path: root/include
diff options
authorGreg Rose <gregory.v.rose@intel.com>2012-02-21 16:54:48 -0500
committerDavid S. Miller <davem@davemloft.net>2012-02-21 16:56:45 -0500
commit115c9b81928360d769a76c632bae62d15206a94a (patch)
treebbbe349bdf3803439cf3a757b9f2a839726348f5 /include
parent84338a6c9dbb6ff3de4749864020f8f25d86fc81 (diff)
rtnetlink: Fix problem with buffer allocation
Implement a new netlink attribute type IFLA_EXT_MASK. The mask is a 32 bit value that can be used to indicate to the kernel that certain extended ifinfo values are requested by the user application. At this time the only mask value defined is RTEXT_FILTER_VF to indicate that the user wants the ifinfo dump to send information about the VFs belonging to the interface. This patch fixes a bug in which certain applications do not have large enough buffers to accommodate the extra information returned by the kernel with large numbers of SR-IOV virtual functions. Those applications will not send the new netlink attribute with the interface info dump request netlink messages so they will not get unexpectedly large request buffers returned by the kernel. Modifies the rtnl_calcit function to traverse the list of net devices and compute the minimum buffer size that can hold the info dumps of all matching devices based upon the filter passed in via the new netlink attribute filter mask. If no filter mask is sent then the buffer allocation defaults to NLMSG_GOODSIZE. With this change it is possible to add yet to be defined netlink attributes to the dump request which should make it fairly extensible in the future. Signed-off-by: Greg Rose <gregory.v.rose@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
3 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/if_link.h b/include/linux/if_link.h
index c52d4b5f872a..4b24ff453aee 100644
--- a/include/linux/if_link.h
+++ b/include/linux/if_link.h
@@ -137,6 +137,7 @@ enum {
IFLA_GROUP, /* Group the device belongs to */
+ IFLA_EXT_MASK, /* Extended info mask, VFs, etc */
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 8e872ead88b5..577592ea0ea0 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -602,6 +602,9 @@ struct tcamsg {
#define TCA_ACT_TAB 1 /* attr type must be >=1 */
#define TCAA_MAX 1
+/* New extended info filters for IFLA_EXT_MASK */
+#define RTEXT_FILTER_VF (1 << 0)
/* End of information exported to user level */
#ifdef __KERNEL__
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index 678f1ffaf843..370293901971 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -6,7 +6,7 @@
typedef int (*rtnl_doit_func)(struct sk_buff *, struct nlmsghdr *, void *);
typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *);
-typedef u16 (*rtnl_calcit_func)(struct sk_buff *);
+typedef u16 (*rtnl_calcit_func)(struct sk_buff *, struct nlmsghdr *);
extern int __rtnl_register(int protocol, int msgtype,
rtnl_doit_func, rtnl_dumpit_func,