iscsi_tcp.c 61.2 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>
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#include <linux/file.h>
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#include <linux/blkdev.h>
#include <linux/crypto.h>
#include <linux/delay.h>
#include <linux/kfifo.h>
#include <linux/scatterlist.h>
#include <net/tcp.h>
#include <scsi/scsi_cmnd.h>
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#include <scsi/scsi_device.h>
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#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 += sizeof(u32);
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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)
{
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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;
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	struct scsi_cmnd *sc = ctask->sc;
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	int datasn = be32_to_cpu(rhdr->datasn);

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	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
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	/*
	 * 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;

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	if (tcp_ctask->exp_datasn != datasn) {
		debug_tcp("%s: ctask->exp_datasn(%d) != rhdr->datasn(%d)\n",
		          __FUNCTION__, tcp_ctask->exp_datasn, datasn);
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		return ISCSI_ERR_DATASN;
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	}
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	tcp_ctask->exp_datasn++;
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	tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
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	if (tcp_ctask->data_offset + tcp_conn->in.datalen > scsi_bufflen(sc)) {
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		debug_tcp("%s: data_offset(%d) + data_len(%d) > total_length_in(%d)\n",
		          __FUNCTION__, tcp_ctask->data_offset,
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		          tcp_conn->in.datalen, scsi_bufflen(sc));
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		return ISCSI_ERR_DATA_OFFSET;
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	}
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	if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
		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 &&
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			    res_count <= scsi_bufflen(sc)) {
				scsi_set_resid(sc, res_count);
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				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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			scsi_set_resid(sc, be32_to_cpu(rhdr->residual_count));
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			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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	int i, sg_count = 0;
	struct scatterlist *sg;
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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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	sg = scsi_sglist(sc);
	r2t->sg = NULL;
	for (i = 0; i < scsi_sg_count(sc); i++, sg += 1) {
		/* FIXME: prefetch ? */
		if (sg_count + sg->length > r2t->data_offset) {
			int page_offset;
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			/* sg page found! */
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			/* offset within this page */
			page_offset = r2t->data_offset - sg_count;
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			/* fill in this buffer */
			iscsi_buf_init_sg(&r2t->sendbuf, sg);
			r2t->sendbuf.sg.offset += page_offset;
			r2t->sendbuf.sg.length -= page_offset;
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			/* xmit logic will continue with next one */
			r2t->sg = sg + 1;
			break;
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		}
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		sg_count += sg->length;
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	}
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	BUG_ON(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_datasn != r2tsn){
		debug_tcp("%s: ctask->exp_datasn(%d) != rhdr->r2tsn(%d)\n",
		          __FUNCTION__, tcp_ctask->exp_datasn, r2tsn);
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		return ISCSI_ERR_R2TSN;
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	}
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	/* fill-in new R2T associated with the task */
	spin_lock(&session->lock);
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	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);

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	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);
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	if (r2t->data_offset + r2t->data_length > scsi_bufflen(ctask->sc)) {
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		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,
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		       r2t->data_offset, scsi_bufflen(ctask->sc));
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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_datasn = r2tsn + 1;
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	__kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
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	tcp_ctask->xmstate |= XMSTATE_SOL_HDR_INIT;
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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)
427
{
428
	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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434
	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",
440
		       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 "
451
		       "%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);
471
		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
		 */
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		if (ISCSI_DEF_MAX_RECV_SEG_LEN <
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		    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,
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			      ISCSI_DEF_MAX_RECV_SEG_LEN, opcode);
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			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;
568 569 570 571
}

/**
 * iscsi_ctask_copy - copy skb bits to the destanation cmd task
572
 * @conn: iscsi tcp connection
573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593
 * @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
594
iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
595 596
		void *buf, int buf_size, int offset)
{
597 598
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
	int buf_left = buf_size - (tcp_conn->data_copied + offset);
599
	unsigned size = min(tcp_conn->in.copy, buf_left);
600 601 602 603 604
	int rc;

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

	debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
605
	       size, tcp_conn->in.offset, tcp_conn->in.copied);
606 607

	BUG_ON(size <= 0);
608
	BUG_ON(tcp_ctask->sent + size > scsi_bufflen(ctask->sc));
609

610 611
	rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
			   (char*)buf + (offset + tcp_conn->data_copied), size);
612 613 614
	/* must fit into skb->len */
	BUG_ON(rc);

615 616 617 618 619
	tcp_conn->in.offset += size;
	tcp_conn->in.copy -= size;
	tcp_conn->in.copied += size;
	tcp_conn->data_copied += size;
	tcp_ctask->sent += size;
620 621
	ctask->data_count -= size;

622
	BUG_ON(tcp_conn->in.copy < 0);
623 624
	BUG_ON(ctask->data_count < 0);

625
	if (buf_size != (tcp_conn->data_copied + offset)) {
626
		if (!ctask->data_count) {
627
			BUG_ON(buf_size - tcp_conn->data_copied < 0);
628
			/* done with this PDU */
629
			return buf_size - tcp_conn->data_copied;
630 631 632 633 634
		}
		return -EAGAIN;
	}

	/* done with this buffer or with both - PDU and buffer */
635
	tcp_conn->data_copied = 0;
636 637 638 639 640
	return 0;
}

/**
 * iscsi_tcp_copy - copy skb bits to the destanation buffer
641
 * @conn: iscsi tcp connection
642 643 644 645 646 647
 *
 * Notes:
 *	The function calls skb_copy_bits() and updates per-connection
 *	byte counters.
 **/
static inline int
648
iscsi_tcp_copy(struct iscsi_conn *conn, int buf_size)
649
{
650
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
651 652
	int buf_left = buf_size - tcp_conn->data_copied;
	int size = min(tcp_conn->in.copy, buf_left);
653 654 655
	int rc;

	debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
656
	       size, tcp_conn->in.offset, tcp_conn->data_copied);
657 658
	BUG_ON(size <= 0);

