sfe_ipv6_icmp.c - codeaurora/qca-nss-sfe - Gitiles

 /*
  * sfe_ipv6_icmp.c
  *	Shortcut forwarding engine file for IPv6 ICMP
  *
  * Copyright (c) 2015-2016, 2019-2020, The Linux Foundation. All rights reserved.
  * Copyright (c) 2021 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/ip.h>
 #include <net/udp.h>
 #include <net/tcp.h>
 #include <net/icmp.h>
 #include <linux/etherdevice.h>
 #include <linux/version.h>

 #include "sfe_debug.h"
 #include "sfe_api.h"
 #include "sfe.h"
 #include "sfe_flow_cookie.h"
 #include "sfe_ipv6.h"

 /*
  * sfe_ipv6_recv_icmp()
  *	Handle ICMP packet receives.
  *
  * ICMP packets aren't handled as a "fast path" and always have us process them
  * through the default Linux stack.  What we do need to do is look for any errors
  * about connections we are handling in the fast path.  If we find any such
  * connections then we want to flush their state so that the ICMP error path
  * within Linux has all of the correct state should it need it.
  */
 int sfe_ipv6_recv_icmp(struct sfe_ipv6 *si, struct sk_buff *skb, struct net_device *dev,
 			      unsigned int len, struct ipv6hdr *iph, unsigned int ihl)
 {
 	struct icmp6hdr *icmph;
 	struct ipv6hdr *icmp_iph;
 	struct udphdr *icmp_udph;
 	struct tcphdr *icmp_tcph;
 	struct sfe_ipv6_addr *src_ip;
 	struct sfe_ipv6_addr *dest_ip;
 	__be16 src_port;
 	__be16 dest_port;
 	struct sfe_ipv6_connection_match *cm;
 	struct sfe_ipv6_connection *c;
 	u8 next_hdr;
 	bool ret;

 	/*
 	 * Is our packet too short to contain a valid ICMP header?
 	 */
 	len -= ihl;
 	if (!pskb_may_pull(skb, ihl + sizeof(struct icmp6hdr))) {
 		sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_HEADER_INCOMPLETE);

 		DEBUG_TRACE("packet too short for ICMP header\n");
 		return 0;
 	}

 	/*
 	 * We only handle "destination unreachable" and "time exceeded" messages.
 	 */
 	icmph = (struct icmp6hdr *)(skb->data + ihl);
 	if ((icmph->icmp6_type != ICMPV6_DEST_UNREACH)
 	    && (icmph->icmp6_type != ICMPV6_TIME_EXCEED)) {

 		sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_UNHANDLED_TYPE);
 		DEBUG_TRACE("unhandled ICMP type: 0x%x\n", icmph->icmp6_type);
 		return 0;
 	}

 	/*
 	 * Do we have the full embedded IP header?
 	 * We should have 8 bytes of next L4 header - that's enough to identify
 	 * the connection.
 	 */
 	len -= sizeof(struct icmp6hdr);
 	ihl += sizeof(struct icmp6hdr);
 	if (!pskb_may_pull(skb, ihl + sizeof(struct ipv6hdr) + sizeof(struct sfe_ipv6_ext_hdr))) {

 		sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_IPV6_HEADER_INCOMPLETE);
 		DEBUG_TRACE("Embedded IP header not complete\n");
 		return 0;
 	}

 	/*
 	 * Is our embedded IP version wrong?
 	 */
 	icmp_iph = (struct ipv6hdr *)(icmph + 1);
 	if (unlikely(icmp_iph->version != 6)) {

 		sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_IPV6_NON_V6);
 		DEBUG_TRACE("IP version: %u\n", icmp_iph->version);
 		return 0;
 	}

 	len -= sizeof(struct ipv6hdr);
 	ihl += sizeof(struct ipv6hdr);
 	next_hdr = icmp_iph->nexthdr;
 	while (unlikely(sfe_ipv6_is_ext_hdr(next_hdr))) {
 		struct sfe_ipv6_ext_hdr *ext_hdr;
 		unsigned int ext_hdr_len;

 		ext_hdr = (struct sfe_ipv6_ext_hdr *)(skb->data + ihl);
 		if (next_hdr == NEXTHDR_FRAGMENT) {
 			struct frag_hdr *frag_hdr = (struct frag_hdr *)ext_hdr;
 			unsigned int frag_off = ntohs(frag_hdr->frag_off);

 			if (frag_off & SFE_IPV6_FRAG_OFFSET) {

 				DEBUG_TRACE("non-initial fragment\n");
 				sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_NON_INITIAL_FRAGMENT);
 				return 0;
 			}
 		}

