X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=bacula%2Fsrc%2Ffiled%2Frestore.c;h=c29f8fc513a804914ac4914c3f3297efb2c427ff;hb=cad283fcd2e639219d6c2fef3362bcc398d959c9;hp=bc50195b7b4b500f43cb68b712a6e770cc0fea4a;hpb=a04f8de3104071de311636c294d908f2db882568;p=bacula%2Fbacula

diff --git a/bacula/src/filed/restore.c b/bacula/src/filed/restore.c
index bc50195b7b..c29f8fc513 100644
--- a/bacula/src/filed/restore.c
+++ b/bacula/src/filed/restore.c
@@ -7,7 +7,7 @@
  *
  */
 /*
-   Copyright (C) 2000-2003 Kern Sibbald and John Walker
+   Copyright (C) 2000-2005 Kern Sibbald
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
@@ -29,70 +29,142 @@
 #include "bacula.h"
 #include "filed.h"
 
+#ifdef HAVE_DARWIN_OS
+#include <sys/attr.h>
+#endif
+
 /* Data received from Storage Daemon */
 static char rec_header[] = "rechdr %ld %ld %ld %ld %ld";
 
 /* Forward referenced functions */
+#ifdef HAVE_LIBZ
+static const char *zlib_strerror(int stat);
+#endif
+int32_t extract_data(JCR *jcr, BFILE *bfd, POOLMEM *buf, int32_t buflen,
+      uint64_t *addr, int flags);
 
 #define RETRY 10		      /* retry wait time */
 
-/* 
+/*
+ * Close a bfd check that we are at the expected file offset.
+ * Makes some code in set_attributes().
+ */
+int bclose_chksize(JCR *jcr, BFILE *bfd, off_t osize)
+{
+   char ec1[50], ec2[50];
+   off_t fsize;
+
+   fsize = blseek(bfd, 0, SEEK_CUR);
+   bclose(bfd); 			     /* first close file */
+   if (fsize > 0 && fsize != osize) {
+      Jmsg3(jcr, M_ERROR, 0, _("Size of data or stream of %s not correct. Original %s, restored %s.\n"),
+	    jcr->last_fname, edit_uint64(osize, ec1),
+	    edit_uint64(fsize, ec2));
+      return -1;
+   }
+   return 0;
+}
+
+/*
  * Restore the requested files.
- * 
+ *
  */
 void do_restore(JCR *jcr)
 {
-   int wherelen;
    BSOCK *sd;
-   int32_t stream;
-   uint32_t size;
+   int32_t stream = 0;
+   int32_t prev_stream;
    uint32_t VolSessionId, VolSessionTime;
+   bool extract = false;
    int32_t file_index;
-   int extract = FALSE;
-   BFILE bfd;
-   int stat;
-   uint32_t total = 0;		      /* Job total but only 32 bits for debug */
-   char *wbuf;			      /* write buffer */
-   uint32_t wsize;		      /* write size */
+   char ec1[50];		      /* Buffer printing huge values */
+
+   BFILE bfd;			      /* File content */
    uint64_t fileAddr = 0;	      /* file write address */
+   uint32_t size;		      /* Size of file */
+   BFILE altbfd;		      /* Alternative data stream */
+   uint64_t alt_addr = 0;	      /* Write address for alternative stream */
+   intmax_t alt_size = 0;	      /* Size of alternate stream */
+   int flags;			      /* Options for extract_data() */
+   int stat;
+   ATTR *attr;
+
+   /* The following variables keep track of "known unknowns" */
    int non_support_data = 0;
    int non_support_attr = 0;
-   int prog_name_msg = 0;
-   ATTR *attr;
-   
-   wherelen = strlen(jcr->where);
+   int non_support_rsrc = 0;
+   int non_support_finfo = 0;
+   int non_support_acl = 0;
+   int non_support_progname = 0;
+
+   /* Finally, set up for special configurations */
+#ifdef HAVE_DARWIN_OS
+   intmax_t rsrc_len = 0;	      /* Original length of resource fork */
+   struct attrlist attrList;
+
+   memset(&attrList, 0, sizeof(attrList));
+   attrList.bitmapcount = ATTR_BIT_MAP_COUNT;
+   attrList.commonattr = ATTR_CMN_FNDRINFO;
+#endif
 
