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/* libguestfs
* Copyright (C) 2012 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 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <libintl.h>
#ifdef HAVE_LIBVIRT
#include <libvirt/virterror.h>
#endif
#include "guestfs.h"
#include "guestfs-internal.h"
#include "guestfs-internal-actions.h"
#if defined(HAVE_LIBVIRT)
static struct {
int credtype;
const char *credname;
} libvirt_credential_types[NR_CREDENTIAL_TYPES] = {
{ VIR_CRED_USERNAME, "username" },
{ VIR_CRED_AUTHNAME, "authname" },
{ VIR_CRED_LANGUAGE, "language" },
{ VIR_CRED_CNONCE, "cnonce" },
{ VIR_CRED_PASSPHRASE, "passphrase" },
{ VIR_CRED_ECHOPROMPT, "echoprompt" },
{ VIR_CRED_NOECHOPROMPT, "noechoprompt" },
{ VIR_CRED_REALM, "realm" },
{ VIR_CRED_EXTERNAL, "external" },
};
static int
get_credtype_from_string (const char *name)
{
size_t i;
for (i = 0; i < NR_CREDENTIAL_TYPES; ++i)
if (STREQ (name, libvirt_credential_types[i].credname))
return libvirt_credential_types[i].credtype;
return -1;
}
static const char *
get_string_of_credtype (int credtype)
{
size_t i;
for (i = 0; i < NR_CREDENTIAL_TYPES; ++i)
if (credtype == libvirt_credential_types[i].credtype)
return libvirt_credential_types[i].credname;
return NULL;
}
/* Note to callers: Should it be possible to say that you don't
* support any libvirt credential types at all? Not clear if that's
* an error or not, so don't depend on the current behaviour.
*/
int
guestfs_impl_set_libvirt_supported_credentials (guestfs_h *g, char *const *creds)
{
size_t i;
int credtype;
/* Try to make this call atomic so it either completely succeeds
* or if it fails it leaves the current state intact.
*/
unsigned int ncredtypes = 0;
int credtypes[NR_CREDENTIAL_TYPES];
for (i = 0; creds[i] != NULL; ++i) {
credtype = get_credtype_from_string (creds[i]);
if (credtype == -1) {
error (g, _("unknown credential type ā%sā"), creds[i]);
return -1;
}
if (ncredtypes >= NR_CREDENTIAL_TYPES) {
error (g, _("list of supported credentials is too long"));
return -1;
}
credtypes[ncredtypes++] = credtype;
}
g->nr_supported_credentials = ncredtypes;
memcpy (g->supported_credentials, credtypes, sizeof g->supported_credentials);
return 0;
}
/* This function is called back from libvirt. In turn it generates a
* libguestfs event to collect the desired credentials.
*/
static int
libvirt_auth_callback (virConnectCredentialPtr cred,
unsigned int ncred,
void *gv)
{
guestfs_h *g = gv;
size_t i;
if (cred == NULL || ncred == 0)
return 0;
/* libvirt probably does this already, but no harm in checking. */
for (i = 0; i < ncred; ++i) {
cred[i].result = NULL;
cred[i].resultlen = 0;
}
g->requested_credentials = cred;
g->nr_requested_credentials = ncred;
guestfs_int_call_callbacks_message (g, GUESTFS_EVENT_LIBVIRT_AUTH,
g->saved_libvirt_uri,
strlen (g->saved_libvirt_uri));
/* Clarified with Dan that it is not an error for some fields to be
* left as NULL.
* https://www.redhat.com/archives/libvir-list/2012-October/msg00707.html
*/
return 0;
}
/* Libvirt provides a default authentication handler. However it is
* confusing to end-users
* (https://bugzilla.redhat.com/show_bug.cgi?id=1044014#c0).
*
* Unfortunately #1 the libvirt handler cannot easily be modified to
* make it non-confusing, but unfortunately #2 we have to actually
* call it because it handles all the policykit crap.
*
* Therefore we add a wrapper around it here.
*/
static int
libvirt_auth_default_wrapper (virConnectCredentialPtr cred,
unsigned int ncred,
void *gv)
{
guestfs_h *g = gv;
if (!g->wrapper_warning_done) {
printf (_("libvirt needs authentication to connect to libvirt URI %s\n"
"(see also: http://libvirt.org/auth.html http://libvirt.org/uri.html)\n"),
g->saved_libvirt_uri ? g->saved_libvirt_uri : "NULL");
g->wrapper_warning_done = true;
}
return virConnectAuthPtrDefault->cb (cred, ncred,
virConnectAuthPtrDefault->cbdata);
}
static int
exists_libvirt_auth_event (guestfs_h *g)
{
size_t i;
for (i = 0; i < g->nr_events; ++i)
if ((g->events[i].event_bitmask & GUESTFS_EVENT_LIBVIRT_AUTH) != 0)
return 1;
return 0;
}
/* Open a libvirt connection (called from other parts of the library). */
virConnectPtr
guestfs_int_open_libvirt_connection (guestfs_h *g, const char *uri,
unsigned int flags)
{
virConnectAuth authdata;
virConnectPtr conn;
const char *authtype;
g->saved_libvirt_uri = uri;
g->wrapper_warning_done = false;
/* Did the caller register a GUESTFS_EVENT_LIBVIRT_AUTH event and
* call guestfs_set_libvirt_supported_credentials?
