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android-kvm / linux / 63c62f1cb980241513c82cacd5b9f878527c6647 / . / drivers / scsi / iscsi_tcp.c
blob: 464de780d95331aebb80f2a84f809fa4d8d7adb4 [file] [log] [blame]
/*
* 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/file.h>
#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>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi.h>
#include <scsi/scsi_transport_iscsi.h>
#include "iscsi_tcp.h"
MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
"Alex Aizman <itn780@yahoo.com>");
MODULE_DESCRIPTION("iSCSI/TCP data-path");
MODULE_LICENSE("GPL");
#undef 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 struct scsi_transport_template *iscsi_tcp_scsi_transport;
static struct scsi_host_template iscsi_sht;
static struct iscsi_transport iscsi_tcp_transport;
static unsigned int iscsi_max_lun = 512;
module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
static int iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn,
struct iscsi_segment *segment);
/*
* Scatterlist handling: inside the iscsi_segment, we
* remember an index into the scatterlist, and set data/size
* to the current scatterlist entry. For highmem pages, we
* kmap as needed.
*
* Note that the page is unmapped when we return from
* TCP's data_ready handler, so we may end up mapping and
* unmapping the same page repeatedly. The whole reason
* for this is that we shouldn't keep the page mapped
* outside the softirq.
*/
/**
* iscsi_tcp_segment_init_sg - init indicated scatterlist entry
* @segment: the buffer object
* @sg: scatterlist
* @offset: byte offset into that sg entry
*
* This function sets up the segment so that subsequent
* data is copied to the indicated sg entry, at the given
* offset.
*/
static inline void
iscsi_tcp_segment_init_sg(struct iscsi_segment *segment,
struct scatterlist *sg, unsigned int offset)
{
segment->sg = sg;
segment->sg_offset = offset;
segment->size = min(sg->length - offset,
segment->total_size - segment->total_copied);
segment->data = NULL;
}
/**
* iscsi_tcp_segment_map - map the current S/G page
* @segment: iscsi_segment
* @recv: 1 if called from recv path
*
* We only need to possibly kmap data if scatter lists are being used,
* because the iscsi passthrough and internal IO paths will never use high
* mem pages.
*/
static inline void
iscsi_tcp_segment_map(struct iscsi_segment *segment, int recv)
{
struct scatterlist *sg;
if (segment->data != NULL || !segment->sg)
return;
sg = segment->sg;
BUG_ON(segment->sg_mapped);
BUG_ON(sg->length == 0);
/*
* If the page count is greater than one it is ok to send
* to the network layer's zero copy send path. If not we
* have to go the slow sendmsg path. We always map for the
* recv path.
*/
if (page_count(sg_page(sg)) >= 1 && !recv)
return;
debug_tcp("iscsi_tcp_segment_map %s %p\n", recv ? "recv" : "xmit",
segment);
segment->sg_mapped = kmap_atomic(sg_page(sg), KM_SOFTIRQ0);
segment->data = segment->sg_mapped + sg->offset + segment->sg_offset;
}
static inline void
iscsi_tcp_segment_unmap(struct iscsi_segment *segment)
{
debug_tcp("iscsi_tcp_segment_unmap %p\n", segment);
if (segment->sg_mapped) {
debug_tcp("iscsi_tcp_segment_unmap valid\n");
kunmap_atomic(segment->sg_mapped, KM_SOFTIRQ0);
segment->sg_mapped = NULL;
segment->data = NULL;
}
}
/*
* Splice the digest buffer into the buffer
*/
static inline void
iscsi_tcp_segment_splice_digest(struct iscsi_segment *segment, void *digest)
{
segment->data = digest;
segment->digest_len = ISCSI_DIGEST_SIZE;
segment->total_size += ISCSI_DIGEST_SIZE;
segment->size = ISCSI_DIGEST_SIZE;
segment->copied = 0;
segment->sg = NULL;
segment->hash = NULL;
}
/**
* iscsi_tcp_segment_done - check whether the segment is complete
* @segment: iscsi segment to check
* @recv: set to one of this is called from the recv path
* @copied: number of bytes copied
*
* Check if we're done receiving this segment. If the receive
* buffer is full but we expect more data, move on to the
* next entry in the scatterlist.
*
* If the amount of data we received isn't a multiple of 4,
* we will transparently receive the pad bytes, too.
*
* This function must be re-entrant.
*/
static inline int
iscsi_tcp_segment_done(struct iscsi_segment *segment, int recv, unsigned copied)
{
static unsigned char padbuf[ISCSI_PAD_LEN];
struct scatterlist sg;
unsigned int pad;
debug_tcp("copied %u %u size %u %s\n", segment->copied, copied,
segment->size, recv ? "recv" : "xmit");
if (segment->hash && copied) {
/*
* If a segment is kmapd we must unmap it before sending
* to the crypto layer since that will try to kmap it again.
*/
iscsi_tcp_segment_unmap(segment);
if (!segment->data) {
sg_init_table(&sg, 1);
sg_set_page(&sg, sg_page(segment->sg), copied,
segment->copied + segment->sg_offset +
segment->sg->offset);
} else
sg_init_one(&sg, segment->data + segment->copied,
copied);
crypto_hash_update(segment->hash, &sg, copied);
}
segment->copied += copied;
if (segment->copied < segment->size) {
iscsi_tcp_segment_map(segment, recv);
return 0;
}
segment->total_copied += segment->copied;
segment->copied = 0;
segment->size = 0;
/* Unmap the current scatterlist page, if there is one. */
iscsi_tcp_segment_unmap(segment);
/* Do we have more scatterlist entries? */
debug_tcp("total copied %u total size %u\n", segment->total_copied,
segment->total_size);
if (segment->total_copied < segment->total_size) {
/* Proceed to the next entry in the scatterlist. */
iscsi_tcp_segment_init_sg(segment, sg_next(segment->sg),
0);
iscsi_tcp_segment_map(segment, recv);
BUG_ON(segment->size == 0);
return 0;
}
/* Do we need to handle padding? */
pad = iscsi_padding(segment->total_copied);
if (pad != 0) {
debug_tcp("consume %d pad bytes\n", pad);
segment->total_size += pad;
segment->size = pad;
segment->data = padbuf;
return 0;
}
/*
* Set us up for transferring the data digest. hdr digest
* is completely handled in hdr done function.
