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 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
 103         if (nla == NULL)
 104                 return -EINVAL;
 105
 106         err = nla_parse_nested_deprecated(tb, TCA_SKBEDIT_MAX, nla,
 107                                           skbedit_policy, NULL);
 108         if (err < 0)
 109                 return err;
 110
 111         if (tb[TCA_SKBEDIT_PARMS] == NULL)
 112                 return -EINVAL;
 113
 114         if (tb[TCA_SKBEDIT_PRIORITY] != NULL) {
 115                 flags |= SKBEDIT_F_PRIORITY;
 116                 priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]);
 117         }
 118
 119         if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) {
 120                 flags |= SKBEDIT_F_QUEUE_MAPPING;
 121                 queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]);
 122         }
 123
 124         if (tb[TCA_SKBEDIT_PTYPE] != NULL) {
 125                 ptype = nla_data(tb[TCA_SKBEDIT_PTYPE]);
 126                 if (!skb_pkt_type_ok(*ptype))
 127                         return -EINVAL;
 128                 flags |= SKBEDIT_F_PTYPE;
 129         }
 130
 131         if (tb[TCA_SKBEDIT_MARK] != NULL) {
 132                 flags |= SKBEDIT_F_MARK;
 133                 mark = nla_data(tb[TCA_SKBEDIT_MARK]);
 134         }
 135
 136         if (tb[TCA_SKBEDIT_MASK] != NULL) {
 137                 flags |= SKBEDIT_F_MASK;
 138                 mask = nla_data(tb[TCA_SKBEDIT_MASK]);
 139         }
 140
 141         if (tb[TCA_SKBEDIT_FLAGS] != NULL) {
 142                 u64 *pure_flags = nla_data(tb[TCA_SKBEDIT_FLAGS]);
 143
 144                 if (*pure_flags & SKBEDIT_F_INHERITDSFIELD)
 145                         flags |= SKBEDIT_F_INHERITDSFIELD;
 146         }
 147
 148         parm = nla_data(tb[TCA_SKBEDIT_PARMS]);
 149
 150         err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
 151         if (err < 0)
 152                 return err;
 153         exists = err;
 154         if (exists && bind)
 155                 return 0;
 156
 157         if (!flags) {
 158                 if (exists)
 159                         tcf_idr_release(*a, bind);
 160                 else
 161                         tcf_idr_cleanup(tn, parm->index);
 162                 return -EINVAL;
 163         }
 164
 165         if (!exists) {
 166                 ret = tcf_idr_create(tn, parm->index, est, a,
 167                                      &act_skbedit_ops, bind, true);
 168                 if (ret) {
 169                         tcf_idr_cleanup(tn, parm->index);
 170                         return ret;
 171                 }
 172
 173                 d = to_skbedit(*a);
 174                 ret = ACT_P_CREATED;
 175         } else {
 176                 d = to_skbedit(*a);
 177                 if (!ovr) {
 178                         tcf_idr_release(*a, bind);
 179                         return -EEXIST;
 180                 }
 181         }
 182         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
 183         if (err < 0)
 184                 goto release_idr;
 185
 186         params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
 187         if (unlikely(!params_new)) {
 188                 err = -ENOMEM;
 189                 goto put_chain;
 190         }
 191
 192         params_new->flags = flags;
 193         if (flags & SKBEDIT_F_PRIORITY)
 194                 params_new->priority = *priority;
 195         if (flags & SKBEDIT_F_QUEUE_MAPPING)
 196                 params_new->queue_mapping = *queue_mapping;
 197         if (flags & SKBEDIT_F_MARK)
 198                 params_new->mark = *mark;
 199         if (flags & SKBEDIT_F_PTYPE)
 200                 params_new->ptype = *ptype;
 201         /* default behaviour is to use all the bits */
 202         params_new->mask = 0xffffffff;
 203         if (flags & SKBEDIT_F_MASK)
 204                 params_new->mask = *mask;
 205
 206         spin_lock_bh(&d->tcf_lock);
 207         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 208         rcu_swap_protected(d->params, params_new,
