src/tools/dumpscan/xfiles.c

   1 /*
   2  * CMUCS AFStools
   3  * dumpscan - routines for scanning and manipulating AFS volume dumps
   4  *
   5  * Copyright (c) 1998 Carnegie Mellon University
   6  * All Rights Reserved.
   7  *
   8  * Permission to use, copy, modify and distribute this software and its
   9  * documentation is hereby granted, provided that both the copyright
  10  * notice and this permission notice appear in all copies of the
  11  * software, derivative works or modified versions, and any portions
  12  * thereof, and that both notices appear in supporting documentation.
  13  *
  14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  16  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  17  *
  18  * Carnegie Mellon requests users of this software to return to
  19  *
  20  *  Software Distribution Coordinator  or  Software_Distribution@CS.CMU.EDU
  21  *  School of Computer Science
  22  *  Carnegie Mellon University
  23  *  Pittsburgh PA 15213-3890
  24  *
  25  * any improvements or extensions that they make and grant Carnegie Mellon
  26  * the rights to redistribute these changes.
  27  */
  28
  29 /* xfiles.c - General support routines for xfiles */
  30 #include <sys/types.h>
  31 #include <string.h>
  32 #include <errno.h>
  33 #include <stdlib.h>
  34
  35 #include "xfiles.h"
  36 #include "xf_errs.h"
  37
  38 #define SKIP_SIZE 65536
  39
  40 extern afs_uint32 xfon_path(XFILE *, int, char *);
  41 extern afs_uint32 xfon_fd(XFILE *, int, char *);
  42 extern afs_uint32 xfon_voldump(XFILE *, int, char *);
  43 extern afs_uint32 xfon_profile(XFILE *, int, char *);
  44 extern afs_uint32 xfon_stdio(XFILE *, int);
  45
  46 struct xftype {
  47     struct xftype *next;
  48     char *name;
  49       afs_uint32(*do_on) (XFILE *, int, char *);
  50 };
  51
  52
  53 static struct xftype *xftypes = 0;
  54 static int did_register_defaults = 0;
  55
  56
  57 afs_uint32
  58 xfread(XFILE * X, void *buf, afs_uint32 count)
  59 {
  60     afs_uint32 code;
  61     dt_uint64 tmp64;
  62
  63     code = (X->do_read) (X, buf, count);
  64     if (code)
  65         return code;
  66
  67     add64_32(tmp64, X->filepos, count);
  68     cp64(X->filepos, tmp64);
  69     if (X->passthru)
  70         return xfwrite(X->passthru, buf, count);
  71     return 0;
  72 }
  73
  74
  75 afs_uint32
  76 xfwrite(XFILE * X, void *buf, afs_uint32 count)
  77 {
  78     afs_uint32 code;
  79     dt_uint64 tmp64;
  80
  81     if (!X->is_writable)
  82         return ERROR_XFILE_RDONLY;
  83     code = (X->do_write) (X, buf, count);
  84     if (code)
  85         return code;
  86
  87     add64_32(tmp64, X->filepos, count);
  88     cp64(X->filepos, tmp64);
  89     return 0;
  90 }
  91
  92
  93 afs_uint32
  94 xftell(XFILE * X, dt_uint64 * offset)
  95 {
  96     if (X->do_tell)
  97         return (X->do_tell) (X, offset);
  98     cp64(*offset, X->filepos);
  99     return 0;
 100 }
 101
 102
 103 afs_uint32
 104 xfseek(XFILE * X, dt_uint64 * offset)
 105 {
 106     afs_uint32 code;
 107
 108     if (!X->do_seek)
 109         return ERROR_XFILE_NOSEEK;
 110     code = (X->do_seek) (X, offset);
 111     if (code)
 112         return code;
 113     cp64(X->filepos, *offset);
 114     return 0;
 115 }
 116
 117
 118 afs_uint32
 119 xfskip(XFILE * X, afs_uint32 count)
 120 {
 121     afs_uint32 code;
 122     dt_uint64 tmp64;
 123
 124     /* Use the skip method, if there is one */
 125     if (X->do_skip && !X->passthru) {
 126         code = (X->do_skip) (X, count);
 127         if (code)
 128             return code;
 129         add64_32(tmp64, X->filepos, count);
 130         cp64(X->filepos, tmp64);
 131         return 0;
 132     }
 133
 134     /* Simulate using absolute seek, if available */
 135     if (X->do_seek && !X->passthru) {
 136         if ((code = xftell(X, &tmp64)))
 137             return code;
 138         add64_32(X->filepos, tmp64, count);
 139         cp64(tmp64, X->filepos);
 140         return xfseek(X, &tmp64);
 141     }
 142
 143     /* Do it the hard/slow way - read all the data to be skipped.
