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 30 #include <linux/tc_act/tc_skbedit.h> 31 #include <net/tc_act/tc_skbedit.h> 32 33 static unsigned int skbedit_net_id; 34 static struct tc_action_ops act_skbedit_ops; 35 36 static int tcf_skbedit_act(struct sk_buff *skb, const struct tc_action *a, 37 struct tcf_result *res) 38 { 39 struct tcf_skbedit *d = to_skbedit(a); 40 struct tcf_skbedit_params *params; 41 int action; 42 43 tcf_lastuse_update(&d->tcf_tm); 44 bstats_cpu_update(this_cpu_ptr(d->common.cpu_bstats), skb); 45 46 params = rcu_dereference_bh(d->params); 47 action = READ_ONCE(d->tcf_action); 48 49 if (params->flags & SKBEDIT_F_PRIORITY) 50 skb->priority = params->priority; 51 if (params->flags & SKBEDIT_F_INHERITDSFIELD) { 52 int wlen = skb_network_offset(skb); 53 54 switch (tc_skb_protocol(skb)) { 55 case htons(ETH_P_IP): 56 wlen += sizeof(struct iphdr); 57 if (!pskb_may_pull(skb, wlen)) 58 goto err; 59 skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2; 60 break; 61 62 case htons(ETH_P_IPV6): 63 wlen += sizeof(struct ipv6hdr); 64 if (!pskb_may_pull(skb, wlen)) 65 goto err; 66 skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2; 67 break; 68 } 69 } 70 if (params->flags & SKBEDIT_F_QUEUE_MAPPING && 71 skb->dev->real_num_tx_queues > params->queue_mapping) 72 skb_set_queue_mapping(skb, params->queue_mapping); 73 if (params->flags & SKBEDIT_F_MARK) { 74 skb->mark &= ~params->mask; 75 skb->mark |= params->mark & params->mask; 76 } 77 if (params->flags & SKBEDIT_F_PTYPE) 78 skb->pkt_type = params->ptype; 79 return action; 80 81 err: 82 qstats_drop_inc(this_cpu_ptr(d->common.cpu_qstats)); 83 return TC_ACT_SHOT; 84 } 85 86 static const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = { 87 [TCA_SKBEDIT_PARMS] = { .len = sizeof(struct tc_skbedit) }, 88 [TCA_SKBEDIT_PRIORITY] = { .len = sizeof(u32) }, 89 [TCA_SKBEDIT_QUEUE_MAPPING] = { .len = sizeof(u16) }, 90 [TCA_SKBEDIT_MARK] = { .len = sizeof(u32) }, 91 [TCA_SKBEDIT_PTYPE] = { .len = sizeof(u16) }, 92 [TCA_SKBEDIT_MASK] = { .len = sizeof(u32) }, 93 [TCA_SKBEDIT_FLAGS] = { .len = sizeof(u64) }, 94 }; 95 96 static int tcf_skbedit_init(struct net *net, struct nlattr *nla, 97 struct nlattr *est, struct tc_action **a, 98 int ovr, int bind, bool rtnl_held, 99 struct netlink_ext_ack *extack) 100 { 101 struct tc_action_net *tn = net_generic(net, skbedit_net_id); 102 struct tcf_skbedit_params *params_new; 103 struct nlattr *tb[TCA_SKBEDIT_MAX + 1]; 104 struct tc_skbedit *parm; 105 struct tcf_skbedit *d; 106 u32 flags = 0, *priority = NULL, *mark = NULL, *mask = NULL; 107 u16 *queue_mapping = NULL, *ptype = NULL; 108 bool exists = false; 109 int ret = 0, err; 110 111 if (nla == NULL) 112 return -EINVAL; 113 114 err = nla_parse_nested(tb, TCA_SKBEDIT_MAX, nla, skbedit_policy, NULL); 115 if (err < 0) 116 return err; 117 118 if (tb[TCA_SKBEDIT_PARMS] == NULL) 119 return -EINVAL; 120 121 if (tb[TCA_SKBEDIT_PRIORITY] != NULL) { 122 flags |= SKBEDIT_F_PRIORITY; 123 priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]); 124 } 125 126 if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) { 127 flags |= SKBEDIT_F_QUEUE_MAPPING; 128 queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]); 