sfe_ipv4_tun6rd.c - codeaurora/qca-nss-sfe - Gitiles

 /*
  * sfe_ipv4_tun6rd.c
  *	Shortcut forwarding engine file for IPv4 TUN6RD
  *
  * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */

 #include <linux/skbuff.h>
 #include <linux/etherdevice.h>
 #include <linux/version.h>
 #include <net/protocol.h>
 #include <net/ip.h>

 #include "sfe_debug.h"
 #include "sfe_api.h"
 #include "sfe.h"
 #include "sfe_flow_cookie.h"
 #include "sfe_ipv4.h"
 #include "sfe_vlan.h"

 /*
  * sfe_ipv4_recv_tun6rd()
  *	Handle TUN6RD packet receives and forwarding.
  */
 int sfe_ipv4_recv_tun6rd(struct sfe_ipv4 *si, struct sk_buff *skb, struct net_device *dev,
 			     unsigned int len, struct iphdr *iph, unsigned int ihl,
 				 bool sync_on_find, struct sfe_l2_info *l2_info, bool tun_outer)
 {
 	__be32 src_ip;
 	__be32 dest_ip;
 	__be16 src_port = 0;
 	__be16 dest_port = 0;
 	struct sfe_ipv4_connection_match *cm;

 	DEBUG_TRACE("%px: sfe: sfe_ipv4_recv_tun6rd called.\n", skb);

 	/*
 	 * Read the IP address information. Read the IP header data first
 	 * because we've almost certainly got that in the cache.
 	 */
 	src_ip = iph->saddr;
 	dest_ip = iph->daddr;

 	rcu_read_lock();

 	/*
 	 * Look for a connection match.
 	 */
 #ifdef CONFIG_NF_FLOW_COOKIE
 	cm = si->sfe_flow_cookie_table[skb->flow_cookie & SFE_FLOW_COOKIE_MASK].match;
 	if (unlikely(!cm)) {
 		cm = sfe_ipv4_find_connection_match_rcu(si, dev, IPPROTO_IPV6, src_ip, src_port, dest_ip, dest_port);
 	}
 #else
 	cm = sfe_ipv4_find_connection_match_rcu(si, dev, IPPROTO_IPV6, src_ip, src_port, dest_ip, dest_port);
 #endif
 	if (unlikely(!cm)) {
 		rcu_read_unlock();
 		sfe_ipv4_exception_stats_inc(si, SFE_IPV4_EXCEPTION_EVENT_TUN6RD_NO_CONNECTION);
 		DEBUG_TRACE("%px: no tun6rd connection found\n", skb);
 		return 0;
 	}

 	/*
 	 * If our packet has been marked as "sync on find" we will sync the status
 	 * and forward it to slowpath.
 	 */
 	if (unlikely(sync_on_find)) {
 		sfe_ipv4_sync_status(si, cm->connection, SFE_SYNC_REASON_STATS);
 		rcu_read_unlock();
 		sfe_ipv4_exception_stats_inc(si, SFE_IPV4_EXCEPTION_EVENT_TUN6RD_SYNC_ON_FIND);
 		DEBUG_TRACE("%px: Sync on find\n", skb);

 		return 0;
 	}

 	/*
 	 * If cm->proto is set, it means the decap path.
 	 * Otherwise we forward the packet in encap path.
 	 */
 	if(cm->proto) {
 #if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 13, 0))
 		const struct net_protocol *ipprot = cm->proto;
 #else
 		struct net_protocol *ipprot = cm->proto;
 #endif

 		/*
 		 * Do we expect an ingress VLAN tag for this flow?
 		 * Note: We will only have ingress tag check in decap direction.
 		 * Here, no modification is needed, we only check tag match between
 		 * vlan hdr stored in cm and l2_info.
 		 */
 		if (unlikely(!sfe_vlan_validate_ingress_tag(skb, cm->ingress_vlan_hdr_cnt, cm->ingress_vlan_hdr, l2_info))) {
 			rcu_read_unlock();
 			sfe_ipv4_exception_stats_inc(si, SFE_IPV4_EXCEPTION_EVENT_INGRESS_VLAN_TAG_MISMATCH);
 			DEBUG_TRACE("VLAN tag mismatch. skb=%px\n"
 				"cm: %u [0]=%x/%x [1]=%x/%x\n"
 				"l2_info+: %u [0]=%x/%x [1]=%x/%x\n", skb,
 				cm->ingress_vlan_hdr_cnt,
 				htons(cm->ingress_vlan_hdr[0].tpid), cm->ingress_vlan_hdr[0].tci,
 				htons(cm->ingress_vlan_hdr[1].tpid), cm->ingress_vlan_hdr[1].tci,
 				l2_info->vlan_hdr_cnt,
 				htons(l2_info->vlan_hdr[0].tpid), l2_info->vlan_hdr[0].tci,
 				htons(l2_info->vlan_hdr[1].tpid), l2_info->vlan_hdr[1].tci);
 			return 0;
 		}
 		skb_reset_network_header(skb);
 		skb_pull(skb, ihl);
 		skb_reset_transport_header(skb);

