chiark / gitweb /
dbus-timer: fix bus_timer_vtable to have the correct times
[elogind.git] / src / core / selinux-access.c
index d9c3f9b..21c7a8c 100644 (file)
@@ -6,16 +6,16 @@
   Copyright 2012 Dan Walsh
 
   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
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 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.
+  Lesser General Public License for more details.
 
-  You should have received a copy of the GNU General Public License
+  You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
 #include <limits.h>
 #include <selinux/selinux.h>
 #include <selinux/avc.h>
+#include <sys/socket.h>
 #ifdef HAVE_AUDIT
 #include <libaudit.h>
 #endif
-#include <dbus.h>
 
+#include "sd-bus.h"
+#include "bus-util.h"
 #include "util.h"
 #include "log.h"
-#include "bus-errors.h"
-#include "dbus-common.h"
 #include "audit.h"
 #include "selinux-util.h"
 #include "audit-fd.h"
+#include "strv.h"
 
 static bool initialized = false;
 
-struct auditstruct {
+struct audit_info {
+        sd_bus_creds *creds;
         const char *path;
-        char *cmdline;
-        uid_t loginuid;
-        uid_t uid;
-        gid_t gid;
+        const char *cmdline;
 };
 
-static int bus_get_selinux_security_context(
-                DBusConnection *connection,
-                const char *name,
-                char **scon,
-                DBusError *error) {
-
-        _cleanup_dbus_message_unref_ DBusMessage *m = NULL, *reply = NULL;
-
-        m = dbus_message_new_method_call(
-                        DBUS_SERVICE_DBUS,
-                        DBUS_PATH_DBUS,
-                        DBUS_INTERFACE_DBUS,
-                        "GetConnectionSELinuxSecurityContext");
-        if (!m) {
-                dbus_set_error_const(error, DBUS_ERROR_NO_MEMORY, NULL);
-                return -ENOMEM;
-        }
-
-        if (!dbus_message_append_args(
-                            m,
-                            DBUS_TYPE_STRING, &name,
-                            DBUS_TYPE_INVALID)) {
-                dbus_set_error_const(error, DBUS_ERROR_NO_MEMORY, NULL);
-                return -ENOMEM;
-        }
-
-        reply = dbus_connection_send_with_reply_and_block(connection, m, -1, error);
-        if (!reply)
-                return -EIO;
-
-        if (dbus_set_error_from_message(error, reply))
-                return -EIO;
-
-        if (!dbus_message_get_args(
-                            reply, error,
-                            DBUS_TYPE_STRING, scon,
-                            DBUS_TYPE_INVALID))
-                return -EIO;
-
-        return 0;
-}
-
-static int bus_get_audit_data(
-                DBusConnection *connection,
-                const char *name,
-                struct auditstruct *audit,
-                DBusError *error) {
-
-        pid_t pid;
-        int r;
-
-        pid = bus_get_unix_process_id(connection, name, error);
-        if (pid <= 0)
-                return -EIO;
-
-        r = audit_loginuid_from_pid(pid, &audit->loginuid);
-        if (r < 0)
-                return r;
-
-        r = get_process_uid(pid, &audit->uid);
-        if (r < 0)
-                return r;
-
-        r = get_process_gid(pid, &audit->gid);
-        if (r < 0)
-                return r;
-
-        r = get_process_cmdline(pid, LINE_MAX, true, &audit->cmdline);
-        if (r < 0)
-                return r;
-
-        return 0;
-}
-
 /*
    Any time an access gets denied this callback will be called
    with the aduit data.  We then need to just copy the audit data into the msgbuf.
@@ -136,19 +61,19 @@ static int audit_callback(
                 char *msgbuf,
                 size_t msgbufsize) {
 
-        struct auditstruct *audit = (struct auditstruct *) auditdata;
+        const struct audit_info *audit = auditdata;
+        uid_t uid = 0, login_uid = 0;
+        gid_t gid = 0;
+
+        sd_bus_creds_get_audit_login_uid(audit->creds, &login_uid);
+        sd_bus_creds_get_uid(audit->creds, &uid);
+        sd_bus_creds_get_gid(audit->creds, &gid);
 
         snprintf(msgbuf, msgbufsize,
                  "auid=%d uid=%d gid=%d%s%s%s%s%s%s",
-                 audit->loginuid,
-                 audit->uid,
-                 audit->gid,
-                 (audit->path ? " path=\"" : ""),
-                 strempty(audit->path),
-                 (audit->path ? "\"" : ""),
-                 (audit->cmdline ? " cmdline=\"" : ""),
-                 strempty(audit->cmdline),
-                 (audit->cmdline ? "\"" : ""));
+                 login_uid, uid, gid,
+                 audit->path ? " path=\"" : "", strempty(audit->path), audit->path ? "\"" : "",
+                 audit->cmdline ? " cmdline=\"" : "", strempty(audit->cmdline), audit->cmdline ? "\"" : "");
 
         msgbuf[msgbufsize-1] = 0;
 
