Re: [patch net-next 1/4] net: introduce new priv_flag indicating iface capable of change mac when running
Fri, Jun 29, 2012 at 12:17:34AM CEST, bhutchi...@solarflare.com wrote: On Thu, 2012-06-28 at 16:10 +0200, Jiri Pirko wrote: Introduce IFF_LIFE_ADDR_CHANGE priv_flag and use it to disable netif_running() check in eth_mac_addr() Signed-off-by: Jiri Pirko jpi...@redhat.com --- include/linux/if.h |2 ++ net/ethernet/eth.c |2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/include/linux/if.h b/include/linux/if.h index f995c66..fd9ee7c 100644 --- a/include/linux/if.h +++ b/include/linux/if.h @@ -81,6 +81,8 @@ #define IFF_UNICAST_FLT 0x2 /* Supports unicast filtering */ #define IFF_TEAM_PORT 0x4 /* device used as team port */ #define IFF_SUPP_NOFCS 0x8 /* device supports sending custom FCS */ +#define IFF_LIFE_ADDR_CHANGE 0x10 /* device supports hardware address + * change when it's running */ [...] Any device that has IFF_UNICAST_FLT can update the unicast MAC filter while it's running; doesn't that go hand-in-hand with being able to handle changes to the primary MAC address? Is the new flag really necessary at all? Hmm, this makes sense. But, can you guarantee that all devices behave like this? Also, there are many devices that does not support unicast filtering and yet they support updating mac adress while running. Jirka Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked. ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
[patch net-next 1/4] net: introduce new priv_flag indicating iface capable of change mac when running
Introduce IFF_LIFE_ADDR_CHANGE priv_flag and use it to disable
netif_running() check in eth_mac_addr()
Signed-off-by: Jiri Pirko jpi...@redhat.com
---
include/linux/if.h |2 ++
net/ethernet/eth.c |2 +-
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/linux/if.h b/include/linux/if.h
index f995c66..fd9ee7c 100644
--- a/include/linux/if.h
+++ b/include/linux/if.h
@@ -81,6 +81,8 @@
#define IFF_UNICAST_FLT0x2 /* Supports unicast filtering
*/
#define IFF_TEAM_PORT 0x4 /* device used as team port */
#define IFF_SUPP_NOFCS 0x8 /* device supports sending custom FCS */
+#define IFF_LIFE_ADDR_CHANGE 0x10 /* device supports hardware address
+* change when it's running */
#define IF_GET_IFACE 0x0001 /* for querying only */
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 36e5880..8f8ded4 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -283,7 +283,7 @@ int eth_mac_addr(struct net_device *dev, void *p)
{
struct sockaddr *addr = p;
- if (netif_running(dev))
+ if (!(dev-priv_flags IFF_LIFE_ADDR_CHANGE) netif_running(dev))
return -EBUSY;
if (!is_valid_ether_addr(addr-sa_data))
return -EADDRNOTAVAIL;
--
1.7.10.4
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Re: [patch net-next 1/4] net: introduce new priv_flag indicating iface capable of change mac when running
On Thu, 2012-06-28 at 16:10 +0200, Jiri Pirko wrote:
Introduce IFF_LIFE_ADDR_CHANGE priv_flag and use it to disable
netif_running() check in eth_mac_addr()
Signed-off-by: Jiri Pirko jpi...@redhat.com
---
include/linux/if.h |2 ++
net/ethernet/eth.c |2 +-
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/linux/if.h b/include/linux/if.h
index f995c66..fd9ee7c 100644
--- a/include/linux/if.h
+++ b/include/linux/if.h
@@ -81,6 +81,8 @@
#define IFF_UNICAST_FLT 0x2 /* Supports unicast filtering
*/
#define IFF_TEAM_PORT0x4 /* device used as team port */
#define IFF_SUPP_NOFCS 0x8 /* device supports sending
custom FCS */
+#define IFF_LIFE_ADDR_CHANGE 0x10/* device supports hardware
address
+ * change when it's running */
#define IF_GET_IFACE 0x0001 /* for querying only */
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 36e5880..8f8ded4 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -283,7 +283,7 @@ int eth_mac_addr(struct net_device *dev, void *p)
{
struct sockaddr *addr = p;
- if (netif_running(dev))
+ if (!(dev-priv_flags IFF_LIFE_ADDR_CHANGE) netif_running(dev))
return -EBUSY;
if (!is_valid_ether_addr(addr-sa_data))
return -EADDRNOTAVAIL;
Since the memcpy() is not atomic, there is a small window where a reader
could get a half-changed mac address. I guess its a detail.
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Re: [patch net-next 1/4] net: introduce new priv_flag indicating iface capable of change mac when running
On Thu, Jun 28, 2012 at 05:24:52PM +0200, Eric Dumazet wrote:
On Thu, 2012-06-28 at 16:10 +0200, Jiri Pirko wrote:
Introduce IFF_LIFE_ADDR_CHANGE priv_flag and use it to disable
netif_running() check in eth_mac_addr()
Signed-off-by: Jiri Pirko jpi...@redhat.com
---
include/linux/if.h |2 ++
net/ethernet/eth.c |2 +-
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/linux/if.h b/include/linux/if.h
index f995c66..fd9ee7c 100644
--- a/include/linux/if.h
+++ b/include/linux/if.h
@@ -81,6 +81,8 @@
#define IFF_UNICAST_FLT0x2 /* Supports unicast filtering
*/
#define IFF_TEAM_PORT 0x4 /* device used as team port */
#define IFF_SUPP_NOFCS 0x8 /* device supports sending
custom FCS */
+#define IFF_LIFE_ADDR_CHANGE 0x10 /* device supports hardware
address
+* change when it's running */
#define IF_GET_IFACE 0x0001 /* for querying only */
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 36e5880..8f8ded4 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -283,7 +283,7 @@ int eth_mac_addr(struct net_device *dev, void *p)
{
struct sockaddr *addr = p;
- if (netif_running(dev))
+ if (!(dev-priv_flags IFF_LIFE_ADDR_CHANGE) netif_running(dev))
return -EBUSY;
if (!is_valid_ether_addr(addr-sa_data))
return -EADDRNOTAVAIL;
Since the memcpy() is not atomic, there is a small window where a reader
could get a half-changed mac address. I guess its a detail.
At least for virtio nothing changes - we had this bug forever.
How'd you fix this?
--
MST
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Re: [patch net-next 1/4] net: introduce new priv_flag indicating iface capable of change mac when running
On Thu, 2012-06-28 at 16:10 +0200, Jiri Pirko wrote: Introduce IFF_LIFE_ADDR_CHANGE priv_flag and use it to disable netif_running() check in eth_mac_addr() Signed-off-by: Jiri Pirko jpi...@redhat.com --- include/linux/if.h |2 ++ net/ethernet/eth.c |2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/include/linux/if.h b/include/linux/if.h index f995c66..fd9ee7c 100644 --- a/include/linux/if.h +++ b/include/linux/if.h @@ -81,6 +81,8 @@ #define IFF_UNICAST_FLT 0x2 /* Supports unicast filtering */ #define IFF_TEAM_PORT0x4 /* device used as team port */ #define IFF_SUPP_NOFCS 0x8 /* device supports sending custom FCS */ +#define IFF_LIFE_ADDR_CHANGE 0x10/* device supports hardware address + * change when it's running */ [...] Any device that has IFF_UNICAST_FLT can update the unicast MAC filter while it's running; doesn't that go hand-in-hand with being able to handle changes to the primary MAC address? Is the new flag really necessary at all? Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked. ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
