FEX-Emu/linux
1
0
Fork 0
mirror of https://github.com/FEX-Emu/linux.git synced 2024-12-17 06:17:35 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

6lowpan: fix first fragment (FRAG1) handling

Browse Source 
The first fragment, FRAG1, must contain some payload according to the
specs. However, as it is currently written, the first fragment will
remain empty and only contain the 6lowpan headers.

This patch also extracts the transport layer information from the first
fragment. This information is used later on when uncompressing UDP
header.

Thanks to Wolf-Bastian Pöttner for noticing that the offset value was
not properly initialized.

Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tony Cheneau 2013-03-25 17:59:26 +00:00 committed by David S. Miller
parent 58ef67c318
commit d991b98f50
1 changed files with 23 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
net/ieee802154/6lowpan.c
View File

@ -661,7 +661,7 @@ static void lowpan_fragment_timer_expired(unsigned long entry_addr)
}
static struct lowpan_fragment *
lowpan_alloc_new_frame(struct sk_buff *skb, u8 len, u16 tag)
lowpan_alloc_new_frame(struct sk_buff *skb, u16 len, u16 tag)
{
struct lowpan_fragment *frame;
@ -731,7 +731,7 @@ lowpan_process_data(struct sk_buff *skb)
{
struct lowpan_fragment *frame;
/* slen stores the rightmost 8 bits of the 11 bits length */
u8 slen, offset;
u8 slen, offset = 0;
u16 len, tag;
bool found = false;
@ -742,6 +742,12 @@ 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 (lowpan_fetch_skb_u8(skb, &offset))
goto unlock_and_drop;
}
/*
* check if frame assembling with the same tag is
* already in progress
@ -761,12 +767,6 @@ lowpan_process_data(struct sk_buff *skb)
goto unlock_and_drop;
}
if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1)
goto unlock_and_drop;
if (lowpan_fetch_skb_u8(skb, &offset)) /* fetch offset */
goto unlock_and_drop;
/* if payload fits buffer, copy it */
if (likely((offset * 8 + skb->len) <= frame->length))
skb_copy_to_linear_data_offset(frame->skb, offset * 8,
@ -982,13 +982,13 @@ static int lowpan_get_mac_header_length(struct sk_buff *skb)
static int
lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
int mlen, int plen, int offset)
int mlen, int plen, int offset, int type)
{
struct sk_buff *frag;
int hlen, ret;
/* if payload length is zero, therefore it's a first fragment */
hlen = (plen == 0 ? LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE);
hlen = (type == LOWPAN_DISPATCH_FRAG1) ?
LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE;
lowpan_raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
@ -1031,7 +1031,13 @@ lowpan_skb_fragmentation(struct sk_buff *skb)
head[2] = tag >> 8;
head[3] = tag & 0xff;
err = lowpan_fragment_xmit(skb, head, header_length, 0, 0);
err = lowpan_fragment_xmit(skb, head, header_length, LOWPAN_FRAG_SIZE,
0, LOWPAN_DISPATCH_FRAG1);
if (err)
goto exit;
offset = LOWPAN_FRAG_SIZE;
/* next fragment header */
head[0] &= ~LOWPAN_DISPATCH_FRAG1;
@ -1046,10 +1052,14 @@ lowpan_skb_fragmentation(struct sk_buff *skb)
len = payload_length - offset;
err = lowpan_fragment_xmit(skb, head, header_length,
len, offset);
len, offset, LOWPAN_DISPATCH_FRAGN);
if (err)
goto exit;
offset += len;
}
exit:
return err;
}