1 #include <stdio.h>
2 #include <xtables.h>
3 #include <linux/netfilter/xt_cgroup.h>
4 
5 enum {
6 	O_CLASSID = 0,
7 	O_PATH = 1,
8 };
9 
cgroup_help_v0(void)10 static void cgroup_help_v0(void)
11 {
12 	printf(
13 "cgroup match options:\n"
14 "[!] --cgroup classid            Match cgroup classid\n");
15 }
16 
cgroup_help_v1(void)17 static void cgroup_help_v1(void)
18 {
19 	printf(
20 "cgroup match options:\n"
21 "[!] --path path                 Recursively match path relative to cgroup2 root\n"
22 "[!] --cgroup classid            Match cgroup classid, can't be used with --path\n");
23 }
24 
25 static const struct xt_option_entry cgroup_opts_v0[] = {
26 	{
27 		.name = "cgroup",
28 		.id = O_CLASSID,
29 		.type = XTTYPE_UINT32,
30 		.flags = XTOPT_INVERT | XTOPT_MAND | XTOPT_PUT,
31 		XTOPT_POINTER(struct xt_cgroup_info_v0, id)
32 	},
33 	XTOPT_TABLEEND,
34 };
35 
36 static const struct xt_option_entry cgroup_opts_v1[] = {
37 	{
38 		.name = "path",
39 		.id = O_PATH,
40 		.type = XTTYPE_STRING,
41 		.flags = XTOPT_INVERT | XTOPT_PUT,
42 		XTOPT_POINTER(struct xt_cgroup_info_v1, path)
43 	},
44 	{
45 		.name = "cgroup",
46 		.id = O_CLASSID,
47 		.type = XTTYPE_UINT32,
48 		.flags = XTOPT_INVERT | XTOPT_PUT,
49 		XTOPT_POINTER(struct xt_cgroup_info_v1, classid)
50 	},
51 	XTOPT_TABLEEND,
52 };
53 
cgroup_parse_v0(struct xt_option_call * cb)54 static void cgroup_parse_v0(struct xt_option_call *cb)
55 {
56 	struct xt_cgroup_info_v0 *cgroupinfo = cb->data;
57 
58 	xtables_option_parse(cb);
59 	if (cb->invert)
60 		cgroupinfo->invert = true;
61 }
62 
cgroup_parse_v1(struct xt_option_call * cb)63 static void cgroup_parse_v1(struct xt_option_call *cb)
64 {
65 	struct xt_cgroup_info_v1 *info = cb->data;
66 
67 	xtables_option_parse(cb);
68 
69 	switch (cb->entry->id) {
70 	case O_PATH:
71 		info->has_path = true;
72 		if (cb->invert)
73 			info->invert_path = true;
74 		break;
75 	case O_CLASSID:
76 		info->has_classid = true;
77 		if (cb->invert)
78 			info->invert_classid = true;
79 		break;
80 	}
81 }
82 
83 static void
cgroup_print_v0(const void * ip,const struct xt_entry_match * match,int numeric)84 cgroup_print_v0(const void *ip, const struct xt_entry_match *match, int numeric)
85 {
86 	const struct xt_cgroup_info_v0 *info = (void *) match->data;
87 
88 	printf(" cgroup %s%u", info->invert ? "! ":"", info->id);
89 }
90 
cgroup_save_v0(const void * ip,const struct xt_entry_match * match)91 static void cgroup_save_v0(const void *ip, const struct xt_entry_match *match)
92 {
93 	const struct xt_cgroup_info_v0 *info = (void *) match->data;
94 
95 	printf("%s --cgroup %u", info->invert ? " !" : "", info->id);
96 }
97 
98 static void
cgroup_print_v1(const void * ip,const struct xt_entry_match * match,int numeric)99 cgroup_print_v1(const void *ip, const struct xt_entry_match *match, int numeric)
100 {
101 	const struct xt_cgroup_info_v1 *info = (void *)match->data;
102 
103 	printf(" cgroup");
104 	if (info->has_path)
105 		printf(" %s%s", info->invert_path ? "! ":"", info->path);
106 	if (info->has_classid)
107 		printf(" %s%u", info->invert_classid ? "! ":"", info->classid);
108 }
109 
cgroup_save_v1(const void * ip,const struct xt_entry_match * match)110 static void cgroup_save_v1(const void *ip, const struct xt_entry_match *match)
111 {
112 	const struct xt_cgroup_info_v1 *info = (void *)match->data;
113 
114 	if (info->has_path) {
115 		printf("%s --path", info->invert_path ? " !" : "");
116 		xtables_save_string(info->path);
117 	}
118 
119 	if (info->has_classid)
120 		printf("%s --cgroup %u", info->invert_classid ? " !" : "",
121 		       info->classid);
122 }
123 
cgroup_xlate_v0(struct xt_xlate * xl,const struct xt_xlate_mt_params * params)124 static int cgroup_xlate_v0(struct xt_xlate *xl,
125 			   const struct xt_xlate_mt_params *params)
126 {
127 	const struct xt_cgroup_info_v0 *info = (void *)params->match->data;
128 
129 	xt_xlate_add(xl, "meta cgroup %s%u", info->invert ? "!= " : "",
130 		     info->id);
131 	return 1;
132 }
133 
cgroup_xlate_v1(struct xt_xlate * xl,const struct xt_xlate_mt_params * params)134 static int cgroup_xlate_v1(struct xt_xlate *xl,
135 			   const struct xt_xlate_mt_params *params)
136 {
137 	const struct xt_cgroup_info_v1 *info = (void *)params->match->data;
138 
139 	if (info->has_path)
140 		return 0;
141 
142 	if (info->has_classid)
143 		xt_xlate_add(xl, "meta cgroup %s%u",
144 			     info->invert_classid ? "!= " : "",
145 			     info->classid);
146 
147 	return 1;
148 }
149 
150 static struct xtables_match cgroup_match[] = {
151 	{
152 		.family		= NFPROTO_UNSPEC,
153 		.revision	= 0,
154 		.name		= "cgroup",
155 		.version	= XTABLES_VERSION,
156 		.size		= XT_ALIGN(sizeof(struct xt_cgroup_info_v0)),
157 		.userspacesize	= XT_ALIGN(sizeof(struct xt_cgroup_info_v0)),
158 		.help		= cgroup_help_v0,
159 		.print		= cgroup_print_v0,
160 		.save		= cgroup_save_v0,
161 		.x6_parse	= cgroup_parse_v0,
162 		.x6_options	= cgroup_opts_v0,
163 		.xlate		= cgroup_xlate_v0,
164 	},
165 	{
166 		.family		= NFPROTO_UNSPEC,
167 		.revision	= 1,
168 		.name		= "cgroup",
169 		.version	= XTABLES_VERSION,
170 		.size		= XT_ALIGN(sizeof(struct xt_cgroup_info_v1)),
171 		.userspacesize	= offsetof(struct xt_cgroup_info_v1, priv),
172 		.help		= cgroup_help_v1,
173 		.print		= cgroup_print_v1,
174 		.save		= cgroup_save_v1,
175 		.x6_parse	= cgroup_parse_v1,
176 		.x6_options	= cgroup_opts_v1,
177 		.xlate		= cgroup_xlate_v1,
178 	},
179 };
180 
_init(void)181 void _init(void)
182 {
183 	xtables_register_matches(cgroup_match, ARRAY_SIZE(cgroup_match));
184 }
185