-   binit(&bfd);
    sd = jcr->store_bsock;
    set_jcr_job_status(jcr, JS_Running);
 
-   if (!bnet_set_buffer_size(sd, MAX_NETWORK_BUFFER_SIZE, BNET_SETBUF_READ)) {
+   LockRes();
+   CLIENT *client = (CLIENT *)GetNextRes(R_CLIENT, NULL);
+   UnlockRes();
+   uint32_t buf_size;
+   if (client) {
+      buf_size = client->max_network_buffer_size;
+   } else {
+      buf_size = 0;		      /* use default */
+   }
+   if (!bnet_set_buffer_size(sd, buf_size, BNET_SETBUF_WRITE)) {
       set_jcr_job_status(jcr, JS_ErrorTerminated);
       return;
    }
    jcr->buf_size = sd->msglen;
 
-   attr = new_attr();
-
 #ifdef HAVE_LIBZ
    uint32_t compress_buf_size = jcr->buf_size + 12 + ((jcr->buf_size+999) / 1000) + 100;
    jcr->compress_buf = (char *)bmalloc(compress_buf_size);
+   jcr->compress_buf_size = compress_buf_size;
 #endif
 
-   /* 
-    * Get a record from the Storage daemon. We are guaranteed to 
+   /*
+    * Get a record from the Storage daemon. We are guaranteed to
     *	receive records in the following order:
     *	1. Stream record header
     *	2. Stream data
     *	     a. Attributes (Unix or Win32)
     *	 or  b. File data for the file
-    *	 or  c. Possibly MD5 or SHA1 record
+    *	 or  c. Alternate data stream (e.g. Resource Fork)
+    *	 or  d. Finder info
+    *	 or  e. ACLs
+    *	 or  f. Possibly MD5 or SHA1 record
     *	3. Repeat step 1
+    *
+    * NOTE: We keep track of two bacula file descriptors:
+    *	1. bfd for file data.
+    *	   This fd is opened for non empty files when an attribute stream is
+    *	   encountered and closed when we find the next attribute stream.
+    *	2. alt_bfd for alternate data streams
+    *	   This fd is opened every time we encounter a new alternate data
+    *	   stream for the current file. When we find any other stream, we
+    *	   close it again.
+    *	   The expected size of the stream, alt_len, should be set when
+    *	   opening the fd.
     */
+   binit(&bfd);
+   binit(&altbfd);
+   attr = new_attr();
+   jcr->acl_text = get_pool_memory(PM_MESSAGE);
+
    while (bget_msg(sd) >= 0 && !job_canceled(jcr)) {
-      /*
-       * First we expect a Stream Record Header 
-       */
+      /* Remember previous stream type */
+      prev_stream = stream;
+
+      /* First we expect a Stream Record Header */
       if (sscanf(sd->msg, rec_header, &VolSessionId, &VolSessionTime, &file_index,
 	  &stream, &size) != 5) {
          Jmsg1(jcr, M_FATAL, 0, _("Record header scan error: %s\n"), sd->msg);
@@ -100,9 +172,7 @@ void do_restore(JCR *jcr)
       }
       Dmsg2(30, "Got hdr: FilInx=%d Stream=%d.\n", file_index, stream);
 
-      /* 
-       * Now we expect the Stream Data
-       */
+      /* * Now we expect the Stream Data */
       if (bget_msg(sd) < 0) {
          Jmsg1(jcr, M_FATAL, 0, _("Data record error. ERR=%s\n"), bnet_strerror(sd));
 	 goto bail_out;
@@ -113,24 +183,39 @@ void do_restore(JCR *jcr)
       }
       Dmsg1(30, "Got stream data, len=%d\n", sd->msglen);
 
