[libvirt] [PATCH 5/5] qemu: Implement usernet address
Laine Stump
laine at laine.org
Tue Sep 12 19:16:10 UTC 2017
On 09/12/2017 05:32 AM, Michal Privoznik wrote:
> https://bugzilla.redhat.com/show_bug.cgi?id=1075520
>
> Apart from generic checks, we need to constrain netmask/prefix
> lenght a bit. Thing is, with current implementation QEMU needs to
> be able to 'assign' some IP addresses to the virtual network. For
> instance, the default gateway is at x.x.x.2, dns is at x.x.x.3,
> the default DHCP range is x.x.x.15-x.x.x.30. Since we don't
> expose these settings yet, it's safer to require shorter prefix
> to have room for the defaults.
>
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> ---
> src/qemu/qemu_command.c | 22 ++++++++++
> src/qemu/qemu_domain.c | 49 ++++++++++++++++++++++
> .../qemuxml2argv-net-user-addr.args | 25 +++++++++++
> tests/qemuxml2argvtest.c | 1 +
> 4 files changed, 97 insertions(+)
> create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-net-user-addr.args
>
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index d553df57f..3e1bc5fa8 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -3805,6 +3805,7 @@ qemuBuildHostNetStr(virDomainNetDefPtr net,
> virDomainNetType netType = virDomainNetGetActualType(net);
> virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
> size_t i;
> + char *addr = NULL;
> char *ret = NULL;
>
> if (net->script && netType != VIR_DOMAIN_NET_TYPE_ETHERNET) {
> @@ -3873,6 +3874,26 @@ qemuBuildHostNetStr(virDomainNetDefPtr net,
> break;
>
> case VIR_DOMAIN_NET_TYPE_USER:
> + virBufferAsprintf(&buf, "user%c", type_sep);
> + for (i = 0; i < net->hostIP.nips; i++) {
> + const virNetDevIPAddr *ip = net->hostIP.ips[i];
> + const char *prefix = "";
> +
> + if (!(addr = virSocketAddrFormat(&ip->address)))
> + goto cleanup;
> +
> + if (VIR_SOCKET_ADDR_IS_FAMILY(&ip->address, AF_INET))
> + prefix = "net=";
> + if (VIR_SOCKET_ADDR_IS_FAMILY(&ip->address, AF_INET6))
> + prefix = "ipv6-net";
You're missing an "=" after ipv6-net.
> +
> + virBufferAsprintf(&buf, "%s%s", prefix, addr);
> + if (ip->prefix)
> + virBufferAsprintf(&buf, "/%u", ip->prefix);
> + virBufferAddChar(&buf, ',');
> + }
> + break;
> +
> case VIR_DOMAIN_NET_TYPE_INTERNAL:
> virBufferAsprintf(&buf, "user%c", type_sep);
> break;
> @@ -3928,6 +3949,7 @@ qemuBuildHostNetStr(virDomainNetDefPtr net,
> cleanup:
> virBufferFreeAndReset(&buf);
> virObjectUnref(cfg);
> + VIR_FREE(addr);
You could have made addr local to the NET_TYPE_USER case, but then we
would have to move it out if we added any additional error checking in
the future (i.e. I agree with you putting it in the scope of the entire
function)
> return ret;
> }
>
> diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
> index 72031893f..bf0c7300c 100644
> --- a/src/qemu/qemu_domain.c
> +++ b/src/qemu/qemu_domain.c
> @@ -3338,9 +3338,11 @@ qemuDomainDeviceDefValidate(const virDomainDeviceDef *dev,
> void *opaque ATTRIBUTE_UNUSED)
> {
> int ret = -1;
> + size_t i;
>
> if (dev->type == VIR_DOMAIN_DEVICE_NET) {
> const virDomainNetDef *net = dev->data.net;
> + bool hasIPv4 = false, hasIPv6 = false;
>
> if (net->guestIP.nroutes || net->guestIP.nips) {
> virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> @@ -3350,6 +3352,53 @@ qemuDomainDeviceDefValidate(const virDomainDeviceDef *dev,
> goto cleanup;
> }
>
> + if (net->type == VIR_DOMAIN_NET_TYPE_USER) {
> + if (net->hostIP.nroutes) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> + _("Invalid attempt to set network interface "
> + "guest-side IP address info, "
> + "not supported by QEMU"));
I agree with Martin that you should specifically say that you can't set
<route>, not "IP address info". Of course this will need to change,
since it's guestIP.nips that we want to allow.
