1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * net/sched/act_connmark.c netfilter connmark retriever action 4 * skb mark is over-written 5 * 6 * Copyright (c) 2011 Felix Fietkau <nbd@openwrt.org> 7 */ 8 9 #include <linux/module.h> 10 #include <linux/init.h> 11 #include <linux/kernel.h> 12 #include <linux/skbuff.h> 13 #include <linux/rtnetlink.h> 14 #include <linux/pkt_cls.h> 15 #include <linux/ip.h> 16 #include <linux/ipv6.h> 17 #include <net/netlink.h> 18 #include <net/pkt_sched.h> 19 #include <net/act_api.h> 20 #include <net/pkt_cls.h> 21 #include <uapi/linux/tc_act/tc_connmark.h> 22 #include <net/tc_act/tc_connmark.h> 23 24 #include <net/netfilter/nf_conntrack.h> 25 #include <net/netfilter/nf_conntrack_core.h> 26 #include <net/netfilter/nf_conntrack_zones.h> 27 28 static unsigned int connmark_net_id; 29 static struct tc_action_ops act_connmark_ops; 30 31 static int tcf_connmark_act(struct sk_buff *skb, const struct tc_action *a, 32 struct tcf_result *res) 33 { 34 const struct nf_conntrack_tuple_hash *thash; 35 struct nf_conntrack_tuple tuple; 36 enum ip_conntrack_info ctinfo; 37 struct tcf_connmark_info *ca = to_connmark(a); 38 struct nf_conntrack_zone zone; 39 struct nf_conn *c; 40 int proto; 41 42 spin_lock(&ca->tcf_lock); 43 tcf_lastuse_update(&ca->tcf_tm); 44 bstats_update(&ca->tcf_bstats, skb); 45 46 switch (skb_protocol(skb, true)) { 47 case htons(ETH_P_IP): 48 if (skb->len < sizeof(struct iphdr)) 49 goto out; 50 51 proto = NFPROTO_IPV4; 52 break; 53 case htons(ETH_P_IPV6): 54 if (skb->len < sizeof(struct ipv6hdr)) 55 goto out; 56 57 proto = NFPROTO_IPV6; 58 break; 59 default: 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 tcf_proto *tp, u32 flags, 101 struct netlink_ext_ack *extack) 102 { 103 struct tc_action_net *tn = net_generic(net, connmark_net_id); 104 struct nlattr *tb[TCA_CONNMARK_MAX + 1]; 105 struct tcf_chain *goto_ch = NULL; 106 struct tcf_connmark_info *ci; 107 struct tc_connmark *parm; 108 int ret = 0, err; 109 u32 index; 110 111 if (!nla) 112 return -EINVAL; 113 114 ret = nla_parse_nested_deprecated(tb, TCA_CONNMARK_MAX, nla, 115 connmark_policy, NULL); 116 if (ret < 0) 117 return ret; 118 119 if (!tb[TCA_CONNMARK_PARMS]) 120 return -EINVAL; 121 122 parm = nla_data(tb[TCA_CONNMARK_PARMS]); 123 index = parm->index; 124 ret = tcf_idr_check_alloc(tn, &index, a, bind); 125 if (!ret) { 126 ret = tcf_idr_create(tn, index, est, a, 127 &act_connmark_ops, bind, false, 0); 128 if (ret) { 129 tcf_idr_cleanup(tn, index); 130 return ret; 131 } 132 133 ci = to_connmark(*a); 134 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, 135 extack); 136 if (err < 0) 137 goto release_idr; 138 tcf_action_set_ctrlact(*a, parm->action, goto_ch); 139 ci->net = net; 140 ci->zone = parm->zone; 141 142 tcf_idr_insert(tn, *a); 143 ret = ACT_P_CREATED; 144 } else if (ret > 0) { 145 ci = to_connmark(*a); 146 if (bind) 147 return 0; 148 if (!ovr) { 149 tcf_idr_release(*a, bind); 150 return -EEXIST; 151 } 152 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, 153 extack); 154 if (err < 0) 155 goto release_idr; 156 /* replacing action and zone */ 157 spin_lock_bh(&ci->tcf_lock); 