sysext: use parse_extension_release and reject extension if not found

This commit is contained in:
Luca Boccassi 2021-01-11 23:00:58 +00:00 committed by Lennart Poettering
parent 6ddd051193
commit 60bb6caaae
2 changed files with 29 additions and 23 deletions

View file

@ -55,10 +55,9 @@
<para>Files and directories contained in the extension images outside of the <filename>/usr/</filename>
and <filename>/opt/</filename> hierarchies are <emphasis>not</emphasis> merged, and hence have no effect
when included in a system extension image (with the exception of <filename>/etc/os-release</filename>,
see below). In particular, files in the <filename>/etc/</filename> and <filename>/var/</filename>
included in a system extension image will <emphasis>not</emphasis> appear in the respective hierarchies
after activation.</para>
when included in a system extension image. In particular, files in the <filename>/etc/</filename> and
<filename>/var/</filename> included in a system extension image will <emphasis>not</emphasis> appear in
the respective hierarchies after activation.</para>
<para>System extension images are strictly read-only, and the host <filename>/usr/</filename> and
<filename>/opt/</filename> hierarchies become read-only too while they are activated.</para>
@ -111,13 +110,17 @@
<para>Note that there is no concept of enabling/disabling installed system extension images: all
installed extension images are automatically activated at boot.</para>
<para>A simple mechanism for version compatibility is enforced: a system extension image may carry an
<filename>/etc/os-release</filename> file that is compared with the host <filename>os-release</filename>
<para>A simple mechanism for version compatibility is enforced: a system extension image must carry a
<filename>/usr/lib/extension-release.d/extension-release.<replaceable>$name</replaceable></filename>
file, which must match its image name, that is compared with the host <filename>os-release</filename>
file: the contained <varname>ID=</varname> fields have to match, as well as the
<varname>SYSEXT_LEVEL=</varname> field (if defined). If the latter is not defined the
<varname>SYSEXT_LEVEL=</varname> field (if defined). If the latter is not defined, the
<varname>VERSION_ID=</varname> field has to match instead. System extensions should not ship a
<filename>/usr/lib/os-release</filename> file (as that would be merged into the host
<filename>/usr/</filename> tree, overriding the host OS version data, which is not desirable).</para>
<filename>/usr/</filename> tree, overriding the host OS version data, which is not desirable). The
<filename>extension-release</filename> file follows the same format and semantics, and carries the same
content, as the <filename>os-release</filename> file of the OS, but it describes the resources carried
in the extension image.</para>
</refsect1>
<refsect1>

View file

@ -441,7 +441,7 @@ static int merge_subprocess(Hashmap *images, const char *workspace) {
/* Let's now mount all images */
HASHMAP_FOREACH(img, images) {
_cleanup_free_ char *p = NULL,
*extension_os_release_id = NULL, *extension_os_release_version_id = NULL, *extension_os_release_sysext_level = NULL;
*extension_release_id = NULL, *extension_release_version_id = NULL, *extension_release_sysext_level = NULL;
p = path_join(workspace, "extensions", img->name);
if (!p)
@ -535,36 +535,39 @@ static int merge_subprocess(Hashmap *images, const char *workspace) {
"Extension image contains /usr/lib/os-release file, which is not allowed (it may carry /etc/os-release), refusing.");
/* Now that we can look into the extension image, let's see if the OS version is compatible */
r = parse_os_release(
r = parse_extension_release(
p,
"ID", &extension_os_release_id,
"VERSION_ID", &extension_os_release_version_id,
"SYSEXT_LEVEL", &extension_os_release_sysext_level,
img->name,
"ID", &extension_release_id,
"VERSION_ID", &extension_release_version_id,
"SYSEXT_LEVEL", &extension_release_sysext_level,
NULL);
if (r == -ENOENT)
log_notice_errno(r, "Extension '%s' carries no os-release data, not checking for version compatibility.", img->name);
else if (r < 0)
if (r == -ENOENT) {
log_notice_errno(r, "Extension '%s' carries no extension-release data, ignoring extension.", img->name);
n_ignored++;
continue;
} else if (r < 0)
return log_error_errno(r, "Failed to acquire 'os-release' data of extension '%s': %m", img->name);
else {
if (!streq_ptr(host_os_release_id, extension_os_release_id)) {
if (!streq_ptr(host_os_release_id, extension_release_id)) {
log_notice("Extension '%s' is for OS '%s', but running on '%s', ignoring extension.",
img->name, strna(extension_os_release_id), strna(host_os_release_id));
img->name, strna(extension_release_id), strna(host_os_release_id));
n_ignored++;
continue;
}
/* If the extension has a sysext API level declared, then it must match the host API level. Otherwise, compare OS version as a whole */
if (extension_os_release_sysext_level) {
if (!streq_ptr(host_os_release_sysext_level, extension_os_release_sysext_level)) {
if (extension_release_sysext_level) {
if (!streq_ptr(host_os_release_sysext_level, extension_release_sysext_level)) {
log_notice("Extension '%s' is for sysext API level '%s', but running on sysext API level '%s', ignoring extension.",
img->name, extension_os_release_sysext_level, strna(host_os_release_sysext_level));
img->name, extension_release_sysext_level, strna(host_os_release_sysext_level));
n_ignored++;
continue;
}
} else {
if (!streq_ptr(host_os_release_version_id, extension_os_release_version_id)) {
if (!streq_ptr(host_os_release_version_id, extension_release_version_id)) {
log_notice("Extension '%s' is for OS version '%s', but running on OS version '%s', ignoring extension.",
img->name, extension_os_release_version_id, strna(host_os_release_version_id));
img->name, extension_release_version_id, strna(host_os_release_version_id));
n_ignored++;
continue;
}