memif.hpp

Go to the documentation of this file.

#ifndef NDNPH_PORT_TRANSPORT_MEMIF_HPP
#define NDNPH_PORT_TRANSPORT_MEMIF_HPP
 
#include "../../face/transport-rxqueue.hpp"
extern "C" {
#include <libmemif.h>
}
 
#ifndef NDNPH_MEMIF_RXBURST
#define NDNPH_MEMIF_RXBURST 64
#endif
 
namespace ndnph {
namespace port_transport_memif {
 
#ifdef NDNPH_MEMIF_DEBUG
#define NDNPH_MEMIF_PRINT_ERR(func)                                                                \
  do {                                                                                             \
    fprintf(stderr, "MemifTransport " #func " %d %s\n", err, memif_strerror(err));                 \
  } while (false)
#else
#define NDNPH_MEMIF_PRINT_ERR(func)                                                                \
  do {                                                                                             \
    (void)err;                                                                                     \
  } while (false)
#endif
 
class MemifTransport : public virtual Transport {
public:
  enum class Role {
    CLIENT = 0,
    SERVER = 1,
  };
 
  using DefaultDataroom = std::integral_constant<uint16_t, 2048>;
 
  struct Options {
    Role role;
    const char* socketName;
    uint32_t id;
    uint16_t dataroom;
    uint16_t ringCapacity;
  };
 
  bool begin(const char* socketName, uint32_t id, uint16_t dataroom = 0) {
    Options opts{};
    opts.socketName = socketName;
    opts.id = id;
    opts.dataroom = dataroom;
    return begin(opts);
  }
 
  bool begin(Options opts) {
    end();
    if (opts.socketName == nullptr || opts.dataroom > 0x8000) {
      return false;
    }
    if (opts.dataroom == 0) {
      opts.dataroom = 2048;
    }
    if (opts.ringCapacity == 0) {
      opts.ringCapacity = 1024;
    }
 
    memif_socket_args_t sa{};
    strncpy(sa.path, opts.socketName, sizeof(sa.path));
    strncpy(sa.app_name, "NDNph", sizeof(sa.app_name));
    int err = memif_create_socket(&m_sock, &sa, this);
    if (err != MEMIF_ERR_SUCCESS) {
      NDNPH_MEMIF_PRINT_ERR(memif_create_socket);
      return false;
    }
 
    memif_conn_args_t ca{};
    ca.is_master = static_cast<uint8_t>(opts.role == Role::SERVER);
    ca.socket = m_sock;
    ca.interface_id = opts.id;
    for (ca.buffer_size = 64; ca.buffer_size < opts.dataroom;) {
      ca.buffer_size <<= 1;
      // libmemif internally assumes buffer_size to be power of two
      // https://github.com/FDio/vpp/blob/v22.02/extras/libmemif/src/main.c#L1538
    }
    m_dataroom = ca.buffer_size;
    for (ca.log2_ring_size = 4;
         ca.log2_ring_size < 14 && (1 << ca.log2_ring_size) < opts.ringCapacity;) {
      ++ca.log2_ring_size;
    }
    err = memif_create(&m_conn, &ca, MemifTransport::handleConnect,
                       MemifTransport::handleDisconnect, MemifTransport::handleInterrupt, this);
    if (err != MEMIF_ERR_SUCCESS) {
      NDNPH_MEMIF_PRINT_ERR(memif_create);
      return false;
    }
 
    return true;
  }
 
  bool end() {
    if (m_conn != nullptr) {
      int err = memif_delete(&m_conn);
      if (err != MEMIF_ERR_SUCCESS) {
        NDNPH_MEMIF_PRINT_ERR(memif_delete);
        return false;
      }
    }
 
    if (m_sock != nullptr) {
      int err = memif_delete_socket(&m_sock);
      if (err != MEMIF_ERR_SUCCESS) {
        NDNPH_MEMIF_PRINT_ERR(memif_delete_socket);
        return false;
      }
    }
 
    m_dataroom = 0;
    return true;
  }
 
  uint16_t getDataroom() const {
    return m_dataroom;
  }
 
private:
  bool doIsUp() const final {
    return m_isUp;
  }
 
  void doLoop() final {
    if (m_sock == nullptr) {
      return;
    }
 
    int err = memif_poll_event(m_sock, 0);
    if (err != MEMIF_ERR_SUCCESS) {
      NDNPH_MEMIF_PRINT_ERR(memif_poll_event);
    }
  }
 
