linux/net/ipv6/seg6_local.c
<<
>>
Prefs
   1/*
   2 *  SR-IPv6 implementation
   3 *
   4 *  Authors:
   5 *  David Lebrun <david.lebrun@uclouvain.be>
   6 *  eBPF support: Mathieu Xhonneux <m.xhonneux@gmail.com>
   7 *
   8 *
   9 *  This program is free software; you can redistribute it and/or
  10 *        modify it under the terms of the GNU General Public License
  11 *        as published by the Free Software Foundation; either version
  12 *        2 of the License, or (at your option) any later version.
  13 */
  14
  15#include <linux/types.h>
  16#include <linux/skbuff.h>
  17#include <linux/net.h>
  18#include <linux/module.h>
  19#include <net/ip.h>
  20#include <net/lwtunnel.h>
  21#include <net/netevent.h>
  22#include <net/netns/generic.h>
  23#include <net/ip6_fib.h>
  24#include <net/route.h>
  25#include <net/seg6.h>
  26#include <linux/seg6.h>
  27#include <linux/seg6_local.h>
  28#include <net/addrconf.h>
  29#include <net/ip6_route.h>
  30#include <net/dst_cache.h>
  31#ifdef CONFIG_IPV6_SEG6_HMAC
  32#include <net/seg6_hmac.h>
  33#endif
  34#include <net/seg6_local.h>
  35#include <linux/etherdevice.h>
  36#include <linux/bpf.h>
  37
  38struct seg6_local_lwt;
  39
  40struct seg6_action_desc {
  41        int action;
  42        unsigned long attrs;
  43        int (*input)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
  44        int static_headroom;
  45};
  46
  47struct bpf_lwt_prog {
  48        struct bpf_prog *prog;
  49        char *name;
  50};
  51
  52struct seg6_local_lwt {
  53        int action;
  54        struct ipv6_sr_hdr *srh;
  55        int table;
  56        struct in_addr nh4;
  57        struct in6_addr nh6;
  58        int iif;
  59        int oif;
  60        struct bpf_lwt_prog bpf;
  61
  62        int headroom;
  63        struct seg6_action_desc *desc;
  64};
  65
  66static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt)
  67{
  68        return (struct seg6_local_lwt *)lwt->data;
  69}
  70
  71static struct ipv6_sr_hdr *get_srh(struct sk_buff *skb)
  72{
  73        struct ipv6_sr_hdr *srh;
  74        int len, srhoff = 0;
  75
  76        if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0)
  77                return NULL;
  78
  79        if (!pskb_may_pull(skb, srhoff + sizeof(*srh)))
  80                return NULL;
  81
  82        srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
  83
  84        len = (srh->hdrlen + 1) << 3;
  85
  86        if (!pskb_may_pull(skb, srhoff + len))
  87                return NULL;
  88
  89        if (!seg6_validate_srh(srh, len))
  90                return NULL;
  91
  92        return srh;
  93}
  94
  95static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb)
  96{
  97        struct ipv6_sr_hdr *srh;
  98
  99        srh = get_srh(skb);
 100        if (!srh)
 101                return NULL;
 102
 103        if (srh->segments_left == 0)
 104                return NULL;
 105
 106#ifdef CONFIG_IPV6_SEG6_HMAC
 107        if (!seg6_hmac_validate_skb(skb))
 108                return NULL;
 109#endif
 110
 111        return srh;
 112}
 113
 114static bool decap_and_validate(struct sk_buff *skb, int proto)
 115{
 116        struct ipv6_sr_hdr *srh;
 117        unsigned int off = 0;
 118
 119        srh = get_srh(skb);
 120        if (srh && srh->segments_left > 0)
 121                return false;
 122
 123#ifdef CONFIG_IPV6_SEG6_HMAC
 124        if (srh && !seg6_hmac_validate_skb(skb))
 125                return false;
 126#endif
 127
 128        if (ipv6_find_hdr(skb, &off, proto, NULL, NULL) < 0)
 129                return false;
 130
 131        if (!pskb_pull(skb, off))
 132                return false;
 133
 134        skb_postpull_rcsum(skb, skb_network_header(skb), off);
 135
 136        skb_reset_network_header(skb);
 137        skb_reset_transport_header(skb);
 138        skb->encapsulation = 0;
 139
 140        return true;
 141}
 142
 143static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr)
 144{
 145        struct in6_addr *addr;
 146
 147        srh->segments_left--;
 148        addr = srh->segments + srh->segments_left;
 149        *daddr = *addr;
 150}
 151
