1/*-
 2 * SPDX-License-Identifier: BSD-2-Clause
 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
28#ifndef __tcp_log_dev_h__
29#define	__tcp_log_dev_h__
30
31/*
32 * This is the common header for data streamed from the log device. All
33 * blocks of data need to start with this header.
34 */
35struct tcp_log_common_header {
36	uint32_t	tlch_version;	/* Version is specific to type. */
37	uint32_t	tlch_type;	/* Type of entry(ies) that follow. */
38	uint64_t	tlch_length;	/* Total length, including header. */
39} __packed;
40
41#define	TCP_LOG_DEV_TYPE_BBR	1	/* black box recorder */
42
43#ifdef _KERNEL
44/*
45 * This is a queue entry. All queue entries need to start with this structure
46 * so the common code can cast them to this structure; however, other modules
47 * are free to include additional data after this structure.
48 *
49 * The elements are explained here:
50 * tldq_queue: used by the common code to maintain this entry's position in the
51 *     queue.
52 * tldq_buf: should be NULL, or a pointer to a chunk of data. The data must be
53 *     as long as the common header indicates.
54 * tldq_xform: If tldq_buf is NULL, the code will call this to create the
55 *     the tldq_buf object. The function should *not* directly modify tldq_buf,
56 *     but should return the buffer (which must meet the restrictions
57 *     indicated for tldq_buf).
58 * tldq_dtor: This function is called to free the queue entry. If tldq_buf is
59 *     not NULL, the dtor function must free that, too.
60 * tldq_refcnt: used by the common code to indicate how many readers still need
61 *     this data.
62 */
63struct tcp_log_dev_queue {
64	STAILQ_ENTRY(tcp_log_dev_queue) tldq_queue;
65	struct tcp_log_common_header *tldq_buf;
66	struct tcp_log_common_header *(*tldq_xform)(struct tcp_log_dev_queue *entry);
67	void	(*tldq_dtor)(struct tcp_log_dev_queue *entry);
68	volatile u_int tldq_refcnt;
69};
70
71STAILQ_HEAD(log_queueh, tcp_log_dev_queue);
72
73struct tcp_log_dev_info {
74	STAILQ_ENTRY(tcp_log_dev_info) tldi_list;
75	struct tcp_log_dev_queue *tldi_head;
76	struct tcp_log_common_header *tldi_cur;
77	off_t			tldi_off;
78};
79STAILQ_HEAD(log_infoh, tcp_log_dev_info);
80
81#ifdef TCP_BLACKBOX
82MALLOC_DECLARE(M_TCPLOGDEV);
83int tcp_log_dev_add_log(struct tcp_log_dev_queue *entry);
84#endif /* TCP_BLACKBOX */
85#endif /* _KERNEL */
86#endif /* !__tcp_log_dev_h__ */