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 nf_conntrack_zone zone; 40 struct nf_conn *c; 41 int proto; 42 43 spin_lock(&ca->tcf_lock); 44 tcf_lastuse_update(&ca->tcf_tm); 45 bstats_update(&ca->tcf_bstats, skb); 46 47 switch (skb_protocol(skb, true)) { 48 case htons(ETH_P_IP): 49 if (skb->len < sizeof(struct iphdr)) 50 goto out; 51 52 proto = NFPROTO_IPV4; 53 break; 54 case htons(ETH_P_IPV6): 55 if (skb->len < sizeof(struct ipv6hdr)) 56 goto out; 57 58 proto = NFPROTO_IPV6; 59 break; 60 default: 61 goto out; 62 } 63 64 c = nf_ct_get(skb, &ctinfo); 65 if (c) { 66 skb->mark = READ_ONCE(c->mark); 67 /* using overlimits stats to count how many packets marked */ 68 ca->tcf_qstats.overlimits++; 69 goto out; 70 } 71 72 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), 73 proto, ca->net, &tuple)) 74 goto out; 75 76 zone.id = ca->zone; 77 zone.dir = NF_CT_DEFAULT_ZONE_DIR; 78 79 thash = nf_conntrack_find_get(ca->net, &zone, &tuple); 80 if (!thash) 81 goto out; 82 83 c = nf_ct_tuplehash_to_ctrack(thash); 84 /* using overlimits stats to count how many packets marked */ 85 ca->tcf_qstats.overlimits++; 86 skb->mark = READ_ONCE(c->mark); 87 nf_ct_put(c); 88 89 out: 90 spin_unlock(&ca->tcf_lock); 91 return 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 nlattr *tb[TCA_CONNMARK_MAX + 1]; 105 bool bind = flags & TCA_ACT_FLAGS_BIND; 106 struct tcf_chain *goto_ch = NULL; 107 struct tcf_connmark_info *ci; 108 struct tc_connmark *parm; 109 int ret = 0, err; 110 u32 index; 111 112 if (!nla) 113 return -EINVAL; 114 115 ret = nla_parse_nested_deprecated(tb, TCA_CONNMARK_MAX, nla, 116 connmark_policy, NULL); 117 if (ret < 0) 118 return ret; 119 120 if (!tb[TCA_CONNMARK_PARMS]) 121 return -EINVAL; 122 123 parm = nla_data(tb[TCA_CONNMARK_PARMS]); 124 index = parm->index; 125 ret = tcf_idr_check_alloc(tn, &index, a, bind); 126 if (!ret) { 127 ret = tcf_idr_create(tn, index, est, a, 128 &act_connmark_ops, bind, false, flags); 129 if (ret) { 130 tcf_idr_cleanup(tn, index); 131 return ret; 132 } 133 134 ci = to_connmark(*a); 135 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, 136 extack); 137 if (err < 0) 138 goto release_idr; 139 tcf_action_set_ctrlact(*a, parm->action, goto_ch); 140 ci->net = net; 141 ci->zone = parm->zone; 142 143 ret = ACT_P_CREATED; 144 } else if (ret > 0) { 145 ci = to_connmark(*a); 146 if (bind) 147 return 0; 148 if (!(flags & TCA_ACT_FLAGS_REPLACE)) { 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 struct tc_action_ops act_connmark_ops = { 205 .kind = "connmark", 206 .id = TCA_ID_CONNMARK, 207 .owner = THIS_MODULE, 208 .act = tcf_connmark_act, 209 .dump = tcf_connmark_dump, 210 .init = tcf_connmark_init, 211 .size = sizeof(struct tcf_connmark_info), 212 }; 213 214 static __net_init int connmark_init_net(struct net *net) 215 { 216 struct tc_action_net *tn = net_generic(net, act_connmark_ops.net_id); 217 218 return tc_action_net_init(net, tn, &act_connmark_ops); 219 } 220 221 static void __net_exit connmark_exit_net(struct list_head *net_list) 222 { 223 tc_action_net_exit(net_list, act_connmark_ops.net_id); 224 } 225 226 static struct pernet_operations connmark_net_ops = { 227 .init = connmark_init_net, 228 .exit_batch = connmark_exit_net, 229 .id = &act_connmark_ops.net_id, 230 .size = sizeof(struct tc_action_net), 231 }; 232 233 static int __init connmark_init_module(void) 234 { 235 return tcf_register_action(&act_connmark_ops, &connmark_net_ops); 236 } 237 238 static void __exit connmark_cleanup_module(void) 239 { 240 tcf_unregister_action(&act_connmark_ops, &connmark_net_ops); 241 } 242 243 module_init(connmark_init_module); 244 module_exit(connmark_cleanup_module); 245 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>"); 246 MODULE_DESCRIPTION("Connection tracking mark restoring"); 247 MODULE_LICENSE("GPL"); 248