;
	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1227 1228
	memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
	hdr->itt = ctask->hdr->itt;
1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241
	hdr->exp_statsn = r2t->exp_statsn;
	new_offset = r2t->data_offset + r2t->sent;
	hdr->offset = cpu_to_be32(new_offset);
	if (left > conn->max_xmit_dlength) {
		hton24(hdr->dlength, conn->max_xmit_dlength);
		r2t->data_count = conn->max_xmit_dlength;
	} else {
		hton24(hdr->dlength, left);
		r2t->data_count = left;
		hdr->flags = ISCSI_FLAG_CMD_FINAL;
	}
	conn->dataout_pdus_cnt++;

1242
	iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
1243
			   sizeof(struct iscsi_hdr));
1244

1245 1246 1247 1248
	if (iscsi_buf_left(&r2t->sendbuf))
		return;

	if (sc->use_sg) {
1249 1250
		iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
		r2t->sg += 1;
1251 1252
	} else {
		iscsi_buf_init_iov(&r2t->sendbuf,
1253 1254
			    (char*)sc->request_buffer + new_offset,
			    r2t->data_count);
1255 1256
		r2t->sg = NULL;
	}
1257 1258
}

1259 1260
static void iscsi_set_padding(struct iscsi_tcp_cmd_task *tcp_ctask,
			      unsigned long len)
1261
{
1262 1263 1264
	tcp_ctask->pad_count = len & (ISCSI_PAD_LEN - 1);
	if (!tcp_ctask->pad_count)
		return;
1265

1266 1267 1268
	tcp_ctask->pad_count = ISCSI_PAD_LEN - tcp_ctask->pad_count;
	debug_scsi("write padding %d bytes\n", tcp_ctask->pad_count);
	tcp_ctask->xmstate |= XMSTATE_W_PAD;
1269 1270 1271
}

/**
1272
 * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1273 1274 1275 1276 1277
 * @conn: iscsi connection
 * @ctask: scsi command task
 * @sc: scsi command
 **/
static void
1278
iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1279
{
1280 1281
	struct scsi_cmnd *sc = ctask->sc;
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1282

1283
	BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1284

1285 1286
	tcp_ctask->sent = 0;
	tcp_ctask->sg_count = 0;
1287 1288

	if (sc->sc_data_direction == DMA_TO_DEVICE) {
1289 1290
		tcp_ctask->xmstate = XMSTATE_W_HDR;
		tcp_ctask->exp_r2tsn = 0;
1291
		BUG_ON(ctask->total_length == 0);
1292

1293 1294 1295
		if (sc->use_sg) {
			struct scatterlist *sg = sc->request_buffer;

1296 1297
			iscsi_buf_init_sg(&tcp_ctask->sendbuf, sg);
			tcp_ctask->sg = sg + 1;
1298
			tcp_ctask->bad_sg = sg + sc->use_sg;
1299
		} else {
1300 1301 1302
			iscsi_buf_init_iov(&tcp_ctask->sendbuf,
					   sc->request_buffer,
					   sc->request_bufflen);
1303 1304
			tcp_ctask->sg = NULL;
			tcp_ctask->bad_sg = NULL;
1305
		}
1306 1307
		debug_scsi("cmd [itt 0x%x total %d imm_data %d "
			   "unsol count %d, unsol offset %d]\n",
1308
			   ctask->itt, ctask->total_length, ctask->imm_count,
1309
			   ctask->unsol_count, ctask->unsol_offset);
1310 1311
	} else
		tcp_ctask->xmstate = XMSTATE_R_HDR;
1312

1313
	iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
1314
			    sizeof(struct iscsi_hdr));
1315 1316 1317
}

/**
1318
 * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331
 * @conn: iscsi connection
 * @mtask: task management task
 *
 * Notes:
 *	The function can return -EAGAIN in which case caller must
 *	call it again later, or recover. '0' return code means successful
 *	xmit.
 *
 *	Management xmit state machine consists of two states:
 *		IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
 *		IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
 **/
static int
1332
iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1333
{
1334
	struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1335
	int rc;
1336 1337

	debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1338
		conn->id, tcp_mtask->xmstate, mtask->itt);
1339

