[libvirt] [PATCH 09/19] util: new internal function to permit silent failure of virNetDevSetMAC()

We will want to allow silent failure of virNetDevSetMAC() in the case that the SIOSIFHWADDR ioctl fails with errno == EADDRNOTAVAIL. (Yes, that is very specific, but we really *do* want a logged failure in all other circumstances, and don't want to duplicate code in the caller for the other possibilities). This patch renames the 3 different virNetDevSetMAC() functions to virNetDevSetMACInternal(), adding a 3rd arg called "quiet" and making them static (because this extra control will only be needed within virnetdev.c). A new global virNetDevSetMAC() is defined that calls whichever of the three *Internal() functions gets compiled with quiet = false. Callers in virnetdev.c that want to notice a failure with errno == EADDRNOTAVAIL and retry with a different strategy rather than immediately failing, can call virNetDevSetMACInternal(..., true). --- src/util/virnetdev.c | 51 +++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 41 insertions(+), 10 deletions(-) diff --git a/src/util/virnetdev.c b/src/util/virnetdev.c index 766638d..ffc2fb4 100644 --- a/src/util/virnetdev.c +++ b/src/util/virnetdev.c @@ -222,17 +222,20 @@ int virNetDevExists(const char *ifname) #if defined(SIOCGIFHWADDR) && defined(SIOCSIFHWADDR) && \ defined(HAVE_STRUCT_IFREQ) /** - * virNetDevSetMAC: + * virNetDevSetMACInternal: * @ifname: interface name to set MTU for * @macaddr: MAC address + * @quiet: true if a failure to set MAC address with errno == EADDRNOTAVAIL + * should be silent (still returns error, but without log) * - * This function sets the @macaddr for a given interface @ifname. This - * gets rid of the kernel's automatically assigned random MAC. + * This function sets the @macaddr for a given interface @ifname. * * Returns 0 in case of success or -1 on failure */ -int virNetDevSetMAC(const char *ifname, - const virMacAddr *macaddr) +static int +virNetDevSetMACInternal(const char *ifname, + const virMacAddr *macaddr, + bool quiet) { int fd = -1; int ret = -1; @@ -254,6 +257,9 @@ int virNetDevSetMAC(const char *ifname, if (ioctl(fd, SIOCSIFHWADDR, &ifr) < 0) { char macstr[VIR_MAC_STRING_BUFLEN]; + if (quiet && errno == EADDRNOTAVAIL) + goto cleanup; + virReportSystemError(errno, _("Cannot set interface MAC to %s on '%s'"), virMacAddrFormat(macaddr, macstr), ifname); @@ -266,10 +272,16 @@ int virNetDevSetMAC(const char *ifname, VIR_FORCE_CLOSE(fd); return ret; } -#elif defined(SIOCSIFLLADDR) && defined(HAVE_STRUCT_IFREQ) && \ + + +#elif defined(SIOCSIFLLADDR) && defined(HAVE_STRUCT_IFREQ) && \ HAVE_DECL_LINK_ADDR -int virNetDevSetMAC(const char *ifname, - const virMacAddr *macaddr) + + +static int +virNetDevSetMACInternal(const char *ifname, + const virMacAddr *macaddr, + bool quiet) { struct ifreq ifr; struct sockaddr_dl sdl; @@ -288,6 +300,9 @@ int virNetDevSetMAC(const char *ifname, ifr.ifr_addr.sa_len = VIR_MAC_BUFLEN; if (ioctl(s, SIOCSIFLLADDR, &ifr) < 0) { + if (quiet && errno == EADDRNOTAVAIL) + goto cleanup; + virReportSystemError(errno, _("Cannot set interface MAC to %s on '%s'"), mac + 1, ifname); @@ -300,18 +315,34 @@ int virNetDevSetMAC(const char *ifname, return ret; } + + #else -int virNetDevSetMAC(const char *ifname, - const virMacAddr *macaddr ATTRIBUTE_UNUSED) + + +static int +virNetDevSetMACInternal(const char *ifname, + const virMacAddr *macaddr ATTRIBUTE_UNUSED, + bool quiet ATTRIBUTE_UNUSED) { virReportSystemError(ENOSYS, _("Cannot set interface MAC on '%s'"), ifname); return -1; } + + #endif +int +virNetDevSetMAC(const char *ifname, + const virMacAddr *macaddr) +{ + return virNetDevSetMACInternal(ifname, macaddr, false); +} + + #if defined(SIOCGIFHWADDR) && defined(HAVE_STRUCT_IFREQ) /** * virNetDevGetMAC: -- 2.9.3