// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2015 Patrick McHardy <kaber@trash.net>
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter/nf_tables.h>
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#include <net/netfilter/nf_tables.h>
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#include <net/netfilter/nf_tables_core.h>
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struct nft_dynset {
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struct nft_set *set;
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struct nft_set_ext_tmpl tmpl;
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enum nft_dynset_ops op:8;
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u8 sreg_key;
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u8 sreg_data;
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bool invert;
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u64 timeout;
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struct nft_expr *expr;
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struct nft_set_binding binding;
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};
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static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr,
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struct nft_regs *regs)
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{
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const struct nft_dynset *priv = nft_expr_priv(expr);
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struct nft_set_ext *ext;
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u64 timeout;
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void *elem;
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if (!atomic_add_unless(&set->nelems, 1, set->size))
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return NULL;
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timeout = priv->timeout ? : set->timeout;
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elem = nft_set_elem_init(set, &priv->tmpl,
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®s->data[priv->sreg_key], NULL,
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®s->data[priv->sreg_data],
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timeout, 0, GFP_ATOMIC);
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if (elem == NULL)
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goto err1;
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ext = nft_set_elem_ext(set, elem);
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if (priv->expr != NULL &&
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nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0)
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goto err2;
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return elem;
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err2:
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nft_set_elem_destroy(set, elem, false);
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err1:
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if (set->size)
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atomic_dec(&set->nelems);
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return NULL;
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}
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void nft_dynset_eval(const struct nft_expr *expr,
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struct nft_regs *regs, const struct nft_pktinfo *pkt)
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{
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const struct nft_dynset *priv = nft_expr_priv(expr);
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struct nft_set *set = priv->set;
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const struct nft_set_ext *ext;
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u64 timeout;
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if (priv->op == NFT_DYNSET_OP_DELETE) {
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set->ops->delete(set, ®s->data[priv->sreg_key]);
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return;
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}
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if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new,
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expr, regs, &ext)) {
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if (priv->op == NFT_DYNSET_OP_UPDATE &&
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nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
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timeout = priv->timeout ? : set->timeout;
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*nft_set_ext_expiration(ext) = get_jiffies_64() + timeout;
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}
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nft_set_elem_update_expr(ext, regs, pkt);
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if (priv->invert)
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regs->verdict.code = NFT_BREAK;
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return;
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}
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if (!priv->invert)
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regs->verdict.code = NFT_BREAK;
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}
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static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
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[NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING,
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.len = NFT_SET_MAXNAMELEN - 1 },
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[NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
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[NFTA_DYNSET_OP] = { .type = NLA_U32 },
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[NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
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[NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
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[NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
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[NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
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[NFTA_DYNSET_FLAGS] = { .type = NLA_U32 },
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};
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static int nft_dynset_init(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_dynset *priv = nft_expr_priv(expr);
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u8 genmask = nft_genmask_next(ctx->net);
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struct nft_set *set;
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u64 timeout;
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int err;
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lockdep_assert_held(&ctx->net->nft.commit_mutex);
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if (tb[NFTA_DYNSET_SET_NAME] == NULL ||
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tb[NFTA_DYNSET_OP] == NULL ||
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tb[NFTA_DYNSET_SREG_KEY] == NULL)
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return -EINVAL;
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if (tb[NFTA_DYNSET_FLAGS]) {
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u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
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if (flags & ~NFT_DYNSET_F_INV)
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return -EOPNOTSUPP;
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if (flags & NFT_DYNSET_F_INV)
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priv->invert = true;
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}
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set = nft_set_lookup_global(ctx->net, ctx->table,
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tb[NFTA_DYNSET_SET_NAME],
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tb[NFTA_DYNSET_SET_ID], genmask);
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if (IS_ERR(set))
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return PTR_ERR(set);
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if (set->ops->update == NULL)
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return -EOPNOTSUPP;
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if (set->flags & NFT_SET_CONSTANT)
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return -EBUSY;
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priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
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if (priv->op > NFT_DYNSET_OP_DELETE)
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return -EOPNOTSUPP;
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timeout = 0;
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if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
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if (!(set->flags & NFT_SET_TIMEOUT))
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return -EOPNOTSUPP;
