libxt_TOS.c revision 36f2eadca556da9bb4979b3f67f38020e80ef7d2 
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@computergmbh.de>
6 */
7#include <getopt.h>
8#include <stdio.h>
9#include <stdlib.h>
10#include <string.h>
11
12#include <xtables.h>
13#include <linux/netfilter/xt_DSCP.h>
14#include <linux/netfilter_ipv4/ipt_TOS.h>
15#include "tos_values.c"
16
17enum {
18	FLAG_TOS = 1 << 0,
19};
20
21static const struct option tos_tg_opts_v0[] = {
22	{.name = "set-tos", .has_arg = true, .val = '='},
23	{},
24};
25
26static const struct option tos_tg_opts[] = {
27	{.name = "set-tos", .has_arg = true, .val = '='},
28	{.name = "and-tos", .has_arg = true, .val = '&'},
29	{.name = "or-tos",  .has_arg = true, .val = '|'},
30	{.name = "xor-tos", .has_arg = true, .val = '^'},
31	{},
32};
33
34static void tos_tg_help_v0(void)
35{
36	const struct tos_symbol_info *symbol;
37
38	printf(
39"TOS target options:\n"
40"  --set-tos value     Set Type of Service/Priority field to value\n"
41"  --set-tos symbol    Set TOS field (IPv4 only) by symbol\n"
42"                      Accepted symbolic names for value are:\n");
43
44	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
45		printf("                        (0x%02x) %2u %s\n",
46		       symbol->value, symbol->value, symbol->name);
47
48	printf("\n");
49}
50
51static void tos_tg_help(void)
52{
53	const struct tos_symbol_info *symbol;
54
55	printf(
56"TOS target v%s options:\n"
57"  --set-tos value[/mask]  Set Type of Service/Priority field to value\n"
58"                          (Zero out bits in mask and XOR value into TOS)\n"
59"  --set-tos symbol        Set TOS field (IPv4 only) by symbol\n"
60"                          (this zeroes the 4-bit Precedence part!)\n"
61"                          Accepted symbolic names for value are:\n",
62IPTABLES_VERSION);
63
64	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
65		printf("                            (0x%02x) %2u %s\n",
66		       symbol->value, symbol->value, symbol->name);
67
68	printf(
69"\n"
70"  --and-tos bits          Binary AND the TOS value with bits\n"
71"  --or-tos  bits          Binary OR the TOS value with bits\n"
72"  --xor-tos bits          Binary XOR the TOS value with bits\n"
73);
74}
75
76static int tos_tg_parse_v0(int c, char **argv, int invert, unsigned int *flags,
77                           const void *entry, struct xt_entry_target **target)
78{
79	struct ipt_tos_target_info *info = (void *)(*target)->data;
80	struct tos_value_mask tvm;
81
82	switch (c) {
83	case '=':
84		param_act(P_ONLY_ONCE, "TOS", "--set-tos", *flags & FLAG_TOS);
85		param_act(P_NO_INVERT, "TOS", "--set-tos", invert);
86		if (!tos_parse_symbolic(optarg, &tvm, 0xFF))
87			param_act(P_BAD_VALUE, "TOS", "--set-tos", optarg);
88		if (tvm.mask != 0xFF)
89			exit_error(PARAMETER_PROBLEM, "tos match: Your kernel "
90			           "is too old to support anything besides "
91				   "/0xFF as a mask.");
92		info->tos = tvm.value;
93		*flags |= FLAG_TOS;
94		return true;
95	}
96
97	return false;
98}
99
100static int tos_tg_parse(int c, char **argv, int invert, unsigned int *flags,
101                         const void *entry, struct xt_entry_target **target)
102{
103	struct xt_tos_target_info *info = (void *)(*target)->data;
104	struct tos_value_mask tvm;
105	unsigned int bits;
106
107	switch (c) {
108	case '=': /* --set-tos */
109		param_act(P_ONLY_ONCE, "TOS", "--set-tos", *flags & FLAG_TOS);
110		param_act(P_NO_INVERT, "TOS", "--set-tos", invert);
111		if (!tos_parse_symbolic(optarg, &tvm, 0x3F))
112			param_act(P_BAD_VALUE, "TOS", "--set-tos", optarg);
113		info->tos_value = tvm.value;
114		info->tos_mask  = tvm.mask;
115		break;
116
117	case '&': /* --and-tos */
118		param_act(P_ONLY_ONCE, "TOS", "--and-tos", *flags & FLAG_TOS);
119		param_act(P_NO_INVERT, "TOS", "--and-tos", invert);
120		if (!strtonum(optarg, NULL, &bits, 0, 0xFF))
121			param_act(P_BAD_VALUE, "TOS", "--and-tos", optarg);
122		info->tos_value = 0;
123		info->tos_mask  = ~bits;
124		break;
125
126	case '|': /* --or-tos */
127		param_act(P_ONLY_ONCE, "TOS", "--or-tos", *flags & FLAG_TOS);
128		param_act(P_NO_INVERT, "TOS", "--or-tos", invert);
