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=1b55da7e56b8b6117b3418d6414444b3bad7c4f0;hp=9e84ac0cb990757d6981d1adef8c8d9507bdea12;hb=e821075a23fdfa3ca7738fc30bb2d4c430fe10c0;hpb=08e1fb68d78b4adf26cce8387fc428b9e370bcf4 diff --git a/src/core/machine-id-setup.c b/src/core/machine-id-setup.c index 9e84ac0cb..1b55da7e5 100644 --- a/src/core/machine-id-setup.c +++ b/src/core/machine-id-setup.c @@ -35,6 +35,7 @@ #include "mkdir.h" #include "log.h" #include "virt.h" +#include "fileio.h" static int shorten_uuid(char destination[36], const char *source) { unsigned i, j; @@ -71,16 +72,19 @@ static int generate(char id[34]) { /* 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); + k = loop_read(fd, id, 33, false); close_nointr_nofail(fd); - if (k >= 32) { - id[32] = '\n'; - id[33] = 0; + if (k == 33 && id[32] == '\n') { - log_info("Initializing machine ID from D-Bus machine ID."); - return 0; + id[32] = 0; + if (id128_is_valid(id)) { + id[32] = '\n'; + id[33] = 0; + + log_info("Initializing machine ID from D-Bus machine ID."); + return 0; + } } } @@ -100,7 +104,7 @@ static int generate(char id[34]) { if (k >= 36) { r = shorten_uuid(id, uuid); if (r >= 0) { - log_info("Initializing machine ID from KVM UUID"); + log_info("Initializing machine ID from KVM UUID."); return 0; } } @@ -110,45 +114,19 @@ static int generate(char id[34]) { /* 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; + _cleanup_free_ char *e = NULL; - 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; - } + 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; } - - } while (!done); - - fclose(f); + } } } @@ -173,62 +151,57 @@ static int generate(char id[34]) { } int machine_id_setup(void) { - int fd, r; - bool writable; + _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; - } - writable = false; - } + 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 /etc/machine-id: %m"); + return -errno; + } - umask(m); + writable = false; + } + } 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); 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); @@ -237,29 +210,28 @@ int machine_id_setup(void) { /* 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; + 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 /etc/machine-id: %m"); + unlink_noerrno("/run/machine-id"); + return -errno; + } -finish: + log_info("Installed transient /etc/machine-id file."); - 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 /etc/machine-id read-only: %m"); - return r; + return 0; }