diff options
Diffstat (limited to 'net/netfilter/nft_ct.c')
| -rw-r--r-- | net/netfilter/nft_ct.c | 421 |
1 files changed, 421 insertions, 0 deletions
diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c new file mode 100644 index 00000000000..cc560301624 --- /dev/null +++ b/net/netfilter/nft_ct.c @@ -0,0 +1,421 @@ +/* + * 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/netfilter/nf_tables.h> +#include <net/netfilter/nf_conntrack.h> +#include <net/netfilter/nf_conntrack_tuple.h> +#include <net/netfilter/nf_conntrack_helper.h> +#include <net/netfilter/nf_conntrack_ecache.h> +#include <net/netfilter/nf_conntrack_labels.h> + +struct nft_ct { + enum nft_ct_keys key:8; + enum ip_conntrack_dir dir:8; + union { + enum nft_registers dreg:8; + enum nft_registers sreg:8; + }; +}; + +static void nft_ct_get_eval(const struct nft_expr *expr, + struct nft_data data[NFT_REG_MAX + 1], + const struct nft_pktinfo *pkt) +{ + const struct nft_ct *priv = nft_expr_priv(expr); + struct nft_data *dest = &data[priv->dreg]; + enum ip_conntrack_info ctinfo; + const struct nf_conn *ct; + const struct nf_conn_help *help; + const struct nf_conntrack_tuple *tuple; + const struct nf_conntrack_helper *helper; + long diff; + unsigned int state; + + ct = nf_ct_get(pkt->skb, &ctinfo); + + switch (priv->key) { + case NFT_CT_STATE: + if (ct == NULL) + state = NF_CT_STATE_INVALID_BIT; + else if (nf_ct_is_untracked(ct)) + state = NF_CT_STATE_UNTRACKED_BIT; + else + state = NF_CT_STATE_BIT(ctinfo); + dest->data[0] = state; + return; + } + + if (ct == NULL) + goto err; + + switch (priv->key) { + case NFT_CT_DIRECTION: + dest->data[0] = CTINFO2DIR(ctinfo); + return; + case NFT_CT_STATUS: + dest->data[0] = ct->status; + return; +#ifdef CONFIG_NF_CONNTRACK_MARK + case NFT_CT_MARK: + dest->data[0] = ct->mark; + return; +#endif +#ifdef CONFIG_NF_CONNTRACK_SECMARK + case NFT_CT_SECMARK: + dest->data[0] = ct->secmark; + return; +#endif + case NFT_CT_EXPIRATION: + diff = (long)jiffies - (long)ct->timeout.expires; + if (diff < 0) + diff = 0; + dest->data[0] = jiffies_to_msecs(diff); + return; + case NFT_CT_HELPER: + if (ct->master == NULL) + goto err; + help = nfct_help(ct->master); + if (help == NULL) + goto err; + helper = rcu_dereference(help->helper); + if (helper == NULL) + goto err; + if (strlen(helper->name) >= sizeof(dest->data)) + goto err; + strncpy((char *)dest->data, helper->name, sizeof(dest->data)); + return; +#ifdef CONFIG_NF_CONNTRACK_LABELS + case NFT_CT_LABELS: { + struct nf_conn_labels *labels = nf_ct_labels_find(ct); + unsigned int size; + + if (!labels) { + memset(dest->data, 0, sizeof(dest->data)); + return; + } + + BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE > sizeof(dest->data)); + size = labels->words * sizeof(long); + + memcpy(dest->data, labels->bits, size); + if (size < sizeof(dest->data)) + memset(((char *) dest->data) + size, 0, + sizeof(dest->data) - size); + return; + } +#endif + } + + tuple = &ct->tuplehash[priv->dir].tuple; + switch (priv->key) { + case NFT_CT_L3PROTOCOL: + dest->data[0] = nf_ct_l3num(ct); + return; + case NFT_CT_SRC: + memcpy(dest->data, tuple->src.u3.all, + nf_ct_l3num(ct) == NFPROTO_IPV4 ? 