Subject: Re: [RFC] Alternate WE-21 support (core API)

From: "John W. Linville" <[email-masked]>
Date: Fri, 8 Sep 2006 16:04:05 -0400

On Fri, Sep 08, 2006 at 09:13:45AM -0700, Jean Tourrilhes wrote:
> On Fri, Sep 08, 2006 at 10:29:23AM -0400, John W. Linville wrote:
> > On Wed, Sep 06, 2006 at 02:30:53PM -0700, Jean Tourrilhes wrote:
> > > On Wed, Sep 06, 2006 at 04:55:44PM -0400, John W. Linville wrote:
> > 
> > > > + * V20 to V21
> > > > + * ----------
> > > > + *	- Remove (struct net_device *)->get_wireless_stats()
> > > > + *	- Change length in ESSID and NICK to strlen() instead of strlen()+1
> > > > + *	- Add IW_RETRY_SHORT/IW_RETRY_LONG retry modifiers
> > > > + *	- Add explicit flag to tell stats are in 802.11k RCPI : IW_QUAL_RCPI
> > > 
> > > 	Personally, I would also add this :
> > > 
> > > + *	- Power/Retry relative values no longer * 100000
> > >
> > > 	Three reason :
> > > 		1) It's a cleanup and does not add any new feature
> > > 		2) It does not change the rest of the patches
> > > 		3) Userspace part has already gone in distro, not
> > > including this bit would mean breaking userspace.
> > 
> > Is there any code that corresponds to that?  Or does the comment
> > simply indicate policy?
> 
> 	There is no code in the core of the WE, so it only indicates
> policy. But, I believe policy change need to be documented.
> 	On the other hand you will find code in the tiacx patch.

Fair enough...

Any objections?

---

This is version 21 of the Wireless Extensions. Changelog :
	o finishes migrating the ESSID API (remove the +1)
	o netdev->get_wireless_stats is no more
	o long/short retry

This is a redacted version of a patch originally submitted by Jean
Tourrilhes.  I removed most of the additions, in order to minimize
future support requirements for nl80211 (or other WE successor).

CC: Jean Tourrilhes <[email-masked]>
Signed-off-by: John W. Linville <[email-masked]>
---
 include/linux/netdevice.h |    1 -
 include/linux/wireless.h  |   23 +++++++++++++--
 net/core/net-sysfs.c      |    5 +--
 net/core/wireless.c       |   67 ++++++++++++++++++++++++++++-----------------
 4 files changed, 61 insertions(+), 35 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 50a4719..91dc36c 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -334,7 +334,6 @@ #define NETIF_F_ALL_CSUM	(NETIF_F_IP_CSU

 	struct net_device_stats* (*get_stats)(struct net_device *dev);
-	struct iw_statistics*	(*get_wireless_stats)(struct net_device *dev);
 
 	/* List of functions to handle Wireless Extensions (instead of ioctl).
 	 * See <net/iw_handler.h> for details. Jean II */
diff --git a/include/linux/wireless.h b/include/linux/wireless.h
index 1358856..7a5860f 100644
--- a/include/linux/wireless.h
+++ b/include/linux/wireless.h
@@ -1,7 +1,7 @@
 /*
  * This file define a set of standard wireless extensions
  *
- * Version :	20	17.2.06
+ * Version :	21	14.3.06
  *
  * Authors :	Jean Tourrilhes - HPL - <[email-masked]>
  * Copyright (c) 1997-2006 Jean Tourrilhes, All Rights Reserved.
@@ -69,9 +69,14 @@ #define _LINUX_WIRELESS_H
 
 /***************************** INCLUDES *****************************/
 
+/* This header is used in user-space, therefore need to be sanitised
+ * for that purpose. Those includes are usually not compatible with glibc.
+ * To know which includes to use in user-space, check iwlib.h. */
+#ifdef __KERNEL__
 #include <linux/types.h>		/* for "caddr_t" et al		*/
 #include <linux/socket.h>		/* for "struct sockaddr" et al	*/
 #include <linux/if.h>			/* for IFNAMSIZ and co... */
+#endif	/* __KERNEL__ */
 
 /***************************** VERSION *****************************/
 /*
@@ -80,7 +85,7 @@ #include <linux/if.h>			/* for IFNAMSIZ 
  * (there is some stuff that will be added in the future...)
  * I just plan to increment with each new version.
  */
-#define WIRELESS_EXT	20
+#define WIRELESS_EXT	21
 
