X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fcore%2Fmachine-id-setup.c;h=ce6d8e02d05d50bf943dfee6c83e67ecb1d15cc3;hp=18e015fe7f09d73a8c96fe7f2e9b03217a1e1b6e;hb=79008bddf679a5e0900369950eb346c9fa687107;hpb=aa96c6cb44a6eeccc506ae055aae2519a7f914e1 diff --git a/src/core/machine-id-setup.c b/src/core/machine-id-setup.c index 18e015fe7..ce6d8e02d 100644 --- a/src/core/machine-id-setup.c +++ b/src/core/machine-id-setup.c @@ -27,7 +27,7 @@ #include #include -#include +#include "systemd/sd-id128.h" #include "machine-id-setup.h" #include "macro.h" @@ -36,8 +36,9 @@ #include "log.h" #include "virt.h" #include "fileio.h" +#include "path-util.h" -static int shorten_uuid(char destination[36], const char *source) { +static int shorten_uuid(char destination[34], const char source[36]) { unsigned i, j; for (i = 0, j = 0; i < 36 && j < 32; i++) { @@ -59,21 +60,26 @@ static int shorten_uuid(char destination[36], const char *source) { return -EINVAL; } -static int generate(char id[34]) { +static int generate(char id[34], const char *root) { int fd, r; unsigned char *p; sd_id128_t buf; - char *q; + char *q; ssize_t k; - const char *vm_id; + const char *vm_id, *dbus_machine_id; assert(id); + if (isempty(root)) + dbus_machine_id = "/var/lib/dbus/machine-id"; + else + dbus_machine_id = strappenda(root, "/var/lib/dbus/machine-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); + fd = open(dbus_machine_id, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); if (fd >= 0) { k = loop_read(fd, id, 33, false); - close_nointr_nofail(fd); + safe_close(fd); if (k == 33 && id[32] == '\n') { @@ -88,43 +94,46 @@ 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 (isempty(root)) { + /* If that didn't work, 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) { + _cleanup_free_ char *e = NULL; + + r = getenv_for_pid(1, "container_uuid", &e); + if (r > 0) { + if (strlen(e) >= 36) { + r = shorten_uuid(id, e); + if (r >= 0) { + log_info("Initializing machine ID from container 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) { - _cleanup_free_ char *e = NULL; - r = getenv_for_pid(1, "container_uuid", &e); - if (r > 0) { - if (strlen(e) >= 36) { - r = shorten_uuid(id, e); - if (r >= 0) { - log_info("Initializing machine ID from container UUID."); - return 0; + } else { + /* If we are not running in a container, 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); + safe_close(fd); + + if (k >= 36) { + r = shorten_uuid(id, uuid); + if (r >= 0) { + log_info("Initializing machine ID from KVM UUID."); + return 0; + } + } } } } @@ -150,12 +159,24 @@ static int generate(char id[34]) { return 0; } -int machine_id_setup(void) { +int machine_id_setup(const char *root) { + const char *etc_machine_id, *run_machine_id; _cleanup_close_ int fd = -1; - int r; - bool writable; + bool writable = true; struct stat st; char id[34]; /* 32 + \n + \0 */ + int r; + + if (isempty(root)) { + etc_machine_id = "/etc/machine-id"; + run_machine_id = "/run/machine-id"; + } else { + etc_machine_id = strappenda(root, "/etc/machine-id"); + path_kill_slashes((char*) etc_machine_id); + + run_machine_id = strappenda(root, "/run/machine-id"); + path_kill_slashes((char*) run_machine_id); + } RUN_WITH_UMASK(0000) { /* We create this 0444, to indicate that this isn't really @@ -163,13 +184,21 @@ int machine_id_setup(void) { * 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); + 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; + + fd = open(etc_machine_id, O_RDONLY|O_CLOEXEC|O_NOCTTY); if (fd < 0) { - log_error("Cannot open /etc/machine-id: %m"); + if (old_errno == EROFS && errno == ENOENT) + log_error("System cannot boot: Missing /etc/machine-id and /etc is mounted read-only.\n" + "Booting up is supported only when:\n" + "1) /etc/machine-id exists and is populated.\n" + "2) /etc/machine-id exists and is empty.\n" + "3) /etc/machine-id is missing and /etc is writable.\n"); + else + log_error("Cannot open %s: %m", etc_machine_id); return -errno; } @@ -193,7 +222,7 @@ int machine_id_setup(void) { /* Hmm, so, the id currently stored is not useful, then let's * generate one */ - r = generate(id); + r = generate(id, root); if (r < 0) return r; @@ -204,34 +233,33 @@ int machine_id_setup(void) { return 0; } - close_nointr_nofail(fd); - fd = -1; + fd = safe_close(fd); /* 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); + r = write_string_file(run_machine_id, id); } if (r < 0) { - log_error("Cannot write /run/machine-id: %s", strerror(-r)); - unlink("/run/machine-id"); + log_error("Cannot write %s: %s", run_machine_id, strerror(-r)); + unlink(run_machine_id); return r; } /* And now, let's mount it over */ - r = mount("/run/machine-id", "/etc/machine-id", NULL, MS_BIND, NULL); + r = mount(run_machine_id, etc_machine_id, NULL, MS_BIND, NULL); if (r < 0) { - log_error("Failed to mount /etc/machine-id: %m"); - unlink_noerrno("/run/machine-id"); + log_error("Failed to mount %s: %m", etc_machine_id); + unlink_noerrno(run_machine_id); return -errno; } - log_info("Installed transient /etc/machine-id file."); + log_info("Installed transient %s file.", etc_machine_id); /* Mark the mount read-only */ - if (mount(NULL, "/etc/machine-id", NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, NULL) < 0) - log_warning("Failed to make transient /etc/machine-id read-only: %m"); + if (mount(NULL, etc_machine_id, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, NULL) < 0) + log_warning("Failed to make transient %s read-only: %m", etc_machine_id); return 0; }