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