xref: /freebsd/sys/dev/tcp_log/tcp_log_dev.h (revision d4eeb02986980bf33dd56c41ceb9fc5f180c0d47)
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  */
37 struct 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  */
65 struct 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 
73 STAILQ_HEAD(log_queueh, tcp_log_dev_queue);
74 
75 struct 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 };
81 STAILQ_HEAD(log_infoh, tcp_log_dev_info);
82 
83 #ifdef TCP_BLACKBOX
84 MALLOC_DECLARE(M_TCPLOGDEV);
85 int 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