commands.c

来自「linux下常用的网络工具的代码」· C语言 代码 · 共 2,831 行 · 第 1/5 页

#ifdef IPV6
	  hints.ai_family = AF_INET;
#endif
	  continue;
	}
      if (hostp == 0)
	{
	  hostp = *argv++;
	  --argc;
	  continue;
	}
      if (portp == 0)
	{
	  portp = *argv++;
	  --argc;
	  continue;
	}
    usage:
      printf("usage: %s [-4] [-6] [-l user] [-a] host-name [port]\n", cmd);
      return 0;
    }
  if (hostp == 0)
    goto usage;

  if (!portp)
    {
      portp = "telnet";
      telnetport = 1;
    }
  else
    {
      if (*portp == '-')
	{
	  portp++;
	  telnetport = 1;
	}
      else
	telnetport = 0;
    }

  if (hostname)
    free (hostname);
  hostname = malloc (strlen (hostp) + 1);
  if (hostname)
    strcpy (hostname, hostp);
  else
    {
      printf ("Can't allocate memory to copy hostname\n");
      return 0;
    }
 
#ifdef IPV6
#ifdef AI_ADDRCONFIG
  hints.ai_flags = AI_ADDRCONFIG;
#endif
  hints.ai_socktype = SOCK_STREAM;

  err = getaddrinfo (hostp, portp, &hints, &result);
  if (err)
    {
      const char *errmsg;

      if (err == EAI_SYSTEM)
	errmsg = strerror (errno);
      else
	errmsg = gai_strerror (err);
      
      printf ("%s/%s: lookup failure: %s\n", hostp, portp, errmsg);
      return 0;
    }

  aip = result;

  do
    {
      char buf[256];

      err = getnameinfo (aip->ai_addr, aip->ai_addrlen, buf, sizeof (buf),
			 NULL, 0, NI_NUMERICHOST);
      if (err)
	{
	  /* I don't know how thing can happen, but we just handle it.  */
	  const char *errmsg;
	  
	  if (err == EAI_SYSTEM)
	    errmsg = strerror (errno);
	  else
	    errmsg = gai_strerror (err);
	  
	  printf ("getnameinfo error: %s\n", errmsg);
	  return 0;
	}
      
      printf ("Trying %s...\n", buf);

      net = socket (aip->ai_family, SOCK_STREAM, 0);
      if (net < 0)
	{
	  perror("telnet: socket");
	  return 0;
	}

      if (debug)
	{
	  err = setsockopt (net, SOL_SOCKET, SO_DEBUG, &on, sizeof(on));
	  if (err < 0)
	    perror("setsockopt (SO_DEBUG)");
	}

      err = connect (net, (struct sockaddr *)aip->ai_addr, aip->ai_addrlen);
      if (err < 0)
	{
	  if (aip->ai_next)
	    {
	      perror ("Connection failed");
	      aip = aip->ai_next;
	      close (net);
	      continue;
	    }
	    
	  perror("telnet: Unable to connect to remote host");
	  return 0;
	}
      
      connected++;
#if	defined(AUTHENTICATION) || defined(ENCRYPTION)
      auth_encrypt_connect(connected);
#endif	/* defined(AUTHENTICATION) || defined(ENCRYPTION) */
    } while (!connected);

  freeaddrinfo (result);
#else /* !IPV6 */
  temp = inet_addr (hostp);
  if (temp != (in_addr_t) -1)
    {
      sin.sin_addr.s_addr = temp;
      sin.sin_family = AF_INET;
    }
  else
    {
      host = gethostbyname (hostp);
      if (host)
	{
	  sin.sin_family = host->h_addrtype;
	  memmove (&sin.sin_addr, host->h_addr_list[0], host->h_length);
	}
      else
	{
	  printf ("Can't lookup hostname %s\n", hostp);
	  return 0;
	}
    }
  
  sin.sin_port = atoi (portp);
  if (sin.sin_port == 0)
    {
      sp = getservbyname (portp, "tcp");
      if (sp == 0)
	{
	  printf ("tcp/%s: unknown service\n", portp);
	  return 0;
	}
      sin.sin_port = sp->s_port;
    }
  else
    sin.sin_port = htons (sin.sin_port);
  