1340 1341
	if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
		tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1342
		if (mtask->data_count)
1343
			tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1344
		if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
M
Mike Christie 已提交
1345
		    conn->stop_stage != STOP_CONN_RECOVER &&
1346
		    conn->hdrdgst_en)
1347 1348
			iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
					(u8*)tcp_mtask->hdrext);
1349 1350 1351
		rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
				   mtask->data_count);
		if (rc) {
1352
			tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1353
			if (mtask->data_count)
1354
				tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1355
			return rc;
1356 1357 1358
		}
	}

1359
	if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1360
		BUG_ON(!mtask->data_count);
1361
		tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1362 1363 1364 1365
		/* FIXME: implement.
		 * Virtual buffer could be spreaded across multiple pages...
		 */
		do {
1366 1367 1368 1369 1370
			int rc;

			rc = iscsi_sendpage(conn, &tcp_mtask->sendbuf,
					&mtask->data_count, &tcp_mtask->sent);
			if (rc) {
1371
				tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1372
				return rc;
1373 1374 1375 1376
			}
		} while (mtask->data_count);
	}

1377 1378 1379 1380 1381 1382 1383 1384 1385 1386
	BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
	if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
		struct iscsi_session *session = conn->session;

		spin_lock_bh(&session->lock);
		list_del(&conn->mtask->running);
		__kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
			    sizeof(void*));
		spin_unlock_bh(&session->lock);
	}
1387 1388 1389 1390
	return 0;
}

static inline int
1391 1392
iscsi_send_read_hdr(struct iscsi_conn *conn,
		    struct iscsi_tcp_cmd_task *tcp_ctask)
1393
{
1394 1395
	int rc;

1396
	tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
1397
	if (conn->hdrdgst_en)
1398 1399
		iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
				 (u8*)tcp_ctask->hdrext);
1400 1401
	rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0);
	if (!rc) {
1402
		BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
1403 1404
		return 0; /* wait for Data-In */
	}
1405
	tcp_ctask->xmstate |= XMSTATE_R_HDR;
1406
	return rc;
1407 1408 1409
}

static inline int
1410
iscsi_send_write_hdr(struct iscsi_conn *conn,
1411
		     struct iscsi_cmd_task *ctask)
1412
{
1413
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1414
	int rc;
1415 1416

	tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
1417
	if (conn->hdrdgst_en)
1418 1419
		iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
				 (u8*)tcp_ctask->hdrext);
1420
	rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
1421
	if (rc) {
1422
		tcp_ctask->xmstate |= XMSTATE_W_HDR;
1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438
		return rc;
	}

	if (ctask->imm_count) {
		tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
		iscsi_set_padding(tcp_ctask, ctask->imm_count);

		if (ctask->conn->datadgst_en) {
			iscsi_data_digest_init(ctask->conn->dd_data, tcp_ctask);
			tcp_ctask->immdigest = 0;
		}
	}

	if (ctask->unsol_count)
		tcp_ctask->xmstate |= XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
	return 0;
1439 1440
}

1441 1442
static int
iscsi_send_padding(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1443
{
1444
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1445 1446
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	int sent = 0, rc;
1447

1448 1449 1450 1451
	if (tcp_ctask->xmstate & XMSTATE_W_PAD) {
		iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
				   tcp_ctask->pad_count);
		if (conn->datadgst_en)
1452 1453 1454
			crypto_hash_update(&tcp_conn->tx_hash,
					   &tcp_ctask->sendbuf.sg,
					   tcp_ctask->sendbuf.sg.length);
1455 1456 1457 1458 1459 1460 1461 1462 1463
	} else if (!(tcp_ctask->xmstate & XMSTATE_W_RESEND_PAD))
		return 0;

	tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
	tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_PAD;
	debug_scsi("sending %d pad bytes for itt 0x%x\n",
		   tcp_ctask->pad_count, ctask->itt);
	rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
			   &sent);
1464
	if (rc) {
1465 1466
		debug_scsi("padding send failed %d\n", rc);
		tcp_ctask->xmstate |= XMSTATE_W_RESEND_PAD;
1467
	}
1468
	return rc;
1469 1470
}

1471 1472 1473
static int
iscsi_send_digest(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
			struct iscsi_buf *buf, uint32_t *digest)
1474
{
1475 1476 1477
	struct iscsi_tcp_cmd_task *tcp_ctask;
	struct iscsi_tcp_conn *tcp_conn;
	int rc, sent = 0;
1478