 152int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
 153                        u32 tbl_id)
 154{
 155        struct net *net = dev_net(skb->dev);
 156        struct ipv6hdr *hdr = ipv6_hdr(skb);
 157        int flags = RT6_LOOKUP_F_HAS_SADDR;
 158        struct dst_entry *dst = NULL;
 159        struct rt6_info *rt;
 160        struct flowi6 fl6;
 161
 162        fl6.flowi6_iif = skb->dev->ifindex;
 163        fl6.daddr = nhaddr ? *nhaddr : hdr->daddr;
 164        fl6.saddr = hdr->saddr;
 165        fl6.flowlabel = ip6_flowinfo(hdr);
 166        fl6.flowi6_mark = skb->mark;
 167        fl6.flowi6_proto = hdr->nexthdr;
 168
 169        if (nhaddr)
 170                fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH;
 171
 172        if (!tbl_id) {
 173                dst = ip6_route_input_lookup(net, skb->dev, &fl6, skb, flags);
 174        } else {
 175                struct fib6_table *table;
 176
 177                table = fib6_get_table(net, tbl_id);
 178                if (!table)
 179                        goto out;
 180
 181                rt = ip6_pol_route(net, table, 0, &fl6, skb, flags);
 182                dst = &rt->dst;
 183        }
 184
 185        if (dst && dst->dev->flags & IFF_LOOPBACK && !dst->error) {
 186                dst_release(dst);
 187                dst = NULL;
 188        }
 189
 190out:
 191        if (!dst) {
 192                rt = net->ipv6.ip6_blk_hole_entry;
 193                dst = &rt->dst;
 194                dst_hold(dst);
 195        }
 196
 197        skb_dst_drop(skb);
 198        skb_dst_set(skb, dst);
 199        return dst->error;
 200}
 201
 202/* regular endpoint function */
 203static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 204{
 205        struct ipv6_sr_hdr *srh;
 206
 207        srh = get_and_validate_srh(skb);
 208        if (!srh)
 209                goto drop;
 210
 211        advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
 212
 213        seg6_lookup_nexthop(skb, NULL, 0);
 214
 215        return dst_input(skb);
 216
 217drop:
 218        kfree_skb(skb);
 219        return -EINVAL;
 220}
 221
 222/* regular endpoint, and forward to specified nexthop */
 223static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 224{
 225        struct ipv6_sr_hdr *srh;
 226
 227        srh = get_and_validate_srh(skb);
 228        if (!srh)
 229                goto drop;
 230
 231        advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
 232
 233        seg6_lookup_nexthop(skb, &slwt->nh6, 0);
 234
 235        return dst_input(skb);
 236
 237drop:
 238        kfree_skb(skb);
 239        return -EINVAL;
 240}
 241
 242static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 243{
 244        struct ipv6_sr_hdr *srh;
 245
 246        srh = get_and_validate_srh(skb);
 247        if (!srh)
 248                goto drop;
 249
 250        advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
 251
 252        seg6_lookup_nexthop(skb, NULL, slwt->table);
 253
 254        return dst_input(skb);
 255
 256drop:
 257        kfree_skb(skb);
 258        return -EINVAL;
 259}
 260
 261/* decapsulate and forward inner L2 frame on specified interface */
 262static int input_action_end_dx2(struct sk_buff *skb,
 263                                struct seg6_local_lwt *slwt)
 264{
 265        struct net *net = dev_net(skb->dev);
 266        struct net_device *odev;
 267        struct ethhdr *eth;
 268
 269        if (!decap_and_validate(skb, NEXTHDR_NONE))
 270                goto drop;
 271
 272        if (!pskb_may_pull(skb, ETH_HLEN))
 273                goto drop;
 274
 275        skb_reset_mac_header(skb);
 276        eth = (struct ethhdr *)skb->data;
 277
 278        /* To determine the frame's protocol, we assume it is 802.3. This avoids
 279         * a call to eth_type_trans(), which is not really relevant for our
 280         * use case.
 281         */
 282        if (!eth_proto_is_802_3(eth->h_proto))
 283                goto drop;
 284
 285        odev = dev_get_by_index_rcu(net, slwt->oif);
 286        if (!odev)
 287                goto drop;
 288
 289        /* As we accept Ethernet frames, make sure the egress device is of
 290         * the correct type.
