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 (skb_protocol(skb, true)) {
  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                                      u64 packets, u64 drops,
  78                                      u64 lastuse, bool hw)
  79 {
  80         struct tcf_skbedit *d = to_skbedit(a);
  81         struct tcf_t *tm = &d->tcf_tm;
  82
  83         tcf_action_update_stats(a, bytes, packets, drops, hw);
  84         tm->lastuse = max_t(u64, tm->lastuse, lastuse);
  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, u32 act_flags,
 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         u32 index;
 114
 115         if (nla == NULL)
 116                 return -EINVAL;
 117
 118         err = nla_parse_nested_deprecated(tb, TCA_SKBEDIT_MAX, nla,
 119                                           skbedit_policy, NULL);
 120         if (err < 0)
 121                 return err;
 122
 123         if (tb[TCA_SKBEDIT_PARMS] == NULL)
 124                 return -EINVAL;
 125
 126         if (tb[TCA_SKBEDIT_PRIORITY] != NULL) {
 127                 flags |= SKBEDIT_F_PRIORITY;
 128                 priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]);
 129         }
 130
 131         if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) {
 132                 flags |= SKBEDIT_F_QUEUE_MAPPING;
 133                 queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]);
 134         }
 135
 136         if (tb[TCA_SKBEDIT_PTYPE] != NULL) {
 137                 ptype = nla_data(tb[TCA_SKBEDIT_PTYPE]);
 138                 if (!skb_pkt_type_ok(*ptype))
 139                         return -EINVAL;
 140                 flags |= SKBEDIT_F_PTYPE;
 141         }
 142
 143         if (tb[TCA_SKBEDIT_MARK] != NULL) {
 144                 flags |= SKBEDIT_F_MARK;
 145                 mark = nla_data(tb[TCA_SKBEDIT_MARK]);
 146         }
 147
 148         if (tb[TCA_SKBEDIT_MASK] != NULL) {
 149                 flags |= SKBEDIT_F_MASK;
 150                 mask = nla_data(tb[TCA_SKBEDIT_MASK]);
 151         }
 152
 153         if (tb[TCA_SKBEDIT_FLAGS] != NULL) {
 154                 u64 *pure_flags = nla_data(tb[TCA_SKBEDIT_FLAGS]);
 155
 156                 if (*pure_flags & SKBEDIT_F_INHERITDSFIELD)
 157                         flags |= SKBEDIT_F_INHERITDSFIELD;
 158         }
 159
 160         parm = nla_data(tb[TCA_SKBEDIT_PARMS]);
 161         index = parm->index;
 162         err = tcf_idr_check_alloc(tn, &index, a, bind);
 163         if (err < 0)
 164                 return err;
 165         exists = err;
 166         if (exists && bind)
 167                 return 0;
 168
 169         if (!flags) {
 170                 if (exists)
 171                         tcf_idr_release(*a, bind);
 172                 else
 173                         tcf_idr_cleanup(tn, index);
 174                 return -EINVAL;
 175         }
 176
 177         if (!exists) {
 178                 ret = tcf_idr_create(tn, index, est, a,
 179                                      &act_skbedit_ops, bind, true, 0);
 180                 if (ret) {
 181                         tcf_idr_cleanup(tn, index);
 182                         return ret;
 183                 }
 184
 185                 d = to_skbedit(*a);
 186                 ret = ACT_P_CREATED;
 187         } else {
 188                 d = to_skbedit(*a);
 189                 if (!ovr) {
 190                         tcf_idr_release(*a, bind);
 191                         return -EEXIST;
 192                 }
 193         }
 194         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
 195         if (err < 0)
 196                 goto release_idr;
 197
 198         params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