+      /* If we change streams, close and reset alternate data streams */
+      if (prev_stream != stream) {
+	 if (is_bopen(&altbfd)) {
+	    bclose_chksize(jcr, &altbfd, alt_size);
+	 }
+	 alt_size = -1; /* Use an impossible value and set a proper one below */
+	 alt_addr = 0;
+      }
+
       /* File Attributes stream */
       switch (stream) {
       case STREAM_UNIX_ATTRIBUTES:
       case STREAM_UNIX_ATTRIBUTES_EX:
-
          Dmsg1(30, "Stream=Unix Attributes. extract=%d\n", extract);
-	 /* If extracting, it was from previous stream, so
+	 /*
+	  * If extracting, it was from previous stream, so
 	  * close the output file.
 	  */
 	 if (extract) {
-	    if (!is_bopen(&bfd)) {
-               Jmsg0(jcr, M_ERROR, 0, _("Logic error output file should be open\n"));
+	    if (size > 0 && !is_bopen(&bfd)) {
+               Jmsg0(jcr, M_ERROR, 0, _("Logic error: output file should be open\n"));
 	    }
 	    set_attributes(jcr, attr, &bfd);
-	    extract = FALSE;
+	    extract = false;
             Dmsg0(30, "Stop extracting.\n");
+	 } else if (is_bopen(&bfd)) {
+            Jmsg0(jcr, M_ERROR, 0, _("Logic error: output file should not be open\n"));
+	    bclose(&bfd);
 	 }
 
+	 /*
+	  * Unpack and do sanity check fo attributes.
+	  */
 	 if (!unpack_attributes_record(jcr, stream, sd->msg, attr)) {
 	    goto bail_out;
 	 }
@@ -140,8 +225,8 @@ void do_restore(JCR *jcr)
             Dmsg0(100, "File index error\n");
 	    goto bail_out;
 	 }
-	    
-         Dmsg3(200, "File %s\nattrib=%s\nattribsEx=%s\n", attr->fname, 
+
+         Dmsg3(200, "File %s\nattrib=%s\nattribsEx=%s\n", attr->fname,
 	       attr->attr, attr->attrEx);
 
 	 attr->data_stream = decode_stat(attr->attr, &attr->statp, &attr->LinkFI);
@@ -156,137 +241,130 @@ void do_restore(JCR *jcr)
 
 	 build_attr_output_fnames(jcr, attr);
 
+	 /*
+	  * Now determine if we are extracting or not.
+	  */
 	 jcr->num_files_examined++;
-
          Dmsg1(30, "Outfile=%s\n", attr->ofname);
-	 extract = FALSE;
+	 extract = false;
 	 stat = create_file(jcr, attr, &bfd, jcr->replace);
 	 switch (stat) {
 	 case CF_ERROR:
 	 case CF_SKIP:
 	    break;
-	 case CF_EXTRACT:
-	    extract = TRUE;
-	    P(jcr->mutex);
-	    pm_strcpy(&jcr->last_fname, attr->ofname);
-	    V(jcr->mutex);
-	    jcr->JobFiles++;
-	    fileAddr = 0;
-	    print_ls_output(jcr, attr);
-	    /* Set attributes after file extracted */
-	    break;
-	 case CF_CREATED:
+	 case CF_EXTRACT:	 /* File created and we expect file data */
+	    extract = true;
+	    /* FALLTHROUGH */
+	 case CF_CREATED:	 /* File created, but there is no content */
 	    P(jcr->mutex);
-	    pm_strcpy(&jcr->last_fname, attr->ofname);
+	    pm_strcpy(jcr->last_fname, attr->ofname);
 	    V(jcr->mutex);
 	    jcr->JobFiles++;
 	    fileAddr = 0;
 	    print_ls_output(jcr, attr);
-	    /* set attributes now because file will not be extracted */
-	    set_attributes(jcr, attr, &bfd);
+#ifdef HAVE_DARWIN_OS
+	    /* Only restore the resource fork for regular files */
+	    from_base64(&rsrc_len, attr->attrEx);
+	    if (attr->type == FT_REG && rsrc_len > 0) {
+	       extract = true;
+	    }
+#endif
+	    if (!extract) {
+	       /* set attributes now because file will not be extracted */
+	       set_attributes(jcr, attr, &bfd);
+	    }
 	    break;
-	 }  
+	 }
 	 break;
 
