Re: [libvirt] [PATCH 12/28] conf/openvz: eliminate incorrect/undocumented use of <source dev='blah'/>

When support for <interface type='ethernet'> was added in commit 9a4b705f back in 2010, it erroneously looked at <source dev='blah'/> for a user-specified guest-side interface name. This was never documented though. (that attribute already existed at the time in the data.ethernet union member of virDomainNetDef, but apparently had no practical use - it was only used as a storage place for a NetDef's bridge name during qemuDomainXMLToNative(), but even then that was never used for anything). When support for similar guest-side device naming was added to the lxc driver several years later, it was put in a new subelement <guest dev='blah'/>. In the intervening years, since there was no validation that ethernet.dev was NULL in the other drivers that didn't actually use it, innocent souls who were adding other features assuming they needed to account for non-NULL ethernet.dev when really they didn't, so little bits of the usual pointless cargo-cult code showed up. This patch not only switches the openvz driver to use the documented <guest dev='blah'/> notation for naming the guest-side device (just in case anyone is still using the openvz driver), and logs an error if anyone tries to set <source dev='blah'/> for a type='ethernet' interface, it also removes the cargo-cult uses of ethernet.dev and <source dev='blah'/>, and eliminates if from the RNG and from virDomainNetDef. NB: I decided on this course of action after mentioning the inconsistency here: https://www.redhat.com/archives/libvir-list/2016-May/msg02038.html and getting encouragement do eliminate it in a later IRC discussion with danpb. --- docs/schemas/domaincommon.rng | 3 --- src/conf/domain_conf.c | 32 +++++++++++++++++++--------- src/conf/domain_conf.h | 1 - src/openvz/openvz_driver.c | 5 ++--- src/qemu/qemu_hotplug.c | 6 +----- tests/xml2sexprdata/xml2sexpr-net-routed.xml | 1 - 6 files changed, 25 insertions(+), 23 deletions(-)

diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 162c2e0..b81b558 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -2142,9 +2142,6 @@ <interleave> <optional> <element name="source"> - <attribute name="dev"> - <ref name="deviceName"/> - </attribute> <empty/> </element> </optional> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 899b6af..4802e03 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -1749,7 +1749,6 @@ virDomainNetDefClear(virDomainNetDefPtr def) switch (def->type) { case VIR_DOMAIN_NET_TYPE_ETHERNET: - VIR_FREE(def->data.ethernet.dev); break; case VIR_DOMAIN_NET_TYPE_VHOSTUSER: @@ -9004,12 +9003,31 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt, def->type == VIR_DOMAIN_NET_TYPE_BRIDGE && xmlStrEqual(cur->name, BAD_CAST "source")) { bridge = virXMLPropString(cur, "bridge"); - } else if (!dev && - (def->type == VIR_DOMAIN_NET_TYPE_ETHERNET || - def->type == VIR_DOMAIN_NET_TYPE_DIRECT) && + } else if (!dev && def->type == VIR_DOMAIN_NET_TYPE_DIRECT && xmlStrEqual(cur->name, BAD_CAST "source")) { dev = virXMLPropString(cur, "dev"); mode = virXMLPropString(cur, "mode"); + } else if (!dev && def->type == VIR_DOMAIN_NET_TYPE_ETHERNET && + xmlStrEqual(cur->name, BAD_CAST "source")) { + /* This clause is only necessary because from 2010 to + * 2016 it was possible (but never documented) to + * configure the name of the guest-side interface of + * an openvz domain with <source dev='blah'/>. That + * was blatant misuse of <source>, so was likely + * (hopefully) never used, but just in case there was + * somebody using it, we need to generate an error. If + * the openvz driver is ever deprecated, this clause + * can be removed from here. + */ + if ((dev = virXMLPropString(cur, "dev"))) { + virReportError(VIR_ERR_XML_ERROR, + _("Invalid attempt to set <interface type='ethernet'> " + "device name with <source dev='%s'/>. " + "Use <target dev='%s'/> (for host-side) " + "or <guest dev='%s'/> (for guest-side) instead."), + dev, dev, dev); + goto error; + } } else if (!vhostuser_path && !vhostuser_mode && !vhostuser_type && def->type == VIR_DOMAIN_NET_TYPE_VHOSTUSER && xmlStrEqual(cur->name, BAD_CAST "source")) { @@ -9260,10 +9278,6 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt, break; case VIR_DOMAIN_NET_TYPE_ETHERNET: - if (dev != NULL) { - def->data.ethernet.dev = dev; - dev = NULL; - } break; case VIR_DOMAIN_NET_TYPE_BRIDGE: @@ -20787,8 +20801,6 @@ virDomainNetDefFormat(virBufferPtr buf, break; case VIR_DOMAIN_NET_TYPE_ETHERNET: - virBufferEscapeString(buf, "<source dev='%s'/>\n", - def->data.ethernet.dev); break; case VIR_DOMAIN_NET_TYPE_VHOSTUSER: diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index b9dc174..e93bd5c 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -931,7 +931,6 @@ struct _virDomainNetDef { } backend; union { struct { - char *dev; } ethernet;

virDomainChrSourceDefPtr vhostuser; struct { diff --git a/src/openvz/openvz_driver.c b/src/openvz/openvz_driver.c index b66883f..b114246 100644 --- a/src/openvz/openvz_driver.c +++ b/src/openvz/openvz_driver.c @@ -862,9 +862,8 @@ openvzDomainSetNetwork(virConnectPtr conn, const char *vpsid, /* if net is ethernet and the user has specified guest interface name, * let's use it; otherwise generate a new one */ - if (net->type == VIR_DOMAIN_NET_TYPE_ETHERNET && - net->data.ethernet.dev != NULL) { - if (VIR_STRDUP(guest_ifname, net->data.ethernet.dev) == -1) + if (net->ifname_guest) { + if (VIR_STRDUP(guest_ifname, net->ifname_guest) < 0)

goto cleanup; } else { guest_ifname = openvzGenerateContainerVethName(veid); diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index f695903..e0b8230 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -2345,11 +2345,7 @@ qemuDomainChangeNet(virQEMUDriverPtr driver, break; case VIR_DOMAIN_NET_TYPE_ETHERNET:

- if (STRNEQ_NULLABLE(olddev->data.ethernet.dev, - newdev->data.ethernet.dev)) { - needReconnect = true; - } - break; + break; case VIR_DOMAIN_NET_TYPE_SERVER: case VIR_DOMAIN_NET_TYPE_CLIENT: diff --git a/tests/xml2sexprdata/xml2sexpr-net-routed.xml b/tests/xml2sexprdata/xml2sexpr-net-routed.xml index f34dbaa..2adc3a7 100644 --- a/tests/xml2sexprdata/xml2sexpr-net-routed.xml +++ b/tests/xml2sexprdata/xml2sexpr-net-routed.xml @@ -20,7 +20,6 @@ <interface type="ethernet"> <mac address="00:11:22:33:44:55"/> <ip address="172.14.5.6"/> - <source dev="eth3"/> <script path="vif-routed"/> <target dev="vif4.0"/> </interface>