 199         if (unlikely(!params_new)) {
 200                 err = -ENOMEM;
 201                 goto put_chain;
 202         }
 203
 204         params_new->flags = flags;
 205         if (flags & SKBEDIT_F_PRIORITY)
 206                 params_new->priority = *priority;
 207         if (flags & SKBEDIT_F_QUEUE_MAPPING)
 208                 params_new->queue_mapping = *queue_mapping;
 209         if (flags & SKBEDIT_F_MARK)
 210                 params_new->mark = *mark;
 211         if (flags & SKBEDIT_F_PTYPE)
 212                 params_new->ptype = *ptype;
 213         /* default behaviour is to use all the bits */
 214         params_new->mask = 0xffffffff;
 215         if (flags & SKBEDIT_F_MASK)
 216                 params_new->mask = *mask;
 217
 218         spin_lock_bh(&d->tcf_lock);
 219         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 220         params_new = rcu_replace_pointer(d->params, params_new,
 221                                          lockdep_is_held(&d->tcf_lock));
 222         spin_unlock_bh(&d->tcf_lock);
 223         if (params_new)
 224                 kfree_rcu(params_new, rcu);
 225         if (goto_ch)
 226                 tcf_chain_put_by_act(goto_ch);
 227
 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 size_t tcf_skbedit_get_fill_size(const struct tc_action *act)
 320 {
 321         return nla_total_size(sizeof(struct tc_skbedit))
 322                 + nla_total_size(sizeof(u32)) /* TCA_SKBEDIT_PRIORITY */
 323                 + nla_total_size(sizeof(u16)) /* TCA_SKBEDIT_QUEUE_MAPPING */
 324                 + nla_total_size(sizeof(u32)) /* TCA_SKBEDIT_MARK */
 325                 + nla_total_size(sizeof(u16)) /* TCA_SKBEDIT_PTYPE */
 326                 + nla_total_size(sizeof(u32)) /* TCA_SKBEDIT_MASK */
 327                 + nla_total_size_64bit(sizeof(u64)); /* TCA_SKBEDIT_FLAGS */
 328 }
 329
 330 static struct tc_action_ops act_skbedit_ops = {
 331         .kind           =       "skbedit",
 332         .id             =       TCA_ID_SKBEDIT,
 333         .owner          =       THIS_MODULE,
 334         .act            =       tcf_skbedit_act,
 335         .stats_update   =       tcf_skbedit_stats_update,
 336         .dump           =       tcf_skbedit_dump,
 337         .init           =       tcf_skbedit_init,
 338         .cleanup        =       tcf_skbedit_cleanup,
 339         .walk           =       tcf_skbedit_walker,
 340         .get_fill_size  =       tcf_skbedit_get_fill_size,
 341         .lookup         =       tcf_skbedit_search,
 342         .size           =       sizeof(struct tcf_skbedit),
 343 };
 344
 345 static __net_init int skbedit_init_net(struct net *net)
 346 {
 347         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 348
 349         return tc_action_net_init(net, tn, &act_skbedit_ops);
 350 }
 351
 352 static void __net_exit skbedit_exit_net(struct list_head *net_list)
 353 {
 354         tc_action_net_exit(net_list, skbedit_net_id);
 355 }
 356
 357 static struct pernet_operations skbedit_net_ops = {
 358         .init = skbedit_init_net,
 359         .exit_batch = skbedit_exit_net,
 360         .id   = &skbedit_net_id,
 361         .size = sizeof(struct tc_action_net),
 362 };
 363
 364 MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>");
 365 MODULE_DESCRIPTION("SKB Editing");
 366 MODULE_LICENSE("GPL");
 367
 368 static int __init skbedit_init_module(void)
 369 {
 370         return tcf_register_action(&act_skbedit_ops, &skbedit_net_ops);
 371 }
 372
 373 static void __exit skbedit_cleanup_module(void)
 374 {
 375         tcf_unregister_action(&act_skbedit_ops, &skbedit_net_ops);
 376 }
 377
 378 module_init(skbedit_init_module);
 379 module_exit(skbedit_cleanup_module);