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 switch (skb_protocol(skb, true)) { 100 case htons(ETH_P_IP): 101 wlen += sizeof(struct iphdr); 102 if (!pskb_may_pull(skb, wlen)) 103 goto out; 104 105 proto = NFPROTO_IPV4; 106 break; 107 case htons(ETH_P_IPV6): 108 wlen += sizeof(struct ipv6hdr); 109 if (!pskb_may_pull(skb, wlen)) 110 goto out; 111 112 proto = NFPROTO_IPV6; 113 break; 114 default: 115 goto out; 116 } 117 118 ct = nf_ct_get(skb, &ctinfo); 119 if (!ct) { /* look harder, usually ingress */ 120 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), 121 proto, cp->net, &tuple)) 122 goto out; 123 zone.id = cp->zone; 124 zone.dir = NF_CT_DEFAULT_ZONE_DIR; 125 126 thash = nf_conntrack_find_get(cp->net, &zone, &tuple); 127 if (!thash) 128 goto out; 129 130 ct = nf_ct_tuplehash_to_ctrack(thash); 131 } 132 133 if (cp->mode & CTINFO_MODE_DSCP) 134 if (!cp->dscpstatemask || (ct->mark & cp->dscpstatemask)) 135 tcf_ctinfo_dscp_set(ct, ca, cp, skb, wlen, proto); 136 137 if (cp->mode & CTINFO_MODE_CPMARK) 138 tcf_ctinfo_cpmark_set(ct, ca, cp, skb); 139 140 if (thash) 141 nf_ct_put(ct); 142 out: 143 return action; 144 } 145 146 static const struct nla_policy ctinfo_policy[TCA_CTINFO_MAX + 1] = { 147 [TCA_CTINFO_ACT] = { .type = NLA_EXACT_LEN, 148 .len = sizeof(struct 149 tc_ctinfo) }, 150 [TCA_CTINFO_ZONE] = { .type = NLA_U16 }, 151 [TCA_CTINFO_PARMS_DSCP_MASK] = { .type = NLA_U32 }, 152 [TCA_CTINFO_PARMS_DSCP_STATEMASK] = { .type = NLA_U32 }, 153 [TCA_CTINFO_PARMS_CPMARK_MASK] = { .type = NLA_U32 }, 154 }; 155 156 static int tcf_ctinfo_init(struct net *net, struct nlattr *nla, 157 struct nlattr *est, struct tc_action **a, 158 int ovr, int bind, bool rtnl_held, 159 struct tcf_proto *tp, u32 flags, 160 struct netlink_ext_ack *extack) 161 { 162 struct tc_action_net *tn = net_generic(net, ctinfo_net_id); 163 u32 dscpmask = 0, dscpstatemask, index; 164 struct nlattr *tb[TCA_CTINFO_MAX + 1]; 165 struct tcf_ctinfo_params *cp_new; 166 struct tcf_chain *goto_ch = NULL; 167 struct tc_ctinfo *actparm; 168 struct tcf_ctinfo *ci; 169 u8 dscpmaskshift; 170 int ret = 0, err; 171 172 if (!nla) { 173 NL_SET_ERR_MSG_MOD(extack, "ctinfo requires attributes to be passed"); 174 return -EINVAL; 175 } 176 177 err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, ctinfo_policy, extack); 178 if (err < 0) 179 return err; 180 181 if (!tb[TCA_CTINFO_ACT]) { 182 NL_SET_ERR_MSG_MOD(extack, 183 "Missing required TCA_CTINFO_ACT attribute"); 184 return -EINVAL; 185 } 186 actparm = nla_data(tb[TCA_CTINFO_ACT]); 187 188 /* do some basic validation here before dynamically allocating things */ 189 /* that we would otherwise have to clean up. */ 190 if (tb[TCA_CTINFO_PARMS_DSCP_MASK]) { 191 dscpmask = nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_MASK]); 192 /* need contiguous 6 bit mask */ 193 dscpmaskshift = dscpmask ? __ffs(dscpmask) : 0; 194 if ((~0 & (dscpmask >> dscpmaskshift)) != 0x3f) { 195 NL_SET_ERR_MSG_ATTR(extack, 196 tb[TCA_CTINFO_PARMS_DSCP_MASK], 197 "dscp mask must be 6 contiguous bits"); 198 return -EINVAL; 199 } 200 dscpstatemask = tb[TCA_CTINFO_PARMS_DSCP_STATEMASK] ? 