 291         */
 292        if (odev->type != ARPHRD_ETHER)
 293                goto drop;
 294
 295        if (!(odev->flags & IFF_UP) || !netif_carrier_ok(odev))
 296                goto drop;
 297
 298        skb_orphan(skb);
 299
 300        if (skb_warn_if_lro(skb))
 301                goto drop;
 302
 303        skb_forward_csum(skb);
 304
 305        if (skb->len - ETH_HLEN > odev->mtu)
 306                goto drop;
 307
 308        skb->dev = odev;
 309        skb->protocol = eth->h_proto;
 310
 311        return dev_queue_xmit(skb);
 312
 313drop:
 314        kfree_skb(skb);
 315        return -EINVAL;
 316}
 317
 318/* decapsulate and forward to specified nexthop */
 319static int input_action_end_dx6(struct sk_buff *skb,
 320                                struct seg6_local_lwt *slwt)
 321{
 322        struct in6_addr *nhaddr = NULL;
 323
 324        /* this function accepts IPv6 encapsulated packets, with either
 325         * an SRH with SL=0, or no SRH.
 326         */
 327
 328        if (!decap_and_validate(skb, IPPROTO_IPV6))
 329                goto drop;
 330
 331        if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 332                goto drop;
 333
 334        /* The inner packet is not associated to any local interface,
 335         * so we do not call netif_rx().
 336         *
 337         * If slwt->nh6 is set to ::, then lookup the nexthop for the
 338         * inner packet's DA. Otherwise, use the specified nexthop.
 339         */
 340
 341        if (!ipv6_addr_any(&slwt->nh6))
 342                nhaddr = &slwt->nh6;
 343
 344        seg6_lookup_nexthop(skb, nhaddr, 0);
 345
 346        return dst_input(skb);
 347drop:
 348        kfree_skb(skb);
 349        return -EINVAL;
 350}
 351
 352static int input_action_end_dx4(struct sk_buff *skb,
 353                                struct seg6_local_lwt *slwt)
 354{
 355        struct iphdr *iph;
 356        __be32 nhaddr;
 357        int err;
 358
 359        if (!decap_and_validate(skb, IPPROTO_IPIP))
 360                goto drop;
 361
 362        if (!pskb_may_pull(skb, sizeof(struct iphdr)))
 363                goto drop;
 364
 365        skb->protocol = htons(ETH_P_IP);
 366
 367        iph = ip_hdr(skb);
 368
 369        nhaddr = slwt->nh4.s_addr ?: iph->daddr;
 370
 371        skb_dst_drop(skb);
 372
 373        err = ip_route_input(skb, nhaddr, iph->saddr, 0, skb->dev);
 374        if (err)
 375                goto drop;
 376
 377        return dst_input(skb);
 378
 379drop:
 380        kfree_skb(skb);
 381        return -EINVAL;
 382}
 383
 384static int input_action_end_dt6(struct sk_buff *skb,
 385                                struct seg6_local_lwt *slwt)
 386{
 387        if (!decap_and_validate(skb, IPPROTO_IPV6))
 388                goto drop;
 389
 390        if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 391                goto drop;
 392
 393        seg6_lookup_nexthop(skb, NULL, slwt->table);
 394
 395        return dst_input(skb);
 396
 397drop:
 398        kfree_skb(skb);
 399        return -EINVAL;
 400}
 401
 402/* push an SRH on top of the current one */
 403static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 404{
 405        struct ipv6_sr_hdr *srh;
 406        int err = -EINVAL;
 407
 408        srh = get_and_validate_srh(skb);
 409        if (!srh)
 410                goto drop;
 411
 412        err = seg6_do_srh_inline(skb, slwt->srh);
 413        if (err)
 414                goto drop;
 415
 416        ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
 417        skb_set_transport_header(skb, sizeof(struct ipv6hdr));
 418
 419        seg6_lookup_nexthop(skb, NULL, 0);
 420
 421        return dst_input(skb);
 422
 423drop:
 424        kfree_skb(skb);
 425        return err;
 426}
 427
 428/* encapsulate within an outer IPv6 header and a specified SRH */
 429static int input_action_end_b6_encap(struct sk_buff *skb,
 430                                     struct seg6_local_lwt *slwt)
 431{
 432        struct ipv6_sr_hdr *srh;
 433        int err = -EINVAL;
 434
 435        srh = get_and_validate_srh(skb);
 436        if (!srh)
 437                goto drop;
 438
 439        advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
 440
 441        skb_reset_inner_headers(skb);
 442        skb->encapsulation = 1;
 443
 444        err = seg6_do_srh_encap(skb, slwt->srh, IPPROTO_IPV6);
 445        if (err)
