xref: /freebsd/sys/net/bpfdesc.h (revision 29363fb446372cb3f10bc98664e9767c53fbb457)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1990, 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from the Stanford/CMU enet packet filter,
8  * (net/enet.c) distributed as part of 4.3BSD, and code contributed
9  * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
10  * Berkeley Laboratory.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef _NET_BPFDESC_H_
38 #define _NET_BPFDESC_H_
39 
40 #include <sys/callout.h>
41 #include <sys/selinfo.h>
42 #include <sys/ck.h>
43 #include <sys/conf.h>
44 #include <sys/counter.h>
45 #include <sys/epoch.h>
46 #include <net/if.h>
47 
48 /*
49  * Descriptor associated with each open bpf file.
50  */
51 struct zbuf;
52 struct bpf_d {
53 	CK_LIST_ENTRY(bpf_d) bd_next;	/* Linked list of descriptors */
54 	/*
55 	 * Buffer slots: two memory buffers store the incoming packets.
56 	 *   The model has three slots.  Sbuf is always occupied.
57 	 *   sbuf (store) - Receive interrupt puts packets here.
58 	 *   hbuf (hold) - When sbuf is full, put buffer here and
59 	 *                 wakeup read (replace sbuf with fbuf).
60 	 *   fbuf (free) - When read is done, put buffer here.
61 	 * On receiving, if sbuf is full and fbuf is 0, packet is dropped.
62 	 */
63 	caddr_t		bd_sbuf;	/* store slot */
64 	caddr_t		bd_hbuf;	/* hold slot */
65 	caddr_t		bd_fbuf;	/* free slot */
66 	int		bd_hbuf_in_use;	/* don't rotate buffers */
67 	int 		bd_slen;	/* current length of store buffer */
68 	int 		bd_hlen;	/* current length of hold buffer */
69 
70 	int		bd_bufsize;	/* absolute length of buffers */
71 
72 	struct bpf_if *	bd_bif;		/* interface descriptor */
73 	u_long		bd_rtout;	/* Read timeout in 'ticks' */
74 	struct bpf_insn *bd_rfilter; 	/* read filter code */
75 	struct bpf_insn *bd_wfilter;	/* write filter code */
76 	void		*bd_bfilter;	/* binary filter code */
77 	counter_u64_t	bd_rcount;	/* number of packets received */
78 	counter_u64_t	bd_dcount;	/* number of packets dropped */
79 
80 	u_char		bd_promisc;	/* true if listening promiscuously */
81 	u_char		bd_state;	/* idle, waiting, or timed out */
82 	u_char		bd_immediate;	/* true to return on packet arrival */
83 	u_char		bd_writer;	/* non-zero if d is writer-only */
84 	int		bd_hdrcmplt;	/* false to fill in src lladdr automatically */
85 	int		bd_direction;	/* select packet direction */
86 	int		bd_tstamp;	/* select time stamping function */
87 	int		bd_feedback;	/* true to feed back sent packets */
88 	int		bd_async;	/* non-zero if packet reception should generate signal */
89 	int		bd_sig;		/* signal to send upon packet reception */
90 	int		bd_pcp;		/* VLAN pcp tag */
91 	struct sigio *	bd_sigio;	/* information for async I/O */
92 	struct selinfo	bd_sel;		/* bsd select info */
93 	struct mtx	bd_lock;	/* per-descriptor lock */
94 	struct callout	bd_callout;	/* for BPF timeouts with select */
95 	struct label	*bd_label;	/* MAC label for descriptor */
96 	counter_u64_t	bd_fcount;	/* number of packets which matched filter */
97 	pid_t		bd_pid;		/* PID which created descriptor */
98 	int		bd_locked;	/* true if descriptor is locked */
99 	u_int		bd_bufmode;	/* Current buffer mode. */
100 	counter_u64_t	bd_wcount;	/* number of packets written */
101 	counter_u64_t	bd_wfcount;	/* number of packets that matched write filter */
102 	counter_u64_t	bd_wdcount;	/* number of packets dropped during a write */
103 	counter_u64_t	bd_zcopy;	/* number of zero copy operations */
104 	u_char		bd_compat32;	/* 32-bit stream on LP64 system */
105 
106 	volatile u_int	bd_refcnt;
107 	struct epoch_context epoch_ctx;
108 };
109 
110 /* Values for bd_state */
111 #define BPF_IDLE	0		/* no select in progress */
112 #define BPF_WAITING	1		/* waiting for read timeout in select */
113 #define BPF_TIMED_OUT	2		/* read timeout has expired in select */
114 
115 #define BPFD_LOCK(bd)		mtx_lock(&(bd)->bd_lock)
116 #define BPFD_UNLOCK(bd)		mtx_unlock(&(bd)->bd_lock)
117 #define BPFD_LOCK_ASSERT(bd)	mtx_assert(&(bd)->bd_lock, MA_OWNED)
118 
119 #define BPF_PID_REFRESH(bd, td)	(bd)->bd_pid = (td)->td_proc->p_pid
120 #define BPF_PID_REFRESH_CUR(bd)	(bd)->bd_pid = curthread->td_proc->p_pid
121 
122 /*
123  * External representation of the bpf descriptor
124  */
125 struct xbpf_d {
126 	u_int		bd_structsize;	/* Size of this structure. */
127 	u_char		bd_promisc;
128 	u_char		bd_immediate;
129 	u_char		__bd_pad[6];
130 	int		bd_hdrcmplt;
131 	int		bd_direction;
132 	int		bd_feedback;
133 	int		bd_async;
134 	u_int64_t	bd_rcount;
135 	u_int64_t	bd_dcount;
136 	u_int64_t	bd_fcount;
137 	int		bd_sig;
138 	int		bd_slen;
139 	int		bd_hlen;
140 	int		bd_bufsize;
141 	pid_t		bd_pid;
142 	char		bd_ifname[IFNAMSIZ];
143 	int		bd_locked;
144 	u_int64_t	bd_wcount;
145 	u_int64_t	bd_wfcount;
146 	u_int64_t	bd_wdcount;
147 	u_int64_t	bd_zcopy;
148 	int		bd_bufmode;
149 	/*
150 	 * Allocate 4 64 bit unsigned integers for future expansion so we do
151 	 * not have to worry about breaking the ABI.
152 	 */
153 	u_int64_t	bd_spare[4];
154 };
155 
156 #define BPFIF_FLAG_DYING	1	/* Reject new bpf consumers */
157 
158 #endif
159