Merge pull request #14178 from poettering/journal-namespace

journal: add concept of "journal namespaces"

src/basic/string-util.c

@@ -1054,6 +1054,8 @@ bool string_is_safe(const char *p) {
         if (!p)
                 return false;
 
+        /* Checks if the specified string contains no quotes or control characters */
+
         for (t = p; *t; t++) {
                 if (*t > 0 && *t < ' ') /* no control characters */
                         return false;

src/basic/syslog-util.c

@@ -2,10 +2,15 @@
 
 #include <syslog.h>
 
+#include "sd-id128.h"
+
+#include "glob-util.h"
 #include "hexdecoct.h"
 #include "macro.h"
+#include "path-util.h"
 #include "string-table.h"
 #include "syslog-util.h"
+#include "unit-name.h"
 
 int syslog_parse_priority(const char **p, int *priority, bool with_facility) {
         int a = 0, b = 0, c = 0;
@@ -96,3 +101,31 @@ DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(log_level, int, LOG_DEBUG);
 bool log_level_is_valid(int level) {
         return level >= 0 && level <= LOG_DEBUG;
 }
+
+/* The maximum size for a log namespace length. This is the file name size limit 255 minus the size of a
+ * formatted machine ID minus a separator char */
+#define LOG_NAMESPACE_MAX (NAME_MAX - (SD_ID128_STRING_MAX - 1) - 1)
+
+bool log_namespace_name_valid(const char *s) {
+        /* Let's make sure the namespace fits in a filename that is prefixed with the machine ID and a dot
+         * (so that /var/log/journal/<machine-id>.<namespace> can be created based on it). Also make sure it
+         * is suitable as unit instance name, and does not contain fishy characters. */
+
+        if (!filename_is_valid(s))
+                return false;
+
+        if (strlen(s) > LOG_NAMESPACE_MAX)
+                return false;
+
+        if (!unit_instance_is_valid(s))
+                return false;
+
+        if (!string_is_safe(s))
+                return false;
+
+        /* Let's avoid globbing for now */
+        if (string_is_glob(s))
+                return false;
+
+        return true;
+}

src/basic/syslog-util.h

@@ -12,3 +12,5 @@ int log_level_from_string(const char *s);
 bool log_level_is_valid(int level);
 
 int syslog_parse_priority(const char **p, int *priority, bool with_facility);
+
+bool log_namespace_name_valid(const char *s);

src/core/dbus-execute.c

@@ -766,6 +766,7 @@ const sd_bus_vtable bus_exec_vtable[] = {
         SD_BUS_PROPERTY("LogRateLimitIntervalUSec", "t", bus_property_get_usec, offsetof(ExecContext, log_ratelimit_interval_usec), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("LogRateLimitBurst", "u", bus_property_get_unsigned, offsetof(ExecContext, log_ratelimit_burst), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("LogExtraFields", "aay", property_get_log_extra_fields, 0, SD_BUS_VTABLE_PROPERTY_CONST),
+        SD_BUS_PROPERTY("LogNamespace", "s", NULL, offsetof(ExecContext, log_namespace), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("SecureBits", "i", bus_property_get_int, offsetof(ExecContext, secure_bits), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("CapabilityBoundingSet", "t", NULL, offsetof(ExecContext, capability_bounding_set), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("AmbientCapabilities", "t", NULL, offsetof(ExecContext, capability_ambient_set), SD_BUS_VTABLE_PROPERTY_CONST),
@@ -1436,6 +1437,32 @@ int bus_exec_context_set_transient_property(
 
                 return 1;
 
+        } else if (streq(name, "LogNamespace")) {
+                const char *n;
+
+                r = sd_bus_message_read(message, "s", &n);
+                if (r < 0)
+                        return r;
+
+                if (!isempty(n) && !log_namespace_name_valid(n))
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Log namespace name not valid");
+
+                if (!UNIT_WRITE_FLAGS_NOOP(flags)) {
+
+                        if (isempty(n)) {
+                                c->log_namespace = mfree(c->log_namespace);
+                                unit_write_settingf(u, flags, name, "%s=", name);
+                        } else {
+                                r = free_and_strdup(&c->log_namespace, n);
+                                if (r < 0)
+                                        return r;
+
+                                unit_write_settingf(u, flags, name, "%s=%s", name, n);
+                        }
+                }
+
+                return 1;
+
         } else if (streq(name, "LogExtraFields")) {
                 size_t n = 0;
 

src/core/execute.c

@@ -265,15 +265,27 @@ static int open_null_as(int flags, int nfd) {
         return move_fd(fd, nfd, false);
 }
 
-static int connect_journal_socket(int fd, uid_t uid, gid_t gid) {
-        static const union sockaddr_union sa = {
+static int connect_journal_socket(
+                int fd,
+                const char *log_namespace,
+                uid_t uid,
+                gid_t gid) {
+
+        union sockaddr_union sa = {
                 .un.sun_family = AF_UNIX,
-                .un.sun_path = "/run/systemd/journal/stdout",
         };
         uid_t olduid = UID_INVALID;
         gid_t oldgid = GID_INVALID;
+        const char *j;
         int r;
 
+        j = log_namespace ?
+                strjoina("/run/systemd/journal.", log_namespace, "/stdout") :
+                "/run/systemd/journal/stdout";
+        r = sockaddr_un_set_path(&sa.un, j);
+        if (r < 0)
+                return r;
+
         if (gid_is_valid(gid)) {
                 oldgid = getgid();
 
@@ -328,7 +340,7 @@ static int connect_logger_as(
         if (fd < 0)
                 return -errno;
 
-        r = connect_journal_socket(fd, uid, gid);
+        r = connect_journal_socket(fd, context->log_namespace, uid, gid);
         if (r < 0)
                 return r;
 
@@ -1686,7 +1698,7 @@ static int build_environment(
         assert(p);
         assert(ret);
 
-        our_env = new0(char*, 14 + _EXEC_DIRECTORY_TYPE_MAX);
+        our_env = new0(char*, 15 + _EXEC_DIRECTORY_TYPE_MAX);
         if (!our_env)
                 return -ENOMEM;
 
@@ -1795,6 +1807,14 @@ static int build_environment(
                 our_env[n_env++] = x;
         }
 
+        if (c->log_namespace) {
+                x = strjoin("LOG_NAMESPACE=", c->log_namespace);
+                if (!x)
+                        return -ENOMEM;
+
+                our_env[n_env++] = x;
+        }
+
         for (t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) {
                 _cleanup_free_ char *pre = NULL, *joined = NULL;
                 const char *n;
@@ -1919,6 +1939,9 @@ static bool exec_needs_mount_namespace(
              !strv_isempty(context->directories[EXEC_DIRECTORY_LOGS].paths)))
                 return true;
 
+        if (context->log_namespace)
+                return true;
+
         return false;
 }
 
@@ -2517,6 +2540,9 @@ static bool insist_on_sandboxing(
                 if (!path_equal(bind_mounts[i].source, bind_mounts[i].destination))
                         return true;
 
+        if (context->log_namespace)
+                return true;
+
         return false;
 }
 
@@ -2600,6 +2626,7 @@ static int apply_mount_namespace(
                             context->n_temporary_filesystems,
                             tmp,
                             var,
+                            context->log_namespace,
                             needs_sandboxing ? context->protect_home : PROTECT_HOME_NO,
                             needs_sandboxing ? context->protect_system : PROTECT_SYSTEM_NO,
                             context->mount_flags,
@@ -4140,6 +4167,8 @@ void exec_context_done(ExecContext *c) {
         c->stdin_data_size = 0;
 
         c->network_namespace_path = mfree(c->network_namespace_path);
+
+        c->log_namespace = mfree(c->log_namespace);
 }
 
 int exec_context_destroy_runtime_directory(const ExecContext *c, const char *runtime_prefix) {
@@ -4675,6 +4704,9 @@ void exec_context_dump(const ExecContext *c, FILE* f, const char *prefix) {
                 }
         }
 
+        if (c->log_namespace)
+                fprintf(f, "%sLogNamespace: %s\n", prefix, c->log_namespace);
+
         if (c->secure_bits) {
                 _cleanup_free_ char *str = NULL;
 

src/core/execute.h

@@ -250,6 +250,8 @@ struct ExecContext {
 
         int log_level_max;
 
+        char *log_namespace;
+
         bool private_tmp;
         bool private_network;
         bool private_devices;

src/core/load-fragment-gperf.gperf.m4

@@ -119,6 +119,7 @@ $1.ProtectKernelLogs,            config_parse_bool,                  0,
 $1.ProtectClock,                 config_parse_bool,                  0,                             offsetof($1, exec_context.protect_clock)
 $1.ProtectControlGroups,         config_parse_bool,                  0,                             offsetof($1, exec_context.protect_control_groups)
 $1.NetworkNamespacePath,         config_parse_unit_path_printf,      0,                             offsetof($1, exec_context.network_namespace_path)
+$1.LogNamespace,                 config_parse_log_namespace,         0,                             offsetof($1, exec_context)
 $1.PrivateNetwork,               config_parse_bool,                  0,                             offsetof($1, exec_context.private_network)
 $1.PrivateUsers,                 config_parse_bool,                  0,                             offsetof($1, exec_context.private_users)
 $1.PrivateMounts,                config_parse_bool,                  0,                             offsetof($1, exec_context.private_mounts)

src/core/load-fragment.c

@@ -52,10 +52,11 @@
 #include "stat-util.h"
 #include "string-util.h"
 #include "strv.h"
+#include "syslog-util.h"
+#include "time-util.h"
 #include "unit-name.h"
 #include "unit-printf.h"
 #include "user-util.h"
-#include "time-util.h"
 #include "web-util.h"
 
 static int parse_socket_protocol(const char *s) {
@@ -2519,6 +2520,48 @@ int config_parse_log_extra_fields(
         }
 }
 