659
	rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
660
			   (char*)conn->data + tcp_conn->data_copied, size);
661 662
	BUG_ON(rc);

663 664 665 666
	tcp_conn->in.offset += size;
	tcp_conn->in.copy -= size;
	tcp_conn->in.copied += size;
	tcp_conn->data_copied += size;
667

668
	if (buf_size != tcp_conn->data_copied)
669 670 671 672 673 674
		return -EAGAIN;

	return 0;
}

static inline void
675
partial_sg_digest_update(struct hash_desc *desc, struct scatterlist *sg,
676
			 int offset, int length)
677 678 679 680 681 682
{
	struct scatterlist temp;

	memcpy(&temp, sg, sizeof(struct scatterlist));
	temp.offset = offset;
	temp.length = length;
683
	crypto_hash_update(desc, &temp, length);
684 685
}

686
static void
687
iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
688 689 690 691
{
	struct scatterlist tmp;

	sg_init_one(&tmp, buf, len);
692
	crypto_hash_update(&tcp_conn->rx_hash, &tmp, len);
693 694
}

695 696
static int iscsi_scsi_data_in(struct iscsi_conn *conn)
{
697 698 699
	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;
700
	struct scsi_cmnd *sc = ctask->sc;
701
	struct scatterlist *sg;
702 703 704 705
	int i, offset, rc = 0;

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

706
	offset = tcp_ctask->data_offset;
707
	sg = scsi_sglist(sc);
708

709 710
	if (tcp_ctask->data_offset)
		for (i = 0; i < tcp_ctask->sg_count; i++)
711 712 713 714 715
			offset -= sg[i].length;
	/* we've passed through partial sg*/
	if (offset < 0)
		offset = 0;

716
	for (i = tcp_ctask->sg_count; i < scsi_sg_count(sc); i++) {
717 718 719
		char *dest;

		dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
720
		rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
721 722 723 724 725 726 727 728
				      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)
729
					crypto_hash_update(
730
							&tcp_conn->rx_hash,
731
							&sg[i], sg[i].length);
732
				else
733
					partial_sg_digest_update(
734
							&tcp_conn->rx_hash,
735
							&sg[i],
736 737 738 739
							sg[i].offset + offset,
							sg[i].length - offset);
			}
			offset = 0;
740
			tcp_ctask->sg_count++;
741 742 743 744 745 746 747
		}

		if (!ctask->data_count) {
			if (rc && conn->datadgst_en)
				/*
				 * data-in is complete, but buffer not...
				 */
748 749 750 751
				partial_sg_digest_update(&tcp_conn->rx_hash,
							 &sg[i],
							 sg[i].offset,
							 sg[i].length-rc);
752 753 754 755
			rc = 0;
			break;
		}

756
		if (!tcp_conn->in.copy)
757 758 759 760 761
			return -EAGAIN;
	}
	BUG_ON(ctask->data_count);

	/* check for non-exceptional status */
762
	if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
763 764 765
		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);
766 767 768
		spin_lock(&conn->session->lock);
		__iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
		spin_unlock(&conn->session->lock);
769 770 771 772 773 774 775 776
	}

	return rc;
}

static int
iscsi_data_recv(struct iscsi_conn *conn)
{
777 778
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	int rc = 0, opcode;
779

780 781
	opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
	switch (opcode) {
782 783 784
	case ISCSI_OP_SCSI_DATA_IN:
		rc = iscsi_scsi_data_in(conn);
		break;
785
	case ISCSI_OP_SCSI_CMD_RSP:
786 787
	case ISCSI_OP_TEXT_RSP:
	case ISCSI_OP_LOGIN_RSP:
788 789
	case ISCSI_OP_ASYNC_EVENT:
	case ISCSI_OP_REJECT:
790 791 792 793
		/*
		 * Collect data segment to the connection's data
		 * placeholder
		 */
794
		if (iscsi_tcp_copy(conn, tcp_conn->in.datalen)) {
795 796 797 798
			rc = -EAGAIN;
			goto exit;
		}

799
		rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, conn->data,
800 801
					tcp_conn->in.datalen);
		if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
802
			iscsi_recv_digest_update(tcp_conn, conn->data,
803 804
			  			tcp_conn->in.datalen);
		break;
805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824
	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;
825
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
826 827 828 829 830 831 832 833
	int processed;
	char pad[ISCSI_PAD_LEN];
	struct scatterlist sg;

	/*
	 * Save current SKB and its offset in the corresponding
	 * connection context.
	 */
834 835 836 837 838 839
	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);
840 841

more:
842
	tcp_conn->in.copied = 0;
843 844 845 846 847 848 849
	rc = 0;

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

850 851 852
	if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
	    tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
		rc = iscsi_hdr_extract(tcp_conn);
853 854 855 856
		if (rc) {
		       if (rc == -EAGAIN)
				goto nomore;
		       else {
857
				iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
858 859 860 861 862 863 864
				return 0;
		       }
		}

		/*
		 * Verify and process incoming PDU header.
		 */
865 866
		rc = iscsi_tcp_hdr_recv(conn);
		if (!rc && tcp_conn->in.datalen) {
867
			if (conn->datadgst_en)
868
				crypto_hash_init(&tcp_conn->rx_hash);
869
			tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
870
		} else if (rc) {
871
			iscsi_conn_failure(conn, rc);
872 873 874 875
			return 0;
		}
	}

876 877
	if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV &&
	    tcp_conn->in.copy) {
878
		uint32_t recv_digest;
879

880
		debug_tcp("extra data_recv offset %d copy %d\n",
881
			  tcp_conn->in.offset, tcp_conn->in.copy);
882 883 884 885 886 887 888 889 890 891 892 893 894 895 896

		if (!tcp_conn->data_copied) {
			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);
				crypto_hash_update(&tcp_conn->rx_hash,
						   &sg, sg.length);
			}
			crypto_hash_final(&tcp_conn->rx_hash,
					  (u8 *) &tcp_conn->in.datadgst);
			debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
		}

