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 #include <linux/static_key.h>
  36
  37 #include <net/ip.h>
  38 #include <net/icmp.h>
  39 #include <net/protocol.h>
  40 #include <net/ip_tunnels.h>
  41 #include <net/arp.h>
  42 #include <net/checksum.h>
  43 #include <net/dsfield.h>
  44 #include <net/inet_ecn.h>
  45 #include <net/xfrm.h>
  46 #include <net/net_namespace.h>
  47 #include <net/netns/generic.h>
  48 #include <net/rtnetlink.h>
  49
  50 int iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
  51                   __be32 src, __be32 dst, __u8 proto,
  52                   __u8 tos, __u8 ttl, __be16 df, bool xnet)
  53 {
  54         int pkt_len = skb->len;
  55         struct iphdr *iph;
  56         int err;
  57
  58         skb_scrub_packet(skb, xnet);
  59
  60         skb_clear_hash(skb);
  61         skb_dst_set(skb, &rt->dst);
  62         memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
  63
  64         /* Push down and install the IP header. */
  65         skb_push(skb, sizeof(struct iphdr));
  66         skb_reset_network_header(skb);
  67
  68         iph = ip_hdr(skb);
  69
  70         iph->version    =       4;
  71         iph->ihl        =       sizeof(struct iphdr) >> 2;
  72         iph->frag_off   =       df;
  73         iph->protocol   =       proto;
  74         iph->tos        =       tos;
  75         iph->daddr      =       dst;
  76         iph->saddr      =       src;
  77         iph->ttl        =       ttl;
  78         __ip_select_ident(dev_net(rt->dst.dev), iph,
  79                           skb_shinfo(skb)->gso_segs ?: 1);
  80
  81         err = ip_local_out_sk(sk, skb);
  82         if (unlikely(net_xmit_eval(err)))
  83                 pkt_len = 0;
  84         return pkt_len;
  85 }
  86 EXPORT_SYMBOL_GPL(iptunnel_xmit);
  87
  88 int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto)
  89 {
  90         if (unlikely(!pskb_may_pull(skb, hdr_len)))
  91                 return -ENOMEM;
  92
  93         skb_pull_rcsum(skb, hdr_len);
  94
  95         if (inner_proto == htons(ETH_P_TEB)) {
  96                 struct ethhdr *eh;
  97
  98                 if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
  99                         return -ENOMEM;
 100
 101                 eh = (struct ethhdr *)skb->data;
 102                 if (likely(eth_proto_is_802_3(eh->h_proto)))
 103                         skb->protocol = eh->h_proto;
 104                 else
 105                         skb->protocol = htons(ETH_P_802_2);
 106
 107         } else {
 108                 skb->protocol = inner_proto;
 109         }
 110
 111         nf_reset(skb);
 112         secpath_reset(skb);
 113         skb_clear_hash_if_not_l4(skb);
 114         skb_dst_drop(skb);
 115         skb->vlan_tci = 0;
 116         skb_set_queue_mapping(skb, 0);
 117         skb->pkt_type = PACKET_HOST;
 118         return 0;
 119 }
 120 EXPORT_SYMBOL_GPL(iptunnel_pull_header);
 121
 122 struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb,
 123                                          bool csum_help,
 124                                          int gso_type_mask)
 125 {
 126         int err;
 127
 128         if (likely(!skb->encapsulation)) {
 129                 skb_reset_inner_headers(skb);
 130                 skb->encapsulation = 1;
 131         }
 132
 133         if (skb_is_gso(skb)) {
 134                 err = skb_unclone(skb, GFP_ATOMIC);
 135                 if (unlikely(err))
 136                         goto error;
 137                 skb_shinfo(skb)->gso_type |= gso_type_mask;
 138                 return skb;
 139         }
 140
 141         /* If packet is not gso and we are resolving any partial checksum,
 142          * clear encapsulation flag. This allows setting CHECKSUM_PARTIAL
 143          * on the outer header without confusing devices that implement
 144          * NETIF_F_IP_CSUM with encapsulation.
