This patch complete reworks the evaluation of 6lowpan dispatch value by
introducing several different handlers for each dispatch value. This
patch also fixes a bug to re-evaluate the dispatch value after reassmble
while fragmentation. Currently we always assume that we have an IPHC
header there.
Signed-off-by: Alexander Aring <alex.aring@xxxxxxxxx>
---
net/ieee802154/6lowpan/rx.c | 155 +++++++++++++++++++++++++++++---------------
1 file changed, 101 insertions(+), 54 deletions(-)
diff --git a/net/ieee802154/6lowpan/rx.c b/net/ieee802154/6lowpan/rx.c
index bf6e857..c7afd4a 100644
--- a/net/ieee802154/6lowpan/rx.c
+++ b/net/ieee802154/6lowpan/rx.c
@@ -15,12 +15,42 @@
#include "6lowpan_i.h"
+typedef unsigned __bitwise__ lowpan_rx_result;
+#define RX_CONTINUE ((__force lowpan_rx_result) 0u)
+#define RX_DROP_UNUSABLE ((__force lowpan_rx_result) 1u)
+#define RX_DROP ((__force lowpan_rx_result) 2u)
+#define RX_QUEUED ((__force lowpan_rx_result) 3u)
+
+static int
+lowpan_rx_handlers_result(struct sk_buff *skb, lowpan_rx_result res)
+{
+ switch (res) {
+ /* nobody cared about this packet */
+ case RX_CONTINUE:
+ case RX_DROP_UNUSABLE:
+ kfree_skb(skb);
+ case RX_DROP:
+ return NET_RX_DROP;
+ default:
+ break;
+ }
+
+ return NET_RX_SUCCESS;
+}
+
static int lowpan_give_skb_to_device(struct sk_buff *skb)
{
+ int ret;
+
skb->protocol = htons(ETH_P_IPV6);
skb->pkt_type = PACKET_HOST;
- return netif_rx(skb);
+ ret = netif_rx(skb);
+ /* kfree_skb handled by netif_rx, so RX_DROP on failure */
+ if (ret == NET_RX_SUCCESS)
+ return RX_QUEUED;
+ else
+ return RX_DROP;
}
static int
@@ -54,69 +84,86 @@ iphc_decompress(struct sk_buff *skb, const struct ieee802154_hdr *hdr)
IEEE802154_ADDR_LEN, iphc0, iphc1);
}
-static int lowpan_rcv(struct sk_buff *skb, struct net_device *wdev,
- struct packet_type *pt, struct net_device *orig_wdev)
+static lowpan_rx_result lowpan_rx_h_ipv6(struct sk_buff *skb)
+{
+ if (skb->data[0] != LOWPAN_DISPATCH_IPV6)
+ return RX_CONTINUE;
+
+ /* Pull off the 1-byte of 6lowpan header. */
+ skb_pull(skb, 1);
+ return lowpan_give_skb_to_device(skb);
+}
+
+static lowpan_rx_result lowpan_rx_h_frag(struct sk_buff *skb)
+{
+ int ret;
+
+ if ((skb->data[0] & 0xe0) != LOWPAN_DISPATCH_FRAG1 &&
+ (skb->data[0] & 0xe0) != LOWPAN_DISPATCH_FRAGN)
+ return RX_CONTINUE;
+
+ ret = lowpan_frag_rcv(skb, skb->data[0] & 0xe0);
+ if (ret == 1)
+ return RX_CONTINUE;
+
+ /* packet is dropped and putted into the frag bucket only */
+ return RX_DROP;
+}
+
+static lowpan_rx_result lowpan_rx_h_iphc(struct sk_buff *skb)
{
- struct ieee802154_hdr hdr;
int ret;
+ struct ieee802154_hdr hdr;
+
+ if ((skb->data[0] & 0xe0) != LOWPAN_DISPATCH_IPHC)
+ return RX_CONTINUE;
+
+ if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0)
+ return RX_DROP_UNUSABLE;
+
+ ret = iphc_decompress(skb, &hdr);
+ if (ret < 0)
+ return RX_DROP_UNUSABLE;
+
+ return lowpan_give_skb_to_device(skb);
+}
+
+int lowpan_invoke_rx_handlers(struct sk_buff *skb)
+{
+ lowpan_rx_result res;
+
+#define CALL_RXH(rxh) \
+ do { \
+ res = rxh(skb); \
+ if (res != RX_CONTINUE) \
+ goto rxh_next; \
+ } while (0)
+
+ /* frag at first, because it contains dispatch value again */
+ CALL_RXH(lowpan_rx_h_frag);
+ /* likely at first */
+ CALL_RXH(lowpan_rx_h_iphc);
+ CALL_RXH(lowpan_rx_h_ipv6);
+
+rxh_next:
+ return lowpan_rx_handlers_result(skb, res);
+#undef CALL_RXH
+}
+
+static int lowpan_rcv(struct sk_buff *skb, struct net_device *wdev,
+ struct packet_type *pt, struct net_device *orig_wdev)
+{
if (skb->pkt_type == PACKET_OTHERHOST ||
wdev->type != ARPHRD_IEEE802154)
- goto drop;
+ return NET_RX_DROP;
skb = skb_share_check(skb, GFP_ATOMIC);
if (!skb)
- goto drop;
-
- if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0)
- goto drop_skb;
+ return NET_RX_DROP;
skb->dev = wdev->ieee802154_ptr->lowpan_dev;
-
- /* check that it's our buffer */
- if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
- /* Pull off the 1-byte of 6lowpan header. */
- skb_pull(skb, 1);
- return lowpan_give_skb_to_device(skb);
- } else {
- switch (skb->data[0] & 0xe0) {
- case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */
- ret = iphc_decompress(skb, &hdr);
- if (ret < 0)
- goto drop_skb;
-
- return lowpan_give_skb_to_device(skb);
- case LOWPAN_DISPATCH_FRAG1: /* first fragment header */
- ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAG1);
- if (ret == 1) {
- ret = iphc_decompress(skb, &hdr);
- if (ret < 0)
- goto drop_skb;
-
- return lowpan_give_skb_to_device(skb);
- }
-
- return NET_RX_DROP;
- case LOWPAN_DISPATCH_FRAGN: /* next fragments headers */
- ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAGN);
- if (ret == 1) {
- ret = iphc_decompress(skb, &hdr);
- if (ret < 0)
- goto drop_skb;
-
- return lowpan_give_skb_to_device(skb);
- }
-
- return NET_RX_DROP;
- default:
- break;
- }
- }
-
-drop_skb:
- kfree_skb(skb);
-drop:
- return NET_RX_DROP;
+ return lowpan_invoke_rx_handlers(skb);
}
static struct packet_type lowpan_packet_type = {
--
2.5.0
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