net/sched/act_skbedit.c

   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);