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?
Libvirt doesn't depend on hostfwd_add, as far as I can tell.
hostwd_remove should be changed to match.
