net/xfrm/xfrm_input.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * xfrm_input.c
   4  *
   5  * Changes:
   6  *      YOSHIFUJI Hideaki @USAGI
   7  *              Split up af-specific portion
   8  *
   9  */
  10
  11 #include <linux/bottom_half.h>
  12 #include <linux/cache.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/slab.h>
  15 #include <linux/module.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/percpu.h>
  18 #include <net/dst.h>
  19 #include <net/ip.h>
  20 #include <net/xfrm.h>
  21 #include <net/ip_tunnels.h>
  22 #include <net/ip6_tunnel.h>
  23
  24 #include "xfrm_inout.h"
  25
  26 struct xfrm_trans_tasklet {
  27         struct tasklet_struct tasklet;
  28         struct sk_buff_head queue;
  29 };
  30
  31 struct xfrm_trans_cb {
  32         union {
  33                 struct inet_skb_parm    h4;
  34 #if IS_ENABLED(CONFIG_IPV6)
  35                 struct inet6_skb_parm   h6;
  36 #endif
  37         } header;
  38         int (*finish)(struct net *net, struct sock *sk, struct sk_buff *skb);
  39 };
  40
  41 #define XFRM_TRANS_SKB_CB(__skb) ((struct xfrm_trans_cb *)&((__skb)->cb[0]))
  42
  43 static DEFINE_SPINLOCK(xfrm_input_afinfo_lock);
  44 static struct xfrm_input_afinfo const __rcu *xfrm_input_afinfo[AF_INET6 + 1];
  45
  46 static struct gro_cells gro_cells;
  47 static struct net_device xfrm_napi_dev;
  48
  49 static DEFINE_PER_CPU(struct xfrm_trans_tasklet, xfrm_trans_tasklet);
  50
  51 int xfrm_input_register_afinfo(const struct xfrm_input_afinfo *afinfo)
  52 {
  53         int err = 0;
  54
  55         if (WARN_ON(afinfo->family >= ARRAY_SIZE(xfrm_input_afinfo)))
  56                 return -EAFNOSUPPORT;
  57
  58         spin_lock_bh(&xfrm_input_afinfo_lock);
  59         if (unlikely(xfrm_input_afinfo[afinfo->family] != NULL))
  60                 err = -EEXIST;
  61         else
  62                 rcu_assign_pointer(xfrm_input_afinfo[afinfo->family], afinfo);
  63         spin_unlock_bh(&xfrm_input_afinfo_lock);
  64         return err;
  65 }
  66 EXPORT_SYMBOL(xfrm_input_register_afinfo);
  67
  68 int xfrm_input_unregister_afinfo(const struct xfrm_input_afinfo *afinfo)
  69 {
  70         int err = 0;
  71
  72         spin_lock_bh(&xfrm_input_afinfo_lock);
  73         if (likely(xfrm_input_afinfo[afinfo->family] != NULL)) {
  74                 if (unlikely(xfrm_input_afinfo[afinfo->family] != afinfo))
  75                         err = -EINVAL;
  76                 else
  77                         RCU_INIT_POINTER(xfrm_input_afinfo[afinfo->family], NULL);
  78         }
  79         spin_unlock_bh(&xfrm_input_afinfo_lock);
  80         synchronize_rcu();
  81         return err;
  82 }
  83 EXPORT_SYMBOL(xfrm_input_unregister_afinfo);
  84
  85 static const struct xfrm_input_afinfo *xfrm_input_get_afinfo(unsigned int family)
  86 {
  87         const struct xfrm_input_afinfo *afinfo;
  88
  89         if (WARN_ON_ONCE(family >= ARRAY_SIZE(xfrm_input_afinfo)))
  90                 return NULL;
  91
  92         rcu_read_lock();
  93         afinfo = rcu_dereference(xfrm_input_afinfo[family]);
  94         if (unlikely(!afinfo))
  95                 rcu_read_unlock();
  96         return afinfo;
  97 }
  98
  99 static int xfrm_rcv_cb(struct sk_buff *skb, unsigned int family, u8 protocol,
 100                        int err)
 101 {
 102         int ret;
 103         const struct xfrm_input_afinfo *afinfo = xfrm_input_get_afinfo(family);
 104
 105         if (!afinfo)
 106                 return -EAFNOSUPPORT;
 107
 108         ret = afinfo->callback(skb, protocol, err);
