inet_lro.c

linux 内核源代码

}

static void lro_flush(struct net_lro_mgr *lro_mgr,
		      struct net_lro_desc *lro_desc)
{
	if (lro_desc->pkt_aggr_cnt > 1)
		lro_update_tcp_ip_header(lro_desc);

	skb_shinfo(lro_desc->parent)->gso_size = lro_desc->mss;

	if (lro_desc->vgrp) {
		if (lro_mgr->features & LRO_F_NAPI)
			vlan_hwaccel_receive_skb(lro_desc->parent,
						 lro_desc->vgrp,
						 lro_desc->vlan_tag);
		else
			vlan_hwaccel_rx(lro_desc->parent,
					lro_desc->vgrp,
					lro_desc->vlan_tag);

	} else {
		if (lro_mgr->features & LRO_F_NAPI)
			netif_receive_skb(lro_desc->parent);
		else
			netif_rx(lro_desc->parent);
	}

	LRO_INC_STATS(lro_mgr, flushed);
	lro_clear_desc(lro_desc);
}

static int __lro_proc_skb(struct net_lro_mgr *lro_mgr, struct sk_buff *skb,
			  struct vlan_group *vgrp, u16 vlan_tag, void *priv)
{
	struct net_lro_desc *lro_desc;
	struct iphdr *iph;
	struct tcphdr *tcph;
	u64 flags;
	int vlan_hdr_len = 0;

	if (!lro_mgr->get_skb_header
	    || lro_mgr->get_skb_header(skb, (void *)&iph, (void *)&tcph,
				       &flags, priv))
		goto out;

	if (!(flags & LRO_IPV4) || !(flags & LRO_TCP))
		goto out;

	lro_desc = lro_get_desc(lro_mgr, lro_mgr->lro_arr, iph, tcph);
	if (!lro_desc)
		goto out;

	if ((skb->protocol == htons(ETH_P_8021Q))
	    && !(lro_mgr->features & LRO_F_EXTRACT_VLAN_ID))
		vlan_hdr_len = VLAN_HLEN;

	if (!lro_desc->active) { /* start new lro session */
		if (lro_tcp_ip_check(iph, tcph, skb->len - vlan_hdr_len, NULL))
			goto out;

		skb->ip_summed = lro_mgr->ip_summed_aggr;
		lro_init_desc(lro_desc, skb, iph, tcph, vlan_tag, vgrp);
		LRO_INC_STATS(lro_mgr, aggregated);
		return 0;
	}

	if (lro_desc->tcp_next_seq != ntohl(tcph->seq))
		goto out2;

	if (lro_tcp_ip_check(iph, tcph, skb->len, lro_desc))
		goto out2;

	lro_add_packet(lro_desc, skb, iph, tcph);
	LRO_INC_STATS(lro_mgr, aggregated);

	if ((lro_desc->pkt_aggr_cnt >= lro_mgr->max_aggr) ||
	    lro_desc->parent->len > (0xFFFF - lro_mgr->dev->mtu))
		lro_flush(lro_mgr, lro_desc);

	return 0;

out2: /* send aggregated SKBs to stack */
	lro_flush(lro_mgr, lro_desc);

out:  /* Original SKB has to be posted to stack */
	skb->ip_summed = lro_mgr->ip_summed;
	return 1;
}


static struct sk_buff *lro_gen_skb(struct net_lro_mgr *lro_mgr,
				   struct skb_frag_struct *frags,
				   int len, int true_size,
				   void *mac_hdr,
				   int hlen, __wsum sum,
				   u32 ip_summed)
{
	struct sk_buff *skb;
	struct skb_frag_struct *skb_frags;
	int data_len = len;
	int hdr_len = min(len, hlen);

	skb = netdev_alloc_skb(lro_mgr->dev, hlen + lro_mgr->frag_align_pad);
	if (!skb)
		return NULL;

	skb_reserve(skb, lro_mgr->frag_align_pad);
	skb->len = len;
	skb->data_len = len - hdr_len;
	skb->truesize += true_size;
	skb->tail += hdr_len;

	memcpy(skb->data, mac_hdr, hdr_len);

	skb_frags = skb_shinfo(skb)->frags;
	while (data_len > 0) {
		*skb_frags = *frags;
		data_len -= frags->size;
		skb_frags++;
		frags++;
		skb_shinfo(skb)->nr_frags++;
	}

	skb_shinfo(skb)->frags[0].page_offset += hdr_len;
	skb_shinfo(skb)->frags[0].size -= hdr_len;

	skb->ip_summed = ip_summed;
	skb->csum = sum;
	skb->protocol = eth_type_trans(skb, lro_mgr->dev);
	return skb;
}

static struct sk_buff *__lro_proc_segment(struct net_lro_mgr *lro_mgr,
					  struct skb_frag_struct *frags,
					  int len, int true_size,
					  struct vlan_group *vgrp,
					  u16 vlan_tag, void *priv, __wsum sum)
{
	struct net_lro_desc *lro_desc;
	struct iphdr *iph;
	struct tcphdr *tcph;
	struct sk_buff *skb;
	u64 flags;
	void *mac_hdr;
	int mac_hdr_len;
	int hdr_len = LRO_MAX_PG_HLEN;
	int vlan_hdr_len = 0;

	if (!lro_mgr->get_frag_header
	    || lro_mgr->get_frag_header(frags, (void *)&mac_hdr, (void *)&iph,
					(void *)&tcph, &flags, priv)) {
		mac_hdr = page_address(frags->page) + frags->page_offset;
		goto out1;
	}

