ip: IPv4 Fragmentation fix for l2fragmetable size
Type: fix
The l2unfragmentable size is not included in the calculation of 'max', the maximum amount of data that can be added to a fragment, therefore the fragments created are too big.
Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: Id1e949ad98203b6f8ea2f55322ef6fa3d507e2a6
diff --git a/src/vnet/ip/ip_frag.c b/src/vnet/ip/ip_frag.c
index 9c223c3..9560011 100644
--- a/src/vnet/ip/ip_frag.c
+++ b/src/vnet/ip/ip_frag.c
@@ -95,7 +95,7 @@
{
vlib_buffer_t *from_b;
ip4_header_t *ip4;
- u16 len, max, rem, ip_frag_id, ip_frag_offset;
+ u16 len, max, rem, ip_frag_id, ip_frag_offset, head_bytes;
u8 *org_from_packet, more;
from_b = vlib_get_buffer (vm, from_bi);
@@ -103,9 +103,9 @@
ip4 = vlib_buffer_get_current (from_b) + l2unfragmentablesize;
rem = clib_net_to_host_u16 (ip4->length) - sizeof (ip4_header_t);
- max =
- (clib_min (mtu, vlib_buffer_get_default_data_size (vm)) -
- sizeof (ip4_header_t)) & ~0x7;
+ head_bytes = sizeof (ip4_header_t) + l2unfragmentablesize;
+ max = (clib_min (mtu, vlib_buffer_get_default_data_size (vm)) - head_bytes) &
+ ~0x7;
if (rem >
(vlib_buffer_length_in_chain (vm, from_b) - sizeof (ip4_header_t)))
@@ -142,8 +142,7 @@
u8 *from_data = (void *) (ip4 + 1);
vlib_buffer_t *org_from_b = from_b;
u16 fo = 0;
- u16 left_in_from_buffer =
- from_b->current_length - (l2unfragmentablesize + sizeof (ip4_header_t));
+ u16 left_in_from_buffer = from_b->current_length - head_bytes;
u16 ptr = 0;
/* Do the actual fragmentation */
@@ -166,8 +165,7 @@
/* Copy ip4 header */
to_data = vlib_buffer_get_current (to_b);
- clib_memcpy_fast (to_data, org_from_packet,
- l2unfragmentablesize + sizeof (ip4_header_t));
+ clib_memcpy_fast (to_data, org_from_packet, head_bytes);
to_ip4 = (ip4_header_t *) (to_data + l2unfragmentablesize);
to_data = (void *) (to_ip4 + 1);
vnet_buffer (to_b)->l3_hdr_offset = to_b->current_data;
@@ -213,8 +211,7 @@
}
to_b->flags |= VNET_BUFFER_F_IS_IP4;
- to_b->current_length =
- len + sizeof (ip4_header_t) + l2unfragmentablesize;
+ to_b->current_length = len + head_bytes;
to_ip4->fragment_id = ip_frag_id;
to_ip4->flags_and_fragment_offset =