On Sun, Feb 26, 2012 at 10:48 PM, Stefan Hajnoczi <stefa...@gmail.com> wrote: > On Sat, Feb 18, 2012 at 9:19 AM, <zwu.ker...@gmail.com> wrote: >> From: Zhi Yong Wu <wu...@linux.vnet.ibm.com> >> >> The -net socket,listen option does not work with the newer -netdev >> syntax: >> http://lists.gnu.org/archive/html/qemu-devel/2011-11/msg01508.html >> >> This patch makes it work now. >> >> Signed-off-by: Zhi Yong Wu <wu...@linux.vnet.ibm.com> >> --- >> net.c | 26 +++++++++++++++++++++ >> net.h | 2 + >> net/socket.c | 72 >> +++++++++++++++++++++++++++++++++++++++++++++------------- >> 3 files changed, 84 insertions(+), 16 deletions(-) > > I wanted to understand the problem better so I tried out -net > socket,listen=. Here is its behavior: > > 1. A client can connect to QEMU, this creates a new socket > VLANClientState on the VLAN. > 2. If another client connects to QEMU, another VLANClientState is > created. That means many socket clients can be added to the same > "VLAN". > 3. When a simple TCP client like netcat connects and then disconnects, > the VLANClientState remains forever. There seems to be no cleanup. > > This patch does not handle the -net socket,listen= case where multiple > clients connect. > > Also, the -netdev socket,listen= semantics cannot match -net > socket-listen= semantics because there is only one peer at any time. > Some options: > > 1. Do not accept new connections while a client is connected. Once > the client disconnects we can accept a new connection. This maintains How will socket server know that the client disconnected?
> the 1-1 peer behavior. > 2. Integrate with vlan-hub so that multiple clients can connect even > with -netdev. Connections will create new NetClientStates and > auto-attach to the hub. This mimics -net socket,listen= but requires > a hub to be used. > 3. Forbid -netdev socket,listen=, only allow -net socket,listen=. > > I think #1 would be okay, although it no longer allows multiple > connections, but I don't have a strong opinion either way. > > Stefan -- Regards, Zhi Yong Wu
