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 if (skb->protocol == htons(ETH_P_IP)) { 47 if (skb->len < sizeof(struct iphdr)) 48 goto out; 49 50 proto = NFPROTO_IPV4; 51 } else if (skb->protocol == htons(ETH_P_IPV6)) { 52 if (skb->len < sizeof(struct ipv6hdr)) 53 goto out; 54 55 proto = NFPROTO_IPV6; 56 } else { 57 goto out; 58 } 59 60 c = nf_ct_get(skb, &ctinfo); 61 if (c) { 62 skb->mark = c->mark; 63 /* using overlimits stats to count how many packets marked */ 64 ca->tcf_qstats.overlimits++; 65 goto out; 66 } 67 68 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), 69 proto, ca->net, &tuple)) 70 goto out; 71 72 zone.id = ca->zone; 73 zone.dir = NF_CT_DEFAULT_ZONE_DIR; 74 75 thash = nf_conntrack_find_get(ca->net, &zone, &tuple); 76 if (!thash) 77 goto out; 78 79 c = nf_ct_tuplehash_to_ctrack(thash); 80 /* using overlimits stats to count how many packets marked */ 81 ca->tcf_qstats.overlimits++; 82 skb->mark = c->mark; 83 nf_ct_put(c); 84 85 out: 86 spin_unlock(&ca->tcf_lock); 87 return ca->tcf_action; 88 } 89 90 static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = { 91 [TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) }, 92 }; 93 94 static int tcf_connmark_init(struct net *net, struct nlattr *nla, 95 struct nlattr *est, struct tc_action **a, 96 int ovr, int bind, bool rtnl_held, 97 struct tcf_proto *tp, 98 struct netlink_ext_ack *extack) 99 { 100 struct tc_action_net *tn = net_generic(net, connmark_net_id); 101 struct nlattr *tb[TCA_CONNMARK_MAX + 1]; 102 struct tcf_chain *goto_ch = NULL; 103 struct tcf_connmark_info *ci; 104 struct tc_connmark *parm; 105 int ret = 0, err; 106 u32 index; 107 108 if (!nla) 109 return -EINVAL; 110 111 ret = nla_parse_nested_deprecated(tb, TCA_CONNMARK_MAX, nla, 112 connmark_policy, 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 index = parm->index; 121 ret = tcf_idr_check_alloc(tn, &index, a, bind); 122 if (!ret) { 123 ret = tcf_idr_create(tn, index, est, a, 124 &act_connmark_ops, bind, false); 125 if (ret) { 126 tcf_idr_cleanup(tn, index); 127 return ret; 128 } 129 130 ci = to_connmark(*a); 131 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, 132 extack); 133 if (err < 0) 134 goto release_idr; 135 tcf_action_set_ctrlact(*a, parm->action, goto_ch); 136 ci->net = net; 137 ci->zone = parm->zone; 138 139 tcf_idr_insert(tn, *a); 140 ret = ACT_P_CREATED; 141 } else if (ret > 0) { 142 ci = to_connmark(*a); 143 if (bind) 144 return 0; 145 if (!ovr) { 146 tcf_idr_release(*a, bind); 147 return -EEXIST; 148 } 149 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, 150 extack); 151 if (err < 0) 152 goto release_idr; 153 /* replacing action and zone */ 154 spin_lock_bh(&ci->tcf_lock); 155 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 156 ci->zone = parm->zone; 157 spin_unlock_bh(&ci->tcf_lock); 158 if (goto_ch) 159 tcf_chain_put_by_act(goto_ch); 160 ret = 0; 161 } 162 163 return ret; 164 release_idr: 165 tcf_idr_release(*a, bind); 166 return err; 167 } 168 169 static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a, 170 int bind, int ref) 171 { 172 unsigned char *b = skb_tail_pointer(skb); 173 struct tcf_connmark_info *ci = to_connmark(a); 174 struct tc_connmark opt = { 175 .index = ci->tcf_index, 176 .refcnt = refcount_read(&ci->tcf_refcnt) - ref, 177 .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind, 178 }; 179 struct tcf_t t; 180 181 spin_lock_bh(&ci->tcf_lock); 182 opt.action = ci->tcf_action; 183 opt.zone = ci->zone; 184 if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt)) 185 goto nla_put_failure; 186 187 tcf_tm_dump(&t, &ci->tcf_tm); 188 if (nla_put_64bit(skb, TCA_CONNMARK_TM, sizeof(t), &t, 189 TCA_CONNMARK_PAD)) 190 goto nla_put_failure; 191 spin_unlock_bh(&ci->tcf_lock); 192 193 return skb->len; 194 195 nla_put_failure: 196 spin_unlock_bh(&ci->tcf_lock); 197 nlmsg_trim(skb, b); 198 return -1; 199 } 200 201 static int tcf_connmark_walker(struct net *net, struct sk_buff *skb, 202 struct netlink_callback *cb, int type, 203 const struct tc_action_ops *ops, 204 struct netlink_ext_ack *extack) 205 { 206 struct tc_action_net *tn = net_generic(net, connmark_net_id); 207 208 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 209 } 210 211 static int tcf_connmark_search(struct net *net, struct tc_action **a, u32 index) 212 { 213 struct tc_action_net *tn = net_generic(net, connmark_net_id); 214 215 return tcf_idr_search(tn, a, index); 216 } 217 218 static struct tc_action_ops act_connmark_ops = { 219 .kind = "connmark", 220 .id = TCA_ID_CONNMARK, 221 .owner = THIS_MODULE, 222 .act = tcf_connmark_act, 223 .dump = tcf_connmark_dump, 224 .init = tcf_connmark_init, 225 .walk = tcf_connmark_walker, 226 .lookup = tcf_connmark_search, 227 .size = sizeof(struct tcf_connmark_info), 228 }; 229 230 static __net_init int connmark_init_net(struct net *net) 231 { 232 struct tc_action_net *tn = net_generic(net, connmark_net_id); 233 234 return tc_action_net_init(net, tn, &act_connmark_ops); 235 } 236 237 static void __net_exit connmark_exit_net(struct list_head *net_list) 238 { 239 tc_action_net_exit(net_list, connmark_net_id); 240 } 241 242 static struct pernet_operations connmark_net_ops = { 243 .init = connmark_init_net, 244 .exit_batch = connmark_exit_net, 245 .id = &connmark_net_id, 246 .size = sizeof(struct tc_action_net), 247 }; 248 249 static int __init connmark_init_module(void) 250 { 251 return tcf_register_action(&act_connmark_ops, &connmark_net_ops); 252 } 253 254 static void __exit connmark_cleanup_module(void) 255 { 256 tcf_unregister_action(&act_connmark_ops, &connmark_net_ops); 257 } 258 259 module_init(connmark_init_module); 260 module_exit(connmark_cleanup_module); 261 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>"); 262 MODULE_DESCRIPTION("Connection tracking mark restoring"); 263 MODULE_LICENSE("GPL"); 264