winsup/cygwin/fhandler_termios.cc

   1 /* fhandler_termios.cc
   2
   3    Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009,
   4    2010, 2011, 2012 Red Hat, Inc.
   5
   6 This file is part of Cygwin.
   7
   8 This software is a copyrighted work licensed under the terms of the
   9 Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
  10 details. */
  11
  12 #include "winsup.h"
  13 #include <stdlib.h>
  14 #include <ctype.h>
  15 #include "cygerrno.h"
  16 #include "path.h"
  17 #include "fhandler.h"
  18 #include "sigproc.h"
  19 #include "pinfo.h"
  20 #include "tty.h"
  21 #include "cygtls.h"
  22 #include "dtable.h"
  23 #include "cygheap.h"
  24 #include "child_info.h"
  25 #include "ntdll.h"
  26
  27 /* Common functions shared by tty/console */
  28
  29 void
  30 fhandler_termios::tcinit (bool is_pty_master)
  31 {
  32   /* Initial termios values */
  33
  34   if (is_pty_master || !tc ()->initialized ())
  35     {
  36       tc ()->ti.c_iflag = BRKINT | ICRNL | IXON;
  37       tc ()->ti.c_oflag = OPOST | ONLCR;
  38       tc ()->ti.c_cflag = B38400 | CS8 | CREAD;
  39       tc ()->ti.c_lflag = ISIG | ICANON | ECHO | IEXTEN;
  40
  41       tc ()->ti.c_cc[VDISCARD]  = CFLUSH;
  42       tc ()->ti.c_cc[VEOL]              = CEOL;
  43       tc ()->ti.c_cc[VEOL2]     = CEOL2;
  44       tc ()->ti.c_cc[VEOF]              = CEOF;
  45       tc ()->ti.c_cc[VERASE]    = CERASE;
  46       tc ()->ti.c_cc[VINTR]     = CINTR;
  47       tc ()->ti.c_cc[VKILL]     = CKILL;
  48       tc ()->ti.c_cc[VLNEXT]    = CLNEXT;
  49       tc ()->ti.c_cc[VMIN]              = 1;
  50       tc ()->ti.c_cc[VQUIT]     = CQUIT;
  51       tc ()->ti.c_cc[VREPRINT]  = CRPRNT;
  52       tc ()->ti.c_cc[VSTART]    = CSTART;
  53       tc ()->ti.c_cc[VSTOP]     = CSTOP;
  54       tc ()->ti.c_cc[VSUSP]     = CSUSP;
  55       tc ()->ti.c_cc[VSWTC]     = CSWTCH;
  56       tc ()->ti.c_cc[VTIME]     = 0;
  57       tc ()->ti.c_cc[VWERASE]   = CWERASE;
  58
  59       tc ()->ti.c_ispeed = tc ()->ti.c_ospeed = B38400;
  60       tc ()->pgid = is_pty_master ? 0 : myself->pgid;
  61       tc ()->initialized (true);
  62     }
  63 }
  64
  65 int
  66 fhandler_termios::tcsetpgrp (const pid_t pgid)
  67 {
  68   termios_printf ("%s, pgid %d, sid %d, tsid %d", tc ()->ttyname (), pgid,
  69                     myself->sid, tc ()->getsid ());
  70   if (myself->sid != tc ()->getsid ())
  71     {
  72       set_errno (EPERM);
  73       return -1;
  74     }
  75   int res;
  76   while (1)
  77     {
  78       res = bg_check (-SIGTTOU);
  79
  80       switch (res)
  81         {
  82         case bg_ok:
  83           tc ()->setpgid (pgid);
  84           if (tc ()->is_console && (strace.active () || !being_debugged ()))
  85             tc ()->kill_pgrp (__SIGSETPGRP);
  86           res = 0;
  87           break;
  88         case bg_signalled:
  89           if (_my_tls.call_signal_handler ())
  90             continue;
  91           set_errno (EINTR);
  92           /* fall through intentionally */
  93         default:
  94           res = -1;
  95           break;
  96         }
  97       break;
  98     }
  99   return res;
 100 }
 101
 102 int
 103 fhandler_termios::tcgetpgrp ()
 104 {
 105   if (myself->ctty > 0 && myself->ctty == tc ()->ntty)
 106     return tc ()->pgid;
 107   set_errno (ENOTTY);
 108   return -1;
 109 }
 110
 111 int
