/* * net/sched/act_connmark.c netfilter connmark retriever action * skb mark is over-written * * Copyright (c) 2011 Felix Fietkau <nbd@openwrt.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. */ #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 <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> #define CONNMARK_TAB_MASK 3 static unsigned int connmark_net_id; static struct tc_action_ops act_connmark_ops; static int tcf_connmark(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); if (skb->protocol == htons(ETH_P_IP)) { if (skb->len < sizeof(struct iphdr)) goto out; proto = NFPROTO_IPV4; } else if (skb->protocol == htons(ETH_P_IPV6)) { if (skb->len < sizeof(struct ipv6hdr)) goto out; proto = NFPROTO_IPV6; } else { goto out; } c = nf_ct_get(skb, &ctinfo); if (c) { skb->mark = 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 = 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) { struct tc_action_net *tn = net_generic(net, connmark_net_id); struct nlattr *tb[TCA_CONNMARK_MAX + 1]; struct tcf_connmark_info *ci; struct tc_connmark *parm; int ret = 0; if (!nla) return -EINVAL; ret = nla_parse_nested(tb, TCA_CONNMARK_MAX, nla, connmark_policy); if (ret < 0) return ret; parm = nla_data(tb[TCA_CONNMARK_PARMS]); if (!tcf_hash_check(tn, parm->index, a, bind)) { ret = tcf_hash_create(tn, parm->index, est, a, &act_connmark_ops, bind, false); if (ret) return ret; ci = to_connmark(*a); ci->tcf_action = parm->action; ci->net = net; ci->zone = parm->zone; tcf_hash_insert(tn, *a); ret = ACT_P_CREATED; } else { ci = to_connmark(*a); if (bind) return 0; tcf_hash_release(*a, bind); if (!ovr) return -EEXIST; /* replacing action and zone */ ci->tcf_action = parm->action; ci->zone = parm->zone; } return ret; } 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 = ci->tcf_refcnt - ref, .bindcnt = ci->tcf_bindcnt - bind, .action = ci->tcf_action, .zone = ci->zone, }; struct tcf_t t; 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; return skb->len; nla_put_failure: 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 tc_action_net *tn = net_generic(net, connmark_net_id); return tcf_generic_walker(tn, skb, cb, type, ops); } 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_hash_search(tn, a, index); } static struct tc_action_ops act_connmark_ops = { .kind = "connmark", .type = TCA_ACT_CONNMARK, .owner = THIS_MODULE, .act = tcf_connmark, .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(tn, &act_connmark_ops, CONNMARK_TAB_MASK); } static void __net_exit connmark_exit_net(struct net *net) { struct tc_action_net *tn = net_generic(net, connmark_net_id); tc_action_net_exit(tn); } static struct pernet_operations connmark_net_ops = { .init = connmark_init_net, .exit = 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");