sunos4/ppp_vdcmd.c

   1 #include <sys/types.h>
   2 #include <sys/errno.h>
   3 #include <sys/conf.h>
   4 #include <sun/vddrv.h>
   5
   6 extern struct streamtab pppinfo;
   7 extern int ppp_count;
   8 extern int nchrdev;
   9
  10 static struct vdldrv vd = {
  11     VDMAGIC_PSEUDO,
  12     "ppp"
  13 };
  14
  15 extern int nodev();
  16
  17 static struct cdevsw ppp_cdevsw = {
  18     nodev, nodev, nodev, nodev, nodev, nodev, nodev, 0,
  19     &pppinfo
  20 };
  21
  22 static struct cdevsw old_entry;
  23
  24 int
  25 ppp_vdcmd(fun, vdp, vdi, vds)
  26     unsigned int fun;
  27     struct vddrv *vdp;
  28     addr_t vdi;
  29     struct vdstat *vds;
  30 {
  31     static int majnum = -1;
  32     int n, maj;
  33
  34     switch (fun) {
  35     case VDLOAD:
  36         /*
  37          * It seems like modload doesn't install the cdevsw entry
  38          * for us.  Oh well...
  39          */
  40         for (maj = 1; maj < nchrdev; ++maj)
  41             if (cdevsw[maj].d_open == vd_unuseddev)
  42                 break;
  43         if (maj >= nchrdev)
  44             return ENODEV;
  45         vd.Drv_charmajor = maj;
  46         old_entry = cdevsw[maj];
  47         cdevsw[maj] = ppp_cdevsw;
  48         vd.Drv_cdevsw = &ppp_cdevsw;
  49         vdp->vdd_vdtab = (struct vdlinkage *) &vd;
  50         majnum = maj;
  51         break;
  52
  53     case VDUNLOAD:
  54         if (ppp_count > 0)
  55             return EBUSY;
  56         if (vd.Drv_charmajor > 0)
  57             cdevsw[vd.Drv_charmajor] = old_entry;
  58         break;
  59
  60     case VDSTAT:
  61         /*
  62          * We have to fool the modstat command into thinking
  63          * that this module is actually a driver! This is
  64          * so that installation commands that use the -exec
  65          * option of modload to run a shell script find out
  66          * the block and/or char major numbers of the driver
  67          * loaded (so that the shell script can go off to
  68          * /dev and *MAKE* the bloody device nodes- remember
  69          * they might change from one load to another if
  70          * you don't hardwire the number!).
  71          */
  72         vds->vds_magic = VDMAGIC_DRV;
  73         vds->vds_modinfo[0] = (char) 0;
  74         vds->vds_modinfo[1] = (char) majnum;
  75         break;
  76
  77     default:
  78         return EIO;
  79     }
  80     return 0;
  81 }