xio-pty.c

   1 /* source: xio-pty.c */
   2 /* Copyright Gerhard Rieger and contributors (see file CHANGES) */
   3 /* Published under the GNU General Public License V.2, see file COPYING */
   4
   5 /* this file contains the source for creating pty addresses */
   6
   7 #include "xiosysincludes.h"
   8 #include "xioopen.h"
   9
  10 #include "xio-named.h"
  11 #include "xio-termios.h"
  12
  13
  14 #if WITH_PTY
  15
  16 /* here define the preferred polling intervall, in seconds */
  17 #define PTY_INTERVALL 1,0       /* for struct timespec */
  18
  19 #define MAXPTYNAMELEN 64
  20
  21 static int xioopen_pty(int argc, const char *argv[], struct opt *opts, int xioflags, xiofile_t *fd, unsigned groups, int dummy1, int dummy2, int dummy3);
  22
  23 const struct addrdesc addr_pty = { "pty",   3, xioopen_pty, GROUP_NAMED|GROUP_FD|GROUP_TERMIOS|GROUP_PTY, 0, 0, 0 HELP("") };
  24
  25 const struct optdesc opt_symbolic_link = { "symbolic-link", "link", OPT_SYMBOLIC_LINK, GROUP_PTY, PH_LATE, TYPE_FILENAME, OFUNC_SPEC, 0, 0 };
  26 #if HAVE_POLL
  27 const struct optdesc opt_pty_wait_slave = { "pty-wait-slave", "wait-slave", OPT_PTY_WAIT_SLAVE, GROUP_PTY, PH_EARLY, TYPE_BOOL,   OFUNC_SPEC, 0, 0 };
  28 const struct optdesc opt_pty_intervall  = { "pty-interval",  NULL,         OPT_PTY_INTERVALL,  GROUP_PTY, PH_EARLY, TYPE_TIMESPEC, OFUNC_SPEC, 0, 0 };
  29 #endif /* HAVE_POLL */
  30
  31 static int xioopen_pty(int argc, const char *argv[], struct opt *opts, int xioflags, xiofile_t *xfd, unsigned groups, int dummy1, int dummy2, int dummy3) {
  32    /* we expect the form: filename */
  33    int ptyfd = -1, ttyfd = -1;
  34 #if defined(HAVE_DEV_PTMX) || defined(HAVE_DEV_PTC)
  35    bool useptmx = false;        /* use /dev/ptmx or equivalent */
  36 #endif
  37 #if HAVE_OPENPTY
  38    bool useopenpty = false;     /* try only openpty */
  39 #endif  /* HAVE_OPENPTY */
  40    char ptyname[MAXPTYNAMELEN];
  41    char *tn = NULL;
  42    char *linkname = NULL;
  43    bool opt_unlink_close = true;        /* remove symlink afterwards */
  44    bool wait_slave = false;     /* true would be better for many platforms, but
  45                                    some OSes cannot handle this, and for common
  46                                    default behaviour as well as backward
  47                                    compatibility we choose "no" as default */
  48    struct timespec pollintv = { PTY_INTERVALL };
  49
  50    if (argc != 1) {
  51       Error2("%s: wrong number of parameters (%d instead of 0)", argv[0], argc-1);
  52    }
  53
  54    xfd->stream.howtoend = END_CLOSE;
  55
  56    if (applyopts_single(&xfd->stream, opts, PH_INIT) < 0)  return -1;
  57    applyopts(-1, opts, PH_INIT);
  58
  59    retropt_bool(opts, OPT_UNLINK_CLOSE, &opt_unlink_close);
  60
  61    /* trying to set user-early, perm-early etc. here might be useless because
  62       file system entry is eventually available only past pty creation */
  63    /* name not yet known; umask should not be handled with this function! */
  64    /* umask does not affect resulting mode, on Linux 2.4 */
