1 // SPDX-License-Identifier: GPL-2.0+ 2 /* net/sched/act_ctinfo.c netfilter ctinfo connmark actions 3 * 4 * Copyright (c) 2019 Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> 5 */ 6 7 #include <linux/module.h> 8 #include <linux/init.h> 9 #include <linux/kernel.h> 10 #include <linux/skbuff.h> 11 #include <linux/rtnetlink.h> 12 #include <linux/pkt_cls.h> 13 #include <linux/ip.h> 14 #include <linux/ipv6.h> 15 #include <net/netlink.h> 16 #include <net/pkt_sched.h> 17 #include <net/act_api.h> 18 #include <net/pkt_cls.h> 19 #include <uapi/linux/tc_act/tc_ctinfo.h> 20 #include <net/tc_act/tc_ctinfo.h> 21 22 #include <net/netfilter/nf_conntrack.h> 23 #include <net/netfilter/nf_conntrack_core.h> 24 #include <net/netfilter/nf_conntrack_ecache.h> 25 #include <net/netfilter/nf_conntrack_zones.h> 26 27 static struct tc_action_ops act_ctinfo_ops; 28 static unsigned int ctinfo_net_id; 29 30 static void tcf_ctinfo_dscp_set(struct nf_conn *ct, struct tcf_ctinfo *ca, 31 struct tcf_ctinfo_params *cp, 32 struct sk_buff *skb, int wlen, int proto) 33 { 34 u8 dscp, newdscp; 35 36 newdscp = (((ct->mark & cp->dscpmask) >> cp->dscpmaskshift) << 2) & 37 ~INET_ECN_MASK; 38 39 switch (proto) { 40 case NFPROTO_IPV4: 41 dscp = ipv4_get_dsfield(ip_hdr(skb)) & ~INET_ECN_MASK; 42 if (dscp != newdscp) { 43 if (likely(!skb_try_make_writable(skb, wlen))) { 44 ipv4_change_dsfield(ip_hdr(skb), 45 INET_ECN_MASK, 46 newdscp); 47 ca->stats_dscp_set++; 48 } else { 49 ca->stats_dscp_error++; 50 } 51 } 52 break; 53 case NFPROTO_IPV6: 54 dscp = ipv6_get_dsfield(ipv6_hdr(skb)) & ~INET_ECN_MASK; 55 if (dscp != newdscp) { 56 if (likely(!skb_try_make_writable(skb, wlen))) { 57 ipv6_change_dsfield(ipv6_hdr(skb), 58 INET_ECN_MASK, 59 newdscp); 60 ca->stats_dscp_set++; 61 } else { 62 ca->stats_dscp_error++; 63 } 64 } 65 break; 66 default: 67 break; 68 } 69 } 70 71 static void tcf_ctinfo_cpmark_set(struct nf_conn *ct, struct tcf_ctinfo *ca, 72 struct tcf_ctinfo_params *cp, 73 struct sk_buff *skb) 74 { 75 ca->stats_cpmark_set++; 76 skb->mark = ct->mark & cp->cpmarkmask; 77 } 78 79 static int tcf_ctinfo_act(struct sk_buff *skb, const struct tc_action *a, 80 struct tcf_result *res) 81 { 82 const struct nf_conntrack_tuple_hash *thash = NULL; 83 struct tcf_ctinfo *ca = to_ctinfo(a); 84 struct nf_conntrack_tuple tuple; 85 struct nf_conntrack_zone zone; 86 enum ip_conntrack_info ctinfo; 87 struct tcf_ctinfo_params *cp; 88 struct nf_conn *ct; 89 int proto, wlen; 90 int action; 91 92 cp = rcu_dereference_bh(ca->params); 93 94 tcf_lastuse_update(&ca->tcf_tm); 95 bstats_update(&ca->tcf_bstats, skb); 96 action = READ_ONCE(ca->tcf_action); 97 98 wlen = skb_network_offset(skb); 99 if (tc_skb_protocol(skb) == htons(ETH_P_IP)) { 100 wlen += sizeof(struct iphdr); 101 if (!pskb_may_pull(skb, wlen)) 102 goto out; 103 104 proto = NFPROTO_IPV4; 105 } else if (tc_skb_protocol(skb) == htons(ETH_P_IPV6)) { 106 wlen += sizeof(struct