linux/net/ipv4/ip_tunnel_core.c
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   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
  49int iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
  50                  __be32 src, __be32 dst, __u8 proto,
  51                  __u8 tos, __u8 ttl, __be16 df, bool xnet)
  52{
  53        int pkt_len = skb->len;
  54        struct iphdr *iph;
  55        int err;
  56
  57        skb_scrub_packet(skb, xnet);
  58
  59        skb_clear_hash(skb);
  60        skb_dst_set(skb, &rt->dst);
  61        memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
  62
  63        /* Push down and install the IP header. */
  64        skb_push(skb, sizeof(struct iphdr));
  65        skb_reset_network_header(skb);
  66
  67        iph = ip_hdr(skb);
  68
  69        iph->version    =       4;
  70        iph->ihl        =       sizeof(struct iphdr) >> 2;
  71        iph->frag_off   =       df;
  72        iph->protocol   =       proto;
  73        iph->tos        =       tos;
  74        iph->daddr      =       dst;
  75        iph->saddr      =       src;
  76        iph->ttl        =       ttl;
  77        __ip_select_ident(iph, &rt->dst, (skb_shinfo(skb)->gso_segs ?: 1) - 1);
  78
  79        err = ip_local_out_sk(sk, skb);
  80        if (unlikely(net_xmit_eval(err)))
  81                pkt_len = 0;
  82        return pkt_len;
  83}
  84EXPORT_SYMBOL_GPL(iptunnel_xmit);
  85
  86int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto)
  87{
  88        if (unlikely(!pskb_may_pull(skb, hdr_len)))
  89                return -ENOMEM;
  90
  91        skb_pull_rcsum(skb, hdr_len);
  92
  93        if (inner_proto == htons(ETH_P_TEB)) {
  94                struct ethhdr *eh = (struct ethhdr *)skb->data;
  95
  96                if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
  97                        return -ENOMEM;
  98
  99                if (likely(ntohs(eh->h_proto) >= ETH_P_802_3_MIN))
 100                        skb->protocol = eh->h_proto;
 101                else
 102                        skb->protocol = htons(ETH_P_802_2);
 103
 104        } else {
 105                skb->protocol = inner_proto;
 106        }
 107
 108        nf_reset(skb);
 109        secpath_reset(skb);
 110        skb_clear_hash_if_not_l4(skb);
 111        skb_dst_drop(skb);
 112        skb->vlan_tci = 0;
 113        skb_set_queue_mapping(skb, 0);
 114        skb->pkt_type = PACKET_HOST;
 115        return 0;
 116}
 117EXPORT_SYMBOL_GPL(iptunnel_pull_header);
 118
 119struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb,
 120                                         bool csum_help,
 121                                         int gso_type_mask)
 122{
 123        int err;
 124
 125        if (likely(!skb->encapsulation)) {
 126                skb_reset_inner_headers(skb);
 127                skb->encapsulation = 1;
 128        }
 129
 130        if (skb_is_gso(skb)) {
 131                err = skb_unclone(skb, GFP_ATOMIC);
 132                if (unlikely(err))
 133                        goto error;
 134                skb_shinfo(skb)->gso_type |= gso_type_mask;
 135                return skb;
 136        }
 137
 138        if (skb->ip_summed == CHECKSUM_PARTIAL && csum_help) {
 139                err = skb_checksum_help(skb);
 140                if (unlikely(err))
 141                        goto error;
 142        } else if (skb->ip_summed != CHECKSUM_PARTIAL)
 143                skb->ip_summed = CHECKSUM_NONE;
 144
 145        return skb;
 146error:
 147        kfree_skb(skb);
 148        return ERR_PTR(err);
 149}
 150EXPORT_SYMBOL_GPL(iptunnel_handle_offloads);
 151
 152/* Often modified stats are per cpu, other are shared (netdev->stats) */
 153struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
 154                                                struct rtnl_link_stats64 *tot)
 155{
 156        int i;
 157
 158        for_each_possible_cpu(i) {
 159                const struct pcpu_sw_netstats *tstats =
 160                                                   per_cpu_ptr(dev->tstats, i);
 161                u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
 162                unsigned int start;
 163
 164                do {
 165                        start = u64_stats_fetch_begin_irq(&tstats->syncp);
 166                        rx_packets = tstats->rx_packets;
 167                        tx_packets = tstats->tx_packets;
 168                        rx_bytes = tstats->rx_bytes;
 169                        tx_bytes = tstats->tx_bytes;
 170                } while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
 171
 172                tot->rx_packets += rx_packets;
 173                tot->tx_packets += tx_packets;
 174                tot->rx_bytes   += rx_bytes;
 175                tot->tx_bytes   += tx_bytes;
 176        }
 177
 178        tot->multicast = dev->stats.multicast;
 179
 180        tot->rx_crc_errors = dev->stats.rx_crc_errors;
 181        tot->rx_fifo_errors = dev->stats.rx_fifo_errors;
 182        tot->rx_length_errors = dev->stats.rx_length_errors;
 183        tot->rx_frame_errors = dev->stats.rx_frame_errors;
 184        tot->rx_errors = dev->stats.rx_errors;
 185
 186        tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
 187        tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
 188        tot->tx_dropped = dev->stats.tx_dropped;
 189        tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
 190        tot->tx_errors = dev->stats.tx_errors;
 191
 192        tot->collisions  = dev->stats.collisions;
 193
 194        return tot;
 195}
 196EXPORT_SYMBOL_GPL(ip_tunnel_get_stats64);
 197