diff options
Diffstat (limited to 'net/netfilter/nf_tables_api.c')
| -rw-r--r-- | net/netfilter/nf_tables_api.c | 1760 |
1 files changed, 1760 insertions, 0 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c new file mode 100644 index 000000000000..7d59c89c6c75 --- /dev/null +++ b/net/netfilter/nf_tables_api.c @@ -0,0 +1,1760 @@ +/* + * Copyright (c) 2007, 2008 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/module.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/skbuff.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nfnetlink.h> +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables_core.h> +#include <net/netfilter/nf_tables.h> +#include <net/sock.h> + +static LIST_HEAD(nf_tables_afinfo); +static LIST_HEAD(nf_tables_expressions); + +/** + * nft_register_afinfo - register nf_tables address family info + * + * @afi: address family info to register + * + * Register the address family for use with nf_tables. Returns zero on + * success or a negative errno code otherwise. + */ +int nft_register_afinfo(struct nft_af_info *afi) +{ + INIT_LIST_HEAD(&afi->tables); + nfnl_lock(NFNL_SUBSYS_NFTABLES); + list_add_tail(&afi->list, &nf_tables_afinfo); + nfnl_unlock(NFNL_SUBSYS_NFTABLES); + return 0; +} +EXPORT_SYMBOL_GPL(nft_register_afinfo); + +/** + * nft_unregister_afinfo - unregister nf_tables address family info + * + * @afi: address family info to unregister + * + * Unregister the address family for use with nf_tables. + */ +void nft_unregister_afinfo(struct nft_af_info *afi) +{ + nfnl_lock(NFNL_SUBSYS_NFTABLES); + list_del(&afi->list); + nfnl_unlock(NFNL_SUBSYS_NFTABLES); +} +EXPORT_SYMBOL_GPL(nft_unregister_afinfo); + +static struct nft_af_info *nft_afinfo_lookup(int family) +{ + struct nft_af_info *afi; + + list_for_each_entry(afi, &nf_tables_afinfo, list) { + if (afi->family == family) + return afi; + } + return NULL; +} + +static struct nft_af_info *nf_tables_afinfo_lookup(int family, bool autoload) +{ + struct nft_af_info *afi; + + afi = nft_afinfo_lookup(family); + if (afi != NULL) + return afi; +#ifdef CONFIG_MODULES + if (autoload) { + nfnl_unlock(NFNL_SUBSYS_NFTABLES); + request_module("nft-afinfo-%u", family); + nfnl_lock(NFNL_SUBSYS_NFTABLES); + afi = nft_afinfo_lookup(family); + if (afi != NULL) + return ERR_PTR(-EAGAIN); + } +#endif + return ERR_PTR(-EAFNOSUPPORT); +} + +/* + * Tables + */ + +static struct nft_table *nft_table_lookup(const struct nft_af_info *afi, + const struct nlattr *nla) +{ + struct nft_table *table; + + list_for_each_entry(table, &afi->tables, list) { + if (!nla_strcmp(nla, table->name)) + return table; + } + return NULL; +} + +static struct nft_table *nf_tables_table_lookup(const struct nft_af_info *afi, + const struct nlattr *nla, + bool autoload) +{ + struct nft_table *table; + + if (nla == NULL) + return ERR_PTR(-EINVAL); + + table = nft_table_lookup(afi, nla); + if (table != NULL) + return table; + +#ifdef CONFIG_MODULES + if (autoload) { + nfnl_unlock(NFNL_SUBSYS_NFTABLES); + request_module("nft-table-%u-%*.s", afi->family, + nla_len(nla)-1, (const char *)nla_data(nla)); + nfnl_lock(NFNL_SUBSYS_NFTABLES); + if (nft_table_lookup(afi, nla)) + return ERR_PTR(-EAGAIN); + } +#endif + return ERR_PTR(-ENOENT); +} + +static inline u64 nf_tables_alloc_handle(struct nft_table *table) +{ + return ++table->hgenerator; +} + +static const struct nla_policy nft_table_policy[NFTA_TABLE_MAX + 1] = { + [NFTA_TABLE_NAME] = { .type = NLA_STRING }, +}; + +static int nf_tables_fill_table_info(struct sk_buff *skb, u32 portid, u32 seq, + int event, u32 flags, int family, + const struct nft_table *table) +{ + struct nlmsghdr *nlh; + struct nfgenmsg *nfmsg; + + event |= NFNL_SUBSYS_NFTABLES << 8; + nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct nfgenmsg), flags); + if (nlh == NULL) + goto nla_put_failure; + + nfmsg = nlmsg_data(nlh); + nfmsg->nfgen_family = family; + nfmsg->version = NFNETLINK_V0; + nfmsg->res_id = 0; + + if (nla_put_string(skb, NFTA_TABLE_NAME, table->name)) + goto nla_put_failure; + + return nlmsg_end(skb, nlh); + +nla_put_failure: + nlmsg_trim(skb, nlh); + return -1; +} + +static int nf_tables_table_notify(const struct sk_buff *oskb, + const struct nlmsghdr *nlh, + const struct nft_table *table, + int event, int family) +{ + struct sk_buff *skb; + u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; + u32 seq = nlh ? nlh->nlmsg_seq : 0; + struct net *net = oskb ? sock_net(oskb->sk) : &init_net; + bool report; + int err; + + report = nlh ? nlmsg_report(nlh) : false; + if (!report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES)) + return 0; + + err = -ENOBUFS; + skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); + if (skb == NULL) + goto err; + + err = nf_tables_fill_table_info(skb, portid, seq, event, 0, + family, table); + if (err < 0) { + kfree_skb(skb); + goto err; + } + + err = nfnetlink_send(skb, net, portid, NFNLGRP_NFTABLES, report, + GFP_KERNEL); +err: + if (err < 0) + nfnetlink_set_err(net, portid, NFNLGRP_NFTABLES, err); + return err; +} + +static int nf_tables_dump_tables(struct sk_buff *skb, + struct netlink_callback *cb) +{ + const struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh); + const struct nft_af_info *afi; + const struct nft_table *table; + unsigned int idx = 0, s_idx = cb->args[0]; + int family = nfmsg->nfgen_family; + + list_for_each_entry(afi, &nf_tables_afinfo, list) { + if (family != NFPROTO_UNSPEC && family != afi->family) + continue; + + list_for_each_entry(table, &afi->tables, list) { + if (idx < s_idx) + goto cont; + if (idx > s_idx) + memset(&cb->args[1], 0, + sizeof(cb->args) - sizeof(cb->args[0])); + if (nf_tables_fill_table_info(skb, + NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, + NFT_MSG_NEWTABLE, + NLM_F_MULTI, + afi->family, table) < 0) + goto done; +cont: + idx++; + } + } +done: + cb->args[0] = idx; + return skb->len; +} + +static int nf_tables_gettable(struct sock *nlsk, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const nla[]) +{ + const struct nfgenmsg *nfmsg = nlmsg_data(nlh); + const struct nft_af_info *afi; + const struct nft_table *table; + struct sk_buff *skb2; + int family = nfmsg->nfgen_family; + int err; + + if (nlh->nlmsg_flags & NLM_F_DUMP) { + struct netlink_dump_control c = { + .dump = nf_tables_dump_tables, + }; + return netlink_dump_start(nlsk, skb, nlh, &c); + } + + afi = nf_tables_afinfo_lookup(family, false); + if (IS_ERR(afi)) + return PTR_ERR(afi); + + table = nf_tables_table_lookup(afi, nla[NFTA_TABLE_NAME], false); + if (IS_ERR(table)) + return PTR_ERR(table); + + skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); + if (!skb2) + return -ENOMEM; + + err = nf_tables_fill_table_info(skb2, NETLINK_CB(skb).portid, + nlh->nlmsg_seq, NFT_MSG_NEWTABLE, 0, + family, table); + if (err < 0) + goto err; + + return nlmsg_unicast(nlsk, skb2, NETLINK_CB(skb).portid); + +err: + kfree_skb(skb2); + return err; +} + +static int nf_tables_newtable(struct sock *nlsk, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const nla[]) +{ + const struct nfgenmsg *nfmsg = nlmsg_data(nlh); + const struct nlattr *name; + struct nft_af_info *afi; + struct nft_table *table; + int family = nfmsg->nfgen_family; + + afi = nf_tables_afinfo_lookup(family, true); + if (IS_ERR(afi)) + return PTR_ERR(afi); + + name = nla[NFTA_TABLE_NAME]; + table = nf_tables_table_lookup(afi, name, false); + if (IS_ERR(table)) { + if (PTR_ERR(table) != -ENOENT) + return PTR_ERR(table); + table = NULL; + } + + if (table != NULL) { + if (nlh->nlmsg_flags & NLM_F_EXCL) + return -EEXIST; + if (nlh->nlmsg_flags & NLM_F_REPLACE) + return -EOPNOTSUPP; + return 0; + } + + table = kzalloc(sizeof(*table) + nla_len(name), GFP_KERNEL); + if (table == NULL) + return -ENOMEM; + + nla_strlcpy(table->name, name, nla_len(name)); + INIT_LIST_HEAD(&table->chains); + + list_add_tail(&table->list, &afi->tables); + nf_tables_table_notify(skb, nlh, table, NFT_MSG_NEWTABLE, family); + return 0; +} + +static int nf_tables_deltable(struct sock *nlsk, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const nla[]) +{ + const struct nfgenmsg *nfmsg = nlmsg_data(nlh); + struct nft_af_info *afi; + struct nft_table *table; + int family = nfmsg->nfgen_family; + + afi = nf_tables_afinfo_lookup(family, false); + if (IS_ERR(afi)) + return PTR_ERR(afi); + + table = nf_tables_table_lookup(afi, nla[NFTA_TABLE_NAME], false); + if (IS_ERR(table)) + return PTR_ERR(table); + + if (table->flags & NFT_TABLE_BUILTIN) + return -EOPNOTSUPP; + + if (table->use) + return -EBUSY; + + list_del(&table->list); + nf_tables_table_notify(skb, nlh, table, NFT_MSG_DELTABLE, family); + kfree(table); + return 0; +} + +static struct nft_table *__nf_tables_table_lookup(const struct nft_af_info *afi, + const char *name) +{ + struct nft_table *table; + + list_for_each_entry(table, &afi->tables, list) { + if (!strcmp(name, table->name)) + return table; + } + + return ERR_PTR(-ENOENT); +} + +static int nf_tables_chain_notify(const struct sk_buff *oskb, + const struct nlmsghdr *nlh, + const struct nft_table *table, + const struct nft_chain *chain, + int event, int family); + +/** + * nft_register_table - register a built-in table + * + * @table: the table to register + * @family: protocol family to register table with + * + * Register a built-in table for use with nf_tables. Returns zero on + * success or a negative errno code otherwise. + */ +int nft_register_table(struct nft_table *table, int family) +{ + struct nft_af_info *afi; + struct nft_table *t; + struct nft_chain *chain; + int err; + + nfnl_lock(NFNL_SUBSYS_NFTABLES); +again: + afi = nf_tables_afinfo_lookup(family, true); + if (IS_ERR(afi)) { + err = PTR_ERR(afi); + if (err == -EAGAIN) + goto again; + goto err; + } + + t = __nf_tables_table_lookup(afi, table->name); + if (IS_ERR(t)) { + err = PTR_ERR(t); + if (err != -ENOENT) + goto err; + t = NULL; + } + + if (t != NULL) { + err = -EEXIST; + goto err; + } + + table->flags |= NFT_TABLE_BUILTIN; + list_add_tail(&table->list, &afi->tables); + nf_tables_table_notify(NULL, NULL, table, NFT_MSG_NEWTABLE, family); + list_for_each_entry(chain, &table->chains, list) + nf_tables_chain_notify(NULL, NULL, table, chain, + NFT_MSG_NEWCHAIN, family); + err = 0; +err: + nfnl_unlock(NFNL_SUBSYS_NFTABLES); + return err; +} +EXPORT_SYMBOL_GPL(nft_register_table); + +/** + * nft_unregister_table - unregister a built-in table + * + * @table: the table to unregister + * @family: protocol family to unregister table with + * + * Unregister a built-in table for use with nf_tables. + */ +void nft_unregister_table(struct nft_table *table, int family) +{ + struct nft_chain *chain; + + nfnl_lock(NFNL_SUBSYS_NFTABLES); + list_del(&table->list); + list_for_each_entry(chain, &table->chains, list) + nf_tables_chain_notify(NULL, NULL, table, chain, + NFT_MSG_DELCHAIN, family); + nf_tables_table_notify(NULL, NULL, table, NFT_MSG_DELTABLE, family); + nfnl_unlock(NFNL_SUBSYS_NFTABLES); +} +EXPORT_SYMBOL_GPL(nft_unregister_table); + +/* + * Chains + */ + +static struct nft_chain * +nf_tables_chain_lookup_byhandle(const struct nft_table *table, u64 handle) +{ + struct nft_chain *chain; + + list_for_each_entry(chain, &table->chains, list) { + if (chain->handle == handle) + return chain; + } + + return ERR_PTR(-ENOENT); +} + +static struct nft_chain *nf_tables_chain_lookup(const struct nft_table *table, + const struct nlattr *nla) +{ + struct nft_chain *chain; + + if (nla == NULL) + return ERR_PTR(-EINVAL); + + list_for_each_entry(chain, &table->chains, list) { + if (!nla_strcmp(nla, chain->name)) + return chain; + } + + return ERR_PTR(-ENOENT); +} + +static const struct nla_policy nft_chain_policy[NFTA_CHAIN_MAX + 1] = { + [NFTA_CHAIN_TABLE] = { .type = NLA_STRING }, + [NFTA_CHAIN_HANDLE] = { .type = NLA_U64 }, + [NFTA_CHAIN_NAME] = { .type = NLA_STRING, + .len = NFT_CHAIN_MAXNAMELEN - 1 }, + [NFTA_CHAIN_HOOK] = { .type = NLA_NESTED }, +}; + +static const struct nla_policy nft_hook_policy[NFTA_HOOK_MAX + 1] = { + [NFTA_HOOK_HOOKNUM] = { .type = NLA_U32 }, + [NFTA_HOOK_PRIORITY] = { .type = NLA_U32 }, +}; + +static int nf_tables_fill_chain_info(struct sk_buff *skb, u32 portid, u32 seq, + int event, u32 flags, int family, + const struct nft_table *table, + const struct nft_chain *chain) +{ + struct nlmsghdr *nlh; + struct nfgenmsg *nfmsg; + + event |= NFNL_SUBSYS_NFTABLES << 8; + nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct nfgenmsg), flags); + if (nlh == NULL) + goto nla_put_failure; + + nfmsg = nlmsg_data(nlh); + nfmsg->nfgen_family = family; + nfmsg->version = NFNETLINK_V0; + nfmsg->res_id = 0; + + if (nla_put_string(skb, NFTA_CHAIN_TABLE, table->name)) + goto nla_put_failure; + if (nla_put_be64(skb, NFTA_CHAIN_HANDLE, cpu_to_be64(chain->handle))) + goto nla_put_failure; + if (nla_put_string(skb, NFTA_CHAIN_NAME, chain->name)) + goto nla_put_failure; + + if (chain->flags & NFT_BASE_CHAIN) { + const struct nf_hook_ops *ops = &nft_base_chain(chain)->ops; + struct nlattr *nest = nla_nest_start(skb, NFTA_CHAIN_HOOK); + if (nest == NULL) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_HOOK_HOOKNUM, htonl(ops->hooknum))) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_HOOK_PRIORITY, htonl(ops->priority))) + goto nla_put_failure; + nla_nest_end(skb, nest); + } + + return nlmsg_end(skb, nlh); + +nla_put_failure: + nlmsg_trim(skb, nlh); + return -1; +} + +static int nf_tables_chain_notify(const struct sk_buff *oskb, + const struct nlmsghdr *nlh, + const struct nft_table *table, + const struct nft_chain *chain, + int event, int family) +{ + struct sk_buff *skb; + u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; + struct net *net = oskb ? sock_net(oskb->sk) : &init_net; + u32 seq = nlh ? nlh->nlmsg_seq : 0; + bool report; + int err; + + report = nlh ? nlmsg_report(nlh) : false; + if (!report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES)) + return 0; + + err = -ENOBUFS; + skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); + if (skb == NULL) + goto err; + + err = nf_tables_fill_chain_info(skb, portid, seq, event, 0, family, + table, chain); + if (err < 0) { + kfree_skb(skb); + goto err; + } + + err = nfnetlink_send(skb, net, portid, NFNLGRP_NFTABLES, report, + GFP_KERNEL); +err: + if (err < 0) + nfnetlink_set_err(net, portid, NFNLGRP_NFTABLES, err); + return err; +} + +static int nf_tables_dump_chains(struct sk_buff *skb, + struct netlink_callback *cb) +{ + const struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh); + const struct nft_af_info *afi; + const struct nft_table *table; + const struct nft_chain *chain; + unsigned int idx = 0, s_idx = cb->args[0]; + int family = nfmsg->nfgen_family; + + list_for_each_entry(afi, &nf_tables_afinfo, list) { + if (family != NFPROTO_UNSPEC && family != afi->family) + continue; + + list_for_each_entry(table, &afi->tables, list) { + list_for_each_entry(chain, &table->chains, list) { + if (idx < s_idx) + goto cont; + if (idx > s_idx) + memset(&cb->args[1], 0, + sizeof(cb->args) - sizeof(cb->args[0])); + if (nf_tables_fill_chain_info(skb, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, + NFT_MSG_NEWCHAIN, + NLM_F_MULTI, + afi->family, table, chain) < 0) + goto done; +cont: + idx++; + } + } + } +done: + cb->args[0] = idx; + return skb->len; +} + + +static int nf_tables_getchain(struct sock *nlsk, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const nla[]) +{ + const struct nfgenmsg *nfmsg = nlmsg_data(nlh); + const struct nft_af_info *afi; + const struct nft_table *table; + const struct nft_chain *chain; + struct sk_buff *skb2; + int family = nfmsg->nfgen_family; + int err; + + if (nlh->nlmsg_flags & NLM_F_DUMP) { + struct netlink_dump_control c = { + .dump = nf_tables_dump_chains, + }; + return netlink_dump_start(nlsk, skb, nlh, &c); + } + + afi = nf_tables_afinfo_lookup(family, false); + if (IS_ERR(afi)) + return PTR_ERR(afi); + + table = nf_tables_table_lookup(afi, nla[NFTA_CHAIN_TABLE], false); + if (IS_ERR(table)) + return PTR_ERR(table); + + chain = nf_tables_chain_lookup(table, nla[NFTA_CHAIN_NAME]); + if (IS_ERR(chain)) + return PTR_ERR(chain); + + skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); + if (!skb2) + return -ENOMEM; + + err = nf_tables_fill_chain_info(skb2, NETLINK_CB(skb).portid, + nlh->nlmsg_seq, NFT_MSG_NEWCHAIN, 0, + family, table, chain); + if (err < 0) + goto err; + + return