freeipa/daemons/ipa-slapi-plugins/ipa-extdom-extop/ipa_extdom_extop.c
Alexander Bokovoy 78ad1cfe4f ipa-extdom-extop: refactor nsswitch operations
Refactor nsswitch operations in ipa-extdom-extop plugin to allow use
of timeout-enabled nsswitch calls provided by libsss_nss_idmap.

Standard POSIX nsswitch API has no way to cancel requests which may
cause ipa-extdom-extop requests to hang far too long and potentially
exhaust LDAP server workers. In addition, glibc nsswitch API iterates
through all nsswitch modules one by one and with multiple parallel
requests a lock up may happen in an unrelated nsswitch module like
nss_files.so.2.

A solution to the latter issue is to directly load nss_sss.so.2 plugin
and utilize it. This, however, does not solve a problem with lack of
cancellable API.

With SSSD 1.16.1, libsss_nss_idmap provides a timeout-enabled variant of
nsswitch API that is directly integrated with SSSD client side machinery
used by nss_sss.so.2. As result, this API can be used instead of loading
nss_sss.so.2 directly.

To support older SSSD version, both direct loading of nss_sss.so.2 and
new timeout-enabled API are supported by this changeset. An API to
abstract both is designed to be a mix between internal glibc nsswitch
API and external nsswitch API that libsss_nss_idmap mimics. API does not
expose per-call timeout. Instead, it allows to set a timeout per
nsswitch operation context to reduce requirements on information
a caller has to maintain.

A choice which API to use is made at configure time.

In order to test the API, a cmocka test is updated to explicitly load
nss_files.so.2 as a backend. Since use of nss_sss.so.2 would always
depend on availablility of SSSD, predictable testing would not be
possible without it otherwise. Also, cmocka test does not use
nss_wrapper anymore because nss_wrapper overrides higher level glibc
nsswitch API while we are loading an individual nsswitch module
directly.

As result, cmocka test overrides fopen() call used by nss_files.so.2 to
load /etc/passwd and /etc/group. An overridden version changes paths to
/etc/passwd and /etc/group to a local test_data/passwd and
test_data/group. This way we can continue testing a backend API for
ipa-extdom-extop with the same data as with nss_wrapper.

Fixes https://pagure.io/freeipa/issue/5464

Reviewed-By: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Simo Sorce <ssorce@redhat.com>
Reviewed-By: Robbie Harwood <rharwood@redhat.com>
2017-11-30 11:38:03 +02:00

