libvirt/tests/nsstest.c
Michal Privoznik a7cbfabc2f libvirt_nss: Report newer addresses first
Ideally, a software that's translating domain names would iterate
over all addresses the NSS returned, but some software does not
bother (e.g. ping). What happens is that for instance when
installing a guest, it's assigned one IP address but once it's
installed and rebooted it gets a different IP address (because
client ID used for the first DHCP traffic when installing the
guest was generated dynamically and never saved so after reboot
the guest generated new ID which resulted in different IP address
to be assigned). This results in 'ping $domain' not working
properly as it still pings the old IP address. Well, it might -
NSS plugin does not guarantee any order of addresses.

To resolve this problem, we can sort the array just before
returning it to the caller (ping) so that the newer IP addresses
come before older ones.

Reported-by: Andrea Bolognani <abologna@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
2019-07-15 13:48:19 +02:00

201 lines
5.8 KiB
C

/*
* Copyright (C) 2016 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include "testutils.h"
#ifdef NSS
# include <arpa/inet.h>
# include "libvirt_nss.h"
# include "virsocketaddr.h"
# define VIR_FROM_THIS VIR_FROM_NONE
# define BUF_SIZE 1024
struct testNSSData {
const char *hostname;
const char *const *ipAddr;
int af;
};
static int
testGetHostByName(const void *opaque)
{
const struct testNSSData *data = opaque;
const bool existent = data->hostname && data->ipAddr && data->ipAddr[0];
int ret = -1;
struct hostent resolved;
char buf[BUF_SIZE] = { 0 };
char **addrList;
int rv, tmp_errno = 0, tmp_herrno = 0;
size_t i = 0;
memset(&resolved, 0, sizeof(resolved));
rv = NSS_NAME(gethostbyname2)(data->hostname,
data->af,
&resolved,
buf, sizeof(buf),
&tmp_errno,
&tmp_herrno);
if (rv == NSS_STATUS_TRYAGAIN ||
rv == NSS_STATUS_UNAVAIL ||
rv == NSS_STATUS_RETURN) {
/* Resolving failed in unexpected fashion. */
virReportError(VIR_ERR_INTERNAL_ERROR,
"Resolving of %s failed due to internal error",
data->hostname);
goto cleanup;
} else if (rv == NSS_STATUS_NOTFOUND) {
/* Resolving failed. Should it? */
if (!existent)
ret = 0;
else
virReportError(VIR_ERR_INTERNAL_ERROR,
"Resolving of %s failed",
data->hostname);
goto cleanup;
}
/* Resolving succeeded. Should it? */
if (!existent) {
virReportError(VIR_ERR_INTERNAL_ERROR,
"Resolving of %s succeeded but was expected to fail",
data->hostname);
goto cleanup;
}
/* Now lets see if resolved address match our expectations. */
if (!resolved.h_name) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
"resolved.h_name empty");
goto cleanup;
}
if (data->af != AF_UNSPEC &&
resolved.h_addrtype != data->af) {
virReportError(VIR_ERR_INTERNAL_ERROR,
"Expected AF_INET (%d) got %d",
data->af, resolved.h_addrtype);
goto cleanup;
}
if ((resolved.h_addrtype == AF_INET && resolved.h_length != 4) ||
(resolved.h_addrtype == AF_INET6 && resolved.h_length != 16)) {
/* IPv4 addresses are encoded into 4 bytes */
virReportError(VIR_ERR_INTERNAL_ERROR,
"Expected %d bytes long address, got %d",
resolved.h_addrtype == AF_INET ? 4 : 16,
resolved.h_length);
goto cleanup;
}
if (!resolved.h_addr_list) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
"resolved.h_addr_list empty");
goto cleanup;
}
addrList = resolved.h_addr_list;
i = 0;
while (*addrList) {
virSocketAddr sa;
char *ipAddr;
void *address = *addrList;
memset(&sa, 0, sizeof(sa));
if (resolved.h_addrtype == AF_INET) {
virSocketAddrSetIPv4AddrNetOrder(&sa, *((uint32_t *) address));
} else {
virSocketAddrSetIPv6AddrNetOrder(&sa, address);
}
if (!(ipAddr = virSocketAddrFormat(&sa))) {
/* error reported by helper */
goto cleanup;
}
if (STRNEQ_NULLABLE(data->ipAddr[i], ipAddr)) {
virReportError(VIR_ERR_INTERNAL_ERROR,
"Unexpected address %s, expecting %s",
ipAddr, NULLSTR(data->ipAddr[i]));
VIR_FREE(ipAddr);
goto cleanup;
}
VIR_FREE(ipAddr);
addrList++;
i++;
}
if (data->ipAddr[i]) {
virReportError(VIR_ERR_INTERNAL_ERROR,
"Expected %s address, got NULL",
data->ipAddr[i]);
goto cleanup;
}
ret = 0;
cleanup:
return ret;
}
static int
mymain(void)
{
int ret = 0;
# define DO_TEST(name, family, ...) \
do { \
const char *addr[] = { __VA_ARGS__, NULL}; \
struct testNSSData data = { \
.hostname = name, .ipAddr = addr, .af = family, \
}; \
if (virTestRun(name, testGetHostByName, &data) < 0) \
ret = -1; \
} while (0)
# if !defined(LIBVIRT_NSS_GUEST)
DO_TEST("fedora", AF_INET, "192.168.122.197", "192.168.122.198", "192.168.122.199");
DO_TEST("gentoo", AF_INET, "192.168.122.254");
DO_TEST("gentoo", AF_INET6, "2001:1234:dead:beef::2");
DO_TEST("gentoo", AF_UNSPEC, "192.168.122.254");
DO_TEST("non-existent", AF_UNSPEC, NULL);
# else /* defined(LIBVIRT_NSS_GUEST) */
DO_TEST("debian", AF_INET, "192.168.122.2");
DO_TEST("suse", AF_INET, "192.168.122.3");
# endif /* defined(LIBVIRT_NSS_GUEST) */
return ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
}
VIR_TEST_MAIN_PRELOAD(mymain, abs_builddir "/.libs/nssmock.so")
#else
int
main(void)
{
return EXIT_AM_SKIP;
}
#endif