nlmsg_unicast(nlsk, skb2, NETLINK_CB(skb).portid); + +err: + kfree_skb(skb2); + return err; +} + +static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const nla[]) +{ + const struct nfgenmsg *nfmsg = nlmsg_data(nlh); + const struct nlattr * uninitialized_var(name); + const struct nft_af_info *afi; + struct nft_table *table; + struct nft_chain *chain; + struct nft_base_chain *basechain; + struct nlattr *ha[NFTA_HOOK_MAX + 1]; + int family = nfmsg->nfgen_family; + u64 handle = 0; + int err; + bool create; + + create = nlh->nlmsg_flags & NLM_F_CREATE ? true : false; + + afi = nf_tables_afinfo_lookup(family, true); + if (IS_ERR(afi)) + return PTR_ERR(afi); + + table = nf_tables_table_lookup(afi, nla[NFTA_CHAIN_TABLE], create); + if (IS_ERR(table)) + return PTR_ERR(table); + + if (table->use == UINT_MAX) + return -EOVERFLOW; + + chain = NULL; + name = nla[NFTA_CHAIN_NAME]; + + if (nla[NFTA_CHAIN_HANDLE]) { + handle = be64_to_cpu(nla_get_be64(nla[NFTA_CHAIN_HANDLE])); + chain = nf_tables_chain_lookup_byhandle(table, handle); + if (IS_ERR(chain)) + return PTR_ERR(chain); + } else { + chain = nf_tables_chain_lookup(table, name); + if (IS_ERR(chain)) { + if (PTR_ERR(chain) != -ENOENT) + return PTR_ERR(chain); + chain = NULL; + } + } + + if (chain != NULL) { + if (nlh->nlmsg_flags & NLM_F_EXCL) + return -EEXIST; + if (nlh->nlmsg_flags & NLM_F_REPLACE) + return -EOPNOTSUPP; + + if (nla[NFTA_CHAIN_HANDLE] && name && + !IS_ERR(nf_tables_chain_lookup(table, nla[NFTA_CHAIN_NAME]))) + return -EEXIST; + + if (nla[NFTA_CHAIN_HANDLE] && name) + nla_strlcpy(chain->name, name, NFT_CHAIN_MAXNAMELEN); + + goto notify; + } + + if (nla[NFTA_CHAIN_HOOK]) { + struct nf_hook_ops *ops; + + err = nla_parse_nested(ha, NFTA_HOOK_MAX, nla[NFTA_CHAIN_HOOK], + nft_hook_policy); + if (err < 0) + return err; + if (ha[NFTA_HOOK_HOOKNUM] == NULL || + ha[NFTA_HOOK_PRIORITY] == NULL) + return -EINVAL; + if (ntohl(nla_get_be32(ha[NFTA_HOOK_HOOKNUM])) >= afi->nhooks) + return -EINVAL; + + basechain = kzalloc(sizeof(*basechain), GFP_KERNEL); + if (basechain == NULL) + return -ENOMEM; + chain = &basechain->chain; + + ops = &basechain->ops; + ops->pf = family; + ops->owner = afi->owner; + ops->hooknum = ntohl(nla_get_be32(ha[NFTA_HOOK_HOOKNUM])); + ops->priority = ntohl(nla_get_be32(ha[NFTA_HOOK_PRIORITY])); + ops->priv = chain; + ops->hook = nft_do_chain; + if (afi->hooks[ops->hooknum]) + ops->hook = afi->hooks[ops->hooknum]; + + chain->flags |= NFT_BASE_CHAIN; + } else { + chain = kzalloc(sizeof(*chain), GFP_KERNEL); + if (chain == NULL) + return -ENOMEM; + } + + INIT_LIST_HEAD(&chain->rules); + chain->handle = nf_tables_alloc_handle(table); + nla_strlcpy(chain->name, name, NFT_CHAIN_MAXNAMELEN); + + list_add_tail(&chain->list, &table->chains); + table->use++; +notify: + nf_tables_chain_notify(skb, nlh, table, chain, NFT_MSG_NEWCHAIN, + family); + return 0; +} + +static void nf_tables_rcu_chain_destroy(struct rcu_head *head) +{ + struct nft_chain *chain = container_of(head, struct nft_chain, rcu_head); + + BUG_ON(chain->use > 0); + + if (chain->flags & NFT_BASE_CHAIN) + kfree(nft_base_chain(chain)); + else + kfree(chain); +} + +static int nf_tables_delchain(struct sock *nlsk, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const nla[]) +{ + const struct nfgenmsg *nfmsg = nlmsg_data(nlh); + const struct nft_af_info *afi; + struct nft_table *table; + struct nft_chain *chain; + int family = nfmsg->nfgen_family; + + afi = nf_tables_afinfo_lookup(family, false); + if (IS_ERR(afi)) + return PTR_ERR(afi); + + table = nf_tables_table_lookup(afi, nla[NFTA_CHAIN_TABLE], false); + if (IS_ERR(table)) + return PTR_ERR(table); + + chain = nf_tables_chain_lookup(table, nla[NFTA_CHAIN_NAME]); + if (IS_ERR(chain)) + return PTR_ERR(chain); + + if (chain->flags & NFT_CHAIN_BUILTIN) + return -EOPNOTSUPP; + + if (!list_empty(&chain->rules)) + return -EBUSY; + + list_del(&chain->list); + table->use--; + + if (chain->flags & NFT_BASE_CHAIN) + nf_unregister_hook(&nft_base_chain(chain)->ops); + + nf_tables_chain_notify(skb, nlh, table, chain, NFT_MSG_DELCHAIN, + family); + + /* Make sure all rule references are gone before this is released */ + call_rcu(&chain->rcu_head, nf_tables_rcu_chain_destroy); + return 0; +} + +static void nft_ctx_init(struct nft_ctx *ctx, + const struct nft_af_info *afi, + const struct nft_table *table, + const struct nft_chain *chain) +{ + ctx->afi = afi; + ctx->table = table; + ctx->chain = chain; +} + +/* + * Expressions + */ + +/** + * nft_register_expr - register nf_tables expr operations + * @ops: expr operations + * + * Registers the expr operations for use with nf_tables. Returns zero on + * success or a negative errno code otherwise. + */ +int nft_register_expr(struct nft_expr_ops *ops) +{ + nfnl_lock(NFNL_SUBSYS_NFTABLES); + list_add_tail(&ops->list, &nf_tables_expressions); + nfnl_unlock(NFNL_SUBSYS_NFTABLES); + return 0; +} +EXPORT_SYMBOL_GPL(nft_register_expr); + +/** + * nft_unregister_expr - unregister nf_tables expr operations + * @ops: expr operations + * + * Unregisters the expr operations for use with nf_tables. + */ +void nft_unregister_expr(struct nft_expr_ops *ops) +{ + nfnl_lock(NFNL_SUBSYS_NFTABLES); + list_del(&ops->list); + nfnl_unlock(NFNL_SUBSYS_NFTABLES); +} +EXPORT_SYMBOL_GPL(nft_unregister_expr); + +static const struct nft_expr_ops *__nft_expr_ops_get(struct nlattr *nla) +{ + const struct nft_expr_ops *ops; + + list_for_each_entry(ops, &nf_tables_expressions, list) { + if (!nla_strcmp(nla, ops->name)) + return ops; + } + return NULL; +} + +static const struct nft_expr_ops *nft_expr_ops_get(struct nlattr *nla) +{ + const struct nft_expr_ops *ops; + + if (nla == NULL) + return ERR_PTR(-EINVAL); + + ops = __nft_expr_ops_get(nla); + if (ops != NULL && try_module_get(ops->owner)) + return ops; + +#ifdef CONFIG_MODULES + if (ops == NULL) { + nfnl_unlock(NFNL_SUBSYS_NFTABLES); + request_module("nft-expr-%.