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rpm-ostree/bwrap-treecompose.patch

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From 88a130da09947c0acdb1d573abfafe24e8971362 Mon Sep 17 00:00:00 2001
From: Colin Walters <walters@verbum.org>
Date: Fri, 12 Aug 2016 13:03:23 -0400
Subject: [PATCH 1/3] lib: Extract bwrap-executing internal API
The treecompose code will learn how to use bwrap instead of
libcontainer in libglnx, since the latter is a buggy copy of a subset
of the former.
Closes: #429
Approved by: jlebon
---
Makefile-libpriv.am | 2 +
src/libpriv/rpmostree-bwrap.c | 109 ++++++++++++++++++++++++++++++++++++++++
src/libpriv/rpmostree-bwrap.h | 32 ++++++++++++
src/libpriv/rpmostree-scripts.c | 82 +++++-------------------------
4 files changed, 155 insertions(+), 70 deletions(-)
create mode 100644 src/libpriv/rpmostree-bwrap.c
create mode 100644 src/libpriv/rpmostree-bwrap.h
diff --git a/Makefile-libpriv.am b/Makefile-libpriv.am
index 687c3b8..52bb9f2 100644
--- a/Makefile-libpriv.am
+++ b/Makefile-libpriv.am
@@ -30,6 +30,8 @@ librpmostreepriv_la_SOURCES = \
src/libpriv/rpmostree-refts.c \
src/libpriv/rpmostree-core.c \
src/libpriv/rpmostree-core.h \
+ src/libpriv/rpmostree-bwrap.c \
+ src/libpriv/rpmostree-bwrap.h \
src/libpriv/rpmostree-scripts.c \
src/libpriv/rpmostree-scripts.h \
src/libpriv/rpmostree-refsack.h \
diff --git a/src/libpriv/rpmostree-bwrap.c b/src/libpriv/rpmostree-bwrap.c
new file mode 100644
index 0000000..29f79d3
--- /dev/null
+++ b/src/libpriv/rpmostree-bwrap.c
@@ -0,0 +1,109 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2016 Red Hat, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2 of the licence or (at
+ * your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "config.h"
+#include "rpmostree-bwrap.h"
+
+#include <err.h>
+
+void
+rpmostree_ptrarray_append_strdup (GPtrArray *argv_array, ...)
+{
+ va_list args;
+ char *arg;
+
+ va_start (args, argv_array);
+ while ((arg = va_arg (args, char *)))
+ g_ptr_array_add (argv_array, g_strdup (arg));
+ va_end (args);
+}
+
+GPtrArray *
+rpmostree_bwrap_base_argv_new_for_rootfs (int rootfs_fd, GError **error)
+{
+ g_autoptr(GPtrArray) bwrap_argv = g_ptr_array_new_with_free_func (g_free);
+ static const char *usr_links[] = {"lib", "lib32", "lib64", "bin", "sbin"};
+
+ rpmostree_ptrarray_append_strdup (bwrap_argv,
+ WITH_BUBBLEWRAP_PATH,
+ "--dev", "/dev",
+ "--proc", "/proc",
+ "--dir", "/tmp",
+ "--chdir", "/",
+ "--ro-bind", "/sys/block", "/sys/block",
+ "--ro-bind", "/sys/bus", "/sys/bus",
+ "--ro-bind", "/sys/class", "/sys/class",
+ "--ro-bind", "/sys/dev", "/sys/dev",
+ "--ro-bind", "/sys/devices", "/sys/devices",
+ NULL);
+
+ for (guint i = 0; i < G_N_ELEMENTS (usr_links); i++)
+ {
+ const char *subdir = usr_links[i];
+ struct stat stbuf;
+ char *path;
+
+ if (fstatat (rootfs_fd, subdir, &stbuf, AT_SYMLINK_NOFOLLOW) < 0)
+ {
+ if (errno != ENOENT)
+ {
+ glnx_set_error_from_errno (error);
+ return FALSE;
+ }
+ continue;
+ }
+ else if (!S_ISLNK (stbuf.st_mode))
+ continue;
+
+ g_ptr_array_add (bwrap_argv, g_strdup ("--symlink"));
+
+ path = g_strconcat ("usr/", subdir, NULL);
+ g_ptr_array_add (bwrap_argv, path);
+
