linux/drivers/scsi/iscsi_tcp.h

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/*
* iSCSI Initiator TCP Transport
* 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.
*/
#ifndef ISCSI_SW_TCP_H
#define ISCSI_SW_TCP_H
#include <scsi/libiscsi.h>
#include <scsi/libiscsi_tcp.h>
struct socket;
struct iscsi_tcp_conn;
/* Socket connection send helper */
struct iscsi_sw_tcp_send {
struct iscsi_hdr *hdr;
struct iscsi_segment segment;
struct iscsi_segment data_segment;
};
struct iscsi_sw_tcp_conn {
struct socket *sock;
struct iscsi_sw_tcp_send out;
/* old values for socket callbacks */
void (*old_data_ready)(struct sock *);
void (*old_state_change)(struct sock *);
void (*old_write_space)(struct sock *);
/* data and header digests */
struct ahash_request *tx_hash; /* CRC32C (Tx) */
struct ahash_request *rx_hash; /* CRC32C (Rx) */
/* MIB custom statistics */
uint32_t sendpage_failures_cnt;
uint32_t discontiguous_hdr_cnt;
ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
};
struct iscsi_sw_tcp_host {
struct iscsi_session *session;
};
struct iscsi_sw_tcp_hdrbuf {
struct iscsi_hdr hdrbuf;
char hdrextbuf[ISCSI_MAX_AHS_SIZE +
[SCSI] iscsi_tcp, libiscsi: initial AHS Support at libiscsi generic code - currently code assumes a storage space of pdu header is allocated at llds ctask and is pointed to by iscsi_cmd_task->hdr. Here I add a hdr_max field pertaining to that storage, and an hdr_len that accumulates the current use of the pdu-header. - Add an iscsi_next_hdr() inline which returns the next free space to write new Header at. Also iscsi_next_hdr() is used to retrieve the address at which to write the header-digest. - Add iscsi_add_hdr(length). What the user do is calls iscsi_next_hdr() for address of the new header, than calls iscsi_add_hdr(length) with the size of the new header. iscsi_add_hdr() will check if space is available and update to the new size. length must be padded according to standard. - Add 2 padding inline helpers thanks to Olaf. Current patch does not use them but Following patches will. Also moved definition of ISCSI_PAD_LEN to iscsi_proto.h which had PAD_WORD_LEN that was never used anywhere. - Let iscsi_prep_scsi_cmd_pdu() signal an Error return since now it is possible that it will fail. - I was tired of yet again writing a "this is a digest" comment next to sizeof(__u32) so I defined a new ISCSI_DIGEST_SIZE. Now I don't need any comments. Changed all places that used sizeof(__u32) or "4" in connection to a digest. iscsi_tcp specific code - At struct iscsi_tcp_cmd_task allocate maximum space allowed in standard for all headers following the iscsi_cmd header. and mark it so in iscsi_tcp_session_create() - At iscsi_send_cmd_hdr() retrieve the correct headers size and write header digest at iscsi_next_hdr(). Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2007-12-13 18:43:23 +00:00
ISCSI_DIGEST_SIZE];
};
#endif /* ISCSI_SW_TCP_H */