linux/net/ipv4/ip_tunnel_core.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (c) 2013 Nicira, Inc.
   4 */
   5
   6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   7
   8#include <linux/types.h>
   9#include <linux/kernel.h>
  10#include <linux/skbuff.h>
  11#include <linux/netdevice.h>
  12#include <linux/in.h>
  13#include <linux/if_arp.h>
  14#include <linux/init.h>
  15#include <linux/in6.h>
  16#include <linux/inetdevice.h>
  17#include <linux/netfilter_ipv4.h>
  18#include <linux/etherdevice.h>
  19#include <linux/if_ether.h>
  20#include <linux/if_vlan.h>
  21#include <linux/static_key.h>
  22
  23#include <net/ip.h>
  24#include <net/icmp.h>
  25#include <net/protocol.h>
  26#include <net/ip_tunnels.h>
  27#include <net/ip6_tunnel.h>
  28#include <net/ip6_checksum.h>
  29#include <net/arp.h>
  30#include <net/checksum.h>
  31#include <net/dsfield.h>
  32#include <net/inet_ecn.h>
  33#include <net/xfrm.h>
  34#include <net/net_namespace.h>
  35#include <net/netns/generic.h>
  36#include <net/rtnetlink.h>
  37#include <net/dst_metadata.h>
  38#include <net/geneve.h>
  39#include <net/vxlan.h>
  40#include <net/erspan.h>
  41
  42const struct ip_tunnel_encap_ops __rcu *
  43                iptun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly;
  44EXPORT_SYMBOL(iptun_encaps);
  45
  46const struct ip6_tnl_encap_ops __rcu *
  47                ip6tun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly;
  48EXPORT_SYMBOL(ip6tun_encaps);
  49
  50void 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 - skb_inner_network_offset(skb);
  55        struct net *net = dev_net(rt->dst.dev);
  56        struct net_device *dev = skb->dev;
  57        struct iphdr *iph;
  58        int err;
  59
  60        skb_scrub_packet(skb, xnet);
  61
  62        skb_clear_hash_if_not_l4(skb);
  63        skb_dst_set(skb, &rt->dst);
  64        memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
  65
  66        /* Push down and install the IP header. */
  67        skb_push(skb, sizeof(struct iphdr));
  68        skb_reset_network_header(skb);
  69
  70        iph = ip_hdr(skb);
  71
  72        iph->version    =       4;
  73        iph->ihl        =       sizeof(struct iphdr) >> 2;
  74        iph->frag_off   =       ip_mtu_locked(&rt->dst) ? 0 : df;
  75        iph->protocol   =       proto;
  76        iph->tos        =       tos;
  77        iph->daddr      =       dst;
  78        iph->saddr      =       src;
  79        iph->ttl        =       ttl;
  80        __ip_select_ident(net, iph, skb_shinfo(skb)->gso_segs ?: 1);
  81
  82        err = ip_local_out(net, sk, skb);
  83
  84        if (dev) {
  85                if (unlikely(net_xmit_eval(err)))
  86                        pkt_len = 0;
  87                iptunnel_xmit_stats(dev, pkt_len);
  88        }
  89}
  90EXPORT_SYMBOL_GPL(iptunnel_xmit);
  91
  92int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
  93                           __be16 inner_proto, bool raw_proto, bool xnet)
  94{
  95        if (unlikely(!pskb_may_pull(skb, hdr_len)))
  96                return -ENOMEM;
  97
  98        skb_pull_rcsum(skb, hdr_len);
  99
 100        if (!raw_proto && inner_proto == htons(ETH_P_TEB)) {
 101                struct ethhdr *eh;
 102
 103                if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
 104                        return -ENOMEM;
 105
 106                eh = (struct ethhdr *)skb->data;
 107                if (likely(eth_proto_is_802_3(eh->h_proto)))
 108                        skb->protocol = eh->h_proto;
 109                else
 110                        skb->protocol = htons(ETH_P_802_2);
 111
 112        } else {
 113                skb->protocol = inner_proto;
 114        }
 115
 116        skb_clear_hash_if_not_l4(skb);
 117        __vlan_hwaccel_clear_tag(skb);
 118        skb_set_queue_mapping(skb, 0);
 119        skb_scrub_packet(skb, xnet);
 120
 121        return iptunnel_pull_offloads(skb);
 122}
 123EXPORT_SYMBOL_GPL(__iptunnel_pull_header);
 124
 125struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
 126                                             gfp_t flags)
 127{
 128        struct metadata_dst *res;
 129        struct ip_tunnel_info *dst, *src;
 130
 131        if (!md || md->type != METADATA_IP_TUNNEL ||
 132            md->u.tun_info.mode & IP_TUNNEL_INFO_TX)
 133                return NULL;
 134
 135        src = &md->u.tun_info;
 136        res = metadata_dst_alloc(src->options_len, METADATA_IP_TUNNEL, flags);
 137        if (!res)
 138                return NULL;
 139
 140        dst = &res->u.tun_info;
 141        dst->key.tun_id = src->key.tun_id;
 142        if (src->mode & IP_TUNNEL_INFO_IPV6)
 143                memcpy(&dst->key.u.ipv6.dst, &src->key.u.ipv6.src,
 144                       sizeof(struct in6_addr));
 145        else
 146                dst->key.u.ipv4.dst = src->key.u.ipv4.src;
 147        dst->key.tun_flags = src->key.tun_flags;
 148        dst->mode = src->mode | IP_TUNNEL_INFO_TX;
 149        ip_tunnel_info_opts_set(dst, ip_tunnel_info_opts(src),
 150                                src->options_len, 0);
 151
 152        return res;
 153}
 154EXPORT_SYMBOL_GPL(iptunnel_metadata_reply);
 155
 156int iptunnel_handle_offloads(struct sk_buff *skb,
 157                             int gso_type_mask)
 158{
 159        int err;
 160
 161        if (likely(!skb->encapsulation)) {
 162                skb_reset_inner_headers(skb);
 163                skb->encapsulation = 1;
 164        }
 165
 166        if (skb_is_gso(skb)) {
 167                err = skb_header_unclone(skb, GFP_ATOMIC);
 168                if (unlikely(err))
 169                        return err;
 170                skb_shinfo(skb)->gso_type |= gso_type_mask;
 171                return 0;
 172        }
 173
 174        if (skb->ip_summed != CHECKSUM_PARTIAL) {
 175                skb->ip_summed = CHECKSUM_NONE;
 176                /* We clear encapsulation here to prevent badly-written
 177                 * drivers potentially deciding to offload an inner checksum
 178                 * if we set CHECKSUM_PARTIAL on the outer header.
