master
  1/*-
  2 * SPDX-License-Identifier: BSD-2-Clause
  3 *
  4 * Copyright (c) 2022 Alexander V. Chernikov <melifaro@FreeBSD.org>
  5 *
  6 * Redistribution and use in source and binary forms, with or without
  7 * modification, are permitted provided that the following conditions
  8 * are met:
  9 * 1. Redistributions of source code must retain the above copyright
 10 *    notice, this list of conditions and the following disclaimer.
 11 * 2. Redistributions in binary form must reproduce the above copyright
 12 *    notice, this list of conditions and the following disclaimer in the
 13 *    documentation and/or other materials provided with the distribution.
 14 *
 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 25 * SUCH DAMAGE.
 26 */
 27#ifndef	_NETLINK_NETLINK_SNL_GENERIC_H_
 28#define	_NETLINK_NETLINK_SNL_GENERIC_H_
 29
 30#include <netlink/netlink.h>
 31#include <netlink/netlink_generic.h>
 32#include <netlink/netlink_snl.h>
 33
 34/* Genetlink helpers */
 35static inline struct nlmsghdr *
 36snl_create_genl_msg_request(struct snl_writer *nw, int genl_family, uint8_t genl_cmd)
 37{
 38	assert(nw->hdr == NULL);
 39
 40	struct nlmsghdr *hdr = snl_reserve_msg_object(nw, struct nlmsghdr);
 41	hdr->nlmsg_type = genl_family;
 42	hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
 43	nw->hdr = hdr;
 44	struct genlmsghdr *ghdr = snl_reserve_msg_object(nw, struct genlmsghdr);
 45	ghdr->cmd = genl_cmd;
 46
 47	return (hdr);
 48}
 49
 50static struct snl_field_parser snl_fp_genl[] = {};
 51
 52#define	SNL_DECLARE_GENL_PARSER(_name, _np)	SNL_DECLARE_PARSER(_name,\
 53    struct genlmsghdr, snl_fp_genl, _np)
 54
 55struct snl_genl_ctrl_mcast_group {
 56	uint32_t mcast_grp_id;
 57	char *mcast_grp_name;
 58};
 59
 60struct snl_genl_ctrl_mcast_groups {
 61	uint32_t num_groups;
 62	struct snl_genl_ctrl_mcast_group **groups;
 63};
 64
 65#define	_OUT(_field)	offsetof(struct snl_genl_ctrl_mcast_group, _field)
 66static struct snl_attr_parser _nla_p_getmc[] = {
 67	{ .type = CTRL_ATTR_MCAST_GRP_NAME, .off = _OUT(mcast_grp_name), .cb = snl_attr_get_string },
 68	{ .type = CTRL_ATTR_MCAST_GRP_ID, .off = _OUT(mcast_grp_id), .cb = snl_attr_get_uint32 },
 69};
 70#undef _OUT
 71SNL_DECLARE_ATTR_PARSER_EXT(_genl_ctrl_mc_parser,
 72		sizeof(struct snl_genl_ctrl_mcast_group),
 73		_nla_p_getmc, NULL);
 74
 75struct _getfamily_attrs {
 76	uint16_t family_id;
 77	char	*family_name;
 78	struct snl_genl_ctrl_mcast_groups mcast_groups;
 79};
 80
 81#define	_IN(_field)	offsetof(struct genlmsghdr, _field)
 82#define	_OUT(_field)	offsetof(struct _getfamily_attrs, _field)
 83static struct snl_attr_parser _nla_p_getfam[] = {
 84	{ .type = CTRL_ATTR_FAMILY_ID , .off = _OUT(family_id), .cb = snl_attr_get_uint16 },
 85	{ .type = CTRL_ATTR_FAMILY_NAME, .off = _OUT(family_name), .cb = snl_attr_get_string },
 86	{
 87		.type = CTRL_ATTR_MCAST_GROUPS,
 88		.off = _OUT(mcast_groups),
 89		.cb = snl_attr_get_parray,
 90		.arg = &_genl_ctrl_mc_parser,
 91	},
 92};
 93#undef _IN
 94#undef _OUT
 95SNL_DECLARE_GENL_PARSER(_genl_ctrl_getfam_parser, _nla_p_getfam);
 96
 97static bool
 98snl_get_genl_family_info(struct snl_state *ss, const char *family_name,
 99    struct _getfamily_attrs *attrs)
100{
101	struct snl_writer nw;
102	struct nlmsghdr *hdr;
103
104	memset(attrs, 0, sizeof(*attrs));
105
106	snl_init_writer(ss, &nw);
107	hdr = snl_create_genl_msg_request(&nw, GENL_ID_CTRL, CTRL_CMD_GETFAMILY);
108	snl_add_msg_attr_string(&nw, CTRL_ATTR_FAMILY_NAME, family_name);
109	if ((hdr = snl_finalize_msg(&nw)) == NULL || !snl_send_message(ss, hdr))
110		return (false);
111
112	hdr = snl_read_reply(ss, hdr->nlmsg_seq);
113	if (hdr != NULL && hdr->nlmsg_type != NLMSG_ERROR) {
114		if (snl_parse_nlmsg(ss, hdr, &_genl_ctrl_getfam_parser, attrs))
115			return (true);
116	}
117
118	return (false);
119}
120
121static inline uint16_t
122snl_get_genl_family(struct snl_state *ss, const char *family_name)
123{
124	struct _getfamily_attrs attrs = {};
125
126	snl_get_genl_family_info(ss, family_name, &attrs);
127	return (attrs.family_id);
128}
129
130static const struct snl_hdr_parser *snl_all_genl_parsers[] = {
131	&_genl_ctrl_getfam_parser, &_genl_ctrl_mc_parser,
132};
133
134#endif