diff options
Diffstat (limited to 'net/netfilter/nft_meta.c')
| -rw-r--r-- | net/netfilter/nft_meta.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c new file mode 100644 index 000000000000..8c28220a90b3 --- /dev/null +++ b/net/netfilter/nft_meta.c @@ -0,0 +1,228 @@ +/* + * Copyright (c) 2008-2009 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. + * + * Development of this code funded by Astaro AG (http://www.astaro.com/) + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <net/dst.h> +#include <net/sock.h> +#include <net/tcp_states.h> /* for TCP_TIME_WAIT */ +#include <net/netfilter/nf_tables.h> + +struct nft_meta { + enum nft_meta_keys key:8; + enum nft_registers dreg:8; +}; + +static void nft_meta_eval(const struct nft_expr *expr, + struct nft_data data[NFT_REG_MAX + 1], + const struct nft_pktinfo *pkt) +{ + const struct nft_meta *priv = nft_expr_priv(expr); + const struct sk_buff *skb = pkt->skb; + const struct net_device *in = pkt->in, *out = pkt->out; + struct nft_data *dest = &data[priv->dreg]; + + switch (priv->key) { + case NFT_META_LEN: + dest->data[0] = skb->len; + break; + case NFT_META_PROTOCOL: + *(__be16 *)dest->data = skb->protocol; + break; + case NFT_META_PRIORITY: + dest->data[0] = skb->priority; + break; + case NFT_META_MARK: + dest->data[0] = skb->mark; + break; + case NFT_META_IIF: + if (in == NULL) + goto err; + dest->data[0] = in->ifindex; + break; + case NFT_META_OIF: + if (out == NULL) + goto err; + dest->data[0] = out->ifindex; + break; + case NFT_META_IIFNAME: + if (in == NULL) + goto err; + strncpy((char *)dest->data, in->name, sizeof(dest->data)); + break; + case NFT_META_OIFNAME: + if (out == NULL) + goto err; + strncpy((char *)dest->data, out->name, sizeof(dest->data)); + break; + case NFT_META_IIFTYPE: + if (in == NULL) + goto err; + *(u16 *)dest->data = in->type; + break; + case NFT_META_OIFTYPE: + if (out == NULL) + goto err; + *(u16 *)dest->data = out->type; + break; + case NFT_META_SKUID: + if (skb->sk == NULL || skb->sk->sk_state == TCP_TIME_WAIT) + goto err; + + read_lock_bh(&skb->sk->sk_callback_lock); + if (skb->sk->sk_socket == NULL || + skb->sk->sk_socket->file == NULL) { + read_unlock_bh(&skb->sk->sk_callback_lock); + goto err; + } + + dest->data[0] = + from_kuid_munged(&init_user_ns, + skb->sk->sk_socket->file->f_cred->fsuid); + read_unlock_bh(&skb->sk->sk_callback_lock); + break; + case NFT_META_SKGID: + if (skb->sk == NULL || skb->sk->sk_state == TCP_TIME_WAIT) + goto err; + + read_lock_bh(&skb->sk->sk_callback_lock); + if (skb->sk->sk_socket == NULL || + skb->sk->sk_socket->file == NULL) { + read_unlock_bh(&skb->sk->sk_callback_lock); + goto err; + } + dest->data[0] = + from_kgid_munged(&init_user_ns, + skb->sk->sk_socket->file->f_cred->fsgid); + read_unlock_bh(&skb->sk->sk_callback_lock); + break; +#ifdef CONFIG_NET_CLS_ROUTE + case NFT_META_RTCLASSID: { + const struct dst_entry *dst = skb_dst(skb); + + if (dst == NULL) + goto err; + dest->data[0] = dst->tclassid; + break; + } +#endif +#ifdef CONFIG_NETWORK_SECMARK + case NFT_META_SECMARK: + dest->data[0] = skb->secmark; + break; +#endif + default: + WARN_ON(1); + goto err; + } + return; + +err: + data[NFT_REG_VERDICT].verdict = NFT_BREAK; +} + +static const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = { + [NFTA_META_DREG] = { .type = NLA_U32 }, + [NFTA_META_KEY] = { .type = NLA_U32 }, +}; + +static int nft_meta_init(const struct nft_ctx *ctx, const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_meta *priv = nft_expr_priv(expr); + int err; + + if (tb[NFTA_META_DREG] == NULL || + tb[NFTA_META_KEY] == NULL) + return -EINVAL; + + priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY])); + switch (priv->key) { + case NFT_META_LEN: + case NFT_META_PROTOCOL: + case NFT_META_PRIORITY: + case NFT_META_MARK: + case NFT_META_IIF: + case NFT_META_OIF: + case NFT_META_IIFNAME: + case NFT_META_OIFNAME: + case NFT_META_IIFTYPE: + case NFT_META_OIFTYPE: + case NFT_META_SKUID: + case NFT_META_SKGID: +#ifdef CONFIG_NET_CLS_ROUTE + case NFT_META_RTCLASSID: +#endif +#ifdef CONFIG_NETWORK_SECMARK + case NFT_META_SECMARK: +#endif + break; + default: + return -EOPNOTSUPP; + } + + priv->dreg = ntohl(nla_get_be32(tb[NFTA_META_DREG])); + err = nft_validate_output_register(priv->dreg); + if (err < 0) + return err; + return nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE); +} + +static int nft_meta_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_meta *priv = nft_expr_priv(expr); + + if (nla_put_be32(skb, NFTA_META_DREG, htonl(priv->dreg))) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key))) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -1; +} + +static struct nft_expr_type nft_meta_type; +static const struct nft_expr_ops nft_meta_ops = { + .type = &nft_meta_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), + .eval = nft_meta_eval, + .init = nft_meta_init, + .dump = nft_meta_dump, +}; + +static struct nft_expr_type nft_meta_type __read_mostly = { + .name = "meta", + .ops = &nft_meta_ops, + .policy = nft_meta_policy, + .maxattr = NFTA_META_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_meta_module_init(void) +{ + return nft_register_expr(&nft_meta_type); +} + +static void __exit nft_meta_module_exit(void) +{ + nft_unregister_expr(&nft_meta_type); +} + +module_init(nft_meta_module_init); +module_exit(nft_meta_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); +MODULE_ALIAS_NFT_EXPR("meta"); |