[Bug 231797] hn driver drops UDP traffic with EIO error when TXCSUM_IPV6 flag on
bugzilla-noreply at freebsd.org
bugzilla-noreply at freebsd.org
Sat Sep 29 07:36:17 UTC 2018
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=231797
Bug ID: 231797
Summary: hn driver drops UDP traffic with EIO error when
TXCSUM_IPV6 flag on
Product: Base System
Version: CURRENT
Hardware: Any
OS: Any
Status: New
Severity: Affects Only Me
Priority: ---
Component: kern
Assignee: bugs at FreeBSD.org
Reporter: dslr.rfmGJfQJmFc9Qt9a at gmail.com
In https://reviews.freebsd.org/D12417, if_hn.c is changed at lines 5590 and
5886, which should allow UDPv6 packets to enter hn_set_hlen at line 780.
However, at line 813, traffic not matching TCPv6 (UDPv6) would error. Thusly,
it seems when IPv6 transmit checksum offloading is on, UDPv6 traffic is dropped
in the hn driver.
I first noticed this in practice with dhcp6c, where the first UDPv6 solicit
would fail with the error,
transmit failed: Input/output error
due to the kernel returning EIO for the UDPv6 packet. As expected, the output
error count rises correspondingly, with no kernel output messages in the
syslogs.
I was able to determine that disabling TXCSUM_IPV6 via,
ifconfig hn0 -txcsum6
Stops the EIO from propogating from the driver, which led me to this area in
the source.
--
You are receiving this mail because:
You are the assignee for the bug.
More information about the freebsd-bugs
mailing list