 179                 * This should go away when the drivers are all fixed.
 180                 */
 181                skb->encapsulation = 0;
 182        }
 183
 184        return 0;
 185}
 186EXPORT_SYMBOL_GPL(iptunnel_handle_offloads);
 187
 188/**
 189 * iptunnel_pmtud_build_icmp() - Build ICMP error message for PMTUD
 190 * @skb:        Original packet with L2 header
 191 * @mtu:        MTU value for ICMP error
 192 *
 193 * Return: length on success, negative error code if message couldn't be built.
 194 */
 195static int iptunnel_pmtud_build_icmp(struct sk_buff *skb, int mtu)
 196{
 197        const struct iphdr *iph = ip_hdr(skb);
 198        struct icmphdr *icmph;
 199        struct iphdr *niph;
 200        struct ethhdr eh;
 201        int len, err;
 202
 203        if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
 204                return -EINVAL;
 205
 206        skb_copy_bits(skb, skb_mac_offset(skb), &eh, ETH_HLEN);
 207        pskb_pull(skb, ETH_HLEN);
 208        skb_reset_network_header(skb);
 209
 210        err = pskb_trim(skb, 576 - sizeof(*niph) - sizeof(*icmph));
 211        if (err)
 212                return err;
 213
 214        len = skb->len + sizeof(*icmph);
 215        err = skb_cow(skb, sizeof(*niph) + sizeof(*icmph) + ETH_HLEN);
 216        if (err)
 217                return err;
 218
 219        icmph = skb_push(skb, sizeof(*icmph));
 220        *icmph = (struct icmphdr) {
 221                .type                   = ICMP_DEST_UNREACH,
 222                .code                   = ICMP_FRAG_NEEDED,
 223                .checksum               = 0,
 224                .un.frag.__unused       = 0,
 225                .un.frag.mtu            = htons(mtu),
 226        };
 227        icmph->checksum = ip_compute_csum(icmph, len);
 228        skb_reset_transport_header(skb);
 229
 230        niph = skb_push(skb, sizeof(*niph));
 231        *niph = (struct iphdr) {
 232                .ihl                    = sizeof(*niph) / 4u,
 233                .version                = 4,
 234                .tos                    = 0,
 235                .tot_len                = htons(len + sizeof(*niph)),
 236                .id                     = 0,
 237                .frag_off               = htons(IP_DF),
 238                .ttl                    = iph->ttl,
 239                .protocol               = IPPROTO_ICMP,
 240                .saddr                  = iph->daddr,
 241                .daddr                  = iph->saddr,
 242        };
 243        ip_send_check(niph);
 244        skb_reset_network_header(skb);
 245
 246        skb->ip_summed = CHECKSUM_NONE;
 247
 248        eth_header(skb, skb->dev, ntohs(eh.h_proto), eh.h_source, eh.h_dest, 0);
 249        skb_reset_mac_header(skb);
 250
 251        return skb->len;
 252}
 253
 254/**
 255 * iptunnel_pmtud_check_icmp() - Trigger ICMP reply if needed and allowed
 256 * @skb:        Buffer being sent by encapsulation, L2 headers expected
 257 * @mtu:        Network MTU for path
 258 *
 259 * Return: 0 for no ICMP reply, length if built, negative value on error.
 260 */
 261static int iptunnel_pmtud_check_icmp(struct sk_buff *skb, int mtu)
 262{
 263        const struct icmphdr *icmph = icmp_hdr(skb);
 264        const struct iphdr *iph = ip_hdr(skb);
 265
 266        if (mtu < 576 || iph->frag_off != htons(IP_DF))
 267                return 0;
 268
 269        if (ipv4_is_lbcast(iph->daddr)  || ipv4_is_multicast(iph->daddr) ||
 270            ipv4_is_zeronet(iph->saddr) || ipv4_is_loopback(iph->saddr)  ||
 271            ipv4_is_lbcast(iph->saddr)  || ipv4_is_multicast(iph->saddr))
 272                return 0;
 273
 274        if (iph->protocol == IPPROTO_ICMP && icmp_is_err(icmph->type))
 275                return 0;
 276
 277        return iptunnel_pmtud_build_icmp(skb, mtu);
 278}
 279
 280#if IS_ENABLED(CONFIG_IPV6)
 281/**
 282 * iptunnel_pmtud_build_icmpv6() - Build ICMPv6 error message for PMTUD
 283 * @skb:        Original packet with L2 header
 284 * @mtu:        MTU value for ICMPv6 error
 285 *
 286 * Return: length on success, negative error code if message couldn't be built.
