1/*
2   Shared library add-on to iptables to add match support for the fuzzy match.
3
4   This file is distributed under the terms of the GNU General Public
5   License (GPL). Copies of the GPL can be obtained from:
6   ftp://prep.ai.mit.edu/pub/gnu/GPL
7
82002-08-07 Hime Aguiar e Oliveira Jr. <hime@engineer.com> : Initial version.
92003-06-09 Hime Aguiar e Oliveira Jr. <hime@engineer.com> : Bug corrections in
10the save function , thanks to information given by Jean-Francois Patenaude .
11
12*/
13
14#include <stdio.h>
15#include <netdb.h>
16#include <string.h>
17#include <stdlib.h>
18#include <syslog.h>
19#include <getopt.h>
20#include <iptables.h>
21#include <linux/netfilter_ipv4/ip_tables.h>
22#include <linux/netfilter_ipv4/ipt_fuzzy.h>
23
24
25static void
26help(void)
27{
28	printf(
29"fuzzy v%s options:\n"
30"                      --lower-limit number (in packets per second)\n"
31"                      --upper-limit number\n"
32,IPTABLES_VERSION);
33};
34
35static struct option opts[] = {
36	{ "lower-limit", 1 , 0 , '1' } ,
37	{ "upper-limit", 1 , 0 , '2' } ,
38	{ 0 }
39};
40
41/* Initialize data structures */
42static void
43init(struct ipt_entry_match *m, unsigned int *nfcache)
44{
45	struct ipt_fuzzy_info *presentinfo = (struct ipt_fuzzy_info *)(m)->data;
46
47	/*
48	 * Default rates ( I'll improve this very soon with something based
49	 * on real statistics of the running machine ) .
50	*/
51
52	presentinfo->minimum_rate = 1000;
53	presentinfo->maximum_rate = 2000;
54}
55
56#define IPT_FUZZY_OPT_MINIMUM	0x01
57#define IPT_FUZZY_OPT_MAXIMUM	0x02
58
59static int
60parse(int c, char **argv, int invert, unsigned int *flags,
61      const struct ipt_entry *entry,
62      unsigned int *nfcache,
63      struct ipt_entry_match **match)
64{
65
66struct ipt_fuzzy_info *fuzzyinfo = (struct ipt_fuzzy_info *)(*match)->data;
67
68	u_int32_t num;
69
70	switch (c) {
71
72	case '1':
73
74	if (invert)
75	       	exit_error(PARAMETER_PROBLEM,"Can't specify ! --lower-limit");
76
77	if (*flags & IPT_FUZZY_OPT_MINIMUM)
78       	      exit_error(PARAMETER_PROBLEM,"Can't specify --lower-limit twice");
79
80	if (string_to_number(optarg,1,MAXFUZZYRATE,&num) == -1 || num < 1)
81			exit_error(PARAMETER_PROBLEM,"BAD --lower-limit");
82
83		fuzzyinfo->minimum_rate = num ;
84
85		*flags |= IPT_FUZZY_OPT_MINIMUM;
86
87		break;
88
89	case '2':
90
91	if (invert)
92		exit_error(PARAMETER_PROBLEM,"Can't specify ! --upper-limit");
93
94	if (*flags & IPT_FUZZY_OPT_MAXIMUM)
95	   exit_error(PARAMETER_PROBLEM,"Can't specify --upper-limit twice");
96
97	if (string_to_number(optarg,1,MAXFUZZYRATE,&num) == -1 || num < 1)
98		exit_error(PARAMETER_PROBLEM,"BAD --upper-limit");
99
100		fuzzyinfo->maximum_rate = num ;
101
102		*flags |= IPT_FUZZY_OPT_MAXIMUM;
103
104		break ;
105
106	default:
107		return 0;
108	}
109	return 1;
110}
111
112static void final_check(unsigned int flags)
113{
114}
115
116static void
117print(const struct ipt_ip *ip,
118      const struct ipt_entry_match *match,
119      int numeric)
120{
121	const struct ipt_fuzzy_info *fuzzyinfo
122		= (const struct ipt_fuzzy_info *)match->data;
123
124	printf(" fuzzy: lower limit = %u pps - upper limit = %u pps ",fuzzyinfo->minimum_rate,fuzzyinfo->maximum_rate);
125
126}
127
128/* Saves the union ipt_targinfo in parsable form to stdout. */
129static void
130save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
131{
132	const struct ipt_fuzzy_info *fuzzyinfo
133		= (const struct ipt_fuzzy_info *)match->data;
134
135	printf("--lower-limit %u ",fuzzyinfo->minimum_rate);
136	printf("--upper-limit %u ",fuzzyinfo->maximum_rate);
137
138}
139
140static struct iptables_match fuzzy_match = {
141	.next 		= NULL,
142	.name		= "fuzzy",
143	.version	= IPTABLES_VERSION,
144	.size		= IPT_ALIGN(sizeof(struct ipt_fuzzy_info)),
145	.userspacesize	= IPT_ALIGN(sizeof(struct ipt_fuzzy_info)),
146	.help		= &help,
147	.init		= &init,
148	.parse		= &parse,
149	.final_check	= &final_check,
150	.print		= &print,
151	.save		= &save,
152	.extra_opts	= opts
153};
154
155void _init(void)
156{
157	register_match(&fuzzy_match);
158}
159