+int config_parse_log_namespace(
+                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) {
+
+        _cleanup_free_ char *k = NULL;
+        ExecContext *c = data;
+        const Unit *u = userdata;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(c);
+
+        if (isempty(rvalue)) {
+                c->log_namespace = mfree(c->log_namespace);
+                return 0;
+        }
+
+        r = unit_full_printf(u, rvalue, &k);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers in %s, ignoring: %m", rvalue);
+                return 0;
+        }
+
+        if (!log_namespace_name_valid(k)) {
+                log_syntax(unit, LOG_ERR, filename, line, SYNTHETIC_ERRNO(EINVAL), "Specified log namespace name is not valid: %s", k);
+                return 0;
+        }
+
+        free_and_replace(c->log_namespace, k);
+        return 0;
+}
+
 int config_parse_unit_condition_path(
                 const char *unit,
                 const char *filename,

src/core/load-fragment.h

@@ -107,6 +107,7 @@ CONFIG_PARSER_PROTOTYPE(config_parse_exec_keyring_mode);
 CONFIG_PARSER_PROTOTYPE(config_parse_job_timeout_sec);
 CONFIG_PARSER_PROTOTYPE(config_parse_job_running_timeout_sec);
 CONFIG_PARSER_PROTOTYPE(config_parse_log_extra_fields);
+CONFIG_PARSER_PROTOTYPE(config_parse_log_namespace);
 CONFIG_PARSER_PROTOTYPE(config_parse_collect_mode);
 CONFIG_PARSER_PROTOTYPE(config_parse_pid_file);
 CONFIG_PARSER_PROTOTYPE(config_parse_exit_status);

src/core/namespace.c

@@ -1132,6 +1132,7 @@ static size_t namespace_calculate_mounts(
                 size_t n_temporary_filesystems,
                 const char* tmp_dir,
                 const char* var_tmp_dir,
+                const char* log_namespace,
                 ProtectHome protect_home,
                 ProtectSystem protect_system) {
 
@@ -1166,7 +1167,8 @@ static size_t namespace_calculate_mounts(
                 (ns_info->protect_control_groups ? 1 : 0) +
                 protect_home_cnt + protect_system_cnt +
                 (ns_info->protect_hostname ? 2 : 0) +
-                (namespace_info_mount_apivfs(ns_info) ? ELEMENTSOF(apivfs_table) : 0);
+                (namespace_info_mount_apivfs(ns_info) ? ELEMENTSOF(apivfs_table) : 0) +
+                !!log_namespace;
 }
 
 static void normalize_mounts(const char *root_directory, MountEntry *mounts, size_t *n_mounts) {
@@ -1247,6 +1249,7 @@ int setup_namespace(
                 size_t n_temporary_filesystems,
                 const char* tmp_dir,
                 const char* var_tmp_dir,
+                const char *log_namespace,
                 ProtectHome protect_home,
                 ProtectSystem protect_system,
                 unsigned long mount_flags,
@@ -1323,6 +1326,7 @@ int setup_namespace(
                         n_bind_mounts,
                         n_temporary_filesystems,
                         tmp_dir, var_tmp_dir,
+                        log_namespace,
                         protect_home, protect_system);
 
         if (n_mounts > 0) {
@@ -1428,6 +1432,23 @@ int setup_namespace(
                         };
                 }
 
+                if (log_namespace) {
+                        _cleanup_free_ char *q;
+
+                        q = strjoin("/run/systemd/journal.", log_namespace);
+                        if (!q) {
+                                r = -ENOMEM;
+                                goto finish;
+                        }
+
+                        *(m++) = (MountEntry) {
+                                .path_const = "/run/systemd/journal",
+                                .mode = BIND_MOUNT_RECURSIVE,
+                                .read_only = true,
+                                .source_malloc = TAKE_PTR(q),
+                        };
+                }
+
                 assert(mounts + n_mounts == m);
 
                 /* Prepend the root directory where that's necessary */

src/core/namespace.h

@@ -84,6 +84,7 @@ int setup_namespace(
                 size_t n_temporary_filesystems,
                 const char *tmp_dir,
                 const char *var_tmp_dir,
+                const char *log_namespace,
                 ProtectHome protect_home,
                 ProtectSystem protect_system,
                 unsigned long mount_flags,

src/core/unit.c

@@ -1059,13 +1059,33 @@ int unit_add_exec_dependencies(Unit *u, ExecContext *c) {
             !IN_SET(c->std_error,
                     EXEC_OUTPUT_JOURNAL, EXEC_OUTPUT_JOURNAL_AND_CONSOLE,
                     EXEC_OUTPUT_KMSG, EXEC_OUTPUT_KMSG_AND_CONSOLE,
-                    EXEC_OUTPUT_SYSLOG, EXEC_OUTPUT_SYSLOG_AND_CONSOLE))
+                    EXEC_OUTPUT_SYSLOG, EXEC_OUTPUT_SYSLOG_AND_CONSOLE) &&
+            !c->log_namespace)
                 return 0;
 
-        /* If syslog or kernel logging is requested, make sure our own
-         * logging daemon is run first. */
+        /* If syslog or kernel logging is requested (or log namespacing is), make sure our own logging daemon
+         * is run first. */
 
-        r = unit_add_dependency_by_name(u, UNIT_AFTER, SPECIAL_JOURNALD_SOCKET, true, UNIT_DEPENDENCY_FILE);
+        if (c->log_namespace) {
+                _cleanup_free_ char *socket_unit = NULL, *varlink_socket_unit = NULL;
+
+                r = unit_name_build_from_type("systemd-journald", c->log_namespace, UNIT_SOCKET, &socket_unit);
+                if (r < 0)
+                        return r;
+
+                r = unit_add_two_dependencies_by_name(u, UNIT_AFTER, UNIT_REQUIRES, socket_unit, true, UNIT_DEPENDENCY_FILE);
+                if (r < 0)
+                        return r;
+
+                r = unit_name_build_from_type("systemd-journald-varlink", c->log_namespace, UNIT_SOCKET, &varlink_socket_unit);
+                if (r < 0)
+                        return r;
+
+                r = unit_add_two_dependencies_by_name(u, UNIT_AFTER, UNIT_REQUIRES, varlink_socket_unit, true, UNIT_DEPENDENCY_FILE);
+                if (r < 0)
+                        return r;
+        } else
+                r = unit_add_dependency_by_name(u, UNIT_AFTER, SPECIAL_JOURNALD_SOCKET, true, UNIT_DEPENDENCY_FILE);
         if (r < 0)
                 return r;
 

src/journal-remote/journal-upload.c

@@ -754,9 +754,13 @@ static int open_journal(sd_journal **j) {
                 r = sd_journal_open_directory(j, arg_directory, arg_journal_type);
         else if (arg_file)
                 r = sd_journal_open_files(j, (const char**) arg_file, 0);
-        else if (arg_machine)
+        else if (arg_machine) {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+                /* FIXME: replace with D-Bus call OpenMachineRootDirectory() so that things also work with raw disk images */
                 r = sd_journal_open_container(j, arg_machine, 0);
-        else
+#pragma GCC diagnostic pop
+        } else
                 r = sd_journal_open(j, !arg_merge*SD_JOURNAL_LOCAL_ONLY + arg_journal_type);
         if (r < 0)
                 log_error_errno(r, "Failed to open %s: %m",

src/journal/journal-internal.h

@@ -69,6 +69,7 @@ struct sd_journal {
 
         char *path;
         char *prefix;
+        char *namespace;
 
         OrderedHashmap *files;
         IteratedCache *files_cache;

src/journal/journalctl.c

@@ -70,36 +70,8 @@
 #include "varlink.h"
 
 #define DEFAULT_FSS_INTERVAL_USEC (15*USEC_PER_MINUTE)
-
 #define PROCESS_INOTIFY_INTERVAL 1024   /* Every 1,024 messages processed */
 
-#if HAVE_PCRE2
-DEFINE_TRIVIAL_CLEANUP_FUNC(pcre2_match_data*, pcre2_match_data_free);
-DEFINE_TRIVIAL_CLEANUP_FUNC(pcre2_code*, pcre2_code_free);
-
-static int pattern_compile(const char *pattern, unsigned flags, pcre2_code **out) {
-        int errorcode, r;
-        PCRE2_SIZE erroroffset;
-        pcre2_code *p;
-
-        p = pcre2_compile((PCRE2_SPTR8) pattern,
-                          PCRE2_ZERO_TERMINATED, flags, &errorcode, &erroroffset, NULL);
-        if (!p) {
-                unsigned char buf[LINE_MAX];
-
-                r = pcre2_get_error_message(errorcode, buf, sizeof buf);
-
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                       "Bad pattern \"%s\": %s", pattern,
-                                       r < 0 ? "unknown error" : (char *)buf);
-        }
-
-        *out = p;
-        return 0;
-}
-
-#endif
-
 enum {
         /* Special values for arg_lines */
         ARG_LINES_DEFAULT = -2,
@@ -143,13 +115,14 @@ static const char *arg_field = NULL;
 static bool arg_catalog = false;
 static bool arg_reverse = false;
 static int arg_journal_type = 0;
+static int arg_namespace_flags = 0;
 static char *arg_root = NULL;
 static const char *arg_machine = NULL;
+static const char *arg_namespace = NULL;
 static uint64_t arg_vacuum_size = 0;
 static uint64_t arg_vacuum_n_files = 0;
 static usec_t arg_vacuum_time = 0;
 static char **arg_output_fields = NULL;
-
 #if HAVE_PCRE2
 static const char *arg_pattern = NULL;
 static pcre2_code *arg_compiled_pattern = NULL;
@@ -184,6 +157,33 @@ typedef struct BootId {
         LIST_FIELDS(struct BootId, boot_list);
 } BootId;
 
