/*
gcc -g -Wall -o ./test_get+setsockopt ./test_get+setsockopt.c
 */

#define _GNU_SOURCE
#include <sys/socket.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>

#define TEST_GETSOCKOPT1 1 
#define TEST_SETSOCKOPT1 1
#define TEST_GETSOCKOPT2 1

#define TEST_GETSOCKOPT3 1  
#define TEST_SETSOCKOPT2 1
#define TEST_GETSOCKOPT4 1  

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

static int32_t
set_sock_size_rcvbuf(int sockfd, int *max_msg_size)
{
  unsigned int optval = 0;
  socklen_t optlen = sizeof(optval);
  error_t err = 0;
  
#if TEST_GETSOCKOPT1
  err = getsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, &optval, &optlen);
  if (err)
    {
      printf ("set_sock_size_rcvbuf():getsockopt(SO_RCVBUF) failed: errno=%d (%s)\n", errno, strerror(errno));
      printf ("set_sock_size_rcvbuf():getsockopt(SO_RCVBUF) failed: optval=%d, optlen=%d\n", optval, optlen);
      return err;
    }
  printf ("set_sock_size_rcvbuf():getsockopt(SO_RCVBUF): optval=%d, optlen=%d\n", optval, optlen);
#endif

#if TEST_SETSOCKOPT1
  printf ("set_sock_size_rcvbuf(): Requested: *max_msg_size = %d\n", *max_msg_size);
  optval = *max_msg_size;
  optlen = sizeof(*max_msg_size);
  err = setsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, &optval, optlen);
  if (err)
    {
      printf ("set_sock_size_rcvbuf():setsockopt(SO_RCVBUF) failed: errno=%d (%s)\n", errno, strerror(errno));
      printf ("set_sock_size_rcvbuf():setsockopt(SO_RCVBUF) failed: optval=%d, *max_msg_size=%d\n", *max_msg_size, optlen);
      return err;
    }
#ifdef __GNU__
  printf ("set_sock_size_rcvbuf():setsockopt(SO_RCVBUF): GNU/Hurd: S_sock_setopt RPC is wrong: No return value\n");
#else
  printf ("set_sock_size_rcvbuf():setsockopt(SO_RCVBUF): optval=%d, optlen=%d\n", optval, optlen);
  printf ("set_sock_size_rcvbuf(): Returned: optval = %d\n", optval);
#endif
#endif

#if TEST_GETSOCKOPT2
  printf( "set_sock_size_rcvbuf: Checking set values\n");
  err = getsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, &optval, &optlen);
  if (err)
    {
      printf ("set_sock_size_rcvbuf():getsockopt(SO_RCVBUF) failed: errno=%d (%s)\n", errno, strerror(errno));
      printf ("set_sock_size_rcvbuf():getsockopt(SO_RCVBUF) failed: optval=%d, optlen=%d\n", optval, optlen);
      return err;
    }
  printf ("set_sock_size_rcvbuf():getsockopt(SO_RCVBUF): optval=%d, optlen=%d\n", optval, optlen);
  *max_msg_size = optval;
#endif

  return err;
}

static int32_t
set_sock_size_sndbuf(int sockfd, int *max_msg_size)
{
  int32_t err;
  unsigned int optval = 0;
  socklen_t optlen = sizeof(optval);

