text: /*
   * Copyright (c) 2016 Chelsio Communications, Inc. All rights reserved.
   *
   * This software is available to you under a choice of one of two
   * licenses.  You may choose to be licensed under the terms of the GNU
   * General Public License (GPL) Version 2, available from the file
   * COPYING in the main directory of this source tree, or the
   * OpenIB.org BSD license below:
   *
   *     Redistribution and use in source and binary forms, with or
   *     without modification, are permitted provided that the following
   *     conditions are met:
   *
   *      - Redistributions of source code must retain the above
   *	  copyright notice, this list of conditions and the following
   *	  disclaimer.
   *
   *      - Redistributions in binary form must reproduce the above
   *	  copyright notice, this list of conditions and the following
   *	  disclaimer in the documentation and/or other materials
   *	  provided with the distribution.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
   * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
   * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  #include <linux/tcp.h>
  #include <linux/ipv6.h>
  #include <net/route.h>
  #include <net/ip6_route.h>
  
  #include "libcxgb_cm.h"
  
  void
  cxgb_get_4tuple(struct cpl_pass_accept_req *req, enum chip_type type,
  		int *iptype, __u8 *local_ip, __u8 *peer_ip,
  		__be16 *local_port, __be16 *peer_port)
  {
  	int eth_len = (CHELSIO_CHIP_VERSION(type) <= CHELSIO_T5) ?
  		      ETH_HDR_LEN_G(be32_to_cpu(req->hdr_len)) :
  		      T6_ETH_HDR_LEN_G(be32_to_cpu(req->hdr_len));
  	int ip_len = (CHELSIO_CHIP_VERSION(type) <= CHELSIO_T5) ?
  		     IP_HDR_LEN_G(be32_to_cpu(req->hdr_len)) :
  		     T6_IP_HDR_LEN_G(be32_to_cpu(req->hdr_len));
  	struct iphdr *ip = (struct iphdr *)((u8 *)(req + 1) + eth_len);
  	struct ipv6hdr *ip6 = (struct ipv6hdr *)((u8 *)(req + 1) + eth_len);
  	struct tcphdr *tcp = (struct tcphdr *)
  			     ((u8 *)(req + 1) + eth_len + ip_len);
  
  	if (ip->version == 4) {
  		pr_debug("%s saddr 0x%x daddr 0x%x sport %u dport %u\n",
  			 __func__, ntohl(ip->saddr), ntohl(ip->daddr),
  			 ntohs(tcp->source), ntohs(tcp->dest));
  		*iptype = 4;
  		memcpy(peer_ip, &ip->saddr, 4);
  		memcpy(local_ip, &ip->daddr, 4);
  	} else {
  		pr_debug("%s saddr %pI6 daddr %pI6 sport %u dport %u\n",
  			 __func__, ip6->saddr.s6_addr, ip6->daddr.s6_addr,
  			 ntohs(tcp->source), ntohs(tcp->dest));
  		*iptype = 6;
  		memcpy(peer_ip, ip6->saddr.s6_addr, 16);
  		memcpy(local_ip, ip6->daddr.s6_addr, 16);
  	}
  	*peer_port = tcp->source;
  	*local_port = tcp->dest;
  }
  EXPORT_SYMBOL(cxgb_get_4tuple);
  
  static bool
  cxgb_our_interface(struct cxgb4_lld_info *lldi,
  		   struct net_device *(*get_real_dev)(struct net_device *),
  		   struct net_device *egress_dev)
  {
  	int i;
  
  	egress_dev = get_real_dev(egress_dev);
  	for (i = 0; i < lldi->nports; i++)
  		if (lldi->ports[i] == egress_dev)
  			return true;
  	return false;
  }
  
  struct dst_entry *
  cxgb_find_route(struct cxgb4_lld_info *lldi,
  		struct net_device *(*get_real_dev)(struct net_device *),
  		__be32 local_ip, __be32 peer_ip, __be16 local_port,
  		__be16 peer_port, u8 tos)
  {
  	struct rtable *rt;
  	struct flowi4 fl4;
  	struct neighbour *n;
  
  	rt = ip_route_output_ports(&init_net, &fl4, NULL, peer_ip, local_ip,
  				   peer_port, local_port, IPPROTO_TCP,
  				   tos, 0);
  	if (IS_ERR(rt))
  		return NULL;
  	n = dst_neigh_lookup(&rt->dst, &peer_ip);
  	if (!n)
  		return NULL;
  	if (!cxgb_our_interface(lldi, get_real_dev, n->dev) &&
  	    !(n->dev->flags & IFF_LOOPBACK)) {
  		neigh_release(n);
  		dst_release(&rt->dst);
  		return NULL;
  	}
  	neigh_release(n);
  	return &rt->dst;
  }
  EXPORT_SYMBOL(cxgb_find_route);
  
  struct dst_entry *
  cxgb_find_route6(struct cxgb4_lld_info *lldi,
  		 struct net_device *(*get_real_dev)(struct net_device *),
  		 __u8 *local_ip, __u8 *peer_ip, __be16 local_port,
  		 __be16 peer_port, u8 tos, __u32 sin6_scope_id)
  {
  	struct dst_entry *dst = NULL;
  
  	if (IS_ENABLED(CONFIG_IPV6)) {
  		struct flowi6 fl6;
  
  		memset(&fl6, 0, sizeof(fl6));
  		memcpy(&fl6.daddr, peer_ip, 16);
  		memcpy(&fl6.saddr, local_ip, 16);
  		if (ipv6_addr_type(&fl6.daddr) & IPV6_ADDR_LINKLOCAL)
  			fl6.flowi6_oif = sin6_scope_id;
  		dst = ip6_route_output(&init_net, NULL, &fl6);
  		if (!dst)
  			goto out;
  		if (!cxgb_our_interface(lldi, get_real_dev,
  					ip6_dst_idev(dst)->dev) &&
  		    !(ip6_dst_idev(dst)->dev->flags & IFF_LOOPBACK)) {
  			dst_release(dst);
  			dst = NULL;
  		}
  	}
  
  out:
  	return dst;
  }
  EXPORT_SYMBOL(cxgb_find_route6);
  