6lowpan: add debug messages for 6LoWPAN fragmentation

Add pr_debug() call in order to debug 6LoWPAN fragmentation and
reassembly.

Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 4 deletions

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 4a62289669b1..61eee9d0dd21 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -742,10 +742,16 @@ lowpan_process_data(struct sk_buff *skb)
                 /* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */
                 len = ((iphc0 & 7) << 8) | slen;
 
-                /* FRAGN */
-                if ((iphc0 & LOWPAN_DISPATCH_MASK) != LOWPAN_DISPATCH_FRAG1) {
+                if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) {
+                        pr_debug("%s received a FRAG1 packet (tag: %d, "
+                                 "size of the entire IP packet: %d)",
+                                 __func__, tag, len);
+                } else { /* FRAGN */
                         if (lowpan_fetch_skb_u8(skb, &offset))
                                 goto unlock_and_drop;
+                        pr_debug("%s received a FRAGN packet (tag: %d, "
+                                 "size of the entire IP packet: %d, "
+                                 "offset: %d)", __func__, tag, len, offset * 8);
                 }
 
                 /*
@@ -762,6 +768,8 @@ lowpan_process_data(struct sk_buff *skb)
 
                 /* alloc new frame structure */
                 if (!found) {
+                        pr_debug("%s first fragment received for tag %d, "
+                                 "begin packet reassembly", __func__, tag);
                         frame = lowpan_alloc_new_frame(skb, len, tag);
                         if (!frame)
                                 goto unlock_and_drop;
@@ -784,6 +792,9 @@ lowpan_process_data(struct sk_buff *skb)
                         list_del(&frame->list);
                         spin_unlock_bh(&flist_lock);
 
+                        pr_debug("%s successfully reassembled fragment "
+                                 "(tag %d)", __func__, tag);
+
                         dev_kfree_skb(skb);
                         skb = frame->skb;
                         kfree(frame);
@@ -1034,8 +1045,11 @@ lowpan_skb_fragmentation(struct sk_buff *skb)
         err = lowpan_fragment_xmit(skb, head, header_length, LOWPAN_FRAG_SIZE,
                                    0, LOWPAN_DISPATCH_FRAG1);
 
-        if (err)
+        if (err) {
+                pr_debug("%s unable to send FRAG1 packet (tag: %d)",
+                         __func__, tag);
                 goto exit;
+        }
 
         offset = LOWPAN_FRAG_SIZE;
 
@@ -1053,8 +1067,11 @@ lowpan_skb_fragmentation(struct sk_buff *skb)
 
                 err = lowpan_fragment_xmit(skb, head, header_length,
                                            len, offset, LOWPAN_DISPATCH_FRAGN);
-                if (err)
+                if (err) {
+                        pr_debug("%s unable to send a subsequent FRAGN packet "
+                                 "(tag: %d, offset: %d", __func__, tag, offset);
                         goto exit;
+                }
 
                 offset += len;
         }