libxt_dscp.c revision ea146a982e26c42f9954f140276f8deeb2edbe98 
1/* Shared library add-on to iptables for DSCP
2 *
3 * (C) 2002 by Harald Welte <laforge@gnumonks.org>
4 *
5 * This program is distributed under the terms of GNU GPL v2, 1991
6 *
7 * libipt_dscp.c borrowed heavily from libipt_tos.c
8 *
9 * --class support added by Iain Barnes
10 *
11 * For a list of DSCP codepoints see
12 * http://www.iana.org/assignments/dscp-registry
13 *
14 */
15#include <stdio.h>
16#include <string.h>
17#include <stdlib.h>
18#include <getopt.h>
19
20#include <xtables.h>
21#include <linux/netfilter/x_tables.h>
22#include <linux/netfilter/xt_dscp.h>
23
24/* This is evil, but it's my code - HW*/
25#include "libipt_dscp_helper.c"
26
27static void help(void)
28{
29	printf(
30"DSCP match v%s options\n"
31"[!] --dscp value		Match DSCP codepoint with numerical value\n"
32"  		                This value can be in decimal (ex: 32)\n"
33"               		or in hex (ex: 0x20)\n"
34"[!] --dscp-class name		Match the DiffServ class. This value may\n"
35"				be any of the BE,EF, AFxx or CSx classes\n"
36"\n"
37"				These two options are mutually exclusive !\n"
38				, IPTABLES_VERSION
39);
40}
41
42static const struct option opts[] = {
43	{ "dscp", 1, 0, 'F' },
44	{ "dscp-class", 1, 0, 'G' },
45	{ 0 }
46};
47
48static void
49parse_dscp(const char *s, struct xt_dscp_info *dinfo)
50{
51	unsigned int dscp;
52
53	if (string_to_number(s, 0, 255, &dscp) == -1)
54		exit_error(PARAMETER_PROBLEM,
55			   "Invalid dscp `%s'\n", s);
56
57	if (dscp > XT_DSCP_MAX)
58		exit_error(PARAMETER_PROBLEM,
59			   "DSCP `%d` out of range\n", dscp);
60
61    	dinfo->dscp = (u_int8_t )dscp;
62    	return;
63}
64
65
66static void
67parse_class(const char *s, struct xt_dscp_info *dinfo)
68{
69	unsigned int dscp = class_to_dscp(s);
70
71	/* Assign the value */
72	dinfo->dscp = (u_int8_t)dscp;
73}
74
75
76static int
77parse(int c, char **argv, int invert, unsigned int *flags,
78      const void *entry,
79      struct xt_entry_match **match)
80{
81	struct xt_dscp_info *dinfo
82		= (struct xt_dscp_info *)(*match)->data;
83
84	switch (c) {
85	case 'F':
86		if (*flags)
87			exit_error(PARAMETER_PROBLEM,
88			           "DSCP match: Only use --dscp ONCE!");
89		check_inverse(optarg, &invert, &optind, 0);
90		parse_dscp(argv[optind-1], dinfo);
91		if (invert)
92			dinfo->invert = 1;
93		*flags = 1;
94		break;
95
96	case 'G':
97		if (*flags)
98			exit_error(PARAMETER_PROBLEM,
99					"DSCP match: Only use --dscp-class ONCE!");
100		check_inverse(optarg, &invert, &optind, 0);
101		parse_class(argv[optind - 1], dinfo);
102		if (invert)
103			dinfo->invert = 1;
104		*flags = 1;
105		break;
106
107	default:
108		return 0;
109	}
110
111	return 1;
112}
113
114static void
115final_check(unsigned int flags)
116{
117	if (!flags)
118		exit_error(PARAMETER_PROBLEM,
119		           "DSCP match: Parameter --dscp is required");
120}
121
122static void
123print_dscp(u_int8_t dscp, int invert, int numeric)
124{
125	if (invert)
126		fputc('!', stdout);
127
128 	printf("0x%02x ", dscp);
129}
130
131/* Prints out the matchinfo. */
132static void
133print(const void *ip,
134      const struct xt_entry_match *match,
135      int numeric)
136{
137	const struct xt_dscp_info *dinfo =
138		(const struct xt_dscp_info *)match->data;
139	printf("DSCP match ");
140	print_dscp(dinfo->dscp, dinfo->invert, numeric);
141}
142
143/* Saves the union ipt_matchinfo in parsable form to stdout. */
144static void
145save(const void *ip, const struct xt_entry_match *match)
146{
147	const struct xt_dscp_info *dinfo =
148		(const struct xt_dscp_info *)match->data;
149
150	printf("--dscp ");
151	print_dscp(dinfo->dscp, dinfo->invert, 1);
152}
153
154static struct xtables_match dscp = {
155	.family		= AF_INET,
156	.name 		= "dscp",
157	.version 	= IPTABLES_VERSION,
158	.size 		= XT_ALIGN(sizeof(struct xt_dscp_info)),
159	.userspacesize	= XT_ALIGN(sizeof(struct xt_dscp_info)),
160	.help		= &help,
161	.parse		= &parse,
162	.final_check	= &final_check,
163	.print		= &print,
164	.save		= &save,
165	.extra_opts	= opts
166};
167
168static struct xtables_match dscp6 = {
169	.family		= AF_INET6,
170	.name 		= "dscp",
171	.version 	= IPTABLES_VERSION,
172	.size 		= XT_ALIGN(sizeof(struct xt_dscp_info)),
173	.userspacesize	= XT_ALIGN(sizeof(struct xt_dscp_info)),
174	.help		= &help,
175	.parse		= &parse,
176	.final_check	= &final_check,
177	.print		= &print,
178	.save		= &save,
179	.extra_opts	= opts
180};
181
182void _init(void)
183{
184	xtables_register_match(&dscp);
185	xtables_register_match(&dscp6);
186}
187