diff options
| author |   Neale Ranns <neale@graphiant.com> | 2022-03-08 13:24:28 +0000 |
|---|---|---|
| committer |   Ole Tr�an <otroan@employees.org> | 2022-03-09 19:15:05 +0000 |
| commit | 346c24723b8060c08542ea84921a997c7951ece7 (patch) | |
| tree | de37feef05fa92b328dade84a93e760b69ca0e30 | |
| parent | 23e5f0923b843f11d79e57b456a4073d4be3e6f9 (diff) | |
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
| -rw-r--r-- | src/vnet/ip/ip_frag.c | 17 | ||||
| -rw-r--r-- | test/test_map.py | 3 |
2 files changed, 9 insertions, 11 deletions
diff --git a/src/vnet/ip/ip_frag.c b/src/vnet/ip/ip_frag.c index 9c223c3d0ae..95600116365 100644 --- a/src/vnet/ip/ip_frag.c +++ b/src/vnet/ip/ip_frag.c @@ -95,7 +95,7 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u16 mtu, { 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_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u16 mtu, 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 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u16 mtu, 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 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u16 mtu, /* 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 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u16 mtu, } 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 = diff --git a/test/test_map.py b/test/test_map.py index 90fee301267..22fe1e1d20a 100644 --- a/test/test_map.py +++ b/test/test_map.py @@ -388,7 +388,8 @@ class TestMAP(VppTestCase): self.pg_send(self.pg0, v4*1) rx = self.pg1.get_capture(2) - frags = fragment_rfc791(v4[1], 1000) + # 1000-sizeof(ip6_header_t) = 960. + frags = fragment_rfc791(v4[1], 960) frags[0].id = 0 frags[1].id = 0 frags[0].ttl -= 1 |