129 } 130 131 if (tb[TCA_SKBEDIT_PTYPE] != NULL) { 132 ptype = nla_data(tb[TCA_SKBEDIT_PTYPE]); 133 if (!skb_pkt_type_ok(*ptype)) 134 return -EINVAL; 135 flags |= SKBEDIT_F_PTYPE; 136 } 137 138 if (tb[TCA_SKBEDIT_MARK] != NULL) { 139 flags |= SKBEDIT_F_MARK; 140 mark = nla_data(tb[TCA_SKBEDIT_MARK]); 141 } 142 143 if (tb[TCA_SKBEDIT_MASK] != NULL) { 144 flags |= SKBEDIT_F_MASK; 145 mask = nla_data(tb[TCA_SKBEDIT_MASK]); 146 } 147 148 if (tb[TCA_SKBEDIT_FLAGS] != NULL) { 149 u64 *pure_flags = nla_data(tb[TCA_SKBEDIT_FLAGS]); 150 151 if (*pure_flags & SKBEDIT_F_INHERITDSFIELD) 152 flags |= SKBEDIT_F_INHERITDSFIELD; 153 } 154 155 parm = nla_data(tb[TCA_SKBEDIT_PARMS]); 156 157 err = tcf_idr_check_alloc(tn, &parm->index, a, bind); 158 if (err < 0) 159 return err; 160 exists = err; 161 if (exists && bind) 162 return 0; 163 164 if (!flags) { 165 if (exists) 166 tcf_idr_release(*a, bind); 167 else 168 tcf_idr_cleanup(tn, parm->index); 169 return -EINVAL; 170 } 171 172 if (!exists) { 173 ret = tcf_idr_create(tn, parm->index, est, a, 174 &act_skbedit_ops, bind, true); 175 if (ret) { 176 tcf_idr_cleanup(tn, parm->index); 177 return ret; 178 } 179 180 d = to_skbedit(*a); 181 ret = ACT_P_CREATED; 182 } else { 183 d = to_skbedit(*a); 184 if (!ovr) { 185 tcf_idr_release(*a, bind); 186 return -EEXIST; 187 } 188 } 189 190 params_new = kzalloc(sizeof(*params_new), GFP_KERNEL); 191 if (unlikely(!params_new)) { 192 tcf_idr_release(*a, bind); 193 return -ENOMEM; 194 } 195 196 params_new->flags = flags; 197 if (flags & SKBEDIT_F_PRIORITY) 198 params_new->priority = *priority; 199 if (flags & SKBEDIT_F_QUEUE_MAPPING) 200 params_new->queue_mapping = *queue_mapping; 201 if (flags & SKBEDIT_F_MARK) 202 params_new->mark = *mark; 203 if (flags & SKBEDIT_F_PTYPE) 204 params_new->ptype = *ptype; 205 /* default behaviour is to use all the bits */ 206 params_new->mask = 0xffffffff; 207 if (flags & SKBEDIT_F_MASK) 208 params_new->mask = *mask; 209 210 spin_lock_bh(&d->tcf_lock); 211 d->tcf_action = parm->action; 212 rcu_swap_protected(d->params, params_new, 213 lockdep_is_held(&d->tcf_lock)); 214 spin_unlock_bh(&d->tcf_lock); 215 if (params_new) 216 kfree_rcu(params_new, rcu); 217 218 if (ret == ACT_P_CREATED) 219 tcf_idr_insert(tn, *a); 220 return ret; 221 } 222 223 static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a, 224 int bind, int ref) 225 { 226 unsigned char *b = skb_tail_pointer(skb); 227 struct tcf_skbedit *d = to_skbedit(a); 228 struct tcf_skbedit_params *params; 229 struct tc_skbedit opt = { 230 .index = d->tcf_index, 231 .refcnt = refcount_read(&d->tcf_refcnt) - ref, 232 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind, 233 }; 234 u64 pure_flags = 0; 235 struct tcf_t t; 236 237 spin_lock_bh(&d->tcf_lock); 238 params = rcu_dereference_protected(d->params, 239 lockdep_is_held(&d->tcf_lock)); 240 opt.action = d->tcf_action; 241 242 if (nla_put(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt)) 243 goto nla_put_failure; 244 if ((params->flags & SKBEDIT_F_PRIORITY) && 245 nla_put_u32(skb, TCA_SKBEDIT_PRIORITY, params->priority)) 246 goto nla_put_failure; 247 if ((params->flags & SKBEDIT_F_QUEUE_MAPPING) && 