#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <errno.h>

#include <xtables.h>

#include <linux/netfilter_ipv6/ip6t_opts.h>

enum {

	O_HBH_LEN = 0,

	O_HBH_OPTS,

};

static void hbh_help(void)

{

	printf(

"hbh match options:\n"

"[!] --hbh-len length            total length of this header\n"

"  --hbh-opts TYPE[:LEN][,TYPE[:LEN]...] \n"

"                                Options and its length (list, max: %d)\n",

IP6T_OPTS_OPTSNR);

}

static const struct xt_option_entry hbh_opts[] = {

	{.name = "hbh-len", .id = O_HBH_LEN, .type = XTTYPE_UINT32,

	 .flags = XTOPT_INVERT | XTOPT_PUT,

	 XTOPT_POINTER(struct ip6t_opts, hdrlen)},

	{.name = "hbh-opts", .id = O_HBH_OPTS, .type = XTTYPE_STRING},

	XTOPT_TABLEEND,

};

static uint32_t

parse_opts_num(const char *idstr, const char *typestr)

{

	unsigned long int id;

	char* ep;

	id =  strtoul(idstr,&ep,0) ;

	if ( idstr == ep ) {

		xtables_error(PARAMETER_PROBLEM,

			   "hbh: no valid digits in %s `%s'", typestr, idstr);

	}

	if ( id == ULONG_MAX  && errno == ERANGE ) {

		xtables_error(PARAMETER_PROBLEM,

			   "%s `%s' specified too big: would overflow",

			   typestr, idstr);

	}	

	if ( *idstr != '\0'  && *ep != '\0' ) {

		xtables_error(PARAMETER_PROBLEM,

			   "hbh: error parsing %s `%s'", typestr, idstr);

	}

	return id;

}

static int

parse_options(const char *optsstr, uint16_t *opts)

{

        char *buffer, *cp, *next, *range;

        unsigned int i;

	buffer = strdup(optsstr);

	if (!buffer) xtables_error(OTHER_PROBLEM, "strdup failed");

        for (cp=buffer, i=0; cp && i

        {

                next=strchr(cp, ',');

                if (next) *next++='\0';

                range = strchr(cp, ':');

                if (range) {

                        if (i == IP6T_OPTS_OPTSNR-1)

				xtables_error(PARAMETER_PROBLEM,

                                           "too many ports specified");

                        *range++ = '\0';

                }

		opts[i] = (parse_opts_num(cp, "opt") & 0xFF) << 8;

                if (range) {

			if (opts[i] == 0)

				xtables_error(PARAMETER_PROBLEM, "PAD0 has not got length");

			opts[i] |= parse_opts_num(range, "length") & 0xFF;

                } else {

                        opts[i] |= (0x00FF);

		}

#ifdef DEBUG

		printf("opts str: %s %s\n", cp, range);

		printf("opts opt: %04X\n", opts[i]);

#endif

	}

	if (cp) xtables_error(PARAMETER_PROBLEM, "too many addresses specified");

	free(buffer);

#ifdef DEBUG

	printf("addr nr: %d\n", i);

#endif

	return i;

}

static void hbh_parse(struct xt_option_call *cb)

{

	struct ip6t_opts *optinfo = cb->data;

	xtables_option_parse(cb);

	switch (cb->entry->id) {

	case O_HBH_LEN:

		if (cb->invert)

			optinfo->invflags |= IP6T_OPTS_INV_LEN;

		optinfo->flags |= IP6T_OPTS_LEN;

		break;

	case O_HBH_OPTS:

		optinfo->optsnr = parse_options(cb->arg, optinfo->opts);

		optinfo->flags |= IP6T_OPTS_OPTS;

		break;

	}

}

static void

print_options(unsigned int optsnr, uint16_t *optsp)

{

	unsigned int i;

	for(i=0; i

		printf("%c", (i==0)?' ':',');

		printf("%d", (optsp[i] & 0xFF00)>>8);

		if ((optsp[i] & 0x00FF) != 0x00FF){

			printf(":%d", (optsp[i] & 0x00FF));

		} 

	}

}

static void hbh_print(const void *ip, const struct xt_entry_match *match,

                      int numeric)

{

	const struct ip6t_opts *optinfo = (struct ip6t_opts *)match->data;

	printf(" hbh");

	if (optinfo->flags & IP6T_OPTS_LEN) {

		printf(" length");

		printf(":%s", optinfo->invflags & IP6T_OPTS_INV_LEN ? "!" : "");

		printf("%u", optinfo->hdrlen);

	}

	if (optinfo->flags & IP6T_OPTS_OPTS) printf(" opts");

	print_options(optinfo->optsnr, (uint16_t *)optinfo->opts);

	if (optinfo->invflags & ~IP6T_OPTS_INV_MASK)

		printf(" Unknown invflags: 0x%X",

		       optinfo->invflags & ~IP6T_OPTS_INV_MASK);

}

static void hbh_save(const void *ip, const struct xt_entry_match *match)

{

	const struct ip6t_opts *optinfo = (struct ip6t_opts *)match->data;

	if (optinfo->flags & IP6T_OPTS_LEN) {

		printf("%s --hbh-len %u",

			(optinfo->invflags & IP6T_OPTS_INV_LEN) ? " !" : "",

			optinfo->hdrlen);

	}

	if (optinfo->flags & IP6T_OPTS_OPTS)

		printf(" --hbh-opts");

	print_options(optinfo->optsnr, (uint16_t *)optinfo->opts);

}

static int hbh_xlate(struct xt_xlate *xl,

		     const struct xt_xlate_mt_params *params)

{

	const struct ip6t_opts *optinfo =

		(struct ip6t_opts *)params->match->data;

	if (!(optinfo->flags & IP6T_OPTS_LEN) ||

	    (optinfo->flags & IP6T_OPTS_OPTS))

		return 0;

	xt_xlate_add(xl, "hbh hdrlength %s%u",

		     (optinfo->invflags & IP6T_OPTS_INV_LEN) ? "!= " : "",

		     optinfo->hdrlen);

	return 1;

}

static struct xtables_match hbh_mt6_reg = {

	.name 		= "hbh",

	.version	= XTABLES_VERSION,

	.family		= NFPROTO_IPV6,

	.size		= XT_ALIGN(sizeof(struct ip6t_opts)),

	.userspacesize	= XT_ALIGN(sizeof(struct ip6t_opts)),

	.help		= hbh_help,

	.print		= hbh_print,

	.save		= hbh_save,

	.x6_parse	= hbh_parse,

	.x6_options	= hbh_opts,

	.xlate		= hbh_xlate,

};

void

_init(void)

{

	xtables_register_match(&hbh_mt6_reg);

}