+#if HAVE_PCRE2
+DEFINE_TRIVIAL_CLEANUP_FUNC(pcre2_match_data*, pcre2_match_data_free);
+DEFINE_TRIVIAL_CLEANUP_FUNC(pcre2_code*, pcre2_code_free);
+
+static int pattern_compile(const char *pattern, unsigned flags, pcre2_code **out) {
+        int errorcode, r;
+        PCRE2_SIZE erroroffset;
+        pcre2_code *p;
+
+        p = pcre2_compile((PCRE2_SPTR8) pattern,
+                          PCRE2_ZERO_TERMINATED, flags, &errorcode, &erroroffset, NULL);
+        if (!p) {
+                unsigned char buf[LINE_MAX];
+
+                r = pcre2_get_error_message(errorcode, buf, sizeof buf);
+
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Bad pattern \"%s\": %s", pattern,
+                                       r < 0 ? "unknown error" : (char *)buf);
+        }
+
+        *out = p;
+        return 0;
+}
+
+#endif
+
 static int add_matches_for_device(sd_journal *j, const char *devpath) {
         _cleanup_(sd_device_unrefp) sd_device *device = NULL;
         sd_device *d = NULL;
@@ -313,9 +313,9 @@ static int help(void) {
         if (r < 0)
                 return log_oom();
 
-        printf("%s [OPTIONS...] [MATCHES...]\n\n"
-               "%sQuery the journal.%s\n\n"
-               "Options:\n"
+        printf("%1$s [OPTIONS...] [MATCHES...]\n\n"
+               "%5$sQuery the journal.%6$s\n\n"
+               "%3$sOptions:%4$s\n"
                "     --system                Show the system journal\n"
                "     --user                  Show the user journal for the current user\n"
                "  -M --machine=CONTAINER     Operate on local container\n"
@@ -356,10 +356,11 @@ static int help(void) {
                "  -D --directory=PATH        Show journal files from directory\n"
                "     --file=PATH             Show journal file\n"
                "     --root=ROOT             Operate on files below a root directory\n"
+               "     --namespace=NAMESPACE   Show journal data from specified namespace\n"
                "     --interval=TIME         Time interval for changing the FSS sealing key\n"
                "     --verify-key=KEY        Specify FSS verification key\n"
                "     --force                 Override of the FSS key pair with --setup-keys\n"
-               "\nCommands:\n"
+               "\n%3$sCommands:%4$s\n"
                "  -h --help                  Show this help text\n"
                "     --version               Show package version\n"
                "  -N --fields                List all field names currently used\n"
@@ -379,10 +380,11 @@ static int help(void) {
                "     --dump-catalog          Show entries in the message catalog\n"
                "     --update-catalog        Update the message catalog database\n"
                "     --setup-keys            Generate a new FSS key pair\n"
-               "\nSee the %s for details.\n"
+               "\nSee the %2$s for details.\n"
                , program_invocation_short_name
-               , ansi_highlight(), ansi_normal()
                , link
+               , ansi_underline(), ansi_normal()
+               , ansi_highlight(), ansi_normal()
         );
 
         return 0;
@@ -428,6 +430,7 @@ static int parse_argv(int argc, char *argv[]) {
                 ARG_VACUUM_TIME,
                 ARG_NO_HOSTNAME,
                 ARG_OUTPUT_FIELDS,
+                ARG_NAMESPACE,
         };
 
         static const struct option options[] = {
@@ -492,6 +495,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { "vacuum-time",          required_argument, NULL, ARG_VACUUM_TIME          },
                 { "no-hostname",          no_argument,       NULL, ARG_NO_HOSTNAME          },
                 { "output-fields",        required_argument, NULL, ARG_OUTPUT_FIELDS        },
+                { "namespace",            required_argument, NULL, ARG_NAMESPACE            },
                 {}
         };
 
@@ -533,10 +537,8 @@ static int parse_argv(int argc, char *argv[]) {
                         }
 
                         arg_output = output_mode_from_string(optarg);
-                        if (arg_output < 0) {
-                                log_error("Unknown output format '%s'.", optarg);
-                                return -EINVAL;
-                        }
+                        if (arg_output < 0)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown output format '%s'.", optarg);
 
                         if (IN_SET(arg_output, OUTPUT_EXPORT, OUTPUT_JSON, OUTPUT_JSON_PRETTY, OUTPUT_JSON_SSE, OUTPUT_JSON_SEQ, OUTPUT_CAT))
                                 arg_quiet = true;
@@ -561,10 +563,8 @@ static int parse_argv(int argc, char *argv[]) {
                                         arg_lines = ARG_LINES_ALL;
                                 else {
                                         r = safe_atoi(optarg, &arg_lines);
-                                        if (r < 0 || arg_lines < 0) {
-                                                log_error("Failed to parse lines '%s'", optarg);
-                                                return -EINVAL;
-                                        }
+                                        if (r < 0 || arg_lines < 0)
+                                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to parse lines '%s'", optarg);
                                 }
                         } else {
                                 arg_lines = 10;
@@ -656,6 +656,23 @@ static int parse_argv(int argc, char *argv[]) {
                         arg_machine = optarg;
                         break;
 
+                case ARG_NAMESPACE:
+                        if (streq(optarg, "*")) {
+                                arg_namespace_flags = SD_JOURNAL_ALL_NAMESPACES;
+                                arg_namespace = NULL;
+                        } else if (startswith(optarg, "+")) {
+                                arg_namespace_flags = SD_JOURNAL_INCLUDE_DEFAULT_NAMESPACE;
+                                arg_namespace = optarg + 1;
+                        } else if (isempty(optarg)) {
+                                arg_namespace_flags = 0;
+                                arg_namespace = NULL;
+                        } else {
+                                arg_namespace_flags = 0;
+                                arg_namespace = optarg;
+                        }
+
+                        break;
+
                 case 'D':
                         arg_directory = optarg;
                         break;
@@ -710,30 +727,24 @@ static int parse_argv(int argc, char *argv[]) {
 
                 case ARG_VACUUM_SIZE:
                         r = parse_size(optarg, 1024, &arg_vacuum_size);
-                        if (r < 0) {
-                                log_error("Failed to parse vacuum size: %s", optarg);
-                                return r;
-                        }
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse vacuum size: %s", optarg);
 
                         arg_action = arg_action == ACTION_ROTATE ? ACTION_ROTATE_AND_VACUUM : ACTION_VACUUM;
                         break;
 
                 case ARG_VACUUM_FILES:
                         r = safe_atou64(optarg, &arg_vacuum_n_files);
-                        if (r < 0) {
-                                log_error("Failed to parse vacuum files: %s", optarg);
-                                return r;
-                        }
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse vacuum files: %s", optarg);
 
                         arg_action = arg_action == ACTION_ROTATE ? ACTION_ROTATE_AND_VACUUM : ACTION_VACUUM;
                         break;
 
                 case ARG_VACUUM_TIME:
                         r = parse_sec(optarg, &arg_vacuum_time);
-                        if (r < 0) {
-                                log_error("Failed to parse vacuum time: %s", optarg);
-                                return r;
-                        }
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse vacuum time: %s", optarg);
 
                         arg_action = arg_action == ACTION_ROTATE ? ACTION_ROTATE_AND_VACUUM : ACTION_VACUUM;
                         break;
@@ -748,7 +759,6 @@ static int parse_argv(int argc, char *argv[]) {
                         break;
 
                 case ARG_VERIFY_KEY:
-                        arg_action = ACTION_VERIFY;
                         r = free_and_strdup(&arg_verify_key, optarg);
                         if (r < 0)
                                 return r;
@@ -756,23 +766,23 @@ static int parse_argv(int argc, char *argv[]) {
                          * in ps or htop output. */
                         memset(optarg, 'x', strlen(optarg));
 
+                        arg_action = ACTION_VERIFY;
                         arg_merge = false;
                         break;
 
                 case ARG_INTERVAL:
                         r = parse_sec(optarg, &arg_interval);
-                        if (r < 0 || arg_interval <= 0) {
-                                log_error("Failed to parse sealing key change interval: %s", optarg);
-                                return -EINVAL;
-                        }
+                        if (r < 0 || arg_interval <= 0)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Failed to parse sealing key change interval: %s", optarg);
                         break;
 #else
                 case ARG_SETUP_KEYS:
                 case ARG_VERIFY_KEY:
                 case ARG_INTERVAL:
                 case ARG_FORCE:
-                        log_error("Compiled without forward-secure sealing support.");
-                        return -EOPNOTSUPP;
+                        return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
+                                               "Compiled without forward-secure sealing support.");
 #endif
 
                 case 'p': {
@@ -780,7 +790,7 @@ static int parse_argv(int argc, char *argv[]) {
 
                         dots = strstr(optarg, "..");
                         if (dots) {
-                                char *a;
+                                _cleanup_free_ char *a = NULL;
                                 int from, to, i;
 
                                 /* a range */
@@ -790,12 +800,10 @@ static int parse_argv(int argc, char *argv[]) {
 
                                 from = log_level_from_string(a);
                                 to = log_level_from_string(dots + 2);
-                                free(a);
 
-                                if (from < 0 || to < 0) {
-                                        log_error("Failed to parse log level range %s", optarg);
-                                        return -EINVAL;
-                                }
+                                if (from < 0 || to < 0)
+                                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                               "Failed to parse log level range %s", optarg);
 
                                 arg_priorities = 0;
 
@@ -811,10 +819,9 @@ static int parse_argv(int argc, char *argv[]) {
                                 int p, i;
 
                                 p = log_level_from_string(optarg);
-                                if (p < 0) {
-                                        log_error("Unknown log level %s", optarg);
-                                        return -EINVAL;
-                                }
+                                if (p < 0)
+                                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                               "Unknown log level %s", optarg);
 