897 898 899 900 901 902 903 904 905
		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));
906
		if (recv_digest != tcp_conn->in.datadgst) {
907 908
			debug_tcp("iscsi_tcp: data digest error!"
				  "0x%x != 0x%x\n", recv_digest,
909
				  tcp_conn->in.datadgst);
910 911 912 913 914
			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,
915 916
				  tcp_conn->in.datadgst);
			tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
917 918 919
		}
	}

920
	if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
921
	    tcp_conn->in.copy) {
922
		debug_tcp("data_recv offset %d copy %d\n",
923
		       tcp_conn->in.offset, tcp_conn->in.copy);
924 925 926

		rc = iscsi_data_recv(conn);
		if (rc) {
927
			if (rc == -EAGAIN)
928
				goto again;
929
			iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
930 931
			return 0;
		}
932 933 934 935

		if (tcp_conn->in.padding)
			tcp_conn->in_progress = IN_PROGRESS_PAD_RECV;
		else if (conn->datadgst_en)
936
			tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955
		else
			tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
		tcp_conn->data_copied = 0;
	}

	if (tcp_conn->in_progress == IN_PROGRESS_PAD_RECV &&
	    tcp_conn->in.copy) {
		int copylen = min(tcp_conn->in.padding - tcp_conn->data_copied,
				  tcp_conn->in.copy);

		tcp_conn->in.copy -= copylen;
		tcp_conn->in.offset += copylen;
		tcp_conn->data_copied += copylen;

		if (tcp_conn->data_copied != tcp_conn->in.padding)
			tcp_conn->in_progress = IN_PROGRESS_PAD_RECV;
		else if (conn->datadgst_en)
			tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
		else
956
			tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
957
		tcp_conn->data_copied = 0;
958 959 960
	}

	debug_tcp("f, processed %d from out of %d padding %d\n",
961 962
	       tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
	BUG_ON(tcp_conn->in.offset - offset > len);
963

964
	if (tcp_conn->in.offset - offset != len) {
965
		debug_tcp("continue to process %d bytes\n",
966
		       (int)len - (tcp_conn->in.offset - offset));
967 968 969 970
		goto more;
	}

nomore:
971
	processed = tcp_conn->in.offset - offset;
972 973 974 975
	BUG_ON(processed == 0);
	return processed;

again:
976
	processed = tcp_conn->in.offset - offset;
977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993
	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);

994 995 996 997 998 999
	/*
	 * 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.
	 */
1000
	rd_desc.arg.data = conn;
1001
	rd_desc.count = 1;
1002 1003 1004 1005 1006 1007 1008 1009
	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)
{
1010
	struct iscsi_tcp_conn *tcp_conn;
1011 1012 1013 1014 1015 1016 1017 1018 1019
	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
1020 1021 1022
	if ((sk->sk_state == TCP_CLOSE_WAIT ||
	     sk->sk_state == TCP_CLOSE) &&
	    !atomic_read(&sk->sk_rmem_alloc)) {
1023 1024 1025 1026
		debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
	}

1027 1028
	tcp_conn = conn->dd_data;
	old_state_change = tcp_conn->old_state_change;
1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042

	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;
1043 1044 1045
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;

	tcp_conn->old_write_space(sk);
1046
	debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1047
	scsi_queue_work(conn->session->host, &conn->xmitwork);
1048 1049 1050 1051 1052
}

static void
iscsi_conn_set_callbacks(struct iscsi_conn *conn)
{
1053 1054
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct sock *sk = tcp_conn->sock->sk;
1055 1056 1057 1058

	/* assign new callbacks */
	write_lock_bh(&sk->sk_callback_lock);
	sk->sk_user_data = conn;
1059 1060 1061
	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;
1062 1063 1064 1065 1066 1067 1068
	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
1069
iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
1070
{
1071
	struct sock *sk = tcp_conn->sock->sk;
1072 1073 1074 1075

	/* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
	write_lock_bh(&sk->sk_callback_lock);
	sk->sk_user_data    = NULL;
1076 1077 1078
	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;
1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090
	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
1091
iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1092
{
1093 1094
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct socket *sk = tcp_conn->sock;
1095
	int offset = buf->sg.offset + buf->sent, res;
1096

1097 1098 1099 1100 1101 1102 1103 1104 1105
	/*
	 * 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)
1106
		res = sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
1107
	else
1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121
		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;
1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143
}

/**
 * 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;

1144
	res = iscsi_send(conn, buf, size, flags);
1145 1146 1147 1148 1149
	debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
	if (res >= 0) {
		if (size != res)
			return -EAGAIN;
		return 0;
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 1175

	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
1176
	if (buf->sent + size != buf->sg.length || *count != size)
1177 1178
		flags |= MSG_MORE;

1179
	res = iscsi_send(conn, buf, size, flags);
1180 1181 1182 1183 1184 1185 1186 1187
	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;
1188
	}
1189 1190 1191 1192 1193

	return res;
}

static inline void
1194
iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1195
		      struct iscsi_tcp_cmd_task *tcp_ctask)
1196
{
1197
	crypto_hash_init(&tcp_conn->tx_hash);
1198
	tcp_ctask->digest_count = 4;
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;
	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
	if (iscsi_buf_left(&r2t->sendbuf))
		return;

1248 1249
	iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
	r2t->sg += 1;
1250 1251
}

1252 1253
static void iscsi_set_padding(struct iscsi_tcp_cmd_task *tcp_ctask,
			      unsigned long len)
1254
{
1255 1256 1257
	tcp_ctask->pad_count = len & (ISCSI_PAD_LEN - 1);
	if (!tcp_ctask->pad_count)
		return;
1258

1259 1260 1261
	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;
1262 1263 1264
}

/**
1265
 * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1266 1267 1268 1269 1270
 * @conn: iscsi connection
 * @ctask: scsi command task
 * @sc: scsi command
 **/
static void
1271
iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1272
{
1273
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1274

