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CP.C
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1990-06-22
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/* cp.c -- file copying (main routines)
Copyright (C) 1989, 1990 Free Software Foundation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 1, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
Written by Torbjorn Granlund, and David MacKenzie. */
/* Yet to be done:
* Symlink translation. */
#include <stdio.h>
#include "cp.h"
#include "getopt.h"
#include "backupfile.h"
#ifndef _POSIX_SOURCE
/* This definition assumes that MODE has the S_IFIFO bit set. */
#define mkfifo(path, mode) (mknod ((path), (mode), 0))
int geteuid ();
#endif
enum backup_type get_version ();
#define INITIAL_HASH_MODULE 100
#define INITIAL_ENTRY_TAB_SIZE 70
/* A pointer to either lstat or stat, depending on
whether dereferencing of symlinks is done. */
int (*xstat) ();
/* The invocation name of this program. */
char *program_name;
/* If nonzero, dereference symbolic links (copy the files they point to). */
int flag_dereference = 1;
/* If nonzero, override protection for target files if possible. */
int flag_force = 0;
/* If nonzero, always query before removing existing targets. */
int flag_interactive = 0;
/* If nonzero, give the copies the original files' permissions. */
int flag_preserve = 0;
/* If nonzero, copy directories recursively and copy special files
as themselves rather than copying their contents. */
int flag_recursive = 0;
/* If nonzero, when copying recursively, skip any subdirectories that are
on different filesystems from the one we started on. */
int flag_one_file_system = 0;
/* If nonzero, display the names of the files before copying them. */
int flag_verbose = 0;
/* The error code to return to the system. */
int exit_status = 0;
/* If nonzero, effective uid is 0. */
int root;
/* The bits to preserve in created files' modes. */
int umask_kill;
/* If nonzero, skip unwritable files if not interactive. */
int stdin_not_tty;
struct option long_opts[] =
{
{"backup", 0, NULL, 'b'},
{"force", 0, &flag_force, 1},
{"interactive", 0, &flag_interactive, 1},
{"no-dereference", 0, &flag_dereference, 0},
{"one-file-system", 0, &flag_one_file_system, 1},
{"preserve", 0, &flag_preserve, 1},
{"recursive", 0, &flag_recursive, 1},
{"suffix", 1, NULL, 'S'},
{"verbose", 0, &flag_verbose, 1},
{"version-control", 1, NULL, 'V'},
{NULL, 0, NULL, 0}
};
void
main (argc, argv)
int argc;
char *argv[];
{
int c;
int ind;
int make_backups = 0;
char *version;
program_name = argv[0];
version = getenv ("SIMPLE_BACKUP_SUFFIX");
if (version)
simple_backup_suffix = version;
version = getenv ("VERSION_CONTROL");
/* Find out the current file creation mask, to knock the right bits
when using chmod. The creation mask is set to to be liberal, so
that created directories can be written, even if it would not
have been allowed with the mask this process was started with. */
umask_kill = 0777777 ^ umask (0);
while ((c = getopt_long (argc, argv, "bdfioprvRS:V:", long_opts, &ind))
!= EOF)
{
if (c == 0 && long_opts[ind].flag == NULL)
c = long_opts[ind].val;
switch (c)
{
case 0:
break;
case 'b':
make_backups = 1;
break;
case 'd':
flag_dereference = 0;
break;
case 'f':
flag_force = 1;
break;
case 'i':
flag_interactive = 1;
break;
case 'o':
flag_one_file_system = 1;
break;
case 'p':
flag_preserve = 1;
break;
case 'r':
case 'R':
flag_recursive = 1;
break;
case 'v':
flag_verbose = 1;
break;
case 'S':
simple_backup_suffix = optarg;
break;
case 'V':
version = optarg;
break;
default:
usage ((char *) 0);
}
}
if (make_backups)
backup_type = get_version (version);
if (flag_interactive)
flag_force = 0;
if (flag_preserve == 1)
umask_kill = 0777777;
/* The key difference between -d (+no-dereference) and not is the version
of `stat' to call. */
if (flag_dereference)
xstat = stat;
else
xstat = lstat;
stdin_not_tty = !isatty (0);
root = (geteuid () == 0);
/* Allocate space for remembering copied and created files. */
hash_init (INITIAL_HASH_MODULE, INITIAL_ENTRY_TAB_SIZE);
exit_status |= do_copy (argc, argv);
exit (exit_status);
}
/* Scan the arguments, and copy each by calling `copy'.
