target/linux/generic/hack-4.19/650-netfilter-add-xt_OFFLOAD-target.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Tue, 20 Feb 2018 15:56:02 +0100
   3 Subject: [PATCH] netfilter: add xt_OFFLOAD target
   4
   5 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   6 ---
   7  create mode 100644 net/netfilter/xt_OFFLOAD.c
   8
   9 --- a/net/ipv4/netfilter/Kconfig
  10 +++ b/net/ipv4/netfilter/Kconfig
  11 @@ -63,8 +63,6 @@ config NF_TABLES_ARP
  12         help
  13           This option enables the ARP support for nf_tables.
  14
  15 -endif # NF_TABLES
  16 -
  17  config NF_FLOW_TABLE_IPV4
  18         tristate "Netfilter flow table IPv4 module"
  19         depends on NF_FLOW_TABLE
  20 @@ -73,6 +71,8 @@ config NF_FLOW_TABLE_IPV4
  21
  22           To compile it as a module, choose M here.
  23
  24 +endif # NF_TABLES
  25 +
  26  config NF_DUP_IPV4
  27         tristate "Netfilter IPv4 packet duplication to alternate destination"
  28         depends on !NF_CONNTRACK || NF_CONNTRACK
  29 --- a/net/ipv6/netfilter/Kconfig
  30 +++ b/net/ipv6/netfilter/Kconfig
  31 @@ -80,7 +80,6 @@ config NFT_FIB_IPV6
  32           multicast or blackhole.
  33
  34  endif # NF_TABLES_IPV6
  35 -endif # NF_TABLES
  36
  37  config NF_FLOW_TABLE_IPV6
  38         tristate "Netfilter flow table IPv6 module"
  39 @@ -90,6 +89,8 @@ config NF_FLOW_TABLE_IPV6
  40
  41           To compile it as a module, choose M here.
  42
  43 +endif # NF_TABLES
  44 +
  45  config NF_DUP_IPV6
  46         tristate "Netfilter IPv6 packet duplication to alternate destination"
  47         depends on !NF_CONNTRACK || NF_CONNTRACK
  48 --- a/net/netfilter/Kconfig
  49 +++ b/net/netfilter/Kconfig
  50 @@ -693,8 +693,6 @@ config NFT_FIB_NETDEV
  51
  52  endif # NF_TABLES_NETDEV
  53
  54 -endif # NF_TABLES
  55 -
  56  config NF_FLOW_TABLE_INET
  57         tristate "Netfilter flow table mixed IPv4/IPv6 module"
  58         depends on NF_FLOW_TABLE
  59 @@ -703,11 +701,12 @@ config NF_FLOW_TABLE_INET
  60
  61           To compile it as a module, choose M here.
  62
  63 +endif # NF_TABLES
  64 +
  65  config NF_FLOW_TABLE
  66         tristate "Netfilter flow table module"
