iprop: Fix default dbname choice on initial prop

If a DB does not already exist, ipropd-slave will use the compiled
default, which is not necessarily what is desired or configured in
`[kdc]`.

This change makes `hdb_default_db()` return the first dbanme in the
`[kdc]` configuration, falling back on `HDB_DEFAULT_DB`.

Also, this adds a `--database` option to `ipropd-slave`.

lib/hdb/dbinfo.c

@@ -271,5 +271,21 @@ hdb_db_dir(krb5_context context)
 const char *
 hdb_default_db(krb5_context context)
 {
-    return HDB_DEFAULT_DB;
+    static char *default_hdb = NULL;
+    struct hdb_dbinfo *dbinfo = NULL;
+    struct hdb_dbinfo *d = NULL;
+    const char *s;
+
+    if (default_hdb)
+        return default_hdb;
+
+    (void) hdb_get_dbinfo(context, &dbinfo);
+    while ((d = hdb_dbinfo_get_next(dbinfo, d)) != NULL) {
+        if ((s = hdb_dbinfo_get_dbname(context, d)) &&
+            (default_hdb = strdup(s)))
+            break;
+    }
+
+    hdb_free_dbinfo(context, &dbinfo);
+    return default_hdb ? default_hdb : HDB_DEFAULT_DB;
 }

lib/kadm5/iprop.8

@@ -66,6 +66,7 @@
 .Nm ipropd-slave
 .Oo Fl c Ar string \*(Ba Xo Fl Fl config-file= Ns Ar string Xc Oc
 .Oo Fl r Ar string \*(Ba Xo Fl Fl realm= Ns Ar string Xc Oc
+.Oo Fl d Ar file \*(Ba Xo Fl Fl database= Ns Ar file Xc Oc
 .Oo Fl k Ar kspec \*(Ba Xo Fl Fl keytab= Ns Ar kspec Xc Oc
 .Op Fl Fl statusfile= Ns Ar file
 .Op Fl Fl hostname= Ns Ar hostname
@@ -168,6 +169,8 @@ Supported options for
 .Bl -tag -width Ds
 .It Fl c Ar string , Fl Fl config-file= Ns Ar string
 .It Fl r Ar string , Fl Fl realm= Ns Ar string
+.It Fl d Ar file , Fl Fl database= Ns Ar file
+Database (default per KDC)
 .It Fl k Ar kspec , Fl Fl keytab= Ns Ar kspec
 Keytab with client credentials for authenticating to
 .Nm ipropd-master .

lib/kadm5/ipropd_slave.c

@@ -676,6 +676,7 @@ is_up_to_date(krb5_context context, const char *file,
 		 (unsigned long)server_context->log_context.version, buf);
 }
 
+static char *database;
 static char *status_file;
 static char *config_file;
 static int version_flag;
@@ -688,6 +689,7 @@ static int daemon_child = -1;
 static struct getargs args[] = {
     { "config-file", 'c', arg_string, &config_file, NULL, NULL },
     { "realm", 'r', arg_string, &realm, NULL, NULL },
+    { "database", 'd', arg_string, &database, "database", "file"},
     { "keytab", 'k', arg_string, &keytab_str,
       "keytab to get authentication from", "kspec" },
     { "time-lost", 0, arg_string, &server_time_lost,
@@ -813,6 +815,10 @@ main(int argc, char **argv)
 	conf.mask |= KADM5_CONFIG_REALM;
 	conf.realm = realm;
     }
+    if (database) {
+	conf.mask |= KADM5_CONFIG_DBNAME;
+	conf.dbname = database;
+    }
     ret = kadm5_init_with_password_ctx (context,
 					KADM5_ADMIN_SERVICE,
 					NULL,