1 #include <stdio.h>
2 #include <string.h>
3 #include <stdlib.h>
4 #include <xtables.h>
5 #include <linux/netfilter_ipv6/ip6t_rt.h>
6 #include <arpa/inet.h>
7
8 enum {
9 O_RT_TYPE = 0,
10 O_RT_SEGSLEFT,
11 O_RT_LEN,
12 O_RT0RES,
13 O_RT0ADDRS,
14 O_RT0NSTRICT,
15 F_RT_TYPE = 1 << O_RT_TYPE,
16 F_RT0ADDRS = 1 << O_RT0ADDRS,
17 };
18
rt_help(void)19 static void rt_help(void)
20 {
21 printf(
22 "rt match options:\n"
23 "[!] --rt-type type match the type\n"
24 "[!] --rt-segsleft num[:num] match the Segments Left field (range)\n"
25 "[!] --rt-len length total length of this header\n"
26 " --rt-0-res check the reserved field too (type 0)\n"
27 " --rt-0-addrs ADDR[,ADDR...] Type=0 addresses (list, max: %d)\n"
28 " --rt-0-not-strict List of Type=0 addresses not a strict list\n",
29 IP6T_RT_HOPS);
30 }
31
32 #define s struct ip6t_rt
33 static const struct xt_option_entry rt_opts[] = {
34 {.name = "rt-type", .id = O_RT_TYPE, .type = XTTYPE_UINT32,
35 .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, rt_type)},
36 {.name = "rt-segsleft", .id = O_RT_SEGSLEFT, .type = XTTYPE_UINT32RC,
37 .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, segsleft)},
38 {.name = "rt-len", .id = O_RT_LEN, .type = XTTYPE_UINT32,
39 .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, hdrlen)},
40 {.name = "rt-0-res", .id = O_RT0RES, .type = XTTYPE_NONE},
41 {.name = "rt-0-addrs", .id = O_RT0ADDRS, .type = XTTYPE_STRING},
42 {.name = "rt-0-not-strict", .id = O_RT0NSTRICT, .type = XTTYPE_NONE},
43 XTOPT_TABLEEND,
44 };
45 #undef s
46
47 static const char *
addr_to_numeric(const struct in6_addr * addrp)48 addr_to_numeric(const struct in6_addr *addrp)
49 {
50 static char buf[50+1];
51 return inet_ntop(AF_INET6, addrp, buf, sizeof(buf));
52 }
53
54 static struct in6_addr *
numeric_to_addr(const char * num)55 numeric_to_addr(const char *num)
56 {
57 static struct in6_addr ap;
58 int err;
59
60 if ((err=inet_pton(AF_INET6, num, &ap)) == 1)
61 return ≈
62 #ifdef DEBUG
63 fprintf(stderr, "\nnumeric2addr: %d\n", err);
64 #endif
65 xtables_error(PARAMETER_PROBLEM, "bad address: %s", num);
66
67 return (struct in6_addr *)NULL;
68 }
69
70
71 static int
parse_addresses(const char * addrstr,struct in6_addr * addrp)72 parse_addresses(const char *addrstr, struct in6_addr *addrp)
73 {
74 char *buffer, *cp, *next;
75 unsigned int i;
76
77 buffer = strdup(addrstr);
78 if (!buffer) xtables_error(OTHER_PROBLEM, "strdup failed");
79
80 for (cp=buffer, i=0; cp && i<IP6T_RT_HOPS; cp=next,i++)
81 {
82 next=strchr(cp, ',');
83 if (next) *next++='\0';
84 memcpy(&(addrp[i]), numeric_to_addr(cp), sizeof(struct in6_addr));
85 #if DEBUG
86 printf("addr str: %s\n", cp);
87 printf("addr ip6: %s\n", addr_to_numeric((numeric_to_addr(cp))));
88 printf("addr [%d]: %s\n", i, addr_to_numeric(&(addrp[i])));
89 #endif
90 }
91 if (cp) xtables_error(PARAMETER_PROBLEM, "too many addresses specified");
92
93 free(buffer);
94
95 #if DEBUG
96 printf("addr nr: %d\n", i);
97 #endif
98
99 return i;
100 }
101
rt_init(struct xt_entry_match * m)102 static void rt_init(struct xt_entry_match *m)
