1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __LINUX_PIM_H
3#define __LINUX_PIM_H
4
5#include <linux/skbuff.h>
6#include <asm/byteorder.h>
7
8/* Message types - V1 */
9#define PIM_V1_VERSION		cpu_to_be32(0x10000000)
10#define PIM_V1_REGISTER		1
11
12/* Message types - V2 */
13#define PIM_VERSION		2
14
15/* RFC7761, sec 4.9:
16 *  Type
17 *        Types for specific PIM messages.  PIM Types are:
18 *
19 *  Message Type                          Destination
20 *  ---------------------------------------------------------------------
21 *  0 = Hello                             Multicast to ALL-PIM-ROUTERS
22 *  1 = Register                          Unicast to RP
23 *  2 = Register-Stop                     Unicast to source of Register
24 *                                        packet
25 *  3 = Join/Prune                        Multicast to ALL-PIM-ROUTERS
26 *  4 = Bootstrap                         Multicast to ALL-PIM-ROUTERS
27 *  5 = Assert                            Multicast to ALL-PIM-ROUTERS
28 *  6 = Graft (used in PIM-DM only)       Unicast to RPF'(S)
29 *  7 = Graft-Ack (used in PIM-DM only)   Unicast to source of Graft
30 *                                        packet
31 *  8 = Candidate-RP-Advertisement        Unicast to Domain's BSR
32 */
33enum {
34	PIM_TYPE_HELLO,
35	PIM_TYPE_REGISTER,
36	PIM_TYPE_REGISTER_STOP,
37	PIM_TYPE_JOIN_PRUNE,
38	PIM_TYPE_BOOTSTRAP,
39	PIM_TYPE_ASSERT,
40	PIM_TYPE_GRAFT,
41	PIM_TYPE_GRAFT_ACK,
42	PIM_TYPE_CANDIDATE_RP_ADV
43};
44
45#define PIM_NULL_REGISTER	cpu_to_be32(0x40000000)
46
47/* RFC7761, sec 4.9:
48 * The PIM header common to all PIM messages is:
49 *   0                   1                   2                   3
50 *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
51 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
52 *  |PIM Ver| Type  |   Reserved    |           Checksum            |
53 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
54 */
55struct pimhdr {
56	__u8	type;
57	__u8	reserved;
58	__be16	csum;
59};
60
61/* PIMv2 register message header layout (ietf-draft-idmr-pimvsm-v2-00.ps */
62struct pimreghdr {
63	__u8	type;
64	__u8	reserved;
65	__be16	csum;
66	__be32	flags;
67};
68
69int pim_rcv_v1(struct sk_buff *skb);
70
71static inline bool ipmr_pimsm_enabled(void)
72{
73	return IS_BUILTIN(CONFIG_IP_PIMSM_V1) || IS_BUILTIN(CONFIG_IP_PIMSM_V2);
74}
75
76static inline struct pimhdr *pim_hdr(const struct sk_buff *skb)
77{
78	return (struct pimhdr *)skb_transport_header(skb);
79}
80
81static inline u8 pim_hdr_version(const struct pimhdr *pimhdr)
82{
83	return pimhdr->type >> 4;
84}
85
86static inline u8 pim_hdr_type(const struct pimhdr *pimhdr)
87{
88	return pimhdr->type & 0xf;
89}
90
91/* check if the address is 224.0.0.13, RFC7761 sec 4.3.1 */
92static inline bool pim_ipv4_all_pim_routers(__be32 addr)
93{
94	return addr == htonl(0xE000000D);
95}
96#endif
97