1479 1480
	if (!conn->datadgst_en)
		return 0;
1481

1482 1483
	tcp_ctask = ctask->dd_data;
	tcp_conn = conn->dd_data;
1484

1485
	if (!(tcp_ctask->xmstate & XMSTATE_W_RESEND_DATA_DIGEST)) {
1486
		crypto_hash_final(&tcp_conn->tx_hash, (u8*)digest);
1487 1488 1489
		iscsi_buf_init_iov(buf, (char*)digest, 4);
	}
	tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_DATA_DIGEST;
1490

1491 1492 1493 1494 1495 1496 1497 1498
	rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
	if (!rc)
		debug_scsi("sent digest 0x%x for itt 0x%x\n", *digest,
			  ctask->itt);
	else {
		debug_scsi("sending digest 0x%x failed for itt 0x%x!\n",
			  *digest, ctask->itt);
		tcp_ctask->xmstate |= XMSTATE_W_RESEND_DATA_DIGEST;
1499
	}
1500 1501
	return rc;
}
1502

1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519
static int
iscsi_send_data(struct iscsi_cmd_task *ctask, struct iscsi_buf *sendbuf,
		struct scatterlist **sg, int *sent, int *count,
		struct iscsi_buf *digestbuf, uint32_t *digest)
{
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
	struct iscsi_conn *conn = ctask->conn;
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	int rc, buf_sent, offset;

	while (*count) {
		buf_sent = 0;
		offset = sendbuf->sent;

		rc = iscsi_sendpage(conn, sendbuf, count, &buf_sent);
		*sent = *sent + buf_sent;
		if (buf_sent && conn->datadgst_en)
1520
			partial_sg_digest_update(&tcp_conn->tx_hash,
1521 1522 1523 1524 1525
				&sendbuf->sg, sendbuf->sg.offset + offset,
				buf_sent);
		if (!iscsi_buf_left(sendbuf) && *sg != tcp_ctask->bad_sg) {
			iscsi_buf_init_sg(sendbuf, *sg);
			*sg = *sg + 1;
1526
		}
1527 1528 1529

		if (rc)
			return rc;
1530 1531
	}

1532 1533 1534 1535 1536
	rc = iscsi_send_padding(conn, ctask);
	if (rc)
		return rc;

	return iscsi_send_digest(conn, ctask, digestbuf, digest);
1537 1538
}

1539 1540
static int
iscsi_send_unsol_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1541
{
1542
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1543
	struct iscsi_data_task *dtask;
1544
	int rc;
1545

1546 1547
	tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
	if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1548 1549
		dtask = &tcp_ctask->unsol_dtask;

1550 1551 1552
		iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr);
		iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
				   sizeof(struct iscsi_hdr));
1553
		if (conn->hdrdgst_en)
1554
			iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1555
					(u8*)dtask->hdrext);
1556

1557
		tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1558
		iscsi_set_padding(tcp_ctask, ctask->data_count);
1559
	}
1560 1561 1562

	rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count);
	if (rc) {
1563 1564
		tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
		tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1565
		return rc;
1566 1567
	}

1568 1569 1570 1571 1572 1573
	if (conn->datadgst_en) {
		dtask = &tcp_ctask->unsol_dtask;
		iscsi_data_digest_init(ctask->conn->dd_data, tcp_ctask);
		dtask->digest = 0;
	}

1574
	debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1575
		   ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1576 1577 1578
	return 0;
}

1579 1580
static int
iscsi_send_unsol_pdu(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1581
{
1582
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1583
	int rc;
1584

1585 1586 1587 1588 1589 1590 1591
	if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
		BUG_ON(!ctask->unsol_count);
		tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
send_hdr:
		rc = iscsi_send_unsol_hdr(conn, ctask);
		if (rc)
			return rc;
1592 1593
	}

1594 1595
	if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
		struct iscsi_data_task *dtask = &tcp_ctask->unsol_dtask;
1596
		int start = tcp_ctask->sent;
1597

