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 const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = {
  77         [TCA_SKBEDIT_PARMS]             = { .len = sizeof(struct tc_skbedit) },
  78         [TCA_SKBEDIT_PRIORITY]          = { .len = sizeof(u32) },
  79         [TCA_SKBEDIT_QUEUE_MAPPING]     = { .len = sizeof(u16) },
  80         [TCA_SKBEDIT_MARK]              = { .len = sizeof(u32) },
  81         [TCA_SKBEDIT_PTYPE]             = { .len = sizeof(u16) },
  82         [TCA_SKBEDIT_MASK]              = { .len = sizeof(u32) },
  83         [TCA_SKBEDIT_FLAGS]             = { .len = sizeof(u64) },
  84 };
  85
  86 static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
  87                             struct nlattr *est, struct tc_action **a,
  88                             int ovr, int bind, bool rtnl_held,
  89                             struct tcf_proto *tp,
  90                             struct netlink_ext_ack *extack)
  91 {
  92         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
  93         struct tcf_skbedit_params *params_new;
  94         struct nlattr *tb[TCA_SKBEDIT_MAX + 1];
  95         struct tcf_chain *goto_ch = NULL;
  96         struct tc_skbedit *parm;
  97         struct tcf_skbedit *d;
  98         u32 flags = 0, *priority = NULL, *mark = NULL, *mask = NULL;
  99         u16 *queue_mapping = NULL, *ptype = NULL;
 100         bool exists = false;
 101         int ret = 0, err;
 102         u32 index;
 103
 104         if (nla == NULL)
 105                 return -EINVAL;
 106
 107         err = nla_parse_nested_deprecated(tb, TCA_SKBEDIT_MAX, nla,
 108                                           skbedit_policy, NULL);
 109         if (err < 0)
 110                 return err;
 111
 112         if (tb[TCA_SKBEDIT_PARMS] == NULL)
 113                 return -EINVAL;
 114
 115         if (tb[TCA_SKBEDIT_PRIORITY] != NULL) {
 116                 flags |= SKBEDIT_F_PRIORITY;
 117                 priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]);
 118         }
 119
 120         if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) {
 121                 flags |= SKBEDIT_F_QUEUE_MAPPING;
 122                 queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]);
 123         }
 124
 125         if (tb[TCA_SKBEDIT_PTYPE] != NULL) {
 126                 ptype = nla_data(tb[TCA_SKBEDIT_PTYPE]);
 127                 if (!skb_pkt_type_ok(*ptype))
 128                         return -EINVAL;
 129                 flags |= SKBEDIT_F_PTYPE;
 130         }
 131
 132         if (tb[TCA_SKBEDIT_MARK] != NULL) {
 133                 flags |= SKBEDIT_F_MARK;
 134                 mark = nla_data(tb[TCA_SKBEDIT_MARK]);
 135         }
 136
 137         if (tb[TCA_SKBEDIT_MASK] != NULL) {
 138                 flags |= SKBEDIT_F_MASK;
 139                 mask = nla_data(tb[TCA_SKBEDIT_MASK]);
 140         }
 141
 142         if (tb[TCA_SKBEDIT_FLAGS] != NULL) {
 143                 u64 *pure_flags = nla_data(tb[TCA_SKBEDIT_FLAGS]);
 144
 145                 if (*pure_flags & SKBEDIT_F_INHERITDSFIELD)
 146                         flags |= SKBEDIT_F_INHERITDSFIELD;
 147         }
 148
 149         parm = nla_data(tb[TCA_SKBEDIT_PARMS]);
 150         index = parm->index;
 151         err = tcf_idr_check_alloc(tn, &index, a, bind);
 152         if (err < 0)
 153                 return err;
 154         exists = err;
 155         if (exists && bind)
 156                 return 0;
 157
 158         if (!flags) {
 159                 if (exists)
 160                         tcf_idr_release(*a, bind);
 161                 else
 162                         tcf_idr_cleanup(tn, index);
 163                 return -EINVAL;
 164         }
 165
 166         if (!exists) {
 167                 ret = tcf_idr_create(tn, index, est, a,
 168                                      &act_skbedit_ops, bind, true);
 169                 if (ret) {
 170                         tcf_idr_cleanup(tn, index);
 171                         return ret;
 172                 }
 173
 174                 d = to_skbedit(*a);
 175                 ret = ACT_P_CREATED;
 176         } else {
 177                 d = to_skbedit(*a);
 178                 if (!ovr) {
 179                         tcf_idr_release(*a, bind);
 180                         return -EEXIST;
 181                 }
 182         }
 183         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
 184         if (err < 0)
 185                 goto release_idr;
 186
 187         params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
 188         if (unlikely(!params_new)) {
 189                 err = -ENOMEM;
 190                 goto put_chain;
 191         }
 192
 193         params_new->flags = flags;
 194         if (flags & SKBEDIT_F_PRIORITY)
 195                 params_new->priority = *priority;
 196         if (flags & SKBEDIT_F_QUEUE_MAPPING)
 197                 params_new->queue_mapping = *queue_mapping;
 198         if (flags & SKBEDIT_F_MARK)
