/*

 * link_gre.c	gre 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:	Herbert Xu <herbert@gondor.apana.org.au>

 *

 */

#include <string.h>

#include <net/if.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <arpa/inet.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 bool gre_is_erspan(struct link_util *lu)

{

	return !strcmp(lu->id, "erspan");

}

static void gre_print_help(struct link_util *lu, int argc, char **argv, FILE *f)

{

	bool is_erspan = gre_is_erspan(lu);

	fprintf(f,

		"Usage: ... %-9s	[ remote ADDR ]\n"

		"			[ local ADDR ]\n"

		"			[ [no][i|o]seq ]\n"

		"			[ [i|o]key KEY | no[i|o]key ]\n"

		"			[ [no][i|o]csum ]\n"

		"			[ ttl TTL ]\n"

		"			[ tos TOS ]\n"

		"			[ [no]pmtudisc ]\n"

		"			[ [no]ignore-df ]\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", lu->id);

	if (is_erspan)

		fprintf(f,

			"			[ erspan_ver version ]\n"

			"			[ erspan IDX ]\n"

			"			[ erspan_dir { ingress | egress } ]\n"

			"			[ erspan_hwid hwid ]\n");

	fprintf(f,

		"\n"

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

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

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

		"	KEY  := { DOTTED_QUAD | NUMBER }\n"

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

}

static int gre_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 *greinfo[IFLA_GRE_MAX + 1];

	int len;

	__u16 iflags = 0;

	__u16 oflags = 0;

	__be32 ikey = 0;

	__be32 okey = 0;

	inet_prefix saddr, daddr;

	__u8 pmtudisc = 1;

	__u8 ignore_df = 0;

	__u8 tos = 0;

	__u8 ttl = 0;

	__u32 link = 0;

	__u16 encaptype = 0;

	__u16 encapflags = 0;

	__u16 encapsport = 0;

	__u16 encapdport = 0;

	__u8 metadata = 0;

	__u32 fwmark = 0;

	bool is_erspan = gre_is_erspan(lu);

	__u32 erspan_idx = 0;

	__u8 erspan_ver = 1;

	__u8 erspan_dir = 0;

	__u16 erspan_hwid = 0;

	inet_prefix_reset(&saddr);

	inet_prefix_reset(&daddr);

	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(greinfo, IFLA_GRE_MAX,

				    linkinfo[IFLA_INFO_DATA]);

		rta = greinfo[IFLA_GRE_LOCAL];

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

			goto get_failed;

		rta = greinfo[IFLA_GRE_REMOTE];

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

			goto get_failed;

		if (greinfo[IFLA_GRE_IKEY])

			ikey = rta_getattr_u32(greinfo[IFLA_GRE_IKEY]);

		if (greinfo[IFLA_GRE_OKEY])

			okey = rta_getattr_u32(greinfo[IFLA_GRE_OKEY]);

		if (greinfo[IFLA_GRE_IFLAGS])

			iflags = rta_getattr_u16(greinfo[IFLA_GRE_IFLAGS]);

		if (greinfo[IFLA_GRE_OFLAGS])

			oflags = rta_getattr_u16(greinfo[IFLA_GRE_OFLAGS]);

		if (greinfo[IFLA_GRE_PMTUDISC])

			pmtudisc = rta_getattr_u8(

				greinfo[IFLA_GRE_PMTUDISC]);

		if (greinfo[IFLA_GRE_IGNORE_DF])

			ignore_df =

				!!rta_getattr_u8(greinfo[IFLA_GRE_IGNORE_DF]);

		if (greinfo[IFLA_GRE_TOS])

			tos = rta_getattr_u8(greinfo[IFLA_GRE_TOS]);

		if (greinfo[IFLA_GRE_TTL])

			ttl = rta_getattr_u8(greinfo[IFLA_GRE_TTL]);

		if (greinfo[IFLA_GRE_LINK])

			link = rta_getattr_u32(greinfo[IFLA_GRE_LINK]);

		if (greinfo[IFLA_GRE_ENCAP_TYPE])

			encaptype = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_TYPE]);

		if (greinfo[IFLA_GRE_ENCAP_FLAGS])

			encapflags = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_FLAGS]);

		if (greinfo[IFLA_GRE_ENCAP_SPORT])

			encapsport = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_SPORT]);

		if (greinfo[IFLA_GRE_ENCAP_DPORT])