 112 fhandler_pty_master::tcgetpgrp ()
 113 {
 114   return tc ()->pgid;
 115 }
 116
 117 void
 118 tty_min::kill_pgrp (int sig)
 119 {
 120   bool killself = false;
 121   winpids pids ((DWORD) PID_MAP_RW);
 122   siginfo_t si = {0};
 123   si.si_signo = sig;
 124   si.si_code = SI_KERNEL;
 125   for (unsigned i = 0; i < pids.npids; i++)
 126     {
 127       _pinfo *p = pids[i];
 128       if (!p->exists () || p->ctty != ntty || p->pgid != pgid)
 129         continue;
 130       if (p == myself)
 131         killself = sig != __SIGSETPGRP;
 132       else
 133         sig_send (p, si);
 134     }
 135   if (killself)
 136     sig_send (myself, si);
 137 }
 138
 139 int
 140 tty_min::is_orphaned_process_group (int pgid)
 141 {
 142   /* An orphaned process group is a process group in which the parent
 143      of every member is either itself a member of the group or is not
 144      a member of the group's session. */
 145   termios_printf ("checking pgid %d, my sid %d, my parent %d", pgid, myself->sid, myself->ppid);
 146   winpids pids ((DWORD) 0);
 147   for (unsigned i = 0; i < pids.npids; i++)
 148     {
 149       _pinfo *p = pids[i];
 150       termios_printf ("checking pid %d - has pgid %d\n", p->pid, p->pgid);
 151       if (!p || !p->exists () || p->pgid != pgid)
 152         continue;
 153       pinfo ppid (p->ppid);
 154       if (!ppid)
 155         continue;
 156       termios_printf ("ppid->pgid %d, ppid->sid %d", ppid->pgid, ppid->sid);
 157       if (ppid->pgid != pgid && ppid->sid == myself->sid)
 158         return 0;
 159     }
 160   return 1;
 161 }
 162
 163 bg_check_types
 164 fhandler_termios::bg_check (int sig)
 165 {
 166   if (!myself->pgid || tc ()->getpgid () == myself->pgid ||
 167         myself->ctty != tc ()->ntty ||
 168         ((sig == SIGTTOU) && !(tc ()->ti.c_lflag & TOSTOP)))
 169     return bg_ok;
 170
 171   if (sig < 0)
 172     sig = -sig;
 173
 174   termios_printf ("%s, bg I/O pgid %d, tpgid %d, myctty %s", tc ()->ttyname (),
 175                   myself->pgid, tc ()->getpgid (), myctty ());
 176
 177   if (tc ()->getsid () == 0)
 178     {
 179       /* The pty has been closed by the master.  Return an EOF
 180          indication.  FIXME: There is nothing to stop somebody
 181          from reallocating this pty.  I think this is the case
 182          which is handled by unlockpt on a Unix system.  */
 183       termios_printf ("closed by master");
 184       return bg_eof;
 185     }
 186
 187   int sigs_ignored =
 188     ((void *) global_sigs[sig].sa_handler == (void *) SIG_IGN) ||
 189     (_main_tls->sigmask & SIGTOMASK (sig));
 190
 191   /* If the process is ignoring SIGTT*, then background IO is OK.  If
 192      the process is not ignoring SIGTT*, then the sig is to be sent to
 193      all processes in the process group (unless the process group of the
 194      process is orphaned, in which case we return EIO). */
 195   if (sigs_ignored)
 196     return bg_ok;   /* Just allow the IO */
 197   else if (tc ()->is_orphaned_process_group (myself->pgid))
 198     {
 199       termios_printf ("process group is orphaned");
 200       set_errno (EIO);   /* This is an IO error */
 201       return bg_error;
 202     }
 203   else
 204     {
 205       /* Don't raise a SIGTT* signal if we have already been
 206          interrupted by another signal. */
