libip6t_rt.c revision e37d45ce390c2f5a7f1e64742b9100ecef0def54 
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
8enum {
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
19static 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",
29IP6T_RT_HOPS);
30}
31
32#define s struct ip6t_rt
33static 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
47static const char *
48addr_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
54static struct in6_addr *
55numeric_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 &ap;
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
71static int
72parse_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
102static void rt_parse(struct xt_option_call *cb)
103{
104	struct ip6t_rt *rtinfo = cb->data;
105
106	xtables_option_parse(cb);
107	switch (cb->entry->id) {
108	case O_RT_TYPE:
109		if (cb->invert)
110			rtinfo->invflags |= IP6T_RT_INV_TYP;
111		rtinfo->flags |= IP6T_RT_TYP;
112		break;
113	case O_RT_SEGSLEFT:
114		if (cb->nvals == 1)
115			rtinfo->segsleft[1] = rtinfo->segsleft[0];
116		if (cb->invert)
117			rtinfo->invflags |= IP6T_RT_INV_SGS;
118		rtinfo->flags |= IP6T_RT_SGS;
119		break;
120	case O_RT_LEN:
121		if (cb->invert)
122			rtinfo->invflags |= IP6T_RT_INV_LEN;
123		rtinfo->flags |= IP6T_RT_LEN;
124		break;
125	case O_RT0RES:
126		if (!(cb->xflags & F_RT_TYPE) || rtinfo->rt_type != 0 ||
127		    rtinfo->invflags & IP6T_RT_INV_TYP)
128			xtables_error(PARAMETER_PROBLEM,
129				   "`--rt-type 0' required before `--rt-0-res'");
130		rtinfo->flags |= IP6T_RT_RES;
131		break;
132	case O_RT0ADDRS:
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-addrs'");
137		rtinfo->addrnr = parse_addresses(cb->arg, rtinfo->addrs);
138		rtinfo->flags |= IP6T_RT_FST;
139		break;
140	case O_RT0NSTRICT:
141		if (!(cb->xflags & F_RT0ADDRS))
142			xtables_error(PARAMETER_PROBLEM,
143				   "`--rt-0-addr ...' required before `--rt-0-not-strict'");
144		rtinfo->flags |= IP6T_RT_FST_NSTRICT;
145		break;
146	}
147}
148
149static void
150print_nums(const char *name, uint32_t min, uint32_t max,
151	    int invert)
152{
153	const char *inv = invert ? "!" : "";
154
155	if (min != 0 || max != 0xFFFFFFFF || invert) {
156		printf(" %s", name);
157		if (min == max) {
158			printf(":%s", inv);
159			printf("%u", min);
160		} else {
161			printf("s:%s", inv);
162			printf("%u",min);
163			printf(":");
164			printf("%u",max);
165		}
166	}
167}
168
169static void
170print_addresses(unsigned int addrnr, struct in6_addr *addrp)
171{
172	unsigned int i;
173
174	for(i=0; i<addrnr; i++){
175		printf("%c%s", (i==0)?' ':',', addr_to_numeric(&(addrp[i])));
176	}
177}
178
179static void rt_print(const void *ip, const struct xt_entry_match *match,
180                     int numeric)
181{
182	const struct ip6t_rt *rtinfo = (struct ip6t_rt *)match->data;
183
184	printf(" rt");
185	if (rtinfo->flags & IP6T_RT_TYP)
186	    printf(" type:%s%d", rtinfo->invflags & IP6T_RT_INV_TYP ? "!" : "",
187		    rtinfo->rt_type);
188	print_nums("segsleft", rtinfo->segsleft[0], rtinfo->segsleft[1],
189		    rtinfo->invflags & IP6T_RT_INV_SGS);
190	if (rtinfo->flags & IP6T_RT_LEN) {
191		printf(" length");
192		printf(":%s", rtinfo->invflags & IP6T_RT_INV_LEN ? "!" : "");
193		printf("%u", rtinfo->hdrlen);
194	}
195	if (rtinfo->flags & IP6T_RT_RES) printf(" reserved");
196	if (rtinfo->flags & IP6T_RT_FST) printf(" 0-addrs");
197	print_addresses(rtinfo->addrnr, (struct in6_addr *)rtinfo->addrs);
198	if (rtinfo->flags & IP6T_RT_FST_NSTRICT) printf(" 0-not-strict");
199	if (rtinfo->invflags & ~IP6T_RT_INV_MASK)
200		printf(" Unknown invflags: 0x%X",
201		       rtinfo->invflags & ~IP6T_RT_INV_MASK);
202}
203
204static void rt_save(const void *ip, const struct xt_entry_match *match)
205{
206	const struct ip6t_rt *rtinfo = (struct ip6t_rt *)match->data;
207
208	if (rtinfo->flags & IP6T_RT_TYP) {
209		printf("%s --rt-type %u",
210			(rtinfo->invflags & IP6T_RT_INV_TYP) ? " !" : "",
211			rtinfo->rt_type);
212	}
213
214	if (!(rtinfo->segsleft[0] == 0
215	    && rtinfo->segsleft[1] == 0xFFFFFFFF)) {
216		printf("%s --rt-segsleft ",
217			(rtinfo->invflags & IP6T_RT_INV_SGS) ? " !" : "");
218		if (rtinfo->segsleft[0]
219		    != rtinfo->segsleft[1])
220			printf("%u:%u",
221			       rtinfo->segsleft[0],
222			       rtinfo->segsleft[1]);
223		else
224			printf("%u",
225			       rtinfo->segsleft[0]);
226	}
227
228	if (rtinfo->flags & IP6T_RT_LEN) {
229		printf("%s --rt-len %u",
230			(rtinfo->invflags & IP6T_RT_INV_LEN) ? " !" : "",
231			rtinfo->hdrlen);
232	}
233
234	if (rtinfo->flags & IP6T_RT_RES) printf(" --rt-0-res");
235	if (rtinfo->flags & IP6T_RT_FST) printf(" --rt-0-addrs");
236	print_addresses(rtinfo->addrnr, (struct in6_addr *)rtinfo->addrs);
237	if (rtinfo->flags & IP6T_RT_FST_NSTRICT) printf(" --rt-0-not-strict");
238
239}
240
241static struct xtables_match rt_mt6_reg = {
242	.name		= "rt",
243	.version	= XTABLES_VERSION,
244	.family		= NFPROTO_IPV6,
245	.size		= XT_ALIGN(sizeof(struct ip6t_rt)),
246	.userspacesize	= XT_ALIGN(sizeof(struct ip6t_rt)),
247	.help		= rt_help,
248	.x6_parse	= rt_parse,
249	.print		= rt_print,
250	.save		= rt_save,
251	.x6_options	= rt_opts,
252};
253
254void
255_init(void)
256{
257	xtables_register_match(&rt_mt6_reg);
258}
259