Expose netdev name in netdev netlink APIs

[PATCH net-next 1/2] netdev-genl: Add ifname for queue and NAPI APIs

Posted by Joe Damato 1 year, 11 months ago

Expose the netdevice name when queue and NAPI netdev-genl APIs are used

Signed-off-by: Joe Damato <jdamato@fastly.com>
---
 include/uapi/linux/netdev.h |  2 ++
 net/core/netdev-genl.c      | 22 +++++++++++++++++-----
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 93cb411..80762bc 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -117,6 +117,7 @@ enum {
 	NETDEV_A_NAPI_ID,
 	NETDEV_A_NAPI_IRQ,
 	NETDEV_A_NAPI_PID,
+	NETDEV_A_NAPI_IFNAME,
 
 	__NETDEV_A_NAPI_MAX,
 	NETDEV_A_NAPI_MAX = (__NETDEV_A_NAPI_MAX - 1)
@@ -127,6 +128,7 @@ enum {
 	NETDEV_A_QUEUE_IFINDEX,
 	NETDEV_A_QUEUE_TYPE,
 	NETDEV_A_QUEUE_NAPI_ID,
+	NETDEV_A_QUEUE_IFNAME,
 
 	__NETDEV_A_QUEUE_MAX,
 	NETDEV_A_QUEUE_MAX = (__NETDEV_A_QUEUE_MAX - 1)
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index fd98936..a886e6a 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -181,6 +181,9 @@ netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi,
 	if (nla_put_u32(rsp, NETDEV_A_NAPI_IFINDEX, napi->dev->ifindex))
 		goto nla_put_failure;
 
+	if (nla_put_string(rsp, NETDEV_A_NAPI_IFNAME, napi->dev->name))
+		goto nla_put_failure;
+
 	if (napi->irq >= 0 && nla_put_u32(rsp, NETDEV_A_NAPI_IRQ, napi->irq))
 		goto nla_put_failure;
 
@@ -307,7 +310,8 @@ netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
 
 	if (nla_put_u32(rsp, NETDEV_A_QUEUE_ID, q_idx) ||
 	    nla_put_u32(rsp, NETDEV_A_QUEUE_TYPE, q_type) ||
-	    nla_put_u32(rsp, NETDEV_A_QUEUE_IFINDEX, netdev->ifindex))
+	    nla_put_u32(rsp, NETDEV_A_QUEUE_IFINDEX, netdev->ifindex) ||
+	    nla_put_string(rsp, NETDEV_A_QUEUE_IFNAME, netdev->name))
 		goto nla_put_failure;
 
 	switch (q_type) {
@@ -369,16 +373,19 @@ int netdev_nl_queue_get_doit(struct sk_buff *skb, struct genl_info *info)
 	u32 q_id, q_type, ifindex;
 	struct net_device *netdev;
 	struct sk_buff *rsp;
+	char *ifname;
 	int err;
 
 	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_ID) ||
 	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_TYPE) ||
-	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFINDEX))
+	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFINDEX) ||
+	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFNAME))
 		return -EINVAL;
 
 	q_id = nla_get_u32(info->attrs[NETDEV_A_QUEUE_ID]);
 	q_type = nla_get_u32(info->attrs[NETDEV_A_QUEUE_TYPE]);
 	ifindex = nla_get_u32(info->attrs[NETDEV_A_QUEUE_IFINDEX]);
+	nla_strscpy(ifname, info->attrs[NETDEV_A_QUEUE_IFNAME], IFNAMSIZ);
 
 	rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!rsp)
@@ -387,10 +394,15 @@ int netdev_nl_queue_get_doit(struct sk_buff *skb, struct genl_info *info)
 	rtnl_lock();
 
 	netdev = __dev_get_by_index(genl_info_net(info), ifindex);
-	if (netdev)
-		err = netdev_nl_queue_fill(rsp, netdev, q_id, q_type, info);
-	else
+
+	if (strcmp(netdev->name, ifname)) {
 		err = -ENODEV;
+	} else {
+		if (netdev)
+			err = netdev_nl_queue_fill(rsp, netdev, q_id, q_type, info);
+		else
+			err = -ENODEV;
+	}
 
 	rtnl_unlock();
 
