Merge pull request #13244 from keszybz/allow-dots-in-usernames

Allow dots in usernames

10 files changed, 146 insertions, 35 deletions

diff --git a/src/basic/user-util.c b/src/basic/user-util.c
index d127b0c107..3b253bc264 100644
--- a/src/basic/user-util.c
+++ b/src/basic/user-util.c
@@ -620,16 +620,19 @@ int take_etc_passwd_lock(const char *root) {
         return fd;
 }
 
-bool valid_user_group_name(const char *u) {
+bool valid_user_group_name_full(const char *u, bool strict) {
         const char *i;
         long sz;
 
         /* Checks if the specified name is a valid user/group name. Also see POSIX IEEE Std 1003.1-2008, 2016 Edition,
          * 3.437. We are a bit stricter here however. Specifically we deviate from POSIX rules:
          *
-         * - We don't allow any dots (this would break chown syntax which permits dots as user/group name separator)
          * - We require that names fit into the appropriate utmp field
          * - We don't allow empty user names
+         * - No dots or digits in the first character
+         *
+         * If strict==true, additionally:
+         * - We don't allow any dots (this conflicts with chown syntax which permits dots as user/group name separator)
          *
          * Note that other systems are even more restrictive, and don't permit underscores or uppercase characters.
          */
@@ -642,12 +645,25 @@ bool valid_user_group_name(const char *u) {
             u[0] != '_')
                 return false;
 
+        bool warned = false;
+
         for (i = u+1; *i; i++) {
-                if (!(*i >= 'a' && *i <= 'z') &&
-                    !(*i >= 'A' && *i <= 'Z') &&
-                    !(*i >= '0' && *i <= '9') &&
-                    !IN_SET(*i, '_', '-'))
-                        return false;
+                if (((*i >= 'a' && *i <= 'z') ||
+                     (*i >= 'A' && *i <= 'Z') ||
+                     (*i >= '0' && *i <= '9') ||
+                     IN_SET(*i, '_', '-')))
+                        continue;
+
+                if (*i == '.' && !strict) {
+                        if (!warned) {
+                                log_warning("Bad user or group name \"%s\", accepting for compatibility.", u);
+                                warned = true;
+                        }
+
+                        continue;
+                }
+
+                return false;
         }
 
         sz = sysconf(_SC_LOGIN_NAME_MAX);
@@ -662,15 +678,15 @@ bool valid_user_group_name(const char *u) {
         return true;
 }
 
-bool valid_user_group_name_or_id(const char *u) {
+bool valid_user_group_name_or_id_full(const char *u, bool strict) {
 
-        /* Similar as above, but is also fine with numeric UID/GID specifications, as long as they are in the right
-         * range, and not the invalid user ids. */
+        /* Similar as above, but is also fine with numeric UID/GID specifications, as long as they are in the
+         * right range, and not the invalid user ids. */
 
         if (isempty(u))
                 return false;
 
-        if (valid_user_group_name(u))
+        if (valid_user_group_name_full(u, strict))
                 return true;
 
         return parse_uid(u, NULL) >= 0;
diff --git a/src/basic/user-util.h b/src/basic/user-util.h
index 52f3df792d..cfa515f5e8 100644
--- a/src/basic/user-util.h
+++ b/src/basic/user-util.h
@@ -85,8 +85,20 @@ static inline bool userns_supported(void) {
         return access("/proc/self/uid_map", F_OK) >= 0;
 }
 
-bool valid_user_group_name(const char *u);
-bool valid_user_group_name_or_id(const char *u);
+bool valid_user_group_name_full(const char *u, bool strict);
+bool valid_user_group_name_or_id_full(const char *u, bool strict);
+static inline bool valid_user_group_name(const char *u) {
+        return valid_user_group_name_full(u, true);
+}
+static inline bool valid_user_group_name_or_id(const char *u) {
+        return valid_user_group_name_or_id_full(u, true);
+}
+static inline bool valid_user_group_name_compat(const char *u) {
+        return valid_user_group_name_full(u, false);
+}
+static inline bool valid_user_group_name_or_id_compat(const char *u) {
+        return valid_user_group_name_or_id_full(u, false);
+}
 bool valid_gecos(const char *d);
 bool valid_home(const char *p);
 
