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
28#ifndef _NETLINK_NETLINK_CTL_H_
29#define _NETLINK_NETLINK_CTL_H_
30
31#ifdef _KERNEL
32/*
33 * This file provides headers for the public KPI of the netlink
34 * subsystem
35 */
36#include <sys/_eventhandler.h>
37
38MALLOC_DECLARE(M_NETLINK);
39
40/*
41 * Macro for handling attribute TLVs
42 */
43#define _roundup2(x, y)         (((x)+((y)-1))&(~((y)-1)))
44
45#define NETLINK_ALIGN_SIZE      sizeof(uint32_t)
46#define NETLINK_ALIGN(_len)     _roundup2(_len, NETLINK_ALIGN_SIZE)
47
48#define NLA_ALIGN_SIZE          sizeof(uint32_t)
49#define NLA_ALIGN(_len)         _roundup2(_len, NLA_ALIGN_SIZE)
50#define	NLA_HDRLEN		((int)sizeof(struct nlattr))
51#define	NLA_DATA_LEN(_nla)	((int)((_nla)->nla_len - NLA_HDRLEN))
52#define	NLA_DATA(_nla)		NL_ITEM_DATA(_nla, NLA_HDRLEN)
53#define	NLA_DATA_CONST(_nla)	NL_ITEM_DATA_CONST(_nla, NLA_HDRLEN)
54#define	NLA_TYPE(_nla)		((_nla)->nla_type & 0x3FFF)
55
56#ifndef	typeof
57#define	typeof	__typeof
58#endif
59
60#define NLA_NEXT(_attr) (struct nlattr *)((char *)_attr + NLA_ALIGN(_attr->nla_len))
61#define	_NLA_END(_start, _len)	((char *)(_start) + (_len))
62#define NLA_FOREACH(_attr, _start, _len)      \
63        for (typeof(_attr) _end = (typeof(_attr))_NLA_END(_start, _len), _attr = (_start);		\
64		((char *)_attr < (char *)_end) && \
65		((char *)NLA_NEXT(_attr) <= (char *)_end);	\
66		_attr = (_len -= NLA_ALIGN(_attr->nla_len), NLA_NEXT(_attr)))
67
68#define	NL_ARRAY_LEN(_a)	(sizeof(_a) / sizeof((_a)[0]))
69
70#include <netlink/netlink_message_writer.h>
71#include <netlink/netlink_message_parser.h>
72
73
74/* Protocol handlers */
75struct nl_pstate;
76typedef int (*nl_handler_f)(struct nlmsghdr *hdr, struct nl_pstate *npt);
77
78bool netlink_register_proto(int proto, const char *proto_name, nl_handler_f handler);
79bool netlink_unregister_proto(int proto);
80
81/* Common helpers */
82bool nl_has_listeners(int netlink_family, uint32_t groups_mask);
83bool nlp_has_priv(struct nlpcb *nlp, int priv);
84struct ucred *nlp_get_cred(struct nlpcb *nlp);
85uint32_t nlp_get_pid(const struct nlpcb *nlp);
86bool nlp_unconstrained_vnet(const struct nlpcb *nlp);
87
88/* netlink_generic.c */
89struct genl_cmd {
90	const char	*cmd_name;
91	nl_handler_f	cmd_cb;
92	uint32_t	cmd_flags;
93	uint32_t	cmd_priv;
94	uint32_t	cmd_num;
95};
96
97uint32_t genl_register_family(const char *family_name, size_t hdrsize,
98    int family_version, int max_attr_idx);
99bool genl_unregister_family(const char *family_name);
100bool genl_register_cmds(const char *family_name, const struct genl_cmd *cmds,
101    int count);
102uint32_t genl_register_group(const char *family_name, const char *group_name);
103
104struct genl_family;
105const char *genl_get_family_name(const struct genl_family *gf);
106uint32_t genl_get_family_id(const struct genl_family *gf);
107
108typedef void (*genl_family_event_handler_t)(void *arg, const struct genl_family *gf, int action);
109EVENTHANDLER_DECLARE(genl_family_event, genl_family_event_handler_t);
110
111struct thread;
112#if defined(NETLINK) || defined(NETLINK_MODULE)
113/* Provide optimized calls to the functions inside the same linking unit */
114struct nlpcb *_nl_get_thread_nlp(struct thread *td);
115
116static inline struct nlpcb *
117nl_get_thread_nlp(struct thread *td)
118{
119	return (_nl_get_thread_nlp(td));
120}
121
122#else
123/* Provide access to the functions via netlink_glue.c */
124struct nlpcb *nl_get_thread_nlp(struct thread *td);
125
126#endif /* defined(NETLINK) || defined(NETLINK_MODULE) */
127
128#endif
129#endif
130