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 struct tc_action_ops act_connmark_ops; 29 30 static int tcf_connmark_act(struct sk_buff *skb, const struct tc_action *a, 31 struct tcf_result *res) 32 { 33 const struct nf_conntrack_tuple_hash *thash; 34 struct nf_conntrack_tuple tuple; 35 enum ip_conntrack_info ctinfo; 36 struct tcf_connmark_info *ca = to_connmark(a); 37 struct nf_conntrack_zone zone; 38 struct nf_conn *c; 39 int proto; 40 41 spin_lock(&ca->tcf_lock); 42 tcf_lastuse_update(&ca->tcf_tm); 43 bstats_update(&ca->tcf_bstats, skb); 44 45 switch (skb_protocol(skb, true)) { 46 case htons(ETH_P_IP): 47 if (skb->len < sizeof(struct iphdr)) 48 goto out; 49 50 proto = NFPROTO_IPV4; 51 break; 52 case htons(ETH_P_IPV6): 53 if (skb->len < sizeof(struct ipv6hdr)) 54 goto out; 55 56 proto = NFPROTO_IPV6; 57 break; 58 default: 59 goto out; 60 } 61 62 c = nf_ct_get(skb, &ctinfo); 63 if (c) { 64 skb->mark = READ_ONCE(c->mark); 65 /* using overlimits stats to count how many packets marked */ 66 ca->tcf_qstats.overlimits++; 67 goto out; 68 } 69 70 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), 71 proto, ca->net, &tuple)) 72 goto out; 73 74 zone.id = ca->zone; 75 zone.dir = NF_CT_DEFAULT_ZONE_DIR; 76 77 thash = nf_conntrack_find_get(ca->net, &zone, &tuple); 78 if (!thash) 79 goto out; 80 81 c = nf_ct_tuplehash_to_ctrack(thash); 82 /* using overlimits stats to count how many packets marked */ 83 ca->tcf_qstats.overlimits++; 84 skb->mark = READ_ONCE(c->mark); 85 nf_ct_put(c); 86 87 out: 88 spin_unlock(&ca->tcf_lock); 89 return ca->tcf_action; 90 } 91 92 static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = { 93 [TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) }, 94 }; 95 96 static int tcf_connmark_init(struct net *net, struct nlattr *nla, 97 struct nlattr *est, struct tc_action **a, 98 struct tcf_proto *tp, u32 flags, 99 struct netlink_ext_ack *extack) 100 { 101 struct tc_action_net *tn = net_generic(net, act_connmark_ops.net_id); 102 struct nlattr *tb[TCA_CONNMARK_MAX + 1]; 103 bool bind = flags & TCA_ACT_FLAGS_BIND; 104 struct tcf_chain *goto_ch = NULL; 105 struct tcf_connmark_info *ci; 106 struct tc_connmark *parm; 107 int ret = 0, err; 108 u32 index; 109 110 if (!nla) 111 return -EINVAL; 112 113 ret = nla_parse_nested_deprecated(tb, TCA_CONNMARK_MAX, nla, 114 connmark_policy, NULL); 115 if (ret < 0) 116 return ret; 117 118 if (!tb[TCA_CONNMARK_PARMS]) 119 return -EINVAL; 120 121 parm = nla_data(tb[TCA_CONNMARK_PARMS]); 122 index = parm->index; 123 ret = tcf_idr_check_alloc(tn, &index, a, bind); 124 if (!ret) { 125 ret = tcf_idr_create(tn, index, est, a, 126 &act_connmark_ops, bind, false, flags); 127 if (ret) { 128 tcf_idr_cleanup(tn, index); 129 return ret; 130 } 131 132 ci = to_connmark(*a); 133 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, 134 extack); 135 if (err < 0) 136 goto release_idr; 137 tcf_action_set_ctrlact(*a, parm->action, goto_ch); 138 ci->net = net; 139 ci->zone = parm->zone; 140 141 ret = ACT_P_CREATED; 142 } else if (ret > 0) { 143 ci = to_connmark(*a); 144 if (bind) 145 return 0; 146 if (!(flags & TCA_ACT_FLAGS_REPLACE)) { 147 tcf_idr_release(*a, bind); 148 return -EEXIST; 149 } 150 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, 151 extack); 152 if (err < 0) 153 goto release_idr; 154 /* replacing action and zone */ 155 spin_lock_bh(&ci->tcf_lock); 156 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 157 ci->zone = parm->zone; 158 spin_unlock_bh(&ci->tcf_lock); 159 if (goto_ch) 160 tcf_chain_put_by_act(goto_ch); 161 ret = 0; 162 } 163 164 return ret; 165 release_idr: 166 tcf_idr_release(*a, bind); 167 return err; 168 } 169 170 static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a, 171 int bind, int ref) 172 { 173 unsigned char *b = skb_tail_pointer(skb); 174 struct tcf_connmark_info *ci = to_connmark(a); 175 struct tc_connmark opt = { 176 .index = ci->tcf_index, 177 .refcnt = refcount_read(&ci->tcf_refcnt) - ref, 178 .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind, 179 }; 180 struct tcf_t t; 181 182 spin_lock_bh(&ci->tcf_lock); 183 opt.action = ci->tcf_action; 184 opt.zone = ci->zone; 185 if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt)) 186 goto nla_put_failure; 187 188 tcf_tm_dump(&t, &ci->tcf_tm); 189 if (nla_put_64bit(skb, TCA_CONNMARK_TM, sizeof(t), &t, 190 TCA_CONNMARK_PAD)) 191 goto nla_put_failure; 192 spin_unlock_bh(&ci->tcf_lock); 193 194 return skb->len; 195 196 nla_put_failure: 197 spin_unlock_bh(&ci->tcf_lock); 198 nlmsg_trim(skb, b); 199 return -1; 200 } 201 202 static struct tc_action_ops act_connmark_ops = { 203 .kind = "connmark", 204 .id = TCA_ID_CONNMARK, 205 .owner = THIS_MODULE, 206 .act = tcf_connmark_act, 207 .dump = tcf_connmark_dump, 208 .init = tcf_connmark_init, 209 .size = sizeof(struct tcf_connmark_info), 210 }; 211 212 static __net_init int connmark_init_net(struct net *net) 213 { 214 struct tc_action_net *tn = net_generic(net, act_connmark_ops.net_id); 215 216 return tc_action_net_init(net, tn, &act_connmark_ops); 217 } 218 219 static void __net_exit connmark_exit_net(struct list_head *net_list) 220 { 221 tc_action_net_exit(net_list, act_connmark_ops.net_id); 222 } 223 224 static struct pernet_operations connmark_net_ops = { 225 .init = connmark_init_net, 226 .exit_batch = connmark_exit_net, 227 .id = &act_connmark_ops.net_id, 228 .size = sizeof(struct tc_action_net), 229 }; 230 231 static int __init connmark_init_module(void) 232 { 233 return tcf_register_action(&act_connmark_ops, &connmark_net_ops); 234 } 235 236 static void __exit connmark_cleanup_module(void) 237 { 238 tcf_unregister_action(&act_connmark_ops, &connmark_net_ops); 239 } 240 241 module_init(connmark_init_module); 242 module_exit(connmark_cleanup_module); 243 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>"); 244 MODULE_DESCRIPTION("Connection tracking mark restoring"); 245 MODULE_LICENSE("GPL"); 246