wext: Emit event stream entries correctly when compat.

Three major portions to this change:

1) Add IW_EV_COMPAT_LCP_LEN, IW_EV_COMPAT_POINT_OFF,
   and IW_EV_COMPAT_POINT_LEN helper defines.

2) Delete iw_stream_check_add_*(), they are unused.

3) Add iw_request_info argument to iwe_stream_add_*(), and use it to
   size the event and pointer lengths correctly depending upon whether
   IW_REQUEST_FLAG_COMPAT is set or not.

4) The mechanical transformations to the drivers and wireless stack
   bits to get the iw_request_info passed down into the routines
   modified in #3.  Also, explicit references to IW_EV_LCP_LEN are
   replaced with iwe_stream_lcp_len(info).

With a lot of help and bug fixes from Masakazu Mokuno.

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 63 insertions, 101 deletions

diff --git a/include/linux/wireless.h b/include/linux/wireless.h
index 79d8468..d7958f9 100644
--- a/include/linux/wireless.h
+++ b/include/linux/wireless.h
@@ -1113,6 +1113,21 @@ struct iw_event
 #define IW_EV_POINT_LEN	(IW_EV_LCP_LEN + sizeof(struct iw_point) - \
 			 IW_EV_POINT_OFF)
 
+#ifdef __KERNEL__
+#ifdef CONFIG_COMPAT
+struct __compat_iw_event {
+	__u16		len;			/* Real length of this stuff */
+	__u16		cmd;			/* Wireless IOCTL */
+	compat_caddr_t	pointer;
+};
+#define IW_EV_COMPAT_LCP_LEN offsetof(struct __compat_iw_event, pointer)
+#define IW_EV_COMPAT_POINT_OFF offsetof(struct compat_iw_point, length)
+#define IW_EV_COMPAT_POINT_LEN	\
+	(IW_EV_COMPAT_LCP_LEN + sizeof(struct compat_iw_point) - \
+	 IW_EV_COMPAT_POINT_OFF)
+#endif
+#endif
+
 /* Size of the Event prefix when packed in stream */
 #define IW_EV_LCP_PK_LEN	(4)
 /* Size of the various events when packed in stream */
diff --git a/include/net/iw_handler.h b/include/net/iw_handler.h
index c99a8ee..51b9a37d 100644
--- a/include/net/iw_handler.h
+++ b/include/net/iw_handler.h
@@ -478,105 +478,58 @@ extern void wireless_spy_update(struct net_device *	dev,
  * Function that are so simple that it's more efficient inlining them
  */
 
-/*------------------------------------------------------------------*/
-/*
- * Wrapper to add an Wireless Event to a stream of events.
- */
-static inline char *
-iwe_stream_add_event(char *	stream,		/* Stream of events */
-		     char *	ends,		/* End of stream */
-		     struct iw_event *iwe,	/* Payload */
-		     int	event_len)	/* Real size of payload */
+static inline int iwe_stream_lcp_len(struct iw_request_info *info)
 {
-	/* Check if it's possible */
-	if(likely((stream + event_len) < ends)) {
-		iwe->len = event_len;
-		/* Beware of alignement issues on 64 bits */
-		memcpy(stream, (char *) iwe, IW_EV_LCP_PK_LEN);
-		memcpy(stream + IW_EV_LCP_LEN,
-		       ((char *) iwe) + IW_EV_LCP_LEN,
-		       event_len - IW_EV_LCP_LEN);
-		stream += event_len;
-	}
-	return stream;
+#ifdef CONFIG_COMPAT
+	if (info->flags & IW_REQUEST_FLAG_COMPAT)
+		return IW_EV_COMPAT_LCP_LEN;
+#endif
+	return IW_EV_LCP_LEN;
 }
 
-/*------------------------------------------------------------------*/
-/*
- * Wrapper to add an short Wireless Event containing a pointer to a
- * stream of events.
- */
-static inline char *
-iwe_stream_add_point(char *	stream,		/* Stream of events */
-		     char *	ends,		/* End of stream */
-		     struct iw_event *iwe,	/* Payload length + flags */
-		     char *	extra)		/* More payload */
+static inline int iwe_stream_point_len(struct iw_request_info *info)
 {
-	int	event_len = IW_EV_POINT_LEN + iwe->u.data.length;
-	/* Check if it's possible */
-	if(likely((stream + event_len) < ends)) {
-		iwe->len = event_len;
-		memcpy(stream, (char *) iwe, IW_EV_LCP_PK_LEN);
-		memcpy(stream + IW_EV_LCP_LEN,
-		       ((char *) iwe) + IW_EV_LCP_LEN + IW_EV_POINT_OFF,
-		       IW_EV_POINT_PK_LEN - IW_EV_LCP_PK_LEN);
-		memcpy(stream + IW_EV_POINT_LEN, extra, iwe->u.data.length);
-		stream += event_len;
-	}
-	return stream;
+#ifdef CONFIG_COMPAT
+	if (info->flags & IW_REQUEST_FLAG_COMPAT)
+		return IW_EV_COMPAT_POINT_LEN;
+#endif
+	return IW_EV_POINT_LEN;
 }
 