 145          */
 146         if (csum_help)
 147                 skb->encapsulation = 0;
 148
 149         if (skb->ip_summed == CHECKSUM_PARTIAL && csum_help) {
 150                 err = skb_checksum_help(skb);
 151                 if (unlikely(err))
 152                         goto error;
 153         } else if (skb->ip_summed != CHECKSUM_PARTIAL)
 154                 skb->ip_summed = CHECKSUM_NONE;
 155
 156         return skb;
 157 error:
 158         kfree_skb(skb);
 159         return ERR_PTR(err);
 160 }
 161 EXPORT_SYMBOL_GPL(iptunnel_handle_offloads);
 162
 163 /* Often modified stats are per cpu, other are shared (netdev->stats) */
 164 struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
 165                                                 struct rtnl_link_stats64 *tot)
 166 {
 167         int i;
 168
 169         netdev_stats_to_stats64(tot, &dev->stats);
 170
 171         for_each_possible_cpu(i) {
 172                 const struct pcpu_sw_netstats *tstats =
 173                                                    per_cpu_ptr(dev->tstats, i);
 174                 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
 175                 unsigned int start;
 176
 177                 do {
 178                         start = u64_stats_fetch_begin_irq(&tstats->syncp);
 179                         rx_packets = tstats->rx_packets;
 180                         tx_packets = tstats->tx_packets;
 181                         rx_bytes = tstats->rx_bytes;
 182                         tx_bytes = tstats->tx_bytes;
 183                 } while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
 184
 185                 tot->rx_packets += rx_packets;
 186                 tot->tx_packets += tx_packets;
 187                 tot->rx_bytes   += rx_bytes;
 188                 tot->tx_bytes   += tx_bytes;
 189         }
 190
 191         return tot;
 192 }
 193 EXPORT_SYMBOL_GPL(ip_tunnel_get_stats64);
 194
 195 static const struct nla_policy ip_tun_policy[LWTUNNEL_IP_MAX + 1] = {
 196         [LWTUNNEL_IP_ID]        = { .type = NLA_U64 },
 197         [LWTUNNEL_IP_DST]       = { .type = NLA_U32 },
 198         [LWTUNNEL_IP_SRC]       = { .type = NLA_U32 },
 199         [LWTUNNEL_IP_TTL]       = { .type = NLA_U8 },
 200         [LWTUNNEL_IP_TOS]       = { .type = NLA_U8 },
 201         [LWTUNNEL_IP_SPORT]     = { .type = NLA_U16 },
 202         [LWTUNNEL_IP_DPORT]     = { .type = NLA_U16 },
 203         [LWTUNNEL_IP_FLAGS]     = { .type = NLA_U16 },
 204 };
 205
 206 static int ip_tun_build_state(struct net_device *dev, struct nlattr *attr,
 207                               unsigned int family, const void *cfg,
 208                               struct lwtunnel_state **ts)
 209 {
 210         struct ip_tunnel_info *tun_info;
 211         struct lwtunnel_state *new_state;
 212         struct nlattr *tb[LWTUNNEL_IP_MAX + 1];
 213         int err;
 214
 215         err = nla_parse_nested(tb, LWTUNNEL_IP_MAX, attr, ip_tun_policy);
 216         if (err < 0)
 217                 return err;
 218
 219         new_state = lwtunnel_state_alloc(sizeof(*tun_info));
 220         if (!new_state)
 221                 return -ENOMEM;
 222
 223         new_state->type = LWTUNNEL_ENCAP_IP;
 224
 225         tun_info = lwt_tun_info(new_state);
 226
 227         if (tb[LWTUNNEL_IP_ID])
 228                 tun_info->key.tun_id = nla_get_u64(tb[LWTUNNEL_IP_ID]);
 229
 230         if (tb[LWTUNNEL_IP_DST])
 231                 tun_info->key.u.ipv4.dst = nla_get_be32(tb[LWTUNNEL_IP_DST]);
 232
 233         if (tb[LWTUNNEL_IP_SRC])
 234                 tun_info->key.u.ipv4.src = nla_get_be32(tb[LWTUNNEL_IP_SRC]);
 235
 236         if (tb[LWTUNNEL_IP_TTL])
 237                 tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP_TTL]);
 238
 239         if (tb[LWTUNNEL_IP_TOS])
 240                 tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP_TOS]);
