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authorOle Troan <ot@cisco.com>2018-03-27 14:48:39 +0200
committerNeale Ranns <nranns@cisco.com>2018-04-13 13:27:44 +0000
commit70083ee74c3141bbefb185525315f1b34497dcaa (patch)
tree2b93f23b853239152864ad5ee0db073d37c341ea /src/vnet/ip/ip4_forward.c
parent25b049484fcf9161edb2c19250066b893c38c264 (diff)
MTU: Setting of MTU on software interface (instead of hardware interface)
Change-Id: I98bd454a761a1032738a21edeb0fe847e801f901 Signed-off-by: Ole Troan <ot@cisco.com>
Diffstat (limited to 'src/vnet/ip/ip4_forward.c')
-rw-r--r--src/vnet/ip/ip4_forward.c98
1 files changed, 57 insertions, 41 deletions
diff --git a/src/vnet/ip/ip4_forward.c b/src/vnet/ip/ip4_forward.c
index 7c56a294436..3dce590c807 100644
--- a/src/vnet/ip/ip4_forward.c
+++ b/src/vnet/ip/ip4_forward.c
@@ -1940,6 +1940,29 @@ typedef enum
IP4_REWRITE_NEXT_ICMP_ERROR,
} ip4_rewrite_next_t;
+always_inline void
+ip4_mtu_check (vlib_buffer_t * b, u16 buffer_packet_bytes,
+ u16 adj_packet_bytes, bool df, u32 * next, u32 * error)
+{
+ if (buffer_packet_bytes > adj_packet_bytes)
+ {
+ *error = IP4_ERROR_MTU_EXCEEDED;
+ if (df)
+ {
+ icmp4_error_set_vnet_buffer
+ (b, ICMP4_destination_unreachable,
+ ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
+ adj_packet_bytes);
+ *next = IP4_REWRITE_NEXT_ICMP_ERROR;
+ }
+ else
+ {
+ /* Add support for fragmentation here */
+ *next = IP4_REWRITE_NEXT_DROP;
+ }
+ }
+}
+
always_inline uword
ip4_rewrite_inline (vlib_main_t * vm,
vlib_node_runtime_t * node,
@@ -2100,26 +2123,20 @@ ip4_rewrite_inline (vlib_main_t * vm,
vnet_buffer (p1)->ip.save_rewrite_length = rw_len1;
/* Check MTU of outgoing interface. */
- if (vlib_buffer_length_in_chain (vm, p0) >
- adj0[0].rewrite_header.max_l3_packet_bytes)
- {
- error0 = IP4_ERROR_MTU_EXCEEDED;
- next0 = IP4_REWRITE_NEXT_ICMP_ERROR;
- icmp4_error_set_vnet_buffer
- (p0, ICMP4_destination_unreachable,
- ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
- 0);
- }
- if (vlib_buffer_length_in_chain (vm, p1) >
- adj1[0].rewrite_header.max_l3_packet_bytes)
- {
- error1 = IP4_ERROR_MTU_EXCEEDED;
- next1 = IP4_REWRITE_NEXT_ICMP_ERROR;
- icmp4_error_set_vnet_buffer
- (p1, ICMP4_destination_unreachable,
- ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
- 0);
- }
+ ip4_mtu_check (p0, vlib_buffer_length_in_chain (vm, p0),
+ adj0[0].rewrite_header.max_l3_packet_bytes,
+ ip0->flags_and_fragment_offset &
+ clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT),
+ &next0, &error0);
+ ip4_mtu_check (p1, vlib_buffer_length_in_chain (vm, p1),
+ adj1[0].rewrite_header.max_l3_packet_bytes,
+ ip1->flags_and_fragment_offset &
+ clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT),
+ &next1, &error1);
+
+ /* Guess we are only writing on simple Ethernet header. */
+ vnet_rewrite_two_headers (adj0[0], adj1[0],
+ ip0, ip1, sizeof (ethernet_header_t));
if (is_mcast)
{
@@ -2143,10 +2160,17 @@ ip4_rewrite_inline (vlib_main_t * vm,
tx_sw_if_index0 = adj0[0].rewrite_header.sw_if_index;
vnet_buffer (p0)->sw_if_index[VLIB_TX] = tx_sw_if_index0;
+ if (is_midchain)
+ {
+ adj0->sub_type.midchain.fixup_func
+ (vm, adj0, p0, adj0->sub_type.midchain.fixup_data);
+ }
+
if (PREDICT_FALSE
(adj0[0].rewrite_header.flags & VNET_REWRITE_HAS_FEATURES))
vnet_feature_arc_start (lm->output_feature_arc_index,
tx_sw_if_index0, &next0, p0);
+
}
if (PREDICT_TRUE (error1 == IP4_ERROR_NONE))
{
@@ -2157,16 +2181,18 @@ ip4_rewrite_inline (vlib_main_t * vm,
tx_sw_if_index1 = adj1[0].rewrite_header.sw_if_index;
vnet_buffer (p1)->sw_if_index[VLIB_TX] = tx_sw_if_index1;
+ if (is_midchain)
+ {
+ adj1->sub_type.midchain.fixup_func
+ (vm, adj1, p1, adj0->sub_type.midchain.fixup_data);
+ }
+
if (PREDICT_FALSE
(adj1[0].rewrite_header.flags & VNET_REWRITE_HAS_FEATURES))
vnet_feature_arc_start (lm->output_feature_arc_index,
tx_sw_if_index1, &next1, p1);
}
- /* Guess we are only writing on simple Ethernet header. */
- vnet_rewrite_two_headers (adj0[0], adj1[0],
- ip0, ip1, sizeof (ethernet_header_t));
-
/*
* Bump the per-adjacency counters
*/
@@ -2185,13 +2211,6 @@ ip4_rewrite_inline (vlib_main_t * vm,
vlib_buffer_length_in_chain (vm, p1) + rw_len1);
}
- if (is_midchain)
- {
- adj0->sub_type.midchain.fixup_func
- (vm, adj0, p0, adj0->sub_type.midchain.fixup_data);
- adj1->sub_type.midchain.fixup_func
- (vm, adj1, p1, adj0->sub_type.midchain.fixup_data);
- }
if (is_mcast)
{
/*
@@ -2272,6 +2291,7 @@ ip4_rewrite_inline (vlib_main_t * vm,
/* Guess we are only writing on simple Ethernet header. */
vnet_rewrite_one_header (adj0[0], ip0, sizeof (ethernet_header_t));
+
if (is_mcast)
{
/*
@@ -2291,16 +2311,12 @@ ip4_rewrite_inline (vlib_main_t * vm,
vlib_buffer_length_in_chain (vm, p0) + rw_len0);
/* Check MTU of outgoing interface. */
- if (vlib_buffer_length_in_chain (vm, p0) >
- adj0[0].rewrite_header.max_l3_packet_bytes)
- {
- error0 = IP4_ERROR_MTU_EXCEEDED;
- next0 = IP4_REWRITE_NEXT_ICMP_ERROR;
- icmp4_error_set_vnet_buffer
- (p0, ICMP4_destination_unreachable,
- ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
- 0);
- }
+ ip4_mtu_check (p0, vlib_buffer_length_in_chain (vm, p0),
+ adj0[0].rewrite_header.max_l3_packet_bytes,
+ ip0->flags_and_fragment_offset &
+ clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT),
+ &next0, &error0);
+
if (is_mcast)
{
error0 = ((adj0[0].rewrite_header.sw_if_index ==