ttapfs.c - plan9port - [fork] Plan 9 from user space
  HTML git clone git://src.adamsgaard.dk/plan9port
   DIR Log
   DIR Files
   DIR Refs
   DIR README
   DIR LICENSE
       ---
       ttapfs.c (1924B)
       ---
            1 #include <u.h>
            2 #include <libc.h>
            3 #include "tapefs.h"
            4 
            5 /*
            6  * File system for old tap tapes.
            7  */
            8 
            9 struct tap {
           10         unsigned char        name[32];
           11         unsigned char        mode[1];
           12         unsigned char        uid[1];
           13         unsigned char        size[2];
           14         unsigned char        tmod[4];
           15         unsigned char        taddress[2];
           16         unsigned char        unused[20];
           17         unsigned char        checksum[2];
           18 } dir[192];
           19 
           20 int        tapefile;
           21 char        buffer[8192];
           22 long        cvtime(unsigned char *);
           23 extern        int verbose;
           24 extern        int newtap;
           25 
           26 void
           27 populate(char *name)
           28 {
           29         int i, isabs;
           30         struct tap *tpp;
           31         Fileinf f;
           32 
           33         replete = 1;
           34         tapefile = open(name, OREAD);
           35         if (tapefile<0)
           36                 error("Can't open argument file");
           37         read(tapefile, dir, sizeof dir);
           38         for (i=0, tpp=&dir[8]; i<192; i++, tpp++) {
           39                 unsigned char *sp = (unsigned char *)tpp;
           40                 int j, cksum = 0;
           41                 for (j=0; j<32; j++, sp+=2)
           42                         cksum += sp[0] + (sp[1]<<8);
           43                 cksum &= 0xFFFF;
           44                 if (cksum!=0) {
           45                         print("cksum failure\n");
           46                         continue;
           47                 }
           48                 if (tpp->name[0]=='\0')
           49                         continue;
           50                 f.addr = tpp->taddress[0] + (tpp->taddress[1]<<8);
           51                 if (f.addr==0)
           52                         continue;
           53                 f.size = tpp->size[0] + (tpp->size[1]<<8);
           54                 f.mdate = cvtime(tpp->tmod);
           55                 f.mode = tpp->mode[0]&0777;
           56                 f.uid = tpp->uid[0]&0377;
           57                 isabs = tpp->name[0]=='/';
           58                 f.name = (char *)tpp->name+isabs;
           59                 if (verbose)
           60                         print("%s mode %o uid %d, %s", f.name, f.mode, f.uid, ctime(f.mdate));
           61                 poppath(f, 1);
           62         }
           63 }
           64 
           65 long
           66 cvtime(unsigned char *tp)
           67 {
           68         unsigned long t = (tp[1]<<24)+(tp[0]<<16)+(tp[3]<<8)+(tp[2]<<0);
           69         if (!newtap) {
           70                 t /= 60;
           71                 t += 3*365*24*3600;
           72         }
           73         return t;
           74 }
           75 
           76 void
           77 popdir(Ram *r)
           78 {
           79         USED(r);
           80 }
           81 
           82 void
           83 dotrunc(Ram *r)
           84 {
           85         USED(r);
           86 }
           87 
           88 void
           89 docreate(Ram *r)
           90 {
           91         USED(r);
           92 }
           93 
           94 char *
           95 doread(Ram *r, vlong off, long cnt)
           96 {
           97         if (cnt>sizeof(buffer))
           98                 print("count too big\n");
           99         seek(tapefile, 512*r->addr+off, 0);
          100         read(tapefile, buffer, cnt);
          101         return buffer;
          102 }
          103 
          104 void
          105 dowrite(Ram *r, char *buf, long off, long cnt)
          106 {
          107         USED(r); USED(buf); USED(off); USED(cnt);
          108 }
          109 
          110 int
          111 dopermw(Ram *r)
          112 {
          113         USED(r);
          114         return 0;
          115 }