bindresvport.c 2.3 KB

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  1. /*
  2. * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
  3. * unrestricted use provided that this legend is included on all tape
  4. * media and as a part of the software program in whole or part. Users
  5. * may copy or modify Sun RPC without charge, but are not authorized
  6. * to license or distribute it to anyone else except as part of a product or
  7. * program developed by the user.
  8. *
  9. * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  10. * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  11. * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  12. *
  13. * Sun RPC is provided with no support and without any obligation on the
  14. * part of Sun Microsystems, Inc. to assist in its use, correction,
  15. * modification or enhancement.
  16. *
  17. * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  18. * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  19. * OR ANY PART THEREOF.
  20. *
  21. * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  22. * or profits or other special, indirect and consequential damages, even if
  23. * Sun has been advised of the possibility of such damages.
  24. *
  25. * Sun Microsystems, Inc.
  26. * 2550 Garcia Avenue
  27. * Mountain View, California 94043
  28. */
  29. /*
  30. * Copyright (c) 1987 by Sun Microsystems, Inc.
  31. */
  32. #define __FORCE_GLIBC
  33. #include <features.h>
  34. #include <errno.h>
  35. #include <unistd.h>
  36. #include <string.h>
  37. #include <sys/types.h>
  38. #include <sys/socket.h>
  39. #include <netinet/in.h>
  40. /*
  41. * Bind a socket to a privileged IP port
  42. */
  43. int
  44. bindresvport (int sd, struct sockaddr_in *sin)
  45. {
  46. int res;
  47. static short port;
  48. struct sockaddr_in myaddr;
  49. int i;
  50. #define STARTPORT 600
  51. #define ENDPORT (IPPORT_RESERVED - 1)
  52. #define NPORTS (ENDPORT - STARTPORT + 1)
  53. if (sin == (struct sockaddr_in *) 0)
  54. {
  55. sin = &myaddr;
  56. __memset (sin, 0, sizeof (*sin));
  57. sin->sin_family = AF_INET;
  58. }
  59. else if (sin->sin_family != AF_INET)
  60. {
  61. __set_errno (EPFNOSUPPORT);
  62. return -1;
  63. }
  64. if (port == 0)
  65. {
  66. port = (__getpid () % NPORTS) + STARTPORT;
  67. }
  68. res = -1;
  69. __set_errno (EADDRINUSE);
  70. for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; ++i)
  71. {
  72. sin->sin_port = htons (port);
  73. if (++port > ENDPORT)
  74. {
  75. port = STARTPORT;
  76. }
  77. res = bind(sd, (struct sockaddr *)sin, sizeof(struct sockaddr_in));
  78. }
  79. return res;
  80. }