xref: /netbsd-src/lib/npf/ext_rndblock/npfext_rndblock.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: npfext_rndblock.c,v 1.1 2012/12/10 00:32:24 rmind Exp $	*/
2 
3 /*-
4  * Copyright (c) 2012 The NetBSD Foundation, Inc.
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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __RCSID("$NetBSD: npfext_rndblock.c,v 1.1 2012/12/10 00:32:24 rmind Exp $");
31 
32 #include <stdlib.h>
33 #include <string.h>
34 #include <assert.h>
35 #include <errno.h>
36 
37 #include <npf.h>
38 
39 int		npfext_rndblock_init(void);
40 nl_ext_t *	npfext_rndblock_construct(const char *);
41 int		npfext_rndblock_param(nl_ext_t *, const char *, const char *);
42 
43 int
44 npfext_rndblock_init(void)
45 {
46 	/* Nothing to initialise. */
47 	return 0;
48 }
49 
50 nl_ext_t *
51 npfext_rndblock_construct(const char *name)
52 {
53 	assert(strcmp(name, "rndblock") == 0);
54 	return npf_ext_construct(name);
55 }
56 
57 int
58 npfext_rndblock_param(nl_ext_t *ext, const char *param, const char *val)
59 {
60 	enum ptype { PARAM_U32 };
61 	static const struct param {
62 		const char *	name;
63 		enum ptype	type;
64 		signed long	min;
65 		signed long	max;
66 	} params[] = {
67 		{ "mod",	PARAM_U32,	1,	LONG_MAX	},
68 		{ "percentage",	PARAM_U32,	1,	9999		},
69 	};
70 
71 	if (val == NULL) {
72 		return EINVAL;
73 	}
74 	for (unsigned i = 0; i < __arraycount(params); i++) {
75 		const char *name = params[i].name;
76 		long ival;
77 
78 		if (strcmp(name, param) != 0) {
79 			continue;
80 		}
81 
82 		/*
83 		 * Note: multiply by 100 and convert floating point to
84 		 * an integer, as 100% is based on 10000 in the kernel.
85 		 */
86 		ival = (i == 1) ? atof(val) * 100 : atol(val);
87 		if (ival < params[i].min || ival > params[i].max) {
88 			return EINVAL;
89 		}
90 		assert(params[i].type == PARAM_U32);
91 		npf_ext_param_u32(ext, name, ival);
92 		return 0;
93 	}
94 
95 	/* Invalid parameter, if not found. */
96 	return EINVAL;
97 }
98