*/
if (g->nr_supported_credentials > 0 && exists_libvirt_auth_event (g)) {
authtype = "custom";
memset (&authdata, 0, sizeof authdata);
authdata.credtype = g->supported_credentials;
authdata.ncredtype = g->nr_supported_credentials;
authdata.cb = libvirt_auth_callback;
authdata.cbdata = g;
}
else {
/* Wrapper around libvirt's virConnectAuthPtrDefault, see comment
* above.
*/
authtype = "default+wrapper";
authdata = *virConnectAuthPtrDefault;
authdata.cb = libvirt_auth_default_wrapper;
authdata.cbdata = g;
}
debug (g, "opening libvirt handle: URI = %s, auth = %s, flags = %u",
uri ? uri : "NULL", authtype, flags);
conn = virConnectOpenAuth (uri, &authdata, flags);
if (conn)
debug (g, "successfully opened libvirt handle: conn = %p", conn);
/* Restore handle fields to "outside event handler" state. */
g->saved_libvirt_uri = NULL;
g->nr_requested_credentials = 0;
g->requested_credentials = NULL;
return conn;
}
/* The calls below are meant to be called recursively from
* the GUESTFS_EVENT_LIBVIRT_AUTH event.
*/
#define CHECK_IN_EVENT_HANDLER(r) \
if (g->nr_requested_credentials == 0) { \
error (g, _("%s should only be called from within the GUESTFS_EVENT_LIBVIRT_AUTH event handler"), \
__func__); \
return r; \
}
char **
guestfs_impl_get_libvirt_requested_credentials (guestfs_h *g)
{
DECLARE_STRINGSBUF (ret);
size_t i;
CHECK_IN_EVENT_HANDLER (NULL);
/* Convert the requested_credentials types to a list of strings. */
for (i = 0; i < g->nr_requested_credentials; ++i)
guestfs_int_add_string (g, &ret,
get_string_of_credtype (g->requested_credentials[i].type));
guestfs_int_end_stringsbuf (g, &ret);
return ret.argv; /* caller frees */
}
char *
guestfs_impl_get_libvirt_requested_credential_prompt (guestfs_h *g, int index)
{
size_t i;
CHECK_IN_EVENT_HANDLER (NULL);
if (index >= 0 && (unsigned int) index < g->nr_requested_credentials)
i = (size_t) index;
else {
error (g, _("credential index out of range"));
return NULL;
}
if (g->requested_credentials[i].prompt)
return safe_strdup (g, g->requested_credentials[i].prompt);
else
return safe_strdup (g, "");
}
char *
guestfs_impl_get_libvirt_requested_credential_challenge (guestfs_h *g, int index)
{
size_t i;
CHECK_IN_EVENT_HANDLER (NULL);
if (index >= 0 && (unsigned int) index < g->nr_requested_credentials)
i = (size_t) index;
else {
error (g, _("credential index out of range"));
return NULL;
}
if (g->requested_credentials[i].challenge)
return safe_strdup (g, g->requested_credentials[i].challenge);
else
return safe_strdup (g, "");
}
char *
guestfs_impl_get_libvirt_requested_credential_defresult (guestfs_h *g, int index)
{
size_t i;
CHECK_IN_EVENT_HANDLER (NULL);
if (index >= 0 && (unsigned int) index < g->nr_requested_credentials)
i = (size_t) index;
else {
error (g, _("credential index out of range"));
return NULL;
}
if (g->requested_credentials[i].defresult)
return safe_strdup (g, g->requested_credentials[i].defresult);
else
return safe_strdup (g, "");
}
int
guestfs_impl_set_libvirt_requested_credential (guestfs_h *g, int index,
const char *cred, size_t cred_size)
{
size_t i;
CHECK_IN_EVENT_HANDLER (-1);
if (index >= 0 && (unsigned int) index < g->nr_requested_credentials)
i = (size_t) index;
else {
error (g, _("credential index out of range"));
return -1;
}
/* All the evidence is that libvirt will free this. */
g->requested_credentials[i].result = safe_malloc (g, cred_size+1 /* sic */);
memcpy (g->requested_credentials[i].result, cred, cred_size);
/* Some libvirt drivers are buggy (eg. libssh2), and they expect
* that the cred field will be \0 terminated. To avoid surprises,
* add a \0 at the end. See also:
* https://www.redhat.com/archives/libvir-list/2012-October/msg00711.html
*/
g->requested_credentials[i].result[cred_size] = 0;
g->requested_credentials[i].resultlen = cred_size;
return 0;
}
#else /* no libvirt at compile time */
#define NOT_IMPL(r) \
error (g, _("libvirt authentication APIs not available since this version of libguestfs was compiled without libvirt")); \
return r
int
guestfs_impl_set_libvirt_supported_credentials (guestfs_h *g, char *const *creds)
{
NOT_IMPL(-1);
}
char **
guestfs_impl_get_libvirt_requested_credentials (guestfs_h *g)
{
NOT_IMPL(NULL);
}
char *
guestfs_impl_get_libvirt_requested_credential_prompt (guestfs_h *g, int index)
{
NOT_IMPL(NULL);
}
char *
guestfs_impl_get_libvirt_requested_credential_challenge (guestfs_h *g, int index)
{
NOT_IMPL(NULL);
}
char *
guestfs_impl_get_libvirt_requested_credential_defresult (guestfs_h *g, int index)
{
NOT_IMPL(NULL);
}
int
guestfs_impl_set_libvirt_requested_credential (guestfs_h *g, int index, const char *cred, size_t cred_size)
{
NOT_IMPL(-1);
}
#endif /* no libvirt at compile time */
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