ipv6hdr); 107 if (!pskb_may_pull(skb, wlen)) 108 goto out; 109 110 proto = NFPROTO_IPV6; 111 } else { 112 goto out; 113 } 114 115 ct = nf_ct_get(skb, &ctinfo); 116 if (!ct) { /* look harder, usually ingress */ 117 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), 118 proto, cp->net, &tuple)) 119 goto out; 120 zone.id = cp->zone; 121 zone.dir = NF_CT_DEFAULT_ZONE_DIR; 122 123 thash = nf_conntrack_find_get(cp->net, &zone, &tuple); 124 if (!thash) 125 goto out; 126 127 ct = nf_ct_tuplehash_to_ctrack(thash); 128 } 129 130 if (cp->mode & CTINFO_MODE_DSCP) 131 if (!cp->dscpstatemask || (ct->mark & cp->dscpstatemask)) 132 tcf_ctinfo_dscp_set(ct, ca, cp, skb, wlen, proto); 133 134 if (cp->mode & CTINFO_MODE_CPMARK) 135 tcf_ctinfo_cpmark_set(ct, ca, cp, skb); 136 137 if (thash) 138 nf_ct_put(ct); 139 out: 140 return action; 141 } 142 143 static const struct nla_policy ctinfo_policy[TCA_CTINFO_MAX + 1] = { 144 [TCA_CTINFO_ACT] = { .type = NLA_EXACT_LEN, 145 .len = sizeof(struct 146 tc_ctinfo) }, 147 [TCA_CTINFO_ZONE] = { .type = NLA_U16 }, 148 [TCA_CTINFO_PARMS_DSCP_MASK] = { .type = NLA_U32 }, 149 [TCA_CTINFO_PARMS_DSCP_STATEMASK] = { .type = NLA_U32 }, 150 [TCA_CTINFO_PARMS_CPMARK_MASK] = { .type = NLA_U32 }, 151 }; 152 153 static int tcf_ctinfo_init(struct net *net, struct nlattr *nla, 154 struct nlattr *est, struct tc_action **a, 155 int ovr, int bind, bool rtnl_held, 156 struct tcf_proto *tp, u32 flags, 157 struct netlink_ext_ack *extack) 158 { 159 struct tc_action_net *tn = net_generic(net, ctinfo_net_id); 160 u32 dscpmask = 0, dscpstatemask, index; 161 struct nlattr *tb[TCA_CTINFO_MAX + 1]; 162 struct tcf_ctinfo_params *cp_new; 163 struct tcf_chain *goto_ch = NULL; 164 struct tc_ctinfo *actparm; 165 struct tcf_ctinfo *ci; 166 u8 dscpmaskshift; 167 int ret = 0, err; 168 169 if (!nla) { 170 NL_SET_ERR_MSG_MOD(extack, "ctinfo requires attributes to be passed"); 171 return -EINVAL; 172 } 173 174 err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, ctinfo_policy, extack); 175 if (err < 0) 176 return err; 177 178 if (!tb[TCA_CTINFO_ACT]) { 179 NL_SET_ERR_MSG_MOD(extack, 180 "Missing required TCA_CTINFO_ACT attribute"); 181 return -EINVAL; 182 } 183 actparm = nla_data(tb[TCA_CTINFO_ACT]); 184 185 /* do some basic validation here before dynamically allocating things */ 186 /* that we would otherwise have to clean up. */ 187 if (tb[TCA_CTINFO_PARMS_DSCP_MASK]) { 188 dscpmask = nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_MASK]); 189 /* need contiguous 6 bit mask */ 190 dscpmaskshift = dscpmask ? __ffs(dscpmask) : 0; 191 if ((~0 & (dscpmask >> dscpmaskshift)) != 0x3f) { 192 NL_SET_ERR_MSG_ATTR(extack, 193 tb[TCA_CTINFO_PARMS_DSCP_MASK], 194 "dscp mask must be 6 contiguous bits"); 195 return -EINVAL; 196 } 197 dscpstatemask = tb[TCA_CTINFO_PARMS_DSCP_STATEMASK] ? 