 446                goto drop;
 447
 448        ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
 449        skb_set_transport_header(skb, sizeof(struct ipv6hdr));
 450
 451        seg6_lookup_nexthop(skb, NULL, 0);
 452
 453        return dst_input(skb);
 454
 455drop:
 456        kfree_skb(skb);
 457        return err;
 458}
 459
 460DEFINE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states);
 461
 462bool seg6_bpf_has_valid_srh(struct sk_buff *skb)
 463{
 464        struct seg6_bpf_srh_state *srh_state =
 465                this_cpu_ptr(&seg6_bpf_srh_states);
 466        struct ipv6_sr_hdr *srh = srh_state->srh;
 467
 468        if (unlikely(srh == NULL))
 469                return false;
 470
 471        if (unlikely(!srh_state->valid)) {
 472                if ((srh_state->hdrlen & 7) != 0)
 473                        return false;
 474
 475                srh->hdrlen = (u8)(srh_state->hdrlen >> 3);
 476                if (!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3))
 477                        return false;
 478
 479                srh_state->valid = true;
 480        }
 481
 482        return true;
 483}
 484
 485static int input_action_end_bpf(struct sk_buff *skb,
 486                                struct seg6_local_lwt *slwt)
 487{
 488        struct seg6_bpf_srh_state *srh_state =
 489                this_cpu_ptr(&seg6_bpf_srh_states);
 490        struct ipv6_sr_hdr *srh;
 491        int ret;
 492
 493        srh = get_and_validate_srh(skb);
 494        if (!srh) {
 495                kfree_skb(skb);
 496                return -EINVAL;
 497        }
 498        advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
 499
 500        /* preempt_disable is needed to protect the per-CPU buffer srh_state,
 501         * which is also accessed by the bpf_lwt_seg6_* helpers
 502         */
 503        preempt_disable();
 504        srh_state->srh = srh;
 505        srh_state->hdrlen = srh->hdrlen << 3;
 506        srh_state->valid = true;
 507
 508        rcu_read_lock();
 509        bpf_compute_data_pointers(skb);
 510        ret = bpf_prog_run_save_cb(slwt->bpf.prog, skb);
 511        rcu_read_unlock();
 512
 513        switch (ret) {
 514        case BPF_OK:
 515        case BPF_REDIRECT:
 516                break;
 517        case BPF_DROP:
 518                goto drop;
 519        default:
 520                pr_warn_once("bpf-seg6local: Illegal return value %u\n", ret);
 521                goto drop;
 522        }
 523
 524        if (srh_state->srh && !seg6_bpf_has_valid_srh(skb))
 525                goto drop;
 526
 527        preempt_enable();
 528        if (ret != BPF_REDIRECT)
 529                seg6_lookup_nexthop(skb, NULL, 0);
 530
 531        return dst_input(skb);
 532
 533drop:
 534        preempt_enable();
 535        kfree_skb(skb);
 536        return -EINVAL;
 537}
 538
 539static struct seg6_action_desc seg6_action_table[] = {
 540        {
 541                .action         = SEG6_LOCAL_ACTION_END,
 542                .attrs          = 0,
 543                .input          = input_action_end,
 544        },
 545        {
 546                .action         = SEG6_LOCAL_ACTION_END_X,
 547                .attrs          = (1 << SEG6_LOCAL_NH6),
 548                .input          = input_action_end_x,
 549        },
 550        {
 551                .action         = SEG6_LOCAL_ACTION_END_T,
 552                .attrs          = (1 << SEG6_LOCAL_TABLE),
 553                .input          = input_action_end_t,
 554        },
 555        {
 556                .action         = SEG6_LOCAL_ACTION_END_DX2,
 557                .attrs          = (1 << SEG6_LOCAL_OIF),
 558                .input          = input_action_end_dx2,
 559        },
 560        {
 561                .action         = SEG6_LOCAL_ACTION_END_DX6,
 562                .attrs          = (1 << SEG6_LOCAL_NH6),
 563                .input          = input_action_end_dx6,
 564        },
 565        {
 566                .action         = SEG6_LOCAL_ACTION_END_DX4,
 567                .attrs          = (1 << SEG6_LOCAL_NH4),
 568                .input          = input_action_end_dx4,
 569        },
 570        {
 571                .action         = SEG6_LOCAL_ACTION_END_DT6,
 572                .attrs          = (1 << SEG6_LOCAL_TABLE),
 573                .input          = input_action_end_dt6,
 574        },
 575        {
