Merge mulgrave-w:git/scsi-misc-2.6
[linux-2.6.git] / drivers / scsi / iscsi_tcp.h
1 /*
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
8  *
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.
13  *
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.
18  *
19  * See the file COPYING included with this distribution for more details.
20  */
21
22 #ifndef ISCSI_TCP_H
23 #define ISCSI_TCP_H
24
25 #include <scsi/libiscsi.h>
26
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
32
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
47
48 #define ISCSI_PAD_LEN                   4
49 #define ISCSI_SG_TABLESIZE              SG_ALL
50 #define ISCSI_TCP_MAX_CMD_LEN           16
51
52 struct crypto_hash;
53 struct socket;
54
55 /* Socket connection recieve helper */
56 struct iscsi_tcp_recv {
57         struct iscsi_hdr        *hdr;
58         struct sk_buff          *skb;
59         int                     offset;
60         int                     len;
61         int                     hdr_offset;
62         int                     copy;
63         int                     copied;
64         int                     padding;
65         struct iscsi_cmd_task   *ctask;         /* current cmd in progress */
66
67         /* copied and flipped values */
68         int                     datalen;
69         int                     datadgst;
70         char                    zero_copy_hdr;
71 };
72
73 struct iscsi_tcp_conn {
74         struct iscsi_conn       *iscsi_conn;
75         struct socket           *sock;
76         struct iscsi_hdr        hdr;            /* header placeholder */
77         char                    hdrext[4*sizeof(__u16) +
78                                     sizeof(__u32)];
79         int                     data_copied;
80         int                     stop_stage;     /* conn_stop() flag: *
81                                                  * stop to recover,  *
82                                                  * stop to terminate */
83         /* iSCSI connection-wide sequencing */
84         int                     hdr_size;       /* PDU header size */
85
86         /* control data */
87         struct iscsi_tcp_recv   in;             /* TCP receive context */
88         int                     in_progress;    /* connection state machine */
89
90         /* old values for socket callbacks */
91         void                    (*old_data_ready)(struct sock *, int);
92         void                    (*old_state_change)(struct sock *);
93         void                    (*old_write_space)(struct sock *);
94
95         /* data and header digests */
96         struct hash_desc        tx_hash;        /* CRC32C (Tx) */
97         struct hash_desc        rx_hash;        /* CRC32C (Rx) */
98
99         /* MIB custom statistics */
100         uint32_t                sendpage_failures_cnt;
101         uint32_t                discontiguous_hdr_cnt;
102
103         ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
104 };
105
106 struct iscsi_buf {
107         struct scatterlist      sg;
108         unsigned int            sent;
109         char                    use_sendmsg;
110 };
111
112 struct iscsi_data_task {
113         struct iscsi_data       hdr;                    /* PDU */
114         char                    hdrext[sizeof(__u32)];  /* Header-Digest */
115         struct iscsi_buf        digestbuf;              /* digest buffer */
116         uint32_t                digest;                 /* data digest */
117 };
118
119 struct iscsi_tcp_mgmt_task {
120         struct iscsi_hdr        hdr;
121         char                    hdrext[sizeof(__u32)]; /* Header-Digest */
122         int                     xmstate;        /* mgmt xmit progress */
123         struct iscsi_buf        headbuf;        /* header buffer */
124         struct iscsi_buf        sendbuf;        /* in progress buffer */
125         int                     sent;
126 };
127
128 struct iscsi_r2t_info {
129         __be32                  ttt;            /* copied from R2T */
130         __be32                  exp_statsn;     /* copied from R2T */
131         uint32_t                data_length;    /* copied from R2T */
132         uint32_t                data_offset;    /* copied from R2T */
133         struct iscsi_buf        headbuf;        /* Data-Out Header Buffer */
134         struct iscsi_buf        sendbuf;        /* Data-Out in progress buffer*/
135         int                     sent;           /* R2T sequence progress */
136         int                     data_count;     /* DATA-Out payload progress */
137         struct scatterlist      *sg;            /* per-R2T SG list */
138         int                     solicit_datasn;
139         struct iscsi_data_task   dtask;        /* which data task */
140 };
141
142 struct iscsi_tcp_cmd_task {
143         struct iscsi_cmd        hdr;
144         char                    hdrext[4*sizeof(__u16)+ /* AHS */
145                                     sizeof(__u32)];     /* HeaderDigest */
146         char                    pad[ISCSI_PAD_LEN];
147         int                     pad_count;              /* padded bytes */
148         struct iscsi_buf        headbuf;                /* header buf (xmit) */
149         struct iscsi_buf        sendbuf;                /* in progress buffer*/
150         int                     xmstate;                /* xmit xtate machine */
151         int                     sent;
152         struct scatterlist      *sg;                    /* per-cmd SG list  */
153         struct scatterlist      *bad_sg;                /* assert statement */
154         int                     sg_count;               /* SG's to process  */
155         uint32_t                exp_r2tsn;
156         int                     data_offset;
157         struct iscsi_r2t_info   *r2t;                   /* in progress R2T    */
158         struct iscsi_queue      r2tpool;
159         struct kfifo            *r2tqueue;
160         struct iscsi_r2t_info   **r2ts;
161         int                     digest_count;
162         uint32_t                immdigest;              /* for imm data */
163         struct iscsi_buf        immbuf;                 /* for imm data digest */
164         struct iscsi_data_task  unsol_dtask;    /* unsol data task */
165 };
166
167 #endif /* ISCSI_H */