diff options
Diffstat (limited to 'net/netfilter/nft_dynset.c')
-rw-r--r-- | net/netfilter/nft_dynset.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/net/netfilter/nft_dynset.c b/net/netfilter/nft_dynset.c new file mode 100644 index 0000000..513a8ef --- /dev/null +++ b/net/netfilter/nft_dynset.c @@ -0,0 +1,265 @@ +/* + * Copyright (c) 2015 Patrick McHardy <kaber@trash.net> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#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; + enum nft_registers sreg_key:8; + enum nft_registers sreg_data:8; + u64 timeout; + struct nft_expr *expr; + struct nft_set_binding binding; +}; + +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 (set->size && !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], + ®s->data[priv->sreg_data], + timeout, GFP_ATOMIC); + if (elem == NULL) { + if (set->size) + atomic_dec(&set->nelems); + return NULL; + } + + ext = nft_set_elem_ext(set, elem); + if (priv->expr != NULL) + nft_expr_clone(nft_set_ext_expr(ext), priv->expr); + + return elem; +} + +static 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; + const struct nft_expr *sexpr; + u64 timeout; + + if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new, + expr, regs, &ext)) { + sexpr = NULL; + if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR)) + sexpr = nft_set_ext_expr(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) = jiffies + timeout; + } else if (sexpr == NULL) + goto out; + + if (sexpr != NULL) + sexpr->ops->eval(sexpr, regs, pkt); + return; + } +out: + regs->verdict.code = NFT_BREAK; +} + +static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = { + [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING }, + [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 }, +}; + +static int nft_dynset_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_dynset *priv = nft_expr_priv(expr); + struct nft_set *set; + u64 timeout; + int err; + + if (tb[NFTA_DYNSET_SET_NAME] == NULL || + tb[NFTA_DYNSET_OP] == NULL || + tb[NFTA_DYNSET_SREG_KEY] == NULL) + return -EINVAL; + + set = nf_tables_set_lookup(ctx->table, tb[NFTA_DYNSET_SET_NAME]); + if (IS_ERR(set)) { + if (tb[NFTA_DYNSET_SET_ID]) + set = nf_tables_set_lookup_byid(ctx->net, + tb[NFTA_DYNSET_SET_ID]); + if (IS_ERR(set)) + return PTR_ERR(set); + } + + if (set->flags & NFT_SET_CONSTANT) + return -EBUSY; + + priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP])); + switch (priv->op) { + case NFT_DYNSET_OP_ADD: + break; + case NFT_DYNSET_OP_UPDATE: + if (!(set->flags & NFT_SET_TIMEOUT)) + return -EOPNOTSUPP; + break; + default: + return -EOPNOTSUPP; + } + + timeout = 0; + if (tb[NFTA_DYNSET_TIMEOUT] != NULL) { + if (!(set->flags & NFT_SET_TIMEOUT)) + return -EINVAL; + timeout = be64_to_cpu(nla_get_be64(tb[NFTA_DYNSET_TIMEOUT])); + } + + priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]); + err = nft_validate_register_load(priv->sreg_key, set->klen);; + if (err < 0) + return err; + + if (tb[NFTA_DYNSET_SREG_DATA] != NULL) { + if (!(set->flags & NFT_SET_MAP)) + return -EINVAL; + if (set->dtype == NFT_DATA_VERDICT) + return -EOPNOTSUPP; + + priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]); + err = nft_validate_register_load(priv->sreg_data, set->dlen); + if (err < 0) + return err; + } else if (set->flags & NFT_SET_MAP) + return -EINVAL; + + if (tb[NFTA_DYNSET_EXPR] != NULL) { + if (!(set->flags & NFT_SET_EVAL)) + return -EINVAL; + if (!(set->flags & NFT_SET_ANONYMOUS)) + return -EOPNOTSUPP; + + priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]); + if (IS_ERR(priv->expr)) + return PTR_ERR(priv->expr); + + err = -EOPNOTSUPP; + if (!(priv->expr->ops->type->flags & NFT_EXPR_STATEFUL)) + goto err1; + } else if (set->flags & NFT_SET_EVAL) + return -EINVAL; + + 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->expr != NULL) + nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR, + priv->expr->ops->size); + if (set->flags & NFT_SET_TIMEOUT) { + if (timeout || set->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 err1; + + priv->set = set; + return 0; + +err1: + if (priv->expr != NULL) + nft_expr_destroy(ctx, priv->expr); + return err; +} + +static void nft_dynset_destroy(const struct nft_ctx *ctx, + const struct nft_expr *expr) +{ + struct nft_dynset *priv = nft_expr_priv(expr); + + nf_tables_unbind_set(ctx, priv->set, &priv->binding); + if (priv->expr != NULL) + nft_expr_destroy(ctx, priv->expr); +} + +static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_dynset *priv = nft_expr_priv(expr); + + 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, cpu_to_be64(priv->timeout))) + goto nla_put_failure; + if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr)) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -1; +} + +static struct nft_expr_type nft_dynset_type; +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, + .dump = nft_dynset_dump, +}; + +static 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, +}; + +int __init nft_dynset_module_init(void) +{ + return nft_register_expr(&nft_dynset_type); +} + +void nft_dynset_module_exit(void) +{ + nft_unregister_expr(&nft_dynset_type); +} |