net/sched/act_csum.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Checksum updating actions
   4  *
   5  * Copyright (c) 2010 Gregoire Baron <baronchon@n7mm.org>
   6  */
   7
   8 #include <linux/types.h>
   9 #include <linux/init.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/spinlock.h>
  13
  14 #include <linux/netlink.h>
  15 #include <net/netlink.h>
  16 #include <linux/rtnetlink.h>
  17
  18 #include <linux/skbuff.h>
  19
  20 #include <net/ip.h>
  21 #include <net/ipv6.h>
  22 #include <net/icmp.h>
  23 #include <linux/icmpv6.h>
  24 #include <linux/igmp.h>
  25 #include <net/tcp.h>
  26 #include <net/udp.h>
  27 #include <net/ip6_checksum.h>
  28 #include <net/sctp/checksum.h>
  29
  30 #include <net/act_api.h>
  31 #include <net/pkt_cls.h>
  32
  33 #include <linux/tc_act/tc_csum.h>
  34 #include <net/tc_act/tc_csum.h>
  35
  36 static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = {
  37         [TCA_CSUM_PARMS] = { .len = sizeof(struct tc_csum), },
  38 };
  39
  40 static unsigned int csum_net_id;
  41 static struct tc_action_ops act_csum_ops;
  42
  43 static int tcf_csum_init(struct net *net, struct nlattr *nla,
  44                          struct nlattr *est, struct tc_action **a, int ovr,
  45                          int bind, bool rtnl_held, struct tcf_proto *tp,
  46                          u32 flags, struct netlink_ext_ack *extack)
  47 {
  48         struct tc_action_net *tn = net_generic(net, csum_net_id);
  49         struct tcf_csum_params *params_new;
  50         struct nlattr *tb[TCA_CSUM_MAX + 1];
  51         struct tcf_chain *goto_ch = NULL;
  52         struct tc_csum *parm;
  53         struct tcf_csum *p;
  54         int ret = 0, err;
  55         u32 index;
  56
  57         if (nla == NULL)
  58                 return -EINVAL;
  59
  60         err = nla_parse_nested_deprecated(tb, TCA_CSUM_MAX, nla, csum_policy,
  61                                           NULL);
  62         if (err < 0)
  63                 return err;
  64
  65         if (tb[TCA_CSUM_PARMS] == NULL)
  66                 return -EINVAL;
  67         parm = nla_data(tb[TCA_CSUM_PARMS]);
  68         index = parm->index;
  69         err = tcf_idr_check_alloc(tn, &index, a, bind);
  70         if (!err) {
  71                 ret = tcf_idr_create_from_flags(tn, index, est, a,
  72                                                 &act_csum_ops, bind, flags);
  73                 if (ret) {
  74                         tcf_idr_cleanup(tn, index);
  75                         return ret;
  76                 }
  77                 ret = ACT_P_CREATED;
  78         } else if (err > 0) {
  79                 if (bind)/* dont override defaults */
  80                         return 0;
  81                 if (!ovr) {
  82                         tcf_idr_release(*a, bind);
  83                         return -EEXIST;
  84                 }
  85         } else {
  86                 return err;
  87         }
  88
  89         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
  90         if (err < 0)
  91                 goto release_idr;
  92
  93         p = to_tcf_csum(*a);
  94
  95         params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
  96         if (unlikely(!params_new)) {
  97                 err = -ENOMEM;
  98                 goto put_chain;
  99         }
 100         params_new->update_flags = parm->update_flags;
 101
 102         spin_lock_bh(&p->tcf_lock);
 103         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 104         params_new = rcu_replace_pointer(p->params, params_new,
 105                                          lockdep_is_held(&p->tcf_lock));
 106         spin_unlock_bh(&p->tcf_lock);
 107
 108         if (goto_ch)
 109                 tcf_chain_put_by_act(goto_ch);
 110         if (params_new)
 111                 kfree_rcu(params_new, rcu);
 112
 113         if (ret == ACT_P_CREATED)
 114                 tcf_idr_insert(tn, *a);
 115
 116         return ret;
 117 put_chain:
 118         if (goto_ch)
 119                 tcf_chain_put_by_act(goto_ch);
 120 release_idr:
 121         tcf_idr_release(*a, bind);
 122         return err;
 123 }
 124
 125 /**
 126  * tcf_csum_skb_nextlayer - Get next layer pointer
 127  * @skb: sk_buff to use
 128  * @ihl: previous summed headers length
 129  * @ipl: complete packet length
 130  * @jhl: next header length
 131  *
 132  * Check the expected next layer availability in the specified sk_buff.
