1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * iSCSI over TCP/IP Data-Path lib
4 *
5 * Copyright (C) 2008 Mike Christie
6 * Copyright (C) 2008 Red Hat, Inc. All rights reserved.
7 * maintained by open-iscsi@googlegroups.com
8 */
9
10 #ifndef LIBISCSI_TCP_H
11 #define LIBISCSI_TCP_H
12
13 #include <scsi/libiscsi.h>
14
15 struct iscsi_tcp_conn;
16 struct iscsi_segment;
17 struct sk_buff;
18 struct ahash_request;
19
20 typedef int iscsi_segment_done_fn_t(struct iscsi_tcp_conn *,
21 struct iscsi_segment *);
22
23 struct iscsi_segment {
24 unsigned char *data;
25 unsigned int size;
26 unsigned int copied;
27 unsigned int total_size;
28 unsigned int total_copied;
29
30 struct ahash_request *hash;
31 unsigned char padbuf[ISCSI_PAD_LEN];
32 unsigned char recv_digest[ISCSI_DIGEST_SIZE];
33 unsigned char digest[ISCSI_DIGEST_SIZE];
34 unsigned int digest_len;
35
36 struct scatterlist *sg;
37 void *sg_mapped;
38 unsigned int sg_offset;
39 bool atomic_mapped;
40
41 iscsi_segment_done_fn_t *done;
42 };
43
44 /* Socket connection receive helper */
45 struct iscsi_tcp_recv {
46 struct iscsi_hdr *hdr;
47 struct iscsi_segment segment;
48
49 /* Allocate buffer for BHS + AHS */
50 uint32_t hdr_buf[64];
51
52 /* copied and flipped values */
53 int datalen;
54 };
55
56 struct iscsi_tcp_conn {
57 struct iscsi_conn *iscsi_conn;
58 void *dd_data;
59 int stop_stage; /* conn_stop() flag: *
60 * stop to recover, *
61 * stop to terminate */
62 /* control data */
63 struct iscsi_tcp_recv in; /* TCP receive context */
64 /* CRC32C (Rx) LLD should set this is they do not offload */
65 struct ahash_request *rx_hash;
66 };
67
68 struct iscsi_tcp_task {
69 uint32_t exp_datasn; /* expected target's R2TSN/DataSN */
70 int data_offset;
71 struct iscsi_r2t_info *r2t; /* in progress solict R2T */
72 struct iscsi_pool r2tpool;
73 struct kfifo r2tqueue;
74 void *dd_data;
75 spinlock_t pool2queue;
76 spinlock_t queue2pool;
77 };
78
79 enum {
80 ISCSI_TCP_SEGMENT_DONE, /* curr seg has been processed */
81 ISCSI_TCP_SKB_DONE, /* skb is out of data */
82 ISCSI_TCP_CONN_ERR, /* iscsi layer has fired a conn err */
83 ISCSI_TCP_SUSPENDED, /* conn is suspended */
84 };
85
86 extern void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn);
87 extern int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,
88 unsigned int offset, bool offloaded, int *status);
89 extern void iscsi_tcp_cleanup_task(struct iscsi_task *task);
90 extern int iscsi_tcp_task_init(struct iscsi_task *task);
91 extern int iscsi_tcp_task_xmit(struct iscsi_task *task);
92
93 /* segment helpers */
94 extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn);
95 extern int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn,
96 struct iscsi_segment *segment, int recv,
97 unsigned copied);
98 extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment);
99
100 extern void iscsi_segment_init_linear(struct iscsi_segment *segment,
101 void *data, size_t size,
102 iscsi_segment_done_fn_t *done,
103 struct ahash_request *hash);
104 extern int
105 iscsi_segment_seek_sg(struct iscsi_segment *segment,
106 struct scatterlist *sg_list, unsigned int sg_count,
107 unsigned int offset, size_t size,
108 iscsi_segment_done_fn_t *done,
109 struct ahash_request *hash);
110
111 /* digest helpers */
112 extern void iscsi_tcp_dgst_header(struct ahash_request *hash, const void *hdr,
113 size_t hdrlen,
114 unsigned char digest[ISCSI_DIGEST_SIZE]);
115 extern struct iscsi_cls_conn *
116 iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size,
117 uint32_t conn_idx);
118 extern void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn);
119
120 /* misc helpers */
121 extern int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session);
122 extern void iscsi_tcp_r2tpool_free(struct iscsi_session *session);
123 extern int iscsi_tcp_set_max_r2t(struct iscsi_conn *conn, char *buf);
124 extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
125 struct iscsi_stats *stats);
126 #endif /* LIBISCSI_TCP_H */
127
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