/*
   Bacula(R) - The Network Backup Solution

   Copyright (C) 2000-2017 Kern Sibbald

   The original author of Bacula is Kern Sibbald, with contributions
   from many others, a complete list can be found in the file AUTHORS.

   You may use this file and others of this release according to the
   license defined in the LICENSE file, which includes the Affero General
   Public License, v3.0 ("AGPLv3") and some additional permissions and
   terms pursuant to its AGPLv3 Section 7.

   This notice must be preserved when any source code is
   conveyed and/or propagated.

   Bacula(R) is a registered trademark of Kern Sibbald.
*/
/*
 *
 *  ansi_label.c routines to handle ANSI (and perhaps one day IBM)
 *   tape labels.
 *
 *   Kern Sibbald, MMV
 */

#include "bacula.h"                   /* pull in global headers */
#include "stored.h"                   /* pull in Storage Deamon headers */

/* Imported functions */
void ascii_to_ebcdic(char *dst, char *src, int count);
void ebcdic_to_ascii(char *dst, char *src, int count);

/* Forward referenced functions */
static char *ansi_date(time_t td, char *buf);
static bool same_label_names(char *bacula_name, char *ansi_name);

/*
 * We read an ANSI label and compare the Volume name. We require
 * a VOL1 record of 80 characters followed by a HDR1 record containing
 * BACULA.DATA in the filename field. We then read up to 3 more
 * header records (they are not required) and an EOF, at which
 * point, all is good.
 *
 * Returns:
 *    VOL_OK            Volume name OK
 *    VOL_NO_LABEL      No ANSI label on Volume
 *    VOL_IO_ERROR      I/O error on read
 *    VOL_NAME_ERROR    Wrong name in VOL1 record
 *    VOL_LABEL_ERROR   Probably an ANSI label, but something wrong
 *
 */
int read_ansi_ibm_label(DCR *dcr)
{
   DEVICE * volatile dev = dcr->dev;
   JCR *jcr = dcr->jcr;
   char label[80];                    /* tape label */
   int stat, i;
   char *VolName = dcr->VolumeName;
   bool ok = false;

   /*
    * Read VOL1, HDR1, HDR2 labels, but ignore the data
    *  If tape read the following EOF mark, on disk do
    *  not read.
    */
   Dmsg0(100, "Read ansi label.\n");
   if (!dev->is_tape()) {
      return VOL_OK;
   }

   dev->label_type = B_BACULA_LABEL;  /* assume Bacula label */

   /* Read a maximum of 5 records VOL1, HDR1, ... HDR4 */
   for (i=0; i < 6; i++) {
      do {
         stat = dev->read(label, sizeof(label));
      } while (stat == -1 && errno == EINTR);
      if (stat < 0) {
         berrno be;
         dev->clrerror(-1);
         Dmsg1(100, "Read device got: ERR=%s\n", be.bstrerror());
         Mmsg2(jcr->errmsg, _("Read error on device %s in ANSI label. ERR=%s\n"),
            dev->dev_name, be.bstrerror());
         Jmsg(jcr, M_ERROR, 0, "%s", dev->errmsg);
         dev->VolCatInfo.VolCatErrors++;
         return VOL_IO_ERROR;
      }
      if (stat == 0) {
         if (dev->at_eof()) {
            dev->set_eot();           /* second eof, set eot bit */
            Dmsg0(100, "EOM on ANSI label\n");
            Mmsg0(jcr->errmsg, _("Insane! End of tape while reading ANSI label.\n"));
            return VOL_LABEL_ERROR;   /* at EOM this shouldn't happen */
         } else {
            dev->set_ateof();        /* set eof state */
         }
      }
      switch (i) {
      case 0:                         /* Want VOL1 label */
         if (stat == 80) {
            if (strncmp("VOL1", label, 4) == 0) {
               ok = true;
               dev->label_type = B_ANSI_LABEL;
               Dmsg0(100, "Got ANSI VOL1 label\n");
            } else {
               /* Try EBCDIC */
               ebcdic_to_ascii(label, label, sizeof(label));
               if (strncmp("VOL1", label, 4) == 0) {
                  ok = true;;
                  dev->label_type = B_IBM_LABEL;
                  Dmsg0(100, "Found IBM label.\n");
                  Dmsg0(100, "Got IBM VOL1 label\n");
               }
            }
         }
         if (!ok) {
            Dmsg0(100, "No VOL1 label\n");
            Mmsg0(jcr->errmsg, _("No VOL1 label while reading ANSI/IBM label.\n"));
            return VOL_NO_LABEL;   /* No ANSI label */
         }


