1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
/* ISC license. */
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include <skalibs/error.h>
#include <skalibs/uint16.h>
#include <skalibs/uint32.h>
#include <skalibs/uint.h>
#include <skalibs/sgetopt.h>
#include <skalibs/allreadwrite.h>
#include <skalibs/bytestr.h>
#include <skalibs/error.h>
#include <skalibs/strerr2.h>
#include <skalibs/tai.h>
#include <skalibs/djbtime.h>
#include <skalibs/iopause.h>
#include <skalibs/allreadwrite.h>
#include <skalibs/socket.h>
#include <skalibs/ip46.h>
#define USAGE "s6-sntpclock [ -f ] [ -v verbosity ] [ -r roundtrips ] [ -t triptimeout ] [ -h throttle ] [ -T totaltimeout ] [ -e errmax ] [ -p port ] ipaddress"
#define dieusage() strerr_dieusage(100, USAGE)
static unsigned int verbosity = 1 ;
int ntp_exchange (int s, ip46_t const *ip, uint16 port, tain_t *stamps, tain_t const *deadline)
{
char query[48] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" ;
char answer[48] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" ;
tain_t starttime ;
uint64 ntpstamp ;
ip46_t dummyip ;
uint16 dummyport ;
int r ;
tain_copynow(&starttime) ;
query[0] = 35 ; /* SNTPv4, client */
if (!ntp_from_tain(&ntpstamp, &starttime)) return 0 ;
uint64_pack_big(query+24, ntpstamp) ;
uint64_pack_big(query+40, ntpstamp) ;
if (verbosity >= 3)
{
char fmtntp[UINT64_XFMT] ;
fmtntp[uint64_xfmt(fmtntp, ntpstamp)] = 0 ;
strerr_warni2x("NTP stamp[0] sent: ", fmtntp) ;
}
r = socket_sendnb46_g(s, query, 48, ip, port, deadline) ;
if (r < 0) return 0 ;
if (r < 48) return (errno = EPIPE, 0) ;
r = socket_recvnb46_g(s, answer, 48, &dummyip, &dummyport, deadline) ;
if (r < 0) return 0 ;
if (r < 48) return (errno = EPROTO, 0) ;
if (((answer[0] & 7) != 2) && ((answer[0] & 7) != 4)) return (errno = EPROTO, 0) ;
if (!(answer[0] & 56)) return (errno = EPROTO, 0) ;
if (byte_diff(query+40, 8, answer+24)) return (errno = EPROTO, 0) ;
stamps[0] = starttime ;
uint64_unpack_big(answer+32, &ntpstamp) ;
tain_from_ntp(stamps+1, ntpstamp) ;
if (verbosity >= 3)
{
char fmtntp[UINT64_XFMT] ;
fmtntp[uint64_xfmt(fmtntp, ntpstamp)] = 0 ;
strerr_warni2x("NTP stamp[1] received: ", fmtntp) ;
}
uint64_unpack_big(answer+40, &ntpstamp) ;
tain_from_ntp(stamps+2, ntpstamp) ;
if (verbosity >= 3)
{
char fmtntp[UINT64_XFMT] ;
fmtntp[uint64_xfmt(fmtntp, ntpstamp)] = 0 ;
strerr_warni2x("NTP stamp[2] received: ", fmtntp) ;
}
tain_copynow(&stamps[3]) ;
return 1 ;
}
int main (int argc, char const *const *argv)
{
tain_t deltamin = TAIN_ZERO ;
tain_t deltaoffset ;
tain_t deltamax ;
tain_t errmax ;
tain_t timeouttto, throttletto, globaltto ;
tain_t globaldeadline ;
unsigned int roundtrips = 10 ;
unsigned int i = 0 ;
int sock ;
int flagforce = 0 ;
ip46_t ipremote ;
uint16 portremote = 123 ;
PROG = "s6-sntpclock" ;
{
unsigned int timeout = 2000 ;
unsigned int throttle = 0 ;
unsigned int bigtimeout = 10000 ;
unsigned int emax = 100 ;
subgetopt_t l = SUBGETOPT_ZERO ;
for (;;)
{
register int opt = subgetopt_r(argc, argv, "fv:r:t:h:T:e:p:", &l) ;
if (opt == -1) break ;
switch (opt)
{
case 'f' : flagforce = 1 ; break ;
case 'v' : if (!uint0_scan(l.arg, &verbosity)) dieusage() ; break ;
case 'r' : if (!uint0_scan(l.arg, &roundtrips)) dieusage() ; break ;
case 't' : if (!uint0_scan(l.arg, &timeout)) dieusage() ; break ;
case 'h' : if (!uint0_scan(l.arg, &throttle)) dieusage() ; break ;
case 'T' : if (!uint0_scan(l.arg, &bigtimeout)) dieusage() ; break ;
case 'e' : if (!uint0_scan(l.arg, &emax)) dieusage() ; break ;
case 'p' : if (!uint160_scan(l.arg, &portremote)) dieusage() ; break ;