1275
	BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1276
	tcp_ctask->xmstate = XMSTATE_CMD_HDR_INIT;
1277 1278 1279
}

/**
1280
 * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1281 1282 1283 1284 1285 1286 1287 1288
 * @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.
 *
1289 1290 1291 1292 1293
 *	Management xmit state machine consists of these states:
 *		XMSTATE_IMM_HDR_INIT	- calculate digest of PDU Header
 *		XMSTATE_IMM_HDR 	- PDU Header xmit in progress
 *		XMSTATE_IMM_DATA 	- PDU Data xmit in progress
 *		XMSTATE_IDLE		- management PDU is done
1294 1295
 **/
static int
1296
iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1297
{
1298
	struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1299
	int rc;
1300 1301

	debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1302
		conn->id, tcp_mtask->xmstate, mtask->itt);
1303

1304 1305 1306 1307 1308
	if (tcp_mtask->xmstate & XMSTATE_IMM_HDR_INIT) {
		iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
				   sizeof(struct iscsi_hdr));

		if (mtask->data_count) {
1309
			tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1310 1311 1312 1313 1314
			iscsi_buf_init_iov(&tcp_mtask->sendbuf,
					   (char*)mtask->data,
					   mtask->data_count);
		}

1315
		if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
M
Mike Christie 已提交
1316
		    conn->stop_stage != STOP_CONN_RECOVER &&
1317
		    conn->hdrdgst_en)
1318 1319
			iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
					(u8*)tcp_mtask->hdrext);
1320 1321 1322 1323 1324 1325 1326

		tcp_mtask->sent = 0;
		tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR_INIT;
		tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
	}

	if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1327 1328
		rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
				   mtask->data_count);
1329
		if (rc)
1330
			return rc;
1331
		tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1332 1333
	}

1334
	if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1335
		BUG_ON(!mtask->data_count);
1336
		tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1337 1338 1339 1340
		/* FIXME: implement.
		 * Virtual buffer could be spreaded across multiple pages...
		 */
		do {
1341 1342 1343 1344 1345
			int rc;

			rc = iscsi_sendpage(conn, &tcp_mtask->sendbuf,
					&mtask->data_count, &tcp_mtask->sent);
			if (rc) {
1346
				tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1347
				return rc;
1348 1349 1350 1351
			}
		} while (mtask->data_count);
	}

1352
	BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
A
Al Viro 已提交
1353
	if (mtask->hdr->itt == RESERVED_ITT) {
1354 1355 1356 1357 1358 1359 1360 1361
		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);
	}
1362 1363 1364
	return 0;
}

1365 1366
static int
iscsi_send_cmd_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1367
{
1368 1369 1370
	struct scsi_cmnd *sc = ctask->sc;
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
	int rc = 0;
1371

1372 1373 1374 1375 1376 1377
	if (tcp_ctask->xmstate & XMSTATE_CMD_HDR_INIT) {
		tcp_ctask->sent = 0;
		tcp_ctask->sg_count = 0;
		tcp_ctask->exp_datasn = 0;

		if (sc->sc_data_direction == DMA_TO_DEVICE) {
1378 1379 1380 1381 1382
			struct scatterlist *sg = scsi_sglist(sc);

			iscsi_buf_init_sg(&tcp_ctask->sendbuf, sg);
			tcp_ctask->sg = sg + 1;
			tcp_ctask->bad_sg = sg + scsi_sg_count(sc);
1383

1384 1385
			debug_scsi("cmd [itt 0x%x total %d imm_data %d "
				   "unsol count %d, unsol offset %d]\n",
1386
				   ctask->itt, scsi_bufflen(sc),
1387 1388 1389
				   ctask->imm_count, ctask->unsol_count,
				   ctask->unsol_offset);
		}
1390

1391 1392 1393 1394 1395 1396 1397 1398
		iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
				  sizeof(struct iscsi_hdr));

		if (conn->hdrdgst_en)
			iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
					 (u8*)tcp_ctask->hdrext);
		tcp_ctask->xmstate &= ~XMSTATE_CMD_HDR_INIT;
		tcp_ctask->xmstate |= XMSTATE_CMD_HDR_XMIT;
1399 1400
	}

1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412
	if (tcp_ctask->xmstate & XMSTATE_CMD_HDR_XMIT) {
		rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
		if (rc)
			return rc;
		tcp_ctask->xmstate &= ~XMSTATE_CMD_HDR_XMIT;

		if (sc->sc_data_direction != DMA_TO_DEVICE)
			return 0;

		if (ctask->imm_count) {
			tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
			iscsi_set_padding(tcp_ctask, ctask->imm_count);
1413

1414 1415 1416 1417 1418
			if (ctask->conn->datadgst_en) {
				iscsi_data_digest_init(ctask->conn->dd_data,
						       tcp_ctask);
				tcp_ctask->immdigest = 0;
			}
1419 1420
		}

1421 1422 1423 1424 1425
		if (ctask->unsol_count)
			tcp_ctask->xmstate |=
					XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
	}
	return rc;
1426 1427
}

1428 1429
static int
iscsi_send_padding(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1430
{
1431
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1432 1433
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	int sent = 0, rc;
1434

1435 1436 1437 1438
	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)
1439 1440 1441
			crypto_hash_update(&tcp_conn->tx_hash,
					   &tcp_ctask->sendbuf.sg,
					   tcp_ctask->sendbuf.sg.length);
1442 1443 1444 1445 1446 1447 1448 1449 1450
	} 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);
1451
	if (rc) {
1452 1453
		debug_scsi("padding send failed %d\n", rc);
		tcp_ctask->xmstate |= XMSTATE_W_RESEND_PAD;
1454
	}
1455
	return rc;
1456 1457
}

1458 1459 1460
static int
iscsi_send_digest(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
			struct iscsi_buf *buf, uint32_t *digest)
1461
{
1462 1463 1464
	struct iscsi_tcp_cmd_task *tcp_ctask;
	struct iscsi_tcp_conn *tcp_conn;
	int rc, sent = 0;
1465

