1/*
2  PIM for Quagga
3  Copyright (C) 2008  Everton da Silva Marques
4
5  This program is free software; you can redistribute it and/or modify
6  it under the terms of the GNU General Public License as published by
7  the Free Software Foundation; either version 2 of the License, or
8  (at your option) any later version.
9
10  This program is distributed in the hope that it will be useful, but
11  WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  General Public License for more details.
14
15  You should have received a copy of the GNU General Public License
16  along with this program; see the file COPYING; if not, write to the
17  Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
18  MA 02110-1301 USA
19
20  $QuaggaId: $Format:%an, %ai, %h$ $
21*/
22
23#include <zebra.h>
24
25#include "pimd.h"
26#include "pim_pim.h"
27#include "pim_msg.h"
28#include "pim_util.h"
29
30void pim_msg_build_header(uint8_t *pim_msg, int pim_msg_size,
31			  uint8_t pim_msg_type)
32{
33  uint16_t checksum;
34
35  zassert(pim_msg_size >= PIM_PIM_MIN_LEN);
36
37  /*
38   * Write header
39   */
40
41  *(uint8_t *) PIM_MSG_HDR_OFFSET_VERSION(pim_msg) = (PIM_PROTO_VERSION << 4) | pim_msg_type;
42  *(uint8_t *) PIM_MSG_HDR_OFFSET_RESERVED(pim_msg) = 0;
43
44  /*
45   * Compute checksum
46   */
47
48  *(uint16_t *) PIM_MSG_HDR_OFFSET_CHECKSUM(pim_msg) = 0;
49  checksum = in_cksum(pim_msg, pim_msg_size);
50  *(uint16_t *) PIM_MSG_HDR_OFFSET_CHECKSUM(pim_msg) = checksum;
51}
52
53uint8_t *pim_msg_addr_encode_ipv4_ucast(uint8_t *buf,
54					int buf_size,
55					struct in_addr addr)
56{
57  const int ENCODED_IPV4_UCAST_SIZE = 6;
58
59  if (buf_size < ENCODED_IPV4_UCAST_SIZE) {
60    return 0;
61  }
62
63  buf[0] = PIM_MSG_ADDRESS_FAMILY_IPV4; /* addr family */
64  buf[1] = '\0';    /* native encoding */
65  memcpy(buf+2, &addr, sizeof(struct in_addr));
66
67  return buf + ENCODED_IPV4_UCAST_SIZE;
68}
69
70uint8_t *pim_msg_addr_encode_ipv4_group(uint8_t *buf,
71					int buf_size,
72					struct in_addr addr)
73{
74  const int ENCODED_IPV4_GROUP_SIZE = 8;
75
76  if (buf_size < ENCODED_IPV4_GROUP_SIZE) {
77    return 0;
78  }
79
80  buf[0] = PIM_MSG_ADDRESS_FAMILY_IPV4; /* addr family */
81  buf[1] = '\0';    /* native encoding */
82  buf[2] = '\0';    /* reserved */
83  buf[3] = 32;      /* mask len */
84  memcpy(buf+4, &addr, sizeof(struct in_addr));
85
86  return buf + ENCODED_IPV4_GROUP_SIZE;
87}
88
89uint8_t *pim_msg_addr_encode_ipv4_source(uint8_t *buf,
90					 int buf_size,
91					 struct in_addr addr)
92{
93  const int ENCODED_IPV4_SOURCE_SIZE = 8;
94
95  if (buf_size < ENCODED_IPV4_SOURCE_SIZE) {
96    return 0;
97  }
98
99  buf[0] = PIM_MSG_ADDRESS_FAMILY_IPV4; /* addr family */
100  buf[1] = '\0';    /* native encoding */
101  buf[2] = 4;       /* reserved = 0 | S bit = 1 | W bit = 0 | R bit = 0 */
102  buf[3] = 32;      /* mask len */
103  memcpy(buf+4, &addr, sizeof(struct in_addr));
104
105  return buf + ENCODED_IPV4_SOURCE_SIZE;
106}
107