1/*
2 * iSCSI over TCP/IP Data-Path lib
3 *
4 * Copyright (C) 2008 Mike Christie
5 * Copyright (C) 2008 Red Hat, Inc. All rights reserved.
6 * maintained by open-iscsi@googlegroups.com
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published
10 * by the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * See the file COPYING included with this distribution for more details.
19 */
20
21#ifndef LIBISCSI_TCP_H
22#define LIBISCSI_TCP_H
23
24#include <scsi/libiscsi.h>
25
26struct iscsi_tcp_conn;
27struct iscsi_segment;
28struct sk_buff;
29struct ahash_request;
30
31typedef int iscsi_segment_done_fn_t(struct iscsi_tcp_conn *,
32 struct iscsi_segment *);
33
34struct iscsi_segment {
35 unsigned char *data;
36 unsigned int size;
37 unsigned int copied;
38 unsigned int total_size;
39 unsigned int total_copied;
40
41 struct ahash_request *hash;
42 unsigned char padbuf[ISCSI_PAD_LEN];
43 unsigned char recv_digest[ISCSI_DIGEST_SIZE];
44 unsigned char digest[ISCSI_DIGEST_SIZE];
45 unsigned int digest_len;
46
47 struct scatterlist *sg;
48 void *sg_mapped;
49 unsigned int sg_offset;
50 bool atomic_mapped;
51
52 iscsi_segment_done_fn_t *done;
53};
54
55/* Socket connection receive helper */
56struct iscsi_tcp_recv {
57 struct iscsi_hdr *hdr;
58 struct iscsi_segment segment;
59
60 /* Allocate buffer for BHS + AHS */
61 uint32_t hdr_buf[64];
62
63 /* copied and flipped values */
64 int datalen;
65};
66
67struct iscsi_tcp_conn {
68 struct iscsi_conn *iscsi_conn;
69 void *dd_data;
70 int stop_stage; /* conn_stop() flag: *
71 * stop to recover, *
72 * stop to terminate */
73 /* control data */
74 struct iscsi_tcp_recv in; /* TCP receive context */
75 /* CRC32C (Rx) LLD should set this is they do not offload */
76 struct ahash_request *rx_hash;
77};
78
79struct iscsi_tcp_task {
80 uint32_t exp_datasn; /* expected target's R2TSN/DataSN */
81 int data_offset;
82 struct iscsi_r2t_info *r2t; /* in progress solict R2T */
83 struct iscsi_pool r2tpool;
84 struct kfifo r2tqueue;
85 void *dd_data;
86 spinlock_t pool2queue;
87 spinlock_t queue2pool;
88};
89
90enum {
91 ISCSI_TCP_SEGMENT_DONE, /* curr seg has been processed */
92 ISCSI_TCP_SKB_DONE, /* skb is out of data */
93 ISCSI_TCP_CONN_ERR, /* iscsi layer has fired a conn err */
94 ISCSI_TCP_SUSPENDED, /* conn is suspended */
95};
96
97extern void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn);
98extern int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,
99 unsigned int offset, bool offloaded, int *status);
100extern void iscsi_tcp_cleanup_task(struct iscsi_task *task);
101extern int iscsi_tcp_task_init(struct iscsi_task *task);
102extern int iscsi_tcp_task_xmit(struct iscsi_task *task);
103
104/* segment helpers */
105extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn);
106extern int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn,
107 struct iscsi_segment *segment, int recv,
108 unsigned copied);
109extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment);
110
111extern void iscsi_segment_init_linear(struct iscsi_segment *segment,
112 void *data, size_t size,
113 iscsi_segment_done_fn_t *done,
114 struct ahash_request *hash);
115extern int
116iscsi_segment_seek_sg(struct iscsi_segment *segment,
117 struct scatterlist *sg_list, unsigned int sg_count,
118 unsigned int offset, size_t size,
119 iscsi_segment_done_fn_t *done,
120 struct ahash_request *hash);
121
122/* digest helpers */
123extern void iscsi_tcp_dgst_header(struct ahash_request *hash, const void *hdr,
124 size_t hdrlen,
125 unsigned char digest[ISCSI_DIGEST_SIZE]);
126extern struct iscsi_cls_conn *
127iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size,
128 uint32_t conn_idx);
129extern void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn);
130
131/* misc helpers */
132extern int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session);
133extern void iscsi_tcp_r2tpool_free(struct iscsi_session *session);
134extern int iscsi_tcp_set_max_r2t(struct iscsi_conn *conn, char *buf);
135extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
136 struct iscsi_stats *stats);
137#endif /* LIBISCSI_TCP_H */
138