 		/*
 		 * ipprot->handler(skb) will always return 0;
 		 * There is no way to tell whether the packet is dropped later in linux or not.
 		 * Hence here inc the byte/packet count always.
 		 */
 		atomic_inc(&cm->rx_packet_count);
 		atomic_add(len, &cm->rx_byte_count);
 		rcu_read_unlock();
 		this_cpu_inc(si->stats_pcpu->packets_forwarded64);
 		DEBUG_TRACE("%px: %s decap done \n", skb, __func__);

 		/*
 		 * Update top interface for tunnel searching.
 		 */
 		skb->dev = cm->top_interface_dev;
 		ipprot->handler(skb);
 		return 1;

 	}

 	/*
 	 * If our packet is larger than the MTU of the transmit interface then
 	 * we can't forward it easily.
 	 */
 	if (unlikely(len > cm->xmit_dev_mtu)) {
 		sfe_ipv4_sync_status(si, cm->connection, SFE_SYNC_REASON_STATS);
 		rcu_read_unlock();

 		sfe_ipv4_exception_stats_inc(si, SFE_IPV4_EXCEPTION_EVENT_TUN6RD_NEEDS_FRAGMENTATION);
 		DEBUG_TRACE("%px: Larger than mtu\n", skb);
 		return 0;
 	}

 	/*
 	 * Update DSCP
 	 */
 	if (unlikely(cm->flags & SFE_IPV4_CONNECTION_MATCH_FLAG_DSCP_REMARK)) {
 		iph->tos = (iph->tos & SFE_IPV4_DSCP_MASK) | cm->dscp;
 	}

 	/*
 	 * Update traffic stats.
 	 */
 	atomic_inc(&cm->rx_packet_count);
 	atomic_add(len, &cm->rx_byte_count);

 	skb->dev = cm->xmit_dev;

 	/*
 	 * Check to see if we need to add VLAN tags
 	 */
 	if (unlikely(cm->flags & SFE_IPV4_CONNECTION_MATCH_FLAG_INSERT_EGRESS_VLAN_TAG)) {

 		/*
 		 * Check if skb has enough headroom to write L2 headers
 		 */
 		if (unlikely(skb_headroom(skb) < cm->l2_hdr_size)) {
 			rcu_read_unlock();
 			DEBUG_WARN("%px: Not enough headroom: %u\n", skb, skb_headroom(skb));
 			sfe_ipv4_exception_stats_inc(si, SFE_IPV4_EXCEPTION_EVENT_NO_HEADROOM);
 			return 0;
 		}
 		sfe_vlan_add_tag(skb, cm->egress_vlan_hdr_cnt, cm->egress_vlan_hdr);
 	}

 	/*
 	 * Check to see if we need to write a header.
 	 */
 	if (likely(cm->flags & SFE_IPV4_CONNECTION_MATCH_FLAG_WRITE_L2_HDR)) {
 		if (unlikely(!(cm->flags & SFE_IPV4_CONNECTION_MATCH_FLAG_WRITE_FAST_ETH_HDR))) {
 			dev_hard_header(skb, cm->xmit_dev, ntohs(skb->protocol),
 					cm->xmit_dest_mac, cm->xmit_src_mac, len);
 		} else {
 			struct ethhdr *eth = (struct ethhdr *)__skb_push(skb, ETH_HLEN);
 			eth->h_proto = skb->protocol;
 			ether_addr_copy((u8 *)eth->h_dest, (u8 *)cm->xmit_dest_mac);
 			ether_addr_copy((u8 *)eth->h_source, (u8 *)cm->xmit_src_mac);
 		}
 	}

 	/*
 	 * Update priority of skb.
 	 */
 	if (unlikely(cm->flags & SFE_IPV4_CONNECTION_MATCH_FLAG_PRIORITY_REMARK)) {
 		skb->priority = cm->priority;
 	}

 	/*
 	 * Mark outgoing packet.
 	 */
 	if (unlikely(cm->flags & SFE_IPV4_CONNECTION_MATCH_FLAG_MARK)) {
 		skb->mark = cm->mark;
 	}

 	rcu_read_unlock();

 	this_cpu_inc(si->stats_pcpu->packets_forwarded64);

 	/*
 	 * We're going to check for GSO flags when we transmit the packet so
 	 * start fetching the necessary cache line now.
 	 */
 	prefetch(skb_shinfo(skb));