-- 
2.7.4

Re: [PATCH net-next 1/2] netdev-genl: Add ifname for queue and NAPI APIs

Posted by Dan Carpenter 1 year, 11 months ago

Hi Joe,

kernel test robot noticed the following build warnings:

url:    https://github.com/intel-lab-lkp/linux/commits/Joe-Damato/netdev-genl-Add-ifname-for-queue-and-NAPI-APIs/20240222-000134
base:   net-next/main
patch link:    https://lore.kernel.org/r/1708531057-67392-2-git-send-email-jdamato%40fastly.com
patch subject: [PATCH net-next 1/2] netdev-genl: Add ifname for queue and NAPI APIs
config: i386-randconfig-141-20240222 (https://download.01.org/0day-ci/archive/20240223/202402231851.2NeORqwi-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202402231851.2NeORqwi-lkp@intel.com/

New smatch warnings:
net/core/netdev-genl.c:388 netdev_nl_queue_get_doit() error: uninitialized symbol 'ifname'.

vim +/ifname +388 net/core/netdev-genl.c

bc877956272f05 Amritha Nambiar 2023-12-01  371  int netdev_nl_queue_get_doit(struct sk_buff *skb, struct genl_info *info)
bc877956272f05 Amritha Nambiar 2023-12-01  372  {
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  373  	u32 q_id, q_type, ifindex;
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  374  	struct net_device *netdev;
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  375  	struct sk_buff *rsp;
f340b224321fa6 Joe Damato      2024-02-21  376  	char *ifname;
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  377  	int err;
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  378  
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  379  	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_ID) ||
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  380  	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_TYPE) ||
f340b224321fa6 Joe Damato      2024-02-21  381  	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFINDEX) ||
f340b224321fa6 Joe Damato      2024-02-21  382  	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFNAME))
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  383  		return -EINVAL;
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  384  
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  385  	q_id = nla_get_u32(info->attrs[NETDEV_A_QUEUE_ID]);
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  386  	q_type = nla_get_u32(info->attrs[NETDEV_A_QUEUE_TYPE]);
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  387  	ifindex = nla_get_u32(info->attrs[NETDEV_A_QUEUE_IFINDEX]);
f340b224321fa6 Joe Damato      2024-02-21 @388  	nla_strscpy(ifname, info->attrs[NETDEV_A_QUEUE_IFNAME], IFNAMSIZ);
                                                                    ^^^^^^
missing initialization

6b6171db7fc8f7 Amritha Nambiar 2023-12-01  389  
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  390  	rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  391  	if (!rsp)
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  392  		return -ENOMEM;
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  393  
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  394  	rtnl_lock();
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  395  
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  396  	netdev = __dev_get_by_index(genl_info_net(info), ifindex);
f340b224321fa6 Joe Damato      2024-02-21  397  
f340b224321fa6 Joe Damato      2024-02-21  398  	if (strcmp(netdev->name, ifname)) {
f340b224321fa6 Joe Damato      2024-02-21  399  		err = -ENODEV;
f340b224321fa6 Joe Damato      2024-02-21  400  	} else {
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  401  		if (netdev)
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  402  			err = netdev_nl_queue_fill(rsp, netdev, q_id, q_type, info);
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  403  		else
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  404  			err = -ENODEV;
f340b224321fa6 Joe Damato      2024-02-21  405  	}
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  406  
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  407  	rtnl_unlock();
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  408  
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  409  	if (err)
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  410  		goto err_free_msg;
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  411  
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  412  	return genlmsg_reply(rsp, info);
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  413  
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  414  err_free_msg:
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  415  	nlmsg_free(rsp);
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  416  	return err;
6b6171db7fc8f7 Amritha Nambiar 2023-12-01  417  }

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH net-next 1/2] netdev-genl: Add ifname for queue and NAPI APIs

Posted by kernel test robot 1 year, 11 months ago

Hi Joe,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Joe-Damato/netdev-genl-Add-ifname-for-queue-and-NAPI-APIs/20240222-000134
base:   net-next/main
patch link:    https://lore.kernel.org/r/1708531057-67392-2-git-send-email-jdamato%40fastly.com
patch subject: [PATCH net-next 1/2] netdev-genl: Add ifname for queue and NAPI APIs
config: powerpc-acadia_defconfig (https://download.01.org/0day-ci/archive/20240223/202402230429.g2qC2zMK-lkp@intel.com/config)
compiler: clang version 19.0.0git (https://github.com/llvm/llvm-project edd4aee4dd9b5b98b2576a6f783e4086173d902a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240223/202402230429.g2qC2zMK-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202402230429.g2qC2zMK-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> net/core/netdev-genl.c:388:14: warning: variable 'ifname' is uninitialized when used here [-Wuninitialized]
     388 |         nla_strscpy(ifname, info->attrs[NETDEV_A_QUEUE_IFNAME], IFNAMSIZ);
         |                     ^~~~~~
   net/core/netdev-genl.c:376:14: note: initialize the variable 'ifname' to silence this warning
     376 |         char *ifname;
         |                     ^
         |                      = NULL
   1 warning generated.