*/
if (segment->hash) {
crypto_hash_final(segment->hash, segment->digest);
iscsi_tcp_segment_splice_digest(segment,
recv ? segment->recv_digest : segment->digest);
return 0;
}
return 1;
}
/**
* iscsi_tcp_xmit_segment - transmit segment
* @tcp_conn: the iSCSI TCP connection
* @segment: the buffer to transmnit
*
* This function transmits as much of the buffer as
* the network layer will accept, and returns the number of
* bytes transmitted.
*
* If CRC hashing is enabled, the function will compute the
* hash as it goes. When the entire segment has been transmitted,
* it will retrieve the hash value and send it as well.
*/
static int
iscsi_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
struct iscsi_segment *segment)
{
struct socket *sk = tcp_conn->sock;
unsigned int copied = 0;
int r = 0;
while (!iscsi_tcp_segment_done(segment, 0, r)) {
struct scatterlist *sg;
unsigned int offset, copy;
int flags = 0;
r = 0;
offset = segment->copied;
copy = segment->size - offset;
if (segment->total_copied + segment->size < segment->total_size)
flags |= MSG_MORE;
/* Use sendpage if we can; else fall back to sendmsg */
if (!segment->data) {
sg = segment->sg;
offset += segment->sg_offset + sg->offset;
r = tcp_conn->sendpage(sk, sg_page(sg), offset, copy,
flags);
} else {
struct msghdr msg = { .msg_flags = flags };
struct kvec iov = {
.iov_base = segment->data + offset,
.iov_len = copy
};
r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
}
if (r < 0) {
iscsi_tcp_segment_unmap(segment);
if (copied || r == -EAGAIN)
break;
return r;
}
copied += r;
}
return copied;
}
/**
* iscsi_tcp_segment_recv - copy data to segment
* @tcp_conn: the iSCSI TCP connection
* @segment: the buffer to copy to
* @ptr: data pointer
* @len: amount of data available
*
* This function copies up to @len bytes to the
* given buffer, and returns the number of bytes
* consumed, which can actually be less than @len.
*
* If hash digest is enabled, the function will update the
* hash while copying.
* Combining these two operations doesn't buy us a lot (yet),
* but in the future we could implement combined copy+crc,
* just way we do for network layer checksums.
*/
static int
iscsi_tcp_segment_recv(struct iscsi_tcp_conn *tcp_conn,
struct iscsi_segment *segment, const void *ptr,
unsigned int len)
{
unsigned int copy = 0, copied = 0;
while (!iscsi_tcp_segment_done(segment, 1, copy)) {
if (copied == len) {
debug_tcp("iscsi_tcp_segment_recv copied %d bytes\n",
len);
break;
}
copy = min(len - copied, segment->size - segment->copied);
debug_tcp("iscsi_tcp_segment_recv copying %d\n", copy);
memcpy(segment->data + segment->copied, ptr + copied, copy);
copied += copy;
}
return copied;
}
static inline void
iscsi_tcp_dgst_header(struct hash_desc *hash, const void *hdr, size_t hdrlen,
unsigned char digest[ISCSI_DIGEST_SIZE])
{
struct scatterlist sg;
sg_init_one(&sg, hdr, hdrlen);
crypto_hash_digest(hash, &sg, hdrlen, digest);
}
static inline int
iscsi_tcp_dgst_verify(struct iscsi_tcp_conn *tcp_conn,
struct iscsi_segment *segment)
{
if (!segment->digest_len)
return 1;
if (memcmp(segment->recv_digest, segment->digest,
segment->digest_len)) {
debug_scsi("digest mismatch\n");
return 0;
}
return 1;
}
/*
* Helper function to set up segment buffer
*/
static inline void
__iscsi_segment_init(struct iscsi_segment *segment, size_t size,
iscsi_segment_done_fn_t *done, struct hash_desc *hash)
{
memset(segment, 0, sizeof(*segment));
segment->total_size = size;
segment->done = done;
if (hash) {
segment->hash = hash;
crypto_hash_init(hash);
}
}
static inline void
iscsi_segment_init_linear(struct iscsi_segment *segment, void *data,
size_t size, iscsi_segment_done_fn_t *done,
struct hash_desc *hash)
{
__iscsi_segment_init(segment, size, done, hash);
segment->data = data;
segment->size = size;
}
static inline int
iscsi_segment_seek_sg(struct iscsi_segment *segment,
struct scatterlist *sg_list, unsigned int sg_count,
unsigned int offset, size_t size,
iscsi_segment_done_fn_t *done, struct hash_desc *hash)
{
struct scatterlist *sg;
unsigned int i;
debug_scsi("iscsi_segment_seek_sg offset %u size %llu\n",
offset, size);
__iscsi_segment_init(segment, size, done, hash);
for_each_sg(sg_list, sg, sg_count, i) {
debug_scsi("sg %d, len %u offset %u\n", i, sg->length,
sg->offset);
if (offset < sg->length) {
iscsi_tcp_segment_init_sg(segment, sg, offset);
return 0;
}
offset -= sg->length;
}
return ISCSI_ERR_DATA_OFFSET;
}
/**
* iscsi_tcp_hdr_recv_prep - prep segment for hdr reception
* @tcp_conn: iscsi connection to prep for
*
* This function always passes NULL for the hash argument, because when this
* function is called we do not yet know the final size of the header and want
* to delay the digest processing until we know that.