+ path = g_strconcat ("/", subdir, NULL);
+ g_ptr_array_add (bwrap_argv, path);
+ }
+
+ return g_steal_pointer (&bwrap_argv);
+}
+
+static void
+child_setup_fchdir (gpointer user_data)
+{
+ int fd = GPOINTER_TO_INT (user_data);
+ if (fchdir (fd) < 0)
+ err (1, "fchdir");
+}
+
+gboolean
+rpmostree_run_sync_fchdir_setup (char **argv_array, GSpawnFlags flags,
+ int rootfs_fd, GError **error)
+{
+ int estatus;
+
+ if (!g_spawn_sync (NULL, argv_array, NULL, flags,
+ child_setup_fchdir, GINT_TO_POINTER (rootfs_fd),
+ NULL, NULL, &estatus, error))
+ return FALSE;
+ if (!g_spawn_check_exit_status (estatus, error))
+ return FALSE;
+
+ return TRUE;
+}
diff --git a/src/libpriv/rpmostree-bwrap.h b/src/libpriv/rpmostree-bwrap.h
new file mode 100644
index 0000000..fbf2113
--- /dev/null
+++ b/src/libpriv/rpmostree-bwrap.h
@@ -0,0 +1,32 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2016 Colin Walters <walters@verbum.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2 of the licence or (at
+ * your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#pragma once
+
+#include <ostree.h>
+
+#include "libglnx.h"
+
+GPtrArray *rpmostree_bwrap_base_argv_new_for_rootfs (int rootfs, GError **error);
+
+void rpmostree_ptrarray_append_strdup (GPtrArray *argv_array, ...) G_GNUC_NULL_TERMINATED;
+
+gboolean rpmostree_run_sync_fchdir_setup (char **argv_array, GSpawnFlags flags,
+ int rootfs_fd, GError **error);
diff --git a/src/libpriv/rpmostree-scripts.c b/src/libpriv/rpmostree-scripts.c
index 0737b59..c33bf35 100644
--- a/src/libpriv/rpmostree-scripts.c
+++ b/src/libpriv/rpmostree-scripts.c
@@ -23,6 +23,7 @@
#include <gio/gio.h>
#include <systemd/sd-journal.h>
#include "rpmostree-output.h"
+#include "rpmostree-bwrap.h"
#include <err.h>
#include "libglnx.h"
@@ -74,26 +75,6 @@ static const KnownRpmScriptKind unsupported_scripts[] = {
};
static void
-child_setup_fchdir (gpointer user_data)
-{
- int fd = GPOINTER_TO_INT (user_data);
- if (fchdir (fd) < 0)
- err (1, "fchdir");
-}
-
-static void
-add_const_args (GPtrArray *argv_array, ...)
-{
- va_list args;
- char *arg;
-
- va_start (args, argv_array);
- while ((arg = va_arg (args, char *)))
- g_ptr_array_add (argv_array, arg);
- va_end (args);
-}
-
-static void
fusermount_cleanup (const char *mountpoint)
{
g_autoptr(GError) tmp_error = NULL;
@@ -188,9 +169,6 @@ run_script_in_bwrap_container (int rootfs_fd,
GError **error)
{
gboolean ret = FALSE;
- int i;
- const char *usr_links[] = {"lib", "lib32", "lib64", "bin", "sbin"};
- int estatus;
char *rofiles_mnt = strdupa ("/tmp/rofiles-fuse.XXXXXX");
const char *rofiles_argv[] = { "rofiles-fuse", "./usr", rofiles_mnt, NULL};
const char *pkg_script = glnx_strjoina (name, ".", scriptdesc+1);
@@ -200,7 +178,6 @@ run_script_in_bwrap_container (int rootfs_fd,
gboolean mntpoint_created = FALSE;
gboolean fuse_mounted = FALSE;
g_autoptr(GPtrArray) bwrap_argv = g_ptr_array_new ();
- g_autoptr(GPtrArray) bwrap_argv_mallocd = g_ptr_array_new_with_free_func (g_free);
GSpawnFlags bwrap_spawnflags = G_SPAWN_SEARCH_PATH;
gboolean created_var_tmp = FALSE;
@@ -209,11 +186,8 @@ run_script_in_bwrap_container (int rootfs_fd,
mntpoint_created = TRUE;