 287 */
 288static int iptunnel_pmtud_build_icmpv6(struct sk_buff *skb, int mtu)
 289{
 290        const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 291        struct icmp6hdr *icmp6h;
 292        struct ipv6hdr *nip6h;
 293        struct ethhdr eh;
 294        int len, err;
 295        __wsum csum;
 296
 297        if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
 298                return -EINVAL;
 299
 300        skb_copy_bits(skb, skb_mac_offset(skb), &eh, ETH_HLEN);
 301        pskb_pull(skb, ETH_HLEN);
 302        skb_reset_network_header(skb);
 303
 304        err = pskb_trim(skb, IPV6_MIN_MTU - sizeof(*nip6h) - sizeof(*icmp6h));
 305        if (err)
 306                return err;
 307
 308        len = skb->len + sizeof(*icmp6h);
 309        err = skb_cow(skb, sizeof(*nip6h) + sizeof(*icmp6h) + ETH_HLEN);
 310        if (err)
 311                return err;
 312
 313        icmp6h = skb_push(skb, sizeof(*icmp6h));
 314        *icmp6h = (struct icmp6hdr) {
 315                .icmp6_type             = ICMPV6_PKT_TOOBIG,
 316                .icmp6_code             = 0,
 317                .icmp6_cksum            = 0,
 318                .icmp6_mtu              = htonl(mtu),
 319        };
 320        skb_reset_transport_header(skb);
 321
 322        nip6h = skb_push(skb, sizeof(*nip6h));
 323        *nip6h = (struct ipv6hdr) {
 324                .priority               = 0,
 325                .version                = 6,
 326                .flow_lbl               = { 0 },
 327                .payload_len            = htons(len),
 328                .nexthdr                = IPPROTO_ICMPV6,
 329                .hop_limit              = ip6h->hop_limit,
 330                .saddr                  = ip6h->daddr,
 331                .daddr                  = ip6h->saddr,
 332        };
 333        skb_reset_network_header(skb);
 334
 335        csum = csum_partial(icmp6h, len, 0);
 336        icmp6h->icmp6_cksum = csum_ipv6_magic(&nip6h->saddr, &nip6h->daddr, len,
 337                                              IPPROTO_ICMPV6, csum);
 338
 339        skb->ip_summed = CHECKSUM_NONE;
 340
 341        eth_header(skb, skb->dev, ntohs(eh.h_proto), eh.h_source, eh.h_dest, 0);
 342        skb_reset_mac_header(skb);
 343
 344        return skb->len;
 345}
 346
 347/**
 348 * iptunnel_pmtud_check_icmpv6() - Trigger ICMPv6 reply if needed and allowed
 349 * @skb:        Buffer being sent by encapsulation, L2 headers expected
 350 * @mtu:        Network MTU for path
 351 *
 352 * Return: 0 for no ICMPv6 reply, length if built, negative value on error.
 353 */
 354static int iptunnel_pmtud_check_icmpv6(struct sk_buff *skb, int mtu)
 355{
 356        const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 357        int stype = ipv6_addr_type(&ip6h->saddr);
 358        u8 proto = ip6h->nexthdr;
 359        __be16 frag_off;
 360        int offset;
 361
 362        if (mtu < IPV6_MIN_MTU)
 363                return 0;
 364
 365        if (stype == IPV6_ADDR_ANY || stype == IPV6_ADDR_MULTICAST ||
 366            stype == IPV6_ADDR_LOOPBACK)
 367                return 0;
 368
 369        offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &proto,
 370                                  &frag_off);
 371        if (offset < 0 || (frag_off & htons(~0x7)))
 372                return 0;
 373
 374        if (proto == IPPROTO_ICMPV6) {
 375                struct icmp6hdr *icmp6h;
 376
 377                if (!pskb_may_pull(skb, skb_network_header(skb) +
 378                                        offset + 1 - skb->data))
 379                        return 0;
 380
 381                icmp6h = (struct icmp6hdr *)(skb_network_header(skb) + offset);
 382                if (icmpv6_is_err(icmp6h->icmp6_type) ||
 383                    icmp6h->icmp6_type == NDISC_REDIRECT)
 384                        return 0;
 385        }
 386
 387        return iptunnel_pmtud_build_icmpv6(skb, mtu);
 388}
 389#endif /* IS_ENABLED(CONFIG_IPV6) */
 390
 391/**
 392 * skb_tunnel_check_pmtu() - Check, update PMTU and trigger ICMP reply as needed
 393 * @skb:        Buffer being sent by encapsulation, L2 headers expected
 394 * @encap_dst:  Destination for tunnel encapsulation (outer IP)
 395 * @headroom:   Encapsulation header size, bytes
 396 * @reply:      Build matching ICMP or ICMPv6 message as a result
 397 *
 398 * L2 tunnel implementations that can carry IP and can be directly bridged
 399 * (currently UDP tunnels) can't always rely on IP forwarding paths to handle
 400 * PMTU discovery. In the bridged case, ICMP or ICMPv6 messages need to be built
 401 * based on payload and sent back by the encapsulation itself.
 402 *
 403 * For routable interfaces, we just need to update the PMTU for the destination.
