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 #define IN_PROGRESS_PAD_RECV 0x4 33 34 /* xmit state machine */ 35 #define XMSTATE_IDLE 0x0 36 #define XMSTATE_CMD_HDR_INIT 0x1 37 #define XMSTATE_CMD_HDR_XMIT 0x2 38 #define XMSTATE_IMM_HDR 0x4 39 #define XMSTATE_IMM_DATA 0x8 40 #define XMSTATE_UNS_INIT 0x10 41 #define XMSTATE_UNS_HDR 0x20 42 #define XMSTATE_UNS_DATA 0x40 43 #define XMSTATE_SOL_HDR 0x80 44 #define XMSTATE_SOL_DATA 0x100 45 #define XMSTATE_W_PAD 0x200 46 #define XMSTATE_W_RESEND_PAD 0x400 47 #define XMSTATE_W_RESEND_DATA_DIGEST 0x800 48 #define XMSTATE_IMM_HDR_INIT 0x1000 49 #define XMSTATE_SOL_HDR_INIT 0x2000 50 51 #define ISCSI_PAD_LEN 4 52 #define ISCSI_SG_TABLESIZE SG_ALL 53 #define ISCSI_TCP_MAX_CMD_LEN 16 54 55 struct crypto_hash; 56 struct socket; 57 58 /* Socket connection recieve helper */ 59 struct iscsi_tcp_recv { 60 struct iscsi_hdr *hdr; 61 struct sk_buff *skb; 62 int offset; 63 int len; 64 int hdr_offset; 65 int copy; 66 int copied; 67 int padding; 68 struct iscsi_cmd_task *ctask; /* current cmd in progress */ 69 70 /* copied and flipped values */ 71 int datalen; 72 int datadgst; 73 char zero_copy_hdr; 74 }; 75 76 struct iscsi_tcp_conn { 77 struct iscsi_conn *iscsi_conn; 78 struct socket *sock; 79 struct iscsi_hdr hdr; /* header placeholder */ 80 char hdrext[4*sizeof(__u16) + 81 sizeof(__u32)]; 82 int data_copied; 83 int stop_stage; /* conn_stop() flag: * 84 * stop to recover, * 85 * stop to terminate */ 86 /* iSCSI connection-wide sequencing */ 87 int hdr_size; /* PDU header size */ 88 89 /* control data */ 90 struct iscsi_tcp_recv in; /* TCP receive context */ 91 int in_progress; /* connection state machine */ 92 93 /* old values for socket callbacks */ 94 void (*old_data_ready)(struct sock *, int); 95 void (*old_state_change)(struct sock *); 96 void (*old_write_space)(struct sock *); 97 98 /* data and header digests */ 99 struct hash_desc tx_hash; /* CRC32C (Tx) */ 100 struct hash_desc rx_hash; /* CRC32C (Rx) */ 101 102 /* MIB custom statistics */ 103 uint32_t sendpage_failures_cnt; 104 uint32_t discontiguous_hdr_cnt; 105 106 ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int); 107 }; 108 109 struct iscsi_buf { 110 struct scatterlist sg; 111 unsigned int sent; 112 char use_sendmsg; 113 }; 114 115 struct iscsi_data_task { 116 struct iscsi_data hdr; /* PDU */ 117 char hdrext[sizeof(__u32)]; /* Header-Digest */ 118 struct iscsi_buf digestbuf; /* digest buffer */ 119 uint32_t digest; /* data digest */ 120 }; 121 122 struct iscsi_tcp_mgmt_task { 123 struct iscsi_hdr hdr; 124 char hdrext[sizeof(__u32)]; /* Header-Digest */ 125 int xmstate; /* mgmt xmit progress */ 126 struct iscsi_buf headbuf; /* header buffer */ 127 struct iscsi_buf sendbuf; /* in progress buffer */ 128 int sent; 129 }; 130 131 struct iscsi_r2t_info { 132 __be32 ttt; /* copied from R2T */ 133 __be32 exp_statsn; /* copied from R2T */ 134 uint32_t data_length; /* copied from R2T */ 135 uint32_t data_offset; /* copied from R2T */ 136 struct iscsi_buf headbuf; /* Data-Out Header Buffer */ 137 struct iscsi_buf sendbuf; /* Data-Out in progress buffer*/ 138 int sent; /* R2T sequence progress */ 139 int data_count; /* DATA-Out payload progress */ 140 struct scatterlist *sg; /* per-R2T SG list */ 141 int solicit_datasn; 142 struct iscsi_data_task dtask; /* which data task */ 143 }; 144 145 struct iscsi_tcp_cmd_task { 146 struct iscsi_cmd hdr; 147 char hdrext[4*sizeof(__u16)+ /* AHS */ 148 sizeof(__u32)]; /* HeaderDigest */ 149 char pad[ISCSI_PAD_LEN]; 150 int pad_count; /* padded bytes */ 151 struct iscsi_buf headbuf; /* header buf (xmit) */ 152 struct iscsi_buf sendbuf; /* in progress buffer*/ 153 int xmstate; /* xmit xtate machine */ 154 int sent; 155 struct scatterlist *sg; /* per-cmd SG list */ 156 struct scatterlist *bad_sg; /* assert statement */ 157 int sg_count; /* SG's to process */ 158 uint32_t exp_datasn; /* expected target's R2TSN/DataSN */ 159 int data_offset; 160 struct iscsi_r2t_info *r2t; /* in progress R2T */ 161 struct iscsi_queue r2tpool; 162 struct kfifo *r2tqueue; 163 struct iscsi_r2t_info **r2ts; 164 int digest_count; 165 uint32_t immdigest; /* for imm data */ 166 struct iscsi_buf immbuf; /* for imm data digest */ 167 struct iscsi_data_task unsol_dtask; /* unsol data task */ 168 }; 169 170 #endif /* ISCSI_H */ 171