/*

 * link_iptnl.c	ipip and sit driver module

 *

 *		This program is free software; you can redistribute 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:	Nicolas Dichtel <nicolas.dichtel@6wind.com>

 *

 */

#include <string.h>

#include <net/if.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <arpa/inet.h>

#include <linux/in.h>

#include <linux/ip.h>

#include <linux/if_tunnel.h>

#include "rt_names.h"

#include "utils.h"

#include "ip_common.h"

#include "tunnel.h"

static void iptunnel_print_help(struct link_util *lu, int argc, char **argv,

				FILE *f)

{

	const char *mode;

	if (strcmp(lu->id, "sit") == 0) {

		mode =	"{ ip6ip | ipip | mplsip | any } ]\n"

			"			[ isatap";

	} else {

		mode = "{ ipip | mplsip | any }";

	}

	fprintf(f,

		"Usage: ... %-6s	[ remote ADDR ]\n"

		"			[ local ADDR ]\n"

		"			[ ttl TTL ]\n"

		"			[ tos TOS ]\n"

		"			[ [no]pmtudisc ]\n"

		"			[ 6rd-prefix ADDR ]\n"

		"			[ 6rd-relay_prefix ADDR ]\n"

		"			[ 6rd-reset ]\n"

		"			[ dev PHYS_DEV ]\n"

		"			[ fwmark MARK ]\n"

		"			[ external ]\n"

		"			[ noencap ]\n"

		"			[ encap { fou | gue | none } ]\n"

		"			[ encap-sport PORT ]\n"

		"			[ encap-dport PORT ]\n"

		"			[ [no]encap-csum ]\n"

		"			[ [no]encap-csum6 ]\n"

		"			[ [no]encap-remcsum ]\n"

		"			[ mode %s ]\n"

		"\n"

		"Where:	ADDR := { IP_ADDRESS | any }\n"

		"	TOS  := { NUMBER | inherit }\n"

		"	TTL  := { 1..255 | inherit }\n"

		"	MARK := { 0x0..0xffffffff }\n",

		lu->id, mode);

}

static int iptunnel_parse_opt(struct link_util *lu, int argc, char **argv,

			      struct nlmsghdr *n)

{

	struct ifinfomsg *ifi = NLMSG_DATA(n);

	struct {

		struct nlmsghdr n;

		struct ifinfomsg i;

	} req = {

		.n.nlmsg_len = NLMSG_LENGTH(sizeof(*ifi)),

		.n.nlmsg_flags = NLM_F_REQUEST,

		.n.nlmsg_type = RTM_GETLINK,

		.i.ifi_family = preferred_family,

		.i.ifi_index = ifi->ifi_index,

	};

	struct nlmsghdr *answer;

	struct rtattr *tb[IFLA_MAX + 1];

	struct rtattr *linkinfo[IFLA_INFO_MAX+1];

	struct rtattr *iptuninfo[IFLA_IPTUN_MAX + 1];

	int len;

	inet_prefix saddr, daddr, ip6rdprefix, ip6rdrelayprefix;

	__u8 pmtudisc = 1;

	__u8 tos = 0;

	__u16 iflags = 0;

	__u8 ttl = 0;

	__u8 proto = 0;

	__u32 link = 0;

	__u16 encaptype = 0;

	__u16 encapflags = 0;

	__u16 encapsport = 0;

	__u16 encapdport = 0;

	__u8 metadata = 0;

	__u32 fwmark = 0;

	inet_prefix_reset(&saddr);

	inet_prefix_reset(&daddr);

	inet_prefix_reset(&ip6rdprefix);

	inet_prefix_reset(&ip6rdrelayprefix);

	if (!(n->nlmsg_flags & NLM_F_CREATE)) {

		const struct rtattr *rta;

		if (rtnl_talk(&rth, &req.n, &answer) < 0) {

get_failed:

			fprintf(stderr,

				"Failed to get existing tunnel info.\n");

			return -1;

