commit 50934ba3d49754887a135c2e165ddd011c8e85c3
author Bi-Ruei, Chiu <biruei.chiu@gmail.com> Mon Sep 11 08:50:59 2017 +0800
committer Lev Walkin <vlm@lionet.info> Fri Oct 20 17:15:57 2017 -0700
tree 51533e23ca673fd8506ced67572704baa3b804a6
parent 4e5edcf06387cd543c78ac1923eed4f086de4501

Fix 'Information Object Set XXX contains no objects' when parsing S1AP's ASN.1

The aforementioned error message displayed during processing the following ASN.1 excerpt.

S1AP-ELEMENTARY-PROCEDURES S1AP-ELEMENTARY-PROCEDURE ::= {
    S1AP-ELEMENTARY-PROCEDURES-CLASS-1 |
    S1AP-ELEMENTARY-PROCEDURES-CLASS-2,
    ...
}

S1AP-ELEMENTARY-PROCEDURES-CLASS-1 S1AP-ELEMENTARY-PROCEDURE ::= {
    handoverPreparation                |
...
    writeReplaceWarning,
    ...,
    uERadioCapabilityMatch             |
....
    uEContextResume
}

S1AP-ELEMENTARY-PROCEDURES-CLASS-2 S1AP-ELEMENTARY-PROCEDURE ::= {
    handoverNotification               |
...
    privateMessage,
    ...,
    downlinkUEAssociatedLPPaTransport  |
...
    mMECPRelocationIndication
}

Because S1AP-ELEMENTARY-PROCEDURES-CLASS-1 and S1AP-ELEMENTARY-PROCEDURES-CLASS-2
are resolved 'after' S1AP-ELEMENTARY-PROCEDURES, so the ioc tables of them are not
available during resolving S1AP-ELEMENTARY-PROCEDURES. So we can not drop the
latter's containedSubtype field at first pass of asn1f_resolve_constraints of fix
process.

We also add second pass of asn1f_resolve_constraints to have a chance to combine
ioc tables of S1AP-ELEMENTARY-PROCEDURES-CLASS-1 and
S1AP-ELEMENTARY-PROCEDURES-CLASS-2.

libasn1fix/asn1fix_constraint.c

diff --git a/libasn1fix/asn1fix_constraint.c b/libasn1fix/asn1fix_constraint.c
index 46eddaa..cf29a33 100644
--- a/libasn1fix/asn1fix_constraint.c
+++ b/libasn1fix/asn1fix_constraint.c
@@ -21,6 +21,7 @@
 	switch(expr->meta_type) {
 	case AMT_TYPE:
 	case AMT_TYPEREF:
+	case AMT_VALUESET:
 		break;
 	default:
 		return 0;	/* Nothing to do */
@@ -273,6 +274,7 @@
 constraint_type_resolve(arg_t *arg, asn1p_constraint_t *ct) {
     asn1p_constraint_t *ct_expr;
     int ret;
+    asn1p_expr_t *rtype = (asn1p_expr_t *)0;
 
     DEBUG("(\"%s\")", asn1f_printable_value(ct->containedSubtype));
 
@@ -280,7 +282,6 @@
         ct_expr = ct->containedSubtype->value.constraint;
         DEBUG("Found %s in constraints", "ValueSet");
     } else if(get_reference_from(ct)) {
-        asn1p_expr_t *rtype;
         arg_t tmparg;
 
         rtype = asn1f_lookup_symbol(arg, arg->expr->rhs_pspecs,
@@ -299,6 +300,14 @@
         ret = asn1constraint_pullup(&tmparg);
         if(ret) return ret;
 
+        if(rtype->ioc_table) {
+            if(!arg->expr->ioc_table)
+                arg->expr->ioc_table = asn1p_ioc_table_new();
+            asn1p_ioc_table_append(arg->expr->ioc_table, rtype->ioc_table);
+            asn1p_value_free(ct->containedSubtype);
+            ct->containedSubtype = NULL;
+        }
+
         ct_expr = rtype->combined_constraints;
         if(!ct_expr) return 0;
     } else {
@@ -330,6 +339,14 @@
     }
 
     ct->type = ACT_CA_SET;
+
+    /* keep constrainedSubtype field for future usage,
+       if valueset has not been resolved yet. */
+    if(rtype &&
+        (rtype->meta_type == AMT_VALUESET) &&
+        (!rtype->ioc_table))
+        return 0;
+
     asn1p_value_free(ct->containedSubtype);
     ct->containedSubtype = NULL;