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 */ 168