core: Add AppArmor profile switching

This permit to switch to a specific apparmor profile when starting a daemon. This
will result in a non operation if apparmor is disabled.
It also add a new build requirement on libapparmor for using this feature.

9 files changed, 113 insertions, 5 deletions

diff --git a/src/core/build.h b/src/core/build.h
index c8117edff3..3d7cd3ea39 100644
--- a/src/core/build.h
+++ b/src/core/build.h
@@ -45,6 +45,12 @@
 #define _SELINUX_FEATURE_ "-SELINUX"
 #endif
 
+#ifdef HAVE_APPARMOR
+#define _APPARMOR_FEATURE_ "+APPARMOR"
+#else
+#define _APPARMOR_FEATURE_ "-APPARMOR"
+#endif
+
 #ifdef HAVE_IMA
 #define _IMA_FEATURE_ "+IMA"
 #else
@@ -87,4 +93,4 @@
 #define _SECCOMP_FEATURE_ "-SECCOMP"
 #endif
 
-#define SYSTEMD_FEATURES _PAM_FEATURE_ " " _LIBWRAP_FEATURE_ " " _AUDIT_FEATURE_ " " _SELINUX_FEATURE_ " " _IMA_FEATURE_ " " _SYSVINIT_FEATURE_ " " _LIBCRYPTSETUP_FEATURE_ " " _GCRYPT_FEATURE_ " " _ACL_FEATURE_ " " _XZ_FEATURE_ " " _SECCOMP_FEATURE_
+#define SYSTEMD_FEATURES _PAM_FEATURE_ " " _LIBWRAP_FEATURE_ " " _AUDIT_FEATURE_ " " _SELINUX_FEATURE_ " " _IMA_FEATURE_ " " _SYSVINIT_FEATURE_ " " _LIBCRYPTSETUP_FEATURE_ " " _GCRYPT_FEATURE_ " " _ACL_FEATURE_ " " _XZ_FEATURE_ " " _SECCOMP_FEATURE_ " " _APPARMOR_FEATURE_
diff --git a/src/core/dbus-execute.c b/src/core/dbus-execute.c
index 41dbbab904..935c62bdf2 100644
--- a/src/core/dbus-execute.c
+++ b/src/core/dbus-execute.c
@@ -482,6 +482,24 @@ static int property_get_selinux_context(
         return sd_bus_message_append(reply, "(bs)", c->selinux_context_ignore, c->selinux_context);
 }
 
+static int property_get_apparmor_profile(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *reply,
+                void *userdata,
+                sd_bus_error *error) {
+
+        ExecContext *c = userdata;
+
+        assert(bus);
+        assert(reply);
+        assert(c);
+
+        return sd_bus_message_append(reply, "(bs)", c->apparmor_profile_ignore, c->apparmor_profile);
+}
+
 static int property_get_personality(
                 sd_bus *bus,
                 const char *path,
@@ -560,6 +578,7 @@ const sd_bus_vtable bus_exec_vtable[] = {
         SD_BUS_PROPERTY("SameProcessGroup", "b", bus_property_get_bool, offsetof(ExecContext, same_pgrp), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("UtmpIdentifier", "s", NULL, offsetof(ExecContext, utmp_id), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("SELinuxContext", "(bs)", property_get_selinux_context, 0, SD_BUS_VTABLE_PROPERTY_CONST),
+        SD_BUS_PROPERTY("AppArmorProfile", "(bs)", property_get_apparmor_profile, 0, SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("IgnoreSIGPIPE", "b", bus_property_get_bool, offsetof(ExecContext, ignore_sigpipe), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("NoNewPrivileges", "b", bus_property_get_bool, offsetof(ExecContext, no_new_privileges), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("SystemCallFilter", "(bas)", property_get_syscall_filter, 0, SD_BUS_VTABLE_PROPERTY_CONST),
diff --git a/src/core/execute.c b/src/core/execute.c
index f8b7521ff9..a328fc265f 100644
--- a/src/core/execute.c
+++ b/src/core/execute.c
@@ -55,6 +55,10 @@
 #include <seccomp.h>
 #endif
 
