ipa_selinux.c revision 21d485184df986e1a123f70c689517386e51a5ce
/*
SSSD
IPA Backend Module -- selinux loading
Authors:
Jan Zeleny <jzeleny@redhat.com>
Copyright (C) 2012 Red Hat
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/>.
*/
#include <security/pam_modules.h>
#include "db/sysdb_selinux.h"
#include "util/sss_selinux.h"
#include "providers/ldap/sdap_async.h"
#include "providers/ipa/ipa_common.h"
#include "providers/ipa/ipa_config.h"
#include "providers/ipa/ipa_selinux.h"
#include "providers/ipa/ipa_hosts.h"
#include "providers/ipa/ipa_hbac_rules.h"
#include "providers/ipa/ipa_hbac_private.h"
#include "providers/ipa/ipa_access.h"
#include "providers/ipa/ipa_selinux_common.h"
#include "providers/ipa/ipa_selinux_maps.h"
struct ipa_get_selinux_state {
struct be_req *be_req;
struct pam_data *pd;
struct ipa_selinux_ctx *selinux_ctx;
struct sdap_id_op *op;
const char *hostname;
struct sysdb_attrs *host;
struct sysdb_attrs *user;
struct sysdb_attrs *defaults;
struct sysdb_attrs **selinuxmaps;
size_t nmaps;
struct sysdb_attrs **possible_match;
size_t possible_matches;
};
static struct
tevent_req *ipa_get_selinux_send(struct be_req *breq,
struct pam_data *pd,
struct ipa_selinux_ctx *selinux_ctx);
static void ipa_selinux_handler_done(struct tevent_req *subreq);
static errno_t ipa_get_selinux_recv(struct tevent_req *req,
TALLOC_CTX *mem_ctx,
size_t *count,
struct sysdb_attrs ***maps,
char **default_user,
char **map_order);
static void ipa_get_selinux_connect_done(struct tevent_req *subreq);
static void ipa_get_selinux_hosts_done(struct tevent_req *subreq);
static void ipa_get_config_step(struct tevent_req *req);
static void ipa_get_selinux_config_done(struct tevent_req *subreq);
static void ipa_get_selinux_maps_done(struct tevent_req *subreq);
static void ipa_get_selinux_hbac_done(struct tevent_req *subreq);
static int
ipa_get_selinux_hbac_process(struct ipa_get_selinux_state *state,
struct sysdb_attrs **rules,
size_t rule_count);
void ipa_selinux_handler(struct be_req *be_req)
{
struct ipa_selinux_ctx *selinux_ctx;
struct tevent_req *req;
struct pam_data *pd;
pd = talloc_get_type(be_req->req_data, struct pam_data);
selinux_ctx = talloc_get_type(
be_req->be_ctx->bet_info[BET_SELINUX].pvt_bet_data,
struct ipa_selinux_ctx);
req = ipa_get_selinux_send(be_req, pd, selinux_ctx);
if (req == NULL) {
goto fail;
}
tevent_req_set_callback(req, ipa_selinux_handler_done, be_req);
return;
fail:
be_req->fn(be_req, DP_ERR_FATAL, PAM_SYSTEM_ERR, NULL);
}
static void ipa_selinux_handler_done(struct tevent_req *req)
{
struct be_req *breq = tevent_req_callback_data(req, struct be_req);
struct sysdb_ctx *sysdb = breq->be_ctx->sysdb;
errno_t ret, sret;
size_t map_count = 0;
struct sysdb_attrs **maps = NULL;
bool in_transaction = false;
char *default_user = NULL;
struct pam_data *pd = talloc_get_type(breq->req_data, struct pam_data);
char *map_order = NULL;
ret = ipa_get_selinux_recv(req, breq, &map_count, &maps,
&default_user, &map_order);
if (ret != EOK) {
goto fail;
}
ret = sysdb_transaction_start(sysdb);
if (ret != EOK) {
DEBUG(SSSDBG_CRIT_FAILURE, ("Failed to start transaction\n"));
goto fail;
}
in_transaction = true;
ret = sysdb_delete_usermaps(breq->sysdb);
if (ret != EOK) {
DEBUG(SSSDBG_CRIT_FAILURE,
("Cannot delete existing maps from sysdb\n"));
goto fail;
}
if (default_user != NULL && map_order != NULL) {
ret = sysdb_store_selinux_config(sysdb, default_user, map_order);
if (ret != EOK) {