 109         rcu_read_unlock();
 110
 111         return ret;
 112 }
 113
 114 struct sec_path *secpath_set(struct sk_buff *skb)
 115 {
 116         struct sec_path *sp, *tmp = skb_ext_find(skb, SKB_EXT_SEC_PATH);
 117
 118         sp = skb_ext_add(skb, SKB_EXT_SEC_PATH);
 119         if (!sp)
 120                 return NULL;
 121
 122         if (tmp) /* reused existing one (was COW'd if needed) */
 123                 return sp;
 124
 125         /* allocated new secpath */
 126         memset(sp->ovec, 0, sizeof(sp->ovec));
 127         sp->olen = 0;
 128         sp->len = 0;
 129
 130         return sp;
 131 }
 132 EXPORT_SYMBOL(secpath_set);
 133
 134 /* Fetch spi and seq from ipsec header */
 135
 136 int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
 137 {
 138         int offset, offset_seq;
 139         int hlen;
 140
 141         switch (nexthdr) {
 142         case IPPROTO_AH:
 143                 hlen = sizeof(struct ip_auth_hdr);
 144                 offset = offsetof(struct ip_auth_hdr, spi);
 145                 offset_seq = offsetof(struct ip_auth_hdr, seq_no);
 146                 break;
 147         case IPPROTO_ESP:
 148                 hlen = sizeof(struct ip_esp_hdr);
 149                 offset = offsetof(struct ip_esp_hdr, spi);
 150                 offset_seq = offsetof(struct ip_esp_hdr, seq_no);
 151                 break;
 152         case IPPROTO_COMP:
 153                 if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
 154                         return -EINVAL;
 155                 *spi = htonl(ntohs(*(__be16 *)(skb_transport_header(skb) + 2)));
 156                 *seq = 0;
 157                 return 0;
 158         default:
 159                 return 1;
 160         }
 161
 162         if (!pskb_may_pull(skb, hlen))
 163                 return -EINVAL;
 164
 165         *spi = *(__be32 *)(skb_transport_header(skb) + offset);
 166         *seq = *(__be32 *)(skb_transport_header(skb) + offset_seq);
 167         return 0;
 168 }
 169 EXPORT_SYMBOL(xfrm_parse_spi);
 170
 171 static int xfrm4_remove_beet_encap(struct xfrm_state *x, struct sk_buff *skb)
 172 {
 173         struct iphdr *iph;
 174         int optlen = 0;
 175         int err = -EINVAL;
 176
 177         if (unlikely(XFRM_MODE_SKB_CB(skb)->protocol == IPPROTO_BEETPH)) {
 178                 struct ip_beet_phdr *ph;
 179                 int phlen;
 180
 181                 if (!pskb_may_pull(skb, sizeof(*ph)))
 182                         goto out;
 183
 184                 ph = (struct ip_beet_phdr *)skb->data;
 185
 186                 phlen = sizeof(*ph) + ph->padlen;
 187                 optlen = ph->hdrlen * 8 + (IPV4_BEET_PHMAXLEN - phlen);
 188                 if (optlen < 0 || optlen & 3 || optlen > 250)
 189                         goto out;
 190
 191                 XFRM_MODE_SKB_CB(skb)->protocol = ph->nexthdr;
 192
 193                 if (!pskb_may_pull(skb, phlen))
 194                         goto out;
 195                 __skb_pull(skb, phlen);
 196         }
 197
 198         skb_push(skb, sizeof(*iph));
 199         skb_reset_network_header(skb);
 200         skb_mac_header_rebuild(skb);
 201
 202         xfrm4_beet_make_header(skb);
 203
 204         iph = ip_hdr(skb);
 205
 206         iph->ihl += optlen / 4;
 207         iph->tot_len = htons(skb->len);
 208         iph->daddr = x->sel.daddr.a4;
 209         iph->saddr = x->sel.saddr.a4;
 210         iph->check = 0;
 211         iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
 212         err = 0;
 213 out:
 214         return err;
 215 }
