--- /dev/null
+/*
+ * Copyright (c) 2010 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.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/gfp.h>
+#include <linux/skbuff.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_CT.h>
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_l4proto.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
+#include <net/netfilter/nf_conntrack_timeout.h>
+#include <net/netfilter/nf_conntrack_zones.h>
+
+static inline int xt_ct_target(struct sk_buff *skb, struct nf_conn *ct)
+{
+ /* Previously seen (loopback)? Ignore. */
+ if (skb->nfct != NULL)
+ return XT_CONTINUE;
+
+ /* special case the untracked ct : we want the percpu object */
+ if (!ct)
+ ct = nf_ct_untracked_get();
+ atomic_inc(&ct->ct_general.use);
+ skb->nfct = &ct->ct_general;
+ skb->nfctinfo = IP_CT_NEW;
+
+ return XT_CONTINUE;
+}
+
+static unsigned int xt_ct_target_v0(struct sk_buff *skb,
+ const struct xt_action_param *par)
+{
+ const struct xt_ct_target_info *info = par->targinfo;
+ struct nf_conn *ct = info->ct;
+
+ return xt_ct_target(skb, ct);
+}
+
+static unsigned int xt_ct_target_v1(struct sk_buff *skb,
+ const struct xt_action_param *par)
+{
+ const struct xt_ct_target_info_v1 *info = par->targinfo;
+ struct nf_conn *ct = info->ct;
+
+ return xt_ct_target(skb, ct);
+}
+
+static u8 xt_ct_find_proto(const struct xt_tgchk_param *par)
+{
+ if (par->family == NFPROTO_IPV4) {
+ const struct ipt_entry *e = par->entryinfo;
+
+ if (e->ip.invflags & IPT_INV_PROTO)
+ return 0;
+ return e->ip.proto;
+ } else if (par->family == NFPROTO_IPV6) {
+ const struct ip6t_entry *e = par->entryinfo;
+
+ if (e->ipv6.invflags & IP6T_INV_PROTO)
+ return 0;
+ return e->ipv6.proto;
+ } else
+ return 0;
+}
+
+static int
+xt_ct_set_helper(struct nf_conn *ct, const char *helper_name,
+ const struct xt_tgchk_param *par)
+{
+ struct nf_conntrack_helper *helper;
+ struct nf_conn_help *help;
+ u8 proto;
+
+ proto = xt_ct_find_proto(par);
+ if (!proto) {
+ pr_info("You must specify a L4 protocol, and not use "
+ "inversions on it.\n");
+ return -ENOENT;
+ }
+
+ helper = nf_conntrack_helper_try_module_get(helper_name, par->family,
+ proto);
+ if (helper == NULL) {
+ pr_info("No such helper \"%s\"\n", helper_name);
+ return -ENOENT;
+ }
+
+ help = nf_ct_helper_ext_add(ct, helper, GFP_KERNEL);
+ if (help == NULL) {
+ module_put(helper->me);
+ return -ENOMEM;
+ }
+
+ help->helper = helper;
+ return 0;
+}
+
+#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
+static void __xt_ct_tg_timeout_put(struct ctnl_timeout *timeout)
+{
+ typeof(nf_ct_timeout_put_hook) timeout_put;
+
+ timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
+ if (timeout_put)
+ timeout_put(timeout);
+}
+#endif
+
+static int
+xt_ct_set_timeout(struct nf_conn *ct, const struct xt_tgchk_param *par,
+ const char *timeout_name)
+{
+#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
+ typeof(nf_ct_timeout_find_get_hook) timeout_find_get;
+ struct ctnl_timeout *timeout;
+ struct nf_conn_timeout *timeout_ext;
+ struct nf_conntrack_l4proto *l4proto;
+ int ret = 0;
+ u8 proto;
+
+ rcu_read_lock();
+ timeout_find_get = rcu_dereference(nf_ct_timeout_find_get_hook);
+ if (timeout_find_get == NULL) {
+ ret = -ENOENT;
+ pr_info("Timeout policy base is empty\n");
+ goto out;
+ }
+
+ proto = xt_ct_find_proto(par);
+ if (!proto) {
+ ret = -EINVAL;
+ pr_info("You must specify a L4 protocol, and not use "
+ "inversions on it.\n");
+ goto out;
+ }
+
+ timeout = timeout_find_get(timeout_name);
+ if (timeout == NULL) {
+ ret = -ENOENT;
+ pr_info("No such timeout policy \"%s\"\n", timeout_name);
+ goto out;
+ }
+
+ if (timeout->l3num != par->family) {
+ ret = -EINVAL;
+ pr_info("Timeout policy `%s' can only be used by L3 protocol "
+ "number %d\n", timeout_name, timeout->l3num);
+ goto err_put_timeout;
+ }
+ /* Make sure the timeout policy matches any existing protocol tracker,
+ * otherwise default to generic.