 133  * Return the next layer pointer if pass, NULL otherwise.
 134  */
 135 static void *tcf_csum_skb_nextlayer(struct sk_buff *skb,
 136                                     unsigned int ihl, unsigned int ipl,
 137                                     unsigned int jhl)
 138 {
 139         int ntkoff = skb_network_offset(skb);
 140         int hl = ihl + jhl;
 141
 142         if (!pskb_may_pull(skb, ipl + ntkoff) || (ipl < hl) ||
 143             skb_try_make_writable(skb, hl + ntkoff))
 144                 return NULL;
 145         else
 146                 return (void *)(skb_network_header(skb) + ihl);
 147 }
 148
 149 static int tcf_csum_ipv4_icmp(struct sk_buff *skb, unsigned int ihl,
 150                               unsigned int ipl)
 151 {
 152         struct icmphdr *icmph;
 153
 154         icmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmph));
 155         if (icmph == NULL)
 156                 return 0;
 157
 158         icmph->checksum = 0;
 159         skb->csum = csum_partial(icmph, ipl - ihl, 0);
 160         icmph->checksum = csum_fold(skb->csum);
 161
 162         skb->ip_summed = CHECKSUM_NONE;
 163
 164         return 1;
 165 }
 166
 167 static int tcf_csum_ipv4_igmp(struct sk_buff *skb,
 168                               unsigned int ihl, unsigned int ipl)
 169 {
 170         struct igmphdr *igmph;
 171
 172         igmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*igmph));
 173         if (igmph == NULL)
 174                 return 0;
 175
 176         igmph->csum = 0;
 177         skb->csum = csum_partial(igmph, ipl - ihl, 0);
 178         igmph->csum = csum_fold(skb->csum);
 179
 180         skb->ip_summed = CHECKSUM_NONE;
 181
 182         return 1;
 183 }
 184
 185 static int tcf_csum_ipv6_icmp(struct sk_buff *skb, unsigned int ihl,
 186                               unsigned int ipl)
 187 {
 188         struct icmp6hdr *icmp6h;
 189         const struct ipv6hdr *ip6h;
 190
 191         icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h));
 192         if (icmp6h == NULL)
 193                 return 0;
 194
 195         ip6h = ipv6_hdr(skb);
 196         icmp6h->icmp6_cksum = 0;
 197         skb->csum = csum_partial(icmp6h, ipl - ihl, 0);
 198         icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
 199                                               ipl - ihl, IPPROTO_ICMPV6,
 200                                               skb->csum);
 201
 202         skb->ip_summed = CHECKSUM_NONE;
 203
 204         return 1;
 205 }
 206
 207 static int tcf_csum_ipv4_tcp(struct sk_buff *skb, unsigned int ihl,
 208                              unsigned int ipl)
 209 {
 210         struct tcphdr *tcph;
 211         const struct iphdr *iph;
 212
 213         if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 214                 return 1;
 215
 216         tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
 217         if (tcph == NULL)
 218                 return 0;
 219
 220         iph = ip_hdr(skb);
 221         tcph->check = 0;
 222         skb->csum = csum_partial(tcph, ipl - ihl, 0);
 223         tcph->check = tcp_v4_check(ipl - ihl,
 224                                    iph->saddr, iph->daddr, skb->csum);
 225
 226         skb->ip_summed = CHECKSUM_NONE;
 227
 228         return 1;
 229 }
 230
 231 static int tcf_csum_ipv6_tcp(struct sk_buff *skb, unsigned int ihl,
 232                              unsigned int ipl)
 233 {
 234         struct tcphdr *tcph;
 235         const struct ipv6hdr *ip6h;
 236
 237         if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 238                 return 1;
 239
 240         tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
 241         if (tcph == NULL)
 242                 return 0;
 243
 244         ip6h = ipv6_hdr(skb);
 245         tcph->check = 0;
 246         skb->csum = csum_partial(tcph, ipl - ihl, 0);
 247         tcph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
 248                                       ipl - ihl, IPPROTO_TCP,
 249                                       skb->csum);
 250
 251         skb->ip_summed = CHECKSUM_NONE;
 252
 253         return 1;
 254 }
 255
 256 static int tcf_csum_ipv4_udp(struct sk_buff *skb, unsigned int ihl,
 257                              unsigned int ipl, int udplite)
 258 {
 259         struct udphdr *udph;
 260         const struct iphdr *iph;
 261         u16 ul;
 262
 263         if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 264                 return 1;
 265
 266         /*
 267          * Support both UDP and UDPLITE checksum algorithms, Don't use
 268          * udph->len to get the real length without any protocol check,
 269          * UDPLITE uses udph->len for another thing,
 270          * Use iph->tot_len, or just ipl.
