Upstream's 0.0.16v0.0.16upstream

1 files changed, 368 insertions, 0 deletions

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+/* $Header: /home/ksheff/src/e2tools/RCS/read.c,v 0.2 2002/08/08 07:58:35 ksheff Exp $ */
+/*
+ * read.c
+ *
+ * Copyright (C) 2002 Keith W Sheffield.  This file may be redistributed
+ * under the terms of the GNU Public License.
+ *
+ * Derived from dump.c Copyright (C) 1994 Theodore Ts'o <tytso@mit.edu>
+ *
+ */
+
+static char rcsid[] = "$Id: read.c,v 0.2 2002/08/08 07:58:35 ksheff Exp $";
+
+static char copyright[] = "Copyright 2002 Keith W Sheffield";
+
+#ifndef READ_C
+#define READ_C
+#endif
+
+/* Description */
+/*
+ *
+ *
+ */
+/*
+ * $Log: read.c,v $
+ * Revision 0.2  2002/08/08 07:58:35  ksheff
+ * Split the read loop from retrieve_data() out to its own function:
+ * read_to_eof() and made retrieve_data() able to seek to an offset before
+ * starting to read.
+ *
+ * Revision 0.1  2002/02/27 04:48:52  ksheff
+ * initial revision
+ *
+ */
+
+/* Feature Test Switches */
+/*  Headers */
+#include "e2tools.h"
+
+/* Local Prototypes */
+
+long
+get_file(ext2_filsys fs, ext2_ino_t root, ext2_ino_t cwd,
+         char *infile, char *outfile, int keep);
+
+long
+retrieve_data(ext2_filsys fs, ext2_ino_t src, int dest_fd,
+              char *dest_name, int keep, ext2_off_t offset,
+              ext2_off_t *ret_pos);
+
+long
+read_to_eof(ext2_file_t infile, int dest_fd, ext2_off_t offset,
+            ext2_off_t *ret_pos);
+
+
+static void
+fix_perms(const struct ext2_inode *inode, int fd, const char *name);
+
+/* Name:	get_file()
+ *
+ * Description:
+ *
+ * This function copies a file from the current ext2fs directory to disk
+ * or stdout.
+ *
+ * Algorithm:
+ *
+ * Check input parameters
+ * If the output file is NULL
+ *     Get the file descriptor for stdout
+ * Otherwise
+ *     Open the output file
+ * Get the inode number for the input file
+ * Copy the contents to the output file
+ * Close output file
+ *
+ * Global Variables:
+ *
+ * None
+ *
+ * Arguments:
+ *
+ * ext2_filsys fs;       The current file system
+ * ext2_ino_t root;      The root directory
+ * ext2_ino_t cwd;       The current working directory
+ * char *infile;         The name of the input file
+ * char *outfile;        The name of the output file
+ * int keep;             Flag indicating if the permissions should be kept
+ *
+ * Return Values:
+ *
+ * 0 - the file was copied successfully
+ * the error code of whatever went wrong.
+ *
+ * Author: Keith W. Sheffield
+ * Date:   02/20/2002
+ *
+ * Modification History:
+ *
+ * MM/DD/YY      Name               Description
+ *
+ */
+
+long
+get_file(ext2_filsys fs, ext2_ino_t root, ext2_ino_t cwd,
+         char *infile, char *outfile, int keep)
+{
+  int fd;
+  ext2_ino_t src;
+  int dest;
+  int retval;
+  
+  if (fs == NULL || infile == NULL)
+    {
+      fputs("Invalid input parameter.  Exiting get_file() with -1\n",
+            stderr);
+      return (-1);
+    }
+
+  /* open the output file if we need to */
+  if (outfile == NULL)
+    dest = fileno(stdout);
+  else if (-1 == (dest = open(outfile, O_CREAT | O_WRONLY | O_TRUNC, 0666)))
+    {
+      perror(outfile);
+      return(-1);
+    }
+
+  /* get the inode number associated with the input file */
+  if ((retval = ext2fs_namei(fs, root, cwd, infile, &src)))
+    {
+      if (retval == EXT2_ET_FILE_NOT_FOUND)
+        {
+          fprintf(stderr, "%s not found\n", infile);
+          if (outfile)
+            {
+              close(dest);
+#ifndef DEBUG
+              unlink(outfile);
+#endif
+            }
+          return(0);
+        }
+      fputs(error_message(retval), stderr);
+      return retval;
+    }
+
+  /* get the data from the ext2fs */
+  if ((retval = retrieve_data(fs, src, dest, outfile, keep, 0, NULL)))
+    {
+      if (outfile)
+        {
+          close(dest);
+#ifndef DEBUG
+          unlink(outfile);
+#endif
+        }
+      return(retval);
+    }
+  if (outfile)
+    close(dest);
+  return(0);
+
+} /* end of get_file */ 
+
+
+/* Name:	retrieve_data()
+ *
+ * Description:
+ *
+ * This function retrieves the data stored as a file in an ext2fs file
+ * system.
