net/ipv4/ip_tunnel_core.c

   1 /*
   2  * Copyright (c) 2013 Nicira, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of version 2 of the GNU General Public
   6  * License as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  16  * 02110-1301, USA
  17  */
  18
  19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  20
  21 #include <linux/types.h>
  22 #include <linux/kernel.h>
  23 #include <linux/skbuff.h>
  24 #include <linux/netdevice.h>
  25 #include <linux/in.h>
  26 #include <linux/if_arp.h>
  27 #include <linux/mroute.h>
  28 #include <linux/init.h>
  29 #include <linux/in6.h>
  30 #include <linux/inetdevice.h>
  31 #include <linux/netfilter_ipv4.h>
  32 #include <linux/etherdevice.h>
  33 #include <linux/if_ether.h>
  34 #include <linux/if_vlan.h>
  35
  36 #include <net/ip.h>
  37 #include <net/icmp.h>
  38 #include <net/protocol.h>
  39 #include <net/ip_tunnels.h>
  40 #include <net/arp.h>
  41 #include <net/checksum.h>
  42 #include <net/dsfield.h>
  43 #include <net/inet_ecn.h>
  44 #include <net/xfrm.h>
  45 #include <net/net_namespace.h>
  46 #include <net/netns/generic.h>
  47 #include <net/rtnetlink.h>
  48
  49 int iptunnel_xmit(struct net *net, struct rtable *rt,
  50                   struct sk_buff *skb,
  51                   __be32 src, __be32 dst, __u8 proto,
  52                   __u8 tos, __u8 ttl, __be16 df)
  53 {
  54         int pkt_len = skb->len;
  55         struct iphdr *iph;
  56         int err;
  57
  58         nf_reset(skb);
  59         secpath_reset(skb);
  60         skb->rxhash = 0;
  61         skb_dst_drop(skb);
  62         skb_dst_set(skb, &rt->dst);
  63         memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
  64
  65         /* Push down and install the IP header. */
  66         __skb_push(skb, sizeof(struct iphdr));
  67         skb_reset_network_header(skb);
  68
  69         iph = ip_hdr(skb);
  70
  71         iph->version    =       4;
  72         iph->ihl        =       sizeof(struct iphdr) >> 2;
  73         iph->frag_off   =       df;
  74         iph->protocol   =       proto;
  75         iph->tos        =       tos;
  76         iph->daddr      =       dst;
  77         iph->saddr      =       src;
  78         iph->ttl        =       ttl;
  79         tunnel_ip_select_ident(skb,
  80                                (const struct iphdr *)skb_inner_network_header(skb),
  81                                &rt->dst);
  82
  83         err = ip_local_out(skb);
  84         if (unlikely(net_xmit_eval(err)))
  85                 pkt_len = 0;
  86         return pkt_len;
  87 }
  88 EXPORT_SYMBOL_GPL(iptunnel_xmit);
  89
  90 int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto)
  91 {
  92         if (unlikely(!pskb_may_pull(skb, hdr_len)))
  93                 return -ENOMEM;
  94
  95         skb_pull_rcsum(skb, hdr_len);
  96
  97         if (inner_proto == htons(ETH_P_TEB)) {
  98                 struct ethhdr *eh = (struct ethhdr *)skb->data;
  99
 100                 if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
 101                         return -ENOMEM;
 102
 103                 if (likely(ntohs(eh->h_proto) >= ETH_P_802_3_MIN))
 104                         skb->protocol = eh->h_proto;
 105                 else
 106                         skb->protocol = htons(ETH_P_802_2);
 107
 108         } else {
 109                 skb->protocol = inner_proto;
 110         }
 111
 112         nf_reset(skb);
 113         secpath_reset(skb);
 114         if (!skb->l4_rxhash)
 115                 skb->rxhash = 0;
 116         skb_dst_drop(skb);
 117         skb->vlan_tci = 0;
 118         skb_set_queue_mapping(skb, 0);
 119         skb->pkt_type = PACKET_HOST;
 120         return 0;
 121 }
 122 EXPORT_SYMBOL_GPL(iptunnel_pull_header);