 	/*
 	 * Mark that this packet has been fast forwarded and send it on its way.
 	 */
 	skb->fast_forwarded = 1;
 	dev_queue_xmit(skb);

 	return 1;
 }
	/*
	* sfe_ipv4_tun6rd.c
	* Shortcut forwarding engine file for IPv4 TUN6RD
	*
	* Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
	*
	* Permission to use, copy, modify, and/or distribute this software for any
	* purpose with or without fee is hereby granted, provided that the above
	* copyright notice and this permission notice appear in all copies.
	*
	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	*/

	#include <linux/skbuff.h>
	#include <linux/etherdevice.h>
	#include <linux/version.h>
	#include <net/protocol.h>
	#include <net/ip.h>

	#include "sfe_debug.h"
	#include "sfe_api.h"
	#include "sfe.h"
	#include "sfe_flow_cookie.h"
	#include "sfe_ipv4.h"
	#include "sfe_vlan.h"

	/*
	* sfe_ipv4_recv_tun6rd()
	* Handle TUN6RD packet receives and forwarding.
	*/
	int sfe_ipv4_recv_tun6rd(struct sfe_ipv4 si, struct sk_buff skb, struct net_device *dev,
	unsigned int len, struct iphdr *iph, unsigned int ihl,
	bool sync_on_find, struct sfe_l2_info *l2_info, bool tun_outer)
	{
	__be32 src_ip;
	__be32 dest_ip;
	__be16 src_port = 0;
	__be16 dest_port = 0;
	struct sfe_ipv4_connection_match *cm;

	DEBUG_TRACE("%px: sfe: sfe_ipv4_recv_tun6rd called.\n", skb);

	/*
	* Read the IP address information. Read the IP header data first
	* because we've almost certainly got that in the cache.
	*/
	src_ip = iph->saddr;
	dest_ip = iph->daddr;

	rcu_read_lock();

	/*
	* Look for a connection match.
	*/
	#ifdef CONFIG_NF_FLOW_COOKIE
	cm = si->sfe_flow_cookie_table[skb->flow_cookie & SFE_FLOW_COOKIE_MASK].match;
	if (unlikely(!cm)) {
	cm = sfe_ipv4_find_connection_match_rcu(si, dev, IPPROTO_IPV6, src_ip, src_port, dest_ip, dest_port);
	}
	#else
	cm = sfe_ipv4_find_connection_match_rcu(si, dev, IPPROTO_IPV6, src_ip, src_port, dest_ip, dest_port);
	#endif
	if (unlikely(!cm)) {
	rcu_read_unlock();
	sfe_ipv4_exception_stats_inc(si, SFE_IPV4_EXCEPTION_EVENT_TUN6RD_NO_CONNECTION);
	DEBUG_TRACE("%px: no tun6rd connection found\n", skb);
	return 0;
	}

	/*
	* If our packet has been marked as "sync on find" we will sync the status
	* and forward it to slowpath.
	*/
	if (unlikely(sync_on_find)) {
	sfe_ipv4_sync_status(si, cm->connection, SFE_SYNC_REASON_STATS);
	rcu_read_unlock();
	sfe_ipv4_exception_stats_inc(si, SFE_IPV4_EXCEPTION_EVENT_TUN6RD_SYNC_ON_FIND);
	DEBUG_TRACE("%px: Sync on find\n", skb);

	return 0;
	}

	/*
	* If cm->proto is set, it means the decap path.
	* Otherwise we forward the packet in encap path.
	*/
	if(cm->proto) {
	#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 13, 0))
	const struct net_protocol *ipprot = cm->proto;
	#else
	struct net_protocol *ipprot = cm->proto;
	#endif

	/*
	* Do we expect an ingress VLAN tag for this flow?
	* Note: We will only have ingress tag check in decap direction.
	* Here, no modification is needed, we only check tag match between
	* vlan hdr stored in cm and l2_info.
	*/
	if (unlikely(!sfe_vlan_validate_ingress_tag(skb, cm->ingress_vlan_hdr_cnt, cm->ingress_vlan_hdr, l2_info))) {
	rcu_read_unlock();
	sfe_ipv4_exception_stats_inc(si, SFE_IPV4_EXCEPTION_EVENT_INGRESS_VLAN_TAG_MISMATCH);
	DEBUG_TRACE("VLAN tag mismatch. skb=%px\n"
	"cm: %u [0]=%x/%x [1]=%x/%x\n"
	"l2_info+: %u [0]=%x/%x [1]=%x/%x\n", skb,
	cm->ingress_vlan_hdr_cnt,
	htons(cm->ingress_vlan_hdr[0].tpid), cm->ingress_vlan_hdr[0].tci,
	htons(cm->ingress_vlan_hdr[1].tpid), cm->ingress_vlan_hdr[1].tci,
	l2_info->vlan_hdr_cnt,
	htons(l2_info->vlan_hdr[0].tpid), l2_info->vlan_hdr[0].tci,
	htons(l2_info->vlan_hdr[1].tpid), l2_info->vlan_hdr[1].tci);
	return 0;
	}
	skb_reset_network_header(skb);
	skb_pull(skb, ihl);
	skb_reset_transport_header(skb);