vim +/ifname +388 net/core/netdev-genl.c

   370	
   371	int netdev_nl_queue_get_doit(struct sk_buff *skb, struct genl_info *info)
   372	{
   373		u32 q_id, q_type, ifindex;
   374		struct net_device *netdev;
   375		struct sk_buff *rsp;
   376		char *ifname;
   377		int err;
   378	
   379		if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_ID) ||
   380		    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_TYPE) ||
   381		    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFINDEX) ||
   382		    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFNAME))
   383			return -EINVAL;
   384	
   385		q_id = nla_get_u32(info->attrs[NETDEV_A_QUEUE_ID]);
   386		q_type = nla_get_u32(info->attrs[NETDEV_A_QUEUE_TYPE]);
   387		ifindex = nla_get_u32(info->attrs[NETDEV_A_QUEUE_IFINDEX]);
 > 388		nla_strscpy(ifname, info->attrs[NETDEV_A_QUEUE_IFNAME], IFNAMSIZ);
   389	
   390		rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
   391		if (!rsp)
   392			return -ENOMEM;
   393	
   394		rtnl_lock();
   395	
   396		netdev = __dev_get_by_index(genl_info_net(info), ifindex);
   397	
   398		if (strcmp(netdev->name, ifname)) {
   399			err = -ENODEV;
   400		} else {
   401			if (netdev)
   402				err = netdev_nl_queue_fill(rsp, netdev, q_id, q_type, info);
   403			else
   404				err = -ENODEV;
   405		}
   406	
   407		rtnl_unlock();
   408	
   409		if (err)
   410			goto err_free_msg;
   411	
   412		return genlmsg_reply(rsp, info);
   413	
   414	err_free_msg:
   415		nlmsg_free(rsp);
   416		return err;
   417	}
   418	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH net-next 1/2] netdev-genl: Add ifname for queue and NAPI APIs

Posted by Jakub Kicinski 1 year, 11 months ago

On Wed, 21 Feb 2024 07:57:29 -0800 Joe Damato wrote:
>  	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_ID) ||
>  	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_TYPE) ||
> -	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFINDEX))
> +	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFINDEX) ||
> +	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFNAME))

This means user always has to provide both ifindex and ifname,
right?

Re: [PATCH net-next 1/2] netdev-genl: Add ifname for queue and NAPI APIs

Posted by Joe Damato 1 year, 11 months ago

On Wed, Feb 21, 2024 at 11:12:20AM -0800, Jakub Kicinski wrote:
> On Wed, 21 Feb 2024 07:57:29 -0800 Joe Damato wrote:
> >  	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_ID) ||
> >  	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_TYPE) ||
> > -	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFINDEX))
> > +	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFINDEX) ||
> > +	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFNAME))
> 
> This means user always has to provide both ifindex and ifname,
> right?

That's right. I'm OK with omitting this requirement, though. I feel like to
your earlier point on name changes, maybe ifindex is enough as far as
required params go.

