bgpd cleanup RTP_ limit checks in parse.y

[Claudio Jeker]

Lets use the same check for both priority checks in parse.y.
Also rephrase the error messages to be less cryptic.
Both checks do the same check since RTP_NONE = 0 and RTP_LOCAL = 1.
Using RTP_LOCAL as a priority is actually not possible since that one is
reserved for the kernel (used by interface address entries). So maybe the
check should be 'if ($2 <= RTP_LOCAL'. That would be a followup diff since
that would change behaviour.

-- 
:wq Claudio

Index: parse.y
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/parse.y,v
retrieving revision 1.426
diff -u -p -r1.426 parse.y
--- parse.y     2 Jun 2022 09:29:34 -0000       1.426
+++ parse.y     2 Jun 2022 09:30:34 -0000
@@ -707,8 +707,9 @@ conf_main   : AS as4number          {
                        TAILQ_INSERT_TAIL(conf->listen_addrs, la, entry);
                }
                | FIBPRIORITY NUMBER            {
-                       if ($2 <= RTP_NONE || $2 > RTP_MAX) {
-                               yyerror("invalid fib-priority");
+                       if ($2 < RTP_LOCAL || $2 > RTP_MAX) {
+                               yyerror("fib-priority %lld must be between "
+                                   "%u and %u", $2, RTP_LOCAL, RTP_MAX);
                                YYERROR;
                        }
                        conf->fib_priority = $2;
@@ -1045,8 +1046,8 @@ network           : NETWORK prefix filter_set     {
                | NETWORK family PRIORITY NUMBER filter_set     {
                        struct network  *n;
                        if ($4 < RTP_LOCAL && $4 > RTP_MAX) {
-                               yyerror("priority %lld > max %d or < min %d", 
$4,
-                                   RTP_MAX, RTP_LOCAL);
+                               yyerror("priority %lld must be between "
+                                   "%u and %u", $4, RTP_LOCAL, RTP_MAX);
                                YYERROR;
                        }