On 2011-11-18 11:07, Markus Armbruster wrote:
> Jan Kiszka <jan.kis...@web.de> writes:
>
>> On 2011-11-16 08:07, Markus Armbruster wrote:
>>> Maybe I'm missing something, but it looks like hostfwd_add doesn't fully
>>> work with -netdev.
>>>
>>> Command definition from hmp-commands.hx:
>>>
>>> {
>>> .name = "hostfwd_add",
>>> .args_type = "arg1:s,arg2:s?,arg3:s?",
>>> .params = "[vlan_id name]
>>> [tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport",
>>> .help = "redirect TCP or UDP connections from host to guest
>>> (requires -net user)",
>>> .mhandler.cmd = net_slirp_hostfwd_add,
>>> },
>>>
>>> Note: params says command takes either 1 or 3 arguments. args_type
>>> can't express that, so it asks for 1-3.
>>>
>>> Command handler:
>>>
>>> void net_slirp_hostfwd_add(Monitor *mon, const QDict *qdict)
>>> {
>>> const char *redir_str;
>>> SlirpState *s;
>>> const char *arg1 = qdict_get_str(qdict, "arg1");
>>> const char *arg2 = qdict_get_try_str(qdict, "arg2");
>>> const char *arg3 = qdict_get_try_str(qdict, "arg3");
>>>
>>> if (arg2) {
>>> s = slirp_lookup(mon, arg1, arg2);
>>> redir_str = arg3;
>>> } else {
>>> s = slirp_lookup(mon, NULL, NULL);
>>> redir_str = arg1;
>>> }
>>> if (s) {
>>> slirp_hostfwd(s, redir_str, 0);
>>> }
>>>
>>> }
>>>
>>> If I understand the code correctly, the command has the following forms:
>>>
>>> * hostfwd_add REDIR
>>>
>>> This form uses the default stack (first member of slirp_stacks).
>>> Seems to work okay with -netdev:
>>>
>>> $ qemu-system-x86_64 --nodefaults --enable-kvm -vnc :0 -S -m 384
>>> -monitor stdio -netdev user,id=net.0 -device
>>> virtio-net-pci,netdev=net.0,id=nic.0
>>> QEMU 0.15.92 monitor - type 'help' for more information
>>> (qemu) hostfwd_add tcp::12345-:22
>>> (qemu) info usernet
>>> VLAN -1 (net.0):
>>> Protocol[State] FD Source Address Port Dest. Address Port
>>> RecvQ SendQ
>>> TCP[HOST_FORWARD] 12 * 12345 10.0.2.15 22
>>> 0 0
>>>
>>> * hostfwd_add VLAN STACK REDIR
>>>
>>> This form was added in commit f13b572c "slirp: Make hostfwd_add/remove
>>> multi-instance-aware".
>>>
>>> I don't like how it overloads the command; adding the optional
>>> arguments at the end would have been cleaner. Water under the bridge.
>>>
>>> Note that slirp_lookup() converts VLAN to an int (without error
>>> checking, i.e. non-integers are silently interpreted as zero, integers
>>> out of bounds are silently truncated).
>>>
>>> Anyway, I can't make it work with -netdev:
>>>
>>> (qemu) hostfwd_add -1 net.0 tcp::12345-:22
>>> unknown VLAN -1
>>>
>>> * Just for giggles: what if I give two arguments?
>>>
>>> $ qemu-system-x86_64--nodefaults --enable-kvm -vnc :0 -S -m 384
>>> -monitor stdio -net user -device virtio-net-pci,id=nic.0,vlan=0QEMU 0.15.92
>>> monitor - type 'help' for more information
>>> (qemu) hostfwd_add 0 user.0
>>> invalid host forwarding rule '(null)'
>>>
>>> The (null) is from a printf-like function printing a null pointer with
>>> conversion %s. Crash bug on some systems.
>>>
>>
>> Agreed, there is some need for improvements. I would not mind changing
>> the command syntax, in fact, if it helps and no major user is already
>> relying on it (can't imagine, specifically as netdev support is broken).
>> What about
>>
>> hostfwd_add rule [name [vlan]]
>>
>> ?
>
> Should work quite nicely, as long as the targeted SlirpState has a name.
> Always the case, isn't it?IIRC, all network clients get model.instance as default name. > > Libvirt doesn't depend on hostfwd_add, as far as I can tell. > > hostwd_remove should be changed to match. Yep. Jan
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