 216
 217 static void ipip_ecn_decapsulate(struct sk_buff *skb)
 218 {
 219         struct iphdr *inner_iph = ipip_hdr(skb);
 220
 221         if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
 222                 IP_ECN_set_ce(inner_iph);
 223 }
 224
 225 static int xfrm4_remove_tunnel_encap(struct xfrm_state *x, struct sk_buff *skb)
 226 {
 227         int err = -EINVAL;
 228
 229         if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPIP)
 230                 goto out;
 231
 232         if (!pskb_may_pull(skb, sizeof(struct iphdr)))
 233                 goto out;
 234
 235         err = skb_unclone(skb, GFP_ATOMIC);
 236         if (err)
 237                 goto out;
 238
 239         if (x->props.flags & XFRM_STATE_DECAP_DSCP)
 240                 ipv4_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, ipip_hdr(skb));
 241         if (!(x->props.flags & XFRM_STATE_NOECN))
 242                 ipip_ecn_decapsulate(skb);
 243
 244         skb_reset_network_header(skb);
 245         skb_mac_header_rebuild(skb);
 246         if (skb->mac_len)
 247                 eth_hdr(skb)->h_proto = skb->protocol;
 248
 249         err = 0;
 250
 251 out:
 252         return err;
 253 }
 254
 255 static void ipip6_ecn_decapsulate(struct sk_buff *skb)
 256 {
 257         struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
 258
 259         if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
 260                 IP6_ECN_set_ce(skb, inner_iph);
 261 }
 262
 263 static int xfrm6_remove_tunnel_encap(struct xfrm_state *x, struct sk_buff *skb)
 264 {
 265         int err = -EINVAL;
 266
 267         if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
 268                 goto out;
 269         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 270                 goto out;
 271
 272         err = skb_unclone(skb, GFP_ATOMIC);
 273         if (err)
 274                 goto out;
 275
 276         if (x->props.flags & XFRM_STATE_DECAP_DSCP)
 277                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
 278                                ipipv6_hdr(skb));
 279         if (!(x->props.flags & XFRM_STATE_NOECN))
 280                 ipip6_ecn_decapsulate(skb);
 281
 282         skb_reset_network_header(skb);
 283         skb_mac_header_rebuild(skb);
 284         if (skb->mac_len)
 285                 eth_hdr(skb)->h_proto = skb->protocol;
 286
 287         err = 0;
 288
 289 out:
 290         return err;
 291 }
 292
 293 static int xfrm6_remove_beet_encap(struct xfrm_state *x, struct sk_buff *skb)
 294 {
 295         struct ipv6hdr *ip6h;
 296         int size = sizeof(struct ipv6hdr);
 297         int err;
 298
 299         err = skb_cow_head(skb, size + skb->mac_len);
 300         if (err)
 301                 goto out;
 302
 303         __skb_push(skb, size);
 304         skb_reset_network_header(skb);
 305         skb_mac_header_rebuild(skb);
 306
 307         xfrm6_beet_make_header(skb);
 308
 309         ip6h = ipv6_hdr(skb);
 310         ip6h->payload_len = htons(skb->len - size);
 311         ip6h->daddr = x->sel.daddr.in6;
 312         ip6h->saddr = x->sel.saddr.in6;
 313         err = 0;
 314 out:
 315         return err;
 316 }
 317
 318 /* Remove encapsulation header.
 319  *
 320  * The IP header will be moved over the top of the encapsulation
 321  * header.
 322  *
 323  * On entry, the transport header shall point to where the IP header
 324  * should be and the network header shall be set to where the IP
 325  * header currently is.  skb->data shall point to the start of the
 326  * payload.
