net/netfilter/nf_tables_offload.c

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #include <linux/init.h>
   3 #include <linux/module.h>
   4 #include <linux/netfilter.h>
   5 #include <net/flow_offload.h>
   6 #include <net/netfilter/nf_tables.h>
   7 #include <net/netfilter/nf_tables_offload.h>
   8 #include <net/pkt_cls.h>
   9
  10 static struct nft_flow_rule *nft_flow_rule_alloc(int num_actions)
  11 {
  12         struct nft_flow_rule *flow;
  13
  14         flow = kzalloc(sizeof(struct nft_flow_rule), GFP_KERNEL);
  15         if (!flow)
  16                 return NULL;
  17
  18         flow->rule = flow_rule_alloc(num_actions);
  19         if (!flow->rule) {
  20                 kfree(flow);
  21                 return NULL;
  22         }
  23
  24         flow->rule->match.dissector     = &flow->match.dissector;
  25         flow->rule->match.mask          = &flow->match.mask;
  26         flow->rule->match.key           = &flow->match.key;
  27
  28         return flow;
  29 }
  30
  31 struct nft_flow_rule *nft_flow_rule_create(const struct nft_rule *rule)
  32 {
  33         struct nft_offload_ctx ctx = {
  34                 .dep    = {
  35                         .type   = NFT_OFFLOAD_DEP_UNSPEC,
  36                 },
  37         };
  38         struct nft_flow_rule *flow;
  39         int num_actions = 0, err;
  40         struct nft_expr *expr;
  41
  42         expr = nft_expr_first(rule);
  43         while (expr->ops && expr != nft_expr_last(rule)) {
  44                 if (expr->ops->offload_flags & NFT_OFFLOAD_F_ACTION)
  45                         num_actions++;
  46
  47                 expr = nft_expr_next(expr);
  48         }
  49
  50         flow = nft_flow_rule_alloc(num_actions);
  51         if (!flow)
  52                 return ERR_PTR(-ENOMEM);
  53
  54         expr = nft_expr_first(rule);
  55         while (expr->ops && expr != nft_expr_last(rule)) {
  56                 if (!expr->ops->offload) {
  57                         err = -EOPNOTSUPP;
  58                         goto err_out;
  59                 }
  60                 err = expr->ops->offload(&ctx, flow, expr);
  61                 if (err < 0)
  62                         goto err_out;
  63
  64                 expr = nft_expr_next(expr);
  65         }
  66         flow->proto = ctx.dep.l3num;
  67
  68         return flow;
  69 err_out:
  70         nft_flow_rule_destroy(flow);
  71
  72         return ERR_PTR(err);
  73 }
  74
  75 void nft_flow_rule_destroy(struct nft_flow_rule *flow)
  76 {
  77         kfree(flow->rule);
  78         kfree(flow);
  79 }
  80
  81 void nft_offload_set_dependency(struct nft_offload_ctx *ctx,
  82                                 enum nft_offload_dep_type type)
  83 {
  84         ctx->dep.type = type;
  85 }
  86
  87 void nft_offload_update_dependency(struct nft_offload_ctx *ctx,
  88                                    const void *data, u32 len)
  89 {
  90         switch (ctx->dep.type) {
  91         case NFT_OFFLOAD_DEP_NETWORK:
  92                 WARN_ON(len != sizeof(__u16));
  93                 memcpy(&ctx->dep.l3num, data, sizeof(__u16));
  94                 break;
  95         case NFT_OFFLOAD_DEP_TRANSPORT:
  96                 WARN_ON(len != sizeof(__u8));
  97                 memcpy(&ctx->dep.protonum, data, sizeof(__u8));
  98                 break;
  99         default:
 100                 break;
 101         }
 102         ctx->dep.type = NFT_OFFLOAD_DEP_UNSPEC;
 103 }
 104
 105 static void nft_flow_offload_common_init(struct flow_cls_common_offload *common,
 106                                          __be16 proto,
 107                                         struct netlink_ext_ack *extack)
 108 {
 109         common->protocol = proto;
 110         common->extack = extack;
 111 }
 112
 113 static int nft_setup_cb_call(struct nft_base_chain *basechain,
 114                              enum tc_setup_type type, void *type_data)
 115 {
 116         struct flow_block_cb *block_cb;
 117         int err;
 118
 119         list_for_each_entry(block_cb, &basechain->flow_block.cb_list, list) {
 120                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
 121                 if (err < 0)
 122                         return err;
 123         }
 124         return 0;
 125 }
 126
 127 static int nft_flow_offload_rule(struct nft_trans *trans,
 128                                  enum flow_cls_command command)
 129 {
 130         struct nft_flow_rule *flow = nft_trans_flow_rule(trans);
 131         struct nft_rule *rule = nft_trans_rule(trans);