*/
static void
iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn)
{
debug_tcp("iscsi_tcp_hdr_recv_prep(%p%s)\n", tcp_conn,
tcp_conn->iscsi_conn->hdrdgst_en ? ", digest enabled" : "");
iscsi_segment_init_linear(&tcp_conn->in.segment,
tcp_conn->in.hdr_buf, sizeof(struct iscsi_hdr),
iscsi_tcp_hdr_recv_done, NULL);
}
/*
* Handle incoming reply to any other type of command
*/
static int
iscsi_tcp_data_recv_done(struct iscsi_tcp_conn *tcp_conn,
struct iscsi_segment *segment)
{
struct iscsi_conn *conn = tcp_conn->iscsi_conn;
int rc = 0;
if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
return ISCSI_ERR_DATA_DGST;
rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr,
conn->data, tcp_conn->in.datalen);
if (rc)
return rc;
iscsi_tcp_hdr_recv_prep(tcp_conn);
return 0;
}
static void
iscsi_tcp_data_recv_prep(struct iscsi_tcp_conn *tcp_conn)
{
struct iscsi_conn *conn = tcp_conn->iscsi_conn;
struct hash_desc *rx_hash = NULL;
if (conn->datadgst_en &
!(conn->session->tt->caps & CAP_DIGEST_OFFLOAD))
rx_hash = &tcp_conn->rx_hash;
iscsi_segment_init_linear(&tcp_conn->in.segment,
conn->data, tcp_conn->in.datalen,
iscsi_tcp_data_recv_done, rx_hash);
}
/*
* must be called with session lock
*/
static void
iscsi_tcp_cleanup_task(struct iscsi_conn *conn, struct iscsi_task *task)
{
struct iscsi_tcp_task *tcp_task = task->dd_data;
struct iscsi_r2t_info *r2t;
/* nothing to do for mgmt tasks */
if (!task->sc)
return;
/* flush task's r2t queues */
while (__kfifo_get(tcp_task->r2tqueue, (void*)&r2t, sizeof(void*))) {
__kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t,
sizeof(void*));
debug_scsi("iscsi_tcp_cleanup_task pending r2t dropped\n");
}
r2t = tcp_task->r2t;
if (r2t != NULL) {
__kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t,
sizeof(void*));
tcp_task->r2t = NULL;
}
}
/**
* iscsi_data_in - SCSI Data-In Response processing
* @conn: iscsi connection
* @task: scsi command task
**/
static int
iscsi_data_in(struct iscsi_conn *conn, struct iscsi_task *task)
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct iscsi_tcp_task *tcp_task = task->dd_data;
struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
int datasn = be32_to_cpu(rhdr->datasn);
unsigned total_in_length = scsi_in(task->sc)->length;
iscsi_update_cmdsn(conn->session, (struct iscsi_nopin*)rhdr);
if (tcp_conn->in.datalen == 0)
return 0;
if (tcp_task->exp_datasn != datasn) {
debug_tcp("%s: task->exp_datasn(%d) != rhdr->datasn(%d)\n",
__func__, tcp_task->exp_datasn, datasn);
return ISCSI_ERR_DATASN;
}
tcp_task->exp_datasn++;
tcp_task->data_offset = be32_to_cpu(rhdr->offset);
if (tcp_task->data_offset + tcp_conn->in.datalen > total_in_length) {
debug_tcp("%s: data_offset(%d) + data_len(%d) > total_length_in(%d)\n",
__func__, tcp_task->data_offset,
tcp_conn->in.datalen, total_in_length);
return ISCSI_ERR_DATA_OFFSET;
}
conn->datain_pdus_cnt++;
return 0;
}
/**
* iscsi_solicit_data_init - initialize first Data-Out
* @conn: iscsi connection
* @task: 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_task *task,
struct iscsi_r2t_info *r2t)
{
struct iscsi_data *hdr;
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, task->hdr->lun, sizeof(hdr->lun));
hdr->itt = task->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_r2t_rsp - iSCSI R2T Response processing
* @conn: iscsi connection
* @task: scsi command task
**/
static int
iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task)
{
struct iscsi_r2t_info *r2t;
struct iscsi_session *session = conn->session;
struct iscsi_tcp_task *tcp_task = task->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) {
iscsi_conn_printk(KERN_ERR, conn,
"invalid R2t with datalen %d\n",
tcp_conn->in.datalen);
return ISCSI_ERR_DATALEN;
}
if (tcp_task->exp_datasn != r2tsn){
debug_tcp("%s: task->exp_datasn(%d) != rhdr->r2tsn(%d)\n",
__func__, tcp_task->exp_datasn, r2tsn);
return ISCSI_ERR_R2TSN;
}
/* fill-in new R2T associated with the task */
iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
if (!task->sc || session->state != ISCSI_STATE_LOGGED_IN) {
iscsi_conn_printk(KERN_INFO, conn,
"dropping R2T itt %d in recovery.\n",
task->itt);
return 0;
}
rc = __kfifo_get(tcp_task->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) {
iscsi_conn_printk(KERN_ERR, conn,
"invalid R2T with zero data len\n");
__kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t,
sizeof(void*));
return ISCSI_ERR_DATALEN;
}
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);
r2t->data_offset = be32_to_cpu(rhdr->data_offset);
if (r2t->data_offset + r2t->data_length > scsi_out(task->sc)->length) {
iscsi_conn_printk(KERN_ERR, conn,
"invalid R2T with data len %u at offset %u "
"and total length %d\n", r2t->data_length,
r2t->data_offset, scsi_out(task->sc)->length);
__kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t,
sizeof(void*));
return ISCSI_ERR_DATALEN;
}
r2t->ttt = rhdr->ttt; /* no flip */
r2t->solicit_datasn = 0;
iscsi_solicit_data_init(conn, task, r2t);
tcp_task->exp_datasn = r2tsn + 1;
__kfifo_put(tcp_task->r2tqueue, (void*)&r2t, sizeof(void*));
conn->r2t_pdus_cnt++;
iscsi_requeue_task(task);
return 0;
}
/*
* Handle incoming reply to DataIn command
*/
static int
iscsi_tcp_process_data_in(struct iscsi_tcp_conn *tcp_conn,
struct iscsi_segment *segment)
{
struct iscsi_conn *conn = tcp_conn->iscsi_conn;
struct iscsi_hdr *hdr = tcp_conn->in.hdr;
int rc;
if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
return ISCSI_ERR_DATA_DGST;
/* check for non-exceptional status */
if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
if (rc)
return rc;
}
iscsi_tcp_hdr_recv_prep(tcp_conn);
return 0;
}
/**
* iscsi_tcp_hdr_dissect - process PDU header
* @conn: iSCSI connection
* @hdr: PDU header
*
* This function analyzes the header of the PDU received,
* and performs several sanity checks. If the PDU is accompanied
* by data, the receive buffer is set up to copy the incoming data
* to the correct location.
*/
static int
iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
{
int rc = 0, opcode, ahslen;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct iscsi_task *task;
/* verify PDU length */
tcp_conn->in.datalen = ntoh24(hdr->dlength);
if (tcp_conn->in.datalen > conn->max_recv_dlength) {
iscsi_conn_printk(KERN_ERR, conn,
"iscsi_tcp: datalen %d > %d\n",
tcp_conn->in.datalen, conn->max_recv_dlength);
return ISCSI_ERR_DATALEN;
}
/* Additional header segments. So far, we don't
* process additional headers.
