Fix scanner buffer re-use for fileItemScanner (#104)

[rbdr/mobius] / hotline / tracker.go

diff --git a/hotline/tracker.go b/hotline/tracker.go
index 4d4c8a601d645e3ece16f623a52008c0388849dd..bd7aa00da966d52b21f1a2b872d3153e78348884 100644 (file)
--- a/hotline/tracker.go
+++ b/hotline/tracker.go
@@ -125,7 +125,10 @@ func GetListing(addr string) ([]ServerRecord, error) {
        for {
                scanner.Scan()
                var srv ServerRecord
        for {
                scanner.Scan()
                var srv ServerRecord

-               _, _ = srv.Read(scanner.Bytes())
+               _, err = srv.Read(scanner.Bytes())
+               if err != nil {
+                       return nil, err
+               }

 
                servers = append(servers, srv)
                if len(servers) == totalSrv {
 
                servers = append(servers, srv)
                if len(servers) == totalSrv {


@@ -146,17 +149,29 @@ func GetListing(addr string) ([]ServerRecord, error) {
 // 00000050  4f 54 4c 2e 63 6f 6d 3a  35 35 30 30 2d 4f 3a b2  |OTL.com:5500-O:.|
 // 00000060  15 7c 00 00 00 00 08 53  65 6e 65 63 74 75 73 20  |.|.....Senectus |
 func serverScanner(data []byte, _ bool) (advance int, token []byte, err error) {
 // 00000050  4f 54 4c 2e 63 6f 6d 3a  35 35 30 30 2d 4f 3a b2  |OTL.com:5500-O:.|
 // 00000060  15 7c 00 00 00 00 08 53  65 6e 65 63 74 75 73 20  |.|.....Senectus |
 func serverScanner(data []byte, _ bool) (advance int, token []byte, err error) {

+       // The name length field is the 11th byte of the server record.  If we don't have that many bytes,
+       // return nil token so the Scanner reads more data and continues scanning.

        if len(data) < 10 {
                return 0, nil, nil
        }
 
        // A server entry has two variable length fields: the name and description.
        if len(data) < 10 {
                return 0, nil, nil
        }
 
        // A server entry has two variable length fields: the name and description.

-       // To get the token length, we first need the name length from the 10th byte:
+       // To get the token length, we first need the name length from the 10th byte

        nameLen := int(data[10])
 
        nameLen := int(data[10])
 

+       // The description length field is at the 12th + nameLen byte of the server record.
+       // If we don't have that many bytes, return nil token so the Scanner reads more data and continues scanning.
+       if len(data) < 11+nameLen {
+               return 0, nil, nil
+       }
+

        // Next we need the description length from the 11+nameLen byte:
        descLen := int(data[11+nameLen])
 
        // Next we need the description length from the 11+nameLen byte:
        descLen := int(data[11+nameLen])
 

+       if len(data) < 12+nameLen+descLen {
+               return 0, nil, nil
+       }
+

        return 12 + nameLen + descLen, data[0 : 12+nameLen+descLen], nil
 }
 
        return 12 + nameLen + descLen, data[0 : 12+nameLen+descLen], nil
 }