  67         depends on NETFILTER_INGRESS
  68         depends on NF_CONNTRACK
  69 -       depends on NF_TABLES
  70         help
  71           This option adds the flow table core infrastructure.
  72
  73 @@ -996,6 +995,15 @@ config NETFILTER_XT_TARGET_NOTRACK
  74         depends on NETFILTER_ADVANCED
  75         select NETFILTER_XT_TARGET_CT
  76
  77 +config NETFILTER_XT_TARGET_FLOWOFFLOAD
  78 +       tristate '"FLOWOFFLOAD" target support'
  79 +       depends on NF_FLOW_TABLE
  80 +       depends on NETFILTER_INGRESS
  81 +       help
  82 +         This option adds a `FLOWOFFLOAD' target, which uses the nf_flow_offload
  83 +         module to speed up processing of packets by bypassing the usual
  84 +         netfilter chains
  85 +
  86  config NETFILTER_XT_TARGET_RATEEST
  87         tristate '"RATEEST" target support'
  88         depends on NETFILTER_ADVANCED
  89 --- a/net/netfilter/Makefile
  90 +++ b/net/netfilter/Makefile
  91 @@ -144,6 +144,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_CLASSIF
  92  obj-$(CONFIG_NETFILTER_XT_TARGET_CONNSECMARK) += xt_CONNSECMARK.o
  93  obj-$(CONFIG_NETFILTER_XT_TARGET_CT) += xt_CT.o
  94  obj-$(CONFIG_NETFILTER_XT_TARGET_DSCP) += xt_DSCP.o
  95 +obj-$(CONFIG_NETFILTER_XT_TARGET_FLOWOFFLOAD) += xt_FLOWOFFLOAD.o
  96  obj-$(CONFIG_NETFILTER_XT_TARGET_HL) += xt_HL.o
  97  obj-$(CONFIG_NETFILTER_XT_TARGET_HMARK) += xt_HMARK.o
  98  obj-$(CONFIG_NETFILTER_XT_TARGET_LED) += xt_LED.o
  99 --- /dev/null
 100 +++ b/net/netfilter/xt_FLOWOFFLOAD.c
 101 @@ -0,0 +1,422 @@
 102 +/*
 103 + * Copyright (C) 2018 Felix Fietkau <nbd@nbd.name>
 104 + *
 105 + * This program is free software; you can redistribute it and/or modify
 106 + * it under the terms of the GNU General Public License version 2 as
 107 + * published by the Free Software Foundation.
 108 + */
 109 +#include <linux/module.h>
 110 +#include <linux/init.h>
 111 +#include <linux/netfilter.h>
 112 +#include <linux/netfilter/xt_FLOWOFFLOAD.h>
 113 +#include <net/ip.h>
 114 +#include <net/netfilter/nf_conntrack.h>
 115 +#include <net/netfilter/nf_conntrack_extend.h>
 116 +#include <net/netfilter/nf_conntrack_helper.h>
 117 +#include <net/netfilter/nf_flow_table.h>
 118 +
 119 +static struct nf_flowtable nf_flowtable;
 120 +static HLIST_HEAD(hooks);
 121 +static DEFINE_SPINLOCK(hooks_lock);
 122 +static struct delayed_work hook_work;
 123 +
 124 +struct xt_flowoffload_hook {
 125 +       struct hlist_node list;
 126 +       struct nf_hook_ops ops;
 127 +       struct net *net;
 128 +       bool registered;
 129 +       bool used;
 130 +};
 131 +
 132 +static unsigned int
 133 +xt_flowoffload_net_hook(void *priv, struct sk_buff *skb,
 134 +                         const struct nf_hook_state *state)
 135 +{
 136 +       switch (skb->protocol) {
 137 +       case htons(ETH_P_IP):
 138 +               return nf_flow_offload_ip_hook(priv, skb, state);
 139 +       case htons(ETH_P_IPV6):
 140 +               return nf_flow_offload_ipv6_hook(priv, skb, state);
 141 +       }
 142 +
 143 +       return NF_ACCEPT;
 144 +}
 145 +
 146 +static int
 147 +xt_flowoffload_create_hook(struct net_device *dev)
 148 +{
 149 +       struct xt_flowoffload_hook *hook;
 150 +       struct nf_hook_ops *ops;
 151 +
 152 +       hook = kzalloc(sizeof(*hook), GFP_ATOMIC);
 153 +       if (!hook)
