sch_atm.c

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	struct atm_qdisc_data *p = PRIV(sch);
	struct atm_flow_data *flow;

	DPRINTK("atm_tc_walk(sch %p,[qdisc %p],walker %p)\n",sch,p,walker);
	if (walker->stop) return;
	for (flow = p->flows; flow; flow = flow->next) {
		if (walker->count >= walker->skip)
			if (walker->fn(sch,(unsigned long) flow,walker) < 0) {
				walker->stop = 1;
				break;
			}
		walker->count++;
	}
}


static struct tcf_proto **atm_tc_find_tcf(struct Qdisc *sch,unsigned long cl)
{
	struct atm_qdisc_data *p = PRIV(sch);
	struct atm_flow_data *flow = (struct atm_flow_data *) cl;

	DPRINTK("atm_tc_find_tcf(sch %p,[qdisc %p],flow %p)\n",sch,p,flow);
        return flow ? &flow->filter_list : &p->link.filter_list;
}


/* --------------------------- Qdisc operations ---------------------------- */


static int atm_tc_enqueue(struct sk_buff *skb,struct Qdisc *sch)
{
	struct atm_qdisc_data *p = PRIV(sch);
	struct atm_flow_data *flow = NULL ; /* @@@ */
	struct tcf_result res;
	int result;
	int ret = NET_XMIT_POLICED;

	D2PRINTK("atm_tc_enqueue(skb %p,sch %p,[qdisc %p])\n",skb,sch,p);
	result = TC_POLICE_OK; /* be nice to gcc */
	if (TC_H_MAJ(skb->priority) != sch->handle ||
	    !(flow = (struct atm_flow_data *) atm_tc_get(sch,skb->priority)))
		for (flow = p->flows; flow; flow = flow->next)
			if (flow->filter_list) {
				result = tc_classify(skb,flow->filter_list,
				    &res);
				if (result < 0) continue;
				flow = (struct atm_flow_data *) res.class;
				if (!flow) flow = lookup_flow(sch,res.classid);
				break;
			}
	if (!flow) flow = &p->link;
	else {
		if (flow->vcc)
			ATM_SKB(skb)->atm_options = flow->vcc->atm_options;
			/*@@@ looks good ... but it's not supposed to work :-)*/
#ifdef CONFIG_NET_CLS_POLICE
		switch (result) {
			case TC_POLICE_SHOT:
				kfree_skb(skb);
				break;
			case TC_POLICE_RECLASSIFY:
				if (flow->excess) flow = flow->excess;
				else {
					ATM_SKB(skb)->atm_options |=
					    ATM_ATMOPT_CLP;
					break;
				}
				/* fall through */
			case TC_POLICE_OK:
				/* fall through */
			default:
				break;
		}
#endif
	}
	if (
#ifdef CONFIG_NET_CLS_POLICE
	    result == TC_POLICE_SHOT ||
#endif
	    (ret = flow->q->enqueue(skb,flow->q)) != 0) {
		sch->stats.drops++;
		if (flow) flow->stats.drops++;
		return ret;
	}
	sch->stats.bytes += skb->len;
	sch->stats.packets++;
	flow->stats.bytes += skb->len;
	flow->stats.packets++;
	/*
	 * Okay, this may seem weird. We pretend we've dropped the packet if
	 * it goes via ATM. The reason for this is that the outer qdisc
	 * expects to be able to q->dequeue the packet later on if we return
	 * success at this place. Also, sch->q.qdisc needs to reflect whether
	 * there is a packet egligible for dequeuing or not. Note that the
	 * statistics of the outer qdisc are necessarily wrong because of all
	 * this. There's currently no correct solution for this.
	 */
	if (flow == &p->link) {
		sch->q.qlen++;
		return 0;
	}
	tasklet_schedule(&p->task);
	return NET_XMIT_BYPASS;
}


/*
 * Dequeue packets and send them over ATM. Note that we quite deliberately
 * avoid checking net_device's flow control here, simply because sch_atm
 * uses its own channels, which have nothing to do with any CLIP/LANE/or
 * non-ATM interfaces.
 */


static void sch_atm_dequeue(unsigned long data)
{
	struct Qdisc *sch = (struct Qdisc *) data;
	struct atm_qdisc_data *p = PRIV(sch);
	struct atm_flow_data *flow;
	struct sk_buff *skb;

