Re: [libvirt] [PATCH v3 2/4] qemu: introduce qemuARPGetInterfaces to get IP from host's arp table

From: Chen Hanxiao <chenhanxiao(a)gmail.com&gt; introduce VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_ARP to get ip address of VM from the output of /proc/net/arp Signed-off-by: Chen Hanxiao <chenhanxiao(a)gmail.com&gt; --- v3: add docs in virDomainInterfaceAddresses remove error label show network interface which did not match the arp table include/libvirt/libvirt-domain.h | 1 + src/libvirt-domain.c | 7 +++ src/qemu/qemu_driver.c | 96 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 104 insertions(+) diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h index 4048acf38..38e2d9a3e 100644 --- a/include/libvirt/libvirt-domain.h +++ b/include/libvirt/libvirt-domain.h @@ -4665,6 +4665,7 @@ typedef virMemoryParameter *virMemoryParameterPtr; typedef enum { VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_LEASE = 0, /* Parse DHCP lease file */ VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_AGENT = 1, /* Query qemu guest agent */ + VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_ARP = 2, /* Query ARP tables */ # ifdef VIR_ENUM_SENTINELS VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_LAST diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c index eaec0979a..1ae83610d 100644 --- a/src/libvirt-domain.c +++ b/src/libvirt-domain.c @@ -11721,6 +11721,13 @@ virDomainFSInfoFree(virDomainFSInfoPtr info) * To match such interface with the one from @dom XML use MAC address or IP * range. * + * If @source is VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_ARP, the /proc/net/arp + * will be check to obtain the interface addresses. + * As the arp cache did not refresh in time, the returned ip address + * may be unreachable. + * As the route config of the guest, the returned mac address + * may be duplicated. + * * @ifaces->name and @ifaces->hwaddr are never NULL. * * The caller *must* free @ifaces when no longer needed. Usual use case diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index a203c9297..d0cb88053 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -70,6 +70,7 @@ #include "virnetdevopenvswitch.h" #include "capabilities.h" #include "viralloc.h" +#include "virarptable.h" #include "viruuid.h" #include "domain_conf.h" #include "domain_audit.h" @@ -160,6 +161,9 @@ static int qemuGetDHCPInterfaces(virDomainPtr dom, virDomainObjPtr vm, virDomainInterfacePtr **ifaces); +static int qemuARPGetInterfaces(virDomainObjPtr vm, + virDomainInterfacePtr **ifaces); + static virQEMUDriverPtr qemu_driver; @@ -20384,6 +20388,10 @@ qemuDomainInterfaceAddresses(virDomainPtr dom, break; + case VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_ARP: + ret = qemuARPGetInterfaces(vm, ifaces); + break; + default: virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, _("Unknown IP address data source %d"), @@ -20494,6 +20502,94 @@ qemuGetDHCPInterfaces(virDomainPtr dom, } +static int +qemuARPGetInterfaces(virDomainObjPtr vm, + virDomainInterfacePtr **ifaces) +{ + size_t i, j; + size_t ifaces_count = 0; + int ret = -1; + char macaddr[VIR_MAC_STRING_BUFLEN]; + virDomainInterfacePtr *ifaces_ret = NULL; + virDomainInterfacePtr iface = NULL; + virArpTablePtr table; + int got_one = 0;

+ + table = virArpTableGet(); + if (!table) + goto cleanup; + + for (i = 0; i < vm->def->nnets; i++) { + got_one = 0; + if (vm->def->nets[i]->type != VIR_DOMAIN_NET_TYPE_NETWORK) + continue; + + virMacAddrFormat(&(vm->def->nets[i]->mac), macaddr); + virArpTableEntry entry; + for (j = 0; j < table->n; j++) { + entry = table->t[j]; + if (STREQ(entry.mac, macaddr)) { + got_one = 1; + if (VIR_EXPAND_N(ifaces_ret, ifaces_count, 1) < 0) + goto cleanup; + if (VIR_ALLOC(ifaces_ret[ifaces_count - 1]) < 0) + goto cleanup; +

+ iface = ifaces_ret[ifaces_count - 1]; + iface->naddrs = 1; + if (VIR_ALLOC_N(iface->addrs, iface->naddrs) < 0) + goto cleanup; + + if (VIR_STRDUP(iface->name, vm->def->nets[i]->ifname) < 0) + goto cleanup; + + if (VIR_STRDUP(iface->hwaddr, macaddr) < 0) + goto cleanup; + + if (VIR_STRDUP(iface->addrs->addr, entry.ipaddr) < 0) + goto cleanup; + } + } + + if (got_one == 0) {

+ if (VIR_EXPAND_N(ifaces_ret, ifaces_count, 1) < 0) + goto cleanup; + if (VIR_ALLOC(ifaces_ret[ifaces_count - 1]) < 0) + goto cleanup; + + iface = ifaces_ret[ifaces_count - 1]; + iface->naddrs = 1; + if (VIR_ALLOC_N(iface->addrs, iface->naddrs) < 0) + goto cleanup; + + if (VIR_STRDUP(iface->name, "") < 0) + goto cleanup; + + if (VIR_STRDUP(iface->hwaddr, macaddr) < 0) + goto cleanup; + + if (VIR_STRDUP(iface->addrs->addr, "") < 0) + goto cleanup; + } + } + + *ifaces = ifaces_ret; + ifaces_ret = NULL;

+ ret = ifaces_count; + + cleanup: + virArpTableFree(table); + + if (ifaces_ret) { + for (i = 0; i < ifaces_count; i++) + virDomainInterfaceFree(ifaces_ret[i]); + } + VIR_FREE(ifaces_ret); + + return ret; +} + + static int qemuDomainSetUserPassword(virDomainPtr dom, const char *user, -- 2.14.3 -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list