1466 1467
	if (!conn->datadgst_en)
		return 0;
1468

1469 1470
	tcp_ctask = ctask->dd_data;
	tcp_conn = conn->dd_data;
1471

1472
	if (!(tcp_ctask->xmstate & XMSTATE_W_RESEND_DATA_DIGEST)) {
1473
		crypto_hash_final(&tcp_conn->tx_hash, (u8*)digest);
1474 1475 1476
		iscsi_buf_init_iov(buf, (char*)digest, 4);
	}
	tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_DATA_DIGEST;
1477

1478 1479 1480 1481 1482 1483 1484 1485
	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;
1486
	}
1487 1488
	return rc;
}
1489

1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506
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)
1507
			partial_sg_digest_update(&tcp_conn->tx_hash,
1508 1509 1510 1511 1512
				&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;
1513
		}
1514 1515 1516

		if (rc)
			return rc;
1517 1518
	}

1519 1520 1521 1522 1523
	rc = iscsi_send_padding(conn, ctask);
	if (rc)
		return rc;

	return iscsi_send_digest(conn, ctask, digestbuf, digest);
1524 1525
}

1526 1527
static int
iscsi_send_unsol_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1528
{
1529
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1530
	struct iscsi_data_task *dtask;
1531
	int rc;
1532

1533 1534
	tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
	if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1535 1536
		dtask = &tcp_ctask->unsol_dtask;

1537 1538 1539
		iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr);
		iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
				   sizeof(struct iscsi_hdr));
1540
		if (conn->hdrdgst_en)
1541
			iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1542
					(u8*)dtask->hdrext);
1543

1544
		tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1545
		iscsi_set_padding(tcp_ctask, ctask->data_count);
1546
	}
1547 1548 1549

	rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count);
	if (rc) {
1550 1551
		tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
		tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1552
		return rc;
1553 1554
	}

1555 1556 1557 1558 1559 1560
	if (conn->datadgst_en) {
		dtask = &tcp_ctask->unsol_dtask;
		iscsi_data_digest_init(ctask->conn->dd_data, tcp_ctask);
		dtask->digest = 0;
	}

1561
	debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1562
		   ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1563 1564 1565
	return 0;
}

1566 1567
static int
iscsi_send_unsol_pdu(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1568
{
1569
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1570
	int rc;
1571

1572 1573 1574 1575 1576 1577 1578
	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;
1579 1580
	}

1581 1582
	if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
		struct iscsi_data_task *dtask = &tcp_ctask->unsol_dtask;
1583
		int start = tcp_ctask->sent;
1584

1585 1586 1587
		rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
				     &tcp_ctask->sent, &ctask->data_count,
				     &dtask->digestbuf, &dtask->digest);
1588
		ctask->unsol_count -= tcp_ctask->sent - start;
1589 1590 1591
		if (rc)
			return rc;
		tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1592
		/*
1593 1594
		 * Done with the Data-Out. Next, check if we need
		 * to send another unsolicited Data-Out.
1595
		 */
1596 1597 1598 1599
		if (ctask->unsol_count) {
			debug_scsi("sending more uns\n");
			tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
			goto send_hdr;
1600 1601 1602 1603 1604
		}
	}
	return 0;
}

1605 1606
static int iscsi_send_sol_pdu(struct iscsi_conn *conn,
			      struct iscsi_cmd_task *ctask)
1607
{
1608
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1609 1610 1611
	struct iscsi_session *session = conn->session;
	struct iscsi_r2t_info *r2t;
	struct iscsi_data_task *dtask;
1612
	int left, rc;
1613

1614
	if (tcp_ctask->xmstate & XMSTATE_SOL_HDR_INIT) {
1615 1616
		if (!tcp_ctask->r2t) {
			spin_lock_bh(&session->lock);
1617 1618
			__kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
				    sizeof(void*));
1619 1620
			spin_unlock_bh(&session->lock);
		}
1621 1622 1623
send_hdr:
		r2t = tcp_ctask->r2t;
		dtask = &r2t->dtask;
1624

1625 1626 1627
		if (conn->hdrdgst_en)
			iscsi_hdr_digest(conn, &r2t->headbuf,
					(u8*)dtask->hdrext);
1628 1629 1630 1631 1632 1633 1634 1635
		tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR_INIT;
		tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
	}

	if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
		r2t = tcp_ctask->r2t;
		dtask = &r2t->dtask;

1636
		rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
1637
		if (rc)
1638
			return rc;
1639 1640
		tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
		tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1641 1642

		if (conn->datadgst_en) {
1643 1644
			iscsi_data_digest_init(conn->dd_data, tcp_ctask);
			dtask->digest = 0;
1645 1646
		}

1647 1648 1649 1650
		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);
1651 1652
	}

1653 1654 1655
	if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
		r2t = tcp_ctask->r2t;
		dtask = &r2t->dtask;
1656

1657 1658 1659 1660 1661 1662
		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;
1663

1664 1665 1666 1667 1668 1669 1670 1671 1672 1673
		/*
		 * 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);
			goto send_hdr;
		}
1674

1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687
		/*
		 * 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;
			spin_unlock_bh(&session->lock);
			goto send_hdr;
1688
		}
1689
		spin_unlock_bh(&session->lock);
1690 1691 1692 1693
	}
	return 0;
}