- if (!g_spawn_sync (NULL, (char**)rofiles_argv, NULL, G_SPAWN_SEARCH_PATH,
- child_setup_fchdir, GINT_TO_POINTER (rootfs_fd),
- NULL, NULL, &estatus, error))
- goto out;
- if (!g_spawn_check_exit_status (estatus, error))
+ if (!rpmostree_run_sync_fchdir_setup ((char**)rofiles_argv, G_SPAWN_SEARCH_PATH,
+ rootfs_fd, error))
{
g_prefix_error (error, "Executing rofiles-fuse: ");
goto out;
@@ -260,65 +234,33 @@ run_script_in_bwrap_container (int rootfs_fd,
else
created_var_tmp = TRUE;
- add_const_args (bwrap_argv,
- WITH_BUBBLEWRAP_PATH,
+ bwrap_argv = rpmostree_bwrap_base_argv_new_for_rootfs (rootfs_fd, error);
+ if (!bwrap_argv)
+ goto out;
+
+ rpmostree_ptrarray_append_strdup (bwrap_argv,
"--bind", rofiles_mnt, "/usr",
- "--dev", "/dev",
- "--proc", "/proc",
- "--dir", "/tmp",
- "--chdir", "/",
/* Scripts can see a /var with compat links like alternatives */
"--ro-bind", "./var", "/var",
/* But no need to access persistent /tmp, so make it /tmp */
"--bind", "/tmp", "/var/tmp",
/* Allow RPM scripts to change the /etc defaults */
"--symlink", "usr/etc", "/etc",
- "--ro-bind", "/sys/block", "/sys/block",
- "--ro-bind", "/sys/bus", "/sys/bus",
- "--ro-bind", "/sys/class", "/sys/class",
- "--ro-bind", "/sys/dev", "/sys/dev",
- "--ro-bind", "/sys/devices", "/sys/devices",
NULL);
- for (i = 0; i < G_N_ELEMENTS (usr_links); i++)
- {
- const char *subdir = usr_links[i];
- struct stat stbuf;
- char *path;
-
- if (!(fstatat (rootfs_fd, subdir, &stbuf, AT_SYMLINK_NOFOLLOW) == 0 && S_ISLNK (stbuf.st_mode)))
- continue;
-
- g_ptr_array_add (bwrap_argv, "--symlink");
-
- path = g_strconcat ("usr/", subdir, NULL);
- g_ptr_array_add (bwrap_argv_mallocd, path);
- g_ptr_array_add (bwrap_argv, path);
-
- path = g_strconcat ("/", subdir, NULL);
- g_ptr_array_add (bwrap_argv_mallocd, path);
- g_ptr_array_add (bwrap_argv, path);
- }
-
{ const char *debugscript = getenv ("RPMOSTREE_DEBUG_SCRIPT");
if (g_strcmp0 (debugscript, pkg_script) == 0)
{
- g_ptr_array_add (bwrap_argv, (char*)"/bin/bash");
+ g_ptr_array_add (bwrap_argv, g_strdup ("/bin/bash"));
bwrap_spawnflags |= G_SPAWN_CHILD_INHERITS_STDIN;
}
else
- g_ptr_array_add (bwrap_argv, (char*)postscript_path_container);
+ g_ptr_array_add (bwrap_argv, g_strdup (postscript_path_container));
}
g_ptr_array_add (bwrap_argv, NULL);
- if (!g_spawn_sync (NULL, (char**)bwrap_argv->pdata, NULL, bwrap_spawnflags,
- child_setup_fchdir, GINT_TO_POINTER (rootfs_fd),
- NULL, NULL, &estatus, error))
- {
- g_prefix_error (error, "Executing bwrap: ");
- goto out;
- }
- if (!g_spawn_check_exit_status (estatus, error))
+ if (!rpmostree_run_sync_fchdir_setup ((char**)bwrap_argv->pdata,
+ bwrap_spawnflags, rootfs_fd, error))
{
g_prefix_error (error, "Executing bwrap: ");
goto out;
--
2.7.4
From 551e4c91f91c4b908dacd50c6d251c57c2544af8 Mon Sep 17 00:00:00 2001
From: Colin Walters <walters@verbum.org>
Date: Fri, 12 Aug 2016 16:17:35 -0400
Subject: [PATCH 2/3] postprocess: Switch to using bwrap for script execution
The previous commit https://github.com/projectatomic/rpm-ostree/pull/422
introduced a regression in the "outside of a container" path - we
get `EINVAL` trying to `mount("proc",...)` and honestly I'm not sure why.