 154 +               return -ENOMEM;
 155 +
 156 +       ops = &hook->ops;
 157 +       ops->pf = NFPROTO_NETDEV;
 158 +       ops->hooknum = NF_NETDEV_INGRESS;
 159 +       ops->priority = 10;
 160 +       ops->priv = &nf_flowtable;
 161 +       ops->hook = xt_flowoffload_net_hook;
 162 +       ops->dev = dev;
 163 +
 164 +       hlist_add_head(&hook->list, &hooks);
 165 +       mod_delayed_work(system_power_efficient_wq, &hook_work, 0);
 166 +
 167 +       return 0;
 168 +}
 169 +
 170 +static struct xt_flowoffload_hook *
 171 +flow_offload_lookup_hook(struct net_device *dev)
 172 +{
 173 +       struct xt_flowoffload_hook *hook;
 174 +
 175 +       hlist_for_each_entry(hook, &hooks, list) {
 176 +               if (hook->ops.dev == dev)
 177 +                       return hook;
 178 +       }
 179 +
 180 +       return NULL;
 181 +}
 182 +
 183 +static void
 184 +xt_flowoffload_check_device(struct net_device *dev)
 185 +{
 186 +       struct xt_flowoffload_hook *hook;
 187 +
 188 +       spin_lock_bh(&hooks_lock);
 189 +       hook = flow_offload_lookup_hook(dev);
 190 +       if (hook)
 191 +               hook->used = true;
 192 +       else
 193 +               xt_flowoffload_create_hook(dev);
 194 +       spin_unlock_bh(&hooks_lock);
 195 +}
 196 +
 197 +static void
 198 +xt_flowoffload_register_hooks(void)
 199 +{
 200 +       struct xt_flowoffload_hook *hook;
 201 +
 202 +restart:
 203 +       hlist_for_each_entry(hook, &hooks, list) {
 204 +               if (hook->registered)
 205 +                       continue;
 206 +
 207 +               hook->registered = true;
 208 +               hook->net = dev_net(hook->ops.dev);
 209 +               spin_unlock_bh(&hooks_lock);
 210 +               nf_register_net_hook(hook->net, &hook->ops);
 211 +               spin_lock_bh(&hooks_lock);
 212 +               goto restart;
 213 +       }
 214 +
 215 +}
 216 +
 217 +static void
 218 +xt_flowoffload_cleanup_hooks(void)
 219 +{
 220 +       struct xt_flowoffload_hook *hook;
 221 +
 222 +restart:
 223 +       hlist_for_each_entry(hook, &hooks, list) {
 224 +               if (hook->used || !hook->registered)
 225 +                       continue;
 226 +
 227 +               hlist_del(&hook->list);
 228 +               spin_unlock_bh(&hooks_lock);
 229 +               nf_unregister_net_hook(hook->net, &hook->ops);
 230 +               kfree(hook);
 231 +               spin_lock_bh(&hooks_lock);
 232 +               goto restart;
 233 +       }
 234 +
 235 +}
 236 +
 237 +static void
 238 +xt_flowoffload_check_hook(struct flow_offload *flow, void *data)
 239 +{
 240 +       struct flow_offload_tuple *tuple = &flow->tuplehash[0].tuple;
 241 +       struct xt_flowoffload_hook *hook;
 242 +       bool *found = data;
 243 +
 244 +       spin_lock_bh(&hooks_lock);
 245 +       hlist_for_each_entry(hook, &hooks, list) {
 246 +               if (hook->ops.dev->ifindex != tuple->iifidx &&
 247 +                   hook->ops.dev->ifindex != tuple->oifidx)
 248 +                       continue;
 249 +
 250 +               hook->used = true;
 251 +               *found = true;
 252 +       }
 253 +       spin_unlock_bh(&hooks_lock);
 254 +}
 255 +
 256 +static void
 257 +xt_flowoffload_hook_work(struct work_struct *work)
 258 +{
 259 +       struct xt_flowoffload_hook *hook;
 260 +       bool found = false;
