machined: set user.userdb.* xattrs on machined socket

diff --git a/src/machine/machined-varlink.c b/src/machine/machined-varlink.c
index acc2137f830b80fb9d612cf783ce363055cb49d7..b136ccf2a2687ee2f9899b4a4a3258c8c47efccf 100644 (file)
--- a/src/machine/machined-varlink.c
+++ b/src/machine/machined-varlink.c
@@ -31,6 +31,7 @@
 #include "varlink-io.systemd.Resolve.Hook.h"
 #include "varlink-io.systemd.service.h"
 #include "varlink-util.h"
+#include "xattr-util.h"
 
 typedef struct LookupParameters {
         const char *user_name;
@@ -774,6 +775,14 @@ static int manager_varlink_init_userdb(Manager *m) {
         if (r < 0)
                 return log_error_errno(r, "Failed to bind to varlink socket %s: %m", VARLINK_PATH_MACHINED_USERDB);
 
+        /* Reduce the noise routed to us: advertise that only look-ups for the higher UID range */
+        char text[DECIMAL_STR_MAX(uid_t) + 1 + DECIMAL_STR_MAX(gid_t) + 1];
+        xsprintf(text, UID_FMT "-" UID_FMT, (uid_t) 0x10000U, (uid_t) UINT32_C(0xfffffffe));
+        FOREACH_STRING(xattr, "user.userdb.uid", "user.userdb.gid")
+                (void) xsetxattr(AT_FDCWD, VARLINK_PATH_MACHINED_USERDB, /* at_flags= */ 0, xattr, text);
+        (void) xsetxattr(AT_FDCWD, VARLINK_PATH_MACHINED_USERDB, /* at_flags= */ 0, "user.userdb.username", "vu-*");
+        (void) xsetxattr(AT_FDCWD, VARLINK_PATH_MACHINED_USERDB, /* at_flags= */ 0, "user.userdb.groupname", "vg-*");
+
         r = sd_varlink_server_attach_event(s, m->event, SD_EVENT_PRIORITY_NORMAL);
         if (r < 0)
                 return log_error_errno(r, "Failed to attach varlink connection to event loop: %m");