Re: [PATCH net-next 1/2] netdev-genl: Add ifname for queue and NAPI APIs

Posted by Nambiar, Amritha 1 year, 11 months ago

On 2/21/2024 7:57 AM, Joe Damato wrote:
> Expose the netdevice name when queue and NAPI netdev-genl APIs are used
> 
> Signed-off-by: Joe Damato <jdamato@fastly.com>
> ---
>   include/uapi/linux/netdev.h |  2 ++
>   net/core/netdev-genl.c      | 22 +++++++++++++++++-----
>   2 files changed, 19 insertions(+), 5 deletions(-)
> 
> diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
> index 93cb411..80762bc 100644
> --- a/include/uapi/linux/netdev.h
> +++ b/include/uapi/linux/netdev.h
> @@ -117,6 +117,7 @@ enum {
>   	NETDEV_A_NAPI_ID,
>   	NETDEV_A_NAPI_IRQ,
>   	NETDEV_A_NAPI_PID,
> +	NETDEV_A_NAPI_IFNAME,
>   
>   	__NETDEV_A_NAPI_MAX,
>   	NETDEV_A_NAPI_MAX = (__NETDEV_A_NAPI_MAX - 1)
> @@ -127,6 +128,7 @@ enum {
>   	NETDEV_A_QUEUE_IFINDEX,
>   	NETDEV_A_QUEUE_TYPE,
>   	NETDEV_A_QUEUE_NAPI_ID,
> +	NETDEV_A_QUEUE_IFNAME,
>   
>   	__NETDEV_A_QUEUE_MAX,
>   	NETDEV_A_QUEUE_MAX = (__NETDEV_A_QUEUE_MAX - 1)
> diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
> index fd98936..a886e6a 100644
> --- a/net/core/netdev-genl.c
> +++ b/net/core/netdev-genl.c
> @@ -181,6 +181,9 @@ netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi,
>   	if (nla_put_u32(rsp, NETDEV_A_NAPI_IFINDEX, napi->dev->ifindex))
>   		goto nla_put_failure;
>   
> +	if (nla_put_string(rsp, NETDEV_A_NAPI_IFNAME, napi->dev->name))
> +		goto nla_put_failure;
> +
>   	if (napi->irq >= 0 && nla_put_u32(rsp, NETDEV_A_NAPI_IRQ, napi->irq))
>   		goto nla_put_failure;
>   
> @@ -307,7 +310,8 @@ netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
>   
>   	if (nla_put_u32(rsp, NETDEV_A_QUEUE_ID, q_idx) ||
>   	    nla_put_u32(rsp, NETDEV_A_QUEUE_TYPE, q_type) ||
> -	    nla_put_u32(rsp, NETDEV_A_QUEUE_IFINDEX, netdev->ifindex))
> +	    nla_put_u32(rsp, NETDEV_A_QUEUE_IFINDEX, netdev->ifindex) ||
> +	    nla_put_string(rsp, NETDEV_A_QUEUE_IFNAME, netdev->name))
>   		goto nla_put_failure;
>   
>   	switch (q_type) {
> @@ -369,16 +373,19 @@ int netdev_nl_queue_get_doit(struct sk_buff *skb, struct genl_info *info)
>   	u32 q_id, q_type, ifindex;
>   	struct net_device *netdev;
>   	struct sk_buff *rsp;
> +	char *ifname;
>   	int err;
>   
>   	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_ID) ||
>   	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_TYPE) ||
> -	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFINDEX))
> +	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFINDEX) ||
> +	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFNAME))
>   		return -EINVAL;
>   
>   	q_id = nla_get_u32(info->attrs[NETDEV_A_QUEUE_ID]);
>   	q_type = nla_get_u32(info->attrs[NETDEV_A_QUEUE_TYPE]);
>   	ifindex = nla_get_u32(info->attrs[NETDEV_A_QUEUE_IFINDEX]);
> +	nla_strscpy(ifname, info->attrs[NETDEV_A_QUEUE_IFNAME], IFNAMSIZ);
>   
>   	rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
>   	if (!rsp)
> @@ -387,10 +394,15 @@ int netdev_nl_queue_get_doit(struct sk_buff *skb, struct genl_info *info)
>   	rtnl_lock();
>   
>   	netdev = __dev_get_by_index(genl_info_net(info), ifindex);
> -	if (netdev)
> -		err = netdev_nl_queue_fill(rsp, netdev, q_id, q_type, info);
> -	else
> +
> +	if (strcmp(netdev->name, ifname)) {
>   		err = -ENODEV;
> +	} else {
> +		if (netdev)
> +			err = netdev_nl_queue_fill(rsp, netdev, q_id, q_type, info);
> +		else
> +			err = -ENODEV;
> +	}
>   

This looks bit incorrect to me that the netdev is checked after 
netdev->name is accessed. Shouldn't this be something like:

if (netdev && !strcmp(netdev->name, ifname))
	err = netdev_nl_queue_fill(rsp, netdev, q_id, q_type, info);
else
	err = -ENODEV;