 271          */
 272
 273         udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
 274         if (udph == NULL)
 275                 return 0;
 276
 277         iph = ip_hdr(skb);
 278         ul = ntohs(udph->len);
 279
 280         if (udplite || udph->check) {
 281
 282                 udph->check = 0;
 283
 284                 if (udplite) {
 285                         if (ul == 0)
 286                                 skb->csum = csum_partial(udph, ipl - ihl, 0);
 287                         else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
 288                                 skb->csum = csum_partial(udph, ul, 0);
 289                         else
 290                                 goto ignore_obscure_skb;
 291                 } else {
 292                         if (ul != ipl - ihl)
 293                                 goto ignore_obscure_skb;
 294
 295                         skb->csum = csum_partial(udph, ul, 0);
 296                 }
 297
 298                 udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
 299                                                 ul, iph->protocol,
 300                                                 skb->csum);
 301
 302                 if (!udph->check)
 303                         udph->check = CSUM_MANGLED_0;
 304         }
 305
 306         skb->ip_summed = CHECKSUM_NONE;
 307
 308 ignore_obscure_skb:
 309         return 1;
 310 }
 311
 312 static int tcf_csum_ipv6_udp(struct sk_buff *skb, unsigned int ihl,
 313                              unsigned int ipl, int udplite)
 314 {
 315         struct udphdr *udph;
 316         const struct ipv6hdr *ip6h;
 317         u16 ul;
 318
 319         if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 320                 return 1;
 321
 322         /*
 323          * Support both UDP and UDPLITE checksum algorithms, Don't use
 324          * udph->len to get the real length without any protocol check,
 325          * UDPLITE uses udph->len for another thing,
 326          * Use ip6h->payload_len + sizeof(*ip6h) ... , or just ipl.
 327          */
 328
 329         udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
 330         if (udph == NULL)
 331                 return 0;
 332
 333         ip6h = ipv6_hdr(skb);
 334         ul = ntohs(udph->len);
 335
 336         udph->check = 0;
 337
 338         if (udplite) {
 339                 if (ul == 0)
 340                         skb->csum = csum_partial(udph, ipl - ihl, 0);
 341
 342                 else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
 343                         skb->csum = csum_partial(udph, ul, 0);
 344
 345                 else
 346                         goto ignore_obscure_skb;
 347         } else {
 348                 if (ul != ipl - ihl)
 349                         goto ignore_obscure_skb;
 350
 351                 skb->csum = csum_partial(udph, ul, 0);
 352         }
 353
 354         udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul,
 355                                       udplite ? IPPROTO_UDPLITE : IPPROTO_UDP,
 356                                       skb->csum);
 357
 358         if (!udph->check)
 359                 udph->check = CSUM_MANGLED_0;
 360
 361         skb->ip_summed = CHECKSUM_NONE;
 362
 363 ignore_obscure_skb:
 364         return 1;
 365 }
 366
 367 static int tcf_csum_sctp(struct sk_buff *skb, unsigned int ihl,
 368                          unsigned int ipl)
 369 {
 370         struct sctphdr *sctph;
 371
 372         if (skb_is_gso(skb) && skb_is_gso_sctp(skb))
 373                 return 1;
 374
 375         sctph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*sctph));
 376         if (!sctph)
 377                 return 0;
 378
 379         sctph->checksum = sctp_compute_cksum(skb,
 380                                              skb_network_offset(skb) + ihl);
 381         skb->ip_summed = CHECKSUM_NONE;
 382         skb->csum_not_inet = 0;
 383
 384         return 1;
 385 }
 386
 387 static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags)
 388 {
 389         const struct iphdr *iph;
 390         int ntkoff;
 391
 392         ntkoff = skb_network_offset(skb);
 393
 394         if (!pskb_may_pull(skb, sizeof(*iph) + ntkoff))
 395                 goto fail;
 396
 397         iph = ip_hdr(skb);
 398
 399         switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
 400         case IPPROTO_ICMP:
 401                 if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
