1 /* 2 * Copyright (c) 2008, Intel Corporation. 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms and conditions of the GNU General Public License, 6 * version 2, as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 11 * more details. 12 * 13 * You should have received a copy of the GNU General Public License along with 14 * this program; if not, see <http://www.gnu.org/licenses/>. 15 * 16 * Author: Alexander Duyck <alexander.h.duyck@intel.com> 17 */ 18 19 #include <linux/module.h> 20 #include <linux/init.h> 21 #include <linux/kernel.h> 22 #include <linux/skbuff.h> 23 #include <linux/rtnetlink.h> 24 #include <net/netlink.h> 25 #include <net/pkt_sched.h> 26 #include <net/ip.h> 27 #include <net/ipv6.h> 28 #include <net/dsfield.h> 29 #include <net/pkt_cls.h> 30 31 #include <linux/tc_act/tc_skbedit.h> 32 #include <net/tc_act/tc_skbedit.h> 33 34 static unsigned int skbedit_net_id; 35 static struct tc_action_ops act_skbedit_ops; 36 37 static int tcf_skbedit_act(struct sk_buff *skb, const struct tc_action *a, 38 struct tcf_result *res) 39 { 40 struct tcf_skbedit *d = to_skbedit(a); 41 struct tcf_skbedit_params *params; 42 int action; 43 44 tcf_lastuse_update(&d->tcf_tm); 45 bstats_cpu_update(this_cpu_ptr(d->common.cpu_bstats), skb); 46 47 params = rcu_dereference_bh(d->params); 48 action = READ_ONCE(d->tcf_action); 49 50 if (params->flags & SKBEDIT_F_PRIORITY) 51 skb->priority = params->priority; 52 if (params->flags & SKBEDIT_F_INHERITDSFIELD) { 53 int wlen = skb_network_offset(skb); 54 55 switch (tc_skb_protocol(skb)) { 56 case htons(ETH_P_IP): 57 wlen += sizeof(struct iphdr); 58 if (!pskb_may_pull(skb, wlen)) 59 goto err; 60 skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2; 61 break; 62 63 case htons(ETH_P_IPV6): 64 wlen += sizeof(struct ipv6hdr); 65 if (!pskb_may_pull(skb, wlen)) 66 goto err; 67 skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2; 68 break; 69 } 70 } 71 if (params->flags & SKBEDIT_F_QUEUE_MAPPING && 72 skb->dev->real_num_tx_queues > params->queue_mapping) 73 skb_set_queue_mapping(skb, params->queue_mapping); 74 if (params->flags & SKBEDIT_F_MARK) { 75 skb->mark &= ~params->mask; 76 skb->mark |= params->mark & params->mask; 77 } 78 if (params->flags & SKBEDIT_F_PTYPE) 79 skb->pkt_type = params->ptype; 80 return action; 81 82 err: 83 qstats_drop_inc(this_cpu_ptr(d->common.cpu_qstats)); 84 return TC_ACT_SHOT; 85 } 86 87 static const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = { 88 [TCA_SKBEDIT_PARMS] = { .len = sizeof(struct tc_skbedit) }, 89 [TCA_SKBEDIT_PRIORITY] = { .len = sizeof(u32) }, 90 [TCA_SKBEDIT_QUEUE_MAPPING] = { .len = sizeof(u16) }, 91 [TCA_SKBEDIT_MARK] = { .len = sizeof(u32) }, 92 [TCA_SKBEDIT_PTYPE] = { .len = sizeof(u16) }, 93 [TCA_SKBEDIT_MASK] = { .len = sizeof(u32) }, 94 [TCA_SKBEDIT_FLAGS] = { .len = sizeof(u64) }, 95 }; 96 97 static int tcf_skbedit_init(struct net *net, struct nlattr *nla, 98 struct nlattr *est, struct tc_action **a, 99 int ovr, int bind, bool rtnl_held, 100 struct tcf_proto *tp, 101 struct netlink_ext_ack *extack) 102 { 103 struct tc_action_net *tn = net_generic(net, skbedit_net_id); 104 struct tcf_skbedit_params *params_new; 105 struct nlattr *tb[TCA_SKBEDIT_MAX + 1]; 106 struct tcf_chain *goto_ch = NULL; 107 struct tc_skbedit *parm; 108 struct tcf_skbedit *d; 109 u32 flags = 0, *priority = NULL, *mark = NULL, *mask = NULL; 110 u16 *queue_mapping = NULL, *ptype = NULL; 111 bool exists = false; 112 int ret = 0, err; 113 114 if (nla == NULL) 115 return -EINVAL; 116 117 err = nla_parse_nested(tb, TCA_SKBEDIT_MAX, nla, skbedit_policy, NULL); 118 if (err < 0) 119 return err; 120 121 if (tb[TCA_SKBEDIT_PARMS] == NULL) 122 return -EINVAL; 123 124 if (tb[TCA_SKBEDIT_PRIORITY] != NULL) { 125 flags |= SKBEDIT_F_PRIORITY; 126 priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]); 127 } 128 129 if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) { 130 flags |= SKBEDIT_F_QUEUE_MAPPING; 131 queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]); 132 } 133 134 if (tb[TCA_SKBEDIT_PTYPE] != NULL) { 135 ptype = nla_data(tb[TCA_SKBEDIT_PTYPE]); 136 if (!skb_pkt_type_ok(*ptype)) 137 return -EINVAL; 138 flags |= SKBEDIT_F_PTYPE; 139 } 140 141 if (tb[TCA_SKBEDIT_MARK] != NULL) { 142 flags |= SKBEDIT_F_MARK; 143 mark = nla_data(tb[TCA_SKBEDIT_MARK]); 144 } 145 146 if (tb[TCA_SKBEDIT_MASK] != NULL) { 147 flags |= SKBEDIT_F_MASK; 148 mask = nla_data(tb[TCA_SKBEDIT_MASK]); 149 } 150 151 if (tb[TCA_SKBEDIT_FLAGS] != NULL) { 152 u64 *pure_flags = nla_data(tb[TCA_SKBEDIT_FLAGS]); 153 154 if (*pure_flags & SKBEDIT_F_INHERITDSFIELD) 155 flags |= SKBEDIT_F_INHERITDSFIELD; 156 } 157 158 parm = nla_data(tb[TCA_SKBEDIT_PARMS]); 159 160 err = tcf_idr_check_alloc(tn, &parm->index, a, bind); 161 if (err < 0) 162 return err; 163 exists = err; 164 if (exists && bind) 165 return 0; 166 167 if (!flags) { 168 if (exists) 169 tcf_idr_release(*a, bind); 170 else 171 tcf_idr_cleanup(tn, parm->index); 172 return -EINVAL; 173 } 174 175 if (!exists) { 176 ret = tcf_idr_create(tn, parm->index, est, a, 177 &act_skbedit_ops, bind, true); 178 if (ret) { 179 tcf_idr_cleanup(tn, parm->index); 180 return ret; 181 } 182 183 d = to_skbedit(*a); 184 ret = ACT_P_CREATED; 185 } else { 186 d = to_skbedit(*a); 187 if (!ovr) { 188 tcf_idr_release(*a, bind); 189 return -EEXIST; 190 } 191 } 192 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); 193 if (err < 0) 194 goto release_idr; 195 196 params_new = kzalloc(sizeof(*params_new), GFP_KERNEL); 197 if (unlikely(!params_new)) { 198 err = -ENOMEM; 199 goto put_chain; 200 } 201 202 params_new->flags = flags; 203 if (flags & SKBEDIT_F_PRIORITY) 204 params_new->priority = *priority; 205 if (flags & SKBEDIT_F_QUEUE_MAPPING) 206 params_new->queue_mapping = *queue_mapping; 207 if (flags & SKBEDIT_F_MARK) 208 params_new->mark = *mark; 209 if (flags & SKBEDIT_F_PTYPE) 210 params_new->ptype = *ptype; 211 /* default behaviour is to use all the bits */ 212 params_new->mask = 0xffffffff; 213 if (flags & SKBEDIT_F_MASK) 214 params_new->mask = *mask; 215 216 spin_lock_bh(&d->tcf_lock); 217 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 218 rcu_swap_protected(d->params, params_new, 219 lockdep_is_held(&d->tcf_lock)); 220 spin_unlock_bh(&d->tcf_lock); 221 if (params_new) 222 kfree_rcu(params_new, rcu); 223 if (goto_ch) 224 tcf_chain_put_by_act(goto_ch); 225 226 if (ret == ACT_P_CREATED) 227 tcf_idr_insert(tn, *a); 228 return ret; 229 put_chain: 230 if (goto_ch) 231 tcf_chain_put_by_act(goto_ch); 232 release_idr: 233 tcf_idr_release(*a, bind); 234 return err; 235 } 236 237 static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a, 238 int bind, int ref) 239 { 240 unsigned char *b = skb_tail_pointer(skb); 241 struct tcf_skbedit *d = to_skbedit(a); 242 struct tcf_skbedit_params *params; 243 struct tc_skbedit opt = { 244 .index = d->tcf_index, 245 .refcnt = refcount_read(&d->tcf_refcnt) - ref, 246 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind, 247 }; 248 u64 pure_flags = 0; 249 struct tcf_t t; 250 251 spin_lock_bh(&d->tcf_lock); 252 params = rcu_dereference_protected(d->params, 