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(canon_host): Don't use he->h_addr directly.

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Based on a patch from Savochkin Andrey Vladimirovich.
This commit is contained in:
Jim Meyering
1999-03-10 15:39:02 +00:00
parent 4ba4999328
commit b910e6ea14
1 changed files with 19 additions and 3 deletions
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22
lib/canon-host.c
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@@ -43,6 +43,8 @@
# include <arpa/inet.h>
#endif
void free ();
/* Returns the canonical hostname associated with HOST (allocated in a static
buffer), or 0 if it can't be determined. */
char *
@@ -67,9 +69,23 @@ canon_host (const char *host)
}
if (addr && strcmp (he->h_name, addr) == 0)
/* gethostbyname() cheated! Lookup the host name via the address
this time to get the actual host name. */
he = gethostbyaddr (he->h_addr, he->h_length, he->h_addrtype);
{
/* gethostbyname has returned a string representation of the IP
address, for example, "127.0.0.1". So now, look up the host
name via the address. Although it may seem reasonable to look
up the host name via the address, we must not pass `he->h_addr'
directly to gethostbyaddr because on some systems he->h_addr
is located in a static library buffer that is reused in the
gethostbyaddr call. Make a copy and use that instead. */
char *h_addr_copy = strdup (he->h_addr);
if (h_addr_copy == NULL)
he = NULL;
else
{
he = gethostbyaddr (h_addr_copy, he->h_length, he->h_addrtype);
free (h_addr_copy);
}
}
# endif /* HAVE_GETHOSTBYADDR */
if (he)