 327  */
 328 static int
 329 xfrm_inner_mode_encap_remove(struct xfrm_state *x,
 330                              const struct xfrm_mode *inner_mode,
 331                              struct sk_buff *skb)
 332 {
 333         switch (inner_mode->encap) {
 334         case XFRM_MODE_BEET:
 335                 if (inner_mode->family == AF_INET)
 336                         return xfrm4_remove_beet_encap(x, skb);
 337                 if (inner_mode->family == AF_INET6)
 338                         return xfrm6_remove_beet_encap(x, skb);
 339                 break;
 340         case XFRM_MODE_TUNNEL:
 341                 if (inner_mode->family == AF_INET)
 342                         return xfrm4_remove_tunnel_encap(x, skb);
 343                 if (inner_mode->family == AF_INET6)
 344                         return xfrm6_remove_tunnel_encap(x, skb);
 345                 break;
 346         }
 347
 348         WARN_ON_ONCE(1);
 349         return -EOPNOTSUPP;
 350 }
 351
 352 static int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
 353 {
 354         const struct xfrm_mode *inner_mode = &x->inner_mode;
 355         const struct xfrm_state_afinfo *afinfo;
 356         int err = -EAFNOSUPPORT;
 357
 358         rcu_read_lock();
 359         afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family);
 360         if (likely(afinfo))
 361                 err = afinfo->extract_input(x, skb);
 362         rcu_read_unlock();
 363
 364         if (err)
 365                 return err;
 366
 367         if (x->sel.family == AF_UNSPEC) {
 368                 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
 369                 if (!inner_mode)
 370                         return -EAFNOSUPPORT;
 371         }
 372
 373         switch (inner_mode->family) {
 374         case AF_INET:
 375                 skb->protocol = htons(ETH_P_IP);
 376                 break;
 377         case AF_INET6:
 378                 skb->protocol = htons(ETH_P_IPV6);
 379                 break;
 380         default:
 381                 WARN_ON_ONCE(1);
 382                 break;
 383         }
 384
 385         return xfrm_inner_mode_encap_remove(x, inner_mode, skb);
 386 }
 387
 388 /* Remove encapsulation header.
 389  *
 390  * The IP header will be moved over the top of the encapsulation header.
 391  *
 392  * On entry, skb_transport_header() shall point to where the IP header
 393  * should be and skb_network_header() shall be set to where the IP header
 394  * currently is.  skb->data shall point to the start of the payload.
 395  */
 396 static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb)
 397 {
 398         int ihl = skb->data - skb_transport_header(skb);
 399
 400         if (skb->transport_header != skb->network_header) {
 401                 memmove(skb_transport_header(skb),
 402                         skb_network_header(skb), ihl);
 403                 skb->network_header = skb->transport_header;
 404         }
 405         ip_hdr(skb)->tot_len = htons(skb->len + ihl);
 406         skb_reset_transport_header(skb);
 407         return 0;
 408 }
 409
 410 static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb)
 411 {
 412 #if IS_ENABLED(CONFIG_IPV6)
 413         int ihl = skb->data - skb_transport_header(skb);
 414
 415         if (skb->transport_header != skb->network_header) {
 416                 memmove(skb_transport_header(skb),
 417                         skb_network_header(skb), ihl);
 418                 skb->network_header = skb->transport_header;
 419         }
 420         ipv6_hdr(skb)->payload_len = htons(skb->len + ihl -
 421                                            sizeof(struct ipv6hdr));
 422         skb_reset_transport_header(skb);
 423         return 0;
 424 #else
 425         WARN_ON_ONCE(1);
 426         return -EAFNOSUPPORT;
 427 #endif
 428 }
 429
 430 static int xfrm_inner_mode_input(struct xfrm_state *x,
 431                                  const struct xfrm_mode *inner_mode,
 432                                  struct sk_buff *skb)
 433 {
 434         switch (inner_mode->encap) {
 435         case XFRM_MODE_BEET:
 436         case XFRM_MODE_TUNNEL:
 437                 return xfrm_prepare_input(x, skb);
 438         case XFRM_MODE_TRANSPORT:
 439                 if (inner_mode->family == AF_INET)
 440                         return xfrm4_transport_input(x, skb);
 441                 if (inner_mode->family == AF_INET6)
 442                         return xfrm6_transport_input(x, skb);
 443                 break;
 444         case XFRM_MODE_ROUTEOPTIMIZATION:
 445                 WARN_ON_ONCE(1);
 446                 break;
 447         default:
 448                 WARN_ON_ONCE(1);
 449                 break;
 450         }
 451
 452         return -EOPNOTSUPP;
 453 }
 454
 455 int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 456 {
 457         const struct xfrm_state_afinfo *afinfo;