		}

		len = answer->nlmsg_len;

		len -= NLMSG_LENGTH(sizeof(*ifi));

		if (len < 0)

			goto get_failed;

		parse_rtattr(tb, IFLA_MAX, IFLA_RTA(NLMSG_DATA(answer)), len);

		if (!tb[IFLA_LINKINFO])

			goto get_failed;

		parse_rtattr_nested(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO]);

		if (!linkinfo[IFLA_INFO_DATA])

			goto get_failed;

		parse_rtattr_nested(iptuninfo, IFLA_IPTUN_MAX,

				    linkinfo[IFLA_INFO_DATA]);

		rta = iptuninfo[IFLA_IPTUN_LOCAL];

		if (rta && get_addr_rta(&saddr, rta, AF_INET))

			goto get_failed;

		rta = iptuninfo[IFLA_IPTUN_REMOTE];

		if (rta && get_addr_rta(&daddr, rta, AF_INET))

			goto get_failed;

		rta = iptuninfo[IFLA_IPTUN_6RD_PREFIX];

		if (rta && get_addr_rta(&ip6rdprefix, rta, AF_INET6))

			goto get_failed;

		rta = iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIX];

		if (rta && get_addr_rta(&ip6rdrelayprefix, rta, AF_INET))

			goto get_failed;

		rta = iptuninfo[IFLA_IPTUN_6RD_PREFIXLEN];

		ip6rdprefix.bitlen = rta ? rta_getattr_u16(rta) : 0;

		rta = iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIXLEN];

		ip6rdrelayprefix.bitlen = rta ? rta_getattr_u16(rta) : 0;

		if (iptuninfo[IFLA_IPTUN_TTL])

			ttl = rta_getattr_u8(iptuninfo[IFLA_IPTUN_TTL]);

		if (iptuninfo[IFLA_IPTUN_PMTUDISC])

			pmtudisc =

				rta_getattr_u8(iptuninfo[IFLA_IPTUN_PMTUDISC]);

		if (iptuninfo[IFLA_IPTUN_TOS])

			tos = rta_getattr_u8(iptuninfo[IFLA_IPTUN_TOS]);

		if (iptuninfo[IFLA_IPTUN_FLAGS])

			iflags = rta_getattr_u16(iptuninfo[IFLA_IPTUN_FLAGS]);

		if (iptuninfo[IFLA_IPTUN_LINK])

			link = rta_getattr_u32(iptuninfo[IFLA_IPTUN_LINK]);

		if (iptuninfo[IFLA_IPTUN_PROTO])

			proto = rta_getattr_u8(iptuninfo[IFLA_IPTUN_PROTO]);

		if (iptuninfo[IFLA_IPTUN_ENCAP_TYPE])

			encaptype = rta_getattr_u16(iptuninfo[IFLA_IPTUN_ENCAP_TYPE]);

		if (iptuninfo[IFLA_IPTUN_ENCAP_FLAGS])

			encapflags = rta_getattr_u16(iptuninfo[IFLA_IPTUN_ENCAP_FLAGS]);

		if (iptuninfo[IFLA_IPTUN_ENCAP_SPORT])

			encapsport = rta_getattr_u16(iptuninfo[IFLA_IPTUN_ENCAP_SPORT]);

		if (iptuninfo[IFLA_IPTUN_ENCAP_DPORT])

			encapdport = rta_getattr_u16(iptuninfo[IFLA_IPTUN_ENCAP_DPORT]);

		if (iptuninfo[IFLA_IPTUN_COLLECT_METADATA])

			metadata = 1;

		if (iptuninfo[IFLA_IPTUN_FWMARK])

			fwmark = rta_getattr_u32(iptuninfo[IFLA_IPTUN_FWMARK]);

		free(answer);

	}

	while (argc > 0) {

		if (strcmp(*argv, "mode") == 0) {

			NEXT_ARG();

			if (strcmp(lu->id, "sit") == 0 &&

			    (strcmp(*argv, "ipv6/ipv4") == 0 ||

			     strcmp(*argv, "ip6ip") == 0))

				proto = IPPROTO_IPV6;

			else if (strcmp(*argv, "ipv4/ipv4") == 0 ||

				 strcmp(*argv, "ipip") == 0 ||

				 strcmp(*argv, "ip4ip4") == 0)

				proto = IPPROTO_IPIP;

			else if (strcmp(*argv, "mpls/ipv4") == 0 ||

				   strcmp(*argv, "mplsip") == 0)

				proto = IPPROTO_MPLS;

			else if (strcmp(*argv, "any/ipv4") == 0 ||

				 strcmp(*argv, "any") == 0)

				proto = 0;

			else

				invarg("Cannot guess tunnel mode.", *argv);

