Merge pull request #3802 from poettering/id128-fixes

Id128 fixes and more

1 files changed, 21 insertions, 9 deletions

diff --git a/src/libsystemd/sd-id128/id128-util.c b/src/libsystemd/sd-id128/id128-util.c
index aaac838b59..c3f527d657 100644
--- a/src/libsystemd/sd-id128/id128-util.c
+++ b/src/libsystemd/sd-id128/id128-util.c
@@ -100,33 +100,45 @@ int id128_read_fd(int fd, Id128Format f, sd_id128_t *ret) {
         assert(f < _ID128_FORMAT_MAX);
 
         /* Reads an 128bit ID from a file, which may either be in plain format (32 hex digits), or in UUID format, both
-         * followed by a newline and nothing else. */
+         * optionally followed by a newline and nothing else. ID files should really be newline terminated, but if they
+         * aren't that's OK too, following the rule of "Be conservative in what you send, be liberal in what you
+         * accept". */
 
-        l = loop_read(fd, buffer, sizeof(buffer), false); /* we expect a short read of either 33 or 37 chars */
+        l = loop_read(fd, buffer, sizeof(buffer), false); /* we expect a short read of either 32/33 or 36/37 chars */
         if (l < 0)
                 return (int) l;
         if (l == 0) /* empty? */
                 return -ENOMEDIUM;
 
-        if (l == 33) {
-                if (f == ID128_UUID)
-                        return -EINVAL;
+        switch (l) {
 
+        case 33: /* plain UUID with trailing newline */
                 if (buffer[32] != '\n')
                         return -EINVAL;
 
+                /* fall through */
+        case 32: /* plain UUID without trailing newline */
+                if (f == ID128_UUID)
+                        return -EINVAL;
+
                 buffer[32] = 0;
+                break;
 
-        } else if (l == 37) {
-                if (f == ID128_PLAIN)
+        case 37: /* RFC UUID with trailing newline */
+                if (buffer[36] != '\n')
                         return -EINVAL;
 
-                if (buffer[36] != '\n')
+                /* fall through */
+        case 36: /* RFC UUID without trailing newline */
+                if (f == ID128_PLAIN)
                         return -EINVAL;
 
                 buffer[36] = 0;
-        } else
+                break;
+
+        default:
                 return -EINVAL;
+        }
 
         return sd_id128_from_string(buffer, ret);
 }