+#ifdef HAVE_APPARMOR
+#include <sys/apparmor.h>
+#endif
+
 #include "execute.h"
 #include "strv.h"
 #include "macro.h"
@@ -77,6 +81,7 @@
 #include "async.h"
 #include "selinux-util.h"
 #include "errno-list.h"
+#include "apparmor-util.h"
 
 #ifdef HAVE_SECCOMP
 #include "seccomp-util.h"
@@ -1597,6 +1602,16 @@ int exec_spawn(ExecCommand *command,
                                 }
                         }
 #endif
+
+#ifdef HAVE_APPARMOR
+                        if (context->apparmor_profile && use_apparmor()) {
+                                err = aa_change_onexec(context->apparmor_profile);
+                                if (err < 0 && !context->apparmor_profile_ignore) {
+                                        r = EXIT_APPARMOR_PROFILE;
+                                        goto fail_child;
+                                }
+                        }
+#endif
                 }
 
                 err = build_environment(context, n_fds, watchdog_usec, home, username, shell, &our_env);
@@ -1759,6 +1774,9 @@ void exec_context_done(ExecContext *c) {
         free(c->selinux_context);
         c->selinux_context = NULL;
 
+        free(c->apparmor_profile);
+        c->apparmor_profile = NULL;
+
 #ifdef HAVE_SECCOMP
         set_free(c->syscall_filter);
         c->syscall_filter = NULL;
@@ -2188,6 +2206,11 @@ void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
                 fprintf(f,
                         "%sSystemCallErrorNumber: %s\n",
                         prefix, strna(errno_to_name(c->syscall_errno)));
+
+        if (c->apparmor_profile)
+                fprintf(f,
+                        "%sAppArmorProfile: %s%s\n",
+                        prefix, c->apparmor_profile_ignore ? "-" : "", c->apparmor_profile);
 }
 
 void exec_status_start(ExecStatus *s, pid_t pid) {
diff --git a/src/core/execute.h b/src/core/execute.h
index 5c4c0b4abe..2bfe227145 100644
--- a/src/core/execute.h
+++ b/src/core/execute.h
@@ -141,6 +141,9 @@ struct ExecContext {
         bool selinux_context_ignore;
         char *selinux_context;
 
+        bool apparmor_profile_ignore;
+        char *apparmor_profile;
+
         char **read_write_dirs, **read_only_dirs, **inaccessible_dirs;
         unsigned long mount_flags;
 
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index e9995bf0c7..e1bab7a264 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -90,7 +90,10 @@ $1.IgnoreSIGPIPE,                config_parse_bool,                  0,
 $1.UtmpIdentifier,               config_parse_unit_string_printf,    0,                             offsetof($1, exec_context.utmp_id)
 m4_ifdef(`HAVE_SELINUX',
 `$1.SELinuxContext,              config_parse_exec_selinux_context,  0,                             offsetof($1, exec_context)',
-`$1.SELinuxContext,              config_parse_warn_compat,           0,                             0')'
+`$1.SELinuxContext,              config_parse_warn_compat,           0,                             0')
+m4_ifdef(`HAVE_APPARMOR',
+`$1.AppArmorProfile,              config_parse_exec_apparmor_profile,0,                             offsetof($1, exec_context)',
+`$1.AppArmorProfile,              config_parse_warn_compat,          0,                             0')'
 )m4_dnl
 m4_define(`KILL_CONTEXT_CONFIG_ITEMS',
 `$1.SendSIGKILL,                 config_parse_bool,                  0,                             offsetof($1, kill_context.send_sigkill)
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index 27666b937c..e74a790e25 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -61,7 +61,7 @@
 #include "seccomp-util.h"
 #endif
 
