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_DATA_DIGEST 0x400
47 #define ISCSI_CONN_RCVBUF_MIN 262144
48 #define ISCSI_CONN_SNDBUF_MIN 262144
49 #define ISCSI_PAD_LEN 4
50 #define ISCSI_R2T_MAX 16
51 #define ISCSI_SG_TABLESIZE SG_ALL
52 #define ISCSI_TCP_MAX_CMD_LEN 16
56 /* Socket connection recieve helper */
57 struct iscsi_tcp_recv
{
58 struct iscsi_hdr
*hdr
;
66 struct iscsi_cmd_task
*ctask
; /* current cmd in progress */
68 /* copied and flipped values */
74 struct iscsi_tcp_conn
{
75 struct iscsi_conn
*iscsi_conn
;
77 struct iscsi_hdr hdr
; /* header placeholder */
78 char hdrext
[4*sizeof(__u16
) +
81 char *data
; /* data placeholder */
82 int data_size
; /* actual recv_dlength */
83 int stop_stage
; /* conn_stop() flag: *
85 * stop to terminate */
86 /* iSCSI connection-wide sequencing */
87 int hdr_size
; /* PDU header size */
89 struct crypto_tfm
*rx_tfm
; /* CRC32C (Rx) */
90 struct crypto_tfm
*data_rx_tfm
; /* CRC32C (Rx) for data */
93 struct iscsi_tcp_recv in
; /* TCP receive context */
94 int in_progress
; /* connection state machine */
96 /* old values for socket callbacks */
97 void (*old_data_ready
)(struct sock
*, int);
98 void (*old_state_change
)(struct sock
*);
99 void (*old_write_space
)(struct sock
*);
102 struct crypto_tfm
*tx_tfm
; /* CRC32C (Tx) */
103 struct crypto_tfm
*data_tx_tfm
; /* CRC32C (Tx) for data */
105 /* MIB custom statistics */
106 uint32_t sendpage_failures_cnt
;
107 uint32_t discontiguous_hdr_cnt
;
109 ssize_t (*sendpage
)(struct socket
*, struct page
*, int, size_t, int);
113 struct scatterlist sg
;
118 struct iscsi_data_task
{
119 struct iscsi_data hdr
; /* PDU */
120 char hdrext
[sizeof(__u32
)]; /* Header-Digest */
121 struct iscsi_buf digestbuf
; /* digest buffer */
122 uint32_t digest
; /* data digest */
125 struct iscsi_tcp_mgmt_task
{
126 struct iscsi_hdr hdr
;
127 char hdrext
[sizeof(__u32
)]; /* Header-Digest */
128 int xmstate
; /* mgmt xmit progress */
129 struct iscsi_buf headbuf
; /* header buffer */
130 struct iscsi_buf sendbuf
; /* in progress buffer */
134 struct iscsi_r2t_info
{
135 __be32 ttt
; /* copied from R2T */
136 __be32 exp_statsn
; /* copied from R2T */
137 uint32_t data_length
; /* copied from R2T */
138 uint32_t data_offset
; /* copied from R2T */
139 struct iscsi_buf headbuf
; /* Data-Out Header Buffer */
140 struct iscsi_buf sendbuf
; /* Data-Out in progress buffer*/
141 int sent
; /* R2T sequence progress */
142 int data_count
; /* DATA-Out payload progress */
143 struct scatterlist
*sg
; /* per-R2T SG list */
145 struct iscsi_data_task dtask
; /* which data task */
148 struct iscsi_tcp_cmd_task
{
149 struct iscsi_cmd hdr
;
150 char hdrext
[4*sizeof(__u16
)+ /* AHS */
151 sizeof(__u32
)]; /* HeaderDigest */
152 char pad
[ISCSI_PAD_LEN
];
153 int pad_count
; /* padded bytes */
154 struct iscsi_buf headbuf
; /* header buf (xmit) */
155 struct iscsi_buf sendbuf
; /* in progress buffer*/
156 int xmstate
; /* xmit xtate machine */
158 struct scatterlist
*sg
; /* per-cmd SG list */
159 struct scatterlist
*bad_sg
; /* assert statement */
160 int sg_count
; /* SG's to process */
162 int r2t_data_count
; /* R2T Data-Out bytes */
164 struct iscsi_r2t_info
*r2t
; /* in progress R2T */
165 struct iscsi_queue r2tpool
;
166 struct kfifo
*r2tqueue
;
167 struct iscsi_r2t_info
**r2ts
;
168 uint32_t datadigest
; /* for recover digest */
170 uint32_t immdigest
; /* for imm data */
171 struct iscsi_buf immbuf
; /* for imm data digest */
172 struct iscsi_data_task
*dtask
; /* data task in progress*/
173 struct iscsi_data_task unsol_dtask
; /* unsol data task */
174 int digest_offset
; /* for partial buff digest */