*/
ahslen = hdr->hlength << 2;
opcode = hdr->opcode & ISCSI_OPCODE_MASK;
/* verify itt (itt encoding: age+cid+itt) */
rc = iscsi_verify_itt(conn, hdr->itt);
if (rc)
return rc;
debug_tcp("opcode 0x%x ahslen %d datalen %d\n",
opcode, ahslen, tcp_conn->in.datalen);
switch(opcode) {
case ISCSI_OP_SCSI_DATA_IN:
spin_lock(&conn->session->lock);
task = iscsi_itt_to_ctask(conn, hdr->itt);
if (!task)
rc = ISCSI_ERR_BAD_ITT;
else
rc = iscsi_data_in(conn, task);
if (rc) {
spin_unlock(&conn->session->lock);
break;
}
if (tcp_conn->in.datalen) {
struct iscsi_tcp_task *tcp_task = task->dd_data;
struct hash_desc *rx_hash = NULL;
struct scsi_data_buffer *sdb = scsi_in(task->sc);
/*
* Setup copy of Data-In into the Scsi_Cmnd
* Scatterlist case:
* We set up the iscsi_segment to point to the next
* scatterlist entry to copy to. As we go along,
* we move on to the next scatterlist entry and
* update the digest per-entry.
*/
if (conn->datadgst_en &&
!(conn->session->tt->caps & CAP_DIGEST_OFFLOAD))
rx_hash = &tcp_conn->rx_hash;
debug_tcp("iscsi_tcp_begin_data_in(%p, offset=%d, "
"datalen=%d)\n", tcp_conn,
tcp_task->data_offset,
tcp_conn->in.datalen);
rc = iscsi_segment_seek_sg(&tcp_conn->in.segment,
sdb->table.sgl,
sdb->table.nents,
tcp_task->data_offset,
tcp_conn->in.datalen,
iscsi_tcp_process_data_in,
rx_hash);
spin_unlock(&conn->session->lock);
return rc;
}
rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
spin_unlock(&conn->session->lock);
break;
case ISCSI_OP_SCSI_CMD_RSP:
if (tcp_conn->in.datalen) {
iscsi_tcp_data_recv_prep(tcp_conn);
return 0;
}
rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
break;
case ISCSI_OP_R2T:
spin_lock(&conn->session->lock);
task = iscsi_itt_to_ctask(conn, hdr->itt);
if (!task)
rc = ISCSI_ERR_BAD_ITT;
else if (ahslen)
rc = ISCSI_ERR_AHSLEN;
else if (task->sc->sc_data_direction == DMA_TO_DEVICE)
rc = iscsi_r2t_rsp(conn, task);
else
rc = ISCSI_ERR_PROTO;
spin_unlock(&conn->session->lock);
break;
case ISCSI_OP_LOGIN_RSP:
case ISCSI_OP_TEXT_RSP:
case ISCSI_OP_REJECT:
case ISCSI_OP_ASYNC_EVENT:
/*
* It is possible that we could get a PDU with a buffer larger
* than 8K, but there are no targets that currently do this.
* For now we fail until we find a vendor that needs it
*/
if (ISCSI_DEF_MAX_RECV_SEG_LEN < tcp_conn->in.datalen) {
iscsi_conn_printk(KERN_ERR, conn,
"iscsi_tcp: received buffer of "
"len %u but conn buffer is only %u "
"(opcode %0x)\n",
tcp_conn->in.datalen,
ISCSI_DEF_MAX_RECV_SEG_LEN, opcode);
rc = ISCSI_ERR_PROTO;
break;
}
/* If there's data coming in with the response,
* receive it to the connection's buffer.
*/
if (tcp_conn->in.datalen) {
iscsi_tcp_data_recv_prep(tcp_conn);
return 0;
}
/* fall through */
case ISCSI_OP_LOGOUT_RSP:
case ISCSI_OP_NOOP_IN:
case ISCSI_OP_SCSI_TMFUNC_RSP:
rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
break;
default:
rc = ISCSI_ERR_BAD_OPCODE;
break;
}
if (rc == 0) {
/* Anything that comes with data should have
* been handled above. */
if (tcp_conn->in.datalen)
return ISCSI_ERR_PROTO;
iscsi_tcp_hdr_recv_prep(tcp_conn);
}
return rc;
}
/**
* iscsi_tcp_hdr_recv_done - process PDU header
*
* This is the callback invoked when the PDU header has
* been received. If the header is followed by additional
* header segments, we go back for more data.
*/
static int
iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn,
struct iscsi_segment *segment)
{
struct iscsi_conn *conn = tcp_conn->iscsi_conn;
struct iscsi_hdr *hdr;
/* Check if there are additional header segments
* *prior* to computing the digest, because we
* may need to go back to the caller for more.
*/
hdr = (struct iscsi_hdr *) tcp_conn->in.hdr_buf;
if (segment->copied == sizeof(struct iscsi_hdr) && hdr->hlength) {
/* Bump the header length - the caller will
* just loop around and get the AHS for us, and
* call again. */
unsigned int ahslen = hdr->hlength << 2;
/* Make sure we don't overflow */
if (sizeof(*hdr) + ahslen > sizeof(tcp_conn->in.hdr_buf))
return ISCSI_ERR_AHSLEN;
segment->total_size += ahslen;
segment->size += ahslen;
return 0;
}
/* We're done processing the header. See if we're doing
* header digests; if so, set up the recv_digest buffer
* and go back for more. */
if (conn->hdrdgst_en) {
if (segment->digest_len == 0) {
/*
* Even if we offload the digest processing we
* splice it in so we can increment the skb/segment
* counters in preparation for the data segment.