>   	rtnl_unlock();
>

Re: [PATCH net-next 1/2] netdev-genl: Add ifname for queue and NAPI APIs

Posted by Joe Damato 1 year, 11 months ago

On Wed, Feb 21, 2024 at 11:12:47AM -0800, Nambiar, Amritha wrote:
> On 2/21/2024 7:57 AM, Joe Damato wrote:
> >Expose the netdevice name when queue and NAPI netdev-genl APIs are used
> >
> >Signed-off-by: Joe Damato <jdamato@fastly.com>
> >---
> >  include/uapi/linux/netdev.h |  2 ++
> >  net/core/netdev-genl.c      | 22 +++++++++++++++++-----
> >  2 files changed, 19 insertions(+), 5 deletions(-)
> >
> >diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
> >index 93cb411..80762bc 100644
> >--- a/include/uapi/linux/netdev.h
> >+++ b/include/uapi/linux/netdev.h
> >@@ -117,6 +117,7 @@ enum {
> >  	NETDEV_A_NAPI_ID,
> >  	NETDEV_A_NAPI_IRQ,
> >  	NETDEV_A_NAPI_PID,
> >+	NETDEV_A_NAPI_IFNAME,
> >  	__NETDEV_A_NAPI_MAX,
> >  	NETDEV_A_NAPI_MAX = (__NETDEV_A_NAPI_MAX - 1)
> >@@ -127,6 +128,7 @@ enum {
> >  	NETDEV_A_QUEUE_IFINDEX,
> >  	NETDEV_A_QUEUE_TYPE,
> >  	NETDEV_A_QUEUE_NAPI_ID,
> >+	NETDEV_A_QUEUE_IFNAME,
> >  	__NETDEV_A_QUEUE_MAX,
> >  	NETDEV_A_QUEUE_MAX = (__NETDEV_A_QUEUE_MAX - 1)
> >diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
> >index fd98936..a886e6a 100644
> >--- a/net/core/netdev-genl.c
> >+++ b/net/core/netdev-genl.c
> >@@ -181,6 +181,9 @@ netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi,
> >  	if (nla_put_u32(rsp, NETDEV_A_NAPI_IFINDEX, napi->dev->ifindex))
> >  		goto nla_put_failure;
> >+	if (nla_put_string(rsp, NETDEV_A_NAPI_IFNAME, napi->dev->name))
> >+		goto nla_put_failure;
> >+
> >  	if (napi->irq >= 0 && nla_put_u32(rsp, NETDEV_A_NAPI_IRQ, napi->irq))
> >  		goto nla_put_failure;
> >@@ -307,7 +310,8 @@ netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
> >  	if (nla_put_u32(rsp, NETDEV_A_QUEUE_ID, q_idx) ||
> >  	    nla_put_u32(rsp, NETDEV_A_QUEUE_TYPE, q_type) ||
> >-	    nla_put_u32(rsp, NETDEV_A_QUEUE_IFINDEX, netdev->ifindex))
> >+	    nla_put_u32(rsp, NETDEV_A_QUEUE_IFINDEX, netdev->ifindex) ||
> >+	    nla_put_string(rsp, NETDEV_A_QUEUE_IFNAME, netdev->name))
> >  		goto nla_put_failure;
> >  	switch (q_type) {
> >@@ -369,16 +373,19 @@ int netdev_nl_queue_get_doit(struct sk_buff *skb, struct genl_info *info)
> >  	u32 q_id, q_type, ifindex;
> >  	struct net_device *netdev;
> >  	struct sk_buff *rsp;
> >+	char *ifname;
> >  	int err;
> >  	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_ID) ||
> >  	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_TYPE) ||
> >-	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFINDEX))
> >+	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFINDEX) ||
> >+	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFNAME))
> >  		return -EINVAL;
> >  	q_id = nla_get_u32(info->attrs[NETDEV_A_QUEUE_ID]);
> >  	q_type = nla_get_u32(info->attrs[NETDEV_A_QUEUE_TYPE]);
> >  	ifindex = nla_get_u32(info->attrs[NETDEV_A_QUEUE_IFINDEX]);
> >+	nla_strscpy(ifname, info->attrs[NETDEV_A_QUEUE_IFNAME], IFNAMSIZ);
> >  	rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
> >  	if (!rsp)
> >@@ -387,10 +394,15 @@ int netdev_nl_queue_get_doit(struct sk_buff *skb, struct genl_info *info)
> >  	rtnl_lock();
> >  	netdev = __dev_get_by_index(genl_info_net(info), ifindex);
> >-	if (netdev)
> >-		err = netdev_nl_queue_fill(rsp, netdev, q_id, q_type, info);
> >-	else
> >+
> >+	if (strcmp(netdev->name, ifname)) {
> >  		err = -ENODEV;
> >+	} else {
> >+		if (netdev)
> >+			err = netdev_nl_queue_fill(rsp, netdev, q_id, q_type, info);
> >+		else
> >+			err = -ENODEV;
> >+	}
> 
> This looks bit incorrect to me that the netdev is checked after netdev->name
> is accessed. Shouldn't this be something like:
> 
> if (netdev && !strcmp(netdev->name, ifname))
> 	err = netdev_nl_queue_fill(rsp, netdev, q_id, q_type, info);
> else
> 	err = -ENODEV;

Yes, you are right. Thanks.

Based on Jakub's comment re exposing names, though, it seems that perhaps
this change is not desirable overall.