diff --git a/src/core/dbus-execute.c b/src/core/dbus-execute.c
index 85c310cd33..eae4bd93f2 100644
--- a/src/core/dbus-execute.c
+++ b/src/core/dbus-execute.c
@@ -1182,10 +1182,10 @@ int bus_exec_context_set_transient_property(
         flags |= UNIT_PRIVATE;
 
         if (streq(name, "User"))
-                return bus_set_transient_user(u, name, &c->user, message, flags, error);
+                return bus_set_transient_user_compat(u, name, &c->user, message, flags, error);
 
         if (streq(name, "Group"))
-                return bus_set_transient_user(u, name, &c->group, message, flags, error);
+                return bus_set_transient_user_compat(u, name, &c->group, message, flags, error);
 
         if (streq(name, "TTYPath"))
                 return bus_set_transient_path(u, name, &c->tty_path, message, flags, error);
@@ -1363,10 +1363,10 @@ int bus_exec_context_set_transient_property(
                 if (r < 0)
                         return r;
 
-                STRV_FOREACH(p, l) {
-                        if (!isempty(*p) && !valid_user_group_name_or_id(*p))
-                                return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid supplementary group names");
-                }
+                STRV_FOREACH(p, l)
+                        if (!isempty(*p) && !valid_user_group_name_or_id_compat(*p))
+                                return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
+                                                         "Invalid supplementary group names");
 
                 if (!UNIT_WRITE_FLAGS_NOOP(flags)) {
                         if (strv_isempty(l)) {
diff --git a/src/core/dbus-socket.c b/src/core/dbus-socket.c
index e895c94e12..25d3d71391 100644
--- a/src/core/dbus-socket.c
+++ b/src/core/dbus-socket.c
@@ -277,10 +277,10 @@ static int bus_socket_set_transient_property(
                 return bus_set_transient_fdname(u, name, &s->fdname, message, flags, error);
 
         if (streq(name, "SocketUser"))
-                return bus_set_transient_user(u, name, &s->user, message, flags, error);
+                return bus_set_transient_user_compat(u, name, &s->user, message, flags, error);
 
         if (streq(name, "SocketGroup"))
-                return bus_set_transient_user(u, name, &s->group, message, flags, error);
+                return bus_set_transient_user_compat(u, name, &s->group, message, flags, error);
 
         if (streq(name, "BindIPv6Only"))
                 return bus_set_transient_bind_ipv6_only(u, name, &s->bind_ipv6_only, message, flags, error);
diff --git a/src/core/dbus-util.c b/src/core/dbus-util.c
index f4fbb72cb9..7862beaacb 100644
--- a/src/core/dbus-util.c
+++ b/src/core/dbus-util.c
@@ -30,7 +30,7 @@ int bus_property_get_triggered_unit(
 
 BUS_DEFINE_SET_TRANSIENT(mode_t, "u", uint32_t, mode_t, "%040o");
 BUS_DEFINE_SET_TRANSIENT(unsigned, "u", uint32_t, unsigned, "%" PRIu32);
-BUS_DEFINE_SET_TRANSIENT_STRING_WITH_CHECK(user, valid_user_group_name_or_id);
+BUS_DEFINE_SET_TRANSIENT_STRING_WITH_CHECK(user_compat, valid_user_group_name_or_id_compat);
 BUS_DEFINE_SET_TRANSIENT_STRING_WITH_CHECK(path, path_is_absolute);
 
 int bus_set_transient_string(
diff --git a/src/core/dbus-util.h b/src/core/dbus-util.h
index 12b055e4ac..a3316c6701 100644
--- a/src/core/dbus-util.h
+++ b/src/core/dbus-util.h
@@ -235,7 +235,7 @@ int bus_property_get_triggered_unit(sd_bus *bus, const char *path, const char *i
 
