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#include <camellia.h>
#include <camellia/flags.h>
#include <camellia/fs/misc.h>
#include <camellia/fsutil.h>
#include <camellia/syscalls.h>
#include <err.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <unistd.h>
// TODO put that in the libc somewhere
#include "netstack/util.h"
enum {
PacketSize = 12 * 4, /* 12 words */
ClientMode = 3,
NtpV4 = 4 << 3,
TxTimestamp = 40,
};
uint64_t offset = 0;
uint64_t
getntptime(const char *addr)
{
char packet[PacketSize] = {0};
packet[0] |= ClientMode;
packet[0] |= NtpV4;
hid_t h = camellia_open(addr, OPEN_READ | OPEN_WRITE);
if (h < 0) {
warn("open %s", addr);
return 0;
}
if (write(h, packet, PacketSize) != PacketSize) {
warnx("partial write");
close(h);
return 0;
}
ssize_t ret = read(h, packet, PacketSize);
if (ret != PacketSize) {
warnx("partial read");
close(h);
return 0;
}
return nget64(packet + TxTimestamp);
}
/* Converts an NTP timestamp to the amount of nanoseconds (10^-9) since the
* Unix epoch. */
uint64_t
ntp2unix(uint64_t ntp)
{
uint64_t seconds = (ntp >> 32) - 2208988800;
uint64_t frac = ntp & 0xFFFFFFFF;
uint64_t prec = 1000000000;
return seconds * prec + ((frac * prec) >> 32);
}
int
main(int argc, const char *argv[])
{
if (argc != 2) {
errx(1, "bad usage");
}
// TODO: error checking, once i actually implement timeouts
uint64_t ntpt = getntptime(argv[1]);
uint64_t unixt = ntp2unix(ntpt);
offset = unixt - _sys_time(0);
char buf[256];
int len;
struct ufs_request req;
hid_t reqh;
while ((reqh = ufs_wait(buf, sizeof(buf), &req))) {
switch (req.op) {
case VFSOP_OPEN:
if (req.len == 0 && !OPEN_WRITEABLE(req.flags)) {
_sys_fs_respond(reqh, NULL, 0, 0);
} else {
_sys_fs_respond(reqh, NULL, -EGENERIC, 0);
}
break;
case VFSOP_READ:
len = snprintf(buf, sizeof(buf), "%lu\n", _sys_time(0) + offset);
if (0 <= len && len < (int)sizeof(buf)) {
fs_normslice(&req.offset, &req.len, len, false);
_sys_fs_respond(reqh, buf + req.offset, req.len, 0);
} else {
_sys_fs_respond(reqh, NULL, -EGENERIC, 0);
}
break;
default:
_sys_fs_respond(reqh, NULL, -ENOSYS, 0);
break;
}
}
}
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