#if TEST_GETSOCKOPT3
  err = getsockopt(sockfd, SOL_SOCKET, SO_SNDBUF, &optval, &optlen);
  if (err)
    {
      printf ("set_sock_size_sndbuf():getsockopt(SO_SNDBUF) failed: errno=%d (%s)\n", errno, strerror(errno));
      printf ("set_sock_size_sndbuf():getsockopt(SO_SNDBUF) failed: optval=%d, optlen=%d\n", optval, optlen);
      return err;
    }
  printf ("set_sock_size_sndbuf():getsockopt(SO_SNDBUF): optval=%d, optlen=%d\n", optval, optlen);
#endif
#if TEST_SETSOCKOPT2
  optval = *max_msg_size;
  optlen = sizeof(*max_msg_size);
  printf ("set_sock_size_sndbuf(): Requested: *max_msg_size = %d\n", optval);
  err = setsockopt(sockfd, SOL_SOCKET, SO_SNDBUF, &optval, optlen);
  if (err)
    {
      printf ("set_sock_size_sndbuf():setsockopt(SO_SNDBUF) failed: errno=%d (%s)\n", errno, strerror(errno));
      printf ("set_sock_size_sndbuf():setsockopt(SO_SNDBUF) failed: optval=%d, *max_msg_size=%d\n", *max_msg_size, optlen);
      return err;
    }
#ifdef __GNU__
  printf ("set_sock_size_sndbuf():setsockopt(SO_SNDBUF): GNU/Hurd: S_sock_setopt RPC is wrong: No return value\n");
#else
  printf ("set_sock_size_sndbuf():setsockopt(SO_SNDBUF): optval=%d, optlen=%d\n", optval, optlen);
  printf ("set_sock_size_sndbuf(): Returned: optval = %d\n", optval);
#endif
#endif

#if TEST_GETSOCKOPT4
  printf( "set_sock_size_rsnduf: Checking set values\n");
  err = getsockopt(sockfd, SOL_SOCKET, SO_SNDBUF, &optval, &optlen);
  if (err)
    {
      printf ("set_sock_size_sndbuf():getsockopt(SO_SNDBUF) failed: errno=%d (%s)\n", errno, strerror(errno));
      printf ("set_sock_size_sndbuf():getsockopt(SO_SNDBUF) failed: optval=%d, optlen=%d\n", optval, optlen);
      return err;
    }
  printf ("set_sock_size_sndbuf():getsockopt(SO_SNDBUF): optval=%d, optlen=%d\n", optval, optlen);
#endif

  return err;
}

#include "./defs.inc"

int
main(void)
{
  //int max_msg_size = 128*1024; /* 131072 = 128 kiB */;
  //int max_msg_size = 256*1024; /* 262144 = 256 kiB */ 
  int max_msg_size = 20*1024; /* 20480 = 20 kiB */ 
  /* Linux default: 208*1024 = 212992 */
  /* Hurd default: libpipe/pipe.c write_limit = 16*1024 = 16384 */
  int err = -1;

#ifdef USE_SOCK_STREAM
#define type SOCK_STREAM
#else
#define type SOCK_DGRAM
#endif

#ifdef USE_AF_UNIX
#define domain AF_UNIX
#else
#define domain AF_INET
#endif

  int sfd = socket(domain, type, 0);
  //int sfd = 5;
  if (sfd == -1)
    handle_error("socket");

  printf("\ntest_get+setsockopt.c:main():\n");
  printf ("domain = %s  ", domain==AF_UNIX ? "AF_UNIX" : "AF_INET");
  printf ("type = %s  ", type==SOCK_DGRAM ? "SOCK_DGRAM" : "SOCK_STREAM");
  printf("Socket sfd = %d\n", sfd);
  
  printf ("\nCASE: SO_RCVBUF\n");
  printf ("main(): Requested: max_msg_size = %d\n", max_msg_size);
  err = set_sock_size_rcvbuf (sfd, &max_msg_size);
  if (err == -1)
    printf ("\nmain():set_sock_size_rcvbuf() failed: errno = %d (%s)\n", errno, strerror(errno));
  else
    printf ("\nmain():set_sock_size_rcvbuf(): max_msg_size=%d\n", max_msg_size);

  printf( "\nCASE: SO_SNDBUF\n");
  max_msg_size = 8*max_msg_size;
  printf ("main(): Requested: max_msg_size = %d\n", max_msg_size);
  err = set_sock_size_sndbuf (sfd, &max_msg_size);
  if (err == -1)
    printf ("\nmain():set_sock_size_sndbuf() failed: errno = %d (%s)\n", errno, strerror(errno));
  else
    printf ("\nmain():set_sock_size_sndbuf(): max_msg_size=%d\n", max_msg_size);

  exit((err == 0) ? EXIT_SUCCESS : EXIT_FAILURE);
}