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 19 typedef int iscsi_segment_done_fn_t(struct iscsi_tcp_conn *, 20 struct iscsi_segment *); 21 22 struct iscsi_segment { 23 unsigned char *data; 24 unsigned int size; 25 unsigned int copied; 26 unsigned int total_size; 27 unsigned int total_copied; 28 29 u32 *crcp; 30 unsigned char padbuf[ISCSI_PAD_LEN]; 31 unsigned char recv_digest[ISCSI_DIGEST_SIZE]; 32 unsigned char digest[ISCSI_DIGEST_SIZE]; 33 unsigned int digest_len; 34 35 struct scatterlist *sg; 36 void *sg_mapped; 37 unsigned int sg_offset; 38 bool atomic_mapped; 39 40 iscsi_segment_done_fn_t *done; 41 }; 42 43 /* Socket connection receive helper */ 44 struct iscsi_tcp_recv { 45 struct iscsi_hdr *hdr; 46 struct iscsi_segment segment; 47 48 /* Allocate buffer for BHS + AHS */ 49 uint32_t hdr_buf[64]; 50 51 /* copied and flipped values */ 52 int datalen; 53 }; 54 55 struct iscsi_tcp_conn { 56 struct iscsi_conn *iscsi_conn; 57 void *dd_data; 58 int stop_stage; /* conn_stop() flag: * 59 * stop to recover, * 60 * stop to terminate */ 61 /* control data */ 62 struct iscsi_tcp_recv in; /* TCP receive context */ 63 /* CRC32C (Rx) LLD should set this if they do not offload */ 64 u32 *rx_crcp; 65 }; 66 67 struct iscsi_tcp_task { 68 uint32_t exp_datasn; /* expected target's R2TSN/DataSN */ 69 int data_offset; 70 struct iscsi_r2t_info *r2t; /* in progress solict R2T */ 71 struct iscsi_pool r2tpool; 72 struct kfifo r2tqueue; 73 void *dd_data; 74 spinlock_t pool2queue; 75 spinlock_t queue2pool; 76 }; 77 78 enum { 79 ISCSI_TCP_SEGMENT_DONE, /* curr seg has been processed */ 80 ISCSI_TCP_SKB_DONE, /* skb is out of data */ 81 ISCSI_TCP_CONN_ERR, /* iscsi layer has fired a conn err */ 82 ISCSI_TCP_SUSPENDED, /* conn is suspended */ 83 }; 84 85 extern void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn); 86 extern int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb, 87 unsigned int offset, bool offloaded, int *status); 88 extern void iscsi_tcp_cleanup_task(struct iscsi_task *task); 89 extern int iscsi_tcp_task_init(struct iscsi_task *task); 90 extern int iscsi_tcp_task_xmit(struct iscsi_task *task); 91 92 /* segment helpers */ 93 extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn); 94 extern int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn, 95 struct iscsi_segment *segment, int recv, 96 unsigned copied); 97 extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment); 98 99 extern void iscsi_segment_init_linear(struct iscsi_segment *segment, 100 void *data, size_t size, 101 iscsi_segment_done_fn_t *done, u32 *crcp); 102 extern int 103 iscsi_segment_seek_sg(struct iscsi_segment *segment, 104 struct scatterlist *sg_list, unsigned int sg_count, 105 unsigned int offset, size_t size, 106 iscsi_segment_done_fn_t *done, u32 *crcp); 107 108 /* digest helpers */ 109 extern void iscsi_tcp_dgst_header(const void *hdr, size_t hdrlen, 110 unsigned char digest[ISCSI_DIGEST_SIZE]); 111 extern struct iscsi_cls_conn * 112 iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size, 113 uint32_t conn_idx); 114 extern void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn); 115 116 /* misc helpers */ 117 extern int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session); 118 extern void iscsi_tcp_r2tpool_free(struct iscsi_session *session); 119 extern int iscsi_tcp_set_max_r2t(struct iscsi_conn *conn, char *buf); 120 extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn, 121 struct iscsi_stats *stats); 122 #endif /* LIBISCSI_TCP_H */ 123