Return 0 if successful, 1 if any errors occur. */
int
do_copy (argc, argv)
int argc;
char *argv[];
{
char *target;
struct stat sb;
int new_dst = 0;
int ret = 0;
if (optind >= argc)
usage ("missing file arguments");
if (optind >= argc - 1)
usage ("missing file argument");
target = argv[argc - 1];
strip_trailing_slashes (target);
if (lstat (target, &sb))
{
if (errno != ENOENT)
{
error (0, errno, "%s", target);
return 1;
}
else
new_dst = 1;
}
else
{
struct stat sbx;
/* If `target' is not a symlink to a nonexistent file, use
the results of stat instead of lstat, so we can copy files
into symlinks to directories. */
if (stat (target, &sbx) == 0)
sb = sbx;
}
if (!new_dst && (sb.st_mode & S_IFMT) == S_IFDIR)
{
/* cp e_file_1...e_file_n e_dir
copy the files `e_file_1' through `e_file_n'
to the existing directory `e_dir'. */
for (;;)
{
char *arg;
char *ap;
char *dst_path;
arg = argv[optind];
strip_trailing_slashes (arg);
/* Append the last component of `arg' to `target'. */
ap = rindex (arg, '/');
if (ap == 0)
ap = arg;
else
ap++;
dst_path = xmalloc (strlen (target) + strlen (ap) + 2);
str_cpy (str_cpy (str_cpy (dst_path, target), "/"), ap);
ret |= copy (arg, dst_path, new_dst, 0, (struct dir_list *) 0);
forget_all ();
++optind;
if (optind == argc - 1)
break;
}
return ret;
}
else if (argc - optind == 2)
return copy (argv[optind], target, new_dst, 0, (struct dir_list *) 0);
else
usage ("when copying multiple files, last argument must be a directory");
}
/* Copy the file `src_path' to the file `dst_path'. The files may be of
any type. If the file `dst_path' cannot exist because its parent
directory was just created, `new_dst' should be non-zero. If
`dst_path' might already exist, `new_dst' should be zero.
`device' is the device number of the parent directory, or 0 if
this file has no known parent. `ancestors' points to a linked, null
terminated list of parent directories of `src_path'.
Return 0 if successful, 1 if an error occurs. */
int
copy (src_path, dst_path, new_dst, device, ancestors)
char *src_path;
char *dst_path;
int new_dst;
dev_t device;
struct dir_list *ancestors;
{
struct stat src_sb;
struct stat dst_sb;
int mode;
int type;
char *earlier_file;
int may_overwrite;
char *dst_backup = NULL;
if ((*xstat) (src_path, &src_sb))
{
error (0, errno, "%s", src_path);
return 1;
}
/* Are we crossing a file system boundary? */
if (flag_one_file_system && device != 0 && device != src_sb.st_dev)
return 0;
/* We wouldn't insert a node unless nlink > 1, except that we need to
find created files so as to not copy infinitely if a directory is
copied into itself. */
earlier_file = remember_copied (dst_path, src_sb.st_ino, src_sb.st_dev);
/* Have we encountered a file just created? */
if (earlier_file == &new_file)
return 0;
if (flag_verbose)
printf (" %s -> %s\n", src_path, dst_path);
/* Did we copy this inode somewhere else (in this command line argument)
and therefore this is a second hard link to the inode? */
if (!flag_dereference && src_sb.st_nlink > 1 && earlier_file)
{
if (!new_dst)
{
if (backup_type != none)
{
dst_backup = find_backup_file_name (dst_path);
if (dst_backup == NULL)
error (1, 0, "virtual memory exhausted");
if (rename (dst_path, dst_backup))
{
if (errno != ENOENT)
{
error (0, errno, "cannot backup `%s'", dst_path);
free (dst_backup);
return 1;
}
else
{
free (dst_backup);
dst_backup = NULL;
}
}
}
else if (unlink (dst_path) && errno != ENOENT)
{
error (0, errno, "cannot remove old link `%s'", dst_path);
return 1;
}
}
if (link (earlier_file, dst_path))
{
error (0, errno, "cannot create link `%s'", dst_path);
goto un_backup;
}
if (dst_backup)
free (dst_backup);
return 0;
