| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (c) 2015 Patrick McHardy <kaber@trash.net> |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/netlink.h> |
| #include <linux/netfilter.h> |
| #include <linux/netfilter/nf_tables.h> |
| #include <net/netfilter/nf_tables.h> |
| #include <net/netfilter/nf_tables_core.h> |
| |
| struct nft_dynset { |
| struct nft_set *set; |
| struct nft_set_ext_tmpl tmpl; |
| enum nft_dynset_ops op:8; |
| u8 sreg_key; |
| u8 sreg_data; |
| bool invert; |
| bool expr; |
| u8 num_exprs; |
| u64 timeout; |
| struct nft_expr *expr_array[NFT_SET_EXPR_MAX]; |
| struct nft_set_binding binding; |
| }; |
| |
| static int nft_dynset_expr_setup(const struct nft_dynset *priv, |
| const struct nft_set_ext *ext) |
| { |
| struct nft_set_elem_expr *elem_expr = nft_set_ext_expr(ext); |
| struct nft_expr *expr; |
| int i; |
| |
| for (i = 0; i < priv->num_exprs; i++) { |
| expr = nft_setelem_expr_at(elem_expr, elem_expr->size); |
| if (nft_expr_clone(expr, priv->expr_array[i]) < 0) |
| return -1; |
| |
| elem_expr->size += priv->expr_array[i]->ops->size; |
| } |
| |
| return 0; |
| } |
| |
| static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr, |
| struct nft_regs *regs) |
| { |
| const struct nft_dynset *priv = nft_expr_priv(expr); |
| struct nft_set_ext *ext; |
| u64 timeout; |
| void *elem; |
| |
| if (!atomic_add_unless(&set->nelems, 1, set->size)) |
| return NULL; |
| |
| timeout = priv->timeout ? : set->timeout; |
| elem = nft_set_elem_init(set, &priv->tmpl, |
| ®s->data[priv->sreg_key], NULL, |
| ®s->data[priv->sreg_data], |
| timeout, 0, GFP_ATOMIC); |
| if (elem == NULL) |
| goto err1; |
| |
| ext = nft_set_elem_ext(set, elem); |
| if (priv->num_exprs && nft_dynset_expr_setup(priv, ext) < 0) |
| goto err2; |
| |
| return elem; |
| |
| err2: |
| nft_set_elem_destroy(set, elem, false); |
| err1: |
| if (set->size) |
| atomic_dec(&set->nelems); |
| return NULL; |
| } |
| |
| void nft_dynset_eval(const struct nft_expr *expr, |
| struct nft_regs *regs, const struct nft_pktinfo *pkt) |
| { |
| const struct nft_dynset *priv = nft_expr_priv(expr); |
| struct nft_set *set = priv->set; |
| const struct nft_set_ext *ext; |
| u64 timeout; |
| |
| if (priv->op == NFT_DYNSET_OP_DELETE) { |
| set->ops->delete(set, ®s->data[priv->sreg_key]); |
| return; |
| } |
| |
| if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new, |
| expr, regs, &ext)) { |
| if (priv->op == NFT_DYNSET_OP_UPDATE && |
| nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) { |
| timeout = priv->timeout ? : set->timeout; |
| *nft_set_ext_expiration(ext) = get_jiffies_64() + timeout; |
| } |
| |
| nft_set_elem_update_expr(ext, regs, pkt); |
| |
| if (priv->invert) |
| regs->verdict.code = NFT_BREAK; |
| return; |
| } |
| |
| if (!priv->invert) |
| regs->verdict.code = NFT_BREAK; |
| } |
| |
| static void nft_dynset_ext_add_expr(struct nft_dynset *priv) |
| { |
| u8 size = 0; |
| int i; |
| |
| for (i = 0; i < priv->num_exprs; i++) |
| size += priv->expr_array[i]->ops->size; |
| |
| nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPRESSIONS, |
| sizeof(struct nft_set_elem_expr) + size); |
| } |
| |
| static struct nft_expr * |
| nft_dynset_expr_alloc(const struct nft_ctx *ctx, const struct nft_set *set, |
| const struct nlattr *attr, int pos) |
| { |
| struct nft_expr *expr; |
| int err; |
| |
| expr = nft_set_elem_expr_alloc(ctx, set, attr); |
| if (IS_ERR(expr)) |
| return expr; |
| |
| if (set->exprs[pos] && set->exprs[pos]->ops != expr->ops) { |
| err = -EOPNOTSUPP; |
| goto err_dynset_expr; |
| } |
| |
| return expr; |
| |
| err_dynset_expr: |
| nft_expr_destroy(ctx, expr); |
| return ERR_PTR(err); |
| } |
| |
| static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = { |
| [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING, |
| .len = NFT_SET_MAXNAMELEN - 1 }, |
