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 "log.h"
26
27#include "pim_util.h"
28
29/*
30  RFC 3376: 4.1.7. QQIC (Querier's Query Interval Code)
31
32  If QQIC < 128,  QQI = QQIC
33  If QQIC >= 128, QQI = (mant | 0x10) << (exp + 3)
34
35  0 1 2 3 4 5 6 7
36  +-+-+-+-+-+-+-+-+
37  |1| exp | mant  |
38  +-+-+-+-+-+-+-+-+
39
40  Since exp=0..7 then (exp+3)=3..10, then QQI has
41  one of the following bit patterns:
42
43  exp=0: QQI = 0000.0000.1MMM.M000
44  exp=1: QQI = 0000.0001.MMMM.0000
45  ...
46  exp=6: QQI = 001M.MMM0.0000.0000
47  exp=7: QQI = 01MM.MM00.0000.0000
48  --------- ---------
49  0x4  0x0  0x0  0x0
50*/
51uint8_t igmp_msg_encode16to8(uint16_t value)
52{
53  uint8_t code;
54
55  if (value < 128) {
56    code = value;
57  }
58  else {
59    uint16_t mask = 0x4000;
60    uint8_t  exp;
61    uint16_t mant;
62    for (exp = 7; exp > 0; --exp) {
63      if (mask & value)
64	break;
65      mask >>= 1;
66    }
67    mant = 0x000F & (value >> (exp + 3));
68    code = ((uint8_t) 1 << 7) | ((uint8_t) exp << 4) | (uint8_t) mant;
69  }
70
71  return code;
72}
73
74/*
75  RFC 3376: 4.1.7. QQIC (Querier's Query Interval Code)
76
77  If QQIC < 128,  QQI = QQIC
78  If QQIC >= 128, QQI = (mant | 0x10) << (exp + 3)
79
80  0 1 2 3 4 5 6 7
81  +-+-+-+-+-+-+-+-+
82  |1| exp | mant  |
83  +-+-+-+-+-+-+-+-+
84*/
85uint16_t igmp_msg_decode8to16(uint8_t code)
86{
87  uint16_t value;
88
89  if (code < 128) {
90    value = code;
91  }
92  else {
93    uint16_t mant = (code & 0x0F);
94    uint8_t  exp  = (code & 0x70) >> 4;
95    value = (mant | 0x10) << (exp + 3);
96  }
97
98  return value;
99}
100
101void pim_pkt_dump(const char *label, const uint8_t *buf, int size)
102{
103  char dump_buf[1000];
104  int i = 0;
105  int j = 0;
106
107  for (; i < size; ++i, j += 2) {
108    int left = sizeof(dump_buf) - j;
109    if (left < 4) {
110      if (left > 1) {
111	strcat(dump_buf + j, "!"); /* mark as truncated */
112      }
113      break;
114    }
115    snprintf(dump_buf + j, left, "%02x", buf[i]);
116  }
117
118  zlog_debug("%s: pkt dump size=%d: %s",
119	     label,
120	     size,
121	     dump_buf);
122}
123