selinux: split off selinux calls into seperate file label.c

1 files changed, 291 insertions, 0 deletions

diff --git a/src/label.c b/src/label.c
new file mode 100644
index 000000000..d18e5dc7b
--- /dev/null
+++ b/src/label.c
@@ -0,0 +1,291 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd 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 2 of the License, or
+  (at your option) any later version.
+
+  systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "label.h"
+#include "util.h"
+
+#ifdef HAVE_SELINUX
+#include <selinux/selinux.h>
+#include <selinux/label.h>
+
+static struct selabel_handle *label_hnd = NULL;
+
+static inline bool use_selinux(void) {
+        static int use_selinux_ind = -1;
+
+        if (use_selinux_ind < 0)
+                use_selinux_ind = is_selinux_enabled() > 0;
+
+        return use_selinux_ind;
+}
+
+static int label_get_file_label_from_path(
+                const char *label,
+                const char *path,
+                const char *class,
+                security_context_t *fcon) {
+
+        security_context_t dir_con = NULL;
+        security_class_t sclass;
+        int r = 0;
+
+        r = getfilecon(path, &dir_con);
+        if (r >= 0) {
+                r = -1;
+                errno = EINVAL;
+
+                if ((sclass = string_to_security_class(class)) != 0)
+                        r = security_compute_create((security_context_t) label, dir_con, sclass, fcon);
+        }
+        if (r < 0)
+                r = -errno;
+
+        freecon(dir_con);
+        return r;
+}
+
+#endif
+
+int label_init(void) {
+        int r = 0;
+
+#ifdef HAVE_SELINUX
+
+        if (!use_selinux())
+                return 0;
+
+        label_hnd = selabel_open(SELABEL_CTX_FILE, NULL, 0);
+        if (!label_hnd) {
+                log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG,
+                         "Failed to initialize SELinux context: %m");
+                r = (security_getenforce() == 1) ? -errno : 0;
+        }
+#endif
+
+        return r;
+}
+
+int label_fix(const char *path) {
+        int r = 0;
+
+#ifdef HAVE_SELINUX
+        struct stat st;
+        security_context_t fcon;
+
+        if (!use_selinux() || !label_hnd)
+                return 0;
+
+        r = lstat(path, &st);
+        if (r == 0) {
+                r = selabel_lookup_raw(label_hnd, &fcon, path, st.st_mode);
+
+                if (r == 0) {
+                        r = setfilecon(path, fcon);
+                        freecon(fcon);
+                }
+        }
+        if (r < 0) {
+                log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG,
+                         "Unable to fix label of %s: %m", path);
+                r = (security_getenforce() == 1) ? -errno : 0;
+        }
+#endif
+
+        return r;
+}
+
+void label_finish(void) {
+
+#ifdef HAVE_SELINUX
+        if (use_selinux() && label_hnd)
+                selabel_close(label_hnd);
+#endif
+}
+
+int label_get_socket_label_from_exe(const char *exe, char **label) {
+
+        int r = 0;
+
+#ifdef HAVE_SELINUX
+        security_context_t mycon = NULL, fcon = NULL;
+        security_class_t sclass;
+
+        if (!use_selinux()) {
+                *label = NULL;
+                return 0;
+        }
+
+        r = getcon(&mycon);
+        if (r < 0)
+                goto fail;
+
+        r = getfilecon(exe, &fcon);
+        if (r < 0)
+                goto fail;
+
+        sclass = string_to_security_class("process");
+        r = security_compute_create(mycon, fcon, sclass, (security_context_t *) label);
+        if (r == 0)
+                log_debug("SELinux Socket context for %s will be set to %s", exe, *label);
+
+fail:
+        if (r < 0 && security_getenforce() == 1)
+                r = -errno;
+
+        freecon(mycon);
+        freecon(fcon);
+#endif
+
+        return r;
+}
+
+int label_fifofile_set(const char *label, const char *path) {
+        int r = 0;
+
+#ifdef HAVE_SELINUX
+        security_context_t filecon = NULL;
+
+        if (!use_selinux() || !label)
+                return 0;
+
+        if (((r = label_get_file_label_from_path(label, path, "fifo_file", &filecon)) == 0)) {
+                if ((r = setfscreatecon(filecon)) < 0) {
+                        log_error("Failed to set SELinux file context (%s) on %s: %m", label, path);
+                        r = -errno;
+                }
+
+                freecon(filecon);
+        }
+
+        if (r < 0 && security_getenforce() == 0)
+                r = 0;
+#endif
+
+        return r;
+}
+
+int label_socket_set(const char *label) {
+
+#ifdef HAVE_SELINUX
+        if (!use_selinux())
+                return 0;
+
+        if (setsockcreatecon((security_context_t) label) < 0) {
+                log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG,
+                         "Failed to set SELinux context (%s) on socket: %m", label);
+
+                if (security_getenforce() == 1)
+                        return -errno;
+        }
+#endif
+
+        return 0;
+}
+
+void label_file_clear(void) {
+
+#ifdef HAVE_SELINUX
+        if (!use_selinux())
+                return;
+
+        setfscreatecon(NULL);
+#endif
+}
+
+void label_socket_clear(void) {
+
+#ifdef HAVE_SELINUX
+        if (!use_selinux())
+                return;
+
+        setsockcreatecon(NULL);
+#endif
+}
+
+void label_free(const char *label) {
+
+#ifdef HAVE_SELINUX
+        if (!use_selinux())
+                return;
+
+        freecon((security_context_t) label);
+#endif
+}
+
+int label_mkdir(
+        const char *path,
+        mode_t mode) {
+
+        /* Creates a directory and labels it according to the SELinux policy */
+
+#ifdef HAVE_SELINUX
+        int r;
+        security_context_t fcon = NULL;
+
+        if (use_selinux() && label_hnd) {
+
+                if (path[0] == '/')
+                        r = selabel_lookup_raw(label_hnd, &fcon, path, mode);
+                else {
+                        char *cwd = NULL, *newpath = NULL;
+
+                        cwd = get_current_dir_name();
+
+                        if (cwd || asprintf(&newpath, "%s/%s", cwd, path) < 0) {
+                                free(cwd);
+                                return -errno;
+                        }
+
+                        r = selabel_lookup_raw(label_hnd, &fcon, newpath, mode);
+                        free(cwd);
+                        free(newpath);
+                }
+
+                if (r == 0)
+                        r = setfscreatecon(fcon);
+
+                if (r < 0 && errno != ENOENT) {
+                        log_error("Failed to set security context %s for %s: %m", fcon, path);
+                        r = -errno;
+
+                        if (security_getenforce() == 1)
+                                goto finish;
+                }
+        }
+
+        if ((r = mkdir(path, mode)) < 0)
+                r = -errno;
+
+finish:
+        if (use_selinux() && label_hnd) {
+                setfscreatecon(NULL);
+                freecon(fcon);
+        }
+
+        return r;
+#else
+        return mkdir(path, mode);
+#endif
+}