rtime.c 4.0 KB

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  1. /*
  2. * Copyright (c) 2010, Oracle America, Inc.
  3. *
  4. * Redistribution and use in source and binary forms, with or without
  5. * modification, are permitted provided that the following conditions are
  6. * met:
  7. *
  8. * * Redistributions of source code must retain the above copyright
  9. * notice, this list of conditions and the following disclaimer.
  10. * * Redistributions in binary form must reproduce the above
  11. * copyright notice, this list of conditions and the following
  12. * disclaimer in the documentation and/or other materials
  13. * provided with the distribution.
  14. * * Neither the name of the "Oracle America, Inc." nor the names of its
  15. * contributors may be used to endorse or promote products derived
  16. * from this software without specific prior written permission.
  17. *
  18. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19. * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20. * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  21. * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  22. * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  23. * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  25. * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26. * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  27. * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  28. * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29. * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30. */
  31. /*
  32. * rtime - get time from remote machine
  33. *
  34. * gets time, obtaining value from host
  35. * on the udp/time socket. Since timeserver returns
  36. * with time of day in seconds since Jan 1, 1900, must
  37. * subtract seconds before Jan 1, 1970 to get
  38. * what unix uses.
  39. */
  40. #include <stdio.h>
  41. #include <unistd.h>
  42. #include <stdint.h>
  43. #include <rpc/rpc.h>
  44. #include <rpc/clnt.h>
  45. #include <sys/types.h>
  46. #include <sys/poll.h>
  47. #include <sys/socket.h>
  48. #include <sys/time.h>
  49. #include <rpc/auth_des.h>
  50. #include <errno.h>
  51. #include <netinet/in.h>
  52. #include <shlib-compat.h>
  53. #define NYEARS (u_long)(1970 - 1900)
  54. #define TOFFSET (u_long)(60*60*24*(365*NYEARS + (NYEARS/4)))
  55. static void do_close (int);
  56. static void
  57. do_close (int s)
  58. {
  59. int save;
  60. save = errno;
  61. __close (s);
  62. __set_errno (save);
  63. }
  64. int
  65. rtime (struct sockaddr_in *addrp, struct rpc_timeval *timep,
  66. struct rpc_timeval *timeout)
  67. {
  68. int s;
  69. struct pollfd fd;
  70. int milliseconds;
  71. int res;
  72. /* RFC 868 says the time is transmitted as a 32-bit value. */
  73. uint32_t thetime;
  74. struct sockaddr_in from;
  75. socklen_t fromlen;
  76. int type;
  77. if (timeout == NULL)
  78. type = SOCK_STREAM;
  79. else
  80. type = SOCK_DGRAM;
  81. s = __socket (AF_INET, type, 0);
  82. if (s < 0)
  83. return (-1);
  84. addrp->sin_family = AF_INET;
  85. addrp->sin_port = htons (IPPORT_TIMESERVER);
  86. if (type == SOCK_DGRAM)
  87. {
  88. res = __sendto (s, (char *) &thetime, sizeof (thetime), 0,
  89. (struct sockaddr *) addrp, sizeof (*addrp));
  90. if (res < 0)
  91. {
  92. do_close (s);
  93. return -1;
  94. }
  95. milliseconds = (timeout->tv_sec * 1000) + (timeout->tv_usec / 1000);
  96. fd.fd = s;
  97. fd.events = POLLIN;
  98. do
  99. res = __poll (&fd, 1, milliseconds);
  100. while (res < 0 && errno == EINTR);
  101. if (res <= 0)
  102. {
  103. if (res == 0)
  104. __set_errno (ETIMEDOUT);
  105. do_close (s);
  106. return (-1);
  107. }
  108. fromlen = sizeof (from);
  109. res = __recvfrom (s, (char *) &thetime, sizeof (thetime), 0,
  110. (struct sockaddr *) &from, &fromlen);
  111. do_close (s);
  112. if (res < 0)
  113. return -1;
  114. }
  115. else
  116. {
  117. if (__connect (s, (struct sockaddr *) addrp, sizeof (*addrp)) < 0)
  118. {
  119. do_close (s);
  120. return -1;
  121. }
  122. res = __read (s, (char *) &thetime, sizeof (thetime));
  123. do_close (s);
  124. if (res < 0)
  125. return (-1);
  126. }
  127. if (res != sizeof (thetime))
  128. {
  129. __set_errno (EIO);
  130. return -1;
  131. }
  132. thetime = ntohl (thetime);
  133. timep->tv_sec = thetime - TOFFSET;
  134. timep->tv_usec = 0;
  135. return 0;
  136. }
  137. libc_hidden_nolink_sunrpc (rtime, GLIBC_2_1)