net/sched/act_skbedit.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2008, Intel Corporation.
   4  *
   5  * Author: Alexander Duyck <alexander.h.duyck@intel.com>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/kernel.h>
  11 #include <linux/skbuff.h>
  12 #include <linux/rtnetlink.h>
  13 #include <net/netlink.h>
  14 #include <net/pkt_sched.h>
  15 #include <net/ip.h>
  16 #include <net/ipv6.h>
  17 #include <net/dsfield.h>
  18 #include <net/pkt_cls.h>
  19
  20 #include <linux/tc_act/tc_skbedit.h>
  21 #include <net/tc_act/tc_skbedit.h>
  22
  23 static unsigned int skbedit_net_id;
  24 static struct tc_action_ops act_skbedit_ops;
  25
  26 static int tcf_skbedit_act(struct sk_buff *skb, const struct tc_action *a,
  27                            struct tcf_result *res)
  28 {
  29         struct tcf_skbedit *d = to_skbedit(a);
  30         struct tcf_skbedit_params *params;
  31         int action;
  32
  33         tcf_lastuse_update(&d->tcf_tm);
  34         bstats_cpu_update(this_cpu_ptr(d->common.cpu_bstats), skb);
  35
  36         params = rcu_dereference_bh(d->params);
  37         action = READ_ONCE(d->tcf_action);
  38
  39         if (params->flags & SKBEDIT_F_PRIORITY)
  40                 skb->priority = params->priority;
  41         if (params->flags & SKBEDIT_F_INHERITDSFIELD) {
  42                 int wlen = skb_network_offset(skb);
  43
  44                 switch (tc_skb_protocol(skb)) {
  45                 case htons(ETH_P_IP):
  46                         wlen += sizeof(struct iphdr);
  47                         if (!pskb_may_pull(skb, wlen))
  48                                 goto err;
  49                         skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
  50                         break;
  51
  52                 case htons(ETH_P_IPV6):
  53                         wlen += sizeof(struct ipv6hdr);
  54                         if (!pskb_may_pull(skb, wlen))
  55                                 goto err;
  56                         skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
  57                         break;
  58                 }
  59         }
  60         if (params->flags & SKBEDIT_F_QUEUE_MAPPING &&
  61             skb->dev->real_num_tx_queues > params->queue_mapping)
  62                 skb_set_queue_mapping(skb, params->queue_mapping);
  63         if (params->flags & SKBEDIT_F_MARK) {
  64                 skb->mark &= ~params->mask;
  65                 skb->mark |= params->mark & params->mask;
  66         }
  67         if (params->flags & SKBEDIT_F_PTYPE)
  68                 skb->pkt_type = params->ptype;
  69         return action;
  70
  71 err:
  72         qstats_drop_inc(this_cpu_ptr(d->common.cpu_qstats));
  73         return TC_ACT_SHOT;
  74 }
  75
  76 static void tcf_skbedit_stats_update(struct tc_action *a, u64 bytes,
  77                                      u32 packets, u64 lastuse, bool hw)
  78 {
  79         struct tcf_skbedit *d = to_skbedit(a);
  80         struct tcf_t *tm = &d->tcf_tm;
  81
  82         tcf_action_update_stats(a, bytes, packets, false, hw);
  83         tm->lastuse = max_t(u64, tm->lastuse, lastuse);
  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 tcf_proto *tp, u32 act_flags,
 100                             struct netlink_ext_ack *extack)
 101 {
 102         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 103         struct tcf_skbedit_params *params_new;
 104         struct nlattr *tb[TCA_SKBEDIT_MAX + 1];
 105         struct tcf_chain *goto_ch = NULL;
 106         struct tc_skbedit *parm;
 107         struct tcf_skbedit *d;
 108         u32 flags = 0, *priority = NULL, *mark = NULL, *mask = NULL;
 109         u16 *queue_mapping = NULL, *ptype = NULL;
 110         bool exists = false;
 111         int ret = 0, err;
 112         u32 index;
 113
 114         if (nla == NULL)
