[PATCH] libdvbv5: cleanup ASTC service location parsing

[Martin Vallevand <emveepee2@xxxxxxxxxx>]

From 0e0aba1f610e7355a9783dfad82dcdacb69ceae4 Mon Sep 17 00:00:00 2001
From: Martin Vallevand <r3o2c7fi@xxxxxxxx>
Date: Thu, 27 Oct 2022 08:45:15 -0400
Subject: [PATCH] libdvbv5: cleanup ASTC service location parsing

Logic attempted  to move raw data from the generic DVB descriptor into a 
linked list with a different structure. Calculation for the destination 
length would always fail as a result.  Commit  moves specific data elements
---
 .../descriptors/desc_atsc_service_location.c    | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/lib/libdvbv5/descriptors/desc_atsc_service_location.c 
b/lib/libdvbv5/descriptors/desc_atsc_service_location.c
index 8b423dc5..ef88facb 100644
--- a/lib/libdvbv5/descriptors/desc_atsc_service_location.c
+++ b/lib/libdvbv5/descriptors/desc_atsc_service_location.c
@@ -34,21 +34,26 @@ int atsc_desc_service_location_init(struct 
dvb_v5_fe_parms *parms,
     int i;
     size_t len, dlen = desc->length;

-    len = sizeof(*s_loc);
+    // raw data should have one element
+    len = sizeof(u_int16_t) + sizeof(u_int8_t) + sizeof(struct 
atsc_desc_service_location_elementary);
+
     if (dlen < len) {
         dvb_logwarn("ATSC service location descriptor is too small");
         return -1;
     }

-    memcpy(s_loc, p, len);
-    p += len;
-    dlen -= len;
-
+    memcpy(&s_loc->bitfield , p, sizeof(u_int16_t));
+    p += sizeof(u_int16_t);
+    dlen -= sizeof(u_int16_t);
     bswap16(s_loc->bitfield);

+    memcpy(&s_loc->number_elements , p, sizeof(u_int8_t));
+    p += sizeof(u_int8_t);
+    dlen -= sizeof(u_int8_t);
+
     len = s_loc->number_elements * sizeof(*s_loc->elementary);
     if (dlen < len) {
-        dvb_logwarn("ATSC service location descriptor is too small");
+        dvb_logwarn("ATSC service location descriptor is too small for 
%d elements", s_loc->number_elements);
         return -1;
     }
     if (dlen > len) {
--
2.25.1