 132         struct flow_cls_offload cls_flow = {};
 133         struct nft_base_chain *basechain;
 134         struct netlink_ext_ack extack;
 135         __be16 proto = ETH_P_ALL;
 136
 137         if (!nft_is_base_chain(trans->ctx.chain))
 138                 return -EOPNOTSUPP;
 139
 140         basechain = nft_base_chain(trans->ctx.chain);
 141
 142         if (flow)
 143                 proto = flow->proto;
 144
 145         nft_flow_offload_common_init(&cls_flow.common, proto, &extack);
 146         cls_flow.command = command;
 147         cls_flow.cookie = (unsigned long) rule;
 148         if (flow)
 149                 cls_flow.rule = flow->rule;
 150
 151         return nft_setup_cb_call(basechain, TC_SETUP_CLSFLOWER, &cls_flow);
 152 }
 153
 154 static int nft_flow_offload_bind(struct flow_block_offload *bo,
 155                                  struct nft_base_chain *basechain)
 156 {
 157         list_splice(&bo->cb_list, &basechain->flow_block.cb_list);
 158         return 0;
 159 }
 160
 161 static int nft_flow_offload_unbind(struct flow_block_offload *bo,
 162                                    struct nft_base_chain *basechain)
 163 {
 164         struct flow_block_cb *block_cb, *next;
 165
 166         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
 167                 list_del(&block_cb->list);
 168                 flow_block_cb_free(block_cb);
 169         }
 170
 171         return 0;
 172 }
 173
 174 static int nft_block_setup(struct nft_base_chain *basechain,
 175                            struct flow_block_offload *bo,
 176                            enum flow_block_command cmd)
 177 {
 178         int err;
 179
 180         switch (cmd) {
 181         case FLOW_BLOCK_BIND:
 182                 err = nft_flow_offload_bind(bo, basechain);
 183                 break;
 184         case FLOW_BLOCK_UNBIND:
 185                 err = nft_flow_offload_unbind(bo, basechain);
 186                 break;
 187         default:
 188                 WARN_ON_ONCE(1);
 189                 err = -EOPNOTSUPP;
 190         }
 191
 192         return err;
 193 }
 194
 195 static int nft_block_offload_cmd(struct nft_base_chain *chain,
 196                                  struct net_device *dev,
 197                                  enum flow_block_command cmd)
 198 {
 199         struct netlink_ext_ack extack = {};
 200         struct flow_block_offload bo = {};
 201         int err;
 202
 203         bo.net = dev_net(dev);
 204         bo.block = &chain->flow_block;
 205         bo.command = cmd;
 206         bo.binder_type = FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS;
 207         bo.extack = &extack;
 208         INIT_LIST_HEAD(&bo.cb_list);
 209
 210         err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
 211         if (err < 0)
 212                 return err;
 213
 214         return nft_block_setup(chain, &bo, cmd);
 215 }
 216
 217 static void nft_indr_block_ing_cmd(struct net_device *dev,
 218                                    struct nft_base_chain *chain,
 219                                    flow_indr_block_bind_cb_t *cb,
 220                                    void *cb_priv,
 221                                    enum flow_block_command cmd)
 222 {
 223         struct netlink_ext_ack extack = {};
 224         struct flow_block_offload bo = {};
 225
 226         if (!chain)
 227                 return;
 228
 229         bo.net = dev_net(dev);
 230         bo.block = &chain->flow_block;
 231         bo.command = cmd;
 232         bo.binder_type = FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS;
 233         bo.extack = &extack;
 234         INIT_LIST_HEAD(&bo.cb_list);
 235
 236         cb(dev, cb_priv, TC_SETUP_BLOCK, &bo);
 237
 238         nft_block_setup(chain, &bo, cmd);
 239 }
 240
 241 static int nft_indr_block_offload_cmd(struct nft_base_chain *chain,
 242                                       struct net_device *dev,
 243                                       enum flow_block_command cmd)
 244 {
 245         struct flow_block_offload bo = {};
 246         struct netlink_ext_ack extack = {};
 247
 248         bo.net = dev_net(dev);
 249         bo.block = &chain->flow_block;
 250         bo.command = cmd;
 251         bo.binder_type = FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS;
 252         bo.extack = &extack;
 253         INIT_LIST_HEAD(&bo.cb_list);
 254
 255         flow_indr_block_call(dev, &bo, cmd);
 256
 257         if (list_empty(&bo.cb_list))
 258                 return -EOPNOTSUPP;