253 lockdep_is_held(&d->tcf_lock)); 254 opt.action = d->tcf_action; 255 256 if (nla_put(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt)) 257 goto nla_put_failure; 258 if ((params->flags & SKBEDIT_F_PRIORITY) && 259 nla_put_u32(skb, TCA_SKBEDIT_PRIORITY, params->priority)) 260 goto nla_put_failure; 261 if ((params->flags & SKBEDIT_F_QUEUE_MAPPING) && 262 nla_put_u16(skb, TCA_SKBEDIT_QUEUE_MAPPING, params->queue_mapping)) 263 goto nla_put_failure; 264 if ((params->flags & SKBEDIT_F_MARK) && 265 nla_put_u32(skb, TCA_SKBEDIT_MARK, params->mark)) 266 goto nla_put_failure; 267 if ((params->flags & SKBEDIT_F_PTYPE) && 268 nla_put_u16(skb, TCA_SKBEDIT_PTYPE, params->ptype)) 269 goto nla_put_failure; 270 if ((params->flags & SKBEDIT_F_MASK) && 271 nla_put_u32(skb, TCA_SKBEDIT_MASK, params->mask)) 272 goto nla_put_failure; 273 if (params->flags & SKBEDIT_F_INHERITDSFIELD) 274 pure_flags |= SKBEDIT_F_INHERITDSFIELD; 275 if (pure_flags != 0 && 276 nla_put(skb, TCA_SKBEDIT_FLAGS, sizeof(pure_flags), &pure_flags)) 277 goto nla_put_failure; 278 279 tcf_tm_dump(&t, &d->tcf_tm); 280 if (nla_put_64bit(skb, TCA_SKBEDIT_TM, sizeof(t), &t, TCA_SKBEDIT_PAD)) 281 goto nla_put_failure; 282 spin_unlock_bh(&d->tcf_lock); 283 284 return skb->len; 285 286 nla_put_failure: 287 spin_unlock_bh(&d->tcf_lock); 288 nlmsg_trim(skb, b); 289 return -1; 290 } 291 292 static void tcf_skbedit_cleanup(struct tc_action *a) 293 { 294 struct tcf_skbedit *d = to_skbedit(a); 295 struct tcf_skbedit_params *params; 296 297 params = rcu_dereference_protected(d->params, 1); 298 if (params) 299 kfree_rcu(params, rcu); 300 } 301 302 static int tcf_skbedit_walker(struct net *net, struct sk_buff *skb, 303 struct netlink_callback *cb, int type, 304 const struct tc_action_ops *ops, 305 struct netlink_ext_ack *extack) 306 { 307 struct tc_action_net *tn = net_generic(net, skbedit_net_id); 308 309 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 310 } 311 312 static int tcf_skbedit_search(struct net *net, struct tc_action **a, u32 index) 313 { 314 struct tc_action_net *tn = net_generic(net, skbedit_net_id); 315 316 return tcf_idr_search(tn, a, index); 317 } 318 319 static struct tc_action_ops act_skbedit_ops = { 320 .kind = "skbedit", 321 .id = TCA_ID_SKBEDIT, 322 .owner = THIS_MODULE, 323 .act = tcf_skbedit_act, 324 .dump = tcf_skbedit_dump, 325 .init = tcf_skbedit_init, 326 .cleanup = tcf_skbedit_cleanup, 327 .walk = tcf_skbedit_walker, 328 .lookup = tcf_skbedit_search, 329 .size = sizeof(struct tcf_skbedit), 330 }; 331 332 static __net_init int skbedit_init_net(struct net *net) 333 { 334 struct tc_action_net *tn = net_generic(net, skbedit_net_id); 335 336 return tc_action_net_init(tn, &act_skbedit_ops); 337 } 338 339 static void __net_exit skbedit_exit_net(struct list_head *net_list) 340 { 341 tc_action_net_exit(net_list, skbedit_net_id); 342 } 343 344 static struct pernet_operations skbedit_net_ops = { 345 .init = skbedit_init_net, 346 .exit_batch = skbedit_exit_net, 347 .id = &skbedit_net_id, 348 .size = sizeof(struct tc_action_net), 349 }; 350 351 MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>"); 352 MODULE_DESCRIPTION("SKB Editing"); 353 MODULE_LICENSE("GPL"); 354 355 static int __init skbedit_init_module(void) 356 { 357 return tcf_register_action(&act_skbedit_ops, &skbedit_net_ops); 358 } 359 360 static void __exit skbedit_cleanup_module(void) 361 { 362 tcf_unregister_action(&act_skbedit_ops, &skbedit_net_ops); 363 } 364 365 module_init(skbedit_init_module); 366 module_exit(skbedit_cleanup_module); 367