 404 *
 405 * Return: 0 if ICMP error not needed, length if built, negative value on error
 406 */
 407int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst,
 408                          int headroom, bool reply)
 409{
 410        u32 mtu = dst_mtu(encap_dst) - headroom;
 411
 412        if ((skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) ||
 413            (!skb_is_gso(skb) && (skb->len - skb_mac_header_len(skb)) <= mtu))
 414                return 0;
 415
 416        skb_dst_update_pmtu_no_confirm(skb, mtu);
 417
 418        if (!reply || skb->pkt_type == PACKET_HOST)
 419                return 0;
 420
 421        if (skb->protocol == htons(ETH_P_IP))
 422                return iptunnel_pmtud_check_icmp(skb, mtu);
 423
 424#if IS_ENABLED(CONFIG_IPV6)
 425        if (skb->protocol == htons(ETH_P_IPV6))
 426                return iptunnel_pmtud_check_icmpv6(skb, mtu);
 427#endif
 428        return 0;
 429}
 430EXPORT_SYMBOL(skb_tunnel_check_pmtu);
 431
 432static const struct nla_policy ip_tun_policy[LWTUNNEL_IP_MAX + 1] = {
 433        [LWTUNNEL_IP_UNSPEC]    = { .strict_start_type = LWTUNNEL_IP_OPTS },
 434        [LWTUNNEL_IP_ID]        = { .type = NLA_U64 },
 435        [LWTUNNEL_IP_DST]       = { .type = NLA_U32 },
 436        [LWTUNNEL_IP_SRC]       = { .type = NLA_U32 },
 437        [LWTUNNEL_IP_TTL]       = { .type = NLA_U8 },
 438        [LWTUNNEL_IP_TOS]       = { .type = NLA_U8 },
 439        [LWTUNNEL_IP_FLAGS]     = { .type = NLA_U16 },
 440        [LWTUNNEL_IP_OPTS]      = { .type = NLA_NESTED },
 441};
 442
 443static const struct nla_policy ip_opts_policy[LWTUNNEL_IP_OPTS_MAX + 1] = {
 444        [LWTUNNEL_IP_OPTS_GENEVE]       = { .type = NLA_NESTED },
 445        [LWTUNNEL_IP_OPTS_VXLAN]        = { .type = NLA_NESTED },
 446        [LWTUNNEL_IP_OPTS_ERSPAN]       = { .type = NLA_NESTED },
 447};
 448
 449static const struct nla_policy
 450geneve_opt_policy[LWTUNNEL_IP_OPT_GENEVE_MAX + 1] = {
 451        [LWTUNNEL_IP_OPT_GENEVE_CLASS]  = { .type = NLA_U16 },
 452        [LWTUNNEL_IP_OPT_GENEVE_TYPE]   = { .type = NLA_U8 },
 453        [LWTUNNEL_IP_OPT_GENEVE_DATA]   = { .type = NLA_BINARY, .len = 128 },
 454};
 455
 456static const struct nla_policy
 457vxlan_opt_policy[LWTUNNEL_IP_OPT_VXLAN_MAX + 1] = {
 458        [LWTUNNEL_IP_OPT_VXLAN_GBP]     = { .type = NLA_U32 },
 459};
 460
 461static const struct nla_policy
 462erspan_opt_policy[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1] = {
 463        [LWTUNNEL_IP_OPT_ERSPAN_VER]    = { .type = NLA_U8 },
 464        [LWTUNNEL_IP_OPT_ERSPAN_INDEX]  = { .type = NLA_U32 },
 465        [LWTUNNEL_IP_OPT_ERSPAN_DIR]    = { .type = NLA_U8 },
 466        [LWTUNNEL_IP_OPT_ERSPAN_HWID]   = { .type = NLA_U8 },
 467};
 468
 469static int ip_tun_parse_opts_geneve(struct nlattr *attr,
 470                                    struct ip_tunnel_info *info, int opts_len,
 471                                    struct netlink_ext_ack *extack)
 472{
 473        struct nlattr *tb[LWTUNNEL_IP_OPT_GENEVE_MAX + 1];
 474        int data_len, err;
 475
 476        err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_GENEVE_MAX, attr,
 477                               geneve_opt_policy, extack);
 478        if (err)
 479                return err;
 480
 481        if (!tb[LWTUNNEL_IP_OPT_GENEVE_CLASS] ||
 482            !tb[LWTUNNEL_IP_OPT_GENEVE_TYPE] ||
 483            !tb[LWTUNNEL_IP_OPT_GENEVE_DATA])
 484                return -EINVAL;
 485
 486        attr = tb[LWTUNNEL_IP_OPT_GENEVE_DATA];
 487        data_len = nla_len(attr);
 488        if (data_len % 4)
 489                return -EINVAL;
 490
 491        if (info) {
 492                struct geneve_opt *opt = ip_tunnel_info_opts(info) + opts_len;
 493
 494                memcpy(opt->opt_data, nla_data(attr), data_len);
 495                opt->length = data_len / 4;
 496                attr = tb[LWTUNNEL_IP_OPT_GENEVE_CLASS];
 497                opt->opt_class = nla_get_be16(attr);
 498                attr = tb[LWTUNNEL_IP_OPT_GENEVE_TYPE];
 499                opt->type = nla_get_u8(attr);
 500                info->key.tun_flags |= TUNNEL_GENEVE_OPT;
 501        }
 502
 503        return sizeof(struct geneve_opt) + data_len;
 504}
 505
 506static int ip_tun_parse_opts_vxlan(struct nlattr *attr,
 507                                   struct ip_tunnel_info *info, int opts_len,
 508                                   struct netlink_ext_ack *extack)
 509{
 510        struct nlattr *tb[LWTUNNEL_IP_OPT_VXLAN_MAX + 1];
 511        int err;
 512
 513        err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_VXLAN_MAX, attr,
 514                               vxlan_opt_policy, extack);
 515        if (err)
 516                return err;
 517
 518        if (!tb[LWTUNNEL_IP_OPT_VXLAN_GBP])
 519                return -EINVAL;
 520
 521        if (info) {
 522                struct vxlan_metadata *md =
 523                        ip_tunnel_info_opts(info) + opts_len;
 524
 525                attr = tb[LWTUNNEL_IP_OPT_VXLAN_GBP];
 526                md->gbp = nla_get_u32(attr);
 527                md->gbp &= VXLAN_GBP_MASK;
 528                info->key.tun_flags |= TUNNEL_VXLAN_OPT;
 529        }
 530
 531        return sizeof(struct vxlan_metadata);
 532}
 533
 534static int ip_tun_parse_opts_erspan(struct nlattr *attr,
 535                                    struct ip_tunnel_info *info, int opts_len,
 536                                    struct netlink_ext_ack *extack)
 537{
 538        struct nlattr *tb[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1];
