sd-id128: make id128_read() optionally take root directory

3 files changed, 11 insertions, 8 deletions

diff --git a/src/libsystemd/sd-id128/id128-util.c b/src/libsystemd/sd-id128/id128-util.c
index a009a110a9..974aafa5b7 100644
--- a/src/libsystemd/sd-id128/id128-util.c
+++ b/src/libsystemd/sd-id128/id128-util.c
@@ -4,6 +4,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 
+#include "chase.h"
 #include "fd-util.h"
 #include "hexdecoct.h"
 #include "id128-util.h"
@@ -101,12 +102,14 @@ int id128_read_fd(int fd, Id128FormatFlag f, sd_id128_t *ret) {
         return r == -EINVAL ? -EUCLEAN : r;
 }
 
-int id128_read(const char *p, Id128FormatFlag f, sd_id128_t *ret) {
+int id128_read(const char *root, const char *p, Id128FormatFlag f, sd_id128_t *ret) {
         _cleanup_close_ int fd = -EBADF;
 
-        fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY);
+        assert(p);
+
+        fd = chase_and_open(p, root, CHASE_PREFIX_ROOT, O_RDONLY|O_CLOEXEC|O_NOCTTY, /* ret_path = */ NULL);
         if (fd < 0)
-                return -errno;
+                return fd;
 
         return id128_read_fd(fd, f, ret);
 }
@@ -184,9 +187,9 @@ int id128_get_product(sd_id128_t *ret) {
         /* Reads the systems product UUID from DMI or devicetree (where it is located on POWER). This is
          * particularly relevant in VM environments, where VM managers typically place a VM uuid there. */
 
-        r = id128_read("/sys/class/dmi/id/product_uuid", ID128_FORMAT_UUID, &uuid);
+        r = id128_read(NULL, "/sys/class/dmi/id/product_uuid", ID128_FORMAT_UUID, &uuid);
         if (r == -ENOENT)
-                r = id128_read("/proc/device-tree/vm,uuid", ID128_FORMAT_UUID, &uuid);
+                r = id128_read(NULL, "/proc/device-tree/vm,uuid", ID128_FORMAT_UUID, &uuid);
         if (r < 0)
                 return r;
 
diff --git a/src/libsystemd/sd-id128/id128-util.h b/src/libsystemd/sd-id128/id128-util.h
index e094de6441..2ebca8fd95 100644
--- a/src/libsystemd/sd-id128/id128-util.h
+++ b/src/libsystemd/sd-id128/id128-util.h
@@ -19,7 +19,7 @@ typedef enum Id128FormatFlag {
 } Id128FormatFlag;
 
 int id128_read_fd(int fd, Id128FormatFlag f, sd_id128_t *ret);
-int id128_read(const char *p, Id128FormatFlag f, sd_id128_t *ret);
+int id128_read(const char *root, const char *p, Id128FormatFlag f, sd_id128_t *ret);
 
 int id128_write_fd(int fd, Id128FormatFlag f, sd_id128_t id);
 int id128_write(const char *p, Id128FormatFlag f, sd_id128_t id);
diff --git a/src/libsystemd/sd-id128/sd-id128.c b/src/libsystemd/sd-id128/sd-id128.c
index 5ce36cf2fc..03f0ddd182 100644
--- a/src/libsystemd/sd-id128/sd-id128.c
+++ b/src/libsystemd/sd-id128/sd-id128.c
@@ -126,7 +126,7 @@ _public_ int sd_id128_get_machine(sd_id128_t *ret) {
         int r;
 
         if (sd_id128_is_null(saved_machine_id)) {
-                r = id128_read("/etc/machine-id", ID128_FORMAT_PLAIN, &saved_machine_id);
+                r = id128_read(NULL, "/etc/machine-id", ID128_FORMAT_PLAIN, &saved_machine_id);
                 if (r < 0)
                         return r;
 
@@ -144,7 +144,7 @@ _public_ int sd_id128_get_boot(sd_id128_t *ret) {
         int r;
 
         if (sd_id128_is_null(saved_boot_id)) {
-                r = id128_read("/proc/sys/kernel/random/boot_id", ID128_FORMAT_UUID, &saved_boot_id);
+                r = id128_read(NULL, "/proc/sys/kernel/random/boot_id", ID128_FORMAT_UUID, &saved_boot_id);
                 if (r == -ENOENT && proc_mounted() == 0)
                         return -ENOSYS;
                 if (r < 0)