[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/kern/tty_ptm.c

Version: -  FREEBSD  -  FREEBSD10  -  FREEBSD9  -  FREEBSD92  -  FREEBSD91  -  FREEBSD90  -  FREEBSD8  -  FREEBSD82  -  FREEBSD81  -  FREEBSD80  -  FREEBSD7  -  FREEBSD74  -  FREEBSD73  -  FREEBSD72  -  FREEBSD71  -  FREEBSD70  -  FREEBSD6  -  FREEBSD64  -  FREEBSD63  -  FREEBSD62  -  FREEBSD61  -  FREEBSD60  -  FREEBSD5  -  FREEBSD55  -  FREEBSD54  -  FREEBSD53  -  FREEBSD52  -  FREEBSD51  -  FREEBSD50  -  FREEBSD4  -  FREEBSD3  -  FREEBSD22  -  cheribsd  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1  -  FREEBSD-LIBC  -  FREEBSD8-LIBC  -  FREEBSD7-LIBC  -  FREEBSD6-LIBC  -  GLIBC27 
SearchContext: -  none  -  3  -  10 

    1 /*      $NetBSD: tty_ptm.c,v 1.27 2010/06/24 13:03:11 hannken Exp $     */
    2 
    3 /*-
    4  * Copyright (c) 2004 The NetBSD Foundation, Inc.
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  *
   16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
   17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
   20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   26  * POSSIBILITY OF SUCH DAMAGE.
   27  */
   28 
   29 #include <sys/cdefs.h>
   30 __KERNEL_RCSID(0, "$NetBSD: tty_ptm.c,v 1.27 2010/06/24 13:03:11 hannken Exp $");
   31 
   32 #include "opt_ptm.h"
   33 
   34 /* pty multiplexor driver /dev/ptm{,x} */
   35 
   36 #include <sys/param.h>
   37 #include <sys/systm.h>
   38 #include <sys/ioctl.h>
   39 #include <sys/proc.h>
   40 #include <sys/tty.h>
   41 #include <sys/stat.h>
   42 #include <sys/file.h>
   43 #include <sys/uio.h>
   44 #include <sys/kernel.h>
   45 #include <sys/vnode.h>
   46 #include <sys/namei.h>
   47 #include <sys/signalvar.h>
   48 #include <sys/filedesc.h>
   49 #include <sys/conf.h>
   50 #include <sys/poll.h>
   51 #include <sys/pty.h>
   52 #include <sys/kauth.h>
   53 
   54 #include <miscfs/specfs/specdev.h>
   55 
   56 #ifdef DEBUG_PTM
   57 #define DPRINTF(a)      printf a
   58 #else
   59 #define DPRINTF(a)
   60 #endif
   61 
   62 #ifdef NO_DEV_PTM
   63 const struct cdevsw ptm_cdevsw = {
   64         noopen, noclose, noread, nowrite, noioctl,
   65         nostop, notty, nopoll, nommap, nokqfilter, D_TTY
   66 };
   67 #else
   68 
   69 static struct ptm_pty *ptm;
   70 int pts_major, ptc_major;
   71 
   72 static dev_t pty_getfree(void);
   73 static int pty_alloc_master(struct lwp *, int *, dev_t *);
   74 static int pty_alloc_slave(struct lwp *, int *, dev_t);
   75 
   76 void ptmattach(int);
   77 
   78 dev_t
   79 pty_makedev(char ms, int minor)
   80 {
   81         return makedev(ms == 't' ? pts_major : ptc_major, minor);
   82 }
   83 
   84 
   85 static dev_t
   86 pty_getfree(void)
   87 {
   88         extern kmutex_t pt_softc_mutex;
   89         int i;
   90 
   91         mutex_enter(&pt_softc_mutex);
   92         for (i = 0; i < npty; i++) {
   93                 if (pty_isfree(i, 0))
   94                         break;
   95         }
   96         mutex_exit(&pt_softc_mutex);
   97         return pty_makedev('t', i);
   98 }
   99 
  100 /*
  101  * Hacked up version of vn_open. We _only_ handle ptys and only open
  102  * them with FREAD|FWRITE and never deal with creat or stuff like that.
  103  *
  104  * We need it because we have to fake up root credentials to open the pty.