			encapdport = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_DPORT]);

		if (greinfo[IFLA_GRE_COLLECT_METADATA])

			metadata = 1;

		if (greinfo[IFLA_GRE_FWMARK])

			fwmark = rta_getattr_u32(greinfo[IFLA_GRE_FWMARK]);

		if (greinfo[IFLA_GRE_ERSPAN_INDEX])

			erspan_idx = rta_getattr_u32(greinfo[IFLA_GRE_ERSPAN_INDEX]);

		if (greinfo[IFLA_GRE_ERSPAN_VER])

			erspan_ver = rta_getattr_u8(greinfo[IFLA_GRE_ERSPAN_VER]);

		if (greinfo[IFLA_GRE_ERSPAN_DIR])

			erspan_dir = rta_getattr_u8(greinfo[IFLA_GRE_ERSPAN_DIR]);

		if (greinfo[IFLA_GRE_ERSPAN_HWID])

			erspan_hwid = rta_getattr_u16(greinfo[IFLA_GRE_ERSPAN_HWID]);

		free(answer);

	}

	while (argc > 0) {

		if (!matches(*argv, "key")) {

			NEXT_ARG();

			iflags |= GRE_KEY;

			oflags |= GRE_KEY;

			ikey = okey = tnl_parse_key("key", *argv);

		} else if (!matches(*argv, "nokey")) {

			iflags &= ~GRE_KEY;

			oflags &= ~GRE_KEY;

			ikey = okey = 0;

		} else if (!matches(*argv, "ikey")) {

			NEXT_ARG();

			iflags |= GRE_KEY;

			ikey = tnl_parse_key("ikey", *argv);

		} else if (!matches(*argv, "noikey")) {

			iflags &= ~GRE_KEY;

			ikey = 0;

		} else if (!matches(*argv, "okey")) {

			NEXT_ARG();

			oflags |= GRE_KEY;

			okey = tnl_parse_key("okey", *argv);

		} else if (!matches(*argv, "nookey")) {

			oflags &= ~GRE_KEY;

			okey = 0;

		} else if (!matches(*argv, "seq")) {

			iflags |= GRE_SEQ;

			oflags |= GRE_SEQ;

		} else if (!matches(*argv, "noseq")) {

			iflags &= ~GRE_SEQ;

			oflags &= ~GRE_SEQ;

		} else if (!matches(*argv, "iseq")) {

			iflags |= GRE_SEQ;

		} else if (!matches(*argv, "noiseq")) {

			iflags &= ~GRE_SEQ;

		} else if (!matches(*argv, "oseq")) {

			oflags |= GRE_SEQ;

		} else if (!matches(*argv, "nooseq")) {

			oflags &= ~GRE_SEQ;

		} else if (!matches(*argv, "csum")) {

			iflags |= GRE_CSUM;

			oflags |= GRE_CSUM;

		} else if (!matches(*argv, "nocsum")) {

			iflags &= ~GRE_CSUM;

			oflags &= ~GRE_CSUM;

		} else if (!matches(*argv, "icsum")) {

			iflags |= GRE_CSUM;

		} else if (!matches(*argv, "noicsum")) {

			iflags &= ~GRE_CSUM;

		} else if (!matches(*argv, "ocsum")) {

			oflags |= GRE_CSUM;

		} else if (!matches(*argv, "noocsum")) {

			oflags &= ~GRE_CSUM;

		} else if (!matches(*argv, "nopmtudisc")) {

			pmtudisc = 0;

		} else if (!matches(*argv, "pmtudisc")) {

			pmtudisc = 1;

		} else if (!matches(*argv, "remote")) {

			NEXT_ARG();

			get_addr(&daddr, *argv, AF_INET);

		} else if (!matches(*argv, "local")) {

			NEXT_ARG();

			get_addr(&saddr, *argv, AF_INET);

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

			NEXT_ARG();

			link = ll_name_to_index(*argv);

			if (!link)

				exit(nodev(*argv));

		} else if (!matches(*argv, "ttl") ||

			   !matches(*argv, "hoplimit") ||

			   !matches(*argv, "hlim")) {

			NEXT_ARG();

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

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

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

			} else

				ttl = 0;

		} else if (!matches(*argv, "tos") ||

			   !matches(*argv, "tclass") ||

			   !matches(*argv, "dsfield")) {

			__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, "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, "ignore-df") == 0) {

			ignore_df = 1;