goto fail;
}
}
if (map_count > 0 && maps != NULL) {
ret = ipa_save_user_maps(sysdb, map_count, maps);
if (ret != EOK) {
goto fail;
}
}
ret = sysdb_transaction_commit(sysdb);
if (ret != EOK) {
DEBUG(SSSDBG_OP_FAILURE, ("Could not commit transaction\n"));
goto fail;
}
/* Just in case more code will follow after this place in the future */
in_transaction = false;
pd->pam_status = PAM_SUCCESS;
breq->fn(breq, DP_ERR_OK, EOK, "Success");
return;
fail:
if (in_transaction) {
sret = sysdb_transaction_cancel(sysdb);
if (sret != EOK) {
DEBUG(SSSDBG_OP_FAILURE, ("Could not cancel transaction\n"));
}
}
if (ret == EAGAIN) {
breq->fn(breq, DP_ERR_OFFLINE, EAGAIN, "Offline");
} else {
breq->fn(breq, DP_ERR_FATAL, ret, NULL);
}
}
static struct tevent_req *ipa_get_selinux_send(struct be_req *breq,
struct pam_data *pd,
struct ipa_selinux_ctx *selinux_ctx)
{
struct tevent_req *req;
struct tevent_req *subreq;
struct be_ctx *bctx = breq->be_ctx;
struct ipa_get_selinux_state *state;
bool offline;
int ret = EOK;
DEBUG(SSSDBG_TRACE_FUNC, ("Retrieving SELinux user mapping\n"));
req = tevent_req_create(breq, &state, struct ipa_get_selinux_state);
if (req == NULL) {
return NULL;
}
state->be_req = breq;
state->pd = pd;
state->selinux_ctx = selinux_ctx;
offline = be_is_offline(bctx);
DEBUG(SSSDBG_TRACE_INTERNAL, ("Connection status is [%s].\n",
offline ? "offline" : "online"));
if (!offline) {
state->op = sdap_id_op_create(state, selinux_ctx->id_ctx->sdap_id_ctx->conn_cache);
if (!state->op) {
DEBUG(SSSDBG_OP_FAILURE, ("sdap_id_op_create failed\n"));
ret = ENOMEM;
goto immediate;
}
subreq = sdap_id_op_connect_send(state->op, state, &ret);
if (!subreq) {
DEBUG(SSSDBG_CRIT_FAILURE, ("sdap_id_op_connect_send failed: "
"%d(%s).\n", ret, strerror(ret)));
talloc_zfree(state->op);
goto immediate;
}
tevent_req_set_callback(subreq, ipa_get_selinux_connect_done, req);
} else {
ret = EAGAIN;
goto immediate;
}
return req;
immediate:
if (ret == EOK) {
tevent_req_done(req);
} else {
tevent_req_error(req, ret);
}
tevent_req_post(req, bctx->ev);
return req;
}
static void ipa_get_selinux_connect_done(struct tevent_req *subreq)
{
struct tevent_req *req = tevent_req_callback_data(subreq,
struct tevent_req);
struct ipa_get_selinux_state *state = tevent_req_data(req,
struct ipa_get_selinux_state);
int dp_error = DP_ERR_FATAL;
int ret;
struct ipa_id_ctx *id_ctx = state->selinux_ctx->id_ctx;
struct be_ctx *bctx = state->be_req->be_ctx;
const char *access_name;
const char *selinux_name;
struct ldb_dn *host_dn;
const char *attrs[] = { SYSDB_ORIG_DN,
SYSDB_ORIG_MEMBEROF,
NULL };
size_t count;
struct ldb_message **msgs;
struct sysdb_attrs **hosts;
struct sss_domain_info *domain;
ret = sdap_id_op_connect_recv(subreq, &dp_error);
talloc_zfree(subreq);
if (dp_error == DP_ERR_OFFLINE) {
talloc_zfree(state->op);
ret = EAGAIN;
}
if (ret != EOK) {
goto fail;
}
state->hostname = dp_opt_get_string(state->selinux_ctx->id_ctx->ipa_options->basic,
IPA_HOSTNAME);
access_name = state->be_req->be_ctx->bet_info[BET_ACCESS].mod_name;
selinux_name = state->be_req->be_ctx->bet_info[BET_SELINUX].mod_name;
if (strcasecmp(access_name, selinux_name) == 0) {
domain = sysdb_ctx_get_domain(bctx->sysdb);
host_dn = sysdb_custom_dn(bctx->sysdb, state, domain->name,
state->hostname, HBAC_HOSTS_SUBDIR);
if (host_dn == NULL) {
ret = ENOMEM;
goto fail;
}
/* Look up the host to get its originalMemberOf entries */
ret = sysdb_search_entry(state, bctx->sysdb, host_dn,