                                 arg_priorities = 0;
 
@@ -848,19 +855,17 @@ static int parse_argv(int argc, char *argv[]) {
 
                 case 'S':
                         r = parse_timestamp(optarg, &arg_since);
-                        if (r < 0) {
-                                log_error("Failed to parse timestamp: %s", optarg);
-                                return -EINVAL;
-                        }
+                        if (r < 0)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Failed to parse timestamp: %s", optarg);
                         arg_since_set = true;
                         break;
 
                 case 'U':
                         r = parse_timestamp(optarg, &arg_until);
-                        if (r < 0) {
-                                log_error("Failed to parse timestamp: %s", optarg);
-                                return -EINVAL;
-                        }
+                        if (r < 0)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Failed to parse timestamp: %s", optarg);
                         arg_until_set = true;
                         break;
 
@@ -1417,7 +1422,6 @@ static int add_boot(sd_journal *j) {
          * so take the slow path if log location is specified. */
         if (arg_boot_offset == 0 && sd_id128_is_null(arg_boot_id) &&
             !arg_directory && !arg_file && !arg_root)
-
                 return add_match_this_boot(j, arg_machine);
 
         boot_id = arg_boot_id;
@@ -1944,15 +1948,19 @@ static int verify(sd_journal *j) {
 
 static int simple_varlink_call(const char *option, const char *method) {
         _cleanup_(varlink_flush_close_unrefp) Varlink *link = NULL;
-        const char *error;
+        const char *error, *fn;
         int r;
 
         if (arg_machine)
                 return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "%s is not supported in conjunction with --machine=.", option);
 
-        r = varlink_connect_address(&link, "/run/systemd/journal/io.systemd.journal");
+        fn = arg_namespace ?
+                strjoina("/run/systemd/journal.", arg_namespace, "/io.systemd.journal") :
+                "/run/systemd/journal/io.systemd.journal";
+
+        r = varlink_connect_address(&link, fn);
         if (r < 0)
-                return log_error_errno(r, "Failed to connect to /run/systemd/journal/io.systemd.journal: %m");
+                return log_error_errno(r, "Failed to connect to %s: %m", fn);
 
         (void) varlink_set_description(link, "journal");
         (void) varlink_set_relative_timeout(link, USEC_INFINITY);
@@ -2122,10 +2130,9 @@ int main(int argc, char *argv[]) {
                 r = sd_journal_open_directory(&j, arg_directory, arg_journal_type);
         else if (arg_root)
                 r = sd_journal_open_directory(&j, arg_root, arg_journal_type | SD_JOURNAL_OS_ROOT);
-        else if (arg_file_stdin) {
-                int ifd = STDIN_FILENO;
-                r = sd_journal_open_files_fd(&j, &ifd, 1, 0);
-        } else if (arg_file)
+        else if (arg_file_stdin)
+                r = sd_journal_open_files_fd(&j, (int[]) { STDIN_FILENO }, 1, 0);
+        else if (arg_file)
                 r = sd_journal_open_files(&j, (const char**) arg_file, 0);
         else if (arg_machine) {
                 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
@@ -2136,8 +2143,7 @@ int main(int argc, char *argv[]) {
                 if (geteuid() != 0) {
                         /* The file descriptor returned by OpenMachineRootDirectory() will be owned by users/groups of
                          * the container, thus we need root privileges to override them. */
-                        log_error("Using the --machine= switch requires root privileges.");
-                        r = -EPERM;
+                        r = log_error_errno(SYNTHETIC_ERRNO(EPERM), "Using the --machine= switch requires root privileges.");
                         goto finish;
                 }
 
@@ -2177,7 +2183,11 @@ int main(int argc, char *argv[]) {
                 if (r < 0)
                         safe_close(fd);
         } else
-                r = sd_journal_open(&j, !arg_merge*SD_JOURNAL_LOCAL_ONLY + arg_journal_type);
+                r = sd_journal_open_namespace(
+                                &j,
+                                arg_namespace,
+                                (arg_merge ? 0 : SD_JOURNAL_LOCAL_ONLY) |
+                                arg_namespace_flags | arg_journal_type);
         if (r < 0) {
                 log_error_errno(r, "Failed to open %s: %m", arg_directory ?: arg_file ? "files" : "journal");
                 goto finish;

src/journal/journald-context.c

@@ -117,23 +117,24 @@ static int client_context_new(Server *s, pid_t pid, ClientContext **ret) {
         if (r < 0)
                 return r;
 
-        c = new0(ClientContext, 1);
+        c = new(ClientContext, 1);
         if (!c)
                 return -ENOMEM;
 
-        c->pid = pid;
-
-        c->uid = UID_INVALID;
-        c->gid = GID_INVALID;
-        c->auditid = AUDIT_SESSION_INVALID;
-        c->loginuid = UID_INVALID;
-        c->owner_uid = UID_INVALID;
-        c->lru_index = PRIOQ_IDX_NULL;
-        c->timestamp = USEC_INFINITY;
-        c->extra_fields_mtime = NSEC_INFINITY;
-        c->log_level_max = -1;
-        c->log_ratelimit_interval = s->ratelimit_interval;
-        c->log_ratelimit_burst = s->ratelimit_burst;
+        *c = (ClientContext) {
+                .pid = pid,
+                .uid = UID_INVALID,
+                .gid = GID_INVALID,
+                .auditid = AUDIT_SESSION_INVALID,
+                .loginuid = UID_INVALID,
+                .owner_uid = UID_INVALID,
+                .lru_index = PRIOQ_IDX_NULL,
+                .timestamp = USEC_INFINITY,
+                .extra_fields_mtime = NSEC_INFINITY,
+                .log_level_max = -1,
+                .log_ratelimit_interval = s->ratelimit_interval,
+                .log_ratelimit_burst = s->ratelimit_burst,
+        };
 
         r = hashmap_put(s->client_contexts, PID_TO_PTR(pid), c);
         if (r < 0) {
@@ -779,7 +780,9 @@ void client_context_acquire_default(Server *s) {
                         log_warning_errno(r, "Failed to acquire our own context, ignoring: %m");
         }
 
-        if (!s->pid1_context) {
+        if (!s->namespace && !s->pid1_context) {
+                /* Acquire PID1's context, but only if we are in non-namespaced mode, since PID 1 is only
+                 * going to log to the non-namespaced journal instance. */
 
                 r = client_context_acquire(s, 1, NULL, NULL, 0, NULL, &s->pid1_context);
                 if (r < 0)

src/journal/journald-kmsg.c

@@ -24,11 +24,11 @@
 #include "string-util.h"
 
 void server_forward_kmsg(
-        Server *s,
-        int priority,
-        const char *identifier,
-        const char *message,
-        const struct ucred *ucred) {
+                Server *s,
+                int priority,
+                const char *identifier,
+                const char *message,
+                const struct ucred *ucred) {
 
         _cleanup_free_ char *ident_buf = NULL;
         struct iovec iovec[5];
@@ -416,19 +416,23 @@ fail:
 }
 
 int server_open_kernel_seqnum(Server *s) {
-        _cleanup_close_ int fd;
+        _cleanup_close_ int fd = -1;
+        const char *fn;
         uint64_t *p;
         int r;
 
         assert(s);
 
-        /* We store the seqnum we last read in an mmaped file. That
-         * way we can just use it like a variable, but it is
-         * persistent and automatically flushed at reboot. */
+        /* We store the seqnum we last read in an mmaped file. That way we can just use it like a variable,
+         * but it is persistent and automatically flushed at reboot. */
 
-        fd = open("/run/systemd/journal/kernel-seqnum", O_RDWR|O_CREAT|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0644);
+        if (!s->read_kmsg)
+                return 0;
+
+        fn = strjoina(s->runtime_directory, "/kernel-seqnum");
+        fd = open(fn, O_RDWR|O_CREAT|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0644);
         if (fd < 0) {
-                log_error_errno(errno, "Failed to open /run/systemd/journal/kernel-seqnum, ignoring: %m");
+                log_error_errno(errno, "Failed to open %s, ignoring: %m", fn);
                 return 0;
         }
 

src/journal/journald-native.c

@@ -450,17 +450,21 @@ void server_process_native_file(
         }
 }
 
-int server_open_native_socket(Server *s) {
-
-        static const union sockaddr_union sa = {
-                .un.sun_family = AF_UNIX,
-                .un.sun_path = "/run/systemd/journal/socket",
-        };
+int server_open_native_socket(Server *s, const char *native_socket) {
         int r;
 
         assert(s);
+        assert(native_socket);
 
         if (s->native_fd < 0) {
+                union sockaddr_union sa = {
+                        .un.sun_family = AF_UNIX,
+                };
+
+                r = sockaddr_un_set_path(&sa.un, native_socket);
+                if (r < 0)
+                        return log_error_errno(r, "Unable to use namespace path %s for AF_UNIX socket: %m", native_socket);
+
                 s->native_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
                 if (s->native_fd < 0)
                         return log_error_errno(errno, "socket() failed: %m");

src/journal/journald-native.h

@@ -20,4 +20,4 @@ void server_process_native_file(
                 const char *label,
                 size_t label_len);
 
-int server_open_native_socket(Server *s);
+int server_open_native_socket(Server *s, const char *native_socket);

src/journal/journald-rate-limit.c

@@ -99,7 +99,7 @@ void journal_ratelimit_free(JournalRateLimit *r) {
         free(r);
 }
 
-_pure_ static bool journal_ratelimit_group_expired(JournalRateLimitGroup *g, usec_t ts) {
+static bool journal_ratelimit_group_expired(JournalRateLimitGroup *g, usec_t ts) {
         unsigned i;
 
         assert(g);

src/journal/journald-server.h

@@ -60,6 +60,8 @@ typedef struct JournalStorage {
 } JournalStorage;
 
 struct Server {
+        char *namespace;
+
         int syslog_fd;
         int native_fd;
         int stdout_fd;
@@ -84,6 +86,7 @@ struct Server {
         sd_event_source *hostname_event_source;
         sd_event_source *notify_event_source;
         sd_event_source *watchdog_event_source;
+        sd_event_source *idle_event_source;
 
