[Spice-devel] [PATCH spice-common] proto: Demarshal Smartcard data field

[Frediano Ziglio]

Currently the demarshaler code is not used by spice-server.
Demarshal all the fields of the header message, not only the header.
Using generated code allows to easily check data and support
big endian machines. Generated code will be used by spice-server.

The resulting change is.

   diff -ru gen/generated_client_marshallers.c common/generated_client_marshallers.c
    --- gen/generated_client_marshallers.c      2019-10-05 20:44:54.000000000 +0100
    +++ common/generated_client_marshallers.c   2019-10-05 20:45:33.000000000 +0100
    @@ -283,6 +283,7 @@
         spice_marshaller_add_uint32(m, src->type);
         spice_marshaller_add_uint32(m, src->reader_id);
         spice_marshaller_add_uint32(m, src->length);
    +    /* Don't marshall @nomarshal data */
     }

     #endif /* USE_SMARTCARD */
    diff -ru gen/generated_server_demarshallers.c common/generated_server_demarshallers.c
    --- gen/generated_server_demarshallers.c    2019-10-05 20:44:54.000000000 +0100
    +++ common/generated_server_demarshallers.c 2019-10-05 20:45:33.000000000 +0100
    @@ -1451,10 +1451,25 @@
         uint64_t nw_size;
         uint64_t mem_size;
         uint8_t *in, *end;
    +    uint64_t data__nw_size, data__mem_size;
    +    uint64_t data__nelements;
         VSCMsgHeader *out;

    -    nw_size = 12;
    -    mem_size = sizeof(VSCMsgHeader);
    +    { /* data */
    +        uint32_t length__value;
    +        pos = start + 8;
    +        if (SPICE_UNLIKELY(pos + 4 > message_end)) {
    +            goto error;
    +        }
    +        length__value = read_uint32(pos);
    +        data__nelements = length__value;
    +
    +        data__nw_size = data__nelements;
    +        data__mem_size = sizeof(uint8_t) * data__nelements;
    +    }
    +
    +    nw_size = 12 + data__nw_size;
    +    mem_size = sizeof(VSCMsgHeader) + data__mem_size;

         /* Check if message fits in reported side */
         if (nw_size > (uintptr_t) (message_end - start)) {
    @@ -1474,6 +1489,10 @@
         out->type = consume_uint32(&in);
         out->reader_id = consume_uint32(&in);
         out->length = consume_uint32(&in);
    +    verify(sizeof(out->data) == 0);
    +    memcpy(out->data, in, data__nelements);
    +    in += data__nelements;
    +    end += data__nelements;

         assert(in <= message_end);
         assert(end <= data + mem_size);

The @nomarshal attribute allows to not change the marshaling code
(used by spice-gtk).

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 spice.proto | 1 +
 1 file changed, 1 insertion(+)

diff --git a/spice.proto b/spice.proto
index 34ba3c8..616b960 100644
--- a/spice.proto
+++ b/spice.proto
@@ -1305,6 +1305,7 @@ channel SmartcardChannel : BaseChannel {
         vsc_message_type type;
         uint32 reader_id;
         uint32 length;
+        uint8 data[length] @end @nomarshal;
     } @ctype(VSCMsgHeader) header = 101;
 /* See comment on client data message above */
 /*
-- 
2.21.0