 259
 260         return nft_block_setup(chain, &bo, cmd);
 261 }
 262
 263 #define FLOW_SETUP_BLOCK TC_SETUP_BLOCK
 264
 265 static int nft_flow_offload_chain(struct nft_trans *trans,
 266                                   enum flow_block_command cmd)
 267 {
 268         struct nft_chain *chain = trans->ctx.chain;
 269         struct nft_base_chain *basechain;
 270         struct net_device *dev;
 271
 272         if (!nft_is_base_chain(chain))
 273                 return -EOPNOTSUPP;
 274
 275         basechain = nft_base_chain(chain);
 276         dev = basechain->ops.dev;
 277         if (!dev)
 278                 return -EOPNOTSUPP;
 279
 280         /* Only default policy to accept is supported for now. */
 281         if (cmd == FLOW_BLOCK_BIND &&
 282             nft_trans_chain_policy(trans) != -1 &&
 283             nft_trans_chain_policy(trans) != NF_ACCEPT)
 284                 return -EOPNOTSUPP;
 285
 286         if (dev->netdev_ops->ndo_setup_tc)
 287                 return nft_block_offload_cmd(basechain, dev, cmd);
 288         else
 289                 return nft_indr_block_offload_cmd(basechain, dev, cmd);
 290 }
 291
 292 int nft_flow_rule_offload_commit(struct net *net)
 293 {
 294         struct nft_trans *trans;
 295         int err = 0;
 296
 297         list_for_each_entry(trans, &net->nft.commit_list, list) {
 298                 if (trans->ctx.family != NFPROTO_NETDEV)
 299                         continue;
 300
 301                 switch (trans->msg_type) {
 302                 case NFT_MSG_NEWCHAIN:
 303                         if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
 304                                 continue;
 305
 306                         err = nft_flow_offload_chain(trans, FLOW_BLOCK_BIND);
 307                         break;
 308                 case NFT_MSG_DELCHAIN:
 309                         if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
 310                                 continue;
 311
 312                         err = nft_flow_offload_chain(trans, FLOW_BLOCK_UNBIND);
 313                         break;
 314                 case NFT_MSG_NEWRULE:
 315                         if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
 316                                 continue;
 317
 318                         if (trans->ctx.flags & NLM_F_REPLACE ||
 319                             !(trans->ctx.flags & NLM_F_APPEND))
 320                                 return -EOPNOTSUPP;
 321
 322                         err = nft_flow_offload_rule(trans, FLOW_CLS_REPLACE);
 323                         nft_flow_rule_destroy(nft_trans_flow_rule(trans));
 324                         break;
 325                 case NFT_MSG_DELRULE:
 326                         if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
 327                                 continue;
 328
 329                         err = nft_flow_offload_rule(trans, FLOW_CLS_DESTROY);
 330                         break;
 331                 }
 332
 333                 if (err)
 334                         return err;
 335         }
 336
 337         return err;
 338 }
 339
 340 void nft_indr_block_get_and_ing_cmd(struct net_device *dev,
 341                                     flow_indr_block_bind_cb_t *cb,
 342                                     void *cb_priv,
 343                                     enum flow_block_command command)
 344 {
 345         struct net *net = dev_net(dev);
 346         const struct nft_table *table;
 347         const struct nft_chain *chain;
 348
 349         list_for_each_entry_rcu(table, &net->nft.tables, list) {
 350                 if (table->family != NFPROTO_NETDEV)
 351                         continue;
 352
 353                 list_for_each_entry_rcu(chain, &table->chains, list) {
 354                         if (nft_is_base_chain(chain)) {
 355                                 struct nft_base_chain *basechain;
 356
 357                                 basechain = nft_base_chain(chain);
 358                                 if (!strncmp(basechain->dev_name, dev->name,
 359                                              IFNAMSIZ)) {
 360                                         nft_indr_block_ing_cmd(dev, basechain,
 361                                                                cb, cb_priv,
 362                                                                command);
 363                                         return;
 364                                 }
 365                         }
 366                 }
 367         }
 368 }