 144      * This is done if no other method is available, or if we are
 145      * supposed to be copying all the data to another XFILE
 146      */
 147     {
 148         char buf[SKIP_SIZE];
 149         afs_uint32 n;
 150
 151         while (count) {
 152             n = (count > SKIP_SIZE) ? SKIP_SIZE : count;
 153             if ((code = xfread(X, buf, n)))
 154                 return code;
 155             count -= n;
 156         }
 157         return 0;
 158     }
 159 }
 160
 161
 162 afs_uint32
 163 xfpass(XFILE * X, XFILE * Y)
 164 {
 165     if (X->passthru)
 166         return ERROR_XFILE_ISPASS;
 167     if (!Y->is_writable)
 168         return ERROR_XFILE_RDONLY;
 169     X->passthru = Y;
 170     return 0;
 171 }
 172
 173
 174 afs_uint32
 175 xfunpass(XFILE * X)
 176 {
 177     if (!X->passthru)
 178         return ERROR_XFILE_NOPASS;
 179     X->passthru = 0;
 180     return 0;
 181 }
 182
 183
 184 afs_uint32
 185 xfclose(XFILE * X)
 186 {
 187     int code = 0;
 188
 189     if (X->do_close)
 190         code = (X->do_close) (X);
 191     memset(X, 0, sizeof(*X));
 192     return code;
 193 }
 194
 195
 196 afs_uint32
 197 xfregister(char *name, afs_uint32(*do_on) (XFILE *, int, char *))
 198 {
 199     struct xftype *x;
 200
 201     if (!(x = calloc(1, sizeof(struct xftype))))
 202         return ENOMEM;
 203     x->next = xftypes;
 204     x->name = name;
 205     x->do_on = do_on;
 206     xftypes = x;
 207     return 0;
 208 }
 209
 210
 211 static void
 212 register_default_types(void)
 213 {
 214     xfregister("FILE", xfon_path);
 215     xfregister("FD", xfon_fd);
 216     xfregister("AFSDUMP", xfon_voldump);
 217     xfregister("PROFILE", xfon_profile);
 218     did_register_defaults = 1;
 219 }
 220
 221
 222 afs_uint32
 223 xfopen(XFILE * X, int flag, char *name)
 224 {
 225     struct xftype *x;
 226     char *type, *sep;
 227
 228     if (!did_register_defaults)
 229         register_default_types();
 230     if (!strcmp(name, "-"))
 231         return xfon_stdio(X, flag);
 232
 233     for (type = name; *name && *name != ':'; name++);
 234     if (*name) {
 235         sep = name;
 236         *name++ = 0;
 237     } else {
 238         sep = 0;
 239         name = type;
 240         type = "FILE";
 241     }
 242
 243     for (x = xftypes; x; x = x->next)
 244         if (!strcmp(type, x->name))
 245             break;
 246     if (sep)
 247         *sep = ':';
 248     if (x)
 249         return (x->do_on) (X, flag, name);
 250     return ERROR_XFILE_TYPE;
 251 }