LDB_SCOPE_BASE, NULL,
attrs, &count, &msgs);
if (ret == ENOENT || count == 0) {
/* We need to query the server */
goto server;
} else if (ret != EOK) {
goto fail;
} else if (count > 1) {
DEBUG(SSSDBG_OP_FAILURE, ("More than one result for a BASE search!\n"));
ret = EIO;
goto fail;
}
ret = sysdb_msg2attrs(state, count, msgs, &hosts);
if (ret != EOK) {
goto fail;
}
state->host = hosts[0];
return ipa_get_config_step(req);
}
server:
subreq = ipa_host_info_send(state, bctx->ev, bctx->sysdb,
sdap_id_op_handle(state->op),
id_ctx->sdap_id_ctx->opts,
state->hostname,
id_ctx->ipa_options->host_map,
NULL,
state->selinux_ctx->host_search_bases);
if (subreq == NULL) {
ret = ENOMEM;
goto fail;
}
tevent_req_set_callback(subreq, ipa_get_selinux_hosts_done, req);
return;
fail:
tevent_req_error(req, ret);
}
static void ipa_get_selinux_hosts_done(struct tevent_req *subreq)
{
errno_t ret;
struct tevent_req *req = tevent_req_callback_data(subreq,
struct tevent_req);
struct ipa_get_selinux_state *state = tevent_req_data(req,
struct ipa_get_selinux_state);
size_t host_count, hostgroup_count;
struct sysdb_attrs **hostgroups;
struct sysdb_attrs **host;
ret = ipa_host_info_recv(subreq, state, &host_count, &host,
&hostgroup_count, &hostgroups);
talloc_free(subreq);
if (ret != EOK) {
goto done;
}
state->host = host[0];
return ipa_get_config_step(req);
done:
if (ret != EOK) {
tevent_req_error(req, ret);
}
}
static void ipa_get_config_step(struct tevent_req *req)
{
errno_t ret;
const char *domain;
struct tevent_req *subreq;
struct ipa_get_selinux_state *state = tevent_req_data(req,
struct ipa_get_selinux_state);
struct be_ctx *bctx = state->be_req->be_ctx;
struct ipa_id_ctx *id_ctx = state->selinux_ctx->id_ctx;
ret = sss_selinux_extract_user(state, bctx->sysdb,
state->pd->user, &state->user);
if (ret != EOK) {
tevent_req_error(req, ret);
return;
}
domain = dp_opt_get_string(state->selinux_ctx->id_ctx->ipa_options->basic,
IPA_KRB5_REALM);
subreq = ipa_get_config_send(state, bctx->ev,
sdap_id_op_handle(state->op),
id_ctx->sdap_id_ctx->opts,
domain, NULL);
if (subreq == NULL) {
tevent_req_error(req, ENOMEM);
}
tevent_req_set_callback(subreq, ipa_get_selinux_config_done, req);
}
static void ipa_get_selinux_config_done(struct tevent_req *subreq)
{
struct tevent_req *req = tevent_req_callback_data(subreq,
struct tevent_req);
struct ipa_get_selinux_state *state = tevent_req_data(req,
struct ipa_get_selinux_state);
struct be_ctx *bctx = state->be_req->be_ctx;
struct sdap_id_ctx *id_ctx = state->selinux_ctx->id_ctx->sdap_id_ctx;
errno_t ret;
ret = ipa_get_config_recv(subreq, state, &state->defaults);
talloc_free(subreq);
if (ret != EOK) {
DEBUG(SSSDBG_OP_FAILURE, ("Could not get IPA config\n"));
goto done;
}
subreq = ipa_selinux_get_maps_send(state, bctx->ev, bctx->sysdb,
sdap_id_op_handle(state->op),
id_ctx->opts,
state->selinux_ctx->id_ctx->ipa_options,
state->selinux_ctx->selinux_search_bases);
if (!subreq) {
ret = ENOMEM;
goto done;
}
tevent_req_set_callback(subreq, ipa_get_selinux_maps_done, req);
return;
done:
if (ret != EOK) {
tevent_req_error(req, ret);
} else {
tevent_req_done(req);
}
}
static void ipa_get_selinux_maps_done(struct tevent_req *subreq)
{
struct tevent_req *req;
struct ipa_get_selinux_state *state;
struct be_ctx *bctx;
struct ipa_id_ctx *id_ctx;
char *selinux_name;
char *access_name;
struct sysdb_attrs **rules;
size_t rule_count;
const char *tmp_str;
uint32_t priority = 0;