}
mode = src_sb.st_mode;
type = src_sb.st_mode & S_IFMT;
if (type == S_IFDIR && !flag_recursive)
{
error (0, 0, "%s: omitting directory", src_path);
return 1;
}
if (!new_dst)
{
if ((*xstat) (dst_path, &dst_sb))
{
if (errno != ENOENT)
{
error (0, errno, "%s", dst_path);
return 1;
}
else
new_dst = 1;
}
else
{
/* The file exists already. */
if (src_sb.st_ino == dst_sb.st_ino && src_sb.st_dev == dst_sb.st_dev)
{
error (0, 0, "`%s' and `%s' are the same file (omitted)",
src_path, dst_path);
return 1;
}
if ((dst_sb.st_mode & S_IFMT) == S_IFDIR && type != S_IFDIR)
{
error (0, 0, "%s: cannot overwrite directory with non-directory",
dst_path);
return 1;
}
/* Treat the file as nonwritable if it lacks write permission bits,
even if we are root. */
#ifdef S_IFLNK
if (type == S_IFLNK)
may_overwrite = 1;
else
#endif
may_overwrite =
eaccess_stat (&dst_sb,
type == S_IFDIR ? (W_OK | X_OK) : W_OK) == 0
&& (dst_sb.st_mode & 0222)
&& (type != S_IFDIR
|| (dst_sb.st_mode & 0111));
if (flag_interactive)
{
fprintf (stderr, "%s: replace `%s'? ", program_name, dst_path);
if (!yesno ())
return 0;
}
else if (!flag_force && !may_overwrite)
{
if (stdin_not_tty)
{
error (0, 0, "%s: no write permission", dst_path);
return 1;
}
fprintf (stderr, "%s: override mode %04o for `%s'? ",
program_name, dst_sb.st_mode & 0777, dst_path);
if (!yesno ())
return 0;
}
if (backup_type != none)
{
dst_backup = find_backup_file_name (dst_path);
if (dst_backup == NULL)
error (1, 0, "virtual memory exhausted");
if (rename (dst_path, dst_backup))
{
if (errno != ENOENT)
{
error (0, errno, "cannot backup `%s'", dst_path);
free (dst_backup);
return 1;
}
else
{
free (dst_backup);
dst_backup = NULL;
}
}
new_dst = 1;
}
else if (!may_overwrite)
{
if (type == S_IFDIR)
{
/* Temporarily change mode to allow overwriting. */
if (chmod (dst_path, dst_sb.st_mode | S_IEXEC | S_IWRITE))
{
error (0, errno, "%s", dst_path);
return 1;
}
}
else
{
if (unlink (dst_path) && errno != ENOENT)
{
error (0, errno, "cannot remove old link to `%s'",
dst_path);
return 1;
}
new_dst = 1;
}
}
}
}
if (!flag_recursive)
{
if (copy_reg (src_path, dst_path))
goto un_backup;
}
else
switch (type)
{
#ifdef S_IFIFO
case S_IFIFO:
/* If a fifo already exists, we cannot do a better one. */
if (new_dst)
{
if (mkfifo (dst_path, mode & umask_kill))
{
error (0, errno, "cannot make fifo `%s'", dst_path);
goto un_backup;
}
}
break;
#endif
case S_IFBLK:
case S_IFCHR:
#ifdef S_IFSOCK
case S_IFSOCK:
#endif
if (!root)
{
error (0, 0, "%s: omitting special file", src_path);
goto un_backup;
}
if (!new_dst && unlink (dst_path) && errno != ENOENT)
{
error (0, errno, "cannot remove old link to `%s'", dst_path);
return 1;
}
if (mknod (dst_path, mode & umask_kill, src_sb.st_rdev))
{
error (0, errno, "cannot create special file `%s'", dst_path);
goto un_backup;
}
break;
case S_IFDIR:
{
struct dir_list *dir;
/* If this directory has been copied before during the
recursion, there's a symbolic link to an ancestor
directory of the symbolic link. It's impossible to
continue to copy this, unless we've got an infinite disk. */
if (is_ancestor (&src_sb, ancestors))
{
error (0, 0, "%s: omitting cyclic symbolic link", src_path);
goto un_backup;
}
/* Insert the current directory in the list of parents. */
dir = (struct dir_list *) alloca (sizeof (struct dir_list));
dir->parent = ancestors;
dir->ino = src_sb.st_ino;
dir->dev = src_sb.st_dev;
/* Create the directory. If a directory already exists, we
cannot create a better one. */
if (new_dst)
{
/* Create the new directory writable and searchable, so
we can create new entries in it. */
if (mkdir (dst_path, 0700))
{
error (0, errno, "cannot create directory `%s'", dst_path);