default : dieusage() ;
}
}
argc -= l.ind ; argv += l.ind ;
if (timeout) tain_from_millisecs(&timeouttto, timeout) ;
else timeouttto = tain_infinite_relative ;
tain_from_millisecs(&throttletto, throttle) ;
if (bigtimeout) tain_from_millisecs(&globaltto, bigtimeout) ;
else globaltto = tain_infinite_relative ;
tain_from_millisecs(&errmax, emax) ;
}
if (!argc) dieusage() ;
if (!ip46_scan(argv[0], &ipremote)) dieusage() ;
sock = socket_udp46(ip46_is6(&ipremote)) ;
if (sock < 0) strerr_diefu1sys(111, "socket_udp") ;
tain_uint(&deltaoffset, 1072224000U) ; /* about 34 years, which is the best we can do with NTP */
tain_add(&deltamax, &deltaoffset, &deltaoffset) ;
tain_now_g() ;
tain_add_g(&globaldeadline, &globaltto) ;
if (!socket_deadlineconnstamp46_g(sock, &ipremote, portremote, &globaldeadline))
strerr_diefu1sys(111, "socket_deadlineconnstamp") ;
for (; i < roundtrips ; i++)
{
tain_t stamps[4] ;
tain_t deadline ;
tain_add_g(&deadline, &timeouttto) ;
if (tain_less(&globaldeadline, &deadline)) deadline = globaldeadline ;
if (verbosity >= 3)
{
char fmt[UINT_FMT] ;
char fmtr[UINT_FMT] ;
fmt[uint_fmt(fmt, i+1)] = 0 ;
fmtr[uint_fmt(fmtr, roundtrips)] = 0 ;
strerr_warni4x("NTP round-trip ", fmt, "/", fmtr) ;
}
if (!ntp_exchange(sock, &ipremote, portremote, stamps, &deadline))
{
if (verbosity >= 2)
{
char fmt[UINT_FMT] ;
char fmtr[UINT_FMT] ;
fmt[uint_fmt(fmt, i+1)] = 0 ;
fmtr[uint_fmt(fmtr, roundtrips)] = 0 ;
strerr_warni5sys("NTP round-trip ", fmt, "/", fmtr, " failed") ;
}
}
else
{
tain_t cur, min, max ;
if (verbosity >= 3)
{
unsigned int j = 0 ;
for (; j < 4 ; j++)
{
uint64 ntp ;
localtmn_t l ;
char fmt[UINT_FMT] ;
char fmtntp[UINT64_XFMT] ;
char fmttaia[TAIN_FMT] ;
char fmtlocal[LOCALTMN_FMT] ;
ntp_from_tain(&ntp, &stamps[j]) ;
localtmn_from_tain(&l, &stamps[j], 1) ;
fmt[uint_fmt(fmt, j)] = 0 ;
fmttaia[tain_fmt(fmttaia, &stamps[j])] = 0 ;
fmtntp[uint64_xfmt(fmtntp, ntp)] = 0 ;
fmtlocal[localtmn_fmt(fmtlocal, &l)] = 0 ;
strerr_warni6x("stamp[", fmt, "] : taia: ", fmttaia, ", ntp: ", fmtntp) ;
strerr_warni2x("localdate: ", fmtlocal) ;
}
}
tain_add(&cur, &stamps[1], &deltaoffset) ;
tain_add(&min, &stamps[0], &deltamin) ;
tain_add(&max, &stamps[0], &deltamax) ;
if (tain_less(&cur, &max) && !tain_less(&cur, &min))
tain_sub(&deltamax, &cur, &stamps[0]) ;
tain_add(&cur, &stamps[2], &deltaoffset) ;
tain_add(&min, &stamps[3], &deltamin) ;
tain_add(&max, &stamps[3], &deltamax) ;
if (tain_less(&cur, &max) && !tain_less(&cur, &min))
tain_sub(&deltamin, &cur, &stamps[3]) ;
}
tain_add_g(&deadline, &throttletto) ;
if (tain_less(&globaldeadline, &deadline)) deadline = globaldeadline ;
deepsleepuntil_g(&deadline) ;
if (!tain_future(&globaldeadline))
{
if (verbosity)
{
errno = ETIMEDOUT ;
strerr_diefu1sys(1, "complete series of SNTP exchanges") ;
}
else return 1 ;
}
}
{
char adj[TAIN_PACK] ;
tain_t delta ;
if (tain_less(&deltamax, &deltamin)) tain_sub(&delta, &deltamin, &deltamax) ;
else tain_sub(&delta, &deltamax, &deltamin) ;
if (tain_less(&errmax, &delta))
{
if (verbosity)
{
char fmtd[TAIN_FMT] ;
char fmte[TAIN_FMT] ;
fmtd[tain_fmt(fmtd, &delta)] = 0 ;
fmte[tain_fmt(fmte, &errmax)] = 0 ;
strerr_warnw2x("maximum acceptable uncertainty: ", fmte) ;
strerr_warnw2x("current calculated uncertainty: ", fmtd) ;
}
if (!flagforce) strerr_dief1x(111, "time uncertainty too large") ;
}
tain_add(&delta, &deltamax, &deltamin) ;
tain_half(&delta, &delta) ;
tain_sub(&delta, &delta, &deltaoffset) ;
tain_pack(adj, &delta) ;
if (allwrite(1, adj, TAIN_PACK) < TAIN_PACK) strerr_diefu1sys(111, "write to stdout") ;
}
return 0 ;
}
|
