sd-id128: make sd_id128_get_machine() or friends return -EUCLEAN when an ID is in an invalid format

EINVAL suggests that the caller passes an invalid argument. EIO is
for "input/output error", i.e. the error you'd get if the disk or
file system is borked, and this error code could be returned by the
underlying read/write functions.

Let's make the functions return an unambiguous error code.

src/libsystemd/sd-id128/id128-util.c

@@ -43,6 +43,7 @@ bool id128_is_valid(const char *s) {
 int id128_read_fd(int fd, Id128FormatFlag f, sd_id128_t *ret) {
         char buffer[SD_ID128_UUID_STRING_MAX + 1]; /* +1 is for trailing newline */
         ssize_t l;
+        int r;
 
         assert(fd >= 0);
 
@@ -54,7 +55,7 @@ int id128_read_fd(int fd, Id128FormatFlag f, sd_id128_t *ret) {
          * This returns the following:
          *     -ENOMEDIUM: an empty string,
          *     -ENOPKG:    "uninitialized" or "uninitialized\n",
-         *     -EINVAL:    other invalid strings. */
+         *     -EUCLEAN:   other invalid strings. */
 
         l = loop_read(fd, buffer, sizeof(buffer), false); /* we expect a short read of either 32/33 or 36/37 chars */
         if (l < 0)
@@ -70,33 +71,34 @@ int id128_read_fd(int fd, Id128FormatFlag f, sd_id128_t *ret) {
 
         case SD_ID128_STRING_MAX: /* plain UUID with trailing newline */
                 if (buffer[SD_ID128_STRING_MAX-1] != '\n')
-                        return -EINVAL;
+                        return -EUCLEAN;
 
                 _fallthrough_;
         case SD_ID128_STRING_MAX-1: /* plain UUID without trailing newline */
                 if (!FLAGS_SET(f, ID128_FORMAT_PLAIN))
-                        return -EINVAL;
+                        return -EUCLEAN;
 
                 buffer[SD_ID128_STRING_MAX-1] = 0;
                 break;
 
         case SD_ID128_UUID_STRING_MAX: /* RFC UUID with trailing newline */
                 if (buffer[SD_ID128_UUID_STRING_MAX-1] != '\n')
-                        return -EINVAL;
+                        return -EUCLEAN;
 
                 _fallthrough_;
         case SD_ID128_UUID_STRING_MAX-1: /* RFC UUID without trailing newline */
                 if (!FLAGS_SET(f, ID128_FORMAT_UUID))
-                        return -EINVAL;
+                        return -EUCLEAN;
 
                 buffer[SD_ID128_UUID_STRING_MAX-1] = 0;
                 break;
 
         default:
-                return -EINVAL;
+                return -EUCLEAN;
         }
 
-        return sd_id128_from_string(buffer, ret);
+        r = sd_id128_from_string(buffer, ret);
+        return r == -EINVAL ? -EUCLEAN : r;
 }
 
 int id128_read(const char *p, Id128FormatFlag f, sd_id128_t *ret) {

src/libsystemd/sd-id128/sd-id128.c

@@ -206,22 +206,22 @@ static int get_invocation_from_keyring(sd_id128_t *ret) {
         /* Chop off the final description string */
         d = strrchr(description, ';');
         if (!d)
-                return -EIO;
+                return -EUCLEAN;
         *d = 0;
 
         /* Look for the permissions */
         p = strrchr(description, ';');
         if (!p)
-                return -EIO;
+                return -EUCLEAN;
 
         errno = 0;
         perms = strtoul(p + 1, &e, 16);
         if (errno > 0)
                 return -errno;
         if (e == p + 1) /* Read at least one character */
-                return -EIO;
+                return -EUCLEAN;
         if (e != d) /* Must reached the end */
-                return -EIO;
+                return -EUCLEAN;
 
         if ((perms & ~MAX_PERMS) != 0)
                 return -EPERM;
@@ -231,7 +231,7 @@ static int get_invocation_from_keyring(sd_id128_t *ret) {
         /* Look for the group ID */
         g = strrchr(description, ';');
         if (!g)
-                return -EIO;
+                return -EUCLEAN;
         r = parse_gid(g + 1, &gid);
         if (r < 0)
                 return r;
@@ -242,7 +242,7 @@ static int get_invocation_from_keyring(sd_id128_t *ret) {
         /* Look for the user ID */
         u = strrchr(description, ';');
         if (!u)
-                return -EIO;
+                return -EUCLEAN;
         r = parse_uid(u + 1, &uid);
         if (r < 0)
                 return r;
@@ -253,13 +253,14 @@ static int get_invocation_from_keyring(sd_id128_t *ret) {
         if (c < 0)
                 return -errno;
         if (c != sizeof(sd_id128_t))
-                return -EIO;
+                return -EUCLEAN;
 
         return 0;
 }
 
 static int get_invocation_from_environment(sd_id128_t *ret) {
         const char *e;
+        int r;
 
         assert(ret);
 
@@ -267,7 +268,8 @@ static int get_invocation_from_environment(sd_id128_t *ret) {
         if (!e)
                 return -ENXIO;
 
-        return sd_id128_from_string(e, ret);
+        r = sd_id128_from_string(e, ret);
+        return r == -EINVAL ? -EUCLEAN : r;
 }
 
 _public_ int sd_id128_get_invocation(sd_id128_t *ret) {