Initial commit

1 files changed, 182 insertions, 0 deletions

diff --git a/src/clock/s6-taiclock.c b/src/clock/s6-taiclock.c
new file mode 100644
index 0000000..99150b5
--- /dev/null
+++ b/src/clock/s6-taiclock.c
@@ -0,0 +1,182 @@
+/* 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/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>
+#include <skalibs/random.h>
+
+#define USAGE "s6-taiclock [ -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 ;
+
+#define N 28
+
+int tain_exchange (int s, ip46_t const *ip, uint16 port, tain_t *serversays, tain_t const *deadline)
+{
+  char query[N] = "ctai" ;
+  char answer[N] ;
+  ip46_t dummyip ;
+  int r ;
+  uint16 dummyport ;
+  tain_pack(query+4, &STAMP) ;
+  if (badrandom_string(query+20, N-20) < N-20) return 0 ; /* cookie */
+  r = socket_sendnb46_g(s, query, N, ip, port, deadline) ;
+  if (r < 0) return 0 ;
+  if (r < N) return (errno = EPIPE, 0) ;
+  r = socket_recvnb46_g(s, answer, N, &dummyip, &dummyport, deadline) ;
+  if (r < 0) return 0 ;
+  if (r < N) return (errno = EPROTO, 0) ;
+  if (byte_diff(answer, 4, "stai")) return (errno = EPROTO, 0) ;
+  if (byte_diff(query+20, N-20, answer+20)) return (errno = EPROTO, 0) ;
+  tain_unpack(answer+4, serversays) ;
+  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 ;
+  ip46_t ipremote ;
+  int sock ;
+  int flagforce = 0 ;
+  uint16 portremote = 4014 ;
+  PROG = "s6-taiclock" ;
+
+  {
+    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, 0xffffffffU) ;
+  tain_add(&deltaoffset, &deltaoffset, &deltaoffset) ; /* about 136 years */
+  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 deadline, before, serversays ;
+    tain_add_g(&deadline, &timeouttto) ;
+    if (tain_less(&globaldeadline, &deadline)) deadline = globaldeadline ;
+    tain_copynow(&before) ;
+    if (!tain_exchange(sock, &ipremote, portremote, &serversays, &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("TAIA round-trip ", fmt, "/", fmtr, " failed") ;
+      }
+    }
+    else
+    {
+      tain_t cur, min, max ;
+      tain_add(&cur, &serversays, &deltaoffset) ;
+      tain_add(&min, &before, &deltamin) ;
+      tain_add(&max, &before, &deltamax) ;
+      if (tain_less(&cur, &max) && !tain_less(&cur, &min))
+        tain_sub(&deltamax, &cur, &before) ;
+      tain_add_g(&min, &deltamin) ;
+      tain_add_g(&max, &deltamax) ;
+      if (tain_less(&cur, &max) && !tain_less(&cur, &min))
+        tain_sub(&deltamin, &cur, &STAMP) ;
+    }
+
+    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 TAIA 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 ;
+}