> + goto cleanup;
> + }
> +
> + for (i = 0; i < net->hostIP.nips; i++) {
> + const virNetDevIPAddr *ip = net->hostIP.ips[i];
> +
> + if (VIR_SOCKET_ADDR_VALID(&ip->peer)) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> + _("peers are not supported by QEMU"));
> + goto cleanup;
Aside from the humor that Martin finds in this message, it's also not
correct. It *is* allowed to set a peer IP on the host side of a
*tap-based* network device with qemu. (and not allowed to set the peer
IP on the guest side of *any* type of network device).
> + }
> +
> + if (VIR_SOCKET_ADDR_IS_FAMILY(&ip->address, AF_INET)) {
> + if (hasIPv4) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> + _("Only one IPv4 address allowed"));
> + goto cleanup;
> + }
> + hasIPv4 = true;
Aha! You *are* checking for this! (maybe say "... per interface ...")
> + }
> +
> + if (VIR_SOCKET_ADDR_IS_FAMILY(&ip->address, AF_INET6)) {
> + if (hasIPv6) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> + _("Only one IPv6 address allowed"));
> + goto cleanup;
> + }
> + hasIPv6 = true;
> + }
> +
> + /* QEMU needs some space to have
> + * some other 'hosts' on the network. */
> + if ((hasIPv4 && ip->prefix > 27) ||
> + (hasIPv6 && ip->prefix > 120)) {
> + virReportError(VIR_ERR_XML_ERROR, "%s",
> + _("prefix too long"));
You should also probably check for conflict with the addresses that are
automatically used by slirp for DNS, default route, dhcp server, etc.
(Although I *hate* needing to hard code stuff like that :-/)
> + goto cleanup;
> + }
> + }
> + }
> +
> if (STREQ_NULLABLE(net->model, "virtio")) {
> if (net->driver.virtio.rx_queue_size & (net->driver.virtio.rx_queue_size - 1)) {
> virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-user-addr.args b/tests/qemuxml2argvdata/qemuxml2argv-net-user-addr.args
> new file mode 100644
> index 000000000..51aacedb3
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-net-user-addr.args
> @@ -0,0 +1,25 @@
> +LC_ALL=C \
> +PATH=/bin \
> +HOME=/home/test \
> +USER=test \
> +LOGNAME=test \
> +QEMU_AUDIO_DRV=none \
> +/usr/bin/qemu-system-i686 \
> +-name QEMUGuest1 \
> +-S \
> +-M pc \
> +-m 214 \
> +-smp 1,sockets=1,cores=1,threads=1 \
> +-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
> +-nographic \
> +-nodefaults \
> +-chardev socket,id=charmonitor,path=/tmp/lib/domain--1-QEMUGuest1/monitor.sock,\
> +server,nowait \
> +-mon chardev=charmonitor,id=monitor,mode=readline \
> +-no-acpi \
> +-boot c \
> +-usb \
> +-drive file=/dev/HostVG/QEMUGuest1,format=raw,if=none,id=drive-ide0-0-0 \
> +-device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 \
> +-device rtl8139,vlan=0,id=net0,mac=00:11:22:33:44:55,bus=pci.0,addr=0x3 \
> +-net user,net=172.17.2.0/24,vlan=0,name=hostnet0
You really should add QEMU_CAPS_NETDEV to the test case (in the previous
patch, too, for consistency) so that this test represents what is
produced on a more modern qemu. (actually, I would propose that all
other tests for network devices be changed to do the same thing - right
now the network test cases are verifying that we generate correct
commandlines for a version of qemu that probably hasn't existed in the
wild for a very long time).
> diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
> index 2c040e4c0..584df017a 100644
> --- a/tests/qemuxml2argvtest.c
> +++ b/tests/qemuxml2argvtest.c
> @@ -1159,6 +1159,7 @@ mymain(void)
> QEMU_CAPS_NETDEV,
> QEMU_CAPS_VHOSTUSER_MULTIQUEUE);
> DO_TEST("net-user", NONE);
> + DO_TEST("net-user-addr", NONE);
> DO_TEST("net-virtio", NONE);
> DO_TEST("net-virtio-device",
> QEMU_CAPS_NODEFCONFIG, QEMU_CAPS_VIRTIO_TX_ALG);
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