         /* Compare Volume Names allow special wild card */
         if (VolName && *VolName && *VolName != '*') {
            if (!same_label_names(VolName, &label[4])) {
               char *p = &label[4];
               char *q;

               free_volume(dev);
               /* Store new Volume name */
               q = dev->VolHdr.VolumeName;
               for (int i=0; *p != ' ' && i < 6; i++) {
                  *q++ = *p++;
               }
               *q = 0;
               Dmsg0(100, "Call reserve_volume\n");
               /* ***FIXME***  why is this reserve_volume() needed???? KES */
               reserve_volume(dcr, dev->VolHdr.VolumeName);
               dev = dcr->dev;            /* may have changed in reserve_volume */
               Dmsg2(100, "Wanted ANSI Vol %s got %6s\n", VolName, dev->VolHdr.VolumeName);
               Mmsg2(jcr->errmsg, _("Wanted ANSI Volume \"%s\" got \"%s\"\n"), VolName, dev->VolHdr.VolumeName);
               return VOL_NAME_ERROR;
            }
         }
         break;
      case 1:
         if (dev->label_type == B_IBM_LABEL) {
            ebcdic_to_ascii(label, label, sizeof(label));
         }
         if (stat != 80 || strncmp("HDR1", label, 4) != 0) {
            Dmsg0(100, "No HDR1 label\n");
            Mmsg0(jcr->errmsg, _("No HDR1 label while reading ANSI label.\n"));
            return VOL_LABEL_ERROR;
         }
         if (strncmp("BACULA.DATA", &label[4], 11) != 0) {
            Dmsg1(100, "HD1 not Bacula label. Wanted  BACULA.DATA got %11s\n",
               &label[4]);
            Mmsg1(jcr->errmsg, _("ANSI/IBM Volume \"%s\" does not belong to Bacula.\n"),
               dev->VolHdr.VolumeName);
            return VOL_NAME_ERROR;     /* Not a Bacula label */
         }
         Dmsg0(100, "Got HDR1 label\n");
         break;
      case 2:
         if (dev->label_type == B_IBM_LABEL) {
            ebcdic_to_ascii(label, label, sizeof(label));
         }
         if (stat != 80 || strncmp("HDR2", label, 4) != 0) {
            Dmsg0(100, "No HDR2 label\n");
            Mmsg0(jcr->errmsg, _("No HDR2 label while reading ANSI/IBM label.\n"));
            return VOL_LABEL_ERROR;
         }
         Dmsg0(100, "Got ANSI HDR2 label\n");
         break;
      default:
         if (stat == 0) {
            Dmsg0(100, "ANSI label OK\n");
            return VOL_OK;
         }
         if (dev->label_type == B_IBM_LABEL) {
            ebcdic_to_ascii(label, label, sizeof(label));
         }
         if (stat != 80 || strncmp("HDR", label, 3) != 0) {
            Dmsg0(100, "Unknown or bad ANSI/IBM label record.\n");
            Mmsg0(jcr->errmsg, _("Unknown or bad ANSI/IBM label record.\n"));
            return VOL_LABEL_ERROR;
         }
         Dmsg0(100, "Got HDR label\n");
         break;
      }
   }
   Dmsg0(100, "Too many records in ANSI/IBM label.\n");
   Mmsg0(jcr->errmsg, _("Too many records in while reading ANSI/IBM label.\n"));
   return VOL_LABEL_ERROR;
}

/*
 * ANSI/IBM VOL1 label
 *  80 characters blank filled
 * Pos   count   Function      What Bacula puts
 * 0-3     4     "VOL1"          VOL1
 * 4-9     6     Volume name     Volume name
 * 10-10   1     Access code
 * 11-36   26    Unused
 *
 * ANSI
 * 37-50   14    Owner
 * 51-78   28    reserved
 * 79       1    ANSI level        3
 *
 * IBM
 * 37-40   4     reserved
 * 41-50   10    Owner
 * 51-79   29    reserved