158 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 159 ci->zone = parm->zone; 160 spin_unlock_bh(&ci->tcf_lock); 161 if (goto_ch) 162 tcf_chain_put_by_act(goto_ch); 163 ret = 0; 164 } 165 166 return ret; 167 release_idr: 168 tcf_idr_release(*a, bind); 169 return err; 170 } 171 172 static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a, 173 int bind, int ref) 174 { 175 unsigned char *b = skb_tail_pointer(skb); 176 struct tcf_connmark_info *ci = to_connmark(a); 177 struct tc_connmark opt = { 178 .index = ci->tcf_index, 179 .refcnt = refcount_read(&ci->tcf_refcnt) - ref, 180 .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind, 181 }; 182 struct tcf_t t; 183 184 spin_lock_bh(&ci->tcf_lock); 185 opt.action = ci->tcf_action; 186 opt.zone = ci->zone; 187 if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt)) 188 goto nla_put_failure; 189 190 tcf_tm_dump(&t, &ci->tcf_tm); 191 if (nla_put_64bit(skb, TCA_CONNMARK_TM, sizeof(t), &t, 192 TCA_CONNMARK_PAD)) 193 goto nla_put_failure; 194 spin_unlock_bh(&ci->tcf_lock); 195 196 return skb->len; 197 198 nla_put_failure: 199 spin_unlock_bh(&ci->tcf_lock); 200 nlmsg_trim(skb, b); 201 return -1; 202 } 203 204 static int tcf_connmark_walker(struct net *net, struct sk_buff *skb, 205 struct netlink_callback *cb, int type, 206 const struct tc_action_ops *ops, 207 struct netlink_ext_ack *extack) 208 { 209 struct tc_action_net *tn = net_generic(net, connmark_net_id); 210 211 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 212 } 213 214 static int tcf_connmark_search(struct net *net, struct tc_action **a, u32 index) 215 { 216 struct tc_action_net *tn = net_generic(net, connmark_net_id); 217 218 return tcf_idr_search(tn, a, index); 219 } 220 221 static struct tc_action_ops act_connmark_ops = { 222 .kind = "connmark", 223 .id = TCA_ID_CONNMARK, 224 .owner = THIS_MODULE, 225 .act = tcf_connmark_act, 226 .dump = tcf_connmark_dump, 227 .init = tcf_connmark_init, 228 .walk = tcf_connmark_walker, 229 .lookup = tcf_connmark_search, 230 .size = sizeof(struct tcf_connmark_info), 231 }; 232 233 static __net_init int connmark_init_net(struct net *net) 234 { 235 struct tc_action_net *tn = net_generic(net, connmark_net_id); 236 237 return tc_action_net_init(net, tn, &act_connmark_ops); 238 } 239 240 static void __net_exit connmark_exit_net(struct list_head *net_list) 241 { 242 tc_action_net_exit(net_list, connmark_net_id); 243 } 244 245 static struct pernet_operations connmark_net_ops = { 246 .init = connmark_init_net, 247 .exit_batch = connmark_exit_net, 248 .id = &connmark_net_id, 249 .size = sizeof(struct tc_action_net), 250 }; 251 252 static int __init connmark_init_module(void) 253 { 254 return tcf_register_action(&act_connmark_ops, &connmark_net_ops); 255 } 256 257 static void __exit connmark_cleanup_module(void) 258 { 259 tcf_unregister_action(&act_connmark_ops, &connmark_net_ops); 260 } 261 262 module_init(connmark_init_module); 263 module_exit(connmark_cleanup_module); 264 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>"); 265 MODULE_DESCRIPTION("Connection tracking mark restoring"); 266 MODULE_LICENSE("GPL"); 267