  printf("Trying %s...\n", inet_ntoa(sin.sin_addr));
  do
    {
      net = socket(AF_INET, SOCK_STREAM, 0);
      if (net < 0)
	{
	  perror("telnet: socket");
	  return 0;
	}
#if defined(IPPROTO_IP) && defined(IP_TOS)
      {
#ifdef IPTOS_LOWDELAY
	const int tos = IPTOS_LOWDELAY;
#else
	const int tos = 0x10;
#endif

	err = setsockopt (net, IPPROTO_IP, IP_TOS,
			  (char *)&tos, sizeof(tos));
	if (err < 0 && errno != ENOPROTOOPT)
	  perror("telnet: setsockopt (IP_TOS) (ignored)");
      }
#endif	/* defined(IPPROTO_IP) && defined(IP_TOS) */

      if (debug && setsockopt(net, SOL_SOCKET, SO_DEBUG, &on, sizeof(on)) < 0)
	perror("setsockopt (SO_DEBUG)");

      if (connect(net, (struct sockaddr *)&sin, sizeof (sin)) < 0)
	{
	  if (host && host->h_addr_list[1])
	    {
	      int oerrno = errno;

	      fprintf(stderr, "telnet: connect to address %s: ",
		      inet_ntoa(sin.sin_addr));
	      errno = oerrno;
	      perror((char *)0);
	      host->h_addr_list++;
	      memmove((caddr_t)&sin.sin_addr,
		      host->h_addr_list[0], host->h_length);
	      close (net);
	      continue;
	    }
	  perror("telnet: Unable to connect to remote host");
	  return 0;
	}
      connected++;
#if	defined(AUTHENTICATION) || defined(ENCRYPTION)
      auth_encrypt_connect(connected);
#endif	/* defined(AUTHENTICATION) || defined(ENCRYPTION) */
    } while (connected == 0);
#endif /* !IPV6 */
  cmdrc(hostp, hostname);
  if (autologin && user == NULL)
    {
      struct passwd *pw;

      user = getenv("USER");
      if (user == NULL ||
	  (pw = getpwnam(user)) && pw->pw_uid != getuid())
	{
	  if (pw = getpwuid(getuid()))
	    user = pw->pw_name;
	  else
	    user = NULL;
	}
    }
  if (user)
    {
      env_define((unsigned char *)"USER", (unsigned char *)user);
      env_export((unsigned char *)"USER");
    }
  call(status, "status", "notmuch", 0);
  if (setjmp(peerdied) == 0)
    telnet(user);

  close (net);
  ExitString("Connection closed by foreign host.\n",1);
  /*NOTREACHED*/

  return 0;
}

#define HELPINDENT (sizeof ("connect"))

static char
	openhelp[] =	"connect to a site",
	closehelp[] =	"close current connection",
	logouthelp[] =	"forcibly logout remote user and close the connection",
	quithelp[] =	"exit telnet",
	statushelp[] =	"print status information",
	helphelp[] =	"print help information",
	sendhelp[] =	"transmit special characters ('send ?' for more)",
	sethelp[] = 	"set operating parameters ('set ?' for more)",
	unsethelp[] = 	"unset operating parameters ('unset ?' for more)",
	togglestring[] ="toggle operating parameters ('toggle ?' for more)",
	slchelp[] =	"change state of special characters ('slc ?' for more)",
	displayhelp[] =	"display operating parameters",
#if	defined(TN3270) && defined(unix)
	transcomhelp[] = "specify Unix command for transparent mode pipe",
#endif	/* defined(TN3270) && defined(unix) */
#if	defined(AUTHENTICATION)
	authhelp[] =	"turn on (off) authentication ('auth ?' for more)",
#endif
#ifdef	ENCRYPTION
	encrypthelp[] =	"turn on (off) encryption ('encrypt ?' for more)",
#endif	/* ENCRYPTION */
#if	defined(unix)
	zhelp[] =	"suspend telnet",
#endif	/* defined(unix) */
	shellhelp[] =	"invoke a subshell",
	envhelp[] =	"change environment variables ('environ ?' for more)",
	modestring[] = "try to enter line or character mode ('mode ?' for more)";