 *
 *
 * ANSI/IBM HDR1 label
 *  80 characters blank filled
 * Pos   count   Function          What Bacula puts
 * 0-3     4     "HDR1"               HDR1
 * 4-20    17    File name           BACULA.DATA
 * 21-26   6     Volume name          Volume name
 * 27-30   4     Vol seq num           0001
 * 31-34   4     file num              0001
 * 35-38   4     Generation            0001
 * 39-40   2     Gen version           00
 * 41-46   6     Create date bYYDDD    yesterday
 * 47-52   6     Expire date bYYDDD    today
 * 53-53   1     Access
 * 54-59   6     Block count           000000
 * 60-72   13    Software name         Bacula
 * 73-79   7     Reserved

 * ANSI/IBM HDR2 label
 *  80 characters blank filled
 * Pos   count   Function          What Bacula puts
 * 0-3     4     "HDR2"               HDR2
 * 4-4     1     Record format        D   (V if IBM) => variable
 * 5-9     5     Block length         32000
 * 10-14   5     Rec length           32000
 * 15-15   1     Density
 * 16-16   1     Continued
 * 17-33   17    Job
 * 34-35   2     Recording
 * 36-36   1     cr/lf ctl
 * 37-37   1     reserved
 * 38-38   1     Blocked flag
 * 39-49   11    reserved
 * 50-51   2     offset
 * 52-79   28    reserved

 */

static const char *labels[] = {"HDR", "EOF", "EOV"};

/*
 * Write an ANSI or IBM 80 character tape label
 *   Type determines whether we are writing HDR, EOF, or EOV labels
 *   Assume we are positioned to write the labels
 *   Returns:  true of OK
 *             false if error
 */
bool write_ansi_ibm_labels(DCR *dcr, int type, const char *VolName)
{
   DEVICE *dev = dcr->dev;
   JCR *jcr = dcr->jcr;
   char ansi_volname[7];              /* 6 char + \0 */
   char label[80];                    /* tape label */
   char date[20];                     /* ansi date buffer */
   time_t now;
   int len, stat, label_type;

   /*
    * If the Device requires a specific label type use it,
    * otherwise, use the type requested by the Director
    */
   if (dcr->device->label_type != B_BACULA_LABEL) {
      label_type = dcr->device->label_type;   /* force label type */
   } else {
      label_type = dcr->VolCatInfo.LabelType; /* accept Dir type */
   }

   switch (label_type) {
   case B_BACULA_LABEL:
      return true;
   case B_ANSI_LABEL:
   case B_IBM_LABEL:
      ser_declare;
      Dmsg1(100, "Write ANSI label type=%d\n", label_type);
      len = strlen(VolName);
      if (len > 6) {
         Jmsg1(jcr, M_FATAL, 0, _("ANSI Volume label name \"%s\" longer than 6 chars.\n"),
            VolName);
         return false;
      }
      /* ANSI labels have 6 characters, and are padded with spaces
       * 'vol1\0' => 'vol1   \0'
       */
      strcpy(ansi_volname, VolName);
      for(int i=len; i < 6; i++) {
         ansi_volname[i]=' ';
      }
      ansi_volname[6]='\0';     /* only for debug */

      if (type == ANSI_VOL_LABEL) {
         ser_begin(label, sizeof(label));
         ser_bytes("VOL1", 4);
         ser_bytes(ansi_volname, 6);
         /* Write VOL1 label */
         if (label_type == B_IBM_LABEL) {
            ascii_to_ebcdic(label, label, sizeof(label));
         } else {
            label[79] = '3';                /* ANSI label flag */
         }
         stat = dev->write(label, sizeof(label));
         if (stat != sizeof(label)) {
            berrno be;
            Jmsg3(jcr, M_FATAL, 0,  _("Could not write ANSI VOL1 label. Wanted size=%d got=%d ERR=%s\n"),
               sizeof(label), stat, be.bstrerror());
            return false;
         }
      }