 261 +       int err;
 262 +
 263 +       spin_lock_bh(&hooks_lock);
 264 +       xt_flowoffload_register_hooks();
 265 +       hlist_for_each_entry(hook, &hooks, list)
 266 +               hook->used = false;
 267 +       spin_unlock_bh(&hooks_lock);
 268 +
 269 +       err = nf_flow_table_iterate(&nf_flowtable, xt_flowoffload_check_hook,
 270 +                                   &found);
 271 +       if (err && err != -EAGAIN)
 272 +           goto out;
 273 +
 274 +       spin_lock_bh(&hooks_lock);
 275 +       xt_flowoffload_cleanup_hooks();
 276 +       spin_unlock_bh(&hooks_lock);
 277 +
 278 +out:
 279 +       if (found)
 280 +               queue_delayed_work(system_power_efficient_wq, &hook_work, HZ);
 281 +}
 282 +
 283 +static bool
 284 +xt_flowoffload_skip(struct sk_buff *skb, int family)
 285 +{
 286 +       if (skb_sec_path(skb))
 287 +               return true;
 288 +
 289 +       if (family == NFPROTO_IPV4) {
 290 +               const struct ip_options *opt = &(IPCB(skb)->opt);
 291 +
 292 +               if (unlikely(opt->optlen))
 293 +                       return true;
 294 +       }
 295 +
 296 +       return false;
 297 +}
 298 +
 299 +static struct dst_entry *
 300 +xt_flowoffload_dst(const struct nf_conn *ct, enum ip_conntrack_dir dir,
 301 +                  const struct xt_action_param *par, int ifindex)
 302 +{
 303 +       struct dst_entry *dst = NULL;
 304 +       struct flowi fl;
 305 +
 306 +       memset(&fl, 0, sizeof(fl));
 307 +       switch (xt_family(par)) {
 308 +       case NFPROTO_IPV4:
 309 +               fl.u.ip4.daddr = ct->tuplehash[dir].tuple.src.u3.ip;
 310 +               fl.u.ip4.flowi4_oif = ifindex;
 311 +               break;
 312 +       case NFPROTO_IPV6:
 313 +               fl.u.ip6.saddr = ct->tuplehash[dir].tuple.dst.u3.in6;
 314 +               fl.u.ip6.daddr = ct->tuplehash[dir].tuple.src.u3.in6;
 315 +               fl.u.ip6.flowi6_oif = ifindex;
 316 +               break;
 317 +       }
 318 +
 319 +       nf_route(xt_net(par), &dst, &fl, false, xt_family(par));
 320 +
 321 +       return dst;
 322 +}
 323 +
 324 +static int
 325 +xt_flowoffload_route(struct sk_buff *skb, const struct nf_conn *ct,
 326 +                  const struct xt_action_param *par,
 327 +                  struct nf_flow_route *route, enum ip_conntrack_dir dir)
 328 +{
 329 +       struct dst_entry *this_dst, *other_dst;
 330 +
 331 +       this_dst = xt_flowoffload_dst(ct, !dir, par, xt_out(par)->ifindex);
 332 +       other_dst = xt_flowoffload_dst(ct, dir, par, xt_in(par)->ifindex);
 333 +
 334 +       route->tuple[dir].dst           = this_dst;
 335 +       route->tuple[!dir].dst          = other_dst;
 336 +
 337 +       if (!this_dst || !other_dst)
 338 +               return -ENOENT;
 339 +
 340 +       if (dst_xfrm(this_dst) || dst_xfrm(other_dst))
 341 +               return -EINVAL;
 342 +
 343 +       return 0;
 344 +}
 345 +
 346 +static unsigned int
 347 +flowoffload_tg(struct sk_buff *skb, const struct xt_action_param *par)
 348 +{
 349 +       const struct xt_flowoffload_target_info *info = par->targinfo;
 350 +       struct tcphdr _tcph, *tcph = NULL;
 351 +       enum ip_conntrack_info ctinfo;
 352 +       enum ip_conntrack_dir dir;
 353 +       struct nf_flow_route route;
 354 +       struct flow_offload *flow = NULL;
