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 +1,368 @@
 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_flow_table.h>
 116 +
 117 +static struct nf_flowtable nf_flowtable;
 118 +static HLIST_HEAD(hooks);
 119 +static DEFINE_SPINLOCK(hooks_lock);
 120 +static struct delayed_work hook_work;
 121 +
 122 +struct xt_flowoffload_hook {
 123 +       struct hlist_node list;
 124 +       struct nf_hook_ops ops;
 125 +       struct net *net;
 126 +       bool registered;
 127 +       bool used;
 128 +};
 129 +
 130 +static unsigned int
 131 +xt_flowoffload_net_hook(void *priv, struct sk_buff *skb,
 132 +                         const struct nf_hook_state *state)
 133 +{
 134 +       switch (skb->protocol) {
 135 +       case htons(ETH_P_IP):
 136 +               return nf_flow_offload_ip_hook(priv, skb, state);
 137 +       case htons(ETH_P_IPV6):
 138 +               return nf_flow_offload_ipv6_hook(priv, skb, state);
 139 +       }
 140 +
 141 +       return NF_ACCEPT;
 142 +}
 143 +
 144 +static int
 145 +xt_flowoffload_create_hook(struct net_device *dev)
 146 +{
 147 +       struct xt_flowoffload_hook *hook;
 148 +       struct nf_hook_ops *ops;
 149 +
 150 +       hook = kzalloc(sizeof(*hook), GFP_ATOMIC);
 151 +       if (!hook)
 152 +               return -ENOMEM;
 153 +
 154 +       ops = &hook->ops;
 155 +       ops->pf = NFPROTO_NETDEV;
 156 +       ops->hooknum = NF_NETDEV_INGRESS;
 157 +       ops->priority = 10;
 158 +       ops->priv = &nf_flowtable;
 159 +       ops->hook = xt_flowoffload_net_hook;
 160 +       ops->dev = dev;
 161 +
 162 +       hlist_add_head(&hook->list, &hooks);
 163 +       mod_delayed_work(system_power_efficient_wq, &hook_work, 0);
 164 +
 165 +       return 0;
 166 +}
 167 +
 168 +static struct xt_flowoffload_hook *
 169 +flow_offload_lookup_hook(struct net_device *dev)
 170 +{
 171 +       struct xt_flowoffload_hook *hook;
 172 +
 173 +       hlist_for_each_entry(hook, &hooks, list) {
 174 +               if (hook->ops.dev == dev)
 175 +                       return hook;
 176 +       }
 177 +
 178 +       return NULL;
 179 +}
 180 +
 181 +static void
 182 +xt_flowoffload_check_device(struct net_device *dev)
 183 +{
 184 +       struct xt_flowoffload_hook *hook;
 185 +
 186 +       spin_lock_bh(&hooks_lock);
 187 +       hook = flow_offload_lookup_hook(dev);
 188 +       if (hook)
 189 +               hook->used = true;
 190 +       else
 191 +               xt_flowoffload_create_hook(dev);
 192 +       spin_unlock_bh(&hooks_lock);
 193 +}
 194 +
 195 +static void
 196 +xt_flowoffload_register_hooks(void)
 197 +{
 198 +       struct xt_flowoffload_hook *hook;
 199 +
 200 +restart:
 201 +       hlist_for_each_entry(hook, &hooks, list) {
 202 +               if (hook->registered)
 203 +                       continue;
 204 +
 205 +               hook->registered = true;
 206 +               hook->net = dev_net(hook->ops.dev);
 207 +               spin_unlock_bh(&hooks_lock);
 208 +               nf_register_net_hook(hook->net, &hook->ops);
 209 +               spin_lock_bh(&hooks_lock);
 210 +               goto restart;
 211 +       }
 212 +
 213 +}
 214 +
