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
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
76 static inline struct pimhdr *pim_hdr(const struct sk_buff *skb)
77 {
78 return (struct pimhdr *)skb_transport_header(skb);
79 }
80
81 static inline u8 pim_hdr_version(const struct pimhdr *pimhdr)
82 {
83 return pimhdr->type >> 4;
84 }
85
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 */
92 static inline bool pim_ipv4_all_pim_routers(__be32 addr)
93 {
94 return addr == htonl(0xE000000D);
95 }
96 #endif