streaming

commit 707e234349846c8aa9f5ace53518e88033627e31
parent 93fcb65d7636c870a60f92ae20415ae33bbc6ab0
Author: Oliver Lowe <o@olowe.co>
Date:   Sat,  3 Aug 2024 21:42:59 +1000

pcap: include which packet, context in decode errors

Diffstat:
M
pcap/parser.go
 | 
11
+++++------

1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/pcap/parser.go b/pcap/parser.go
@@ -50,23 +50,22 @@ func decode(reader io.Reader) (*File, error) {
 
 	var header GlobalHeader
 	if err := binary.Read(reader, binary.LittleEndian, &header); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("read global header: %w", err)
 	}
 
 	var packets []Packet
-	for {
+	for i := 1; ; i++ {
 		var header Header
 		err := binary.Read(reader, binary.LittleEndian, &header)
 		if err == io.EOF {
 			break
-		}
-		if err != nil {
-			return nil, err
+		} else if err != nil {
+			return nil, fmt.Errorf("packet %d: read header: %w", i, err)
 		}
 
 		data := make([]byte, header.InclLen)
 		if _, err = io.ReadFull(reader, data); err != nil {
-			return nil, err
+			return nil, fmt.Errorf("packet %d: read data: %w", i, err)
 		}
 
 		packets = append(packets, Packet{