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-rw-r--r--src/core/machine-id-setup.c224
-rw-r--r--src/core/machine-id-setup.h2
-rw-r--r--src/core/main.c8
3 files changed, 65 insertions, 169 deletions
diff --git a/src/core/machine-id-setup.c b/src/core/machine-id-setup.c
index ea6b085e4f..76dfcfa6d7 100644
--- a/src/core/machine-id-setup.c
+++ b/src/core/machine-id-setup.c
@@ -17,11 +17,8 @@
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
-#include <errno.h>
#include <fcntl.h>
#include <sched.h>
-#include <stdio.h>
-#include <string.h>
#include <sys/mount.h>
#include <unistd.h>
@@ -29,10 +26,8 @@
#include "alloc-util.h"
#include "fd-util.h"
-#include "fileio.h"
#include "fs-util.h"
-#include "hexdecoct.h"
-#include "io-util.h"
+#include "id128-util.h"
#include "log.h"
#include "machine-id-setup.h"
#include "macro.h"
@@ -46,101 +41,23 @@
#include "util.h"
#include "virt.h"
-static int shorten_uuid(char destination[34], const char source[36]) {
- unsigned i, j;
-
- assert(destination);
- assert(source);
-
- /* Converts a UUID into a machine ID, by lowercasing it and
- * removing dashes. Validates everything. */
-
- for (i = 0, j = 0; i < 36 && j < 32; i++) {
- int t;
-
- t = unhexchar(source[i]);
- if (t < 0)
- continue;
-
- destination[j++] = hexchar(t);
- }
-
- if (i != 36 || j != 32)
- return -EINVAL;
-
- destination[32] = '\n';
- destination[33] = 0;
- return 0;
-}
-
-static int read_machine_id(int fd, char id[34]) {
- char id_to_validate[34];
- int r;
-
- assert(fd >= 0);
- assert(id);
-
- /* Reads a machine ID from a file, validates it, and returns
- * it. The returned ID ends in a newline. */
-
- r = loop_read_exact(fd, id_to_validate, 33, false);
- if (r < 0)
- return r;
-
- if (id_to_validate[32] != '\n')
- return -EINVAL;
-
- id_to_validate[32] = 0;
-
- if (!id128_is_valid(id_to_validate))
- return -EINVAL;
-
- memcpy(id, id_to_validate, 32);
- id[32] = '\n';
- id[33] = 0;
- return 0;
-}
-
-static int write_machine_id(int fd, const char id[34]) {
- int r;
-
- assert(fd >= 0);
- assert(id);
-
- if (lseek(fd, 0, SEEK_SET) < 0)
- return -errno;
-
- r = loop_write(fd, id, 33, false);
- if (r < 0)
- return r;
-
- if (fsync(fd) < 0)
- return -errno;
-
- return 0;
-}
-
-static int generate_machine_id(char id[34], const char *root) {
- int fd, r;
- unsigned char *p;
- sd_id128_t buf;
- char *q;
+static int generate_machine_id(const char *root, sd_id128_t *ret) {
const char *dbus_machine_id;
+ _cleanup_close_ int fd = -1;
+ int r;
- assert(id);
-
- dbus_machine_id = prefix_roota(root, "/var/lib/dbus/machine-id");
+ assert(ret);
/* First, try reading the D-Bus machine id, unless it is a symlink */
+ dbus_machine_id = prefix_roota(root, "/var/lib/dbus/machine-id");
fd = open(dbus_machine_id, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
if (fd >= 0) {
- r = read_machine_id(fd, id);
- safe_close(fd);
-
- if (r >= 0) {
+ if (id128_read_fd(fd, ID128_PLAIN, ret) >= 0) {
log_info("Initializing machine ID from D-Bus machine ID.");
return 0;
}
+
+ fd = safe_close(fd);
}
if (isempty(root)) {
@@ -151,13 +68,10 @@ static int generate_machine_id(char id[34], const char *root) {
if (detect_container() > 0) {
_cleanup_free_ char *e = NULL;
- r = getenv_for_pid(1, "container_uuid", &e);
- if (r > 0) {
- r = shorten_uuid(id, e);
- if (r >= 0) {
- log_info("Initializing machine ID from container UUID.");
- return 0;
- }
+ if (getenv_for_pid(1, "container_uuid", &e) > 0 &&
+ sd_id128_from_string(e, ret) >= 0) {
+ log_info("Initializing machine ID from container UUID.");
+ return 0;
}
} else if (detect_vm() == VIRTUALIZATION_KVM) {
@@ -166,51 +80,29 @@ static int generate_machine_id(char id[34], const char *root) {
* running in qemu/kvm and a machine ID was passed in
* via -uuid on the qemu/kvm command line */
