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/* Copyright 1998, 2010 by the Massachusetts Institute of Technology.
*
* Permission to use, copy, modify, and distribute this
* software and its documentation for any purpose and without
* fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting
* documentation, and that the name of M.I.T. not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is"
* without express or implied warranty.
*/
#include "ares_setup.h"
#ifdef HAVE_SYS_SOCKET_H
# include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#ifdef HAVE_NETDB_H
# include <netdb.h>
#endif
#ifdef HAVE_ARPA_INET_H
# include <arpa/inet.h>
#endif
#include "ares.h"
#include "inet_net_pton.h"
#include "ares_private.h"
int ares__get_hostent(FILE *fp, int family, struct hostent **host)
{
char *line = NULL, *p, *q, **alias;
char *txtaddr, *txthost, *txtalias;
int status;
size_t addrlen, linesize, naliases;
struct ares_addr addr;
struct hostent *hostent = NULL;
*host = NULL; /* Assume failure */
/* Validate family */
switch (family) {
case AF_INET:
case AF_INET6:
case AF_UNSPEC:
break;
default:
return ARES_EBADFAMILY;
}
while ((status = ares__read_line(fp, &line, &linesize)) == ARES_SUCCESS)
{
/* Trim line comment. */
p = line;
while (*p && (*p != '#'))
p++;
*p = '\0';
/* Trim trailing whitespace. */
q = p - 1;
while ((q >= line) && ISSPACE(*q))
q--;
*++q = '\0';
/* Skip leading whitespace. */
p = line;
while (*p && ISSPACE(*p))
p++;
if (!*p)
/* Ignore line if empty. */
continue;
/* Pointer to start of IPv4 or IPv6 address part. */
txtaddr = p;
/* Advance past address part. */
while (*p && !ISSPACE(*p))
p++;
if (!*p)
/* Ignore line if reached end of line. */
continue;
/* Null terminate address part. */
*p = '\0';
/* Advance to host name */
p++;
while (*p && ISSPACE(*p))
p++;
if (!*p)
/* Ignore line if reached end of line. */
continue;
/* Pointer to start of host name. */
txthost = p;
/* Advance past host name. */
while (*p && !ISSPACE(*p))
p++;
/* Pointer to start of first alias. */
txtalias = NULL;
if (*p)
{
q = p + 1;
while (*q && ISSPACE(*q))
q++;
if (*q)
txtalias = q;
}
/* Null terminate host name. */
*p = '\0';
/* find out number of aliases. */
naliases = 0;
if (txtalias)
{
p = txtalias;
while (*p)
{
while (*p && !ISSPACE(*p))
p++;
while (*p && ISSPACE(*p))
p++;
naliases++;
}
}
/* Convert address string to network address for the requested family. */
addrlen = 0;
addr.family = AF_UNSPEC;
addr.addrV4.s_addr = INADDR_NONE;
if ((family == AF_INET) || (family == AF_UNSPEC))
{
addr.addrV4.s_addr = inet_addr(txtaddr);
if (addr.addrV4.s_addr != INADDR_NONE)
{
/* Actual network address family and length. */
addr.family = AF_INET;
addrlen = sizeof(addr.addrV4);
}
}
if ((family == AF_INET6) || ((family == AF_UNSPEC) && (!addrlen)))
{
if (ares_inet_pton(AF_INET6, txtaddr, &addr.addrV6) > 0)
{
/* Actual network address family and length. */
addr.family = AF_INET6;
addrlen = sizeof(addr.addrV6);
}
}
if (!addrlen)
/* Ignore line if invalid address string for the requested family. */
continue;
/*
** Actual address family possible values are AF_INET and AF_INET6 only.
*/
/* Allocate memory for the hostent structure. */
hostent = malloc(sizeof(struct hostent));
if (!hostent)
break;
/* Initialize fields for out of memory condition. */
hostent->h_aliases = NULL;
hostent->h_addr_list = NULL;
/* Copy official host name. */
hostent->h_name = strdup(txthost);
if (!hostent->h_name)
break;
/* Copy network address. */
hostent->h_addr_list = malloc(2 * sizeof(char *));
if (!hostent->h_addr_list)
break;
hostent->h_addr_list[1] = NULL;
hostent->h_addr_list[0] = malloc(addrlen);
if (!hostent->h_addr_list[0])
break;
if (addr.family == AF_INET)
memcpy(hostent->h_addr_list[0], &addr.addrV4, sizeof(addr.addrV4));
else
memcpy(hostent->h_addr_list[0], &addr.addrV6, sizeof(addr.addrV6));
/* Copy aliases. */
hostent->h_aliases = malloc((naliases + 1) * sizeof(char *));
if (!hostent->h_aliases)
break;
alias = hostent->h_aliases;
while (naliases)
*(alias + naliases--) = NULL;
*alias = NULL;
while (txtalias)
{
p = txtalias;
while (*p && !ISSPACE(*p))
p++;
q = p;
while (*q && ISSPACE(*q))
q++;
*p = '\0';
if ((*alias = strdup(txtalias)) == NULL)
break;
alias++;
txtalias = *q ? q : NULL;
}
if (txtalias)
/* Alias memory allocation failure. */
break;
/* Copy actual network address family and length. */
hostent->h_addrtype = addr.family;
hostent->h_length = (int)addrlen;
/* Free line buffer. */
free(line);
/* Return hostent successfully */
*host = hostent;
return ARES_SUCCESS;
}
/* If allocated, free line buffer. */
if (line)
free(line);
if (status == ARES_SUCCESS)
{
/* Memory allocation failure; clean up. */
if (hostent)
{
if (hostent->h_name)
free((char *) hostent->h_name);
if (hostent->h_aliases)
{
for (alias = hostent->h_aliases; *alias; alias++)
free(*alias);
free(hostent->h_aliases);
}
if (hostent->h_addr_list)
{
if (hostent->h_addr_list[0])
free(hostent->h_addr_list[0]);
free(hostent->h_addr_list);
}
free(hostent);
}
return ARES_ENOMEM;
}
return status;
}
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