 576                .action         = SEG6_LOCAL_ACTION_END_B6,
 577                .attrs          = (1 << SEG6_LOCAL_SRH),
 578                .input          = input_action_end_b6,
 579        },
 580        {
 581                .action         = SEG6_LOCAL_ACTION_END_B6_ENCAP,
 582                .attrs          = (1 << SEG6_LOCAL_SRH),
 583                .input          = input_action_end_b6_encap,
 584                .static_headroom        = sizeof(struct ipv6hdr),
 585        },
 586        {
 587                .action         = SEG6_LOCAL_ACTION_END_BPF,
 588                .attrs          = (1 << SEG6_LOCAL_BPF),
 589                .input          = input_action_end_bpf,
 590        },
 591
 592};
 593
 594static struct seg6_action_desc *__get_action_desc(int action)
 595{
 596        struct seg6_action_desc *desc;
 597        int i, count;
 598
 599        count = ARRAY_SIZE(seg6_action_table);
 600        for (i = 0; i < count; i++) {
 601                desc = &seg6_action_table[i];
 602                if (desc->action == action)
 603                        return desc;
 604        }
 605
 606        return NULL;
 607}
 608
 609static int seg6_local_input(struct sk_buff *skb)
 610{
 611        struct dst_entry *orig_dst = skb_dst(skb);
 612        struct seg6_action_desc *desc;
 613        struct seg6_local_lwt *slwt;
 614
 615        if (skb->protocol != htons(ETH_P_IPV6)) {
 616                kfree_skb(skb);
 617                return -EINVAL;
 618        }
 619
 620        slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
 621        desc = slwt->desc;
 622
 623        return desc->input(skb, slwt);
 624}
 625
 626static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
 627        [SEG6_LOCAL_ACTION]     = { .type = NLA_U32 },
 628        [SEG6_LOCAL_SRH]        = { .type = NLA_BINARY },
 629        [SEG6_LOCAL_TABLE]      = { .type = NLA_U32 },
 630        [SEG6_LOCAL_NH4]        = { .type = NLA_BINARY,
 631                                    .len = sizeof(struct in_addr) },
 632        [SEG6_LOCAL_NH6]        = { .type = NLA_BINARY,
 633                                    .len = sizeof(struct in6_addr) },
 634        [SEG6_LOCAL_IIF]        = { .type = NLA_U32 },
 635        [SEG6_LOCAL_OIF]        = { .type = NLA_U32 },
 636        [SEG6_LOCAL_BPF]        = { .type = NLA_NESTED },
 637};
 638
 639static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt)
 640{
 641        struct ipv6_sr_hdr *srh;
 642        int len;
 643
 644        srh = nla_data(attrs[SEG6_LOCAL_SRH]);
 645        len = nla_len(attrs[SEG6_LOCAL_SRH]);
 646
 647        /* SRH must contain at least one segment */
 648        if (len < sizeof(*srh) + sizeof(struct in6_addr))
 649                return -EINVAL;
 650
 651        if (!seg6_validate_srh(srh, len))
 652                return -EINVAL;
 653
 654        slwt->srh = kmalloc(len, GFP_KERNEL);
 655        if (!slwt->srh)
 656                return -ENOMEM;
 657
 658        memcpy(slwt->srh, srh, len);
 659
 660        slwt->headroom += len;
 661
 662        return 0;
 663}
 664
 665static int put_nla_srh(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 666{
 667        struct ipv6_sr_hdr *srh;
 668        struct nlattr *nla;
 669        int len;
 670
 671        srh = slwt->srh;
 672        len = (srh->hdrlen + 1) << 3;
 673
 674        nla = nla_reserve(skb, SEG6_LOCAL_SRH, len);
 675        if (!nla)
 676                return -EMSGSIZE;
 677
 678        memcpy(nla_data(nla), srh, len);
 679
 680        return 0;
 681}
 682
 683static int cmp_nla_srh(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
 684{
 685        int len = (a->srh->hdrlen + 1) << 3;
 686
 687        if (len != ((b->srh->hdrlen + 1) << 3))
 688                return 1;
 689
 690        return memcmp(a->srh, b->srh, len);
 691}
 692
 693static int parse_nla_table(struct nlattr **attrs, struct seg6_local_lwt *slwt)
 694{
 695        slwt->table = nla_get_u32(attrs[SEG6_LOCAL_TABLE]);
 696
 697        return 0;
 698}
 699
 700static int put_nla_table(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 701{
 702        if (nla_put_u32(skb, SEG6_LOCAL_TABLE, slwt->table))
 703                return -EMSGSIZE;
 704
 705        return 0;
 706}
 707
 708static int cmp_nla_table(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
 709{
 710        if (a->table != b->table)
 711                return 1;
 712
 713        return 0;
 714}
