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 <xtables.h>
15 #include <linux/netfilter/xt_DSCP.h>
16 
17 /* This is evil, but it's my code - HW*/
18 #include "dscp_helper.c"
19 
20 enum {
21 	O_SET_DSCP = 0,
22 	O_SET_DSCP_CLASS,
23 	F_SET_DSCP       = 1 << O_SET_DSCP,
24 	F_SET_DSCP_CLASS = 1 << O_SET_DSCP_CLASS,
25 };
26 
DSCP_help(void)27 static void DSCP_help(void)
28 {
29 	printf(
30 "DSCP target options\n"
31 "  --set-dscp value		Set DSCP field in packet header to value\n"
32 "  		                This value can be in decimal (ex: 32)\n"
33 "               		or in hex (ex: 0x20)\n"
34 "  --set-dscp-class class	Set the DSCP field in packet header to the\n"
35 "				value represented by the DiffServ class value.\n"
36 "				This class may be EF,BE or any of the CSxx\n"
37 "				or AFxx classes.\n"
38 "\n"
39 "				These two options are mutually exclusive !\n"
40 );
41 }
42 
43 static const struct xt_option_entry DSCP_opts[] = {
44 	{.name = "set-dscp", .id = O_SET_DSCP, .excl = F_SET_DSCP_CLASS,
45 	 .type = XTTYPE_UINT8, .min = 0, .max = XT_DSCP_MAX,
46 	 .flags = XTOPT_PUT,
47 	 XTOPT_POINTER(struct xt_DSCP_info, dscp)},
48 	{.name = "set-dscp-class", .id = O_SET_DSCP_CLASS, .excl = F_SET_DSCP,
49 	 .type = XTTYPE_STRING},
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_SET_DSCP_CLASS:
60 		dinfo->dscp = class_to_dscp(cb->arg);
61 		break;
62 	}
63 }
64 
DSCP_check(struct xt_fcheck_call * cb)65 static void DSCP_check(struct xt_fcheck_call *cb)
66 {
67 	if (cb->xflags == 0)
68 		xtables_error(PARAMETER_PROBLEM,
69 		           "DSCP target: Parameter --set-dscp is required");
70 }
71 
72 static void
print_dscp(uint8_t dscp,int numeric)73 print_dscp(uint8_t dscp, int numeric)
74 {
75 	printf(" 0x%02x", dscp);
76 }
77 
DSCP_print(const void * ip,const struct xt_entry_target * target,int numeric)78 static void DSCP_print(const void *ip, const struct xt_entry_target *target,
79                        int numeric)
80 {
81 	const struct xt_DSCP_info *dinfo =
82 		(const struct xt_DSCP_info *)target->data;
83 	printf(" DSCP set");
84 	print_dscp(dinfo->dscp, numeric);
85 }
86 
DSCP_save(const void * ip,const struct xt_entry_target * target)87 static void DSCP_save(const void *ip, const struct xt_entry_target *target)
88 {
89 	const struct xt_DSCP_info *dinfo =
90 		(const struct xt_DSCP_info *)target->data;
91 
92 	printf(" --set-dscp 0x%02x", dinfo->dscp);
93 }
94 
95 static struct xtables_target dscp_target = {
96 	.family		= NFPROTO_UNSPEC,
97 	.name		= "DSCP",
98 	.version	= XTABLES_VERSION,
99 	.size		= XT_ALIGN(sizeof(struct xt_DSCP_info)),
100 	.userspacesize	= XT_ALIGN(sizeof(struct xt_DSCP_info)),
101 	.help		= DSCP_help,
102 	.print		= DSCP_print,
103 	.save		= DSCP_save,
104 	.x6_parse	= DSCP_parse,
105 	.x6_fcheck	= DSCP_check,
106 	.x6_options	= DSCP_opts,
107 };
108 
_init(void)109 void _init(void)
110 {
111 	xtables_register_target(&dscp_target);
112 }
113