From f162252e25d55efbec257a3ad0320ae6c20f3c14 Mon Sep 17 00:00:00 2001 From: Stefan Berger Date: Thu, 18 Feb 2010 15:13:48 +0100 Subject: [PATCH] macvtap teardown rework Rework and simplification of teardown of the macvtap device. Basically all devices with the same MAC address and link device are kept alive and not attempted to be torn down. If a macvtap device linked to a physical interface with a certain MAC address 'M' is to be created it will automatically fail if the interface is 'up'ed and another macvtap with the same properties (MAC addr 'M', link dev) happens to be 'up'. This will prevent the VM from starting or the device from being attached to a running VM. Stale interfaces are assumed to be there for some reason and not stem from libvirt. In the VM shutdown path, it's assuming that an interface name is always available so that if the device type is DIRECT it can be torn down using its name. * src/util/macvtap.h src/libvirt_macvtap.syms: change of deleting routine * src/util/macvtap.c: cleanups and change of deleting routine * src/qemu/qemu_driver.c: change cleanup on shutdown * src/qemu/qemu_conf.c: don't delete Macvtap in qemudPhysIfaceConnect() --- src/libvirt_macvtap.syms | 2 +- src/qemu/qemu_conf.c | 10 ---- src/qemu/qemu_driver.c | 26 +++++----- src/util/macvtap.c | 106 +++++++-------------------------------- src/util/macvtap.h | 3 +- 5 files changed, 32 insertions(+), 115 deletions(-) diff --git a/src/libvirt_macvtap.syms b/src/libvirt_macvtap.syms index d02213dbec..ae229a0af0 100644 --- a/src/libvirt_macvtap.syms +++ b/src/libvirt_macvtap.syms @@ -2,4 +2,4 @@ # macvtap.h openMacvtapTap; -delMacvtapByMACAddress; +delMacvtap; diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index c9fe55bebd..646b3ed4e9 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -1439,15 +1439,6 @@ qemudPhysIfaceConnect(virConnectPtr conn, int rc; #if WITH_MACVTAP char *res_ifname = NULL; - int hasBusyDev = 0; - - delMacvtapByMACAddress(net->mac, &hasBusyDev); - - if (hasBusyDev) { - virReportSystemError(errno, "%s", - _("A macvtap with the same MAC address is in use")); - return -1; - } rc = openMacvtapTap(conn, net->ifname, net->mac, linkdev, brmode, &res_ifname); @@ -1460,7 +1451,6 @@ qemudPhysIfaceConnect(virConnectPtr conn, (void)net; (void)linkdev; (void)brmode; - (void)conn; qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("No support for macvtap device")); rc = -1; diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 8766ca2427..aaeb7f615b 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -2942,17 +2942,6 @@ static void qemudShutdownVMDaemon(struct qemud_driver *driver, } } -#if WITH_MACVTAP - def = vm->def; - for (i = 0; i < def->nnets; i++) { - virDomainNetDefPtr net = def->nets[i]; - if (net->type == VIR_DOMAIN_NET_TYPE_DIRECT) { - int dummy; - delMacvtapByMACAddress(net->mac, &dummy); - } - } -#endif - if (virKillProcess(vm->pid, 0) == 0 && virKillProcess(vm->pid, SIGTERM) < 0) virReportSystemError(errno, @@ -2999,6 +2988,17 @@ static void qemudShutdownVMDaemon(struct qemud_driver *driver, qemuDomainReAttachHostDevices(driver, vm->def); +#if WITH_MACVTAP + def = vm->def; + for (i = 0; i < def->nnets; i++) { + virDomainNetDefPtr net = def->nets[i]; + if (net->type == VIR_DOMAIN_NET_TYPE_DIRECT) { + if (net->ifname) + delMacvtap(net->ifname); + } + } +#endif + retry: if ((ret = qemuRemoveCgroup(driver, vm, 0)) < 0) { if (ret == -EBUSY && (retries++ < 5)) { @@ -6347,8 +6347,8 @@ qemudDomainDetachNetDevice(struct qemud_driver *driver, #if WITH_MACVTAP if (detach->type == VIR_DOMAIN_NET_TYPE_DIRECT) { - int dummy; - delMacvtapByMACAddress(detach->mac, &dummy); + if (detach->ifname) + delMacvtap(detach->ifname); } #endif diff --git a/src/util/macvtap.c b/src/util/macvtap.c index 194ad366c7..88a64ceb88 100644 --- a/src/util/macvtap.c +++ b/src/util/macvtap.c @@ -40,7 +40,6 @@ #include #include -#include "c-ctype.h" #include "util.h" #include "memory.h" #include "macvtap.h" @@ -447,15 +446,14 @@ buffer_too_small: static int -link_del(const char *type, - const char *name) +link_del(const char *name) { int rc = 0; char nlmsgbuf[256]; struct nlmsghdr *nlm = (struct nlmsghdr *)nlmsgbuf, *resp; struct nlmsgerr *err; char rtattbuf[64]; - struct rtattr *rta, *rta1; + struct rtattr *rta; struct ifinfomsg ifinfo = { .ifi_family = AF_UNSPEC }; char *recvbuf = NULL; int recvbuflen; @@ -467,23 +465,6 @@ link_del(const char *type, if (!nlAppend(nlm, sizeof(nlmsgbuf), &ifinfo, sizeof(ifinfo))) goto buffer_too_small; - rta = rtattrCreate(rtattbuf, sizeof(rtattbuf), IFLA_LINKINFO, NULL, 0); - if (!rta) - goto buffer_too_small; - - if (!(rta1 = nlAppend(nlm, sizeof(nlmsgbuf), rtattbuf, rta->rta_len))) - goto buffer_too_small; - - rta = rtattrCreate(rtattbuf, sizeof(rtattbuf), IFLA_INFO_KIND, - type, strlen(type)); - if (!rta) - goto buffer_too_small; - - if (!nlAppend(nlm, sizeof(nlmsgbuf), rtattbuf, rta->rta_len)) - goto buffer_too_small; - - rta1->rta_len = (char *)nlm + nlm->nlmsg_len - (char *)rta1; - rta = rtattrCreate(rtattbuf, sizeof(rtattbuf), IFLA_IFNAME, name, strlen(name)+1); if (!rta) @@ -633,7 +614,8 @@ macvtapModeFromInt(enum virDomainNetdevMacvtapType mode) } -/* openMacvtapTap: +/** + * openMacvtapTap: * Create an instance of a macvtap device and open its tap character * device. * @conn: Pointer to virConnect object @@ -707,14 +689,17 @@ create_name: rc = ifUp(cr_ifname, 1); if (rc != 0) { virReportSystemError(errno, - _("cannot 'up' interface %s"), cr_ifname); + _("cannot 'up' interface %s -- another " + "macvtap device may be 'up' and have the same " + "MAC address"), + cr_ifname); rc = -1; goto link_del_exit; } rc = openTap(cr_ifname, 10); - if (rc > 0) + if (rc >= 0) *res_ifname = strdup(cr_ifname); else goto link_del_exit; @@ -722,79 +707,22 @@ create_name: return rc; link_del_exit: - link_del(type, ifname); + link_del(cr_ifname); return rc; } -/* Delete a macvtap type of interface given the MAC address. This - * function will delete all macvtap type of interfaces that have the - * given MAC address. - * @macaddress : Pointer to 6 bytes holding the MAC address of the - * macvtap device(s) to destroy +/** + * delMacvtapByName: + * @ifname : The name of the macvtap interface * - * Returns 0 in case of success, negative value in case of error. + * Delete an interface given its name. */ -int -delMacvtapByMACAddress(const unsigned char *macaddress, - int *hasBusyDev) +void +delMacvtap(const char *ifname) { - struct ifreq ifr; - FILE *file; - char *ifname, *pos; - char buffer[1024]; - off_t oldpos = 0; - int tapfd; - - *hasBusyDev = 0; - - file = fopen("/proc/net/dev", "r"); - - if (!file) { - virReportSystemError(errno, "%s", - _("cannot open file to read network interfaces " - "from")); - return -1; - } - - int sock = socket(AF_INET, SOCK_DGRAM, 0); - if (sock < 0) { - virReportSystemError(errno, "%s", - _("cannot open socket")); - goto sock_err; - } - - while (NULL != (ifname = fgets(buffer, sizeof(buffer), file))) { - if (c_isspace(ifname[0])) - ifname++; - if ((pos = strchr(ifname, ':')) != NULL) { - pos[0] = 0; - if (virStrncpy(ifr.ifr_name, ifname, strlen(ifname), - sizeof(ifr.ifr_name)) == NULL) - continue; - if (ioctl(sock, SIOCGIFHWADDR, (char *)&ifr) >= 0) { - if (memcmp(&ifr.ifr_hwaddr.sa_data[0], macaddress, 6) == 0) { - tapfd = openTap(ifname, 0); - if (tapfd > 0) { - close(tapfd); - ifUp(ifname, 0); - if (link_del("macvtap", ifname) == 0) - fseeko(file, oldpos, SEEK_SET); - } else { - *hasBusyDev = 1; - } - } - } - } - oldpos = ftello(file); - } - - close(sock); -sock_err: - fclose(file); - - return 0; + link_del(ifname); } #endif diff --git a/src/util/macvtap.h b/src/util/macvtap.h index aa961dd22a..a1a0a7a8af 100644 --- a/src/util/macvtap.h +++ b/src/util/macvtap.h @@ -35,8 +35,7 @@ int openMacvtapTap(virConnectPtr conn, int mode, char **res_ifname); -int delMacvtapByMACAddress(const unsigned char *macaddress, - int *hasBusyDev); +void delMacvtap(const char *name); #endif /* WITH_MACVTAP */