1 /* 2 * net/sched/act_connmark.c netfilter connmark retriever action 3 * skb mark is over-written 4 * 5 * Copyright (c) 2011 Felix Fietkau <nbd@openwrt.org> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 */ 12 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/kernel.h> 16 #include <linux/skbuff.h> 17 #include <linux/rtnetlink.h> 18 #include <linux/pkt_cls.h> 19 #include <linux/ip.h> 20 #include <linux/ipv6.h> 21 #include <net/netlink.h> 22 #include <net/pkt_sched.h> 23 #include <net/act_api.h> 24 #include <uapi/linux/tc_act/tc_connmark.h> 25 #include <net/tc_act/tc_connmark.h> 26 27 #include <net/netfilter/nf_conntrack.h> 28 #include <net/netfilter/nf_conntrack_core.h> 29 #include <net/netfilter/nf_conntrack_zones.h> 30 31 #define CONNMARK_TAB_MASK 3 32 33 static int tcf_connmark(struct sk_buff *skb, const struct tc_action *a, 34 struct tcf_result *res) 35 { 36 const struct nf_conntrack_tuple_hash *thash; 37 struct nf_conntrack_tuple tuple; 38 enum ip_conntrack_info ctinfo; 39 struct tcf_connmark_info *ca = a->priv; 40 struct nf_conn *c; 41 int proto; 42 43 spin_lock(&ca->tcf_lock); 44 ca->tcf_tm.lastuse = jiffies; 45 bstats_update(&ca->tcf_bstats, skb); 46 47 if (skb->protocol == htons(ETH_P_IP)) { 48 if (skb->len < sizeof(struct iphdr)) 49 goto out; 50 51 proto = NFPROTO_IPV4; 52 } else if (skb->protocol == htons(ETH_P_IPV6)) { 53 if (skb->len < sizeof(struct ipv6hdr)) 54 goto out; 55 56 proto = NFPROTO_IPV6; 57 } else { 58 goto out; 59 } 60 61 c = nf_ct_get(skb, &ctinfo); 62 if (c) { 63 skb->mark = c->mark; 64 /* using overlimits stats to count how many packets marked */ 65 ca->tcf_qstats.overlimits++; 66 goto out; 67 } 68 69 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), 70 proto, &tuple)) 71 goto out; 72 73 thash = nf_conntrack_find_get(dev_net(skb->dev), ca->zone, &tuple); 74 if (!thash) 75 goto out; 76 77 c = nf_ct_tuplehash_to_ctrack(thash); 78 /* using overlimits stats to count how many packets marked */ 79 ca->tcf_qstats.overlimits++; 80 skb->mark = c->mark; 81 nf_ct_put(c); 82 83 out: 84 spin_unlock(&ca->tcf_lock); 85 return ca->tcf_action; 86 } 87 88 static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = { 89 [TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) }, 90 }; 91 92 static int tcf_connmark_init(struct net *net, struct nlattr *nla, 93 struct nlattr *est, struct tc_action *a, 94 int ovr, int bind) 95 { 96 struct nlattr *tb[TCA_CONNMARK_MAX + 1]; 97 struct tcf_connmark_info *ci; 98 struct tc_connmark *parm; 99 int ret = 0; 100 101 if (!nla) 102 return -EINVAL; 103 104 ret = nla_parse_nested(tb, TCA_CONNMARK_MAX, nla, connmark_policy); 105 if (ret < 0) 106 return ret; 107 108 parm = nla_data(tb[TCA_CONNMARK_PARMS]); 109 110 if (!tcf_hash_check(parm->index, a, bind)) { 111 ret = tcf_hash_create(parm->index, est, a, sizeof(*ci), bind); 112 if (ret) 113 return ret; 114 115 ci = to_connmark(a); 116 ci->tcf_action = parm->action; 117 ci->zone = parm->zone; 118 119 tcf_hash_insert(a); 120 ret = ACT_P_CREATED; 121 } else { 122 ci = to_connmark(a); 123 if (bind) 124 return 0; 125 tcf_hash_release(a, bind); 126 if (!ovr) 127 return -EEXIST; 128 /* replacing action and zone */ 129 ci->tcf_action = parm->action; 130 ci->zone = parm->zone; 131 } 132 133 return ret; 134 } 135 136 static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a, 137 int bind, int ref) 138 { 139 unsigned char *b = skb_tail_pointer(skb); 140 struct tcf_connmark_info *ci = a->priv; 141 142 struct tc_connmark opt = { 143 .index = ci->tcf_index, 144 .refcnt = ci->tcf_refcnt - ref, 145 .bindcnt = ci->tcf_bindcnt - bind, 146 .action = ci->tcf_action, 147 .zone = ci->zone, 148 }; 149 struct tcf_t t; 150 151 if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt)) 152 goto nla_put_failure; 153 154 t.install = jiffies_to_clock_t(jiffies - ci->tcf_tm.install); 155 t.lastuse = jiffies_to_clock_t(jiffies - ci->tcf_tm.lastuse); 156 t.expires = jiffies_to_clock_t(ci->tcf_tm.expires); 157 if (nla_put(skb, TCA_CONNMARK_TM, sizeof(t), &t)) 158 goto nla_put_failure; 159 160 return skb->len; 161 nla_put_failure: 162 nlmsg_trim(skb, b); 163 return -1; 164 } 165 166 static struct tc_action_ops act_connmark_ops = { 167 .kind = "connmark", 168 .type = TCA_ACT_CONNMARK, 169 .owner = THIS_MODULE, 170 .act = tcf_connmark, 171 .dump = tcf_connmark_dump, 172 .init = tcf_connmark_init, 173 }; 174 175 static int __init connmark_init_module(void) 176 { 177 return tcf_register_action(&act_connmark_ops, CONNMARK_TAB_MASK); 178 } 179 180 static void __exit connmark_cleanup_module(void) 181 { 182 tcf_unregister_action(&act_connmark_ops); 183 } 184 185 module_init(connmark_init_module); 186 module_exit(connmark_cleanup_module); 187 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>"); 188 MODULE_DESCRIPTION("Connection tracking mark restoring"); 189 MODULE_LICENSE("GPL"); 190 191