 /*
  * Changes :
@@ -208,6 +213,14 @@ #define WIRELESS_EXT	20
  * V19 to V20
  * ----------
  *	- RtNetlink requests support (SET/GET)
+ *
+ * V20 to V21
+ * ----------
+ *	- Remove (struct net_device *)->get_wireless_stats()
+ *	- Change length in ESSID and NICK to strlen() instead of strlen()+1
+ *	- Add IW_RETRY_SHORT/IW_RETRY_LONG retry modifiers
+ *	- Power/Retry relative values no longer * 100000
+ *	- Add explicit flag to tell stats are in 802.11k RCPI : IW_QUAL_RCPI
  */
 
 /**************************** CONSTANTS ****************************/
@@ -448,6 +460,7 @@ #define IW_QUAL_DBM		0x08	/* Level + Noi
 #define IW_QUAL_QUAL_INVALID	0x10	/* Driver doesn't provide value */
 #define IW_QUAL_LEVEL_INVALID	0x20
 #define IW_QUAL_NOISE_INVALID	0x40
+#define IW_QUAL_RCPI		0x80	/* Level + Noise are 802.11k RCPI */
 #define IW_QUAL_ALL_INVALID	0x70
 
 /* Frequency flags */
@@ -500,10 +513,12 @@ #define IW_RETRY_ON		0x0000	/* No detail
 #define IW_RETRY_TYPE		0xF000	/* Type of parameter */
 #define IW_RETRY_LIMIT		0x1000	/* Maximum number of retries*/
 #define IW_RETRY_LIFETIME	0x2000	/* Maximum duration of retries in us */
-#define IW_RETRY_MODIFIER	0x000F	/* Modify a parameter */
+#define IW_RETRY_MODIFIER	0x00FF	/* Modify a parameter */
 #define IW_RETRY_MIN		0x0001	/* Value is a minimum  */
 #define IW_RETRY_MAX		0x0002	/* Value is a maximum */
 #define IW_RETRY_RELATIVE	0x0004	/* Value is not in seconds/ms/us */
+#define IW_RETRY_SHORT		0x0010	/* Value is for short packets  */
+#define IW_RETRY_LONG		0x0020	/* Value is for long packets */
 
 /* Scanning request flags */
 #define IW_SCAN_DEFAULT		0x0000	/* Default scan of the driver */
@@ -1017,7 +1032,7 @@ struct	iw_range
 	/* Note : this frequency list doesn't need to fit channel numbers,
 	 * because each entry contain its channel index */
 
-	__u32		enc_capa; /* IW_ENC_CAPA_* bit field */
+	__u32		enc_capa;	/* IW_ENC_CAPA_* bit field */
 };
 
 /*
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 1347276..f47f319 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -344,8 +344,6 @@ static ssize_t wireless_show(struct clas
 		if(dev->wireless_handlers &&
 		   dev->wireless_handlers->get_wireless_stats)
 			iw = dev->wireless_handlers->get_wireless_stats(dev);
-		else if (dev->get_wireless_stats)
-			iw = dev->get_wireless_stats(dev);
 		if (iw != NULL)
 			ret = (*format)(iw, buf);
 	}
@@ -465,8 +463,7 @@ int netdev_register_sysfs(struct net_dev
 		*groups++ = &netstat_group;
 
 #ifdef WIRELESS_EXT
-	if (net->get_wireless_stats
-	    || (net->wireless_handlers && net->wireless_handlers->get_wireless_stats))
+	if (net->wireless_handlers && net->wireless_handlers->get_wireless_stats)
 		*groups++ = &wireless_group;
 #endif
 
diff --git a/net/core/wireless.c b/net/core/wireless.c
index de0bde4..61457d8 100644
--- a/net/core/wireless.c
+++ b/net/core/wireless.c
@@ -68,6 +68,14 @@
  *
  * v8 - 17.02.06 - Jean II
  *	o RtNetlink requests support (SET/GET)
+ *
+ * v8b - 03.08.06 - Herbert Xu
+ *	o Fix Wireless Event locking issues.
+ *
+ * v9 - 14.3.06 - Jean II
+ *	o Change length in ESSID and NICK to strlen() instead of strlen()+1
+ *	o Make standard_ioctl_num and standard_event_num unsigned
+ *	o Remove (struct net_device *)->get_wireless_stats()
  */
 