	D2PRINTK("sch_atm_dequeue(sch %p,[qdisc %p])\n",sch,p);
	for (flow = p->link.next; flow; flow = flow->next)
		/*
		 * If traffic is properly shaped, this won't generate nasty
		 * little bursts. Otherwise, it may ... (but that's okay)
		 */
		while ((skb = flow->q->dequeue(flow->q))) {
			if (!atm_may_send(flow->vcc,skb->truesize)) {
				(void) flow->q->ops->requeue(skb,flow->q);
				break;
			}
			D2PRINTK("atm_tc_deqeueue: sending on class %p\n",flow);
			/* remove any LL header somebody else has attached */
			skb_pull(skb,(char *) skb->nh.iph-(char *) skb->data);
			if (skb_headroom(skb) < flow->hdr_len) {
				struct sk_buff *new;

				new = skb_realloc_headroom(skb,flow->hdr_len);
				dev_kfree_skb(skb);
				if (!new) continue;
				skb = new;
			}
			D2PRINTK("sch_atm_dequeue: ip %p, data %p\n",
			    skb->nh.iph,skb->data);
			ATM_SKB(skb)->vcc = flow->vcc;
			memcpy(skb_push(skb,flow->hdr_len),flow->hdr,
			    flow->hdr_len);
			atomic_add(skb->truesize,&flow->vcc->tx_inuse);
			ATM_SKB(skb)->iovcnt = 0;
			/* atm.atm_options are already set by atm_tc_enqueue */
			(void) flow->vcc->send(flow->vcc,skb);
		}
}


static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch)
{
	struct atm_qdisc_data *p = PRIV(sch);
	struct sk_buff *skb;

	D2PRINTK("atm_tc_dequeue(sch %p,[qdisc %p])\n",sch,p);
	tasklet_schedule(&p->task);
	skb = p->link.q->dequeue(p->link.q);
	if (skb) sch->q.qlen--;
	return skb;
}


static int atm_tc_requeue(struct sk_buff *skb,struct Qdisc *sch)
{
	struct atm_qdisc_data *p = PRIV(sch);
	int ret;

	D2PRINTK("atm_tc_requeue(skb %p,sch %p,[qdisc %p])\n",skb,sch,p);
	ret = p->link.q->ops->requeue(skb,p->link.q);
	if (!ret) sch->q.qlen++;
	else {
		sch->stats.drops++;
		p->link.stats.drops++;
	}
	return ret;
}


static int atm_tc_drop(struct Qdisc *sch)
{
	struct atm_qdisc_data *p = PRIV(sch);
	struct atm_flow_data *flow;

	DPRINTK("atm_tc_drop(sch %p,[qdisc %p])\n",sch,p);
	for (flow = p->flows; flow; flow = flow->next)
		if (flow->q->ops->drop && flow->q->ops->drop(flow->q))
			return 1;
	return 0;
}


static int atm_tc_init(struct Qdisc *sch,struct rtattr *opt)
{
	struct atm_qdisc_data *p = PRIV(sch);

	DPRINTK("atm_tc_init(sch %p,[qdisc %p],opt %p)\n",sch,p,opt);
	memset(p,0,sizeof(*p));
	p->flows = &p->link;
	if(!(p->link.q = qdisc_create_dflt(sch->dev,&pfifo_qdisc_ops)))
		p->link.q = &noop_qdisc;
	DPRINTK("atm_tc_init: link (%p) qdisc %p\n",&p->link,p->link.q);
	p->link.filter_list = NULL;
	p->link.vcc = NULL;
	p->link.sock = NULL;
	p->link.classid = sch->handle;
	p->link.ref = 1;
	p->link.next = NULL;
	tasklet_init(&p->task,sch_atm_dequeue,(unsigned long) sch);
	MOD_INC_USE_COUNT;
	return 0;
}


static void atm_tc_reset(struct Qdisc *sch)
{
	struct atm_qdisc_data *p = PRIV(sch);
	struct atm_flow_data *flow;

	DPRINTK("atm_tc_reset(sch %p,[qdisc %p])\n",sch,p);
	for (flow = p->flows; flow; flow = flow->next) qdisc_reset(flow->q);
	sch->q.qlen = 0;
}


static void atm_tc_destroy(struct Qdisc *sch)
{
	struct atm_qdisc_data *p = PRIV(sch);
	struct atm_flow_data *flow;