 207       if (WaitForSingleObject (signal_arrived, 0) != WAIT_OBJECT_0)
 208         {
 209           siginfo_t si = {0};
 210           si.si_signo = sig;
 211           si.si_code = SI_KERNEL;
 212           kill_pgrp (myself->pgid, si);
 213         }
 214       return bg_signalled;
 215     }
 216 }
 217
 218 #define set_input_done(x) input_done = input_done || (x)
 219
 220 inline void
 221 fhandler_termios::echo_erase (int force)
 222 {
 223   if (force || tc ()->ti.c_lflag & ECHO)
 224     doecho ("\b \b", 3);
 225 }
 226
 227 line_edit_status
 228 fhandler_termios::line_edit (const char *rptr, int nread, termios& ti)
 229 {
 230   line_edit_status ret = line_edit_ok;
 231   char c;
 232   int input_done = 0;
 233   bool sawsig = false;
 234   int iscanon = ti.c_lflag & ICANON;
 235
 236   while (nread-- > 0)
 237     {
 238       c = *rptr++;
 239
 240       termios_printf ("char %c", c);
 241
 242       /* Check for special chars */
 243
 244       if (c == '\r')
 245         {
 246           if (ti.c_iflag & IGNCR)
 247             continue;
 248           if (ti.c_iflag & ICRNL)
 249             {
 250               c = '\n';
 251               set_input_done (iscanon);
 252             }
 253         }
 254       else if (c == '\n')
 255         {
 256           if (ti.c_iflag & INLCR)
 257             c = '\r';
 258           else
 259             set_input_done (iscanon);
 260         }
 261
 262       if (ti.c_iflag & ISTRIP)
 263         c &= 0x7f;
 264       if (ti.c_lflag & ISIG)
 265         {
 266           int sig;
 267           if (CCEQ (ti.c_cc[VINTR], c))
 268             sig = SIGINT;
 269           else if (CCEQ (ti.c_cc[VQUIT], c))
 270             sig = SIGQUIT;
 271           else if (CCEQ (ti.c_cc[VSUSP], c))
 272             sig = SIGTSTP;
 273           else
 274             goto not_a_sig;
 275
 276           termios_printf ("got interrupt %d, sending signal %d", c, sig);
 277           eat_readahead (-1);
 278           tc ()->kill_pgrp (sig);
 279           ti.c_lflag &= ~FLUSHO;
 280           sawsig = true;
 281           goto restart_output;
 282         }
 283     not_a_sig:
 284       if (ti.c_iflag & IXON)
 285         {
 286           if (CCEQ (ti.c_cc[VSTOP], c))
 287             {
 288               if (!tc ()->output_stopped)
 289                 {
 290                   tc ()->output_stopped = 1;
 291                   acquire_output_mutex (INFINITE);
 292                 }
 293               continue;
 294             }
 295           else if (CCEQ (ti.c_cc[VSTART], c))
 296             {
 297     restart_output:
 298               tc ()->output_stopped = 0;
 299               release_output_mutex ();
 300               continue;
 301             }
 302           else if ((ti.c_iflag & IXANY) && tc ()->output_stopped)
 303             goto restart_output;
 304         }
 305       if (iscanon && ti.c_lflag & IEXTEN && CCEQ (ti.c_cc[VDISCARD], c))
 306         {
 307           ti.c_lflag ^= FLUSHO;
 308           continue;
 309         }
 310       if (!iscanon)
 311         /* nothing */;
 312       else if (CCEQ (ti.c_cc[VERASE], c))
 313         {
 314           if (eat_readahead (1))
 315             echo_erase ();
 316           continue;
 317         }
 318       else if (CCEQ (ti.c_cc[VWERASE], c))
 319         {
 320           int ch;
 321           do
 322             if (!eat_readahead (1))
 323               break;
