ieee802154: handle datagram variables as u16

This reverts commit 9abc378c66e3d6f437eed77c1c534cbc183523f7
("ieee802154: 6lowpan: change datagram var types").

The reason is that I forgot the IPv6 fragmentation here. Our MTU of
lowpan interface is 1280 and skb->len should not above of that. If we
reach a payload above 1280 in IPv6 header then we have a IPv6
fragmentation above 802.15.4 6LoWPAN fragmentation. The type "u16" was
fine, instead I added now a WARN_ON_ONCE if skb->len is above MTU which
should never happen otherwise IPv6 on minimum MTU size is broken.

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

diff --git a/net/ieee802154/6lowpan/6lowpan_i.h b/net/ieee802154/6lowpan/6lowpan_i.h
index 10d44d0..b4e17a7 100644 (file)
--- a/net/ieee802154/6lowpan/6lowpan_i.h
+++ b/net/ieee802154/6lowpan/6lowpan_i.h
@@ -18,7 +18,7 @@ typedef unsigned __bitwise__ lowpan_rx_result;
 
 struct lowpan_create_arg {
        u16 tag;
-       unsigned int d_size;
+       u16 d_size;
        const struct ieee802154_addr *src;
        const struct ieee802154_addr *dst;
 };
@@ -29,7 +29,7 @@ struct lowpan_frag_queue {
        struct inet_frag_queue  q;
 
        u16                     tag;
-       unsigned int            d_size;
+       u16                     d_size;
        struct ieee802154_addr  saddr;
        struct ieee802154_addr  daddr;
 };

diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c
index af663cb..12e8cf4 100644 (file)
--- a/net/ieee802154/6lowpan/reassembly.c
+++ b/net/ieee802154/6lowpan/reassembly.c
@@ -37,7 +37,7 @@ static struct inet_frags lowpan_frags;
 static int lowpan_frag_reasm(struct lowpan_frag_queue *fq,
                             struct sk_buff *prev, struct net_device *ldev);
 
-static unsigned int lowpan_hash_frag(u16 tag, unsigned int d_size,
+static unsigned int lowpan_hash_frag(u16 tag, u16 d_size,
                                     const struct ieee802154_addr *saddr,
                                     const struct ieee802154_addr *daddr)
 {

diff --git a/net/ieee802154/6lowpan/tx.c b/net/ieee802154/6lowpan/tx.c
index 5736302..62a21f6 100644 (file)
--- a/net/ieee802154/6lowpan/tx.c
+++ b/net/ieee802154/6lowpan/tx.c
@@ -137,8 +137,8 @@ lowpan_xmit_fragment(struct sk_buff *skb, const struct ieee802154_hdr *wpan_hdr,
 
 static int
 lowpan_xmit_fragmented(struct sk_buff *skb, struct net_device *ldev,
-                      const struct ieee802154_hdr *wpan_hdr,
-                      unsigned int dgram_size, unsigned int dgram_offset)
+                      const struct ieee802154_hdr *wpan_hdr, u16 dgram_size,
+                      u16 dgram_offset)
 {
        __be16 frag_tag;
        u8 frag_hdr[5];
@@ -203,7 +203,7 @@ err:
 }
 
 static int lowpan_header(struct sk_buff *skb, struct net_device *ldev,
-                        unsigned int *dgram_size, unsigned int *dgram_offset)
+                        u16 *dgram_size, u16 *dgram_offset)
 {
        struct wpan_dev *wpan_dev = lowpan_dev_info(ldev)->wdev->ieee802154_ptr;
        struct ieee802154_addr sa, da;
@@ -253,10 +253,12 @@ netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev)
 {
        struct ieee802154_hdr wpan_hdr;
        int max_single, ret;
-       unsigned int dgram_size, dgram_offset;
+       u16 dgram_size, dgram_offset;
 
        pr_debug("package xmit\n");
 
+       WARN_ON_ONCE(skb->len > IPV6_MIN_MTU);
+
        /* We must take a copy of the skb before we modify/replace the ipv6
         * header as the header could be used elsewhere
         */