inetd.c

压缩包中包含LINUX下多个命令的源码

			    timingout = 1;
			    alarm (RETRYTIME);
			  }
			continue;
		      }
		  }
		pid = fork ();
	      }
	    if (pid < 0)
	      {
		syslog (LOG_ERR, "fork: %m");
		if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
		  close (ctrl);
#ifdef HAVE_SIGACTION
		{
		  sigset_t empty;
		  sigemptyset (&empty);
		  sigprocmask (SIG_SETMASK, &empty, 0);
		}
#else
		sigsetmask (0L);
#endif
		sleep (1);
		continue;
	      }
	    if (pid && sep->se_wait)
	      {
		sep->se_wait = pid;
		if (sep->se_fd >= 0)
		  {
		    FD_CLR (sep->se_fd, &allsock);
		    nsock--;
		  }
	      }
#ifdef HAVE_SIGACTION
	    {
	      sigset_t empty;
	      sigemptyset (&empty);
	      sigprocmask (SIG_SETMASK, &empty, 0);
	    }
#else
	    sigsetmask (0L);
#endif
	    if (pid == 0)
	      {
		if (debug && dofork)
		  setsid ();
		if (dofork)
		  {
		    int sock;
		    if (debug)
		      fprintf (stderr, "+ Closing from %d\n", maxsock);
		    for (sock = maxsock; sock > 2; sock--)
		      if (sock != ctrl)
			close (sock);
		  }
		run_service (ctrl, sep);
	      }
	    if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
	      close (ctrl);
	  }
    }
}

void
run_service (int ctrl, struct servtab *sep)
{
  struct passwd *pwd;
  char buf[50];

  if (sep->se_bi)
    {
      (*sep->se_bi->bi_fn) (ctrl, sep);
    }
  else
    {
      if (debug)
	fprintf (stderr, "%d execl %s\n", getpid (), sep->se_server);
      dup2 (ctrl, 0);
      close (ctrl);
      dup2 (0, 1);
      dup2 (0, 2);
      if ((pwd = getpwnam (sep->se_user)) == NULL)
	{
	  syslog (LOG_ERR, "%s/%s: %s: No such user",
		  sep->se_service, sep->se_proto, sep->se_user);
	  if (sep->se_socktype != SOCK_STREAM)
	    recv (0, buf, sizeof buf, 0);
	  _exit (1);
	}
      if (pwd->pw_uid)
	{
	  if (setgid (pwd->pw_gid) < 0)
	    {
	      syslog (LOG_ERR, "%s: can't set gid %d: %m",
		      sep->se_service, pwd->pw_gid);
	      _exit (1);
	    }
#ifdef HAVE_INITGROUPS
	  (void) initgroups (pwd->pw_name, pwd->pw_gid);
#endif
	  if (setuid (pwd->pw_uid) < 0)
	    {
	      syslog (LOG_ERR, "%s: can't set uid %d: %m",
		      sep->se_service, pwd->pw_uid);
	      _exit (1);
	    }
	}
      execv (sep->se_server, sep->se_argv);
      if (sep->se_socktype != SOCK_STREAM)
	recv (0, buf, sizeof buf, 0);
      syslog (LOG_ERR, "cannot execute %s: %m", sep->se_server);
      _exit (1);
    }
}

void
reapchild (int signo)
{
  int status;
  pid_t pid;
  struct servtab *sep;

  (void)signo; /* shutup gcc */
  for (;;)
    {
#ifdef HAVE_WAIT3
      pid = wait3 (&status, WNOHANG, (struct rusage *)0);
#else
      pid = wait (&status);
#endif
      if (pid <= 0)
	break;
      if (debug)
	fprintf (stderr, "%d reaped, status %#x\n", pid, status);
      for (sep = servtab; sep; sep = sep->se_next)
	if (sep->se_wait == pid)
	  {
	    if (status)
	      syslog (LOG_WARNING, "%s: exit status 0x%x",
		      sep->se_server, status);
	    if (debug)
	      fprintf (stderr, "restored %s, fd %d\n",
		       sep->se_service, sep->se_fd);
	    FD_SET (sep->se_fd, &allsock);
	    nsock++;
	    sep->se_wait = 1;
	  }
    }
}

void
config (int signo)
{
  int i;
  struct stat stats;
  struct servtab *sep;

  (void)signo; /* Shutup gcc.  */

  for (sep = servtab; sep; sep = sep->se_next)
    sep->se_checked = 0;

  for (i = 0; config_files[i]; i++)
    {
      struct stat statbuf;

      if (stat (config_files[i], &statbuf) == 0)
	{
	  if (S_ISDIR (statbuf.st_mode))
	    {
	      DIR *dirp = opendir (config_files[i]);

	      if (dirp)
		{
		  struct dirent *dp;