       /* Data stream */
       case STREAM_FILE_DATA:
-      case STREAM_SPARSE_DATA:	
-      case STREAM_WIN32_DATA:  
-
-	 if (extract) {
-	    if (stream == STREAM_SPARSE_DATA) {
-	       ser_declare;
-	       uint64_t faddr;
-	       char ec1[50];
-
-	       wbuf = sd->msg + SPARSE_FADDR_SIZE;
-	       wsize = sd->msglen - SPARSE_FADDR_SIZE;
-	       ser_begin(sd->msg, SPARSE_FADDR_SIZE);
-	       unser_uint64(faddr);
-	       if (fileAddr != faddr) {
-		  fileAddr = faddr;
-		  if (blseek(&bfd, (off_t)fileAddr, SEEK_SET) < 0) {
-                     Jmsg3(jcr, M_ERROR, 0, _("Seek to %s error on %s: ERR=%s\n"),
-			 edit_uint64(fileAddr, ec1), attr->ofname, berror(&bfd));
-		     extract = FALSE;
-		     continue;
-		  }
-	       }
-	    } else {
-	       wbuf = sd->msg;
-	       wsize = sd->msglen;
+      case STREAM_SPARSE_DATA:
+      case STREAM_WIN32_DATA:
+      case STREAM_GZIP_DATA:
+      case STREAM_SPARSE_GZIP_DATA:
+      case STREAM_WIN32_GZIP_DATA:
+	 /* Force an expected, consistent stream type here */
+	 if (extract && (prev_stream == stream || prev_stream == STREAM_UNIX_ATTRIBUTES
+		  || prev_stream == STREAM_UNIX_ATTRIBUTES_EX)) {
+	    flags = 0;
+	    if (stream == STREAM_SPARSE_DATA || stream == STREAM_SPARSE_GZIP_DATA) {
+	       flags |= FO_SPARSE;
 	    }
-            Dmsg2(30, "Write %u bytes, total before write=%u\n", wsize, total);
-	    if ((uint32_t)bwrite(&bfd, wbuf, wsize) != wsize) {
-               Dmsg0(0, "===Write error===\n");
-               Jmsg2(jcr, M_ERROR, 0, _("Write error on %s: ERR=%s\n"), attr->ofname, berror(&bfd));
-	       extract = FALSE;
+	    if (stream == STREAM_GZIP_DATA || stream == STREAM_SPARSE_GZIP_DATA
+		  || stream == STREAM_WIN32_GZIP_DATA) {
+	       flags |= FO_GZIP;
+	    }
+	    if (extract_data(jcr, &bfd, sd->msg, sd->msglen, &fileAddr, flags) < 0) {
+	       extract = false;
+	       bclose(&bfd);
 	       continue;
-	    } 
-	    total += wsize;
-	    jcr->JobBytes += wsize;
-	    jcr->ReadBytes += wsize;
-	    fileAddr += wsize;
+	    }
 	 }
 	 break;
 