We can either back up or plow forward, and it turns out to be
pretty straightforward to complete the port to using bwrap.
I extracted the bwrap-execution code out of the RPM script engine,
because the treecompose model is currently different (no hardlinks
yet).
NOTE: A *very* important side effect of this is that we now
require "privileged" containers on hosts without user namespaces,
and on userns hosts, require `CLONE_NEWUSER` to be exported to the
container host.
In general though, the previous path of blindly executing scripts as root
without e.g. `proc` mounted was just bad.
Closes: #429
Approved by: jlebon
---
src/libpriv/rpmostree-postprocess.c | 48 +++++++++++++++++++++++++++----------
1 file changed, 36 insertions(+), 12 deletions(-)
diff --git a/src/libpriv/rpmostree-postprocess.c b/src/libpriv/rpmostree-postprocess.c
index 57b8785..17ec151 100644
--- a/src/libpriv/rpmostree-postprocess.c
+++ b/src/libpriv/rpmostree-postprocess.c
@@ -27,6 +27,7 @@
#include <json-glib/json-glib.h>
#include <stdio.h>
#include <utime.h>
+#include <err.h>
#include <sys/types.h>
#include <pwd.h>
#include <grp.h>
@@ -37,6 +38,7 @@
#include <gio/gunixoutputstream.h>
#include "rpmostree-postprocess.h"
+#include "rpmostree-bwrap.h"
#include "rpmostree-passwd-util.h"
#include "rpmostree-rpm-util.h"
#include "rpmostree-json-parsing.h"
@@ -66,21 +68,43 @@ run_sync_in_root_at (int rootfs_fd,
char **child_argv,
GError **error)
{
- gboolean ret = FALSE;
- pid_t child = glnx_libcontainer_run_chroot_at_private (rootfs_fd, binpath, child_argv);
+ const GSpawnFlags bwrap_spawnflags = G_SPAWN_SEARCH_PATH;
+ g_autoptr(GPtrArray) bwrap_argv = NULL;
+
+ bwrap_argv = rpmostree_bwrap_base_argv_new_for_rootfs (rootfs_fd, error);
+ if (!bwrap_argv)
+ return FALSE;
+
+ /* Bind all of the primary toplevel dirs; unlike the script case, treecompose
+ * isn't yet operating on hardlinks, so we can just bind mount things mutably.
+ */
+ rpmostree_ptrarray_append_strdup (bwrap_argv,
+ "--bind", "usr", "/usr",
+ "--bind", "var", "/var",
+ "--bind", "etc", "/etc",
+ NULL);
+
+ g_ptr_array_add (bwrap_argv, g_strdup (binpath));
+ /* https://github.com/projectatomic/bubblewrap/issues/91 */
+ { gboolean first = TRUE;
+ for (char **iter = child_argv; iter && *iter; iter++)
+ {
+ if (first)
+ first = FALSE;
+ else
+ g_ptr_array_add (bwrap_argv, g_strdup (*iter));
+ }
+ }
+ g_ptr_array_add (bwrap_argv, NULL);
- if (child == -1)
+ if (!rpmostree_run_sync_fchdir_setup ((char**)bwrap_argv->pdata, bwrap_spawnflags,
+ rootfs_fd, error))
{
- _rpmostree_set_error_from_errno (error, errno);
- goto out;
+ g_prefix_error (error, "Executing bwrap: ");
+ return FALSE;
}
-
- if (!_rpmostree_sync_wait_on_pid (child, error))
- goto out;
-
- ret = TRUE;
- out:
- return ret;
+
+ return TRUE;
}
static gboolean
--
2.7.4
From 7455e262733bff92a6e64ae08f4ebedb7fb64e3d Mon Sep 17 00:00:00 2001
From: Colin Walters <walters@verbum.org>
Date: Fri, 12 Aug 2016 16:53:49 -0400
Subject: [PATCH 3/3] bwrap: Add a selftest
I want a better error message if the user happens to execute
inside e.g. a Docker container without sufficient privileges
for recursive containerization.