 215 +static void
 216 +xt_flowoffload_cleanup_hooks(void)
 217 +{
 218 +       struct xt_flowoffload_hook *hook;
 219 +
 220 +restart:
 221 +       hlist_for_each_entry(hook, &hooks, list) {
 222 +               if (hook->used || !hook->registered)
 223 +                       continue;
 224 +
 225 +               hlist_del(&hook->list);
 226 +               spin_unlock_bh(&hooks_lock);
 227 +               nf_unregister_net_hook(hook->net, &hook->ops);
 228 +               kfree(hook);
 229 +               spin_lock_bh(&hooks_lock);
 230 +               goto restart;
 231 +       }
 232 +
 233 +}
 234 +
 235 +static void
 236 +xt_flowoffload_check_hook(struct flow_offload *flow, void *data)
 237 +{
 238 +       struct flow_offload_tuple *tuple = &flow->tuplehash[0].tuple;
 239 +       struct xt_flowoffload_hook *hook;
 240 +       bool *found = data;
 241 +
 242 +       spin_lock_bh(&hooks_lock);
 243 +       hlist_for_each_entry(hook, &hooks, list) {
 244 +               if (hook->ops.dev->ifindex != tuple->iifidx &&
 245 +                   hook->ops.dev->ifindex != tuple->oifidx)
 246 +                       continue;
 247 +
 248 +               hook->used = true;
 249 +               *found = true;
 250 +       }
 251 +       spin_unlock_bh(&hooks_lock);
 252 +}
 253 +
 254 +static void
 255 +xt_flowoffload_hook_work(struct work_struct *work)
 256 +{
 257 +       struct xt_flowoffload_hook *hook;
 258 +       bool found = false;
 259 +       int err;
 260 +
 261 +       spin_lock_bh(&hooks_lock);
 262 +       xt_flowoffload_register_hooks();
 263 +       hlist_for_each_entry(hook, &hooks, list)
 264 +               hook->used = false;
 265 +       spin_unlock_bh(&hooks_lock);
 266 +
 267 +       err = nf_flow_table_iterate(&nf_flowtable, xt_flowoffload_check_hook,
 268 +                                   &found);
 269 +       if (err && err != -EAGAIN)
 270 +           goto out;
 271 +
 272 +       spin_lock_bh(&hooks_lock);
 273 +       xt_flowoffload_cleanup_hooks();
 274 +       spin_unlock_bh(&hooks_lock);
 275 +
 276 +out:
 277 +       if (found)
 278 +               queue_delayed_work(system_power_efficient_wq, &hook_work, HZ);
 279 +}
 280 +
 281 +static bool
 282 +xt_flowoffload_skip(struct sk_buff *skb)
 283 +{
 284 +       struct ip_options *opt = &(IPCB(skb)->opt);
 285 +
 286 +       if (unlikely(opt->optlen))
 287 +               return true;
 288 +       if (skb_sec_path(skb))
 289 +               return true;
 290 +
 291 +       return false;
 292 +}
 293 +
 294 +static struct dst_entry *
 295 +xt_flowoffload_dst(const struct nf_conn *ct, enum ip_conntrack_dir dir,
 296 +                  const struct xt_action_param *par)
 297 +{
 298 +       struct dst_entry *dst = NULL;
 299 +       struct flowi fl;
 300 +
 301 +       memset(&fl, 0, sizeof(fl));
 302 +       switch (xt_family(par)) {
 303 +       case NFPROTO_IPV4:
 304 +               fl.u.ip4.daddr = ct->tuplehash[dir].tuple.src.u3.ip;
 305 +               break;
 306 +       case NFPROTO_IPV6:
 307 +               fl.u.ip6.saddr = ct->tuplehash[dir].tuple.dst.u3.in6;
 308 +               fl.u.ip6.daddr = ct->tuplehash[dir].tuple.src.u3.in6;
