[Libguestfs] [PATCH 5/6] New APIs: copy-in and copy-out
Richard W.M. Jones
rjones at redhat.com
Mon Feb 2 13:40:44 UTC 2015
On Mon, Jan 26, 2015 at 05:04:10PM +0100, Pino Toscano wrote:
> Currently implemented as guestfish commands, provide them instead as
> single source -> destination functions for the library, so they can be
> used also in other places.
>
> These functions are not added to guestfish, since guestfish has its own
> implementation (which will soon switch to call copy-in and copy-out for
> multiple paths).
> ---
> generator/actions.ml | 28 ++++++
> po/POTFILES | 1 +
> src/Makefile.am | 1 +
> src/copy-in-out.c | 244 +++++++++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 274 insertions(+)
> create mode 100644 src/copy-in-out.c
>
> diff --git a/generator/actions.ml b/generator/actions.ml
> index 25f4bb5..ab97891 100644
> --- a/generator/actions.ml
> +++ b/generator/actions.ml
> @@ -3310,6 +3310,34 @@ In non-C language bindings, this allows you to retrieve the underlying
> C pointer to the handle (ie. C<guestfs_h *>). The purpose of this is
> to allow other libraries to interwork with libguestfs." };
>
> + { defaults with
> + name = "copy_in";
> + style = RErr, [String "localpath"; Pathname "remotedir"], [];
> + visibility = VPublicNoFish;
> + shortdesc = "copy local files or directories into an image";
> + longdesc = "\
> +C<guestfs_copy_in> copies local files or directories recursively into
> +the disk image, placing them in the directory called C</remotedir>
^
You don't need the / here.
> +(which must exist).
> +
> +Wildcards cannot be used." };
> +
> + { defaults with
> + name = "copy_out";
> + style = RErr, [Pathname "remotepath"; String "localdir"], [];
> + visibility = VPublicNoFish;
> + shortdesc = "copy remote files or directories out of an image";
> + longdesc = "\
> +C<guestfs_copy_out> copies remote files or directories recursively
> +out of the disk image, placing them on the host disk in a local
> +directory called C<localdir> (which must exist).
> +
> +To download to the current directory, use C<.> as in:
> +
> + C<guestfs_copy_out> /home .
> +
> +Wildcards cannot be used." };
> +
> ]
>
> (* daemon_functions are any functions which cause some action
> diff --git a/po/POTFILES b/po/POTFILES
> index 4194e5f..6e65377 100644
> --- a/po/POTFILES
> +++ b/po/POTFILES
> @@ -297,6 +297,7 @@ src/canonical-name.c
> src/cleanup.c
> src/command.c
> src/conn-socket.c
> +src/copy-in-out.c
> src/create.c
> src/dbdump.c
> src/drives.c
> diff --git a/src/Makefile.am b/src/Makefile.am
> index a83f257..2496887 100644
> --- a/src/Makefile.am
> +++ b/src/Makefile.am
> @@ -90,6 +90,7 @@ libguestfs_la_SOURCES = \
> canonical-name.c \
> command.c \
> conn-socket.c \
> + copy-in-out.c \
> create.c \
> dbdump.c \
> drives.c \
> diff --git a/src/copy-in-out.c b/src/copy-in-out.c
> new file mode 100644
> index 0000000..8e2edd3
> --- /dev/null
> +++ b/src/copy-in-out.c
> @@ -0,0 +1,244 @@
> +/* libguestfs
> + * Copyright (C) 2015 Red Hat Inc.
> + *
> + * 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 2 of the License, 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
> + */
> +
> +#include <config.h>
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <stdint.h>
> +#include <inttypes.h>
> +#include <unistd.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <sys/wait.h>
> +#include <errno.h>
> +#include <string.h>
> +
> +#include "guestfs.h"
> +#include "guestfs-internal.h"
> +#include "guestfs-internal-actions.h"
> +
> +static int split_path (char *buf, size_t buf_size, const char *path, const char **dirname, const char **basename);
> +
> +int
> +guestfs__copy_in (guestfs_h *g, const char *localpath, const char *remotedir)
> +{
> + CLEANUP_CMD_CLOSE struct command *cmd = guestfs___new_command (g);
> + int fd;
> + int r;
> + char fdbuf[64];
> + size_t buf_len = strlen (localpath) + 1;
> + char buf[buf_len];
> + const char *dirname, *basename;
> +
> + if (guestfs_is_dir (g, remotedir) == -1)
> + return -1;
I suppose this is here to check that remotedir is a directory, but
that's not what the code here does. The original guestfish code is:
int remote_is_dir = guestfs_is_dir (g, remote);
if (remote_is_dir == -1)
return -1;
if (!remote_is_dir) {
fprintf (stderr, _("copy-in: target '%s' is not a directory\n"), remote);
return -1;
}
> + if (split_path (buf, buf_len, localpath, &dirname, &basename) == -1)
> + return -1;
> +
> + guestfs___cmd_add_arg (cmd, "tar");
> + if (dirname) {
> + guestfs___cmd_add_arg (cmd, "-C");
> + guestfs___cmd_add_arg (cmd, dirname);
> + }
> + guestfs___cmd_add_arg (cmd, "-cf");
> + guestfs___cmd_add_arg (cmd, "-");
> + guestfs___cmd_add_arg (cmd, basename);
> +
> + r = guestfs___cmd_run_async (cmd, NULL, NULL, &fd, NULL);
> + if (r == -1)
> + return -1;
> +
> + snprintf (fdbuf, sizeof fdbuf, "/dev/fd/%d", fd);
> +
> + r = guestfs_tar_in (g, fdbuf, remotedir);
> +
> + if (close (fd) == -1) {
> + perror ("close (tar subprocess)");
> + return -1;
> + }
> +
> + r = guestfs___cmd_wait (cmd);
> + if (r == -1)
> + return -1;
> + if (!(WIFEXITED (r) && WEXITSTATUS (r) == 0))
> + return -1;
> +
> + return 0;
> +}
> +
> +struct copy_out_child_data {
> + const char *localdir;
> + const char *basename;
> +};
> +
> +static int
> +child_setup (guestfs_h *g, void *data)
> +{
> + struct copy_out_child_data d = *(struct copy_out_child_data *) data;
> +
> + if (chdir (d.localdir) == -1) {
> + perror (d.localdir);
> + return -1;
> + }
> +
> + if (mkdir (d.basename, 0777) == -1 && errno != EEXIST) {
> + perror (d.basename);
> + return -1;
> + }
> +
> + if (chdir (d.basename) == -1) {
> + perror (d.basename);
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> +int
> +guestfs__copy_out (guestfs_h *g, const char *remotepath, const char *localdir)
> +{
> + struct stat statbuf;
> + int r;
> +
> + if (stat (localdir, &statbuf) == -1 ||
> + ! (S_ISDIR (statbuf.st_mode))) {
> + error (g, _("target '%s' is not a directory"), localdir);
> + return -1;
> + }
> +
> + /* If the remote is a file, download it. If it's a directory,
> + * create the directory in localdir first before using tar-out.
