Avahi can not send queries on FreeBSD VLAN Interfaces

[lathiat]

It appears that Avahi does not operate correctly with VLAN interfaces on a FreeBSD setup

It can receiving information passively but outgoign queries are not recorded.

The reporter is able to use Avahi normally on non-vlan interfaces successfully on the same machine.

See this thread for discussion http://lists.freedesktop.org/archives/avahi/2006-October/000904.html

[lennart]

This really smells like a FreeBSD issue to me.

[lennart]

I am sorry, we cannot do anything about this, since none of use Avahi maintainers is a FreeBSD guy. If this is still a problem, please contact the FreeBSD ports maintainer of Avahi.

Might be related to the newly created #114.

[zml]

It looks to me like the pcap code in autoipd isn't using the correct size for VLAN packets, but I'm not comfortable enough with pcap to fix it (yet).

[zml]

Ignore my previous comment. However, I just opened ticket #163, which may explain this bug. I looked through the thread, but I never saw 'netstat -rn' output. If there's a default route in place, the packets may be going out some random interface into the void because of the use of IP_SENDSRCADDR (and sendmsg won't even complain).

I'm not certain that's the explanation for this bug, though, but if I have some time I'll futz with VLANs on BSD.

[zml]

I've confirmed that using the patch from ticket #163, I can browse in a pure-VLAN environment:

1# ifconfig
em0: flags=408802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500
        options=30b<RXCSUM,TXCSUM,VLAN_MTU,TSO4,TSO6>
        ether 00:0c:29:60:3f:55
        media: Ethernet autoselect
        status: no carrier
        flexnet: internal
em1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=30b<RXCSUM,TXCSUM,VLAN_MTU,TSO4,TSO6>
        ether 00:0c:29:60:3f:5f
        media: Ethernet autoselect (1000baseTX <full-duplex>)
        status: active
        flexnet: unused
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
        inet 127.0.0.1 netmask 0xff000000 
        flexnet: unused
vlan1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 (realmtu zero!)
        inet 192.168.1.100 netmask 0xffffff00 broadcast 192.168.1.255
        ether 00:0c:29:60:3f:5f
        media: Ethernet autoselect (1000baseTX <full-duplex>)
        status: active
        vlan: 1 parent interface: em1
        flexnet: unused
vlan2: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 (realmtu zero!)
        inet 192.168.2.100 netmask 0xffffff00 broadcast 192.168.2.255
        ether 00:0c:29:60:3f:5f
        media: Ethernet autoselect (1000baseTX <full-duplex>)
        status: active
        vlan: 2 parent interface: em1
        flexnet: unused

Please note, on my BSD box it's important to add a route for the IP multicast network, and it's import that address be routed to lo0! Example:

# route add 224./4 -iface lo0
# netstat -rn                
Routing tables

Internet:
Destination        Gateway            Flags    Refs      Use  Netif Expire
127.0.0.1          127.0.0.1          UH          0      744    lo0
192.168.1          link#4             UC          0        0  vlan1
192.168.1.101      00:0c:29:e1:50:9c  UHLW        1       34  vlan1     91
192.168.2          link#5             UC          0        0  vlan2
192.168.2.101      00:0c:29:e1:50:9c  UHLW        1       27  vlan2    143
224.0.0/4          lo0                US          0        0    lo0

If you don't have a multicast route configured, and you do have a default route configured, older BSD kernels will first route the packet to the default route. If you configure the multicast route to the loopback address, though, it'll tickle the multicast-bind-to-interface code into working:

+ vlan2 IPv4 zc-2                                          _ssh._tcp            local
+ vlan2 IPv4 zc-1                                          _ssh._tcp            local
+ vlan1 IPv4 zc-2                                          _ssh._tcp            local
+ vlan1 IPv4 zc-1                                          _ssh._tcp            local
= vlan2 IPv4 zc-2                                          _ssh._tcp            local
   hostname = [zc-2.local]
   address = [192.168.1.101]
   port = [22]
   txt = []
= vlan2 IPv4 zc-1                                          _ssh._tcp            local
   hostname = [zc-1.local]
   address = [192.168.2.100]
   port = [22]
   txt = []
= vlan1 IPv4 zc-2                                          _ssh._tcp            local
   hostname = [zc-2.local]
   address = [192.168.2.101]
   port = [22]
   txt = []
= vlan1 IPv4 zc-1                                          _ssh._tcp            local
   hostname = [zc-1.local]
   address = [192.168.1.100]
   port = [22]
   txt = []

Hope this helps!

[lennart]

Following zml suggestions I will now assume that this bug is fixed by the patch from #163 which I just commited. I will close this bug now. If the problem persists, feel free to reopen.