libxt_TOS.c revision 1829ed482efbc8b390cc760d012b3a4450494e1a 
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#include <netinet/in.h>
12
13#include <xtables.h>
14#include <linux/netfilter/xt_DSCP.h>
15#include <linux/netfilter_ipv4/ipt_TOS.h>
16#include "tos_values.c"
17
18enum {
19	FLAG_TOS = 1 << 0,
20};
21
22static const struct option tos_tg_opts_v0[] = {
23	{.name = "set-tos", .has_arg = true, .val = '='},
24	{ .name = NULL }
25};
26
27static const struct option tos_tg_opts[] = {
28	{.name = "set-tos", .has_arg = true, .val = '='},
29	{.name = "and-tos", .has_arg = true, .val = '&'},
30	{.name = "or-tos",  .has_arg = true, .val = '|'},
31	{.name = "xor-tos", .has_arg = true, .val = '^'},
32	{ .name = NULL }
33};
34
35static void tos_tg_help_v0(void)
36{
37	const struct tos_symbol_info *symbol;
38
39	printf(
40"TOS target options:\n"
41"  --set-tos value     Set Type of Service/Priority field to value\n"
42"  --set-tos symbol    Set TOS field (IPv4 only) by symbol\n"
43"                      Accepted symbolic names for value are:\n");
44
45	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
46		printf("                        (0x%02x) %2u %s\n",
47		       symbol->value, symbol->value, symbol->name);
48
49	printf("\n");
50}
51
52static void tos_tg_help(void)
53{
54	const struct tos_symbol_info *symbol;
55
56	printf(
57"TOS target v%s options:\n"
58"  --set-tos value[/mask]  Set Type of Service/Priority field to value\n"
59"                          (Zero out bits in mask and XOR value into TOS)\n"
60"  --set-tos symbol        Set TOS field (IPv4 only) by symbol\n"
61"                          (this zeroes the 4-bit Precedence part!)\n"
62"                          Accepted symbolic names for value are:\n",
63XTABLES_VERSION);
64
65	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
66		printf("                            (0x%02x) %2u %s\n",
67		       symbol->value, symbol->value, symbol->name);
68
69	printf(
70"\n"
71"  --and-tos bits          Binary AND the TOS value with bits\n"
72"  --or-tos  bits          Binary OR the TOS value with bits\n"
73"  --xor-tos bits          Binary XOR the TOS value with bits\n"
74);
75}
76
77static int tos_tg_parse_v0(int c, char **argv, int invert, unsigned int *flags,
78                           const void *entry, struct xt_entry_target **target)
79{
80	struct ipt_tos_target_info *info = (void *)(*target)->data;
81	struct tos_value_mask tvm;
82
83	switch (c) {
84	case '=':
85		xtables_param_act(XTF_ONLY_ONCE, "TOS", "--set-tos", *flags & FLAG_TOS);
86		xtables_param_act(XTF_NO_INVERT, "TOS", "--set-tos", invert);
87		if (!tos_parse_symbolic(optarg, &tvm, 0xFF))
88			xtables_param_act(XTF_BAD_VALUE, "TOS", "--set-tos", optarg);
89		if (tvm.mask != 0xFF)
90			xtables_error(PARAMETER_PROBLEM, "tos match: Your kernel "
91			           "is too old to support anything besides "
92				   "/0xFF as a mask.");
93		info->tos = tvm.value;
94		*flags |= FLAG_TOS;
95		return true;
96	}
97
98	return false;
99}
100
101static int tos_tg_parse(int c, char **argv, int invert, unsigned int *flags,
102                         const void *entry, struct xt_entry_target **target)
103{
104	struct xt_tos_target_info *info = (void *)(*target)->data;
105	struct tos_value_mask tvm;
106	unsigned int bits;
107
108	switch (c) {
109	case '=': /* --set-tos */
110		xtables_param_act(XTF_ONLY_ONCE, "TOS", "--set-tos", *flags & FLAG_TOS);
111		xtables_param_act(XTF_NO_INVERT, "TOS", "--set-tos", invert);
112		if (!tos_parse_symbolic(optarg, &tvm, 0x3F))
113			xtables_param_act(XTF_BAD_VALUE, "TOS", "--set-tos", optarg);
114		info->tos_value = tvm.value;
115		info->tos_mask  = tvm.mask;
116		break;
117
118	case '&': /* --and-tos */
119		xtables_param_act(XTF_ONLY_ONCE, "TOS", "--and-tos", *flags & FLAG_TOS);
120		xtables_param_act(XTF_NO_INVERT, "TOS", "--and-tos", invert);
121		if (!xtables_strtoui(optarg, NULL, &bits, 0, UINT8_MAX))
122			xtables_param_act(XTF_BAD_VALUE, "TOS", "--and-tos", optarg);
123		info->tos_value = 0;
124		info->tos_mask  = ~bits;
125		break;
126
127	case '|': /* --or-tos */
128		xtables_param_act(XTF_ONLY_ONCE, "TOS", "--or-tos", *flags & FLAG_TOS);
129		xtables_param_act(XTF_NO_INVERT, "TOS", "--or-tos", invert);
