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 79d84687582..d7958f9b52c 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 c99a8eec84e..51b9a37de99 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;
 }