 		ext_hdr_len = ext_hdr->hdr_len;
 		ext_hdr_len <<= 3;
 		ext_hdr_len += sizeof(struct sfe_ipv6_ext_hdr);
 		len -= ext_hdr_len;
 		ihl += ext_hdr_len;
 		/*
 		 * We should have 8 bytes of next header - that's enough to identify
 		 * the connection.
 		 */
 		if (!pskb_may_pull(skb, ihl + sizeof(struct sfe_ipv6_ext_hdr))) {

 			sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_HEADER_INCOMPLETE);
 			DEBUG_TRACE("extension header %d not completed\n", next_hdr);
 			return 0;
 		}

 		next_hdr = ext_hdr->next_hdr;
 	}

 	/*
 	 * Handle the embedded transport layer header.
 	 */
 	switch (next_hdr) {
 	case IPPROTO_UDP:
 		icmp_udph = (struct udphdr *)(skb->data + ihl);
 		src_port = icmp_udph->source;
 		dest_port = icmp_udph->dest;
 		break;

 	case IPPROTO_TCP:
 		icmp_tcph = (struct tcphdr *)(skb->data + ihl);
 		src_port = icmp_tcph->source;
 		dest_port = icmp_tcph->dest;
 		break;

 	default:

 		sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_IPV6_UNHANDLED_PROTOCOL);
 		DEBUG_TRACE("Unhandled embedded IP protocol: %u\n", next_hdr);
 		return 0;
 	}

 	src_ip = (struct sfe_ipv6_addr *)icmp_iph->saddr.s6_addr32;
 	dest_ip = (struct sfe_ipv6_addr *)icmp_iph->daddr.s6_addr32;

 	rcu_read_lock();
 	/*
 	 * Look for a connection match.  Note that we reverse the source and destination
 	 * here because our embedded message contains a packet that was sent in the
 	 * opposite direction to the one in which we just received it.  It will have
 	 * been sent on the interface from which we received it though so that's still
 	 * ok to use.
 	 */
 	cm = sfe_ipv6_find_connection_match_rcu(si, dev, icmp_iph->nexthdr, dest_ip, dest_port, src_ip, src_port);
 	if (unlikely(!cm)) {
 		rcu_read_unlock();
 		sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_NO_CONNECTION);
 		DEBUG_TRACE("no connection found\n");
 		return 0;
 	}

 	/*
 	 * We found a connection so now remove it from the connection list and flush
 	 * its state.
 	 */
 	c = cm->connection;
 	spin_lock_bh(&si->lock);
 	ret = sfe_ipv6_remove_connection(si, c);
 	spin_unlock_bh(&si->lock);

 	if (ret) {
 		sfe_ipv6_flush_connection(si, c, SFE_SYNC_REASON_FLUSH);
 	}

 	rcu_read_unlock();

 	sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_FLUSHED_CONNECTION);
 	return 0;
 }
	/*
	* sfe_ipv6_icmp.c
	* Shortcut forwarding engine file for IPv6 ICMP
	*
	* Copyright (c) 2015-2016, 2019-2020, The Linux Foundation. All rights reserved.
	* Copyright (c) 2021 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/ip.h>
	#include <net/udp.h>
	#include <net/tcp.h>
	#include <net/icmp.h>
	#include <linux/etherdevice.h>
	#include <linux/version.h>

	#include "sfe_debug.h"
	#include "sfe_api.h"
	#include "sfe.h"
	#include "sfe_flow_cookie.h"
	#include "sfe_ipv6.h"

	/*
	* sfe_ipv6_recv_icmp()
	* Handle ICMP packet receives.
	*
	* ICMP packets aren't handled as a "fast path" and always have us process them
	* through the default Linux stack. What we do need to do is look for any errors
	* about connections we are handling in the fast path. If we find any such
	* connections then we want to flush their state so that the ICMP error path
	* within Linux has all of the correct state should it need it.
	*/
	int sfe_ipv6_recv_icmp(struct sfe_ipv6 si, struct sk_buff skb, struct net_device *dev,
	unsigned int len, struct ipv6hdr *iph, unsigned int ihl)
	{
	struct icmp6hdr *icmph;
	struct ipv6hdr *icmp_iph;
	struct udphdr *icmp_udph;
	struct tcphdr *icmp_tcph;
	struct sfe_ipv6_addr *src_ip;
	struct sfe_ipv6_addr *dest_ip;
	__be16 src_port;
	__be16 dest_port;
	struct sfe_ipv6_connection_match *cm;
	struct sfe_ipv6_connection *c;
	u8 next_hdr;
	bool ret;

	/*
	* Is our packet too short to contain a valid ICMP header?
	*/
	len -= ihl;
	if (!pskb_may_pull(skb, ihl + sizeof(struct icmp6hdr))) {
	sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_HEADER_INCOMPLETE);

