2 * iSCSI Initiator TCP Transport
3 * Copyright (C) 2004 Dmitry Yusupov
4 * Copyright (C) 2004 Alex Aizman
5 * Copyright (C) 2005 - 2006 Mike Christie
6 * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
7 * maintained by open-iscsi@googlegroups.com
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published
11 * by the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
19 * See the file COPYING included with this distribution for more details.
25 #include <scsi/libiscsi.h>
27 /* Socket's Receive state machine */
28 #define IN_PROGRESS_WAIT_HEADER 0x0
29 #define IN_PROGRESS_HEADER_GATHER 0x1
30 #define IN_PROGRESS_DATA_RECV 0x2
31 #define IN_PROGRESS_DDIGEST_RECV 0x3
33 /* xmit state machine */
34 #define XMSTATE_IDLE 0x0
35 #define XMSTATE_R_HDR 0x1
36 #define XMSTATE_W_HDR 0x2
37 #define XMSTATE_IMM_HDR 0x4
38 #define XMSTATE_IMM_DATA 0x8
39 #define XMSTATE_UNS_INIT 0x10
40 #define XMSTATE_UNS_HDR 0x20
41 #define XMSTATE_UNS_DATA 0x40
42 #define XMSTATE_SOL_HDR 0x80
43 #define XMSTATE_SOL_DATA 0x100
44 #define XMSTATE_W_PAD 0x200
45 #define XMSTATE_W_RESEND_PAD 0x400
46 #define XMSTATE_W_RESEND_DATA_DIGEST 0x800
48 #define ISCSI_PAD_LEN 4
49 #define ISCSI_SG_TABLESIZE SG_ALL
50 #define ISCSI_TCP_MAX_CMD_LEN 16
54 /* Socket connection recieve helper */
55 struct iscsi_tcp_recv
{
56 struct iscsi_hdr
*hdr
;
64 struct iscsi_cmd_task
*ctask
; /* current cmd in progress */
66 /* copied and flipped values */
72 struct iscsi_tcp_conn
{
73 struct iscsi_conn
*iscsi_conn
;
75 struct iscsi_hdr hdr
; /* header placeholder */
76 char hdrext
[4*sizeof(__u16
) +
79 int stop_stage
; /* conn_stop() flag: *
81 * stop to terminate */
82 /* iSCSI connection-wide sequencing */
83 int hdr_size
; /* PDU header size */
85 struct iscsi_tcp_recv in
; /* TCP receive context */
86 int in_progress
; /* connection state machine */
88 /* old values for socket callbacks */
89 void (*old_data_ready
)(struct sock
*, int);
90 void (*old_state_change
)(struct sock
*);
91 void (*old_write_space
)(struct sock
*);
93 /* data and header digests */
94 struct crypto_tfm
*tx_tfm
; /* CRC32C (Tx) */
95 struct crypto_tfm
*rx_tfm
; /* CRC32C (Rx) */
97 /* MIB custom statistics */
98 uint32_t sendpage_failures_cnt
;
99 uint32_t discontiguous_hdr_cnt
;
101 ssize_t (*sendpage
)(struct socket
*, struct page
*, int, size_t, int);
105 struct scatterlist sg
;
110 struct iscsi_data_task
{
111 struct iscsi_data hdr
; /* PDU */
112 char hdrext
[sizeof(__u32
)]; /* Header-Digest */
113 struct iscsi_buf digestbuf
; /* digest buffer */
114 uint32_t digest
; /* data digest */
117 struct iscsi_tcp_mgmt_task
{
118 struct iscsi_hdr hdr
;
119 char hdrext
[sizeof(__u32
)]; /* Header-Digest */
120 int xmstate
; /* mgmt xmit progress */
121 struct iscsi_buf headbuf
; /* header buffer */
122 struct iscsi_buf sendbuf
; /* in progress buffer */
126 struct iscsi_r2t_info
{
127 __be32 ttt
; /* copied from R2T */
128 __be32 exp_statsn
; /* copied from R2T */
129 uint32_t data_length
; /* copied from R2T */
130 uint32_t data_offset
; /* copied from R2T */
131 struct iscsi_buf headbuf
; /* Data-Out Header Buffer */
132 struct iscsi_buf sendbuf
; /* Data-Out in progress buffer*/
133 int sent
; /* R2T sequence progress */
134 int data_count
; /* DATA-Out payload progress */
135 struct scatterlist
*sg
; /* per-R2T SG list */
137 struct iscsi_data_task dtask
; /* which data task */
140 struct iscsi_tcp_cmd_task
{
141 struct iscsi_cmd hdr
;
142 char hdrext
[4*sizeof(__u16
)+ /* AHS */
143 sizeof(__u32
)]; /* HeaderDigest */
144 char pad
[ISCSI_PAD_LEN
];
145 int pad_count
; /* padded bytes */
146 struct iscsi_buf headbuf
; /* header buf (xmit) */
147 struct iscsi_buf sendbuf
; /* in progress buffer*/
148 int xmstate
; /* xmit xtate machine */
150 struct scatterlist
*sg
; /* per-cmd SG list */
151 struct scatterlist
*bad_sg
; /* assert statement */
152 int sg_count
; /* SG's to process */
155 struct iscsi_r2t_info
*r2t
; /* in progress R2T */
156 struct iscsi_queue r2tpool
;
157 struct kfifo
*r2tqueue
;
158 struct iscsi_r2t_info
**r2ts
;
160 uint32_t immdigest
; /* for imm data */
161 struct iscsi_buf immbuf
; /* for imm data digest */
162 struct iscsi_data_task unsol_dtask
; /* unsol data task */