+ *
+ * Algorithm:
+ *
+ * Get the inode associated with the file name
+ * Open the file in the ext2fs file system
+ * Copy the contents of the ext2fs file to the output file descriptor
+ * Close the ext2fs file
+ * If the permissions are to be kept
+ *     Call fix_perms
+ *
+ * Global Variables:
+ *
+ * None
+ *
+ * Arguments:
+ *
+ * ext2_filsys fs;            The filesystem being read from
+ * ext2_ino_t src;            The source inode number
+ * int dest_fd;               The destination file descriptor
+ * char *dest_name;           The name of the destination file
+ * int keep;                  Keep the permissions/ownership, etc. from ext2fs
+ *
+ * Return Values:
+ *
+ * 0 - file read successfully
+ * error code of what went wrong.
+ *
+ * Author: Keith W. Sheffield
+ * Date:   02/20/2002
+ *
+ * Modification History:
+ *
+ * MM/DD/YY      Name               Description
+ * 08/07/02      K.Sheffield        Moved the copy loop to read_to_eof()
+ *
+ */
+
+long
+retrieve_data(ext2_filsys fs, ext2_ino_t src, int dest_fd,
+              char *dest_name, int keep, ext2_off_t offset,
+              ext2_off_t *ret_pos)
+{
+  struct ext2_inode inode;
+  ext2_file_t infile;    
+  int retval;
+    
+  if (keep && (retval = ext2fs_read_inode(fs, src, &inode)))
+    {
+      fputs(error_message(retval), stderr);
+      return retval;
+    }
+
+  if ((retval = ext2fs_file_open(fs, src, 0, &infile)))
+    {
+      fputs(error_message(retval), stderr);
+      return retval;
+    }
+
+  if (read_to_eof(infile, dest_fd, offset, ret_pos))
+    {
+      if ((retval = ext2fs_file_close(infile)))
+        fputs(error_message(retval), stderr);
+      return(-1);
+    }
+  
+  if ((retval = ext2fs_file_close(infile)))
+    {
+      fputs(error_message(retval), stderr);
+      return retval;
+    }
+        
+  if (keep)
+    fix_perms(&inode, dest_fd, dest_name);
+
+  return(0);
+    
+} /* end of retrieve_data */ 
+
+/* Name:	read_to_eof()
+ *
+ * Description:
+ *
+ * This function reads from an ext2_file_t file and outputs the contents
+ * to a standard file descriptor.
+ *
+ * Algorithm:
+ *
+ * Seek to the desired location
+ * While one is able to read data from the ext2fs file
+ *     Write data to the output file descriptor.
+ *
+ * Global Variables:
+ *
+ * None.
+ *
+ * Arguments:
+ *
+ * ext2_file_t infile;        Input file
+ * int dest_fd;               The destination file descriptor
+ * ext2_off_t offset;         The offset in the file to seek
+ * ext2_off_t *ret_pos;       The returned file position
+ *
+ * Return Values:
+ *
+ *
+ * Author: Keith W. Sheffield
+ * Date:   08/07/2002
+ *
+ * Modification History:
+ *
+ * MM/DD/YY      Name               Description
+ *
+ */
+long
+read_to_eof(ext2_file_t infile, int dest_fd, ext2_off_t offset,
+            ext2_off_t *ret_pos)
+{
+  char buf[4096];
+  unsigned int bytes_read;
+  int bytes_written;
+  int retval;
+
+  if (offset != 0 &&
+      (retval = ext2fs_file_lseek(infile, offset, EXT2_SEEK_SET, NULL)))
+    {
+      fputs(error_message(retval), stderr);
+      return retval;
+    }
+  
+  /* read all that we can and dump it to the output file descriptor */
+  do
+    {
+      if ((retval = ext2fs_file_read(infile, buf, sizeof(buf), &bytes_read)))
+        {
+          fputs(error_message(retval), stderr);
+          return retval;
+        }
+    }
+  while (bytes_read > 0 &&
+         bytes_read == (bytes_written = write(dest_fd, buf, bytes_read)));
+
+  if (bytes_read)
+    {
+      perror("read_to_eof");
+      return(-1);
+    }
+
+  if (ret_pos != NULL &&
+      (retval = ext2fs_file_lseek(infile, 0, EXT2_SEEK_CUR, ret_pos)))
+    {
+      fputs(error_message(retval), stderr);
+      return retval;
+    }
+
+  return(0);
+  
+} /* end of read_to_eof */ 
+
+/* blatantly copied from code written by T Ts'o w/ minor changes */
+static void
+fix_perms(const struct ext2_inode *inode, int fd, const char *name)
+{
+  struct utimbuf ut;
+  int i;
+
+  if (fd != -1)
+    i = fchmod(fd, ext2_mode_xlate(inode->i_mode));
+  else
+    i = chmod(name, ext2_mode_xlate(inode->i_mode));
+  if (i == -1)
+    perror(name);
+
+#ifndef HAVE_FCHOWN
+  i = chown(name, inode->i_uid, inode->i_gid);
+#else
+  if (fd != -1)
+    i = fchown(fd, inode->i_uid, inode->i_gid);
+  else
+    i = chown(name, inode->i_uid, inode->i_gid);
+#endif
+  if (i == -1)
+    perror(name);
+
+  if (fd != -1)
+    close(fd);
+
+  ut.actime = inode->i_atime;
+  ut.modtime = inode->i_mtime;
+  if (utime(name, &ut) == -1)
+    perror(name);
+    
+}
+
+
+