sd-id128: introduce id128_get_machine() and id128_get_machine_at()

diff --git a/src/libsystemd/sd-id128/id128-util.h b/src/libsystemd/sd-id128/id128-util.h
index 6f7660d9b420366e84c398add9908e6a500a5c71..7bcbd8e55840cec02bfed6f2c8f6ef3dfd11cccb 100644 (file)
--- a/src/libsystemd/sd-id128/id128-util.h
+++ b/src/libsystemd/sd-id128/id128-util.h
@@ -32,6 +32,9 @@ static inline int id128_write(const char *path, Id128Flag f, sd_id128_t id) {
         return id128_write_at(AT_FDCWD, path, f, id);
 }
 
+int id128_get_machine(const char *root, sd_id128_t *ret);
+int id128_get_machine_at(int rfd, sd_id128_t *ret);
+
 void id128_hash_func(const sd_id128_t *p, struct siphash *state);
 int id128_compare_func(const sd_id128_t *a, const sd_id128_t *b) _pure_;
 extern const struct hash_ops id128_hash_ops;

diff --git a/src/libsystemd/sd-id128/sd-id128.c b/src/libsystemd/sd-id128/sd-id128.c
index 075e64d5537def90756803bce15abe34053be535..6a82a7f7b890b8b1db308927a806ca0a17907e07 100644 (file)
--- a/src/libsystemd/sd-id128/sd-id128.c
+++ b/src/libsystemd/sd-id128/sd-id128.c
@@ -7,6 +7,7 @@
 #include "sd-id128.h"
 
 #include "alloc-util.h"
+#include "chase.h"
 #include "fd-util.h"
 #include "hexdecoct.h"
 #include "hmac.h"
@@ -15,6 +16,7 @@
 #include "macro.h"
 #include "missing_syscall.h"
 #include "missing_threads.h"
+#include "path-util.h"
 #include "random-util.h"
 #include "stat-util.h"
 #include "user-util.h"
@@ -136,6 +138,38 @@ _public_ int sd_id128_get_machine(sd_id128_t *ret) {
         return 0;
 }
 
+int id128_get_machine_at(int rfd, sd_id128_t *ret) {
+        _cleanup_close_ int fd = -EBADF;
+        int r;
+
+        assert(rfd >= 0 || rfd == AT_FDCWD);
+
+        r = dir_fd_is_root_or_cwd(rfd);
+        if (r < 0)
+                return r;
+        if (r > 0)
+                return sd_id128_get_machine(ret);
+
+        fd = chase_and_openat(rfd, "/etc/machine-id", CHASE_AT_RESOLVE_IN_ROOT, O_RDONLY|O_CLOEXEC|O_NOCTTY, NULL);
+        if (fd < 0)
+                return fd;
+
+        return id128_read_fd(fd, ID128_FORMAT_PLAIN | ID128_REFUSE_NULL, ret);
+}
+
+int id128_get_machine(const char *root, sd_id128_t *ret) {
+        _cleanup_close_ int fd = -EBADF;
+
+        if (empty_or_root(root))
+                return sd_id128_get_machine(ret);
+
+        fd = chase_and_open("/etc/machine-id", root, CHASE_PREFIX_ROOT, O_RDONLY|O_CLOEXEC|O_NOCTTY, NULL);
+        if (fd < 0)
+                return fd;
+
+        return id128_read_fd(fd, ID128_FORMAT_PLAIN | ID128_REFUSE_NULL, ret);
+}
+
 _public_ int sd_id128_get_boot(sd_id128_t *ret) {
         static thread_local sd_id128_t saved_boot_id = {};
         int r;