 402                         if (!tcf_csum_ipv4_icmp(skb, iph->ihl * 4,
 403                                                 ntohs(iph->tot_len)))
 404                                 goto fail;
 405                 break;
 406         case IPPROTO_IGMP:
 407                 if (update_flags & TCA_CSUM_UPDATE_FLAG_IGMP)
 408                         if (!tcf_csum_ipv4_igmp(skb, iph->ihl * 4,
 409                                                 ntohs(iph->tot_len)))
 410                                 goto fail;
 411                 break;
 412         case IPPROTO_TCP:
 413                 if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
 414                         if (!tcf_csum_ipv4_tcp(skb, iph->ihl * 4,
 415                                                ntohs(iph->tot_len)))
 416                                 goto fail;
 417                 break;
 418         case IPPROTO_UDP:
 419                 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
 420                         if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
 421                                                ntohs(iph->tot_len), 0))
 422                                 goto fail;
 423                 break;
 424         case IPPROTO_UDPLITE:
 425                 if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
 426                         if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
 427                                                ntohs(iph->tot_len), 1))
 428                                 goto fail;
 429                 break;
 430         case IPPROTO_SCTP:
 431                 if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
 432                     !tcf_csum_sctp(skb, iph->ihl * 4, ntohs(iph->tot_len)))
 433                         goto fail;
 434                 break;
 435         }
 436
 437         if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) {
 438                 if (skb_try_make_writable(skb, sizeof(*iph) + ntkoff))
 439                         goto fail;
 440
 441                 ip_send_check(ip_hdr(skb));
 442         }
 443
 444         return 1;
 445
 446 fail:
 447         return 0;
 448 }
 449
 450 static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr *ip6xh, unsigned int ixhl,
 451                                  unsigned int *pl)
 452 {
 453         int off, len, optlen;
 454         unsigned char *xh = (void *)ip6xh;
 455
 456         off = sizeof(*ip6xh);
 457         len = ixhl - off;
 458
 459         while (len > 1) {
 460                 switch (xh[off]) {
 461                 case IPV6_TLV_PAD1:
 462                         optlen = 1;
 463                         break;
 464                 case IPV6_TLV_JUMBO:
 465                         optlen = xh[off + 1] + 2;
 466                         if (optlen != 6 || len < 6 || (off & 3) != 2)
 467                                 /* wrong jumbo option length/alignment */
 468                                 return 0;
 469                         *pl = ntohl(*(__be32 *)(xh + off + 2));
 470                         goto done;
 471                 default:
 472                         optlen = xh[off + 1] + 2;
 473                         if (optlen > len)
 474                                 /* ignore obscure options */
 475                                 goto done;
 476                         break;
 477                 }
 478                 off += optlen;
 479                 len -= optlen;
 480         }
 481
 482 done:
 483         return 1;
 484 }
 485
 486 static int tcf_csum_ipv6(struct sk_buff *skb, u32 update_flags)
 487 {
 488         struct ipv6hdr *ip6h;
 489         struct ipv6_opt_hdr *ip6xh;
 490         unsigned int hl, ixhl;
 491         unsigned int pl;
 492         int ntkoff;
 493         u8 nexthdr;
 494
 495         ntkoff = skb_network_offset(skb);
 496
 497         hl = sizeof(*ip6h);
 498
 499         if (!pskb_may_pull(skb, hl + ntkoff))
 500                 goto fail;
 501
 502         ip6h = ipv6_hdr(skb);
 503
 504         pl = ntohs(ip6h->payload_len);
 505         nexthdr = ip6h->nexthdr;
 506
 507         do {
 508                 switch (nexthdr) {
 509                 case NEXTHDR_FRAGMENT:
 510                         goto ignore_skb;
 511                 case NEXTHDR_ROUTING:
 512                 case NEXTHDR_HOP:
 513                 case NEXTHDR_DEST:
 514                         if (!pskb_may_pull(skb, hl + sizeof(*ip6xh) + ntkoff))
 515                                 goto fail;
