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 connmark_net_id; 34 35 static int tcf_connmark(struct sk_buff *skb, const struct tc_action *a, 36 struct tcf_result *res) 37 { 38 const struct nf_conntrack_tuple_hash *thash; 39 struct nf_conntrack_tuple tuple; 40 enum ip_conntrack_info ctinfo; 41 struct tcf_connmark_info *ca = a->priv; 42 struct nf_conntrack_zone zone; 43 struct nf_conn *c; 44 int proto; 45 46 spin_lock(&ca->tcf_lock); 47 ca->tcf_tm.lastuse = jiffies; 48 bstats_update(&ca->tcf_bstats, skb); 49 50 if (skb->protocol == htons(ETH_P_IP)) { 51 if (skb->len < sizeof(struct iphdr)) 52 goto out; 53 54 proto = NFPROTO_IPV4; 55 } else if (skb->protocol == htons(ETH_P_IPV6)) { 56 if (skb->len < sizeof(struct ipv6hdr)) 57 goto out; 58 59 proto = NFPROTO_IPV6; 60 } else { 61 goto out; 62 } 63 64 c = nf_ct_get(skb, &ctinfo); 65 if (c) { 66 skb->mark = c->mark; 67 /* using overlimits stats to count how many packets marked */ 68 ca->tcf_qstats.overlimits++; 69 goto out; 70 } 71 72 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), 73 proto, ca->net, &tuple)) 74 goto out; 75 76 zone.id = ca->zone; 77 zone.dir = NF_CT_DEFAULT_ZONE_DIR; 78 79 thash = nf_conntrack_find_get(ca->net, &zone, &tuple); 80 if (!thash) 81 goto out; 82 83 c = nf_ct_tuplehash_to_ctrack(thash); 84 /* using overlimits stats to count how many packets marked */ 85 ca->tcf_qstats.overlimits++; 86 skb->mark = c->mark; 87 nf_ct_put(c); 88 89 out: 90 spin_unlock(&ca->tcf_lock); 91 return ca->tcf_action; 92 } 93 94 static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = { 95 [TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) }, 96 }; 97 98 static int tcf_connmark_init(struct net *net, struct nlattr *nla, 99 struct nlattr *est, struct tc_action *a, 100 int ovr, int bind) 101 { 102 struct tc_action_net *tn = net_generic(net, connmark_net_id); 103 struct nlattr *tb[TCA_CONNMARK_MAX + 1]; 104 struct tcf_connmark_info *ci; 105 struct tc_connmark *parm; 106 int ret = 0; 107 108 if (!nla) 109 return -EINVAL; 110 111 ret = nla_parse_nested(tb, TCA_CONNMARK_MAX, nla, connmark_policy); 112 if (ret < 0) 113 return ret; 114 115 parm = nla_data(tb[TCA_CONNMARK_PARMS]); 116 117 if (!tcf_hash_check(tn, parm->index, a, bind)) { 118 ret = tcf_hash_create(tn, parm->index, est, a, 119 sizeof(*ci), bind, false); 120 if (ret) 121 return ret; 122 123 ci = to_connmark(a); 124 ci->tcf_action = parm->action; 125 ci->net = net; 126 ci->zone = parm->zone; 127 128 tcf_hash_insert(tn, a); 129 ret = ACT_P_CREATED; 130 } else { 131 ci = to_connmark(a); 132 if (bind) 133 return 0; 134 tcf_hash_release(a, bind); 135 if (!ovr) 136 return -EEXIST; 137 /* replacing action and zone */ 138 ci->tcf_action = parm->action; 139 ci->zone = parm->zone; 140 } 141 142 return ret; 143 } 144 145 static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a, 146 int bind, int ref) 147 { 148 unsigned char *b = skb_tail_pointer(skb); 149 struct tcf_connmark_info *ci = a->priv; 150 151 struct tc_connmark opt = { 152 .index = ci->tcf_index, 153 .refcnt = ci->tcf_refcnt - ref, 154 .bindcnt = ci->tcf_bindcnt - bind, 155 .action = ci->tcf_action, 156 .zone = ci->zone, 157 }; 158 struct tcf_t t; 159 160 if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt)) 161 goto nla_put_failure; 162 163 t.install = jiffies_to_clock_t(jiffies - ci->tcf_tm.install); 164 t.lastuse = jiffies_to_clock_t(jiffies - ci->tcf_tm.lastuse); 165 t.expires = jiffies_to_clock_t(ci->tcf_tm.expires); 166 if (nla_put_64bit(skb, TCA_CONNMARK_TM, sizeof(t), &t, 167 TCA_CONNMARK_PAD)) 168 goto nla_put_failure; 169 170 return skb->len; 171 nla_put_failure: 172 nlmsg_trim(skb, b); 173 return -1; 174 } 175 176 static int tcf_connmark_walker(struct net *net, struct sk_buff *skb, 177 struct netlink_callback *cb, int type, 178 struct tc_action *a) 179 { 180 struct tc_action_net *tn = net_generic(net, connmark_net_id); 181 182 return tcf_generic_walker(tn, skb, cb, type, a); 183 } 184 185 static int tcf_connmark_search(struct net *net, struct tc_action *a, u32 index) 186 { 187 struct tc_action_net *tn = net_generic(net, connmark_net_id); 188 189 return tcf_hash_search(tn, a, index); 190 } 191 192 static struct tc_action_ops act_connmark_ops = { 193 .kind = "connmark", 194 .type = TCA_ACT_CONNMARK, 195 .owner = THIS_MODULE, 196 .act = tcf_connmark, 197 .dump = tcf_connmark_dump, 198 .init = tcf_connmark_init, 199 .walk = tcf_connmark_walker, 200 .lookup = tcf_connmark_search, 201 }; 202 203 static __net_init int connmark_init_net(struct net *net) 204 { 205 struct tc_action_net *tn = net_generic(net, connmark_net_id); 206 207 return tc_action_net_init(tn, &act_connmark_ops, CONNMARK_TAB_MASK); 208 } 209 210 static void __net_exit connmark_exit_net(struct net *net) 211 { 212 struct tc_action_net *tn = net_generic(net, connmark_net_id); 213 214 tc_action_net_exit(tn); 215 } 216 217 static struct pernet_operations connmark_net_ops = { 218 .init = connmark_init_net, 219 .exit = connmark_exit_net, 220 .id = &connmark_net_id, 221 .size = sizeof(struct tc_action_net), 222 }; 223 224 static int __init connmark_init_module(void) 225 { 226 return tcf_register_action(&act_connmark_ops, &connmark_net_ops); 227 } 228 229 static void __exit connmark_cleanup_module(void) 230 { 231 tcf_unregister_action(&act_connmark_ops, &connmark_net_ops); 232 } 233 234 module_init(connmark_init_module); 235 module_exit(connmark_cleanup_module); 236 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>"); 237 MODULE_DESCRIPTION("Connection tracking mark restoring"); 238 MODULE_LICENSE("GPL"); 239 240