Closes: #429
Approved by: jlebon
---
src/app/rpmostree-compose-builtin-tree.c | 6 ++++++
src/libpriv/rpmostree-bwrap.c | 29 +++++++++++++++++++++++++++++
src/libpriv/rpmostree-bwrap.h | 2 ++
3 files changed, 37 insertions(+)
diff --git a/src/app/rpmostree-compose-builtin-tree.c b/src/app/rpmostree-compose-builtin-tree.c
index ecdd6bc..5ea1cbe 100644
--- a/src/app/rpmostree-compose-builtin-tree.c
+++ b/src/app/rpmostree-compose-builtin-tree.c
@@ -31,6 +31,7 @@
#include "rpmostree-compose-builtins.h"
#include "rpmostree-util.h"
+#include "rpmostree-bwrap.h"
#include "rpmostree-core.h"
#include "rpmostree-json-parsing.h"
#include "rpmostree-postprocess.h"
@@ -629,6 +630,11 @@ rpmostree_compose_builtin_tree (int argc,
"compose tree must presently be run as uid 0 (root)");
goto out;
}
+ /* Test whether or not bwrap is going to work - we will fail inside e.g. a Docker
+ * container without --privileged or userns exposed.
+ */
+ if (!rpmostree_bwrap_selftest (error))
+ goto out;
repo_path = g_file_new_for_path (opt_repo);
repo = self->repo = ostree_repo_new (repo_path);
diff --git a/src/libpriv/rpmostree-bwrap.c b/src/libpriv/rpmostree-bwrap.c
index 29f79d3..bd7c793 100644
--- a/src/libpriv/rpmostree-bwrap.c
+++ b/src/libpriv/rpmostree-bwrap.c
@@ -107,3 +107,32 @@ rpmostree_run_sync_fchdir_setup (char **argv_array, GSpawnFlags flags,
return TRUE;
}
+
+/* Execute /bin/true inside a bwrap container on the host */
+gboolean
+rpmostree_bwrap_selftest (GError **error)
+{
+ glnx_fd_close int host_root_dfd = -1;
+ g_autoptr(GPtrArray) bwrap_argv = NULL;
+
+ if (!glnx_opendirat (AT_FDCWD, "/", TRUE, &host_root_dfd, error))
+ return FALSE;
+
+ bwrap_argv = rpmostree_bwrap_base_argv_new_for_rootfs (host_root_dfd, error);
+ if (!bwrap_argv)
+ return FALSE;
+
+ rpmostree_ptrarray_append_strdup (bwrap_argv,
+ "--ro-bind", "usr", "/usr",
+ NULL);
+ g_ptr_array_add (bwrap_argv, g_strdup ("true"));
+ g_ptr_array_add (bwrap_argv, NULL);
+ if (!rpmostree_run_sync_fchdir_setup ((char**)bwrap_argv->pdata, G_SPAWN_SEARCH_PATH,
+ host_root_dfd, error))
+ {
+ g_prefix_error (error, "bwrap test failed, see https://github.com/projectatomic/rpm-ostree/pull/429: ");
+ return FALSE;
+ }
+
+ return TRUE;
+}
diff --git a/src/libpriv/rpmostree-bwrap.h b/src/libpriv/rpmostree-bwrap.h
index fbf2113..b4bb88c 100644
--- a/src/libpriv/rpmostree-bwrap.h
+++ b/src/libpriv/rpmostree-bwrap.h
@@ -30,3 +30,5 @@ void rpmostree_ptrarray_append_strdup (GPtrArray *argv_array, ...) G_GNUC_NULL_T
gboolean rpmostree_run_sync_fchdir_setup (char **argv_array, GSpawnFlags flags,
int rootfs_fd, GError **error);
+
+gboolean rpmostree_bwrap_selftest (GError **error);
--
2.7.4
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