 int bus_set_transient_mode_t(Unit *u, const char *name, mode_t *p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
 int bus_set_transient_unsigned(Unit *u, const char *name, unsigned *p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
-int bus_set_transient_user(Unit *u, const char *name, char **p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
+int bus_set_transient_user_compat(Unit *u, const char *name, char **p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
 int bus_set_transient_path(Unit *u, const char *name, char **p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
 int bus_set_transient_string(Unit *u, const char *name, char **p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
 int bus_set_transient_bool(Unit *u, const char *name, bool *p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index 10e4801cfe..58a28e3241 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -25,9 +25,9 @@ m4_define(`EXEC_CONTEXT_CONFIG_ITEMS',
 `$1.WorkingDirectory,            config_parse_working_directory,     0,                             offsetof($1, exec_context)
 $1.RootDirectory,                config_parse_unit_path_printf,      true,                          offsetof($1, exec_context.root_directory)
 $1.RootImage,                    config_parse_unit_path_printf,      true,                          offsetof($1, exec_context.root_image)
-$1.User,                         config_parse_user_group,            0,                             offsetof($1, exec_context.user)
-$1.Group,                        config_parse_user_group,            0,                             offsetof($1, exec_context.group)
-$1.SupplementaryGroups,          config_parse_user_group_strv,       0,                             offsetof($1, exec_context.supplementary_groups)
+$1.User,                         config_parse_user_group_compat,     0,                             offsetof($1, exec_context.user)
+$1.Group,                        config_parse_user_group_compat,     0,                             offsetof($1, exec_context.group)
+$1.SupplementaryGroups,          config_parse_user_group_strv_compat, 0,                            offsetof($1, exec_context.supplementary_groups)
 $1.Nice,                         config_parse_exec_nice,             0,                             offsetof($1, exec_context)
 $1.OOMScoreAdjust,               config_parse_exec_oom_score_adjust, 0,                             offsetof($1, exec_context)
 $1.IOSchedulingClass,            config_parse_exec_io_class,         0,                             offsetof($1, exec_context)
@@ -365,8 +365,8 @@ Socket.ExecStartPost,            config_parse_exec,                  SOCKET_EXEC
 Socket.ExecStopPre,              config_parse_exec,                  SOCKET_EXEC_STOP_PRE,          offsetof(Socket, exec_command)
 Socket.ExecStopPost,             config_parse_exec,                  SOCKET_EXEC_STOP_POST,         offsetof(Socket, exec_command)
 Socket.TimeoutSec,               config_parse_sec_fix_0,             0,                             offsetof(Socket, timeout_usec)
-Socket.SocketUser,               config_parse_user_group,            0,                             offsetof(Socket, user)
-Socket.SocketGroup,              config_parse_user_group,            0,                             offsetof(Socket, group)
+Socket.SocketUser,               config_parse_user_group_compat,     0,                             offsetof(Socket, user)
+Socket.SocketGroup,              config_parse_user_group_compat,     0,                             offsetof(Socket, group)
 Socket.SocketMode,               config_parse_mode,                  0,                             offsetof(Socket, socket_mode)
 Socket.DirectoryMode,            config_parse_mode,                  0,                             offsetof(Socket, directory_mode)
 Socket.Accept,                   config_parse_bool,                  0,                             offsetof(Socket, accept)
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index c7827df95d..8eaf8b33e9 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -2002,7 +2002,7 @@ int config_parse_sec_fix_0(
         return 0;
 }
 
-int config_parse_user_group(
+int config_parse_user_group_compat(
                 const char *unit,
                 const char *filename,
                 unsigned line,
@@ -2035,7 +2035,7 @@ int config_parse_user_group(
                 return -ENOEXEC;
         }
 
-        if (!valid_user_group_name_or_id(k)) {
+        if (!valid_user_group_name_or_id_compat(k)) {
                 log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid user/group name or numeric ID: %s", k);
                 return -ENOEXEC;
         }
@@ -2043,7 +2043,7 @@ int config_parse_user_group(
         return free_and_replace(*user, k);
 }
 
-int config_parse_user_group_strv(
+int config_parse_user_group_strv_compat(
                 const char *unit,
                 const char *filename,
                 unsigned line,
@@ -2089,7 +2089,7 @@ int config_parse_user_group_strv(
                         return -ENOEXEC;
                 }
 