		} else if (strcmp(*argv, "remote") == 0) {

			NEXT_ARG();

			get_addr(&daddr, *argv, AF_INET);

		} else if (strcmp(*argv, "local") == 0) {

			NEXT_ARG();

			get_addr(&saddr, *argv, AF_INET);

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

			NEXT_ARG();

			link = ll_name_to_index(*argv);

			if (!link)

				exit(nodev(*argv));

		} else if (strcmp(*argv, "ttl") == 0 ||

			   strcmp(*argv, "hoplimit") == 0 ||

			   strcmp(*argv, "hlim") == 0) {

			NEXT_ARG();

			if (strcmp(*argv, "inherit") != 0) {

				if (get_u8(&ttl, *argv, 0))

					invarg("invalid TTL\n", *argv);

			} else

				ttl = 0;

		} else if (strcmp(*argv, "tos") == 0 ||

			   strcmp(*argv, "tclass") == 0 ||

			   strcmp(*argv, "tc") == 0 ||

			   matches(*argv, "dsfield") == 0) {

			__u32 uval;

			NEXT_ARG();

			if (strcmp(*argv, "inherit") != 0) {

				if (rtnl_dsfield_a2n(&uval, *argv))

					invarg("bad TOS value", *argv);

				tos = uval;

			} else

				tos = 1;

		} else if (strcmp(*argv, "nopmtudisc") == 0) {

			pmtudisc = 0;

		} else if (strcmp(*argv, "pmtudisc") == 0) {

			pmtudisc = 1;

		} else if (strcmp(lu->id, "sit") == 0 &&

			   strcmp(*argv, "isatap") == 0) {

			iflags |= SIT_ISATAP;

		} else if (strcmp(*argv, "noencap") == 0) {

			encaptype = TUNNEL_ENCAP_NONE;

		} else if (strcmp(*argv, "encap") == 0) {

			NEXT_ARG();

			if (strcmp(*argv, "fou") == 0)

				encaptype = TUNNEL_ENCAP_FOU;

			else if (strcmp(*argv, "gue") == 0)

				encaptype = TUNNEL_ENCAP_GUE;

			else if (strcmp(*argv, "none") == 0)

				encaptype = TUNNEL_ENCAP_NONE;

			else

				invarg("Invalid encap type.", *argv);

		} else if (strcmp(*argv, "encap-sport") == 0) {

			NEXT_ARG();

			if (strcmp(*argv, "auto") == 0)

				encapsport = 0;

			else if (get_u16(&encapsport, *argv, 0))

				invarg("Invalid source port.", *argv);

		} else if (strcmp(*argv, "encap-dport") == 0) {

			NEXT_ARG();

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

				invarg("Invalid destination port.", *argv);

		} else if (strcmp(*argv, "encap-csum") == 0) {

			encapflags |= TUNNEL_ENCAP_FLAG_CSUM;

		} else if (strcmp(*argv, "noencap-csum") == 0) {

			encapflags &= ~TUNNEL_ENCAP_FLAG_CSUM;

		} else if (strcmp(*argv, "encap-udp6-csum") == 0) {

			encapflags |= TUNNEL_ENCAP_FLAG_CSUM6;

		} else if (strcmp(*argv, "noencap-udp6-csum") == 0) {

			encapflags &= ~TUNNEL_ENCAP_FLAG_CSUM6;

		} else if (strcmp(*argv, "encap-remcsum") == 0) {

			encapflags |= TUNNEL_ENCAP_FLAG_REMCSUM;

		} else if (strcmp(*argv, "noencap-remcsum") == 0) {

			encapflags &= ~TUNNEL_ENCAP_FLAG_REMCSUM;

		} else if (strcmp(*argv, "external") == 0) {

			metadata = 1;

		} else if (strcmp(*argv, "6rd-prefix") == 0) {

			NEXT_ARG();

			if (get_prefix(&ip6rdprefix, *argv, AF_INET6))

				invarg("invalid 6rd_prefix\n", *argv);