static int	help();

static Command cmdtab[] = {
	{ "close",	closehelp,	bye,		1 },
	{ "logout",	logouthelp,	logout,		1 },
	{ "display",	displayhelp,	display,	0 },
	{ "mode",	modestring,	modecmd,	0 },
	{ "open",	openhelp,	tn,		0 },
	{ "quit",	quithelp,	quit,		0 },
	{ "send",	sendhelp,	sendcmd,	0 },
	{ "set",	sethelp,	setcmd,		0 },
	{ "unset",	unsethelp,	unsetcmd,	0 },
	{ "status",	statushelp,	status,		0 },
	{ "toggle",	togglestring,	toggle,		0 },
	{ "slc",	slchelp,	slccmd,		0 },
#if	defined(TN3270) && defined(unix)
	{ "transcom",	transcomhelp,	settranscom,	0 },
#endif	/* defined(TN3270) && defined(unix) */
#if	defined(AUTHENTICATION)
	{ "auth",	authhelp,	auth_cmd,	0 },
#endif
#ifdef	ENCRYPTION
	{ "encrypt",	encrypthelp,	encrypt_cmd,	0 },
#endif	/* ENCRYPTION */
#if	defined(unix)
	{ "z",		zhelp,		suspend,	0 },
#endif	/* defined(unix) */
#if	defined(TN3270)
	{ "!",		shellhelp,	shell,		1 },
#else
	{ "!",		shellhelp,	shell,		0 },
#endif
	{ "environ",	envhelp,	env_cmd,	0 },
	{ "?",		helphelp,	help,		0 },
	0
};

static char	crmodhelp[] =	"deprecated command -- use 'toggle crmod' instead";
static char	escapehelp[] =	"deprecated command -- use 'set escape' instead";

static Command cmdtab2[] = {
	{ "help",	0,		help,		0 },
	{ "escape",	escapehelp,	setescape,	0 },
	{ "crmod",	crmodhelp,	togcrmod,	0 },
	0
};


/*
 * Call routine with argc, argv set from args (terminated by 0).
 */

    /*VARARGS1*/
    static
#if defined(HAVE_STDARG_H) && defined(__STDC__) && __STDC__
call(intrtn_t routine, ...)
#else
call(va_alist)
    va_dcl
#endif
{
    va_list ap;
#if !(defined(HAVE_STDARG_H) && defined(__STDC__) && __STDC__)
    intrtn_t routine;
#endif
    char *args[100];
    int argno = 0;

#if defined(HAVE_STDARG_H) && defined(__STDC__) && __STDC__
    va_start(ap, routine);
#else
    va_start(ap);
    routine = (va_arg(ap, intrtn_t));
#endif
    while ((args[argno++] = va_arg(ap, char *)) != 0) {
	;
    }
    va_end(ap);
    return (*routine)(argno-1, args);
}


static Command *
getcmd(char *name)
{
    Command *cm;

    if (cm = (Command *) genget(name, (char **) cmdtab, sizeof(Command)))
	return cm;
    return (Command *) genget(name, (char **) cmdtab2, sizeof(Command));
}

void
command(int top, char *tbuf, int cnt)
{
    register Command *c;