*s", + nla_len(nla), (char *)nla_data(nla)); + nfnl_lock(NFNL_SUBSYS_NFTABLES); + if (__nft_expr_ops_get(nla)) + return ERR_PTR(-EAGAIN); + } +#endif + return ERR_PTR(-ENOENT); +} + +static const struct nla_policy nft_expr_policy[NFTA_EXPR_MAX + 1] = { + [NFTA_EXPR_NAME] = { .type = NLA_STRING }, + [NFTA_EXPR_DATA] = { .type = NLA_NESTED }, +}; + +static int nf_tables_fill_expr_info(struct sk_buff *skb, + const struct nft_expr *expr) +{ + if (nla_put_string(skb, NFTA_EXPR_NAME, expr->ops->name)) + goto nla_put_failure; + + if (expr->ops->dump) { + struct nlattr *data = nla_nest_start(skb, NFTA_EXPR_DATA); + if (data == NULL) + goto nla_put_failure; + if (expr->ops->dump(skb, expr) < 0) + goto nla_put_failure; + nla_nest_end(skb, data); + } + + return skb->len; + +nla_put_failure: + return -1; +}; + +struct nft_expr_info { + const struct nft_expr_ops *ops; + struct nlattr *tb[NFTA_EXPR_MAX + 1]; +}; + +static int nf_tables_expr_parse(const struct nlattr *nla, + struct nft_expr_info *info) +{ + const struct nft_expr_ops *ops; + int err; + + err = nla_parse_nested(info->tb, NFTA_EXPR_MAX, nla, nft_expr_policy); + if (err < 0) + return err; + + ops = nft_expr_ops_get(info->tb[NFTA_EXPR_NAME]); + if (IS_ERR(ops)) + return PTR_ERR(ops); + info->ops = ops; + return 0; +} + +static int nf_tables_newexpr(const struct nft_ctx *ctx, + struct nft_expr_info *info, + struct nft_expr *expr) +{ + const struct nft_expr_ops *ops = info->ops; + int err; + + expr->ops = ops; + if (ops->init) { + struct nlattr *ma[ops->maxattr + 1]; + + if (info->tb[NFTA_EXPR_DATA]) { + err = nla_parse_nested(ma, ops->maxattr, + info->tb[NFTA_EXPR_DATA], + ops->policy); + if (err < 0) + goto err1; + } else + memset(ma, 0, sizeof(ma[0]) * (ops->maxattr + 1)); + + err = ops->init(ctx, expr, (const struct nlattr **)ma); + if (err < 0) + goto err1; + } + + info->ops = NULL; + return 0; + +err1: + expr->ops = NULL; + return err; +} + +static void nf_tables_expr_destroy(struct nft_expr *expr) +{ + if (expr->ops->destroy) + expr->ops->destroy(expr); + module_put(expr->ops->owner); +} + +/* + * Rules + */ + +static struct nft_rule *__nf_tables_rule_lookup(const struct nft_chain *chain, + u64 handle) +{ + struct nft_rule *rule; + + // FIXME: this sucks + list_for_each_entry(rule, &chain->rules, list) { + if (handle == rule->handle) + return rule; + } + + return ERR_PTR(-ENOENT); +} + +static struct nft_rule *nf_tables_rule_lookup(const struct nft_chain *chain, + const struct nlattr *nla) +{ + if (nla == NULL) + return ERR_PTR(-EINVAL); + + return __nf_tables_rule_lookup(chain, be64_to_cpu(nla_get_be64(nla))); +} + +static const struct nla_policy nft_rule_policy[NFTA_RULE_MAX + 1] = { + [NFTA_RULE_TABLE] = { .type = NLA_STRING }, + [NFTA_RULE_CHAIN] = { .type = NLA_STRING, + .len = NFT_CHAIN_MAXNAMELEN - 1 }, + [NFTA_RULE_HANDLE] = { .type = NLA_U64 }, + [NFTA_RULE_EXPRESSIONS] = { .type = NLA_NESTED }, +}; + +static int nf_tables_fill_rule_info(struct sk_buff *skb, u32 portid, u32 seq, + int event, u32 flags, int family, + const struct nft_table *table, + const struct nft_chain *chain, + const struct nft_rule *rule) +{ + struct nlmsghdr *nlh; + struct nfgenmsg *nfmsg; + const struct nft_expr *expr, *next; + struct nlattr *list; + + event |= NFNL_SUBSYS_NFTABLES << 8; + nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct nfgenmsg), + flags); + if (nlh == NULL) + goto nla_put_failure; + + nfmsg = nlmsg_data(nlh); + nfmsg->nfgen_family = family; + nfmsg->version = NFNETLINK_V0; + nfmsg->res_id = 0; + + if (nla_put_string(skb, NFTA_RULE_TABLE, table->name)) + goto nla_put_failure; + if (nla_put_string(skb, NFTA_RULE_CHAIN, chain->name)) + goto nla_put_failure; + if (nla_put_be64(skb, NFTA_RULE_HANDLE, cpu_to_be64(rule->handle))) + goto nla_put_failure; + + list = nla_nest_start(skb, NFTA_RULE_EXPRESSIONS); + if (list == NULL) + goto nla_put_failure; + nft_rule_for_each_expr(expr, next, rule) { + struct nlattr *elem = nla_nest_start(skb, NFTA_LIST_ELEM); + if (elem == NULL) + goto nla_put_failure; + if (nf_tables_fill_expr_info(skb, expr) < 0) + goto nla_put_failure; + nla_nest_end(skb, elem); + } + nla_nest_end(skb, list); + + return nlmsg_end(skb, nlh); + +nla_put_failure: + nlmsg_trim(skb, nlh); + return -1; +} + +static int nf_tables_rule_notify(const struct sk_buff *oskb, + const struct nlmsghdr *nlh, + const struct nft_table *table, + const struct nft_chain *chain, + const struct nft_rule *rule, + int event, u32 flags, int family) +{ + struct sk_buff *skb; + u32 portid = NETLINK_CB(oskb).portid; + struct net *net = oskb ? sock_net(oskb->sk) : &init_net; + u32 seq = nlh->nlmsg_seq; + bool report; + int err; + + report = nlmsg_report(nlh); + if (!report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES)) + return 0; + + err = -ENOBUFS; + skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); + if (skb == NULL) + goto err; + + err = nf_tables_fill_rule_info(skb, portid, seq, event, flags, + family, table, chain, rule); + if (err < 0) { + kfree_skb(skb); + goto