	DPRINTK("atm_tc_destroy(sch %p,[qdisc %p])\n",sch,p);
	/* races ? */
	while ((flow = p->flows)) {
		destroy_filters(flow);
		if (flow->ref > 1)
			printk(KERN_ERR "atm_destroy: %p->ref = %d\n",flow,
			    flow->ref);
		atm_tc_put(sch,(unsigned long) flow);
		if (p->flows == flow) {
			printk(KERN_ERR "atm_destroy: putting flow %p didn't "
			    "kill it\n",flow);
			p->flows = flow->next; /* brute force */
			break;
		}
	}
	tasklet_kill(&p->task);
	MOD_DEC_USE_COUNT;
}


#ifdef CONFIG_RTNETLINK

static int atm_tc_dump_class(struct Qdisc *sch, unsigned long cl,
    struct sk_buff *skb, struct tcmsg *tcm)
{
	struct atm_qdisc_data *p = PRIV(sch);
	struct atm_flow_data *flow = (struct atm_flow_data *) cl;
	unsigned char *b = skb->tail;
	struct rtattr *rta;

	DPRINTK("atm_tc_dump_class(sch %p,[qdisc %p],flow %p,skb %p,tcm %p)\n",
	    sch,p,flow,skb,tcm);
	if (!find_flow(p,flow)) return -EINVAL;
	tcm->tcm_handle = flow->classid;
	rta = (struct rtattr *) b;
	RTA_PUT(skb,TCA_OPTIONS,0,NULL);
	RTA_PUT(skb,TCA_ATM_HDR,flow->hdr_len,flow->hdr);
	if (flow->vcc) {
		struct sockaddr_atmpvc pvc;
		int state;

		pvc.sap_family = AF_ATMPVC;
		pvc.sap_addr.itf = flow->vcc->dev ? flow->vcc->dev->number : -1;
		pvc.sap_addr.vpi = flow->vcc->vpi;
		pvc.sap_addr.vci = flow->vcc->vci;
		RTA_PUT(skb,TCA_ATM_ADDR,sizeof(pvc),&pvc);
		state = ATM_VF2VS(flow->vcc->flags);
		RTA_PUT(skb,TCA_ATM_STATE,sizeof(state),&state);
	}
	if (flow->excess)
		RTA_PUT(skb,TCA_ATM_EXCESS,sizeof(u32),&flow->classid);
	else {
		static u32 zero = 0;

		RTA_PUT(skb,TCA_ATM_EXCESS,sizeof(zero),&zero);
	}
	rta->rta_len = skb->tail-b;
	return skb->len;

rtattr_failure:
	skb_trim(skb,b-skb->data);
	return -1;
}

static int atm_tc_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	return 0;
}

#endif


static struct Qdisc_class_ops atm_class_ops =
{
	atm_tc_graft,			/* graft */
	atm_tc_leaf,			/* leaf */
	atm_tc_get,			/* get */
	atm_tc_put,			/* put */
	atm_tc_change,			/* change */
	atm_tc_delete,			/* delete */
	atm_tc_walk,			/* walk */

	atm_tc_find_tcf,		/* tcf_chain */
	atm_tc_bind_filter,		/* bind_tcf */
	atm_tc_put,			/* unbind_tcf */

#ifdef CONFIG_RTNETLINK
	atm_tc_dump_class,		/* dump */
#endif
};

struct Qdisc_ops atm_qdisc_ops =
{
	NULL,				/* next */
	&atm_class_ops,			/* cl_ops */
	"atm",
	sizeof(struct atm_qdisc_data),

	atm_tc_enqueue,			/* enqueue */
	atm_tc_dequeue,			/* dequeue */
	atm_tc_requeue,			/* requeue */
	atm_tc_drop,			/* drop */

	atm_tc_init,			/* init */
	atm_tc_reset,			/* reset */
	atm_tc_destroy,			/* destroy */
	NULL,				/* change */

#ifdef CONFIG_RTNETLINK
	atm_tc_dump			/* dump */
#endif
};


#ifdef MODULE
int init_module(void)
{
	return register_qdisc(&atm_qdisc_ops);
}


void cleanup_module(void) 
{
	unregister_qdisc(&atm_qdisc_ops);
}
#endif