129		if (!strtonum(optarg, NULL, &bits, 0, 0xFF))
130			param_act(P_BAD_VALUE, "TOS", "--or-tos", optarg);
131		info->tos_value = bits;
132		info->tos_mask  = bits;
133		break;
134
135	case '^': /* --xor-tos */
136		param_act(P_ONLY_ONCE, "TOS", "--xor-tos", *flags & FLAG_TOS);
137		param_act(P_NO_INVERT, "TOS", "--xor-tos", invert);
138		if (!strtonum(optarg, NULL, &bits, 0, 0xFF))
139			param_act(P_BAD_VALUE, "TOS", "--xor-tos", optarg);
140		info->tos_value = bits;
141		info->tos_mask  = 0;
142		break;
143
144	default:
145		return false;
146	}
147
148	*flags |= FLAG_TOS;
149	return true;
150}
151
152static void tos_tg_check(unsigned int flags)
153{
154	if (flags == 0)
155		exit_error(PARAMETER_PROBLEM,
156		           "TOS: The --set-tos parameter is required");
157}
158
159static void tos_tg_print_v0(const void *ip,
160                            const struct xt_entry_target *target, int numeric)
161{
162	const struct ipt_tos_target_info *info = (const void *)target->data;
163
164	printf("TOS set ");
165	if (numeric || !tos_try_print_symbolic("", info->tos, 0xFF))
166		printf("0x%02x ", info->tos);
167}
168
169static void tos_tg_print(const void *ip, const struct xt_entry_target *target,
170                         int numeric)
171{
172	const struct xt_tos_target_info *info = (const void *)target->data;
173
174	if (numeric)
175		printf("TOS set 0x%02x/0x%02x ",
176		       info->tos_value, info->tos_mask);
177	else if (tos_try_print_symbolic("TOS set ",
178	    info->tos_value, info->tos_mask))
179		/* already printed by call */
180		return;
181	else if (info->tos_value == 0)
182		printf("TOS and 0x%02x ",
183		       (unsigned int)(u_int8_t)~info->tos_mask);
184	else if (info->tos_value == info->tos_mask)
185		printf("TOS or 0x%02x ", info->tos_value);
186	else if (info->tos_mask == 0)
187		printf("TOS xor 0x%02x ", info->tos_value);
188	else
189		printf("TOS set 0x%02x/0x%02x ",
190		       info->tos_value, info->tos_mask);
191}
192
193static void tos_tg_save_v0(const void *ip, const struct xt_entry_target *target)
194{
195	const struct ipt_tos_target_info *info = (const void *)target->data;
196
197	printf("--set-tos 0x%02x ", info->tos);
198}
199
200static void tos_tg_save(const void *ip, const struct xt_entry_target *target)
201{
202	const struct xt_tos_target_info *info = (const void *)target->data;
203
204	printf("--set-tos 0x%02x/0x%02x ", info->tos_value, info->tos_mask);
205}
206
207static struct xtables_target tos_tg_reg_v0 = {
208	.version       = IPTABLES_VERSION,
209	.name          = "TOS",
210	.revision      = 0,
211	.family        = AF_INET,
212	.size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
213	.userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
214	.help          = tos_tg_help_v0,
215	.parse         = tos_tg_parse_v0,
216	.final_check   = tos_tg_check,
217	.print         = tos_tg_print_v0,
218	.save          = tos_tg_save_v0,
219	.extra_opts    = tos_tg_opts_v0,
220};
221
222static struct xtables_target tos_tg_reg = {
223	.version       = IPTABLES_VERSION,
224	.name          = "TOS",
225	.revision      = 1,
226	.family        = AF_INET,
227	.size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
228	.userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
229	.help          = tos_tg_help,
230	.parse         = tos_tg_parse,
231	.final_check   = tos_tg_check,
232	.print         = tos_tg_print,
233	.save          = tos_tg_save,
234	.extra_opts    = tos_tg_opts,
235};
236
237static struct xtables_target tos_tg6_reg = {
238	.version       = IPTABLES_VERSION,
239	.name          = "TOS",
240	.family        = AF_INET6,
241	.revision      = 1,
242	.size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
243	.userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
244	.help          = tos_tg_help,
245	.parse         = tos_tg_parse,
246	.final_check   = tos_tg_check,
247	.print         = tos_tg_print,
248	.save          = tos_tg_save,
249	.extra_opts    = tos_tg_opts,
250};
251
252void _init(void)
253{
254	xtables_register_target(&tos_tg_reg_v0);
255	xtables_register_target(&tos_tg_reg);
256	xtables_register_target(&tos_tg6_reg);
257}
258