+ */
+ l4proto = __nf_ct_l4proto_find(par->family, proto);
+ if (timeout->l4proto->l4proto != l4proto->l4proto) {
+ ret = -EINVAL;
+ pr_info("Timeout policy `%s' can only be used by L4 protocol "
+ "number %d\n",
+ timeout_name, timeout->l4proto->l4proto);
+ goto err_put_timeout;
+ }
+ timeout_ext = nf_ct_timeout_ext_add(ct, timeout, GFP_ATOMIC);
+ if (timeout_ext == NULL)
+ ret = -ENOMEM;
+
+err_put_timeout:
+ __xt_ct_tg_timeout_put(timeout);
+out:
+ rcu_read_unlock();
+ return ret;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int xt_ct_tg_check(const struct xt_tgchk_param *par,
+ struct xt_ct_target_info_v1 *info)
+{
+ struct nf_conntrack_tuple t;
+ struct nf_conn *ct;
+ int ret = -EOPNOTSUPP;
+
+ if (info->flags & XT_CT_NOTRACK) {
+ ct = NULL;
+ goto out;
+ }
+
+#ifndef CONFIG_NF_CONNTRACK_ZONES
+ if (info->zone)
+ goto err1;
+#endif
+
+ ret = nf_ct_l3proto_try_module_get(par->family);
+ if (ret < 0)
+ goto err1;
+
+ memset(&t, 0, sizeof(t));
+ ct = nf_conntrack_alloc(par->net, info->zone, &t, &t, GFP_KERNEL);
+ ret = PTR_ERR(ct);
+ if (IS_ERR(ct))
+ goto err2;
+
+ ret = 0;
+ if ((info->ct_events || info->exp_events) &&
+ !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events,
+ GFP_KERNEL)) {
+ ret = -EINVAL;
+ goto err3;
+ }
+
+ if (info->helper[0]) {
+ ret = xt_ct_set_helper(ct, info->helper, par);
+ if (ret < 0)
+ goto err3;
+ }
+
+ if (info->timeout[0]) {
+ ret = xt_ct_set_timeout(ct, par, info->timeout);
+ if (ret < 0)
+ goto err3;
+ }
+
+ nf_conntrack_tmpl_insert(par->net, ct);
+out:
+ info->ct = ct;
+ return 0;
+
+err3:
+ nf_conntrack_free(ct);
+err2:
+ nf_ct_l3proto_module_put(par->family);
+err1:
+ return ret;
+}
+
+static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par)
+{
+ struct xt_ct_target_info *info = par->targinfo;
+ struct xt_ct_target_info_v1 info_v1 = {
+ .flags = info->flags,
+ .zone = info->zone,
+ .ct_events = info->ct_events,
+ .exp_events = info->exp_events,
+ };
+ int ret;
+
+ if (info->flags & ~XT_CT_NOTRACK)
+ return -EINVAL;
+
+ memcpy(info_v1.helper, info->helper, sizeof(info->helper));
+
+ ret = xt_ct_tg_check(par, &info_v1);
+ if (ret < 0)
+ return ret;
+
+ info->ct = info_v1.ct;
+
+ return ret;
+}
+
+static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par)
+{
+ struct xt_ct_target_info_v1 *info = par->targinfo;
+
+ if (info->flags & ~XT_CT_NOTRACK)
+ return -EINVAL;
+
+ return xt_ct_tg_check(par, par->targinfo);
+}
+
+static int xt_ct_tg_check_v2(const struct xt_tgchk_param *par)
+{
+ struct xt_ct_target_info_v1 *info = par->targinfo;
+
+ if (info->flags & ~XT_CT_MASK)
+ return -EINVAL;
+
+ return xt_ct_tg_check(par, par->targinfo);
+}
+
+static void xt_ct_destroy_timeout(struct nf_conn *ct)
+{
+#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
+ struct nf_conn_timeout *timeout_ext;
+ typeof(nf_ct_timeout_put_hook) timeout_put;
+
+ rcu_read_lock();
+ timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
+
+ if (timeout_put) {
+ timeout_ext = nf_ct_timeout_find(ct);
+ if (timeout_ext)
+ timeout_put(timeout_ext->timeout);
+ }
+ rcu_read_unlock();
+#endif
+}
+
+static void xt_ct_tg_destroy(const struct xt_tgdtor_param *par,
+ struct xt_ct_target_info_v1 *info)
