smb2_get_data_area_len
smb2_get_data_area_len(&offset, &data_length, shdr);
security_blob = smb2_get_data_area_len(&blob_offset, &blob_length,
char *smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *shdr);
ret = smb2_get_data_area_len(&offset, &data_length, hdr);