buffer_read
static int buffer_read(BIO *h, char *buf, int size);
.bread = buffer_read,
buffer_read(packet, buf + dname_length, length);
buffer_read(buf, &local_addr, addrlen);
buffer_read(buf, &addr, addrlen);
buffer_read(b, acl, sizeof(*acl));
buffer_read(packet, (*rr)->rdata, rdlength);
buffer_read(packet, (*rr)->rdata + 2 * sizeof(void*), 20);
buffer_read(packet, (*rr)->rdata + sizeof(void*), bitmap_size);
buffer_read(packet, (*rr)->rdata + 3 + gateway_length, keylen);
buffer_read(packet, (*rr)->rdata+memrdlen, b64len);