 458         struct net *net = dev_net(skb->dev);
 459         const struct xfrm_mode *inner_mode;
 460         int err;
 461         __be32 seq;
 462         __be32 seq_hi;
 463         struct xfrm_state *x = NULL;
 464         xfrm_address_t *daddr;
 465         u32 mark = skb->mark;
 466         unsigned int family = AF_UNSPEC;
 467         int decaps = 0;
 468         int async = 0;
 469         bool xfrm_gro = false;
 470         bool crypto_done = false;
 471         struct xfrm_offload *xo = xfrm_offload(skb);
 472         struct sec_path *sp;
 473
 474         if (encap_type < 0) {
 475                 x = xfrm_input_state(skb);
 476
 477                 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
 478                         if (x->km.state == XFRM_STATE_ACQ)
 479                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
 480                         else
 481                                 XFRM_INC_STATS(net,
 482                                                LINUX_MIB_XFRMINSTATEINVALID);
 483                         goto drop;
 484                 }
 485
 486                 family = x->outer_mode.family;
 487
 488                 /* An encap_type of -1 indicates async resumption. */
 489                 if (encap_type == -1) {
 490                         async = 1;
 491                         seq = XFRM_SKB_CB(skb)->seq.input.low;
 492                         goto resume;
 493                 }
 494
 495                 /* encap_type < -1 indicates a GRO call. */
 496                 encap_type = 0;
 497                 seq = XFRM_SPI_SKB_CB(skb)->seq;
 498
 499                 if (xo && (xo->flags & CRYPTO_DONE)) {
 500                         crypto_done = true;
 501                         family = XFRM_SPI_SKB_CB(skb)->family;
 502
 503                         if (!(xo->status & CRYPTO_SUCCESS)) {
 504                                 if (xo->status &
 505                                     (CRYPTO_TRANSPORT_AH_AUTH_FAILED |
 506                                      CRYPTO_TRANSPORT_ESP_AUTH_FAILED |
 507                                      CRYPTO_TUNNEL_AH_AUTH_FAILED |
 508                                      CRYPTO_TUNNEL_ESP_AUTH_FAILED)) {
 509
 510                                         xfrm_audit_state_icvfail(x, skb,
 511                                                                  x->type->proto);
 512                                         x->stats.integrity_failed++;
 513                                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
 514                                         goto drop;
 515                                 }
 516
 517                                 if (xo->status & CRYPTO_INVALID_PROTOCOL) {
 518                                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
 519                                         goto drop;
 520                                 }
 521
 522                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
 523                                 goto drop;
 524                         }
 525
 526                         if ((err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) {
 527                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
 528                                 goto drop;
 529                         }
 530                 }
 531
 532                 goto lock;
 533         }
 534
 535         family = XFRM_SPI_SKB_CB(skb)->family;
 536
 537         /* if tunnel is present override skb->mark value with tunnel i_key */
 538         switch (family) {
 539         case AF_INET:
 540                 if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4)
 541                         mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4->parms.i_key);
 542                 break;
 543         case AF_INET6:
 544                 if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6)
 545                         mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6->parms.i_key);
 546                 break;
 547         }
 548
 549         sp = secpath_set(skb);
 550         if (!sp) {
 551                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
 552                 goto drop;
 553         }
 554
 555         seq = 0;
 556         if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) {
 557                 secpath_reset(skb);
 558                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
 559                 goto drop;
 560         }
 561
 562         daddr = (xfrm_address_t *)(skb_network_header(skb) +
 563                                    XFRM_SPI_SKB_CB(skb)->daddroff);
 564         do {
 565                 sp = skb_sec_path(skb);
 566
 567                 if (sp->len == XFRM_MAX_DEPTH) {
 568                         secpath_reset(skb);
 569                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
 570                         goto drop;