 516                         ip6xh = (void *)(skb_network_header(skb) + hl);
 517                         ixhl = ipv6_optlen(ip6xh);
 518                         if (!pskb_may_pull(skb, hl + ixhl + ntkoff))
 519                                 goto fail;
 520                         ip6xh = (void *)(skb_network_header(skb) + hl);
 521                         if ((nexthdr == NEXTHDR_HOP) &&
 522                             !(tcf_csum_ipv6_hopopts(ip6xh, ixhl, &pl)))
 523                                 goto fail;
 524                         nexthdr = ip6xh->nexthdr;
 525                         hl += ixhl;
 526                         break;
 527                 case IPPROTO_ICMPV6:
 528                         if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
 529                                 if (!tcf_csum_ipv6_icmp(skb,
 530                                                         hl, pl + sizeof(*ip6h)))
 531                                         goto fail;
 532                         goto done;
 533                 case IPPROTO_TCP:
 534                         if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
 535                                 if (!tcf_csum_ipv6_tcp(skb,
 536                                                        hl, pl + sizeof(*ip6h)))
 537                                         goto fail;
 538                         goto done;
 539                 case IPPROTO_UDP:
 540                         if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
 541                                 if (!tcf_csum_ipv6_udp(skb, hl,
 542                                                        pl + sizeof(*ip6h), 0))
 543                                         goto fail;
 544                         goto done;
 545                 case IPPROTO_UDPLITE:
 546                         if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
 547                                 if (!tcf_csum_ipv6_udp(skb, hl,
 548                                                        pl + sizeof(*ip6h), 1))
 549                                         goto fail;
 550                         goto done;
 551                 case IPPROTO_SCTP:
 552                         if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
 553                             !tcf_csum_sctp(skb, hl, pl + sizeof(*ip6h)))
 554                                 goto fail;
 555                         goto done;
 556                 default:
 557                         goto ignore_skb;
 558                 }
 559         } while (pskb_may_pull(skb, hl + 1 + ntkoff));
 560
 561 done:
 562 ignore_skb:
 563         return 1;
 564
 565 fail:
 566         return 0;
 567 }
 568
 569 static int tcf_csum_act(struct sk_buff *skb, const struct tc_action *a,
 570                         struct tcf_result *res)
 571 {
 572         struct tcf_csum *p = to_tcf_csum(a);
 573         bool orig_vlan_tag_present = false;
 574         unsigned int vlan_hdr_count = 0;
 575         struct tcf_csum_params *params;
 576         u32 update_flags;
 577         __be16 protocol;
 578         int action;
 579
 580         params = rcu_dereference_bh(p->params);
 581
 582         tcf_lastuse_update(&p->tcf_tm);
 583         tcf_action_update_bstats(&p->common, skb);
 584
 585         action = READ_ONCE(p->tcf_action);
 586         if (unlikely(action == TC_ACT_SHOT))
 587                 goto drop;
 588
 589         update_flags = params->update_flags;
 590         protocol = tc_skb_protocol(skb);
 591 again:
 592         switch (protocol) {
 593         case cpu_to_be16(ETH_P_IP):
 594                 if (!tcf_csum_ipv4(skb, update_flags))
 595                         goto drop;
 596                 break;
 597         case cpu_to_be16(ETH_P_IPV6):
 598                 if (!tcf_csum_ipv6(skb, update_flags))
 599                         goto drop;
 600                 break;
 601         case cpu_to_be16(ETH_P_8021AD): /* fall through */
 602         case cpu_to_be16(ETH_P_8021Q):
 603                 if (skb_vlan_tag_present(skb) && !orig_vlan_tag_present) {
 604                         protocol = skb->protocol;
 605                         orig_vlan_tag_present = true;
 606                 } else {
 607                         struct vlan_hdr *vlan = (struct vlan_hdr *)skb->data;
 608
 609                         protocol = vlan->h_vlan_encapsulated_proto;
 610                         skb_pull(skb, VLAN_HLEN);
 611                         skb_reset_network_header(skb);
 612                         vlan_hdr_count++;