 539        int err;
 540        u8 ver;
 541
 542        err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_ERSPAN_MAX, attr,
 543                               erspan_opt_policy, extack);
 544        if (err)
 545                return err;
 546
 547        if (!tb[LWTUNNEL_IP_OPT_ERSPAN_VER])
 548                return -EINVAL;
 549
 550        ver = nla_get_u8(tb[LWTUNNEL_IP_OPT_ERSPAN_VER]);
 551        if (ver == 1) {
 552                if (!tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX])
 553                        return -EINVAL;
 554        } else if (ver == 2) {
 555                if (!tb[LWTUNNEL_IP_OPT_ERSPAN_DIR] ||
 556                    !tb[LWTUNNEL_IP_OPT_ERSPAN_HWID])
 557                        return -EINVAL;
 558        } else {
 559                return -EINVAL;
 560        }
 561
 562        if (info) {
 563                struct erspan_metadata *md =
 564                        ip_tunnel_info_opts(info) + opts_len;
 565
 566                md->version = ver;
 567                if (ver == 1) {
 568                        attr = tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX];
 569                        md->u.index = nla_get_be32(attr);
 570                } else {
 571                        attr = tb[LWTUNNEL_IP_OPT_ERSPAN_DIR];
 572                        md->u.md2.dir = nla_get_u8(attr);
 573                        attr = tb[LWTUNNEL_IP_OPT_ERSPAN_HWID];
 574                        set_hwid(&md->u.md2, nla_get_u8(attr));
 575                }
 576
 577                info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
 578        }
 579
 580        return sizeof(struct erspan_metadata);
 581}
 582
 583static int ip_tun_parse_opts(struct nlattr *attr, struct ip_tunnel_info *info,
 584                             struct netlink_ext_ack *extack)
 585{
 586        int err, rem, opt_len, opts_len = 0;
 587        struct nlattr *nla;
 588        __be16 type = 0;
 589
 590        if (!attr)
 591                return 0;
 592
 593        err = nla_validate(nla_data(attr), nla_len(attr), LWTUNNEL_IP_OPTS_MAX,
 594                           ip_opts_policy, extack);
 595        if (err)
 596                return err;
 597
 598        nla_for_each_attr(nla, nla_data(attr), nla_len(attr), rem) {
 599                switch (nla_type(nla)) {
 600                case LWTUNNEL_IP_OPTS_GENEVE:
 601                        if (type && type != TUNNEL_GENEVE_OPT)
 602                                return -EINVAL;
 603                        opt_len = ip_tun_parse_opts_geneve(nla, info, opts_len,
 604                                                           extack);
 605                        if (opt_len < 0)
 606                                return opt_len;
 607                        opts_len += opt_len;
 608                        if (opts_len > IP_TUNNEL_OPTS_MAX)
 609                                return -EINVAL;
 610                        type = TUNNEL_GENEVE_OPT;
 611                        break;
 612                case LWTUNNEL_IP_OPTS_VXLAN:
 613                        if (type)
 614                                return -EINVAL;
 615                        opt_len = ip_tun_parse_opts_vxlan(nla, info, opts_len,
 616                                                          extack);
 617                        if (opt_len < 0)
 618                                return opt_len;
 619                        opts_len += opt_len;
 620                        type = TUNNEL_VXLAN_OPT;
 621                        break;
 622                case LWTUNNEL_IP_OPTS_ERSPAN:
 623                        if (type)
 624                                return -EINVAL;
 625                        opt_len = ip_tun_parse_opts_erspan(nla, info, opts_len,
 626                                                           extack);
 627                        if (opt_len < 0)
 628                                return opt_len;
 629                        opts_len += opt_len;
 630                        type = TUNNEL_ERSPAN_OPT;
 631                        break;
 632                default:
 633                        return -EINVAL;
 634                }
 635        }
 636
 637        return opts_len;
 638}
 639
 640static int ip_tun_get_optlen(struct nlattr *attr,
 641                             struct netlink_ext_ack *extack)
 642{
 643        return ip_tun_parse_opts(attr, NULL, extack);
 644}
 645
 646static int ip_tun_set_opts(struct nlattr *attr, struct ip_tunnel_info *info,
 647                           struct netlink_ext_ack *extack)
 648{
 649        return ip_tun_parse_opts(attr, info, extack);
 650}
 651
 652static int ip_tun_build_state(struct net *net, struct nlattr *attr,
 653                              unsigned int family, const void *cfg,
 654                              struct lwtunnel_state **ts,
 655                              struct netlink_ext_ack *extack)
 656{
 657        struct nlattr *tb[LWTUNNEL_IP_MAX + 1];
 658        struct lwtunnel_state *new_state;
 659        struct ip_tunnel_info *tun_info;
 660        int err, opt_len;
 661
 662        err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP_MAX, attr,
 663                                          ip_tun_policy, extack);
 664        if (err < 0)
 665                return err;
 666
 667        opt_len = ip_tun_get_optlen(tb[LWTUNNEL_IP_OPTS], extack);
 668        if (opt_len < 0)
 669                return opt_len;
 670
 671        new_state = lwtunnel_state_alloc(sizeof(*tun_info) + opt_len);
 672        if (!new_state)
 673                return -ENOMEM;
 674