-#if !defined(HAVE_SYSV_COMPAT) || !defined(HAVE_SECCOMP) || !defined(HAVE_LIBWRAP) || !defined(HAVE_PAM) || !defined(HAVE_SELINUX) || !defined(HAVE_SMACK)
+#if !defined(HAVE_SYSV_COMPAT) || !defined(HAVE_SECCOMP) || !defined(HAVE_LIBWRAP) || !defined(HAVE_PAM) || !defined(HAVE_SELINUX) || !defined(HAVE_SMACK) || !defined(HAVE_APPARMOR)
 int config_parse_warn_compat(
                 const char *unit,
                 const char *filename,
@@ -1192,6 +1192,55 @@ int config_parse_exec_selinux_context(
         return 0;
 }
 
+int config_parse_exec_apparmor_profile(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        ExecContext *c = data;
+        Unit *u = userdata;
+        bool ignore;
+        char *k;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        if (isempty(rvalue)) {
+                free(c->apparmor_profile);
+                c->apparmor_profile = NULL;
+                c->apparmor_profile_ignore = false;
+                return 0;
+        }
+
+        if (rvalue[0] == '-') {
+                ignore = true;
+                rvalue++;
+        } else
+                ignore = false;
+
+        r = unit_name_printf(u, rvalue, &k);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, -r, "Failed to resolve specifiers, ignoring: %s", strerror(-r));
+                return 0;
+        }
+
+        free(c->apparmor_profile);
+        c->apparmor_profile = k;
+        c->apparmor_profile_ignore = ignore;
+
+        return 0;
+}
+
 int config_parse_timer(const char *unit,
                        const char *filename,
                        unsigned line,
@@ -2910,7 +2959,7 @@ void unit_dump_config_items(FILE *f) {
                 const ConfigParserCallback callback;
                 const char *rvalue;
         } table[] = {
-#if !defined(HAVE_SYSV_COMPAT) || !defined(HAVE_SECCOMP) || !defined(HAVE_LIBWRAP) || !defined(HAVE_PAM) || !defined(HAVE_SELINUX) || !defined(HAVE_SMACK)
+#if !defined(HAVE_SYSV_COMPAT) || !defined(HAVE_SECCOMP) || !defined(HAVE_LIBWRAP) || !defined(HAVE_PAM) || !defined(HAVE_SELINUX) || !defined(HAVE_SMACK) || !defined(HAVE_APPARMOR)
                 { config_parse_warn_compat,           "NOTSUPPORTED" },
 #endif
                 { config_parse_int,                   "INTEGER" },
diff --git a/src/core/load-fragment.h b/src/core/load-fragment.h
index 83ecea5da1..4a5ec35cbe 100644
--- a/src/core/load-fragment.h
+++ b/src/core/load-fragment.h
@@ -89,6 +89,7 @@ int config_parse_job_mode(const char *unit, const char *filename, unsigned line,
 int config_parse_job_mode_isolate(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_exec_selinux_context(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_personality(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_exec_apparmor_profile(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 
 /* gperf prototypes */
 const struct ConfigPerfItem* load_fragment_gperf_lookup(const char *key, unsigned length);
diff --git a/src/shared/exit-status.c b/src/shared/exit-status.c
index 8b096da7e1..902f55ac65 100644
--- a/src/shared/exit-status.c
+++ b/src/shared/exit-status.c
@@ -136,6 +136,9 @@ const char* exit_status_to_string(ExitStatus status, ExitStatusLevel level) {
 
                 case EXIT_PERSONALITY:
                         return "PERSONALITY";
+
+                case EXIT_APPARMOR_PROFILE:
+                        return "APPARMOR";
                 }
         }
 
diff --git a/src/shared/exit-status.h b/src/shared/exit-status.h
index dde5bdda8b..de379f1aa0 100644
--- a/src/shared/exit-status.h
+++ b/src/shared/exit-status.h
@@ -69,7 +69,8 @@ typedef enum ExitStatus {
         EXIT_NO_NEW_PRIVILEGES,
         EXIT_SECCOMP,
         EXIT_SELINUX_CONTEXT,
-        EXIT_PERSONALITY  /* 230 */
+        EXIT_PERSONALITY,  /* 230 */
+        EXIT_APPARMOR_PROFILE
 } ExitStatus;
 
 typedef enum ExitStatusLevel {