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 #include <net/tc_wrapper.h>
  36
  37 static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = {
  38         [TCA_CSUM_PARMS] = { .len = sizeof(struct tc_csum), },
  39 };
  40
  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,
  45                          struct tcf_proto *tp,
  46                          u32 flags, struct netlink_ext_ack *extack)
  47 {
  48         struct tc_action_net *tn = net_generic(net, act_csum_ops.net_id);
  49         bool bind = flags & TCA_ACT_FLAGS_BIND;
  50         struct tcf_csum_params *params_new;
  51         struct nlattr *tb[TCA_CSUM_MAX + 1];
  52         struct tcf_chain *goto_ch = NULL;
  53         struct tc_csum *parm;
  54         struct tcf_csum *p;
  55         int ret = 0, err;
  56         u32 index;
  57
  58         if (nla == NULL)
  59                 return -EINVAL;
  60
  61         err = nla_parse_nested_deprecated(tb, TCA_CSUM_MAX, nla, csum_policy,
  62                                           NULL);
  63         if (err < 0)
  64                 return err;
  65
  66         if (tb[TCA_CSUM_PARMS] == NULL)
  67                 return -EINVAL;
  68         parm = nla_data(tb[TCA_CSUM_PARMS]);
  69         index = parm->index;
  70         err = tcf_idr_check_alloc(tn, &index, a, bind);
  71         if (!err) {
  72                 ret = tcf_idr_create_from_flags(tn, index, est, a,
  73                                                 &act_csum_ops, bind, flags);
  74                 if (ret) {
  75                         tcf_idr_cleanup(tn, index);
  76                         return ret;
  77                 }
  78                 ret = ACT_P_CREATED;
  79         } else if (err > 0) {
  80                 if (bind) /* dont override defaults */
  81                         return ACT_P_BOUND;
  82                 if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
  83                         tcf_idr_release(*a, bind);
  84                         return -EEXIST;
  85                 }
  86         } else {
  87                 return err;
  88         }
  89
  90         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
  91         if (err < 0)
  92                 goto release_idr;
  93
  94         p = to_tcf_csum(*a);
  95
  96         params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
  97         if (unlikely(!params_new)) {
  98                 err = -ENOMEM;
  99                 goto put_chain;
 100         }
 101         params_new->update_flags = parm->update_flags;
 102
 103         spin_lock_bh(&p->tcf_lock);
 104         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 105         params_new = rcu_replace_pointer(p->params, params_new,
 106                                          lockdep_is_held(&p->tcf_lock));
 107         spin_unlock_bh(&p->tcf_lock);
 108
 109         if (goto_ch)
 110                 tcf_chain_put_by_act(goto_ch);
 111         if (params_new)
 112                 kfree_rcu(params_new, rcu);
 113
 114         return ret;
 115 put_chain:
 116         if (goto_ch)
 117                 tcf_chain_put_by_act(goto_ch);
 118 release_idr:
 119         tcf_idr_release(*a, bind);
 120         return err;
 121 }
 122
 123 /**
 124  * tcf_csum_skb_nextlayer - Get next layer pointer
 125  * @skb: sk_buff to use
 126  * @ihl: previous summed headers length
 127  * @ipl: complete packet length
 128  * @jhl: next header length
 129  *
 130  * Check the expected next layer availability in the specified sk_buff.
 131  * Return the next layer pointer if pass, NULL otherwise.
