ARP.cpp

Go to the documentation of this file.

 
#include <arpa/inet.h>
#include <rte_arp.h>
#include <rte_ethdev.h>
 
#include <iostream>
#include <sstream>
#include <iomanip>
 
#include "dpdklibs/arp/ARP.hpp"
 
namespace dunedaq {
namespace dpdklibs {
namespace arp {
 
void 
pktgen_send_garp(struct rte_mbuf *m, uint32_t port_id, rte_be32_t ip_add_bin)
{
  struct rte_ether_hdr *eth = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
  struct rte_arp_hdr *arp = (struct rte_arp_hdr *)&eth[1];
 
  /* src and dest addr */
    memset(&eth->dst_addr, 0xFF, 6);
  // MAC addr of port
    struct rte_ether_addr mac_addr;
  rte_eth_macaddr_get(port_id, &mac_addr);
    rte_ether_addr_copy(&mac_addr, &eth->src_addr);
  // Set ETH type
    eth->ether_type = htons(RTE_ETHER_TYPE_ARP);
 
  
  memset(arp, 0, sizeof(struct rte_arp_hdr));
  rte_memcpy(&arp->arp_data.arp_sha, &mac_addr, 6);
  
  uint32_t addr = htonl(ip_add_bin);
  inetAddrCopy(&arp->arp_data.arp_sip, &addr);
 
  //if (likely(type == GRATUITOUS_ARP) ) {
        rte_memcpy(&arp->arp_data.arp_tha, &mac_addr, 6);
        inetAddrCopy(&arp->arp_data.arp_tip, &addr);
  //} else {
  //  memset(&arp->arp_data.arp_tha, 0, 6);
  //  addr = htonl(pkt->ip_dst_addr.addr.ipv4.s_addr);
  //  inetAddrCopy(&arp->arp_data.arp_tip, &addr);
  //}
 
  /* Fill in the rest of the ARP packet header */
    arp->arp_hardware = htons(RTE_ARP_HRD_ETHER);
    arp->arp_protocol = htons(RTE_ETHER_TYPE_IPV4);
    arp->arp_hlen     = 6;
    arp->arp_plen     = 4;
    arp->arp_opcode   = htons(RTE_ARP_OP_REQUEST);
 
  m->pkt_len  = 60;
    m->data_len = 60;
 
  struct rte_mbuf *arp_tx_mbuf[1];
  arp_tx_mbuf[0] = m;
  rte_eth_tx_burst(port_id, 0, arp_tx_mbuf, 1);
  //printf("Sending ARP reply\n");
}
 
 
inline void
hex_digits_to_stream(std::ostringstream& ostrs, int value, char separator = ':', char fill = '0', int digits = 2) {
  ostrs << std::setfill(fill) << std::setw(digits) << std::hex << value << std::dec << separator;
}
 
 
void
pktgen_process_arp(struct rte_mbuf *m, uint32_t port_id, rte_be32_t ip_add_bin)
{
  struct rte_ether_hdr *eth = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
  struct rte_arp_hdr *arp = (struct rte_arp_hdr *)&eth[1];
 
  if (arp->arp_opcode == rte_cpu_to_be_16(RTE_ARP_OP_REQUEST)) {
    arp->arp_opcode = rte_cpu_to_be_16(RTE_ARP_OP_REPLY);
 
 
    /* Grab the source MAC addresses */
    struct rte_ether_addr mac_addr;
    rte_eth_macaddr_get(port_id, &mac_addr);
 
      std::string srcaddr = dunedaq::dpdklibs::udp::get_ipv4_decimal_addr_str(dunedaq::dpdklibs::udp::ip_address_binary_to_dotdecimal(rte_be_to_cpu_32(arp->arp_data.arp_sip)));
      TLOG_DEBUG(10) << "SRC IP: " << srcaddr;
      std::string dstaddr = dunedaq::dpdklibs::udp::get_ipv4_decimal_addr_str(dunedaq::dpdklibs::udp::ip_address_binary_to_dotdecimal(rte_be_to_cpu_32(arp->arp_data.arp_tip)));
      TLOG_DEBUG(10) << "DEST IP: " << dstaddr;
      std::string localaddr = dunedaq::dpdklibs::udp::get_ipv4_decimal_addr_str(dunedaq::dpdklibs::udp::ip_address_binary_to_dotdecimal(rte_be_to_cpu_32(ip_add_bin)));
      TLOG_DEBUG(10) << "LOCAL IP: " << localaddr;
      
      // Bail out if not our ipaddress
      if ( arp->arp_data.arp_tip != ip_add_bin) return;
 
      TLOG_DEBUG(10) << "ARP Received " << dstaddr << " I'm the target " << localaddr;
 
      /* Swap the two MAC addresses */
      ethAddrSwap(&arp->arp_data.arp_sha, &arp->arp_data.arp_tha);
 
      /* Swap the two IP addresses */
      inetAddrSwap(&arp->arp_data.arp_tip, &arp->arp_data.arp_sip);
 
      /* Set the packet to ARP reply */
      arp->arp_opcode = htons(RTE_ARP_OP_REPLY);
 
      /* Swap the MAC addresses */
      ethAddrSwap(&eth->dst_addr, &eth->src_addr);
 
      /* Copy in the MAC address for the reply. */
      rte_memcpy(&arp->arp_data.arp_sha, &mac_addr, 6);
      rte_memcpy(&eth->src_addr, &mac_addr, 6);
 
      struct rte_mbuf *arp_tx_mbuf[1];
      arp_tx_mbuf[0] = m;
 
      rte_eth_tx_burst(port_id, 0, arp_tx_mbuf, 1);
      TLOG_DEBUG(10)  << "Sending ARP reply";
 
      /* No need to free mbuf as it was reused */
      return;
  }
}
 
} // namespace arp
} // namespace dpdklibs
} // namespace dunedaq