 324             else
 325               echo_erase ();
 326           while ((ch = peek_readahead (1)) >= 0 && !isspace (ch));
 327           continue;
 328         }
 329       else if (CCEQ (ti.c_cc[VKILL], c))
 330         {
 331           int nchars = eat_readahead (-1);
 332           if (ti.c_lflag & ECHO)
 333             while (nchars--)
 334               echo_erase (1);
 335           continue;
 336         }
 337       else if (CCEQ (ti.c_cc[VREPRINT], c))
 338         {
 339           if (ti.c_lflag & ECHO)
 340             {
 341               doecho ("\n\r", 2);
 342               doecho (rabuf, ralen);
 343             }
 344           continue;
 345         }
 346       else if (CCEQ (ti.c_cc[VEOF], c))
 347         {
 348           termios_printf ("EOF");
 349           accept_input ();
 350           ret = line_edit_input_done;
 351           continue;
 352         }
 353       else if (CCEQ (ti.c_cc[VEOL], c) ||
 354                CCEQ (ti.c_cc[VEOL2], c) ||
 355                c == '\n')
 356         {
 357           set_input_done (1);
 358           termios_printf ("EOL");
 359         }
 360
 361       if (ti.c_iflag & IUCLC && isupper (c))
 362         c = cyg_tolower (c);
 363
 364       put_readahead (c);
 365       if (ti.c_lflag & ECHO)
 366         doecho (&c, 1);
 367       if (!iscanon || input_done)
 368         {
 369           int status = accept_input ();
 370           if (status != 1)
 371             {
 372               ret = status ? line_edit_error : line_edit_pipe_full;
 373               eat_readahead (1);
 374               break;
 375             }
 376           ret = line_edit_input_done;
 377           input_done = 0;
 378         }
 379     }
 380
 381   if (!iscanon && ralen > 0)
 382     ret = line_edit_input_done;
 383
 384   if (sawsig)
 385     ret = line_edit_signalled;
 386
 387   return ret;
 388 }
 389
 390 _off64_t
 391 fhandler_termios::lseek (_off64_t, int)
 392 {
 393   set_errno (ESPIPE);
 394   return -1;
 395 }
 396
 397 void
 398 fhandler_termios::sigflush ()
 399 {
 400   /* FIXME: Checking get_ttyp() for NULL is not right since it should not
 401      be NULL while this is alive.  However, we can conceivably close a
 402      ctty while exiting and that will zero this. */
 403   if ((!have_execed || have_execed_cygwin) && get_ttyp ()
 404       && !(get_ttyp ()->ti.c_lflag & NOFLSH))
 405     tcflush (TCIFLUSH);
 406 }
 407
 408 pid_t
 409 fhandler_termios::tcgetsid ()
 410 {
 411   if (myself->ctty > 0 && myself->ctty == tc ()->ntty)
 412     return tc ()->getsid ();
 413   set_errno (ENOTTY);
 414   return -1;
 415 }
 416
 417 int
 418 fhandler_termios::ioctl (int cmd, void *varg)
 419 {
 420   if (cmd != TIOCSCTTY)
 421     return 1;           /* Not handled by this function */
 422
 423   int arg = (int) varg;
 424
 425   if (arg != 0 && arg != 1)
 426     {
 427       set_errno (EINVAL);
 428       return -1;
 429     }
 430
 431   termios_printf ("myself->ctty %d, myself->sid %d, myself->pid %d, arg %d, tc()->getsid () %d\n",
 432                   myself->ctty, myself->sid, myself->pid, arg, tc ()->getsid ());
 433   if (myself->ctty > 0 || myself->sid != myself->pid || (!arg && tc ()->getsid () > 0))
 434     {
 435       set_errno (EPERM);
 436       return -1;
 437     }
 438
 439   myself->ctty = -1;
 440   myself->set_ctty (this, 0);
 441   return 0;
 442 }