finger.c

/*
 * Support for a finger daemon that shows the BBS who list.
 */
#include "defs.h"
#include "ext.h"

#define MAXCONN 60

static void
setup_socket(void)
{
  struct sockaddr_in sa;
  int one = 1;

  close(0);
  if (socket(AF_INET, SOCK_STREAM, 0) != 0)
    _exit(1);
  one = 1;
  if (setsockopt(0, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one) < 0)
    _exit(1);
  sa.sin_family = AF_INET;
  sa.sin_addr.s_addr = htonl(0);
  sa.sin_port = htons(79);
  if (bind(0, (const struct sockaddr*)&sa, sizeof sa) < 0)
    _exit(1);
  if (listen(0, SOMAXCONN) < 0)
    _exit(1);
}


static void
s_sigalrm2(int signo)
{
  signal(SIGALRM, s_sigalrm2);
  alarm(30);
}


void
bbsfinger(void)
{
int n;
int i;
int x;
char *p;
fd_set rfd;
struct fd
{
  short conn;
  short pos;
  char buf[24];
} fd[MAXCONN];

  if (!getenv("INIT_STATE") && fork())
    _exit(0);
  nice(-20);
  nice(-20);
  nice(20);

  close(0);
  close(1);
  close(2);
  setsid();

  signal(SIGPIPE, SIG_IGN);
  signal(SIGALRM, s_sigalrm2);
  alarm(30);

#ifdef _WHIP
  ouruser = getuser("Guest");
#else
  ouruser = NULL;
#endif
  if (!ouruser)
    _exit(1);

  rows = 32000;

  setup_socket();

  const size_t bigstdoutbuf_size = 262143;
  char * bigstdoutbuf = calloc(bigstdoutbuf_size, sizeof(char));
  setvbuf(stdout, bigstdoutbuf, _IOFBF, bigstdoutbuf_size);

  for (;;)
  {
    FD_ZERO(&rfd);
    for (x = 0, i = 2; i < MAXCONN; i++)
      if (fd[i].conn)
      {
        FD_SET(i, &rfd);
	x = i;
      }
      else
	FD_SET(0, &rfd);

    if ((i = select(x + 1, &rfd, 0, 0, 0)) < 0 && errno != EINTR)
    {
      errlog("FINGER: select error %d", errno);
      _exit(1);
    }
    else if (!i)
    {
      errlog("FINGER: 0 return from select");
      continue;
    }
    else if (i < 0)
    {
      for (i = 2; i < MAXCONN; i++)
        if ((fd[i].conn > 0 && ++fd[i].conn > 4) || (fd[i].conn < 0 && --fd[i].conn < -4))
        {
          close(i);
          fd[i].conn = 0;
        }

      if (fd[0].conn++ > 5)
        setup_socket();

      continue;
    }

    while (FD_ISSET(0, &rfd))
    {
      struct sockaddr_in sa;
      struct linger linger;

      fd[0].conn = 0;
      socklen_t size = sizeof sa;
      if ((i = accept(0, (struct sockaddr*)&sa, &size)) < 0)
        break;
      if (i != 1)
      {
        errlog("FINGER: accepted on fd %d", i);
        close(i);
        break;
      }

      linger.l_onoff = 1;
      linger.l_linger = 0;
      if (setsockopt(1, SOL_SOCKET, SO_LINGER, &linger, sizeof linger) < 0)
      {
        close(1);
        break;
      }

      size = bigstdoutbuf_size;
      if (setsockopt(1, SOL_SOCKET, SO_SNDBUF, &size, sizeof size) < 0)
      {
        close(1);
        break;
      }

      if (fcntl(1, F_SETFL, O_NONBLOCK) < 0)
      {
        close(1);
        break;
      }

      i = dup(1);
      close(1);
      fd[i].conn = 1;
      fd[i].pos = 0;
      break;
    }

    for (n = 2; n < MAXCONN; n++)
    {
      if (!FD_ISSET(n, &rfd))
        continue;
      if (fd[n].conn < 0 || (i = read(n, fd[n].buf + fd[n].pos, sizeof fd[n].buf - fd[n].pos)) <= 0 || (fd[n].pos += i) == sizeof fd[n].buf)
      {
        close(n);
        fd[n].conn = 0;
        continue;
      }

      if (fd[n].pos < 2 || strncmp(fd[n].buf + fd[n].pos - 2, "\r\n", 2))
        continue;
      fd[n].buf[fd[n].pos - 2] = 0;

      dup2(n, 1);

#ifdef _WHIP
      if (!strcmp(fd[n].buf, "__FULL__"))
#else
      if (!strncmp(fd[n].buf, "/W", 2) || *fd[n].buf == '@')
#endif
        show_online(2);
      else if (!*fd[n].buf)
        show_online(3);
      else
      {
        for (x = 1, p = fd[n].buf; *p; p++)
          if (x && islower(*p))
          {
	    *p = toupper(*p);
            x = 0;
          }
          else if (*p == '_' || *p == ' ')
	    x = (*p = ' ') != 0;
	  else
	    x = 0;

        if (profile(fd[n].buf, NULL, PROF_REG) < 0)
          printf("There is no user %s on this BBS.\n", fd[n].buf);
      }

      fd[n].conn = -1;
      fflush(stdout);
      close(1);
      shutdown(n, 1);
    }
  }

  free(bigstdoutbuf);
}