*/
iscsi_tcp_segment_splice_digest(segment,
segment->recv_digest);
return 0;
}
if (!(conn->session->tt->caps & CAP_DIGEST_OFFLOAD)) {
iscsi_tcp_dgst_header(&tcp_conn->rx_hash, hdr,
segment->total_copied - ISCSI_DIGEST_SIZE,
segment->digest);
if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
return ISCSI_ERR_HDR_DGST;
}
}
tcp_conn->in.hdr = hdr;
return iscsi_tcp_hdr_dissect(conn, hdr);
}
inline int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn)
{
return tcp_conn->in.segment.done == iscsi_tcp_hdr_recv_done;
}
enum {
ISCSI_TCP_SEGMENT_DONE, /* curr seg has been processed */
ISCSI_TCP_SKB_DONE, /* skb is out of data */
ISCSI_TCP_CONN_ERR, /* iscsi layer has fired a conn err */
ISCSI_TCP_SUSPENDED, /* conn is suspended */
};
/**
* iscsi_tcp_recv_skb - Process skb
* @conn: iscsi connection
* @skb: network buffer with header and/or data segment
* @offset: offset in skb
* @offload: bool indicating if transfer was offloaded
*/
int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,
unsigned int offset, bool offloaded, int *status)
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct iscsi_segment *segment = &tcp_conn->in.segment;
struct skb_seq_state seq;
unsigned int consumed = 0;
int rc = 0;
debug_tcp("in %d bytes\n", skb->len - offset);
if (unlikely(conn->suspend_rx)) {
debug_tcp("conn %d Rx suspended!\n", conn->id);
*status = ISCSI_TCP_SUSPENDED;
return 0;
}
if (offloaded) {
segment->total_copied = segment->total_size;
goto segment_done;
}
skb_prepare_seq_read(skb, offset, skb->len, &seq);
while (1) {
unsigned int avail;
const u8 *ptr;
avail = skb_seq_read(consumed, &ptr, &seq);
if (avail == 0) {
debug_tcp("no more data avail. Consumed %d\n",
consumed);
*status = ISCSI_TCP_SKB_DONE;
skb_abort_seq_read(&seq);
goto skb_done;
}
BUG_ON(segment->copied >= segment->size);
debug_tcp("skb %p ptr=%p avail=%u\n", skb, ptr, avail);
rc = iscsi_tcp_segment_recv(tcp_conn, segment, ptr, avail);
BUG_ON(rc == 0);
consumed += rc;
if (segment->total_copied >= segment->total_size) {
skb_abort_seq_read(&seq);
goto segment_done;
}
}
segment_done:
*status = ISCSI_TCP_SEGMENT_DONE;
debug_tcp("segment done\n");
rc = segment->done(tcp_conn, segment);
if (rc != 0) {
*status = ISCSI_TCP_CONN_ERR;
debug_tcp("Error receiving PDU, errno=%d\n", rc);
iscsi_conn_failure(conn, rc);
return 0;
}
/* The done() functions sets up the next segment. */
skb_done:
conn->rxdata_octets += consumed;
return consumed;
}
EXPORT_SYMBOL_GPL(iscsi_tcp_recv_skb);
/**
* iscsi_tcp_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_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
unsigned int offset, size_t len)
{
struct iscsi_conn *conn = rd_desc->arg.data;
unsigned int consumed, total_consumed = 0;
int status;
debug_tcp("in %d bytes\n", skb->len - offset);
do {
status = 0;
consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
offset += consumed;
total_consumed += consumed;
} while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
debug_tcp("read %d bytes status %d\n", skb->len - offset, status);
return total_consumed;
}
static void
iscsi_tcp_data_ready(struct sock *sk, int flag)
{
struct iscsi_conn *conn = sk->sk_user_data;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
read_descriptor_t rd_desc;
read_lock(&sk->sk_callback_lock);
/*
* Use rd_desc to pass 'conn' to iscsi_tcp_recv.
* We set count to 1 because we want the network layer to
* hand us all the skbs that are available. iscsi_tcp_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_recv);
read_unlock(&sk->sk_callback_lock);
/* If we had to (atomically) map a highmem page,
* unmap it now. */
iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
}
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_tcp_conn *tcp_conn)
{
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_xmit - TCP transmit
**/
static int
iscsi_xmit(struct iscsi_conn *conn)
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct iscsi_segment *segment = &tcp_conn->out.segment;
unsigned int consumed = 0;
int rc = 0;
while (1) {
rc = iscsi_tcp_xmit_segment(tcp_conn, segment);
if (rc < 0) {
rc = ISCSI_ERR_XMIT_FAILED;
goto error;
}
if (rc == 0)
break;
consumed += rc;
if (segment->total_copied >= segment->total_size) {
if (segment->done != NULL) {
rc = segment->done(tcp_conn, segment);
if (rc != 0)
goto error;
}
}
}
debug_tcp("xmit %d bytes\n", consumed);
conn->txdata_octets += consumed;
return consumed;
error:
/* Transmit error. We could initiate error recovery
* here. */
debug_tcp("Error sending PDU, errno=%d\n", rc);
iscsi_conn_failure(conn, rc);
return -EIO;
}
/**
* iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
*/
static inline int
iscsi_tcp_xmit_qlen(struct iscsi_conn *conn)
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct iscsi_segment *segment = &tcp_conn->out.segment;
return segment->total_copied - segment->total_size;
}
static inline int
iscsi_tcp_flush(struct iscsi_conn *conn)
{
int rc;
while (iscsi_tcp_xmit_qlen(conn)) {
rc = iscsi_xmit(conn);
if (rc == 0)
return -EAGAIN;
if (rc < 0)
return rc;
}
return 0;
}
/*
* This is called when we're done sending the header.
* Simply copy the data_segment to the send segment, and return.
*/
static int
iscsi_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
struct iscsi_segment *segment)
{
tcp_conn->out.segment = tcp_conn->out.data_segment;
debug_tcp("Header done. Next segment size %u total_size %u\n",
tcp_conn->out.segment.size, tcp_conn->out.segment.total_size);
return 0;
}
static void
iscsi_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr, size_t hdrlen)
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
debug_tcp("%s(%p%s)\n", __func__, tcp_conn,
conn->hdrdgst_en? ", digest enabled" : "");
/* Clear the data segment - needs to be filled in by the
* caller using iscsi_tcp_send_data_prep() */
memset(&tcp_conn->out.data_segment, 0, sizeof(struct iscsi_segment));
/* If header digest is enabled, compute the CRC and
* place the digest into the same buffer. We make
* sure that both iscsi_tcp_task and mtask have
* sufficient room.
*/
if (conn->hdrdgst_en) {
iscsi_tcp_dgst_header(&tcp_conn->tx_hash, hdr, hdrlen,
hdr + hdrlen);
hdrlen += ISCSI_DIGEST_SIZE;
}
/* Remember header pointer for later, when we need
* to decide whether there's a payload to go along
* with the header. */
tcp_conn->out.hdr = hdr;
iscsi_segment_init_linear(&tcp_conn->out.segment, hdr, hdrlen,
iscsi_tcp_send_hdr_done, NULL);
}
/*
* Prepare the send buffer for the payload data.
* Padding and checksumming will all be taken care
* of by the iscsi_segment routines.
