caif: fix a signedness bug in cfpkt_iterate()

The cfpkt_iterate() function can return -EPROTO on error, but the
function is a u16 so the negative value gets truncated to a positive
unsigned short.  This causes a static checker warning.

The only caller which might care is cffrml_receive(), when it's checking
the frame checksum.  I modified cffrml_receive() so that it never says
-EPROTO is a valid checksum.

Also this isn't ever going to be inlined so I removed the "inline".

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 5 insertions, 5 deletions

diff --git a/include/net/caif/cfpkt.h b/include/net/caif/cfpkt.h
index 1c1ad46250d5..fe328c52c46b 100644
--- a/include/net/caif/cfpkt.h
+++ b/include/net/caif/cfpkt.h
@@ -171,7 +171,7 @@ struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos);
  * @return    Checksum of buffer.
  */
 
-u16 cfpkt_iterate(struct cfpkt *pkt,
+int cfpkt_iterate(struct cfpkt *pkt,
                 u16 (*iter_func)(u16 chks, void *buf, u16 len),
                 u16 data);
 
diff --git a/net/caif/cffrml.c b/net/caif/cffrml.c
index 8bc7caa28e64..434ba8557826 100644
--- a/net/caif/cffrml.c
+++ b/net/caif/cffrml.c
@@ -84,7 +84,7 @@ static int cffrml_receive(struct cflayer *layr, struct cfpkt *pkt)
         u16 tmp;
         u16 len;
         u16 hdrchks;
-        u16 pktchks;
+        int pktchks;
         struct cffrml *this;
         this = container_obj(layr);
 
diff --git a/net/caif/cfpkt_skbuff.c b/net/caif/cfpkt_skbuff.c
index 1be0b521ac49..f6c3b2137eea 100644
--- a/net/caif/cfpkt_skbuff.c
+++ b/net/caif/cfpkt_skbuff.c
@@ -255,9 +255,9 @@ inline u16 cfpkt_getlen(struct cfpkt *pkt)
         return skb->len;
 }
 
-inline u16 cfpkt_iterate(struct cfpkt *pkt,
-                         u16 (*iter_func)(u16, void *, u16),
-                         u16 data)
+int cfpkt_iterate(struct cfpkt *pkt,
+                  u16 (*iter_func)(u16, void *, u16),
+                  u16 data)
 {
         /*
          * Don't care about the performance hit of linearizing,