[Qemu-devel] [Bug 589564] Re: Windows host tap (tap-win32) is not working on QEMU ver 0.12.X

[address@hidden]

I also had the same problem with 0.12.x version. 
BTW, I slightly changed source code to avoid this problem. 
Here is what I did for this below.  
I haven't taken analysis of this operation details so my apporach may not be 
the right solution. (Sorry for that). 
Anyway, refer to my comment (deleted for tap). 

file : net.c 
static ssize_t qemu_vlan_deliver_packet(VLANClientState *sender,
                                        unsigned flags,
                                        const uint8_t *buf,
                                        size_t size,
                                        void *opaque)
{
    VLANState *vlan = opaque;
    VLANClientState *vc;
    ssize_t ret = -1;

    QTAILQ_FOREACH(vc, &vlan->clients, next) {
        ssize_t len;

        if (vc == sender) {
            continue;
        }

        if (vc->link_down) {
            ret = size;
            continue;
        }

        /* deleted for tap
        if (vc->receive_disabled) {
            ret = 0;
            continue;
        }
        */

        if (flags & QEMU_NET_PACKET_FLAG_RAW && vc->info->receive_raw) {
            len = vc->info->receive_raw(vc, buf, size);
        } else {
            len = vc->info->receive(vc, buf, size);
        }

        /*  deleted for tap
        if (len == 0) {
            vc->receive_disabled = 1;
        }
        */

        ret = (ret >= 0) ? ret : len;

    }

    return ret;
}

-- 
Windows host tap (tap-win32) is not working on QEMU ver 0.12.X
https://bugs.launchpad.net/bugs/589564
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Status in QEMU: New

Bug description:
To reproduce the bug: 

1) Install tap driver from openvpn (either v8/v9). Rename the tap connection to 
"mytap" and set the IP to 192.168.1.1 (or any ip)

2) use any QEMU 0.12.X and issue the following command 

c:\qemu> qemu -net nic -net tap,ifname=mytap -cdrom ../linux.iso

3) Inside linux guest system, set the ip of the nic

# ifconfig eth0 192.168.1.2

4) In the windows host try to ping the linux guest (or the other way around, 
after you disable the windows firewall)

c:\qemu> ping 192.168.1.2
Pinging 192.168.1.2 with 32 bytes of data:
Reply from 192.168.1.1: Destination host unreachable.

Those above steps is not working on QEMU 0.12.X. But confirmed working (ping 
successful) on:
- QEMU 0.9.X
- QEMU 0.10.X
- QEMU 0.11.X

I have tried with windows XP and windows 7 host system. I haven't tried the 
qemu latest from git repository, but looking at the "net/tap-win32.c" revision 
date, I guess the bug has been around for a while.

Thanks.