		  while ((dp = readdir (dirp)) != NULL)
		    {
		      char *path = calloc (strlen (config_files[i])
					   + strlen (dp->d_name) + 2, 1);
		      if (path)
			{
			  sprintf (path,"%s/%s", config_files[i], dp->d_name);
			  if (stat (path, &stats) == 0
			      && S_ISREG(stats.st_mode))
			    {
			      nextconfig (path);
			    }
			  free (path);
			}
		    }
		  closedir (dirp);
		}
	    }
	  else if (S_ISREG (statbuf.st_mode))
	    {
	      nextconfig (config_files[i]);
	    }
	}
      else
	{
	  if (signo == 0)
	    fprintf (stderr, "inetd: %s, %s\n",
		     config_files[i], strerror(errno));
	  else
	    syslog (LOG_ERR, "%s: %m", config_files[i]);
	}
    }
}

void
nextconfig (const char *file)
{
  struct servtab *sep, *cp, **sepp;
  struct passwd *pwd;
  FILE * fconfig;
#ifdef HAVE_SIGACTION
  sigset_t sigs, osigs;
#else
  long omask;
#endif

  fconfig = setconfig (file);
  if (!fconfig)
    {
      syslog (LOG_ERR, "%s: %m", file);
      return;
    }
  while ((cp = getconfigent (fconfig, file)))
    {
      if ((pwd = getpwnam (cp->se_user)) == NULL)
	{
	  syslog(LOG_ERR, "%s/%s: No such user '%s', service ignored",
		 cp->se_service, cp->se_proto, cp->se_user);
	  continue;
	}
      /* Checking/Removing duplicates */
      for (sep = servtab; sep; sep = sep->se_next)
	if (strcmp (sep->se_service, cp->se_service) == 0
	    && strcmp (sep->se_proto, cp->se_proto) == 0
	    && ISMUX(sep) == ISMUX (cp))
	  break;
      if (sep != 0)
	{
	  int i;

#ifdef HAVE_SIGACTION
	  sigemptyset (&sigs);
	  sigaddset (&sigs, SIGCHLD);
	  sigaddset (&sigs, SIGHUP);
	  sigaddset (&sigs, SIGALRM);
	  sigprocmask (SIG_BLOCK, &sigs, &osigs);
#else
	  omask = sigblock (SIGBLOCK);
#endif
	  /*
	   * sep->se_wait may be holding the pid of a daemon
	   * that we're waiting for.  If so, don't overwrite
	   * it unless the config file explicitly says don't
	   * wait.
	   */
	  if (cp->se_bi == 0
	      && (sep->se_wait == 1 || cp->se_wait == 0))
	    sep->se_wait = cp->se_wait;
#define SWAP(a, b) { char *c = a; a = b; b = c; }
	  if (cp->se_user)
	    SWAP(sep->se_user, cp->se_user);
	  if (cp->se_server)
	    SWAP(sep->se_server, cp->se_server);
	  for (i = 0; i < MAXARGV; i++)
	    SWAP(sep->se_argv[i], cp->se_argv[i]);
#ifdef HAVE_SIGACTION
	  sigprocmask (SIG_SETMASK, &osigs, 0);
#else
	  sigsetmask (omask);
#endif
	  freeconfig (cp);
	  if (debug)
	    print_service (file, "REDO", sep);
	}
      else
	{
	  sep = enter (cp);
	  if (debug)
	    print_service (file, "ADD ", sep);
	}
      sep->se_checked = 1;
      if (ISMUX (sep))
	{
	  sep->se_fd = -1;
	  continue;
	}
      sp = getservbyname (sep->se_service, sep->se_proto);
      if (sp == 0)
	{
	  syslog (LOG_ERR, "%s/%s: unknown service",
		  sep->se_service, sep->se_proto);
	  sep->se_checked = 0;
	  continue;
	}
      if (sp->s_port != sep->se_ctrladdr.sin_port)
	{
	  sep->se_ctrladdr.sin_family = AF_INET;
	  sep->se_ctrladdr.sin_port = sp->s_port;
	  if (sep->se_fd >= 0)
	    close_sep (sep);
	}
      if (sep->se_fd == -1)
	setup (sep);
    }
  endconfig (fconfig);
  /*
   * Purge anything not looked at above.
   */
#ifdef HAVE_SIGACTION
  sigemptyset (&sigs);
  sigaddset (&sigs, SIGCHLD);
  sigaddset (&sigs, SIGHUP);
  sigaddset (&sigs, SIGALRM);
  sigprocmask (SIG_BLOCK, &sigs, &osigs);
#else
  omask = sigblock (SIGBLOCK);
#endif
  sepp = &servtab;
  while ((sep = *sepp))
    {
      if (sep->se_checked)
	{
	  sepp = &sep->se_next;
	  continue;
	}
      *sepp = sep->se_next;
      if (sep->se_fd >= 0)
	close_sep (sep);
      if (debug)
	print_service (file, "FREE", sep);
      freeconfig (sep);
      free ((char *)sep);
    }
#ifdef HAVE_SIGACTION
  sigprocmask (SIG_SETMASK, &osigs, 0);
#else
  (void) sigsetmask (omask);
#endif
}

void
retry (int signo)
{
  struct servtab *sep;