err; + } + + err = nfnetlink_send(skb, net, portid, NFNLGRP_NFTABLES, report, + GFP_KERNEL); +err: + if (err < 0) + nfnetlink_set_err(net, portid, NFNLGRP_NFTABLES, err); + return err; +} + +static int nf_tables_dump_rules(struct sk_buff *skb, + struct netlink_callback *cb) +{ + const struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh); + const struct nft_af_info *afi; + const struct nft_table *table; + const struct nft_chain *chain; + const struct nft_rule *rule; + unsigned int idx = 0, s_idx = cb->args[0]; + int family = nfmsg->nfgen_family; + + list_for_each_entry(afi, &nf_tables_afinfo, list) { + if (family != NFPROTO_UNSPEC && family != afi->family) + continue; + + list_for_each_entry(table, &afi->tables, list) { + list_for_each_entry(chain, &table->chains, list) { + list_for_each_entry(rule, &chain->rules, list) { + if (idx < s_idx) + goto cont; + if (idx > s_idx) + memset(&cb->args[1], 0, + sizeof(cb->args) - sizeof(cb->args[0])); + if (nf_tables_fill_rule_info(skb, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, + NFT_MSG_NEWRULE, + NLM_F_MULTI | NLM_F_APPEND, + afi->family, table, chain, rule) < 0) + goto done; +cont: + idx++; + } + } + } + } +done: + cb->args[0] = idx; + return skb->len; +} + +static int nf_tables_getrule(struct sock *nlsk, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const nla[]) +{ + const struct nfgenmsg *nfmsg = nlmsg_data(nlh); + const struct nft_af_info *afi; + const struct nft_table *table; + const struct nft_chain *chain; + const struct nft_rule *rule; + struct sk_buff *skb2; + int family = nfmsg->nfgen_family; + int err; + + if (nlh->nlmsg_flags & NLM_F_DUMP) { + struct netlink_dump_control c = { + .dump = nf_tables_dump_rules, + }; + return netlink_dump_start(nlsk, skb, nlh, &c); + } + + afi = nf_tables_afinfo_lookup(family, false); + if (IS_ERR(afi)) + return PTR_ERR(afi); + + table = nf_tables_table_lookup(afi, nla[NFTA_RULE_TABLE], false); + if (IS_ERR(table)) + return PTR_ERR(table); + + chain = nf_tables_chain_lookup(table, nla[NFTA_RULE_CHAIN]); + if (IS_ERR(chain)) + return PTR_ERR(chain); + + rule = nf_tables_rule_lookup(chain, nla[NFTA_RULE_HANDLE]); + if (IS_ERR(rule)) + return PTR_ERR(rule); + + skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); + if (!skb2) + return -ENOMEM; + + err = nf_tables_fill_rule_info(skb2, NETLINK_CB(skb).portid, + nlh->nlmsg_seq, NFT_MSG_NEWRULE, 0, + family, table, chain, rule); + if (err < 0) + goto err; + + return nlmsg_unicast(nlsk, skb2, NETLINK_CB(skb).portid); + +err: + kfree_skb(skb2); + return err; +} + +static void nf_tables_rcu_rule_destroy(struct rcu_head *head) +{ + struct nft_rule *rule = container_of(head, struct nft_rule, rcu_head); + struct nft_expr *expr; + + /* + * Careful: some expressions might not be initialized in case this + * is called on error from nf_tables_newrule(). + */ + expr = nft_expr_first(rule); + while (expr->ops && expr != nft_expr_last(rule)) { + nf_tables_expr_destroy(expr); + expr = nft_expr_next(expr); + } + kfree(rule); +} + +static void nf_tables_rule_destroy(struct nft_rule *rule) +{ + call_rcu(&rule->rcu_head, nf_tables_rcu_rule_destroy); +} + +#define NFT_RULE_MAXEXPRS 128 + +static struct nft_expr_info *info; + +static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const nla[]) +{ + const struct nfgenmsg *nfmsg = nlmsg_data(nlh); + const struct nft_af_info *afi; + struct nft_table *table; + struct nft_chain *chain; + struct nft_rule *rule, *old_rule = NULL; + struct nft_expr *expr; + struct nft_ctx ctx; + struct nlattr *tmp; + unsigned int size, i, n; + int err, rem; + bool create; + u64 handle; + + create = nlh->nlmsg_flags & NLM_F_CREATE ? true : false; + + afi = nf_tables_afinfo_lookup(nfmsg->nfgen_family, create); + if (IS_ERR(afi)) + return PTR_ERR(afi); + + table = nf_tables_table_lookup(afi, nla[NFTA_RULE_TABLE], create); + if (IS_ERR(table)) + return PTR_ERR(table); + + chain = nf_tables_chain_lookup(table, nla[NFTA_RULE_CHAIN]); + if (IS_ERR(chain)) + return PTR_ERR(chain); + + if (nla[NFTA_RULE_HANDLE]) { + handle = be64_to_cpu(nla_get_be64(nla[NFTA_RULE_HANDLE])); + rule = __nf_tables_rule_lookup(chain, handle); + if (IS_ERR(rule)) + return PTR_ERR(rule); + + if (nlh->nlmsg_flags & NLM_F_EXCL) + return -EEXIST; + if (nlh->nlmsg_flags & NLM_F_REPLACE) + old_rule = rule; + else + return -EOPNOTSUPP; + } else { + if (!create || nlh->nlmsg_flags & NLM_F_REPLACE) + return -EINVAL; + handle = nf_tables_alloc_handle(table); + } + + n = 0; + size = 0; + if (nla[NFTA_RULE_EXPRESSIONS]) { + nla_for_each_nested(tmp, nla[NFTA_RULE_EXPRESSIONS], rem) { + err = -EINVAL; + if (nla_type(tmp) != NFTA_LIST_ELEM) + goto err1; + if (n == NFT_RULE_MAXEXPRS) + goto err1; + err = nf_tables_expr_parse(tmp, &info[n]); + if (err < 0) + goto err1; + size += info[n].ops->size; + n++; + } + } + + err = -ENOMEM; + rule = kzalloc(sizeof(*rule) + size, GFP_KERNEL); + if (rule == NULL) + goto err1; + + rule->handle = handle; + rule->dlen = size; + + nft_ctx_init(&ctx, afi, table, chain); + expr = nft_expr_first(rule); + for (i = 0; i < n; i++) { + err = nf_tables_newexpr(&ctx, &info[i], expr); + if (err < 0) + goto err2; + expr = nft_expr_next(expr); + } + + /* Register hook when first rule is inserted into a base chain */ + if (list_empty(&chain->rules) && chain->flags & NFT_BASE_CHAIN) { + err = nf_register_hook(&nft_base_chain(chain)->ops); + if (err < 0) + goto err2; + } + + if (nlh->nlmsg_flags & NLM_F_REPLACE) { + list_replace_rcu(&old_rule->list, &rule->list); + nf_tables_rule_destroy(old_rule); + } else if (nlh->nlmsg_flags & NLM_F_APPEND) + list_add_tail_rcu(&rule->list, &chain->rules); + else + list_add_rcu(&rule->list, &chain->rules); + + nf_tables_rule_notify(skb, nlh, table, chain, rule, NFT_MSG_NEWRULE, + nlh->nlmsg_flags & (NLM_F_APPEND | NLM_F_REPLACE), + nfmsg->nfgen_family); + return 0; + +err2: + nf_tables_rule_destroy(rule); +err1: + for (i = 0; i < n; i++) { + if (info[i].ops != NULL) + module_put(info[i].ops->owner); + } + return err; +} + +static int nf_tables_delrule(struct sock *nlsk, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const nla[]) +{ + const struct nfgenmsg *nfmsg = nlmsg_data(nlh); + const struct nft_af_info *afi; + const struct nft_table *table; + struct nft_chain *chain; + struct nft_rule *rule, *tmp; + int family = nfmsg->nfgen_family; + + afi = nf_tables_afinfo_lookup(family, false); + if (IS_ERR(afi)) + return PTR_ERR(afi); + + table = nf_tables_table_lookup(afi, nla[NFTA_RULE_TABLE], false); + if (IS_ERR(table)) + return PTR_ERR(table); + + chain = nf_tables_chain_lookup(table, nla[NFTA_RULE_CHAIN]); + if (IS_ERR(chain)) + return PTR_ERR(chain); + + if (nla[NFTA_RULE_HANDLE]) { + rule = nf_tables_rule_lookup(chain, nla[NFTA_RULE_HANDLE]); + if (IS_ERR(rule)) + return PTR_ERR(rule); + + /* List removal must be visible before destroying expressions */ + list_del_rcu(&rule->list); + + nf_tables_rule_notify(skb, nlh, table, chain, rule, + NFT_MSG_DELRULE, 0, family); + nf_tables_rule_destroy(rule); + } else { + /* Remove all rules in this chain */ + list_for_each_entry_safe(rule, tmp, &chain->rules, list) { + list_del_rcu(&rule->list); + + nf_tables_rule_notify(skb, nlh, table, chain, rule, + NFT_MSG_DELRULE, 0, family); + nf_tables_rule_destroy(rule); + } + } + + /* Unregister hook when last rule from base chain is deleted */ + if (list_empty(&chain->rules) && chain->flags & NFT_BASE_CHAIN) + nf_unregister_hook(&nft_base_chain(chain)->ops); + + return 0; +} + +static const struct nfnl_callback nf_tables_cb[NFT_MSG_MAX] = { + [NFT_MSG_NEWTABLE] = { + .call = nf_tables_newtable, + .attr_count = NFTA_TABLE_MAX, + .policy = nft_table_policy, + }, + [NFT_MSG_GETTABLE] = { + .call = nf_tables_gettable, + .attr_count = NFTA_TABLE_MAX, + .policy = nft_table_policy, + }, + [NFT_MSG_DELTABLE] = { + .call = nf_tables_deltable, + .attr_count = NFTA_TABLE_MAX, + .policy = nft_table_policy, + }, + [NFT_MSG_NEWCHAIN] = { + .call = nf_tables_newchain, + .attr_count = NFTA_CHAIN_MAX, + .policy = nft_chain_policy, + }, + [NFT_MSG_GETCHAIN] = { + .call = nf_tables_getchain, + .attr_count = NFTA_CHAIN_MAX, + .policy = nft_chain_policy, + }, + [NFT_MSG_DELCHAIN] = { + .call = nf_tables_delchain, + .attr_count = NFTA_CHAIN_MAX, + .policy = nft_chain_policy, + }, + [NFT_MSG_NEWRULE] = { + .call = nf_tables_newrule, + .attr_count = NFTA_RULE_MAX, + .policy = nft_rule_policy, + }, + [NFT_MSG_GETRULE] = { + .call = nf_tables_getrule, + .attr_count = NFTA_RULE_MAX, + .policy = nft_rule_policy, + }, + [NFT_MSG_DELRULE] = { + .call = nf_tables_delrule, + .attr_count = NFTA_RULE_MAX, + .policy = nft_rule_policy, + }, +}; + +static const struct nfnetlink_subsystem nf_tables_subsys = { + .name = "nf_tables", + .subsys_id = NFNL_SUBSYS_NFTABLES, + .cb_count = NFT_MSG_MAX, + .cb = nf_tables_cb, +}; + +/** + * nft_validate_input_register - validate an expressions' input register + * + * @reg: the register number + * + * Validate that the input register is one of the general purpose + * registers. + */ +int nft_validate_input_register(enum nft_registers reg) +{ + if (reg <= NFT_REG_VERDICT) + return -EINVAL; + if (reg > NFT_REG_MAX) + return -ERANGE; + return 0; +} +EXPORT_SYMBOL_GPL(nft_validate_input_register); + +/** + * nft_validate_output_register - validate an expressions' output register + * + * @reg: the register number + * + * Validate that the output register is one of the general purpose + * registers or the verdict register. + */ +int nft_validate_output_register(enum nft_registers reg) +{ + if (reg < NFT_REG_VERDICT) + return -EINVAL; + if (reg > NFT_REG_MAX) + return -ERANGE; + return 0; +} +EXPORT_SYMBOL_GPL(nft_validate_output_register); + +/** + * nft_validate_data_load - validate an expressions' data load + * + * @ctx: context of the expression performing the load + * @reg: the destination register number + * @data: the data to load + * @type: the data type + * + * Validate that a data load uses the appropriate data type for + * the destination register. A value of NULL for the data means + * that its runtime gathered data, which is always of type + * NFT_DATA_VALUE. + */ +int nft_validate_data_load(const struct nft_ctx *ctx, enum nft_registers reg, + const struct nft_data *data, + enum nft_data_types type) +{ + switch (reg) { + case NFT_REG_VERDICT: + if (data == NULL || type != NFT_DATA_VERDICT) + return -EINVAL; + // FIXME: do loop detection + return 0; + default: + if (data != NULL && type != NFT_DATA_VALUE) + return -EINVAL; + return 0; + } +} +EXPORT_SYMBOL_GPL(nft_validate_data_load); + +static const struct nla_policy nft_verdict_policy[NFTA_VERDICT_MAX + 1] = { + [NFTA_VERDICT_CODE] = { .type = NLA_U32 }, + [NFTA_VERDICT_CHAIN] = { .type = NLA_STRING, + .len = NFT_CHAIN_MAXNAMELEN - 1 }, +}; + +static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data, + struct nft_data_desc *desc, const struct nlattr *nla) +{ + struct