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 #include <net/tc_wrapper.h> 24 25 #include <net/netfilter/nf_conntrack.h> 26 #include <net/netfilter/nf_conntrack_core.h> 27 #include <net/netfilter/nf_conntrack_zones.h> 28 29 static struct tc_action_ops act_connmark_ops; 30 31 TC_INDIRECT_SCOPE int tcf_connmark_act(struct sk_buff *skb, 32 const struct tc_action *a, 33 struct tcf_result *res) 34 { 35 const struct nf_conntrack_tuple_hash *thash; 36 struct nf_conntrack_tuple tuple; 37 enum ip_conntrack_info ctinfo; 38 struct tcf_connmark_info *ca = to_connmark(a); 39 struct tcf_connmark_parms *parms; 40 struct nf_conntrack_zone zone; 41 struct nf_conn *c; 42 int proto; 43 44 tcf_lastuse_update(&ca->tcf_tm); 45 tcf_action_update_bstats(&ca->common, skb); 46 47 parms = rcu_dereference_bh(ca->parms); 48 49 switch (skb_protocol(skb, true)) { 50 case htons(ETH_P_IP): 51 if (skb->len < sizeof(struct iphdr)) 52 goto out; 53 54 proto = NFPROTO_IPV4; 55 break; 56 case htons(ETH_P_IPV6): 57 if (skb->len < sizeof(struct ipv6hdr)) 58 goto out; 59 60 proto = NFPROTO_IPV6; 61 break; 62 default: 63 goto out; 64 } 65 66 c = nf_ct_get(skb, &ctinfo); 67 if (c) { 68 skb->mark = READ_ONCE(c->mark); 69 goto count; 70 } 71 72 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, parms->net, 73 &tuple)) 74 goto out; 75 76 zone.id = parms->zone; 77 zone.dir = NF_CT_DEFAULT_ZONE_DIR; 78 79 thash = nf_conntrack_find_get(parms->net, &zone, &tuple); 80 if (!thash) 81 goto out; 82 83 c = nf_ct_tuplehash_to_ctrack(thash); 84 skb->mark = READ_ONCE(c->mark); 85 nf_ct_put(c); 86 87 count: 88 /* using overlimits stats to count how many packets marked */ 89 tcf_action_inc_overlimit_qstats(&ca->common); 90 out: 91 return READ_ONCE(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 struct tcf_proto *tp, u32 flags, 101 struct netlink_ext_ack *extack) 102 { 103 struct tc_action_net *tn = net_generic(net, act_connmark_ops.net_id); 104 struct tcf_connmark_parms *nparms, *oparms; 105 struct nlattr *tb[TCA_CONNMARK_MAX + 1]; 106 bool bind = flags & TCA_ACT_FLAGS_BIND; 107 struct tcf_chain *goto_ch = NULL; 108 struct tcf_connmark_info *ci; 109 struct tc_connmark *parm; 110 int ret = 0, err; 111 u32 index; 112 113 if (!nla) 114 return -EINVAL; 115 116 ret = nla_parse_nested_deprecated(tb, TCA_CONNMARK_MAX, nla, 117 connmark_policy, NULL); 118 if (ret < 0) 119 return ret; 120 121 if (!tb[TCA_CONNMARK_PARMS]) 122 return -EINVAL; 123 124 nparms = kzalloc(sizeof(*nparms), GFP_KERNEL); 125 if (!nparms) 126 return -ENOMEM; 127 128 parm = nla_data(tb[TCA_CONNMARK_PARMS]); 129 index = parm->index; 130 ret = tcf_idr_check_alloc(tn, &index, a, bind); 131 if (!ret) { 132 ret = tcf_idr_create_from_flags(tn, index, est, a, 133 &act_connmark_ops, bind, flags); 134 if (ret) { 135 tcf_idr_cleanup(tn, index); 136 err = ret; 137 goto out_free; 138 } 139 140 ci = to_connmark(*a); 141 142 nparms->net = net; 143 nparms->zone = parm->zone; 144 145 ret = ACT_P_CREATED; 146 } else if (ret > 0) { 147 ci = to_connmark(*a); 148 if (bind) { 149 err = 0; 150 goto out_free; 151 } 152 if (!