 132  */
 133 static void *tcf_csum_skb_nextlayer(struct sk_buff *skb,
 134                                     unsigned int ihl, unsigned int ipl,
 135                                     unsigned int jhl)
 136 {
 137         int ntkoff = skb_network_offset(skb);
 138         int hl = ihl + jhl;
 139
 140         if (!pskb_may_pull(skb, ipl + ntkoff) || (ipl < hl) ||
 141             skb_try_make_writable(skb, hl + ntkoff))
 142                 return NULL;
 143         else
 144                 return (void *)(skb_network_header(skb) + ihl);
 145 }
 146
 147 static int tcf_csum_ipv4_icmp(struct sk_buff *skb, unsigned int ihl,
 148                               unsigned int ipl)
 149 {
 150         struct icmphdr *icmph;
 151
 152         icmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmph));
 153         if (icmph == NULL)
 154                 return 0;
 155
 156         icmph->checksum = 0;
 157         skb->csum = csum_partial(icmph, ipl - ihl, 0);
 158         icmph->checksum = csum_fold(skb->csum);
 159
 160         skb->ip_summed = CHECKSUM_NONE;
 161
 162         return 1;
 163 }
 164
 165 static int tcf_csum_ipv4_igmp(struct sk_buff *skb,
 166                               unsigned int ihl, unsigned int ipl)
 167 {
 168         struct igmphdr *igmph;
 169
 170         igmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*igmph));
 171         if (igmph == NULL)
 172                 return 0;
 173
 174         igmph->csum = 0;
 175         skb->csum = csum_partial(igmph, ipl - ihl, 0);
 176         igmph->csum = csum_fold(skb->csum);
 177
 178         skb->ip_summed = CHECKSUM_NONE;
 179
 180         return 1;
 181 }
 182
 183 static int tcf_csum_ipv6_icmp(struct sk_buff *skb, unsigned int ihl,
 184                               unsigned int ipl)
 185 {
 186         struct icmp6hdr *icmp6h;
 187         const struct ipv6hdr *ip6h;
 188
 189         icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h));
 190         if (icmp6h == NULL)
 191                 return 0;
 192
 193         ip6h = ipv6_hdr(skb);
 194         icmp6h->icmp6_cksum = 0;
 195         skb->csum = csum_partial(icmp6h, ipl - ihl, 0);
 196         icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
 197                                               ipl - ihl, IPPROTO_ICMPV6,
 198                                               skb->csum);
 199
 200         skb->ip_summed = CHECKSUM_NONE;
 201
 202         return 1;
 203 }
 204
 205 static int tcf_csum_ipv4_tcp(struct sk_buff *skb, unsigned int ihl,
 206                              unsigned int ipl)
 207 {
 208         struct tcphdr *tcph;
 209         const struct iphdr *iph;
 210
 211         if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 212                 return 1;
 213
 214         tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
 215         if (tcph == NULL)
 216                 return 0;
 217
 218         iph = ip_hdr(skb);
 219         tcph->check = 0;
 220         skb->csum = csum_partial(tcph, ipl - ihl, 0);
 221         tcph->check = tcp_v4_check(ipl - ihl,
 222                                    iph->saddr, iph->daddr, skb->csum);
 223
 224         skb->ip_summed = CHECKSUM_NONE;
 225
 226         return 1;
 227 }
 228
 229 static int tcf_csum_ipv6_tcp(struct sk_buff *skb, unsigned int ihl,
 230                              unsigned int ipl)
 231 {
 232         struct tcphdr *tcph;
 233         const struct ipv6hdr *ip6h;
 234
 235         if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 236                 return 1;
 237
 238         tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
 239         if (tcph == NULL)
 240                 return 0;
 241
 242         ip6h = ipv6_hdr(skb);
 243         tcph->check = 0;
 244         skb->csum = csum_partial(tcph, ipl - ihl, 0);
 245         tcph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
 246                                       ipl - ihl, IPPROTO_TCP,
 247                                       skb->csum);
 248
 249         skb->ip_summed = CHECKSUM_NONE;
 250
 251         return 1;
 252 }
 253
 254 static int tcf_csum_ipv4_udp(struct sk_buff *skb, unsigned int ihl,
 255                              unsigned int ipl, int udplite)
 256 {
 257         struct udphdr *udph;
 258         const struct iphdr *iph;
 259         u16 ul;
 260
 261         if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 262                 return 1;
 263
 264         /*
 265          * Support both UDP and UDPLITE checksum algorithms, Don't use
 266          * udph->len to get the real length without any protocol check,
 267          * UDPLITE uses udph->len for another thing,
 268          * Use iph->tot_len, or just ipl.
