diff options
Diffstat (limited to 'net/sched/act_connmark.c')
| -rw-r--r-- | net/sched/act_connmark.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/net/sched/act_connmark.c b/net/sched/act_connmark.c new file mode 100644 index 000000000..b6576a250 --- /dev/null +++ b/net/sched/act_connmark.c @@ -0,0 +1,265 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * net/sched/act_connmark.c netfilter connmark retriever action + * skb mark is over-written + * + * Copyright (c) 2011 Felix Fietkau <nbd@openwrt.org> +*/ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/skbuff.h> +#include <linux/rtnetlink.h> +#include <linux/pkt_cls.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <net/netlink.h> +#include <net/pkt_sched.h> +#include <net/act_api.h> +#include <net/pkt_cls.h> +#include <uapi/linux/tc_act/tc_connmark.h> +#include <net/tc_act/tc_connmark.h> + +#include <net/netfilter/nf_conntrack.h> +#include <net/netfilter/nf_conntrack_core.h> +#include <net/netfilter/nf_conntrack_zones.h> + +static unsigned int connmark_net_id; +static struct tc_action_ops act_connmark_ops; + +static int tcf_connmark_act(struct sk_buff *skb, const struct tc_action *a, + struct tcf_result *res) +{ + const struct nf_conntrack_tuple_hash *thash; + struct nf_conntrack_tuple tuple; + enum ip_conntrack_info ctinfo; + struct tcf_connmark_info *ca = to_connmark(a); + struct nf_conntrack_zone zone; + struct nf_conn *c; + int proto; + + spin_lock(&ca->tcf_lock); + tcf_lastuse_update(&ca->tcf_tm); + bstats_update(&ca->tcf_bstats, skb); + + switch (skb_protocol(skb, true)) { + case htons(ETH_P_IP): + if (skb->len < sizeof(struct iphdr)) + goto out; + + proto = NFPROTO_IPV4; + break; + case htons(ETH_P_IPV6): + if (skb->len < sizeof(struct ipv6hdr)) + goto out; + + proto = NFPROTO_IPV6; + break; + default: + goto out; + } + + c = nf_ct_get(skb, &ctinfo); + if (c) { + skb->mark = READ_ONCE(c->mark); + /* using overlimits stats to count how many packets marked */ + ca->tcf_qstats.overlimits++; + goto out; + } + + if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), + proto, ca->net, &tuple)) + goto out; + + zone.id = ca->zone; + zone.dir = NF_CT_DEFAULT_ZONE_DIR; + + thash = nf_conntrack_find_get(ca->net, &zone, &tuple); + if (!thash) + goto out; + + c = nf_ct_tuplehash_to_ctrack(thash); + /* using overlimits stats to count how many packets marked */ + ca->tcf_qstats.overlimits++; + skb->mark = READ_ONCE(c->mark); + nf_ct_put(c); + +out: + spin_unlock(&ca->tcf_lock); + return ca->tcf_action; +} + +static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = { + [TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) }, +}; + +static int tcf_connmark_init(struct net *net, struct nlattr *nla, + struct nlattr *est, struct tc_action **a, + int ovr, int bind, bool rtnl_held, + struct tcf_proto *tp, u32 flags, + struct netlink_ext_ack *extack) +{ + struct tc_action_net *tn = net_generic(net, connmark_net_id); + struct nlattr *tb[TCA_CONNMARK_MAX + 1]; + struct tcf_chain *goto_ch = NULL; + struct tcf_connmark_info *ci; + struct tc_connmark *parm; + int ret = 0, err; + u32 index; + + if (!nla) + return -EINVAL; + + ret = nla_parse_nested_deprecated(tb, TCA_CONNMARK_MAX, nla, + connmark_policy, NULL); + if (ret < 0) + return ret; + + if (!tb[TCA_CONNMARK_PARMS]) + return -EINVAL; + + parm = nla_data(tb[TCA_CONNMARK_PARMS]); + index = parm->index; + ret = tcf_idr_check_alloc(tn, &index, a, bind); + if (!ret) { + ret = tcf_idr_create(tn, index, est, a, + &act_connmark_ops, bind, false, flags); + if (ret) { + tcf_idr_cleanup(tn, index); + return ret; + } + + ci = to_connmark(*a); + err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, + extack); + if (err < 0) + goto release_idr; + tcf_action_set_ctrlact(*a, parm->action, goto_ch); + ci->net = net; + ci->zone = parm->zone; + + ret = ACT_P_CREATED; + } else if (ret > 0) { + ci = to_connmark(*a); + if (bind) + return 0; + if (!ovr) { + tcf_idr_release(*a, bind); + return -EEXIST; + } + err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, + extack); + if (err < 0) + goto release_idr; + /* replacing action and zone */ + spin_lock_bh(&ci->tcf_lock); + goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); + ci->zone = parm->zone; + spin_unlock_bh(&ci->tcf_lock); + if (goto_ch) + tcf_chain_put_by_act(goto_ch); + ret = 0; + } + + return ret; +release_idr: + tcf_idr_release(*a, bind); + return err; +} + +static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a, + int bind, int ref) +{ + unsigned char *b = skb_tail_pointer(skb); + struct tcf_connmark_info *ci = to_connmark(a); + struct tc_connmark opt = { + .index = ci->tcf_index, + .refcnt = refcount_read(&ci->tcf_refcnt) - ref, + .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind, + }; + struct tcf_t t; + + spin_lock_bh(&ci->tcf_lock); + opt.action = ci->tcf_action; + opt.zone = ci->zone; + if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt)) + goto nla_put_failure; + + tcf_tm_dump(&t, &ci->tcf_tm); + if (nla_put_64bit(skb, TCA_CONNMARK_TM, sizeof(t), &t, + TCA_CONNMARK_PAD)) + goto nla_put_failure; + spin_unlock_bh(&ci->tcf_lock); + + return skb->len; + +nla_put_failure: + spin_unlock_bh(&ci->tcf_lock); + nlmsg_trim(skb, b); + return -1; +} + +static int tcf_connmark_walker(struct net *net, struct sk_buff *skb, + struct netlink_callback *cb, int type, + const struct tc_action_ops *ops, + struct netlink_ext_ack *extack) +{ + struct tc_action_net *tn = net_generic(net, connmark_net_id); + + return tcf_generic_walker(tn, skb, cb, type, ops, extack); +} + +static int tcf_connmark_search(struct net *net, struct tc_action **a, u32 index) +{ + struct tc_action_net *tn = net_generic(net, connmark_net_id); + + return tcf_idr_search(tn, a, index); +} + +static struct tc_action_ops act_connmark_ops = { + .kind = "connmark", + .id = TCA_ID_CONNMARK, + .owner = THIS_MODULE, + .act = tcf_connmark_act, + .dump = tcf_connmark_dump, + .init = tcf_connmark_init, + .walk = tcf_connmark_walker, + .lookup = tcf_connmark_search, + .size = sizeof(struct tcf_connmark_info), +}; + +static __net_init int connmark_init_net(struct net *net) +{ + struct tc_action_net *tn = net_generic(net, connmark_net_id); + + return tc_action_net_init(net, tn, &act_connmark_ops); +} + +static void __net_exit connmark_exit_net(struct list_head *net_list) +{ + tc_action_net_exit(net_list, connmark_net_id); +} + +static struct pernet_operations connmark_net_ops = { + .init = connmark_init_net, + .exit_batch = connmark_exit_net, + .id = &connmark_net_id, + .size = sizeof(struct tc_action_net), +}; + +static int __init connmark_init_module(void) +{ + return tcf_register_action(&act_connmark_ops, &connmark_net_ops); +} + +static void __exit connmark_cleanup_module(void) +{ + tcf_unregister_action(&act_connmark_ops, &connmark_net_ops); +} + +module_init(connmark_init_module); +module_exit(connmark_cleanup_module); +MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>"); +MODULE_DESCRIPTION("Connection tracking mark restoring"); +MODULE_LICENSE("GPL"); |