[Libguestfs] [PATCH 3/3] New API: get-sockdir
Richard W.M. Jones
rjones at redhat.com
Wed Feb 3 10:31:20 UTC 2016
On Tue, Feb 02, 2016 at 03:27:41PM +0100, Pino Toscano wrote:
> Introduce a new read-only API to get a path where to store temporary
> sockets: this is different than tmpdir, as we need short paths for
> sockets (due to sockaddr_un::sun_path), and is either XDG_RUNTIME_DIR
> if set, or /tmp.
>
> Adapt guestfs_int_create_socketname to create sockets in that location,
> checking whether the resulting path still fits in the limited buffer.
>
> Furthermore, print sockdir and XDG_RUNTIME_DIR in test-tool for
> debugging.
> ---
> fish/guestfish.pod | 11 +++++++++++
> generator/actions.ml | 16 ++++++++++++++++
> src/guestfs-internal.h | 7 ++++++-
> src/handle.c | 9 ++++++++-
> src/launch.c | 10 ++++++++--
> src/tmpdirs.c | 33 +++++++++++++++++++++++++++++++++
> test-tool/test-tool.c | 6 ++++++
> 7 files changed, 88 insertions(+), 4 deletions(-)
>
> diff --git a/fish/guestfish.pod b/fish/guestfish.pod
> index c6f5663..bbeea82 100644
> --- a/fish/guestfish.pod
> +++ b/fish/guestfish.pod
> @@ -1519,6 +1519,17 @@ about kernel selection, see L<supermin(1)>.
>
> See L</LIBGUESTFS_CACHEDIR>, L</LIBGUESTFS_TMPDIR>.
>
> +=item XDG_RUNTIME_DIR
> +
> +This directory represents a user-specific directory for storing
> +non-essential runtime files.
> +
> +If it is set, then is used to store temporary sockets. Otherwise,
> +F</tmp> is used.
> +
> +See also L</get-sockdir>,
> +L<http://www.freedesktop.org/wiki/Specifications/basedir-spec/>.
> +
> =back
I think this section needs to be duplicated in guestfs(3) too? Since
both man pages list environment variables.
> =head1 FILES
> diff --git a/generator/actions.ml b/generator/actions.ml
> index 24c6eb7..5b6898c 100644
> --- a/generator/actions.ml
> +++ b/generator/actions.ml
> @@ -3504,6 +3504,22 @@ call it returns a simple true/false boolean result, instead
> of throwing an exception if a feature is not found. For
> other documentation see C<guestfs_available>." };
>
> + { defaults with
> + name = "get_sockdir"; added = (1, 33, 8);
> + style = RString "sockdir", [], [];
> + blocking = false;
> + shortdesc = "get the temporary directory for sockets";
> + longdesc = "\
> +Get the directory used by the handle to store temporary socket files.
> +
> +This is different than C<guestfs_tmpdir>, as we need shorter paths for
different from
> +sockets (due to the limited buffers of filenames for UNIX sockets),
> +and C<guestfs_tmpdir> may be too long for them.
> +
> +The environment variable C<XDG_RUNTIME_DIR> controls the default
> +value: If C<XDG_RUNTIME_DIR> is set, then that is the default.
> +Else F</tmp> is the default." };
> +
> ]
>
> (* daemon_functions are any functions which cause some action
> diff --git a/src/guestfs-internal.h b/src/guestfs-internal.h
> index bff9f64..6e441e4 100644
> --- a/src/guestfs-internal.h
> +++ b/src/guestfs-internal.h
> @@ -434,8 +434,10 @@ struct guestfs_h
> * handle, you have to call guestfs_int_lazy_make_tmpdir.
> */
> char *tmpdir;
> - /* Environment variables that affect tmpdir/cachedir locations. */
> + char *sockdir;
> + /* Environment variables that affect tmpdir/cachedir/sockdir locations. */
> char *env_tmpdir; /* $TMPDIR (NULL if not set) */
> + char *env_runtimedir; /* $XDG_RUNTIME_DIR (NULL if not set)*/
> char *int_tmpdir; /* $LIBGUESTFS_TMPDIR or guestfs_set_tmpdir or NULL */
> char *int_cachedir; /* $LIBGUESTFS_CACHEDIR or guestfs_set_cachedir or NULL */
>
> @@ -757,8 +759,11 @@ extern void guestfs_int_call_callbacks_array (guestfs_h *g, uint64_t event, cons
>
> /* tmpdirs.c */
> extern int guestfs_int_set_env_tmpdir (guestfs_h *g, const char *tmpdir);
> +extern int guestfs_int_set_env_runtimedir (guestfs_h *g, const char *runtimedir);
> extern int guestfs_int_lazy_make_tmpdir (guestfs_h *g);
> +extern int guestfs_int_lazy_make_sockdir (guestfs_h *g);
> extern void guestfs_int_remove_tmpdir (guestfs_h *g);
> +extern void guestfs_int_remove_sockdir (guestfs_h *g);
> extern void guestfs_int_recursive_remove_dir (guestfs_h *g, const char *dir);
>
> /* whole-file.c */
> diff --git a/src/handle.c b/src/handle.c
> index 947818c..25d3c99 100644
> --- a/src/handle.c
> +++ b/src/handle.c
> @@ -273,6 +273,10 @@ parse_environment (guestfs_h *g,
