libxt_TOS.c revision 61cc52b6f9edfa3efb1d0c9ea9531abb42828ec2 
1/*
2 * Shared library add-on to iptables to add TOS target support
3 *
4 * Copyright © CC Computer Consultants GmbH, 2007
5 * Contact: Jan Engelhardt <jengelh@medozas.de>
6 */
7#include <getopt.h>
8#include <stdbool.h>
9#include <stdio.h>
10#include <stdlib.h>
11#include <string.h>
12#include <netinet/in.h>
13
14#include <xtables.h>
15#include <linux/netfilter/xt_DSCP.h>
16#include "tos_values.c"
17
18struct ipt_tos_target_info {
19	uint8_t tos;
20};
21
22enum {
23	O_SET_TOS = 0,
24	O_AND_TOS,
25	O_OR_TOS,
26	O_XOR_TOS,
27	F_SET_TOS = 1 << O_SET_TOS,
28	F_AND_TOS = 1 << O_AND_TOS,
29	F_OR_TOS  = 1 << O_OR_TOS,
30	F_XOR_TOS = 1 << O_XOR_TOS,
31	F_ANY     = F_SET_TOS | F_AND_TOS | F_OR_TOS | F_XOR_TOS,
32};
33
34static const struct xt_option_entry tos_tg_opts_v0[] = {
35	{.name = "set-tos", .id = O_SET_TOS, .type = XTTYPE_TOSMASK,
36	 .excl = F_ANY, .max = 0xFF},
37	XTOPT_TABLEEND,
38};
39
40static const struct xt_option_entry tos_tg_opts[] = {
41	{.name = "set-tos", .id = O_SET_TOS, .type = XTTYPE_TOSMASK,
42	 .excl = F_ANY, .max = 0x3F},
43	{.name = "and-tos", .id = O_AND_TOS, .type = XTTYPE_UINT8,
44	 .excl = F_ANY},
45	{.name = "or-tos", .id = O_OR_TOS, .type = XTTYPE_UINT8,
46	 .excl = F_ANY},
47	{.name = "xor-tos", .id = O_XOR_TOS, .type = XTTYPE_UINT8,
48	 .excl = F_ANY},
49	XTOPT_TABLEEND,
50};
51
52static void tos_tg_help_v0(void)
53{
54	const struct tos_symbol_info *symbol;
55
56	printf(
57"TOS target options:\n"
58"  --set-tos value     Set Type of Service/Priority field to value\n"
59"  --set-tos symbol    Set TOS field (IPv4 only) by symbol\n"
60"                      Accepted symbolic names for value are:\n");
61
62	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
63		printf("                        (0x%02x) %2u %s\n",
64		       symbol->value, symbol->value, symbol->name);
65
66	printf("\n");
67}
68
69static void tos_tg_help(void)
70{
71	const struct tos_symbol_info *symbol;
72
73	printf(
74"TOS target v%s options:\n"
75"  --set-tos value[/mask]  Set Type of Service/Priority field to value\n"
76"                          (Zero out bits in mask and XOR value into TOS)\n"
77"  --set-tos symbol        Set TOS field (IPv4 only) by symbol\n"
78"                          (this zeroes the 4-bit Precedence part!)\n"
79"                          Accepted symbolic names for value are:\n",
80XTABLES_VERSION);
81
82	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
83		printf("                            (0x%02x) %2u %s\n",
84		       symbol->value, symbol->value, symbol->name);
85
86	printf(
87"\n"
88"  --and-tos bits          Binary AND the TOS value with bits\n"
89"  --or-tos  bits          Binary OR the TOS value with bits\n"
90"  --xor-tos bits          Binary XOR the TOS value with bits\n"
91);
92}
93
94static void tos_tg_parse_v0(struct xt_option_call *cb)
95{
96	struct ipt_tos_target_info *info = cb->data;
97
98	xtables_option_parse(cb);
99	if (cb->val.tos_mask != 0xFF)
100		xtables_error(PARAMETER_PROBLEM, "tos match: Your kernel "
101		           "is too old to support anything besides "
102			   "/0xFF as a mask.");
103	info->tos = cb->val.tos_value;
104}
105
106static void tos_tg_parse(struct xt_option_call *cb)
107{
108	struct xt_tos_target_info *info = cb->data;
109
110	xtables_option_parse(cb);
111	switch (cb->entry->id) {
112	case O_SET_TOS:
