libxt_mark.c revision bf97128c7262f17a02fec41cdae75b472ba77f88 
1/* Shared library add-on to iptables to add NFMARK matching support. */
2#include <stdbool.h>
3#include <stdio.h>
4#include <netdb.h>
5#include <string.h>
6#include <stdlib.h>
7#include <getopt.h>
8
9#include <xtables.h>
10#include <linux/netfilter/xt_mark.h>
11
12enum {
13	F_MARK = 1 << 0,
14};
15
16static void mark_mt_help(void)
17{
18	printf(
19"mark match options:\n"
20"[!] --mark value[/mask]    Match nfmark value with optional mask\n");
21}
22
23static const struct option mark_mt_opts[] = {
24	{.name = "mark", .has_arg = true, .val = '1'},
25	{ .name = NULL }
26};
27
28static int mark_mt_parse(int c, char **argv, int invert, unsigned int *flags,
29                         const void *entry, struct xt_entry_match **match)
30{
31	struct xt_mark_mtinfo1 *info = (void *)(*match)->data;
32	unsigned int mark, mask = UINT32_MAX;
33	char *end;
34
35	switch (c) {
36	case '1': /* --mark */
37		xtables_param_act(XTF_ONLY_ONCE, "mark", "--mark", *flags & F_MARK);
38		if (!xtables_strtoui(optarg, &end, &mark, 0, UINT32_MAX))
39			xtables_param_act(XTF_BAD_VALUE, "mark", "--mark", optarg);
40		if (*end == '/')
41			if (!xtables_strtoui(end + 1, &end, &mask, 0, UINT32_MAX))
42				xtables_param_act(XTF_BAD_VALUE, "mark", "--mark", optarg);
43		if (*end != '\0')
44			xtables_param_act(XTF_BAD_VALUE, "mark", "--mark", optarg);
45
46		if (invert)
47			info->invert = true;
48		info->mark = mark;
49		info->mask = mask;
50		*flags    |= F_MARK;
51		return true;
52	}
53	return false;
54}
55
56static int
57mark_parse(int c, char **argv, int invert, unsigned int *flags,
58           const void *entry, struct xt_entry_match **match)
59{
60	struct xt_mark_info *markinfo = (struct xt_mark_info *)(*match)->data;
61
62	switch (c) {
63		char *end;
64	case '1':
65		xtables_check_inverse(optarg, &invert, &optind, 0, argv);
66		markinfo->mark = strtoul(optarg, &end, 0);
67		if (*end == '/') {
68			markinfo->mask = strtoul(end+1, &end, 0);
69		} else
70			markinfo->mask = 0xffffffff;
71		if (*end != '\0' || end == optarg)
72			xtables_error(PARAMETER_PROBLEM, "Bad MARK value \"%s\"", optarg);
73		if (invert)
74			markinfo->invert = 1;
75		*flags = 1;
76		break;
77
78	default:
79		return 0;
80	}
81	return 1;
82}
83
84static void print_mark(unsigned int mark, unsigned int mask)
85{
86	if (mask != 0xffffffffU)
87		printf("0x%x/0x%x ", mark, mask);
88	else
89		printf("0x%x ", mark);
90}
91
92static void mark_mt_check(unsigned int flags)
93{
94	if (flags == 0)
95		xtables_error(PARAMETER_PROBLEM,
96			   "mark match: The --mark option is required");
97}
98
99static void
100mark_mt_print(const void *ip, const struct xt_entry_match *match, int numeric)
101{
102	const struct xt_mark_mtinfo1 *info = (const void *)match->data;
103
104	printf("mark match ");
105	if (info->invert)
106		printf("!");
107	print_mark(info->mark, info->mask);
108}
109
110static void
111mark_print(const void *ip, const struct xt_entry_match *match, int numeric)
112{
113	const struct xt_mark_info *info = (const void *)match->data;
114
115	printf("MARK match ");
116
117	if (info->invert)
118		printf("!");
119
120	print_mark(info->mark, info->mask);
121}
122
123static void mark_mt_save(const void *ip, const struct xt_entry_match *match)
124{
125	const struct xt_mark_mtinfo1 *info = (const void *)match->data;
126
127	if (info->invert)
128		printf("! ");
129
130	printf("--mark ");
131	print_mark(info->mark, info->mask);
132}
133
134static void
135mark_save(const void *ip, const struct xt_entry_match *match)
136{
137	const struct xt_mark_info *info = (const void *)match->data;
138
139	if (info->invert)
140		printf("! ");
141
142	printf("--mark ");
143	print_mark(info->mark, info->mask);
144}
145
146static struct xtables_match mark_mt_reg[] = {
147	{
148		.family        = NFPROTO_UNSPEC,
149		.name          = "mark",
150		.revision      = 0,
151		.version       = XTABLES_VERSION,
152		.size          = XT_ALIGN(sizeof(struct xt_mark_info)),
153		.userspacesize = XT_ALIGN(sizeof(struct xt_mark_info)),
154		.help          = mark_mt_help,
155		.parse         = mark_parse,
156		.final_check   = mark_mt_check,
157		.print         = mark_print,
158		.save          = mark_save,
159		.extra_opts    = mark_mt_opts,
160	},
161	{
162		.version       = XTABLES_VERSION,
163		.name          = "mark",
164		.revision      = 1,
165		.family        = NFPROTO_UNSPEC,
166		.size          = XT_ALIGN(sizeof(struct xt_mark_mtinfo1)),
167		.userspacesize = XT_ALIGN(sizeof(struct xt_mark_mtinfo1)),
168		.help          = mark_mt_help,
169		.parse         = mark_mt_parse,
170		.final_check   = mark_mt_check,
171		.print         = mark_mt_print,
172		.save          = mark_mt_save,
173		.extra_opts    = mark_mt_opts,
174	},
175};
176
177void _init(void)
178{
179	xtables_register_matches(mark_mt_reg, ARRAY_SIZE(mark_mt_reg));
180}
181