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
  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(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         rcu_read_lock();
  47         params = rcu_dereference(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
  81 unlock:
  82         rcu_read_unlock();
  83         return action;
  84 err:
  85         qstats_drop_inc(this_cpu_ptr(d->common.cpu_qstats));
  86         action = TC_ACT_SHOT;
  87         goto unlock;
  88 }
  89
  90 static const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = {
  91         [TCA_SKBEDIT_PARMS]             = { .len = sizeof(struct tc_skbedit) },
  92         [TCA_SKBEDIT_PRIORITY]          = { .len = sizeof(u32) },
  93         [TCA_SKBEDIT_QUEUE_MAPPING]     = { .len = sizeof(u16) },
  94         [TCA_SKBEDIT_MARK]              = { .len = sizeof(u32) },
  95         [TCA_SKBEDIT_PTYPE]             = { .len = sizeof(u16) },
  96         [TCA_SKBEDIT_MASK]              = { .len = sizeof(u32) },
  97         [TCA_SKBEDIT_FLAGS]             = { .len = sizeof(u64) },
  98 };
  99
 100 static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
 101                             struct nlattr *est, struct tc_action **a,
 102                             int ovr, int bind, bool rtnl_held,
 103                             struct netlink_ext_ack *extack)
 104 {
 105         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 106         struct tcf_skbedit_params *params_old, *params_new;
 107         struct nlattr *tb[TCA_SKBEDIT_MAX + 1];
 108         struct tc_skbedit *parm;
 109         struct tcf_skbedit *d;
 110         u32 flags = 0, *priority = NULL, *mark = NULL, *mask = NULL;
 111         u16 *queue_mapping = NULL, *ptype = NULL;
 112         bool exists = false;
 113         int ret = 0, err;
 114
 115         if (nla == NULL)
 116                 return -EINVAL;
 117
 118         err = nla_parse_nested(tb, TCA_SKBEDIT_MAX, nla, skbedit_policy, NULL);
 119         if (err < 0)
 120                 return err;
 121
 122         if (tb[TCA_SKBEDIT_PARMS] == NULL)
 123                 return -EINVAL;
 124
 125         if (tb[TCA_SKBEDIT_PRIORITY] != NULL) {
 126                 flags |= SKBEDIT_F_PRIORITY;
 127                 priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]);
 128         }
 129
 130         if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) {
 131                 flags |= SKBEDIT_F_QUEUE_MAPPING;
 132                 queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]);
 133         }
 134
 135         if (tb[TCA_SKBEDIT_PTYPE] != NULL) {
 136                 ptype = nla_data(tb[TCA_SKBEDIT_PTYPE]);
 137                 if (!skb_pkt_type_ok(*ptype))
 138                         return -EINVAL;
 139                 flags |= SKBEDIT_F_PTYPE;
 140         }
 141
 142         if (tb[TCA_SKBEDIT_MARK] != NULL) {
 143                 flags |= SKBEDIT_F_MARK;
 144                 mark = nla_data(tb[TCA_SKBEDIT_MARK]);
 145         }
 146
 147         if (tb[TCA_SKBEDIT_MASK] != NULL) {
 148                 flags |= SKBEDIT_F_MASK;
 149                 mask = nla_data(tb[TCA_SKBEDIT_MASK]);
 150         }
 151
 152         if (tb[TCA_SKBEDIT_FLAGS] != NULL) {
 153                 u64 *pure_flags = nla_data(tb[TCA_SKBEDIT_FLAGS]);
 154
 155                 if (*pure_flags & SKBEDIT_F_INHERITDSFIELD)
 156                         flags |= SKBEDIT_F_INHERITDSFIELD;
 157         }
 158
 159         parm = nla_data(tb[TCA_SKBEDIT_PARMS]);
 160
 161         err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
 162         if (err < 0)
 163                 return err;
 164         exists = err;
 165         if (exists && bind)
 166                 return 0;
 167
 168         if (!flags) {
 169                 if (exists)
 170                         tcf_idr_release(*a, bind);
 171                 else
 172                         tcf_idr_cleanup(tn, parm->index);
 173                 return -EINVAL;
 174         }
 175
 176         if (!exists) {
 177                 ret = tcf_idr_create(tn, parm->index, est, a,
 178                                      &act_skbedit_ops, bind, true);
 179                 if (ret) {
 180                         tcf_idr_cleanup(tn, parm->index);
 181                         return ret;
 182                 }
 183
 184                 d = to_skbedit(*a);
 185                 ret = ACT_P_CREATED;
 186         } else {
 187                 d = to_skbedit(*a);
 188                 if (!ovr) {
 189                         tcf_idr_release(*a, bind);
 190                         return -EEXIST;
 191                 }
 192         }
 193
 194         ASSERT_RTNL();
 195
 196         params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
 197         if (unlikely(!params_new)) {
 198                 if (ret == ACT_P_CREATED)
 199                         tcf_idr_release(*a, bind);
 200                 return -ENOMEM;
 201         }
 202
 203         params_new->flags = flags;
 204         if (flags & SKBEDIT_F_PRIORITY)
 205                 params_new->priority = *priority;
 206         if (flags & SKBEDIT_F_QUEUE_MAPPING)