| [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 }, |
| [NFTA_DYNSET_OP] = { .type = NLA_U32 }, |
| [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 }, |
| [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 }, |
| [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 }, |
| [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED }, |
| [NFTA_DYNSET_FLAGS] = { .type = NLA_U32 }, |
| [NFTA_DYNSET_EXPRESSIONS] = { .type = NLA_NESTED }, |
| }; |
| |
| static int nft_dynset_init(const struct nft_ctx *ctx, |
| const struct nft_expr *expr, |
| const struct nlattr * const tb[]) |
| { |
| struct nftables_pernet *nft_net = nft_pernet(ctx->net); |
| struct nft_dynset *priv = nft_expr_priv(expr); |
| u8 genmask = nft_genmask_next(ctx->net); |
| struct nft_set *set; |
| u64 timeout; |
| int err, i; |
| |
| lockdep_assert_held(&nft_net->commit_mutex); |
| |
| if (tb[NFTA_DYNSET_SET_NAME] == NULL || |
| tb[NFTA_DYNSET_OP] == NULL || |
| tb[NFTA_DYNSET_SREG_KEY] == NULL) |
| return -EINVAL; |
| |
| if (tb[NFTA_DYNSET_FLAGS]) { |
| u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS])); |
| if (flags & ~(NFT_DYNSET_F_INV | NFT_DYNSET_F_EXPR)) |
| return -EOPNOTSUPP; |
| if (flags & NFT_DYNSET_F_INV) |
| priv->invert = true; |
| if (flags & NFT_DYNSET_F_EXPR) |
| priv->expr = true; |
| } |
| |
| set = nft_set_lookup_global(ctx->net, ctx->table, |
| tb[NFTA_DYNSET_SET_NAME], |
| tb[NFTA_DYNSET_SET_ID], genmask); |
| if (IS_ERR(set)) |
| return PTR_ERR(set); |
| |
| if (set->ops->update == NULL) |
| return -EOPNOTSUPP; |
| |
| if (set->flags & NFT_SET_CONSTANT) |
| return -EBUSY; |
| |
| priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP])); |
| if (priv->op > NFT_DYNSET_OP_DELETE) |
| return -EOPNOTSUPP; |
| |
| timeout = 0; |
| if (tb[NFTA_DYNSET_TIMEOUT] != NULL) { |
| if (!(set->flags & NFT_SET_TIMEOUT)) |
| return -EOPNOTSUPP; |
| |
| err = nf_msecs_to_jiffies64(tb[NFTA_DYNSET_TIMEOUT], &timeout); |
| if (err) |
| return err; |
| } |
| |
| err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_KEY], &priv->sreg_key, |
| set->klen); |
| if (err < 0) |
| return err; |
| |
| if (tb[NFTA_DYNSET_SREG_DATA] != NULL) { |
| if (!(set->flags & NFT_SET_MAP)) |
| return -EOPNOTSUPP; |
| if (set->dtype == NFT_DATA_VERDICT) |
| return -EOPNOTSUPP; |
| |
| err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_DATA], |
| &priv->sreg_data, set->dlen); |
| if (err < 0) |
| return err; |
| } else if (set->flags & NFT_SET_MAP) |
| return -EINVAL; |
| |
| if ((tb[NFTA_DYNSET_EXPR] || tb[NFTA_DYNSET_EXPRESSIONS]) && |
| !(set->flags & NFT_SET_EVAL)) |
| return -EINVAL; |
| |
| if (tb[NFTA_DYNSET_EXPR]) { |
| struct nft_expr *dynset_expr; |
| |
| dynset_expr = nft_dynset_expr_alloc(ctx, set, |
| tb[NFTA_DYNSET_EXPR], 0); |
| if (IS_ERR(dynset_expr)) |
| return PTR_ERR(dynset_expr); |
| |
| priv->num_exprs++; |
| priv->expr_array[0] = dynset_expr; |
| |
| if (set->num_exprs > 1 || |
| (set->num_exprs == 1 && |
| dynset_expr->ops != set->exprs[0]->ops)) { |
| err = -EOPNOTSUPP; |
| goto err_expr_free; |
| } |
| } else if (tb[NFTA_DYNSET_EXPRESSIONS]) { |
| struct nft_expr *dynset_expr; |
| struct nlattr *tmp; |
| int left; |
| |
| if (!priv->expr) |
| return -EINVAL; |
| |
| i = 0; |
| nla_for_each_nested(tmp, tb[NFTA_DYNSET_EXPRESSIONS], left) { |
| if (i == NFT_SET_EXPR_MAX) { |
| err = -E2BIG; |
| goto err_expr_free; |
| } |
| if (nla_type(tmp) != NFTA_LIST_ELEM) { |
| err = -EINVAL; |
| goto err_expr_free; |
| } |
| dynset_expr = nft_dynset_expr_alloc(ctx, set, tmp, i); |
| if (IS_ERR(dynset_expr)) { |
| err = PTR_ERR(dynset_expr); |
| goto err_expr_free; |
| } |
| priv->expr_array[i] = dynset_expr; |
| priv->num_exprs++; |
| |
| if (set->num_exprs && |
| dynset_expr->ops != set->exprs[i]->ops) { |
| err = -EOPNOTSUPP; |
| goto err_expr_free; |
| } |
| i++; |
| } |
| if (set->num_exprs && set->num_exprs != i) { |
| err = -EOPNOTSUPP; |