  65    applyopts_named("", opts, PH_EARLY); /* umask! */
  66
  67 #if defined(HAVE_DEV_PTMX) || defined(HAVE_DEV_PTC)
  68    retropt_bool(opts, OPT_PTMX, &useptmx);
  69 #endif
  70 #if HAVE_OPENPTY
  71    retropt_bool(opts, OPT_OPENPTY, &useopenpty);
  72 #endif
  73
  74 #if (defined(HAVE_DEV_PTMX) || defined(HAVE_DEV_PTC))
  75 #  if  HAVE_OPENPTY
  76    useopenpty = !useptmx;
  77 #  else /* !HAVE_OPENPTY */
  78    useptmx = true;
  79 #  endif /* !HAVE_OPENPTY */
  80 #else
  81 # if HAVE_OPENPTY
  82    useopenpty = true;
  83 # endif /* HAVE_OPENPTY */
  84 #endif /* ! (defined(HAVE_DEV_PTMX) || defined(HAVE_DEV_PTC)) */
  85
  86 #if HAVE_POLL
  87    retropt_bool(opts, OPT_PTY_WAIT_SLAVE, &wait_slave);
  88    retropt_timespec(opts, OPT_PTY_INTERVALL, &pollintv);
  89 #endif /* HAVE_POLL */
  90
  91    if (applyopts_single(&xfd->stream, opts, PH_INIT) < 0)  return -1;
  92    applyopts2(-1, opts, PH_INIT, PH_EARLY);
  93
  94    applyopts(-1, opts, PH_PREBIGEN);
  95
  96 #if defined(HAVE_DEV_PTMX)
  97 #  define PTMX "/dev/ptmx"      /* Linux */
  98 #elif HAVE_DEV_PTC
  99 #  define PTMX "/dev/ptc"       /* AIX 4.3.3 */
 100 #endif
 101 #if HAVE_DEV_PTMX || HAVE_DEV_PTC
 102    if (useptmx) {
 103       if ((ptyfd = Open(PTMX, O_RDWR|O_NOCTTY, 0620)) < 0) {
 104          Warn1("open(\""PTMX"\", O_RDWR|O_NOCTTY, 0620): %s",
 105                strerror(errno));
 106          /*!*/
 107       } else {
 108          ;/*0 Info1("open(\""PTMX"\", O_RDWR|O_NOCTTY, 0620) -> %d", ptyfd);*/
 109       }
 110       if (ptyfd >= 0 && ttyfd < 0) {
 111          /* we used PTMX before forking */
 112          /*0 extern char *ptsname(int);*/
 113 #if HAVE_GRANTPT        /* AIX, not Linux */
 114          if (Grantpt(ptyfd)/*!*/ < 0) {
 115             Warn2("grantpt(%d): %s", ptyfd, strerror(errno));
 116          }
 117 #endif /* HAVE_GRANTPT */
 118 #if HAVE_UNLOCKPT
 119          if (Unlockpt(ptyfd)/*!*/ < 0) {
 120             Warn2("unlockpt(%d): %s", ptyfd, strerror(errno));
 121          }
 122 #endif /* HAVE_UNLOCKPT */
 123 #if HAVE_PROTOTYPE_LIB_ptsname  /* AIX, not Linux */
 124          if ((tn = Ptsname(ptyfd)) == NULL) {
 125             Warn2("ptsname(%d): %s", ptyfd, strerror(errno));
 126          } else {
 127             Notice1("PTY is %s", tn);
 128          }
 129 #endif /* HAVE_PROTOTYPE_LIB_ptsname */
 130          if (tn == NULL) {
 131             if ((tn = Ttyname(ptyfd)) == NULL) {
 132                Warn2("ttyname(%d): %s", ptyfd, strerror(errno));
 133             }
 134          }
 135          ptyname[0] = '\0'; strncat(ptyname, tn, MAXPTYNAMELEN-1);
 136       }
 137    }
 138 #endif /* HAVE_DEV_PTMX || HAVE_DEV_PTC */
 139 #if HAVE_OPENPTY
 140    if (ptyfd < 0) {
 141       int result;
 142       if ((result = Openpty(&ptyfd, &ttyfd, ptyname, NULL, NULL)) < 0) {
 143          Error4("openpty(%p, %p, %p, NULL, NULL): %s",
 144                 &ptyfd, &ttyfd, ptyname, strerror(errno));
 145          return -1;
 146       }
 147       Notice1("PTY is %s", ptyname);
 148    }
 149 #endif /* HAVE_OPENPTY */
 150
