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 nf_ct_put(c); 67 goto out; 68 } 69 70 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), 71 proto, &tuple)) 72 goto out; 73 74 thash = nf_conntrack_find_get(dev_net(skb->dev), ca->zone, &tuple); 75 if (!thash) 76 goto out; 77 78 c = nf_ct_tuplehash_to_ctrack(thash); 79 /* using overlimits stats to count how many packets marked */ 80 ca->tcf_qstats.overlimits++; 81 skb->mark = c->mark; 82 nf_ct_put(c); 83 84 out: 85 skb->nfct = NULL; 86 spin_unlock(&ca->tcf_lock); 87 return ca->tcf_action; 88 } 89 90 static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = { 91 [TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) }, 92 }; 93 94 static int tcf_connmark_init(struct net *net, struct nlattr *nla, 95 struct nlattr *est, struct tc_action *a, 96 int ovr, int bind) 97 { 98 struct nlattr *tb[TCA_CONNMARK_MAX + 1]; 99 struct tcf_connmark_info *ci; 100 struct tc_connmark *parm; 101 int ret = 0; 102 103 if (!nla) 104 return -EINVAL; 105 106 ret = nla_parse_nested(tb, TCA_CONNMARK_MAX, nla, connmark_policy); 107 if (ret < 0) 108 return ret; 109 110 parm = nla_data(tb[TCA_CONNMARK_PARMS]); 111 112 if (!tcf_hash_check(parm->index, a, bind)) { 113 ret = tcf_hash_create(parm->index, est, a, sizeof(*ci), bind); 114 if (ret) 115 return ret; 116 117 ci = to_connmark(a); 118 ci->tcf_action = parm->action; 119 ci->zone = parm->zone; 120 121 tcf_hash_insert(a); 122 ret = ACT_P_CREATED; 123 } else { 124 ci = to_connmark(a); 125 if (bind) 126 return 0; 127 tcf_hash_release(a, bind); 128 if (!ovr) 129 return -EEXIST; 130 /* replacing action and zone */ 131 ci->tcf_action = parm->action; 132 ci->zone = parm->zone; 133 } 134 135 return ret; 136 } 137 138 static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a, 139 int bind, int ref) 140 { 141 unsigned char *b = skb_tail_pointer(skb); 142 struct tcf_connmark_info *ci = a->priv; 143 144 struct tc_connmark opt = { 145 .index = ci->tcf_index, 146 .refcnt = ci->tcf_refcnt - ref, 147 .bindcnt = ci->tcf_bindcnt - bind, 148 .action = ci->tcf_action, 149 .zone = ci->zone, 150 }; 151 struct tcf_t t; 152 153 if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt)) 154 goto nla_put_failure; 155 156 t.install = jiffies_to_clock_t(jiffies - ci->tcf_tm.install); 157 t.lastuse = jiffies_to_clock_t(jiffies - ci->tcf_tm.lastuse); 158 t.expires = jiffies_to_clock_t(ci->tcf_tm.expires); 159 if (nla_put(skb, TCA_CONNMARK_TM, sizeof(t), &t)) 160 goto nla_put_failure; 161 162 return skb->len; 163 nla_put_failure: 164 nlmsg_trim(skb, b); 165 return -1; 166 } 167 168 static struct tc_action_ops act_connmark_ops = { 169 .kind = "connmark", 170 .type = TCA_ACT_CONNMARK, 171 .owner = THIS_MODULE, 172 .act = tcf_connmark, 173 .dump = tcf_connmark_dump, 174 .init = tcf_connmark_init, 175 }; 176 177 static int __init connmark_init_module(void) 178 { 179 return tcf_register_action(&act_connmark_ops, CONNMARK_TAB_MASK); 180 } 181 182 static void __exit connmark_cleanup_module(void) 183 { 184 tcf_unregister_action(&act_connmark_ops); 185 } 186 187 module_init(connmark_init_module); 188 module_exit(connmark_cleanup_module); 189 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>"); 190 MODULE_DESCRIPTION("Connection tracking mark restoring"); 191 MODULE_LICENSE("GPL"); 192 193