 571                 }
 572
 573                 x = xfrm_state_lookup(net, mark, daddr, spi, nexthdr, family);
 574                 if (x == NULL) {
 575                         secpath_reset(skb);
 576                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
 577                         xfrm_audit_state_notfound(skb, family, spi, seq);
 578                         goto drop;
 579                 }
 580
 581                 skb->mark = xfrm_smark_get(skb->mark, x);
 582
 583                 sp->xvec[sp->len++] = x;
 584
 585                 skb_dst_force(skb);
 586                 if (!skb_dst(skb)) {
 587                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
 588                         goto drop;
 589                 }
 590
 591 lock:
 592                 spin_lock(&x->lock);
 593
 594                 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
 595                         if (x->km.state == XFRM_STATE_ACQ)
 596                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
 597                         else
 598                                 XFRM_INC_STATS(net,
 599                                                LINUX_MIB_XFRMINSTATEINVALID);
 600                         goto drop_unlock;
 601                 }
 602
 603                 if ((x->encap ? x->encap->encap_type : 0) != encap_type) {
 604                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
 605                         goto drop_unlock;
 606                 }
 607
 608                 if (x->repl->check(x, skb, seq)) {
 609                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
 610                         goto drop_unlock;
 611                 }
 612
 613                 if (xfrm_state_check_expire(x)) {
 614                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEEXPIRED);
 615                         goto drop_unlock;
 616                 }
 617
 618                 spin_unlock(&x->lock);
 619
 620                 if (xfrm_tunnel_check(skb, x, family)) {
 621                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
 622                         goto drop;
 623                 }
 624
 625                 seq_hi = htonl(xfrm_replay_seqhi(x, seq));
 626
 627                 XFRM_SKB_CB(skb)->seq.input.low = seq;
 628                 XFRM_SKB_CB(skb)->seq.input.hi = seq_hi;
 629
 630                 dev_hold(skb->dev);
 631
 632                 if (crypto_done)
 633                         nexthdr = x->type_offload->input_tail(x, skb);
 634                 else
 635                         nexthdr = x->type->input(x, skb);
 636
 637                 if (nexthdr == -EINPROGRESS)
 638                         return 0;
 639 resume:
 640                 dev_put(skb->dev);
 641
 642                 spin_lock(&x->lock);
 643                 if (nexthdr <= 0) {
 644                         if (nexthdr == -EBADMSG) {
 645                                 xfrm_audit_state_icvfail(x, skb,
 646                                                          x->type->proto);
 647                                 x->stats.integrity_failed++;
 648                         }
 649                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
 650                         goto drop_unlock;
 651                 }
 652
 653                 /* only the first xfrm gets the encap type */
 654                 encap_type = 0;
 655
 656                 if (async && x->repl->recheck(x, skb, seq)) {
 657                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
 658                         goto drop_unlock;
 659                 }
 660
 661                 x->repl->advance(x, seq);
 662
 663                 x->curlft.bytes += skb->len;
 664                 x->curlft.packets++;
 665
 666                 spin_unlock(&x->lock);
 667
 668                 XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
 669
 670                 inner_mode = &x->inner_mode;
 671
 672                 if (x->sel.family == AF_UNSPEC) {
 673                         inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
 674                         if (inner_mode == NULL) {
 675                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
 676                                 goto drop;
 677                         }
 678                 }
 679
 680                 if (xfrm_inner_mode_input(x, inner_mode, skb)) {
 681                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
 682                         goto drop;
 683                 }
 684
 685                 if (x->outer_mode.flags & XFRM_MODE_FLAG_TUNNEL) {
 686                         decaps = 1;
 687                         break;
 688                 }
 689
 690                 /*
 691                  * We need the inner address.  However, we only get here for
 692                  * transport mode so the outer address is identical.
