/*

 * m_skbmod.c	skb modifier action module

 *

 *		This program is free software; you can distribute it and/or

 *		modify it under the terms of the GNU General Public License

 *		as published by the Free Software Foundation; either version

 *		2 of the License, or (at your option) any later version.

 *

 * Authors:  J Hadi Salim (jhs@mojatatu.com)

 *

 */

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <fcntl.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <string.h>

#include <linux/netdevice.h>

#include "rt_names.h"

#include "utils.h"

#include "tc_util.h"

#include <linux/tc_act/tc_skbmod.h>

static void skbmod_explain(void)

{

	fprintf(stderr,

		"Usage:... skbmod {[set <SETTABLE>] [swap <SWAPABLE>]} [CONTROL] [index INDEX]\n"

		"where SETTABLE is: [dmac DMAC] [smac SMAC] [etype ETYPE]\n"

		"where SWAPABLE is: \"mac\" to swap mac addresses\n"

		"note: \"swap mac\" is done after any outstanding D/SMAC change\n"

		"\tDMAC := 6 byte Destination MAC address\n"

		"\tSMAC := optional 6 byte Source MAC address\n"

		"\tETYPE := optional 16 bit ethertype\n"

		"\tCONTROL := reclassify | pipe | drop | continue | ok |\n"

		"\t           goto chain <CHAIN_INDEX>\n"

		"\tINDEX := skbmod index value to use\n");

}

static void skbmod_usage(void)

{

	skbmod_explain();

	exit(-1);

}

static int parse_skbmod(struct action_util *a, int *argc_p, char ***argv_p,

			int tca_id, struct nlmsghdr *n)

{

	int argc = *argc_p;

	char **argv = *argv_p;

	int ok = 0;

	struct tc_skbmod p;

	struct rtattr *tail;

	char dbuf[ETH_ALEN];

	char sbuf[ETH_ALEN];

	__u16 skbmod_etype = 0;

	char *daddr = NULL;

	char *saddr = NULL;

	memset(&p, 0, sizeof(p));

	if (argc <= 0)

		return -1;

	while (argc > 0) {

		if (matches(*argv, "skbmod") == 0) {

			NEXT_ARG();

			continue;

		} else if (matches(*argv, "swap") == 0) {

			NEXT_ARG();

			continue;

		} else if (matches(*argv, "mac") == 0) {

			p.flags |= SKBMOD_F_SWAPMAC;

			ok += 1;

		} else if (matches(*argv, "set") == 0) {

			NEXT_ARG();

			continue;

		} else if (matches(*argv, "etype") == 0) {

			NEXT_ARG();

			if (get_u16(&skbmod_etype, *argv, 0))

				invarg("ethertype is invalid", *argv);

			fprintf(stderr, "skbmod etype 0x%x\n", skbmod_etype);

			p.flags |= SKBMOD_F_ETYPE;

			ok += 1;

		} else if (matches(*argv, "dmac") == 0) {

			NEXT_ARG();

			daddr = *argv;

			if (sscanf(daddr, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",

				   dbuf, dbuf + 1, dbuf + 2,

				   dbuf + 3, dbuf + 4, dbuf + 5) != 6) {

				fprintf(stderr, "Invalid dst mac address %s\n",

					daddr);

				return -1;

			}

			p.flags |= SKBMOD_F_DMAC;

			fprintf(stderr, "dst MAC address <%s>\n", daddr);

			ok += 1;

		} else if (matches(*argv, "smac") == 0) {

			NEXT_ARG();

			saddr = *argv;

			if (sscanf(saddr, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",

				   sbuf, sbuf + 1, sbuf + 2,

				   sbuf + 3, sbuf + 4, sbuf + 5) != 6) {

				fprintf(stderr, "Invalid smac address %s\n",

					saddr);

				return -1;

			}

			p.flags |= SKBMOD_F_SMAC;

			fprintf(stderr, "src MAC address <%s>\n", saddr);

			ok += 1;

