include/linux/pim.h

   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