  105  */
  106 int
  107 pty_vn_open(struct vnode *vp, struct lwp *l)
  108 {
  109         int error;
  110 
  111         if (vp->v_type != VCHR) {
  112                 vput(vp);
  113                 return EINVAL;
  114         }
  115 
  116         error = VOP_OPEN(vp, FREAD|FWRITE, lwp0.l_cred);
  117 
  118         if (error) {
  119                 vput(vp);
  120                 return error;
  121         }
  122 
  123         vp->v_writecount++;
  124 
  125         return 0;
  126 }
  127 
  128 static int
  129 pty_alloc_master(struct lwp *l, int *fd, dev_t *dev)
  130 {
  131         int error;
  132         struct file *fp;
  133         struct vnode *vp;
  134         int md;
  135 
  136         if ((error = fd_allocfile(&fp, fd)) != 0) {
  137                 DPRINTF(("fd_allocfile %d\n", error));
  138                 return error;
  139         }
  140 retry:
  141         /* Find and open a free master pty. */
  142         *dev = pty_getfree();
  143         md = minor(*dev);
  144         if ((error = pty_check(md)) != 0) {
  145                 DPRINTF(("pty_check %d\n", error));
  146                 goto bad;
  147         }
  148         if (ptm == NULL) {
  149                 DPRINTF(("no ptm\n"));
  150                 error = EOPNOTSUPP;
  151                 goto bad;
  152         }
  153         if ((error = (*ptm->allocvp)(ptm, l, &vp, *dev, 'p')) != 0) {
  154                 DPRINTF(("pty_allocvp %d\n", error));
  155                 goto bad;
  156         }
  157 
  158         if ((error = pty_vn_open(vp, l)) != 0) {
  159                 DPRINTF(("pty_vn_open %d\n", error));
  160                 /*
  161                  * Check if the master open failed because we lost
  162                  * the race to grab it.
  163                  */
  164                 if (error != EIO)
  165                         goto bad;
  166                 error = !pty_isfree(md, 1);
  167                 DPRINTF(("pty_isfree %d\n", error));
  168                 if (error)
  169                         goto retry;
  170                 else
  171                         goto bad;
  172         }
  173         fp->f_flag = FREAD|FWRITE;
  174         fp->f_type = DTYPE_VNODE;
  175         fp->f_ops = &vnops;
  176         fp->f_data = vp;
  177         VOP_UNLOCK(vp);
  178         fd_affix(curproc, fp, *fd);
  179         return 0;
  180 bad:
  181         fd_abort(curproc, fp, *fd);
  182         return error;
  183 }
  184 
  185 int
  186 pty_grant_slave(struct lwp *l, dev_t dev)
  187 {
  188         int error;
  189         struct vnode *vp;
  190 
  191         /*
  192          * Open the slave.
  193          * namei -> setattr -> unlock -> revoke -> vrele ->
  194          * namei -> open -> unlock
  195          * Three stage rocket:
  196          * 1. Change the owner and permissions on the slave.
  197          * 2. Revoke all the users of the slave.
  198          * 3. open the slave.
  199          */
  200         if (ptm == NULL)
  201                 return EOPNOTSUPP;
  202         if ((error = (*ptm->allocvp)(ptm, l, &vp, dev, 't')) != 0)
  203                 return error;
  204 
  205         if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
  206                 struct vattr vattr;
  207                 (*ptm->getvattr)(ptm, l, &vattr);
  208                 /* Do the VOP_SETATTR() as root. */
  209                 error = VOP_SETATTR(vp, &vattr, lwp0.l_cred);
  210                 if (error) {
  211                         DPRINTF(("setattr %d\n", error));
  212                         VOP_UNLOCK(vp);
  213                         vrele(vp);
  214                         return error;
  215                 }
  216         }
  217         VOP_UNLOCK(vp);
  218         VOP_REVOKE(vp, REVOKEALL);
  219 
  220         /*
  221          * The vnode is useless after the revoke, we need to get it again.