		} else if (matches(*argv, "help") == 0) {

			skbmod_usage();

		} else {

			break;

		}

		argc--;

		argv++;

	}

	parse_action_control_dflt(&argc, &argv, &p.action, false, TC_ACT_PIPE);

	if (argc) {

		if (matches(*argv, "index") == 0) {

			NEXT_ARG();

			if (get_u32(&p.index, *argv, 0)) {

				fprintf(stderr, "skbmod: Illegal \"index\"\n");

				return -1;

			}

			ok++;

			argc--;

			argv++;

		}

	}

	if (!ok) {

		fprintf(stderr, "skbmod requires at least one option\n");

		skbmod_usage();

	}

	tail = addattr_nest(n, MAX_MSG, tca_id);

	addattr_l(n, MAX_MSG, TCA_SKBMOD_PARMS, &p, sizeof(p));

	if (daddr)

		addattr_l(n, MAX_MSG, TCA_SKBMOD_DMAC, dbuf, ETH_ALEN);

	if (skbmod_etype)

		addattr16(n, MAX_MSG, TCA_SKBMOD_ETYPE, skbmod_etype);

	if (saddr)

		addattr_l(n, MAX_MSG, TCA_SKBMOD_SMAC, sbuf, ETH_ALEN);

	addattr_nest_end(n, tail);

	*argc_p = argc;

	*argv_p = argv;

	return 0;

}

static int print_skbmod(struct action_util *au, FILE *f, struct rtattr *arg)

{

	struct tc_skbmod *p;

	struct rtattr *tb[TCA_SKBMOD_MAX + 1];

	__u16 skbmod_etype = 0;

	int has_optional = 0;

	SPRINT_BUF(b1);

	SPRINT_BUF(b2);

	if (arg == NULL)

		return -1;

	parse_rtattr_nested(tb, TCA_SKBMOD_MAX, arg);

	if (tb[TCA_SKBMOD_PARMS] == NULL) {

		fprintf(stderr, "Missing skbmod parameters\n");

		return -1;

	}

	p = RTA_DATA(tb[TCA_SKBMOD_PARMS]);

	fprintf(f, "skbmod ");

	print_action_control(f, "", p->action, " ");

	if (tb[TCA_SKBMOD_ETYPE]) {

		skbmod_etype = rta_getattr_u16(tb[TCA_SKBMOD_ETYPE]);

		has_optional = 1;

		fprintf(f, "set etype 0x%X ", skbmod_etype);

	}

	if (has_optional)

		fprintf(f, "\n\t ");

	if (tb[TCA_SKBMOD_DMAC]) {

		has_optional = 1;

		fprintf(f, "set dmac %s ",

			ll_addr_n2a(RTA_DATA(tb[TCA_SKBMOD_DMAC]),

				    RTA_PAYLOAD(tb[TCA_SKBMOD_DMAC]), 0, b1,

				    sizeof(b1)));

	}

	if (tb[TCA_SKBMOD_SMAC]) {

		has_optional = 1;

		fprintf(f, "set smac %s ",

			ll_addr_n2a(RTA_DATA(tb[TCA_SKBMOD_SMAC]),

				    RTA_PAYLOAD(tb[TCA_SKBMOD_SMAC]), 0, b2,

				    sizeof(b2)));

	}

	if (p->flags & SKBMOD_F_SWAPMAC)

		fprintf(f, "swap mac ");

	fprintf(f, "\n\t index %u ref %d bind %d", p->index, p->refcnt,

		p->bindcnt);

	if (show_stats) {

		if (tb[TCA_SKBMOD_TM]) {

			struct tcf_t *tm = RTA_DATA(tb[TCA_SKBMOD_TM]);

			print_tm(f, tm);

		}

	}

	fprintf(f, "\n");

	return 0;

}

struct action_util skbmod_action_util = {

	.id = "skbmod",

	.parse_aopt = parse_skbmod,

	.print_aopt = print_skbmod,

};