1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2005 Paolo Pisati <piso@FreeBSD.org>
5 * 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/*
32 * Alias_mod.h defines the outside world interfaces for the packet aliasing
33 * modular framework
34 */
35
36#ifndef _ALIAS_MOD_H_
37#define _ALIAS_MOD_H_
38
39#ifdef _KERNEL
40MALLOC_DECLARE(M_ALIAS);
41
42/* Use kernel allocator. */
43#if defined(_SYS_MALLOC_H_)
44#undef malloc
45#define	malloc(x)	malloc(x, M_ALIAS, M_NOWAIT|M_ZERO)
46#define	calloc(n, x)	mallocarray((n), (x), M_ALIAS, M_NOWAIT|M_ZERO)
47#define	free(x)		free(x, M_ALIAS)
48#endif
49#endif
50
51/* Packet flow direction flags. */
52#define IN	0x0001
53#define OUT	0x0002
54#define	NODIR	0x4000
55
56/* Working protocol flags. */
57#define IP	0x01
58#define TCP	0x02
59#define UDP	0x04
60
61/*
62 * Data passed to protocol handler module, it must be filled
63 * right before calling find_handler() to determine which
64 * module is elegible to be called.
65 */
66struct alias_data {
67	struct alias_link	*lnk;
68	struct in_addr		*oaddr;		/* Original address. */
69	struct in_addr		*aaddr;		/* Alias address. */
70	uint16_t		*aport;		/* Alias port. */
71	uint16_t		*sport, *dport;	/* Source & destination port */
72	uint16_t		maxpktsize;	/* Max packet size. */
73};
74
75/*
76 * This structure contains all the information necessary to make
77 * a protocol handler correctly work.
78 */
79struct proto_handler {
80	u_int pri;		/* Handler priority. */
81	int16_t dir;		/* Flow direction. */
82	uint8_t proto;		/* Working protocol. */
83	/* Fingerprint * function. */
84	int (*fingerprint)(struct libalias *, struct alias_data *);
85	/* Aliasing * function. */
86	int (*protohandler)(struct libalias *, struct ip *,
87	    struct alias_data *);
88	TAILQ_ENTRY(proto_handler) link;
89};
90
91/* End of handlers. */
92#define EOH	.dir = NODIR
93
94/* Functions used with protocol handlers. */
95int LibAliasAttachHandlers(struct proto_handler *);
96int LibAliasDetachHandlers(struct proto_handler *);
97int find_handler(int8_t, int8_t, struct libalias *, struct ip *,
98    struct alias_data *);
99struct proto_handler *first_handler(void);
100
101#ifndef _KERNEL
102/*
103 * Used only in userland when libalias needs to keep track of all
104 * module loaded. In kernel land (kld mode) we don't need to care
105 * care about libalias modules cause it's kld to do it for us.
106 */
107#define DLL_LEN	 32
108struct dll {
109	char	name[DLL_LEN];	/* Name of module. */
110	void	*handle;	/*
111				 * Ptr to shared obj obtained through
112				 * dlopen() - use this ptr to get access
113				 * to any symbols from a loaded module
114				 * via dlsym().
115				 */
116	SLIST_ENTRY(dll)	next;
117};
118
119/* Functions used with dll module. */
120void dll_chain_init(void);
121void dll_chain_destroy(void);
122int attach_dll(struct dll *);
123void *detach_dll(char *);
124struct dll *walk_dll_chain(void);
125
126/*
127 * Some defines borrowed from sys/module.h used to compile a kld
128 * in userland as a shared lib.
129 */
130typedef enum modeventtype {
131	MOD_LOAD,
132	MOD_UNLOAD,
133	MOD_SHUTDOWN,
134	MOD_QUIESCE
135} modeventtype_t;
136
137typedef struct module *module_t;
138typedef int (*modeventhand_t)(module_t, int /* modeventtype_t */, void *);
139
140/*
141 * Struct for registering modules statically via SYSINIT.
142 */
143typedef struct moduledata {
144	const char	*name;	/* module name */
145	modeventhand_t	evhand;	/* event handler */
146	void		*priv;	/* extra data */
147} moduledata_t;
148#endif /* !_KERNEL */
149
150#endif /* !_ALIAS_MOD_H_ */
151