1/*
2 * Copyright (c) 2017 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29#include <netinet/in_stat.h>
30
31#define IN_STAT_ACTIVITY_GRANULARITY 8 /* 8 sec granularity */
32#define IN_STAT_ACTIVITY_TIME_SEC_SHIFT 3 /* 8 sec per bit */
33#define IN_STAT_ACTIVITY_BITMAP_TOTAL_SIZE ((uint64_t) 128)
34#define IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE ((uint64_t) 64)
35#define IN_STAT_ACTIVITY_TOTAL_TIME ((uint64_t) (8 * 128))
36#define IN_STAT_SET_MOST_SIGNIFICANT_BIT ((u_int64_t )0x8000000000000000)
37
38void
39in_stat_set_activity_bitmap(activity_bitmap_t *activity, uint64_t now)
40{
41 uint64_t elapsed_time, slot;
42 uint64_t *bitmap;
43 if (activity->start == 0)
44 activity->start = now;
45 elapsed_time = now - activity->start;
46
47 slot = elapsed_time >> IN_STAT_ACTIVITY_TIME_SEC_SHIFT;
48 if (slot < IN_STAT_ACTIVITY_BITMAP_TOTAL_SIZE) {
49 if (slot < IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE) {
50 bitmap = &activity->bitmap[0];
51 } else {
52 bitmap = &activity->bitmap[1];
53 slot -= IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE;
54 }
55 *bitmap |= (((u_int64_t) 1) << slot);
56 } else {
57 if (slot >= (IN_STAT_ACTIVITY_BITMAP_TOTAL_SIZE * 2)) {
58 activity->start = now - IN_STAT_ACTIVITY_TOTAL_TIME;
59 activity->bitmap[0] = activity->bitmap[1] = 0;
60 } else {
61 uint64_t shift =
62 slot - (IN_STAT_ACTIVITY_BITMAP_TOTAL_SIZE - 1);
63 /*
64 * Move the start time and bitmap forward to
65 * cover the lost time
66 */
67 activity->start +=
68 (shift << IN_STAT_ACTIVITY_TIME_SEC_SHIFT);
69 if (shift > IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE) {
70 activity->bitmap[0] = activity->bitmap[1];
71 activity->bitmap[1] = 0;
72 shift -= IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE;
73 if (shift == IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE)
74 activity->bitmap[0] = 0;
75 else
76 activity->bitmap[0] >>= shift;
77 } else {
78 uint64_t mask_lower, tmp;
79 uint64_t b1_low, b0_high;
80
81 /*
82 * generate a mask with all of lower
83 * 'shift' bits set
84 */
85 tmp = (((uint64_t)1) << (shift - 1));
86 mask_lower = ((tmp - 1) ^ tmp);
87 activity->bitmap[0] >>= shift;
88 b1_low = (activity->bitmap[1] & mask_lower);
89
90 b0_high = (b1_low <<
91 (IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE -
92 shift));
93 activity->bitmap[0] |= b0_high;
94 activity->bitmap[1] >>= shift;
95 }
96 }
97 activity->bitmap[1] |= IN_STAT_SET_MOST_SIGNIFICANT_BIT;
98 }
99}
100