 241
 242         if (tb[LWTUNNEL_IP_SPORT])
 243                 tun_info->key.tp_src = nla_get_be16(tb[LWTUNNEL_IP_SPORT]);
 244
 245         if (tb[LWTUNNEL_IP_DPORT])
 246                 tun_info->key.tp_dst = nla_get_be16(tb[LWTUNNEL_IP_DPORT]);
 247
 248         if (tb[LWTUNNEL_IP_FLAGS])
 249                 tun_info->key.tun_flags = nla_get_u16(tb[LWTUNNEL_IP_FLAGS]);
 250
 251         tun_info->mode = IP_TUNNEL_INFO_TX;
 252         tun_info->options_len = 0;
 253
 254         *ts = new_state;
 255
 256         return 0;
 257 }
 258
 259 static int ip_tun_fill_encap_info(struct sk_buff *skb,
 260                                   struct lwtunnel_state *lwtstate)
 261 {
 262         struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
 263
 264         if (nla_put_u64(skb, LWTUNNEL_IP_ID, tun_info->key.tun_id) ||
 265             nla_put_be32(skb, LWTUNNEL_IP_DST, tun_info->key.u.ipv4.dst) ||
 266             nla_put_be32(skb, LWTUNNEL_IP_SRC, tun_info->key.u.ipv4.src) ||
 267             nla_put_u8(skb, LWTUNNEL_IP_TOS, tun_info->key.tos) ||
 268             nla_put_u8(skb, LWTUNNEL_IP_TTL, tun_info->key.ttl) ||
 269             nla_put_u16(skb, LWTUNNEL_IP_SPORT, tun_info->key.tp_src) ||
 270             nla_put_u16(skb, LWTUNNEL_IP_DPORT, tun_info->key.tp_dst) ||
 271             nla_put_u16(skb, LWTUNNEL_IP_FLAGS, tun_info->key.tun_flags))
 272                 return -ENOMEM;
 273
 274         return 0;
 275 }
 276
 277 static int ip_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
 278 {
 279         return nla_total_size(8)        /* LWTUNNEL_IP_ID */
 280                 + nla_total_size(4)     /* LWTUNNEL_IP_DST */
 281                 + nla_total_size(4)     /* LWTUNNEL_IP_SRC */
 282                 + nla_total_size(1)     /* LWTUNNEL_IP_TOS */
 283                 + nla_total_size(1)     /* LWTUNNEL_IP_TTL */
 284                 + nla_total_size(2)     /* LWTUNNEL_IP_SPORT */
 285                 + nla_total_size(2)     /* LWTUNNEL_IP_DPORT */
 286                 + nla_total_size(2);    /* LWTUNNEL_IP_FLAGS */
 287 }
 288
 289 static int ip_tun_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
 290 {
 291         return memcmp(lwt_tun_info(a), lwt_tun_info(b),
 292                       sizeof(struct ip_tunnel_info));
 293 }
 294
 295 static const struct lwtunnel_encap_ops ip_tun_lwt_ops = {
 296         .build_state = ip_tun_build_state,
 297         .fill_encap = ip_tun_fill_encap_info,
 298         .get_encap_size = ip_tun_encap_nlsize,
 299         .cmp_encap = ip_tun_cmp_encap,
 300 };
 301
 302 static const struct nla_policy ip6_tun_policy[LWTUNNEL_IP6_MAX + 1] = {
 303         [LWTUNNEL_IP6_ID]               = { .type = NLA_U64 },
 304         [LWTUNNEL_IP6_DST]              = { .len = sizeof(struct in6_addr) },
 305         [LWTUNNEL_IP6_SRC]              = { .len = sizeof(struct in6_addr) },
 306         [LWTUNNEL_IP6_HOPLIMIT]         = { .type = NLA_U8 },
 307         [LWTUNNEL_IP6_TC]               = { .type = NLA_U8 },
 308         [LWTUNNEL_IP6_SPORT]            = { .type = NLA_U16 },
 309         [LWTUNNEL_IP6_DPORT]            = { .type = NLA_U16 },
 310         [LWTUNNEL_IP6_FLAGS]            = { .type = NLA_U16 },
 311 };
 312
 313 static int ip6_tun_build_state(struct net_device *dev, struct nlattr *attr,
 314                                unsigned int family, const void *cfg,
 315                                struct lwtunnel_state **ts)
 316 {
 317         struct ip_tunnel_info *tun_info;
 318         struct lwtunnel_state *new_state;
 319         struct nlattr *tb[LWTUNNEL_IP6_MAX + 1];
 320         int err;
 321
 322         err = nla_parse_nested(tb, LWTUNNEL_IP6_MAX, attr, ip6_tun_policy);
 323         if (err < 0)
 324                 return err;
 325
 326         new_state = lwtunnel_state_alloc(sizeof(*tun_info));
 327         if (!new_state)