		} else if (strcmp(*argv, "6rd-relay_prefix") == 0) {

			NEXT_ARG();

			if (get_prefix(&ip6rdrelayprefix, *argv, AF_INET))

				invarg("invalid 6rd-relay_prefix\n", *argv);

		} else if (strcmp(*argv, "6rd-reset") == 0) {

			get_prefix(&ip6rdprefix, "2002::/16", AF_INET6);

			inet_prefix_reset(&ip6rdrelayprefix);

		} else if (strcmp(*argv, "fwmark") == 0) {

			NEXT_ARG();

			if (get_u32(&fwmark, *argv, 0))

				invarg("invalid fwmark\n", *argv);

		} else {

			iptunnel_print_help(lu, argc, argv, stderr);

			return -1;

		}

		argc--, argv++;

	}

	if (ttl && pmtudisc == 0) {

		fprintf(stderr, "ttl != 0 and nopmtudisc are incompatible\n");

		exit(-1);

	}

	addattr8(n, 1024, IFLA_IPTUN_PROTO, proto);

	if (metadata) {

		addattr_l(n, 1024, IFLA_IPTUN_COLLECT_METADATA, NULL, 0);

		return 0;

	}

	if (is_addrtype_inet_not_unspec(&saddr)) {

		addattr_l(n, 1024, IFLA_IPTUN_LOCAL,

			  saddr.data, saddr.bytelen);

	}

	if (is_addrtype_inet_not_unspec(&daddr)) {

		addattr_l(n, 1024, IFLA_IPTUN_REMOTE,

			  daddr.data, daddr.bytelen);

	}

	addattr8(n, 1024, IFLA_IPTUN_PMTUDISC, pmtudisc);

	addattr8(n, 1024, IFLA_IPTUN_TOS, tos);

	addattr8(n, 1024, IFLA_IPTUN_TTL, ttl);

	addattr32(n, 1024, IFLA_IPTUN_LINK, link);

	addattr32(n, 1024, IFLA_IPTUN_FWMARK, fwmark);

	addattr16(n, 1024, IFLA_IPTUN_ENCAP_TYPE, encaptype);

	addattr16(n, 1024, IFLA_IPTUN_ENCAP_FLAGS, encapflags);

	addattr16(n, 1024, IFLA_IPTUN_ENCAP_SPORT, htons(encapsport));

	addattr16(n, 1024, IFLA_IPTUN_ENCAP_DPORT, htons(encapdport));

	if (strcmp(lu->id, "sit") == 0) {

		addattr16(n, 1024, IFLA_IPTUN_FLAGS, iflags);

		if (is_addrtype_inet(&ip6rdprefix)) {

			addattr_l(n, 1024, IFLA_IPTUN_6RD_PREFIX,

				  ip6rdprefix.data, ip6rdprefix.bytelen);

			addattr16(n, 1024, IFLA_IPTUN_6RD_PREFIXLEN,

				  ip6rdprefix.bitlen);

		}

		if (is_addrtype_inet(&ip6rdrelayprefix)) {

			addattr32(n, 1024, IFLA_IPTUN_6RD_RELAY_PREFIX,

				  ip6rdrelayprefix.data[0]);

			addattr16(n, 1024, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,

				  ip6rdrelayprefix.bitlen);

		}

	}

	return 0;

}

static void iptunnel_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])

{

	char s2[64];

	__u16 prefixlen;

	__u8 ttl = 0;

	__u8 tos = 0;

	if (!tb)

		return;

	if (tb[IFLA_IPTUN_COLLECT_METADATA]) {

		print_bool(PRINT_ANY, "external", "external ", true);

		return;

	}

	if (tb[IFLA_IPTUN_PROTO]) {

		switch (rta_getattr_u8(tb[IFLA_IPTUN_PROTO])) {

		case IPPROTO_IPIP:

			print_string(PRINT_ANY, "proto", "%s ", "ipip");

			break;

		case IPPROTO_IPV6:

			print_string(PRINT_ANY, "proto", "%s ", "ip6ip");

			break;

		case IPPROTO_MPLS:

			print_string(PRINT_ANY, "proto", "%s ", "mplsip");

			break;

		case 0:

			print_string(PRINT_ANY, "proto", "%s ", "any");

			break;