 675        new_state->type = LWTUNNEL_ENCAP_IP;
 676
 677        tun_info = lwt_tun_info(new_state);
 678
 679        err = ip_tun_set_opts(tb[LWTUNNEL_IP_OPTS], tun_info, extack);
 680        if (err < 0) {
 681                lwtstate_free(new_state);
 682                return err;
 683        }
 684
 685#ifdef CONFIG_DST_CACHE
 686        err = dst_cache_init(&tun_info->dst_cache, GFP_KERNEL);
 687        if (err) {
 688                lwtstate_free(new_state);
 689                return err;
 690        }
 691#endif
 692
 693        if (tb[LWTUNNEL_IP_ID])
 694                tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP_ID]);
 695
 696        if (tb[LWTUNNEL_IP_DST])
 697                tun_info->key.u.ipv4.dst = nla_get_in_addr(tb[LWTUNNEL_IP_DST]);
 698
 699        if (tb[LWTUNNEL_IP_SRC])
 700                tun_info->key.u.ipv4.src = nla_get_in_addr(tb[LWTUNNEL_IP_SRC]);
 701
 702        if (tb[LWTUNNEL_IP_TTL])
 703                tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP_TTL]);
 704
 705        if (tb[LWTUNNEL_IP_TOS])
 706                tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP_TOS]);
 707
 708        if (tb[LWTUNNEL_IP_FLAGS])
 709                tun_info->key.tun_flags |=
 710                                (nla_get_be16(tb[LWTUNNEL_IP_FLAGS]) &
 711                                 ~TUNNEL_OPTIONS_PRESENT);
 712
 713        tun_info->mode = IP_TUNNEL_INFO_TX;
 714        tun_info->options_len = opt_len;
 715
 716        *ts = new_state;
 717
 718        return 0;
 719}
 720
 721static void ip_tun_destroy_state(struct lwtunnel_state *lwtstate)
 722{
 723#ifdef CONFIG_DST_CACHE
 724        struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
 725
 726        dst_cache_destroy(&tun_info->dst_cache);
 727#endif
 728}
 729
 730static int ip_tun_fill_encap_opts_geneve(struct sk_buff *skb,
 731                                         struct ip_tunnel_info *tun_info)
 732{
 733        struct geneve_opt *opt;
 734        struct nlattr *nest;
 735        int offset = 0;
 736
 737        nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_GENEVE);
 738        if (!nest)
 739                return -ENOMEM;
 740
 741        while (tun_info->options_len > offset) {
 742                opt = ip_tunnel_info_opts(tun_info) + offset;
 743                if (nla_put_be16(skb, LWTUNNEL_IP_OPT_GENEVE_CLASS,
 744                                 opt->opt_class) ||
 745                    nla_put_u8(skb, LWTUNNEL_IP_OPT_GENEVE_TYPE, opt->type) ||
 746                    nla_put(skb, LWTUNNEL_IP_OPT_GENEVE_DATA, opt->length * 4,
 747                            opt->opt_data)) {
 748                        nla_nest_cancel(skb, nest);
 749                        return -ENOMEM;
 750                }
 751                offset += sizeof(*opt) + opt->length * 4;
 752        }
 753
 754        nla_nest_end(skb, nest);
 755        return 0;
 756}
 757
 758static int ip_tun_fill_encap_opts_vxlan(struct sk_buff *skb,
 759                                        struct ip_tunnel_info *tun_info)
 760{
 761        struct vxlan_metadata *md;
 762        struct nlattr *nest;
 763
 764        nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_VXLAN);
 765        if (!nest)
 766                return -ENOMEM;
 767
 768        md = ip_tunnel_info_opts(tun_info);
 769        if (nla_put_u32(skb, LWTUNNEL_IP_OPT_VXLAN_GBP, md->gbp)) {
 770                nla_nest_cancel(skb, nest);
 771                return -ENOMEM;
 772        }
 773
 774        nla_nest_end(skb, nest);
 775        return 0;
 776}
 777
 778static int ip_tun_fill_encap_opts_erspan(struct sk_buff *skb,
 779                                         struct ip_tunnel_info *tun_info)
 780{
 781        struct erspan_metadata *md;
 782        struct nlattr *nest;
 783
 784        nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_ERSPAN);
 785        if (!nest)
 786                return -ENOMEM;
 787
 788        md = ip_tunnel_info_opts(tun_info);
 789        if (nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_VER, md->version))
 790                goto err;
 791
 792        if (md->version == 1 &&
 793            nla_put_be32(skb, LWTUNNEL_IP_OPT_ERSPAN_INDEX, md->u.index))
 794                goto err;
 795
 796        if (md->version == 2 &&
 797            (nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_DIR, md->u.md2.dir) ||
 798             nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_HWID,
 799                        get_hwid(&md->u.md2))))
 800                goto err;
 801
 802        nla_nest_end(skb, nest);
 803        return 0;
 804err:
 805        nla_nest_cancel(skb, nest);
 806        return -ENOMEM;
 807}
 808
 809static int ip_tun_fill_encap_opts(struct sk_buff *skb, int type,
 810                                  struct ip_tunnel_info *tun_info)
 811{
 812        struct nlattr *nest;
 813        int err = 0;
 814
 815        if (!(tun_info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))
 816                return 0;
 817
 818        nest = nla_nest_start_noflag(skb, type);
 819        if (!nest)
 820                return -ENOMEM;
 821
 822        if (tun_info->key.tun_flags & TUNNEL_GENEVE_OPT)
 823                err = ip_tun_fill_encap_opts_geneve(skb, tun_info);
 824        else if (tun_info->key.tun_flags & TUNNEL_VXLAN_OPT)
 825                err = ip_tun_fill_encap_opts_vxlan(skb, tun_info);
 826        else if (tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)
 827                err = ip_tun_fill_encap_opts_erspan(skb, tun_info);
 828