         JournalFile *runtime_journal;
         JournalFile *system_journal;
@@ -147,6 +150,8 @@ struct Server {
         char machine_id_field[sizeof("_MACHINE_ID=") + 32];
         char boot_id_field[sizeof("_BOOT_ID=") + 32];
         char *hostname_field;
+        char *namespace_field;
+        char *runtime_directory;
 
         /* Cached cgroup root, so that we don't have to query that all the time */
         char *cgroup_root;
@@ -172,7 +177,7 @@ struct Server {
 #define SERVER_MACHINE_ID(s) ((s)->machine_id_field + STRLEN("_MACHINE_ID="))
 
 /* Extra fields for any log messages */
-#define N_IOVEC_META_FIELDS 22
+#define N_IOVEC_META_FIELDS 23
 
 /* Extra fields for log messages that contain OBJECT_PID= (i.e. log about another process) */
 #define N_IOVEC_OBJECT_FIELDS 18
@@ -204,7 +209,7 @@ CONFIG_PARSER_PROTOTYPE(config_parse_split_mode);
 const char *split_mode_to_string(SplitMode s) _const_;
 SplitMode split_mode_from_string(const char *s) _pure_;
 
-int server_init(Server *s);
+int server_init(Server *s, const char *namespace);
 void server_done(Server *s);
 void server_sync(Server *s);
 int server_vacuum(Server *s, bool verbose);
@@ -214,3 +219,6 @@ int server_flush_to_var(Server *s, bool require_flag_file);
 void server_maybe_append_tags(Server *s);
 int server_process_datagram(sd_event_source *es, int fd, uint32_t revents, void *userdata);
 void server_space_usage_message(Server *s, JournalStorage *storage);
+
+int server_start_or_stop_idle_timer(Server *s);
+int server_refresh_idle_timer(Server *s);

src/journal/journald-stream.c

@@ -17,6 +17,7 @@
 #include "escape.h"
 #include "fd-util.h"
 #include "fileio.h"
+#include "fs-util.h"
 #include "io-util.h"
 #include "journald-console.h"
 #include "journald-context.h"
@@ -109,6 +110,8 @@ void stdout_stream_free(StdoutStream *s) {
 
                 if (s->in_notify_queue)
                         LIST_REMOVE(stdout_stream_notify_queue, s->server->stdout_streams_notify_queue, s);
+
+                (void) server_start_or_stop_idle_timer(s->server); /* Maybe we are idle now? */
         }
 
         if (s->event_source) {
@@ -139,7 +142,7 @@ void stdout_stream_destroy(StdoutStream *s) {
 }
 
 static int stdout_stream_save(StdoutStream *s) {
-        _cleanup_free_ char *temp_path = NULL;
+        _cleanup_(unlink_and_freep) char *temp_path = NULL;
         _cleanup_fclose_ FILE *f = NULL;
         int r;
 
@@ -156,11 +159,12 @@ static int stdout_stream_save(StdoutStream *s) {
                         return log_warning_errno(errno, "Failed to stat connected stream: %m");
 
                 /* We use device and inode numbers as identifier for the stream */
-                if (asprintf(&s->state_file, "/run/systemd/journal/streams/%lu:%lu", (unsigned long) st.st_dev, (unsigned long) st.st_ino) < 0)
+                r = asprintf(&s->state_file, "%s/streams/%lu:%lu", s->server->runtime_directory, (unsigned long) st.st_dev, (unsigned long) st.st_ino);
+                if (r < 0)
                         return log_oom();
         }
 
-        (void) mkdir_p("/run/systemd/journal/streams", 0755);
+        (void) mkdir_parents(s->state_file, 0755);
 
         r = fopen_temporary(s->state_file, &f, &temp_path);
         if (r < 0)
@@ -214,6 +218,8 @@ static int stdout_stream_save(StdoutStream *s) {
                 goto fail;
         }
 
+        temp_path = mfree(temp_path);
+
         if (!s->fdstore && !s->in_notify_queue) {
                 LIST_PREPEND(stdout_stream_notify_queue, s->server->stdout_streams_notify_queue, s);
                 s->in_notify_queue = true;
@@ -229,10 +235,6 @@ static int stdout_stream_save(StdoutStream *s) {
 
 fail:
         (void) unlink(s->state_file);
-
-        if (temp_path)
-                (void) unlink(temp_path);
-
         return log_error_errno(r, "Failed to save stream data %s: %m", s->state_file);
 }
 
@@ -590,12 +592,14 @@ int stdout_stream_install(Server *s, int fd, StdoutStream **ret) {
         if (r < 0)
                 return log_error_errno(r, "Failed to generate stream ID: %m");
 
-        stream = new0(StdoutStream, 1);
+        stream = new(StdoutStream, 1);
         if (!stream)
                 return log_oom();
 
-        stream->fd = -1;
-        stream->priority = LOG_INFO;
+        *stream = (StdoutStream) {
+                .fd = -1,
+                .priority = LOG_INFO,
+        };
 
         xsprintf(stream->id_field, "_STREAM_ID=" SD_ID128_FORMAT_STR, SD_ID128_FORMAT_VAL(id));
 
@@ -629,11 +633,12 @@ int stdout_stream_install(Server *s, int fd, StdoutStream **ret) {
         LIST_PREPEND(stdout_stream, s->stdout_streams, stream);
         s->n_stdout_streams++;
 
+        (void) server_start_or_stop_idle_timer(s); /* Maybe no longer idle? */
+
         if (ret)
                 *ret = stream;
 
-        stream = NULL;
-
+        TAKE_PTR(stream);
         return 0;
 }
 
@@ -676,7 +681,7 @@ static int stdout_stream_new(sd_event_source *es, int listen_fd, uint32_t revent
         if (r < 0)
                 return r;
 
-        fd = -1;
+        TAKE_FD(fd);
         return 0;
 }
 
@@ -694,7 +699,7 @@ static int stdout_stream_load(StdoutStream *stream, const char *fname) {
         assert(fname);
 
         if (!stream->state_file) {
-                stream->state_file = path_join("/run/systemd/journal/streams", fname);
+                stream->state_file = path_join(stream->server->runtime_directory, "streams", fname);
                 if (!stream->state_file)
                         return log_oom();
         }
@@ -783,14 +788,16 @@ static int stdout_stream_restore(Server *s, const char *fname, int fd) {
 int server_restore_streams(Server *s, FDSet *fds) {
         _cleanup_closedir_ DIR *d = NULL;
         struct dirent *de;
+        const char *path;
         int r;
 
-        d = opendir("/run/systemd/journal/streams");
+        path = strjoina(s->runtime_directory, "/streams");
+        d = opendir(path);
         if (!d) {
                 if (errno == ENOENT)
                         return 0;
 
-                return log_warning_errno(errno, "Failed to enumerate /run/systemd/journal/streams: %m");
+                return log_warning_errno(errno, "Failed to enumerate %s: %m", path);
         }
 
         FOREACH_DIRENT(de, d, goto fail) {
@@ -818,8 +825,7 @@ int server_restore_streams(Server *s, FDSet *fds) {
                         /* No file descriptor? Then let's delete the state file */
                         log_debug("Cannot restore stream file %s", de->d_name);
                         if (unlinkat(dirfd(d), de->d_name, 0) < 0)
-                                log_warning_errno(errno, "Failed to remove /run/systemd/journal/streams/%s: %m",
-                                                  de->d_name);
+                                log_warning_errno(errno, "Failed to remove %s%s: %m", path, de->d_name);
                         continue;
                 }
 
@@ -836,16 +842,21 @@ fail:
         return log_error_errno(errno, "Failed to read streams directory: %m");
 }
 
-int server_open_stdout_socket(Server *s) {
-        static const union sockaddr_union sa = {
-                .un.sun_family = AF_UNIX,
-                .un.sun_path = "/run/systemd/journal/stdout",
-        };
+int server_open_stdout_socket(Server *s, const char *stdout_socket) {
         int r;
 
         assert(s);
+        assert(stdout_socket);
 
         if (s->stdout_fd < 0) {
+                union sockaddr_union sa = {
+                        .un.sun_family = AF_UNIX,
+                };
+
+                r = sockaddr_un_set_path(&sa.un, stdout_socket);
+                if (r < 0)
+                        return log_error_errno(r, "Unable to use namespace path %s for AF_UNIX socket: %m", stdout_socket);
+
                 s->stdout_fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
                 if (s->stdout_fd < 0)
                         return log_error_errno(errno, "socket() failed: %m");

src/journal/journald-stream.h

@@ -6,7 +6,7 @@ typedef struct StdoutStream StdoutStream;
 #include "fdset.h"
 #include "journald-server.h"
 
-int server_open_stdout_socket(Server *s);
+int server_open_stdout_socket(Server *s, const char *stdout_socket);
 int server_restore_streams(Server *s, FDSet *fds);
 
 void stdout_stream_free(StdoutStream *s);

src/journal/journald-syslog.c

@@ -25,11 +25,15 @@
 /* Warn once every 30s if we missed syslog message */
 #define WARN_FORWARD_SYSLOG_MISSED_USEC (30 * USEC_PER_SEC)
 
-static void forward_syslog_iovec(Server *s, const struct iovec *iovec, unsigned n_iovec, const struct ucred *ucred, const struct timeval *tv) {
+static void forward_syslog_iovec(
+                Server *s,
+                const struct iovec *iovec,
+                unsigned n_iovec,
+                const struct ucred *ucred,
+                const struct timeval *tv) {
 
