include/denc: Add missing check for compat

Now decoder throws if compat signalled in message is higher than version of decoder.

Signed-off-by: Adam Kupczyk <akupczyk@ibm.com>
(cherry picked from commit 62aba6df38df7203b2565f77afc2fb09e4bc43d6)

diff --git a/src/include/denc.h b/src/include/denc.h
index d075dd518318567667358024c302b44dd77c384b..623e4639cb57f6a4637ee1b4807fada31d8519f3 100644 (file)
--- a/src/include/denc.h
+++ b/src/include/denc.h
@@ -1818,8 +1818,13 @@ inline std::enable_if_t<traits::supported && !traits::featured> decode_nohead(
                          __u8 *struct_compat,                          \
                          char **start_pos,                             \
                          uint32_t *struct_len) {                       \
+    __u8 code_v = *struct_v;                                           \
     denc(*struct_v, p);                                                        \
     denc(*struct_compat, p);                                           \
+    if (code_v < *struct_compat)                                       \
+      throw ::ceph::buffer::malformed_input(fmt::format(               \
+      "Decoder at '{}' v={} cannot decode v={} minimal_decoder={}",    \
+      __PRETTY_FUNCTION__, code_v, *struct_v, *struct_compat));                \
     denc(*struct_len, p);                                              \
     *start_pos = const_cast<char*>(p.get_pos());                       \
   }                                                                    \