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 * See the file COPYING included with this distribution for more details. 10 */ 11 12 #ifndef LIBISCSI_TCP_H 13 #define LIBISCSI_TCP_H 14 15 #include <scsi/libiscsi.h> 16 17 struct iscsi_tcp_conn; 18 struct iscsi_segment; 19 struct sk_buff; 20 struct ahash_request; 21 22 typedef int iscsi_segment_done_fn_t(struct iscsi_tcp_conn *, 23 struct iscsi_segment *); 24 25 struct iscsi_segment { 26 unsigned char *data; 27 unsigned int size; 28 unsigned int copied; 29 unsigned int total_size; 30 unsigned int total_copied; 31 32 struct ahash_request *hash; 33 unsigned char padbuf[ISCSI_PAD_LEN]; 34 unsigned char recv_digest[ISCSI_DIGEST_SIZE]; 35 unsigned char digest[ISCSI_DIGEST_SIZE]; 36 unsigned int digest_len; 37 38 struct scatterlist *sg; 39 void *sg_mapped; 40 unsigned int sg_offset; 41 bool atomic_mapped; 42 43 iscsi_segment_done_fn_t *done; 44 }; 45 46 /* Socket connection receive helper */ 47 struct iscsi_tcp_recv { 48 struct iscsi_hdr *hdr; 49 struct iscsi_segment segment; 50 51 /* Allocate buffer for BHS + AHS */ 52 uint32_t hdr_buf[64]; 53 54 /* copied and flipped values */ 55 int datalen; 56 }; 57 58 struct iscsi_tcp_conn { 59 struct iscsi_conn *iscsi_conn; 60 void *dd_data; 61 int stop_stage; /* conn_stop() flag: * 62 * stop to recover, * 63 * stop to terminate */ 64 /* control data */ 65 struct iscsi_tcp_recv in; /* TCP receive context */ 66 /* CRC32C (Rx) LLD should set this is they do not offload */ 67 struct ahash_request *rx_hash; 68 }; 69 70 struct iscsi_tcp_task { 71 uint32_t exp_datasn; /* expected target's R2TSN/DataSN */ 72 int data_offset; 73 struct iscsi_r2t_info *r2t; /* in progress solict R2T */ 74 struct iscsi_pool r2tpool; 75 struct kfifo r2tqueue; 76 void *dd_data; 77 spinlock_t pool2queue; 78 spinlock_t queue2pool; 79 }; 80 81 enum { 82 ISCSI_TCP_SEGMENT_DONE, /* curr seg has been processed */ 83 ISCSI_TCP_SKB_DONE, /* skb is out of data */ 84 ISCSI_TCP_CONN_ERR, /* iscsi layer has fired a conn err */ 85 ISCSI_TCP_SUSPENDED, /* conn is suspended */ 86 }; 87 88 extern void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn); 89 extern int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb, 90 unsigned int offset, bool offloaded, int *status); 91 extern void iscsi_tcp_cleanup_task(struct iscsi_task *task); 92 extern int iscsi_tcp_task_init(struct iscsi_task *task); 93 extern int iscsi_tcp_task_xmit(struct iscsi_task *task); 94 95 /* segment helpers */ 96 extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn); 97 extern int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn, 98 struct iscsi_segment *segment, int recv, 99 unsigned copied); 100 extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment); 101 102 extern void iscsi_segment_init_linear(struct iscsi_segment *segment, 103 void *data, size_t size, 104 iscsi_segment_done_fn_t *done, 105 struct ahash_request *hash); 106 extern int 107 iscsi_segment_seek_sg(struct iscsi_segment *segment, 108 struct scatterlist *sg_list, unsigned int sg_count, 109 unsigned int offset, size_t size, 110 iscsi_segment_done_fn_t *done, 111 struct ahash_request *hash); 112 113 /* digest helpers */ 114 extern void iscsi_tcp_dgst_header(struct ahash_request *hash, const void *hdr, 115 size_t hdrlen, 116 unsigned char digest[ISCSI_DIGEST_SIZE]); 117 extern struct iscsi_cls_conn * 118 iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size, 119 uint32_t conn_idx); 120 extern void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn); 121 122 /* misc helpers */ 123 extern int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session); 124 extern void iscsi_tcp_r2tpool_free(struct iscsi_session *session); 125 extern int iscsi_tcp_set_max_r2t(struct iscsi_conn *conn, char *buf); 126 extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn, 127 struct iscsi_stats *stats); 128 #endif /* LIBISCSI_TCP_H */ 129