/*
* iSCSI Initiator over TCP/IP Data-Path
*
* Copyright (C) 2004 Dmitry Yusupov
* Copyright (C) 2004 Alex Aizman
* Copyright (C) 2005 - 2006 Mike Christie
* Copyright (C) 2006 Red Hat, Inc. All rights reserved.
* 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>
#include <linux/mutex.h>
#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"
#define ISCSI_TCP_VERSION "1.0-595"
MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
"Alex Aizman <itn780@yahoo.com>");
MODULE_DESCRIPTION("iSCSI/TCP data-path");
MODULE_LICENSE("GPL");
MODULE_VERSION(ISCSI_TCP_VERSION);
/* #define DEBUG_TCP */
#define DEBUG_ASSERT
#ifdef DEBUG_TCP
#define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
#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)
{
ibuf->sg.page = virt_to_page(vbuf);
ibuf->sg.offset = offset_in_page(vbuf);
ibuf->sg.length = size;
ibuf->sent = 0;
ibuf->use_sendmsg = 1;
}
static inline void
iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
{
ibuf->sg.page = sg->page;
ibuf->sg.offset = sg->offset;
ibuf->sg.length = sg->length;
/*
* Fastpath: sg element fits into single page
*/
if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg->page))
ibuf->use_sendmsg = 0;
else
ibuf->use_sendmsg = 1;
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
iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
u8* crc)
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
crypto_digest_digest(tcp_conn->tx_tfm, &buf->sg, 1, crc);
buf->sg.length += sizeof(uint32_t);
}
static inline int
iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
{
struct sk_buff *skb = tcp_conn->in.skb;
tcp_conn->in.zero_copy_hdr = 0;
if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
/*
* Zero-copy PDU Header: using connection context
* to store header pointer.
*/
if (skb_shinfo(skb)->frag_list == NULL &&
!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 {
/* ignoring return code since we checked
* in.copy before */
skb_copy_bits(skb, tcp_conn->in.offset,
&tcp_conn->hdr, tcp_conn->hdr_size);
tcp_conn->in.hdr = &tcp_conn->hdr;
}
tcp_conn->in.offset += tcp_conn->hdr_size;
tcp_conn->in.copy -= tcp_conn->hdr_size;
} else {
int hdr_remains;
int copylen;
/*
* PDU header scattered across SKB's,
* copying it... This'll happen quite rarely.
*/
if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
tcp_conn->in.hdr_offset = 0;
hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
BUG_ON(hdr_remains <= 0);
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);
debug_tcp("PDU gather offset %d bytes %d in.offset %d "
"in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
tcp_conn->in.offset, tcp_conn->in.copy);
tcp_conn->in.offset += copylen;
tcp_conn->in.copy -= copylen;
if (copylen < hdr_remains) {
tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
tcp_conn->in.hdr_offset += copylen;
return -EAGAIN;
}
tcp_conn->in.hdr = &tcp_conn->hdr;
tcp_conn->discontiguous_hdr_cnt++;
tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
}
return 0;
}
/*
* must be called with session lock
*/
static void
__iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
struct scsi_cmnd *sc;
sc = ctask->sc;
if (unlikely(!sc))
return;
tcp_ctask->xmstate = XMSTATE_IDLE;
tcp_ctask->r2t = NULL;
}
/**
* 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;
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;
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..)
