[mirror_frr.git] / vrrpd / vrrp_packet.h

/*
 * VRRPD packet crafting
 * Copyright (C) 2018 Cumulus Networks, Inc.
 *               Quentin Young
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */
#include <zebra.h>

#include "memory.h"
#include "ipaddr.h"
#include "prefix.h"

#define VRRP_VERSION 3
#define VRRP_TYPE_ADVERTISEMENT 1

/*
 * Shared header for VRRPv2/v3 packets.
 */
struct vrrp_hdr {
	/*
	 * H  L H  L
	 * 0000 0000
	 * ver  type
	 */
	uint8_t vertype;
	uint8_t vrid;
	uint8_t priority;
	uint8_t naddr;
	union {
		struct {
			uint8_t auth_type;
			/* advertisement interval (in sec) */
			uint8_t adver_int;
		} v2;
		struct {
			/*
			 * advertisement interval (in centiseconds)
			 * H  L H          L
			 * 0000 000000000000
			 * rsvd adver_int
			 */
			uint16_t adver_int;
		} v3;
	};
	uint16_t chksum;
};

struct vrrp_pkt {
	struct vrrp_hdr hdr;
	union {
		struct in_addr v4;
		struct in6_addr v6;
	} addrs[];
} __attribute((packed, aligned(1)));

/*
 * Builds a VRRP packet.
 *
 * pkt
 *    Pointer to store pointer to result buffer in
 *
 * vrid
 *    Virtual Router Identifier
 *
 * prio
 *    Virtual Router Priority
 *
 * max_adver_int
 *    time between ADVERTISEMENTs
 *
 * v6
 *    whether 'ips' is an array of v4 or v6 addresses
 *
 * numip
 *    number of IPvX addresses in 'ips'
 *
 * ips
 *    array of pointer to either struct in_addr (v6 = false) or struct in6_addr
 *    (v6 = true)
 */
ssize_t vrrp_pkt_build(struct vrrp_pkt **pkt, uint8_t vrid, uint8_t prio,
		       uint16_t max_adver_int, uint8_t numip,
		       struct ipaddr **ips);
Commit	Line	Data
5435a2bf QY	1	/*
	2	* VRRPD packet crafting
	3	* Copyright (C) 2018 Cumulus Networks, Inc.
	4	* Quentin Young
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License as published by the Free
	8	* Software Foundation; either version 2 of the License, or (at your option)
	9	* any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful, but WITHOUT
	12	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	13	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	14	* more details.
	15	*
	16	* You should have received a copy of the GNU General Public License along
	17	* with this program; see the file COPYING; if not, write to the Free Software
	18	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	19	*/
	20	#include <zebra.h>
	21
	22	#include "memory.h"
	23	#include "ipaddr.h"
	24	#include "prefix.h"
	25
	26	#define VRRP_VERSION 3
	27	#define VRRP_TYPE_ADVERTISEMENT 1
	28
ef4cc1eb QY	29	/*
	30	* Shared header for VRRPv2/v3 packets.
	31	*/
	32	struct vrrp_hdr {
3eca3857 QY	33	/*
	34	* H L H L
	35	* 0000 0000
	36	* ver type
	37	*/
	38	uint8_t vertype;
5435a2bf QY	39	uint8_t vrid;
5435a2bf QY	40	uint8_t priority;
ef4cc1eb QY	41	uint8_t naddr;
	42	union {
	43	struct {
	44	uint8_t auth_type;
	45	/* advertisement interval (in sec) */
	46	uint8_t adver_int;
	47	} v2;
	48	struct {
3eca3857 QY	49	/*
	50	* advertisement interval (in centiseconds)
	51	* H L H L
	52	* 0000 000000000000
	53	* rsvd adver_int
	54	*/
	55	uint16_t adver_int;
ef4cc1eb QY	56	} v3;
	57	};
	58	uint16_t chksum;
	59	};
	60
	61	struct vrrp_pkt {
	62	struct vrrp_hdr hdr;
5435a2bf QY	63	union {
	64	struct in_addr v4;
	65	struct in6_addr v6;
	66	} addrs[];
	67	} __attribute((packed, aligned(1)));
	68
	69	/*
	70	* Builds a VRRP packet.
3eca3857 QY	71	*
	72	* pkt
	73	* Pointer to store pointer to result buffer in
	74	*
	75	* vrid
	76	* Virtual Router Identifier
	77	*
	78	* prio
	79	* Virtual Router Priority
	80	*
	81	* max_adver_int
	82	* time between ADVERTISEMENTs
	83	*
	84	* v6
	85	* whether 'ips' is an array of v4 or v6 addresses
	86	*
	87	* numip
	88	* number of IPvX addresses in 'ips'
	89	*
	90	* ips
	91	* array of pointer to either struct in_addr (v6 = false) or struct in6_addr
	92	* (v6 = true)
5435a2bf	93	*/
3eca3857	94	ssize_t vrrp_pkt_build(struct vrrp_pkt **pkt, uint8_t vrid, uint8_t prio,
862f2f37 QY	95	uint16_t max_adver_int, uint8_t numip,
862f2f37 QY	96	struct ipaddr **ips);