-/*------------------------------------------------------------------*/
-/*
- * Wrapper to add a value to a Wireless Event in a stream of events.
- * Be careful, this one is tricky to use properly :
- * At the first run, you need to have (value = event + IW_EV_LCP_LEN).
- */
-static inline char *
-iwe_stream_add_value(char *	event,		/* Event in the stream */
-		     char *	value,		/* Value in event */
-		     char *	ends,		/* End of stream */
-		     struct iw_event *iwe,	/* Payload */
-		     int	event_len)	/* Real size of payload */
+static inline int iwe_stream_event_len_adjust(struct iw_request_info *info,
+					      int event_len)
 {
-	/* Don't duplicate LCP */
-	event_len -= IW_EV_LCP_LEN;
-
-	/* Check if it's possible */
-	if(likely((value + event_len) < ends)) {
-		/* Add new value */
-		memcpy(value, (char *) iwe + IW_EV_LCP_LEN, event_len);
-		value += event_len;
-		/* Patch LCP */
-		iwe->len = value - event;
-		memcpy(event, (char *) iwe, IW_EV_LCP_LEN);
+#ifdef CONFIG_COMPAT
+	if (info->flags & IW_REQUEST_FLAG_COMPAT) {
+		event_len -= IW_EV_LCP_LEN;
+		event_len += IW_EV_COMPAT_LCP_LEN;
 	}
-	return value;
+#endif
+
+	return event_len;
 }
 
 /*------------------------------------------------------------------*/
 /*
  * Wrapper to add an Wireless Event to a stream of events.
- * Same as above, with explicit error check...
  */
 static inline char *
-iwe_stream_check_add_event(char *	stream,		/* Stream of events */
-			   char *	ends,		/* End of stream */
-			   struct iw_event *iwe,	/* Payload */
-			   int		event_len,	/* Size of payload */
-			   int *	perr)		/* Error report */
+iwe_stream_add_event(struct iw_request_info *info, char *stream, char *ends,
+		     struct iw_event *iwe, int event_len)
 {
-	/* Check if it's possible, set error if not */
+	int lcp_len = iwe_stream_lcp_len(info);
+
+	event_len = iwe_stream_event_len_adjust(info, event_len);
+
+	/* Check if it's possible */
 	if(likely((stream + event_len) < ends)) {
 		iwe->len = event_len;
 		/* Beware of alignement issues on 64 bits */
 		memcpy(stream, (char *) iwe, IW_EV_LCP_PK_LEN);
-		memcpy(stream + IW_EV_LCP_LEN,
-		       ((char *) iwe) + IW_EV_LCP_LEN,
-		       event_len - IW_EV_LCP_LEN);
+		memcpy(stream + lcp_len, &iwe->u,
+		       event_len - lcp_len);
 		stream += event_len;
-	} else
-		*perr = -E2BIG;
+	}
 	return stream;
 }
 
@@ -584,27 +537,25 @@ iwe_stream_check_add_event(char *	stream,		/* Stream of events */
 /*
  * Wrapper to add an short Wireless Event containing a pointer to a
  * stream of events.
- * Same as above, with explicit error check...
  */
 static inline char *
-iwe_stream_check_add_point(char *	stream,		/* Stream of events */
-			   char *	ends,		/* End of stream */
-			   struct iw_event *iwe,	/* Payload length + flags */
-			   char *	extra,		/* More payload */
-			   int *	perr)		/* Error report */
+iwe_stream_add_point(struct iw_request_info *info, char *stream, char *ends,
+		     struct iw_event *iwe, char *extra)
 {
-	int	event_len = IW_EV_POINT_LEN + iwe->u.data.length;
+	int event_len = iwe_stream_point_len(info) + iwe->u.data.length;
+	int point_len = iwe_stream_point_len(info);
+	int lcp_len   = iwe_stream_lcp_len(info);
+
 	/* Check if it's possible */
 	if(likely((stream + event_len) < ends)) {
 		iwe->len = event_len;
 		memcpy(stream, (char *) iwe, IW_EV_LCP_PK_LEN);
-		memcpy(stream + IW_EV_LCP_LEN,
-		       ((char *) iwe) + IW_EV_LCP_LEN + IW_EV_POINT_OFF,
+		memcpy(stream + lcp_len,
+		       ((char *) &iwe->u) + IW_EV_POINT_OFF,
 		       IW_EV_POINT_PK_LEN - IW_EV_LCP_PK_LEN);
-		memcpy(stream + IW_EV_POINT_LEN, extra, iwe->u.data.length);
+		memcpy(stream + point_len, extra, iwe->u.data.length);
 		stream += event_len;
-	} else
-		*perr = -E2BIG;
+	}
 	return stream;
 }
 
@@ -613,29 +564,25 @@ iwe_stream_check_add_point(char *	stream,		/* Stream of events */
  * Wrapper to add a value to a Wireless Event in a stream of events.
  * Be careful, this one is tricky to use properly :
  * At the first run, you need to have (value = event + IW_EV_LCP_LEN).
- * Same as above, with explicit error check...
  */
 static inline char *
-iwe_stream_check_add_value(char *	event,		/* Event in the stream */
-			   char *	value,		/* Value in event */
-			   char *	ends,		/* End of stream */
-			   struct iw_event *iwe,	/* Payload */
-			   int		event_len,	/* Size of payload */
-			   int *	perr)		/* Error report */
+iwe_stream_add_value(struct iw_request_info *info, char *event, char *value,
+		     char *ends, struct iw_event *iwe, int event_len)
 {
+	int lcp_len = iwe_stream_lcp_len(info);
+
 	/* Don't duplicate LCP */
 	event_len -= IW_EV_LCP_LEN;
 
 	/* Check if it's possible */
 	if(likely((value + event_len) < ends)) {
 		/* Add new value */
-		memcpy(value, (char *) iwe + IW_EV_LCP_LEN, event_len);
+		memcpy(value, &iwe->u, event_len);
 		value += event_len;
 		/* Patch LCP */
 		iwe->len = value - event;
-		memcpy(event, (char *) iwe, IW_EV_LCP_LEN);
-	} else
-		*perr = -E2BIG;
+		memcpy(event, (char *) iwe, lcp_len);
+	}
 	return value;
 }