6lowpan: udp use lowpan_fetch_skb function

Cleanup the lowpan_uncompress_udp_header function to use the
lowpan_fetch_skb function.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 18 insertions, 19 deletions

diff --git a/net/ieee802154/6lowpan_iphc.c b/net/ieee802154/6lowpan_iphc.c
index a70fa66b5357..8857285b418b 100644
--- a/net/ieee802154/6lowpan_iphc.c
+++ b/net/ieee802154/6lowpan_iphc.c
@@ -265,40 +265,37 @@ lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
 static int
 uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
 {
-        u8 tmp;
+        bool fail;
+        u8 tmp = 0, val = 0;
 
         if (!uh)
                 goto err;
 
-        if (lowpan_fetch_skb_u8(skb, &tmp))
-                goto err;
+        fail = lowpan_fetch_skb(skb, &tmp, 1);
 
         if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
                 pr_debug("UDP header uncompression\n");
                 switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
                 case LOWPAN_NHC_UDP_CS_P_00:
-                        memcpy(&uh->source, &skb->data[0], 2);
-                        memcpy(&uh->dest, &skb->data[2], 2);
-                        skb_pull(skb, 4);
+                        fail |= lowpan_fetch_skb(skb, &uh->source, 2);
+                        fail |= lowpan_fetch_skb(skb, &uh->dest, 2);
                         break;
                 case LOWPAN_NHC_UDP_CS_P_01:
-                        memcpy(&uh->source, &skb->data[0], 2);
-                        uh->dest = htons(skb->data[2] +
-                                         LOWPAN_NHC_UDP_8BIT_PORT);
-                        skb_pull(skb, 3);
+                        fail |= lowpan_fetch_skb(skb, &uh->source, 2);
+                        fail |= lowpan_fetch_skb(skb, &val, 1);
+                        uh->dest = htons(val + LOWPAN_NHC_UDP_8BIT_PORT);
                         break;
                 case LOWPAN_NHC_UDP_CS_P_10:
-                        uh->source = htons(skb->data[0] +
-                                           LOWPAN_NHC_UDP_8BIT_PORT);
-                        memcpy(&uh->dest, &skb->data[1], 2);
-                        skb_pull(skb, 3);
+                        fail |= lowpan_fetch_skb(skb, &val, 1);
+                        uh->source = htons(val + LOWPAN_NHC_UDP_8BIT_PORT);
+                        fail |= lowpan_fetch_skb(skb, &uh->dest, 2);
                         break;
                 case LOWPAN_NHC_UDP_CS_P_11:
+                        fail |= lowpan_fetch_skb(skb, &val, 1);
                         uh->source = htons(LOWPAN_NHC_UDP_4BIT_PORT +
-                                           (skb->data[0] >> 4));
+                                           (val >> 4));
                         uh->dest = htons(LOWPAN_NHC_UDP_4BIT_PORT +
-                                         (skb->data[0] & 0x0f));
-                        skb_pull(skb, 1);
+                                         (val & 0x0f));
                         break;
                 default:
                         pr_debug("ERROR: unknown UDP format\n");
@@ -314,8 +311,7 @@ uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
                         pr_debug_ratelimited("checksum elided currently not supported\n");
                         goto err;
                 } else {
-                        memcpy(&uh->check, &skb->data[0], 2);
-                        skb_pull(skb, 2);
+                        fail |= lowpan_fetch_skb(skb, &uh->check, 2);
                 }
 
                 /*
@@ -330,6 +326,9 @@ uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
                 goto err;
         }
 
+        if (fail)
+                goto err;
+
         return 0;
 err:
         return -EINVAL;