130		if (!xtables_strtoui(optarg, NULL, &bits, 0, UINT8_MAX))
131			xtables_param_act(XTF_BAD_VALUE, "TOS", "--or-tos", optarg);
132		info->tos_value = bits;
133		info->tos_mask  = bits;
134		break;
135
136	case '^': /* --xor-tos */
137		xtables_param_act(XTF_ONLY_ONCE, "TOS", "--xor-tos", *flags & FLAG_TOS);
138		xtables_param_act(XTF_NO_INVERT, "TOS", "--xor-tos", invert);
139		if (!xtables_strtoui(optarg, NULL, &bits, 0, UINT8_MAX))
140			xtables_param_act(XTF_BAD_VALUE, "TOS", "--xor-tos", optarg);
141		info->tos_value = bits;
142		info->tos_mask  = 0;
143		break;
144
145	default:
146		return false;
147	}
148
149	*flags |= FLAG_TOS;
150	return true;
151}
152
153static void tos_tg_check(unsigned int flags)
154{
155	if (flags == 0)
156		xtables_error(PARAMETER_PROBLEM,
157		           "TOS: The --set-tos parameter is required");
158}
159
160static void tos_tg_print_v0(const void *ip,
161                            const struct xt_entry_target *target, int numeric)
162{
163	const struct ipt_tos_target_info *info = (const void *)target->data;
164
165	printf("TOS set ");
166	if (numeric || !tos_try_print_symbolic("", info->tos, 0xFF))
167		printf("0x%02x ", info->tos);
168}
169
170static void tos_tg_print(const void *ip, const struct xt_entry_target *target,
171                         int numeric)
172{
173	const struct xt_tos_target_info *info = (const void *)target->data;
174
175	if (numeric)
176		printf("TOS set 0x%02x/0x%02x ",
177		       info->tos_value, info->tos_mask);
178	else if (tos_try_print_symbolic("TOS set ",
179	    info->tos_value, info->tos_mask))
180		/* already printed by call */
181		return;
182	else if (info->tos_value == 0)
183		printf("TOS and 0x%02x ",
184		       (unsigned int)(u_int8_t)~info->tos_mask);
185	else if (info->tos_value == info->tos_mask)
186		printf("TOS or 0x%02x ", info->tos_value);
187	else if (info->tos_mask == 0)
188		printf("TOS xor 0x%02x ", info->tos_value);
189	else
190		printf("TOS set 0x%02x/0x%02x ",
191		       info->tos_value, info->tos_mask);
192}
193
194static void tos_tg_save_v0(const void *ip, const struct xt_entry_target *target)
195{
196	const struct ipt_tos_target_info *info = (const void *)target->data;
197
198	printf("--set-tos 0x%02x ", info->tos);
199}
200
201static void tos_tg_save(const void *ip, const struct xt_entry_target *target)
202{
203	const struct xt_tos_target_info *info = (const void *)target->data;
204
205	printf("--set-tos 0x%02x/0x%02x ", info->tos_value, info->tos_mask);
206}
207
208static struct xtables_target tos_tg_reg_v0 = {
209	.version       = XTABLES_VERSION,
210	.name          = "TOS",
211	.revision      = 0,
212	.family        = NFPROTO_IPV4,
213	.size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
214	.userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
215	.help          = tos_tg_help_v0,
216	.parse         = tos_tg_parse_v0,
217	.final_check   = tos_tg_check,
218	.print         = tos_tg_print_v0,
219	.save          = tos_tg_save_v0,
220	.extra_opts    = tos_tg_opts_v0,
221};
222
223static struct xtables_target tos_tg_reg = {
224	.version       = XTABLES_VERSION,
225	.name          = "TOS",
226	.revision      = 1,
227	.family        = NFPROTO_IPV4,
228	.size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
229	.userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
230	.help          = tos_tg_help,
231	.parse         = tos_tg_parse,
232	.final_check   = tos_tg_check,
233	.print         = tos_tg_print,
234	.save          = tos_tg_save,
235	.extra_opts    = tos_tg_opts,
236};
237
238static struct xtables_target tos_tg6_reg = {
239	.version       = XTABLES_VERSION,
240	.name          = "TOS",
241	.family        = NFPROTO_IPV6,
242	.revision      = 1,
243	.size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
244	.userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
245	.help          = tos_tg_help,
246	.parse         = tos_tg_parse,
247	.final_check   = tos_tg_check,
248	.print         = tos_tg_print,
249	.save          = tos_tg_save,
250	.extra_opts    = tos_tg_opts,
251};
252
253void _init(void)
254{
255	xtables_register_target(&tos_tg_reg_v0);
256	xtables_register_target(&tos_tg_reg);
257	xtables_register_target(&tos_tg6_reg);
258}
259