/*

 * m_xt.c	xtables based targets

 *		utilities mostly ripped from iptables <duh, its the linux way>

 *

 *		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 (hadi@cyberus.ca)

 */

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <net/if.h>

#include <limits.h>

#include <linux/netfilter.h>

#include <linux/netfilter_ipv4/ip_tables.h>

#include <xtables.h>

#include "utils.h"

#include "tc_util.h"

#include <linux/tc_act/tc_ipt.h>

#include <stdio.h>

#include <dlfcn.h>

#include <getopt.h>

#include <errno.h>

#include <string.h>

#include <netdb.h>

#include <stdlib.h>

#include <ctype.h>

#include <stdarg.h>

#include <unistd.h>

#include <fcntl.h>

#include <sys/wait.h>

#ifndef XT_LIB_DIR

#       define XT_LIB_DIR "/lib/xtables"

#endif

#ifndef __ALIGN_KERNEL

#define __ALIGN_KERNEL(x, a)	\

	__ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)

#define __ALIGN_KERNEL_MASK(x, mask) \

	(((x) + (mask)) & ~(mask))

#endif

#ifndef ALIGN

#define ALIGN(x, a)	__ALIGN_KERNEL((x), (a))

#endif

static const char *tname = "mangle";

char *lib_dir;

static const char * const ipthooks[] = {

	"NF_IP_PRE_ROUTING",

	"NF_IP_LOCAL_IN",

	"NF_IP_FORWARD",

	"NF_IP_LOCAL_OUT",

	"NF_IP_POST_ROUTING",

};

static struct option original_opts[] = {

	{

		.name = "jump",

		.has_arg = 1,

		.val = 'j'

	},

	{0, 0, 0, 0}

};

static struct xtables_globals tcipt_globals = {

	.option_offset = 0,

	.program_name = "tc-ipt",

	.program_version = "0.2",

	.orig_opts = original_opts,

	.opts = original_opts,

	.exit_err = NULL,

#if XTABLES_VERSION_CODE >= 11

	.compat_rev = xtables_compatible_revision,

#endif

};

/*

 * we may need to check for version mismatch

*/

static int

build_st(struct xtables_target *target, struct xt_entry_target *t)

{

	size_t size =

		    XT_ALIGN(sizeof(struct xt_entry_target)) + target->size;

	if (t == NULL) {

		target->t = xtables_calloc(1, size);

		target->t->u.target_size = size;

		strncpy(target->t->u.user.name, target->name,

			sizeof(target->t->u.user.name) - 1);

		target->t->u.user.revision = target->revision;

		if (target->init != NULL)

			target->init(target->t);

	} else {

		target->t = t;

	}

	return 0;

}

static void set_lib_dir(void)

{

	lib_dir = getenv("XTABLES_LIBDIR");

	if (!lib_dir) {

		lib_dir = getenv("IPTABLES_LIB_DIR");

		if (lib_dir)

			fprintf(stderr, "using deprecated IPTABLES_LIB_DIR\n");

	}

	if (lib_dir == NULL)

		lib_dir = XT_LIB_DIR;

}

static int get_xtables_target_opts(struct xtables_globals *globals,

				   struct xtables_target *m)

{

	struct option *opts;

#if XTABLES_VERSION_CODE >= 6

	opts = xtables_options_xfrm(globals->orig_opts,

				    globals->opts,

				    m->x6_options,

				    &m->option_offset);

#else

	opts = xtables_merge_options(globals->opts,

				     m->extra_opts,

				     &m->option_offset);

#endif

	if (!opts)

		return -1;

	globals->opts = opts;

	return 0;

}

static int parse_ipt(struct action_util *a, int *argc_p,

		     char ***argv_p, int tca_id, struct nlmsghdr *n)

{

	struct xtables_target *m = NULL;

#if XTABLES_VERSION_CODE >= 6

	struct ipt_entry fw = {};

#endif

	struct rtattr *tail;

	int c;

	char **argv = *argv_p;

	int argc;

	char k[FILTER_NAMESZ];

	int size = 0;

	int iok = 0, ok = 0;

	__u32 hook = 0, index = 0;

	/* copy tcipt_globals because .opts will be modified by iptables */

	struct xtables_globals tmp_tcipt_globals = tcipt_globals;

	xtables_init_all(&tmp_tcipt_globals, NFPROTO_IPV4);

	set_lib_dir();

	/* parse only up until the next action */

	for (argc = 0; argc < *argc_p; argc++) {

		if (!argv[argc] || !strcmp(argv[argc], "action"))

			break;

	}

	if (argc <= 2) {

		fprintf(stderr,

			"too few arguments for xt, need at least '-j <target>'\n");

		return -1;

	}

	while (1) {

		c = getopt_long(argc, argv, "j:", tmp_tcipt_globals.opts, NULL);

		if (c == -1)

			break;

		switch (c) {

		case 'j':

			m = xtables_find_target(optarg, XTF_TRY_LOAD);

			if (!m) {

				fprintf(stderr,

					" failed to find target %s\n\n",

					optarg);

				return -1;

			}

			if (build_st(m, NULL) < 0) {

				printf(" %s error\n", m->name);

				return -1;

			}

			if (get_xtables_target_opts(&tmp_tcipt_globals,

						    m) < 0) {

				fprintf(stderr,

					" failed to find additional options for target %s\n\n",

					optarg);

				return -1;

			}

			ok++;

			break;

		default:

#if XTABLES_VERSION_CODE >= 6

			if (m != NULL && m->x6_parse != NULL) {

				xtables_option_tpcall(c, argv, 0, m, &fw;;