 309 +               break;
 310 +       }
 311 +
 312 +       nf_route(xt_net(par), &dst, &fl, false, xt_family(par));
 313 +
 314 +       return dst;
 315 +}
 316 +
 317 +static int
 318 +xt_flowoffload_route(struct sk_buff *skb, const struct nf_conn *ct,
 319 +                  const struct xt_action_param *par,
 320 +                  struct nf_flow_route *route, enum ip_conntrack_dir dir)
 321 +{
 322 +       struct dst_entry *this_dst, *other_dst;
 323 +
 324 +       this_dst = xt_flowoffload_dst(ct, dir, par);
 325 +       other_dst = xt_flowoffload_dst(ct, !dir, par);
 326 +       if (!this_dst || !other_dst)
 327 +               return -ENOENT;
 328 +
 329 +       if (dst_xfrm(this_dst) || dst_xfrm(other_dst))
 330 +               return -EINVAL;
 331 +
 332 +       route->tuple[dir].dst           = this_dst;
 333 +       route->tuple[dir].ifindex       = xt_in(par)->ifindex;
 334 +       route->tuple[!dir].dst          = other_dst;
 335 +       route->tuple[!dir].ifindex      = xt_out(par)->ifindex;
 336 +
 337 +       return 0;
 338 +}
 339 +
 340 +static unsigned int
 341 +flowoffload_tg(struct sk_buff *skb, const struct xt_action_param *par)
 342 +{
 343 +       const struct xt_flowoffload_target_info *info = par->targinfo;
 344 +       enum ip_conntrack_info ctinfo;
 345 +       enum ip_conntrack_dir dir;
 346 +       struct nf_flow_route route;
 347 +       struct flow_offload *flow;
 348 +       struct nf_conn *ct;
 349 +
 350 +       if (xt_flowoffload_skip(skb))
 351 +               return XT_CONTINUE;
 352 +
 353 +       ct = nf_ct_get(skb, &ctinfo);
 354 +       if (ct == NULL)
 355 +               return XT_CONTINUE;
 356 +
 357 +       switch (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum) {
 358 +       case IPPROTO_TCP:
 359 +               if (ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED)
 360 +                       return XT_CONTINUE;
 361 +               break;
 362 +       case IPPROTO_UDP:
 363 +               break;
 364 +       default:
 365 +               return XT_CONTINUE;
 366 +       }
 367 +
 368 +       if (test_bit(IPS_HELPER_BIT, &ct->status))
 369 +               return XT_CONTINUE;
 370 +
 371 +       if (ctinfo == IP_CT_NEW ||
 372 +           ctinfo == IP_CT_RELATED)
 373 +               return XT_CONTINUE;
 374 +
 375 +       if (!xt_in(par) || !xt_out(par))
 376 +               return XT_CONTINUE;
 377 +
 378 +       if (test_and_set_bit(IPS_OFFLOAD_BIT, &ct->status))
 379 +               return XT_CONTINUE;
 380 +
 381 +       dir = CTINFO2DIR(ctinfo);
 382 +
 383 +       if (xt_flowoffload_route(skb, ct, par, &route, dir) < 0)
 384 +               goto err_flow_route;
 385 +
 386 +       flow = flow_offload_alloc(ct, &route);
 387 +       if (!flow)
 388 +               goto err_flow_alloc;
 389 +
 390 +       if (flow_offload_add(&nf_flowtable, flow) < 0)
 391 +               goto err_flow_add;
 392 +
 393 +       xt_flowoffload_check_device(xt_in(par));
 394 +       xt_flowoffload_check_device(xt_out(par));
 395 +
 396 +       if (info->flags & XT_FLOWOFFLOAD_HW)
 397 +               nf_flow_offload_hw_add(xt_net(par), flow, ct);
