This patch fix the fragmentation on sending side according to rfc4944.
Also add improvement to use the full payload of a PDU which calculate the
nearest divided to 8 payload length for the fragmentation datagram
offset attribute.
Signed-off-by: Alexander Aring <alex.ar...@gmail.com>
---
include/net/ieee802154_netdev.h | 2 ++
net/ieee802154/6lowpan.c | 76 +++++++++++++++++++++++++++--------------
2 files changed, 52 insertions(+), 26 deletions(-)
diff --git a/include/net/ieee802154_netdev.h b/include/net/ieee802154_netdev.h
index 8196d5d..f93296d 100644
--- a/include/net/ieee802154_netdev.h
+++ b/include/net/ieee802154_netdev.h
@@ -39,6 +39,8 @@ struct ieee802154_mac_cb {
struct ieee802154_addr da;
u8 flags;
u8 seq;
+ u16 dgram_size;
+ u16 dgram_offset;
};
static inline struct ieee802154_mac_cb *mac_cb(struct sk_buff *skb)
diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 9c077a4..5d2c565 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -375,6 +375,7 @@ lowpan_compress_udp_header(u8 **hc06_ptr, struct sk_buff
*skb)
memcpy(*hc06_ptr, &uh->check, 2);
*hc06_ptr += 2;
+ mac_cb(skb)->dgram_offset += sizeof(struct udphdr);
/* skip the UDP header */
skb_pull(skb, sizeof(struct udphdr));
}
@@ -486,6 +487,7 @@ static int lowpan_header_create(struct sk_buff *skb,
if (type != ETH_P_IPV6)
return 0;
+ mac_cb(skb)->dgram_offset = 0;
hdr = ipv6_hdr(skb);
hc06_ptr = head + 2;
@@ -655,8 +657,16 @@ static int lowpan_header_create(struct sk_buff *skb,
head[0] = iphc0;
head[1] = iphc1;
+ /* Before replace ipv6hdr to 6lowpan header we save the dgram_size */
+ mac_cb(skb)->dgram_size = ntohs(hdr->payload_len) +
+ sizeof(struct ipv6hdr);
+ mac_cb(skb)->dgram_offset += sizeof(struct ipv6hdr);
+
skb_pull(skb, sizeof(struct ipv6hdr));
+ skb_reset_transport_header(skb);
memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
+ skb_reset_network_header(skb);
+ skb->hdr_len = hc06_ptr - head;
lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
skb->len);
@@ -1074,80 +1084,93 @@ static int lowpan_set_address(struct net_device *dev,
void *p)
static int
lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
- int mlen, int plen, int offset, int type)
+ int plen, int offset, int type)
{
struct sk_buff *frag;
- int hlen, ret;
+ int hlen;
hlen = (type == LOWPAN_DISPATCH_FRAG1) ?
LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE;
lowpan_raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
- frag = dev_alloc_skb(hlen + mlen + plen + IEEE802154_MFR_SIZE);
+ frag = netdev_alloc_skb(skb->dev, hlen + skb->mac_len
+ + plen + IEEE802154_MFR_SIZE);
if (!frag)
return -ENOMEM;
frag->priority = skb->priority;
- frag->dev = skb->dev;
/* copy header, MFR and payload */
- memcpy(skb_put(frag, mlen), skb->data, mlen);
- memcpy(skb_put(frag, hlen), head, hlen);
+ skb_put(frag, skb->mac_len);
+ skb_copy_to_linear_data(frag, skb_mac_header(skb), skb->mac_len);
- if (plen)
- skb_copy_from_linear_data_offset(skb, offset + mlen,
- skb_put(frag, plen), plen);
+ skb_put(frag, hlen);
+ skb_copy_to_linear_data_offset(frag, skb->mac_len, head, hlen);
- lowpan_raw_dump_table(__func__, " raw fragment dump", frag->data,
- frag->len);
+ skb_put(frag, plen);
+ skb_copy_to_linear_data_offset(frag, skb->mac_len + hlen,
+ skb_network_header(skb) + offset, plen);
- ret = dev_queue_xmit(frag);
+ lowpan_raw_dump_table(__func__, " raw fragment dump",
+ frag->data, frag->len);
- return ret;
+ return dev_queue_xmit(frag);
}
static int
lowpan_skb_fragmentation(struct sk_buff *skb, struct net_device *dev)
{
- int err, header_length, payload_length, tag, offset = 0;
+ int err, payload_length, tag, dgram_size,
+ dgram_offset, lowpan_size, frag_plen, offset = 0;
u8 head[5];
- header_length = skb->mac_len;
- payload_length = skb->len - header_length;
+ payload_length = skb->len - skb->mac_len;
tag = lowpan_dev_info(dev)->fragment_tag++;
+ lowpan_size = skb->transport_header - skb->network_header;
+ dgram_size = mac_cb(skb)->dgram_size;
/* first fragment header */
- head[0] = LOWPAN_DISPATCH_FRAG1 | ((payload_length >> 8) & 0x7);
- head[1] = payload_length & 0xff;
+ head[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x7);
+ head[1] = dgram_size & 0xff;
head[2] = tag >> 8;
head[3] = tag & 0xff;
- err = lowpan_fragment_xmit(skb, head, header_length, LOWPAN_FRAG_SIZE,
- 0, LOWPAN_DISPATCH_FRAG1);
+ /* calc the nearest payload length(divided to 8) for first fragment
+ * which fits into a IEEE802154_MTU
+ */
+ frag_plen = round_down(IEEE802154_MTU - skb->mac_len -
+ LOWPAN_FRAG1_HEAD_SIZE - lowpan_size -
+ IEEE802154_MFR_SIZE, 8);
+ err = lowpan_fragment_xmit(skb, head, frag_plen + lowpan_size,
+ 0, LOWPAN_DISPATCH_FRAG1);
if (err) {
pr_debug("%s unable to send FRAG1 packet (tag: %d)",
__func__, tag);
goto exit;
}
- offset = LOWPAN_FRAG_SIZE;
+ offset = lowpan_size + frag_plen;
+ dgram_offset = mac_cb(skb)->dgram_offset + frag_plen;
/* next fragment header */
head[0] &= ~LOWPAN_DISPATCH_FRAG1;
head[0] |= LOWPAN_DISPATCH_FRAGN;
- while ((payload_length - offset > 0) && (err >= 0)) {
- int len = LOWPAN_FRAG_SIZE;
+ frag_plen = round_down(IEEE802154_MTU - skb->mac_len -
+ LOWPAN_FRAGN_HEAD_SIZE - IEEE802154_MFR_SIZE, 8);
+
+ while (payload_length - offset > 0) {
+ int len = frag_plen;
- head[4] = offset / 8;
+ head[4] = dgram_offset / 8;
if (payload_length - offset < len)
len = payload_length - offset;
- err = lowpan_fragment_xmit(skb, head, header_length,
- len, offset, LOWPAN_DISPATCH_FRAGN);
+ err = lowpan_fragment_xmit(skb, head, len,
+ offset, LOWPAN_DISPATCH_FRAGN);
if (err) {
pr_debug("%s unable to send a subsequent FRAGN packet "
"(tag: %d, offset: %d", __func__, tag, offset);
@@ -1155,6 +1178,7 @@ lowpan_skb_fragmentation(struct sk_buff *skb, struct
net_device *dev)
}
offset += len;
+ dgram_offset += len;
}
exit:
--
1.8.4
------------------------------------------------------------------------------
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