#else

			if (m != NULL && m->parse != NULL) {

				m->parse(c - m->option_offset, argv, 0,

					 &m->tflags, NULL, &m->t);

#endif

			} else {

				fprintf(stderr,

					"failed to find target %s\n\n", optarg);

				return -1;

			}

			ok++;

			break;

		}

	}

	if (argc > optind) {

		if (matches(argv[optind], "index") == 0) {

			if (get_u32(&index, argv[optind + 1], 10)) {

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

				xtables_free_opts(1);

				return -1;

			}

			iok++;

			optind += 2;

		}

	}

	if (!ok && !iok) {

		fprintf(stderr, " ipt Parser BAD!! (%s)\n", *argv);

		return -1;

	}

	/* check that we passed the correct parameters to the target */

#if XTABLES_VERSION_CODE >= 6

	if (m)

		xtables_option_tfcall(m);

#else

	if (m && m->final_check)

		m->final_check(m->tflags);

#endif

	{

		struct tcmsg *t = NLMSG_DATA(n);

		if (t->tcm_parent != TC_H_ROOT

		    && t->tcm_parent == TC_H_MAJ(TC_H_INGRESS)) {

			hook = NF_IP_PRE_ROUTING;

		} else {

			hook = NF_IP_POST_ROUTING;

		}

	}

	tail = addattr_nest(n, MAX_MSG, tca_id);

	fprintf(stdout, "tablename: %s hook: %s\n ", tname, ipthooks[hook]);

	fprintf(stdout, "\ttarget: ");

	if (m) {

		if (m->print)

			m->print(NULL, m->t, 0);

		else

			printf("%s ", m->name);

	}

	fprintf(stdout, " index %d\n", index);

	if (strlen(tname) >= 16) {

		size = 15;

		k[15] = 0;

	} else {

		size = 1 + strlen(tname);

	}

	strncpy(k, tname, size);

	addattr_l(n, MAX_MSG, TCA_IPT_TABLE, k, size);

	addattr_l(n, MAX_MSG, TCA_IPT_HOOK, &hook, 4);

	addattr_l(n, MAX_MSG, TCA_IPT_INDEX, &index, 4);

	if (m)

		addattr_l(n, MAX_MSG, TCA_IPT_TARG, m->t, m->t->u.target_size);

	addattr_nest_end(n, tail);

	argv += optind;

	*argc_p -= argc;

	*argv_p = argv;

	optind = 0;

	xtables_free_opts(1);

	if (m) {

		/* Clear flags if target will be used again */

		m->tflags = 0;

		m->used = 0;

		/* Free allocated memory */

		if (m->t)

			free(m->t);

	}

	return 0;

}

static int

print_ipt(struct action_util *au, FILE *f, struct rtattr *arg)

{

	struct xtables_target *m;

	struct rtattr *tb[TCA_IPT_MAX + 1];

	struct xt_entry_target *t = NULL;

	__u32 hook;

	if (arg == NULL)

		return -1;

	/* copy tcipt_globals because .opts will be modified by iptables */

	struct xtables_globals tmp_tcipt_globals = tcipt_globals;

	xtables_init_all(&tmp_tcipt_globals, NFPROTO_IPV4);

	set_lib_dir();

	parse_rtattr_nested(tb, TCA_IPT_MAX, arg);

	if (tb[TCA_IPT_TABLE] == NULL) {

		fprintf(stderr, "Missing ipt table name, assuming mangle\n");

	} else {

		fprintf(f, "tablename: %s ",

			rta_getattr_str(tb[TCA_IPT_TABLE]));

	}

	if (tb[TCA_IPT_HOOK] == NULL) {

		fprintf(stderr, "Missing ipt hook name\n ");

		return -1;

	}

	if (tb[TCA_IPT_TARG] == NULL) {

		fprintf(stderr, "Missing ipt target parameters\n");

		return -1;

	}

	hook = rta_getattr_u32(tb[TCA_IPT_HOOK]);

	fprintf(f, " hook: %s\n", ipthooks[hook]);

	t = RTA_DATA(tb[TCA_IPT_TARG]);

	m = xtables_find_target(t->u.user.name, XTF_TRY_LOAD);

	if (!m) {

		fprintf(stderr, " failed to find target %s\n\n",

			t->u.user.name);

		return -1;

	}

	if (build_st(m, t) < 0) {

		fprintf(stderr, " %s error\n", m->name);

		return -1;

	}

	if (get_xtables_target_opts(&tmp_tcipt_globals, m) < 0) {

		fprintf(stderr,

			" failed to find additional options for target %s\n\n",

			t->u.user.name);

		return -1;

	}

	fprintf(f, "\ttarget ");

	m->print(NULL, m->t, 0);

	if (tb[TCA_IPT_INDEX] == NULL) {

		fprintf(f, " [NULL ipt target index ]\n");

	} else {

		__u32 index;

		index = rta_getattr_u32(tb[TCA_IPT_INDEX]);

		fprintf(f, "\n\tindex %u", index);

	}

	if (tb[TCA_IPT_CNT]) {

		struct tc_cnt *c  = RTA_DATA(tb[TCA_IPT_CNT]);

		fprintf(f, " ref %d bind %d", c->refcnt, c->bindcnt);

	}

	if (show_stats) {

		if (tb[TCA_IPT_TM]) {

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

			print_tm(f, tm);

		}

	}

	print_nl();

	xtables_free_opts(1);

	return 0;

}

struct action_util xt_action_util = {

	.id = "xt",

	.parse_aopt = parse_ipt,

	.print_aopt = print_ipt,

};