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#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <xtables.h>
#include <linux/netfilter_ipv6/ip6t_rt.h>
#include <arpa/inet.h>
enum {
O_RT_TYPE = 0,
O_RT_SEGSLEFT,
O_RT_LEN,
O_RT0RES,
O_RT0ADDRS,
O_RT0NSTRICT,
F_RT_TYPE = 1 << O_RT_TYPE,
F_RT0ADDRS = 1 << O_RT0ADDRS,
};
static void rt_help(void)
{
printf(
"rt match options:\n"
"[!] --rt-type type match the type\n"
"[!] --rt-segsleft num[:num] match the Segments Left field (range)\n"
"[!] --rt-len length total length of this header\n"
" --rt-0-res check the reserved field too (type 0)\n"
" --rt-0-addrs ADDR[,ADDR...] Type=0 addresses (list, max: %d)\n"
" --rt-0-not-strict List of Type=0 addresses not a strict list\n",
IP6T_RT_HOPS);
}
#define s struct ip6t_rt
static const struct xt_option_entry rt_opts[] = {
{.name = "rt-type", .id = O_RT_TYPE, .type = XTTYPE_UINT32RC,
.flags = XTOPT_INVERT},
{.name = "rt-segsleft", .id = O_RT_SEGSLEFT, .type = XTTYPE_UINT32RC,
.flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, segsleft)},
{.name = "rt-len", .id = O_RT_LEN, .type = XTTYPE_UINT32,
.flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, hdrlen)},
{.name = "rt-0-res", .id = O_RT0RES, .type = XTTYPE_NONE},
{.name = "rt-0-addrs", .id = O_RT0ADDRS, .type = XTTYPE_STRING},
{.name = "rt-0-not-strict", .id = O_RT0NSTRICT, .type = XTTYPE_STRING},
XTOPT_TABLEEND,
};
#undef s
static const char *
addr_to_numeric(const struct in6_addr *addrp)
{
static char buf[50+1];
return inet_ntop(AF_INET6, addrp, buf, sizeof(buf));
}
static struct in6_addr *
numeric_to_addr(const char *num)
{
static struct in6_addr ap;
int err;
if ((err=inet_pton(AF_INET6, num, &ap)) == 1)
return ≈
#ifdef DEBUG
fprintf(stderr, "\nnumeric2addr: %d\n", err);
#endif
xtables_error(PARAMETER_PROBLEM, "bad address: %s", num);
return (struct in6_addr *)NULL;
}
static int
parse_addresses(const char *addrstr, struct in6_addr *addrp)
{
char *buffer, *cp, *next;
unsigned int i;
buffer = strdup(addrstr);
if (!buffer) xtables_error(OTHER_PROBLEM, "strdup failed");
for (cp=buffer, i=0; cp && i<IP6T_RT_HOPS; cp=next,i++)
{
next=strchr(cp, ',');
if (next) *next++='\0';
memcpy(&(addrp[i]), numeric_to_addr(cp), sizeof(struct in6_addr));
#if DEBUG
printf("addr str: %s\n", cp);
printf("addr ip6: %s\n", addr_to_numeric((numeric_to_addr(cp))));
printf("addr [%d]: %s\n", i, addr_to_numeric(&(addrp[i])));
#endif
}
if (cp) xtables_error(PARAMETER_PROBLEM, "too many addresses specified");
free(buffer);
#if DEBUG
printf("addr nr: %d\n", i);
#endif
return i;
}
static void rt_init(struct xt_entry_match *m)
{
struct ip6t_rt *rtinfo = (struct ip6t_rt *)m->data;
rtinfo->segsleft[1] = 0xFFFFFFFF;
}
static void rt_parse(struct xt_option_call *cb)
{
struct ip6t_rt *rtinfo = cb->data;
xtables_option_parse(cb);
switch (cb->entry->id) {
case O_RT_TYPE:
if (cb->invert)
rtinfo->invflags |= IP6T_RT_INV_TYP;
rtinfo->flags |= IP6T_RT_TYP;
break;
case O_RT_SEGSLEFT:
if (cb->invert)
rtinfo->invflags |= IP6T_RT_INV_SGS;
rtinfo->flags |= IP6T_RT_SGS;
break;
case O_RT_LEN:
if (cb->invert)
rtinfo->invflags |= IP6T_RT_INV_LEN;
rtinfo->flags |= IP6T_RT_LEN;
break;
case O_RT0RES:
if (!(cb->xflags & F_RT_TYPE) || rtinfo->rt_type != 0 ||
rtinfo->invflags & IP6T_RT_INV_TYP)
xtables_error(PARAMETER_PROBLEM,
"`--rt-type 0' required before `--rt-0-res'");