@@ -161,22 +86,26 @@ static int audit_callback(
    user_avc's into the /var/log/audit/audit.log, otherwise they will be
    sent to syslog.
 */
-static int log_callback(int type, const char *fmt, ...) {
+_printf_(2, 3) static int log_callback(int type, const char *fmt, ...) {
         va_list ap;
 
-        va_start(ap, fmt);
-
 #ifdef HAVE_AUDIT
         if (get_audit_fd() >= 0) {
-                char buf[LINE_MAX];
+                _cleanup_free_ char *buf = NULL;
+                int r;
 
-                vsnprintf(buf, sizeof(buf), fmt, ap);
-                audit_log_user_avc_message(get_audit_fd(), AUDIT_USER_AVC, buf, NULL, NULL, NULL, 0);
+                va_start(ap, fmt);
+                r = vasprintf(&buf, fmt, ap);
                 va_end(ap);
 
-                return 0;
+                if (r >= 0) {
+                        audit_log_user_avc_message(get_audit_fd(), AUDIT_USER_AVC, buf, NULL, NULL, NULL, 0);
+                        return 0;
+                }
         }
 #endif
+
+        va_start(ap, fmt);
         log_metav(LOG_USER | LOG_INFO, __FILE__, __LINE__, __FUNCTION__, fmt, ap);
         va_end(ap);
 
@@ -189,7 +118,7 @@ static int log_callback(int type, const char *fmt, ...) {
    If you want to cleanup memory you should need to call selinux_access_finish.
 */
 static int access_init(void) {
-        int r;
+        int r = 0;
 
         if (avc_open(NULL, 0)) {
                 log_error("avc_open() failed: %m");
@@ -199,34 +128,33 @@ static int access_init(void) {
         selinux_set_callback(SELINUX_CB_AUDIT, (union selinux_callback) audit_callback);
         selinux_set_callback(SELINUX_CB_LOG, (union selinux_callback) log_callback);
 
-        if (security_getenforce() >= 0)
-                return 0;
-
-        r = -errno;
-        avc_destroy();
+        if (security_getenforce() < 0){
+                r = -errno;
+                avc_destroy();
+        }
 
         return r;
 }
 
-static int selinux_access_init(DBusError *error) {
+static int selinux_access_init(sd_bus_error *error) {
         int r;
 
         if (initialized)
                 return 0;
 
-        if (use_selinux()) {
-                r = access_init();
-                if (r < 0) {
-                        dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "Failed to initialize SELinux.");
-                        return r;
-                }
-        }
+        if (!use_selinux())
+                return 0;
+
+        r = access_init();
+        if (r < 0)
+                return sd_bus_error_set(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to initialize SELinux.");
 
         initialized = true;
         return 0;
 }
 
 void selinux_access_free(void) {
+
         if (!initialized)
                 return;
 
@@ -234,106 +162,28 @@ void selinux_access_free(void) {
         initialized = false;
 }
 
-static int get_audit_data(
-                DBusConnection *connection,
-                DBusMessage *message,
-                struct auditstruct *audit,
-                DBusError *error) {
-
-        const char *sender;
-        int r, fd;
-        struct ucred ucred;
-        socklen_t len;
-
-        sender = dbus_message_get_sender(message);
-        if (sender)
-                return bus_get_audit_data(connection, sender, audit, error);
-
-        if (!dbus_connection_get_unix_fd(connection, &fd))
-                return -EINVAL;
-
-        r = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len);
-        if (r < 0) {
-                log_error("Failed to determine peer credentials: %m");
-                return -errno;
-        }
-
-        audit->uid = ucred.uid;
-        audit->gid = ucred.gid;
-
-        r = audit_loginuid_from_pid(ucred.pid, &audit->loginuid);
-        if (r < 0)
-                return r;
-
-        r = get_process_cmdline(ucred.pid, LINE_MAX, true, &audit->cmdline);
-        if (r < 0)
-                return r;
-
-        return 0;
-}
-
-/*
-   This function returns the security context of the remote end of the dbus
-   connections.  Whether it is on the bus or a local connection.
-*/
-static int get_calling_context(
-                DBusConnection *connection,
-                DBusMessage *message,
-                security_context_t *scon,
-                DBusError *error) {
-
-        const char *sender;
-        int r;
-        int fd;
-
-        /*
-           If sender exists then
-           if sender is NULL this indicates a local connection.  Grab the fd
-           from dbus and do an getpeercon to peers process context
-        */
-        sender = dbus_message_get_sender(message);
-        if (sender) {
-                r = bus_get_selinux_security_context(connection, sender, scon, error);
-                if (r >= 0)
-                        return r;
-
-                log_debug("bus_get_selinux_security_context failed %m");
-                dbus_error_free(error);
-        }
-
-        if (!dbus_connection_get_unix_fd(connection, &fd)) {
-                log_error("bus_connection_get_unix_fd failed %m");
-                return -EINVAL;
-        }
-
-        r = getpeercon(fd, scon);
-        if (r < 0) {
-                log_error("getpeercon failed %m");
-                return -errno;
-        }
-
-        return 0;
-}
-
 /*
    This function communicates with the kernel to check whether or not it should
    allow the access.
    If the machine is in permissive mode it will return ok.  Audit messages will
    still be generated if the access would be denied in enforcing mode.
 */
-int selinux_access_check(
-                DBusConnection *connection,
-                DBusMessage *message,
+int selinux_generic_access_check(
+                sd_bus *bus,
+                sd_bus_message *message,
                 const char *path,
                 const char *permission,
-                DBusError *error) {
-
-        security_context_t scon = NULL, fcon = NULL;
+                sd_bus_error *error) {
+
+        _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+        const char *tclass = NULL, *scon = NULL;
+        struct audit_info audit_info = {};
+        _cleanup_free_ char *cl = NULL;
+        security_context_t fcon = NULL;
+        char **cmdline = NULL;
         int r = 0;
-        const char *tclass = NULL;
-        struct auditstruct audit;
 