*/
ctask->data_count = tcp_conn->in.datalen;
if (tcp_conn->in.datalen == 0)
return 0;
if (ctask->datasn != datasn)
return ISCSI_ERR_DATASN;
ctask->datasn++;
tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
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;
if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
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;
} else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
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;
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
hdr = &r2t->dtask.hdr;
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;
memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
hdr->itt = ctask->hdr->itt;
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;
iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
sizeof(struct iscsi_hdr));
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);
} else
iscsi_buf_init_iov(&tcp_ctask->sendbuf,
(char*)sc->request_buffer + r2t->data_offset,
r2t->data_count);
}
/**
* 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;
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;
int r2tsn = be32_to_cpu(rhdr->r2tsn);
int rc;
if (tcp_conn->in.datalen)
return ISCSI_ERR_DATALEN;
if (tcp_ctask->exp_r2tsn && tcp_ctask->exp_r2tsn != r2tsn)
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;
}
rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
BUG_ON(!rc);
r2t->exp_statsn = rhdr->statsn;
r2t->data_length = be32_to_cpu(rhdr->data_length);
if (r2t->data_length == 0 ||
r2t->data_length > session->max_burst) {
spin_unlock(&session->lock);
return ISCSI_ERR_DATALEN;
}
r2t->data_offset = be32_to_cpu(rhdr->data_offset);
if (r2t->data_offset + r2t->data_length > ctask->total_length) {
spin_unlock(&session->lock);
return ISCSI_ERR_DATALEN;
}
r2t->ttt = rhdr->ttt; /* no flip */
r2t->solicit_datasn = 0;
iscsi_solicit_data_init(conn, ctask, r2t);
tcp_ctask->exp_r2tsn = r2tsn + 1;
tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
__kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
__kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
scsi_queue_work(session->host, &conn->xmitwork);
conn->r2t_pdus_cnt++;
spin_unlock(&session->lock);
return 0;
}
static int
iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
{
int rc = 0, opcode, ahslen;
struct iscsi_hdr *hdr;
struct iscsi_session *session = conn->session;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
uint32_t cdgst, rdgst = 0, itt;
hdr = tcp_conn->in.hdr;
/* verify PDU length */
tcp_conn->in.datalen = ntoh24(hdr->dlength);
if (tcp_conn->in.datalen > conn->max_recv_dlength) {
printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
tcp_conn->in.datalen, conn->max_recv_dlength);
return ISCSI_ERR_DATALEN;
}
tcp_conn->data_copied = 0;
/* read AHS */
ahslen = hdr->hlength << 2;
tcp_conn->in.offset += ahslen;
tcp_conn->in.copy -= ahslen;
if (tcp_conn->in.copy < 0) {
printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
"%d bytes\n", ahslen);
return ISCSI_ERR_AHSLEN;
}
/* calculate read padding */
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);
}
if (conn->hdrdgst_en) {
struct scatterlist sg;
sg_init_one(&sg, (u8 *)hdr,
sizeof(struct iscsi_hdr) + ahslen);
crypto_digest_digest(tcp_conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
ahslen);
if (cdgst != rdgst) {
printk(KERN_ERR "iscsi_tcp: hdrdgst error "
"recv 0x%x calc 0x%x\n", rdgst, cdgst);
return ISCSI_ERR_HDR_DGST;
}
}
opcode = hdr->opcode & ISCSI_OPCODE_MASK;
/* verify itt (itt encoding: age+cid+itt) */
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;
debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
opcode, tcp_conn->in.offset, tcp_conn->in.copy,
ahslen, tcp_conn->in.datalen);
switch(opcode) {
case ISCSI_OP_SCSI_DATA_IN:
tcp_conn->in.ctask = session->cmds[itt];
rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
/* fall through */
case ISCSI_OP_SCSI_CMD_RSP:
tcp_conn->in.ctask = session->cmds[itt];
if (tcp_conn->in.datalen)
goto copy_hdr;
spin_lock(&session->lock);
__iscsi_ctask_cleanup(conn, tcp_conn->in.ctask);
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_LOGOUT_RSP:
case ISCSI_OP_NOOP_IN:
case ISCSI_OP_REJECT:
case ISCSI_OP_ASYNC_EVENT:
if (tcp_conn->in.datalen)
goto copy_hdr;
/* fall through */
case ISCSI_OP_SCSI_TMFUNC_RSP:
rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
break;
default:
rc = ISCSI_ERR_BAD_OPCODE;
break;
}
return rc;
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
*/
if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <
(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;
}
/**
* iscsi_ctask_copy - copy skb bits to the destanation cmd task
* @conn: iscsi tcp connection
* @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
iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
void *buf, int buf_size, int offset)
{
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);
int rc;
size = min(size, ctask->data_count);
debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
size, tcp_conn->in.offset, tcp_conn->in.copied);
BUG_ON(size <= 0);
BUG_ON(tcp_ctask->sent + size > ctask->total_length);
rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
(char*)buf + (offset + tcp_conn->data_copied), size);
/* must fit into skb->len */
BUG_ON(rc);
tcp_conn->in.offset += size;
tcp_conn->in.copy -= size;
tcp_conn->in.copied += size;
tcp_conn->data_copied += size;
tcp_ctask->sent += size;
ctask->data_count -= size;
BUG_ON(tcp_conn->in.copy < 0);
BUG_ON(ctask->data_count < 0);
if (buf_size != (tcp_conn->data_copied + offset)) {
if (!ctask->data_count) {
BUG_ON(buf_size - tcp_conn->data_copied < 0);
/* done with this PDU */
return buf_size - tcp_conn->data_copied;
}
return -EAGAIN;
}
/* done with this buffer or with both - PDU and buffer */
tcp_conn->data_copied = 0;
return 0;
}
/**
* iscsi_tcp_copy - copy skb bits to the destanation buffer
* @conn: iscsi tcp connection
*
* Notes:
* The function calls skb_copy_bits() and updates per-connection
* byte counters.