 355 +       struct nf_conn *ct;
 356 +       struct net *net;
 357 +
 358 +       if (xt_flowoffload_skip(skb, xt_family(par)))
 359 +               return XT_CONTINUE;
 360 +
 361 +       ct = nf_ct_get(skb, &ctinfo);
 362 +       if (ct == NULL)
 363 +               return XT_CONTINUE;
 364 +
 365 +       switch (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum) {
 366 +       case IPPROTO_TCP:
 367 +               if (ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED)
 368 +                       return XT_CONTINUE;
 369 +
 370 +               tcph = skb_header_pointer(skb, par->thoff,
 371 +                                         sizeof(_tcph), &_tcph);
 372 +               if (unlikely(!tcph || tcph->fin || tcph->rst))
 373 +                       return XT_CONTINUE;
 374 +               break;
 375 +       case IPPROTO_UDP:
 376 +               break;
 377 +       default:
 378 +               return XT_CONTINUE;
 379 +       }
 380 +
 381 +       if (nf_ct_ext_exist(ct, NF_CT_EXT_HELPER) ||
 382 +           ct->status & IPS_SEQ_ADJUST)
 383 +               return XT_CONTINUE;
 384 +
 385 +       if (!nf_ct_is_confirmed(ct))
 386 +               return XT_CONTINUE;
 387 +
 388 +       if (!xt_in(par) || !xt_out(par))
 389 +               return XT_CONTINUE;
 390 +
 391 +       if (test_and_set_bit(IPS_OFFLOAD_BIT, &ct->status))
 392 +               return XT_CONTINUE;
 393 +
 394 +       dir = CTINFO2DIR(ctinfo);
 395 +
 396 +       if (xt_flowoffload_route(skb, ct, par, &route, dir) == 0)
 397 +               flow = flow_offload_alloc(ct, &route);
 398 +
 399 +       dst_release(route.tuple[dir].dst);
 400 +       dst_release(route.tuple[!dir].dst);
 401 +
 402 +       if (!flow)
 403 +               goto err_flow_route;
 404 +
 405 +       if (tcph) {
 406 +               ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
 407 +               ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
 408 +       }
 409 +
 410 +       if (flow_offload_add(&nf_flowtable, flow) < 0)
 411 +               goto err_flow_add;
 412 +
 413 +       xt_flowoffload_check_device(xt_in(par));
 414 +       xt_flowoffload_check_device(xt_out(par));
 415 +
 416 +       net = read_pnet(&nf_flowtable.ft_net);
 417 +       if (!net)
 418 +               write_pnet(&nf_flowtable.ft_net, xt_net(par));
 419 +
 420 +       if (info->flags & XT_FLOWOFFLOAD_HW)
 421 +               nf_flow_offload_hw_add(xt_net(par), flow, ct);
 422 +
 423 +       return XT_CONTINUE;
 424 +
 425 +err_flow_add:
 426 +       flow_offload_free(flow);
 427 +err_flow_route:
 428 +       clear_bit(IPS_OFFLOAD_BIT, &ct->status);
 429 +       return XT_CONTINUE;
 430 +}
 431 +
 432 +
 433 +static int flowoffload_chk(const struct xt_tgchk_param *par)
 434 +{
 435 +       struct xt_flowoffload_target_info *info = par->targinfo;
 436 +
 437 +       if (info->flags & ~XT_FLOWOFFLOAD_MASK)
 438 +               return -EINVAL;
 439 +
 440 +       return 0;
 441 +}
 442 +
 443 +static struct xt_target offload_tg_reg __read_mostly = {
 444 +       .family         = NFPROTO_UNSPEC,
 445 +       .name           = "FLOWOFFLOAD",
 446 +       .revision       = 0,
 447 +       .targetsize     = sizeof(struct xt_flowoffload_target_info),
 448 +       .usersize       = sizeof(struct xt_flowoffload_target_info),
