util: Move semanage related functions to src/util

These functions will be reused by IPA provider.

Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

2 files changed, 364 insertions, 0 deletions

diff --git a/src/util/sss_semanage.c b/src/util/sss_semanage.c
new file mode 100644
index 000000000..dbef3b343
--- /dev/null
+++ b/src/util/sss_semanage.c
@@ -0,0 +1,360 @@
+/*
+   SSSD
+
+   sss_semanage.c
+
+   Copyright (C) Jakub Hrozek <jhrozek@redhat.com>        2010
+
+   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 "config.h"
+
+#include <stdio.h>
+
+#ifdef HAVE_SEMANAGE
+#include <semanage/semanage.h>
+#endif
+
+#include "util/util.h"
+
+#ifndef DEFAULT_SERANGE
+#define DEFAULT_SERANGE "s0"
+#endif
+
+#ifdef HAVE_SEMANAGE
+/* turn libselinux messages into SSSD DEBUG() calls */
+static void sss_semanage_error_callback(void *varg,
+                                        semanage_handle_t *handle,
+                                        const char *fmt, ...)
+{
+    int level = SSSDBG_INVALID;
+    int ret;
+    char * message = NULL;
+    va_list ap;
+
+    switch (semanage_msg_get_level(handle)) {
+        case SEMANAGE_MSG_ERR:
+            level = SSSDBG_CRIT_FAILURE;
+            break;
+        case SEMANAGE_MSG_WARN:
+            level = SSSDBG_MINOR_FAILURE;
+            break;
+        case SEMANAGE_MSG_INFO:
+            level = SSSDBG_TRACE_FUNC;
+            break;
+    }
+
+    va_start(ap, fmt);
+    ret = vasprintf(&message, fmt, ap);
+    va_end(ap);
+    if (ret < 0) {
+        /* ENOMEM */
+        return;
+    }
+
+    if (DEBUG_IS_SET(level))
+        debug_fn(__FILE__, __LINE__, "libsemanage", level, "%s\n", message);
+    free(message);
+}
+
+static semanage_handle_t *sss_semanage_init(void)
+{
+    int ret;
+    semanage_handle_t *handle = NULL;
+
+    handle = semanage_handle_create();
+    if (!handle) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Cannot create SELinux management handle\n");
+        return NULL;
+    }
+
+    semanage_msg_set_callback(handle,
+                              sss_semanage_error_callback,
+                              NULL);
+
+    ret = semanage_is_managed(handle);
+    if (ret != 1) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "SELinux policy not managed\n");
+        goto fail;
+    }
+
+    ret = semanage_access_check(handle);
+    if (ret < SEMANAGE_CAN_READ) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Cannot read SELinux policy store\n");
+        goto fail;
+    }
+
+    ret = semanage_connect(handle);
+    if (ret != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE,
+              "Cannot estabilish SELinux management connection\n");
+        goto fail;
+    }
+
+    ret = semanage_begin_transaction(handle);
+    if (ret != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Cannot begin SELinux transaction\n");
+        goto fail;
+    }
+
+    return handle;
+fail:
+    semanage_handle_destroy(handle);
+    return NULL;
+}
+
+static int sss_semanage_user_add(semanage_handle_t *handle,
+                                 semanage_seuser_key_t *key,
+                                 const char *login_name,
+                                 const char *seuser_name)
+{
+    int ret;
+    semanage_seuser_t *seuser = NULL;
+
+    ret = semanage_seuser_create(handle, &seuser);
+    if (ret != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE,
+              "Cannot create SELinux login mapping for %s\n", login_name);
+        ret = EIO;
+        goto done;
+    }
+
+    ret = semanage_seuser_set_name(handle, seuser, login_name);
+    if (ret != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Could not set name for %s\n", login_name);
+        ret = EIO;
+        goto done;
+    }
+
+    ret = semanage_seuser_set_mlsrange(handle, seuser, DEFAULT_SERANGE);
+    if (ret != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE,
+              "Could not set serange for %s\n", login_name);
+        ret = EIO;
+        goto done;
+    }
+
+    ret = semanage_seuser_set_sename(handle, seuser, seuser_name);
+    if (ret != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE,
+              "Could not set SELinux user for %s\n", login_name);
+        ret = EIO;
+        goto done;
+    }
+
+    ret = semanage_seuser_modify_local(handle, key, seuser);
+    if (ret != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE,
+              "Could not add login mapping for %s\n", login_name);
+        ret = EIO;
+        goto done;
+    }
+
+    ret = EOK;
+done:
+    semanage_seuser_free(seuser);
+    return ret;
+}
+
+static int sss_semanage_user_mod(semanage_handle_t *handle,
+                                 semanage_seuser_key_t *key,
+                                 const char *login_name,
+                                 const char *seuser_name)
+{
+    int ret;
+    semanage_seuser_t *seuser = NULL;
+
+    semanage_seuser_query(handle, key, &seuser);
+    if (seuser == NULL) {
+        DEBUG(SSSDBG_CRIT_FAILURE,
+              "Could not query seuser for %s\n", login_name);
+        ret = EIO;
+        goto done;
+    }
+
+    ret = semanage_seuser_set_mlsrange(handle, seuser, DEFAULT_SERANGE);
