libxt_cpu.c revision 32b8e61e4e5bd405d9ad07bf9468498dfbb19f9e 
1/* Shared library add-on to iptables to add CPU match 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#include <xtables.h>
9#include <linux/netfilter/xt_cpu.h>
10
11static void cpu_help(void)
12{
13	printf(
14"cpu match options:\n"
15"[!] --cpu number   Match CPU number\n");
16}
17
18static const struct option cpu_opts[] = {
19	{.name = "cpu", .has_arg = true, .val = '1'},
20	XT_GETOPT_TABLEEND,
21};
22
23static void
24parse_cpu(const char *s, struct xt_cpu_info *info)
25{
26	unsigned int cpu;
27	char *end;
28
29	if (!xtables_strtoui(s, &end, &cpu, 0, UINT32_MAX))
30		xtables_param_act(XTF_BAD_VALUE, "cpu", "--cpu", s);
31
32	if (*end != '\0')
33		xtables_param_act(XTF_BAD_VALUE, "cpu", "--cpu", s);
34
35	info->cpu = cpu;
36}
37
38static int
39cpu_parse(int c, char **argv, int invert, unsigned int *flags,
40          const void *entry, struct xt_entry_match **match)
41{
42	struct xt_cpu_info *cpuinfo = (struct xt_cpu_info *)(*match)->data;
43
44	switch (c) {
45	case '1':
46		xtables_check_inverse(optarg, &invert, &optind, 0, argv);
47		parse_cpu(optarg, cpuinfo);
48		if (invert)
49			cpuinfo->invert = 1;
50		*flags = 1;
51		break;
52
53	default:
54		return 0;
55	}
56
57	return 1;
58}
59
60static void cpu_check(unsigned int flags)
61{
62	if (!flags)
63		xtables_error(PARAMETER_PROBLEM,
64			      "You must specify `--cpu'");
65}
66
67static void
68cpu_print(const void *ip, const struct xt_entry_match *match, int numeric)
69{
70	const struct xt_cpu_info *info = (void *)match->data;
71
72	printf("cpu %s%u ", info->invert ? "! ":"", info->cpu);
73}
74
75static void cpu_save(const void *ip, const struct xt_entry_match *match)
76{
77	const struct xt_cpu_info *info = (void *)match->data;
78
79	printf("%s--cpu %u ", info->invert ? "! ":"", info->cpu);
80}
81
82static struct xtables_match cpu_match = {
83	.family		= NFPROTO_UNSPEC,
84 	.name		= "cpu",
85	.version	= XTABLES_VERSION,
86	.size		= XT_ALIGN(sizeof(struct xt_cpu_info)),
87	.userspacesize	= XT_ALIGN(sizeof(struct xt_cpu_info)),
88	.help		= cpu_help,
89	.parse		= cpu_parse,
90	.final_check	= cpu_check,
91	.print		= cpu_print,
92	.save		= cpu_save,
93	.extra_opts	= cpu_opts,
94};
95
96void _init(void)
97{
98	xtables_register_match(&cpu_match);
99}
100