Re: [libvirt] [PATCH] util: improve virNetDevTapGetRealDeviceName

On 04/08/2018 05:40 PM, Roman Bogorodskiy wrote: > virNetDevTapGetRealDeviceName() is used on FreeBSD because interface > names (such as one sees in output of tools like ifconfig(8)) might not > match their /dev entity names, and for bhyve we need the latter. > > Current implementation is not very efficient because in order to find > /dev name, it goes through all /dev/tap* entries and tries to issue > TAPGIFNAME ioctl on it. Not only this is slow, but also there's a bug in > this implementation when more than one NIC is passed to a VM: once we > find the tap interface we're looking for, we set its state to UP because > opening it for issuing ioctl sets it DOWN, even if it was UP before. > When we have more than 1 NIC for a VM, we have only last one UP because > others remain DOWN after unsuccessful attempts to match interface name. > > New implementation just uses sysctl(3), so it should be faster and > won't make interfaces go down to get name. > --- > src/util/virnetdevtap.c | 71 +++++++++++++++++++++---------------------------- > 1 file changed, 30 insertions(+), 41 deletions(-) ACK with this squashed in: diff --git i/src/util/virnetdevtap.c w/src/util/virnetdevtap.c index afe4f0b3c1..bd0710ad2e 100644 --- i/src/util/virnetdevtap.c +++ w/src/util/virnetdevtap.c @@ -40,7 +40,6 @@ #include <string.h> #include <unistd.h> #include <regex.h> -#include <dirent.h> #include <sys/types.h> #include <sys/ioctl.h> #include <net/if.h> @@ -129,13 +128,14 @@ virNetDevTapGetRealDeviceName(char *ifname ATTRIBUTE_UNUSED) return NULL; } - ret = malloc(len); + if (VIR_ALLOC_N(ret, len) < 0) + return NULL; if (sysctl(name, 6, ret, &len, 0, 0) < 0) { virReportSystemError(errno, _("Unable to get driver name for '%s'"), ifname); - free(ret); + VIR_FREE(ret); return NULL; } Michal