248 nla_put_u16(skb, TCA_SKBEDIT_QUEUE_MAPPING, params->queue_mapping)) 249 goto nla_put_failure; 250 if ((params->flags & SKBEDIT_F_MARK) && 251 nla_put_u32(skb, TCA_SKBEDIT_MARK, params->mark)) 252 goto nla_put_failure; 253 if ((params->flags & SKBEDIT_F_PTYPE) && 254 nla_put_u16(skb, TCA_SKBEDIT_PTYPE, params->ptype)) 255 goto nla_put_failure; 256 if ((params->flags & SKBEDIT_F_MASK) && 257 nla_put_u32(skb, TCA_SKBEDIT_MASK, params->mask)) 258 goto nla_put_failure; 259 if (params->flags & SKBEDIT_F_INHERITDSFIELD) 260 pure_flags |= SKBEDIT_F_INHERITDSFIELD; 261 if (pure_flags != 0 && 262 nla_put(skb, TCA_SKBEDIT_FLAGS, sizeof(pure_flags), &pure_flags)) 263 goto nla_put_failure; 264 265 tcf_tm_dump(&t, &d->tcf_tm); 266 if (nla_put_64bit(skb, TCA_SKBEDIT_TM, sizeof(t), &t, TCA_SKBEDIT_PAD)) 267 goto nla_put_failure; 268 spin_unlock_bh(&d->tcf_lock); 269 270 return skb->len; 271 272 nla_put_failure: 273 spin_unlock_bh(&d->tcf_lock); 274 nlmsg_trim(skb, b); 275 return -1; 276 } 277 278 static void tcf_skbedit_cleanup(struct tc_action *a) 279 { 280 struct tcf_skbedit *d = to_skbedit(a); 281 struct tcf_skbedit_params *params; 282 283 params = rcu_dereference_protected(d->params, 1); 284 if (params) 285 kfree_rcu(params, rcu); 286 } 287 288 static int tcf_skbedit_walker(struct net *net, struct sk_buff *skb, 289 struct netlink_callback *cb, int type, 290 const struct tc_action_ops *ops, 291 struct netlink_ext_ack *extack) 292 { 293 struct tc_action_net *tn = net_generic(net, skbedit_net_id); 294 295 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 296 } 297 298 static int tcf_skbedit_search(struct net *net, struct tc_action **a, u32 index) 299 { 300 struct tc_action_net *tn = net_generic(net, skbedit_net_id); 301 302 return tcf_idr_search(tn, a, index); 303 } 304 305 static struct tc_action_ops act_skbedit_ops = { 306 .kind = "skbedit", 307 .id = TCA_ID_SKBEDIT, 308 .owner = THIS_MODULE, 309 .act = tcf_skbedit_act, 310 .dump = tcf_skbedit_dump, 311 .init = tcf_skbedit_init, 312 .cleanup = tcf_skbedit_cleanup, 313 .walk = tcf_skbedit_walker, 314 .lookup = tcf_skbedit_search, 315 .size = sizeof(struct tcf_skbedit), 316 }; 317 318 static __net_init int skbedit_init_net(struct net *net) 319 { 320 struct tc_action_net *tn = net_generic(net, skbedit_net_id); 321 322 return tc_action_net_init(tn, &act_skbedit_ops); 323 } 324 325 static void __net_exit skbedit_exit_net(struct list_head *net_list) 326 { 327 tc_action_net_exit(net_list, skbedit_net_id); 328 } 329 330 static struct pernet_operations skbedit_net_ops = { 331 .init = skbedit_init_net, 332 .exit_batch = skbedit_exit_net, 333 .id = &skbedit_net_id, 334 .size = sizeof(struct tc_action_net), 335 }; 336 337 MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>"); 338 MODULE_DESCRIPTION("SKB Editing"); 339 MODULE_LICENSE("GPL"); 340 341 static int __init skbedit_init_module(void) 342 { 343 return tcf_register_action(&act_skbedit_ops, &skbedit_net_ops); 344 } 345 346 static void __exit skbedit_cleanup_module(void) 347 { 348 tcf_unregister_action(&act_skbedit_ops, &skbedit_net_ops); 349 } 350 351 module_init(skbedit_init_module); 352 module_exit(skbedit_cleanup_module); 353