-        static const union sockaddr_union sa = {
+        union sockaddr_union sa = {
                 .un.sun_family = AF_UNIX,
-                .un.sun_path = "/run/systemd/journal/syslog",
         };
         struct msghdr msghdr = {
                 .msg_iov = (struct iovec *) iovec,
@@ -42,11 +46,20 @@ static void forward_syslog_iovec(Server *s, const struct iovec *iovec, unsigned
                 struct cmsghdr cmsghdr;
                 uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
         } control;
+        const char *j;
+        int r;
 
         assert(s);
         assert(iovec);
         assert(n_iovec > 0);
 
+        j = strjoina(s->runtime_directory, "/syslog");
+        r = sockaddr_un_set_path(&sa.un, j);
+        if (r < 0) {
+                log_debug_errno(r, "Forwarding socket path %s too long for AF_UNIX, not forwarding: %m", j);
+                return;
+        }
+
         if (ucred) {
                 zero(control);
                 msghdr.msg_control = &control;
@@ -441,17 +454,21 @@ void server_process_syslog_message(
         server_dispatch_message(s, iovec, n, m, context, tv, priority, 0);
 }
 
-int server_open_syslog_socket(Server *s) {
-
-        static const union sockaddr_union sa = {
-                .un.sun_family = AF_UNIX,
-                .un.sun_path = "/run/systemd/journal/dev-log",
-        };
+int server_open_syslog_socket(Server *s, const char *syslog_socket) {
         int r;
 
         assert(s);
+        assert(syslog_socket);
 
         if (s->syslog_fd < 0) {
+                union sockaddr_union sa = {
+                        .un.sun_family = AF_UNIX,
+                };
+
+                r = sockaddr_un_set_path(&sa.un, syslog_socket);
+                if (r < 0)
+                        return log_error_errno(r, "Unable to use namespace path %s for AF_UNIX socket: %m", syslog_socket);
+
                 s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
                 if (s->syslog_fd < 0)
                         return log_error_errno(errno, "socket() failed: %m");

src/journal/journald-syslog.h

@@ -10,6 +10,6 @@ size_t syslog_parse_identifier(const char **buf, char **identifier, char **pid);
 void server_forward_syslog(Server *s, int priority, const char *identifier, const char *message, const struct ucred *ucred, const struct timeval *tv);
 
 void server_process_syslog_message(Server *s, const char *buf, size_t buf_len, const struct ucred *ucred, const struct timeval *tv, const char *label, size_t label_len);
-int server_open_syslog_socket(Server *s);
+int server_open_syslog_socket(Server *s, const char *syslog_socket);
 
 void server_maybe_warn_forward_syslog_missed(Server *s);

src/journal/journald.c

@@ -14,14 +14,17 @@
 #include "sigbus.h"
 
 int main(int argc, char *argv[]) {
+        const char *namespace;
         Server server;
         int r;
 
-        if (argc > 1) {
-                log_error("This program does not take arguments.");
+        if (argc > 2) {
+                log_error("This program takes one or no arguments.");
                 return EXIT_FAILURE;
         }
 
+        namespace = argc > 1 ? empty_to_null(argv[1]) : NULL;
+
         log_set_prohibit_ipc(true);
         log_set_target(LOG_TARGET_AUTO);
         log_set_facility(LOG_SYSLOG);
@@ -32,7 +35,7 @@ int main(int argc, char *argv[]) {
 
         sigbus_install();
 
-        r = server_init(&server);
+        r = server_init(&server, namespace);
         if (r < 0)
                 goto finish;
 
@@ -40,7 +43,11 @@ int main(int argc, char *argv[]) {
         server_flush_to_var(&server, true);
         server_flush_dev_kmsg(&server);
 
-        log_debug("systemd-journald running as pid "PID_FMT, getpid_cached());
+        if (server.namespace)
+                log_debug("systemd-journald running as PID "PID_FMT" for namespace '%s'.", getpid_cached(), server.namespace ?: "<system>");
+        else
+                log_debug("systemd-journald running as PID "PID_FMT" for the system.", getpid_cached());
+
         server_driver_message(&server, 0,
                               "MESSAGE_ID=" SD_MESSAGE_JOURNAL_START_STR,
                               LOG_MESSAGE("Journal started"),
@@ -55,8 +62,10 @@ int main(int argc, char *argv[]) {
                 usec_t t = USEC_INFINITY, n;
 
                 r = sd_event_get_state(server.event);
-                if (r < 0)
+                if (r < 0) {
+                        log_error_errno(r, "Failed to get event loop state: %m");
                         goto finish;
+                }
                 if (r == SD_EVENT_FINISHED)
                         break;
 
@@ -99,7 +108,11 @@ int main(int argc, char *argv[]) {
                 server_maybe_warn_forward_syslog_missed(&server);
         }
 
-        log_debug("systemd-journald stopped as pid "PID_FMT, getpid_cached());
+        if (server.namespace)
+                log_debug("systemd-journald stopped as PID "PID_FMT" for namespace '%s'.", getpid_cached(), server.namespace ?: "<system>");
+        else
+                log_debug("systemd-journald stopped as PID "PID_FMT" for the system.", getpid_cached());
+
         server_driver_message(&server, 0,
                               "MESSAGE_ID=" SD_MESSAGE_JOURNAL_STOP_STR,
                               LOG_MESSAGE("Journal stopped"),

src/journal/sd-journal.c

@@ -39,6 +39,7 @@
 #include "stdio-util.h"
 #include "string-util.h"
 #include "strv.h"
+#include "syslog-util.h"
 
 #define JOURNAL_FILES_MAX 7168
 
@@ -204,16 +205,17 @@ static bool same_field(const void *_a, size_t s, const void *_b, size_t t) {
 static Match *match_new(Match *p, MatchType t) {
         Match *m;
 
-        m = new0(Match, 1);
+        m = new(Match, 1);
         if (!m)
                 return NULL;
 
-        m->type = t;
+        *m = (Match) {
+                .type = t,
+                .parent = p,
+        };
 
-        if (p) {
-                m->parent = p;
+        if (p)
                 LIST_PREPEND(matches, p->matches, m);
-        }
 
         return m;
 }
@@ -1434,22 +1436,63 @@ static void remove_file_real(sd_journal *j, JournalFile *f) {
 
 static int dirname_is_machine_id(const char *fn) {
         sd_id128_t id, machine;
+        const char *e;
         int r;
 
+        /* Returns true if the specified directory name matches the local machine ID */
+
         r = sd_id128_get_machine(&machine);
         if (r < 0)
                 return r;
 
-        r = sd_id128_from_string(fn, &id);
+        e = strchr(fn, '.');
+        if (e) {
+                const char *k;
+
+                /* Looks like it has a namespace suffix. Verify that. */
+                if (!log_namespace_name_valid(e + 1))
+                        return false;
+
+                k = strndupa(fn, e - fn);
+                r = sd_id128_from_string(k, &id);
+        } else
+                r = sd_id128_from_string(fn, &id);
         if (r < 0)
                 return r;
 
         return sd_id128_equal(id, machine);
 }
 
+static int dirname_has_namespace(const char *fn, const char *namespace) {
+        const char *e;
+
+        /* Returns true if the specified directory name matches the specified namespace */
+
+        e = strchr(fn, '.');
+        if (e) {
+                const char *k;
+
+                if (!namespace)
+                        return false;
+
+                if (!streq(e + 1, namespace))
+                        return false;
+
+                k = strndupa(fn, e - fn);
+                return id128_is_valid(k);
+        }
+
+        if (namespace)
+                return false;
+
+        return id128_is_valid(fn);
+}
+
 static bool dirent_is_journal_file(const struct dirent *de) {
         assert(de);
 
+        /* Returns true if the specified directory entry looks like a journal file we might be interested in */
+
         if (!IN_SET(de->d_type, DT_REG, DT_LNK, DT_UNKNOWN))
                 return false;
 
@@ -1457,13 +1500,26 @@ static bool dirent_is_journal_file(const struct dirent *de) {
                 endswith(de->d_name, ".journal~");
 }
 
-static bool dirent_is_id128_subdir(const struct dirent *de) {
+static bool dirent_is_journal_subdir(const struct dirent *de) {
+        const char *e, *n;
         assert(de);
 
+        /* returns true if the specified directory entry looks like a directory that might contain journal
+         * files we might be interested in, i.e. is either a 128bit ID or a 128bit ID suffixed by a
+         * namespace. */
+
         if (!IN_SET(de->d_type, DT_DIR, DT_LNK, DT_UNKNOWN))
                 return false;
 
-        return id128_is_valid(de->d_name);
+        e = strchr(de->d_name, '.');
+        if (!e)
+                return id128_is_valid(de->d_name); /* No namespace */
+
+        n = strndupa(de->d_name, e - de->d_name);
+        if (!id128_is_valid(n))
+                return false;
+
+        return log_namespace_name_valid(e + 1);
 }
 
 static int directory_open(sd_journal *j, const char *path, DIR **ret) {
@@ -1500,7 +1556,7 @@ static void directory_enumerate(sd_journal *j, Directory *m, DIR *d) {
                 if (dirent_is_journal_file(de))
                         (void) add_file_by_name(j, m->path, de->d_name);
 
-                if (m->is_root && dirent_is_id128_subdir(de))
+                if (m->is_root && dirent_is_journal_subdir(de))
                         (void) add_directory(j, m->path, de->d_name);
         }
 
@@ -1540,7 +1596,11 @@ static void directory_watch(sd_journal *j, Directory *m, int fd, uint32_t mask)
         }
 }
 