**/
static inline int
iscsi_tcp_copy(struct iscsi_tcp_conn *tcp_conn)
{
void *buf = tcp_conn->data;
int buf_size = tcp_conn->in.datalen;
int buf_left = buf_size - tcp_conn->data_copied;
int size = min(tcp_conn->in.copy, buf_left);
int rc;
debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
size, tcp_conn->in.offset, tcp_conn->data_copied);
BUG_ON(size <= 0);
rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
(char*)buf + tcp_conn->data_copied, size);
BUG_ON(rc);
tcp_conn->in.offset += size;
tcp_conn->in.copy -= size;
tcp_conn->in.copied += size;
tcp_conn->data_copied += size;
if (buf_size != tcp_conn->data_copied)
return -EAGAIN;
return 0;
}
static inline void
partial_sg_digest_update(struct iscsi_tcp_conn *tcp_conn,
struct scatterlist *sg, int offset, int length)
{
struct scatterlist temp;
memcpy(&temp, sg, sizeof(struct scatterlist));
temp.offset = offset;
temp.length = length;
crypto_digest_update(tcp_conn->data_rx_tfm, &temp, 1);
}
static void
iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
{
struct scatterlist tmp;
sg_init_one(&tmp, buf, len);
crypto_digest_update(tcp_conn->data_rx_tfm, &tmp, 1);
}
static int iscsi_scsi_data_in(struct iscsi_conn *conn)
{
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;
struct scsi_cmnd *sc = ctask->sc;
struct scatterlist *sg;
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;
rc = iscsi_ctask_copy(tcp_conn, ctask, sc->request_buffer,
sc->request_bufflen,
tcp_ctask->data_offset);
if (rc == -EAGAIN)
return rc;
if (conn->datadgst_en)
iscsi_recv_digest_update(tcp_conn, sc->request_buffer,
i);
rc = 0;
goto done;
}
offset = tcp_ctask->data_offset;
sg = sc->request_buffer;
if (tcp_ctask->data_offset)
for (i = 0; i < tcp_ctask->sg_count; i++)
offset -= sg[i].length;
/* we've passed through partial sg*/
if (offset < 0)
offset = 0;
for (i = tcp_ctask->sg_count; i < sc->use_sg; i++) {
char *dest;
dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
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)
crypto_digest_update(
tcp_conn->data_rx_tfm,
&sg[i], 1);
else
partial_sg_digest_update(tcp_conn,
&sg[i],
sg[i].offset + offset,
sg[i].length - offset);
}
offset = 0;
tcp_ctask->sg_count++;
}
if (!ctask->data_count) {
if (rc && conn->datadgst_en)
/*
* data-in is complete, but buffer not...