  (void)signo; /* shutup gcc */
  timingout = 0;
  for (sep = servtab; sep; sep = sep->se_next)
    if (sep->se_fd == -1 && !ISMUX (sep))
      setup (sep);
}

void
setup (struct servtab *sep)
{
  int on = 1;

  if ((sep->se_fd = socket (AF_INET, sep->se_socktype, 0)) < 0)
    {
      if (debug)
	fprintf (stderr, "socket failed on %s/%s: %s\n",
		 sep->se_service, sep->se_proto, strerror (errno));
      syslog(LOG_ERR, "%s/%s: socket: %m", sep->se_service, sep->se_proto);
      return;
    }
#define	turnon(fd, opt) \
setsockopt(fd, SOL_SOCKET, opt, (char *)&on, sizeof (on))
  if (strcmp (sep->se_proto, "tcp") == 0 && (options & SO_DEBUG)
      && turnon(sep->se_fd, SO_DEBUG) < 0)
    syslog (LOG_ERR, "setsockopt (SO_DEBUG): %m");
  if (turnon (sep->se_fd, SO_REUSEADDR) < 0)
    syslog (LOG_ERR, "setsockopt (SO_REUSEADDR): %m");
#undef turnon
  if (bind (sep->se_fd, (struct sockaddr *)&sep->se_ctrladdr,
	    sizeof (sep->se_ctrladdr)) < 0)
    {
      if (debug)
	fprintf (stderr, "bind failed on %s/%s: %s\n",
		 sep->se_service, sep->se_proto, strerror (errno));
      syslog(LOG_ERR, "%s/%s: bind: %m", sep->se_service, sep->se_proto);
      (void) close (sep->se_fd);
      sep->se_fd = -1;
      if (!timingout)
	{
	  timingout = 1;
	  alarm (RETRYTIME);
	}
      return;
    }
  if (sep->se_socktype == SOCK_STREAM)
    listen (sep->se_fd, 10);
  FD_SET (sep->se_fd, &allsock);
  nsock++;
  if (sep->se_fd > maxsock)
    maxsock = sep->se_fd;
  if (debug)
    {
      fprintf(stderr, "registered %s on %d\n", sep->se_server, sep->se_fd);
    }
}

/*
 * Finish with a service and its socket.
 */
void
close_sep (struct servtab *sep)
{
  if (sep->se_fd >= 0)
    {
      nsock--;
      FD_CLR (sep->se_fd, &allsock);
      (void) close (sep->se_fd);
      sep->se_fd = -1;
    }
  sep->se_count = 0;
  /*
   * Don't keep the pid of this running deamon: when reapchild()
   * reaps this pid, it would erroneously increment nsock.
   */
  if (sep->se_wait > 1)
    sep->se_wait = 1;
}

struct servtab *
enter (struct servtab *cp)
{
  struct servtab *sep;
#ifdef HAVE_SIGACTION
  sigset_t sigs, osigs;
#else
  long omask;
#endif

  sep = (struct servtab *)malloc (sizeof (*sep));
  if (sep == (struct servtab *)0)
    {
      syslog (LOG_ERR, "Out of memory.");
      exit (-1);
    }
  *sep = *cp;
  sep->se_fd = -1;
#ifdef HAVE_SIGACTION
  sigemptyset (&sigs);
  sigaddset (&sigs, SIGCHLD);
  sigaddset (&sigs, SIGHUP);
  sigaddset (&sigs, SIGALRM);
  sigprocmask (SIG_BLOCK, &sigs, &osigs);
#else
  omask = sigblock (SIGBLOCK);
#endif
  sep->se_next = servtab;
  servtab = sep;
#ifdef HAVE_SIGACTION
  sigprocmask (SIG_SETMASK, &osigs, 0);
#else
  sigsetmask (omask);
#endif
  return sep;
}

struct	servtab serv;
#ifdef LINE_MAX
char	line[LINE_MAX];
#else
char 	line[2048];
#endif

FILE *
setconfig (const char *file)
{
  return fopen (file, "r");
}

void
endconfig (FILE *fconfig)
{
  if (fconfig)
    {
      (void) fclose (fconfig);
    }
}

struct servtab *
getconfigent (FILE *fconfig, const char *file)
{
  struct servtab *sep = &serv;
  int argc;
  char *cp, *arg;
  static char TCPMUX_TOKEN[] = "tcpmux/";
#define MUX_LEN		(sizeof(TCPMUX_TOKEN)-1)

more:
  while ((cp = nextline (fconfig)) && (*cp == '#' || *cp == '\0'))
    ;
  if (cp == NULL)
    return ((struct servtab *)0);
  /*
   * clear the static buffer, since some fields (se_ctrladdr,
   * for example) don't get initialized here.
   */
  memset ((caddr_t)sep, 0, sizeof *sep);
  arg = skip (&cp, fconfig);
  if (cp == NULL)
    {
      /* got an empty line containing just blanks/tabs. */
      goto more;
    }
  if (strncmp (arg, TCPMUX_TOKEN, MUX_LEN) == 0)
    {
      char *c = arg + MUX_LEN;
      if (*c == '+')
	{
	  sep->se_type = MUXPLUS_TYPE;
	  c++;
	}