From 4ebaf75b8d1650d1067483b16ad243cb204ba8dc Mon Sep 17 00:00:00 2001

Message-Id: <4ebaf75b8d1650d1067483b16ad243cb204ba8dc@dist-git>

From: Laine Stump <laine@laine.org>

Date: Thu, 13 Apr 2017 14:29:27 -0400

Subject: [PATCH] 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).

Resolves: https://bugzilla.redhat.com/1442040 (RHEL 7.3.z)

Resolves: https://bugzilla.redhat.com/1415609 (RHEL 7.4)

(cherry picked from commit f4ef3a71f8abc83771952604d309b39ca3ea64cf)

---

 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 766638dd3..ffc2fb4e4 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:

-- 

2.12.2