int offset = body ? pkt->data - body : 0;
int offset = body ? body - pkt->data : 0;
static void ssh_pkt_ensure(struct Packet *pkt, int length){    if (pkt->maxlen < length) {	unsigned char *body = pkt->body;	int offset = body ? pkt->data - body : 0;	pkt->maxlen = length + 256;	pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);	if (body) pkt->body = pkt->data + offset;    }}