-                if (!valid_user_group_name_or_id(k)) {
+                if (!valid_user_group_name_or_id_compat(k)) {
                         log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid user/group name or numeric ID: %s", k);
                         return -ENOEXEC;
                 }
diff --git a/src/core/load-fragment.h b/src/core/load-fragment.h
index 326e80893b..664643f08e 100644
--- a/src/core/load-fragment.h
+++ b/src/core/load-fragment.h
@@ -99,8 +99,8 @@ CONFIG_PARSER_PROTOTYPE(config_parse_exec_utmp_mode);
 CONFIG_PARSER_PROTOTYPE(config_parse_working_directory);
 CONFIG_PARSER_PROTOTYPE(config_parse_fdname);
 CONFIG_PARSER_PROTOTYPE(config_parse_sec_fix_0);
-CONFIG_PARSER_PROTOTYPE(config_parse_user_group);
-CONFIG_PARSER_PROTOTYPE(config_parse_user_group_strv);
+CONFIG_PARSER_PROTOTYPE(config_parse_user_group_compat);
+CONFIG_PARSER_PROTOTYPE(config_parse_user_group_strv_compat);
 CONFIG_PARSER_PROTOTYPE(config_parse_restrict_namespaces);
 CONFIG_PARSER_PROTOTYPE(config_parse_bind_paths);
 CONFIG_PARSER_PROTOTYPE(config_parse_exec_keyring_mode);
diff --git a/src/test/test-user-util.c b/src/test/test-user-util.c
index e6d7262e78..9475b99c28 100644
--- a/src/test/test-user-util.c
+++ b/src/test/test-user-util.c
@@ -61,6 +61,43 @@ static void test_uid_ptr(void) {
         assert_se(PTR_TO_UID(UID_TO_PTR(1000)) == 1000);
 }
 
+static void test_valid_user_group_name_compat(void) {
+        log_info("/* %s */", __func__);
+
+        assert_se(!valid_user_group_name_compat(NULL));
+        assert_se(!valid_user_group_name_compat(""));
+        assert_se(!valid_user_group_name_compat("1"));
+        assert_se(!valid_user_group_name_compat("65535"));
+        assert_se(!valid_user_group_name_compat("-1"));
+        assert_se(!valid_user_group_name_compat("-kkk"));
+        assert_se(!valid_user_group_name_compat("rööt"));
+        assert_se(!valid_user_group_name_compat("."));
+        assert_se(!valid_user_group_name_compat(".eff"));
+        assert_se(!valid_user_group_name_compat("foo\nbar"));
+        assert_se(!valid_user_group_name_compat("0123456789012345678901234567890123456789"));
+        assert_se(!valid_user_group_name_or_id_compat("aaa:bbb"));
+        assert_se(!valid_user_group_name_compat("."));
+        assert_se(!valid_user_group_name_compat(".1"));
+        assert_se(!valid_user_group_name_compat(".65535"));
+        assert_se(!valid_user_group_name_compat(".-1"));
+        assert_se(!valid_user_group_name_compat(".-kkk"));
+        assert_se(!valid_user_group_name_compat(".rööt"));
+        assert_se(!valid_user_group_name_or_id_compat(".aaa:bbb"));
+
+        assert_se(valid_user_group_name_compat("root"));
+        assert_se(valid_user_group_name_compat("lennart"));
+        assert_se(valid_user_group_name_compat("LENNART"));
+        assert_se(valid_user_group_name_compat("_kkk"));
+        assert_se(valid_user_group_name_compat("kkk-"));
+        assert_se(valid_user_group_name_compat("kk-k"));
+        assert_se(valid_user_group_name_compat("eff.eff"));
+        assert_se(valid_user_group_name_compat("eff."));
+
+        assert_se(valid_user_group_name_compat("some5"));
+        assert_se(!valid_user_group_name_compat("5some"));
+        assert_se(valid_user_group_name_compat("INNER5NUMBER"));
+}
+
 static void test_valid_user_group_name(void) {
         log_info("/* %s */", __func__);
 
@@ -72,10 +109,17 @@ static void test_valid_user_group_name(void) {
         assert_se(!valid_user_group_name("-kkk"));
         assert_se(!valid_user_group_name("rööt"));
         assert_se(!valid_user_group_name("."));
-        assert_se(!valid_user_group_name("eff.eff"));
+        assert_se(!valid_user_group_name(".eff"));
         assert_se(!valid_user_group_name("foo\nbar"));
         assert_se(!valid_user_group_name("0123456789012345678901234567890123456789"));
         assert_se(!valid_user_group_name_or_id("aaa:bbb"));
+        assert_se(!valid_user_group_name("."));
+        assert_se(!valid_user_group_name(".1"));
+        assert_se(!valid_user_group_name(".65535"));
+        assert_se(!valid_user_group_name(".-1"));
+        assert_se(!valid_user_group_name(".-kkk"));
+        assert_se(!valid_user_group_name(".rööt"));
+        assert_se(!valid_user_group_name_or_id(".aaa:bbb"));
 
