picnoir/Systemd
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

core: rework machine-id-setup.c to use the calls from id128-util.[ch]

Browse source 
This allows us to delete quite a bit of code and make the whole thing a lot
shorter.
This commit is contained in:
Lennart Poettering 2016-07-22 12:12:27 +02:00
parent 9ca8d43479
commit 4b1afed01f
4 changed files with 50 additions and 155 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

199
src/core/machine-id-setup.c
View file

@ -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>
@ -29,11 +26,8 @@
#include "alloc-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "fs-util.h"
#include "hexdecoct.h"
#include "id128-util.h"
#include "io-util.h"
#include "log.h"
#include "machine-id-setup.h"
#include "macro.h"
@ -47,101 +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)) {
@ -152,13 +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) {
@ -167,51 +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
@ -219,7 +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;
@ -240,41 +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)
/* A we got a valid machine ID argument, that's what counts */
if (sd_id128_is_null(machine_id)) {
/* Try to read any existing machine ID */
if (id128_read_fd(fd, ID128_PLAIN, ret) >= 0)
return 0;
/* Hmm, so, the id currently stored is not useful, then let's
* generate one */
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 */
@ -287,7 +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;
}

2
src/core/machine-id-setup.h
View file

@ -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);

2
src/core/main.c
View file

@ -1719,7 +1719,7 @@ 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();

2
src/machine-id-setup/machine-id-setup-main.c
View file

@ -110,7 +110,7 @@ int main(int argc, char *argv[]) {
if (arg_commit)
r = machine_id_commit(arg_root);
else
r = machine_id_setup(arg_root, SD_ID128_NULL);
r = machine_id_setup(arg_root, SD_ID128_NULL, NULL);
finish:
free(arg_root);