1598 1599 1600
		rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
				     &tcp_ctask->sent, &ctask->data_count,
				     &dtask->digestbuf, &dtask->digest);
1601
		ctask->unsol_count -= tcp_ctask->sent - start;
1602 1603 1604
		if (rc)
			return rc;
		tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1605
		/*
1606 1607
		 * Done with the Data-Out. Next, check if we need
		 * to send another unsolicited Data-Out.
1608
		 */
1609 1610 1611 1612
		if (ctask->unsol_count) {
			debug_scsi("sending more uns\n");
			tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
			goto send_hdr;
1613 1614 1615 1616 1617
		}
	}
	return 0;
}

1618 1619
static int iscsi_send_sol_pdu(struct iscsi_conn *conn,
			      struct iscsi_cmd_task *ctask)
1620
{
1621
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1622 1623 1624
	struct iscsi_session *session = conn->session;
	struct iscsi_r2t_info *r2t;
	struct iscsi_data_task *dtask;
1625
	int left, rc;
1626

1627 1628
	if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
		tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1629
		tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1630 1631
		if (!tcp_ctask->r2t) {
			spin_lock_bh(&session->lock);
1632 1633
			__kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
				    sizeof(void*));
1634 1635
			spin_unlock_bh(&session->lock);
		}
1636 1637 1638
send_hdr:
		r2t = tcp_ctask->r2t;
		dtask = &r2t->dtask;
1639

1640 1641 1642 1643
		if (conn->hdrdgst_en)
			iscsi_hdr_digest(conn, &r2t->headbuf,
					(u8*)dtask->hdrext);
		rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
1644
		if (rc) {
1645 1646
			tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
			tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1647
			return rc;
1648 1649 1650
		}

		if (conn->datadgst_en) {
1651 1652
			iscsi_data_digest_init(conn->dd_data, tcp_ctask);
			dtask->digest = 0;
1653 1654
		}

1655 1656 1657 1658
		iscsi_set_padding(tcp_ctask, r2t->data_count);
		debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
			r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
			r2t->sent);
1659 1660
	}

1661 1662 1663
	if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
		r2t = tcp_ctask->r2t;
		dtask = &r2t->dtask;
1664

1665 1666 1667 1668 1669 1670
		rc = iscsi_send_data(ctask, &r2t->sendbuf, &r2t->sg,
				     &r2t->sent, &r2t->data_count,
				     &dtask->digestbuf, &dtask->digest);
		if (rc)
			return rc;
		tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1671

1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683
		/*
		 * Done with this Data-Out. Next, check if we have
		 * to send another Data-Out for this R2T.
		 */
		BUG_ON(r2t->data_length - r2t->sent < 0);
		left = r2t->data_length - r2t->sent;
		if (left) {
			iscsi_solicit_data_cont(conn, ctask, r2t, left);
			tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
			tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
			goto send_hdr;
		}
1684

1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699
		/*
		 * Done with this R2T. Check if there are more
		 * outstanding R2Ts ready to be processed.
		 */
		spin_lock_bh(&session->lock);
		tcp_ctask->r2t = NULL;
		__kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
			    sizeof(void*));
		if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t,
				sizeof(void*))) {
			tcp_ctask->r2t = r2t;
			tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
			tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
			spin_unlock_bh(&session->lock);
			goto send_hdr;
1700
		}
1701
		spin_unlock_bh(&session->lock);
1702 1703 1704 1705 1706
	}
	return 0;
}

static int
1707
iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1708
{
1709
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1710 1711 1712
	int rc = 0;

	debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1713
		conn->id, tcp_ctask->xmstate, ctask->itt);
1714 1715 1716 1717 1718 1719 1720

	/*
	 * serialize with TMF AbortTask
	 */
	if (ctask->mtask)
		return rc;

1721
	if (tcp_ctask->xmstate & XMSTATE_R_HDR)
1722
		return iscsi_send_read_hdr(conn, tcp_ctask);
1723

1724
	if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
1725
		rc = iscsi_send_write_hdr(conn, ctask);
1726 1727 1728 1729
		if (rc)
			return rc;
	}

1730
	if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1731 1732 1733
		rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
				     &tcp_ctask->sent, &ctask->imm_count,
				     &tcp_ctask->immbuf, &tcp_ctask->immdigest);
1734 1735
		if (rc)
			return rc;
1736
		tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1737 1738
	}

1739 1740 1741
	rc = iscsi_send_unsol_pdu(conn, ctask);
	if (rc)
		return rc;
1742