		} else if (strcmp(*argv, "noignore-df") == 0) {

			/*

			 *only the lsb is significant, use 2 for presence

			 */

			ignore_df = 2;

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

			NEXT_ARG();

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

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

		} else if (is_erspan && strcmp(*argv, "erspan") == 0) {

			NEXT_ARG();

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

				invarg("invalid erspan index\n", *argv);

			if (erspan_idx & ~((1<<20) - 1) || erspan_idx == 0)

				invarg("erspan index must be > 0 and <= 20-bit\n", *argv);

		} else if (is_erspan && strcmp(*argv, "erspan_ver") == 0) {

			NEXT_ARG();

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

				invarg("invalid erspan version\n", *argv);

			if (erspan_ver > 2)

				invarg("erspan version must be 0/1/2\n", *argv);

		} else if (is_erspan && strcmp(*argv, "erspan_dir") == 0) {

			NEXT_ARG();

			if (matches(*argv, "ingress") == 0)

				erspan_dir = 0;

			else if (matches(*argv, "egress") == 0)

				erspan_dir = 1;

			else

				invarg("Invalid erspan direction.", *argv);

		} else if (is_erspan && strcmp(*argv, "erspan_hwid") == 0) {

			NEXT_ARG();

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

				invarg("invalid erspan hwid\n", *argv);

		} else {

			gre_print_help(lu, argc, argv, stderr);

			return -1;

		}

		argc--; argv++;

	}

	if (is_addrtype_inet_multi(&daddr)) {

		if (!ikey) {

			ikey = daddr.data[0];

			iflags |= GRE_KEY;

		}

		if (!okey) {

			okey = daddr.data[0];

			oflags |= GRE_KEY;

		}

		if (!is_addrtype_inet_not_unspec(&saddr)) {

			fprintf(stderr,

				"A broadcast tunnel requires a source address.\n");

			return -1;

		}

	}

	if (metadata) {

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

		return 0;

	}

	addattr32(n, 1024, IFLA_GRE_IKEY, ikey);

	addattr32(n, 1024, IFLA_GRE_OKEY, okey);

	addattr_l(n, 1024, IFLA_GRE_IFLAGS, &iflags, 2);

	addattr_l(n, 1024, IFLA_GRE_OFLAGS, &oflags, 2);

	if (is_addrtype_inet_not_unspec(&saddr))

		addattr_l(n, 1024, IFLA_GRE_LOCAL, saddr.data, saddr.bytelen);

	if (is_addrtype_inet_not_unspec(&daddr))

		addattr_l(n, 1024, IFLA_GRE_REMOTE, daddr.data, daddr.bytelen);

	addattr_l(n, 1024, IFLA_GRE_PMTUDISC, &pmtudisc, 1);

	if (ignore_df)

		addattr8(n, 1024, IFLA_GRE_IGNORE_DF, ignore_df & 1);

	addattr_l(n, 1024, IFLA_GRE_TOS, &tos, 1);

	if (link)

		addattr32(n, 1024, IFLA_GRE_LINK, link);

	addattr_l(n, 1024, IFLA_GRE_TTL, &ttl, 1);

	addattr32(n, 1024, IFLA_GRE_FWMARK, fwmark);

	if (is_erspan) {

		addattr8(n, 1024, IFLA_GRE_ERSPAN_VER, erspan_ver);

		if (erspan_ver == 1 && erspan_idx != 0) {

			addattr32(n, 1024, IFLA_GRE_ERSPAN_INDEX, erspan_idx);

		} else if (erspan_ver == 2) {

			addattr8(n, 1024, IFLA_GRE_ERSPAN_DIR, erspan_dir);

			addattr16(n, 1024, IFLA_GRE_ERSPAN_HWID, erspan_hwid);

		}

	}

	addattr16(n, 1024, IFLA_GRE_ENCAP_TYPE, encaptype);

	addattr16(n, 1024, IFLA_GRE_ENCAP_FLAGS, encapflags);

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

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

	return 0;

}

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

{

	char s2[64];

	__u16 iflags = 0;

	__u16 oflags = 0;

	__u8 ttl = 0;

	__u8 tos = 0;

	if (!tb)

		return;

	if (tb[IFLA_GRE_COLLECT_METADATA]) {

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

		return;

	}

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

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

	if (tb[IFLA_GRE_LINK]) {

		__u32 link = rta_getattr_u32(tb[IFLA_GRE_LINK]);

		if (link) {

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

				     ll_index_to_name(link));