1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733
/**
 * iscsi_tcp_ctask_xmit - xmit normal PDU task
 * @conn: iscsi connection
 * @ctask: iscsi command task
 *
 * Notes:
 *	The function can return -EAGAIN in which case caller must
 *	call it again later, or recover. '0' return code means successful
 *	xmit.
 *	The function is devided to logical helpers (above) for the different
 *	xmit stages.
 *
 *iscsi_send_cmd_hdr()
 *	XMSTATE_CMD_HDR_INIT - prepare Header and Data buffers Calculate
 *	                       Header Digest
 *	XMSTATE_CMD_HDR_XMIT - Transmit header in progress
 *
 *iscsi_send_padding
 *	XMSTATE_W_PAD        - Prepare and send pading
 *	XMSTATE_W_RESEND_PAD - retry send pading
 *
 *iscsi_send_digest
 *	XMSTATE_W_RESEND_DATA_DIGEST - Finalize and send Data Digest
 *	XMSTATE_W_RESEND_DATA_DIGEST - retry sending digest
 *
 *iscsi_send_unsol_hdr
 *	XMSTATE_UNS_INIT     - prepare un-solicit data header and digest
 *	XMSTATE_UNS_HDR      - send un-solicit header
 *
 *iscsi_send_unsol_pdu
 *	XMSTATE_UNS_DATA     - send un-solicit data in progress
 *
 *iscsi_send_sol_pdu
 *	XMSTATE_SOL_HDR_INIT - solicit data header and digest initialize
 *	XMSTATE_SOL_HDR      - send solicit header
 *	XMSTATE_SOL_DATA     - send solicit data
 *
 *iscsi_tcp_ctask_xmit
 *	XMSTATE_IMM_DATA     - xmit managment data (??)
 **/
1734
static int
1735
iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1736
{
1737
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1738 1739 1740
	int rc = 0;

	debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1741
		conn->id, tcp_ctask->xmstate, ctask->itt);
1742

1743 1744 1745 1746 1747
	rc = iscsi_send_cmd_hdr(conn, ctask);
	if (rc)
		return rc;
	if (ctask->sc->sc_data_direction != DMA_TO_DEVICE)
		return 0;
1748

1749
	if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1750 1751 1752
		rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
				     &tcp_ctask->sent, &ctask->imm_count,
				     &tcp_ctask->immbuf, &tcp_ctask->immdigest);
1753 1754
		if (rc)
			return rc;
1755
		tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1756 1757
	}

1758 1759 1760
	rc = iscsi_send_unsol_pdu(conn, ctask);
	if (rc)
		return rc;
1761

1762 1763 1764
	rc = iscsi_send_sol_pdu(conn, ctask);
	if (rc)
		return rc;
1765 1766 1767 1768

	return rc;
}

1769 1770
static struct iscsi_cls_conn *
iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1771
{
1772 1773 1774
	struct iscsi_conn *conn;
	struct iscsi_cls_conn *cls_conn;
	struct iscsi_tcp_conn *tcp_conn;
1775

1776 1777 1778 1779
	cls_conn = iscsi_conn_setup(cls_session, conn_idx);
	if (!cls_conn)
		return NULL;
	conn = cls_conn->dd_data;
1780
	/*
1781 1782
	 * due to strange issues with iser these are not set
	 * in iscsi_conn_setup
1783
	 */
1784
	conn->max_recv_dlength = ISCSI_DEF_MAX_RECV_SEG_LEN;
1785

1786 1787 1788
	tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
	if (!tcp_conn)
		goto tcp_conn_alloc_fail;
1789

1790 1791 1792 1793 1794
	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);
1795

1796 1797 1798
	tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
						  CRYPTO_ALG_ASYNC);
	tcp_conn->tx_hash.flags = 0;
1799 1800 1801 1802 1803
	if (IS_ERR(tcp_conn->tx_hash.tfm)) {
		printk(KERN_ERR "Could not create connection due to crc32c "
		       "loading error %ld. Make sure the crc32c module is "
		       "built as a module or into the kernel\n",
			PTR_ERR(tcp_conn->tx_hash.tfm));
1804
		goto free_tcp_conn;
1805
	}
1806

1807 1808 1809
	tcp_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
						  CRYPTO_ALG_ASYNC);
	tcp_conn->rx_hash.flags = 0;
1810 1811 1812 1813 1814
	if (IS_ERR(tcp_conn->rx_hash.tfm)) {
		printk(KERN_ERR "Could not create connection due to crc32c "
		       "loading error %ld. Make sure the crc32c module is "
		       "built as a module or into the kernel\n",
			PTR_ERR(tcp_conn->rx_hash.tfm));
1815
		goto free_tx_tfm;
1816
	}
1817

1818
	return cls_conn;
1819

1820
free_tx_tfm:
1821
	crypto_free_hash(tcp_conn->tx_hash.tfm);
1822 1823
free_tcp_conn:
	kfree(tcp_conn);
1824 1825 1826
tcp_conn_alloc_fail:
	iscsi_conn_teardown(cls_conn);
	return NULL;
1827 1828
}

1829 1830 1831
static void
iscsi_tcp_release_conn(struct iscsi_conn *conn)
{
1832
	struct iscsi_session *session = conn->session;
1833
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1834
	struct socket *sock = tcp_conn->sock;
1835

1836
	if (!sock)
1837 1838
		return;

1839
	sock_hold(sock->sk);
1840
	iscsi_conn_restore_callbacks(tcp_conn);
1841
	sock_put(sock->sk);
1842

1843
	spin_lock_bh(&session->lock);
1844 1845
	tcp_conn->sock = NULL;
	conn->recv_lock = NULL;
1846 1847
	spin_unlock_bh(&session->lock);
	sockfd_put(sock);
1848 1849
}

1850
static void
1851
iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1852
{
1853 1854
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1855

1856
	iscsi_tcp_release_conn(conn);
1857
	iscsi_conn_teardown(cls_conn);
1858

P
Pete Wyckoff 已提交
1859 1860 1861 1862
	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);
1863

1864 1865
	kfree(tcp_conn);
}
1866

1867 1868 1869 1870
static void
iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
1871
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1872 1873 1874

	iscsi_conn_stop(cls_conn, flag);
	iscsi_tcp_release_conn(conn);
1875
	tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1876 1877
}