nlattr *tb[NFTA_VERDICT_MAX + 1]; + struct nft_chain *chain; + int err; + + err = nla_parse_nested(tb, NFTA_VERDICT_MAX, nla, nft_verdict_policy); + if (err < 0) + return err; + + if (!tb[NFTA_VERDICT_CODE]) + return -EINVAL; + data->verdict = ntohl(nla_get_be32(tb[NFTA_VERDICT_CODE])); + + switch (data->verdict) { + case NF_ACCEPT: + case NF_DROP: + case NF_QUEUE: + case NFT_CONTINUE: + case NFT_BREAK: + case NFT_RETURN: + desc->len = sizeof(data->verdict); + break; + case NFT_JUMP: + case NFT_GOTO: + if (!tb[NFTA_VERDICT_CHAIN]) + return -EINVAL; + chain = nf_tables_chain_lookup(ctx->table, + tb[NFTA_VERDICT_CHAIN]); + if (IS_ERR(chain)) + return PTR_ERR(chain); + if (chain->flags & NFT_BASE_CHAIN) + return -EOPNOTSUPP; + + if (ctx->chain->level + 1 > chain->level) { + if (ctx->chain->level + 1 == 16) + return -EMLINK; + chain->level = ctx->chain->level + 1; + } + chain->use++; + data->chain = chain; + desc->len = sizeof(data); + break; + default: + return -EINVAL; + } + + desc->type = NFT_DATA_VERDICT; + return 0; +} + +static void nft_verdict_uninit(const struct nft_data *data) +{ + switch (data->verdict) { + case NFT_JUMP: + case NFT_GOTO: + data->chain->use--; + break; + } +} + +static int nft_verdict_dump(struct sk_buff *skb, const struct nft_data *data) +{ + struct nlattr *nest; + + nest = nla_nest_start(skb, NFTA_DATA_VERDICT); + if (!nest) + goto nla_put_failure; + + if (nla_put_be32(skb, NFTA_VERDICT_CODE, htonl(data->verdict))) + goto nla_put_failure; + + switch (data->verdict) { + case NFT_JUMP: + case NFT_GOTO: + if (nla_put_string(skb, NFTA_VERDICT_CHAIN, data->chain->name)) + goto nla_put_failure; + } + nla_nest_end(skb, nest); + return 0; + +nla_put_failure: + return -1; +} + +static int nft_value_init(const struct nft_ctx *ctx, struct nft_data *data, + struct nft_data_desc *desc, const struct nlattr *nla) +{ + unsigned int len; + + len = nla_len(nla); + if (len == 0) + return -EINVAL; + if (len > sizeof(data->data)) + return -EOVERFLOW; + + nla_memcpy(data->data, nla, sizeof(data->data)); + desc->type = NFT_DATA_VALUE; + desc->len = len; + return 0; +} + +static int nft_value_dump(struct sk_buff *skb, const struct nft_data *data, + unsigned int len) +{ + return nla_put(skb, NFTA_DATA_VALUE, len, data->data); +} + +static const struct nla_policy nft_data_policy[NFTA_DATA_MAX + 1] = { + [NFTA_DATA_VALUE] = { .type = NLA_BINARY, + .len = FIELD_SIZEOF(struct nft_data, data) }, + [NFTA_DATA_VERDICT] = { .type = NLA_NESTED }, +}; + +/** + * nft_data_init - parse nf_tables data netlink attributes + * + * @ctx: context of the expression using the data + * @data: destination struct nft_data + * @desc: data description + * @nla: netlink attribute containing data + * + * Parse the netlink data attributes and initialize a struct nft_data. + * The type and length of data are returned in the data description. + * + * The caller can indicate that it only wants to accept data of type + * NFT_DATA_VALUE by passing NULL for the ctx argument. + */ +int nft_data_init(const struct nft_ctx *ctx, struct nft_data *data, + struct nft_data_desc *desc, const struct nlattr *nla) +{ + struct nlattr *tb[NFTA_DATA_MAX + 1]; + int err; + + err = nla_parse_nested(tb, NFTA_DATA_MAX, nla, nft_data_policy); + if (err < 0) + return err; + + if (tb[NFTA_DATA_VALUE]) + return nft_value_init(ctx, data, desc, tb[NFTA_DATA_VALUE]); + if (tb[NFTA_DATA_VERDICT] && ctx != NULL) + return nft_verdict_init(ctx, data, desc, tb[NFTA_DATA_VERDICT]); + return -EINVAL; +} +EXPORT_SYMBOL_GPL(nft_data_init); + +/** + * nft_data_uninit - release a nft_data item + * + * @data: struct nft_data to release + * @type: type of data + * + * Release a nft_data item. NFT_DATA_VALUE types can be silently discarded, + * all others need to be released by calling this function. + */ +void nft_data_uninit(const struct nft_data *data, enum nft_data_types type) +{ + switch (type) { + case NFT_DATA_VALUE: + return; + case NFT_DATA_VERDICT: + return nft_verdict_uninit(data); + default: + WARN_ON(1); + } +} +EXPORT_SYMBOL_GPL(nft_data_uninit); + +int nft_data_dump(struct sk_buff *skb, int attr, const struct nft_data *data, + enum nft_data_types type, unsigned int len) +{ + struct nlattr *nest; + int err; + + nest = nla_nest_start(skb, attr); + if (nest == NULL) + return -1; + + switch (type) { + case NFT_DATA_VALUE: + err = nft_value_dump(skb, data, len); + break; + case NFT_DATA_VERDICT: + err = nft_verdict_dump(skb, data); + break; + default: + err = -EINVAL; + WARN_ON(1); + } + + nla_nest_end(skb, nest); + return err; +} +EXPORT_SYMBOL_GPL(nft_data_dump); + +static int __init nf_tables_module_init(void) +{ + int err; + + info = kmalloc(sizeof(struct nft_expr_info) * NFT_RULE_MAXEXPRS, + GFP_KERNEL); + if (info == NULL) { + err = -ENOMEM; + goto err1; + } + + err = nf_tables_core_module_init(); + if (err < 0) + goto err2; + + err = nfnetlink_subsys_register(&nf_tables_subsys); + if (err < 0) + goto err3; + + pr_info("nf_tables: (c) 2007-2009 Patrick McHardy <kaber@trash.net>\n"); + return 0; +err3: + nf_tables_core_module_exit(); +err2: + kfree(info); +err1: + return err; +} + +static void __exit nf_tables_module_exit(void) +{ + nfnetlink_subsys_unregister(&nf_tables_subsys); + nf_tables_core_module_exit(); + kfree(info); +} + +module_init(nf_tables_module_init); +module_exit(nf_tables_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); +MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFTABLES); |