198 nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_STATEMASK]) : 0; 199 /* mask & statemask must not overlap */ 200 if (dscpmask & dscpstatemask) { 201 NL_SET_ERR_MSG_ATTR(extack, 202 tb[TCA_CTINFO_PARMS_DSCP_STATEMASK], 203 "dscp statemask must not overlap dscp mask"); 204 return -EINVAL; 205 } 206 } 207 208 /* done the validation:now to the actual action allocation */ 209 index = actparm->index; 210 err = tcf_idr_check_alloc(tn, &index, a, bind); 211 if (!err) { 212 ret = tcf_idr_create(tn, index, est, a, 213 &act_ctinfo_ops, bind, false, 0); 214 if (ret) { 215 tcf_idr_cleanup(tn, index); 216 return ret; 217 } 218 ret = ACT_P_CREATED; 219 } else if (err > 0) { 220 if (bind) /* don't override defaults */ 221 return 0; 222 if (!ovr) { 223 tcf_idr_release(*a, bind); 224 return -EEXIST; 225 } 226 } else { 227 return err; 228 } 229 230 err = tcf_action_check_ctrlact(actparm->action, tp, &goto_ch, extack); 231 if (err < 0) 232 goto release_idr; 233 234 ci = to_ctinfo(*a); 235 236 cp_new = kzalloc(sizeof(*cp_new), GFP_KERNEL); 237 if (unlikely(!cp_new)) { 238 err = -ENOMEM; 239 goto put_chain; 240 } 241 242 cp_new->net = net; 243 cp_new->zone = tb[TCA_CTINFO_ZONE] ? 244 nla_get_u16(tb[TCA_CTINFO_ZONE]) : 0; 245 if (dscpmask) { 246 cp_new->dscpmask = dscpmask; 247 cp_new->dscpmaskshift = dscpmaskshift; 248 cp_new->dscpstatemask = dscpstatemask; 249 cp_new->mode |= CTINFO_MODE_DSCP; 250 } 251 252 if (tb[TCA_CTINFO_PARMS_CPMARK_MASK]) { 253 cp_new->cpmarkmask = 254 nla_get_u32(tb[TCA_CTINFO_PARMS_CPMARK_MASK]); 255 cp_new->mode |= CTINFO_MODE_CPMARK; 256 } 257 258 spin_lock_bh(&ci->tcf_lock); 259 goto_ch = tcf_action_set_ctrlact(*a, actparm->action, goto_ch); 260 cp_new = rcu_replace_pointer(ci->params, cp_new, 261 lockdep_is_held(&ci->tcf_lock)); 262 spin_unlock_bh(&ci->tcf_lock); 263 264 if (goto_ch) 265 tcf_chain_put_by_act(goto_ch); 266 if (cp_new) 267 kfree_rcu(cp_new, rcu); 268 269 if (ret == ACT_P_CREATED) 270 tcf_idr_insert(tn, *a); 271 272 return ret; 273 274 put_chain: 275 if (goto_ch) 276 tcf_chain_put_by_act(goto_ch); 277 release_idr: 278 tcf_idr_release(*a, bind); 279 return err; 280 } 281 282 static int tcf_ctinfo_dump(struct sk_buff *skb, struct tc_action *a, 283 int bind, int ref) 284 { 285 struct tcf_ctinfo *ci = to_ctinfo(a); 286 struct tc_ctinfo opt = { 287 .index = ci->tcf_index, 288 .refcnt = refcount_read(&ci->tcf_refcnt) - ref, 289 .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind, 290 }; 291 unsigned char *b = skb_tail_pointer(skb); 292 struct tcf_ctinfo_params *cp; 293 struct tcf_t t; 294 295 spin_lock_bh(&ci->tcf_lock); 296 cp = rcu_dereference_protected(ci->params, 297 lockdep_is_held(&ci->tcf_lock)); 298 299 tcf_tm_dump(&t, &ci->tcf_tm); 300 if (nla_put_64bit(skb, TCA_CTINFO_TM, sizeof(t), &t, TCA_CTINFO_PAD)) 301 goto nla_put_failure; 302 303 opt.action = ci->tcf_action; 304 if (nla_put(skb, TCA_CTINFO_ACT, sizeof(opt), &opt)) 305 goto nla_put_failure; 306 307 if (nla_put_u16(skb, TCA_CTINFO_ZONE, cp->zone)) 308 goto