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[libvirt] [PATCH 3/9] qemu: reorganize qemuInterfaceEthernetConnect()

Laine Stump posted 9 patches 6 years, 3 months ago
[libvirt] [PATCH 3/9] qemu: reorganize qemuInterfaceEthernetConnect()
Posted by Laine Stump 6 years, 3 months ago 
This just moves around a few things in qemuInterfaceConnect() with no
functional difference (except that a few failures that would have
previously resulted in a "success" audit log will now properly produce
a "fail" audit). The change is so that adding support for unmanaged
tap/macvtap devices will be more easily reviewable.

Signed-off-by: Laine Stump <laine@redhat.com>
---
 src/qemu/qemu_interface.c | 69 ++++++++++++++++++++-------------------
 1 file changed, 35 insertions(+), 34 deletions(-)

diff --git a/src/qemu/qemu_interface.c b/src/qemu/qemu_interface.c
index 72ed51cb1f..1e3b7f0d06 100644
--- a/src/qemu/qemu_interface.c
+++ b/src/qemu/qemu_interface.c
@@ -414,6 +414,7 @@ qemuInterfaceEthernetConnect(virDomainDefPtr def,
     bool template_ifname = false;
     virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
     const char *tunpath = "/dev/net/tun";
+    const char *auditdev = tunpath;
 
     if (net->backend.tap) {
         tunpath = net->backend.tap;
@@ -424,43 +425,39 @@ qemuInterfaceEthernetConnect(virDomainDefPtr def,
         }
     }
 
-    if (!net->ifname ||
-        STRPREFIX(net->ifname, VIR_NET_GENERATED_TAP_PREFIX) ||
-        strchr(net->ifname, '%')) {
-        VIR_FREE(net->ifname);
-        if (VIR_STRDUP(net->ifname, VIR_NET_GENERATED_TAP_PREFIX "%d") < 0)
-            goto cleanup;
-        /* avoid exposing vnet%d in getXMLDesc or error outputs */
-        template_ifname = true;
-    }
-
     if (virDomainNetIsVirtioModel(net))
         tap_create_flags |= VIR_NETDEV_TAP_CREATE_VNET_HDR;
 
-    if (virNetDevTapCreate(&net->ifname, tunpath, tapfd, tapfdSize,
-                           tap_create_flags) < 0) {
-        virDomainAuditNetDevice(def, net, tunpath, false);
-        goto cleanup;
-    }
-
-    virDomainAuditNetDevice(def, net, tunpath, true);
-
-    /* The tap device's MAC address cannot match the MAC address
-     * used by the guest. This results in "received packet on
-     * vnetX with own address as source address" error logs from
-     * the kernel.
-     */
-    virMacAddrSet(&tapmac, &net->mac);
-    if (tapmac.addr[0] == 0xFE)
-        tapmac.addr[0] = 0xFA;
-    else
-        tapmac.addr[0] = 0xFE;
-
-    if (virNetDevSetMAC(net->ifname, &tapmac) < 0)
-        goto cleanup;
-
-    if (virNetDevSetOnline(net->ifname, true) < 0)
-        goto cleanup;
+   if (!net->ifname ||
+       STRPREFIX(net->ifname, VIR_NET_GENERATED_TAP_PREFIX) ||
+       strchr(net->ifname, '%')) {
+       VIR_FREE(net->ifname);
+       if (VIR_STRDUP(net->ifname, VIR_NET_GENERATED_TAP_PREFIX "%d") < 0)
+           goto cleanup;
+       /* avoid exposing vnet%d in getXMLDesc or error outputs */
+       template_ifname = true;
+   }
+   if (virNetDevTapCreate(&net->ifname, tunpath, tapfd, tapfdSize,
+                          tap_create_flags) < 0) {
+       goto cleanup;
+   }
+
+   /* The tap device's MAC address cannot match the MAC address
+    * used by the guest. This results in "received packet on
+    * vnetX with own address as source address" error logs from
+    * the kernel.
+    */
+   virMacAddrSet(&tapmac, &net->mac);
+   if (tapmac.addr[0] == 0xFE)
+       tapmac.addr[0] = 0xFA;
+   else
+       tapmac.addr[0] = 0xFE;
+
+   if (virNetDevSetMAC(net->ifname, &tapmac) < 0)
+       goto cleanup;
+
+   if (virNetDevSetOnline(net->ifname, true) < 0)
+       goto cleanup;
 
     if (net->script &&
         virNetDevRunEthernetScript(net->ifname, net->script) < 0)
@@ -477,11 +474,15 @@ qemuInterfaceEthernetConnect(virDomainDefPtr def,
         goto cleanup;
     }
 
+    virDomainAuditNetDevice(def, net, auditdev, true);
+
     ret = 0;
 
  cleanup:
     if (ret < 0) {
         size_t i;
+
+        virDomainAuditNetDevice(def, net, auditdev, false);
         for (i = 0; i < tapfdSize && tapfd[i] >= 0; i++)
             VIR_FORCE_CLOSE(tapfd[i]);
         if (template_ifname)
-- 
2.21.0