103 {
104 struct ip6t_rt *rtinfo = (void *)m->data;
105
106 rtinfo->segsleft[1] = ~0U;
107 }
108
rt_parse(struct xt_option_call * cb)109 static void rt_parse(struct xt_option_call *cb)
110 {
111 struct ip6t_rt *rtinfo = cb->data;
112
113 xtables_option_parse(cb);
114 switch (cb->entry->id) {
115 case O_RT_TYPE:
116 if (cb->invert)
117 rtinfo->invflags |= IP6T_RT_INV_TYP;
118 rtinfo->flags |= IP6T_RT_TYP;
119 break;
120 case O_RT_SEGSLEFT:
121 if (cb->nvals == 1)
122 rtinfo->segsleft[1] = rtinfo->segsleft[0];
123 if (cb->invert)
124 rtinfo->invflags |= IP6T_RT_INV_SGS;
125 rtinfo->flags |= IP6T_RT_SGS;
126 break;
127 case O_RT_LEN:
128 if (cb->invert)
129 rtinfo->invflags |= IP6T_RT_INV_LEN;
130 rtinfo->flags |= IP6T_RT_LEN;
131 break;
132 case O_RT0RES:
133 if (!(cb->xflags & F_RT_TYPE) || rtinfo->rt_type != 0 ||
134 rtinfo->invflags & IP6T_RT_INV_TYP)
135 xtables_error(PARAMETER_PROBLEM,
136 "`--rt-type 0' required before `--rt-0-res'");
137 rtinfo->flags |= IP6T_RT_RES;
138 break;
139 case O_RT0ADDRS:
140 if (!(cb->xflags & F_RT_TYPE) || rtinfo->rt_type != 0 ||
141 rtinfo->invflags & IP6T_RT_INV_TYP)
142 xtables_error(PARAMETER_PROBLEM,
143 "`--rt-type 0' required before `--rt-0-addrs'");
144 rtinfo->addrnr = parse_addresses(cb->arg, rtinfo->addrs);
145 rtinfo->flags |= IP6T_RT_FST;
146 break;
147 case O_RT0NSTRICT:
148 if (!(cb->xflags & F_RT0ADDRS))
149 xtables_error(PARAMETER_PROBLEM,
150 "`--rt-0-addr ...' required before `--rt-0-not-strict'");
151 rtinfo->flags |= IP6T_RT_FST_NSTRICT;
152 break;
153 }
154 }
155
156 static void
print_nums(const char * name,uint32_t min,uint32_t max,int invert)157 print_nums(const char *name, uint32_t min, uint32_t max,
158 int invert)
159 {
160 const char *inv = invert ? "!" : "";
161
162 if (min != 0 || max != 0xFFFFFFFF || invert) {
163 printf(" %s", name);
164 if (min == max) {
165 printf(":%s", inv);
166 printf("%u", min);
167 } else {
168 printf("s:%s", inv);
169 printf("%u",min);
170 printf(":");
171 printf("%u",max);
172 }
173 }
174 }
175
176 static void
print_addresses(unsigned int addrnr,struct in6_addr * addrp)177 print_addresses(unsigned int addrnr, struct in6_addr *addrp)
178 {
179 unsigned int i;
180
181 for(i=0; i<addrnr; i++){
182 printf("%c%s", (i==0)?' ':',', addr_to_numeric(&(addrp[i])));
183 }
184 }
185
rt_print(const void * ip,const struct xt_entry_match * match,int numeric)186 static void rt_print(const void *ip, const struct xt_entry_match *match,
187 int numeric)
188 {
189 const struct ip6t_rt *rtinfo = (struct ip6t_rt *)match->data;
190
191 printf(" rt");
192 if (rtinfo->flags & IP6T_RT_TYP)
193 printf(" type:%s%d", rtinfo->invflags & IP6T_RT_INV_TYP ? "!" : "",
194 rtinfo->rt_type);
195 print_nums("segsleft", rtinfo->segsleft[0], rtinfo->segsleft[1],
196 rtinfo->invflags & IP6T_RT_INV_SGS);
197 if (rtinfo->flags & IP6T_RT_LEN) {
198 printf(" length");
199 printf(":%s", rtinfo->invflags & IP6T_RT_INV_LEN ? "!" : "");
200 printf("%u", rtinfo->hdrlen);
201 }
202 if (rtinfo->flags & IP6T_RT_RES) printf(" reserved");
203 if (rtinfo->flags & IP6T_RT_FST) printf(" 0-addrs");