 715
 716static int parse_nla_nh4(struct nlattr **attrs, struct seg6_local_lwt *slwt)
 717{
 718        memcpy(&slwt->nh4, nla_data(attrs[SEG6_LOCAL_NH4]),
 719               sizeof(struct in_addr));
 720
 721        return 0;
 722}
 723
 724static int put_nla_nh4(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 725{
 726        struct nlattr *nla;
 727
 728        nla = nla_reserve(skb, SEG6_LOCAL_NH4, sizeof(struct in_addr));
 729        if (!nla)
 730                return -EMSGSIZE;
 731
 732        memcpy(nla_data(nla), &slwt->nh4, sizeof(struct in_addr));
 733
 734        return 0;
 735}
 736
 737static int cmp_nla_nh4(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
 738{
 739        return memcmp(&a->nh4, &b->nh4, sizeof(struct in_addr));
 740}
 741
 742static int parse_nla_nh6(struct nlattr **attrs, struct seg6_local_lwt *slwt)
 743{
 744        memcpy(&slwt->nh6, nla_data(attrs[SEG6_LOCAL_NH6]),
 745               sizeof(struct in6_addr));
 746
 747        return 0;
 748}
 749
 750static int put_nla_nh6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 751{
 752        struct nlattr *nla;
 753
 754        nla = nla_reserve(skb, SEG6_LOCAL_NH6, sizeof(struct in6_addr));
 755        if (!nla)
 756                return -EMSGSIZE;
 757
 758        memcpy(nla_data(nla), &slwt->nh6, sizeof(struct in6_addr));
 759
 760        return 0;
 761}
 762
 763static int cmp_nla_nh6(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
 764{
 765        return memcmp(&a->nh6, &b->nh6, sizeof(struct in6_addr));
 766}
 767
 768static int parse_nla_iif(struct nlattr **attrs, struct seg6_local_lwt *slwt)
 769{
 770        slwt->iif = nla_get_u32(attrs[SEG6_LOCAL_IIF]);
 771
 772        return 0;
 773}
 774
 775static int put_nla_iif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 776{
 777        if (nla_put_u32(skb, SEG6_LOCAL_IIF, slwt->iif))
 778                return -EMSGSIZE;
 779
 780        return 0;
 781}
 782
 783static int cmp_nla_iif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
 784{
 785        if (a->iif != b->iif)
 786                return 1;
 787
 788        return 0;
 789}
 790
 791static int parse_nla_oif(struct nlattr **attrs, struct seg6_local_lwt *slwt)
 792{
 793        slwt->oif = nla_get_u32(attrs[SEG6_LOCAL_OIF]);
 794
 795        return 0;
 796}
 797
 798static int put_nla_oif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 799{
 800        if (nla_put_u32(skb, SEG6_LOCAL_OIF, slwt->oif))
 801                return -EMSGSIZE;
 802
 803        return 0;
 804}
 805
 806static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
 807{
 808        if (a->oif != b->oif)
 809                return 1;
 810
 811        return 0;
 812}
 813
 814#define MAX_PROG_NAME 256
 815static const struct nla_policy bpf_prog_policy[SEG6_LOCAL_BPF_PROG_MAX + 1] = {
 816        [SEG6_LOCAL_BPF_PROG]      = { .type = NLA_U32, },
 817        [SEG6_LOCAL_BPF_PROG_NAME] = { .type = NLA_NUL_STRING,
 818                                       .len = MAX_PROG_NAME },
 819};
 820
 821static int parse_nla_bpf(struct nlattr **attrs, struct seg6_local_lwt *slwt)
 822{
 823        struct nlattr *tb[SEG6_LOCAL_BPF_PROG_MAX + 1];
 824        struct bpf_prog *p;
 825        int ret;
 826        u32 fd;
 827
 828        ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_BPF_PROG_MAX,
 829                                          attrs[SEG6_LOCAL_BPF],
 830                                          bpf_prog_policy, NULL);
 831        if (ret < 0)
 832                return ret;
 833
 834        if (!tb[SEG6_LOCAL_BPF_PROG] || !tb[SEG6_LOCAL_BPF_PROG_NAME])
 835                return -EINVAL;
 836
 837        slwt->bpf.name = nla_memdup(tb[SEG6_LOCAL_BPF_PROG_NAME], GFP_KERNEL);
 838        if (!slwt->bpf.name)
 839                return -ENOMEM;
 840
 841        fd = nla_get_u32(tb[SEG6_LOCAL_BPF_PROG]);
 842        p = bpf_prog_get_type(fd, BPF_PROG_TYPE_LWT_SEG6LOCAL);
 843        if (IS_ERR(p)) {
 844                kfree(slwt->bpf.name);
 845                return PTR_ERR(p);
 846        }
 847
 848        slwt->bpf.prog = p;
 849        return 0;
 850}
 851
 852static int put_nla_bpf(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 853{
 854        struct nlattr *nest;
 855
 856        if (!slwt->bpf.prog)
 857                return 0;
 858
 859        nest = nla_nest_start_noflag(skb, SEG6_LOCAL_BPF);
 860        if (!nest)