    setcommandmode();
    if (!top) {
	putchar('\n');
#if	defined(unix)
    } else {
	signal(SIGINT, SIG_DFL);
	signal(SIGQUIT, SIG_DFL);
#endif	/* defined(unix) */
    }
    for (;;) {
	if (rlogin == _POSIX_VDISABLE)
		printf("%s> ", prompt);
	if (tbuf) {
	    register char *cp;
	    cp = line;
	    while (cnt > 0 && (*cp++ = *tbuf++) != '\n')
		cnt--;
	    tbuf = 0;
	    if (cp == line || *--cp != '\n' || cp == line)
		goto getline;
	    *cp = '\0';
	    if (rlogin == _POSIX_VDISABLE)
	        printf("%s\n", line);
	} else {
	getline:
	    if (rlogin != _POSIX_VDISABLE)
		printf("%s> ", prompt);
	    if (fgets(line, sizeof(line), stdin) == NULL) {
		if (feof(stdin) || ferror(stdin)) {
		    quit();
		    /*NOTREACHED*/
		}
		break;
	    }
	}
	if (line[0] == 0)
	    break;
	makeargv();
	if (margv[0] == 0) {
	    break;
	}
	c = getcmd(margv[0]);
	if (Ambiguous(c)) {
	    printf("?Ambiguous command\n");
	    continue;
	}
	if (c == 0) {
	    printf("?Invalid command\n");
	    continue;
	}
	if (c->needconnect && !connected) {
	    printf("?Need to be connected first.\n");
	    continue;
	}
	if ((*c->handler)(margc, margv)) {
	    break;
	}
    }
    if (!top) {
	if (!connected) {
	    longjmp(toplevel, 1);
	    /*NOTREACHED*/
	}
#if	defined(TN3270)
	if (shell_active == 0) {
	    setconnmode(0);
	}
#else	/* defined(TN3270) */
	setconnmode(0);
#endif	/* defined(TN3270) */
    }
}

/*
 * Help command.
 */
static int
help(int argc, char *argv[])
{
	register Command *c;

	if (argc == 1) {
		printf("Commands may be abbreviated.  Commands are:\n\n");
		for (c = cmdtab; c->name; c++)
			if (c->help) {
				printf("%-*s\t%s\n", HELPINDENT, c->name,
								    c->help);
			}
		return 0;
	}
	while (--argc > 0) {
		register char *arg;
		arg = *++argv;
		c = getcmd(arg);
		if (Ambiguous(c))
			printf("?Ambiguous help command %s\n", arg);
		else if (c == (Command *)0)
			printf("?Invalid help command %s\n", arg);
		else
			printf("%s\n", c->help);
	}
	return 0;
}

static char *rcname = 0;
static char rcbuf[128];

int
cmdrc(char *m1, char *m2)
{
    register Command *c;
    FILE *rcfile;
    int gotmachine = 0;
    int l1 = strlen(m1);
    int l2 = strlen(m2);
    char m1save[64];

    if (skiprc)
	return;

    strcpy(m1save, m1);
    m1 = m1save;

    if (rcname == 0) {
	rcname = getenv("HOME");
	if (rcname)
	    strcpy(rcbuf, rcname);
	else
	    rcbuf[0] = '\0';
	strcat(rcbuf, "/.telnetrc");
	rcname = rcbuf;
    }

    if ((rcfile = fopen(rcname, "r")) == 0) {
	return;
    }

    for (;;) {
	if (fgets(line, sizeof(line), rcfile) == NULL)
	    break;
	if (line[0] == 0)
	    break;
	if (line[0] == '#')
	    continue;
	if (gotmachine) {
	    if (!isspace(line[0]))
		gotmachine = 0;
	}
	if (gotmachine == 0) {
	    if (isspace(line[0]))
		continue;
	    if (strncasecmp(line, m1, l1) == 0)
		strncpy(line, &line[l1], sizeof(line) - l1);
	    else if (strncasecmp(line, m2, l2) == 0)
		strncpy(line, &line[l2], sizeof(line) - l2);
	    else if (strncasecmp(line, "DEFAULT", 7) == 0)
		strncpy(line, &line[7], sizeof(line) - 7);
	    else
		continue;
	    if (line[0] != ' ' && line[0] != '\t' && line[0] != '\n')
		continue;
	    gotmachine = 1;
	}
	makeargv();
	if (margv[0] == 0)
	    continue;
	c = getcmd(margv[0]);
	if (Ambiguous(c)) {
	    printf("?Ambiguous command: %s\n", margv[0]);
	    continue;
	}
	if (c == 0) {
	    printf("?Invalid command: %s\n", margv[0]);
	    continue;
	}
	/*
	 * This should never happen...
	 */
	if (c->needconnect && !connected) {
	    printf("?Need to be connected first for %s.\n", margv[0]);
	    continue;
	}
	(*c->handler)(margc, margv);
    }