rtinfo->flags |= IP6T_RT_RES;
break;
case O_RT0ADDRS:
if (!(cb->xflags & F_RT_TYPE) || rtinfo->rt_type != 0 ||
rtinfo->invflags & IP6T_RT_INV_TYP)
xtables_error(PARAMETER_PROBLEM,
"`--rt-type 0' required before `--rt-0-addrs'");
rtinfo->addrnr = parse_addresses(cb->arg, rtinfo->addrs);
rtinfo->flags |= IP6T_RT_FST;
break;
case O_RT0NSTRICT:
if (!(cb->xflags & F_RT0ADDRS))
xtables_error(PARAMETER_PROBLEM,
"`--rt-0-addr ...' required before `--rt-0-not-strict'");
rtinfo->flags |= IP6T_RT_FST_NSTRICT;
break;
}
}
static void
print_nums(const char *name, uint32_t min, uint32_t max,
int invert)
{
const char *inv = invert ? "!" : "";
if (min != 0 || max != 0xFFFFFFFF || invert) {
printf(" %s", name);
if (min == max) {
printf(":%s", inv);
printf("%u", min);
} else {
printf("s:%s", inv);
printf("%u",min);
printf(":");
printf("%u",max);
}
}
}
static void
print_addresses(unsigned int addrnr, struct in6_addr *addrp)
{
unsigned int i;
for(i=0; i<addrnr; i++){
printf("%c%s", (i==0)?' ':',', addr_to_numeric(&(addrp[i])));
}
}
static void rt_print(const void *ip, const struct xt_entry_match *match,
int numeric)
{
const struct ip6t_rt *rtinfo = (struct ip6t_rt *)match->data;
printf(" rt");
if (rtinfo->flags & IP6T_RT_TYP)
printf(" type:%s%d", rtinfo->invflags & IP6T_RT_INV_TYP ? "!" : "",
rtinfo->rt_type);
print_nums("segsleft", rtinfo->segsleft[0], rtinfo->segsleft[1],
rtinfo->invflags & IP6T_RT_INV_SGS);
if (rtinfo->flags & IP6T_RT_LEN) {
printf(" length");
printf(":%s", rtinfo->invflags & IP6T_RT_INV_LEN ? "!" : "");
printf("%u", rtinfo->hdrlen);
}
if (rtinfo->flags & IP6T_RT_RES) printf(" reserved");
if (rtinfo->flags & IP6T_RT_FST) printf(" 0-addrs");
print_addresses(rtinfo->addrnr, (struct in6_addr *)rtinfo->addrs);
if (rtinfo->flags & IP6T_RT_FST_NSTRICT) printf(" 0-not-strict");
if (rtinfo->invflags & ~IP6T_RT_INV_MASK)
printf(" Unknown invflags: 0x%X",
rtinfo->invflags & ~IP6T_RT_INV_MASK);
}
static void rt_save(const void *ip, const struct xt_entry_match *match)
{
const struct ip6t_rt *rtinfo = (struct ip6t_rt *)match->data;
if (rtinfo->flags & IP6T_RT_TYP) {
printf("%s --rt-type %u",
(rtinfo->invflags & IP6T_RT_INV_TYP) ? " !" : "",
rtinfo->rt_type);
}
if (!(rtinfo->segsleft[0] == 0
&& rtinfo->segsleft[1] == 0xFFFFFFFF)) {
printf("%s --rt-segsleft ",
(rtinfo->invflags & IP6T_RT_INV_SGS) ? " !" : "");
if (rtinfo->segsleft[0]
!= rtinfo->segsleft[1])
printf("%u:%u",
rtinfo->segsleft[0],
rtinfo->segsleft[1]);
else
printf("%u",
rtinfo->segsleft[0]);
}
if (rtinfo->flags & IP6T_RT_LEN) {
printf("%s --rt-len %u",
(rtinfo->invflags & IP6T_RT_INV_LEN) ? " !" : "",
rtinfo->hdrlen);
}
if (rtinfo->flags & IP6T_RT_RES) printf(" --rt-0-res");
if (rtinfo->flags & IP6T_RT_FST) printf(" --rt-0-addrs");
print_addresses(rtinfo->addrnr, (struct in6_addr *)rtinfo->addrs);
if (rtinfo->flags & IP6T_RT_FST_NSTRICT) printf(" --rt-0-not-strict");
}
static struct xtables_match rt_mt6_reg = {
.name = "rt",
.version = XTABLES_VERSION,
.family = NFPROTO_IPV6,
.size = XT_ALIGN(sizeof(struct ip6t_rt)),
.userspacesize = XT_ALIGN(sizeof(struct ip6t_rt)),
.help = rt_help,
.init = rt_init,
.x6_parse = rt_parse,
.print = rt_print,
.save = rt_save,
.x6_options = rt_opts,
};
void
_init(void)
{
xtables_register_match(&rt_mt6_reg);
}
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