 613                 }
 614                 goto again;
 615         }
 616
 617 out:
 618         /* Restore the skb for the pulled VLAN tags */
 619         while (vlan_hdr_count--) {
 620                 skb_push(skb, VLAN_HLEN);
 621                 skb_reset_network_header(skb);
 622         }
 623
 624         return action;
 625
 626 drop:
 627         tcf_action_inc_drop_qstats(&p->common);
 628         action = TC_ACT_SHOT;
 629         goto out;
 630 }
 631
 632 static int tcf_csum_dump(struct sk_buff *skb, struct tc_action *a, int bind,
 633                          int ref)
 634 {
 635         unsigned char *b = skb_tail_pointer(skb);
 636         struct tcf_csum *p = to_tcf_csum(a);
 637         struct tcf_csum_params *params;
 638         struct tc_csum opt = {
 639                 .index   = p->tcf_index,
 640                 .refcnt  = refcount_read(&p->tcf_refcnt) - ref,
 641                 .bindcnt = atomic_read(&p->tcf_bindcnt) - bind,
 642         };
 643         struct tcf_t t;
 644
 645         spin_lock_bh(&p->tcf_lock);
 646         params = rcu_dereference_protected(p->params,
 647                                            lockdep_is_held(&p->tcf_lock));
 648         opt.action = p->tcf_action;
 649         opt.update_flags = params->update_flags;
 650
 651         if (nla_put(skb, TCA_CSUM_PARMS, sizeof(opt), &opt))
 652                 goto nla_put_failure;
 653
 654         tcf_tm_dump(&t, &p->tcf_tm);
 655         if (nla_put_64bit(skb, TCA_CSUM_TM, sizeof(t), &t, TCA_CSUM_PAD))
 656                 goto nla_put_failure;
 657         spin_unlock_bh(&p->tcf_lock);
 658
 659         return skb->len;
 660
 661 nla_put_failure:
 662         spin_unlock_bh(&p->tcf_lock);
 663         nlmsg_trim(skb, b);
 664         return -1;
 665 }
 666
 667 static void tcf_csum_cleanup(struct tc_action *a)
 668 {
 669         struct tcf_csum *p = to_tcf_csum(a);
 670         struct tcf_csum_params *params;
 671
 672         params = rcu_dereference_protected(p->params, 1);
 673         if (params)
 674                 kfree_rcu(params, rcu);
 675 }
 676
 677 static int tcf_csum_walker(struct net *net, struct sk_buff *skb,
 678                            struct netlink_callback *cb, int type,
 679                            const struct tc_action_ops *ops,
 680                            struct netlink_ext_ack *extack)
 681 {
 682         struct tc_action_net *tn = net_generic(net, csum_net_id);
 683
 684         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 685 }
 686
 687 static int tcf_csum_search(struct net *net, struct tc_action **a, u32 index)
 688 {
 689         struct tc_action_net *tn = net_generic(net, csum_net_id);
 690
 691         return tcf_idr_search(tn, a, index);
 692 }
 693
 694 static size_t tcf_csum_get_fill_size(const struct tc_action *act)
 695 {
 696         return nla_total_size(sizeof(struct tc_csum));
 697 }
 698
 699 static struct tc_action_ops act_csum_ops = {
 700         .kind           = "csum",
 701         .id             = TCA_ID_CSUM,
 702         .owner          = THIS_MODULE,
 703         .act            = tcf_csum_act,
 704         .dump           = tcf_csum_dump,
 705         .init           = tcf_csum_init,
 706         .cleanup        = tcf_csum_cleanup,
 707         .walk           = tcf_csum_walker,
 708         .lookup         = tcf_csum_search,
 709         .get_fill_size  = tcf_csum_get_fill_size,
 710         .size           = sizeof(struct tcf_csum),
 711 };
 712
 713 static __net_init int csum_init_net(struct net *net)
 714 {
 715         struct tc_action_net *tn = net_generic(net, csum_net_id);
 716
 717         return tc_action_net_init(net, tn, &act_csum_ops);
 718 }
 719
 720 static void __net_exit csum_exit_net(struct list_head *net_list)
 721 {
 722         tc_action_net_exit(net_list, csum_net_id);
 723 }
 724
 725 static struct pernet_operations csum_net_ops = {
 726         .init = csum_init_net,
 727         .exit_batch = csum_exit_net,
 728         .id   = &csum_net_id,
 729         .size = sizeof(struct tc_action_net),
 730 };
 731
 732 MODULE_DESCRIPTION("Checksum updating actions");
 733 MODULE_LICENSE("GPL");
 734
 735 static int __init csum_init_module(void)
 736 {
 737         return tcf_register_action(&act_csum_ops, &csum_net_ops);
 738 }
 739
 740 static void __exit csum_cleanup_module(void)
 741 {
 742         tcf_unregister_action(&act_csum_ops, &csum_net_ops);
 743 }
 744
 745 module_init(csum_init_module);
 746 module_exit(csum_cleanup_module);