Disable for-us udp/tcp checksum validation by default

This patch alters behavior for dpdk rx packets. Depending on test
results, it may be necessary to extend the scheme to packets received
on non-dpdk paravirtualized interfaces, and packets originating in the
vpp stack itself.

Change-Id: I8444232a90ff176e7d6a688e36801174575251a1
Signed-off-by: Dave Barach <dave@barachs.net>

3 files changed, 28 insertions, 4 deletions

diff --git a/vnet/vnet/devices/dpdk/dpdk.h b/vnet/vnet/devices/dpdk/dpdk.h
index 8f852bc2..2dab4eff 100644
--- a/vnet/vnet/devices/dpdk/dpdk.h
+++ b/vnet/vnet/devices/dpdk/dpdk.h
@@ -301,6 +301,9 @@ typedef struct {
   /* per-thread recycle lists */
   u32 ** recycle;
 
+  /* buffer flags template, configurable to enable/disable tcp / udp cksum */
+  u32 buffer_flags_template;
+
   /* flow control callback. If 0 then flow control is disabled */
   dpdk_flowcontrol_callback_t flowcontrol_callback;
 
diff --git a/vnet/vnet/devices/dpdk/init.c b/vnet/vnet/devices/dpdk/init.c
index b91fe3c1..28a661f5 100644
--- a/vnet/vnet/devices/dpdk/init.c
+++ b/vnet/vnet/devices/dpdk/init.c
@@ -1008,6 +1008,12 @@ dpdk_config (vlib_main_t * vm, unformat_input_t * input)
           no_huge = 1;
         }
 
+      else if (unformat (input, "enable-tcp-udp-checksum"))
+        {
+          dm->buffer_flags_template &= 
+            ~(IP_BUFFER_L4_CHECKSUM_CORRECT | IP_BUFFER_L4_CHECKSUM_COMPUTED);
+        }
+
       else if (unformat (input, "decimal-interface-names"))
         dm->interface_name_format_decimal = 1;
 
@@ -1767,6 +1773,12 @@ _(rte_nicvf_pmd_init)
   dm->vhost_coalesce_frames = 32;
   dm->vhost_coalesce_time = 1e-3;
 
+  /* Default vlib_buffer_t flags, DISABLES tcp/udp checksumming... */
+  dm->buffer_flags_template = 
+    (VLIB_BUFFER_TOTAL_LENGTH_VALID 
+     | IP_BUFFER_L4_CHECKSUM_COMPUTED
+     | IP_BUFFER_L4_CHECKSUM_CORRECT);
+
   /* init CLI */
   if ((error = vlib_call_init_function (vm, dpdk_cli_init)))
     return error;
diff --git a/vnet/vnet/devices/dpdk/node.c b/vnet/vnet/devices/dpdk/node.c
index 770af2a0..b13d1368 100644
--- a/vnet/vnet/devices/dpdk/node.c
+++ b/vnet/vnet/devices/dpdk/node.c
@@ -542,7 +542,8 @@ static inline u32 dpdk_device_input ( dpdk_main_t * dm,
   vlib_buffer_free_list_t * fl;
   u8 efd_discard_burst = 0;
   u16 ip_align_offset = 0;
-
+  u32 buffer_flags_template;
+  
   if (xd->admin_up == 0)
     return 0;
 
@@ -563,6 +564,8 @@ static inline u32 dpdk_device_input ( dpdk_main_t * dm,
   if (xd->pmd == VNET_DPDK_PMD_THUNDERX)
       ip_align_offset = 6;
 
+  buffer_flags_template = dm->buffer_flags_template;
+
   vec_reset_length (xd->d_trace_buffers);
   trace_cnt = n_trace = vlib_get_trace_count (vm, node);
 
@@ -718,7 +721,7 @@ static inline u32 dpdk_device_input ( dpdk_main_t * dm,
                 b0->current_data += ip_align_offset;
             }
              
-          b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
+          b0->flags = buffer_flags_template;
 
           if (VMWARE_LENGTH_BUG_WORKAROUND)
               b0->current_length -= 4;
@@ -1142,6 +1145,7 @@ void dpdk_io_thread (vlib_worker_thread_t * w,
   u16 queue_id = 0;
   vlib_node_runtime_t * node_trace;
   u32 first_worker_index = 0;
+  u32 buffer_flags_template;
   
   /* Wait until the dpdk init sequence is complete */
   while (dm->io_thread_release == 0)
@@ -1186,6 +1190,8 @@ void dpdk_io_thread (vlib_worker_thread_t * w,
   /* packet tracing is triggered on the dpdk-input node for ease-of-use */
   node_trace = vlib_node_get_runtime (vm, dpdk_input_node.index);
 
+  buffer_flags_template = dm->buffer_flags_template;
+
   /* And handle them... */
   while (1)
     {
@@ -1382,7 +1388,7 @@ void dpdk_io_thread (vlib_worker_thread_t * w,
               b0->current_data = l3_offset0;
               b0->current_length = mb->data_len - l3_offset0;
 
-              b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
+              b0->flags = buffer_flags_template;
 
               if (VMWARE_LENGTH_BUG_WORKAROUND)
                   b0->current_length -= 4;
@@ -1585,6 +1591,7 @@ dpdk_io_input (vlib_main_t * vm,
   u16 queue_id = 0;
   vlib_node_runtime_t * node_trace;
   static u32 first_worker_index;
+  u32 buffer_flags_template;
 
   if (PREDICT_FALSE(num_workers_set == 0))
     {
@@ -1613,6 +1620,8 @@ dpdk_io_input (vlib_main_t * vm,
   /* packet tracing is triggered on the dpdk-input node for ease-of-use */
   node_trace = vlib_node_get_runtime (vm, dpdk_input_node.index);
 
+  buffer_flags_template = dm->buffer_flags_template;
+
   vec_foreach (xd, dm->devices)
     {
       u32 n_buffers;
@@ -1780,7 +1789,7 @@ dpdk_io_input (vlib_main_t * vm,
           b0->current_data = l3_offset0;
           b0->current_length = mb->data_len - l3_offset0;
 
-          b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
+          b0->flags = buffer_flags_template;
                 
           if (VMWARE_LENGTH_BUG_WORKAROUND)
               b0->current_length -= 4;