	if (!(flags & LRO_IPV4) || !(flags & LRO_TCP))
		goto out1;

	hdr_len = (int)((void *)(tcph) + TCP_HDR_LEN(tcph) - mac_hdr);
	mac_hdr_len = (int)((void *)(iph) - mac_hdr);

	lro_desc = lro_get_desc(lro_mgr, lro_mgr->lro_arr, iph, tcph);
	if (!lro_desc)
		goto out1;

	if (!lro_desc->active) { /* start new lro session */
		if (lro_tcp_ip_check(iph, tcph, len - mac_hdr_len, NULL))
			goto out1;

		skb = lro_gen_skb(lro_mgr, frags, len, true_size, mac_hdr,
				  hdr_len, 0, lro_mgr->ip_summed_aggr);
		if (!skb)
			goto out;

		if ((skb->protocol == htons(ETH_P_8021Q))
		    && !(lro_mgr->features & LRO_F_EXTRACT_VLAN_ID))
			vlan_hdr_len = VLAN_HLEN;

		iph = (void *)(skb->data + vlan_hdr_len);
		tcph = (void *)((u8 *)skb->data + vlan_hdr_len
				+ IP_HDR_LEN(iph));

		lro_init_desc(lro_desc, skb, iph, tcph, 0, NULL);
		LRO_INC_STATS(lro_mgr, aggregated);
		return NULL;
	}

	if (lro_desc->tcp_next_seq != ntohl(tcph->seq))
		goto out2;

	if (lro_tcp_ip_check(iph, tcph, len - mac_hdr_len, lro_desc))
		goto out2;

	lro_add_frags(lro_desc, len, hdr_len, true_size, frags, iph, tcph);
	LRO_INC_STATS(lro_mgr, aggregated);

	if ((skb_shinfo(lro_desc->parent)->nr_frags >= lro_mgr->max_aggr) ||
	    lro_desc->parent->len > (0xFFFF - lro_mgr->dev->mtu))
		lro_flush(lro_mgr, lro_desc);

	return NULL;

out2: /* send aggregated packets to the stack */
	lro_flush(lro_mgr, lro_desc);

out1:  /* Original packet has to be posted to the stack */
	skb = lro_gen_skb(lro_mgr, frags, len, true_size, mac_hdr,
			  hdr_len, sum, lro_mgr->ip_summed);
out:
	return skb;
}

void lro_receive_skb(struct net_lro_mgr *lro_mgr,
		     struct sk_buff *skb,
		     void *priv)
{
	if (__lro_proc_skb(lro_mgr, skb, NULL, 0, priv)) {
		if (lro_mgr->features & LRO_F_NAPI)
			netif_receive_skb(skb);
		else
			netif_rx(skb);
	}
}
EXPORT_SYMBOL(lro_receive_skb);

void lro_vlan_hwaccel_receive_skb(struct net_lro_mgr *lro_mgr,
				  struct sk_buff *skb,
				  struct vlan_group *vgrp,
				  u16 vlan_tag,
				  void *priv)
{
	if (__lro_proc_skb(lro_mgr, skb, vgrp, vlan_tag, priv)) {
		if (lro_mgr->features & LRO_F_NAPI)
			vlan_hwaccel_receive_skb(skb, vgrp, vlan_tag);
		else
			vlan_hwaccel_rx(skb, vgrp, vlan_tag);
	}
}
EXPORT_SYMBOL(lro_vlan_hwaccel_receive_skb);

void lro_receive_frags(struct net_lro_mgr *lro_mgr,
		       struct skb_frag_struct *frags,
		       int len, int true_size, void *priv, __wsum sum)
{
	struct sk_buff *skb;

	skb = __lro_proc_segment(lro_mgr, frags, len, true_size, NULL, 0,
				 priv, sum);
	if (!skb)
		return;

	if (lro_mgr->features & LRO_F_NAPI)
		netif_receive_skb(skb);
	else
		netif_rx(skb);
}
EXPORT_SYMBOL(lro_receive_frags);

void lro_vlan_hwaccel_receive_frags(struct net_lro_mgr *lro_mgr,
				    struct skb_frag_struct *frags,
				    int len, int true_size,
				    struct vlan_group *vgrp,
				    u16 vlan_tag, void *priv, __wsum sum)
{
	struct sk_buff *skb;

	skb = __lro_proc_segment(lro_mgr, frags, len, true_size, vgrp,
				 vlan_tag, priv, sum);
	if (!skb)
		return;

	if (lro_mgr->features & LRO_F_NAPI)
		vlan_hwaccel_receive_skb(skb, vgrp, vlan_tag);
	else
		vlan_hwaccel_rx(skb, vgrp, vlan_tag);
}
EXPORT_SYMBOL(lro_vlan_hwaccel_receive_frags);

void lro_flush_all(struct net_lro_mgr *lro_mgr)
{
	int i;
	struct net_lro_desc *lro_desc = lro_mgr->lro_arr;

	for (i = 0; i < lro_mgr->max_desc; i++) {
		if (lro_desc[i].active)
			lro_flush(lro_mgr, &lro_desc[i]);
	}
}
EXPORT_SYMBOL(lro_flush_all);

void lro_flush_pkt(struct net_lro_mgr *lro_mgr,
		  struct iphdr *iph, struct tcphdr *tcph)
{
	struct net_lro_desc *lro_desc;

	lro_desc = lro_get_desc(lro_mgr, lro_mgr->lro_arr, iph, tcph);
	if (lro_desc->active)
		lro_flush(lro_mgr, lro_desc);
}
EXPORT_SYMBOL(lro_flush_pkt);