253 lines
5.8 KiB
C
253 lines
5.8 KiB
C
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/*
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* Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Development of this code funded by Astaro AG (http://www.astaro.com/)
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.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_conntrack.h>
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#include <net/netfilter/nf_conntrack_tuple.h>
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#include <net/netfilter/nf_conntrack_helper.h>
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struct nft_ct {
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enum nft_ct_keys key:8;
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enum ip_conntrack_dir dir:8;
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enum nft_registers dreg:8;
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uint8_t family;
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};
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static void nft_ct_eval(const struct nft_expr *expr,
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struct nft_data data[NFT_REG_MAX + 1],
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const struct nft_pktinfo *pkt)
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{
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const struct nft_ct *priv = nft_expr_priv(expr);
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struct nft_data *dest = &data[priv->dreg];
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enum ip_conntrack_info ctinfo;
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const struct nf_conn *ct;
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const struct nf_conn_help *help;
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const struct nf_conntrack_tuple *tuple;
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const struct nf_conntrack_helper *helper;
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long diff;
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unsigned int state;
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ct = nf_ct_get(pkt->skb, &ctinfo);
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switch (priv->key) {
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case NFT_CT_STATE:
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if (ct == NULL)
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state = NF_CT_STATE_INVALID_BIT;
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else if (nf_ct_is_untracked(ct))
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state = NF_CT_STATE_UNTRACKED_BIT;
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else
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state = NF_CT_STATE_BIT(ctinfo);
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dest->data[0] = state;
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return;
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}
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if (ct == NULL)
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goto err;
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switch (priv->key) {
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case NFT_CT_DIRECTION:
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dest->data[0] = CTINFO2DIR(ctinfo);
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return;
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case NFT_CT_STATUS:
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dest->data[0] = ct->status;
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return;
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#ifdef CONFIG_NF_CONNTRACK_MARK
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case NFT_CT_MARK:
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dest->data[0] = ct->mark;
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return;
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#endif
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#ifdef CONFIG_NF_CONNTRACK_SECMARK
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case NFT_CT_SECMARK:
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dest->data[0] = ct->secmark;
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return;
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#endif
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case NFT_CT_EXPIRATION:
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diff = (long)jiffies - (long)ct->timeout.expires;
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if (diff < 0)
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diff = 0;
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dest->data[0] = jiffies_to_msecs(diff);
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return;
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case NFT_CT_HELPER:
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if (ct->master == NULL)
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goto err;
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help = nfct_help(ct->master);
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if (help == NULL)
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goto err;
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helper = rcu_dereference(help->helper);
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if (helper == NULL)
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goto err;
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if (strlen(helper->name) >= sizeof(dest->data))
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goto err;
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strncpy((char *)dest->data, helper->name, sizeof(dest->data));
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return;
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}
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tuple = &ct->tuplehash[priv->dir].tuple;
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switch (priv->key) {
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case NFT_CT_L3PROTOCOL:
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dest->data[0] = nf_ct_l3num(ct);
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return;
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case NFT_CT_SRC:
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memcpy(dest->data, tuple->src.u3.all,
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nf_ct_l3num(ct) == NFPROTO_IPV4 ? 4 : 16);
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return;
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case NFT_CT_DST:
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memcpy(dest->data, tuple->dst.u3.all,
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nf_ct_l3num(ct) == NFPROTO_IPV4 ? 4 : 16);
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return;
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case NFT_CT_PROTOCOL:
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dest->data[0] = nf_ct_protonum(ct);
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return;
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case NFT_CT_PROTO_SRC:
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dest->data[0] = (__force __u16)tuple->src.u.all;
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return;
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case NFT_CT_PROTO_DST:
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dest->data[0] = (__force __u16)tuple->dst.u.all;
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return;
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}
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return;
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err:
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data[NFT_REG_VERDICT].verdict = NFT_BREAK;
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}
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static const struct nla_policy nft_ct_policy[NFTA_CT_MAX + 1] = {
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[NFTA_CT_DREG] = { .type = NLA_U32 },
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[NFTA_CT_KEY] = { .type = NLA_U32 },
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[NFTA_CT_DIRECTION] = { .type = NLA_U8 },
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};
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static int nft_ct_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_ct *priv = nft_expr_priv(expr);
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int err;
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if (tb[NFTA_CT_DREG] == NULL ||
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tb[NFTA_CT_KEY] == NULL)
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return -EINVAL;
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priv->key = ntohl(nla_get_be32(tb[NFTA_CT_KEY]));
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if (tb[NFTA_CT_DIRECTION] != NULL) {
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priv->dir = nla_get_u8(tb[NFTA_CT_DIRECTION]);
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switch (priv->dir) {
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case IP_CT_DIR_ORIGINAL:
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case IP_CT_DIR_REPLY:
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break;
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default:
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return -EINVAL;
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}
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}
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switch (priv->key) {
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case NFT_CT_STATE:
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case NFT_CT_DIRECTION:
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case NFT_CT_STATUS:
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#ifdef CONFIG_NF_CONNTRACK_MARK
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case NFT_CT_MARK:
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#endif
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#ifdef CONFIG_NF_CONNTRACK_SECMARK
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case NFT_CT_SECMARK:
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#endif
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case NFT_CT_EXPIRATION:
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case NFT_CT_HELPER:
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if (tb[NFTA_CT_DIRECTION] != NULL)
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return -EINVAL;
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break;
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case NFT_CT_PROTOCOL:
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case NFT_CT_SRC:
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case NFT_CT_DST:
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case NFT_CT_PROTO_SRC:
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case NFT_CT_PROTO_DST:
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if (tb[NFTA_CT_DIRECTION] == NULL)
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return -EINVAL;
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break;
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default:
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return -EOPNOTSUPP;
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}
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err = nf_ct_l3proto_try_module_get(ctx->afi->family);
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if (err < 0)
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return err;
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priv->family = ctx->afi->family;
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priv->dreg = ntohl(nla_get_be32(tb[NFTA_CT_DREG]));
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err = nft_validate_output_register(priv->dreg);
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if (err < 0)
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goto err1;
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err = nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE);
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if (err < 0)
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goto err1;
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return 0;
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err1:
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nf_ct_l3proto_module_put(ctx->afi->family);
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return err;
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}
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static void nft_ct_destroy(const struct nft_expr *expr)
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{
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struct nft_ct *priv = nft_expr_priv(expr);
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nf_ct_l3proto_module_put(priv->family);
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}
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static int nft_ct_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_ct *priv = nft_expr_priv(expr);
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if (nla_put_be32(skb, NFTA_CT_DREG, htonl(priv->dreg)))
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goto nla_put_failure;
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if (nla_put_be32(skb, NFTA_CT_KEY, htonl(priv->key)))
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goto nla_put_failure;
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if (nla_put_u8(skb, NFTA_CT_DIRECTION, priv->dir))
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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 struct nft_expr_ops nft_ct_ops __read_mostly = {
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.name = "ct",
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.size = NFT_EXPR_SIZE(sizeof(struct nft_ct)),
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.owner = THIS_MODULE,
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.eval = nft_ct_eval,
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.init = nft_ct_init,
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.destroy = nft_ct_destroy,
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.dump = nft_ct_dump,
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.policy = nft_ct_policy,
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.maxattr = NFTA_CT_MAX,
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};
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static int __init nft_ct_module_init(void)
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{
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return nft_register_expr(&nft_ct_ops);
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}
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static void __exit nft_ct_module_exit(void)
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{
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nft_unregister_expr(&nft_ct_ops);
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}
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module_init(nft_ct_module_init);
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module_exit(nft_ct_module_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
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MODULE_ALIAS_NFT_EXPR("ct");
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