 199                 params_new->mark = *mark;
 200         if (flags & SKBEDIT_F_PTYPE)
 201                 params_new->ptype = *ptype;
 202         /* default behaviour is to use all the bits */
 203         params_new->mask = 0xffffffff;
 204         if (flags & SKBEDIT_F_MASK)
 205                 params_new->mask = *mask;
 206
 207         spin_lock_bh(&d->tcf_lock);
 208         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 209         rcu_swap_protected(d->params, params_new,
 210                            lockdep_is_held(&d->tcf_lock));
 211         spin_unlock_bh(&d->tcf_lock);
 212         if (params_new)
 213                 kfree_rcu(params_new, rcu);
 214         if (goto_ch)
 215                 tcf_chain_put_by_act(goto_ch);
 216
 217         return ret;
 218 put_chain:
 219         if (goto_ch)
 220                 tcf_chain_put_by_act(goto_ch);
 221 release_idr:
 222         tcf_idr_release(*a, bind);
 223         return err;
 224 }
 225
 226 static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
 227                             int bind, int ref)
 228 {
 229         unsigned char *b = skb_tail_pointer(skb);
 230         struct tcf_skbedit *d = to_skbedit(a);
 231         struct tcf_skbedit_params *params;
 232         struct tc_skbedit opt = {
 233                 .index   = d->tcf_index,
 234                 .refcnt  = refcount_read(&d->tcf_refcnt) - ref,
 235                 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
 236         };
 237         u64 pure_flags = 0;
 238         struct tcf_t t;
 239
 240         spin_lock_bh(&d->tcf_lock);
 241         params = rcu_dereference_protected(d->params,
 242                                            lockdep_is_held(&d->tcf_lock));
 243         opt.action = d->tcf_action;
 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         spin_unlock_bh(&d->tcf_lock);
 272
 273         return skb->len;
 274
 275 nla_put_failure:
 276         spin_unlock_bh(&d->tcf_lock);
 277         nlmsg_trim(skb, b);
 278         return -1;
 279 }
 280
 281 static void tcf_skbedit_cleanup(struct tc_action *a)
 282 {
 283         struct tcf_skbedit *d = to_skbedit(a);
 284         struct tcf_skbedit_params *params;
 285
 286         params = rcu_dereference_protected(d->params, 1);
 287         if (params)
 288                 kfree_rcu(params, rcu);
 289 }
 290
 291 static int tcf_skbedit_walker(struct net *net, struct sk_buff *skb,
 292                               struct netlink_callback *cb, int type,
 293                               const struct tc_action_ops *ops,
 294                               struct netlink_ext_ack *extack)
 295 {
 296         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 297
 298         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 299 }
 300
 301 static int tcf_skbedit_search(struct net *net, struct tc_action **a, u32 index)
 302 {
 303         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 304
 305         return tcf_idr_search(tn, a, index);
 306 }
 307
 308 static size_t tcf_skbedit_get_fill_size(const struct tc_action *act)
 309 {
 310         return nla_total_size(sizeof(struct tc_skbedit))
 311                 + nla_total_size(sizeof(u32)) /* TCA_SKBEDIT_PRIORITY */
 312                 + nla_total_size(sizeof(u16)) /* TCA_SKBEDIT_QUEUE_MAPPING */
 313                 + nla_total_size(sizeof(u32)) /* TCA_SKBEDIT_MARK */
 314                 + nla_total_size(sizeof(u16)) /* TCA_SKBEDIT_PTYPE */
 315                 + nla_total_size(sizeof(u32)) /* TCA_SKBEDIT_MASK */
 316                 + nla_total_size_64bit(sizeof(u64)); /* TCA_SKBEDIT_FLAGS */
 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         .get_fill_size  =       tcf_skbedit_get_fill_size,
 329         .lookup         =       tcf_skbedit_search,
 330         .size           =       sizeof(struct tcf_skbedit),
 331 };
 332
 333 static __net_init int skbedit_init_net(struct net *net)
 334 {
 335         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 336
 337         return tc_action_net_init(net, tn, &act_skbedit_ops);
 338 }
 339
 340 static void __net_exit skbedit_exit_net(struct list_head *net_list)
 341 {
 342         tc_action_net_exit(net_list, skbedit_net_id);
 343 }
 344
 345 static struct pernet_operations skbedit_net_ops = {
 346         .init = skbedit_init_net,
 347         .exit_batch = skbedit_exit_net,
 348         .id   = &skbedit_net_id,
 349         .size = sizeof(struct tc_action_net),
 350 };
 351
 352 MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>");
 353 MODULE_DESCRIPTION("SKB Editing");
 354 MODULE_LICENSE("GPL");
 355
 356 static int __init skbedit_init_module(void)
 357 {
 358         return tcf_register_action(&act_skbedit_ops, &skbedit_net_ops);
 359 }
 360
 361 static void __exit skbedit_cleanup_module(void)
 362 {
 363         tcf_unregister_action(&act_skbedit_ops, &skbedit_net_ops);
 364 }
 365
 366 module_init(skbedit_init_module);
 367 module_exit(skbedit_cleanup_module);