-static int add_directory(sd_journal *j, const char *prefix, const char *dirname) {
+static int add_directory(
+                sd_journal *j,
+                const char *prefix,
+                const char *dirname) {
+
         _cleanup_free_ char *path = NULL;
         _cleanup_closedir_ DIR *d = NULL;
         Directory *m;
@@ -1565,6 +1625,11 @@ static int add_directory(sd_journal *j, const char *prefix, const char *dirname)
             !((dirname && dirname_is_machine_id(dirname) > 0) || path_has_prefix(j, path, "/run")))
                 return 0;
 
+        if (!(FLAGS_SET(j->flags, SD_JOURNAL_ALL_NAMESPACES) ||
+              dirname_has_namespace(dirname, j->namespace) > 0 ||
+              (FLAGS_SET(j->flags, SD_JOURNAL_INCLUDE_DEFAULT_NAMESPACE) && dirname_has_namespace(dirname, NULL) > 0)))
+                return 0;
+
         r = directory_open(j, path, &d);
         if (r < 0) {
                 log_debug_errno(r, "Failed to open directory '%s': %m", path);
@@ -1573,14 +1638,16 @@ static int add_directory(sd_journal *j, const char *prefix, const char *dirname)
 
         m = hashmap_get(j->directories_by_path, path);
         if (!m) {
-                m = new0(Directory, 1);
+                m = new(Directory, 1);
                 if (!m) {
                         r = -ENOMEM;
                         goto fail;
                 }
 
-                m->is_root = false;
-                m->path = path;
+                *m = (Directory) {
+                        .is_root = false,
+                        .path = path,
+                };
 
                 if (hashmap_put(j->directories_by_path, m->path, m) < 0) {
                         free(m);
@@ -1803,7 +1870,7 @@ static int allocate_inotify(sd_journal *j) {
         return hashmap_ensure_allocated(&j->directories_by_wd, NULL);
 }
 
-static sd_journal *journal_new(int flags, const char *path) {
+static sd_journal *journal_new(int flags, const char *path, const char *namespace) {
         _cleanup_(sd_journal_closep) sd_journal *j = NULL;
 
         j = new0(sd_journal, 1);
@@ -1829,6 +1896,12 @@ static sd_journal *journal_new(int flags, const char *path) {
                         j->path = t;
         }
 
+        if (namespace) {
+                j->namespace = strdup(namespace);
+                if (!j->namespace)
+                        return NULL;
+        }
+
         j->files = ordered_hashmap_new(&path_hash_ops);
         if (!j->files)
                 return NULL;
@@ -1845,16 +1918,19 @@ static sd_journal *journal_new(int flags, const char *path) {
 #define OPEN_ALLOWED_FLAGS                              \
         (SD_JOURNAL_LOCAL_ONLY |                        \
          SD_JOURNAL_RUNTIME_ONLY |                      \
-         SD_JOURNAL_SYSTEM | SD_JOURNAL_CURRENT_USER)
+         SD_JOURNAL_SYSTEM |                            \
+         SD_JOURNAL_CURRENT_USER |                      \
+         SD_JOURNAL_ALL_NAMESPACES |                    \
+         SD_JOURNAL_INCLUDE_DEFAULT_NAMESPACE)
 
-_public_ int sd_journal_open(sd_journal **ret, int flags) {
+_public_ int sd_journal_open_namespace(sd_journal **ret, const char *namespace, int flags) {
         _cleanup_(sd_journal_closep) sd_journal *j = NULL;
         int r;
 
         assert_return(ret, -EINVAL);
         assert_return((flags & ~OPEN_ALLOWED_FLAGS) == 0, -EINVAL);
 
-        j = journal_new(flags, NULL);
+        j = journal_new(flags, NULL, namespace);
         if (!j)
                 return -ENOMEM;
 
@@ -1866,6 +1942,10 @@ _public_ int sd_journal_open(sd_journal **ret, int flags) {
         return 0;
 }
 
+_public_ int sd_journal_open(sd_journal **ret, int flags) {
+        return sd_journal_open_namespace(ret, NULL, flags);
+}
+
 #define OPEN_CONTAINER_ALLOWED_FLAGS                    \
         (SD_JOURNAL_LOCAL_ONLY | SD_JOURNAL_SYSTEM)
 
@@ -1875,7 +1955,7 @@ _public_ int sd_journal_open_container(sd_journal **ret, const char *machine, in
         char *p;
         int r;
 
-        /* This is pretty much deprecated, people should use machined's OpenMachineRootDirectory() call instead in
+        /* This is deprecated, people should use machined's OpenMachineRootDirectory() call instead in
          * combination with sd_journal_open_directory_fd(). */
 
         assert_return(machine, -EINVAL);
@@ -1897,7 +1977,7 @@ _public_ int sd_journal_open_container(sd_journal **ret, const char *machine, in
         if (!streq_ptr(class, "container"))
                 return -EIO;
 
-        j = journal_new(flags, root);
+        j = journal_new(flags, root, NULL);
         if (!j)
                 return -ENOMEM;
 
@@ -1921,7 +2001,7 @@ _public_ int sd_journal_open_directory(sd_journal **ret, const char *path, int f
         assert_return(path, -EINVAL);
         assert_return((flags & ~OPEN_DIRECTORY_ALLOWED_FLAGS) == 0, -EINVAL);
 
-        j = journal_new(flags, path);
+        j = journal_new(flags, path, NULL);
         if (!j)
                 return -ENOMEM;
 
@@ -1944,7 +2024,7 @@ _public_ int sd_journal_open_files(sd_journal **ret, const char **paths, int fla
         assert_return(ret, -EINVAL);
         assert_return(flags == 0, -EINVAL);
 
-        j = journal_new(flags, NULL);
+        j = journal_new(flags, NULL, NULL);
         if (!j)
                 return -ENOMEM;
 
@@ -1979,7 +2059,7 @@ _public_ int sd_journal_open_directory_fd(sd_journal **ret, int fd, int flags) {
         if (!S_ISDIR(st.st_mode))
                 return -EBADFD;
 
-        j = journal_new(flags, NULL);
+        j = journal_new(flags, NULL, NULL);
         if (!j)
                 return -ENOMEM;
 
@@ -2007,7 +2087,7 @@ _public_ int sd_journal_open_files_fd(sd_journal **ret, int fds[], unsigned n_fd
         assert_return(n_fds > 0, -EBADF);
         assert_return(flags == 0, -EINVAL);
 
-        j = journal_new(flags, NULL);
+        j = journal_new(flags, NULL, NULL);
         if (!j)
                 return -ENOMEM;
 
@@ -2079,6 +2159,7 @@ _public_ void sd_journal_close(sd_journal *j) {
 
         free(j->path);
         free(j->prefix);
+        free(j->namespace);
         free(j->unique_field);
         free(j->fields_buffer);
         free(j);
@@ -2480,7 +2561,7 @@ static void process_q_overflow(sd_journal *j) {
         log_debug("Reiteration complete.");
 }
 
-static void process_inotify_event(sd_journal *j, struct inotify_event *e) {
+static void process_inotify_event(sd_journal *j, const struct inotify_event *e) {
         Directory *d;
 
         assert(j);

src/libsystemd/libsystemd.sym

@@ -693,4 +693,5 @@ global:
         sd_event_source_get_child_process_own;
         sd_event_source_set_child_process_own;
         sd_event_source_send_child_signal;
+        sd_journal_open_namespace;
 } LIBSYSTEMD_243;

src/login/loginctl.c

@@ -576,6 +576,7 @@ static int print_session_status_info(sd_bus *bus, const char *path, bool *new_li
                         show_journal_by_unit(
                                         stdout,
                                         i.scope,
+                                        NULL,
                                         arg_output,
                                         0,
                                         i.timestamp.monotonic,
@@ -660,6 +661,7 @@ static int print_user_status_info(sd_bus *bus, const char *path, bool *new_line)
                 show_journal_by_unit(
                                 stdout,
                                 i.slice,
+                                NULL,
                                 arg_output,
                                 0,
                                 i.timestamp.monotonic,

src/machine/machinectl.c

@@ -626,6 +626,7 @@ static void print_machine_status_info(sd_bus *bus, MachineStatusInfo *i) {
                         show_journal_by_unit(
                                         stdout,
                                         i->unit,
+                                        NULL,
                                         arg_output,
                                         0,
                                         i->timestamp.monotonic,

src/shared/bus-unit-util.c

@@ -833,7 +833,8 @@ static int bus_append_execute_property(sd_bus_message *m, const char *field, con
                               "RuntimeDirectoryPreserve",
                               "Personality",
                               "KeyringMode",
-                              "NetworkNamespacePath"))
+                              "NetworkNamespacePath",
+                              "LogNamespace"))
                 return bus_append_string(m, field, eq);
 
         if (STR_IN_SET(field, "IgnoreSIGPIPE",

src/shared/logs-show.c

@@ -1453,6 +1453,7 @@ int add_match_this_boot(sd_journal *j, const char *machine) {
 int show_journal_by_unit(
                 FILE *f,
                 const char *unit,
+                const char *log_namespace,
                 OutputMode mode,
                 unsigned n_columns,
                 usec_t not_before,
@@ -1473,7 +1474,7 @@ int show_journal_by_unit(
         if (how_many <= 0)
                 return 0;
 
-        r = sd_journal_open(&j, journal_open_flags);
+        r = sd_journal_open_namespace(&j, log_namespace, journal_open_flags | SD_JOURNAL_INCLUDE_DEFAULT_NAMESPACE);
         if (r < 0)
                 return log_error_errno(r, "Failed to open journal: %m");
 

src/shared/logs-show.h

@@ -46,6 +46,7 @@ int add_matches_for_user_unit(
 int show_journal_by_unit(
                 FILE *f,
                 const char *unit,
+                const char *namespace,
                 OutputMode mode,
                 unsigned n_columns,
                 usec_t not_before,

src/shared/varlink.c

@@ -168,6 +168,7 @@ struct VarlinkServer {
 
         Hashmap *methods;
         VarlinkConnect connect_callback;
+        VarlinkDisconnect disconnect_callback;
 
         sd_event *event;
         int64_t event_priority;
@@ -1146,6 +1147,7 @@ int varlink_flush(Varlink *v) {
 }
 
 static void varlink_detach_server(Varlink *v) {
+        VarlinkServer *saved_server;
         assert(v);
 
         if (!v->server)
@@ -1169,8 +1171,15 @@ static void varlink_detach_server(Varlink *v) {
         v->server->n_connections--;
 