nla_put_failure; 309 310 if (cp->mode & CTINFO_MODE_DSCP) { 311 if (nla_put_u32(skb, TCA_CTINFO_PARMS_DSCP_MASK, 312 cp->dscpmask)) 313 goto nla_put_failure; 314 if (nla_put_u32(skb, TCA_CTINFO_PARMS_DSCP_STATEMASK, 315 cp->dscpstatemask)) 316 goto nla_put_failure; 317 } 318 319 if (cp->mode & CTINFO_MODE_CPMARK) { 320 if (nla_put_u32(skb, TCA_CTINFO_PARMS_CPMARK_MASK, 321 cp->cpmarkmask)) 322 goto nla_put_failure; 323 } 324 325 if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_DSCP_SET, 326 ci->stats_dscp_set, TCA_CTINFO_PAD)) 327 goto nla_put_failure; 328 329 if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_DSCP_ERROR, 330 ci->stats_dscp_error, TCA_CTINFO_PAD)) 331 goto nla_put_failure; 332 333 if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_CPMARK_SET, 334 ci->stats_cpmark_set, TCA_CTINFO_PAD)) 335 goto nla_put_failure; 336 337 spin_unlock_bh(&ci->tcf_lock); 338 return skb->len; 339 340 nla_put_failure: 341 spin_unlock_bh(&ci->tcf_lock); 342 nlmsg_trim(skb, b); 343 return -1; 344 } 345 346 static int tcf_ctinfo_walker(struct net *net, struct sk_buff *skb, 347 struct netlink_callback *cb, int type, 348 const struct tc_action_ops *ops, 349 struct netlink_ext_ack *extack) 350 { 351 struct tc_action_net *tn = net_generic(net, ctinfo_net_id); 352 353 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 354 } 355 356 static int tcf_ctinfo_search(struct net *net, struct tc_action **a, u32 index) 357 { 358 struct tc_action_net *tn = net_generic(net, ctinfo_net_id); 359 360 return tcf_idr_search(tn, a, index); 361 } 362 363 static struct tc_action_ops act_ctinfo_ops = { 364 .kind = "ctinfo", 365 .id = TCA_ID_CTINFO, 366 .owner = THIS_MODULE, 367 .act = tcf_ctinfo_act, 368 .dump = tcf_ctinfo_dump, 369 .init = tcf_ctinfo_init, 370 .walk = tcf_ctinfo_walker, 371 .lookup = tcf_ctinfo_search, 372 .size = sizeof(struct tcf_ctinfo), 373 }; 374 375 static __net_init int ctinfo_init_net(struct net *net) 376 { 377 struct tc_action_net *tn = net_generic(net, ctinfo_net_id); 378 379 return tc_action_net_init(net, tn, &act_ctinfo_ops); 380 } 381 382 static void __net_exit ctinfo_exit_net(struct list_head *net_list) 383 { 384 tc_action_net_exit(net_list, ctinfo_net_id); 385 } 386 387 static struct pernet_operations ctinfo_net_ops = { 388 .init = ctinfo_init_net, 389 .exit_batch = ctinfo_exit_net, 390 .id = &ctinfo_net_id, 391 .size = sizeof(struct tc_action_net), 392 }; 393 394 static int __init ctinfo_init_module(void) 395 { 396 return tcf_register_action(&act_ctinfo_ops, &ctinfo_net_ops); 397 } 398 399 static void __exit ctinfo_cleanup_module(void) 400 { 401 tcf_unregister_action(&act_ctinfo_ops, &ctinfo_net_ops); 402 } 403 404 module_init(ctinfo_init_module); 405 module_exit(ctinfo_cleanup_module); 406 MODULE_AUTHOR("Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>"); 407 MODULE_DESCRIPTION("Connection tracking mark actions"); 408 MODULE_LICENSE("GPL"); 409