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