sms: Fix alphanumeric TP-OA handling

TP-OA max length comparisons were incorrect because TP-OA's 7-bit
coded octets transport eleven 8-bit chars.  The current code assumed
only 10 chars were possible.

The patch
- increases the array size to 23, (maximum of 22 bytes for UTF8
  encoding + null terminator)
- Updates the sanity check to account for the correct maximum
- For encoding, checks the maximum length in UTF8 characters instead of
  bytes

1 files changed, 5 insertions, 1 deletions

diff --git a/src/smsutil.h b/src/smsutil.h
index b1001f8f..f293350f 100644
--- a/src/smsutil.h
+++ b/src/smsutil.h
@@ -220,7 +220,11 @@ enum cbs_geo_scope {
 struct sms_address {
 	enum sms_number_type number_type;
 	enum sms_numbering_plan numbering_plan;
-	char address[21]; /* Max 20 in semi-octet, 11 in alnum */
+	/*
+	 * An alphanum TP-OA is 10 7-bit coded octets, which can carry
+	 * 11 8-bit characters. 22 bytes + terminator in UTF-8.
+	 */
+	char address[23];
 };
 
 struct sms_scts {