1878 1879 1880 1881 1882 1883 1884 1885 1886 1887
static int iscsi_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
			      char *buf, int *port,
			      int (*getname)(struct socket *, struct sockaddr *,
					int *addrlen))
{
	struct sockaddr_storage *addr;
	struct sockaddr_in6 *sin6;
	struct sockaddr_in *sin;
	int rc = 0, len;

1888
	addr = kmalloc(sizeof(*addr), GFP_KERNEL);
1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917
	if (!addr)
		return -ENOMEM;

	if (getname(sock, (struct sockaddr *) addr, &len)) {
		rc = -ENODEV;
		goto free_addr;
	}

	switch (addr->ss_family) {
	case AF_INET:
		sin = (struct sockaddr_in *)addr;
		spin_lock_bh(&conn->session->lock);
		sprintf(buf, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr));
		*port = be16_to_cpu(sin->sin_port);
		spin_unlock_bh(&conn->session->lock);
		break;
	case AF_INET6:
		sin6 = (struct sockaddr_in6 *)addr;
		spin_lock_bh(&conn->session->lock);
		sprintf(buf, NIP6_FMT, NIP6(sin6->sin6_addr));
		*port = be16_to_cpu(sin6->sin6_port);
		spin_unlock_bh(&conn->session->lock);
		break;
	}
free_addr:
	kfree(addr);
	return rc;
}

1918 1919
static int
iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1920
		    struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1921 1922 1923 1924 1925 1926 1927
		    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;
1928

1929
	/* lookup for existing socket */
1930
	sock = sockfd_lookup((int)transport_eph, &err);
1931 1932 1933
	if (!sock) {
		printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
		return -EEXIST;
1934
	}
1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948
	/*
	 * copy these values now because if we drop the session
	 * userspace may still want to query the values since we will
	 * be using them for the reconnect
	 */
	err = iscsi_tcp_get_addr(conn, sock, conn->portal_address,
				 &conn->portal_port, kernel_getpeername);
	if (err)
		goto free_socket;

	err = iscsi_tcp_get_addr(conn, sock, conn->local_address,
				&conn->local_port, kernel_getsockname);
	if (err)
		goto free_socket;
1949

1950 1951
	err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
	if (err)
1952
		goto free_socket;
1953

1954 1955
	/* bind iSCSI connection and socket */
	tcp_conn->sock = sock;
1956

1957 1958 1959 1960 1961
	/* setup Socket parameters */
	sk = sock->sk;
	sk->sk_reuse = 1;
	sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
	sk->sk_allocation = GFP_ATOMIC;
1962

1963
	/* FIXME: disable Nagle's algorithm */
1964

1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975
	/*
	 * 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;
1976
	return 0;
1977 1978 1979 1980

free_socket:
	sockfd_put(sock);
	return err;
1981 1982
}

1983
/* called with host lock */
M
Mike Christie 已提交
1984
static void
1985
iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1986
{
1987
	struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1988
	tcp_mtask->xmstate = XMSTATE_IMM_HDR_INIT;
1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
}

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];
2002
		struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2003 2004 2005 2006 2007 2008 2009 2010

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

		/* R2T pool */
2011 2012 2013
		if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
				    (void***)&tcp_ctask->r2ts,
				    sizeof(struct iscsi_r2t_info))) {
2014 2015 2016 2017
			goto r2t_alloc_fail;
		}

		/* R2T xmit queue */
2018
		tcp_ctask->r2tqueue = kfifo_alloc(
2019
		      session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
2020 2021 2022
		if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
			iscsi_pool_free(&tcp_ctask->r2tpool,
					(void**)tcp_ctask->r2ts);
2023 2024 2025 2026 2027 2028 2029 2030
			goto r2t_alloc_fail;
		}
	}

	return 0;

r2t_alloc_fail:
	for (i = 0; i < cmd_i; i++) {
2031 2032 2033 2034 2035 2036
		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);
2037 2038 2039 2040 2041 2042 2043 2044 2045 2046
	}
	return -ENOMEM;
}

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

	for (i = 0; i < session->cmds_max; i++) {
2047 2048
		struct iscsi_cmd_task *ctask = session->cmds[i];
		struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2049

2050 2051 2052
		kfifo_free(tcp_ctask->r2tqueue);
		iscsi_pool_free(&tcp_ctask->r2tpool,
				(void**)tcp_ctask->r2ts);
2053 2054 2055 2056
	}
}

static int
2057
iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
2058
		     char *buf, int buflen)
2059
{
2060
	struct iscsi_conn *conn = cls_conn->dd_data;
2061
	struct iscsi_session *session = conn->session;
2062
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2063
	int value;
2064 2065 2066

	switch(param) {
	case ISCSI_PARAM_HDRDGST_EN:
2067
		iscsi_set_param(cls_conn, param, buf, buflen);
2068
		tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
2069
		if (conn->hdrdgst_en)
2070
			tcp_conn->hdr_size += sizeof(__u32);
2071 2072
		break;
	case ISCSI_PARAM_DATADGST_EN:
2073
		iscsi_set_param(cls_conn, param, buf, buflen);
2074 2075
		tcp_conn->sendpage = conn->datadgst_en ?
			sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2076 2077
		break;
	case ISCSI_PARAM_MAX_R2T:
2078
		sscanf(buf, "%d", &value);
2079 2080 2081
		if (session->max_r2t == roundup_pow_of_two(value))
			break;
		iscsi_r2tpool_free(session);
2082
		iscsi_set_param(cls_conn, param, buf, buflen);
2083 2084 2085 2086 2087 2088
		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:
2089
		return iscsi_set_param(cls_conn, param, buf, buflen);
2090 2091 2092 2093 2094 2095
	}

	return 0;
}

static int
2096 2097
iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
			 enum iscsi_param param, char *buf)
2098
{
2099
	struct iscsi_conn *conn = cls_conn->dd_data;
2100
	int len;
2101 2102