errno_t ret;
int i;
req = tevent_req_callback_data(subreq, struct tevent_req);
state = tevent_req_data(req, struct ipa_get_selinux_state);
bctx = state->be_req->be_ctx;
id_ctx = state->selinux_ctx->id_ctx;
ret = ipa_selinux_get_maps_recv(subreq, state,
&state->nmaps, &state->selinuxmaps);
talloc_free(subreq);
if (ret != EOK) {
if (ret == ENOENT) {
/* This is returned if no SELinux mapping
* rules were found. In that case no error
* occurred, but we don't want any more processing.*/
ret = EOK;
}
goto done;
}
DEBUG(SSSDBG_TRACE_FUNC,
("Found %d SELinux user maps\n", state->nmaps));
state->possible_match = talloc_zero_array(state, struct sysdb_attrs *,
state->nmaps + 1);
if (state->possible_match == NULL) {
ret = ENOMEM;
goto done;
}
for (i = 0; i < state->nmaps; i++) {
if (sss_selinux_match(state->selinuxmaps[i], state->user,
state->host, &priority)) {
priority &= ~(SELINUX_PRIORITY_USER_NAME |
SELINUX_PRIORITY_USER_GROUP |
SELINUX_PRIORITY_USER_CAT);
ret = sysdb_attrs_add_uint32(state->selinuxmaps[i],
SYSDB_SELINUX_HOST_PRIORITY,
priority);
if (ret != EOK) {
goto done;
}
continue;
}
ret = sysdb_attrs_get_string(state->selinuxmaps[i],
SYSDB_SELINUX_SEEALSO, &tmp_str);
if (ret == ENOENT) {
continue;
}
state->possible_match[state->possible_matches] = state->selinuxmaps[i];
state->possible_matches++;
}
if (state->possible_matches) {
access_name = state->be_req->be_ctx->bet_info[BET_ACCESS].mod_name;
selinux_name = state->be_req->be_ctx->bet_info[BET_SELINUX].mod_name;
if (strcasecmp(access_name, selinux_name) == 0) {
ret = hbac_get_cached_rules(state, state->be_req->be_ctx->sysdb,
&rule_count, &rules);
if (ret != EOK) {
goto done;
}
ret = ipa_get_selinux_hbac_process(state, rules, rule_count);
goto done;
}
DEBUG(SSSDBG_TRACE_FUNC, ("%d SELinux maps referenced an HBAC rule. "
"Need to refresh HBAC rules\n", state->possible_matches));
subreq = ipa_hbac_rule_info_send(state, false, bctx->ev,
sdap_id_op_handle(state->op),
id_ctx->sdap_id_ctx->opts,
state->selinux_ctx->hbac_search_bases,
state->host);
if (subreq == NULL) {
ret = ENOMEM;
goto done;
}
tevent_req_set_callback(subreq, ipa_get_selinux_hbac_done, req);
return;
}
ret = EOK;
done:
if (ret == EOK) {
tevent_req_done(req);
} else {
tevent_req_error(req, ret);
}
}
static void ipa_get_selinux_hbac_done(struct tevent_req *subreq)
{
struct tevent_req *req = tevent_req_callback_data(subreq,
struct tevent_req);
struct ipa_get_selinux_state *state = tevent_req_data(req,
struct ipa_get_selinux_state);
struct sysdb_attrs **rules;
size_t rule_count;
errno_t ret;
ret = ipa_hbac_rule_info_recv(subreq, state, &rule_count,
&rules);
DEBUG(SSSDBG_TRACE_INTERNAL,
("Received %d HBAC rules\n", rule_count));
talloc_free(subreq);
if (ret != EOK) {
goto done;
}
ret = ipa_get_selinux_hbac_process(state, rules, rule_count);
done:
if (ret != EOK) {
tevent_req_error(req, ret);
} else {
tevent_req_done(req);
}
}
static int
ipa_get_selinux_hbac_process(struct ipa_get_selinux_state *state,
struct sysdb_attrs **rules,
size_t rule_count)
{
int i, j;
errno_t ret;
uint32_t priority = 0;
const char *hbac_dn;
const char *seealso_dn;
struct sysdb_attrs *usermap;
struct ldb_message_element *el;
for (i = 0; i < rule_count; i++) {
ret = sysdb_attrs_get_string(rules[i], SYSDB_ORIG_DN, &hbac_dn);
if (ret != EOK) {
goto done;
}
/* We need to do this translation for further processing. We have to
* do it manually because no map was used to retrieve HBAC rules.
