vpp收包发包插件示例

以下是使用VPP进行收包发包的插件示例：

1. 接收插件示例：

#include <vlib/vlib.h>

static uword
my_input_node (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  u32 n_left_from, * from, * to_next;
  my_input_next_t next_index;
  my_input_trace_t * t;
  vnet_main_t * vnm = vnet_get_main();

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;
      vlib_get_next_frame (vm, node, next_index,
                           to_next, n_left_to_next);
      while (n_left_from > 0 && n_left_to_next > 0)
        {
          u32 bi0;
          vlib_buffer_t * b0;
          u32 next0;

          bi0 = from[0];
          from += 1;
          n_left_from -= 1;
          to_next[0] = bi0;
          to_next += 1;
          n_left_to_next -= 1;

          b0 = vlib_get_buffer (vm, bi0);
          t = vlib_add_trace (vm, node, b0, sizeof (*t));
          t->sw_if_index = vnet_buffer(b0)->sw_if_index[VLIB_RX];
          next0 = MY_INPUT_NEXT_NORMAL;

          vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
                                           to_next, n_left_to_next,
                                           bi0, next0);
        }
      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  return frame->n_vectors;
}

2. 发送插件示例：

#include <vnet/vnet.h>
#include <vnet/ip/ip.h>

static u32
my_output_node_fn (vlib_main_t * vm,
                   vlib_node_runtime_t * node,
                   vlib_frame_t * frame)
{
  u32 n_left_from, * from;
  u32 n_left_to_next, * to_next;
  my_output_next_t next_index;
  u32 pkts_sent = 0;
  vlib_frame_t *f;
  u32 thread_index = vm->thread_index;

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;

  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;
      vlib_get_next_frame (vm, node, next_index,
                           to_next, n_left_to_next);

      while (n_left_from > 0 && n_left_to_next > 0)
        {
          u32 bi0;
          vlib_buffer_t * b0;
          u32 next0 = 0;
          u32 error0 = 0;
          u32 sw_if_index0;

          bi0 = from[0];
          from += 1;
          n_left_from -= 1;
          to_next[0] = bi0;
          to_next += 1;
          n_left_to_next -= 1;

          b0 = vlib_get_buffer (vm, bi0);
          sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];

          vlib_buffer_advance (b0, -sizeof (ethernet_header_t));
          ethernet_header_t *eth = vlib_buffer_get_current (b0);

          eth->type = clib_host_to_net_u16 (ETHERNET_TYPE_IP4);

          if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
            {
              my_output_trace_t *tr = vlib_add_trace (vm, node,
                                                      b0, sizeof (*tr));
              tr->sw_if_index = sw_if_index0;
              tr->next_index = next0;
            }

          vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
                                           to_next, n_left_to_next,
                                           bi0, next0);

          pkts_sent++;
        }

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  vlib_node_increment_counter (vm, my_output_node.index,
                                MY_OUTPUT_ERROR_TX,
                                pkts_sent);

  return frame->n_vectors;
}

这里仅是简单的示例，实际使用中需要根据具体需求进行修改和完善。