When running cdparanoia (a CDDA grabber) on my system as an ordinary
user (the app is not suid root), I begin to encounter substantial
packet loss and a number of TCPv4 Bad Checksums.
The same symptoms have since been demonstrated using cdda2wav (another
CDDA grabber). I believe both were using the ATAPI interface, rather
than SCSI emulation.
For instance, on an uncongested link, without cdparanoia running (fox
is two hops away, one of them being an annex):
--- fox.uq.net.au ping statistics ---
26 packets transmitted, 26 packets received, 0% packet loss
round-trip min/avg/max = 109.8/113.2/120.2 ms
Doing the same thing with cdparanoia running:
--- fox.uq.net.au ping statistics ---
29 packets transmitted, 13 packets received, 55% packet loss
round-trip min/avg/max = 99.6/113.3/137.8 ms
Attempting to telnet with cdparanoia running produces a completely
unresponsive link, accompanied by a number of:
TCPv4 bad checksum from 203.101.255.1:0017 to 203.100.20.39:08ad,
len=214/214/234
TCPv4 bad checksum from 203.101.255.1:0017 to 203.100.20.39:08ad,
len=20/20/40
I have tried to duplicate this problem by copying large files from a
CD-ROM to a hard drive, but the ppp link was unaffected.
The machine in question is a P2-300 (stepping 4), with a BX chipset.
The CD-ROM in question is detected as:
hdd: Pioneer CD-ROM ATAPI Model DR-A14S 0104, ATAPI CDROM drive
VERSION INFORMATION:
Linux zzaover 2.2.0-pre7-ac4 #1 Sat Jan 16 14:10:31 EST 1999 i686 unknown
Kernel modules 2.1.121
Gnu C 2.7.2.3
Binutils 2.9.1.0.19
Linux C Library 2.0.7
Dynamic linker ldd (GNU libc) 2.0.7
Procps 1.2.9
Mount 2.9g
Net-tools (1998-03-02)
Kbd 0.96
Sh-utils 1.16
pppd version 2.3 patch level 5
cdparanoia III alpha prerelease 9.4 (December 16, 1998)
cdda2wav: Version 0.95beta08
Cheers,
--Andrew
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