| goto err_expr_free; |
| } |
| } else if (set->num_exprs > 0) { |
| err = nft_set_elem_expr_clone(ctx, set, priv->expr_array); |
| if (err < 0) |
| return err; |
| |
| priv->num_exprs = set->num_exprs; |
| } |
| |
| nft_set_ext_prepare(&priv->tmpl); |
| nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen); |
| if (set->flags & NFT_SET_MAP) |
| nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen); |
| |
| if (priv->num_exprs) |
| nft_dynset_ext_add_expr(priv); |
| |
| if (set->flags & NFT_SET_TIMEOUT) { |
| if (timeout || set->timeout) { |
| nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_TIMEOUT); |
| nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION); |
| } |
| } |
| |
| priv->timeout = timeout; |
| |
| err = nf_tables_bind_set(ctx, set, &priv->binding); |
| if (err < 0) |
| goto err_expr_free; |
| |
| if (set->size == 0) |
| set->size = 0xffff; |
| |
| priv->set = set; |
| return 0; |
| |
| err_expr_free: |
| for (i = 0; i < priv->num_exprs; i++) |
| nft_expr_destroy(ctx, priv->expr_array[i]); |
| return err; |
| } |
| |
| static void nft_dynset_deactivate(const struct nft_ctx *ctx, |
| const struct nft_expr *expr, |
| enum nft_trans_phase phase) |
| { |
| struct nft_dynset *priv = nft_expr_priv(expr); |
| |
| nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase); |
| } |
| |
| static void nft_dynset_activate(const struct nft_ctx *ctx, |
| const struct nft_expr *expr) |
| { |
| struct nft_dynset *priv = nft_expr_priv(expr); |
| |
| priv->set->use++; |
| } |
| |
| static void nft_dynset_destroy(const struct nft_ctx *ctx, |
| const struct nft_expr *expr) |
| { |
| struct nft_dynset *priv = nft_expr_priv(expr); |
| int i; |
| |
| for (i = 0; i < priv->num_exprs; i++) |
| nft_expr_destroy(ctx, priv->expr_array[i]); |
| |
| nf_tables_destroy_set(ctx, priv->set); |
| } |
| |
| static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr) |
| { |
| const struct nft_dynset *priv = nft_expr_priv(expr); |
| u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0; |
| int i; |
| |
| if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key)) |
| goto nla_put_failure; |
| if (priv->set->flags & NFT_SET_MAP && |
| nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data)) |
| goto nla_put_failure; |
| if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op))) |
| goto nla_put_failure; |
| if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name)) |
| goto nla_put_failure; |
| if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT, |
| nf_jiffies64_to_msecs(priv->timeout), |
| NFTA_DYNSET_PAD)) |
| goto nla_put_failure; |
| if (priv->set->num_exprs == 0) { |
| if (priv->num_exprs == 1) { |
| if (nft_expr_dump(skb, NFTA_DYNSET_EXPR, |
| priv->expr_array[0])) |
| goto nla_put_failure; |
| } else if (priv->num_exprs > 1) { |
| struct nlattr *nest; |
| |
| nest = nla_nest_start_noflag(skb, NFTA_DYNSET_EXPRESSIONS); |
| if (!nest) |
| goto nla_put_failure; |
| |
| for (i = 0; i < priv->num_exprs; i++) { |
| if (nft_expr_dump(skb, NFTA_LIST_ELEM, |
| priv->expr_array[i])) |
| goto nla_put_failure; |
| } |
| nla_nest_end(skb, nest); |
| } |
| } |
| if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags))) |
| goto nla_put_failure; |
| return 0; |
| |
| nla_put_failure: |
| return -1; |
| } |
| |
| static const struct nft_expr_ops nft_dynset_ops = { |
| .type = &nft_dynset_type, |
| .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)), |
| .eval = nft_dynset_eval, |
| .init = nft_dynset_init, |
| .destroy = nft_dynset_destroy, |
| .activate = nft_dynset_activate, |
| .deactivate = nft_dynset_deactivate, |
| .dump = nft_dynset_dump, |
| .reduce = NFT_REDUCE_READONLY, |
| }; |
| |
| struct nft_expr_type nft_dynset_type __read_mostly = { |
| .name = "dynset", |
| .ops = &nft_dynset_ops, |
| .policy = nft_dynset_policy, |
| .maxattr = NFTA_DYNSET_MAX, |
| .owner = THIS_MODULE, |
| }; |