- char uuid[36];
-
- fd = open("/sys/class/dmi/id/product_uuid", O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
- if (fd >= 0) {
- r = loop_read_exact(fd, uuid, 36, false);
- safe_close(fd);
-
- if (r >= 0) {
- r = shorten_uuid(id, uuid);
- if (r >= 0) {
- log_info("Initializing machine ID from KVM UUID.");
- return 0;
- }
- }
+ if (id128_read("/sys/class/dmi/id/product_uuid", ID128_UUID, ret) >= 0) {
+ log_info("Initializing machine ID from KVM UUID.");
+ return 0;
}
}
}
/* If that didn't work, generate a random machine id */
- r = sd_id128_randomize(&buf);
+ r = sd_id128_randomize(ret);
if (r < 0)
- return log_error_errno(r, "Failed to open /dev/urandom: %m");
-
- for (p = buf.bytes, q = id; p < buf.bytes + sizeof(buf); p++, q += 2) {
- q[0] = hexchar(*p >> 4);
- q[1] = hexchar(*p & 15);
- }
-
- id[32] = '\n';
- id[33] = 0;
+ return log_error_errno(r, "Failed to generate randomized : %m");
log_info("Initializing machine ID from random generator.");
-
return 0;
}
-int machine_id_setup(const char *root, sd_id128_t machine_id) {
+int machine_id_setup(const char *root, sd_id128_t machine_id, sd_id128_t *ret) {
const char *etc_machine_id, *run_machine_id;
_cleanup_close_ int fd = -1;
- bool writable = true;
- char id[34]; /* 32 + \n + \0 */
+ bool writable;
int r;
etc_machine_id = prefix_roota(root, "/etc/machine-id");
- run_machine_id = prefix_roota(root, "/run/machine-id");
RUN_WITH_UMASK(0000) {
/* We create this 0444, to indicate that this isn't really
@@ -218,7 +110,7 @@ int machine_id_setup(const char *root, sd_id128_t machine_id) {
* will be owned by root it doesn't matter much, but maybe
* people look. */
- mkdir_parents(etc_machine_id, 0755);
+ (void) mkdir_parents(etc_machine_id, 0755);
fd = open(etc_machine_id, O_RDWR|O_CREAT|O_CLOEXEC|O_NOCTTY, 0444);
if (fd < 0) {
int old_errno = errno;
@@ -239,41 +131,41 @@ int machine_id_setup(const char *root, sd_id128_t machine_id) {
}
writable = false;
- }
+ } else
+ writable = true;
}
- /* A machine id argument overrides all other machined-ids */
- if (!sd_id128_is_null(machine_id)) {
- sd_id128_to_string(machine_id, id);
- id[32] = '\n';
- id[33] = 0;
- } else {
- if (read_machine_id(fd, id) >= 0)
- return 0;
+ /* A we got a valid machine ID argument, that's what counts */
+ if (sd_id128_is_null(machine_id)) {
- /* Hmm, so, the id currently stored is not useful, then let's
- * generate one */
+ /* Try to read any existing machine ID */
+ if (id128_read_fd(fd, ID128_PLAIN, ret) >= 0)
+ return 0;
- r = generate_machine_id(id, root);
+ /* Hmm, so, the id currently stored is not useful, then let's generate one */
+ r = generate_machine_id(root, &machine_id);
if (r < 0)
return r;
+
+ if (lseek(fd, 0, SEEK_SET) == (off_t) -1)
+ return log_error_errno(errno, "Failed to seek: %m");
}
if (writable)
- if (write_machine_id(fd, id) >= 0)
- return 0;
+ if (id128_write_fd(fd, ID128_PLAIN, machine_id, true) >= 0)
+ goto finish;
fd = safe_close(fd);
- /* Hmm, we couldn't write it? So let's write it to
- * /run/machine-id as a replacement */
+ /* Hmm, we couldn't write it? So let's write it to /run/machine-id as a replacement */
- RUN_WITH_UMASK(0022) {
- r = write_string_file(run_machine_id, id, WRITE_STRING_FILE_CREATE);
- if (r < 0) {
- (void) unlink(run_machine_id);
- return log_error_errno(r, "Cannot write %s: %m", run_machine_id);
- }
+ run_machine_id = prefix_roota(root, "/run/machine-id");
+
+ RUN_WITH_UMASK(0022)
+ r = id128_write(run_machine_id, ID128_PLAIN, machine_id, false);
+ if (r < 0) {
+ (void) unlink(run_machine_id);
+ return log_error_errno(r, "Cannot write %s: %m", run_machine_id);
}
/* And now, let's mount it over */
@@ -286,7 +178,11 @@ int machine_id_setup(const char *root, sd_id128_t machine_id) {
/* Mark the mount read-only */
