src/tools/dumpscan/stagehdr.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 /* stagehdr.c - Parse and dump stage backup headers */
  30
  31 #include <sys/types.h>
  32 #include <netinet/in.h>
  33 #include <stdlib.h>
  34 #include <errno.h>
  35
  36 #include "dumpscan.h"
  37 #include "dumpscan_errs.h"
  38 #include "xf_errs.h"
  39 #include "stagehdr.h"
  40
  41 static afs_uint32
  42 hdr_checksum(char *buf, int size)
  43 {
  44     afs_uint32 sum = 0, n = size / sizeof(afs_uint32), *words =
  45         (afs_uint32 *) buf;
  46
  47     while (--n)
  48         sum += ntohl(*words++);
  49     return sum;
  50 }
  51
  52
  53 /* Parse a stage backup header.
  54  * If tag is non-NULL, *tag should contain the first byte (already read),
  55  * and will be filled in with the first byte after the header, if one exists.
  56  * On success, returns 0 and leaves us positioned after the header
  57  * On failure, returns an error and position is undefined
  58  * Iff there is no header, returns DSERR_MAGIC and leaves us
  59  * positioned where we started.
  60  */
  61 afs_uint32
  62 ParseStageHdr(XFILE * X, unsigned char *tag, backup_system_header * hdr)
  63 {
  64     char buf[STAGE_HDRLEN];
  65     struct stage_header *bckhdr = (struct stage_header *)buf;
  66     dt_uint64 where;
  67     afs_int32 r;
  68
  69     if ((r = xftell(X, &where)))
  70         return r;
  71     if (hdr)
  72         memset(hdr, 0, sizeof(*hdr));
  73     if (tag) {
  74         if (*tag != STAGE_VERSMIN)
  75             return DSERR_MAGIC;
  76         buf[0] = *tag;
  77         r = xfread(X, buf + 1, STAGE_HDRLEN - 1);
  78     } else {
  79         r = xfread(X, buf, STAGE_HDRLEN);
  80     }
  81
  82     if (r == ERROR_XFILE_EOF) {
  83         r = xfseek(X, &where);
  84         return r ? r : DSERR_MAGIC;
  85     } else if (r)
  86         return r;
  87
  88     if (bckhdr->c_vers < STAGE_VERSMIN
  89         || ntohl(bckhdr->c_magic) != STAGE_MAGIC
  90         || hdr_checksum(buf, STAGE_HDRLEN) != STAGE_CHECKSUM) {
  91         r = xfseek(X, &where);
  92         return r ? r : DSERR_MAGIC;
  93     }
  94
  95     if (hdr) {
  96         hdr->version = bckhdr->c_vers;
  97         hdr->from_date = ntohl(bckhdr->c_fdate);
  98         hdr->to_date = ntohl(bckhdr->c_tdate);
  99         hdr->dump_date = ntohl(bckhdr->c_time);
 100         hdr->filenum = ntohl(bckhdr->c_filenum);
 101         hdr->volid = ntohl(bckhdr->c_id);
 102 #ifdef NATIVE_UINT64
 103         hdr->dumplen = ntohl(bckhdr->c_length);
 104 #else
 105         hdr->dumplen.hi = 0;
 106         hdr->dumplen.lo = ntohl(bckhdr->c_length);
 107 #endif
 108         hdr->level = ntohl(bckhdr->c_level);
 109         hdr->magic = ntohl(bckhdr->c_magic);
 110         hdr->cksum = ntohl(bckhdr->c_checksum);
 111         hdr->flags = ntohl(bckhdr->c_flags);
 112         hdr->server = (unsigned char *) strdup(bckhdr->c_host);
 113         hdr->part = (unsigned char *) strdup(bckhdr->c_disk);
 114         hdr->volname = (unsigned char *) strdup(bckhdr->c_name);
 115
 116         if (!hdr->server || !hdr->part || !hdr->volname) {
 117             if (hdr->server)
 118                 free(hdr->server);
 119             if (hdr->part)
 120                 free(hdr->part);
 121             if (hdr->volname)
 122                 free(hdr->volname);
 123             return ENOMEM;
 124         }
 125     }
 126
 127     if (tag)
 128         return ReadByte(X, tag);
 129     else
 130         return 0;
 131 }
 132
 133
 134 /* Dump a stage backup header */
 135 afs_uint32
 136 DumpStageHdr(XFILE * OX, backup_system_header * hdr)
 137 {
 138     char buf[STAGE_HDRLEN];
 139     struct stage_header *bckhdr = (struct stage_header *)buf;
 140     afs_uint32 checksum;
 141     afs_uint32 r;
 142
 143     memset(buf, 0, STAGE_HDRLEN);
 144     bckhdr->c_vers = hdr->version;
 145     bckhdr->c_fdate = htonl(hdr->from_date);
 146     bckhdr->c_tdate = htonl(hdr->to_date);
 147     bckhdr->c_filenum = htonl(hdr->filenum);
 148     bckhdr->c_time = htonl(hdr->dump_date);
 149     bckhdr->c_id = htonl(hdr->volid);
 150 #ifdef NATIVE_UINT64
 151     bckhdr->c_length = htonl((afs_uint32) hdr->dumplen);
 152 #else
 153     bckhdr->c_length = htonl(hdr->dumplen.lo);
 154 #endif
 155     bckhdr->c_level = htonl(hdr->level);
 156     bckhdr->c_magic = htonl(STAGE_MAGIC);
 157     bckhdr->c_flags = htonl(hdr->flags);
 158
 159     strcpy(bckhdr->c_host, (char *)hdr->server);
 160     strcpy(bckhdr->c_disk, (char *)hdr->part);
 161     strcpy(bckhdr->c_name, (char *)hdr->volname);
 162
 163     /* Now, compute the checksum */
 164     checksum = hdr_checksum(buf, STAGE_HDRLEN);
 165     bckhdr->c_checksum = htonl(STAGE_CHECKSUM - checksum);
 166
 167     if ((r = xfwrite(OX, buf, STAGE_HDRLEN)))
 168         return r;
 169     return 0;
 170 }