4 : 16); + return; + case NFT_CT_DST: + memcpy(dest->data, tuple->dst.u3.all, + nf_ct_l3num(ct) == NFPROTO_IPV4 ? 4 : 16); + return; + case NFT_CT_PROTOCOL: + dest->data[0] = nf_ct_protonum(ct); + return; + case NFT_CT_PROTO_SRC: + dest->data[0] = (__force __u16)tuple->src.u.all; + return; + case NFT_CT_PROTO_DST: + dest->data[0] = (__force __u16)tuple->dst.u.all; + return; + } + return; +err: + data[NFT_REG_VERDICT].verdict = NFT_BREAK; +} + +static void nft_ct_set_eval(const struct nft_expr *expr, + struct nft_data data[NFT_REG_MAX + 1], + const struct nft_pktinfo *pkt) +{ + const struct nft_ct *priv = nft_expr_priv(expr); + struct sk_buff *skb = pkt->skb; +#ifdef CONFIG_NF_CONNTRACK_MARK + u32 value = data[priv->sreg].data[0]; +#endif + enum ip_conntrack_info ctinfo; + struct nf_conn *ct; + + ct = nf_ct_get(skb, &ctinfo); + if (ct == NULL) + return; + + switch (priv->key) { +#ifdef CONFIG_NF_CONNTRACK_MARK + case NFT_CT_MARK: + if (ct->mark != value) { + ct->mark = value; + nf_conntrack_event_cache(IPCT_MARK, ct); + } + break; +#endif + } +} + +static const struct nla_policy nft_ct_policy[NFTA_CT_MAX + 1] = { + [NFTA_CT_DREG] = { .type = NLA_U32 }, + [NFTA_CT_KEY] = { .type = NLA_U32 }, + [NFTA_CT_DIRECTION] = { .type = NLA_U8 }, + [NFTA_CT_SREG] = { .type = NLA_U32 }, +}; + +static int nft_ct_l3proto_try_module_get(uint8_t family) +{ + int err; + + if (family == NFPROTO_INET) { + err = nf_ct_l3proto_try_module_get(NFPROTO_IPV4); + if (err < 0) + goto err1; + err = nf_ct_l3proto_try_module_get(NFPROTO_IPV6); + if (err < 0) + goto err2; + } else { + err = nf_ct_l3proto_try_module_get(family); + if (err < 0) + goto err1; + } + return 0; + +err2: + nf_ct_l3proto_module_put(NFPROTO_IPV4); +err1: + return err; +} + +static void nft_ct_l3proto_module_put(uint8_t family) +{ + if (family == NFPROTO_INET) { + nf_ct_l3proto_module_put(NFPROTO_IPV4); + nf_ct_l3proto_module_put(NFPROTO_IPV6); + } else + nf_ct_l3proto_module_put(family); +} + +static int nft_ct_get_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_ct *priv = nft_expr_priv(expr); + int err; + + priv->key = ntohl(nla_get_be32(tb[NFTA_CT_KEY])); + switch (priv->key) { + case NFT_CT_STATE: + case NFT_CT_DIRECTION: + case NFT_CT_STATUS: +#ifdef CONFIG_NF_CONNTRACK_MARK + case NFT_CT_MARK: +#endif +#ifdef CONFIG_NF_CONNTRACK_SECMARK + case NFT_CT_SECMARK: +#endif +#ifdef CONFIG_NF_CONNTRACK_LABELS + case NFT_CT_LABELS: +#endif + case NFT_CT_EXPIRATION: + case NFT_CT_HELPER: + if (tb[NFTA_CT_DIRECTION] != NULL) + return -EINVAL; + break; + case NFT_CT_L3PROTOCOL: + case NFT_CT_PROTOCOL: + case NFT_CT_SRC: + case NFT_CT_DST: + case NFT_CT_PROTO_SRC: + case NFT_CT_PROTO_DST: + if (tb[NFTA_CT_DIRECTION] == NULL) + return -EINVAL; + break; + default: + return -EOPNOTSUPP; + } + + if (tb[NFTA_CT_DIRECTION] != NULL) { + priv->dir = nla_get_u8(tb[NFTA_CT_DIRECTION]); + switch (priv->dir) { + case IP_CT_DIR_ORIGINAL: + case IP_CT_DIR_REPLY: + break; + default: + return -EINVAL; + } + } + + priv->dreg = ntohl(nla_get_be32(tb[NFTA_CT_DREG])); + err = nft_validate_output_register(priv->dreg); + if (err < 0) + return err; + + err = nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE); + if (err < 0) + return err; + + err = nft_ct_l3proto_try_module_get(ctx->afi->family); + if (err < 0) + return err; + + return 0; +} + +static int nft_ct_set_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_ct *priv = nft_expr_priv(expr); + int err; + + priv->key = ntohl(nla_get_be32(tb[NFTA_CT_KEY])); + switch (priv->key) { +#ifdef CONFIG_NF_CONNTRACK_MARK + case NFT_CT_MARK: + break; +#endif + default: + return -EOPNOTSUPP; + } + + priv->sreg = ntohl(nla_get_be32(tb[NFTA_CT_SREG])); + err = nft_validate_input_register(priv->sreg); + if (err < 0) + return err; + + err = nft_ct_l3proto_try_module_get(ctx->afi->family); + if (err < 0) + return err; + + return 0; +} + +static void nft_ct_destroy(const struct nft_ctx *ctx, + const struct nft_expr *expr) +{ + nft_ct_l3proto_module_put(ctx->afi->family); +} + +static int nft_ct_get_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_ct *priv = nft_expr_priv(expr); + + if (nla_put_be32(skb, NFTA_CT_DREG, htonl(priv->dreg))) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_CT_KEY, htonl(priv->key))) + goto nla_put_failure; + + switch (priv->key) { + case NFT_CT_PROTOCOL: + case NFT_CT_SRC: + case NFT_CT_DST: + case NFT_CT_PROTO_SRC: + case NFT_CT_PROTO_DST: + if (nla_put_u8(skb, NFTA_CT_DIRECTION, priv->dir)) + goto nla_put_failure; + default: + break; + } + + return 0; + +nla_put_failure: + return -1; +} + +static int nft_ct_set_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_ct *priv = nft_expr_priv(expr); + + if (nla_put_be32(skb, NFTA_CT_SREG, htonl(priv->sreg))) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_CT_KEY, htonl(priv->key))) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -1; +} + +static struct nft_expr_type nft_ct_type; +static const struct nft_expr_ops nft_ct_get_ops = { + .type = &nft_ct_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_ct)), + .eval = nft_ct_get_eval, + .init = nft_ct_get_init, + .destroy = nft_ct_destroy, + .dump = nft_ct_get_dump, +}; + +static const struct nft_expr_ops nft_ct_set_ops = { + .type = &nft_ct_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_ct)), + .eval = nft_ct_set_eval, + .init = nft_ct_set_init, + .destroy = nft_ct_destroy, + .dump = nft_ct_set_dump, +}; + +static const struct nft_expr_ops * +nft_ct_select_ops(const struct nft_ctx *ctx, + const struct nlattr * const tb[]) +{ + if (tb[NFTA_CT_KEY] == NULL) + return ERR_PTR(-EINVAL); + + if (tb[NFTA_CT_DREG] && tb[NFTA_CT_SREG]) + return ERR_PTR(-EINVAL); + + if (tb[NFTA_CT_DREG]) + return &nft_ct_get_ops; + + if (tb[NFTA_CT_SREG]) + return &nft_ct_set_ops; + + return ERR_PTR(-EINVAL); +} + +static struct nft_expr_type nft_ct_type __read_mostly = { + .name = "ct", + .select_ops = &nft_ct_select_ops, + .policy = nft_ct_policy, + .maxattr = NFTA_CT_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_ct_module_init(void) +{ + return nft_register_expr(&nft_ct_type); +} + +static void __exit nft_ct_module_exit(void) +{ + nft_unregister_expr(&nft_ct_type); +} + +module_init(nft_ct_module_init); +module_exit(nft_ct_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); +MODULE_ALIAS_NFT_EXPR("ct"); |