/*

 * Shared library add-on to iptables to add TOS target support

 *

 * Copyright © CC Computer Consultants GmbH, 2007

 * Contact: Jan Engelhardt <jengelh@medozas.de>

 */

#include <getopt.h>

#include <stdbool.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <netinet/in.h>

#include <xtables.h>

#include <linux/netfilter/xt_DSCP.h>

#include "tos_values.c"

struct ipt_tos_target_info {

	uint8_t tos;

};

enum {

	O_SET_TOS = 0,

	O_AND_TOS,

	O_OR_TOS,

	O_XOR_TOS,

	F_SET_TOS = 1 << O_SET_TOS,

	F_AND_TOS = 1 << O_AND_TOS,

	F_OR_TOS  = 1 << O_OR_TOS,

	F_XOR_TOS = 1 << O_XOR_TOS,

	F_ANY     = F_SET_TOS | F_AND_TOS | F_OR_TOS | F_XOR_TOS,

};

static const struct xt_option_entry tos_tg_opts_v0[] = {

	{.name = "set-tos", .id = O_SET_TOS, .type = XTTYPE_TOSMASK,

	 .excl = F_ANY, .max = 0xFF},

	XTOPT_TABLEEND,

};

static const struct xt_option_entry tos_tg_opts[] = {

	{.name = "set-tos", .id = O_SET_TOS, .type = XTTYPE_TOSMASK,

	 .excl = F_ANY, .max = 0x3F},

	{.name = "and-tos", .id = O_AND_TOS, .type = XTTYPE_UINT8,

	 .excl = F_ANY},

	{.name = "or-tos", .id = O_OR_TOS, .type = XTTYPE_UINT8,

	 .excl = F_ANY},

	{.name = "xor-tos", .id = O_XOR_TOS, .type = XTTYPE_UINT8,

	 .excl = F_ANY},

	XTOPT_TABLEEND,

};

static void tos_tg_help_v0(void)

{

	const struct tos_symbol_info *symbol;

	printf(

"TOS target options:\n"

"  --set-tos value     Set Type of Service/Priority field to value\n"

"  --set-tos symbol    Set TOS field (IPv4 only) by symbol\n"

"                      Accepted symbolic names for value are:\n");

	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)

		printf("                        (0x%02x) %2u %s\n",

		       symbol->value, symbol->value, symbol->name);

	printf("\n");

}

static void tos_tg_help(void)

{

	const struct tos_symbol_info *symbol;

	printf(

"TOS target v%s options:\n"

"  --set-tos value[/mask]  Set Type of Service/Priority field to value\n"

"                          (Zero out bits in mask and XOR value into TOS)\n"

"  --set-tos symbol        Set TOS field (IPv4 only) by symbol\n"

"                          (this zeroes the 4-bit Precedence part!)\n"

"                          Accepted symbolic names for value are:\n",

XTABLES_VERSION);

	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)

		printf("                            (0x%02x) %2u %s\n",

		       symbol->value, symbol->value, symbol->name);

	printf(

"\n"

"  --and-tos bits          Binary AND the TOS value with bits\n"

"  --or-tos  bits          Binary OR the TOS value with bits\n"

"  --xor-tos bits          Binary XOR the TOS value with bits\n"

);

}

static void tos_tg_parse_v0(struct xt_option_call *cb)

{

	struct ipt_tos_target_info *info = cb->data;

	xtables_option_parse(cb);

	if (cb->val.tos_mask != 0xFF)

		xtables_error(PARAMETER_PROBLEM, "tos match: Your kernel "

		           "is too old to support anything besides "

			   "/0xFF as a mask.");

	info->tos = cb->val.tos_value;

}

static void tos_tg_parse(struct xt_option_call *cb)

{

	struct xt_tos_target_info *info = cb->data;

	xtables_option_parse(cb);

	switch (cb->entry->id) {

	case O_SET_TOS:

		info->tos_value = cb->val.tos_value;

		info->tos_mask  = cb->val.tos_mask;

		break;

	case O_AND_TOS:

		info->tos_value = 0;

		info->tos_mask  = ~cb->val.u8;

		break;

	case O_OR_TOS:

		info->tos_value = cb->val.u8;

		info->tos_mask  = cb->val.u8;

		break;

	case O_XOR_TOS:

		info->tos_value = cb->val.u8;

		info->tos_mask  = 0;

		break;