*/
static int
iscsi_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
unsigned int count, unsigned int offset,
unsigned int len)
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct hash_desc *tx_hash = NULL;
unsigned int hdr_spec_len;
debug_tcp("%s(%p, offset=%d, datalen=%d%s)\n", __func__,
tcp_conn, offset, len,
conn->datadgst_en? ", digest enabled" : "");
/* Make sure the datalen matches what the caller
said he would send. */
hdr_spec_len = ntoh24(tcp_conn->out.hdr->dlength);
WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
if (conn->datadgst_en)
tx_hash = &tcp_conn->tx_hash;
return iscsi_segment_seek_sg(&tcp_conn->out.data_segment,
sg, count, offset, len,
NULL, tx_hash);
}
static void
iscsi_tcp_send_linear_data_prepare(struct iscsi_conn *conn, void *data,
size_t len)
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct hash_desc *tx_hash = NULL;
unsigned int hdr_spec_len;
debug_tcp("%s(%p, datalen=%d%s)\n", __func__, tcp_conn, len,
conn->datadgst_en? ", digest enabled" : "");
/* Make sure the datalen matches what the caller
said he would send. */
hdr_spec_len = ntoh24(tcp_conn->out.hdr->dlength);
WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
if (conn->datadgst_en)
tx_hash = &tcp_conn->tx_hash;
iscsi_segment_init_linear(&tcp_conn->out.data_segment,
data, len, NULL, tx_hash);
}
/**
* iscsi_solicit_data_cont - initialize next Data-Out
* @conn: iscsi connection
* @task: 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 int
iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_task *task,
struct iscsi_r2t_info *r2t)
{
struct iscsi_data *hdr;
int new_offset, left;
BUG_ON(r2t->data_length - r2t->sent < 0);
left = r2t->data_length - r2t->sent;
if (left == 0)
return 0;
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, task->hdr->lun, sizeof(hdr->lun));
hdr->itt = task->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++;
return 1;
}
/**
* iscsi_tcp_task - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
* @conn: iscsi connection
* @task: scsi command task
* @sc: scsi command
**/
static int
iscsi_tcp_task_init(struct iscsi_task *task)
{
struct iscsi_tcp_task *tcp_task = task->dd_data;
struct iscsi_conn *conn = task->conn;
struct scsi_cmnd *sc = task->sc;
int err;
if (!sc) {
/*
* mgmt tasks do not have a scatterlist since they come
* in from the iscsi interface.
*/
debug_scsi("mtask deq [cid %d itt 0x%x]\n", conn->id,
task->itt);
/* Prepare PDU, optionally w/ immediate data */
iscsi_tcp_send_hdr_prep(conn, task->hdr, sizeof(*task->hdr));
/* If we have immediate data, attach a payload */
if (task->data_count)
iscsi_tcp_send_linear_data_prepare(conn, task->data,
task->data_count);
return 0;
}
BUG_ON(__kfifo_len(tcp_task->r2tqueue));
tcp_task->sent = 0;
tcp_task->exp_datasn = 0;
/* Prepare PDU, optionally w/ immediate data */
debug_scsi("task deq [cid %d itt 0x%x imm %d unsol %d]\n",
conn->id, task->itt, task->imm_count,
task->unsol_count);
iscsi_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
if (!task->imm_count)
return 0;
/* If we have immediate data, attach a payload */
err = iscsi_tcp_send_data_prep(conn, scsi_out(sc)->table.sgl,
scsi_out(sc)->table.nents,
0, task->imm_count);
if (err)
return err;
tcp_task->sent += task->imm_count;
task->imm_count = 0;
return 0;
}
/*
* iscsi_tcp_task_xmit - xmit normal PDU task
* @task: iscsi command task
*
* We're expected to return 0 when everything was transmitted succesfully,
* -EAGAIN if there's still data in the queue, or != 0 for any other kind
* of error.
*/
static int
iscsi_tcp_task_xmit(struct iscsi_task *task)
{
struct iscsi_conn *conn = task->conn;
struct iscsi_tcp_task *tcp_task = task->dd_data;
struct scsi_cmnd *sc = task->sc;
struct scsi_data_buffer *sdb;
int rc = 0;
flush:
/* Flush any pending data first. */
rc = iscsi_tcp_flush(conn);
if (rc < 0)
return rc;
/* mgmt command */
if (!sc) {
if (task->hdr->itt == RESERVED_ITT)
iscsi_put_task(task);
return 0;
}
/* Are we done already? */
if (sc->sc_data_direction != DMA_TO_DEVICE)
return 0;
sdb = scsi_out(sc);
if (task->unsol_count != 0) {
struct iscsi_data *hdr = &tcp_task->unsol_dtask.hdr;
/* Prepare a header for the unsolicited PDU.
* The amount of data we want to send will be
* in task->data_count.
* FIXME: return the data count instead.
*/
iscsi_prep_unsolicit_data_pdu(task, hdr);
debug_tcp("unsol dout [itt 0x%x doff %d dlen %d]\n",
task->itt, tcp_task->sent, task->data_count);
iscsi_tcp_send_hdr_prep(conn, hdr, sizeof(*hdr));
rc = iscsi_tcp_send_data_prep(conn, sdb->table.sgl,
sdb->table.nents, tcp_task->sent,
task->data_count);
if (rc)
goto fail;
tcp_task->sent += task->data_count;
task->unsol_count -= task->data_count;
goto flush;
} else {
struct iscsi_session *session = conn->session;
struct iscsi_r2t_info *r2t;
/* All unsolicited PDUs sent. Check for solicited PDUs.