1743 1744 1745
	rc = iscsi_send_sol_pdu(conn, ctask);
	if (rc)
		return rc;
1746 1747 1748 1749

	return rc;
}

1750 1751
static struct iscsi_cls_conn *
iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1752
{
1753 1754 1755
	struct iscsi_conn *conn;
	struct iscsi_cls_conn *cls_conn;
	struct iscsi_tcp_conn *tcp_conn;
1756

1757 1758 1759 1760
	cls_conn = iscsi_conn_setup(cls_session, conn_idx);
	if (!cls_conn)
		return NULL;
	conn = cls_conn->dd_data;
1761
	/*
1762 1763
	 * due to strange issues with iser these are not set
	 * in iscsi_conn_setup
1764
	 */
1765
	conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1766

1767 1768 1769
	tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
	if (!tcp_conn)
		goto tcp_conn_alloc_fail;
1770

1771 1772 1773 1774 1775
	conn->dd_data = tcp_conn;
	tcp_conn->iscsi_conn = conn;
	tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
	/* initial operational parameters */
	tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1776

1777 1778 1779
	tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
						  CRYPTO_ALG_ASYNC);
	tcp_conn->tx_hash.flags = 0;
1780
	if (IS_ERR(tcp_conn->tx_hash.tfm))
1781 1782
		goto free_tcp_conn;

1783 1784 1785
	tcp_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
						  CRYPTO_ALG_ASYNC);
	tcp_conn->rx_hash.flags = 0;
1786
	if (IS_ERR(tcp_conn->rx_hash.tfm))
1787 1788
		goto free_tx_tfm;

1789
	return cls_conn;
1790

1791
free_tx_tfm:
1792
	crypto_free_hash(tcp_conn->tx_hash.tfm);
1793 1794
free_tcp_conn:
	kfree(tcp_conn);
1795 1796 1797
tcp_conn_alloc_fail:
	iscsi_conn_teardown(cls_conn);
	return NULL;
1798 1799
}

1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816
static void
iscsi_tcp_release_conn(struct iscsi_conn *conn)
{
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;

	if (!tcp_conn->sock)
		return;

	sock_hold(tcp_conn->sock->sk);
	iscsi_conn_restore_callbacks(tcp_conn);
	sock_put(tcp_conn->sock->sk);

	sock_release(tcp_conn->sock);
	tcp_conn->sock = NULL;
	conn->recv_lock = NULL;
}

1817
static void
1818
iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1819
{
1820 1821
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1822

1823
	iscsi_tcp_release_conn(conn);
1824
	iscsi_conn_teardown(cls_conn);
1825

P
Pete Wyckoff 已提交
1826 1827 1828 1829
	if (tcp_conn->tx_hash.tfm)
		crypto_free_hash(tcp_conn->tx_hash.tfm);
	if (tcp_conn->rx_hash.tfm)
		crypto_free_hash(tcp_conn->rx_hash.tfm);
1830

1831 1832
	kfree(tcp_conn);
}
1833

1834 1835 1836 1837
static void
iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
1838
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1839 1840 1841

	iscsi_conn_stop(cls_conn, flag);
	iscsi_tcp_release_conn(conn);
1842
	tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1843 1844
}

1845 1846
static int
iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1847
		    struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1848 1849 1850 1851 1852 1853 1854
		    int is_leading)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct sock *sk;
	struct socket *sock;
	int err;
1855

1856
	/* lookup for existing socket */
1857
	sock = sockfd_lookup((int)transport_eph, &err);
1858 1859 1860
	if (!sock) {
		printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
		return -EEXIST;
1861 1862
	}

1863 1864 1865
	err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
	if (err)
		return err;
1866

1867 1868
	/* bind iSCSI connection and socket */
	tcp_conn->sock = sock;
1869

1870 1871 1872 1873 1874
	/* setup Socket parameters */
	sk = sock->sk;
	sk->sk_reuse = 1;
	sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
	sk->sk_allocation = GFP_ATOMIC;
1875

1876
	/* FIXME: disable Nagle's algorithm */
1877

1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888
	/*
	 * Intercept TCP callbacks for sendfile like receive
	 * processing.
	 */
	conn->recv_lock = &sk->sk_callback_lock;
	iscsi_conn_set_callbacks(conn);
	tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
	/*
	 * set receive state machine into initial state
	 */
	tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1889 1890 1891 1892

	return 0;
}

1893
/* called with host lock */
M
Mike Christie 已提交
1894
static void
1895 1896
iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask,
		    char *data, uint32_t data_size)
1897
{
1898
	struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1899