 207                 params_new->queue_mapping = *queue_mapping;
 208         if (flags & SKBEDIT_F_MARK)
 209                 params_new->mark = *mark;
 210         if (flags & SKBEDIT_F_PTYPE)
 211                 params_new->ptype = *ptype;
 212         /* default behaviour is to use all the bits */
 213         params_new->mask = 0xffffffff;
 214         if (flags & SKBEDIT_F_MASK)
 215                 params_new->mask = *mask;
 216
 217         d->tcf_action = parm->action;
 218         params_old = rtnl_dereference(d->params);
 219         rcu_assign_pointer(d->params, params_new);
 220         if (params_old)
 221                 kfree_rcu(params_old, rcu);
 222
 223         if (ret == ACT_P_CREATED)
 224                 tcf_idr_insert(tn, *a);
 225         return ret;
 226 }
 227
 228 static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
 229                             int bind, int ref)
 230 {
 231         unsigned char *b = skb_tail_pointer(skb);
 232         struct tcf_skbedit *d = to_skbedit(a);
 233         struct tcf_skbedit_params *params;
 234         struct tc_skbedit opt = {
 235                 .index   = d->tcf_index,
 236                 .refcnt  = refcount_read(&d->tcf_refcnt) - ref,
 237                 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
 238                 .action  = d->tcf_action,
 239         };
 240         u64 pure_flags = 0;
 241         struct tcf_t t;
 242
 243         params = rtnl_dereference(d->params);
 244
 245         if (nla_put(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt))
 246                 goto nla_put_failure;
 247         if ((params->flags & SKBEDIT_F_PRIORITY) &&
 248             nla_put_u32(skb, TCA_SKBEDIT_PRIORITY, params->priority))
 249                 goto nla_put_failure;
 250         if ((params->flags & SKBEDIT_F_QUEUE_MAPPING) &&
 251             nla_put_u16(skb, TCA_SKBEDIT_QUEUE_MAPPING, params->queue_mapping))
 252                 goto nla_put_failure;
 253         if ((params->flags & SKBEDIT_F_MARK) &&
 254             nla_put_u32(skb, TCA_SKBEDIT_MARK, params->mark))
 255                 goto nla_put_failure;
 256         if ((params->flags & SKBEDIT_F_PTYPE) &&
 257             nla_put_u16(skb, TCA_SKBEDIT_PTYPE, params->ptype))
 258                 goto nla_put_failure;
 259         if ((params->flags & SKBEDIT_F_MASK) &&
 260             nla_put_u32(skb, TCA_SKBEDIT_MASK, params->mask))
 261                 goto nla_put_failure;
 262         if (params->flags & SKBEDIT_F_INHERITDSFIELD)
 263                 pure_flags |= SKBEDIT_F_INHERITDSFIELD;
 264         if (pure_flags != 0 &&
 265             nla_put(skb, TCA_SKBEDIT_FLAGS, sizeof(pure_flags), &pure_flags))
 266                 goto nla_put_failure;
 267
 268         tcf_tm_dump(&t, &d->tcf_tm);
 269         if (nla_put_64bit(skb, TCA_SKBEDIT_TM, sizeof(t), &t, TCA_SKBEDIT_PAD))
 270                 goto nla_put_failure;
 271         return skb->len;
 272
 273 nla_put_failure:
 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                               struct netlink_ext_ack *extack)
 300 {
 301         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 302
 303         return tcf_idr_search(tn, a, index);
 304 }
 305
 306 static int tcf_skbedit_delete(struct net *net, u32 index)
 307 {
 308         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 309
 310         return tcf_idr_delete_index(tn, index);
 311 }
 312
 313 static struct tc_action_ops act_skbedit_ops = {
 314         .kind           =       "skbedit",
 315         .type           =       TCA_ACT_SKBEDIT,
 316         .owner          =       THIS_MODULE,
 317         .act            =       tcf_skbedit,
 318         .dump           =       tcf_skbedit_dump,
 319         .init           =       tcf_skbedit_init,
 320         .cleanup        =       tcf_skbedit_cleanup,
 321         .walk           =       tcf_skbedit_walker,
 322         .lookup         =       tcf_skbedit_search,
 323         .delete         =       tcf_skbedit_delete,
 324         .size           =       sizeof(struct tcf_skbedit),
 325 };
 326
 327 static __net_init int skbedit_init_net(struct net *net)
 328 {
 329         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 330
 331         return tc_action_net_init(tn, &act_skbedit_ops);
 332 }
 333
 334 static void __net_exit skbedit_exit_net(struct list_head *net_list)
 335 {
 336         tc_action_net_exit(net_list, skbedit_net_id);
 337 }
 338
 339 static struct pernet_operations skbedit_net_ops = {
 340         .init = skbedit_init_net,
 341         .exit_batch = skbedit_exit_net,
 342         .id   = &skbedit_net_id,
 343         .size = sizeof(struct tc_action_net),
 344 };
 345
 346 MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>");
 347 MODULE_DESCRIPTION("SKB Editing");
 348 MODULE_LICENSE("GPL");
 349
 350 static int __init skbedit_init_module(void)
 351 {
 352         return tcf_register_action(&act_skbedit_ops, &skbedit_net_ops);
 353 }
 354
 355 static void __exit skbedit_cleanup_module(void)
 356 {
 357         tcf_unregister_action(&act_skbedit_ops, &skbedit_net_ops);
 358 }
 359
 360 module_init(skbedit_init_module);
 361 module_exit(skbedit_cleanup_module);