inet_aton.c 4.6 KB

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  1. /*
  2. * Copyright (c) 1983, 1990, 1993
  3. * The Regents of the University of California. All rights reserved.
  4. *
  5. * Redistribution and use in source and binary forms, with or without
  6. * modification, are permitted provided that the following conditions
  7. * are met:
  8. * 1. Redistributions of source code must retain the above copyright
  9. * notice, this list of conditions and the following disclaimer.
  10. * 2. Redistributions in binary form must reproduce the above copyright
  11. * notice, this list of conditions and the following disclaimer in the
  12. * documentation and/or other materials provided with the distribution.
  13. * 3. All advertising materials mentioning features or use of this software
  14. * must display the following acknowledgement:
  15. * This product includes software developed by the University of
  16. * California, Berkeley and its contributors.
  17. * 4. Neither the name of the University nor the names of its contributors
  18. * may be used to endorse or promote products derived from this software
  19. * without specific prior written permission.
  20. *
  21. * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24. * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31. * SUCH DAMAGE.
  32. */
  33. #if defined(LIBC_SCCS) && !defined(lint)
  34. static char sccsid[] = "@(#)inet_addr.c 8.1 (Berkeley) 6/17/93";
  35. #endif /* LIBC_SCCS and not lint */
  36. #include <ctype.h>
  37. #ifdef __MINGW32__
  38. #include <winsock2.h>
  39. #else
  40. #include <sys/param.h>
  41. #include <netinet/in.h>
  42. #include <arpa/inet.h>
  43. #endif
  44. #if 0
  45. /*
  46. * Ascii internet address interpretation routine.
  47. * The value returned is in network order.
  48. */
  49. u_long
  50. inet_addr(const char *cp)
  51. {
  52. struct in_addr val;
  53. if (inet_aton(cp, &val))
  54. return (val.s_addr);
  55. return (INADDR_NONE);
  56. }
  57. #endif
  58. /* We provide this prototype to avoid compiler warnings. If this ever
  59. conflicts with a declaration in a system header file, we'll find
  60. out, because we should include that header file here. */
  61. int inet_aton (const char *cp, struct in_addr *addr);
  62. /*
  63. * Check whether "cp" is a valid ascii representation
  64. * of an Internet address and convert to a binary address.
  65. * Returns 1 if the address is valid, 0 if not.
  66. * This replaces inet_addr, the return value from which
  67. * cannot distinguish between failure and a local broadcast address. */
  68. int
  69. inet_aton(const char *cp_arg, struct in_addr *addr)
  70. {
  71. register unsigned long val;
  72. register int base, n;
  73. register unsigned char c;
  74. register unsigned const char *cp = (unsigned const char *) cp_arg;
  75. unsigned int parts[4];
  76. register unsigned int *pp = parts;
  77. for (;;) {
  78. /*
  79. * Collect number up to ``.''.
  80. * Values are specified as for C:
  81. * 0x=hex, 0=octal, other=decimal.
  82. */
  83. val = 0; base = 10;
  84. if (*cp == '0') {
  85. if (*++cp == 'x' || *cp == 'X')
  86. base = 16, cp++;
  87. else
  88. base = 8;
  89. }
  90. while ((c = *cp) != '\0') {
  91. if (isascii(c) && isdigit(c)) {
  92. val = (val * base) + (c - '0');
  93. cp++;
  94. continue;
  95. }
  96. if (base == 16 && isascii(c) && isxdigit(c)) {
  97. val = (val << 4) +
  98. (c + 10 - (islower(c) ? 'a' : 'A'));
  99. cp++;
  100. continue;
  101. }
  102. break;
  103. }
  104. if (*cp == '.') {
  105. /*
  106. * Internet format:
  107. * a.b.c.d
  108. * a.b.c (with c treated as 16-bits)
  109. * a.b (with b treated as 24 bits)
  110. */
  111. if (pp >= parts + 3 || val > 0xff)
  112. return (0);
  113. *pp++ = val, cp++;
  114. } else
  115. break;
  116. }
  117. /*
  118. * Check for trailing characters.
  119. */
  120. if (*cp && (!isascii(*cp) || !isspace(*cp)))
  121. return (0);
  122. /*
  123. * Concoct the address according to
  124. * the number of parts specified.
  125. */
  126. n = pp - parts + 1;
  127. switch (n) {
  128. case 1: /* a -- 32 bits */
  129. break;
  130. case 2: /* a.b -- 8.24 bits */
  131. if (val > 0xffffff)
  132. return (0);
  133. val |= parts[0] << 24;
  134. break;
  135. case 3: /* a.b.c -- 8.8.16 bits */
  136. if (val > 0xffff)
  137. return (0);
  138. val |= (parts[0] << 24) | (parts[1] << 16);
  139. break;
  140. case 4: /* a.b.c.d -- 8.8.8.8 bits */
  141. if (val > 0xff)
  142. return (0);
  143. val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
  144. break;
  145. }
  146. if (addr)
  147. addr->s_addr = htonl(val);
  148. return (1);
  149. }
  150. /*
  151. Local Variables:
  152. c-file-style: "gnu"
  153. End:
  154. */