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_conntrack_zone zone; 41 struct nf_conn *c; 42 int proto; 43 44 spin_lock(&ca->tcf_lock); 45 ca->tcf_tm.lastuse = jiffies; 46 bstats_update(&ca->tcf_bstats, skb); 47 48 if (skb->protocol == htons(ETH_P_IP)) { 49 if (skb->len < sizeof(struct iphdr)) 50 goto out; 51 52 proto = NFPROTO_IPV4; 53 } else if (skb->protocol == htons(ETH_P_IPV6)) { 54 if (skb->len < sizeof(struct ipv6hdr)) 55 goto out; 56 57 proto = NFPROTO_IPV6; 58 } else { 59 goto out; 60 } 61 62 c = nf_ct_get(skb, &ctinfo); 63 if (c) { 64 skb->mark = c->mark; 65 /* using overlimits stats to count how many packets marked */ 66 ca->tcf_qstats.overlimits++; 67 goto out; 68 } 69 70 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), 71 proto, &tuple)) 72 goto out; 73 74 zone.id = ca->zone; 75 zone.dir = NF_CT_DEFAULT_ZONE_DIR; 76 77 thash = nf_conntrack_find_get(dev_net(skb->dev), &zone, &tuple); 78 if (!thash) 79 goto out; 80 81 c = nf_ct_tuplehash_to_ctrack(thash); 82 /* using overlimits stats to count how many packets marked */ 83 ca->tcf_qstats.overlimits++; 84 skb->mark = c->mark; 85 nf_ct_put(c); 86 87 out: 88 spin_unlock(&ca->tcf_lock); 89 return ca->tcf_action; 90 } 91 92 static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = { 93 [TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) }, 94 }; 95 96 static int tcf_connmark_init(struct net *net, struct nlattr *nla, 97 struct nlattr *est, struct tc_action *a, 98 int ovr, int bind) 99 { 100 struct nlattr *tb[TCA_CONNMARK_MAX + 1]; 101 struct tcf_connmark_info *ci; 102 struct tc_connmark *parm; 103 int ret = 0; 104 105 if (!nla) 106 return -EINVAL; 107 108 ret = nla_parse_nested(tb, TCA_CONNMARK_MAX, nla, connmark_policy); 109 if (ret < 0) 110 return ret; 111 112 parm = nla_data(tb[TCA_CONNMARK_PARMS]); 113 114 if (!tcf_hash_check(parm->index, a, bind)) { 115 ret = tcf_hash_create(parm->index, est, a, sizeof(*ci), 116 bind, false); 117 if (ret) 118 return ret; 119 120 ci = to_connmark(a); 121 ci->tcf_action = parm->action; 122 ci->zone = parm->zone; 123 124 tcf_hash_insert(a); 125 ret = ACT_P_CREATED; 126 } else { 127 ci = to_connmark(a); 128 if (bind) 129 return 0; 130 tcf_hash_release(a, bind); 131 if (!ovr) 132 return -EEXIST; 133 /* replacing action and zone */ 134 ci->tcf_action = parm->action; 135 ci->zone = parm->zone; 136 } 137 138 return ret; 139 } 140 141 static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a, 142 int bind, int ref) 143 { 144 unsigned char *b = skb_tail_pointer(skb); 145 struct tcf_connmark_info *ci = a->priv; 146 147 struct tc_connmark opt = { 148 .index = ci->tcf_index, 149 .refcnt = ci->tcf_refcnt - ref, 150 .bindcnt = ci->tcf_bindcnt - bind, 151 .action = ci->tcf_action, 152 .zone = ci->zone, 153 }; 154 struct tcf_t t; 155 156 if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt)) 157 goto nla_put_failure; 158 159 t.install = jiffies_to_clock_t(jiffies - ci->tcf_tm.install); 160 t.lastuse = jiffies_to_clock_t(jiffies - ci->tcf_tm.lastuse); 161 t.expires = jiffies_to_clock_t(ci->tcf_tm.expires); 162 if (nla_put(skb, TCA_CONNMARK_TM, sizeof(t), &t)) 163 goto nla_put_failure; 164 165 return skb->len; 166 nla_put_failure: 167 nlmsg_trim(skb, b); 168 return -1; 169 } 170 171 static struct tc_action_ops act_connmark_ops = { 172 .kind = "connmark", 173 .type = TCA_ACT_CONNMARK, 174 .owner = THIS_MODULE, 175 .act = tcf_connmark, 176 .dump = tcf_connmark_dump, 177 .init = tcf_connmark_init, 178 }; 179 180 static int __init connmark_init_module(void) 181 { 182 return tcf_register_action(&act_connmark_ops, CONNMARK_TAB_MASK); 183 } 184 185 static void __exit connmark_cleanup_module(void) 186 { 187 tcf_unregister_action(&act_connmark_ops); 188 } 189 190 module_init(connmark_init_module); 191 module_exit(connmark_cleanup_module); 192 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>"); 193 MODULE_DESCRIPTION("Connection tracking mark restoring"); 194 MODULE_LICENSE("GPL"); 195 196