1 #include <stdio.h>
2 #include <string.h>
3 #include <stdlib.h>
4 #include <errno.h>
5 #if defined(__GLIBC__) && __GLIBC__ == 2
6 #include <net/ethernet.h>
7 #else
8 #include <linux/if_ether.h>
9 #endif
10 #include <xtables.h>
11 #include <linux/netfilter_ipv4/ipt_realm.h>
12
13 enum {
14 O_REALM = 0,
15 };
16
realm_help(void)17 static void realm_help(void)
18 {
19 printf(
20 "realm match options:\n"
21 "[!] --realm value[/mask]\n"
22 " Match realm\n");
23 }
24
25 static const struct xt_option_entry realm_opts[] = {
26 {.name = "realm", .id = O_REALM, .type = XTTYPE_STRING,
27 .flags = XTOPT_MAND | XTOPT_INVERT},
28 XTOPT_TABLEEND,
29 };
30
31 /* array of realms from /etc/iproute2/rt_realms */
32 static struct xtables_lmap *realms;
33
realm_init(struct xt_entry_match * m)34 static void realm_init(struct xt_entry_match *m)
35 {
36 const char file[] = "/etc/iproute2/rt_realms";
37
38 realms = xtables_lmap_init(file);
39 if (realms == NULL && errno != ENOENT)
40 fprintf(stderr, "Warning: %s: %s\n", file, strerror(errno));
41 }
42
realm_parse(struct xt_option_call * cb)43 static void realm_parse(struct xt_option_call *cb)
44 {
45 struct xt_realm_info *realminfo = cb->data;
46 int id;
47 char *end;
48
49 xtables_option_parse(cb);
50 realminfo->id = strtoul(cb->arg, &end, 0);
51 if (end != cb->arg && (*end == '/' || *end == '\0')) {
52 if (*end == '/')
53 realminfo->mask = strtoul(end+1, &end, 0);
54 else
55 realminfo->mask = 0xffffffff;
56 if (*end != '\0' || end == cb->arg)
57 xtables_error(PARAMETER_PROBLEM,
58 "Bad realm value \"%s\"", cb->arg);
59 } else {
60 id = xtables_lmap_name2id(realms, cb->arg);
61 if (id == -1)
62 xtables_error(PARAMETER_PROBLEM,
63 "Realm \"%s\" not found", cb->arg);
64 realminfo->id = id;
65 realminfo->mask = 0xffffffff;
66 }
67 if (cb->invert)
68 realminfo->invert = 1;
69 }
70
71 static void
print_realm(unsigned long id,unsigned long mask,int numeric)72 print_realm(unsigned long id, unsigned long mask, int numeric)
73 {
74 const char *name = NULL;
75
76 if (mask != 0xffffffff)
77 printf(" 0x%lx/0x%lx", id, mask);
78 else {
79 if (numeric == 0)
80 name = xtables_lmap_id2name(realms, id);
81 if (name)
82 printf(" %s", name);
83 else
84 printf(" 0x%lx", id);
85 }
86 }
87
realm_print(const void * ip,const struct xt_entry_match * match,int numeric)88 static void realm_print(const void *ip, const struct xt_entry_match *match,
89 int numeric)
90 {
91 const struct xt_realm_info *ri = (const void *)match->data;
92
93 if (ri->invert)
94 printf(" !");
95
96 printf(" realm");
97 print_realm(ri->id, ri->mask, numeric);
98 }
99
realm_save(const void * ip,const struct xt_entry_match * match)100 static void realm_save(const void *ip, const struct xt_entry_match *match)
101 {
102 const struct xt_realm_info *ri = (const void *)match->data;
103
104 if (ri->invert)
105 printf(" !");
106
107 printf(" --realm");
108 print_realm(ri->id, ri->mask, 0);
109 }
110
111 static void
print_realm_xlate(unsigned long id,unsigned long mask,int numeric,struct xt_xlate * xl,uint32_t op)112 print_realm_xlate(unsigned long id, unsigned long mask,
113 int numeric, struct xt_xlate *xl, uint32_t op)
114 {
115 const char *name = NULL;
116
117 if (mask != 0xffffffff)
118 xt_xlate_add(xl, " and 0x%lx %s 0x%lx", mask,
119 op == XT_OP_EQ ? "==" : "!=", id);
120 else {
121 if (numeric == 0)
122 name = xtables_lmap_id2name(realms, id);
123 if (name)
124 xt_xlate_add(xl, " %s%s",
125 op == XT_OP_EQ ? "" : "!= ", name);
126 else
127 xt_xlate_add(xl, " %s0x%lx",
128 op == XT_OP_EQ ? "" : "!= ", id);
129 }
130 }
131
realm_xlate(struct xt_xlate * xl,const struct xt_xlate_mt_params * params)132 static int realm_xlate(struct xt_xlate *xl,
133 const struct xt_xlate_mt_params *params)
134 {
135 const struct xt_realm_info *ri = (const void *)params->match->data;
136 enum xt_op op = XT_OP_EQ;
137
138 if (ri->invert)
139 op = XT_OP_NEQ;
140
141 xt_xlate_add(xl, "rtclassid");
142 print_realm_xlate(ri->id, ri->mask, 0, xl, op);
143
144 return 1;
145 }
146
147 static struct xtables_match realm_mt_reg = {
148 .name = "realm",
149 .version = XTABLES_VERSION,
150 .family = NFPROTO_IPV4,
151 .size = XT_ALIGN(sizeof(struct xt_realm_info)),
152 .userspacesize = XT_ALIGN(sizeof(struct xt_realm_info)),
153 .help = realm_help,
154 .init = realm_init,
155 .print = realm_print,
156 .save = realm_save,
157 .x6_parse = realm_parse,
158 .x6_options = realm_opts,
159 .xlate = realm_xlate,
160 };
161
_init(void)162 void _init(void)
163 {
164 xtables_register_match(&realm_mt_reg);
165 }
166