1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2016 Netflix, Inc.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 */
29
30#ifndef __tcp_log_dev_h__
31#define	__tcp_log_dev_h__
32
33/*
34 * This is the common header for data streamed from the log device. All
35 * blocks of data need to start with this header.
36 */
37struct tcp_log_common_header {
38	uint32_t	tlch_version;	/* Version is specific to type. */
39	uint32_t	tlch_type;	/* Type of entry(ies) that follow. */
40	uint64_t	tlch_length;	/* Total length, including header. */
41} __packed;
42
43#define	TCP_LOG_DEV_TYPE_BBR	1	/* black box recorder */
44
45#ifdef _KERNEL
46/*
47 * This is a queue entry. All queue entries need to start with this structure
48 * so the common code can cast them to this structure; however, other modules
49 * are free to include additional data after this structure.
50 *
51 * The elements are explained here:
52 * tldq_queue: used by the common code to maintain this entry's position in the
53 *     queue.
54 * tldq_buf: should be NULL, or a pointer to a chunk of data. The data must be
55 *     as long as the common header indicates.
56 * tldq_xform: If tldq_buf is NULL, the code will call this to create the
57 *     the tldq_buf object. The function should *not* directly modify tldq_buf,
58 *     but should return the buffer (which must meet the restrictions
59 *     indicated for tldq_buf).
60 * tldq_dtor: This function is called to free the queue entry. If tldq_buf is
61 *     not NULL, the dtor function must free that, too.
62 * tldq_refcnt: used by the common code to indicate how many readers still need
63 *     this data.
64 */
65struct tcp_log_dev_queue {
66	STAILQ_ENTRY(tcp_log_dev_queue) tldq_queue;
67	struct tcp_log_common_header *tldq_buf;
68	struct tcp_log_common_header *(*tldq_xform)(struct tcp_log_dev_queue *entry);
69	void	(*tldq_dtor)(struct tcp_log_dev_queue *entry);
70	volatile u_int tldq_refcnt;
71};
72
73STAILQ_HEAD(log_queueh, tcp_log_dev_queue);
74
75struct tcp_log_dev_info {
76	STAILQ_ENTRY(tcp_log_dev_info) tldi_list;
77	struct tcp_log_dev_queue *tldi_head;
78	struct tcp_log_common_header *tldi_cur;
79	off_t			tldi_off;
80};
81STAILQ_HEAD(log_infoh, tcp_log_dev_info);
82
83#ifdef TCP_BLACKBOX
84MALLOC_DECLARE(M_TCPLOGDEV);
85int tcp_log_dev_add_log(struct tcp_log_dev_queue *entry);
86#endif /* TCP_BLACKBOX */
87#endif /* _KERNEL */
88#endif /* !__tcp_log_dev_h__ */
89