X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fmachine-id-setup.c;h=94198cb83bba4de4ed6d3b8ac74589064bc8e6f2;hb=6996295f85a0402b8a72d76c1eab02fb8152f81d;hp=531f3b207382b4709a3bc6db51f9a5dac8ce93d1;hpb=81527be142678057215665be66e4b3c8306a7ab3;p=elogind.git

diff --git a/src/machine-id-setup.c b/src/machine-id-setup.c
index 531f3b207..94198cb83 100644
--- a/src/machine-id-setup.c
+++ b/src/machine-id-setup.c
@@ -32,7 +32,31 @@
 #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;
@@ -40,6 +64,7 @@ static int generate(char id[34]) {
         sd_id128_t buf;
         char *q;
         ssize_t k;
+        const char *vm_id;
 
         assert(id);
 
@@ -47,7 +72,7 @@ static int generate(char id[34]) {
         fd = open("/var/lib/dbus/machine-id", O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
         if (fd >= 0) {
 
-                k = loop_read(fd, id, 33, false);
+                k = loop_read(fd, id, 32, false);
                 close_nointr_nofail(fd);
 
                 if (k >= 32) {
@@ -59,6 +84,74 @@ static int generate(char id[34]) {
                 }
         }
 
+        /* 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) {
@@ -142,28 +235,25 @@ int machine_id_setup(void) {
         fd = -1;
 
         /* Hmm, we couldn't write it? So let's write it to
-         * /run/systemd/machine-id as a replacement */
-
-        mkdir_p("/run/systemd", 0755);
+         * /run/machine-id as a replacement */
 
         m = umask(0022);
-        r = write_one_line_file("/run/systemd/machine-id", id);
+        r = write_one_line_file("/run/machine-id", id);
         umask(m);
 
         if (r < 0) {
-                log_error("Cannot write /run/systemd/machine-id: %s", strerror(-r));
+                log_error("Cannot write /run/machine-id: %s", strerror(-r));
 
-                unlink("/run/systemd/machine-id");
+                unlink("/run/machine-id");
                 goto finish;
         }
 
         /* And now, let's mount it over */
-        r = mount("/run/systemd/machine-id", "/etc/machine-id", "bind", MS_BIND|MS_RDONLY, NULL) < 0 ? -errno : 0;
-        unlink("/run/systemd/machine-id");
-
-        if (r < 0)
+        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
+        } else
                 log_info("Installed transient /etc/machine-id file.");
 
 finish: