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