276 lines
7.8 KiB
C

/** BEGIN COPYRIGHT BLOCK
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Additional permission under GPLv3 section 7:
*
* In the following paragraph, "GPL" means the GNU General Public
* License, version 3 or any later version, and "Non-GPL Code" means
* code that is governed neither by the GPL nor a license
* compatible with the GPL.
*
* You may link the code of this Program with Non-GPL Code and convey
* linked combinations including the two, provided that such Non-GPL
* Code only links to the code of this Program through those well
* defined interfaces identified in the file named EXCEPTION found in
* the source code files (the "Approved Interfaces"). The files of
* Non-GPL Code may instantiate templates or use macros or inline
* functions from the Approved Interfaces without causing the resulting
* work to be covered by the GPL. Only the copyright holders of this
* Program may make changes or additions to the list of Approved
* Interfaces.
*
* Authors:
* Sumit Bose <sbose@redhat.com>
*
* Copyright (C) 2011 Red Hat, Inc.
* All rights reserved.
* END COPYRIGHT BLOCK **/
#include "ipa_extdom.h"
#include "back_extdom.h"
#include "util.h"
#define DEFAULT_MAX_NSS_BUFFER (128*1024*1024)
#define DEFAULT_MAX_NSS_TIMEOUT (10*1000)
Slapi_PluginDesc ipa_extdom_plugin_desc = {
IPA_EXTDOM_FEATURE_DESC,
"FreeIPA project",
"FreeIPA/1.0",
IPA_EXTDOM_PLUGIN_DESC
};
static char *ipa_extdom_oid_list[] = {
EXOP_EXTDOM_OID,
EXOP_EXTDOM_V1_OID,
NULL
};
static char *ipa_extdom_name_list[] = {
IPA_EXTDOM_PLUGIN_DESC,
NULL
};
static int ipa_extdom_start(Slapi_PBlock *pb)
{
return LDAP_SUCCESS;
}
static int ipa_extdom_extop(Slapi_PBlock *pb)
{
char *oid = NULL;
char *err_msg = NULL;
int rc;
int ret;
struct berval *req_val = NULL;
struct berval *ret_val = NULL;
struct extdom_req *req = NULL;
struct ipa_extdom_ctx *ctx;
enum extdom_version version;
ret = slapi_pblock_get(pb, SLAPI_EXT_OP_REQ_OID, &oid);
if (ret != 0) {
rc = LDAP_OPERATIONS_ERROR;
err_msg = "Could not get OID value from request.\n";
goto done;
}
LOG("Received extended operation request with OID %s\n", oid);
if (strcasecmp(oid, EXOP_EXTDOM_OID) == 0) {
version = EXTDOM_V0;
} else if (strcasecmp(oid, EXOP_EXTDOM_V1_OID) == 0) {
version = EXTDOM_V1;
} else {
return SLAPI_PLUGIN_EXTENDED_NOT_HANDLED;
}
ret = slapi_pblock_get(pb, SLAPI_EXT_OP_REQ_VALUE, &req_val);
if (ret != 0) {
rc = LDAP_UNWILLING_TO_PERFORM;
err_msg = "Missing request data.\n";
goto done;
}
ret = slapi_pblock_get(pb, SLAPI_PLUGIN_PRIVATE, &ctx);
if (ret != 0) {
rc = LDAP_OPERATIONS_ERROR;
err_msg = "Missing plugin context.\n";
goto done;
}
ret = parse_request_data(req_val, &req);
if (ret != LDAP_SUCCESS) {
rc = LDAP_UNWILLING_TO_PERFORM;
err_msg = "Cannot parse request data.\n";
goto done;
}
ret = check_request(req, version);
if (ret != LDAP_SUCCESS) {
rc = LDAP_UNWILLING_TO_PERFORM;
err_msg = "Error in request data.\n";
goto done;
}
ret = handle_request(ctx, req, &ret_val);
if (ret != LDAP_SUCCESS) {
if (ret == LDAP_NO_SUCH_OBJECT) {
rc = LDAP_NO_SUCH_OBJECT;
} else {
rc = LDAP_OPERATIONS_ERROR;
err_msg = "Failed to handle the request.\n";
}
goto done;
}
ret = slapi_pblock_set(pb, SLAPI_EXT_OP_RET_OID, oid);
if (ret != 0) {
rc = LDAP_OPERATIONS_ERROR;
err_msg = "Failed to set the OID for the response.\n";
goto done;
}
ret = slapi_pblock_set( pb, SLAPI_EXT_OP_RET_VALUE, ret_val);
if (ret != 0) {
rc = LDAP_OPERATIONS_ERROR;
err_msg = "Failed to set the value for the response.\n";
goto done;
}
rc = LDAP_SUCCESS;
done:
if ((req != NULL) && (req->err_msg != NULL)) {
err_msg = req->err_msg;
}
if (err_msg != NULL) {
LOG("%s", err_msg);
}
slapi_send_ldap_result(pb, rc, NULL, err_msg, 0, NULL);
ber_bvfree(ret_val);
free_req_data(req);
return SLAPI_PLUGIN_EXTENDED_SENT_RESULT;
}
static int ipa_extdom_init_ctx(Slapi_PBlock *pb, struct ipa_extdom_ctx **_ctx)
{
struct ipa_extdom_ctx *ctx;
Slapi_Entry *e;
int ret;
unsigned int timeout;
ctx = calloc(1, sizeof(struct ipa_extdom_ctx));
if (!ctx) {
return LDAP_OPERATIONS_ERROR;
}
ret = slapi_pblock_get(pb, SLAPI_PLUGIN_IDENTITY, &ctx->plugin_id);
if ((ret != 0) || (NULL == ctx->plugin_id)) {
LOG_FATAL("Could not get identity or identity was NULL\n");
if (ret == 0) {
ret = -1;
}
goto done;
}
slapi_pblock_get(pb, SLAPI_PLUGIN_CONFIG_ENTRY, &e);
if (!e) {
LOG_FATAL("Plugin configuration not found!\n");
ret = -1;
goto done;
}
ctx->base_dn = slapi_entry_attr_get_charptr(e, "nsslapd-basedn");
if (!ctx->base_dn) {
LOG_FATAL("Base DN not found in plugin configuration not found!\n");
ret = -1;
goto done;
}
ctx->max_nss_buf_size = slapi_entry_attr_get_uint(e,
"ipaExtdomMaxNssBufSize");
if (ctx->max_nss_buf_size == 0) {
ctx->max_nss_buf_size = DEFAULT_MAX_NSS_BUFFER;
}
LOG("Maximal nss buffer size set to [%zu]!\n", ctx->max_nss_buf_size);
ret = back_extdom_init_context(&ctx->nss_ctx);
if (ret != 0) {
LOG("Unable to initialize nss interface: returned [%d]!\n", ret);
goto done;
}
timeout = slapi_entry_attr_get_uint(e, "ipaExtdomMaxNssTimeout");
if (timeout == 0) {
timeout = DEFAULT_MAX_NSS_TIMEOUT;
}
back_extdom_set_timeout(ctx->nss_ctx, timeout);
LOG("Maximal nss timeout (in ms) set to [%u]!\n", timeout);
ret = 0;
done:
if (ret) {
free(ctx);
} else {
*_ctx = ctx;
}
return ret;
}
int ipa_extdom_init(Slapi_PBlock *pb)
{
int ret;
struct ipa_extdom_ctx *extdom_ctx;
ret = ipa_extdom_init_ctx(pb, &extdom_ctx);
if (ret) {
LOG_FATAL("Failed ot initialize external domain extended operation.\n");
/* do not cause DS to stop, simply do nothing */
return 0;
}
ret = slapi_pblock_set(pb, SLAPI_PLUGIN_VERSION, SLAPI_PLUGIN_VERSION_01);
if (!ret) {
ret = slapi_pblock_set(pb, SLAPI_PLUGIN_DESCRIPTION,
(void *)&ipa_extdom_plugin_desc);
}
if (!ret) {
ret = slapi_pblock_set(pb, SLAPI_PLUGIN_START_FN,
(void *)ipa_extdom_start);
}
if (!ret) {
ret = slapi_pblock_set(pb, SLAPI_PLUGIN_EXT_OP_OIDLIST,
ipa_extdom_oid_list);
}
if (!ret) {
ret = slapi_pblock_set(pb, SLAPI_PLUGIN_EXT_OP_NAMELIST,
ipa_extdom_name_list);
}
if (!ret) {
ret = slapi_pblock_set(pb, SLAPI_PLUGIN_EXT_OP_FN,
(void *)ipa_extdom_extop);
}
if (!ret) {
ret = slapi_pblock_set(pb, SLAPI_PLUGIN_PRIVATE, extdom_ctx);
}
if (ret) {
LOG("Failed to set plug-in version, function, and OID.\n" );
return -1;
}
return 0;
}