-        assert(connection);
+        assert(bus);
         assert(message);
         assert(permission);
         assert(error);
@@ -345,60 +195,57 @@ int selinux_access_check(
         if (r < 0)
                 return r;
 
-        log_debug("SELinux access check for path=%s permission=%s", strna(path), permission);
-
-        audit.uid = audit.loginuid = (uid_t) -1;
-        audit.gid = (gid_t) -1;
-        audit.cmdline = NULL;
-        audit.path = path;
+        r = sd_bus_query_sender_creds(
+                        message,
+                        SD_BUS_CREDS_PID|SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|
+                        SD_BUS_CREDS_CMDLINE|SD_BUS_CREDS_AUDIT_LOGIN_UID|
+                        SD_BUS_CREDS_SELINUX_CONTEXT,
+                        &creds);
+        if (r < 0)
+                goto finish;
 
-        r = get_calling_context(connection, message, &scon, error);
-        if (r < 0) {
-                log_error("Failed to get caller's security context on: %m");
+        r = sd_bus_creds_get_selinux_context(creds, &scon);
+        if (r < 0)
                 goto finish;
-        }
 
         if (path) {
-                tclass = "service";
-                /* get the file context of the unit file */
+                /* Get the file context of the unit file */
+
                 r = getfilecon(path, &fcon);
                 if (r < 0) {
-                        dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "Failed to get file context on %s.", path);
-                        r = -errno;
-                        log_error("Failed to get security context on %s: %m",path);
+                        r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to get file context on %s.", path);
                         goto finish;
                 }
 
+                tclass = "service";
         } else {
-                tclass = "system";
                 r = getcon(&fcon);
                 if (r < 0) {
-                        dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "Failed to get current context.");
-                        r = -errno;
-                        log_error("Failed to get current process context on: %m");
+                        r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to get current context.");
                         goto finish;
                 }
+
+                tclass = "system";
         }
 
-        (void) get_audit_data(connection, message, &audit, error);
+        sd_bus_creds_get_cmdline(creds, &cmdline);
+        cl = strv_join(cmdline, " ");
 
-        errno = 0;
-        r = selinux_check_access(scon, fcon, tclass, permission, &audit);
-        if (r < 0) {
-                dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "SELinux policy denies access.");
-                r = -errno;
-                log_error("SELinux policy denies access.");
-        }
+        audit_info.creds = creds;
+        audit_info.path = path;
+        audit_info.cmdline = cl;
+
+        r = selinux_check_access((security_context_t) scon, fcon, tclass, permission, &audit_info);
+        if (r < 0)
+                r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "SELinux policy denies access.");
 
-        log_debug("SELinux access check scon=%s tcon=%s tclass=%s perm=%s path=%s cmdline=%s: %i", scon, fcon, tclass, permission, path, audit.cmdline, r);
+        log_debug("SELinux access check scon=%s tcon=%s tclass=%s perm=%s path=%s cmdline=%s: %i", scon, fcon, tclass, permission, path, cl, r);
 
 finish:
-        free(audit.cmdline);
-        freecon(scon);
         freecon(fcon);
 
-        if (r && security_getenforce() != 1) {
-                dbus_error_init(error);
+        if (r < 0 && security_getenforce() != 1) {
+                sd_bus_error_free(error);
                 r = 0;
         }
 
@@ -407,12 +254,12 @@ finish:
 
 #else
 
-int selinux_access_check(
-                DBusConnection *connection,
-                DBusMessage *message,
+int selinux_generic_access_check(
+                sd_bus *bus,
+                sd_bus_message *message,
                 const char *path,
                 const char *permission,
-                DBusError *error) {
+                sd_bus_error *error) {
 
         return 0;
 }