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err = nf_msecs_to_jiffies64(tb[NFTA_DYNSET_TIMEOUT], &timeout);
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if (err)
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return err;
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}
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err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_KEY], &priv->sreg_key,
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set->klen);
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if (err < 0)
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return err;
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if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
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if (!(set->flags & NFT_SET_MAP))
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return -EOPNOTSUPP;
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if (set->dtype == NFT_DATA_VERDICT)
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return -EOPNOTSUPP;
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err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_DATA],
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&priv->sreg_data, set->dlen);
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if (err < 0)
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return err;
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} else if (set->flags & NFT_SET_MAP)
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return -EINVAL;
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if (tb[NFTA_DYNSET_EXPR] != NULL) {
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if (!(set->flags & NFT_SET_EVAL))
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return -EINVAL;
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priv->expr = nft_set_elem_expr_alloc(ctx, set,
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tb[NFTA_DYNSET_EXPR]);
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if (IS_ERR(priv->expr))
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return PTR_ERR(priv->expr);
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if (set->expr && set->expr->ops != priv->expr->ops) {
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err = -EOPNOTSUPP;
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goto err_expr_free;
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}
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}
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nft_set_ext_prepare(&priv->tmpl);
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nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
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if (set->flags & NFT_SET_MAP)
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nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
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if (priv->expr != NULL)
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nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR,
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priv->expr->ops->size);
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if (set->flags & NFT_SET_TIMEOUT) {
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if (timeout || set->timeout) {
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nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_TIMEOUT);
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nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
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}
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}
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priv->timeout = timeout;
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err = nf_tables_bind_set(ctx, set, &priv->binding);
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if (err < 0)
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goto err_expr_free;
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if (set->size == 0)
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set->size = 0xffff;
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priv->set = set;
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return 0;
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err_expr_free:
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if (priv->expr != NULL)
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nft_expr_destroy(ctx, priv->expr);
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return err;
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}
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static void nft_dynset_deactivate(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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enum nft_trans_phase phase)
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{
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struct nft_dynset *priv = nft_expr_priv(expr);
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nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
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}
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static void nft_dynset_activate(const struct nft_ctx *ctx,
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const struct nft_expr *expr)
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{
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struct nft_dynset *priv = nft_expr_priv(expr);
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priv->set->use++;
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}
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static void nft_dynset_destroy(const struct nft_ctx *ctx,
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const struct nft_expr *expr)
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{
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struct nft_dynset *priv = nft_expr_priv(expr);
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if (priv->expr != NULL)
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nft_expr_destroy(ctx, priv->expr);
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nf_tables_destroy_set(ctx, priv->set);
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}
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static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_dynset *priv = nft_expr_priv(expr);
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u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
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if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
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goto nla_put_failure;
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if (priv->set->flags & NFT_SET_MAP &&
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nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
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goto nla_put_failure;
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if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
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goto nla_put_failure;
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if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
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goto nla_put_failure;
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if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
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nf_jiffies64_to_msecs(priv->timeout),
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NFTA_DYNSET_PAD))
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goto nla_put_failure;
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if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
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goto nla_put_failure;
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if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -1;
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}
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static const struct nft_expr_ops nft_dynset_ops = {
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.type = &nft_dynset_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
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.eval = nft_dynset_eval,
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.init = nft_dynset_init,
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.destroy = nft_dynset_destroy,
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.activate = nft_dynset_activate,
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.deactivate = nft_dynset_deactivate,
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.dump = nft_dynset_dump,
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};
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struct nft_expr_type nft_dynset_type __read_mostly = {
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.name = "dynset",
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.ops = &nft_dynset_ops,
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.policy = nft_dynset_policy,
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.maxattr = NFTA_DYNSET_MAX,
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.owner = THIS_MODULE,
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};
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