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 static unsigned int connmark_net_id; 32 static struct tc_action_ops act_connmark_ops; 33 34 static int tcf_connmark_act(struct sk_buff *skb, const struct tc_action *a, 35 struct tcf_result *res) 36 { 37 const struct nf_conntrack_tuple_hash *thash; 38 struct nf_conntrack_tuple tuple; 39 enum ip_conntrack_info ctinfo; 40 struct tcf_connmark_info *ca = to_connmark(a); 41 struct nf_conntrack_zone zone; 42 struct nf_conn *c; 43 int proto; 44 45 spin_lock(&ca->tcf_lock); 46 tcf_lastuse_update(&ca->tcf_tm); 47 bstats_update(&ca->tcf_bstats, skb); 48 49 if (skb->protocol == htons(ETH_P_IP)) { 50 if (skb->len < sizeof(struct iphdr)) 51 goto out; 52 53 proto = NFPROTO_IPV4; 54 } else if (skb->protocol == htons(ETH_P_IPV6)) { 55 if (skb->len < sizeof(struct ipv6hdr)) 56 goto out; 57 58 proto = NFPROTO_IPV6; 59 } else { 60 goto out; 61 } 62 63 c = nf_ct_get(skb, &ctinfo); 64 if (c) { 65 skb->mark = c->mark; 66 /* using overlimits stats to count how many packets marked */ 67 ca->tcf_qstats.overlimits++; 68 goto out; 69 } 70 71 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), 72 proto, ca->net, &tuple)) 73 goto out; 74 75 zone.id = ca->zone; 76 zone.dir = NF_CT_DEFAULT_ZONE_DIR; 77 78 thash = nf_conntrack_find_get(ca->net, &zone, &tuple); 79 if (!thash) 80 goto out; 81 82 c = nf_ct_tuplehash_to_ctrack(thash); 83 /* using overlimits stats to count how many packets marked */ 84 ca->tcf_qstats.overlimits++; 85 skb->mark = c->mark; 86 nf_ct_put(c); 87 88 out: 89 spin_unlock(&ca->tcf_lock); 90 return ca->tcf_action; 91 } 92 93 static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = { 94 [TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) }, 95 }; 96 97 static int tcf_connmark_init(struct net *net, struct nlattr *nla, 98 struct nlattr *est, struct tc_action **a, 99 int ovr, int bind, bool rtnl_held, 100 struct netlink_ext_ack *extack) 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 NULL); 113 if (ret < 0) 114 return ret; 115 116 if (!tb[TCA_CONNMARK_PARMS]) 117 return -EINVAL; 118 119 parm = nla_data(tb[TCA_CONNMARK_PARMS]); 120 121 ret = tcf_idr_check_alloc(tn, &parm->index, a, bind); 122 if (!ret) { 123 ret = tcf_idr_create(tn, parm->index, est, a, 124 &act_connmark_ops, bind, false); 125 if (ret) { 126 tcf_idr_cleanup(tn, parm->index); 127 return ret; 128 } 129 130 ci = to_connmark(*a); 131 ci->tcf_action = parm->action; 132 ci->net = net; 133 ci->zone = parm->zone; 134 135 tcf_idr_insert(tn, *a); 136 ret = ACT_P_CREATED; 137 } else if (ret > 0) { 138 ci = to_connmark(*a); 139 if (bind) 140 return 0; 141 if (!ovr) { 142 tcf_idr_release(*a, bind); 143 return -EEXIST; 144 } 145 /* replacing action and zone */ 146 spin_lock_bh(&ci->tcf_lock); 147 ci->tcf_action = parm->action; 148 ci->zone = parm->zone; 149 spin_unlock_bh(&ci->tcf_lock); 150 ret = 0; 151 } 152 153 return ret; 154 } 155 156 static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a, 157 int bind, int ref) 158 { 159 unsigned char *b = skb_tail_pointer(skb); 160 struct tcf_connmark_info *ci = to_connmark(a); 161 struct tc_connmark opt = { 162 .index = ci->tcf_index, 163 .refcnt = refcount_read(&ci->tcf_refcnt) - ref, 164 .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind, 165 }; 166 struct tcf_t t; 167 168 spin_lock_bh(&ci->tcf_lock); 169 opt.action = ci->tcf_action; 170 opt.zone = ci->zone; 171 if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt)) 172 goto nla_put_failure; 173 174 tcf_tm_dump(&t, &ci->tcf_tm); 175 if (nla_put_64bit(skb, TCA_CONNMARK_TM, sizeof(t), &t, 176 TCA_CONNMARK_PAD)) 177 goto nla_put_failure; 178 spin_unlock_bh(&ci->tcf_lock); 179 180 return skb->len; 181 182 nla_put_failure: 183 spin_unlock_bh(&ci->tcf_lock); 184 nlmsg_trim(skb, b); 185 return -1; 186 } 187 188 static int tcf_connmark_walker(struct net *net, struct sk_buff *skb, 189 struct netlink_callback *cb, int type, 190 const struct tc_action_ops *ops, 191 struct netlink_ext_ack *extack) 192 { 193 struct tc_action_net *tn = net_generic(net, connmark_net_id); 194 195 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 196 } 197 198 static int tcf_connmark_search(struct net *net, struct tc_action **a, u32 index) 199 { 200 struct tc_action_net *tn = net_generic(net, connmark_net_id); 201 202 return tcf_idr_search(tn, a, index); 203 } 204 205 static struct tc_action_ops act_connmark_ops = { 206 .kind = "connmark", 207 .type = TCA_ACT_CONNMARK, 208 .owner = THIS_MODULE, 209 .act = tcf_connmark_act, 210 .dump = tcf_connmark_dump, 211 .init = tcf_connmark_init, 212 .walk = tcf_connmark_walker, 213 .lookup = tcf_connmark_search, 214 .size = sizeof(struct tcf_connmark_info), 215 }; 216 217 static __net_init int connmark_init_net(struct net *net) 218 { 219 struct tc_action_net *tn = net_generic(net, connmark_net_id); 220 221 return tc_action_net_init(tn, &act_connmark_ops); 222 } 223 224 static void __net_exit connmark_exit_net(struct list_head *net_list) 225 { 226 tc_action_net_exit(net_list, connmark_net_id); 227 } 228 229 static struct pernet_operations connmark_net_ops = { 230 .init = connmark_init_net, 231 .exit_batch = connmark_exit_net, 232 .id = &connmark_net_id, 233 .size = sizeof(struct tc_action_net), 234 }; 235 236 static int __init connmark_init_module(void) 237 { 238 return tcf_register_action(&act_connmark_ops, &connmark_net_ops); 239 } 240 241 static void __exit connmark_cleanup_module(void) 242 { 243 tcf_unregister_action(&act_connmark_ops, &connmark_net_ops); 244 } 245 246 module_init(connmark_init_module); 247 module_exit(connmark_cleanup_module); 248 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>"); 249 MODULE_DESCRIPTION("Connection tracking mark restoring"); 250 MODULE_LICENSE("GPL"); 251