-      /* GZIP data stream */
-      case STREAM_GZIP_DATA:
-      case STREAM_SPARSE_GZIP_DATA:  
-      case STREAM_WIN32_GZIP_DATA:  
-#ifdef HAVE_LIBZ
+      /* Resource fork stream - only recorded after a file to be restored */
+      /* Silently ignore if we cannot write - we already reported that */
+      case STREAM_MACOS_FORK_DATA:
+#ifdef HAVE_DARWIN_OS
 	 if (extract) {
-	    ser_declare;
-	    uLong compress_len;
-	    uint64_t faddr;
-	    char ec1[50];
-	    int stat;
-
-	    if (stream == STREAM_SPARSE_GZIP_DATA) {
-	       wbuf = sd->msg + SPARSE_FADDR_SIZE;
-	       wsize = sd->msglen - SPARSE_FADDR_SIZE;
-	       ser_begin(sd->msg, SPARSE_FADDR_SIZE);
-	       unser_uint64(faddr);
-	       if (fileAddr != faddr) {
-		  fileAddr = faddr;
-		  if (blseek(&bfd, (off_t)fileAddr, SEEK_SET) < 0) {
-                     Jmsg3(jcr, M_ERROR, 0, _("Seek to %s error on %s: ERR=%s\n"),
-			 edit_uint64(fileAddr, ec1), attr->ofname, berror(&bfd));
-		     extract = FALSE;
-		     continue;
-		  }
+	    if (prev_stream != stream) {
+	       if (bopen_rsrc(&altbfd, jcr->last_fname, O_WRONLY | O_TRUNC | O_BINARY, 0) < 0) {
+                  Jmsg(jcr, M_ERROR, 0, _("     Cannot open resource fork for %s\n"), jcr->last_fname);
+		  extract = false;
+		  continue;
 	       }
-	    } else {
-	       wbuf = sd->msg;
-	       wsize = sd->msglen;
-	    }
-	    compress_len = compress_buf_size;
-            Dmsg2(100, "Comp_len=%d msglen=%d\n", compress_len, wsize);
-	    if ((stat=uncompress((Byte *)jcr->compress_buf, &compress_len, 
-		  (const Byte *)wbuf, (uLong)wsize)) != Z_OK) {
-               Jmsg(jcr, M_ERROR, 0, _("Uncompression error. ERR=%d\n"), stat);
-	       extract = FALSE;
-	       continue;
+	       alt_size = rsrc_len;
+               Dmsg0(30, "Restoring resource fork\n");
 	    }
-
-            Dmsg2(100, "Write uncompressed %d bytes, total before write=%d\n", compress_len, total);
-	    if ((uLong)bwrite(&bfd, jcr->compress_buf, compress_len) != compress_len) {
-               Dmsg0(0, "===Write error===\n");
-               Jmsg2(jcr, M_ERROR, 0, _("Write error on %s: %s\n"), attr->ofname, berror(&bfd));
-	       extract = FALSE;
+	    flags = 0;
+	    if (extract_data(jcr, &altbfd, sd->msg, sd->msglen, &alt_addr, flags) < 0) {
+	       extract = false;
+	       bclose(&altbfd);
 	       continue;
 	    }
-	    total += compress_len;
-	    jcr->JobBytes += compress_len;
-	    jcr->ReadBytes += wsize;
-	    fileAddr += compress_len;
 	 }
 #else
-	 if (extract) {
-            Jmsg(jcr, M_ERROR, 0, _("GZIP data stream found, but GZIP not configured!\n"));
-	    extract = FALSE;
+	 non_support_rsrc++;
+#endif
+	 break;
+
+      case STREAM_HFSPLUS_ATTRIBUTES:
+#ifdef HAVE_DARWIN_OS
+         Dmsg0(30, "Restoring Finder Info\n");
+	 if (sd->msglen != 32) {
+            Jmsg(jcr, M_ERROR, 0, _("     Invalid length of Finder Info (got %d, not 32)\n"), sd->msglen);
+	    continue;
+	 }
+	 if (setattrlist(jcr->last_fname, &attrList, sd->msg, sd->msglen, 0) != 0) {
+            Jmsg(jcr, M_ERROR, 0, _("     Could not set Finder Info on %s\n"), jcr->last_fname);
 	    continue;
 	 }
+#else
+	 non_support_finfo++;
+#endif
+
+      case STREAM_UNIX_ATTRIBUTES_ACCESS_ACL:
+#ifdef HAVE_ACL
+	 pm_strcpy(jcr->acl_text, sd->msg);
+         Dmsg2(400, "Restoring ACL type 0x%2x <%s>\n", BACL_TYPE_ACCESS, jcr->acl_text);
+	 if (bacl_set(jcr, BACL_TYPE_ACCESS) != 0) {
+               Jmsg1(jcr, M_WARNING, 0, "Can't restore ACL of %s\n", jcr->last_fname);
+	 }
+#else 
+	 non_support_acl++;
+#endif
+	 break;
+
+      case STREAM_UNIX_ATTRIBUTES_DEFAULT_ACL:
+#ifdef HAVE_ACL
+	 pm_strcpy(jcr->acl_text, sd->msg);
+         Dmsg2(400, "Restoring ACL type 0x%2x <%s>\n", BACL_TYPE_DEFAULT, jcr->acl_text);
+	 if (bacl_set(jcr, BACL_TYPE_DEFAULT) != 0) {
+               Jmsg1(jcr, M_WARNING, 0, "Can't restore default ACL of %s\n", jcr->last_fname);
+	 }
+#else 
+	 non_support_acl++;
 #endif
 	 break;
 