	DEBUG_TRACE("packet too short for ICMP header\n");
	return 0;
	}

	/*
	* We only handle "destination unreachable" and "time exceeded" messages.
	*/
	icmph = (struct icmp6hdr *)(skb->data + ihl);
	if ((icmph->icmp6_type != ICMPV6_DEST_UNREACH)
	&& (icmph->icmp6_type != ICMPV6_TIME_EXCEED)) {

	sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_UNHANDLED_TYPE);
	DEBUG_TRACE("unhandled ICMP type: 0x%x\n", icmph->icmp6_type);
	return 0;
	}

	/*
	* Do we have the full embedded IP header?
	* We should have 8 bytes of next L4 header - that's enough to identify
	* the connection.
	*/
	len -= sizeof(struct icmp6hdr);
	ihl += sizeof(struct icmp6hdr);
	if (!pskb_may_pull(skb, ihl + sizeof(struct ipv6hdr) + sizeof(struct sfe_ipv6_ext_hdr))) {

	sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_IPV6_HEADER_INCOMPLETE);
	DEBUG_TRACE("Embedded IP header not complete\n");
	return 0;
	}

	/*
	* Is our embedded IP version wrong?
	*/
	icmp_iph = (struct ipv6hdr *)(icmph + 1);
	if (unlikely(icmp_iph->version != 6)) {

	sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_IPV6_NON_V6);
	DEBUG_TRACE("IP version: %u\n", icmp_iph->version);
	return 0;
	}

	len -= sizeof(struct ipv6hdr);
	ihl += sizeof(struct ipv6hdr);
	next_hdr = icmp_iph->nexthdr;
	while (unlikely(sfe_ipv6_is_ext_hdr(next_hdr))) {
	struct sfe_ipv6_ext_hdr *ext_hdr;
	unsigned int ext_hdr_len;

	ext_hdr = (struct sfe_ipv6_ext_hdr *)(skb->data + ihl);
	if (next_hdr == NEXTHDR_FRAGMENT) {
	struct frag_hdr frag_hdr = (struct frag_hdr )ext_hdr;
	unsigned int frag_off = ntohs(frag_hdr->frag_off);

	if (frag_off & SFE_IPV6_FRAG_OFFSET) {

	DEBUG_TRACE("non-initial fragment\n");
	sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_NON_INITIAL_FRAGMENT);
	return 0;
	}
	}

	ext_hdr_len = ext_hdr->hdr_len;
	ext_hdr_len <<= 3;
	ext_hdr_len += sizeof(struct sfe_ipv6_ext_hdr);
	len -= ext_hdr_len;
	ihl += ext_hdr_len;
	/*
	* We should have 8 bytes of next header - that's enough to identify
	* the connection.
	*/
	if (!pskb_may_pull(skb, ihl + sizeof(struct sfe_ipv6_ext_hdr))) {

	sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_HEADER_INCOMPLETE);
	DEBUG_TRACE("extension header %d not completed\n", next_hdr);
	return 0;
	}

	next_hdr = ext_hdr->next_hdr;
	}

	/*
	* Handle the embedded transport layer header.
	*/
	switch (next_hdr) {
	case IPPROTO_UDP:
	icmp_udph = (struct udphdr *)(skb->data + ihl);
	src_port = icmp_udph->source;
	dest_port = icmp_udph->dest;
	break;

	case IPPROTO_TCP:
	icmp_tcph = (struct tcphdr *)(skb->data + ihl);
	src_port = icmp_tcph->source;
	dest_port = icmp_tcph->dest;
	break;

	default:

	sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_IPV6_UNHANDLED_PROTOCOL);
	DEBUG_TRACE("Unhandled embedded IP protocol: %u\n", next_hdr);
	return 0;
	}

	src_ip = (struct sfe_ipv6_addr *)icmp_iph->saddr.s6_addr32;
	dest_ip = (struct sfe_ipv6_addr *)icmp_iph->daddr.s6_addr32;

	rcu_read_lock();
	/*
	* Look for a connection match. Note that we reverse the source and destination
	* here because our embedded message contains a packet that was sent in the
	* opposite direction to the one in which we just received it. It will have
	* been sent on the interface from which we received it though so that's still
	* ok to use.
	*/
	cm = sfe_ipv6_find_connection_match_rcu(si, dev, icmp_iph->nexthdr, dest_ip, dest_port, src_ip, src_port);
	if (unlikely(!cm)) {
	rcu_read_unlock();
	sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_NO_CONNECTION);
	DEBUG_TRACE("no connection found\n");
	return 0;
	}

	/*
	* We found a connection so now remove it from the connection list and flush
	* its state.
	*/
	c = cm->connection;
	spin_lock_bh(&si->lock);
	ret = sfe_ipv6_remove_connection(si, c);
	spin_unlock_bh(&si->lock);

	if (ret) {
	sfe_ipv6_flush_connection(si, c, SFE_SYNC_REASON_FLUSH);
	}

	rcu_read_unlock();

	sfe_ipv6_exception_stats_inc(si, SFE_IPV6_EXCEPTION_EVENT_ICMP_FLUSHED_CONNECTION);
	return 0;
	}