	switch(param) {
2103
	case ISCSI_PARAM_CONN_PORT:
2104 2105 2106
		spin_lock_bh(&conn->session->lock);
		len = sprintf(buf, "%hu\n", conn->portal_port);
		spin_unlock_bh(&conn->session->lock);
2107
		break;
2108
	case ISCSI_PARAM_CONN_ADDRESS:
2109 2110 2111
		spin_lock_bh(&conn->session->lock);
		len = sprintf(buf, "%s\n", conn->portal_address);
		spin_unlock_bh(&conn->session->lock);
2112 2113
		break;
	default:
2114
		return iscsi_conn_get_param(cls_conn, param, buf);
2115 2116 2117 2118 2119
	}

	return len;
}

2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142
static int
iscsi_tcp_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
			 char *buf)
{
        struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
	int len;

	switch (param) {
	case ISCSI_HOST_PARAM_IPADDRESS:
		spin_lock_bh(&session->lock);
		if (!session->leadconn)
			len = -ENODEV;
		else
			len = sprintf(buf, "%s\n",
				     session->leadconn->local_address);
		spin_unlock_bh(&session->lock);
		break;
	default:
		return iscsi_host_get_param(shost, param, buf);
	}
	return len;
}

2143
static void
2144
iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2145
{
2146
	struct iscsi_conn *conn = cls_conn->dd_data;
2147
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159

	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");
2160
	stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2161
	strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2162
	stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2163 2164 2165 2166
	strcpy(stats->custom[2].desc, "eh_abort_cnt");
	stats->custom[2].value = conn->eh_abort_cnt;
}

2167 2168 2169
static struct iscsi_cls_session *
iscsi_tcp_session_create(struct iscsi_transport *iscsit,
			 struct scsi_transport_template *scsit,
2170
			 uint16_t cmds_max, uint16_t qdepth,
2171
			 uint32_t initial_cmdsn, uint32_t *hostno)
2172
{
2173 2174 2175 2176
	struct iscsi_cls_session *cls_session;
	struct iscsi_session *session;
	uint32_t hn;
	int cmd_i;
2177

2178
	cls_session = iscsi_session_setup(iscsit, scsit, cmds_max, qdepth,
2179 2180 2181 2182 2183 2184
					 sizeof(struct iscsi_tcp_cmd_task),
					 sizeof(struct iscsi_tcp_mgmt_task),
					 initial_cmdsn, &hn);
	if (!cls_session)
		return NULL;
	*hostno = hn;
2185

2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214
	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);
2215 2216
}

2217 2218 2219 2220 2221 2222
static int iscsi_tcp_slave_configure(struct scsi_device *sdev)
{
	blk_queue_dma_alignment(sdev->request_queue, 0);
	return 0;
}

2223
static struct scsi_host_template iscsi_sht = {
2224
	.name			= "iSCSI Initiator over TCP/IP",
2225 2226
	.queuecommand           = iscsi_queuecommand,
	.change_queue_depth	= iscsi_change_queue_depth,
2227
	.can_queue		= ISCSI_DEF_XMIT_CMDS_MAX - 1,
2228
	.sg_tablesize		= ISCSI_SG_TABLESIZE,
2229
	.max_sectors		= 0xFFFF,
2230 2231 2232 2233
	.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,
2234
	.slave_configure        = iscsi_tcp_slave_configure,
2235 2236 2237 2238
	.proc_name		= "iscsi_tcp",
	.this_id		= -1,
};

2239 2240 2241 2242 2243
static struct iscsi_transport iscsi_tcp_transport = {
	.owner			= THIS_MODULE,
	.name			= "tcp",
	.caps			= CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
				  | CAP_DATADGST,
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	.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 |
2257
				  ISCSI_CONN_ADDRESS |
2258 2259 2260
				  ISCSI_EXP_STATSN |
				  ISCSI_PERSISTENT_PORT |
				  ISCSI_PERSISTENT_ADDRESS |
2261 2262 2263
				  ISCSI_TARGET_NAME | ISCSI_TPGT |
				  ISCSI_USERNAME | ISCSI_PASSWORD |
				  ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN,
2264
	.host_param_mask	= ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
2265 2266
				  ISCSI_HOST_INITIATOR_NAME |
				  ISCSI_HOST_NETDEV_NAME,
2267
	.host_template		= &iscsi_sht,
2268
	.conndata_size		= sizeof(struct iscsi_conn),
2269 2270
	.max_conn		= 1,
	.max_cmd_len		= ISCSI_TCP_MAX_CMD_LEN,
2271 2272 2273 2274 2275 2276 2277
	/* 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,
2278
	.set_param		= iscsi_conn_set_param,
2279
	.get_conn_param		= iscsi_tcp_conn_get_param,
2280
	.get_session_param	= iscsi_session_get_param,
2281
	.start_conn		= iscsi_conn_start,
2282
	.stop_conn		= iscsi_tcp_conn_stop,
2283
	/* iscsi host params */
2284
	.get_host_param		= iscsi_tcp_host_get_param,
2285
	.set_host_param		= iscsi_host_set_param,
2286
	/* IO */
2287 2288
	.send_pdu		= iscsi_conn_send_pdu,
	.get_stats		= iscsi_conn_get_stats,
2289 2290 2291 2292 2293 2294
	.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
2295
	.session_recovery_timedout = iscsi_session_recovery_timedout,
2296 2297 2298 2299 2300 2301
};

static int __init
iscsi_tcp_init(void)
{
	if (iscsi_max_lun < 1) {
O
Or Gerlitz 已提交
2302 2303
		printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
		       iscsi_max_lun);
2304 2305 2306 2307
		return -EINVAL;
	}
	iscsi_tcp_transport.max_lun = iscsi_max_lun;

2308
	if (!iscsi_register_transport(&iscsi_tcp_transport))
2309
		return -ENODEV;
2310

2311
	return 0;
2312 2313 2314 2315 2316 2317 2318 2319 2320 2321
}

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

module_init(iscsi_tcp_init);
module_exit(iscsi_tcp_exit);