1/*
2 * Copyright �� 2018 Alexey Dobriyan <adobriyan@gmail.com>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16#undef NDEBUG
17#include <assert.h>
18#include <errno.h>
19#include <string.h>
20#include <stdlib.h>
21#include <unistd.h>
22#include <time.h>
23
24#include "proc.h"
25
26static uint64_t clock_boottime(void)
27{
28	struct timespec ts;
29	int err;
30
31	err = clock_gettime(CLOCK_BOOTTIME, &ts);
32	assert(err >= 0);
33
34	return (ts.tv_sec * 100) + (ts.tv_nsec / 10000000);
35}
36
37static uint64_t proc_uptime(int fd)
38{
39	uint64_t val1, val2;
40	char buf[64], *p;
41	ssize_t rv;
42
43	/* save "p < end" checks */
44	memset(buf, 0, sizeof(buf));
45	rv = pread(fd, buf, sizeof(buf), 0);
46	assert(0 <= rv && rv <= sizeof(buf));
47	buf[sizeof(buf) - 1] = '\0';
48
49	p = buf;
50
51	val1 = xstrtoull(p, &p);
52	assert(p[0] == '.');
53	assert('0' <= p[1] && p[1] <= '9');
54	assert('0' <= p[2] && p[2] <= '9');
55	assert(p[3] == ' ');
56
57	val2 = (p[1] - '0') * 10 + p[2] - '0';
58
59	return val1 * 100 + val2;
60}
61