@@ -296,9 +374,9 @@ void do_restore(JCR *jcr)
 
       case STREAM_PROGRAM_NAMES:
       case STREAM_PROGRAM_DATA:
-	 if (!prog_name_msg) {
+	 if (!non_support_progname) {
             Pmsg0(000, "Got Program Name or Data Stream. Ignored.\n");
-	    prog_name_msg++;
+	    non_support_progname++;
 	 }
 	 break;
 
@@ -306,11 +384,14 @@ void do_restore(JCR *jcr)
 	 /* If extracting, wierd stream (not 1 or 2), close output file anyway */
 	 if (extract) {
             Dmsg1(30, "Found wierd stream %d\n", stream);
-	    if (!is_bopen(&bfd)) {
-               Jmsg0(jcr, M_ERROR, 0, _("Logic error output file should be open but is not.\n"));
+	    if (size > 0 && !is_bopen(&bfd)) {
+               Jmsg0(jcr, M_ERROR, 0, _("Logic error: output file should be open\n"));
 	    }
 	    set_attributes(jcr, attr, &bfd);
-	    extract = FALSE;
+	    extract = false;
+	 } else if (is_bopen(&bfd)) {
+            Jmsg0(jcr, M_ERROR, 0, _("Logic error: output file should not be open\n"));
+	    bclose(&bfd);
 	 }
          Jmsg(jcr, M_ERROR, 0, _("Unknown stream=%d ignored. This shouldn't happen!\n"), stream);
          Dmsg2(0, "None of above!!! stream=%d data=%s\n", stream,sd->msg);
@@ -320,11 +401,17 @@ void do_restore(JCR *jcr)
    } /* end while get_msg() */
 
    /* If output file is still open, it was the last one in the
-    * archive since we just hit an end of file, so close the file. 
+    * archive since we just hit an end of file, so close the file.
     */
-   if (is_bopen(&bfd)) {
+   if (is_bopen(&altbfd)) {
+      bclose_chksize(jcr, &altbfd, alt_size);
+   }
+   if (extract) {
       set_attributes(jcr, attr, &bfd);
    }
+   if (is_bopen(&bfd)) {
+      bclose(&bfd);
+   }
    set_jcr_job_status(jcr, JS_Terminated);
    goto ok_out;
 
