net/sched/act_csum.c

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