		}

	}

	tnl_print_endpoint("remote", tb[IFLA_IPTUN_REMOTE], AF_INET);

	tnl_print_endpoint("local", tb[IFLA_IPTUN_LOCAL], AF_INET);

	if (tb[IFLA_IPTUN_LINK]) {

		__u32 link = rta_getattr_u32(tb[IFLA_IPTUN_LINK]);

		if (link) {

			print_string(PRINT_ANY, "link", "dev %s ",

				     ll_index_to_name(link));

		}

	}

	if (tb[IFLA_IPTUN_TTL])

		ttl = rta_getattr_u8(tb[IFLA_IPTUN_TTL]);

	if (is_json_context() || ttl)

		print_uint(PRINT_ANY, "ttl", "ttl %u ", ttl);

	else

		print_string(PRINT_FP, NULL, "ttl %s ", "inherit");

	if (tb[IFLA_IPTUN_TOS])

		tos = rta_getattr_u8(tb[IFLA_IPTUN_TOS]);

	if (tos) {

		if (is_json_context() || tos != 1)

			print_0xhex(PRINT_ANY, "tos", "tos %#llx ", tos);

		else

			print_string(PRINT_FP, NULL, "tos %s ", "inherit");

	}

	if (tb[IFLA_IPTUN_PMTUDISC] && rta_getattr_u8(tb[IFLA_IPTUN_PMTUDISC]))

		print_bool(PRINT_ANY, "pmtudisc", "pmtudisc ", true);

	else

		print_bool(PRINT_ANY, "pmtudisc", "nopmtudisc ", false);

	if (tb[IFLA_IPTUN_FLAGS]) {

		__u16 iflags = rta_getattr_u16(tb[IFLA_IPTUN_FLAGS]);

		if (iflags & SIT_ISATAP)

			print_bool(PRINT_ANY, "isatap", "isatap ", true);

	}

	if (tb[IFLA_IPTUN_6RD_PREFIXLEN] &&

	    (prefixlen = rta_getattr_u16(tb[IFLA_IPTUN_6RD_PREFIXLEN]))) {

		__u16 relayprefixlen =

			rta_getattr_u16(tb[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);

		__u32 relayprefix =

			rta_getattr_u32(tb[IFLA_IPTUN_6RD_RELAY_PREFIX]);

		const char *prefix = inet_ntop(AF_INET6,

					       RTA_DATA(tb[IFLA_IPTUN_6RD_PREFIX]),

					       s2, sizeof(s2));

		if (is_json_context()) {

			print_string(PRINT_JSON, "prefix", NULL, prefix);

			print_int(PRINT_JSON, "prefixlen", NULL, prefixlen);

			if (relayprefix) {

				print_string(PRINT_JSON,

					     "relay_prefix",

					     NULL,

					     format_host(AF_INET,

							 4,

							 &relayprefix));

				print_int(PRINT_JSON,

					  "relay_prefixlen",

					  NULL,

					  relayprefixlen);

			}

		} else {

			printf("6rd-prefix %s/%u ", prefix, prefixlen);

			if (relayprefix) {

				printf("6rd-relay_prefix %s/%u ",

				       format_host(AF_INET, 4, &relayprefix),

				       relayprefixlen);

			}

		}

	}

	if (tb[IFLA_IPTUN_FWMARK]) {

		__u32 fwmark = rta_getattr_u32(tb[IFLA_IPTUN_FWMARK]);

		if (fwmark) {

			print_0xhex(PRINT_ANY,

				    "fwmark", "fwmark %#llx ", fwmark);

		}

	}

	tnl_print_encap(tb,

			IFLA_IPTUN_ENCAP_TYPE,

			IFLA_IPTUN_ENCAP_FLAGS,

			IFLA_IPTUN_ENCAP_SPORT,

			IFLA_IPTUN_ENCAP_DPORT);

}

struct link_util ipip_link_util = {

	.id = "ipip",

	.maxattr = IFLA_IPTUN_MAX,

	.parse_opt = iptunnel_parse_opt,

	.print_opt = iptunnel_print_opt,

	.print_help = iptunnel_print_help,

};

struct link_util sit_link_util = {

	.id = "sit",

	.maxattr = IFLA_IPTUN_MAX,

	.parse_opt = iptunnel_parse_opt,

	.print_opt = iptunnel_print_opt,

	.print_help = iptunnel_print_help,

};