*/
partial_sg_digest_update(tcp_conn, &sg[i],
sg[i].offset, sg[i].length-rc);
rc = 0;
break;
}
if (!tcp_conn->in.copy)
return -EAGAIN;
}
BUG_ON(ctask->data_count);
done:
/* check for non-exceptional status */
if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
debug_scsi("done [sc %lx res %d itt 0x%x]\n",
(long)sc, sc->result, ctask->itt);
spin_lock(&conn->session->lock);
__iscsi_ctask_cleanup(conn, ctask);
__iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
spin_unlock(&conn->session->lock);
}
return rc;
}
static int
iscsi_data_recv(struct iscsi_conn *conn)
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
int rc = 0, opcode;
opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
switch (opcode) {
case ISCSI_OP_SCSI_DATA_IN:
rc = iscsi_scsi_data_in(conn);
break;
case ISCSI_OP_SCSI_CMD_RSP:
spin_lock(&conn->session->lock);
__iscsi_ctask_cleanup(conn, tcp_conn->in.ctask);
spin_unlock(&conn->session->lock);
case ISCSI_OP_TEXT_RSP:
case ISCSI_OP_LOGIN_RSP:
case ISCSI_OP_NOOP_IN:
case ISCSI_OP_ASYNC_EVENT:
case ISCSI_OP_REJECT:
/*
* Collect data segment to the connection's data
* placeholder
*/
if (iscsi_tcp_copy(tcp_conn)) {
rc = -EAGAIN;
goto exit;
}
rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, tcp_conn->data,
tcp_conn->in.datalen);
if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
iscsi_recv_digest_update(tcp_conn, tcp_conn->data,
tcp_conn->in.datalen);
break;
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;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
int processed;
char pad[ISCSI_PAD_LEN];
struct scatterlist sg;
/*
* Save current SKB and its offset in the corresponding
* connection context.
*/
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);
more:
tcp_conn->in.copied = 0;
rc = 0;
if (unlikely(conn->suspend_rx)) {
debug_tcp("conn %d Rx suspended!\n", conn->id);
return 0;
}
if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
rc = iscsi_hdr_extract(tcp_conn);
if (rc) {
if (rc == -EAGAIN)
goto nomore;
else {
iscsi_conn_failure(conn, rc);
return 0;
}
}
/*
* Verify and process incoming PDU header.
*/
rc = iscsi_tcp_hdr_recv(conn);
if (!rc && tcp_conn->in.datalen) {
if (conn->datadgst_en) {
BUG_ON(!tcp_conn->data_rx_tfm);
crypto_digest_init(tcp_conn->data_rx_tfm);
}
tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
} else if (rc) {
iscsi_conn_failure(conn, rc);
return 0;
}
}
if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
uint32_t recv_digest;
debug_tcp("extra data_recv offset %d copy %d\n",
tcp_conn->in.offset, tcp_conn->in.copy);
skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
&recv_digest, 4);
tcp_conn->in.offset += 4;
tcp_conn->in.copy -= 4;
if (recv_digest != tcp_conn->in.datadgst) {
debug_tcp("iscsi_tcp: data digest error!"
"0x%x != 0x%x\n", recv_digest,
tcp_conn->in.datadgst);
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,
tcp_conn->in.datadgst);
tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
}
}
if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
tcp_conn->in.copy) {
debug_tcp("data_recv offset %d copy %d\n",
tcp_conn->in.offset, tcp_conn->in.copy);
rc = iscsi_data_recv(conn);
if (rc) {
if (rc == -EAGAIN)
goto again;
iscsi_conn_failure(conn, rc);
return 0;
}
tcp_conn->in.copy -= tcp_conn->in.padding;
tcp_conn->in.offset += tcp_conn->in.padding;
if (conn->datadgst_en) {
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_digest_update(tcp_conn->data_rx_tfm,
&sg, 1);
}
crypto_digest_final(tcp_conn->data_rx_tfm,
(u8 *) & tcp_conn->in.datadgst);
debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
} else
tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
}
debug_tcp("f, processed %d from out of %d padding %d\n",
tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
BUG_ON(tcp_conn->in.offset - offset > len);
if (tcp_conn->in.offset - offset != len) {
debug_tcp("continue to process %d bytes\n",
(int)len - (tcp_conn->in.offset - offset));
goto more;
}
nomore:
processed = tcp_conn->in.offset - offset;
BUG_ON(processed == 0);
return processed;
again:
processed = tcp_conn->in.offset - offset;
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);
/*
* 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.