(flags & TCA_ACT_FLAGS_REPLACE)) { 153 err = -EEXIST; 154 goto release_idr; 155 } 156 157 nparms->net = rtnl_dereference(ci->parms)->net; 158 nparms->zone = parm->zone; 159 160 ret = 0; 161 } else { 162 err = ret; 163 goto out_free; 164 } 165 166 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); 167 if (err < 0) 168 goto release_idr; 169 170 spin_lock_bh(&ci->tcf_lock); 171 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 172 oparms = rcu_replace_pointer(ci->parms, nparms, lockdep_is_held(&ci->tcf_lock)); 173 spin_unlock_bh(&ci->tcf_lock); 174 175 if (goto_ch) 176 tcf_chain_put_by_act(goto_ch); 177 178 if (oparms) 179 kfree_rcu(oparms, rcu); 180 181 return ret; 182 183 release_idr: 184 tcf_idr_release(*a, bind); 185 out_free: 186 kfree(nparms); 187 return err; 188 } 189 190 static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a, 191 int bind, int ref) 192 { 193 unsigned char *b = skb_tail_pointer(skb); 194 struct tcf_connmark_info *ci = to_connmark(a); 195 struct tc_connmark opt = { 196 .index = ci->tcf_index, 197 .refcnt = refcount_read(&ci->tcf_refcnt) - ref, 198 .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind, 199 }; 200 struct tcf_connmark_parms *parms; 201 struct tcf_t t; 202 203 spin_lock_bh(&ci->tcf_lock); 204 parms = rcu_dereference_protected(ci->parms, lockdep_is_held(&ci->tcf_lock)); 205 206 opt.action = ci->tcf_action; 207 opt.zone = parms->zone; 208 if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt)) 209 goto nla_put_failure; 210 211 tcf_tm_dump(&t, &ci->tcf_tm); 212 if (nla_put_64bit(skb, TCA_CONNMARK_TM, sizeof(t), &t, 213 TCA_CONNMARK_PAD)) 214 goto nla_put_failure; 215 spin_unlock_bh(&ci->tcf_lock); 216 217 return skb->len; 218 219 nla_put_failure: 220 spin_unlock_bh(&ci->tcf_lock); 221 nlmsg_trim(skb, b); 222 return -1; 223 } 224 225 static void tcf_connmark_cleanup(struct tc_action *a) 226 { 227 struct tcf_connmark_info *ci = to_connmark(a); 228 struct tcf_connmark_parms *parms; 229 230 parms = rcu_dereference_protected(ci->parms, 1); 231 if (parms) 232 kfree_rcu(parms, rcu); 233 } 234 235 static struct tc_action_ops act_connmark_ops = { 236 .kind = "connmark", 237 .id = TCA_ID_CONNMARK, 238 .owner = THIS_MODULE, 239 .act = tcf_connmark_act, 240 .dump = tcf_connmark_dump, 241 .init = tcf_connmark_init, 242 .cleanup = tcf_connmark_cleanup, 243 .size = sizeof(struct tcf_connmark_info), 244 }; 245 246 static __net_init int connmark_init_net(struct net *net) 247 { 248 struct tc_action_net *tn = net_generic(net, act_connmark_ops.net_id); 249 250 return tc_action_net_init(net, tn, &act_connmark_ops); 251 } 252 253 static void __net_exit connmark_exit_net(struct list_head *net_list) 254 { 255 tc_action_net_exit(net_list, act_connmark_ops.net_id); 256 } 257 258 static struct pernet_operations connmark_net_ops = { 259 .init = connmark_init_net, 260 .exit_batch = connmark_exit_net, 261 .id = &act_connmark_ops.net_id, 262 .size = sizeof(struct tc_action_net), 263 }; 264 265 static int __init connmark_init_module(void) 266 { 267 return tcf_register_action(&act_connmark_ops, &connmark_net_ops); 268 } 269 270 static void __exit connmark_cleanup_module(void) 271 { 272 tcf_unregister_action(&act_connmark_ops, &connmark_net_ops); 273 } 274 275 module_init(connmark_init_module); 276 module_exit(connmark_cleanup_module); 277 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>"); 278 MODULE_DESCRIPTION("Connection tracking mark restoring"); 279 MODULE_LICENSE("GPL"); 280