linux_emul_base/miscdev.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <ureg.h>
   4 #include <mp.h>
   5 #include <libsec.h>
   6
   7 #include "dat.h"
   8 #include "fns.h"
   9 #include "linux.h"
  10
  11 enum
  12 {
  13         Mnull,
  14         Mzero,
  15         Mfull,
  16         Mrandom,
  17         Murandom,
  18         Mmax,
  19 };
  20
  21 typedef struct Miscfile Miscfile;
  22 struct Miscfile
  23 {
  24         Ufile;
  25         int     m;
  26 };
  27
  28 static int
  29 path2m(char *path)
  30 {
  31         int m;
  32
  33         m = -1;
  34         if(strcmp(path, "/dev/null")==0){
  35                 m = Mnull;
  36         } else if(strcmp(path, "/dev/zero")==0){
  37                 m = Mzero;
  38         } else if(strcmp(path, "/dev/full")==0){
  39                 m = Mfull;
  40         } else if(strcmp(path, "/dev/random")==0){
  41                 m = Mrandom;
  42         } else if(strcmp(path, "/dev/urandom")==0){
  43                 m = Murandom;
  44         }
  45
  46         return m;
  47 }
  48
  49 static int
  50 openmisc(char *path, int mode, int, Ufile **pf)
  51 {
  52         Miscfile *f;
  53         int m;
  54
  55         if((m = path2m(path)) < 0)
  56                 return -ENOENT;
  57         f = kmallocz(sizeof(*f), 1);
  58         f->ref = 1;
  59         f->mode = mode;
  60         f->path = kstrdup(path);
  61         f->fd = -1;
  62         f->dev = MISCDEV;
  63         f->m = m;
  64         *pf = f;
  65         return 0;
  66 }
  67
  68 static int
  69 closemisc(Ufile *)
  70 {
  71         return 0;
  72 }
  73
  74 static int
  75 readmisc(Ufile *f, void *buf, int len, vlong)
  76 {
  77         switch(((Miscfile*)f)->m){
  78         case Mnull:
  79                 return 0;
  80         case Mzero:
  81                 memset(buf, 0, len);
  82                 return len;
  83         case Mfull:
  84                 return -EIO;
  85         case Mrandom:
  86                 genrandom(buf, len);
  87                 return len;
  88         case Murandom:
  89                 prng(buf, len);
  90                 return len;
  91         default:
  92                 return -EIO;
  93         }
  94 }
  95
  96 static int
  97 writemisc(Ufile *f, void *, int len, vlong)
  98 {
  99         switch(((Miscfile*)f)->m){
 100         case Mnull:
 101         case Mzero:
 102         case Mrandom:
 103         case Murandom:
 104                 return len;
 105         case Mfull:
 106                 return -ENOSPC;
 107         default:
 108                 return -EIO;
 109         }
 110 }
 111
 112 static int
 113 statmisc(char *path, int, Ustat *s)
 114 {
 115         if(path2m(path) < 0)
 116                 return -ENOENT;
 117
 118         s->mode = 0666 | S_IFCHR;
 119         s->uid = current->uid;
 120         s->gid = current->gid;
 121         s->size = 0;
 122         s->ino = hashpath(path);
 123         s->dev = 0;
 124         s->rdev = 0;
 125         s->atime = s->mtime = s->ctime = boottime/1000000000LL;
 126         return 0;
 127 }
 128
 129 static int
 130 fstatmisc(Ufile *f, Ustat *s)
 131 {
 132         return fsstat(f->path, 0, s);
 133 };
 134
 135 static Udev miscdev =
 136 {
 137         .open = openmisc,
 138         .read = readmisc,
 139         .write = writemisc,
 140         .close = closemisc,
 141         .stat = statmisc,
 142         .fstat = fstatmisc,
 143 };
 144
 145 void miscdevinit(void)
 146 {
 147         devtab[MISCDEV] = &miscdev;
 148
 149         fsmount(&miscdev, "/dev/null");
 150         fsmount(&miscdev, "/dev/zero");
 151         fsmount(&miscdev, "/dev/full");
 152         fsmount(&miscdev, "/dev/random");
 153         fsmount(&miscdev, "/dev/urandom");
 154
 155         srand(truerand());
 156 }