53 lines
1.2 KiB
C
53 lines
1.2 KiB
C
/* Test case for gethostbyname_r bug when buffer expansion required. */
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#include <netdb.h>
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#include <arpa/inet.h>
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#include <errno.h>
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#include <string.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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int
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main (void)
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{
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const char *host = "www.gnu.org";
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/* This code approximates the example code in the library manual. */
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struct hostent hostbuf, *hp;
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size_t hstbuflen;
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char *tmphstbuf;
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int res;
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int herr;
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hstbuflen = 16; /* Make it way small to ensure ERANGE. */
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/* Allocate buffer, remember to free it to avoid memory leakage. */
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tmphstbuf = malloc (hstbuflen);
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while ((res = gethostbyname_r (host, &hostbuf, tmphstbuf, hstbuflen,
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&hp, &herr)) == ERANGE)
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{
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/* Enlarge the buffer. */
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hstbuflen *= 2;
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tmphstbuf = realloc (tmphstbuf, hstbuflen);
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}
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if (res != 0 || hp == NULL)
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{
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printf ("gethostbyname_r failed: %s (errno: %m)\n", strerror (res));
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if (access ("/etc/resolv.conf", R_OK))
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{
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puts ("DNS probably not set up");
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return 0;
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}
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return 1;
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}
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printf ("Got: %s %s\n", hp->h_name,
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inet_ntoa (*(struct in_addr *) hp->h_addr));
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return 0;
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}
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