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 #define ISCSI_SG_TABLESIZE SG_ALL
28 #define ISCSI_TCP_MAX_CMD_LEN 16
32 struct iscsi_tcp_conn;
35 typedef int iscsi_segment_done_fn_t(struct iscsi_tcp_conn *,
36 struct iscsi_segment *);
38 struct iscsi_segment {
42 unsigned int total_size;
43 unsigned int total_copied;
45 struct hash_desc *hash;
46 unsigned char recv_digest[ISCSI_DIGEST_SIZE];
47 unsigned char digest[ISCSI_DIGEST_SIZE];
48 unsigned int digest_len;
50 struct scatterlist *sg;
52 unsigned int sg_offset;
54 iscsi_segment_done_fn_t *done;
57 /* Socket connection recieve helper */
58 struct iscsi_tcp_recv {
59 struct iscsi_hdr *hdr;
60 struct iscsi_segment segment;
62 /* Allocate buffer for BHS + AHS */
65 /* copied and flipped values */
69 /* Socket connection send helper */
70 struct iscsi_tcp_send {
71 struct iscsi_hdr *hdr;
72 struct iscsi_segment segment;
73 struct iscsi_segment data_segment;
76 struct iscsi_tcp_conn {
77 struct iscsi_conn *iscsi_conn;
79 int stop_stage; /* conn_stop() flag: *
81 * stop to terminate */
83 struct iscsi_tcp_recv in; /* TCP receive context */
84 struct iscsi_tcp_send out; /* TCP send context */
86 /* old values for socket callbacks */
87 void (*old_data_ready)(struct sock *, int);
88 void (*old_state_change)(struct sock *);
89 void (*old_write_space)(struct sock *);
91 /* data and header digests */
92 struct hash_desc tx_hash; /* CRC32C (Tx) */
93 struct hash_desc rx_hash; /* CRC32C (Rx) */
95 /* MIB custom statistics */
96 uint32_t sendpage_failures_cnt;
97 uint32_t discontiguous_hdr_cnt;
101 ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
104 struct iscsi_data_task {
105 struct iscsi_data hdr; /* PDU */
106 char hdrext[ISCSI_DIGEST_SIZE];/* Header-Digest */
109 struct iscsi_tcp_mgmt_task {
110 struct iscsi_hdr hdr;
111 char hdrext[ISCSI_DIGEST_SIZE]; /* Header-Digest */
114 struct iscsi_r2t_info {
115 __be32 ttt; /* copied from R2T */
116 __be32 exp_statsn; /* copied from R2T */
117 uint32_t data_length; /* copied from R2T */
118 uint32_t data_offset; /* copied from R2T */
119 int sent; /* R2T sequence progress */
120 int data_count; /* DATA-Out payload progress */
122 struct iscsi_data_task dtask; /* Data-Out header buf */
125 struct iscsi_tcp_cmd_task {
126 struct iscsi_hdr_buff {
127 struct iscsi_cmd cmd_hdr;
128 char hdrextbuf[ISCSI_MAX_AHS_SIZE +
133 uint32_t exp_datasn; /* expected target's R2TSN/DataSN */
135 struct iscsi_r2t_info *r2t; /* in progress R2T */
136 struct iscsi_pool r2tpool;
137 struct kfifo *r2tqueue;
138 struct iscsi_data_task unsol_dtask; /* Data-Out header buf */