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bluca wants to merge 3 commits into from
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sysext: verity and extension-release #3

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9b256ca
sysext: add verity boilerplate
bluca Jan 10, 2021
fa6036a
os-release: add support for /usr/lib/extension-release.d/
bluca Jan 10, 2021
46e09a3
sysext: use parse_extension_release and reject extension if not found
bluca Jan 11, 2021
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43 changes: 32 additions & 11 deletions src/shared/os-util.c
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Original file line number Diff line number Diff line change
Expand Up @@ -31,13 +31,17 @@ int path_is_os_tree(const char *path) {
return 1;
}

int open_os_release(const char *root, char **ret_path, int *ret_fd) {
int open_extension_release(const char *root, const char *extension, char **ret_path, int *ret_fd) {
_cleanup_free_ char *q = NULL;
const char *p;
char **paths, **p;
int r, fd;

FOREACH_STRING(p, "/etc/os-release", "/usr/lib/os-release") {
r = chase_symlinks(p, root, CHASE_PREFIX_ROOT,
if (extension)
paths = STRV_MAKE(strjoina("/usr/lib/extension-release.d/extension-release.", extension));
else
paths = STRV_MAKE("/etc/os-release", "/usr/lib/os-release");
STRV_FOREACH(p, paths) {
r = chase_symlinks(*p, root, CHASE_PREFIX_ROOT,
ret_path ? &q : NULL,
ret_fd ? &fd : NULL);
if (r != -ENOENT)
Expand All @@ -64,16 +68,16 @@ int open_os_release(const char *root, char **ret_path, int *ret_fd) {
return 0;
}

int fopen_os_release(const char *root, char **ret_path, FILE **ret_file) {
int fopen_extension_release(const char *root, const char *extension, char **ret_path, FILE **ret_file) {
_cleanup_free_ char *p = NULL;
_cleanup_close_ int fd = -1;
FILE *f;
int r;

if (!ret_file)
return open_os_release(root, ret_path, NULL);
return open_extension_release(root, extension, ret_path, NULL);

r = open_os_release(root, ret_path ? &p : NULL, &fd);
r = open_extension_release(root, extension, ret_path ? &p : NULL, &fd);
if (r < 0)
return r;

Expand All @@ -89,18 +93,35 @@ int fopen_os_release(const char *root, char **ret_path, FILE **ret_file) {
return 0;
}

int parse_os_release(const char *root, ...) {
static int parse_release_internal(const char *root, const char *extension, va_list ap) {
_cleanup_fclose_ FILE *f = NULL;
_cleanup_free_ char *p = NULL;
va_list ap;
int r;

r = fopen_os_release(root, &p, &f);
r = fopen_extension_release(root, extension, &p, &f);
if (r < 0)
return r;

return parse_env_filev(f, p, ap);
}

int parse_extension_release(const char *root, const char *extension, ...) {
va_list ap;
int r;

va_start(ap, extension);
r = parse_release_internal(root, extension, ap);
va_end(ap);

return r;
}

int parse_os_release(const char *root, ...) {
va_list ap;
int r;

va_start(ap, root);
r = parse_env_filev(f, p, ap);
r = parse_release_internal(root, NULL, ap);
va_end(ap);

return r;
Expand Down
14 changes: 12 additions & 2 deletions src/shared/os-util.h
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Original file line number Diff line number Diff line change
Expand Up @@ -5,9 +5,19 @@

int path_is_os_tree(const char *path);

int open_os_release(const char *root, char **ret_path, int *ret_fd);
int fopen_os_release(const char *root, char **ret_path, FILE **ret_file);
/* The *_extension_release flavours will look for /usr/lib/extension-release/extension-release.NAME
* in accordance with the OS extension specification, rather than for /usr/lib/ or /etc/os-release. */
int open_extension_release(const char *root, const char *extension, char **ret_path, int *ret_fd);
static inline int open_os_release(const char *root, char **ret_path, int *ret_fd) {
return open_extension_release(root, NULL, ret_path, ret_fd);
}

int fopen_extension_release(const char *root, const char *extension, char **ret_path, FILE **ret_file);
static inline int fopen_os_release(const char *root, char **ret_path, FILE **ret_file) {
return fopen_extension_release(root, NULL, ret_path, ret_file);
}

int parse_extension_release(const char *root, const char *extension, ...) _sentinel_;
int parse_os_release(const char *root, ...) _sentinel_;
int load_os_release_pairs(const char *root, char ***ret);
int load_os_release_pairs_with_prefix(const char *root, const char *prefix, char ***ret);
17 changes: 13 additions & 4 deletions src/sysext/sysext.c
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Original file line number Diff line number Diff line change
Expand Up @@ -455,16 +455,24 @@ static int merge_subprocess(Hashmap *images, const char *workspace) {
_cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
_cleanup_(loop_device_unrefp) LoopDevice *d = NULL;
_cleanup_(decrypted_image_unrefp) DecryptedImage *di = NULL;
_cleanup_(verity_settings_done) VeritySettings verity_settings = VERITY_SETTINGS_DEFAULT;
DissectImageFlags flags = DISSECT_IMAGE_READ_ONLY|DISSECT_IMAGE_REQUIRE_ROOT|DISSECT_IMAGE_MOUNT_ROOT_ONLY;

r = verity_settings_load(&verity_settings, img->path, NULL, NULL);
if (r < 0)
return log_error_errno(r, "Failed to read verity artifacts for %s: %m", img->path);

if (verity_settings.data_path)
flags |= DISSECT_IMAGE_NO_PARTITION_TABLE;

r = loop_device_make_by_path(img->path, O_RDONLY, 0, &d);
if (r < 0)
return log_error_errno(r, "Failed to set up loopback device: %m");

r = dissect_image_and_warn(
d->fd,
img->path,
NULL,
&verity_settings,
NULL,
flags,
&m);
Expand All @@ -473,7 +481,7 @@ static int merge_subprocess(Hashmap *images, const char *workspace) {

r = dissected_image_decrypt_interactively(
m, NULL,
NULL,
&verity_settings,
flags,
&di);
if (r < 0)
Expand Down Expand Up @@ -501,14 +509,15 @@ static int merge_subprocess(Hashmap *images, const char *workspace) {
}

/* Now that we can look into the extension image, let's see of the OS version is compatible */
r = parse_os_release(
r = parse_extension_release(
p,
img->name,
"ID", &extension_os_release_id,
"VERSION_ID", &extension_os_release_version_id,
"SYSEXT_LEVEL", &extension_os_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);
return log_notice_errno(r, "Extension '%s' carries no extension-release data, ignoring extension.", img->name);
else if (r < 0)
return log_error_errno(r, "Failed to acquire 'os-release' data of extension '%s': %m", img->name);
else {
Expand Down