diff options
| -rw-r--r-- | doc/README.dissector | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/doc/README.dissector b/doc/README.dissector index ae6980e464..a693284381 100644 --- a/doc/README.dissector +++ b/doc/README.dissector @@ -2645,16 +2645,22 @@ static dissector_handle_t sub_dissector_handle; Information can be stored for each data packet that is processed by the dissector. The information is added with the p_add_proto_data function and retrieved with the p_get_proto_data function. The data pointers passed into -the p_add_proto_data are not managed by the proto_data routines. If you use -malloc or any other dynamic memory allocation scheme, you must release the -data when it isn't required. +the p_add_proto_data are not managed by the proto_data routines, however the +data pointer memory scope must match that of the scope parameter. +The two most common use cases for p_add_proto_data/p_get_proto_data are for +persistent data about the packet for the lifetime of the capture (file scope) +and to exchange data between dissectors across a single packet (packet scope). +It is also used to provide packet data for Decode As dialog (packet scope). void -p_add_proto_data(frame_data *fd, int proto, void *proto_data) +p_add_proto_data(wmem_allocator_t *scope, frame_data *fd, int proto, void *proto_data) void * -p_get_proto_data(frame_data *fd, int proto) +p_get_proto_data(wmem_allocator_t *scope, frame_data *fd, int proto) Where: + scope - Lifetime of the data to be stored, typically wmem_file_scope() + or pinfo->pool (packet scope). Must match scope of data + allocated. fd - The fd pointer in the pinfo structure, pinfo->fd proto - Protocol id returned by the proto_register_protocol call during initialization |