 151    if (!retropt_string(opts, OPT_SYMBOLIC_LINK, &linkname)) {
 152       if (Unlink(linkname) < 0 && errno != ENOENT) {
 153          Error2("unlink(\"%s\"): %s", linkname, strerror(errno));
 154       }
 155       if (Symlink(ptyname, linkname) < 0) {
 156          Error3("symlink(\"%s\", \"%s\"): %s",
 157                 ptyname, linkname, strerror(errno));
 158       }
 159       if (opt_unlink_close) {
 160          if ((xfd->stream.unlink_close = strdup(linkname)) == NULL) {
 161             Error1("strdup(\"%s\"): out of memory", linkname);
 162          }
 163          xfd->stream.opt_unlink_close = true;
 164       }
 165    }
 166
 167    applyopts_named(ptyname, opts, PH_PASTOPEN);
 168    applyopts_named(ptyname, opts, PH_FD);
 169
 170    applyopts_cloexec(ptyfd, opts);/*!*/
 171    xfd->stream.dtype    = XIODATA_PTY;
 172
 173    applyopts(ptyfd, opts, PH_FD);
 174
 175    {
 176       /* special handling of user-late etc.; with standard behaviour (up to
 177          1.7.1.1) they affected /dev/ptmx instead of /dev/pts/N */
 178       uid_t uid = -1, gid = -1;
 179       mode_t perm;
 180
 181       bool dont;
 182       dont = retropt_uid(opts, OPT_USER_LATE, &uid);
 183       dont &= retropt_gid(opts, OPT_GROUP_LATE, &gid);
 184
 185       if (!dont) {
 186          if (Chown(ptyname, uid, gid) < 0) {
 187             Error4("chown(\"%s\", %d, %d): %s",
 188                    ptyname, uid, gid, strerror(errno));
 189          }
 190       }
 191
 192       if (retropt_mode(opts, OPT_PERM_LATE, &perm) == 0) {
 193          if (Chmod(ptyname, perm) < 0) {
 194             Error3("chmod(\"%s\", %03o): %s",
 195                    ptyname, perm, strerror(errno));
 196          }
 197       }
 198
 199    }
 200
 201    xfd->stream.fd = ptyfd;
 202    applyopts(ptyfd, opts, PH_LATE);
 203    if (applyopts_single(&xfd->stream, opts, PH_LATE) < 0)  return -1;
 204
 205 #if HAVE_POLL
 206    /* if you can and wish: */
 207    if (wait_slave) {
 208       /* try to wait until someone opens the slave side of the pty */
 209       /* we want to get a HUP (hangup) condition on the pty */
 210 #if HAVE_DEV_PTMX || HAVE_DEV_PTC
 211       if (useptmx) {
 212          ttyfd = Open(tn, O_RDWR|O_NOCTTY, 0620);
 213          Close(ttyfd);
 214       }
 215 #endif
 216 #if HAVE_OPENPTY
 217       if (useopenpty) {
 218          Close(ttyfd);
 219       }
 220 #endif /* HAVE_OPENPTY */
 221
 222       /* now we poll until the HUP vanishes - this indicates a slave conn. */
 223       while (true) {
 224          struct pollfd ufd;
 225          ufd.fd = ptyfd;
 226          ufd.events = (POLLHUP);
 227          if (Poll(&ufd, 1, 0) < 0) {
 228             Error3("poll({%d, 0x%04hu,}, 1, 0): %s",
 229                    ufd.fd, ufd.events, strerror(errno));
 230             /*! close something */
 231             return -1;
 232          }
 233          if (!(ufd.revents & POLLHUP)) {
 234             break;
 235          }
 236          Nanosleep(&pollintv, NULL);
 237          continue;
 238       }
 239    }
 240 #endif /* HAVE_POLL */
 241
 242    return STAT_OK;
 243 }
 244 #endif /* WITH_PTY */