1900 1901
	iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
			   sizeof(struct iscsi_hdr));
1902
	tcp_mtask->xmstate = XMSTATE_IMM_HDR;
1903
	tcp_mtask->sent = 0;
1904

1905 1906
	if (mtask->data_count)
		iscsi_buf_init_iov(&tcp_mtask->sendbuf, (char*)mtask->data,
1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920
				    mtask->data_count);
}

static int
iscsi_r2tpool_alloc(struct iscsi_session *session)
{
	int i;
	int cmd_i;

	/*
	 * initialize per-task: R2T pool and xmit queue
	 */
	for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
	        struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1921
		struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1922 1923 1924 1925 1926 1927 1928 1929

		/*
		 * pre-allocated x4 as much r2ts to handle race when
		 * target acks DataOut faster than we data_xmit() queues
		 * could replenish r2tqueue.
		 */

		/* R2T pool */
1930 1931 1932
		if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
				    (void***)&tcp_ctask->r2ts,
				    sizeof(struct iscsi_r2t_info))) {
1933 1934 1935 1936
			goto r2t_alloc_fail;
		}

		/* R2T xmit queue */
1937
		tcp_ctask->r2tqueue = kfifo_alloc(
1938
		      session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
1939 1940 1941
		if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
			iscsi_pool_free(&tcp_ctask->r2tpool,
					(void**)tcp_ctask->r2ts);
1942 1943 1944 1945 1946 1947 1948 1949
			goto r2t_alloc_fail;
		}
	}

	return 0;

r2t_alloc_fail:
	for (i = 0; i < cmd_i; i++) {
1950 1951 1952 1953 1954 1955
		struct iscsi_cmd_task *ctask = session->cmds[i];
		struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;

		kfifo_free(tcp_ctask->r2tqueue);
		iscsi_pool_free(&tcp_ctask->r2tpool,
				(void**)tcp_ctask->r2ts);
1956 1957 1958 1959 1960 1961 1962 1963 1964 1965
	}
	return -ENOMEM;
}

static void
iscsi_r2tpool_free(struct iscsi_session *session)
{
	int i;

	for (i = 0; i < session->cmds_max; i++) {
1966 1967
		struct iscsi_cmd_task *ctask = session->cmds[i];
		struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1968

1969 1970 1971
		kfifo_free(tcp_ctask->r2tqueue);
		iscsi_pool_free(&tcp_ctask->r2tpool,
				(void**)tcp_ctask->r2ts);
1972 1973 1974 1975
	}
}

static int
1976
iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
1977
		     char *buf, int buflen)
1978
{
1979
	struct iscsi_conn *conn = cls_conn->dd_data;
1980
	struct iscsi_session *session = conn->session;
1981
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1982
	int value;
1983 1984 1985

	switch(param) {
	case ISCSI_PARAM_HDRDGST_EN:
1986
		iscsi_set_param(cls_conn, param, buf, buflen);
1987
		tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1988
		if (conn->hdrdgst_en)
1989
			tcp_conn->hdr_size += sizeof(__u32);
1990 1991
		break;
	case ISCSI_PARAM_DATADGST_EN:
1992
		iscsi_set_param(cls_conn, param, buf, buflen);
1993 1994
		tcp_conn->sendpage = conn->datadgst_en ?
			sock_no_sendpage : tcp_conn->sock->ops->sendpage;
1995 1996
		break;
	case ISCSI_PARAM_MAX_R2T:
1997
		sscanf(buf, "%d", &value);
1998 1999 2000
		if (session->max_r2t == roundup_pow_of_two(value))
			break;
		iscsi_r2tpool_free(session);
2001
		iscsi_set_param(cls_conn, param, buf, buflen);
2002 2003 2004 2005 2006 2007
		if (session->max_r2t & (session->max_r2t - 1))
			session->max_r2t = roundup_pow_of_two(session->max_r2t);
		if (iscsi_r2tpool_alloc(session))
			return -ENOMEM;
		break;
	default:
2008
		return iscsi_set_param(cls_conn, param, buf, buflen);
2009 2010 2011 2012 2013 2014
	}