> + */
> + r = guestfs_is_file (g, remotepath);
> + if (r == -1)
> + return -1;
> +
> + if (r == 1) { /* is file */
> + CLEANUP_FREE char *filename = NULL;
> + size_t buf_len = strlen (remotepath) + 1;
> + char buf[buf_len];
> + const char *basename;
> +
> + if (split_path (buf, buf_len, remotepath, NULL, &basename) == -1)
> + return -1;
> +
> + if (asprintf (&filename, "%s/%s", localdir, basename) == -1) {
> + perror ("asprintf");
> + return -1;
> + }
> + if (guestfs_download (g, remotepath, filename) == -1)
> + return -1;
> + } else { /* not a regular file */
> + CLEANUP_CMD_CLOSE struct command *cmd = guestfs___new_command (g);
> + struct copy_out_child_data data;
> + char fdbuf[64];
> + int fd;
> +
> + r = guestfs_is_dir (g, remotepath);
> + if (r == -1)
> + return -1;
> +
> + if (r == 0) {
> + error (g, _("'%s' is not a file or directory"), remotepath);
> + return -1;
> + }
> +
> + size_t buf_len = strlen (remotepath) + 1;
> + char buf[buf_len];
> + const char *basename;
> + if (split_path (buf, buf_len, remotepath, NULL, &basename) == -1)
> + return -1;
> +
> + /* RHBZ#845522: If remotepath == "/" then basename would be an empty
> + * string. Replace it with "." so that make_tar_output writes
> + * to "localdir/."
> + */
> + if (STREQ (basename, ""))
> + basename = ".";
> +
> + data.localdir = localdir;
> + data.basename = basename;
> +
> + guestfs___cmd_set_child_callback (cmd, &child_setup, &data);
> +
> + guestfs___cmd_add_arg (cmd, "tar");
> + guestfs___cmd_add_arg (cmd, "-xf");
> + guestfs___cmd_add_arg (cmd, "-");
> +
> + r = guestfs___cmd_run_async (cmd, NULL, &fd, NULL, NULL);
> + if (r == -1)
> + return -1;
> +
> + snprintf (fdbuf, sizeof fdbuf, "/dev/fd/%d", fd);
> +
> + r = guestfs_tar_out (g, remotepath, fdbuf);
> +
> + if (close (fd) == -1) {
> + perror ("close (tar-output subprocess)");
> + return -1;
> + }
> +
> + r = guestfs___cmd_wait (cmd);
> + if (r == -1)
> + return -1;
> + if (!(WIFEXITED (r) && WEXITSTATUS (r) == 0))
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> +/* Split path into directory name and base name, using the buffer
> + * provided as a working area. If there is no directory name
> + * (eg. path == "/") then this can return dirname as NULL.
> + */
> +static int
> +split_path (char *buf, size_t buf_size,
> + const char *path, const char **dirname, const char **basename)
> +{
> + size_t len = strlen (path);
> + if (len == 0 || len > buf_size - 1) {
> + fprintf (stderr, _("error: argument is zero length or longer than maximum permitted\n"));
> + return -1;
> + }
> +
> + strcpy (buf, path);
> +
> + if (len >= 2 && buf[len-1] == '/') {
> + buf[len-1] = '\0';
> + len--;
> + }
> +
> + char *p = strrchr (buf, '/');
> + if (p && p > buf) { /* "foo/bar" */
> + *p = '\0';
> + p++;
> + if (dirname) *dirname = buf;
> + if (basename) *basename = p;
> + } else if (p && p == buf) { /* "/foo" */
> + if (dirname) *dirname = "/";
> + if (basename) *basename = buf+1;
> + } else {
> + if (dirname) *dirname = NULL;
> + if (basename) *basename = buf;
> + }
> +
> + return 0;
> +}
> --
> 1.9.3
The guestfish code (which took *ages* to get right) is a lot more
complicated ...
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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