 328                 return -ENOMEM;
 329
 330         new_state->type = LWTUNNEL_ENCAP_IP6;
 331
 332         tun_info = lwt_tun_info(new_state);
 333
 334         if (tb[LWTUNNEL_IP6_ID])
 335                 tun_info->key.tun_id = nla_get_u64(tb[LWTUNNEL_IP6_ID]);
 336
 337         if (tb[LWTUNNEL_IP6_DST])
 338                 tun_info->key.u.ipv6.dst = nla_get_in6_addr(tb[LWTUNNEL_IP6_DST]);
 339
 340         if (tb[LWTUNNEL_IP6_SRC])
 341                 tun_info->key.u.ipv6.src = nla_get_in6_addr(tb[LWTUNNEL_IP6_SRC]);
 342
 343         if (tb[LWTUNNEL_IP6_HOPLIMIT])
 344                 tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP6_HOPLIMIT]);
 345
 346         if (tb[LWTUNNEL_IP6_TC])
 347                 tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP6_TC]);
 348
 349         if (tb[LWTUNNEL_IP6_SPORT])
 350                 tun_info->key.tp_src = nla_get_be16(tb[LWTUNNEL_IP6_SPORT]);
 351
 352         if (tb[LWTUNNEL_IP6_DPORT])
 353                 tun_info->key.tp_dst = nla_get_be16(tb[LWTUNNEL_IP6_DPORT]);
 354
 355         if (tb[LWTUNNEL_IP6_FLAGS])
 356                 tun_info->key.tun_flags = nla_get_u16(tb[LWTUNNEL_IP6_FLAGS]);
 357
 358         tun_info->mode = IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_IPV6;
 359         tun_info->options_len = 0;
 360
 361         *ts = new_state;
 362
 363         return 0;
 364 }
 365
 366 static int ip6_tun_fill_encap_info(struct sk_buff *skb,
 367                                    struct lwtunnel_state *lwtstate)
 368 {
 369         struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
 370
 371         if (nla_put_u64(skb, LWTUNNEL_IP6_ID, tun_info->key.tun_id) ||
 372             nla_put_in6_addr(skb, LWTUNNEL_IP6_DST, &tun_info->key.u.ipv6.dst) ||
 373             nla_put_in6_addr(skb, LWTUNNEL_IP6_SRC, &tun_info->key.u.ipv6.src) ||
 374             nla_put_u8(skb, LWTUNNEL_IP6_HOPLIMIT, tun_info->key.tos) ||
 375             nla_put_u8(skb, LWTUNNEL_IP6_TC, tun_info->key.ttl) ||
 376             nla_put_u16(skb, LWTUNNEL_IP6_SPORT, tun_info->key.tp_src) ||
 377             nla_put_u16(skb, LWTUNNEL_IP6_DPORT, tun_info->key.tp_dst) ||
 378             nla_put_u16(skb, LWTUNNEL_IP6_FLAGS, tun_info->key.tun_flags))
 379                 return -ENOMEM;
 380
 381         return 0;
 382 }
 383
 384 static int ip6_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
 385 {
 386         return nla_total_size(8)        /* LWTUNNEL_IP6_ID */
 387                 + nla_total_size(16)    /* LWTUNNEL_IP6_DST */
 388                 + nla_total_size(16)    /* LWTUNNEL_IP6_SRC */
 389                 + nla_total_size(1)     /* LWTUNNEL_IP6_HOPLIMIT */
 390                 + nla_total_size(1)     /* LWTUNNEL_IP6_TC */
 391                 + nla_total_size(2)     /* LWTUNNEL_IP6_SPORT */
 392                 + nla_total_size(2)     /* LWTUNNEL_IP6_DPORT */
 393                 + nla_total_size(2);    /* LWTUNNEL_IP6_FLAGS */
 394 }
 395
 396 static const struct lwtunnel_encap_ops ip6_tun_lwt_ops = {
 397         .build_state = ip6_tun_build_state,
 398         .fill_encap = ip6_tun_fill_encap_info,
 399         .get_encap_size = ip6_tun_encap_nlsize,
 400         .cmp_encap = ip_tun_cmp_encap,
 401 };
 402
 403 void __init ip_tunnel_core_init(void)
 404 {
 405         lwtunnel_encap_add_ops(&ip_tun_lwt_ops, LWTUNNEL_ENCAP_IP);
 406         lwtunnel_encap_add_ops(&ip6_tun_lwt_ops, LWTUNNEL_ENCAP_IP6);
 407 }
 408
 409 struct static_key ip_tunnel_metadata_cnt = STATIC_KEY_INIT_FALSE;
 410 EXPORT_SYMBOL(ip_tunnel_metadata_cnt);
 411
 412 void ip_tunnel_need_metadata(void)
 413 {
 414         static_key_slow_inc(&ip_tunnel_metadata_cnt);
 415 }
 416 EXPORT_SYMBOL_GPL(ip_tunnel_need_metadata);
 417
 418 void ip_tunnel_unneed_metadata(void)
 419 {
 420         static_key_slow_dec(&ip_tunnel_metadata_cnt);
 421 }
 422 EXPORT_SYMBOL_GPL(ip_tunnel_unneed_metadata);