summaryrefslogtreecommitdiffstats
path: root/extensions/libipt_dscp.c
blob: 837881549a0bb1471884a6d21648d1ce62a4bd56 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
/* Shared library add-on to iptables for DSCP
 *
 * (C) 2002 by Harald Welte <laforge@gnumonks.org>
 *
 * This program is distributed under the terms of GNU GPL v2, 1991
 *
 * libipt_dscp.c borrowed heavily from libipt_tos.c
 *
 * For a list of DSCP codepoints see 
 * http://www.iana.org/assignments/dscp-registry
 *
 */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>

#include <iptables.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_dscp.h>

static void init(struct ipt_entry_match *m, unsigned int *nfcache) 
{
	*nfcache |= NFC_IP_TOS;
}

static void help(void) 
{
	printf(
"DSCP match v%s options\n"
"[!] --dscp value		Match DSCP codepoint with numerical value\n"
"  		                This value can be in decimal (ex: 32)\n"
"               		or in hex (ex: 0x20)\n", IPTABLES_VERSION
);
}

static struct option opts[] = {
	{ "dscp", 1, 0, 'F' },
	{ 0 }
};

static void
parse_dscp(const unsigned char *s, struct ipt_dscp_info *dinfo)
{
	unsigned int dscp;
       
	if (string_to_number(s, 0, 255, &dscp) == -1)
		exit_error(PARAMETER_PROBLEM,
			   "Invalid dscp `%s'\n", s);

	if (dscp > IPT_DSCP_MAX)
		exit_error(PARAMETER_PROBLEM,
			   "DSCP `%d` out of range\n", dscp);

    	dinfo->dscp = (u_int8_t )dscp;
    	return;
}

static int
parse(int c, char **argv, int invert, unsigned int *flags,
      const struct ipt_entry *entry,
      unsigned int *nfcache,
      struct ipt_entry_match **match)
{
	struct ipt_dscp_info *dinfo
		= (struct ipt_dscp_info *)(*match)->data;

	switch (c) {
	case 'F':
		if (*flags)
			exit_error(PARAMETER_PROBLEM,
			           "DSCP match: Only use --dscp ONCE!");
		check_inverse(optarg, &invert, &optind, 0);
		parse_dscp(argv[optind-1], dinfo);
		if (invert)
			dinfo->invert = 1;
		*flags = 1;
		break;

	default:
		return 0;
	}

	return 1;
}

static void
final_check(unsigned int flags)
{
	if (!flags)
		exit_error(PARAMETER_PROBLEM,
		           "DSCP match: Parameter --dscp is required");
}

static void
print_dscp(u_int8_t dscp, int invert, int numeric)
{
	if (invert)
		fputc('!', stdout);

 	printf("0x%02x ", dscp);
}

/* Prints out the matchinfo. */
static void
print(const struct ipt_ip *ip,
      const struct ipt_entry_match *match,
      int numeric)
{
	const struct ipt_dscp_info *dinfo =
		(const struct ipt_dscp_info *)match->data;
	printf("DSCP match ");
	print_dscp(dinfo->dscp, dinfo->invert, numeric);
}

/* Saves the union ipt_matchinfo in parsable form to stdout. */
static void
save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
{
	const struct ipt_dscp_info *dinfo =
		(const struct ipt_dscp_info *)match->data;

	printf("--dscp ");
	print_dscp(dinfo->dscp, dinfo->invert, 1);
}

static
struct iptables_match dscp
= { NULL,
    "dscp",
    IPTABLES_VERSION,
    IPT_ALIGN(sizeof(struct ipt_dscp_info)),
    IPT_ALIGN(sizeof(struct ipt_dscp_info)),
    &help,
    &init,
    &parse,
    &final_check,
    &print,
    &save,
    opts
};

void _init(void)
{
	register_match(&dscp);
}