Revert "VPP-1001 - update AF Packet Driver to for modern kernels"

Issues observed with specific kernel versions, e.g. stock Ubuntu 16.04
kernel.

This reverts commit 3eab064e3fadaf2a6a128f167ad04ca0319b4e17.

Change-Id: I24241f3b580df749fc686af3a319011ca035fb5e
Signed-off-by: Damjan Marion <damarion@cisco.com>

4 files changed, 10 insertions, 119 deletions

diff --git a/src/vnet/devices/af_packet/af_packet.c b/src/vnet/devices/af_packet/af_packet.c
index fbcd488ac9b..32696014727 100644
--- a/src/vnet/devices/af_packet/af_packet.c
+++ b/src/vnet/devices/af_packet/af_packet.c
@@ -23,7 +23,6 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <fcntl.h>
-#include <linux/virtio_net.h>
 
 #include <vppinfra/linux/sysfs.h>
 #include <vlib/vlib.h>
@@ -129,7 +128,6 @@ static int
 create_packet_v2_sock (int host_if_index, tpacket_req_t * rx_req,
 		       tpacket_req_t * tx_req, int *fd, u8 ** ring)
 {
-  af_packet_main_t *apm = &af_packet_main;
   int ret, err;
   struct sockaddr_ll sll;
   int ver = TPACKET_V2;
@@ -143,31 +141,7 @@ create_packet_v2_sock (int host_if_index, tpacket_req_t * rx_req,
       ret = VNET_API_ERROR_SYSCALL_ERROR_1;
       goto error;
     }
-  int opt = 1;
-  if (setsockopt (*fd, SOL_PACKET, PACKET_VNET_HDR, &opt, sizeof (opt)) != 0)
-    {
-      DBG_SOCK ("Failed to enable vnet headers on the socket");
-      if ((apm->flags & AF_PACKET_USES_VNET_HEADERS) != 0)
-	{
-	  /* Should never happen - vnet was already enabled once,
-	   * but we fail to reenable it on a new interface
-	   **/
-	  ret = VNET_API_ERROR_SYSCALL_ERROR_1;
-	  goto error;
-	}
-    }
-  else
-    {
-      apm->flags |= AF_PACKET_USES_VNET_HEADERS;
-    }
-#ifdef PACKET_QDISC_BYPASS
-  opt = 1;
-  if (setsockopt (*fd, SOL_PACKET, PACKET_QDISC_BYPASS, &opt, sizeof (opt)) !=
-      0)
-    {
-      DBG_SOCK ("Failed to bypass Linux QDISC");
-    }
-#endif
+
   if ((err =
        setsockopt (*fd, SOL_PACKET, PACKET_VERSION, &ver, sizeof (ver))) < 0)
     {
@@ -176,7 +150,7 @@ create_packet_v2_sock (int host_if_index, tpacket_req_t * rx_req,
       goto error;
     }
 
-  opt = 1;
+  int opt = 1;
   if ((err =
        setsockopt (*fd, SOL_PACKET, PACKET_LOSS, &opt, sizeof (opt))) < 0)
     {
diff --git a/src/vnet/devices/af_packet/af_packet.h b/src/vnet/devices/af_packet/af_packet.h
index f731427c6b5..95c7e7cf5a7 100644
--- a/src/vnet/devices/af_packet/af_packet.h
+++ b/src/vnet/devices/af_packet/af_packet.h
@@ -19,8 +19,6 @@
 
 #include <vppinfra/lock.h>
 
-#define AF_PACKET_USES_VNET_HEADERS 1
-
 typedef struct
 {
   CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
@@ -56,7 +54,6 @@ typedef struct
 
   /* hash of host interface names */
   mhash_t if_index_by_host_if_name;
-  u32 flags;
 } af_packet_main_t;
 
 af_packet_main_t af_packet_main;
diff --git a/src/vnet/devices/af_packet/device.c b/src/vnet/devices/af_packet/device.c
index a48ae5cf25d..e01b1c71b32 100644
--- a/src/vnet/devices/af_packet/device.c
+++ b/src/vnet/devices/af_packet/device.c
@@ -23,8 +23,6 @@
 #include <net/if.h>
 #include <net/if_arp.h>
 
-#include <linux/virtio_net.h>
-
 #include <vlib/vlib.h>
 #include <vlib/unix/unix.h>
 #include <vnet/ip/ip.h>
@@ -52,6 +50,7 @@ static char *af_packet_tx_func_error_strings[] = {
 #undef _
 };
 
+
 static u8 *
 format_af_packet_device_name (u8 * s, va_list * args)
 {
@@ -77,23 +76,6 @@ format_af_packet_tx_trace (u8 * s, va_list * args)
   return s;
 }
 