if (mount(NULL, etc_machine_id, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, NULL) < 0)
- log_warning_errno(errno, "Failed to make transient %s read-only: %m", etc_machine_id);
+ log_warning_errno(errno, "Failed to make transient %s read-only, ignoring: %m", etc_machine_id);
+
+finish:
+ if (ret)
+ *ret = machine_id;
return 0;
}
@@ -294,9 +190,13 @@ int machine_id_setup(const char *root, sd_id128_t machine_id) {
int machine_id_commit(const char *root) {
_cleanup_close_ int fd = -1, initial_mntns_fd = -1;
const char *etc_machine_id;
- char id[34]; /* 32 + \n + \0 */
+ sd_id128_t id;
int r;
+ /* Replaces a tmpfs bind mount of /etc/machine-id by a proper file, atomically. For this, the umount is removed
+ * in a mount namespace, a new file is created at the right place. Afterwards the mount is also removed in the
+ * original mount namespace, thus revealing the file that was just created. */
+
etc_machine_id = prefix_roota(root, "/etc/machine-id");
r = path_is_mount_point(etc_machine_id, 0);
@@ -312,10 +212,6 @@ int machine_id_commit(const char *root) {
if (fd < 0)
return log_error_errno(errno, "Cannot open %s: %m", etc_machine_id);
- r = read_machine_id(fd, id);
- if (r < 0)
- return log_error_errno(r, "We didn't find a valid machine ID in %s.", etc_machine_id);
-
r = fd_is_temporary_fs(fd);
if (r < 0)
return log_error_errno(r, "Failed to determine whether %s is on a temporary file system: %m", etc_machine_id);
@@ -324,6 +220,10 @@ int machine_id_commit(const char *root) {
return -EROFS;
}
+ r = id128_read_fd(fd, ID128_PLAIN, &id);
+ if (r < 0)
+ return log_error_errno(r, "We didn't find a valid machine ID in %s.", etc_machine_id);
+
fd = safe_close(fd);
/* Store current mount namespace */
@@ -342,15 +242,9 @@ int machine_id_commit(const char *root) {
return log_error_errno(errno, "Failed to unmount transient %s file in our private namespace: %m", etc_machine_id);
/* Update a persistent version of etc_machine_id */
- fd = open(etc_machine_id, O_RDWR|O_CREAT|O_CLOEXEC|O_NOCTTY, 0444);
- if (fd < 0)
- return log_error_errno(errno, "Cannot open for writing %s. This is mandatory to get a persistent machine-id: %m", etc_machine_id);
-
- r = write_machine_id(fd, id);
+ r = id128_write(etc_machine_id, ID128_PLAIN, id, true);
if (r < 0)
- return log_error_errno(r, "Cannot write %s: %m", etc_machine_id);
-
- fd = safe_close(fd);
+ return log_error_errno(r, "Cannot write %s. This is mandatory to get a persistent machine ID: %m", etc_machine_id);
/* Return to initial namespace and proceed a lazy tmpfs unmount */
r = namespace_enter(-1, initial_mntns_fd, -1, -1, -1);
diff --git a/src/core/machine-id-setup.h b/src/core/machine-id-setup.h
index a7e7678ed9..29f4620646 100644
--- a/src/core/machine-id-setup.h
+++ b/src/core/machine-id-setup.h
@@ -20,4 +20,4 @@
***/
int machine_id_commit(const char *root);
-int machine_id_setup(const char *root, sd_id128_t machine_id);
+int machine_id_setup(const char *root, sd_id128_t requested, sd_id128_t *ret);
diff --git a/src/core/main.c b/src/core/main.c
index c59228ad53..f2adca7d2b 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -291,14 +291,16 @@ static int parse_crash_chvt(const char *value) {
}
static int set_machine_id(const char *m) {
+ sd_id128_t t;
assert(m);
- if (sd_id128_from_string(m, &arg_machine_id) < 0)
+ if (sd_id128_from_string(m, &t) < 0)
return -EINVAL;
- if (sd_id128_is_null(arg_machine_id))
+ if (sd_id128_is_null(t))
return -EINVAL;
+ arg_machine_id = t;
return 0;
}
@@ -1721,7 +1723,7 @@ int main(int argc, char *argv[]) {
status_welcome();
hostname_setup();
- machine_id_setup(NULL, arg_machine_id);
+ machine_id_setup(NULL, arg_machine_id, NULL);
loopback_setup();
bump_unix_max_dgram_qlen();
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-12-22 15:19:10 +0000