*/
ret = sysdb_attrs_get_el(rules[i], IPA_MEMBER_HOST, &el);
if (ret != EOK) goto done;
el->name = SYSDB_ORIG_MEMBER_HOST;
ret = sysdb_attrs_get_el(rules[i], IPA_MEMBER_USER, &el);
if (ret != EOK) goto done;
el->name = SYSDB_ORIG_MEMBER_USER;
DEBUG(SSSDBG_TRACE_ALL,
("Matching HBAC rule %s with SELinux mappings\n", hbac_dn));
if (!sss_selinux_match(rules[i], state->user, state->host, &priority)) {
DEBUG(SSSDBG_TRACE_ALL, ("Rule did not match\n"));
continue;
}
/* HBAC rule matched, find if it is in the "possible" list */
for (j = 0; j < state->possible_matches; j++) {
usermap = state->possible_match[j];
if (usermap == NULL) {
continue;
}
ret = sysdb_attrs_get_string(usermap, SYSDB_SELINUX_SEEALSO, &seealso_dn);
if (ret != EOK) {
goto done;
}
if (strcasecmp(hbac_dn, seealso_dn) == 0) {
DEBUG(SSSDBG_TRACE_FUNC, ("HBAC rule [%s] matched, copying its"
"attributes to SELinux user map [%s]\n",
hbac_dn, seealso_dn));
priority &= ~(SELINUX_PRIORITY_USER_NAME |
SELINUX_PRIORITY_USER_GROUP |
SELINUX_PRIORITY_USER_CAT);
ret = sysdb_attrs_add_uint32(usermap,
SYSDB_SELINUX_HOST_PRIORITY,
priority);
if (ret != EOK) {
goto done;
}
ret = sysdb_attrs_copy_values(rules[i], usermap, SYSDB_ORIG_MEMBER_USER);
if (ret != EOK) {
goto done;
}
ret = sysdb_attrs_copy_values(rules[i], usermap, SYSDB_USER_CATEGORY);
if (ret != EOK) {
goto done;
}
/* Just to boost the following lookup */
state->possible_match[j] = NULL;
}
}
}
/* Now we can dispose all possible rules, since they aren't possible any more */
talloc_zfree(state->possible_match);
ret = EOK;
done:
return ret;
}
static errno_t
ipa_get_selinux_recv(struct tevent_req *req,
TALLOC_CTX *mem_ctx,
size_t *count,
struct sysdb_attrs ***maps,
char **default_user,
char **map_order)
{
struct ipa_get_selinux_state *state =
tevent_req_data(req, struct ipa_get_selinux_state);
const char *tmp_str;
errno_t ret;
TEVENT_REQ_RETURN_ON_ERROR(req);
if (state->defaults != NULL) {
ret = sysdb_attrs_get_string(state->defaults, IPA_CONFIG_SELINUX_DEFAULT_MAP,
&tmp_str);
if (ret != EOK) {
return ret;
}
*default_user = talloc_strdup(mem_ctx, tmp_str);
if (*default_user == NULL) {
return ENOMEM;
}
ret = sysdb_attrs_get_string(state->defaults, IPA_CONFIG_SELINUX_MAP_ORDER,
&tmp_str);
if (ret != EOK) {
return ret;
}
*map_order = talloc_strdup(mem_ctx, tmp_str);
if (*map_order == NULL) {
talloc_zfree(*default_user);
return ENOMEM;
}
} else {
*map_order = NULL;
*default_user = NULL;
}
if (state->selinuxmaps != NULL) {
*count = state->nmaps;
*maps = talloc_steal(mem_ctx, state->selinuxmaps);
} else {
*count = 0;
*maps = NULL;
}
return EOK;
}