	}

}

static void tos_tg_check(struct xt_fcheck_call *cb)

{

	if (!(cb->xflags & F_ANY))

		xtables_error(PARAMETER_PROBLEM,

		           "TOS: An action is required");

}

static void tos_tg_print_v0(const void *ip,

                            const struct xt_entry_target *target, int numeric)

{

	const struct ipt_tos_target_info *info = (const void *)target->data;

	printf(" TOS set ");

	if (numeric || !tos_try_print_symbolic("", info->tos, 0xFF))

		printf("0x%02x", info->tos);

}

static void tos_tg_print(const void *ip, const struct xt_entry_target *target,

                         int numeric)

{

	const struct xt_tos_target_info *info = (const void *)target->data;

	if (numeric)

		printf(" TOS set 0x%02x/0x%02x",

		       info->tos_value, info->tos_mask);

	else if (tos_try_print_symbolic(" TOS set",

	    info->tos_value, info->tos_mask))

		/* already printed by call */

		return;

	else if (info->tos_value == 0)

		printf(" TOS and 0x%02x",

		       (unsigned int)(uint8_t)~info->tos_mask);

	else if (info->tos_value == info->tos_mask)

		printf(" TOS or 0x%02x", info->tos_value);

	else if (info->tos_mask == 0)

		printf(" TOS xor 0x%02x", info->tos_value);

	else

		printf(" TOS set 0x%02x/0x%02x",

		       info->tos_value, info->tos_mask);

}

static void tos_tg_save_v0(const void *ip, const struct xt_entry_target *target)

{

	const struct ipt_tos_target_info *info = (const void *)target->data;

	printf(" --set-tos 0x%02x", info->tos);

}

static void tos_tg_save(const void *ip, const struct xt_entry_target *target)

{

	const struct xt_tos_target_info *info = (const void *)target->data;

	printf(" --set-tos 0x%02x/0x%02x", info->tos_value, info->tos_mask);

}

static int tos_xlate(struct xt_xlate *xl,

		     const struct xt_xlate_tg_params *params)

{

	const struct ipt_tos_target_info *info =

			(struct ipt_tos_target_info *) params->target->data;

	uint8_t dscp = info->tos >> 2;

	xt_xlate_add(xl, "ip dscp set 0x%02x", dscp);

	return 1;

}

static int tos_xlate6(struct xt_xlate *xl,

		     const struct xt_xlate_tg_params *params)

{

	const struct ipt_tos_target_info *info =

			(struct ipt_tos_target_info *) params->target->data;

	uint8_t dscp = info->tos >> 2;

	xt_xlate_add(xl, "ip6 dscp set 0x%02x", dscp);

	return 1;

}

static struct xtables_target tos_tg_reg[] = {

	{

		.version       = XTABLES_VERSION,

		.name          = "TOS",

		.revision      = 0,

		.family        = NFPROTO_IPV4,

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

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

		.help          = tos_tg_help_v0,

		.print         = tos_tg_print_v0,

		.save          = tos_tg_save_v0,

		.x6_parse      = tos_tg_parse_v0,

		.x6_fcheck     = tos_tg_check,

		.x6_options    = tos_tg_opts_v0,

		.xlate	       = tos_xlate,

	},

	{

		.version       = XTABLES_VERSION,

		.name          = "TOS",

		.revision      = 1,

		.family        = NFPROTO_UNSPEC,

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

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

		.help          = tos_tg_help,

		.print         = tos_tg_print,

		.save          = tos_tg_save,

		.x6_parse      = tos_tg_parse,

		.x6_fcheck     = tos_tg_check,

		.x6_options    = tos_tg_opts,

		.xlate	       = tos_xlate6,

	},

};

void _init(void)

{

	xtables_register_targets(tos_tg_reg, ARRAY_SIZE(tos_tg_reg));

}