 115                 return -EINVAL;
 116
 117         err = nla_parse_nested_deprecated(tb, TCA_SKBEDIT_MAX, nla,
 118                                           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         index = parm->index;
 161         err = tcf_idr_check_alloc(tn, &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, index);
 173                 return -EINVAL;
 174         }
 175
 176         if (!exists) {
 177                 ret = tcf_idr_create(tn, index, est, a,
 178                                      &act_skbedit_ops, bind, true, 0);
 179                 if (ret) {
 180                         tcf_idr_cleanup(tn, 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         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
 194         if (err < 0)
 195                 goto release_idr;
 196
 197         params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
 198         if (unlikely(!params_new)) {
 199                 err = -ENOMEM;
 200                 goto put_chain;
 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         spin_lock_bh(&d->tcf_lock);
 218         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 219         params_new = rcu_replace_pointer(d->params, params_new,
 220                                          lockdep_is_held(&d->tcf_lock));
 221         spin_unlock_bh(&d->tcf_lock);
 222         if (params_new)
 223                 kfree_rcu(params_new, rcu);
 224         if (goto_ch)
 225                 tcf_chain_put_by_act(goto_ch);
 226
 227         if (ret == ACT_P_CREATED)
 228                 tcf_idr_insert(tn, *a);
 229         return ret;
 230 put_chain:
 231         if (goto_ch)
 232                 tcf_chain_put_by_act(goto_ch);
 233 release_idr:
 234         tcf_idr_release(*a, bind);
 235         return err;
 236 }
 237
 238 static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
 239                             int bind, int ref)
 240 {
 241         unsigned char *b = skb_tail_pointer(skb);
 242         struct tcf_skbedit *d = to_skbedit(a);
 243         struct tcf_skbedit_params *params;
 244         struct tc_skbedit opt = {
 245                 .index   = d->tcf_index,
 246                 .refcnt  = refcount_read(&d->tcf_refcnt) - ref,
 247                 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
 248         };
 249         u64 pure_flags = 0;
 250         struct tcf_t t;
 251
 252         spin_lock_bh(&d->tcf_lock);
 253         params = rcu_dereference_protected(d->params,
 254                                            lockdep_is_held(&d->tcf_lock));
 255         opt.action = d->tcf_action;
 256
 257         if (nla_put(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt))
 258                 goto nla_put_failure;
 259         if ((params->flags & SKBEDIT_F_PRIORITY) &&
 260             nla_put_u32(skb, TCA_SKBEDIT_PRIORITY, params->priority))
 261                 goto nla_put_failure;
 262         if ((params->flags & SKBEDIT_F_QUEUE_MAPPING) &&
 263             nla_put_u16(skb, TCA_SKBEDIT_QUEUE_MAPPING, params->queue_mapping))
 264                 goto nla_put_failure;
 265         if ((params->flags & SKBEDIT_F_MARK) &&
 266             nla_put_u32(skb, TCA_SKBEDIT_MARK, params->mark))
 267                 goto nla_put_failure;
 268         if ((params->flags & SKBEDIT_F_PTYPE) &&
 269             nla_put_u16(skb, TCA_SKBEDIT_PTYPE, params->ptype))
 270                 goto nla_put_failure;
 271         if ((params->flags & SKBEDIT_F_MASK) &&
 272             nla_put_u32(skb, TCA_SKBEDIT_MASK, params->mask))
 273                 goto nla_put_failure;
 274         if (params->flags & SKBEDIT_F_INHERITDSFIELD)
 275                 pure_flags |= SKBEDIT_F_INHERITDSFIELD;
 276         if (pure_flags != 0 &&
 277             nla_put(skb, TCA_SKBEDIT_FLAGS, sizeof(pure_flags), &pure_flags))