113		info->tos_value = cb->val.tos_value;
114		info->tos_mask  = cb->val.tos_mask;
115		break;
116	case O_AND_TOS:
117		info->tos_value = 0;
118		info->tos_mask  = ~cb->val.u8;
119		break;
120	case O_OR_TOS:
121		info->tos_value = cb->val.u8;
122		info->tos_mask  = cb->val.u8;
123		break;
124	case O_XOR_TOS:
125		info->tos_value = cb->val.u8;
126		info->tos_mask  = 0;
127		break;
128	}
129}
130
131static void tos_tg_check(struct xt_fcheck_call *cb)
132{
133	if (!(cb->xflags & F_ANY))
134		xtables_error(PARAMETER_PROBLEM,
135		           "TOS: An action is required");
136}
137
138static void tos_tg_print_v0(const void *ip,
139                            const struct xt_entry_target *target, int numeric)
140{
141	const struct ipt_tos_target_info *info = (const void *)target->data;
142
143	printf(" TOS set ");
144	if (numeric || !tos_try_print_symbolic("", info->tos, 0xFF))
145		printf("0x%02x", info->tos);
146}
147
148static void tos_tg_print(const void *ip, const struct xt_entry_target *target,
149                         int numeric)
150{
151	const struct xt_tos_target_info *info = (const void *)target->data;
152
153	if (numeric)
154		printf(" TOS set 0x%02x/0x%02x",
155		       info->tos_value, info->tos_mask);
156	else if (tos_try_print_symbolic(" TOS set",
157	    info->tos_value, info->tos_mask))
158		/* already printed by call */
159		return;
160	else if (info->tos_value == 0)
161		printf(" TOS and 0x%02x",
162		       (unsigned int)(uint8_t)~info->tos_mask);
163	else if (info->tos_value == info->tos_mask)
164		printf(" TOS or 0x%02x", info->tos_value);
165	else if (info->tos_mask == 0)
166		printf(" TOS xor 0x%02x", info->tos_value);
167	else
168		printf(" TOS set 0x%02x/0x%02x",
169		       info->tos_value, info->tos_mask);
170}
171
172static void tos_tg_save_v0(const void *ip, const struct xt_entry_target *target)
173{
174	const struct ipt_tos_target_info *info = (const void *)target->data;
175
176	printf(" --set-tos 0x%02x", info->tos);
177}
178
179static void tos_tg_save(const void *ip, const struct xt_entry_target *target)
180{
181	const struct xt_tos_target_info *info = (const void *)target->data;
182
183	printf(" --set-tos 0x%02x/0x%02x", info->tos_value, info->tos_mask);
184}
185
186static struct xtables_target tos_tg_reg[] = {
187	{
188		.version       = XTABLES_VERSION,
189		.name          = "TOS",
190		.revision      = 0,
191		.family        = NFPROTO_IPV4,
192		.size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
193		.userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
194		.help          = tos_tg_help_v0,
195		.print         = tos_tg_print_v0,
196		.save          = tos_tg_save_v0,
197		.x6_parse      = tos_tg_parse_v0,
198		.x6_fcheck     = tos_tg_check,
199		.x6_options    = tos_tg_opts_v0,
200	},
201	{
202		.version       = XTABLES_VERSION,
203		.name          = "TOS",
204		.revision      = 1,
205		.family        = NFPROTO_UNSPEC,
206		.size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
207		.userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
208		.help          = tos_tg_help,
209		.print         = tos_tg_print,
210		.save          = tos_tg_save,
211		.x6_parse      = tos_tg_parse,
212		.x6_fcheck     = tos_tg_check,
213		.x6_options    = tos_tg_opts,
214	},
215};
216
217void _init(void)
218{
219	xtables_register_targets(tos_tg_reg, ARRAY_SIZE(tos_tg_reg));
220}
221