204 print_addresses(rtinfo->addrnr, (struct in6_addr *)rtinfo->addrs);
205 if (rtinfo->flags & IP6T_RT_FST_NSTRICT) printf(" 0-not-strict");
206 if (rtinfo->invflags & ~IP6T_RT_INV_MASK)
207 printf(" Unknown invflags: 0x%X",
208 rtinfo->invflags & ~IP6T_RT_INV_MASK);
209 }
210
rt_save(const void * ip,const struct xt_entry_match * match)211 static void rt_save(const void *ip, const struct xt_entry_match *match)
212 {
213 const struct ip6t_rt *rtinfo = (struct ip6t_rt *)match->data;
214
215 if (rtinfo->flags & IP6T_RT_TYP) {
216 printf("%s --rt-type %u",
217 (rtinfo->invflags & IP6T_RT_INV_TYP) ? " !" : "",
218 rtinfo->rt_type);
219 }
220
221 if (!(rtinfo->segsleft[0] == 0
222 && rtinfo->segsleft[1] == 0xFFFFFFFF)) {
223 printf("%s --rt-segsleft ",
224 (rtinfo->invflags & IP6T_RT_INV_SGS) ? " !" : "");
225 if (rtinfo->segsleft[0]
226 != rtinfo->segsleft[1])
227 printf("%u:%u",
228 rtinfo->segsleft[0],
229 rtinfo->segsleft[1]);
230 else
231 printf("%u",
232 rtinfo->segsleft[0]);
233 }
234
235 if (rtinfo->flags & IP6T_RT_LEN) {
236 printf("%s --rt-len %u",
237 (rtinfo->invflags & IP6T_RT_INV_LEN) ? " !" : "",
238 rtinfo->hdrlen);
239 }
240
241 if (rtinfo->flags & IP6T_RT_RES) printf(" --rt-0-res");
242 if (rtinfo->flags & IP6T_RT_FST) printf(" --rt-0-addrs");
243 print_addresses(rtinfo->addrnr, (struct in6_addr *)rtinfo->addrs);
244 if (rtinfo->flags & IP6T_RT_FST_NSTRICT) printf(" --rt-0-not-strict");
245
246 }
247
rt_xlate(struct xt_xlate * xl,const struct xt_xlate_mt_params * params)248 static int rt_xlate(struct xt_xlate *xl,
249 const struct xt_xlate_mt_params *params)
250 {
251 const struct ip6t_rt *rtinfo = (struct ip6t_rt *)params->match->data;
252 char *space = "";
253
254 if (rtinfo->flags & IP6T_RT_TYP) {
255 xt_xlate_add(xl, "rt type%s %u",
256 (rtinfo->invflags & IP6T_RT_INV_TYP) ? " !=" : "",
257 rtinfo->rt_type);
258 space = " ";
259 }
260
261 if (!(rtinfo->segsleft[0] == 0 && rtinfo->segsleft[1] == 0xFFFFFFFF)) {
262 xt_xlate_add(xl, "%srt seg-left%s ", space,
263 (rtinfo->invflags & IP6T_RT_INV_SGS) ? " !=" : "");
264
265 if (rtinfo->segsleft[0] != rtinfo->segsleft[1])
266 xt_xlate_add(xl, "%u-%u", rtinfo->segsleft[0],
267 rtinfo->segsleft[1]);
268 else
269 xt_xlate_add(xl, "%u", rtinfo->segsleft[0]);
270 space = " ";
271 }
272
273 if (rtinfo->flags & IP6T_RT_LEN) {
274 xt_xlate_add(xl, "%srt hdrlength%s %u", space,
275 (rtinfo->invflags & IP6T_RT_INV_LEN) ? " !=" : "",
276 rtinfo->hdrlen);
277 }
278
279 if (rtinfo->flags & (IP6T_RT_RES | IP6T_RT_FST | IP6T_RT_FST_NSTRICT))
280 return 0;
281
282 return 1;
283 }
284
285 static struct xtables_match rt_mt6_reg = {
286 .name = "rt",
287 .version = XTABLES_VERSION,
288 .family = NFPROTO_IPV6,
289 .size = XT_ALIGN(sizeof(struct ip6t_rt)),
290 .userspacesize = XT_ALIGN(sizeof(struct ip6t_rt)),
291 .help = rt_help,
292 .init = rt_init,
293 .x6_parse = rt_parse,
294 .print = rt_print,
295 .save = rt_save,
296 .x6_options = rt_opts,
297 .xlate = rt_xlate,
298 };
299
300 void
_init(void)301 _init(void)
302 {
303 xtables_register_match(&rt_mt6_reg);
304 }
305