  222          */
  223         vrele(vp);
  224         return 0;
  225 }
  226 
  227 static int
  228 pty_alloc_slave(struct lwp *l, int *fd, dev_t dev)
  229 {
  230         int error;
  231         struct file *fp;
  232         struct vnode *vp;
  233 
  234         /* Grab a filedescriptor for the slave */
  235         if ((error = fd_allocfile(&fp, fd)) != 0) {
  236                 DPRINTF(("fd_allocfile %d\n", error));
  237                 return error;
  238         }
  239 
  240         if (ptm == NULL) {
  241                 error = EOPNOTSUPP;
  242                 goto bad;
  243         }
  244 
  245         if ((error = (*ptm->allocvp)(ptm, l, &vp, dev, 't')) != 0)
  246                 goto bad;
  247         if ((error = pty_vn_open(vp, l)) != 0)
  248                 goto bad;
  249 
  250         fp->f_flag = FREAD|FWRITE;
  251         fp->f_type = DTYPE_VNODE;
  252         fp->f_ops = &vnops;
  253         fp->f_data = vp;
  254         VOP_UNLOCK(vp);
  255         fd_affix(curproc, fp, *fd);
  256         return 0;
  257 bad:
  258         fd_abort(curproc, fp, *fd);
  259         return error;
  260 }
  261 
  262 struct ptm_pty *
  263 pty_sethandler(struct ptm_pty *nptm)
  264 {
  265         struct ptm_pty *optm = ptm;
  266         ptm = nptm;
  267         return optm;
  268 }
  269 
  270 int
  271 pty_fill_ptmget(struct lwp *l, dev_t dev, int cfd, int sfd, void *data)
  272 {
  273         struct ptmget *ptmg = data;
  274         int error;
  275 
  276         if (ptm == NULL)
  277                 return EOPNOTSUPP;
  278 
  279         ptmg->cfd = cfd == -1 ? minor(dev) : cfd;
  280         ptmg->sfd = sfd == -1 ? minor(dev) : sfd;
  281 
  282         error = (*ptm->makename)(ptm, l, ptmg->cn, sizeof(ptmg->cn), dev, 'p');
  283         if (error)
  284                 return error;
  285 
  286         return (*ptm->makename)(ptm, l, ptmg->sn, sizeof(ptmg->sn), dev, 't');
  287 }
  288 
  289 void
  290 /*ARGSUSED*/
  291 ptmattach(int n)
  292 {
  293         extern const struct cdevsw pts_cdevsw, ptc_cdevsw;
  294         /* find the major and minor of the pty devices */
  295         if ((pts_major = cdevsw_lookup_major(&pts_cdevsw)) == -1)
  296                 panic("ptmattach: Can't find pty slave in cdevsw");
  297         if ((ptc_major = cdevsw_lookup_major(&ptc_cdevsw)) == -1)
  298                 panic("ptmattach: Can't find pty master in cdevsw");
  299 #ifdef COMPAT_BSDPTY
  300         ptm = &ptm_bsdpty;
  301 #endif
  302 }
  303 
  304 static int
  305 /*ARGSUSED*/
  306 ptmopen(dev_t dev, int flag, int mode, struct lwp *l)
  307 {
  308         int error;
  309         int fd;
  310         dev_t ttydev;
  311 
  312         switch(minor(dev)) {
  313         case 0:         /* /dev/ptmx */
  314         case 2:         /* /emul/linux/dev/ptmx */
  315                 if ((error = pty_alloc_master(l, &fd, &ttydev)) != 0)
  316                         return error;
  317                 if (minor(dev) == 2) {
  318                         /*
  319                          * Linux ptyfs grants the pty right here.
  320                          * Handle this case here, instead of writing
  321                          * a new linux module.
  322                          */
  323                         if ((error = pty_grant_slave(l, ttydev)) != 0) {
  324                                 file_t *fp = fd_getfile(fd);
  325                                 if (fp != NULL) {
  326                                         fd_close(fd);
  327                                 }
  328                                 return error;
  329                         }
  330                 }
  331                 curlwp->l_dupfd = fd;
  332                 return EMOVEFD;
  333         case 1:         /* /dev/ptm */
  334                 return 0;
  335         default:
  336                 return ENODEV;
  337         }
  338 }
  339 
  340 static int
  341 /*ARGSUSED*/
  342 ptmclose(dev_t dev, int flag, int mode, struct lwp *l)
  343 {
  344 
  345         return (0);
  346 }
  347 
  348 static int
  349 /*ARGSUSED*/
  350 ptmioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
  351 {
  352         int error;
  353         dev_t newdev;
  354         int cfd, sfd;
  355         file_t *fp;
  356 
  357         error = 0;
  358         switch (cmd) {
  359         case TIOCPTMGET:
  360                 if ((error = pty_alloc_master(l, &cfd, &newdev)) != 0)
  361                         return error;
  362 
  363                 if ((error = pty_grant_slave(l, newdev)) != 0)
  364                         goto bad;
  365 
  366                 if ((error = pty_alloc_slave(l, &sfd, newdev)) != 0)
  367                         goto bad;
  368 
  369                 /* now, put the indices and names into struct ptmget */
  370                 return pty_fill_ptmget(l, newdev, cfd, sfd, data);
  371         default:
  372                 DPRINTF(("ptmioctl EINVAL\n"));
  373                 return EINVAL;
  374         }
  375  bad:
  376         fp = fd_getfile(cfd);
  377         if (fp != NULL) {
  378                 fd_close(cfd);
  379         }
  380         return error;
  381 }
  382 
  383 const struct cdevsw ptm_cdevsw = {
  384         ptmopen, ptmclose, noread, nowrite, ptmioctl,
  385         nullstop, notty, nopoll, nommap, nokqfilter, D_TTY
  386 };
  387 #endif

Cache object: a0b7f68d76d5351920d6871f7f2147c4


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.