+++ /dev/null
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- This file is part of systemd.
-
- Copyright 2010 Lennart Poettering
-
- systemd 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 2.1 of the License, or
- (at your option) any later version.
-
- systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <unistd.h>
-#include <stdio.h>
-#include <errno.h>
-#include <string.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <sys/mount.h>
-
-#include <systemd/sd-id128.h>
-
-#include "machine-id-setup.h"
-#include "macro.h"
-#include "util.h"
-#include "mkdir.h"
-#include "log.h"
-#include "virt.h"
-
-static int shorten_uuid(char destination[36], const char *source) {
- unsigned i, j;
-
- 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) {
- destination[32] = '\n';
- destination[33] = 0;
- return 0;
- }
-
- return -EINVAL;
-}
-
-static int generate(char id[34]) {
- int fd, r;
- unsigned char *p;
- sd_id128_t buf;
- char *q;
- ssize_t k;
- const char *vm_id;
-
- assert(id);
-
- /* First, try reading the D-Bus machine id, unless it is a symlink */
- fd = open("/var/lib/dbus/machine-id", O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
- if (fd >= 0) {
-
- k = loop_read(fd, id, 32, false);
- close_nointr_nofail(fd);
-
- if (k >= 32) {
- id[32] = '\n';
- id[33] = 0;
-
- log_info("Initializing machine ID from D-Bus machine ID.");
- return 0;
- }
- }
-
- /* If that didn't work, see if we are running in qemu/kvm and a
- * machine ID was passed in via -uuid on the qemu/kvm command
- * line */
-
- r = detect_vm(&vm_id);
- if (r > 0 && streq(vm_id, "kvm")) {
- char uuid[37];
-
- fd = open("/sys/class/dmi/id/product_uuid", O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
- if (fd >= 0) {
- k = loop_read(fd, uuid, 36, false);
- close_nointr_nofail(fd);
-
- if (k >= 36) {
- r = shorten_uuid(id, uuid);
- if (r >= 0) {
- log_info("Initializing machine ID from KVM UUID");
- return 0;
- }
- }
- }
- }
-
- /* If that didn't work either, see if we are running in a
- * container, and a machine ID was passed in via
- * $container_uuid the way libvirt/LXC does it */
-
- r = detect_container(NULL);
- if (r > 0) {
- FILE *f;
-
- f = fopen("/proc/1/environ", "re");
- if (f) {
- bool done = false;
-
- do {
- char line[LINE_MAX];
- unsigned i;
-
- for (i = 0; i < sizeof(line)-1; i++) {
- int c;
-
- c = getc(f);
- if (_unlikely_(c == EOF)) {
- done = true;
- break;
- } else if (c == 0)
- break;
-
- line[i] = c;
- }
- line[i] = 0;
-
- if (startswith(line, "container_uuid=") &&
- strlen(line + 15) >= 36) {
- r = shorten_uuid(id, line + 15);
- if (r >= 0) {
- log_info("Initializing machine ID from container UUID");
- return 0;
- }
- }
-
- } while (!done);
-
- fclose(f);
- }
- }
-
- /* If that didn't work, generate a random machine id */
- r = sd_id128_randomize(&buf);
- if (r < 0) {
- log_error("Failed to open /dev/urandom: %s", strerror(-r));
- return r;
- }
-
- 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;
-
- log_info("Initializing machine ID from random generator.");
-
- return 0;
-}
-
-int machine_id_setup(void) {
- int fd, r;
- bool writable;
- struct stat st;
- char id[34]; /* 32 + \n + \0 */
- mode_t m;
-
- m = umask(0000);
-
- /* We create this 0444, to indicate that this isn't really
- * something you should ever modify. Of course, since the file
- * will be owned by root it doesn't matter much, but maybe
- * people look. */
-
- fd = open("/etc/machine-id", O_RDWR|O_CREAT|O_CLOEXEC|O_NOCTTY, 0444);
- if (fd >= 0)
- writable = true;
- else {
- fd = open("/etc/machine-id", O_RDONLY|O_CLOEXEC|O_NOCTTY);
- if (fd < 0) {
- umask(m);
- log_error("Cannot open /etc/machine-id: %m");
- return -errno;
- }
-
- writable = false;
- }
-
- umask(m);
-
- if (fstat(fd, &st) < 0) {
- log_error("fstat() failed: %m");
- r = -errno;
- goto finish;
- }
-
- if (S_ISREG(st.st_mode)) {
- if (loop_read(fd, id, 32, false) >= 32) {
- r = 0;
- goto finish;
- }
- }
-
- /* Hmm, so, the id currently stored is not useful, then let's
- * generate one */
-
- r = generate(id);
- if (r < 0)
- goto finish;
-
- if (S_ISREG(st.st_mode) && writable) {
- lseek(fd, 0, SEEK_SET);
-
- if (loop_write(fd, id, 33, false) == 33) {
- r = 0;
- goto finish;
- }
- }
-
- close_nointr_nofail(fd);
- fd = -1;
-
- /* Hmm, we couldn't write it? So let's write it to
- * /run/machine-id as a replacement */
-
- m = umask(0022);
- r = write_one_line_file("/run/machine-id", id);
- umask(m);
-
- if (r < 0) {
- log_error("Cannot write /run/machine-id: %s", strerror(-r));
-
- unlink("/run/machine-id");
- goto finish;
- }
-
- /* And now, let's mount it over */
- r = mount("/run/machine-id", "/etc/machine-id", "bind", MS_BIND|MS_RDONLY, NULL) < 0 ? -errno : 0;
- if (r < 0) {
- unlink("/run/machine-id");
- log_error("Failed to mount /etc/machine-id: %s", strerror(-r));
- } else
- log_info("Installed transient /etc/machine-id file.");
-
-finish:
-
- if (fd >= 0)
- close_nointr_nofail(fd);
-
- return r;
-}
~ianmdlvl / elogind.git / blobdiff