	return 0;
}

static int
2015 2016
iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
			 enum iscsi_param param, char *buf)
2017
{
2018
	struct iscsi_conn *conn = cls_conn->dd_data;
2019
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2020
	struct inet_sock *inet;
2021 2022 2023
	struct ipv6_pinfo *np;
	struct sock *sk;
	int len;
2024 2025

	switch(param) {
2026 2027
	case ISCSI_PARAM_CONN_PORT:
		mutex_lock(&conn->xmitmutex);
2028
		if (!tcp_conn->sock) {
2029 2030 2031 2032
			mutex_unlock(&conn->xmitmutex);
			return -EINVAL;
		}

2033
		inet = inet_sk(tcp_conn->sock->sk);
2034
		len = sprintf(buf, "%hu\n", be16_to_cpu(inet->dport));
2035
		mutex_unlock(&conn->xmitmutex);
2036
		break;
2037 2038
	case ISCSI_PARAM_CONN_ADDRESS:
		mutex_lock(&conn->xmitmutex);
2039
		if (!tcp_conn->sock) {
2040 2041 2042 2043
			mutex_unlock(&conn->xmitmutex);
			return -EINVAL;
		}

2044
		sk = tcp_conn->sock->sk;
2045 2046
		if (sk->sk_family == PF_INET) {
			inet = inet_sk(sk);
2047
			len = sprintf(buf, NIPQUAD_FMT "\n",
2048 2049 2050
				      NIPQUAD(inet->daddr));
		} else {
			np = inet6_sk(sk);
2051
			len = sprintf(buf, NIP6_FMT "\n", NIP6(np->daddr));
2052 2053 2054 2055
		}
		mutex_unlock(&conn->xmitmutex);
		break;
	default:
2056
		return iscsi_conn_get_param(cls_conn, param, buf);
2057 2058 2059 2060 2061
	}

	return len;
}

2062
static void
2063
iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2064
{
2065
	struct iscsi_conn *conn = cls_conn->dd_data;
2066
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078

	stats->txdata_octets = conn->txdata_octets;
	stats->rxdata_octets = conn->rxdata_octets;
	stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
	stats->dataout_pdus = conn->dataout_pdus_cnt;
	stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
	stats->datain_pdus = conn->datain_pdus_cnt;
	stats->r2t_pdus = conn->r2t_pdus_cnt;
	stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
	stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
	stats->custom_length = 3;
	strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2079
	stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2080
	strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2081
	stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2082 2083 2084 2085
	strcpy(stats->custom[2].desc, "eh_abort_cnt");
	stats->custom[2].value = conn->eh_abort_cnt;
}

2086 2087 2088 2089
static struct iscsi_cls_session *
iscsi_tcp_session_create(struct iscsi_transport *iscsit,
			 struct scsi_transport_template *scsit,
			 uint32_t initial_cmdsn, uint32_t *hostno)
2090
{
2091 2092 2093 2094
	struct iscsi_cls_session *cls_session;
	struct iscsi_session *session;
	uint32_t hn;
	int cmd_i;
2095

2096 2097 2098 2099 2100 2101 2102
	cls_session = iscsi_session_setup(iscsit, scsit,
					 sizeof(struct iscsi_tcp_cmd_task),
					 sizeof(struct iscsi_tcp_mgmt_task),
					 initial_cmdsn, &hn);
	if (!cls_session)
		return NULL;
	*hostno = hn;
2103

2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132
	session = class_to_transport_session(cls_session);
	for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
		struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
		struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;

		ctask->hdr = &tcp_ctask->hdr;
	}

	for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
		struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
		struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;

		mtask->hdr = &tcp_mtask->hdr;
	}

	if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
		goto r2tpool_alloc_fail;

	return cls_session;

r2tpool_alloc_fail:
	iscsi_session_teardown(cls_session);
	return NULL;
}

static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
{
	iscsi_r2tpool_free(class_to_transport_session(cls_session));
	iscsi_session_teardown(cls_session);
2133 2134
}

