PER, asn2wrs: Handle VAL_PTR for known multiplier string types

Have the single octet known multiplier string types (IA5String,
NumericString, PrintableString, VisibleString, the yet unsupported
ISO646String) support returning the tvb containing the item in a
VAL_PTR if they don't have a permitted alphabet.

We currently handle a VAL_PTR of one of those types if they do
have a permitted alphabet.

Note that this also applies to UTCTime and GeneralizedTime, since
under the hood we treat those as VisibleStrings anyway.

It does *not* apply to BMPString (UCS2) nor UniversalSTring (UCS4),
even though those are known multiplier string types.

This should fix handling of ENBname and MMEname in S1AP as well.

Related to #19036

1 files changed, 4 insertions, 2 deletions

diff --git a/epan/dissectors/packet-m2ap.c b/epan/dissectors/packet-m2ap.c
index 2b0a7ddd30..38ca7ff3f0 100644
--- a/epan/dissectors/packet-m2ap.c
+++ b/epan/dissectors/packet-m2ap.c
@@ -1307,7 +1307,8 @@ dissect_m2ap_ENB_MBMS_M2AP_ID(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *act
 static int
 dissect_m2ap_ENBname(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
   offset = dissect_per_PrintableString(tvb, offset, actx, tree, hf_index,
-                                          1, 150, TRUE);
+                                          1, 150, TRUE,
+                                          NULL);
 
   return offset;
 }
@@ -1928,7 +1929,8 @@ dissect_m2ap_MCCHrelatedBCCH_ExtConfigPerMBSFNArea_Item(tvbuff_t *tvb _U_, int o
 static int
 dissect_m2ap_MCEname(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
   offset = dissect_per_PrintableString(tvb, offset, actx, tree, hf_index,
-                                          1, 150, TRUE);
+                                          1, 150, TRUE,
+                                          NULL);
 
   return offset;
 }