		}

	}

	if (tb[IFLA_GRE_TTL])

		ttl = rta_getattr_u8(tb[IFLA_GRE_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_GRE_TOS])

		tos = rta_getattr_u8(tb[IFLA_GRE_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_GRE_PMTUDISC]) {

		if (!rta_getattr_u8(tb[IFLA_GRE_PMTUDISC]))

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

		else

			print_bool(PRINT_JSON, "pmtudisc", NULL, true);

	}

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

		print_bool(PRINT_ANY, "ignore_df", "ignore-df ", true);

	if (tb[IFLA_GRE_IFLAGS])

		iflags = rta_getattr_u16(tb[IFLA_GRE_IFLAGS]);

	if (tb[IFLA_GRE_OFLAGS])

		oflags = rta_getattr_u16(tb[IFLA_GRE_OFLAGS]);

	if ((iflags & GRE_KEY) && tb[IFLA_GRE_IKEY]) {

		inet_ntop(AF_INET, RTA_DATA(tb[IFLA_GRE_IKEY]), s2, sizeof(s2));

		print_string(PRINT_ANY, "ikey", "ikey %s ", s2);

	}

	if ((oflags & GRE_KEY) && tb[IFLA_GRE_OKEY]) {

		inet_ntop(AF_INET, RTA_DATA(tb[IFLA_GRE_OKEY]), s2, sizeof(s2));

		print_string(PRINT_ANY, "okey", "okey %s ", s2);

	}

	if (iflags & GRE_SEQ)

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

	if (oflags & GRE_SEQ)

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

	if (iflags & GRE_CSUM)

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

	if (oflags & GRE_CSUM)

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

	if (tb[IFLA_GRE_FWMARK]) {

		__u32 fwmark = rta_getattr_u32(tb[IFLA_GRE_FWMARK]);

		if (fwmark) {

			print_0xhex(PRINT_ANY,

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

		}

	}

	if (tb[IFLA_GRE_ERSPAN_INDEX]) {

		__u32 erspan_idx = rta_getattr_u32(tb[IFLA_GRE_ERSPAN_INDEX]);

		print_uint(PRINT_ANY,

			   "erspan_index", "erspan_index %u ", erspan_idx);

	}

	if (tb[IFLA_GRE_ERSPAN_VER]) {

		__u8 erspan_ver = rta_getattr_u8(tb[IFLA_GRE_ERSPAN_VER]);

		print_uint(PRINT_ANY,

			   "erspan_ver", "erspan_ver %u ", erspan_ver);

	}

	if (tb[IFLA_GRE_ERSPAN_DIR]) {

		__u8 erspan_dir = rta_getattr_u8(tb[IFLA_GRE_ERSPAN_DIR]);

		if (erspan_dir == 0)

			print_string(PRINT_ANY, "erspan_dir",

				     "erspan_dir ingress ", NULL);

		else

			print_string(PRINT_ANY, "erspan_dir",

				     "erspan_dir egress ", NULL);

	}

	if (tb[IFLA_GRE_ERSPAN_HWID]) {

		__u16 erspan_hwid = rta_getattr_u16(tb[IFLA_GRE_ERSPAN_HWID]);

		print_0xhex(PRINT_ANY,

			    "erspan_hwid", "erspan_hwid %#llx ", erspan_hwid);

	}

	tnl_print_encap(tb,

			IFLA_GRE_ENCAP_TYPE,

			IFLA_GRE_ENCAP_FLAGS,

			IFLA_GRE_ENCAP_SPORT,

			IFLA_GRE_ENCAP_DPORT);

}

struct link_util gre_link_util = {

	.id = "gre",

	.maxattr = IFLA_GRE_MAX,

	.parse_opt = gre_parse_opt,

	.print_opt = gre_print_opt,

	.print_help = gre_print_help,

};

struct link_util gretap_link_util = {

	.id = "gretap",

	.maxattr = IFLA_GRE_MAX,

	.parse_opt = gre_parse_opt,

	.print_opt = gre_print_opt,

	.print_help = gre_print_help,

};

struct link_util erspan_link_util = {

	.id = "erspan",

	.maxattr = IFLA_GRE_MAX,

	.parse_opt = gre_parse_opt,

	.print_opt = gre_print_opt,

	.print_help = gre_print_help,

};