From 8f14d7223d0bf49fce550a5d18722a6c1d0cc352 Mon Sep 17 00:00:00 2001
From: Justin Maggard <jmaggard10@gmail.com>
Date: Mon, 9 Dec 2019 21:10:10 -0800
Subject: [PATCH] upnpsoap: Return truncated results on full buffer

If our response buffer fills up to the max buffer size on a UPnP Browse
request, we should return short results rather than erroring out.

Fixes: #314 (Cannot browse MiniDLNA 1.2.1 with VLC 2.2.6 (UPnPError 709: Unsupported or invalid sort criteria))
---
 clients.h  |  3 ++-
 upnpsoap.c | 32 +++++++++++++++++++++-----------
 2 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/clients.h b/clients.h
index cffc7d5..43762bd 100644
--- a/clients.h
+++ b/clients.h
@@ -40,7 +40,8 @@
 #define FLAG_SKIP_DLNA_PN       0x00002000 /* during browsing */
 #define FLAG_CONVERT_MS         0x00004000 /* convert ms to s */
 /* Response-related flags */
-#define FLAG_HAS_CAPTIONS       0x80000000
+#define FLAG_HAS_CAPTIONS       0x10000000
+#define RESPONSE_TRUNCATED      0x80000000
 #define RESPONSE_FLAGS          0xF0000000
 
 enum match_types {
diff --git a/upnpsoap.c b/upnpsoap.c
index d7db050..744a01b 100644
--- a/upnpsoap.c
+++ b/upnpsoap.c
@@ -858,15 +858,17 @@ callback(void *args, int argc, char **argv, char **azColName)
 			}
 			else
 			{
-				DPRINTF(E_ERROR, L_HTTP, "UPnP SOAP response was too big, and realloc failed!\n");
-				return -1;
+				DPRINTF(E_ERROR, L_HTTP, "UPnP SOAP response truncated, realloc failed\n");
+				passed_args->flags |= RESPONSE_TRUNCATED;
+				return 1;
 			}
 #if MAX_RESPONSE_SIZE > 0
 		}
 		else
 		{
-			DPRINTF(E_ERROR, L_HTTP, "UPnP SOAP response cut short, to not exceed the max response size [%lld]!\n", (long long int)MAX_RESPONSE_SIZE);
-			return -1;
+			DPRINTF(E_ERROR, L_HTTP, "UPnP SOAP response would exceed the max response size [%lld], truncating\n", (long long int)MAX_RESPONSE_SIZE);
+			passed_args->flags |= RESPONSE_TRUNCATED;
+			return 1;
 		}
 #endif
 	}
@@ -1478,12 +1480,19 @@ BrowseContentDirectory(struct upnphttp * h, const char * action)
 		DPRINTF(E_DEBUG, L_HTTP, "Browse SQL: %s\n", sql);
 		ret = sqlite3_exec(db, sql, callback, (void *) &args, &zErrMsg);
 	}
-	if( (ret != SQLITE_OK) && (zErrMsg != NULL) )
+	if( ret != SQLITE_OK )
 	{
-		DPRINTF(E_WARN, L_HTTP, "SQL error: %s\nBAD SQL: %s\n", zErrMsg, sql);
-		sqlite3_free(zErrMsg);
-		SoapError(h, 709, "Unsupported or invalid sort criteria");
-		goto browse_error;
+		if( args.flags & RESPONSE_TRUNCATED )
+		{
+			sqlite3_free(zErrMsg);
+		}
+		else
+		{
+			DPRINTF(E_WARN, L_HTTP, "SQL error: %s\nBAD SQL: %s\n", zErrMsg, sql);
+			sqlite3_free(zErrMsg);
+			SoapError(h, 709, "Unsupported or invalid sort criteria");
+			goto browse_error;
+		}
 	}
 	sqlite3_free(sql);
 	/* Does the object even exist? */
@@ -1936,9 +1945,10 @@ SearchContentDirectory(struct upnphttp * h, const char * action)
 	                      orderBy, StartingIndex, RequestedCount);
 	DPRINTF(E_DEBUG, L_HTTP, "Search SQL: %s\n", sql);
 	ret = sqlite3_exec(db, sql, callback, (void *) &args, &zErrMsg);
-	if( (ret != SQLITE_OK) && (zErrMsg != NULL) )
+	if( ret != SQLITE_OK )
 	{
-		DPRINTF(E_WARN, L_HTTP, "SQL error: %s\nBAD SQL: %s\n", zErrMsg, sql);
+		if( !(args.flags & RESPONSE_TRUNCATED) )
+			DPRINTF(E_WARN, L_HTTP, "SQL error: %s\nBAD SQL: %s\n", zErrMsg, sql);
 		sqlite3_free(zErrMsg);
 	}
 	sqlite3_free(sql);