-/* Shared library add-on to iptables to add AH support. */
-#include <stdio.h>
-#include <netdb.h>
-#include <string.h>
-#include <stdlib.h>
-#include <getopt.h>
-#include <errno.h>
-#include <iptables.h>
-#include <linux/netfilter_ipv4/ipt_ah.h>
-
-/* Function which prints out usage message. */
-static void ah_help(void)
-{
- printf(
-"ah match options:\n"
-" --ahspi [!] spi[:spi]\n"
-" match spi (range)\n");
-}
-
-static const struct option ah_opts[] = {
- { "ahspi", 1, NULL, '1' },
- { .name = NULL }
-};
-
-static u_int32_t
-parse_ah_spi(const char *spistr)
-{
- unsigned long int spi;
- char* ep;
-
- spi = strtoul(spistr,&ep,0) ;
-
- if ( spistr == ep ) {
- exit_error(PARAMETER_PROBLEM,
- "AH no valid digits in spi `%s'", spistr);
- }
- if ( spi == ULONG_MAX && errno == ERANGE ) {
- exit_error(PARAMETER_PROBLEM,
- "spi `%s' specified too big: would overflow", spistr);
- }
- if ( *spistr != '\0' && *ep != '\0' ) {
- exit_error(PARAMETER_PROBLEM,
- "AH error parsing spi `%s'", spistr);
- }
- return (u_int32_t) spi;
-}
-
-static void
-parse_ah_spis(const char *spistring, u_int32_t *spis)
-{
- char *buffer;
- char *cp;
-
- buffer = strdup(spistring);
- if ((cp = strchr(buffer, ':')) == NULL)
- spis[0] = spis[1] = parse_ah_spi(buffer);
- else {
- *cp = '\0';
- cp++;
-
- spis[0] = buffer[0] ? parse_ah_spi(buffer) : 0;
- spis[1] = cp[0] ? parse_ah_spi(cp) : 0xFFFFFFFF;
- }
- free(buffer);
-}
-
-/* Initialize the match. */
-static void ah_init(struct xt_entry_match *m)
-{
- struct ipt_ah *ahinfo = (struct ipt_ah *)m->data;
-
- ahinfo->spis[1] = 0xFFFFFFFF;
-}
-
-#define AH_SPI 0x01
-
-/* Function which parses command options; returns true if it
- ate an option */
-static int ah_parse(int c, char **argv, int invert, unsigned int *flags,
- const void *entry, struct xt_entry_match **match)
-{
- struct ipt_ah *ahinfo = (struct ipt_ah *)(*match)->data;
-
- switch (c) {
- case '1':
- if (*flags & AH_SPI)
- exit_error(PARAMETER_PROBLEM,
- "Only one `--ahspi' allowed");
- check_inverse(optarg, &invert, &optind, 0);
- parse_ah_spis(argv[optind-1], ahinfo->spis);
- if (invert)
- ahinfo->invflags |= IPT_AH_INV_SPI;
- *flags |= AH_SPI;
- break;
- default:
- return 0;
- }
-
- return 1;
-}
-
-static void
-print_spis(const char *name, u_int32_t min, u_int32_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);
- }
- printf(" ");
- }
-}
-
-/* Prints out the union ipt_matchinfo. */
-static void ah_print(const void *ip, const struct xt_entry_match *match,
- int numeric)
-{
- const struct ipt_ah *ah = (struct ipt_ah *)match->data;
-
- printf("ah ");
- print_spis("spi", ah->spis[0], ah->spis[1],
- ah->invflags & IPT_AH_INV_SPI);
- if (ah->invflags & ~IPT_AH_INV_MASK)
- printf("Unknown invflags: 0x%X ",
- ah->invflags & ~IPT_AH_INV_MASK);
-}
-
-/* Saves the union ipt_matchinfo in parsable form to stdout. */
-static void ah_save(const void *ip, const struct xt_entry_match *match)
-{
- const struct ipt_ah *ahinfo = (struct ipt_ah *)match->data;
-
- if (!(ahinfo->spis[0] == 0
- && ahinfo->spis[1] == 0xFFFFFFFF)) {
- printf("--ahspi %s",
- (ahinfo->invflags & IPT_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]);
- }
-
-}
-
-static struct xtables_match ah_mt_reg = {
- .name = "ah",
- .version = XTABLES_VERSION,
- .family = PF_INET,
- .size = XT_ALIGN(sizeof(struct ipt_ah)),
- .userspacesize = XT_ALIGN(sizeof(struct ipt_ah)),
- .help = ah_help,
- .init = ah_init,
- .parse = ah_parse,
- .print = ah_print,
- .save = ah_save,
- .extra_opts = ah_opts,
-};
-
-void
-_init(void)
-{
- xtables_register_match(&ah_mt_reg);
-}