libxt_tos.c revision f2a77520693f0a6dd1df1f87be4b81913961c1f5 
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 <linux/netfilter_ipv4/ipt_tos.h>
17#include "tos_values.c"
18
19enum {
20	FLAG_TOS = 1 << 0,
21};
22
23static const struct option tos_mt_opts[] = {
24	{.name = "tos", .has_arg = true, .val = 't'},
25	{ .name = NULL }
26};
27
28static void tos_mt_help(void)
29{
30	const struct tos_symbol_info *symbol;
31
32	printf(
33"tos match options:\n"
34"[!] --tos value[/mask]    Match Type of Service/Priority field value\n"
35"[!] --tos symbol          Match TOS field (IPv4 only) by symbol\n"
36"                          Accepted symbolic names for value are:\n");
37
38	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
39		printf("                          (0x%02x) %2u %s\n",
40		       symbol->value, symbol->value, symbol->name);
41
42	printf("\n");
43}
44
45static int tos_mt_parse_v0(int c, char **argv, int invert, unsigned int *flags,
46                           const void *entry, struct xt_entry_match **match)
47{
48	struct ipt_tos_info *info = (void *)(*match)->data;
49	struct tos_value_mask tvm;
50
51	switch (c) {
52	case 't':
53		xtables_param_act(XTF_ONLY_ONCE, "tos", "--tos", *flags & FLAG_TOS);
54		if (!tos_parse_symbolic(optarg, &tvm, 0xFF))
55			xtables_param_act(XTF_BAD_VALUE, "tos", "--tos", optarg);
56		if (tvm.mask != 0xFF)
57			xtables_error(PARAMETER_PROBLEM, "tos: Your kernel is "
58			           "too old to support anything besides /0xFF "
59				   "as a mask.");
60		info->tos = tvm.value;
61		if (invert)
62			info->invert = true;
63		*flags |= FLAG_TOS;
64		return true;
65	}
66	return false;
67}
68
69static int tos_mt_parse(int c, char **argv, int invert, unsigned int *flags,
70                        const void *entry, struct xt_entry_match **match)
71{
72	struct xt_tos_match_info *info = (void *)(*match)->data;
73	struct tos_value_mask tvm = {.mask = 0xFF};
74
75	switch (c) {
76	case 't':
77		xtables_param_act(XTF_ONLY_ONCE, "tos", "--tos", *flags & FLAG_TOS);
78		if (!tos_parse_symbolic(optarg, &tvm, 0x3F))
79			xtables_param_act(XTF_BAD_VALUE, "tos", "--tos", optarg);
80		info->tos_value = tvm.value;
81		info->tos_mask  = tvm.mask;
82		if (invert)
83			info->invert = true;
84		*flags |= FLAG_TOS;
85		return true;
86	}
87	return false;
88}
89
90static void tos_mt_check(unsigned int flags)
91{
92	if (flags == 0)
93		xtables_error(PARAMETER_PROBLEM,
94		           "tos: --tos parameter required");
95}
96
97static void tos_mt_print_v0(const void *ip, const struct xt_entry_match *match,
98                            int numeric)
99{
100	const struct ipt_tos_info *info = (const void *)match->data;
101
102	printf("tos match ");
103	if (info->invert)
104		printf("!");
105	if (numeric || !tos_try_print_symbolic("", info->tos, 0x3F))
106		printf("0x%02x ", info->tos);
107}
108
109static void tos_mt_print(const void *ip, const struct xt_entry_match *match,
110                         int numeric)
111{
112	const struct xt_tos_match_info *info = (const void *)match->data;
113
114	printf("tos match ");
115	if (info->invert)
116		printf("!");
117	if (numeric ||
118	    !tos_try_print_symbolic("", info->tos_value, info->tos_mask))
119		printf("0x%02x/0x%02x ", info->tos_value, info->tos_mask);
120}
121
122static void tos_mt_save_v0(const void *ip, const struct xt_entry_match *match)
123{
124	const struct ipt_tos_info *info = (const void *)match->data;
125
126	if (info->invert)
127		printf("! ");
128	printf("--tos 0x%02x ", info->tos);
129}
130
131static void tos_mt_save(const void *ip, const struct xt_entry_match *match)
132{
133	const struct xt_tos_match_info *info = (const void *)match->data;
134
135	if (info->invert)
136		printf("! ");
137	printf("--tos 0x%02x/0x%02x ", info->tos_value, info->tos_mask);
138}
139
140static struct xtables_match tos_mt_reg[] = {
141	{
142		.version       = XTABLES_VERSION,
143		.name          = "tos",
144		.family        = NFPROTO_IPV4,
145		.revision      = 0,
146		.size          = XT_ALIGN(sizeof(struct ipt_tos_info)),
147		.userspacesize = XT_ALIGN(sizeof(struct ipt_tos_info)),
148		.help          = tos_mt_help,
149		.parse         = tos_mt_parse_v0,
150		.final_check   = tos_mt_check,
151		.print         = tos_mt_print_v0,
152		.save          = tos_mt_save_v0,
153		.extra_opts    = tos_mt_opts,
154	},
155	{
156		.version       = XTABLES_VERSION,
157		.name          = "tos",
158		.family        = NFPROTO_UNSPEC,
159		.revision      = 1,
160		.size          = XT_ALIGN(sizeof(struct xt_tos_match_info)),
161		.userspacesize = XT_ALIGN(sizeof(struct xt_tos_match_info)),
162		.help          = tos_mt_help,
163		.parse         = tos_mt_parse,
164		.final_check   = tos_mt_check,
165		.print         = tos_mt_print,
166		.save          = tos_mt_save,
167		.extra_opts    = tos_mt_opts,
168	},
169};
170
171void _init(void)
172{
173	xtables_register_matches(tos_mt_reg, ARRAY_SIZE(tos_mt_reg));
174}
175