	/*
	* ipprot->handler(skb) will always return 0;
	* There is no way to tell whether the packet is dropped later in linux or not.
	* Hence here inc the byte/packet count always.
	*/
	atomic_inc(&cm->rx_packet_count);
	atomic_add(len, &cm->rx_byte_count);
	rcu_read_unlock();
	this_cpu_inc(si->stats_pcpu->packets_forwarded64);
	DEBUG_TRACE("%px: %s decap done \n", skb, __func__);

	/*
	* Update top interface for tunnel searching.
	*/
	skb->dev = cm->top_interface_dev;
	ipprot->handler(skb);
	return 1;

	}

	/*
	* If our packet is larger than the MTU of the transmit interface then
	* we can't forward it easily.
	*/
	if (unlikely(len > cm->xmit_dev_mtu)) {
	sfe_ipv4_sync_status(si, cm->connection, SFE_SYNC_REASON_STATS);
	rcu_read_unlock();

	sfe_ipv4_exception_stats_inc(si, SFE_IPV4_EXCEPTION_EVENT_TUN6RD_NEEDS_FRAGMENTATION);
	DEBUG_TRACE("%px: Larger than mtu\n", skb);
	return 0;
	}

	/*
	* Update DSCP
	*/
	if (unlikely(cm->flags & SFE_IPV4_CONNECTION_MATCH_FLAG_DSCP_REMARK)) {
	iph->tos = (iph->tos & SFE_IPV4_DSCP_MASK) \| cm->dscp;
	}

	/*
	* Update traffic stats.
	*/
	atomic_inc(&cm->rx_packet_count);
	atomic_add(len, &cm->rx_byte_count);

	skb->dev = cm->xmit_dev;

	/*
	* Check to see if we need to add VLAN tags
	*/
	if (unlikely(cm->flags & SFE_IPV4_CONNECTION_MATCH_FLAG_INSERT_EGRESS_VLAN_TAG)) {

	/*
	* Check if skb has enough headroom to write L2 headers
	*/
	if (unlikely(skb_headroom(skb) < cm->l2_hdr_size)) {
	rcu_read_unlock();
	DEBUG_WARN("%px: Not enough headroom: %u\n", skb, skb_headroom(skb));
	sfe_ipv4_exception_stats_inc(si, SFE_IPV4_EXCEPTION_EVENT_NO_HEADROOM);
	return 0;
	}
	sfe_vlan_add_tag(skb, cm->egress_vlan_hdr_cnt, cm->egress_vlan_hdr);
	}

	/*
	* Check to see if we need to write a header.
	*/
	if (likely(cm->flags & SFE_IPV4_CONNECTION_MATCH_FLAG_WRITE_L2_HDR)) {
	if (unlikely(!(cm->flags & SFE_IPV4_CONNECTION_MATCH_FLAG_WRITE_FAST_ETH_HDR))) {
	dev_hard_header(skb, cm->xmit_dev, ntohs(skb->protocol),
	cm->xmit_dest_mac, cm->xmit_src_mac, len);
	} else {
	struct ethhdr eth = (struct ethhdr )__skb_push(skb, ETH_HLEN);
	eth->h_proto = skb->protocol;
	ether_addr_copy((u8 )eth->h_dest, (u8 )cm->xmit_dest_mac);
	ether_addr_copy((u8 )eth->h_source, (u8 )cm->xmit_src_mac);
	}
	}

	/*
	* Update priority of skb.
	*/
	if (unlikely(cm->flags & SFE_IPV4_CONNECTION_MATCH_FLAG_PRIORITY_REMARK)) {
	skb->priority = cm->priority;
	}

	/*
	* Mark outgoing packet.
	*/
	if (unlikely(cm->flags & SFE_IPV4_CONNECTION_MATCH_FLAG_MARK)) {
	skb->mark = cm->mark;
	}

	rcu_read_unlock();

	this_cpu_inc(si->stats_pcpu->packets_forwarded64);

	/*
	* We're going to check for GSO flags when we transmit the packet so
	* start fetching the necessary cache line now.
	*/
	prefetch(skb_shinfo(skb));

	/*
	* Mark that this packet has been fast forwarded and send it on its way.
	*/
	skb->fast_forwarded = 1;
	dev_queue_xmit(skb);

	return 1;
	}