xref: /linux-6.15/include/linux/pim.h (revision aff985fd)
1 #ifndef __LINUX_PIM_H
2 #define __LINUX_PIM_H
3 
4 #include <linux/skbuff.h>
5 #include <asm/byteorder.h>
6 
7 /* Message types - V1 */
8 #define PIM_V1_VERSION		cpu_to_be32(0x10000000)
9 #define PIM_V1_REGISTER		1
10 
11 /* Message types - V2 */
12 #define PIM_VERSION		2
13 
14 /* RFC7761, sec 4.9:
15  *  Type
16  *        Types for specific PIM messages.  PIM Types are:
17  *
18  *  Message Type                          Destination
19  *  ---------------------------------------------------------------------
20  *  0 = Hello                             Multicast to ALL-PIM-ROUTERS
21  *  1 = Register                          Unicast to RP
22  *  2 = Register-Stop                     Unicast to source of Register
23  *                                        packet
24  *  3 = Join/Prune                        Multicast to ALL-PIM-ROUTERS
25  *  4 = Bootstrap                         Multicast to ALL-PIM-ROUTERS
26  *  5 = Assert                            Multicast to ALL-PIM-ROUTERS
27  *  6 = Graft (used in PIM-DM only)       Unicast to RPF'(S)
28  *  7 = Graft-Ack (used in PIM-DM only)   Unicast to source of Graft
29  *                                        packet
30  *  8 = Candidate-RP-Advertisement        Unicast to Domain's BSR
31  */
32 enum {
33 	PIM_TYPE_HELLO,
34 	PIM_TYPE_REGISTER,
35 	PIM_TYPE_REGISTER_STOP,
36 	PIM_TYPE_JOIN_PRUNE,
37 	PIM_TYPE_BOOTSTRAP,
38 	PIM_TYPE_ASSERT,
39 	PIM_TYPE_GRAFT,
40 	PIM_TYPE_GRAFT_ACK,
41 	PIM_TYPE_CANDIDATE_RP_ADV
42 };
43 
44 #define PIM_NULL_REGISTER	cpu_to_be32(0x40000000)
45 
46 /* RFC7761, sec 4.9:
47  * The PIM header common to all PIM messages is:
48  *   0                   1                   2                   3
49  *   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
50  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
51  *  |PIM Ver| Type  |   Reserved    |           Checksum            |
52  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
53  */
54 struct pimhdr {
55 	__u8	type;
56 	__u8	reserved;
57 	__be16	csum;
58 };
59 
60 /* PIMv2 register message header layout (ietf-draft-idmr-pimvsm-v2-00.ps */
61 struct pimreghdr {
62 	__u8	type;
63 	__u8	reserved;
64 	__be16	csum;
65 	__be32	flags;
66 };
67 
68 int pim_rcv_v1(struct sk_buff *skb);
69 
70 static inline bool ipmr_pimsm_enabled(void)
71 {
72 	return IS_BUILTIN(CONFIG_IP_PIMSM_V1) || IS_BUILTIN(CONFIG_IP_PIMSM_V2);
73 }
74 
75 static inline struct pimhdr *pim_hdr(const struct sk_buff *skb)
76 {
77 	return (struct pimhdr *)skb_transport_header(skb);
78 }
79 
80 static inline u8 pim_hdr_version(const struct pimhdr *pimhdr)
81 {
82 	return pimhdr->type >> 4;
83 }
84 
85 static inline u8 pim_hdr_type(const struct pimhdr *pimhdr)
86 {
87 	return pimhdr->type & 0xf;
88 }
89 
90 /* check if the address is 224.0.0.13, RFC7761 sec 4.3.1 */
91 static inline bool pim_ipv4_all_pim_routers(__be32 addr)
92 {
93 	return addr == htonl(0xE000000D);
94 }
95 #endif
96