lib/decode.c

   1 /*
   2 **  Copyright 1998-2003 University of Illinois Board of Trustees
   3 **  Copyright 1998-2003 Mark D. Roth
   4 **  All rights reserved.
   5 **
   6 **  decode.c - libtar code to decode tar header blocks
   7 **
   8 **  Mark D. Roth <roth@uiuc.edu>
   9 **  Campus Information Technologies and Educational Services
  10 **  University of Illinois at Urbana-Champaign
  11 */
  12
  13 #include <internal.h>
  14
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <sys/param.h>
  18 #include <pwd.h>
  19 #include <grp.h>
  20
  21 #ifdef STDC_HEADERS
  22 # include <string.h>
  23 #endif
  24
  25
  26 /* determine full path name */
  27 char *
  28 th_get_pathname(TAR *t)
  29 {
  30         if (t->th_buf.gnu_longname)
  31                 return t->th_buf.gnu_longname;
  32
  33         /* allocate the th_pathname buffer if not already */
  34         if (t->th_pathname == NULL)
  35         {
  36                 t->th_pathname = malloc(MAXPATHLEN * sizeof(char));
  37                 if (t->th_pathname == NULL)
  38                         /* out of memory */
  39                         return NULL;
  40         }
  41
  42         if (t->th_buf.prefix[0] == '\0')
  43         {
  44                 snprintf(t->th_pathname, MAXPATHLEN, "%.100s", t->th_buf.name);
  45         }
  46         else
  47         {
  48                 snprintf(t->th_pathname, MAXPATHLEN, "%.155s/%.100s",
  49                          t->th_buf.prefix, t->th_buf.name);
  50         }
  51
  52         /* will be deallocated in tar_close() */
  53         return t->th_pathname;
  54 }
  55
  56
  57 uid_t
  58 th_get_uid(TAR *t)
  59 {
  60         int uid;
  61         struct passwd *pw;
  62
  63         pw = getpwnam(t->th_buf.uname);
  64         if (pw != NULL)
  65                 return pw->pw_uid;
  66
  67         /* if the password entry doesn't exist */
  68         sscanf(t->th_buf.uid, "%o", &uid);
  69         return uid;
  70 }
  71
  72
  73 gid_t
  74 th_get_gid(TAR *t)
  75 {
  76         int gid;
  77         struct group *gr;
  78
  79         gr = getgrnam(t->th_buf.gname);
  80         if (gr != NULL)
  81                 return gr->gr_gid;
  82
  83         /* if the group entry doesn't exist */
  84         sscanf(t->th_buf.gid, "%o", &gid);
  85         return gid;
  86 }
  87
  88
  89 mode_t
  90 th_get_mode(TAR *t)
  91 {
  92         mode_t mode;
  93
  94         mode = (mode_t)oct_to_int(t->th_buf.mode);
  95         if (! (mode & S_IFMT))
  96         {
  97                 switch (t->th_buf.typeflag)
  98                 {
  99                 case SYMTYPE:
 100                         mode |= S_IFLNK;
 101                         break;
 102                 case CHRTYPE:
 103                         mode |= S_IFCHR;
 104                         break;
 105                 case BLKTYPE:
 106                         mode |= S_IFBLK;
 107                         break;
 108                 case DIRTYPE:
 109                         mode |= S_IFDIR;
 110                         break;
 111                 case FIFOTYPE:
 112                         mode |= S_IFIFO;
 113                         break;
 114                 case AREGTYPE:
 115                         if (t->th_buf.name[strlen(t->th_buf.name) - 1] == '/')
 116                         {
 117                                 mode |= S_IFDIR;
 118                                 break;
 119                         }
 120                         /* FALLTHROUGH */
 121                 case LNKTYPE:
 122                 case REGTYPE:
 123                 default:
 124                         mode |= S_IFREG;
 125                 }
 126         }
 127
 128         return mode;
 129 }
 130
 131