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