 449 +       .checkentry     = flowoffload_chk,
 450 +       .target         = flowoffload_tg,
 451 +       .me             = THIS_MODULE,
 452 +};
 453 +
 454 +static int xt_flowoffload_table_init(struct nf_flowtable *table)
 455 +{
 456 +       table->flags = NF_FLOWTABLE_F_HW;
 457 +       nf_flow_table_init(table);
 458 +       return 0;
 459 +}
 460 +
 461 +static void xt_flowoffload_table_cleanup(struct nf_flowtable *table)
 462 +{
 463 +       nf_flow_table_free(table);
 464 +}
 465 +
 466 +static int flow_offload_netdev_event(struct notifier_block *this,
 467 +                                    unsigned long event, void *ptr)
 468 +{
 469 +       struct xt_flowoffload_hook *hook = NULL;
 470 +       struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 471 +
 472 +       if (event != NETDEV_UNREGISTER)
 473 +               return NOTIFY_DONE;
 474 +
 475 +       spin_lock_bh(&hooks_lock);
 476 +       hook = flow_offload_lookup_hook(dev);
 477 +       if (hook) {
 478 +               hlist_del(&hook->list);
 479 +       }
 480 +       spin_unlock_bh(&hooks_lock);
 481 +       if (hook) {
 482 +               nf_unregister_net_hook(hook->net, &hook->ops);
 483 +               kfree(hook);
 484 +       }
 485 +
 486 +       nf_flow_table_cleanup(dev_net(dev), dev);
 487 +
 488 +       return NOTIFY_DONE;
 489 +}
 490 +
 491 +static struct notifier_block flow_offload_netdev_notifier = {
 492 +       .notifier_call  = flow_offload_netdev_event,
 493 +};
 494 +
 495 +static int __init xt_flowoffload_tg_init(void)
 496 +{
 497 +       int ret;
 498 +
 499 +       register_netdevice_notifier(&flow_offload_netdev_notifier);
 500 +
 501 +       INIT_DELAYED_WORK(&hook_work, xt_flowoffload_hook_work);
 502 +
 503 +       ret = xt_flowoffload_table_init(&nf_flowtable);
 504 +       if (ret)
 505 +               return ret;
 506 +
 507 +       ret = xt_register_target(&offload_tg_reg);
 508 +       if (ret)
 509 +               xt_flowoffload_table_cleanup(&nf_flowtable);
 510 +
 511 +       return ret;
 512 +}
 513 +
 514 +static void __exit xt_flowoffload_tg_exit(void)
 515 +{
 516 +       xt_unregister_target(&offload_tg_reg);
 517 +       xt_flowoffload_table_cleanup(&nf_flowtable);
 518 +       unregister_netdevice_notifier(&flow_offload_netdev_notifier);
 519 +}
 520 +
 521 +MODULE_LICENSE("GPL");
 522 +module_init(xt_flowoffload_tg_init);
 523 +module_exit(xt_flowoffload_tg_exit);
 524 --- a/net/netfilter/nf_flow_table_core.c
 525 +++ b/net/netfilter/nf_flow_table_core.c
 526 @@ -6,7 +6,6 @@
 527  #include <linux/netdevice.h>
 528  #include <net/ip.h>
 529  #include <net/ip6_route.h>
 530 -#include <net/netfilter/nf_tables.h>
 531  #include <net/netfilter/nf_flow_table.h>
 532  #include <net/netfilter/nf_conntrack.h>
 533  #include <net/netfilter/nf_conntrack_core.h>
 534 --- /dev/null
 535 +++ b/include/uapi/linux/netfilter/xt_FLOWOFFLOAD.h
 536 @@ -0,0 +1,17 @@
 537 +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
 538 +#ifndef _XT_FLOWOFFLOAD_H
 539 +#define _XT_FLOWOFFLOAD_H
 540 +
 541 +#include <linux/types.h>
 542 +
 543 +enum {
 544 +       XT_FLOWOFFLOAD_HW       = 1 << 0,
 545 +
 546 +       XT_FLOWOFFLOAD_MASK     = XT_FLOWOFFLOAD_HW
 547 +};
 548 +
 549 +struct xt_flowoffload_target_info {
 550 +       __u32 flags;
 551 +};
 552 +
 553 +#endif /* _XT_FLOWOFFLOAD_H */