 693                  */
 694                 daddr = &x->id.daddr;
 695                 family = x->outer_mode.family;
 696
 697                 err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
 698                 if (err < 0) {
 699                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
 700                         goto drop;
 701                 }
 702                 crypto_done = false;
 703         } while (!err);
 704
 705         err = xfrm_rcv_cb(skb, family, x->type->proto, 0);
 706         if (err)
 707                 goto drop;
 708
 709         nf_reset_ct(skb);
 710
 711         if (decaps) {
 712                 sp = skb_sec_path(skb);
 713                 if (sp)
 714                         sp->olen = 0;
 715                 skb_dst_drop(skb);
 716                 gro_cells_receive(&gro_cells, skb);
 717                 return 0;
 718         } else {
 719                 xo = xfrm_offload(skb);
 720                 if (xo)
 721                         xfrm_gro = xo->flags & XFRM_GRO;
 722
 723                 err = -EAFNOSUPPORT;
 724                 rcu_read_lock();
 725                 afinfo = xfrm_state_afinfo_get_rcu(x->inner_mode.family);
 726                 if (likely(afinfo))
 727                         err = afinfo->transport_finish(skb, xfrm_gro || async);
 728                 rcu_read_unlock();
 729                 if (xfrm_gro) {
 730                         sp = skb_sec_path(skb);
 731                         if (sp)
 732                                 sp->olen = 0;
 733                         skb_dst_drop(skb);
 734                         gro_cells_receive(&gro_cells, skb);
 735                         return err;
 736                 }
 737
 738                 return err;
 739         }
 740
 741 drop_unlock:
 742         spin_unlock(&x->lock);
 743 drop:
 744         xfrm_rcv_cb(skb, family, x && x->type ? x->type->proto : nexthdr, -1);
 745         kfree_skb(skb);
 746         return 0;
 747 }
 748 EXPORT_SYMBOL(xfrm_input);
 749
 750 int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
 751 {
 752         return xfrm_input(skb, nexthdr, 0, -1);
 753 }
 754 EXPORT_SYMBOL(xfrm_input_resume);
 755
 756 static void xfrm_trans_reinject(unsigned long data)
 757 {
 758         struct xfrm_trans_tasklet *trans = (void *)data;
 759         struct sk_buff_head queue;
 760         struct sk_buff *skb;
 761
 762         __skb_queue_head_init(&queue);
 763         skb_queue_splice_init(&trans->queue, &queue);
 764
 765         while ((skb = __skb_dequeue(&queue)))
 766                 XFRM_TRANS_SKB_CB(skb)->finish(dev_net(skb->dev), NULL, skb);
 767 }
 768
 769 int xfrm_trans_queue(struct sk_buff *skb,
 770                      int (*finish)(struct net *, struct sock *,
 771                                    struct sk_buff *))
 772 {
 773         struct xfrm_trans_tasklet *trans;
 774
 775         trans = this_cpu_ptr(&xfrm_trans_tasklet);
 776
 777         if (skb_queue_len(&trans->queue) >= netdev_max_backlog)
 778                 return -ENOBUFS;
 779
 780         XFRM_TRANS_SKB_CB(skb)->finish = finish;
 781         __skb_queue_tail(&trans->queue, skb);
 782         tasklet_schedule(&trans->tasklet);
 783         return 0;
 784 }
 785 EXPORT_SYMBOL(xfrm_trans_queue);
 786
 787 void __init xfrm_input_init(void)
 788 {
 789         int err;
 790         int i;
 791
 792         init_dummy_netdev(&xfrm_napi_dev);
 793         err = gro_cells_init(&gro_cells, &xfrm_napi_dev);
 794         if (err)
 795                 gro_cells.cells = NULL;
 796
 797         for_each_possible_cpu(i) {
 798                 struct xfrm_trans_tasklet *trans;
 799
 800                 trans = &per_cpu(xfrm_trans_tasklet, i);
 801                 __skb_queue_head_init(&trans->queue);
 802                 tasklet_init(&trans->tasklet, xfrm_trans_reinject,
 803                              (unsigned long)trans);
 804         }
 805 }