 829        if (err) {
 830                nla_nest_cancel(skb, nest);
 831                return err;
 832        }
 833
 834        nla_nest_end(skb, nest);
 835        return 0;
 836}
 837
 838static int ip_tun_fill_encap_info(struct sk_buff *skb,
 839                                  struct lwtunnel_state *lwtstate)
 840{
 841        struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
 842
 843        if (nla_put_be64(skb, LWTUNNEL_IP_ID, tun_info->key.tun_id,
 844                         LWTUNNEL_IP_PAD) ||
 845            nla_put_in_addr(skb, LWTUNNEL_IP_DST, tun_info->key.u.ipv4.dst) ||
 846            nla_put_in_addr(skb, LWTUNNEL_IP_SRC, tun_info->key.u.ipv4.src) ||
 847            nla_put_u8(skb, LWTUNNEL_IP_TOS, tun_info->key.tos) ||
 848            nla_put_u8(skb, LWTUNNEL_IP_TTL, tun_info->key.ttl) ||
 849            nla_put_be16(skb, LWTUNNEL_IP_FLAGS, tun_info->key.tun_flags) ||
 850            ip_tun_fill_encap_opts(skb, LWTUNNEL_IP_OPTS, tun_info))
 851                return -ENOMEM;
 852
 853        return 0;
 854}
 855
 856static int ip_tun_opts_nlsize(struct ip_tunnel_info *info)
 857{
 858        int opt_len;
 859
 860        if (!(info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))
 861                return 0;
 862
 863        opt_len = nla_total_size(0);            /* LWTUNNEL_IP_OPTS */
 864        if (info->key.tun_flags & TUNNEL_GENEVE_OPT) {
 865                struct geneve_opt *opt;
 866                int offset = 0;
 867
 868                opt_len += nla_total_size(0);   /* LWTUNNEL_IP_OPTS_GENEVE */
 869                while (info->options_len > offset) {
 870                        opt = ip_tunnel_info_opts(info) + offset;
 871                        opt_len += nla_total_size(2)    /* OPT_GENEVE_CLASS */
 872                                   + nla_total_size(1)  /* OPT_GENEVE_TYPE */
 873                                   + nla_total_size(opt->length * 4);
 874                                                        /* OPT_GENEVE_DATA */
 875                        offset += sizeof(*opt) + opt->length * 4;
 876                }
 877        } else if (info->key.tun_flags & TUNNEL_VXLAN_OPT) {
 878                opt_len += nla_total_size(0)    /* LWTUNNEL_IP_OPTS_VXLAN */
 879                           + nla_total_size(4); /* OPT_VXLAN_GBP */
 880        } else if (info->key.tun_flags & TUNNEL_ERSPAN_OPT) {
 881                struct erspan_metadata *md = ip_tunnel_info_opts(info);
 882
 883                opt_len += nla_total_size(0)    /* LWTUNNEL_IP_OPTS_ERSPAN */
 884                           + nla_total_size(1)  /* OPT_ERSPAN_VER */
 885                           + (md->version == 1 ? nla_total_size(4)
 886                                                /* OPT_ERSPAN_INDEX (v1) */
 887                                               : nla_total_size(1) +
 888                                                 nla_total_size(1));
 889                                                /* OPT_ERSPAN_DIR + HWID (v2) */
 890        }
 891
 892        return opt_len;
 893}
 894
 895static int ip_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
 896{
 897        return nla_total_size_64bit(8)  /* LWTUNNEL_IP_ID */
 898                + nla_total_size(4)     /* LWTUNNEL_IP_DST */
 899                + nla_total_size(4)     /* LWTUNNEL_IP_SRC */
 900                + nla_total_size(1)     /* LWTUNNEL_IP_TOS */
 901                + nla_total_size(1)     /* LWTUNNEL_IP_TTL */
 902                + nla_total_size(2)     /* LWTUNNEL_IP_FLAGS */
 903                + ip_tun_opts_nlsize(lwt_tun_info(lwtstate));
 904                                        /* LWTUNNEL_IP_OPTS */
 905}
 906
 907static int ip_tun_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
 908{
 909        struct ip_tunnel_info *info_a = lwt_tun_info(a);
 910        struct ip_tunnel_info *info_b = lwt_tun_info(b);
 911
 912        return memcmp(info_a, info_b, sizeof(info_a->key)) ||
 913               info_a->mode != info_b->mode ||
 914               info_a->options_len != info_b->options_len ||
 915               memcmp(ip_tunnel_info_opts(info_a),
 916                      ip_tunnel_info_opts(info_b), info_a->options_len);
 917}
 918
 919static const struct lwtunnel_encap_ops ip_tun_lwt_ops = {
 920        .build_state = ip_tun_build_state,
 921        .destroy_state = ip_tun_destroy_state,
 922        .fill_encap = ip_tun_fill_encap_info,
 923        .get_encap_size = ip_tun_encap_nlsize,
 924        .cmp_encap = ip_tun_cmp_encap,
 925        .owner = THIS_MODULE,
 926};
 927
 928static const struct nla_policy ip6_tun_policy[LWTUNNEL_IP6_MAX + 1] = {
 929        [LWTUNNEL_IP6_UNSPEC]   = { .strict_start_type = LWTUNNEL_IP6_OPTS },
 930        [LWTUNNEL_IP6_ID]               = { .type = NLA_U64 },
 931        [LWTUNNEL_IP6_DST]              = { .len = sizeof(struct in6_addr) },
 932        [LWTUNNEL_IP6_SRC]              = { .len = sizeof(struct in6_addr) },
 933        [LWTUNNEL_IP6_HOPLIMIT]         = { .type = NLA_U8 },
 934        [LWTUNNEL_IP6_TC]               = { .type = NLA_U8 },
 935        [LWTUNNEL_IP6_FLAGS]            = { .type = NLA_U16 },
 936        [LWTUNNEL_IP6_OPTS]             = { .type = NLA_NESTED },
 937};
 938
 939static int ip6_tun_build_state(struct net *net, struct nlattr *attr,
 940                               unsigned int family, const void *cfg,
 941                               struct lwtunnel_state **ts,
 942                               struct netlink_ext_ack *extack)
 943{
 944        struct nlattr *tb[LWTUNNEL_IP6_MAX + 1];
