Re: qemu couldn't connect the unix domain socket

Hi Stefano,

The previous test has included the fix.
This is my repo HEAD:
* 2c7431f - (HEAD -> master, origin/master, origin/HEAD) README:
Feature list, links to lists, bugs, chat (6 days ago) <Stefano Brivio>
* a77c5ef - README, perf_report: Markdown and CSS fixes (7 days ago)
<Stefano Brivio>
* 94c7c1d - slirp4netns.sh: Fix up usage, exit 0 on --help (7 days
ago) <Stefano Brivio>
* 1fc6416 - seccomp: Add newfstatat to list of allowed syscalls (7
days ago) <Stefano Brivio>
* d36e429 - netlink: Fix length of address attribute (7 days ago)
<Stefano Brivio>

My OS is Fedora 35, x64 version.
I will try to dig it when I have some time.

Thanks,
Feng Li

On Thu, Oct 28, 2021 at 3:30 PM Stefano Brivio &lt;sbrivio(a)redhat.com&gt; wrote:
...
 
 Hi Feng Li,

 On Thu, 28 Oct 2021 12:25:29 +0800
 Li Feng &lt;fengli(a)smartx.com&gt; wrote:

  Add cc. 
 Sorry, I missed your email. It looks like on Mailman3, if I'm the owner
 of a list, I'm not automatically a member receiving posts from the list
 itself -- added myself as member, too.

  On Tue, Oct 26, 2021 at 1:28 PM Li Feng
&lt;fengli(a)smartx.com&gt; wrote:
 >
 > Hi,
 > I just tested the master code, the passt just exited without any error.
 >
 > ```
 > $ ./passt
 > Outbound interface: ens192
 > ARP:
 >     address: 00:50:56:be:9d:1f
 > DHCP:
 >     assign: 192.168.64.217
 >     mask: 255.255.240.0
 >     router: 192.168.64.1
 >         search:
 >             .
 > UNIX domain socket bound at /tmp/passt_1.socket
 >
 > You can now start qrap:
 >     ./qrap 5 kvm ... -net socket,fd=5 -net nic,model=virtio
 > or directly qemu, patched with:
 >     qemu/0001-net-Allow-also-UNIX-domain-sockets-to-be-used-as-net.patch
 > as follows:
 >     kvm ... -net socket,connect=/tmp/passt_1.socket -net nic,model=virtio
 > 21-10-26 13:23:43 root@192.168.64.217:~/passt(master✗) 
 passt will fork into background as soon as it gets a connection. Can
 you retry running it as:

         ./passt -f -d

 so we can see if something strange is going on (-f stands for
 --foreground, -d for --debug)? Because:

  > ```
 > Another terminal:
 > ```
 > $ bash x.sh
 > recv: Connection reset by peer
 > Probe of /tmp/passt_1.socket failed
 > connect: No such file or directory
 > Probe of /tmp/passt_2.socket failed
 > connect: No such file or directory
 > Probe of /tmp/passt_3.socket failed
 > ...
 > ``` 
 ...well, this shouldn't happen. It's probing /tmp/passt_1.socket and
 failing to get an answer.

 This just happened to another user, in that case seccomp was
 terminating passt because on his system daemon() called a different set
 of syscalls compared to my system:

         https://passt.top/passt/commit/?id=1fc6416cf9446cbf75818fd61772610e74709065

 and I expect some more issues like these at the beginning, I didn't
 test it on different distributions yet.

 By the way, I'm working on adding tests for a few distributions right
 now, so that we can catch those early.

 --
 Stefano