*/
rd_desc.arg.data = conn;
rd_desc.count = 1;
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)
{
struct iscsi_tcp_conn *tcp_conn;
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;
if ((sk->sk_state == TCP_CLOSE_WAIT ||
sk->sk_state == TCP_CLOSE) &&
!atomic_read(&sk->sk_rmem_alloc)) {
debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
}
tcp_conn = conn->dd_data;
old_state_change = tcp_conn->old_state_change;
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;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
tcp_conn->old_write_space(sk);
debug_tcp("iscsi_write_space: cid %d\n", conn->id);
scsi_queue_work(conn->session->host, &conn->xmitwork);
}
static void
iscsi_conn_set_callbacks(struct iscsi_conn *conn)
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct sock *sk = tcp_conn->sock->sk;
/* assign new callbacks */
write_lock_bh(&sk->sk_callback_lock);
sk->sk_user_data = conn;
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;
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
iscsi_conn_restore_callbacks(struct iscsi_conn *conn)
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct sock *sk = tcp_conn->sock->sk;
/* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
write_lock_bh(&sk->sk_callback_lock);
sk->sk_user_data = NULL;
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;
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
iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct socket *sk = tcp_conn->sock;
int offset = buf->sg.offset + buf->sent, res;
/*
* 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)
res = sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
else
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;
}
/**
* 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;
res = iscsi_send(conn, buf, size, flags);
debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
if (res >= 0) {
if (size != res)
return -EAGAIN;
return 0;
}
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;
if (buf->sent + size != buf->sg.length || *count != size)
flags |= MSG_MORE;
res = iscsi_send(conn, buf, size, flags);
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;
}
return res;
}
static inline void
iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
struct iscsi_cmd_task *ctask)
{
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
BUG_ON(!tcp_conn->data_tx_tfm);
crypto_digest_init(tcp_conn->data_tx_tfm);
tcp_ctask->digest_count = 4;
}
static int
iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
struct iscsi_buf *buf, uint32_t *digest, int final)
{
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
int rc = 0;
int sent = 0;
if (final)
crypto_digest_final(tcp_conn->data_tx_tfm, (u8*)digest);
iscsi_buf_init_iov(buf, (char*)digest, 4);
rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
if (rc) {
tcp_ctask->datadigest = *digest;
tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
} else
tcp_ctask->digest_count = 4;
return rc;
}
/**
* 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_tcp_cmd_task *tcp_ctask = ctask->dd_data;
struct iscsi_data *hdr;
struct scsi_cmnd *sc = ctask->sc;
int new_offset;
hdr = &r2t->dtask.hdr;
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;
memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
hdr->itt = ctask->hdr->itt;
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++;
iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
sizeof(struct iscsi_hdr));
if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
BUG_ON(tcp_ctask->bad_sg == r2t->sg);
iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
r2t->sg += 1;
} else
iscsi_buf_init_iov(&tcp_ctask->sendbuf,
(char*)sc->request_buffer + new_offset,
r2t->data_count);
}
static void
iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
struct iscsi_data_task *dtask;
dtask = tcp_ctask->dtask = &tcp_ctask->unsol_dtask;
iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr,
tcp_ctask->r2t_data_count);
iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
sizeof(struct iscsi_hdr));
}
/**
* iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
* @conn: iscsi connection
* @ctask: scsi command task
* @sc: scsi command
**/
static void
iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
{
struct scsi_cmnd *sc = ctask->sc;
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
tcp_ctask->sent = 0;
tcp_ctask->sg_count = 0;
if (sc->sc_data_direction == DMA_TO_DEVICE) {
tcp_ctask->xmstate = XMSTATE_W_HDR;
tcp_ctask->exp_r2tsn = 0;
BUG_ON(ctask->total_length == 0);
if (sc->use_sg) {
struct scatterlist *sg = sc->request_buffer;
iscsi_buf_init_sg(&tcp_ctask->sendbuf,
&sg[tcp_ctask->sg_count++]);
tcp_ctask->sg = sg;
tcp_ctask->bad_sg = sg + sc->use_sg;
} else
iscsi_buf_init_iov(&tcp_ctask->sendbuf,
sc->request_buffer,
sc->request_bufflen);
if (ctask->imm_count)
tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
tcp_ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
if (tcp_ctask->pad_count) {
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;
}
if (ctask->unsol_count)
tcp_ctask->xmstate |= XMSTATE_UNS_HDR |
XMSTATE_UNS_INIT;
tcp_ctask->r2t_data_count = ctask->total_length -
ctask->imm_count -
ctask->unsol_count;
debug_scsi("cmd [itt %x total %d imm %d imm_data %d "
"r2t_data %d]\n",
ctask->itt, ctask->total_length, ctask->imm_count,
ctask->unsol_count, tcp_ctask->r2t_data_count);
} else
tcp_ctask->xmstate = XMSTATE_R_HDR;
iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
sizeof(struct iscsi_hdr));
}
/**