  bool doSend(const uint8_t* pkt, size_t pktLen, uint64_t) final {
    if (!m_isUp) {
#ifdef NDNPH_MEMIF_DEBUG
      fprintf(stderr, "MemifTransport send drop=transport-disconnected\n");
#endif
      return false;
    }
 
    if (pktLen > m_dataroom) {
#ifdef NDNPH_MEMIF_DEBUG
      fprintf(stderr, "MemifTransport send drop=pkt-too-long len=%zu\n", pktLen);
#endif
      return false;
    }
 
    memif_buffer_t b{};
    uint16_t nAlloc = 0;
    int err = memif_buffer_alloc(m_conn, 0, &b, 1, &nAlloc, pktLen);
    if (err != MEMIF_ERR_SUCCESS || nAlloc != 1) {
      NDNPH_MEMIF_PRINT_ERR(memif_buffer_alloc);
      return false;
    }
 
    NDNPH_ASSERT(b.len >= pktLen);
    NDNPH_ASSERT((b.flags & MEMIF_BUFFER_FLAG_NEXT) == 0);
    std::copy_n(pkt, pktLen, static_cast<uint8_t*>(b.data));
    b.len = pktLen;
 
    uint16_t nTx = 0;
    err = memif_tx_burst(m_conn, 0, &b, 1, &nTx);
    if (err != MEMIF_ERR_SUCCESS || nTx != 1) {
      NDNPH_MEMIF_PRINT_ERR(memif_tx_burst);
      return false;
    }
    return true;
  }
 
  static int handleConnect(memif_conn_handle_t conn, void* self0) {
    MemifTransport* self = reinterpret_cast<MemifTransport*>(self0);
    NDNPH_ASSERT(self->m_conn == conn);
    self->m_isUp = true;
#ifdef NDNPH_MEMIF_DEBUG
    fprintf(stderr, "MemifTransport connected\n");
#endif
 
    int err = memif_refill_queue(conn, 0, -1, 0);
    if (err != MEMIF_ERR_SUCCESS) {
      NDNPH_MEMIF_PRINT_ERR(memif_refill_queue);
    }
    return 0;
  }
 
  static int handleDisconnect(memif_conn_handle_t conn, void* self0) {
    MemifTransport* self = reinterpret_cast<MemifTransport*>(self0);
    NDNPH_ASSERT(self->m_conn == conn);
    self->m_isUp = false;
#ifdef NDNPH_MEMIF_DEBUG
    fprintf(stderr, "MemifTransport disconnected\n");
#endif
    return 0;
  }
 
  static int handleInterrupt(memif_conn_handle_t conn, void* self0, uint16_t qid) {
    MemifTransport* self = reinterpret_cast<MemifTransport*>(self0);
    NDNPH_ASSERT(self->m_conn == conn);
 
    std::array<memif_buffer_t, NDNPH_MEMIF_RXBURST> burst{};
    uint16_t nRx = 0;
    int err = memif_rx_burst(conn, qid, burst.data(), burst.size(), &nRx);
    if (err != MEMIF_ERR_SUCCESS) {
      NDNPH_MEMIF_PRINT_ERR(memif_rx_burst);
      return 0;
    }
 
    for (uint16_t i = 0; i < nRx; ++i) {
      const memif_buffer_t& b = burst[i];
      self->invokeRxCallback(static_cast<const uint8_t*>(b.data), b.len);
    }
 
    err = memif_refill_queue(conn, qid, nRx, 0);
    if (err != MEMIF_ERR_SUCCESS) {
      NDNPH_MEMIF_PRINT_ERR(memif_rx_burst);
    }
    return 0;
  }
 
private:
  memif_socket_handle_t m_sock = nullptr;
  memif_conn_handle_t m_conn = nullptr;
  uint16_t m_dataroom = 0;
  bool m_isUp = false;
};
 
#undef NDNPH_MEMIF_PRINT_ERR
 
} // namespace port_transport_memif
 
using MemifTransport = port_transport_memif::MemifTransport;
 
} // namespace ndnph
 
#endif // NDNPH_PORT_TRANSPORT_MEMIF_HPP