 278                 goto nla_put_failure;
 279
 280         tcf_tm_dump(&t, &d->tcf_tm);
 281         if (nla_put_64bit(skb, TCA_SKBEDIT_TM, sizeof(t), &t, TCA_SKBEDIT_PAD))
 282                 goto nla_put_failure;
 283         spin_unlock_bh(&d->tcf_lock);
 284
 285         return skb->len;
 286
 287 nla_put_failure:
 288         spin_unlock_bh(&d->tcf_lock);
 289         nlmsg_trim(skb, b);
 290         return -1;
 291 }
 292
 293 static void tcf_skbedit_cleanup(struct tc_action *a)
 294 {
 295         struct tcf_skbedit *d = to_skbedit(a);
 296         struct tcf_skbedit_params *params;
 297
 298         params = rcu_dereference_protected(d->params, 1);
 299         if (params)
 300                 kfree_rcu(params, rcu);
 301 }
 302
 303 static int tcf_skbedit_walker(struct net *net, struct sk_buff *skb,
 304                               struct netlink_callback *cb, int type,
 305                               const struct tc_action_ops *ops,
 306                               struct netlink_ext_ack *extack)
 307 {
 308         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 309
 310         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 311 }
 312
 313 static int tcf_skbedit_search(struct net *net, struct tc_action **a, u32 index)
 314 {
 315         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 316
 317         return tcf_idr_search(tn, a, index);
 318 }
 319
 320 static size_t tcf_skbedit_get_fill_size(const struct tc_action *act)
 321 {
 322         return nla_total_size(sizeof(struct tc_skbedit))
 323                 + nla_total_size(sizeof(u32)) /* TCA_SKBEDIT_PRIORITY */
 324                 + nla_total_size(sizeof(u16)) /* TCA_SKBEDIT_QUEUE_MAPPING */
 325                 + nla_total_size(sizeof(u32)) /* TCA_SKBEDIT_MARK */
 326                 + nla_total_size(sizeof(u16)) /* TCA_SKBEDIT_PTYPE */
 327                 + nla_total_size(sizeof(u32)) /* TCA_SKBEDIT_MASK */
 328                 + nla_total_size_64bit(sizeof(u64)); /* TCA_SKBEDIT_FLAGS */
 329 }
 330
 331 static struct tc_action_ops act_skbedit_ops = {
 332         .kind           =       "skbedit",
 333         .id             =       TCA_ID_SKBEDIT,
 334         .owner          =       THIS_MODULE,
 335         .act            =       tcf_skbedit_act,
 336         .stats_update   =       tcf_skbedit_stats_update,
 337         .dump           =       tcf_skbedit_dump,
 338         .init           =       tcf_skbedit_init,
 339         .cleanup        =       tcf_skbedit_cleanup,
 340         .walk           =       tcf_skbedit_walker,
 341         .get_fill_size  =       tcf_skbedit_get_fill_size,
 342         .lookup         =       tcf_skbedit_search,
 343         .size           =       sizeof(struct tcf_skbedit),
 344 };
 345
 346 static __net_init int skbedit_init_net(struct net *net)
 347 {
 348         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 349
 350         return tc_action_net_init(net, tn, &act_skbedit_ops);
 351 }
 352
 353 static void __net_exit skbedit_exit_net(struct list_head *net_list)
 354 {
 355         tc_action_net_exit(net_list, skbedit_net_id);
 356 }
 357
 358 static struct pernet_operations skbedit_net_ops = {
 359         .init = skbedit_init_net,
 360         .exit_batch = skbedit_exit_net,
 361         .id   = &skbedit_net_id,
 362         .size = sizeof(struct tc_action_net),
 363 };
 364
 365 MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>");
 366 MODULE_DESCRIPTION("SKB Editing");
 367 MODULE_LICENSE("GPL");
 368
 369 static int __init skbedit_init_module(void)
 370 {
 371         return tcf_register_action(&act_skbedit_ops, &skbedit_net_ops);
 372 }
 373
 374 static void __exit skbedit_cleanup_module(void)
 375 {
 376         tcf_unregister_action(&act_skbedit_ops, &skbedit_net_ops);
 377 }
 378
 379 module_init(skbedit_init_module);
 380 module_exit(skbedit_cleanup_module);