Commit b2e653bc authored by Petr Machata's avatar Petr Machata Committed by Jakub Kicinski
Browse files

net: ipv4: ipmr: Split ipmr_queue_xmit() in two 



Some of the work of ipmr_queue_xmit() is specific to IPMR forwarding, and
should not take place on the output path. In order to allow reuse of the
common parts, split the function into two: the ipmr_prepare_xmit() helper
that takes care of the common bits, and the ipmr_queue_fwd_xmit(), which
invokes the former and encapsulates the whole forwarding algorithm.

Signed-off-by: default avatarPetr Machata <petrm@nvidia.com>
Reviewed-by: default avatarIdo Schimmel <idosch@nvidia.com>
Reviewed-by: default avatarNikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/4e8db165572a4f8bd29a723a801e854e9d20df4d.1750113335.git.petrm@nvidia.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 3b7bc938

net/ipv4/ipmr.c

+29 −16
Original line number Diff line number Diff line
@@ -1853,8 +1853,8 @@ static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt, 


/* Processing handlers for ipmr_forward, under rcu_read_lock() */



static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,

			    int in_vifi, struct sk_buff *skb, int vifi)

static int ipmr_prepare_xmit(struct net *net, struct mr_table *mrt,

			     struct sk_buff *skb, int vifi)

{

	const struct iphdr *iph = ip_hdr(skb);

	struct vif_device *vif = &mrt->vif_table[vifi];
@@ -1865,7 +1865,7 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt, 


	vif_dev = vif_dev_read(vif);

	if (!vif_dev)

		goto out_free;

		return -1;



	if (vif->flags & VIFF_REGISTER) {

		WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
@@ -1873,12 +1873,9 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt, 
		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);

		DEV_STATS_INC(vif_dev, tx_packets);

		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);

		goto out_free;

		return -1;

	}



	if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi))

		goto out_free;



	if (vif->flags & VIFF_TUNNEL) {

		rt = ip_route_output_ports(net, &fl4, NULL,

					   vif->remote, vif->local,
@@ -1886,7 +1883,7 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt, 
					   IPPROTO_IPIP,

					   iph->tos & INET_DSCP_MASK, vif->link);

		if (IS_ERR(rt))

			goto out_free;

			return -1;

		encap = sizeof(struct iphdr);

	} else {

		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
@@ -1894,7 +1891,7 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt, 
					   IPPROTO_IPIP,

					   iph->tos & INET_DSCP_MASK, vif->link);

		if (IS_ERR(rt))

			goto out_free;

			return -1;

	}



	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
@@ -1904,14 +1901,14 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt, 
		 */

		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);

		ip_rt_put(rt);

		goto out_free;

		return -1;

	}



	encap += LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len;



	if (skb_cow(skb, encap)) {

		ip_rt_put(rt);

		goto out_free;

		return -1;

	}



	WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
@@ -1931,6 +1928,22 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt, 
		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);

	}



	return 0;

}



static void ipmr_queue_fwd_xmit(struct net *net, struct mr_table *mrt,

				int in_vifi, struct sk_buff *skb, int vifi)

{

	struct rtable *rt;



	if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi))

		goto out_free;



	if (ipmr_prepare_xmit(net, mrt, skb, vifi))

		goto out_free;



	rt = skb_rtable(skb);



	IPCB(skb)->flags |= IPSKB_FORWARDED;



	/* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
@@ -2062,7 +2075,7 @@ static void ip_mr_forward(struct net *net, struct mr_table *mrt, 
				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);



				if (skb2)

					ipmr_queue_xmit(net, mrt, true_vifi,

					ipmr_queue_fwd_xmit(net, mrt, true_vifi,

							    skb2, psend);

			}

			psend = ct;
@@ -2074,10 +2087,10 @@ static void ip_mr_forward(struct net *net, struct mr_table *mrt, 
			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);



			if (skb2)

				ipmr_queue_xmit(net, mrt, true_vifi, skb2,

				ipmr_queue_fwd_xmit(net, mrt, true_vifi, skb2,

						    psend);

		} else {

			ipmr_queue_xmit(net, mrt, true_vifi, skb, psend);

			ipmr_queue_fwd_xmit(net, mrt, true_vifi, skb, psend);

			return;

		}

	}