*/
spin_lock_bh(&session->lock);
r2t = tcp_task->r2t;
if (r2t != NULL) {
/* Continue with this R2T? */
if (!iscsi_solicit_data_cont(conn, task, r2t)) {
debug_scsi(" done with r2t %p\n", r2t);
__kfifo_put(tcp_task->r2tpool.queue,
(void*)&r2t, sizeof(void*));
tcp_task->r2t = r2t = NULL;
}
}
if (r2t == NULL) {
__kfifo_get(tcp_task->r2tqueue, (void*)&tcp_task->r2t,
sizeof(void*));
r2t = tcp_task->r2t;
}
spin_unlock_bh(&session->lock);
/* Waiting for more R2Ts to arrive. */
if (r2t == NULL) {
debug_tcp("no R2Ts yet\n");
return 0;
}
debug_scsi("sol dout %p [dsn %d itt 0x%x doff %d dlen %d]\n",
r2t, r2t->solicit_datasn - 1, task->itt,
r2t->data_offset + r2t->sent, r2t->data_count);
iscsi_tcp_send_hdr_prep(conn, &r2t->dtask.hdr,
sizeof(struct iscsi_hdr));
rc = iscsi_tcp_send_data_prep(conn, sdb->table.sgl,
sdb->table.nents,
r2t->data_offset + r2t->sent,
r2t->data_count);
if (rc)
goto fail;
tcp_task->sent += r2t->data_count;
r2t->sent += r2t->data_count;
goto flush;
}
return 0;
fail:
iscsi_conn_failure(conn, rc);
return -EIO;
}
static struct iscsi_cls_conn *
iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
{
struct iscsi_conn *conn;
struct iscsi_cls_conn *cls_conn;
struct iscsi_tcp_conn *tcp_conn;
cls_conn = iscsi_conn_setup(cls_session, sizeof(*tcp_conn), conn_idx);
if (!cls_conn)
return NULL;
conn = cls_conn->dd_data;
/*
* due to strange issues with iser these are not set
* in iscsi_conn_setup
*/
conn->max_recv_dlength = ISCSI_DEF_MAX_RECV_SEG_LEN;
tcp_conn = conn->dd_data;
tcp_conn->iscsi_conn = conn;
tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
CRYPTO_ALG_ASYNC);
tcp_conn->tx_hash.flags = 0;
if (IS_ERR(tcp_conn->tx_hash.tfm))
goto free_conn;
tcp_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
CRYPTO_ALG_ASYNC);
tcp_conn->rx_hash.flags = 0;
if (IS_ERR(tcp_conn->rx_hash.tfm))
goto free_tx_tfm;
return cls_conn;
free_tx_tfm:
crypto_free_hash(tcp_conn->tx_hash.tfm);
free_conn:
iscsi_conn_printk(KERN_ERR, conn,
"Could not create connection due to crc32c "
"loading error. Make sure the crc32c "
"module is built as a module or into the "
"kernel\n");
iscsi_conn_teardown(cls_conn);
return NULL;
}
static void
iscsi_tcp_release_conn(struct iscsi_conn *conn)
{
struct iscsi_session *session = conn->session;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct socket *sock = tcp_conn->sock;
if (!sock)
return;
sock_hold(sock->sk);
iscsi_conn_restore_callbacks(tcp_conn);
sock_put(sock->sk);
spin_lock_bh(&session->lock);
tcp_conn->sock = NULL;
spin_unlock_bh(&session->lock);
sockfd_put(sock);
}
static void
iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
{
struct iscsi_conn *conn = cls_conn->dd_data;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
iscsi_tcp_release_conn(conn);
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);
iscsi_conn_teardown(cls_conn);
}
static void
iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
{
struct iscsi_conn *conn = cls_conn->dd_data;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
/* userspace may have goofed up and not bound us */
if (!tcp_conn->sock)
return;
/*
* Make sure our recv side is stopped.
* Older tools called conn stop before ep_disconnect
* so IO could still be coming in.
*/
write_lock_bh(&tcp_conn->sock->sk->sk_callback_lock);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
write_unlock_bh(&tcp_conn->sock->sk->sk_callback_lock);
iscsi_conn_stop(cls_conn, flag);
iscsi_tcp_release_conn(conn);
}
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;
addr = kmalloc(sizeof(*addr), GFP_KERNEL);
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, "%pI4", &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, "%pI6", &sin6->sin6_addr);
*port = be16_to_cpu(sin6->sin6_port);
spin_unlock_bh(&conn->session->lock);
break;
}
free_addr:
kfree(addr);
return rc;
}
static int
iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
int is_leading)
{
struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
struct iscsi_host *ihost = shost_priv(shost);
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;
/* lookup for existing socket */
sock = sockfd_lookup((int)transport_eph, &err);
if (!sock) {
iscsi_conn_printk(KERN_ERR, conn,
"sockfd_lookup failed %d\n", err);
return -EEXIST;
}
/*
* 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, ihost->local_address,
&ihost->local_port, kernel_getsockname);
if (err)
goto free_socket;
err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
if (err)
goto free_socket;
/* bind iSCSI connection and socket */
tcp_conn->sock = sock;
/* setup Socket parameters */
sk = sock->sk;
sk->sk_reuse = 1;
sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
sk->sk_allocation = GFP_ATOMIC;
iscsi_conn_set_callbacks(conn);
tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
/*
* set receive state machine into initial state
*/
iscsi_tcp_hdr_recv_prep(tcp_conn);
return 0;
free_socket:
sockfd_put(sock);
return err;
}
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_task *task = session->cmds[cmd_i];
struct iscsi_tcp_task *tcp_task = task->dd_data;
/*
* pre-allocated x4 as much r2ts to handle race when
* target acks DataOut faster than we data_xmit() queues
* could replenish r2tqueue.
*/
/* R2T pool */
if (iscsi_pool_init(&tcp_task->r2tpool, session->max_r2t * 4, NULL,
sizeof(struct iscsi_r2t_info))) {
goto r2t_alloc_fail;
}
/* R2T xmit queue */
tcp_task->r2tqueue = kfifo_alloc(
session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
if (tcp_task->r2tqueue == ERR_PTR(-ENOMEM)) {
iscsi_pool_free(&tcp_task->r2tpool);
goto r2t_alloc_fail;
}
}
return 0;
r2t_alloc_fail:
for (i = 0; i < cmd_i; i++) {
struct iscsi_task *task = session->cmds[i];
struct iscsi_tcp_task *tcp_task = task->dd_data;
kfifo_free(tcp_task->r2tqueue);
iscsi_pool_free(&tcp_task->r2tpool);
}
return -ENOMEM;
}
static void
iscsi_r2tpool_free(struct iscsi_session *session)
{
int i;
for (i = 0; i < session->cmds_max; i++) {
struct iscsi_task *task = session->cmds[i];
struct iscsi_tcp_task *tcp_task = task->dd_data;
kfifo_free(tcp_task->r2tqueue);
iscsi_pool_free(&tcp_task->r2tpool);
}
}
static int
iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
char *buf, int buflen)
{
struct iscsi_conn *conn = cls_conn->dd_data;
struct iscsi_session *session = conn->session;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
int value;
switch(param) {
case ISCSI_PARAM_HDRDGST_EN:
iscsi_set_param(cls_conn, param, buf, buflen);
break;
case ISCSI_PARAM_DATADGST_EN:
iscsi_set_param(cls_conn, param, buf, buflen);
tcp_conn->sendpage = conn->datadgst_en ?
