/*
This file is part of GNUnet.
Copyright (C) 2012 GNUnet e.V.
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
SPDX-License-Identifier: AGPL3.0-or-later
*/
#include
#include
#include
#include "nss_gns_query.h"
#include
#include
#include
#include
#include
#include
#include
#include
#define TIMEOUT "5s"
static void
kwait (pid_t chld)
{
int ret;
kill (chld, SIGKILL);
waitpid (chld, &ret, 0);
}
/**
* Wrapper function that uses gnunet-gns cli tool to resolve
* an IPv4/6 address.
*
* @param af address family
* @param name the name to resolve
* @param u the userdata (result struct)
* @return -1 on internal error,
* -2 if request is not for GNS,
* -3 on timeout,
* else 0
*/
int
gns_resolve_name (int af, const char *name, struct userdata *u)
{
FILE *p;
char line[128];
int ret;
int retry = 0;
int out[2];
pid_t pid;
if (0 == getuid ())
return -2; /* GNS via NSS is NEVER for root */
query_gns:
if (0 != pipe (out))
return -1;
pid = fork ();
if (-1 == pid)
return -1;
if (0 == pid)
{
char *argv[] = { "gnunet-gns",
"-r", /* Raw output for easier parsing */
"-d", /* DNS compatibility (allow IDNA names, no UTF-8) */
"-t",
(AF_INET6 == af) ? "AAAA" : "A",
"-u",
(char *) name,
"-T",
TIMEOUT,
NULL };
(void) close (STDOUT_FILENO);
if ((0 != close (out[0])) ||
(STDOUT_FILENO != dup2 (out[1], STDOUT_FILENO)))
_exit (1);
(void) execvp ("gnunet-gns", argv);
_exit (1);
}
(void) close (out[1]);
p = fdopen (out[0], "r");
if (NULL == p)
{
kwait (pid);
return -1;
}
while (NULL != fgets (line, sizeof(line), p))
{
if (u->count >= MAX_ENTRIES)
break;
if (line[strlen (line) - 1] == '\n')
{
line[strlen (line) - 1] = '\0';
if (AF_INET == af)
{
if (inet_pton (af, line, &u->data.ipv4[u->count]))
{
u->count++;
u->data_len += sizeof(ipv4_address_t);
}
else
{
(void) fclose (p);
kwait (pid);
errno = EINVAL;
return -1;
}
}
else if (AF_INET6 == af)
{
if (inet_pton (af, line, &u->data.ipv6[u->count]))
{
u->count++;
u->data_len += sizeof(ipv6_address_t);
}
else
{
(void) fclose (p);
kwait (pid);
errno = EINVAL;
return -1;
}
}
}
}
(void) fclose (p);
waitpid (pid, &ret, 0);
if (! WIFEXITED (ret))
return -1;
if (4 == WEXITSTATUS (ret))
return -2; /* not for GNS */
if (5 == WEXITSTATUS (ret))
{
if (1 == retry)
return -2; /* no go -> service unavailable */
retry = 1;
system ("gnunet-arm -s");
goto query_gns; /* Try again */
}
if (3 == WEXITSTATUS (ret))
return -2; /* timeout -> service unavailable */
if ((2 == WEXITSTATUS (ret)) || (1 == WEXITSTATUS (ret)))
return -2; /* launch failure -> service unavailable */
return 0;
}
/* end of nss_gns_query.c */