libxt_tos.c revision 06312dab6c530a214a4e7bad1b2329381430bddc 
1/*
2 * Shared library add-on to iptables to add tos match support
3 *
4 * Copyright © CC Computer Consultants GmbH, 2007
5 * Contact: Jan Engelhardt <jengelh@computergmbh.de>
6 */
7#include <getopt.h>
8#include <netdb.h>
9#include <stdbool.h>
10#include <stdio.h>
11#include <stdlib.h>
12#include <string.h>
13
14#include <xtables.h>
15#include <linux/netfilter/xt_dscp.h>
16#include "tos_values.c"
17
18struct ipt_tos_info {
19	uint8_t tos;
20	uint8_t invert;
21};
22
23enum {
24	O_TOS = 1 << 0,
25};
26
27static const struct xt_option_entry tos_mt_opts_v0[] = {
28	{.name = "tos", .id = O_TOS, .type = XTTYPE_TOSMASK,
29	 .flags = XTOPT_INVERT | XTOPT_MAND, .max = 0xFF},
30	XTOPT_TABLEEND,
31};
32
33static const struct xt_option_entry tos_mt_opts[] = {
34	{.name = "tos", .id = O_TOS, .type = XTTYPE_TOSMASK,
35	 .flags = XTOPT_INVERT | XTOPT_MAND, .max = 0x3F},
36	XTOPT_TABLEEND,
37};
38
39static void tos_mt_help(void)
40{
41	const struct tos_symbol_info *symbol;
42
43	printf(
44"tos match options:\n"
45"[!] --tos value[/mask]    Match Type of Service/Priority field value\n"
46"[!] --tos symbol          Match TOS field (IPv4 only) by symbol\n"
47"                          Accepted symbolic names for value are:\n");
48
49	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
50		printf("                          (0x%02x) %2u %s\n",
51		       symbol->value, symbol->value, symbol->name);
52
53	printf("\n");
54}
55
56static void tos_mt_parse_v0(struct xt_option_call *cb)
57{
58	struct ipt_tos_info *info = cb->data;
59
60	xtables_option_parse(cb);
61	if (cb->val.tos_mask != 0xFF)
62		xtables_error(PARAMETER_PROBLEM, "tos: Your kernel is "
63		           "too old to support anything besides /0xFF "
64			   "as a mask.");
65	info->tos = cb->val.tos_value;
66	if (cb->invert)
67		info->invert = true;
68}
69
70static void tos_mt_parse(struct xt_option_call *cb)
71{
72	struct xt_tos_match_info *info = cb->data;
73
74	xtables_option_parse(cb);
75	info->tos_value = cb->val.tos_value;
76	info->tos_mask  = cb->val.tos_mask;
77	if (cb->invert)
78		info->invert = true;
79}
80
81static void tos_mt_print_v0(const void *ip, const struct xt_entry_match *match,
82                            int numeric)
83{
84	const struct ipt_tos_info *info = (const void *)match->data;
85
86	printf(" tos match ");
87	if (info->invert)
88		printf("!");
89	if (numeric || !tos_try_print_symbolic("", info->tos, 0x3F))
90		printf("0x%02x", info->tos);
91}
92
93static void tos_mt_print(const void *ip, const struct xt_entry_match *match,
94                         int numeric)
95{
96	const struct xt_tos_match_info *info = (const void *)match->data;
97
98	printf(" tos match");
99	if (info->invert)
100		printf("!");
101	if (numeric ||
102	    !tos_try_print_symbolic("", info->tos_value, info->tos_mask))
103		printf("0x%02x/0x%02x", info->tos_value, info->tos_mask);
104}
105
106static void tos_mt_save_v0(const void *ip, const struct xt_entry_match *match)
107{
108	const struct ipt_tos_info *info = (const void *)match->data;
109
110	if (info->invert)
111		printf(" !");
112	printf(" --tos 0x%02x", info->tos);
113}
114
115static void tos_mt_save(const void *ip, const struct xt_entry_match *match)
116{
117	const struct xt_tos_match_info *info = (const void *)match->data;
118
119	if (info->invert)
120		printf(" !");
121	printf(" --tos 0x%02x/0x%02x", info->tos_value, info->tos_mask);
122}
123
124static struct xtables_match tos_mt_reg[] = {
125	{
126		.version       = XTABLES_VERSION,
127		.name          = "tos",
128		.family        = NFPROTO_IPV4,
129		.revision      = 0,
130		.size          = XT_ALIGN(sizeof(struct ipt_tos_info)),
131		.userspacesize = XT_ALIGN(sizeof(struct ipt_tos_info)),
132		.help          = tos_mt_help,
133		.print         = tos_mt_print_v0,
134		.save          = tos_mt_save_v0,
135		.x6_parse      = tos_mt_parse_v0,
136		.x6_options    = tos_mt_opts_v0,
137	},
138	{
139		.version       = XTABLES_VERSION,
140		.name          = "tos",
141		.family        = NFPROTO_UNSPEC,
142		.revision      = 1,
143		.size          = XT_ALIGN(sizeof(struct xt_tos_match_info)),
144		.userspacesize = XT_ALIGN(sizeof(struct xt_tos_match_info)),
145		.help          = tos_mt_help,
146		.print         = tos_mt_print,
147		.save          = tos_mt_save,
148		.x6_parse      = tos_mt_parse,
149		.x6_options    = tos_mt_opts,
150	},
151};
152
153void _init(void)
154{
155	xtables_register_matches(tos_mt_reg, ARRAY_SIZE(tos_mt_reg));
156}
157