[PATCH] nl80211: Add generic netlink module alias for cfg80211/nl80211

[PATCH] nl80211: Add generic netlink module alias for cfg80211/nl80211

[Marcel Holtmann]

To support auto-loading of wireless modules from netlink users, add module
alias for nl80211 family.

This also adds NL80211_GENL_NAME constant to define the "nl80211" netlink
family name as part of uapi.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
---
 include/uapi/linux/nl80211.h | 2 ++
 net/wireless/core.c          | 1 +
 net/wireless/nl80211.c       | 8 ++++----
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index d1e48b5..b573a55 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -27,6 +27,8 @@
 
 #include <linux/types.h>
 
+#define NL80211_GENL_NAME "nl80211"
+
 /**
  * DOC: Station handling
  *
diff --git a/net/wireless/core.c b/net/wireless/core.c
index 84c9ad7..68f0c96 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -34,6 +34,7 @@
 MODULE_AUTHOR("Johannes Berg");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("wireless configuration support");
+MODULE_ALIAS_GENL_FAMILY(NL80211_GENL_NAME);
 
 /* RCU-protected (and cfg80211_mutex for writers) */
 LIST_HEAD(cfg80211_rdev_list);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index afa2838..3c2da0a 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -37,10 +37,10 @@ static void nl80211_post_doit(struct genl_ops *ops, struct sk_buff *skb,
 
 /* the netlink family */
 static struct genl_family nl80211_fam = {
-	.id = GENL_ID_GENERATE,	/* don't bother with a hardcoded ID */
-	.name = "nl80211",	/* have users key off the name instead */
-	.hdrsize = 0,		/* no private header */
-	.version = 1,		/* no particular meaning now */
+	.id = GENL_ID_GENERATE,		/* don't bother with a hardcoded ID */
+	.name = NL80211_GENL_NAME,	/* have users key off the name instead */
+	.hdrsize = 0,			/* no private header */
+	.version = 1,			/* no particular meaning now */
 	.maxattr = NL80211_ATTR_MAX,
 	.netnsok = true,
 	.pre_doit = nl80211_pre_doit,
-- 
1.8.1.4

Re: [PATCH] nl80211: Add generic netlink module alias for cfg80211/nl80211

[Arend van Spriel]

On 04/29/2013 01:22 AM, Marcel Holtmann wrote:
> diff --git a/net/wireless/core.c b/net/wireless/core.c
> index 84c9ad7..68f0c96 100644
> --- a/net/wireless/core.c
> +++ b/net/wireless/core.c
> @@ -34,6 +34,7 @@
>   MODULE_AUTHOR("Johannes Berg");
>   MODULE_LICENSE("GPL");
>   MODULE_DESCRIPTION("wireless configuration support");
> +MODULE_ALIAS_GENL_FAMILY(NL80211_GENL_NAME);

Just being curious here (might learn something). What does this macro 
provide? Is it intended to help user-space tools identify the netlink 
API/family it provides?

>   /* RCU-protected (and cfg80211_mutex for writers) */
>   LIST_HEAD(cfg80211_rdev_list);

Regards,
Arend

Re: [PATCH] nl80211: Add generic netlink module alias for cfg80211/nl80211

[Arend van Spriel]

On 04/29/2013 10:06 AM, Arend van Spriel wrote:
> On 04/29/2013 01:22 AM, Marcel Holtmann wrote:
>> diff --git a/net/wireless/core.c b/net/wireless/core.c
>> index 84c9ad7..68f0c96 100644
>> --- a/net/wireless/core.c
>> +++ b/net/wireless/core.c
>> @@ -34,6 +34,7 @@
>>   MODULE_AUTHOR("Johannes Berg");
>>   MODULE_LICENSE("GPL");
>>   MODULE_DESCRIPTION("wireless configuration support");
>> +MODULE_ALIAS_GENL_FAMILY(NL80211_GENL_NAME);
>
> Just being curious here (might learn something). What does this macro
> provide? Is it intended to help user-space tools identify the netlink
> API/family it provides?
>

Yikes, the answer is probably in the commit message:

"To support auto-loading of wireless modules from netlink users"

Sorry for the noise.

Gr. AvS

Re: [PATCH] nl80211: Add generic netlink module alias for cfg80211/nl80211

[Johannes Berg]

On Sun, 2013-04-28 at 16:22 -0700, Marcel Holtmann wrote:
> To support auto-loading of wireless modules from netlink users, add module
> alias for nl80211 family.
> 
> This also adds NL80211_GENL_NAME constant to define the "nl80211" netlink
> family name as part of uapi.

Applied, thanks.

johannes