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 
94 static struct xtables_match dscp_match = {
95 	.family		= NFPROTO_UNSPEC,
96 	.name 		= "dscp",
97 	.version 	= XTABLES_VERSION,
98 	.size 		= XT_ALIGN(sizeof(struct xt_dscp_info)),
99 	.userspacesize	= XT_ALIGN(sizeof(struct xt_dscp_info)),
100 	.help		= dscp_help,
101 	.print		= dscp_print,
102 	.save		= dscp_save,
103 	.x6_parse	= dscp_parse,
104 	.x6_fcheck	= dscp_check,
105 	.x6_options	= dscp_opts,
106 };
107 
_init(void)108 void _init(void)
109 {
110 	xtables_register_match(&dscp_match);
111 }
112