sock_no_sendpage : tcp_conn->sock->ops->sendpage;
break;
case ISCSI_PARAM_MAX_R2T:
sscanf(buf, "%d", &value);
if (value <= 0 || !is_power_of_2(value))
return -EINVAL;
if (session->max_r2t == value)
break;
iscsi_r2tpool_free(session);
iscsi_set_param(cls_conn, param, buf, buflen);
if (iscsi_r2tpool_alloc(session))
return -ENOMEM;
break;
default:
return iscsi_set_param(cls_conn, param, buf, buflen);
}
return 0;
}
static int
iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
enum iscsi_param param, char *buf)
{
struct iscsi_conn *conn = cls_conn->dd_data;
int len;
switch(param) {
case ISCSI_PARAM_CONN_PORT:
spin_lock_bh(&conn->session->lock);
len = sprintf(buf, "%hu\n", conn->portal_port);
spin_unlock_bh(&conn->session->lock);
break;
case ISCSI_PARAM_CONN_ADDRESS:
spin_lock_bh(&conn->session->lock);
len = sprintf(buf, "%s\n", conn->portal_address);
spin_unlock_bh(&conn->session->lock);
break;
default:
return iscsi_conn_get_param(cls_conn, param, buf);
}
return len;
}
static void
iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
{
struct iscsi_conn *conn = cls_conn->dd_data;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
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");
stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
strcpy(stats->custom[2].desc, "eh_abort_cnt");
stats->custom[2].value = conn->eh_abort_cnt;
}
static struct iscsi_cls_session *
iscsi_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
uint16_t qdepth, uint32_t initial_cmdsn,
uint32_t *hostno)
{
struct iscsi_cls_session *cls_session;
struct iscsi_session *session;
struct Scsi_Host *shost;
int cmd_i;
if (ep) {
printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
return NULL;
}
shost = iscsi_host_alloc(&iscsi_sht, 0, qdepth);
if (!shost)
return NULL;
shost->transportt = iscsi_tcp_scsi_transport;
shost->max_lun = iscsi_max_lun;
shost->max_id = 0;
shost->max_channel = 0;
shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
if (iscsi_host_add(shost, NULL))
goto free_host;
*hostno = shost->host_no;
cls_session = iscsi_session_setup(&iscsi_tcp_transport, shost, cmds_max,
sizeof(struct iscsi_tcp_task),
initial_cmdsn, 0);
if (!cls_session)
goto remove_host;
session = cls_session->dd_data;
shost->can_queue = session->scsi_cmds_max;
for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
struct iscsi_task *task = session->cmds[cmd_i];
struct iscsi_tcp_task *tcp_task = task->dd_data;
task->hdr = &tcp_task->hdr.cmd_hdr;
task->hdr_max = sizeof(tcp_task->hdr) - ISCSI_DIGEST_SIZE;
}
if (iscsi_r2tpool_alloc(session))
goto remove_session;
return cls_session;
remove_session:
iscsi_session_teardown(cls_session);
remove_host:
iscsi_host_remove(shost);
free_host:
iscsi_host_free(shost);
return NULL;
}
static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
{
struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
iscsi_r2tpool_free(cls_session->dd_data);
iscsi_session_teardown(cls_session);
iscsi_host_remove(shost);
iscsi_host_free(shost);
}
static int iscsi_tcp_slave_configure(struct scsi_device *sdev)
{
blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
blk_queue_dma_alignment(sdev->request_queue, 0);
return 0;
}
static struct scsi_host_template iscsi_sht = {
.module = THIS_MODULE,
.name = "iSCSI Initiator over TCP/IP",
.queuecommand = iscsi_queuecommand,
.change_queue_depth = iscsi_change_queue_depth,
.can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
.sg_tablesize = 4096,
.max_sectors = 0xFFFF,
.cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
.eh_abort_handler = iscsi_eh_abort,
.eh_device_reset_handler= iscsi_eh_device_reset,
.eh_target_reset_handler= iscsi_eh_target_reset,
.use_clustering = DISABLE_CLUSTERING,
.slave_configure = iscsi_tcp_slave_configure,
.proc_name = "iscsi_tcp",
.this_id = -1,
};
static struct iscsi_transport iscsi_tcp_transport = {
.owner = THIS_MODULE,
.name = "tcp",
.caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
| CAP_DATADGST,
.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 |
ISCSI_CONN_ADDRESS |
ISCSI_EXP_STATSN |
ISCSI_PERSISTENT_PORT |
ISCSI_PERSISTENT_ADDRESS |
ISCSI_TARGET_NAME | ISCSI_TPGT |
ISCSI_USERNAME | ISCSI_PASSWORD |
ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
ISCSI_FAST_ABORT | ISCSI_ABORT_TMO |
ISCSI_LU_RESET_TMO |
ISCSI_PING_TMO | ISCSI_RECV_TMO |
ISCSI_IFACE_NAME | ISCSI_INITIATOR_NAME,
.host_param_mask = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
ISCSI_HOST_INITIATOR_NAME |
ISCSI_HOST_NETDEV_NAME,
/* 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,
.set_param = iscsi_conn_set_param,
.get_conn_param = iscsi_tcp_conn_get_param,
.get_session_param = iscsi_session_get_param,
.start_conn = iscsi_conn_start,
.stop_conn = iscsi_tcp_conn_stop,
/* iscsi host params */
.get_host_param = iscsi_host_get_param,
.set_host_param = iscsi_host_set_param,
/* IO */
.send_pdu = iscsi_conn_send_pdu,
.get_stats = iscsi_conn_get_stats,
.init_task = iscsi_tcp_task_init,
.xmit_task = iscsi_tcp_task_xmit,
.cleanup_task = iscsi_tcp_cleanup_task,
/* recovery */
.session_recovery_timedout = iscsi_session_recovery_timedout,
};
static int __init
iscsi_tcp_init(void)
{
if (iscsi_max_lun < 1) {
printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
iscsi_max_lun);
return -EINVAL;
}
iscsi_tcp_scsi_transport = iscsi_register_transport(
&iscsi_tcp_transport);
if (!iscsi_tcp_scsi_transport)
return -ENODEV;
return 0;
}
static void __exit
iscsi_tcp_exit(void)
{
iscsi_unregister_transport(&iscsi_tcp_transport);
}
module_init(iscsi_tcp_init);
module_exit(iscsi_tcp_exit);