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  */
33 enum {
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  */
55 struct 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 */
62 struct pimreghdr {
63 	__u8	type;
64 	__u8	reserved;
65 	__be16	csum;
66 	__be32	flags;
67 };
68 
69 int pim_rcv_v1(struct sk_buff *skb);
70 
ipmr_pimsm_enabled(void)71 static inline bool ipmr_pimsm_enabled(void)
72 {
73 	return IS_BUILTIN(CONFIG_IP_PIMSM_V1) || IS_BUILTIN(CONFIG_IP_PIMSM_V2);
74 }
75 
pim_hdr(const struct sk_buff * skb)76 static inline struct pimhdr *pim_hdr(const struct sk_buff *skb)
77 {
78 	return (struct pimhdr *)skb_transport_header(skb);
79 }
80 
pim_hdr_version(const struct pimhdr * pimhdr)81 static inline u8 pim_hdr_version(const struct pimhdr *pimhdr)
82 {
83 	return pimhdr->type >> 4;
84 }
85 
pim_hdr_type(const struct pimhdr * pimhdr)86 static 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 */
pim_ipv4_all_pim_routers(__be32 addr)92 static inline bool pim_ipv4_all_pim_routers(__be32 addr)
93 {
94 	return addr == htonl(0xE000000D);
95 }
96 #endif
97