xref: /freebsd/sys/dev/tcp_log/tcp_log_dev.h (revision d3d381b2b194b4d24853e92eecef55f262688d1a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2016
5  *	Netflix Inc.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #ifndef __tcp_log_dev_h__
32 #define	__tcp_log_dev_h__
33 
34 /*
35  * This is the common header for data streamed from the log device. All
36  * blocks of data need to start with this header.
37  */
38 struct tcp_log_common_header {
39 	uint32_t	tlch_version;	/* Version is specific to type. */
40 	uint32_t	tlch_type;	/* Type of entry(ies) that follow. */
41 	uint64_t	tlch_length;	/* Total length, including header. */
42 } __packed;
43 
44 #define	TCP_LOG_DEV_TYPE_BBR	1	/* black box recorder */
45 
46 #ifdef _KERNEL
47 /*
48  * This is a queue entry. All queue entries need to start with this structure
49  * so the common code can cast them to this structure; however, other modules
50  * are free to include additional data after this structure.
51  *
52  * The elements are explained here:
53  * tldq_queue: used by the common code to maintain this entry's position in the
54  *     queue.
55  * tldq_buf: should be NULL, or a pointer to a chunk of data. The data must be
56  *     as long as the common header indicates.
57  * tldq_xform: If tldq_buf is NULL, the code will call this to create the
58  *     the tldq_buf object. The function should *not* directly modify tldq_buf,
59  *     but should return the buffer (which must meet the restrictions
60  *     indicated for tldq_buf).
61  * tldq_dtor: This function is called to free the queue entry. If tldq_buf is
62  *     not NULL, the dtor function must free that, too.
63  * tldq_refcnt: used by the common code to indicate how many readers still need
64  *     this data.
65  */
66 struct tcp_log_dev_queue {
67 	STAILQ_ENTRY(tcp_log_dev_queue) tldq_queue;
68 	struct tcp_log_common_header *tldq_buf;
69 	struct tcp_log_common_header *(*tldq_xform)(struct tcp_log_dev_queue *entry);
70 	void	(*tldq_dtor)(struct tcp_log_dev_queue *entry);
71 	volatile u_int tldq_refcnt;
72 };
73 
74 STAILQ_HEAD(log_queueh, tcp_log_dev_queue);
75 
76 struct tcp_log_dev_info {
77 	STAILQ_ENTRY(tcp_log_dev_info) tldi_list;
78 	struct tcp_log_dev_queue *tldi_head;
79 	struct tcp_log_common_header *tldi_cur;
80 	off_t			tldi_off;
81 };
82 STAILQ_HEAD(log_infoh, tcp_log_dev_info);
83 
84 #ifdef TCP_BLACKBOX
85 MALLOC_DECLARE(M_TCPLOGDEV);
86 int tcp_log_dev_add_log(struct tcp_log_dev_queue *entry);
87 #endif /* TCP_BLACKBOX */
88 #endif /* _KERNEL */
89 #endif /* !__tcp_log_dev_h__ */
90