         /* If this is a connection associated to a server, then let's disconnect the server and the
-         * connection from each other. This drops the dangling reference that connect_callback() set up. */
-        v->server = varlink_server_unref(v->server);
+         * connection from each other. This drops the dangling reference that connect_callback() set up. But
+         * before we release the references, let's call the disconnection callback if it is defined. */
+
+        saved_server = TAKE_PTR(v->server);
+
+        if (saved_server->disconnect_callback)
+                saved_server->disconnect_callback(saved_server, v, saved_server->userdata);
+
+        varlink_server_unref(saved_server);
         varlink_unref(v);
 }
 
@@ -2413,6 +2422,16 @@ int varlink_server_bind_connect(VarlinkServer *s, VarlinkConnect callback) {
         return 0;
 }
 
+int varlink_server_bind_disconnect(VarlinkServer *s, VarlinkDisconnect callback) {
+        assert_return(s, -EINVAL);
+
+        if (callback && s->disconnect_callback && callback != s->disconnect_callback)
+                return -EBUSY;
+
+        s->disconnect_callback = callback;
+        return 0;
+}
+
 unsigned varlink_server_connections_max(VarlinkServer *s) {
         int dts;
 
@@ -2460,6 +2479,12 @@ int varlink_server_set_connections_max(VarlinkServer *s, unsigned m) {
         return 0;
 }
 
+unsigned varlink_server_current_connections(VarlinkServer *s) {
+        assert_return(s, UINT_MAX);
+
+        return s->n_connections;
+}
+
 int varlink_server_set_description(VarlinkServer *s, const char *description) {
         assert_return(s, -EINVAL);
 

src/shared/varlink.h

@@ -51,6 +51,7 @@ typedef enum VarlinkServerFlags {
 typedef int (*VarlinkMethod)(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata);
 typedef int (*VarlinkReply)(Varlink *link, JsonVariant *parameters, const char *error_id, VarlinkReplyFlags flags, void *userdata);
 typedef int (*VarlinkConnect)(VarlinkServer *server, Varlink *link, void *userdata);
+typedef void (*VarlinkDisconnect)(VarlinkServer *server, Varlink *link, void *userdata);
 
 int varlink_connect_address(Varlink **ret, const char *address);
 int varlink_connect_fd(Varlink **ret, int fd);
@@ -134,6 +135,7 @@ int varlink_server_bind_method(VarlinkServer *s, const char *method, VarlinkMeth
 int varlink_server_bind_method_many_internal(VarlinkServer *s, ...);
 #define varlink_server_bind_method_many(s, ...) varlink_server_bind_method_many_internal(s, __VA_ARGS__, NULL)
 int varlink_server_bind_connect(VarlinkServer *s, VarlinkConnect connect);
+int varlink_server_bind_disconnect(VarlinkServer *s, VarlinkDisconnect disconnect);
 
 void* varlink_server_set_userdata(VarlinkServer *s, void *userdata);
 void* varlink_server_get_userdata(VarlinkServer *s);
@@ -150,6 +152,8 @@ unsigned varlink_server_connections_per_uid_max(VarlinkServer *s);
 int varlink_server_set_connections_per_uid_max(VarlinkServer *s, unsigned m);
 int varlink_server_set_connections_max(VarlinkServer *s, unsigned m);
 
+unsigned varlink_server_current_connections(VarlinkServer *s);
+
 int varlink_server_set_description(VarlinkServer *s, const char *description);
 
 DEFINE_TRIVIAL_CLEANUP_FUNC(Varlink *, varlink_unref);

src/systemctl/systemctl.c

@@ -4007,6 +4007,8 @@ typedef struct UnitStatusInfo {
 
         int exit_code, exit_status;
 
+        const char *log_namespace;
+
         usec_t condition_timestamp;
         bool condition_result;
         LIST_HEAD(UnitCondition, conditions);
@@ -4545,6 +4547,7 @@ static void print_status_info(
                 show_journal_by_unit(
                                 stdout,
                                 i->id,
+                                i->log_namespace,
                                 arg_output,
                                 0,
                                 i->inactive_exit_timestamp_monotonic,
@@ -5491,6 +5494,7 @@ static int show_one(
                 { "ExecMainExitTimestamp",          "t",               NULL,           offsetof(UnitStatusInfo, exit_timestamp)                    },
                 { "ExecMainCode",                   "i",               NULL,           offsetof(UnitStatusInfo, exit_code)                         },
                 { "ExecMainStatus",                 "i",               NULL,           offsetof(UnitStatusInfo, exit_status)                       },
+                { "LogNamespace",                   "s",               NULL,           offsetof(UnitStatusInfo, log_namespace)                     },
                 { "ConditionTimestamp",             "t",               NULL,           offsetof(UnitStatusInfo, condition_timestamp)               },
                 { "ConditionResult",                "b",               NULL,           offsetof(UnitStatusInfo, condition_result)                  },
                 { "Conditions",                     "a(sbbsi)",        map_conditions, 0                                                           },

src/systemd/_sd-common.h

@@ -45,6 +45,18 @@ typedef void (*_sd_destroy_t)(void *userdata);
 #  define _sd_pure_ __attribute__((__pure__))
 #endif
 
+/* Note that strictly speaking __deprecated__ has been available before GCC 6. However, starting with GCC 6
+ * it also works on enum values, which we are interested in. Since this is a developer-facing feature anyway
+ * (as opposed to build engineer-facing), let's hence conditionalize this to gcc 6, given that the developers
+ * are probably going to use something newer anyway. */
+#ifndef _sd_deprecated_
+#  if __GNUC__ >= 6
+#    define _sd_deprecated_ __attribute__((__deprecated__))
+#  else
+#    define _sd_deprecated_
+#  endif
+#endif
+
 #ifndef _SD_STRINGIFY
 #  define _SD_XSTRINGIFY(x) #x
 #  define _SD_STRINGIFY(x) _SD_XSTRINGIFY(x)

src/systemd/sd-journal.h

@@ -64,13 +64,15 @@ typedef struct sd_journal sd_journal;
 
 /* Open flags */
 enum {
-        SD_JOURNAL_LOCAL_ONLY   = 1 << 0,
-        SD_JOURNAL_RUNTIME_ONLY = 1 << 1,
-        SD_JOURNAL_SYSTEM       = 1 << 2,
-        SD_JOURNAL_CURRENT_USER = 1 << 3,
-        SD_JOURNAL_OS_ROOT      = 1 << 4,
+        SD_JOURNAL_LOCAL_ONLY                = 1 << 0,
+        SD_JOURNAL_RUNTIME_ONLY              = 1 << 1,
+        SD_JOURNAL_SYSTEM                    = 1 << 2,
+        SD_JOURNAL_CURRENT_USER              = 1 << 3,
+        SD_JOURNAL_OS_ROOT                   = 1 << 4,
+        SD_JOURNAL_ALL_NAMESPACES            = 1 << 5, /* Show all namespaces, not just the default or specified one */
+        SD_JOURNAL_INCLUDE_DEFAULT_NAMESPACE = 1 << 6, /* Show default namespace in addition to specified one */
 
-        SD_JOURNAL_SYSTEM_ONLY = SD_JOURNAL_SYSTEM /* deprecated name */
+        SD_JOURNAL_SYSTEM_ONLY _sd_deprecated_ = SD_JOURNAL_SYSTEM /* deprecated name */
 };
 
 /* Wakeup event types */
@@ -81,11 +83,12 @@ enum {
 };
 
 int sd_journal_open(sd_journal **ret, int flags);
+int sd_journal_open_namespace(sd_journal **ret, const char *name_space, int flags);
 int sd_journal_open_directory(sd_journal **ret, const char *path, int flags);
 int sd_journal_open_directory_fd(sd_journal **ret, int fd, int flags);
 int sd_journal_open_files(sd_journal **ret, const char **paths, int flags);
 int sd_journal_open_files_fd(sd_journal **ret, int fds[], unsigned n_fds, int flags);
-int sd_journal_open_container(sd_journal **ret, const char *machine, int flags); /* deprecated */
+int sd_journal_open_container(sd_journal **ret, const char *machine, int flags) _sd_deprecated_; /* deprecated */
 void sd_journal_close(sd_journal *j);
 
 int sd_journal_previous(sd_journal *j);

src/test/generate-sym-test.py

@@ -6,6 +6,9 @@ for header in sys.argv[2:]:
     print('#include "{}"'.format(header.split('/')[-1]))
 
 print('''
+/* We want to check deprecated symbols too, without complaining */
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+
 const void* symbols[] = {''')
 
 for line in open(sys.argv[1]):

src/test/test-namespace.c

@@ -148,6 +148,7 @@ static void test_protect_kernel_logs(void) {
                                     NULL, 0,
                                     NULL,
                                     NULL,
+                                    NULL,
                                     PROTECT_HOME_NO,
                                     PROTECT_SYSTEM_NO,
                                     0,

src/test/test-ns.c

@@ -72,6 +72,7 @@ int main(int argc, char *argv[]) {
                             &(TemporaryFileSystem) { .path = (char*) "/var", .options = (char*) "ro" }, 1,
                             tmp_dir,
                             var_tmp_dir,
+                            NULL,
                             PROTECT_HOME_NO,
                             PROTECT_SYSTEM_NO,
                             0,