         assert_se(valid_user_group_name("root"));
         assert_se(valid_user_group_name("lennart"));
@@ -83,12 +127,47 @@ static void test_valid_user_group_name(void) {
         assert_se(valid_user_group_name("_kkk"));
         assert_se(valid_user_group_name("kkk-"));
         assert_se(valid_user_group_name("kk-k"));
+        assert_se(!valid_user_group_name("eff.eff"));
+        assert_se(!valid_user_group_name("eff."));
 
         assert_se(valid_user_group_name("some5"));
         assert_se(!valid_user_group_name("5some"));
         assert_se(valid_user_group_name("INNER5NUMBER"));
 }
 
+static void test_valid_user_group_name_or_id_compat(void) {
+        log_info("/* %s */", __func__);
+
+        assert_se(!valid_user_group_name_or_id_compat(NULL));
+        assert_se(!valid_user_group_name_or_id_compat(""));
+        assert_se(valid_user_group_name_or_id_compat("0"));
+        assert_se(valid_user_group_name_or_id_compat("1"));
+        assert_se(valid_user_group_name_or_id_compat("65534"));
+        assert_se(!valid_user_group_name_or_id_compat("65535"));
+        assert_se(valid_user_group_name_or_id_compat("65536"));
+        assert_se(!valid_user_group_name_or_id_compat("-1"));
+        assert_se(!valid_user_group_name_or_id_compat("-kkk"));
+        assert_se(!valid_user_group_name_or_id_compat("rööt"));
+        assert_se(!valid_user_group_name_or_id_compat("."));
+        assert_se(!valid_user_group_name_or_id_compat(".eff"));
+        assert_se(valid_user_group_name_or_id_compat("eff.eff"));
+        assert_se(valid_user_group_name_or_id_compat("eff."));
+        assert_se(!valid_user_group_name_or_id_compat("foo\nbar"));
+        assert_se(!valid_user_group_name_or_id_compat("0123456789012345678901234567890123456789"));
+        assert_se(!valid_user_group_name_or_id_compat("aaa:bbb"));
+
+        assert_se(valid_user_group_name_or_id_compat("root"));
+        assert_se(valid_user_group_name_or_id_compat("lennart"));
+        assert_se(valid_user_group_name_or_id_compat("LENNART"));
+        assert_se(valid_user_group_name_or_id_compat("_kkk"));
+        assert_se(valid_user_group_name_or_id_compat("kkk-"));
+        assert_se(valid_user_group_name_or_id_compat("kk-k"));
+
+        assert_se(valid_user_group_name_or_id_compat("some5"));
+        assert_se(!valid_user_group_name_or_id_compat("5some"));
+        assert_se(valid_user_group_name_or_id_compat("INNER5NUMBER"));
+}
+
 static void test_valid_user_group_name_or_id(void) {
         log_info("/* %s */", __func__);
 
@@ -103,7 +182,9 @@ static void test_valid_user_group_name_or_id(void) {
         assert_se(!valid_user_group_name_or_id("-kkk"));
         assert_se(!valid_user_group_name_or_id("rööt"));
         assert_se(!valid_user_group_name_or_id("."));
+        assert_se(!valid_user_group_name_or_id(".eff"));
         assert_se(!valid_user_group_name_or_id("eff.eff"));
+        assert_se(!valid_user_group_name_or_id("eff."));
         assert_se(!valid_user_group_name_or_id("foo\nbar"));
         assert_se(!valid_user_group_name_or_id("0123456789012345678901234567890123456789"));
         assert_se(!valid_user_group_name_or_id("aaa:bbb"));
@@ -230,7 +311,9 @@ int main(int argc, char *argv[]) {
         test_parse_uid();
         test_uid_ptr();
 
+        test_valid_user_group_name_compat();
         test_valid_user_group_name();
+        test_valid_user_group_name_or_id_compat();
         test_valid_user_group_name_or_id();
         test_valid_gecos();
         test_valid_home();