 /***************************** INCLUDES *****************************/
@@ -234,24 +242,24 @@ static const struct iw_ioctl_description
 	[SIOCSIWESSID	- SIOCIWFIRST] = {
 		.header_type	= IW_HEADER_TYPE_POINT,
 		.token_size	= 1,
-		.max_tokens	= IW_ESSID_MAX_SIZE + 1,
+		.max_tokens	= IW_ESSID_MAX_SIZE,
 		.flags		= IW_DESCR_FLAG_EVENT,
 	},
 	[SIOCGIWESSID	- SIOCIWFIRST] = {
 		.header_type	= IW_HEADER_TYPE_POINT,
 		.token_size	= 1,
-		.max_tokens	= IW_ESSID_MAX_SIZE + 1,
+		.max_tokens	= IW_ESSID_MAX_SIZE,
 		.flags		= IW_DESCR_FLAG_DUMP,
 	},
 	[SIOCSIWNICKN	- SIOCIWFIRST] = {
 		.header_type	= IW_HEADER_TYPE_POINT,
 		.token_size	= 1,
-		.max_tokens	= IW_ESSID_MAX_SIZE + 1,
+		.max_tokens	= IW_ESSID_MAX_SIZE,
 	},
 	[SIOCGIWNICKN	- SIOCIWFIRST] = {
 		.header_type	= IW_HEADER_TYPE_POINT,
 		.token_size	= 1,
-		.max_tokens	= IW_ESSID_MAX_SIZE + 1,
+		.max_tokens	= IW_ESSID_MAX_SIZE,
 	},
 	[SIOCSIWRATE	- SIOCIWFIRST] = {
 		.header_type	= IW_HEADER_TYPE_PARAM,
@@ -338,8 +346,8 @@ static const struct iw_ioctl_description
 		.max_tokens	= sizeof(struct iw_pmksa),
 	},
 };
-static const int standard_ioctl_num = (sizeof(standard_ioctl) /
-				       sizeof(struct iw_ioctl_description));
+static const unsigned standard_ioctl_num = (sizeof(standard_ioctl) /
+					    sizeof(struct iw_ioctl_description));
 
 /*
  * Meta-data about all the additional standard Wireless Extension events
@@ -389,8 +397,8 @@ static const struct iw_ioctl_description
 		.max_tokens	= sizeof(struct iw_pmkid_cand),
 	},
 };
-static const int standard_event_num = (sizeof(standard_event) /
-				       sizeof(struct iw_ioctl_description));
+static const unsigned standard_event_num = (sizeof(standard_event) /
+					    sizeof(struct iw_ioctl_description));
 
 /* Size (in bytes) of the various private data types */
 static const char iw_priv_type_size[] = {
@@ -465,17 +473,6 @@ static inline struct iw_statistics *get_
 	   (dev->wireless_handlers->get_wireless_stats != NULL))
 		return dev->wireless_handlers->get_wireless_stats(dev);
 
-	/* Old location, field to be removed in next WE */
-	if(dev->get_wireless_stats) {
-		static int printed_message;
-
-		if (!printed_message++)
-			printk(KERN_DEBUG "%s (WE) : Driver using old /proc/net/wireless support, please fix driver !\n",
-				dev->name);
-
-		return dev->get_wireless_stats(dev);
-	}
-
 	/* Not found */
 	return (struct iw_statistics *) NULL;
 }
@@ -1843,8 +1840,33 @@ #endif	/* CONFIG_NET_WIRELESS_RTNETLINK 
  */
 
 #ifdef WE_EVENT_RTNETLINK
+/* ---------------------------------------------------------------- */
+/*
+ * Locking...
+ * ----------
+ *
+ * Thanks to Herbert Xu <[email-masked]> for fixing
+ * the locking issue in here and implementing this code !
+ *
+ * The issue : wireless_send_event() is often called in interrupt context,
+ * while the Netlink layer can never be called in interrupt context.
+ * The fully formed RtNetlink events are queued, and then a tasklet is run
+ * to feed those to Netlink.
+ * The skb_queue is interrupt safe, and its lock is not held while calling
+ * Netlink, so there is no possibility of dealock.
+ * Jean II
+ */
+
 static struct sk_buff_head wireless_nlevent_queue;
 
+static int __init wireless_nlevent_init(void)
+{
+	skb_queue_head_init(&wireless_nlevent_queue);
+	return 0;
+}
+
+subsys_initcall(wireless_nlevent_init);
+
 static void wireless_nlevent_process(unsigned long data)
 {
 	struct sk_buff *skb;
@@ -1921,13 +1943,6 @@ static inline void rtmsg_iwinfo(struct n
 	tasklet_schedule(&wireless_nlevent_tasklet);
 }
 
-static int __init wireless_nlevent_init(void)
-{
-	skb_queue_head_init(&wireless_nlevent_queue);
-	return 0;
-}
-
-subsys_initcall(wireless_nlevent_init);
 #endif	/* WE_EVENT_RTNETLINK */
 
 /* ---------------------------------------------------------------- */
-- 
1.4.2.GIT

-- 
John W. Linville
[email-masked]