xref: /freebsd/sys/netinet/libalias/alias_mod.h (revision 1de7b4b805ddbf2429da511c053686ac4591ed89)
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
40 MALLOC_DECLARE(M_ALIAS);
41 
42 /* Use kernel allocator. */
43 #if defined(_SYS_MALLOC_H_)
44 #define	malloc(x)	malloc(x, M_ALIAS, M_NOWAIT|M_ZERO)
45 #define	calloc(x, n)	malloc(x*n)
46 #define	free(x)		free(x, M_ALIAS)
47 #endif
48 #endif
49 
50 /* Packet flow direction flags. */
51 #define IN	0x0001
52 #define OUT	0x0002
53 #define	NODIR	0x4000
54 
55 /* Working protocol flags. */
56 #define IP	0x01
57 #define TCP	0x02
58 #define UDP	0x04
59 
60 /*
61  * Data passed to protocol handler module, it must be filled
62  * right before calling find_handler() to determine which
63  * module is elegible to be called.
64  */
65 struct alias_data {
66 	struct alias_link	*lnk;
67 	struct in_addr		*oaddr;		/* Original address. */
68 	struct in_addr		*aaddr;		/* Alias address. */
69 	uint16_t		*aport;		/* Alias port. */
70 	uint16_t		*sport, *dport;	/* Source & destination port */
71 	uint16_t		maxpktsize;	/* Max packet size. */
72 };
73 
74 /*
75  * This structure contains all the information necessary to make
76  * a protocol handler correctly work.
77  */
78 struct proto_handler {
79 	u_int pri;		/* Handler priority. */
80 	int16_t dir;		/* Flow direction. */
81 	uint8_t proto;		/* Working protocol. */
82 	/* Fingerprint * function. */
83 	int (*fingerprint)(struct libalias *, struct alias_data *);
84 	/* Aliasing * function. */
85 	int (*protohandler)(struct libalias *, struct ip *,
86 	    struct alias_data *);
87 	TAILQ_ENTRY(proto_handler) link;
88 };
89 
90 /* End of handlers. */
91 #define EOH	.dir = NODIR
92 
93 /* Functions used with protocol handlers. */
94 int LibAliasAttachHandlers(struct proto_handler *);
95 int LibAliasDetachHandlers(struct proto_handler *);
96 int find_handler(int8_t, int8_t, struct libalias *, struct ip *,
97     struct alias_data *);
98 struct proto_handler *first_handler(void);
99 
100 #ifndef _KERNEL
101 /*
102  * Used only in userland when libalias needs to keep track of all
103  * module loaded. In kernel land (kld mode) we don't need to care
104  * care about libalias modules cause it's kld to do it for us.
105  */
106 #define DLL_LEN	 32
107 struct dll {
108 	char	name[DLL_LEN];	/* Name of module. */
109 	void	*handle;	/*
110 				 * Ptr to shared obj obtained through
111 				 * dlopen() - use this ptr to get access
112 				 * to any symbols from a loaded module
113 				 * via dlsym().
114 				 */
115 	SLIST_ENTRY(dll)	next;
116 };
117 
118 /* Functions used with dll module. */
119 void dll_chain_init(void);
120 void dll_chain_destroy(void);
121 int attach_dll(struct dll *);
122 void *detach_dll(char *);
123 struct dll *walk_dll_chain(void);
124 
125 /*
126  * Some defines borrowed from sys/module.h used to compile a kld
127  * in userland as a shared lib.
128  */
129 typedef enum modeventtype {
130 	MOD_LOAD,
131 	MOD_UNLOAD,
132 	MOD_SHUTDOWN,
133 	MOD_QUIESCE
134 } modeventtype_t;
135 
136 typedef struct module *module_t;
137 typedef int (*modeventhand_t)(module_t, int /* modeventtype_t */, void *);
138 
139 /*
140  * Struct for registering modules statically via SYSINIT.
141  */
142 typedef struct moduledata {
143 	const char	*name;	/* module name */
144 	modeventhand_t	evhand;	/* event handler */
145 	void		*priv;	/* extra data */
146 } moduledata_t;
147 #endif /* !_KERNEL */
148 
149 #endif /* !_ALIAS_MOD_H_ */
150