      /* Now construct HDR1 label */
      memset(label, ' ', sizeof(label));
      ser_begin(label, sizeof(label));
      ser_bytes(labels[type], 3);
      ser_bytes("1", 1);
      ser_bytes("BACULA.DATA", 11);            /* Filename field */
      ser_begin(&label[21], sizeof(label)-21); /* fileset field */
      ser_bytes(ansi_volname, 6);              /* write Vol Ser No. */
      ser_begin(&label[27], sizeof(label)-27);
      ser_bytes("00010001000100", 14);  /* File section, File seq no, Generation no */
      now = time(NULL);
      ser_bytes(ansi_date(now, date), 6); /* current date */
      ser_bytes(ansi_date(now - 24 * 3600, date), 6); /* created yesterday */
      ser_bytes(" 000000Bacula              ", 27);
      /* Write HDR1 label */
      if (label_type == B_IBM_LABEL) {
         ascii_to_ebcdic(label, label, sizeof(label));
      }

      /*
       * This could come at the end of a tape, ignore
       *  EOT errors.
       */
      stat = dev->write(label, sizeof(label));
      if (stat != sizeof(label)) {
         berrno be;
         if (stat == -1) {
            dev->clrerror(-1);
            if (dev->dev_errno == 0) {
               dev->dev_errno = ENOSPC; /* out of space */
            }
            if (dev->dev_errno != ENOSPC) {
               Jmsg1(jcr, M_FATAL, 0, _("Could not write ANSI HDR1 label. ERR=%s\n"),
               be.bstrerror());
               return false;
            }
         } else {
            Jmsg(jcr, M_FATAL, 0, _("Could not write ANSI HDR1 label.\n"));
            return false;
         }
      }

      /* Now construct HDR2 label */
      memset(label, ' ', sizeof(label));
      ser_begin(label, sizeof(label));
      ser_bytes(labels[type], 3);
      ser_bytes("2D3200032000", 12);
      /* Write HDR2 label */
      if (label_type == B_IBM_LABEL) {
         label[4] = 'V';
         ascii_to_ebcdic(label, label, sizeof(label));
      }
      stat = dev->write(label, sizeof(label));
      if (stat != sizeof(label)) {
         berrno be;
         if (stat == -1) {
            dev->clrerror(-1);
            if (dev->dev_errno == 0) {
               dev->dev_errno = ENOSPC; /* out of space */
            }
            if (dev->dev_errno != ENOSPC) {
               Jmsg1(jcr, M_FATAL, 0, _("Could not write ANSI HDR1 label. ERR=%s\n"),
               be.bstrerror());
               return false;
            }
            dev->weof(NULL, 1);
            return true;
         } else {
            Jmsg(jcr, M_FATAL, 0, _("Could not write ANSI HDR1 label.\n"));
            return false;
         }
      }
      if (!dev->weof(NULL, 1)) {
         Jmsg(jcr, M_FATAL, 0, _("Error writing EOF to tape. ERR=%s"), dev->errmsg);
         return false;
      }
      return true;
   default:
      Jmsg0(jcr, M_ABORT, 0, _("write_ansi_ibm_label called for non-ANSI/IBM type\n"));
      return false; /* should not get here */
   }
}

/* Check a Bacula Volume name against an ANSI Volume name */
static bool same_label_names(char *bacula_name, char *ansi_name)
{
   char *a = ansi_name;
   char *b = bacula_name;
   /* Six characters max */
   for (int i=0; i < 6; i++) {
      if (*a == *b) {
         a++;
         b++;
         continue;
      }
      /* ANSI labels are blank filled, Bacula's are zero terminated */
      if (*a == ' ' && *b == 0) {
         return true;
      }
      return false;
   }
   /* Reached 6 characters */
   b++;
   if (*b == 0) {
      return true;
   }
   return false;
}

/*
 * ANSI date
 *  ' 'YYDDD
 */
static char *ansi_date(time_t td, char *buf)
{
   struct tm *tm;

   if (td == 0) {
      td = time(NULL);
   }
   tm = gmtime(&td);
   bsnprintf(buf, 10, " %05d ", 1000 * (tm->tm_year + 1900 - 2000) + tm->tm_yday);
   return buf;
}
