1/* Shared library add-on to iptables for DSCP
2 *
3 * (C) 2000- 2002 by Matthew G. Marsh <mgm@paktronix.com>,
4 * 		     Harald Welte <laforge@gnumonks.org>
5 *
6 * This program is distributed under the terms of GNU GPL v2, 1991
7 *
8 * libipt_DSCP.c borrowed heavily from libipt_TOS.c
9 *
10 * --set-class added by Iain Barnes
11 */
12#include <stdio.h>
13#include <string.h>
14#include <stdlib.h>
15#include <getopt.h>
16
17#include <iptables.h>
18#include <linux/netfilter_ipv4/ip_tables.h>
19#include <linux/netfilter_ipv4/ipt_DSCP.h>
20
21/* This is evil, but it's my code - HW*/
22#include "libipt_dscp_helper.c"
23
24
25static void init(struct ipt_entry_target *t, unsigned int *nfcache)
26{
27}
28
29static void help(void)
30{
31	printf(
32"DSCP target options\n"
33"  --set-dscp value		Set DSCP field in packet header to value\n"
34"  		                This value can be in decimal (ex: 32)\n"
35"               		or in hex (ex: 0x20)\n"
36"  --set-dscp-class class	Set the DSCP field in packet header to the\n"
37"				value represented by the DiffServ class value.\n"
38"				This class may be EF,BE or any of the CSxx "
39"				or AFxx classes.\n"
40"\n"
41"				These two options are mutually exclusive !\n"
42);
43}
44
45static struct option opts[] = {
46	{ "set-dscp", 1, 0, 'F' },
47	{ "set-dscp-class", 1, 0, 'G' },
48	{ 0 }
49};
50
51static void
52parse_dscp(const unsigned char *s, struct ipt_DSCP_info *dinfo)
53{
54	unsigned int dscp;
55
56	if (string_to_number(s, 0, 255, &dscp) == -1)
57		exit_error(PARAMETER_PROBLEM,
58			   "Invalid dscp `%s'\n", s);
59
60	if (dscp > IPT_DSCP_MAX)
61		exit_error(PARAMETER_PROBLEM,
62			   "DSCP `%d` out of range\n", dscp);
63
64    	dinfo->dscp = (u_int8_t )dscp;
65    	return;
66}
67
68
69static void
70parse_class(const unsigned char *s, struct ipt_DSCP_info *dinfo)
71{
72	unsigned int dscp = class_to_dscp(s);
73
74	/* Assign the value */
75	dinfo->dscp = (u_int8_t)dscp;
76}
77
78
79static int
80parse(int c, char **argv, int invert, unsigned int *flags,
81      const struct ipt_entry *entry,
82      struct ipt_entry_target **target)
83{
84	struct ipt_DSCP_info *dinfo
85		= (struct ipt_DSCP_info *)(*target)->data;
86
87	switch (c) {
88	case 'F':
89		if (*flags)
90			exit_error(PARAMETER_PROBLEM,
91			           "DSCP target: Only use --set-dscp ONCE!");
92		parse_dscp(optarg, dinfo);
93		*flags = 1;
94		break;
95	case 'G':
96		if (*flags)
97			exit_error(PARAMETER_PROBLEM,
98				   "DSCP target: Only use --set-dscp-class ONCE!");
99		parse_class(optarg, dinfo);
100		*flags = 1;
101		break;
102
103	default:
104		return 0;
105	}
106
107	return 1;
108}
109
110static void
111final_check(unsigned int flags)
112{
113	if (!flags)
114		exit_error(PARAMETER_PROBLEM,
115		           "DSCP target: Parameter --set-dscp is required");
116}
117
118static void
119print_dscp(u_int8_t dscp, int numeric)
120{
121 	printf("0x%02x ", dscp);
122}
123
124/* Prints out the targinfo. */
125static void
126print(const struct ipt_ip *ip,
127      const struct ipt_entry_target *target,
128      int numeric)
129{
130	const struct ipt_DSCP_info *dinfo =
131		(const struct ipt_DSCP_info *)target->data;
132	printf("DSCP set ");
133	print_dscp(dinfo->dscp, numeric);
134}
135
136/* Saves the union ipt_targinfo in parsable form to stdout. */
137static void
138save(const struct ipt_ip *ip, const struct ipt_entry_target *target)
139{
140	const struct ipt_DSCP_info *dinfo =
141		(const struct ipt_DSCP_info *)target->data;
142
143	printf("--set-dscp 0x%02x ", dinfo->dscp);
144}
145
146static
147struct iptables_target dscp
148= { NULL,
149    "DSCP",
150    IPTABLES_VERSION,
151    IPT_ALIGN(sizeof(struct ipt_DSCP_info)),
152    IPT_ALIGN(sizeof(struct ipt_DSCP_info)),
153    &help,
154    &init,
155    &parse,
156    &final_check,
157    &print,
158    &save,
159    opts
160};
161
162void _init(void)
163{
164	register_target(&dscp);
165}
166