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 <iptables.h>
21#include <linux/netfilter_ipv4/ip_tables.h>
22#include <linux/netfilter_ipv4/ipt_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 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 ipt_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 > IPT_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 ipt_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 struct ipt_entry *entry,
79      unsigned int *nfcache,
80      struct ipt_entry_match **match)
81{
82	struct ipt_dscp_info *dinfo
83		= (struct ipt_dscp_info *)(*match)->data;
84
85	switch (c) {
86	case 'F':
87		if (*flags)
88			exit_error(PARAMETER_PROBLEM,
89			           "DSCP match: Only use --dscp ONCE!");
90		check_inverse(optarg, &invert, &optind, 0);
91		parse_dscp(argv[optind-1], dinfo);
92		if (invert)
93			dinfo->invert = 1;
94		*flags = 1;
95		break;
96
97	case 'G':
98		if (*flags)
99			exit_error(PARAMETER_PROBLEM,
100					"DSCP match: Only use --dscp-class ONCE!");
101		check_inverse(optarg, &invert, &optind, 0);
102		parse_class(argv[optind - 1], dinfo);
103		if (invert)
104			dinfo->invert = 1;
105		*flags = 1;
106		break;
107
108	default:
109		return 0;
110	}
111
112	return 1;
113}
114
115static void
116final_check(unsigned int flags)
117{
118	if (!flags)
119		exit_error(PARAMETER_PROBLEM,
120		           "DSCP match: Parameter --dscp is required");
121}
122
123static void
124print_dscp(u_int8_t dscp, int invert, int numeric)
125{
126	if (invert)
127		fputc('!', stdout);
128
129 	printf("0x%02x ", dscp);
130}
131
132/* Prints out the matchinfo. */
133static void
134print(const struct ipt_ip *ip,
135      const struct ipt_entry_match *match,
136      int numeric)
137{
138	const struct ipt_dscp_info *dinfo =
139		(const struct ipt_dscp_info *)match->data;
140	printf("DSCP match ");
141	print_dscp(dinfo->dscp, dinfo->invert, numeric);
142}
143
144/* Saves the union ipt_matchinfo in parsable form to stdout. */
145static void
146save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
147{
148	const struct ipt_dscp_info *dinfo =
149		(const struct ipt_dscp_info *)match->data;
150
151	printf("--dscp ");
152	print_dscp(dinfo->dscp, dinfo->invert, 1);
153}
154
155static struct iptables_match dscp = {
156	.next 		= NULL,
157	.name 		= "dscp",
158	.version 	= IPTABLES_VERSION,
159	.size 		= IPT_ALIGN(sizeof(struct ipt_dscp_info)),
160	.userspacesize	= IPT_ALIGN(sizeof(struct ipt_dscp_info)),
161	.help		= &help,
162	.parse		= &parse,
163	.final_check	= &final_check,
164	.print		= &print,
165	.save		= &save,
166	.extra_opts	= opts
167};
168
169void _init(void)
170{
171	register_match(&dscp);
172}
173