+++ /dev/null
-/* $Id: inet_aton.c 5049 2001-12-12 09:06:00Z rra $
-**
-** Replacement for a missing inet_aton.
-**
-** Written by Russ Allbery <rra@stanford.edu>
-** This work is hereby placed in the public domain by its author.
-**
-** Provides the same functionality as the standard library routine
-** inet_aton for those platforms that don't have it. inet_aton is
-** thread-safe.
-*/
-
-#include "config.h"
-#include "clibrary.h"
-#include <netinet/in.h>
-
-/* If we're running the test suite, rename inet_ntoa to avoid conflicts with
- the system version. */
-#if TESTING
-# define inet_aton test_inet_aton
-int test_inet_aton(const char *, struct in_addr *);
-#endif
-
-int
-inet_aton(const char *s, struct in_addr *addr)
-{
- unsigned long octet[4], address;
- const char *p;
- int base, i;
- int part = 0;
-
- if (s == NULL) return 0;
-
- /* Step through each period-separated part of the address. If we see
- more than four parts, the address is invalid. */
- for (p = s; *p != 0; part++) {
- if (part > 3) return 0;
-
- /* Determine the base of the section we're looking at. Numbers are
- represented the same as in C; octal starts with 0, hex starts
- with 0x, and anything else is decimal. */
- if (*p == '0') {
- p++;
- if (*p == 'x') {
- p++;
- base = 16;
- } else {
- base = 8;
- }
- } else {
- base = 10;
- }
-
- /* Make sure there's actually a number. (A section of just "0"
- would set base to 8 and leave us pointing at a period; allow
- that.) */
- if (*p == '.' && base != 8) return 0;
- octet[part] = 0;
-
- /* Now, parse this segment of the address. For each digit, multiply
- the result so far by the base and then add the value of the
- digit. Be careful of arithmetic overflow in cases where an
- unsigned long is 32 bits; we need to detect it *before* we
- multiply by the base since otherwise we could overflow and wrap
- and then not detect the error. */
- for (; *p != 0 && *p != '.'; p++) {
- if (octet[part] > 0xffffffffUL / base) return 0;
-
- /* Use a switch statement to parse each digit rather than
- assuming ASCII. Probably pointless portability.... */
- switch (*p) {
- case '0': i = 0; break;
- case '1': i = 1; break;
- case '2': i = 2; break;
- case '3': i = 3; break;
- case '4': i = 4; break;
- case '5': i = 5; break;
- case '6': i = 6; break;
- case '7': i = 7; break;
- case '8': i = 8; break;
- case '9': i = 9; break;
- case 'A': case 'a': i = 10; break;
- case 'B': case 'b': i = 11; break;
- case 'C': case 'c': i = 12; break;
- case 'D': case 'd': i = 13; break;
- case 'E': case 'e': i = 14; break;
- case 'F': case 'f': i = 15; break;
- default: return 0;
- }
- if (i >= base) return 0;
- octet[part] = (octet[part] * base) + i;
- }
-
- /* Advance over periods; the top of the loop will increment the
- count of parts we've seen. We need a check here to detect an
- illegal trailing period. */
- if (*p == '.') {
- p++;
- if (*p == 0) return 0;
- }
- }
- if (part == 0) return 0;
-
- /* IPv4 allows three types of address specification:
-
- a.b
- a.b.c
- a.b.c.d
-
- If there are fewer than four segments, the final segment accounts for
- all of the remaining portion of the address. For example, in the a.b
- form, b is the final 24 bits of the address. We also allow a simple
- number, which is interpreted as the 32-bit number corresponding to
- the full IPv4 address.
-
- The first for loop below ensures that any initial segments represent
- only 8 bits of the address and builds the upper portion of the IPv4
- address. Then, the remaining segment is checked to make sure it's no
- bigger than the remaining space in the address and then is added into
- the result. */
- address = 0;
- for (i = 0; i < part - 1; i++) {
- if (octet[i] > 0xff) return 0;
- address |= octet[i] << (8 * (3 - i));
- }
- if (octet[i] > (0xffffffffUL >> (i * 8))) return 0;
- address |= octet[i];
- if (addr != NULL) addr->s_addr = htonl(address);
- return 1;
-}
~ian / innduct.git / blobdiff