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Re: [libvirt] [PATCH 3/9] qemu: reorganize qemuInterfaceEthernetConnect()
Posted by Daniel P. Berrangé 6 years, 3 months ago 
On Tue, Aug 27, 2019 at 09:46:33PM -0400, Laine Stump wrote:
> This just moves around a few things in qemuInterfaceConnect() with no
> functional difference (except that a few failures that would have
> previously resulted in a "success" audit log will now properly produce
> a "fail" audit). The change is so that adding support for unmanaged
> tap/macvtap devices will be more easily reviewable.
> 
> Signed-off-by: Laine Stump <laine@redhat.com>
> ---
>  src/qemu/qemu_interface.c | 69 ++++++++++++++++++++-------------------
>  1 file changed, 35 insertions(+), 34 deletions(-)
> 
> diff --git a/src/qemu/qemu_interface.c b/src/qemu/qemu_interface.c
> index 72ed51cb1f..1e3b7f0d06 100644
> --- a/src/qemu/qemu_interface.c
> +++ b/src/qemu/qemu_interface.c
> @@ -414,6 +414,7 @@ qemuInterfaceEthernetConnect(virDomainDefPtr def,
>      bool template_ifname = false;
>      virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
>      const char *tunpath = "/dev/net/tun";
> +    const char *auditdev = tunpath;
>  
>      if (net->backend.tap) {
>          tunpath = net->backend.tap;
> @@ -424,43 +425,39 @@ qemuInterfaceEthernetConnect(virDomainDefPtr def,
>          }
>      }
>  
> -    if (!net->ifname ||
> -        STRPREFIX(net->ifname, VIR_NET_GENERATED_TAP_PREFIX) ||
> -        strchr(net->ifname, '%')) {
> -        VIR_FREE(net->ifname);
> -        if (VIR_STRDUP(net->ifname, VIR_NET_GENERATED_TAP_PREFIX "%d") < 0)
> -            goto cleanup;
> -        /* avoid exposing vnet%d in getXMLDesc or error outputs */
> -        template_ifname = true;
> -    }
> -
>      if (virDomainNetIsVirtioModel(net))
>          tap_create_flags |= VIR_NETDEV_TAP_CREATE_VNET_HDR;
>  
> -    if (virNetDevTapCreate(&net->ifname, tunpath, tapfd, tapfdSize,
> -                           tap_create_flags) < 0) {
> -        virDomainAuditNetDevice(def, net, tunpath, false);
> -        goto cleanup;
> -    }
> -
> -    virDomainAuditNetDevice(def, net, tunpath, true);
> -
> -    /* The tap device's MAC address cannot match the MAC address
> -     * used by the guest. This results in "received packet on
> -     * vnetX with own address as source address" error logs from
> -     * the kernel.
> -     */
> -    virMacAddrSet(&tapmac, &net->mac);
> -    if (tapmac.addr[0] == 0xFE)
> -        tapmac.addr[0] = 0xFA;
> -    else
> -        tapmac.addr[0] = 0xFE;
> -
> -    if (virNetDevSetMAC(net->ifname, &tapmac) < 0)
> -        goto cleanup;
> -
> -    if (virNetDevSetOnline(net->ifname, true) < 0)
> -        goto cleanup;
> +   if (!net->ifname ||
> +       STRPREFIX(net->ifname, VIR_NET_GENERATED_TAP_PREFIX) ||
> +       strchr(net->ifname, '%')) {
> +       VIR_FREE(net->ifname);
> +       if (VIR_STRDUP(net->ifname, VIR_NET_GENERATED_TAP_PREFIX "%d") < 0)
> +           goto cleanup;
> +       /* avoid exposing vnet%d in getXMLDesc or error outputs */
> +       template_ifname = true;
> +   }
> +   if (virNetDevTapCreate(&net->ifname, tunpath, tapfd, tapfdSize,
> +                          tap_create_flags) < 0) {
> +       goto cleanup;
> +   }
> +
> +   /* The tap device's MAC address cannot match the MAC address
> +    * used by the guest. This results in "received packet on
> +    * vnetX with own address as source address" error logs from
> +    * the kernel.
> +    */
> +   virMacAddrSet(&tapmac, &net->mac);
> +   if (tapmac.addr[0] == 0xFE)
> +       tapmac.addr[0] = 0xFA;
> +   else
> +       tapmac.addr[0] = 0xFE;
> +
> +   if (virNetDevSetMAC(net->ifname, &tapmac) < 0)
> +       goto cleanup;
> +
> +   if (virNetDevSetOnline(net->ifname, true) < 0)
> +       goto cleanup;
>

Indentation here is all off-by-1 which makes the diffstat bigger

>      if (net->script &&
>          virNetDevRunEthernetScript(net->ifname, net->script) < 0)
> @@ -477,11 +474,15 @@ qemuInterfaceEthernetConnect(virDomainDefPtr def,
>          goto cleanup;
>      }
>  
> +    virDomainAuditNetDevice(def, net, auditdev, true);
> +
>      ret = 0;
>  
>   cleanup:
>      if (ret < 0) {
>          size_t i;
> +
> +        virDomainAuditNetDevice(def, net, auditdev, false);
>          for (i = 0; i < tapfdSize && tapfd[i] >= 0; i++)
>              VIR_FORCE_CLOSE(tapfd[i]);
>          if (template_ifname)
> -- 
> 2.21.0
> 
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Regards,
Daniel
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