2135
static struct scsi_host_template iscsi_sht = {
2136
	.name			= "iSCSI Initiator over TCP/IP",
2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148
	.queuecommand           = iscsi_queuecommand,
	.change_queue_depth	= iscsi_change_queue_depth,
	.can_queue		= ISCSI_XMIT_CMDS_MAX - 1,
	.sg_tablesize		= ISCSI_SG_TABLESIZE,
	.cmd_per_lun		= ISCSI_DEF_CMD_PER_LUN,
	.eh_abort_handler       = iscsi_eh_abort,
	.eh_host_reset_handler	= iscsi_eh_host_reset,
	.use_clustering         = DISABLE_CLUSTERING,
	.proc_name		= "iscsi_tcp",
	.this_id		= -1,
};

2149 2150 2151 2152 2153
static struct iscsi_transport iscsi_tcp_transport = {
	.owner			= THIS_MODULE,
	.name			= "tcp",
	.caps			= CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
				  | CAP_DATADGST,
2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166
	.param_mask		= ISCSI_MAX_RECV_DLENGTH |
				  ISCSI_MAX_XMIT_DLENGTH |
				  ISCSI_HDRDGST_EN |
				  ISCSI_DATADGST_EN |
				  ISCSI_INITIAL_R2T_EN |
				  ISCSI_MAX_R2T |
				  ISCSI_IMM_DATA_EN |
				  ISCSI_FIRST_BURST |
				  ISCSI_MAX_BURST |
				  ISCSI_PDU_INORDER_EN |
				  ISCSI_DATASEQ_INORDER_EN |
				  ISCSI_ERL |
				  ISCSI_CONN_PORT |
2167
				  ISCSI_CONN_ADDRESS |
2168 2169 2170 2171 2172
				  ISCSI_EXP_STATSN |
				  ISCSI_PERSISTENT_PORT |
				  ISCSI_PERSISTENT_ADDRESS |
				  ISCSI_TARGET_NAME |
				  ISCSI_TPGT,
2173
	.host_template		= &iscsi_sht,
2174
	.conndata_size		= sizeof(struct iscsi_conn),
2175 2176
	.max_conn		= 1,
	.max_cmd_len		= ISCSI_TCP_MAX_CMD_LEN,
2177 2178 2179 2180 2181 2182 2183
	/* session management */
	.create_session		= iscsi_tcp_session_create,
	.destroy_session	= iscsi_tcp_session_destroy,
	/* connection management */
	.create_conn		= iscsi_tcp_conn_create,
	.bind_conn		= iscsi_tcp_conn_bind,
	.destroy_conn		= iscsi_tcp_conn_destroy,
2184
	.set_param		= iscsi_conn_set_param,
2185
	.get_conn_param		= iscsi_tcp_conn_get_param,
2186
	.get_session_param	= iscsi_session_get_param,
2187
	.start_conn		= iscsi_conn_start,
2188
	.stop_conn		= iscsi_tcp_conn_stop,
2189
	/* IO */
2190 2191
	.send_pdu		= iscsi_conn_send_pdu,
	.get_stats		= iscsi_conn_get_stats,
2192 2193 2194 2195 2196 2197
	.init_cmd_task		= iscsi_tcp_cmd_init,
	.init_mgmt_task		= iscsi_tcp_mgmt_init,
	.xmit_cmd_task		= iscsi_tcp_ctask_xmit,
	.xmit_mgmt_task		= iscsi_tcp_mtask_xmit,
	.cleanup_cmd_task	= iscsi_tcp_cleanup_ctask,
	/* recovery */
M
Mike Christie 已提交
2198
	.session_recovery_timedout = iscsi_session_recovery_timedout,
2199 2200 2201 2202 2203 2204
};

static int __init
iscsi_tcp_init(void)
{
	if (iscsi_max_lun < 1) {
O
Or Gerlitz 已提交
2205 2206
		printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
		       iscsi_max_lun);
2207 2208 2209 2210
		return -EINVAL;
	}
	iscsi_tcp_transport.max_lun = iscsi_max_lun;

2211
	if (!iscsi_register_transport(&iscsi_tcp_transport))
2212
		return -ENODEV;
2213

2214
	return 0;
2215 2216 2217 2218 2219 2220 2221 2222 2223 2224
}

static void __exit
iscsi_tcp_exit(void)
{
	iscsi_unregister_transport(&iscsi_tcp_transport);
}

module_init(iscsi_tcp_init);
module_exit(iscsi_tcp_exit);