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 <xtables.h>
18 #include <linux/netfilter/xt_dscp.h>
19 
20 /* This is evil, but it's my code - HW*/
21 #include "dscp_helper.c"
22 
23 enum {
24 	O_DSCP = 0,
25 	O_DSCP_CLASS,
26 	F_DSCP       = 1 << O_DSCP,
27 	F_DSCP_CLASS = 1 << O_DSCP_CLASS,
28 };
29 
dscp_help(void)30 static void dscp_help(void)
31 {
32 	printf(
33 "dscp match options\n"
34 "[!] --dscp value		Match DSCP codepoint with numerical value\n"
35 "  		                This value can be in decimal (ex: 32)\n"
36 "               		or in hex (ex: 0x20)\n"
37 "[!] --dscp-class name		Match the DiffServ class. This value may\n"
38 "				be any of the BE,EF, AFxx or CSx classes\n"
39 "\n"
40 "				These two options are mutually exclusive !\n");
41 }
42 
43 static const struct xt_option_entry dscp_opts[] = {
44 	{.name = "dscp", .id = O_DSCP, .excl = F_DSCP_CLASS,
45 	 .type = XTTYPE_UINT8, .min = 0, .max = XT_DSCP_MAX,
46 	 .flags = XTOPT_INVERT | XTOPT_PUT,
47 	 XTOPT_POINTER(struct xt_dscp_info, dscp)},
48 	{.name = "dscp-class", .id = O_DSCP_CLASS, .excl = F_DSCP,
49 	 .type = XTTYPE_STRING, .flags = XTOPT_INVERT},
50 	XTOPT_TABLEEND,
51 };
52 
dscp_parse(struct xt_option_call * cb)53 static void dscp_parse(struct xt_option_call *cb)
54 {
55 	struct xt_dscp_info *dinfo = cb->data;
56 
57 	xtables_option_parse(cb);
58 	switch (cb->entry->id) {
59 	case O_DSCP:
60 		if (cb->invert)
61 			dinfo->invert = 1;
62 		break;
63 	case O_DSCP_CLASS:
64 		dinfo->dscp = class_to_dscp(cb->arg);
65 		if (cb->invert)
66 			dinfo->invert = 1;
67 		break;
68 	}
69 }
70 
dscp_check(struct xt_fcheck_call * cb)71 static void dscp_check(struct xt_fcheck_call *cb)
72 {
73 	if (cb->xflags == 0)
74 		xtables_error(PARAMETER_PROBLEM,
75 		           "DSCP match: Parameter --dscp is required");
76 }
77 
78 static void
dscp_print(const void * ip,const struct xt_entry_match * match,int numeric)79 dscp_print(const void *ip, const struct xt_entry_match *match, int numeric)
80 {
81 	const struct xt_dscp_info *dinfo =
82 		(const struct xt_dscp_info *)match->data;
83 	printf(" DSCP match %s0x%02x", dinfo->invert ? "!" : "", dinfo->dscp);
84 }
85 
dscp_save(const void * ip,const struct xt_entry_match * match)86 static void dscp_save(const void *ip, const struct xt_entry_match *match)
87 {
88 	const struct xt_dscp_info *dinfo =
89 		(const struct xt_dscp_info *)match->data;
90 
91 	printf("%s --dscp 0x%02x", dinfo->invert ? " !" : "", dinfo->dscp);
92 }
93 
__dscp_xlate(struct xt_xlate * xl,const struct xt_xlate_mt_params * params)94 static int __dscp_xlate(struct xt_xlate *xl,
95 			const struct xt_xlate_mt_params *params)
96 {
97 	const struct xt_dscp_info *dinfo =
98 		(const struct xt_dscp_info *)params->match->data;
99 
100 	xt_xlate_add(xl, "dscp %s0x%02x", dinfo->invert ? "!= " : "",
101 		     dinfo->dscp);
102 
103 	return 1;
104 }
105 
dscp_xlate(struct xt_xlate * xl,const struct xt_xlate_mt_params * params)106 static int dscp_xlate(struct xt_xlate *xl,
107 		      const struct xt_xlate_mt_params *params)
108 {
109 	xt_xlate_add(xl, "ip ");
110 
111 	return __dscp_xlate(xl, params);
112 }
113 
dscp_xlate6(struct xt_xlate * xl,const struct xt_xlate_mt_params * params)114 static int dscp_xlate6(struct xt_xlate *xl,
115 		       const struct xt_xlate_mt_params *params)
116 {
117 	xt_xlate_add(xl, "ip6 ");
118 
119 	return __dscp_xlate(xl, params);
120 }
121 
122 static struct xtables_match dscp_mt_reg[] = {
123 	{
124 		.family		= NFPROTO_IPV4,
125 		.name           = "dscp",
126 		.version        = XTABLES_VERSION,
127 		.size           = XT_ALIGN(sizeof(struct xt_dscp_info)),
128 		.userspacesize	= XT_ALIGN(sizeof(struct xt_dscp_info)),
129 		.help		= dscp_help,
130 		.print		= dscp_print,
131 		.save		= dscp_save,
132 		.x6_parse	= dscp_parse,
133 		.x6_fcheck	= dscp_check,
134 		.x6_options	= dscp_opts,
135 		.xlate		= dscp_xlate,
136 	},
137 	{
138 		.family		= NFPROTO_IPV6,
139 		.name           = "dscp",
140 		.version        = XTABLES_VERSION,
141 		.size           = XT_ALIGN(sizeof(struct xt_dscp_info)),
142 		.userspacesize	= XT_ALIGN(sizeof(struct xt_dscp_info)),
143 		.help		= dscp_help,
144 		.print		= dscp_print,
145 		.save		= dscp_save,
146 		.x6_parse	= dscp_parse,
147 		.x6_fcheck	= dscp_check,
148 		.x6_options	= dscp_opts,
149 		.xlate		= dscp_xlate6,
150 	},
151 };
152 
_init(void)153 void _init(void)
154 {
155 	xtables_register_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
156 }
157