-
-static_always_inline void
-af_packet_buffer_tx_offload (vlib_buffer_t * b, struct virtio_net_hdr *vhdr)
-{
-  /* For now - just mark the data as valid,
-   * DPDK csums on input, tap presently operates in legacy
-   * compatibility mode where the kernel checksums CSUM_PARTIAL
-   * for it and we have fixed the af_packet input
-   *
-   * In the future, locally originated frames, etc can be made
-   * to fit this convention so that they are not checksummed
-   * unless needed.
-   **/
-  vhdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
-}
-
-
 static uword
 af_packet_interface_tx (vlib_main_t * vm,
 			vlib_node_runtime_t * node, vlib_frame_t * frame)
@@ -120,10 +102,6 @@ af_packet_interface_tx (vlib_main_t * vm,
     {
       u32 len;
       u32 offset = 0;
-      if (PREDICT_TRUE ((apm->flags & AF_PACKET_USES_VNET_HEADERS) != 0))
-	{
-	  offset = sizeof (struct virtio_net_hdr);
-	}
       vlib_buffer_t *b0;
       n_left--;
       u32 bi = buffers[0];
@@ -141,12 +119,6 @@ af_packet_interface_tx (vlib_main_t * vm,
       do
 	{
 	  b0 = vlib_get_buffer (vm, bi);
-	  if (PREDICT_TRUE ((apm->flags & AF_PACKET_USES_VNET_HEADERS) != 0))
-	    {
-	      u8 *vh =
-		(u8 *) tph + TPACKET_ALIGN (sizeof (struct tpacket2_hdr));
-	      af_packet_buffer_tx_offload (b0, (struct virtio_net_hdr *) vh);
-	    }
 	  len = b0->current_length;
 	  clib_memcpy ((u8 *) tph +
 		       TPACKET_ALIGN (sizeof (struct tpacket2_hdr)) + offset,
diff --git a/src/vnet/devices/af_packet/node.c b/src/vnet/devices/af_packet/node.c
index ec7c273b0e5..8539ff56b5c 100644
--- a/src/vnet/devices/af_packet/node.c
+++ b/src/vnet/devices/af_packet/node.c
@@ -1,4 +1,5 @@
-/*------------------------------------------------------------------
+/*
+ *------------------------------------------------------------------
  * af_packet.c - linux kernel packet interface
  *
  * Copyright (c) 2016 Cisco and/or its affiliates.
@@ -17,7 +18,6 @@
  */
 
 #include <linux/if_packet.h>
-#include <linux/virtio_net.h>
 
 #include <vlib/vlib.h>
 #include <vlib/unix/unix.h>
@@ -155,18 +155,9 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
       while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
 	     n_left_to_next)
 	{
-
-	  struct virtio_net_hdr *vh =
-	    (struct virtio_net_hdr *) (((u8 *) tph) + tph->tp_mac -
-				       sizeof (struct virtio_net_hdr));
 	  u32 data_len = tph->tp_snaplen;
 	  u32 offset = 0;
 	  u32 bi0 = 0, first_bi0 = 0, prev_bi0;
-	  u32 vlan_len = 0;
-	  ip_csum_t wsum = 0;
-	  u16 *wsum_addr = NULL;
-	  u32 do_vnet = apm->flags & AF_PACKET_USES_VNET_HEADERS;
-	  u32 do_csum = tph->tp_status & TP_STATUS_CSUMNOTREADY;
 
 	  while (data_len)
 	    {
@@ -182,6 +173,7 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 	      /* copy data */
 	      u32 bytes_to_copy =
 		data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
+	      u32 vlan_len = 0;
 	      u32 bytes_copied = 0;
 	      b0->current_data = 0;
 	      /* Kernel removes VLAN headers, so reconstruct VLAN */
@@ -203,50 +195,10 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 		      bytes_copied = sizeof (ethernet_header_t);
 		    }
 		}
-	      /* Check if the incoming skb is marked as CSUM_PARTIAL,
-	       * If VNET Headers are enabled TP_STATUS_CSUMNOTREADY is
-	       * equivalent to the vnet csum flag.
-	       **/
-	      if (PREDICT_TRUE ((do_vnet != 0) && (do_csum != 0)))
-		{
-		  wsum_addr = (u16 *) (((u8 *) vlib_buffer_get_current (b0)) +
-				       vlan_len + vh->csum_start +
-				       vh->csum_offset);
-		  if (bytes_copied <= vh->csum_start)
-		    {
-		      clib_memcpy (((u8 *) vlib_buffer_get_current (b0)) +
-				   bytes_copied + vlan_len,
-				   (u8 *) tph + tph->tp_mac + offset +
-				   bytes_copied,
-				   (vh->csum_start - bytes_copied));
-		      wsum =
-			ip_csum_and_memcpy (wsum,
-					    ((u8 *)
-					     vlib_buffer_get_current (b0)) +
-					    vh->csum_start + vlan_len,
-					    (u8 *) tph + tph->tp_mac +
-					    offset + vh->csum_start,
-					    (bytes_to_copy - vh->csum_start));
-		    }
-		  else
-		    {
-		      wsum =
-			ip_csum_and_memcpy (wsum,
-					    ((u8 *)
-					     vlib_buffer_get_current (b0)) +
-					    bytes_copied + vlan_len,
-					    (u8 *) tph + tph->tp_mac +
-					    offset + bytes_copied,
-					    (bytes_to_copy - bytes_copied));
-		    }
-		}
-	      else
-		{
-		  clib_memcpy (((u8 *) vlib_buffer_get_current (b0)) +
-			       bytes_copied + vlan_len,
-			       (u8 *) tph + tph->tp_mac + offset +
-			       bytes_copied, (bytes_to_copy - bytes_copied));
-		}
+	      clib_memcpy (((u8 *) vlib_buffer_get_current (b0)) +
+			   bytes_copied + vlan_len,
+			   (u8 *) tph + tph->tp_mac + offset + bytes_copied,
+			   (bytes_to_copy - bytes_copied));
 
 	      /* fill buffer header */
 	      b0->current_length = bytes_to_copy + vlan_len;
@@ -266,10 +218,6 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 	      offset += bytes_to_copy;
 	      data_len -= bytes_to_copy;
 	    }
-	  if (PREDICT_TRUE ((do_vnet != 0) && (do_csum != 0)))
-	    {
-	      *wsum_addr = ~ip_csum_fold (wsum);
-	    }
 	  n_rx_packets++;
 	  n_rx_bytes += tph->tp_snaplen;
 	  to_next[0] = first_bi0;