 269          */
 270
 271         udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
 272         if (udph == NULL)
 273                 return 0;
 274
 275         iph = ip_hdr(skb);
 276         ul = ntohs(udph->len);
 277
 278         if (udplite || udph->check) {
 279
 280                 udph->check = 0;
 281
 282                 if (udplite) {
 283                         if (ul == 0)
 284                                 skb->csum = csum_partial(udph, ipl - ihl, 0);
 285                         else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
 286                                 skb->csum = csum_partial(udph, ul, 0);
 287                         else
 288                                 goto ignore_obscure_skb;
 289                 } else {
 290                         if (ul != ipl - ihl)
 291                                 goto ignore_obscure_skb;
 292
 293                         skb->csum = csum_partial(udph, ul, 0);
 294                 }
 295
 296                 udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
 297                                                 ul, iph->protocol,
 298                                                 skb->csum);
 299
 300                 if (!udph->check)
 301                         udph->check = CSUM_MANGLED_0;
 302         }
 303
 304         skb->ip_summed = CHECKSUM_NONE;
 305
 306 ignore_obscure_skb:
 307         return 1;
 308 }
 309
 310 static int tcf_csum_ipv6_udp(struct sk_buff *skb, unsigned int ihl,
 311                              unsigned int ipl, int udplite)
 312 {
 313         struct udphdr *udph;
 314         const struct ipv6hdr *ip6h;
 315         u16 ul;
 316
 317         if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 318                 return 1;
 319
 320         /*
 321          * Support both UDP and UDPLITE checksum algorithms, Don't use
 322          * udph->len to get the real length without any protocol check,
 323          * UDPLITE uses udph->len for another thing,
 324          * Use ip6h->payload_len + sizeof(*ip6h) ... , or just ipl.
 325          */
 326
 327         udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
 328         if (udph == NULL)
 329                 return 0;
 330
 331         ip6h = ipv6_hdr(skb);
 332         ul = ntohs(udph->len);
 333
 334         udph->check = 0;
 335
 336         if (udplite) {
 337                 if (ul == 0)
 338                         skb->csum = csum_partial(udph, ipl - ihl, 0);
 339
 340                 else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
 341                         skb->csum = csum_partial(udph, ul, 0);
 342
 343                 else
 344                         goto ignore_obscure_skb;
 345         } else {
 346                 if (ul != ipl - ihl)
 347                         goto ignore_obscure_skb;
 348
 349                 skb->csum = csum_partial(udph, ul, 0);
 350         }
 351
 352         udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul,
 353                                       udplite ? IPPROTO_UDPLITE : IPPROTO_UDP,
 354                                       skb->csum);
 355
 356         if (!udph->check)
 357                 udph->check = CSUM_MANGLED_0;
 358
 359         skb->ip_summed = CHECKSUM_NONE;
 360
 361 ignore_obscure_skb:
 362         return 1;
 363 }
 364
 365 static int tcf_csum_sctp(struct sk_buff *skb, unsigned int ihl,
 366                          unsigned int ipl)
 367 {
 368         struct sctphdr *sctph;
 369
 370         if (skb_is_gso(skb) && skb_is_gso_sctp(skb))
 371                 return 1;
 372
 373         sctph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*sctph));
 374         if (!sctph)
 375                 return 0;
 376
 377         sctph->checksum = sctp_compute_cksum(skb,
 378                                              skb_network_offset(skb) + ihl);
 379         skb_reset_csum_not_inet(skb);