 398 +
 399 +       return XT_CONTINUE;
 400 +
 401 +err_flow_add:
 402 +       flow_offload_free(flow);
 403 +err_flow_alloc:
 404 +       dst_release(route.tuple[!dir].dst);
 405 +err_flow_route:
 406 +       clear_bit(IPS_OFFLOAD_BIT, &ct->status);
 407 +       return XT_CONTINUE;
 408 +}
 409 +
 410 +
 411 +static int flowoffload_chk(const struct xt_tgchk_param *par)
 412 +{
 413 +       struct xt_flowoffload_target_info *info = par->targinfo;
 414 +
 415 +       if (info->flags & ~XT_FLOWOFFLOAD_MASK)
 416 +               return -EINVAL;
 417 +
 418 +       return 0;
 419 +}
 420 +
 421 +static struct xt_target offload_tg_reg __read_mostly = {
 422 +       .family         = NFPROTO_UNSPEC,
 423 +       .name           = "FLOWOFFLOAD",
 424 +       .revision       = 0,
 425 +       .targetsize     = sizeof(struct xt_flowoffload_target_info),
 426 +       .usersize       = sizeof(struct xt_flowoffload_target_info),
 427 +       .checkentry     = flowoffload_chk,
 428 +       .target         = flowoffload_tg,
 429 +       .me             = THIS_MODULE,
 430 +};
 431 +
 432 +static int xt_flowoffload_table_init(struct nf_flowtable *table)
 433 +{
 434 +       table->flags = NF_FLOWTABLE_F_HW;
 435 +       nf_flow_table_init(table);
 436 +       return 0;
 437 +}
 438 +
 439 +static void xt_flowoffload_table_cleanup(struct nf_flowtable *table)
 440 +{
 441 +       nf_flow_table_free(table);
 442 +}
 443 +
 444 +static int __init xt_flowoffload_tg_init(void)
 445 +{
 446 +       int ret;
 447 +
 448 +       INIT_DELAYED_WORK(&hook_work, xt_flowoffload_hook_work);
 449 +
 450 +       ret = xt_flowoffload_table_init(&nf_flowtable);
 451 +       if (ret)
 452 +               return ret;
 453 +
 454 +       ret = xt_register_target(&offload_tg_reg);
 455 +       if (ret)
 456 +               xt_flowoffload_table_cleanup(&nf_flowtable);
 457 +
 458 +       return ret;
 459 +}
 460 +
 461 +static void __exit xt_flowoffload_tg_exit(void)
 462 +{
 463 +       xt_unregister_target(&offload_tg_reg);
 464 +       xt_flowoffload_table_cleanup(&nf_flowtable);
 465 +}
 466 +
 467 +MODULE_LICENSE("GPL");
 468 +module_init(xt_flowoffload_tg_init);
 469 +module_exit(xt_flowoffload_tg_exit);
 470 --- a/net/netfilter/nf_flow_table_core.c
 471 +++ b/net/netfilter/nf_flow_table_core.c
 472 @@ -6,7 +6,6 @@
 473  #include <linux/netdevice.h>
 474  #include <net/ip.h>
 475  #include <net/ip6_route.h>
 476 -#include <net/netfilter/nf_tables.h>
 477  #include <net/netfilter/nf_flow_table.h>
 478  #include <net/netfilter/nf_conntrack.h>
 479  #include <net/netfilter/nf_conntrack_core.h>
 480 --- /dev/null
 481 +++ b/include/uapi/linux/netfilter/xt_FLOWOFFLOAD.h
 482 @@ -0,0 +1,17 @@
 483 +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
 484 +#ifndef _XT_FLOWOFFLOAD_H
 485 +#define _XT_FLOWOFFLOAD_H
 486 +
 487 +#include <linux/types.h>
 488 +
 489 +enum {
 490 +       XT_FLOWOFFLOAD_HW       = 1 << 0,
 491 +
 492 +       XT_FLOWOFFLOAD_MASK     = XT_FLOWOFFLOAD_HW
 493 +};
 494 +
 495 +struct xt_flowoffload_target_info {
 496 +       __u32 flags;
 497 +};
 498 +
 499 +#endif /* _XT_FLOWOFFLOAD_H */