@@ -334,12 +421,134 @@ ok_out:
    if (jcr->compress_buf) {
       free(jcr->compress_buf);
       jcr->compress_buf = NULL;
+      jcr->compress_buf_size = 0;
    }
+   bclose(&altbfd);
+   bclose(&bfd);
    free_attr(attr);
-   Dmsg2(10, "End Do Restore. Files=%d Bytes=%" lld "\n", jcr->JobFiles,
-      jcr->JobBytes);
+   free_pool_memory(jcr->acl_text);
+   Dmsg2(10, "End Do Restore. Files=%d Bytes=%s\n", jcr->JobFiles,
+      edit_uint64(jcr->JobBytes, ec1));
    if (non_support_data > 1 || non_support_attr > 1) {
       Jmsg(jcr, M_ERROR, 0, _("%d non-supported data streams and %d non-supported attrib streams ignored.\n"),
 	 non_support_data, non_support_attr);
    }
-}	   
+   if (non_support_rsrc) {
+      Jmsg(jcr, M_INFO, 0, _("%d non-supported resource fork streams ignored.\n"), non_support_rsrc);
+   }
+   if (non_support_finfo) {
+      Jmsg(jcr, M_INFO, 0, _("%d non-supported Finder Info streams ignored.\n"), non_support_rsrc);
+   }
+   if (non_support_acl) {
+      Jmsg(jcr, M_INFO, 0, _("%d non-supported acl streams ignored.\n"), non_support_acl);
+   }
+
+}
+
+#ifdef HAVE_LIBZ
+/*
+ * Convert ZLIB error code into an ASCII message
+ */
+static const char *zlib_strerror(int stat)
+{
+   if (stat >= 0) {
+      return "None";
+   }
+   switch (stat) {
+   case Z_ERRNO:
+      return "Zlib errno";
+   case Z_STREAM_ERROR:
+      return "Zlib stream error";
+   case Z_DATA_ERROR:
+      return "Zlib data error";
+   case Z_MEM_ERROR:
+      return "Zlib memory error";
+   case Z_BUF_ERROR:
+      return "Zlib buffer error";
+   case Z_VERSION_ERROR:
+      return "Zlib version error";
+   default:
+      return "*none*";
+   }
+}
+#endif
+
+/*
+ * In the context of jcr, write data to bfd.
+ * We write buflen bytes in buf at addr. addr is updated in place.
+ * The flags specify whether to use sparse files or compression.
+ * Return value is the number of bytes written, or -1 on errors.
+ */
+int32_t extract_data(JCR *jcr, BFILE *bfd, POOLMEM *buf, int32_t buflen,
+      uint64_t *addr, int flags)
+{
+   int stat;
+   char *wbuf;			      /* write buffer */
+   uint32_t wsize;		      /* write size */
+   uint32_t rsize;		      /* read size */
+   char ec1[50];		      /* Buffer printing huge values */
+
+   if (flags & FO_SPARSE) {
+      ser_declare;
+      uint64_t faddr;
+      char ec1[50];
+      wbuf = buf + SPARSE_FADDR_SIZE;
+      rsize = buflen - SPARSE_FADDR_SIZE;
+      ser_begin(buf, SPARSE_FADDR_SIZE);
+      unser_uint64(faddr);
+      if (*addr != faddr) {
+	 *addr = faddr;
+	 if (blseek(bfd, (off_t)*addr, SEEK_SET) < 0) {
+	    berrno be;
+            Jmsg3(jcr, M_ERROR, 0, _("Seek to %s error on %s: ERR=%s\n"),
+		  edit_uint64(*addr, ec1), jcr->last_fname, 
+		  be.strerror(bfd->berrno));
+	    return -1;
+	 }
+      }
+   } else {
+      wbuf = buf;
+      rsize = buflen;
+   }
+   wsize = rsize;
+
+   if (flags & FO_GZIP) {
+#ifdef HAVE_LIBZ
+      uLong compress_len;
+      /* 
+       * NOTE! We only use uLong and Byte because they are
+       *  needed by the zlib routines, they should not otherwise
+       *  be used in Bacula.
+       */
+      compress_len = jcr->compress_buf_size;
+      Dmsg2(100, "Comp_len=%d msglen=%d\n", compress_len, wsize);
+      if ((stat=uncompress((Byte *)jcr->compress_buf, &compress_len,
+		  (const Byte *)wbuf, (uLong)rsize)) != Z_OK) {
+         Jmsg(jcr, M_ERROR, 0, _("Uncompression error on file %s. ERR=%s\n"),
+	       jcr->last_fname, zlib_strerror(stat));
+	 return -1;
+      }
+      wbuf = jcr->compress_buf;
+      wsize = compress_len;
+      Dmsg2(100, "Write uncompressed %d bytes, total before write=%s\n", compress_len, edit_uint64(jcr->JobBytes, ec1));
+#else
+      Jmsg(jcr, M_ERROR, 0, _("GZIP data stream found, but GZIP not configured!\n"));
+      return -1;
+#endif
+   } else {
+      Dmsg2(30, "Write %u bytes, total before write=%s\n", wsize, edit_uint64(jcr->JobBytes, ec1));
+   }
+
+   if (bwrite(bfd, wbuf, wsize) != (ssize_t)wsize) {
+      berrno be;
+      Jmsg2(jcr, M_ERROR, 0, _("Write error on %s: %s\n"), 
+	    jcr->last_fname, be.strerror(bfd->berrno));
+      return -1;
+   }
+
+   jcr->JobBytes += wsize;
+   jcr->ReadBytes += rsize;
+   *addr += wsize;
+
+   return wsize;
+}