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#include <stdio.h>
#include <xtables.h>
#include <linux/netfilter_ipv6/ip6t_ah.h>
enum {
O_AHSPI = 0,
O_AHLEN,
O_AHRES,
};
static void ah_help(void)
{
printf(
"ah match options:\n"
"[!] --ahspi spi[:spi] match spi (range)\n"
"[!] --ahlen length total length of this header\n"
" --ahres check the reserved field too\n");
}
#define s struct ip6t_ah
static const struct xt_option_entry ah_opts[] = {
{.name = "ahspi", .id = O_AHSPI, .type = XTTYPE_UINT32RC,
.flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, spis)},
{.name = "ahlen", .id = O_AHLEN, .type = XTTYPE_UINT32,
.flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, hdrlen)},
{.name = "ahres", .id = O_AHRES, .type = XTTYPE_NONE},
XTOPT_TABLEEND,
};
#undef s
static void ah_init(struct xt_entry_match *m)
{
struct ip6t_ah *ahinfo = (void *)m->data;
/* Defaults for when no --ahspi is used at all */
ahinfo->spis[1] = ~0U;
}
static void ah_parse(struct xt_option_call *cb)
{
struct ip6t_ah *ahinfo = cb->data;
xtables_option_parse(cb);
switch (cb->entry->id) {
case O_AHSPI:
if (cb->nvals == 1)
ahinfo->spis[1] = ahinfo->spis[0];
if (cb->invert)
ahinfo->invflags |= IP6T_AH_INV_SPI;
break;
case O_AHLEN:
if (cb->invert)
ahinfo->invflags |= IP6T_AH_INV_LEN;
break;
case O_AHRES:
ahinfo->hdrres = 1;
break;
}
}
static void
print_spis(const char *name, uint32_t min, uint32_t max,
int invert)
{
const char *inv = invert ? "!" : "";
if (min != 0 || max != 0xFFFFFFFF || invert) {
if (min == max)
printf("%s:%s%u", name, inv, min);
else
printf("%ss:%s%u:%u", name, inv, min, max);
}
}
static void
print_len(const char *name, uint32_t len, int invert)
{
const char *inv = invert ? "!" : "";
if (len != 0 || invert)
printf("%s:%s%u", name, inv, len);
}
static void ah_print(const void *ip, const struct xt_entry_match *match,
int numeric)
{
const struct ip6t_ah *ah = (struct ip6t_ah *)match->data;
printf(" ah ");
print_spis("spi", ah->spis[0], ah->spis[1],
ah->invflags & IP6T_AH_INV_SPI);
print_len("length", ah->hdrlen,
ah->invflags & IP6T_AH_INV_LEN);
if (ah->hdrres)
printf(" reserved");
if (ah->invflags & ~IP6T_AH_INV_MASK)
printf(" Unknown invflags: 0x%X",
ah->invflags & ~IP6T_AH_INV_MASK);
}
static void ah_save(const void *ip, const struct xt_entry_match *match)
{
const struct ip6t_ah *ahinfo = (struct ip6t_ah *)match->data;
if (!(ahinfo->spis[0] == 0
&& ahinfo->spis[1] == 0xFFFFFFFF)) {
printf("%s --ahspi ",
(ahinfo->invflags & IP6T_AH_INV_SPI) ? " !" : "");
if (ahinfo->spis[0]
!= ahinfo->spis[1])
printf("%u:%u",
ahinfo->spis[0],
ahinfo->spis[1]);
else
printf("%u",
ahinfo->spis[0]);
}
if (ahinfo->hdrlen != 0 || (ahinfo->invflags & IP6T_AH_INV_LEN) ) {
printf("%s --ahlen %u",
(ahinfo->invflags & IP6T_AH_INV_LEN) ? " !" : "",
ahinfo->hdrlen);
}
if (ahinfo->hdrres != 0 )
printf(" --ahres");
}
static struct xtables_match ah_mt6_reg = {
.name = "ah",
.version = XTABLES_VERSION,
.family = NFPROTO_IPV6,
.size = XT_ALIGN(sizeof(struct ip6t_ah)),
.userspacesize = XT_ALIGN(sizeof(struct ip6t_ah)),
.help = ah_help,
.init = ah_init,
.print = ah_print,
.save = ah_save,
.x6_parse = ah_parse,
.x6_options = ah_opts,
};
void
_init(void)
{
xtables_register_match(&ah_mt6_reg);
}
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