+{
+ struct nf_conn *ct = info->ct;
+ struct nf_conn_help *help;
+
+ if (ct && !nf_ct_is_untracked(ct)) {
+ help = nfct_help(ct);
+ if (help)
+ module_put(help->helper->me);
+
+ nf_ct_l3proto_module_put(par->family);
+
+ xt_ct_destroy_timeout(ct);
+ nf_ct_put(info->ct);
+ }
+}
+
+static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par)
+{
+ struct xt_ct_target_info *info = par->targinfo;
+ struct xt_ct_target_info_v1 info_v1 = {
+ .flags = info->flags,
+ .zone = info->zone,
+ .ct_events = info->ct_events,
+ .exp_events = info->exp_events,
+ .ct = info->ct,
+ };
+ memcpy(info_v1.helper, info->helper, sizeof(info->helper));
+
+ xt_ct_tg_destroy(par, &info_v1);
+}
+
+static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param *par)
+{
+ xt_ct_tg_destroy(par, par->targinfo);
+}
+
+static struct xt_target xt_ct_tg_reg[] __read_mostly = {
+ {
+ .name = "CT",
+ .family = NFPROTO_UNSPEC,
+ .targetsize = sizeof(struct xt_ct_target_info),
+ .checkentry = xt_ct_tg_check_v0,
+ .destroy = xt_ct_tg_destroy_v0,
+ .target = xt_ct_target_v0,
+ .table = "raw",
+ .me = THIS_MODULE,
+ },
+ {
+ .name = "CT",
+ .family = NFPROTO_UNSPEC,
+ .revision = 1,
+ .targetsize = sizeof(struct xt_ct_target_info_v1),
+ .checkentry = xt_ct_tg_check_v1,
+ .destroy = xt_ct_tg_destroy_v1,
+ .target = xt_ct_target_v1,
+ .table = "raw",
+ .me = THIS_MODULE,
+ },
+ {
+ .name = "CT",
+ .family = NFPROTO_UNSPEC,
+ .revision = 2,
+ .targetsize = sizeof(struct xt_ct_target_info_v1),
+ .checkentry = xt_ct_tg_check_v2,
+ .destroy = xt_ct_tg_destroy_v1,
+ .target = xt_ct_target_v1,
+ .table = "raw",
+ .me = THIS_MODULE,
+ },
+};
+
+static unsigned int
+notrack_tg(struct sk_buff *skb, const struct xt_action_param *par)
+{
+ /* Previously seen (loopback)? Ignore. */
+ if (skb->nfct != NULL)
+ return XT_CONTINUE;
+
+ skb->nfct = &nf_ct_untracked_get()->ct_general;
+ skb->nfctinfo = IP_CT_NEW;
+ nf_conntrack_get(skb->nfct);
+
+ return XT_CONTINUE;
+}
+
+static int notrack_chk(const struct xt_tgchk_param *par)
+{
+ if (!par->net->xt.notrack_deprecated_warning) {
+ pr_info("netfilter: NOTRACK target is deprecated, "
+ "use CT instead or upgrade iptables\n");
+ par->net->xt.notrack_deprecated_warning = true;
+ }
+ return 0;
+}
+
+static struct xt_target notrack_tg_reg __read_mostly = {
+ .name = "NOTRACK",
+ .revision = 0,
+ .family = NFPROTO_UNSPEC,
+ .checkentry = notrack_chk,
+ .target = notrack_tg,
+ .table = "raw",
+ .me = THIS_MODULE,
+};
+
+static int __init xt_ct_tg_init(void)
+{
+ int ret;
+
+ ret = xt_register_target(¬rack_tg_reg);
+ if (ret < 0)
+ return ret;
+
+ ret = xt_register_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
+ if (ret < 0) {
+ xt_unregister_target(¬rack_tg_reg);
+ return ret;
+ }
+ return 0;
+}
+
+static void __exit xt_ct_tg_exit(void)
+{
+ xt_unregister_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
+ xt_unregister_target(¬rack_tg_reg);
+}
+
+module_init(xt_ct_tg_init);
+module_exit(xt_ct_tg_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Xtables: connection tracking target");
+MODULE_ALIAS("ipt_CT");
+MODULE_ALIAS("ip6t_CT");
+MODULE_ALIAS("ipt_NOTRACK");
+MODULE_ALIAS("ip6t_NOTRACK");
Code Review / kvmfornfv.git / blobdiff