+    if (ret != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE,
+              "Could not set serange for %s\n", login_name);
+        ret = EIO;
+        goto done;
+    }
+
+    ret = semanage_seuser_set_sename(handle, seuser, seuser_name);
+    if (ret != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Could not set sename for %s\n", login_name);
+        ret = EIO;
+        goto done;
+    }
+
+    ret = semanage_seuser_modify_local(handle, key, seuser);
+    if (ret != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE,
+              ("Could not modify login mapping for %s\n"), login_name);
+        ret = EIO;
+        goto done;
+    }
+
+    ret = EOK;
+done:
+    semanage_seuser_free(seuser);
+    return ret;
+}
+
+int set_seuser(const char *login_name, const char *seuser_name)
+{
+    semanage_handle_t *handle = NULL;
+    semanage_seuser_key_t *key = NULL;
+    int ret;
+    int seuser_exists = 0;
+
+    if (seuser_name == NULL) {
+        /* don't care, just let system pick the defaults */
+        return EOK;
+    }
+
+    handle = sss_semanage_init();
+    if (!handle) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Cannot init SELinux management\n");
+        ret = EIO;
+        goto done;
+    }
+
+    ret = semanage_seuser_key_create(handle, login_name, &key);
+    if (ret != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Cannot create SELinux user key\n");
+        ret = EIO;
+        goto done;
+    }
+
+    ret = semanage_seuser_exists(handle, key, &seuser_exists);
+    if (ret < 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Cannot verify the SELinux user\n");
+        ret = EIO;
+        goto done;
+    }
+
+    if (seuser_exists) {
+        ret = sss_semanage_user_mod(handle, key, login_name, seuser_name);
+        if (ret != 0) {
+            DEBUG(SSSDBG_CRIT_FAILURE, "Cannot modify SELinux user mapping\n");
+            ret = EIO;
+            goto done;
+        }
+    } else {
+        ret = sss_semanage_user_add(handle, key, login_name, seuser_name);
+        if (ret != 0) {
+            DEBUG(SSSDBG_CRIT_FAILURE, "Cannot add SELinux user mapping\n");
+            ret = EIO;
+            goto done;
+        }
+    }
+
+    ret = semanage_commit(handle);
+    if (ret < 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Cannot commit SELinux transaction\n");
+        ret = EIO;
+        goto done;
+    }
+
+    ret = EOK;
+done:
+    semanage_seuser_key_free(key);
+    semanage_handle_destroy(handle);
+    return ret;
+}
+
+int del_seuser(const char *login_name)
+{
+    semanage_handle_t *handle = NULL;
+    semanage_seuser_key_t *key = NULL;
+    int ret;
+    int exists = 0;
+
+    handle = sss_semanage_init();
+    if (!handle) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Cannot init SELinux management\n");
+        ret = EIO;
+        goto done;
+    }
+
+    ret = semanage_seuser_key_create(handle, login_name, &key);
+    if (ret != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Cannot create SELinux user key\n");
+        ret = EIO;
+        goto done;
+    }
+
+    ret = semanage_seuser_exists(handle, key, &exists);
+    if (ret < 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Cannot verify the SELinux user\n");
+        ret = EIO;
+        goto done;
+    }
+
+    if (!exists) {
+        DEBUG(SSSDBG_FUNC_DATA,
+              "Login mapping for %s is not defined, OK if default mapping "
+                  "was used\n", login_name);
+        ret = EOK;  /* probably default mapping */
+        goto done;
+    }
+
+    ret = semanage_seuser_exists_local(handle, key, &exists);
+    if (ret < 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Cannot verify the SELinux user\n");
+        ret = EIO;
+        goto done;
+    }
+
+    if (!exists) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Login mapping for %s is defined in policy, "
+                  "cannot be deleted", login_name);
+        ret = ENOENT;
+        goto done;
+    }
+
+    ret = semanage_seuser_del_local(handle, key);
+    if (ret != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE,
+              "Could not delete login mapping for %s", login_name);
+        ret = EIO;
+        goto done;
+    }
+
+    ret = semanage_commit(handle);
+    if (ret < 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Cannot commit SELinux transaction\n");
+        ret = EIO;
+        goto done;
+    }
+
+    ret = EOK;
+done:
+    semanage_handle_destroy(handle);
+    return ret;
+}
+
+#else /* HAVE_SEMANAGE */
+int set_seuser(const char *login_name, const char *seuser_name)
+{
+    return EOK;
+}
+
+int del_seuser(const char *login_name)
+{
+    return EOK;
+}
+#endif  /* HAVE_SEMANAGE */
diff --git a/src/util/util.h b/src/util/util.h
index 0ac9b0104..b43ce6f50 100644
--- a/src/util/util.h
+++ b/src/util/util.h
@@ -591,4 +591,8 @@ errno_t switch_creds(TALLOC_CTX *mem_ctx,
                      struct sss_creds **saved_creds);
 errno_t restore_creds(struct sss_creds *saved_creds);
 
+/* from sss_semanage.c */
+int set_seuser(const char *login_name, const char *seuser_name);
+int del_seuser(const char *login_name);
+
 #endif /* __SSSD_UTIL_H__ */