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_DATA_DIGEST 0x400 46 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 53 54 struct crypto_hash; 55 struct socket; 56 57 /* Socket connection recieve helper */ 58 struct iscsi_tcp_recv { 59 struct iscsi_hdr *hdr; 60 struct sk_buff *skb; 61 int offset; 62 int len; 63 int hdr_offset; 64 int copy; 65 int copied; 66 int padding; 67 struct iscsi_cmd_task *ctask; /* current cmd in progress */ 68 69 /* copied and flipped values */ 70 int datalen; 71 int datadgst; 72 char zero_copy_hdr; 73 }; 74 75 struct iscsi_tcp_conn { 76 struct iscsi_conn *iscsi_conn; 77 struct socket *sock; 78 struct iscsi_hdr hdr; /* header placeholder */ 79 char hdrext[4*sizeof(__u16) + 80 sizeof(__u32)]; 81 int data_copied; 82 int stop_stage; /* conn_stop() flag: * 83 * stop to recover, * 84 * stop to terminate */ 85 /* iSCSI connection-wide sequencing */ 86 int hdr_size; /* PDU header size */ 87 88 struct crypto_hash *rx_tfm; /* CRC32C (Rx) */ 89 struct hash_desc data_rx_hash; /* CRC32C (Rx) for data */ 90 91 /* control data */ 92 struct iscsi_tcp_recv in; /* TCP receive context */ 93 int in_progress; /* connection state machine */ 94 95 /* old values for socket callbacks */ 96 void (*old_data_ready)(struct sock *, int); 97 void (*old_state_change)(struct sock *); 98 void (*old_write_space)(struct sock *); 99 100 /* xmit */ 101 struct crypto_hash *tx_tfm; /* CRC32C (Tx) */ 102 struct hash_desc data_tx_hash; /* CRC32C (Tx) for data */ 103 104 /* MIB custom statistics */ 105 uint32_t sendpage_failures_cnt; 106 uint32_t discontiguous_hdr_cnt; 107 108 ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int); 109 }; 110 111 struct iscsi_buf { 112 struct scatterlist sg; 113 unsigned int sent; 114 char use_sendmsg; 115 }; 116 117 struct iscsi_data_task { 118 struct iscsi_data hdr; /* PDU */ 119 char hdrext[sizeof(__u32)]; /* Header-Digest */ 120 struct iscsi_buf digestbuf; /* digest buffer */ 121 uint32_t digest; /* data digest */ 122 }; 123 124 struct iscsi_tcp_mgmt_task { 125 struct iscsi_hdr hdr; 126 char hdrext[sizeof(__u32)]; /* Header-Digest */ 127 int xmstate; /* mgmt xmit progress */ 128 struct iscsi_buf headbuf; /* header buffer */ 129 struct iscsi_buf sendbuf; /* in progress buffer */ 130 int sent; 131 }; 132 133 struct iscsi_r2t_info { 134 __be32 ttt; /* copied from R2T */ 135 __be32 exp_statsn; /* copied from R2T */ 136 uint32_t data_length; /* copied from R2T */ 137 uint32_t data_offset; /* copied from R2T */ 138 struct iscsi_buf headbuf; /* Data-Out Header Buffer */ 139 struct iscsi_buf sendbuf; /* Data-Out in progress buffer*/ 140 int sent; /* R2T sequence progress */ 141 int data_count; /* DATA-Out payload progress */ 142 struct scatterlist *sg; /* per-R2T SG list */ 143 int solicit_datasn; 144 struct iscsi_data_task dtask; /* which data task */ 145 }; 146 147 struct iscsi_tcp_cmd_task { 148 struct iscsi_cmd hdr; 149 char hdrext[4*sizeof(__u16)+ /* AHS */ 150 sizeof(__u32)]; /* HeaderDigest */ 151 char pad[ISCSI_PAD_LEN]; 152 int pad_count; /* padded bytes */ 153 struct iscsi_buf headbuf; /* header buf (xmit) */ 154 struct iscsi_buf sendbuf; /* in progress buffer*/ 155 int xmstate; /* xmit xtate machine */ 156 int sent; 157 struct scatterlist *sg; /* per-cmd SG list */ 158 struct scatterlist *bad_sg; /* assert statement */ 159 int sg_count; /* SG's to process */ 160 uint32_t exp_r2tsn; 161 int r2t_data_count; /* R2T Data-Out bytes */ 162 int data_offset; 163 struct iscsi_r2t_info *r2t; /* in progress R2T */ 164 struct iscsi_queue r2tpool; 165 struct kfifo *r2tqueue; 166 struct iscsi_r2t_info **r2ts; 167 uint32_t datadigest; /* for recover digest */ 168 int digest_count; 169 uint32_t immdigest; /* for imm data */ 170 struct iscsi_buf immbuf; /* for imm data digest */ 171 struct iscsi_data_task *dtask; /* data task in progress*/ 172 struct iscsi_data_task unsol_dtask; /* unsol data task */ 173 int digest_offset; /* for partial buff digest */ 174 }; 175 176 #endif /* ISCSI_H */ 177