X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fcore%2Fmachine-id-setup.c;h=2a58e48d6f191d9ff42a5903bc0984be4c6c12c1;hb=68a8723c8592c06b2c978f391cb47db266d9d6de;hp=636519c00c81d7d17b41fc675642fd114bbac3f5;hpb=ab94af9201496ea3aa59bbf2a01eb750fbd1c08a;p=elogind.git diff --git a/src/core/machine-id-setup.c b/src/core/machine-id-setup.c index 636519c00..2a58e48d6 100644 --- a/src/core/machine-id-setup.c +++ b/src/core/machine-id-setup.c @@ -35,6 +35,8 @@ #include "mkdir.h" #include "log.h" #include "virt.h" +#include "fileio.h" +#include "path-util.h" static int shorten_uuid(char destination[36], const char *source) { unsigned i, j; @@ -58,74 +60,79 @@ 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; ssize_t k; const char *vm_id; + _cleanup_free_ char *dbus_machine_id = NULL; assert(id); + if (asprintf(&dbus_machine_id, "%s/var/lib/dbus/machine-id", root) < 0) + return log_oom(); + /* 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); + safe_close(fd); - 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]; + if (k == 33 && id[32] == '\n') { - 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); + id[32] = 0; + if (id128_is_valid(id)) { + id[32] = '\n'; + id[33] = 0; - if (k >= 36) { - r = shorten_uuid(id, uuid); - if (r >= 0) { - log_info("Initializing machine ID from KVM UUID"); - return 0; - } + log_info("Initializing machine ID from D-Bus machine ID."); + 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 */ + /* 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) { - char *e; + _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"); - free(e); + log_info("Initializing machine ID from container UUID."); return 0; } } + } - free(e); + } 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; + } + } + } } } @@ -149,94 +156,94 @@ static int generate(char id[34]) { return 0; } -int machine_id_setup(void) { - int fd, r; - bool writable; +int machine_id_setup(const char *root) { + _cleanup_close_ int fd = -1; + int r; + bool writable = false; 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; - } + char *etc_machine_id, *run_machine_id; + + etc_machine_id = strappenda(root, "/etc/machine-id"); + path_kill_slashes(etc_machine_id); + + run_machine_id = strappenda(root, "/run/machine-id"); + path_kill_slashes(run_machine_id); + + RUN_WITH_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) { + log_error("Cannot open %s: %m", etc_machine_id); + return -errno; + } - writable = false; + writable = false; + } } - umask(m); - if (fstat(fd, &st) < 0) { log_error("fstat() failed: %m"); - r = -errno; - goto finish; + return -errno; } - if (S_ISREG(st.st_mode)) { - if (loop_read(fd, id, 32, false) >= 32) { - r = 0; - goto finish; + if (S_ISREG(st.st_mode)) + if (loop_read(fd, id, 33, false) == 33 && id[32] == '\n') { + id[32] = 0; + + if (id128_is_valid(id)) + return 0; } - } /* Hmm, so, the id currently stored is not useful, then let's * generate one */ - r = generate(id); + r = generate(id, root); if (r < 0) - goto finish; + return r; if (S_ISREG(st.st_mode) && writable) { lseek(fd, 0, SEEK_SET); - if (loop_write(fd, id, 33, false) == 33) { - r = 0; - goto finish; - } + if (loop_write(fd, id, 33, false) == 33) + 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 */ - m = umask(0022); - r = write_one_line_file("/run/machine-id", id); - umask(m); - + RUN_WITH_UMASK(0022) { + 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"); - goto finish; + 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", "bind", MS_BIND|MS_RDONLY, NULL) < 0 ? -errno : 0; + r = mount(run_machine_id, etc_machine_id, NULL, MS_BIND, NULL); 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."); + log_error("Failed to mount %s: %m", etc_machine_id); + unlink_noerrno(run_machine_id); + return -errno; + } -finish: + log_info("Installed transient %s file.", etc_machine_id); - if (fd >= 0) - close_nointr_nofail(fd); + /* 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 %s read-only: %m", etc_machine_id); - return r; + return 0; }