goto un_backup;
}
/* Insert the created directory's inode and device
numbers into the search structure, so that we can
avoid copying it again. */
if (remember_created (dst_path))
goto un_backup;
}
/* Now, copy the contents of the directory. */
if (copy_dir (src_path, dst_path, new_dst, &src_sb, dir))
goto err_return;
}
break;
case S_IFREG:
if (copy_reg (src_path, dst_path))
goto un_backup;
break;
#ifdef S_IFLNK
case S_IFLNK:
{
char *link_val = (char *) alloca (src_sb.st_size + 1);
if (readlink (src_path, link_val, src_sb.st_size) < 0)
{
error (0, errno, "cannot read symbolic link `%s'", src_path);
goto un_backup;
}
link_val[src_sb.st_size] = '\0';
if (!new_dst && unlink (dst_path) && errno != ENOENT)
{
error (0, errno, "cannot remove old link to `%s'", dst_path);
return 1;
}
if (symlink (link_val, dst_path))
{
error (0, errno, "cannot create symbolic link `%s'", dst_path);
goto un_backup;
}
}
return 0;
#endif
default:
error (0, 0, "%s: unknown file type (omitted)", src_path);
goto un_backup;
}
if ((flag_preserve || new_dst) && (type == S_IFREG || type == S_IFDIR))
{
if (chmod (dst_path, mode & umask_kill))
{
error (0, errno, "%s", dst_path);
goto err_return;
}
}
else if (type == S_IFDIR && !new_dst && !may_overwrite)
{
/* Reset the temporarily changed mode. */
if (chmod (dst_path, dst_sb.st_mode))
{
error (0, errno, "%s", dst_path);
goto err_return;
}
}
/* Adjust the times (and if possible, ownership) for the copy. */
if (flag_preserve)
{
struct utimbuf tv;
tv.actime = src_sb.st_atime;
tv.modtime = src_sb.st_mtime;
if (utime (dst_path, &tv))
{
error (0, errno, "%s", dst_path);
goto err_return;
}
if (chown (dst_path, src_sb.st_uid, src_sb.st_gid) && errno != EPERM)
{
error (0, errno, "%s", dst_path);
goto err_return;
}
}
if (dst_backup)
free (dst_backup);
return 0;
err_return:
if (dst_backup)
free (dst_backup);
return 1;
un_backup:
if (dst_backup)
{
if (rename (dst_backup, dst_path))
error (0, errno, "cannot un-backup `%s'", dst_path);
free (dst_backup);
}
return 1;
}
/* Read the contents of the directory `src_path_in', and recursively
copy the contents to `dst_path_in'. `new_dst' is non-zero if
`dst_path_in' is a directory that was created previously in the
recursion. Return 0 if successful, -1 if an error occurs. */
int
copy_dir (src_path_in, dst_path_in, new_dst, src_sb, ancestors)
char *src_path_in;
char *dst_path_in;
int new_dst;
struct stat *src_sb;
struct dir_list *ancestors;
{
char *name_space;
char *namep;
char *src_path;
char *dst_path;
int ret = 0;
errno = 0;
name_space = savedir (src_path_in, src_sb->st_size);
if (name_space == 0)
{
if (errno)
{
error (0, errno, "%s", src_path_in);
return -1;
}
else
error (1, 0, "virtual memory exhausted");
}
namep = name_space;
while (*namep != '\0')
{
int fn_length = strlen (namep) + 1;
dst_path = xmalloc (strlen (dst_path_in) + fn_length + 1);
src_path = xmalloc (strlen (src_path_in) + fn_length + 1);
str_cpy (str_cpy (str_cpy (src_path, src_path_in), "/"), namep);
str_cpy (str_cpy (str_cpy (dst_path, dst_path_in), "/"), namep);
ret |= copy (src_path, dst_path, new_dst, src_sb->st_dev, ancestors);
/* Free the memory for `src_path'. The memory for `dst_path'
cannot be deallocated, since it is used to create multiple
hard links. (Of course it is possible to optimize memory
allocation, as most files have only one link.) */
free (src_path);
namep += fn_length;
}
free (name_space);
return -ret;
}
/* Copy a regular file from `src_path' to `dst_path'. Large blocks of zeroes,
as well as holes in the source file, are made into holes in the
target file. (Holes are read as zero by the `read' system call.)
Return 0 if successful, -1 if an error occurred. */
int
copy_reg (src_path, dst_path)
char *src_path;
char *dst_path;
{
char *buf;
int buf_size;
int target_desc;
int source_desc;
int n_read;
int n_written;
struct stat sb;
int return_val = 0;
long n_read_total = 0;
char *cp;
int *ip;
int last_write_made_hole = 0;
source_desc = open (src_path, O_RDONLY);
if (source_desc < 0)
{
error (0, errno, "%s", src_path);
return -1;
}
/* Create the new regular file with small permissions initially,
not to create a security hole. */
target_desc = open (dst_path, O_WRONLY | O_CREAT | O_TRUNC, 0600);
if (target_desc < 0)
{
error (0, errno, "cannot create regular file `%s'", dst_path);
return_val = -1;
goto ret2;
}
/* Find out the appropriate buffer length. */
if (fstat (target_desc, &sb))
{
error (0, errno, "%s", dst_path);
return_val = -1;
goto ret;
}
buf_size = ST_BLKSIZE (sb);
/* Make a buffer with space for a sentinel at the end. */
buf = (char *) alloca (buf_size + sizeof (int));
for (;;)
{
n_read = read (source_desc, buf, buf_size);
if (n_read < 0)
{
error (0, errno, "%s", src_path);
return_val = -1;
goto ret;
}
if (n_read == 0)
break;
n_read_total += n_read;
buf[n_read] = 1; /* Sentinel to stop loop. */
/* Find first non-zero *word*, or the word with the sentinel. */
ip = (int *) buf;
while (*ip++ == 0)
;
/* Find the first non-zero *byte*, or the sentinel. */
cp = (char *) (ip - 1);
while (*cp++ == 0)
;
/* If we found the sentinel, the whole input block was zero,
and we can make a hole. */
if (cp > buf + n_read)
{
/* Make a hole. */
if (lseek (target_desc, (off_t) n_read, L_INCR) < 0L)
{
error (0, errno, "%s", dst_path);
return_val = -1;
goto ret;
}
last_write_made_hole = 1;
}
else
{
n_written = write (target_desc, buf, n_read);
if (n_written < n_read)
{
error (0, errno, "%s", dst_path);
return_val = -1;
goto ret;
}
last_write_made_hole = 0;
}
}
/* If the file ends with a `hole', something needs to be written at
the end. Otherwise the kernel would truncate the file at the end
of the last write operation. */
if (last_write_made_hole)
{
#ifndef FTRUNCATE_MISSING
/* Write a null character and truncate it again. */
if (write (target_desc, "", 1) != 1
|| ftruncate (target_desc, n_read_total) < 0)
#else
/* Seek backwards one character and write a null. */
if (lseek (target_desc, (off_t) -1, L_INCR) < 0L
|| write (target_desc, "", 1) != 1)
#endif
{
error (0, errno, "%s", dst_path);
return_val = -1;
}
}
ret:
close (target_desc);
ret2:
close (source_desc);
return return_val;
}