curl/ares/ares__get_hostent.c

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/* Copyright 1998 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 <sys/types.h>
#ifdef WIN32
#else
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "ares.h"
#include "ares_private.h"
int ares__get_hostent(FILE *fp, struct hostent **host)
{
char *line = NULL, *p, *q, *canonical, **alias;
int status, linesize, end_at_hostname, naliases;
struct in_addr addr;
struct hostent *hostent = NULL;
while ((status = ares__read_line(fp, &line, &linesize)) == ARES_SUCCESS)
{
/* Skip comment lines; terminate line at comment character. */
if (*line == '#' || !*line)
continue;
p = strchr(line, '#');
if (p)
*p = 0;
/* Get the address part. */
p = line;
while (*p && !isspace((unsigned char)*p))
p++;
if (!*p)
continue;
*p = 0;
addr.s_addr = inet_addr(line);
if (addr.s_addr == INADDR_NONE)
continue;
/* Get the canonical hostname. */
p++;
while (isspace((unsigned char)*p))
p++;
if (!*p)
continue;
q = p;
while (*q && !isspace((unsigned char)*q))
q++;
end_at_hostname = (*q == 0);
*q = 0;
canonical = p;
naliases = 0;
if (!end_at_hostname)
{
/* Count the aliases. */
p = q + 1;
while (isspace((unsigned char)*p))
p++;
while (*p)
{
while (*p && !isspace((unsigned char)*p))
p++;
while (isspace((unsigned char)*p))
p++;
naliases++;
}
}
/* Allocate memory for the host structure. */
hostent = malloc(sizeof(struct hostent));
if (!hostent)
break;
hostent->h_aliases = NULL;
hostent->h_addr_list = NULL;
hostent->h_name = strdup(canonical);
if (!hostent->h_name)
break;
hostent->h_addr_list = malloc(2 * sizeof(char *));
if (!hostent->h_addr_list)
break;
hostent->h_addr_list[0] = malloc(sizeof(struct in_addr));
if (!hostent->h_addr_list[0])
break;
hostent->h_aliases = malloc((naliases + 1) * sizeof(char *));
if (!hostent->h_aliases)
break;
/* Copy in aliases. */
naliases = 0;
if (!end_at_hostname)
{
p = canonical + strlen(canonical) + 1;
while (isspace((unsigned char)*p))
p++;
while (*p)
{
q = p;
while (*q && !isspace((unsigned char)*q))
q++;
hostent->h_aliases[naliases] = malloc(q - p + 1);
if (hostent->h_aliases[naliases] == NULL)
break;
memcpy(hostent->h_aliases[naliases], p, q - p);
hostent->h_aliases[naliases][q - p] = 0;
p = q;
while (isspace((unsigned char)*p))
p++;
naliases++;
}
if (*p)
break;
}
hostent->h_aliases[naliases] = NULL;
hostent->h_addrtype = AF_INET;
hostent->h_length = sizeof(struct in_addr);
memcpy(hostent->h_addr_list[0], &addr, sizeof(struct in_addr));
hostent->h_addr_list[1] = NULL;
*host = hostent;
free(line);
return ARES_SUCCESS;
}
free(line);
if (status == ARES_SUCCESS)
{
/* Memory allocation failure; clean up. */
if (hostent)
{
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)
free(hostent->h_addr_list[0]);
free(hostent->h_addr_list);
}
free(hostent);
return ARES_ENOMEM;
}
return status;
}