#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <sys/inotify.h>
#include <sys/time.h>
#include <errno.h>
#include "ipc_msg.h"


#define errExit(msg)    do { perror(msg); exit(EXIT_FAILURE); \
} while (0)


int memfd_open(char* fd_path)
{
  ssize_t  len;
  int fd;
  struct stat st;
  fd = open(fd_path, O_RDWR);
  if (fd == -1)
    errExit("open");

  if (fstat (fd, &st))
    errExit ("fstat");
  len = st.st_size;

  printf("length: %zu, atime: %lu.%lu\n", len, st.st_atim.tv_sec, st.st_atim.tv_nsec);

  return fd;
}

int memfd_read(int fd)
{
  unsigned char* addr;
  struct stat st;

  ssize_t  i, len;
  if (fstat (fd, &st))
    errExit ("fstat");
  len = st.st_size;

  addr = (unsigned char*) mmap (NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
  if (addr == MAP_FAILED)
    errExit("mmap");

  printf ("start: ");
  for (i = 0; i < 32; ++i)
    printf ("%i ", addr[i]);
  printf ("\nend: ");
  for (i = 0; i < 32; ++i)
    printf ("%i ", addr[len-32+i]);
  printf ("\ndone\n");
  return len;
}

int main(int argc, char **argv)
{
  int fd;
  int connect_fd;
  struct sockaddr_un srv_addr;
  char snd_buf[MAX_LEN] = {0};
  char rcv_buf[MAX_LEN] = {0};
  int ret;
  int i;
  char *fd_path;
  memfd_data_st  memfd_data = {0};
  int rcv_num = 0;

  connect_fd = socket(AF_UNIX, SOCK_STREAM, 0);

  if(connect_fd < 0)
  {
    perror("client create socket failed");
    return 1;
  }
  srv_addr.sun_family = AF_UNIX;
  strcpy(srv_addr.sun_path, UNIX_DOMAIN);
  ret = connect(connect_fd, (struct sockaddr*)&srv_addr, sizeof(srv_addr));

  if(ret == -1)
  {
    perror("connect to server failed!");
    close(connect_fd);
    unlink(UNIX_DOMAIN);
    return 1;
  }

  printf("connect to server path:%s success!", srv_addr.sun_path);

  //memset(rcv_buf, 0, sizeof(rcv_buf));
  //int rcv_num = read(connect_fd, rcv_buf, sizeof(rcv_buf));
  //memcpy(&memfd_data, rcv_buf, sizeof(memfd_data_st));

  memset(snd_buf, 0, 256);
  strcpy(snd_buf, HELLO_MSG);
  printf("sizeof(snd_buf): %ld\n", sizeof(snd_buf));

  printf("send data to server... ...\n");
 // for(i = 0; i < 4; i++)
  {
    write(connect_fd, snd_buf, sizeof(snd_buf));
  }
  printf("send end!\n");


  memset(rcv_buf, 0, sizeof(rcv_buf));
  rcv_num = read(connect_fd, rcv_buf, sizeof(rcv_buf));
  if(rcv_num == 0)
  {
    close(connect_fd);    
    return 0;
  }
  memcpy(&memfd_data, rcv_buf, rcv_num);

  printf("receive message from server,pid:%d, memfd:%d\n", memfd_data.pid, memfd_data.memfd);
  if ((memfd_data.pid != 0) && (memfd_data.memfd != 0))
  {
    char fd_path[256] = {0};
    snprintf(fd_path, sizeof(fd_path), "/proc/%d/fd/%d", memfd_data.pid, memfd_data.memfd);
    fd = memfd_open(fd_path);
    ret = memfd_read(fd);
  }

  close(connect_fd);
  return 0;

}