 861                return -EMSGSIZE;
 862
 863        if (nla_put_u32(skb, SEG6_LOCAL_BPF_PROG, slwt->bpf.prog->aux->id))
 864                return -EMSGSIZE;
 865
 866        if (slwt->bpf.name &&
 867            nla_put_string(skb, SEG6_LOCAL_BPF_PROG_NAME, slwt->bpf.name))
 868                return -EMSGSIZE;
 869
 870        return nla_nest_end(skb, nest);
 871}
 872
 873static int cmp_nla_bpf(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
 874{
 875        if (!a->bpf.name && !b->bpf.name)
 876                return 0;
 877
 878        if (!a->bpf.name || !b->bpf.name)
 879                return 1;
 880
 881        return strcmp(a->bpf.name, b->bpf.name);
 882}
 883
 884struct seg6_action_param {
 885        int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt);
 886        int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
 887        int (*cmp)(struct seg6_local_lwt *a, struct seg6_local_lwt *b);
 888};
 889
 890static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = {
 891        [SEG6_LOCAL_SRH]        = { .parse = parse_nla_srh,
 892                                    .put = put_nla_srh,
 893                                    .cmp = cmp_nla_srh },
 894
 895        [SEG6_LOCAL_TABLE]      = { .parse = parse_nla_table,
 896                                    .put = put_nla_table,
 897                                    .cmp = cmp_nla_table },
 898
 899        [SEG6_LOCAL_NH4]        = { .parse = parse_nla_nh4,
 900                                    .put = put_nla_nh4,
 901                                    .cmp = cmp_nla_nh4 },
 902
 903        [SEG6_LOCAL_NH6]        = { .parse = parse_nla_nh6,
 904                                    .put = put_nla_nh6,
 905                                    .cmp = cmp_nla_nh6 },
 906
 907        [SEG6_LOCAL_IIF]        = { .parse = parse_nla_iif,
 908                                    .put = put_nla_iif,
 909                                    .cmp = cmp_nla_iif },
 910
 911        [SEG6_LOCAL_OIF]        = { .parse = parse_nla_oif,
 912                                    .put = put_nla_oif,
 913                                    .cmp = cmp_nla_oif },
 914
 915        [SEG6_LOCAL_BPF]        = { .parse = parse_nla_bpf,
 916                                    .put = put_nla_bpf,
 917                                    .cmp = cmp_nla_bpf },
 918
 919};
 920
 921static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt)
 922{
 923        struct seg6_action_param *param;
 924        struct seg6_action_desc *desc;
 925        int i, err;
 926
 927        desc = __get_action_desc(slwt->action);
 928        if (!desc)
 929                return -EINVAL;
 930
 931        if (!desc->input)
 932                return -EOPNOTSUPP;
 933
 934        slwt->desc = desc;
 935        slwt->headroom += desc->static_headroom;
 936
 937        for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
 938                if (desc->attrs & (1 << i)) {
 939                        if (!attrs[i])
 940                                return -EINVAL;
 941
 942                        param = &seg6_action_params[i];
 943
 944                        err = param->parse(attrs, slwt);
 945                        if (err < 0)
 946                                return err;
 947                }
 948        }
 949
 950        return 0;
 951}
 952
 953static int seg6_local_build_state(struct nlattr *nla, unsigned int family,
 954                                  const void *cfg, struct lwtunnel_state **ts,
 955                                  struct netlink_ext_ack *extack)
 956{
 957        struct nlattr *tb[SEG6_LOCAL_MAX + 1];
 958        struct lwtunnel_state *newts;
 959        struct seg6_local_lwt *slwt;
 960        int err;
 961
 962        if (family != AF_INET6)
 963                return -EINVAL;
 964
 965        err = nla_parse_nested_deprecated(tb, SEG6_LOCAL_MAX, nla,
 966                                          seg6_local_policy, extack);
 967
 968        if (err < 0)
 969                return err;
 970
 971        if (!tb[SEG6_LOCAL_ACTION])
 972                return -EINVAL;
 973
 974        newts = lwtunnel_state_alloc(sizeof(*slwt));
 975        if (!newts)
 976                return -ENOMEM;
 977
 978        slwt = seg6_local_lwtunnel(newts);
 979        slwt->action = nla_get_u32(tb[SEG6_LOCAL_ACTION]);
 980
 981        err = parse_nla_action(tb, slwt);
 982        if (err < 0)
