[PATCH] usb gadget: ethernet/rndis updates

Updates to the Ethernet/RNDIS gadget driver (mostly for RNDIS):

  - Fix brown-paper bag goof with RNDIS packet TX ... the wrong length
    field got set, so Windows would ignore data packets it received.

  - More consistent handling of CDC output filters (but not yet hooking
    things up so RNDIS uses the mechanism).

  - Zerocopy RX for RNDIS packets too (saving CPU cycles).

  - Use the pre-allocated interrupt/status request and buffer, rather
    than allocating and freeing one of each every few seconds (which
    could fail).

  - Some more "sparse" tweaks, making both dual-speed and single-speed
    configurations happier.

  - RNDIS speeds are reported in units of 100bps, not bps.

Plus two minor cleanups (whitespace, messaging).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 19 insertions, 21 deletions

diff --git a/drivers/usb/gadget/rndis.c b/drivers/usb/gadget/rndis.c
index 6c5197850edc..7457268d5f28 100644
--- a/drivers/usb/gadget/rndis.c
+++ b/drivers/usb/gadget/rndis.c
@@ -37,6 +37,7 @@
 #include <asm/io.h>
 #include <asm/byteorder.h>
 #include <asm/system.h>
+#include <asm/unaligned.h>
 
 
 #undef  RNDIS_PM
@@ -165,7 +166,7 @@ static int gen_ndis_query_resp (int configNr, u32 OID, rndis_resp_t *r)
                 
         /* mandatory */
         case OID_GEN_LINK_SPEED:
-                DEBUG("%s: OID_GEN_LINK_SPEED\n", __FUNCTION__);
+//              DEBUG("%s: OID_GEN_LINK_SPEED\n", __FUNCTION__);
                 length = 4;
                 if (rndis_per_dev_params [configNr].media_state
                         == NDIS_MEDIA_STATE_DISCONNECTED)
@@ -729,7 +730,7 @@ static int gen_ndis_set_resp (u8 configNr, u32 OID, u8 *buf, u32 buf_len,
                 retval = 0;
 
                 /* FIXME use these NDIS_PACKET_TYPE_* bitflags to
-                 * filter packets in hard_start_xmit()
+                 * set the cdc_filter; it's not RNDIS-specific
                  * NDIS_PACKET_TYPE_x == USB_CDC_PACKET_TYPE_x for x in:
                  *      PROMISCUOUS, DIRECTED,
                  *      MULTICAST, ALL_MULTICAST, BROADCAST
@@ -1194,10 +1195,10 @@ void rndis_add_hdr (struct sk_buff *skb)
                 return;
         header = (void *) skb_push (skb, sizeof *header);
         memset (header, 0, sizeof *header);
-        header->MessageType = __constant_cpu_to_le32 (1);
+        header->MessageType = __constant_cpu_to_le32(REMOTE_NDIS_PACKET_MSG);
         header->MessageLength = cpu_to_le32(skb->len);
         header->DataOffset = __constant_cpu_to_le32 (36);
-        header->OOBDataOffset = cpu_to_le32(skb->len - 44);
+        header->DataLength = cpu_to_le32(skb->len - sizeof *header);
 }
 
 void rndis_free_response (int configNr, u8 *buf)
@@ -1253,26 +1254,23 @@ static rndis_resp_t *rndis_add_response (int configNr, u32 length)
         return r;
 }
 
-int rndis_rm_hdr (u8 *buf, u32 *length)
+int rndis_rm_hdr(struct sk_buff *skb)
 {
-        u32 i, messageLen, dataOffset;
-        __le32 *tmp;
-        
-        tmp = (__le32 *) buf; 
+        /* tmp points to a struct rndis_packet_msg_type */
+        __le32          *tmp = (void *) skb->data;
 
-        if (!buf || !length) return -1;
-        if (le32_to_cpup(tmp++) != 1) return -1;
-        
-        messageLen = le32_to_cpup(tmp++);
-        dataOffset = le32_to_cpup(tmp++) + 8;
+        /* MessageType, MessageLength */
+        if (__constant_cpu_to_le32(REMOTE_NDIS_PACKET_MSG)
+                        != get_unaligned(tmp++))
+                return -EINVAL;
+        tmp++;
+
+        /* DataOffset, DataLength */
+        if (!skb_pull(skb, le32_to_cpu(get_unaligned(tmp++))
+                        + 8 /* offset of DataOffset */))
+                return -EOVERFLOW;
+        skb_trim(skb, le32_to_cpu(get_unaligned(tmp++)));
 
-        if (messageLen < dataOffset || messageLen > *length) return -1;
-        
-        for (i = dataOffset; i < messageLen; i++)
-                buf [i - dataOffset] = buf [i];
-                
-        *length = messageLen - dataOffset;
-        
         return 0;
 }