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 26 struct iscsi_tcp_conn; 27 struct iscsi_segment; 28 struct sk_buff; 29 struct hash_desc; 30 31 typedef int iscsi_segment_done_fn_t(struct iscsi_tcp_conn *, 32 struct iscsi_segment *); 33 34 struct 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 hash_desc *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 */ 56 struct 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 67 struct 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 hash_desc *rx_hash; 77 }; 78 79 struct 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 }; 87 88 enum { 89 ISCSI_TCP_SEGMENT_DONE, /* curr seg has been processed */ 90 ISCSI_TCP_SKB_DONE, /* skb is out of data */ 91 ISCSI_TCP_CONN_ERR, /* iscsi layer has fired a conn err */ 92 ISCSI_TCP_SUSPENDED, /* conn is suspended */ 93 }; 94 95 extern void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn); 96 extern int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb, 97 unsigned int offset, bool offloaded, int *status); 98 extern void iscsi_tcp_cleanup_task(struct iscsi_task *task); 99 extern int iscsi_tcp_task_init(struct iscsi_task *task); 100 extern int iscsi_tcp_task_xmit(struct iscsi_task *task); 101 102 /* segment helpers */ 103 extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn); 104 extern int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn, 105 struct iscsi_segment *segment, int recv, 106 unsigned copied); 107 extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment); 108 109 extern void iscsi_segment_init_linear(struct iscsi_segment *segment, 110 void *data, size_t size, 111 iscsi_segment_done_fn_t *done, 112 struct hash_desc *hash); 113 extern int 114 iscsi_segment_seek_sg(struct iscsi_segment *segment, 115 struct scatterlist *sg_list, unsigned int sg_count, 116 unsigned int offset, size_t size, 117 iscsi_segment_done_fn_t *done, struct hash_desc *hash); 118 119 /* digest helpers */ 120 extern void iscsi_tcp_dgst_header(struct hash_desc *hash, const void *hdr, 121 size_t hdrlen, 122 unsigned char digest[ISCSI_DIGEST_SIZE]); 123 extern struct iscsi_cls_conn * 124 iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size, 125 uint32_t conn_idx); 126 extern void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn); 127 128 /* misc helpers */ 129 extern int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session); 130 extern void iscsi_tcp_r2tpool_free(struct iscsi_session *session); 131 extern int iscsi_tcp_set_max_r2t(struct iscsi_conn *conn, char *buf); 132 extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn, 133 struct iscsi_stats *stats); 134 #endif /* LIBISCSI_TCP_H */ 135