> return -1;
> }
>
> + str = do_getenv (data, "XDG_RUNTIME_DIR");
> + if (guestfs_int_set_env_runtimedir (g, str) == -1)
> + return -1;
> +
> return 0;
> }
>
> @@ -347,8 +351,9 @@ guestfs_close (guestfs_h *g)
> if (g->test_fp != NULL)
> fclose (g->test_fp);
>
> - /* Remove temporary directory. */
> + /* Remove temporary directories. */
> guestfs_int_remove_tmpdir (g);
> + guestfs_int_remove_sockdir (g);
>
> /* Mark the handle as dead and then free up all memory. */
> g->state = NO_HANDLE;
> @@ -377,7 +382,9 @@ guestfs_close (guestfs_h *g)
> if (g->pda)
> hash_free (g->pda);
> free (g->tmpdir);
> + free (g->sockdir);
> free (g->env_tmpdir);
> + free (g->env_runtimedir);
> free (g->int_tmpdir);
> free (g->int_cachedir);
> free (g->last_error);
> diff --git a/src/launch.c b/src/launch.c
> index ec061e3..e6972d1 100644
> --- a/src/launch.c
> +++ b/src/launch.c
> @@ -425,9 +425,15 @@ int
> guestfs_int_create_socketname (guestfs_h *g, const char *filename,
> char (*sockpath)[UNIX_PATH_MAX])
> {
> - char *path = g->tmpdir;
> + if (guestfs_int_lazy_make_sockdir (g) == -1)
> + return -1;
> +
> + if (strlen (g->sockdir) + 1 + strlen (filename) > UNIX_PATH_MAX-1) {
> + error (g, _("socket path too long: %s/%s"), g->sockdir, filename);
> + return -1;
> + }
>
> - snprintf (*sockpath, UNIX_PATH_MAX-1, "%s/%s", path, filename);
> + snprintf (*sockpath, UNIX_PATH_MAX-1, "%s/%s", g->sockdir, filename);
> (*sockpath)[UNIX_PATH_MAX-1] = '\0';
>
> return 0;
> diff --git a/src/tmpdirs.c b/src/tmpdirs.c
> index 2ae9c74..e66ab9c 100644
> --- a/src/tmpdirs.c
> +++ b/src/tmpdirs.c
> @@ -76,6 +76,12 @@ guestfs_int_set_env_tmpdir (guestfs_h *g, const char *tmpdir)
> }
>
> int
> +guestfs_int_set_env_runtimedir (guestfs_h *g, const char *runtimedir)
> +{
> + return set_abs_path (g, runtimedir, &g->env_runtimedir);
> +}
> +
> +int
> guestfs_impl_set_tmpdir (guestfs_h *g, const char *tmpdir)
> {
> return set_abs_path (g, tmpdir, &g->int_tmpdir);
> @@ -119,6 +125,20 @@ guestfs_impl_get_cachedir (guestfs_h *g)
> return safe_strdup (g, str);
> }
>
> +/* Note this actually calculates the sockdir, so it never returns NULL. */
> +char *
> +guestfs_impl_get_sockdir (guestfs_h *g)
> +{
> + const char *str;
> +
> + if (g->env_runtimedir)
> + str = g->env_runtimedir;
> + else
> + str = "/tmp";
> +
> + return safe_strdup (g, str);
> +}
> +
> static int
> lazy_make_tmpdir (guestfs_h *g, char *(*getdir) (guestfs_h *g), char **dest)
> {
> @@ -145,6 +165,12 @@ guestfs_int_lazy_make_tmpdir (guestfs_h *g)
> return lazy_make_tmpdir (g, guestfs_get_tmpdir, &g->tmpdir);
> }
>
> +int
> +guestfs_int_lazy_make_sockdir (guestfs_h *g)
> +{
> + return lazy_make_tmpdir (g, guestfs_get_sockdir, &g->sockdir);
> +}
> +
> /* Recursively remove a temporary directory. If removal fails, just
> * return (it's a temporary directory so it'll eventually be cleaned
> * up by a temp cleaner). This is done using "rm -rf" because that's
> @@ -167,3 +193,10 @@ guestfs_int_remove_tmpdir (guestfs_h *g)
> if (g->tmpdir)
> guestfs_int_recursive_remove_dir (g, g->tmpdir);
> }
> +
> +void
> +guestfs_int_remove_sockdir (guestfs_h *g)
> +{
> + if (g->sockdir)
> + guestfs_int_recursive_remove_dir (g, g->sockdir);
> +}
> diff --git a/test-tool/test-tool.c b/test-tool/test-tool.c
> index 9d23d6d..495316b 100644
> --- a/test-tool/test-tool.c
> +++ b/test-tool/test-tool.c
> @@ -210,6 +210,9 @@ main (int argc, char *argv[])
> p = getenv ("PATH");
> if (p)
> printf ("PATH=%s\n", p);
> + p = getenv ("XDG_RUNTIME_DIR");
> + if (p)
> + printf ("XDG_RUNTIME_DIR=%s\n", p);
>
> /* Print SELinux mode (don't worry if this fails, or if the command
> * doesn't even exist).
> @@ -255,6 +258,9 @@ main (int argc, char *argv[])
> printf ("guestfs_get_recovery_proc: %d\n", guestfs_get_recovery_proc (g));
> printf ("guestfs_get_selinux: %d\n", guestfs_get_selinux (g));
> printf ("guestfs_get_smp: %d\n", guestfs_get_smp (g));
> + p = guestfs_get_sockdir (g);
> + printf ("guestfs_get_sockdir: %s\n", p ? : "(null)");
> + free (p);
> p = guestfs_get_tmpdir (g);
> printf ("guestfs_get_tmpdir: %s\n", p ? : "(null)");
> free (p);
> --
> 2.5.0
>
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--
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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