 945        struct lwtunnel_state *new_state;
 946        struct ip_tunnel_info *tun_info;
 947        int err, opt_len;
 948
 949        err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP6_MAX, attr,
 950                                          ip6_tun_policy, extack);
 951        if (err < 0)
 952                return err;
 953
 954        opt_len = ip_tun_get_optlen(tb[LWTUNNEL_IP6_OPTS], extack);
 955        if (opt_len < 0)
 956                return opt_len;
 957
 958        new_state = lwtunnel_state_alloc(sizeof(*tun_info) + opt_len);
 959        if (!new_state)
 960                return -ENOMEM;
 961
 962        new_state->type = LWTUNNEL_ENCAP_IP6;
 963
 964        tun_info = lwt_tun_info(new_state);
 965
 966        err = ip_tun_set_opts(tb[LWTUNNEL_IP6_OPTS], tun_info, extack);
 967        if (err < 0) {
 968                lwtstate_free(new_state);
 969                return err;
 970        }
 971
 972        if (tb[LWTUNNEL_IP6_ID])
 973                tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP6_ID]);
 974
 975        if (tb[LWTUNNEL_IP6_DST])
 976                tun_info->key.u.ipv6.dst = nla_get_in6_addr(tb[LWTUNNEL_IP6_DST]);
 977
 978        if (tb[LWTUNNEL_IP6_SRC])
 979                tun_info->key.u.ipv6.src = nla_get_in6_addr(tb[LWTUNNEL_IP6_SRC]);
 980
 981        if (tb[LWTUNNEL_IP6_HOPLIMIT])
 982                tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP6_HOPLIMIT]);
 983
 984        if (tb[LWTUNNEL_IP6_TC])
 985                tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP6_TC]);
 986
 987        if (tb[LWTUNNEL_IP6_FLAGS])
 988                tun_info->key.tun_flags |=
 989                                (nla_get_be16(tb[LWTUNNEL_IP6_FLAGS]) &
 990                                 ~TUNNEL_OPTIONS_PRESENT);
 991
 992        tun_info->mode = IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_IPV6;
 993        tun_info->options_len = opt_len;
 994
 995        *ts = new_state;
 996
 997        return 0;
 998}
 999
1000static int ip6_tun_fill_encap_info(struct sk_buff *skb,
1001                                   struct lwtunnel_state *lwtstate)
1002{
1003        struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
1004
1005        if (nla_put_be64(skb, LWTUNNEL_IP6_ID, tun_info->key.tun_id,
1006                         LWTUNNEL_IP6_PAD) ||
1007            nla_put_in6_addr(skb, LWTUNNEL_IP6_DST, &tun_info->key.u.ipv6.dst) ||
1008            nla_put_in6_addr(skb, LWTUNNEL_IP6_SRC, &tun_info->key.u.ipv6.src) ||
1009            nla_put_u8(skb, LWTUNNEL_IP6_TC, tun_info->key.tos) ||
1010            nla_put_u8(skb, LWTUNNEL_IP6_HOPLIMIT, tun_info->key.ttl) ||
1011            nla_put_be16(skb, LWTUNNEL_IP6_FLAGS, tun_info->key.tun_flags) ||
1012            ip_tun_fill_encap_opts(skb, LWTUNNEL_IP6_OPTS, tun_info))
1013                return -ENOMEM;
1014
1015        return 0;
1016}
1017
1018static int ip6_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
1019{
1020        return nla_total_size_64bit(8)  /* LWTUNNEL_IP6_ID */
1021                + nla_total_size(16)    /* LWTUNNEL_IP6_DST */
1022                + nla_total_size(16)    /* LWTUNNEL_IP6_SRC */
1023                + nla_total_size(1)     /* LWTUNNEL_IP6_HOPLIMIT */
1024                + nla_total_size(1)     /* LWTUNNEL_IP6_TC */
1025                + nla_total_size(2)     /* LWTUNNEL_IP6_FLAGS */
1026                + ip_tun_opts_nlsize(lwt_tun_info(lwtstate));
1027                                        /* LWTUNNEL_IP6_OPTS */
1028}
1029
1030static const struct lwtunnel_encap_ops ip6_tun_lwt_ops = {
1031        .build_state = ip6_tun_build_state,
1032        .fill_encap = ip6_tun_fill_encap_info,
1033        .get_encap_size = ip6_tun_encap_nlsize,
1034        .cmp_encap = ip_tun_cmp_encap,
1035        .owner = THIS_MODULE,
1036};
1037
1038void __init ip_tunnel_core_init(void)
1039{
1040        /* If you land here, make sure whether increasing ip_tunnel_info's
1041         * options_len is a reasonable choice with its usage in front ends
1042         * (f.e., it's part of flow keys, etc).
1043         */
1044        BUILD_BUG_ON(IP_TUNNEL_OPTS_MAX != 255);
1045
1046        lwtunnel_encap_add_ops(&ip_tun_lwt_ops, LWTUNNEL_ENCAP_IP);
1047        lwtunnel_encap_add_ops(&ip6_tun_lwt_ops, LWTUNNEL_ENCAP_IP6);
1048}
1049
1050DEFINE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
1051EXPORT_SYMBOL(ip_tunnel_metadata_cnt);
1052
1053void ip_tunnel_need_metadata(void)
1054{
1055        static_branch_inc(&ip_tunnel_metadata_cnt);
1056}
1057EXPORT_SYMBOL_GPL(ip_tunnel_need_metadata);
1058
1059void ip_tunnel_unneed_metadata(void)
1060{
1061        static_branch_dec(&ip_tunnel_metadata_cnt);
1062}
1063EXPORT_SYMBOL_GPL(ip_tunnel_unneed_metadata);
1064
1065/* Returns either the correct skb->protocol value, or 0 if invalid. */
1066__be16 ip_tunnel_parse_protocol(const struct sk_buff *skb)
1067{
1068        if (skb_network_header(skb) >= skb->head &&
1069            (skb_network_header(skb) + sizeof(struct iphdr)) <= skb_tail_pointer(skb) &&
1070            ip_hdr(skb)->version == 4)
1071                return htons(ETH_P_IP);
1072        if (skb_network_header(skb) >= skb->head &&
1073            (skb_network_header(skb) + sizeof(struct ipv6hdr)) <= skb_tail_pointer(skb) &&
1074            ipv6_hdr(skb)->version == 6)
1075                return htons(ETH_P_IPV6);
1076        return 0;
1077}
1078EXPORT_SYMBOL(ip_tunnel_parse_protocol);
1079
1080const struct header_ops ip_tunnel_header_ops = { .parse_protocol = ip_tunnel_parse_protocol };
1081EXPORT_SYMBOL(ip_tunnel_header_ops);
1082