 983                goto out_free;
 984
 985        newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL;
 986        newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT;
 987        newts->headroom = slwt->headroom;
 988
 989        *ts = newts;
 990
 991        return 0;
 992
 993out_free:
 994        kfree(slwt->srh);
 995        kfree(newts);
 996        return err;
 997}
 998
 999static void seg6_local_destroy_state(struct lwtunnel_state *lwt)
1000{
1001        struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
1002
1003        kfree(slwt->srh);
1004
1005        if (slwt->desc->attrs & (1 << SEG6_LOCAL_BPF)) {
1006                kfree(slwt->bpf.name);
1007                bpf_prog_put(slwt->bpf.prog);
1008        }
1009
1010        return;
1011}
1012
1013static int seg6_local_fill_encap(struct sk_buff *skb,
1014                                 struct lwtunnel_state *lwt)
1015{
1016        struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
1017        struct seg6_action_param *param;
1018        int i, err;
1019
1020        if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action))
1021                return -EMSGSIZE;
1022
1023        for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
1024                if (slwt->desc->attrs & (1 << i)) {
1025                        param = &seg6_action_params[i];
1026                        err = param->put(skb, slwt);
1027                        if (err < 0)
1028                                return err;
1029                }
1030        }
1031
1032        return 0;
1033}
1034
1035static int seg6_local_get_encap_size(struct lwtunnel_state *lwt)
1036{
1037        struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
1038        unsigned long attrs;
1039        int nlsize;
1040
1041        nlsize = nla_total_size(4); /* action */
1042
1043        attrs = slwt->desc->attrs;
1044
1045        if (attrs & (1 << SEG6_LOCAL_SRH))
1046                nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3);
1047
1048        if (attrs & (1 << SEG6_LOCAL_TABLE))
1049                nlsize += nla_total_size(4);
1050
1051        if (attrs & (1 << SEG6_LOCAL_NH4))
1052                nlsize += nla_total_size(4);
1053
1054        if (attrs & (1 << SEG6_LOCAL_NH6))
1055                nlsize += nla_total_size(16);
1056
1057        if (attrs & (1 << SEG6_LOCAL_IIF))
1058                nlsize += nla_total_size(4);
1059
1060        if (attrs & (1 << SEG6_LOCAL_OIF))
1061                nlsize += nla_total_size(4);
1062
1063        if (attrs & (1 << SEG6_LOCAL_BPF))
1064                nlsize += nla_total_size(sizeof(struct nlattr)) +
1065                       nla_total_size(MAX_PROG_NAME) +
1066                       nla_total_size(4);
1067
1068        return nlsize;
1069}
1070
1071static int seg6_local_cmp_encap(struct lwtunnel_state *a,
1072                                struct lwtunnel_state *b)
1073{
1074        struct seg6_local_lwt *slwt_a, *slwt_b;
1075        struct seg6_action_param *param;
1076        int i;
1077
1078        slwt_a = seg6_local_lwtunnel(a);
1079        slwt_b = seg6_local_lwtunnel(b);
1080
1081        if (slwt_a->action != slwt_b->action)
1082                return 1;
1083
1084        if (slwt_a->desc->attrs != slwt_b->desc->attrs)
1085                return 1;
1086
1087        for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
1088                if (slwt_a->desc->attrs & (1 << i)) {
1089                        param = &seg6_action_params[i];
1090                        if (param->cmp(slwt_a, slwt_b))
1091                                return 1;
1092                }
1093        }
1094
1095        return 0;
1096}
1097
1098static const struct lwtunnel_encap_ops seg6_local_ops = {
1099        .build_state    = seg6_local_build_state,
1100        .destroy_state  = seg6_local_destroy_state,
1101        .input          = seg6_local_input,
1102        .fill_encap     = seg6_local_fill_encap,
1103        .get_encap_size = seg6_local_get_encap_size,
1104        .cmp_encap      = seg6_local_cmp_encap,
1105        .owner          = THIS_MODULE,
1106};
1107
1108int __init seg6_local_init(void)
1109{
1110        return lwtunnel_encap_add_ops(&seg6_local_ops,
1111                                      LWTUNNEL_ENCAP_SEG6_LOCAL);
1112}
1113
1114void seg6_local_exit(void)
1115{
1116        lwtunnel_encap_del_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL);
1117}
1118