Bug#969365: USB-C dock lacks multicast Ethernet functionality (so IPv6 is broken)
Hi Santiago, On Tue, Sep 01, 2020 at 01:01:27PM +0200, Santiago R.R. wrote: > Source: linux > Version: 4.19.118-2 > Severity: important > Tags: ipv6 upstream fixed-upstream > > IPv6 connectivity (and other network protocols relying on multicast) are > broken when using a Dell D6000 USB-C dock. > Quoting Miguel Rodríguez that filed the equivalent bug in ubuntu: > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1779173: > > "Dell D6000 exposes a CDC_NCM device for Ethernet traffic. However, > multicast Ethernet traffic is not processed making IPv6 not functional. > Other services, like mDNS used for LAN service discovery are also > hindered. > > The actual reason is that CDC_NCM driver was not processing requests to > filter (admit) multicast traffic. I provide two patches to the linux > kernel that admit all Ethernet multicast traffic whenever a multicast > group is being joined. > > The solution is not optimal, as it makes the system receive more traffic > than that strictly needed, but otherwise this only happens when the > computer is connected to a dock and thus is running on AC power. I > believe it is not worth the hassle to join only the requested groups. > This is the same that is done in the CDN_ETHER driver." > > The patches proposed by Miguel Rodríguez have been merged upstream, and > are part of 5.9-rc1 now. C.f. commits: > 37a2ebdd9e597ae1a0270ac747883ea8f6f767b6 > e10dcb1b6ba714243ad5a35a11b91cc14103a9a9 > e506addeff844237d60545ef4f6141de21471caf > 0226009ce0f6089f9b31211f7a2703cf9a327a01 Thanks for the report, if I'm not mistaken this is the same as #965074. Can you request upstream backports of the needed fixes into the applicable stable releases (and as I understand you back to v4.19.y)? Regards, Salvatore
Bug#969365: USB-C dock lacks multicast Ethernet functionality (so IPv6 is broken)
"Santiago R.R." writes:
> The patches proposed by Miguel Rodríguez have been merged upstream, and
> are part of 5.9-rc1 now. C.f. commits:
> 37a2ebdd9e597ae1a0270ac747883ea8f6f767b6
> e10dcb1b6ba714243ad5a35a11b91cc14103a9a9
> e506addeff844237d60545ef4f6141de21471caf
> 0226009ce0f6089f9b31211f7a2703cf9a327a01
Note that
5fd99b5d9950 ("net: cdc_ncm: Fix build error")
should be included in this series for completeness.
It won't make any difference with the default Debian configuration,
where cdc_ether always is enabled, but it was an unfortunate glitch on
my side.
Bjørn
Bug#969365: USB-C dock lacks multicast Ethernet functionality (so IPv6 is broken)
Source: linux Version: 4.19.118-2 Severity: important Tags: ipv6 upstream fixed-upstream IPv6 connectivity (and other network protocols relying on multicast) are broken when using a Dell D6000 USB-C dock. Quoting Miguel Rodríguez that filed the equivalent bug in ubuntu: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1779173: "Dell D6000 exposes a CDC_NCM device for Ethernet traffic. However, multicast Ethernet traffic is not processed making IPv6 not functional. Other services, like mDNS used for LAN service discovery are also hindered. The actual reason is that CDC_NCM driver was not processing requests to filter (admit) multicast traffic. I provide two patches to the linux kernel that admit all Ethernet multicast traffic whenever a multicast group is being joined. The solution is not optimal, as it makes the system receive more traffic than that strictly needed, but otherwise this only happens when the computer is connected to a dock and thus is running on AC power. I believe it is not worth the hassle to join only the requested groups. This is the same that is done in the CDN_ETHER driver." The patches proposed by Miguel Rodríguez have been merged upstream, and are part of 5.9-rc1 now. C.f. commits: 37a2ebdd9e597ae1a0270ac747883ea8f6f767b6 e10dcb1b6ba714243ad5a35a11b91cc14103a9a9 e506addeff844237d60545ef4f6141de21471caf 0226009ce0f6089f9b31211f7a2703cf9a327a01 Cheers, -- Santiago -- System Information: Debian Release: bullseye/sid APT prefers unstable APT policy: (500, 'unstable'), (500, 'testing'), (500, 'stable'), (500, 'oldstable'), (1, 'experimental') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 5.5.0-2-amd64 (SMP w/8 CPU threads) Kernel taint flags: TAINT_WARN, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE Locale: LANG=es_CO.UTF-8, LC_CTYPE=es_CO.UTF-8 (charmap=UTF-8), LANGUAGE not set Shell: /bin/sh linked to /usr/bin/dash Init: systemd (via /run/systemd/system) LSM: AppArmor: enabled signature.asc Description: PGP signature
