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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 | ||
21 | #include <zebra.h> | |
22 | ||
23 | #include "log.h" | |
24 | ||
25 | #include "pim_util.h" | |
26 | ||
27 | /* | |
28 | RFC 3376: 4.1.7. QQIC (Querier's Query Interval Code) | |
29 | ||
30 | If QQIC < 128, QQI = QQIC | |
31 | If QQIC >= 128, QQI = (mant | 0x10) << (exp + 3) | |
32 | ||
33 | 0 1 2 3 4 5 6 7 | |
34 | +-+-+-+-+-+-+-+-+ | |
35 | |1| exp | mant | | |
36 | +-+-+-+-+-+-+-+-+ | |
37 | ||
38 | Since exp=0..7 then (exp+3)=3..10, then QQI has | |
39 | one of the following bit patterns: | |
40 | ||
41 | exp=0: QQI = 0000.0000.1MMM.M000 | |
42 | exp=1: QQI = 0000.0001.MMMM.0000 | |
43 | ... | |
44 | exp=6: QQI = 001M.MMM0.0000.0000 | |
45 | exp=7: QQI = 01MM.MM00.0000.0000 | |
46 | --------- --------- | |
47 | 0x4 0x0 0x0 0x0 | |
48 | */ | |
49 | uint8_t igmp_msg_encode16to8(uint16_t value) | |
50 | { | |
51 | uint8_t code; | |
52 | ||
53 | if (value < 128) { | |
54 | code = value; | |
55 | } | |
56 | else { | |
57 | uint16_t mask = 0x4000; | |
58 | uint8_t exp; | |
59 | uint16_t mant; | |
60 | for (exp = 7; exp > 0; --exp) { | |
61 | if (mask & value) | |
62 | break; | |
63 | mask >>= 1; | |
64 | } | |
65 | mant = 0x000F & (value >> (exp + 3)); | |
66 | code = ((uint8_t) 1 << 7) | ((uint8_t) exp << 4) | (uint8_t) mant; | |
67 | } | |
68 | ||
69 | return code; | |
70 | } | |
71 | ||
72 | /* | |
73 | RFC 3376: 4.1.7. QQIC (Querier's Query Interval Code) | |
74 | ||
75 | If QQIC < 128, QQI = QQIC | |
76 | If QQIC >= 128, QQI = (mant | 0x10) << (exp + 3) | |
77 | ||
78 | 0 1 2 3 4 5 6 7 | |
79 | +-+-+-+-+-+-+-+-+ | |
80 | |1| exp | mant | | |
81 | +-+-+-+-+-+-+-+-+ | |
82 | */ | |
83 | uint16_t igmp_msg_decode8to16(uint8_t code) | |
84 | { | |
85 | uint16_t value; | |
86 | ||
87 | if (code < 128) { | |
88 | value = code; | |
89 | } | |
90 | else { | |
91 | uint16_t mant = (code & 0x0F); | |
92 | uint8_t exp = (code & 0x70) >> 4; | |
93 | value = (mant | 0x10) << (exp + 3); | |
94 | } | |
95 | ||
96 | return value; | |
97 | } | |
98 | ||
99 | void pim_pkt_dump(const char *label, const uint8_t *buf, int size) | |
100 | { | |
101 | zlog_debug("%s: pkt dump size=%d", | |
102 | label, | |
103 | size); | |
104 | zlog_hexdump(buf, size); | |
105 | } |