201 nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_STATEMASK]) : 0; 202 /* mask & statemask must not overlap */ 203 if (dscpmask & dscpstatemask) { 204 NL_SET_ERR_MSG_ATTR(extack, 205 tb[TCA_CTINFO_PARMS_DSCP_STATEMASK], 206 "dscp statemask must not overlap dscp mask"); 207 return -EINVAL; 208 } 209 } 210 211 /* done the validation:now to the actual action allocation */ 212 index = actparm->index; 213 err = tcf_idr_check_alloc(tn, &index, a, bind); 214 if (!err) { 215 ret = tcf_idr_create(tn, index, est, a, 216 &act_ctinfo_ops, bind, false, 0); 217 if (ret) { 218 tcf_idr_cleanup(tn, index); 219 return ret; 220 } 221 ret = ACT_P_CREATED; 222 } else if (err > 0) { 223 if (bind) /* don't override defaults */ 224 return 0; 225 if (!ovr) { 226 tcf_idr_release(*a, bind); 227 return -EEXIST; 228 } 229 } else { 230 return err; 231 } 232 233 err = tcf_action_check_ctrlact(actparm->action, tp, &goto_ch, extack); 234 if (err < 0) 235 goto release_idr; 236 237 ci = to_ctinfo(*a); 238 239 cp_new = kzalloc(sizeof(*cp_new), GFP_KERNEL); 240 if (unlikely(!cp_new)) { 241 err = -ENOMEM; 242 goto put_chain; 243 } 244 245 cp_new->net = net; 246 cp_new->zone = tb[TCA_CTINFO_ZONE] ? 247 nla_get_u16(tb[TCA_CTINFO_ZONE]) : 0; 248 if (dscpmask) { 249 cp_new->dscpmask = dscpmask; 250 cp_new->dscpmaskshift = dscpmaskshift; 251 cp_new->dscpstatemask = dscpstatemask; 252 cp_new->mode |= CTINFO_MODE_DSCP; 253 } 254 255 if (tb[TCA_CTINFO_PARMS_CPMARK_MASK]) { 256 cp_new->cpmarkmask = 257 nla_get_u32(tb[TCA_CTINFO_PARMS_CPMARK_MASK]); 258 cp_new->mode |= CTINFO_MODE_CPMARK; 259 } 260 261 spin_lock_bh(&ci->tcf_lock); 262 goto_ch = tcf_action_set_ctrlact(*a, actparm->action, goto_ch); 263 cp_new = rcu_replace_pointer(ci->params, cp_new, 264 lockdep_is_held(&ci->tcf_lock)); 265 spin_unlock_bh(&ci->tcf_lock); 266 267 if (goto_ch) 268 tcf_chain_put_by_act(goto_ch); 269 if (cp_new) 270 kfree_rcu(cp_new, rcu); 271 272 if (ret == ACT_P_CREATED) 273 tcf_idr_insert(tn, *a); 274 275 return ret; 276 277 put_chain: 278 if (goto_ch) 279 tcf_chain_put_by_act(goto_ch); 280 release_idr: 281 tcf_idr_release(*a, bind); 282 return err; 283 } 284 285 static int tcf_ctinfo_dump(struct sk_buff *skb, struct tc_action *a, 286 int bind, int ref) 287 { 288 struct tcf_ctinfo *ci = to_ctinfo(a); 289 struct tc_ctinfo opt = { 290 .index = ci->tcf_index, 291 .refcnt = refcount_read(&ci->tcf_refcnt) - ref, 292 .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind, 293 }; 294 unsigned char *b = skb_tail_pointer(skb); 295 struct tcf_ctinfo_params *cp; 296 struct tcf_t t; 297 298 spin_lock_bh(&ci->tcf_lock); 299 cp = rcu_dereference_protected(ci->params, 300 lockdep_is_held(&ci->tcf_lock)); 301 302 tcf_tm_dump(&t, &ci->tcf_tm); 303 if (nla_put_64bit(skb, TCA_CTINFO_TM, sizeof(t), &t, TCA_CTINFO_PAD)) 304 goto nla_put_failure; 305 306 opt.action = ci->tcf_action; 307 if (nla_put(skb, TCA_CTINFO_ACT, sizeof(opt), &opt)) 308 goto nla_put_failure; 309 310 if (nla_put_u16(skb, TCA_CTINFO_ZONE, cp->zone)) 311 goto nla_put_failure; 312 313 if (cp->mode & CTINFO_MODE_DSCP) { 314 if (nla_put_u32(skb, TCA_CTINFO_PARMS_DSCP_MASK, 315 cp->dscpmask)) 316 goto nla_put_failure; 317 if (nla_put_u32(skb, TCA_CTINFO_PARMS_DSCP_STATEMASK, 318 cp->dscpstatemask)) 319 goto nla_put_failure; 320 } 321 322 if (cp->mode & CTINFO_MODE_CPMARK) { 323 if (nla_put_u32(skb, TCA_CTINFO_PARMS_CPMARK_MASK, 324 cp->cpmarkmask)) 325 goto nla_put_failure; 326 } 327 328 if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_DSCP_SET, 329 ci->stats_dscp_set, TCA_CTINFO_PAD)) 330 goto nla_put_failure; 331 332 if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_DSCP_ERROR, 333 ci->stats_dscp_error, TCA_CTINFO_PAD)) 334 goto nla_put_failure; 335 336 if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_CPMARK_SET, 337 ci->stats_cpmark_set, TCA_CTINFO_PAD)) 338 goto nla_put_failure; 339 340 spin_unlock_bh(&ci->tcf_lock); 341 return skb->len; 342 343 nla_put_failure: 344 spin_unlock_bh(&ci->tcf_lock); 345 nlmsg_trim(skb, b); 346 return -1; 347 } 348 349 static int tcf_ctinfo_walker(struct net *net, struct sk_buff *skb, 350 struct netlink_callback *cb, int type, 351 const struct tc_action_ops *ops, 352 struct netlink_ext_ack *extack) 353 { 354 struct tc_action_net *tn = net_generic(net, ctinfo_net_id); 355 356 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 357 } 358 359 static int tcf_ctinfo_search(struct net *net, struct tc_action **a, u32 index) 360 { 361 struct tc_action_net *tn = net_generic(net, ctinfo_net_id); 362 363 return tcf_idr_search(tn, a, index); 364 } 365 366 static void tcf_ctinfo_cleanup(struct tc_action *a) 367 { 368 struct tcf_ctinfo *ci = to_ctinfo(a); 369 struct tcf_ctinfo_params *cp; 370 371 cp = rcu_dereference_protected(ci->params, 1); 372 if (cp) 373 kfree_rcu(cp, rcu); 374 } 375 376 static struct tc_action_ops act_ctinfo_ops = { 377 .kind = "ctinfo", 378 .id = TCA_ID_CTINFO, 379 .owner = THIS_MODULE, 380 .act = tcf_ctinfo_act, 381 .dump = tcf_ctinfo_dump, 382 .init = tcf_ctinfo_init, 383 .cleanup= tcf_ctinfo_cleanup, 384 .walk = tcf_ctinfo_walker, 385 .lookup = tcf_ctinfo_search, 386 .size = sizeof(struct tcf_ctinfo), 387 }; 388 389 static __net_init int ctinfo_init_net(struct net *net) 390 { 391 struct tc_action_net *tn = net_generic(net, ctinfo_net_id); 392 393 return tc_action_net_init(net, tn, &act_ctinfo_ops); 394 } 395 396 static void __net_exit ctinfo_exit_net(struct list_head *net_list) 397 { 398 tc_action_net_exit(net_list, ctinfo_net_id); 399 } 400 401 static struct pernet_operations ctinfo_net_ops = { 402 .init = ctinfo_init_net, 403 .exit_batch = ctinfo_exit_net, 404 .id = &ctinfo_net_id, 405 .size = sizeof(struct tc_action_net), 406 }; 407 408 static int __init ctinfo_init_module(void) 409 { 410 return tcf_register_action(&act_ctinfo_ops, &ctinfo_net_ops); 411 } 412 413 static void __exit ctinfo_cleanup_module(void) 414 { 415 tcf_unregister_action(&act_ctinfo_ops, &ctinfo_net_ops); 416 } 417 418 module_init(ctinfo_init_module); 419 module_exit(ctinfo_cleanup_module); 420 MODULE_AUTHOR("Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>"); 421 MODULE_DESCRIPTION("Connection tracking mark actions"); 422 MODULE_LICENSE("GPL"); 423