snmpd(8): Allow for symbolic OID names in snmpd.conf

[Martijn van Duren]

When playing with the blocklist I noticed that the oid directive only
supports numeric OIDs. So if florian wants to use filter-pf-table in the
future he'd have to set:
blocklist 1.3.6.1.4.1.30155.1.9.129
which is pure insanity, if:
blocklist pfTblAddrTable
could be an option.

Diff below changes the "oid" parse.y definition from ober_string2oid to
smi_string2oid, which allows for the locally known symbolic names.
This also helps out with existing statements ("system oid",
"trap handle oid", and "trap receiver", and "oid").

While here, rename sysoid to oid, since it's not used by the system
oid anymore and do a little KNF.

OK?

martijn@

Index: parse.y
===================================================================
RCS file: /cvs/src/usr.sbin/snmpd/parse.y,v
retrieving revision 1.73
diff -u -p -r1.73 parse.y
--- parse.y     21 Nov 2021 13:33:53 -0000      1.73
+++ parse.y     28 Jun 2022 09:02:36 -0000
@@ -666,21 +666,20 @@ optwrite  : READONLY                              { $$ = 
0; }
                ;
 
 oid            : STRING                                {
-                       struct ber_oid  *sysoid;
-                       if ((sysoid =
-                           calloc(1, sizeof(*sysoid))) == NULL) {
+                       struct ber_oid  *oid;
+                       if ((oid = calloc(1, sizeof(*oid))) == NULL) {
                                yyerror("calloc");
                                free($1);
                                YYERROR;
                        }
-                       if (ober_string2oid($1, sysoid) == -1) {
+                       if (smi_string2oid($1, oid) == -1) {
                                yyerror("invalid OID: %s", $1);
-                               free(sysoid);
+                               free(oid);
                                free($1);
                                YYERROR;
                        }
                        free($1);
-                       $$ = sysoid;
+                       $$ = oid;
                }
                ;