 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 TC_INDIRECT_SCOPE int tcf_csum_act(struct sk_buff *skb,
 567                                    const struct tc_action *a,
 568                                    struct tcf_result *res)
 569 {
 570         struct tcf_csum *p = to_tcf_csum(a);
 571         bool orig_vlan_tag_present = false;
 572         unsigned int vlan_hdr_count = 0;
 573         struct tcf_csum_params *params;
 574         u32 update_flags;
 575         __be16 protocol;
 576         int action;
 577
 578         params = rcu_dereference_bh(p->params);
 579
 580         tcf_lastuse_update(&p->tcf_tm);
 581         tcf_action_update_bstats(&p->common, skb);
 582
 583         action = READ_ONCE(p->tcf_action);
 584         if (unlikely(action == TC_ACT_SHOT))
 585                 goto drop;
 586
 587         update_flags = params->update_flags;
 588         protocol = skb_protocol(skb, false);
 589 again:
 590         switch (protocol) {
 591         case cpu_to_be16(ETH_P_IP):
 592                 if (!tcf_csum_ipv4(skb, update_flags))
 593                         goto drop;
 594                 break;
 595         case cpu_to_be16(ETH_P_IPV6):
 596                 if (!tcf_csum_ipv6(skb, update_flags))
 597                         goto drop;
 598                 break;
 599         case cpu_to_be16(ETH_P_8021AD):
 600                 fallthrough;
 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         tcf_action_inc_drop_qstats(&p->common);
 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 size_t tcf_csum_get_fill_size(const struct tc_action *act)
 677 {
 678         return nla_total_size(sizeof(struct tc_csum));
 679 }
 680
 681 static int tcf_csum_offload_act_setup(struct tc_action *act, void *entry_data,
 682                                       u32 *index_inc, bool bind,
 683                                       struct netlink_ext_ack *extack)
 684 {
 685         if (bind) {
 686                 struct flow_action_entry *entry = entry_data;
 687
 688                 entry->id = FLOW_ACTION_CSUM;
 689                 entry->csum_flags = tcf_csum_update_flags(act);
 690                 *index_inc = 1;
 691         } else {
 692                 struct flow_offload_action *fl_action = entry_data;
 693
 694                 fl_action->id = FLOW_ACTION_CSUM;
 695         }
 696
 697         return 0;
 698 }
 699
 700 static struct tc_action_ops act_csum_ops = {
 701         .kind           = "csum",
 702         .id             = TCA_ID_CSUM,
 703         .owner          = THIS_MODULE,
 704         .act            = tcf_csum_act,
 705         .dump           = tcf_csum_dump,
 706         .init           = tcf_csum_init,
 707         .cleanup        = tcf_csum_cleanup,
 708         .get_fill_size  = tcf_csum_get_fill_size,
 709         .offload_act_setup = tcf_csum_offload_act_setup,
 710         .size           = sizeof(struct tcf_csum),
 711 };
 712 MODULE_ALIAS_NET_ACT("csum");
 713
 714 static __net_init int csum_init_net(struct net *net)
 715 {
 716         struct tc_action_net *tn = net_generic(net, act_csum_ops.net_id);
 717
 718         return tc_action_net_init(net, tn, &act_csum_ops);
 719 }
 720
 721 static void __net_exit csum_exit_net(struct list_head *net_list)
 722 {
 723         tc_action_net_exit(net_list, act_csum_ops.net_id);
 724 }
 725
 726 static struct pernet_operations csum_net_ops = {
 727         .init = csum_init_net,
 728         .exit_batch = csum_exit_net,
 729         .id   = &act_csum_ops.net_id,
 730         .size = sizeof(struct tc_action_net),
 731 };
 732
 733 MODULE_DESCRIPTION("Checksum updating actions");
 734 MODULE_LICENSE("GPL");
 735
 736 static int __init csum_init_module(void)
 737 {
 738         return tcf_register_action(&act_csum_ops, &csum_net_ops);
 739 }
 740
 741 static void __exit csum_cleanup_module(void)
 742 {
 743         tcf_unregister_action(&act_csum_ops, &csum_net_ops);
 744 }
 745
 746 module_init(csum_init_module);
 747 module_exit(csum_cleanup_module);