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, int priority,
 107                                          struct netlink_ext_ack *extack)
 108 {
 109         common->protocol = proto;
 110         common->prio = priority;
 111         common->extack = extack;
 112 }
 113
 114 static int nft_setup_cb_call(struct nft_base_chain *basechain,
 115                              enum tc_setup_type type, void *type_data)
 116 {
 117         struct flow_block_cb *block_cb;
 118         int err;
 119
 120         list_for_each_entry(block_cb, &basechain->flow_block.cb_list, list) {
 121                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
 122                 if (err < 0)
 123                         return err;
 124         }
 125         return 0;
 126 }
 127
 128 int nft_chain_offload_priority(struct nft_base_chain *basechain)
 129 {
 130         if (basechain->ops.priority <= 0 ||
 131             basechain->ops.priority > USHRT_MAX)
 132                 return -1;
 133
 134         return 0;
 135 }
 136
 137 static int nft_flow_offload_rule(struct nft_trans *trans,
 138                                  enum flow_cls_command command)
 139 {
 140         struct nft_flow_rule *flow = nft_trans_flow_rule(trans);
 141         struct nft_rule *rule = nft_trans_rule(trans);
 142         struct flow_cls_offload cls_flow = {};
 143         struct nft_base_chain *basechain;
 144         struct netlink_ext_ack extack;
 145         __be16 proto = ETH_P_ALL;
 146
 147         if (!nft_is_base_chain(trans->ctx.chain))
 148                 return -EOPNOTSUPP;
 149
 150         basechain = nft_base_chain(trans->ctx.chain);
 151
 152         if (flow)
 153                 proto = flow->proto;
 154
 155         nft_flow_offload_common_init(&cls_flow.common, proto,
 156                                      basechain->ops.priority, &extack);
 157         cls_flow.command = command;
 158         cls_flow.cookie = (unsigned long) rule;
 159         if (flow)
 160                 cls_flow.rule = flow->rule;
 161
 162         return nft_setup_cb_call(basechain, TC_SETUP_CLSFLOWER, &cls_flow);
 163 }
 164
 165 static int nft_flow_offload_bind(struct flow_block_offload *bo,
 166                                  struct nft_base_chain *basechain)
 167 {
 168         list_splice(&bo->cb_list, &basechain->flow_block.cb_list);
 169         return 0;
 170 }
 171
 172 static int nft_flow_offload_unbind(struct flow_block_offload *bo,
 173                                    struct nft_base_chain *basechain)
 174 {
 175         struct flow_block_cb *block_cb, *next;
 176
 177         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
 178                 list_del(&block_cb->list);
 179                 flow_block_cb_free(block_cb);
 180         }
 181
 182         return 0;
 183 }
 184
 185 #define FLOW_SETUP_BLOCK TC_SETUP_BLOCK
 186
 187 static int nft_flow_offload_chain(struct nft_trans *trans,
 188                                   enum flow_block_command cmd)
 189 {
 190         struct nft_chain *chain = trans->ctx.chain;
 191         struct netlink_ext_ack extack = {};
 192         struct flow_block_offload bo = {};
 193         struct nft_base_chain *basechain;
 194         struct net_device *dev;
 195         int err;
 196
 197         if (!nft_is_base_chain(chain))
 198                 return -EOPNOTSUPP;
 199
 200         basechain = nft_base_chain(chain);
 201         dev = basechain->ops.dev;
 202         if (!dev || !dev->netdev_ops->ndo_setup_tc)
 203                 return -EOPNOTSUPP;
 204
 205         /* Only default policy to accept is supported for now. */
 206         if (cmd == FLOW_BLOCK_BIND &&
 207             nft_trans_chain_policy(trans) != -1 &&
 208             nft_trans_chain_policy(trans) != NF_ACCEPT)
 209                 return -EOPNOTSUPP;
 210
 211         bo.command = cmd;
 212         bo.block = &basechain->flow_block;
 213         bo.binder_type = FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS;
 214         bo.extack = &extack;
 215         INIT_LIST_HEAD(&bo.cb_list);
 216
 217         err = dev->netdev_ops->ndo_setup_tc(dev, FLOW_SETUP_BLOCK, &bo);
 218         if (err < 0)
 219                 return err;
 220
 221         switch (cmd) {
 222         case FLOW_BLOCK_BIND:
 223                 err = nft_flow_offload_bind(&bo, basechain);
 224                 break;
 225         case FLOW_BLOCK_UNBIND:
 226                 err = nft_flow_offload_unbind(&bo, basechain);
 227                 break;
 228         }
 229
 230         return err;
 231 }
 232
 233 int nft_flow_rule_offload_commit(struct net *net)
 234 {
 235         struct nft_trans *trans;
 236         int err = 0;
 237
 238         list_for_each_entry(trans, &net->nft.commit_list, list) {
 239                 if (trans->ctx.family != NFPROTO_NETDEV)
 240                         continue;
 241
 242                 switch (trans->msg_type) {
 243                 case NFT_MSG_NEWCHAIN:
 244                         if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
 245                                 continue;
 246
 247                         err = nft_flow_offload_chain(trans, FLOW_BLOCK_BIND);
 248                         break;
 249                 case NFT_MSG_DELCHAIN:
 250                         if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
 251                                 continue;
 252
 253                         err = nft_flow_offload_chain(trans, FLOW_BLOCK_UNBIND);
 254                         break;
 255                 case NFT_MSG_NEWRULE:
 256                         if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
 257                                 continue;
 258
 259                         if (trans->ctx.flags & NLM_F_REPLACE ||
 260                             !(trans->ctx.flags & NLM_F_APPEND))
 261                                 return -EOPNOTSUPP;
 262
 263                         err = nft_flow_offload_rule(trans, FLOW_CLS_REPLACE);
 264                         nft_flow_rule_destroy(nft_trans_flow_rule(trans));
 265                         break;
 266                 case NFT_MSG_DELRULE:
 267                         if (!(trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD))
 268                                 continue;
 269
 270                         err = nft_flow_offload_rule(trans, FLOW_CLS_DESTROY);
 271                         break;
 272                 }
 273
 274                 if (err)
 275                         return err;
 276         }
 277
 278         return err;
 279 }