datatype: display description for header field < 8 bits

 # nft describe ip dscp
 payload expression, datatype dscp (Differentiated Services Code Point) (basetype integer), 6 bits

 pre-defined symbolic constants (in hexadecimal):
 nft: datatype.c:209: switch_byteorder: Assertion `len > 0' failed.
 Aborted

Fixes: c89a0801d077 ("datatype: Display pre-defined inet_service values in host byte order")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/src/datatype.c b/src/datatype.c
index 873f7d4d358b586f7e4ba2ee12d8e2693b3f9d6e..b9e167e03765bd9b07a7e992895defe466e79913 100644 (file)
--- a/src/datatype.c
+++ b/src/datatype.c
@@ -216,8 +216,8 @@ void symbol_table_print(const struct symbol_table *tbl,
                        enum byteorder byteorder,
                        struct output_ctx *octx)
 {
+       unsigned int len = div_round_up(dtype->size, BITS_PER_BYTE);
        const struct symbolic_constant *s;
-       unsigned int len = dtype->size / BITS_PER_BYTE;
        uint64_t value;
 
        for (s = tbl->symbols; s->identifier != NULL; s++) {