 209                            lockdep_is_held(&d->tcf_lock));
 210         spin_unlock_bh(&d->tcf_lock);
 211         if (params_new)
 212                 kfree_rcu(params_new, rcu);
 213         if (goto_ch)
 214                 tcf_chain_put_by_act(goto_ch);
 215
 216         if (ret == ACT_P_CREATED)
 217                 tcf_idr_insert(tn, *a);
 218         return ret;
 219 put_chain:
 220         if (goto_ch)
 221                 tcf_chain_put_by_act(goto_ch);
 222 release_idr:
 223         tcf_idr_release(*a, bind);
 224         return err;
 225 }
 226
 227 static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
 228                             int bind, int ref)
 229 {
 230         unsigned char *b = skb_tail_pointer(skb);
 231         struct tcf_skbedit *d = to_skbedit(a);
 232         struct tcf_skbedit_params *params;
 233         struct tc_skbedit opt = {
 234                 .index   = d->tcf_index,
 235                 .refcnt  = refcount_read(&d->tcf_refcnt) - ref,
 236                 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
 237         };
 238         u64 pure_flags = 0;
 239         struct tcf_t t;
 240
 241         spin_lock_bh(&d->tcf_lock);
 242         params = rcu_dereference_protected(d->params,
 243                                            lockdep_is_held(&d->tcf_lock));
 244         opt.action = d->tcf_action;
 245
 246         if (nla_put(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt))
 247                 goto nla_put_failure;
 248         if ((params->flags & SKBEDIT_F_PRIORITY) &&
 249             nla_put_u32(skb, TCA_SKBEDIT_PRIORITY, params->priority))
 250                 goto nla_put_failure;
 251         if ((params->flags & SKBEDIT_F_QUEUE_MAPPING) &&
 252             nla_put_u16(skb, TCA_SKBEDIT_QUEUE_MAPPING, params->queue_mapping))
 253                 goto nla_put_failure;
 254         if ((params->flags & SKBEDIT_F_MARK) &&
 255             nla_put_u32(skb, TCA_SKBEDIT_MARK, params->mark))
 256                 goto nla_put_failure;
 257         if ((params->flags & SKBEDIT_F_PTYPE) &&
 258             nla_put_u16(skb, TCA_SKBEDIT_PTYPE, params->ptype))
 259                 goto nla_put_failure;
 260         if ((params->flags & SKBEDIT_F_MASK) &&
 261             nla_put_u32(skb, TCA_SKBEDIT_MASK, params->mask))
 262                 goto nla_put_failure;
 263         if (params->flags & SKBEDIT_F_INHERITDSFIELD)
 264                 pure_flags |= SKBEDIT_F_INHERITDSFIELD;
 265         if (pure_flags != 0 &&
 266             nla_put(skb, TCA_SKBEDIT_FLAGS, sizeof(pure_flags), &pure_flags))
 267                 goto nla_put_failure;
 268
 269         tcf_tm_dump(&t, &d->tcf_tm);
 270         if (nla_put_64bit(skb, TCA_SKBEDIT_TM, sizeof(t), &t, TCA_SKBEDIT_PAD))
 271                 goto nla_put_failure;
 272         spin_unlock_bh(&d->tcf_lock);
 273
 274         return skb->len;
 275
 276 nla_put_failure:
 277         spin_unlock_bh(&d->tcf_lock);
 278         nlmsg_trim(skb, b);
 279         return -1;
 280 }
 281
 282 static void tcf_skbedit_cleanup(struct tc_action *a)
 283 {
 284         struct tcf_skbedit *d = to_skbedit(a);
 285         struct tcf_skbedit_params *params;
 286
 287         params = rcu_dereference_protected(d->params, 1);
 288         if (params)
 289                 kfree_rcu(params, rcu);
 290 }
 291
 292 static int tcf_skbedit_walker(struct net *net, struct sk_buff *skb,
 293                               struct netlink_callback *cb, int type,
 294                               const struct tc_action_ops *ops,
 295                               struct netlink_ext_ack *extack)
 296 {
 297         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 298
 299         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 300 }
 301
 302 static int tcf_skbedit_search(struct net *net, struct tc_action **a, u32 index)
 303 {
 304         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 305
 306         return tcf_idr_search(tn, a, index);
 307 }
 308
 309 static struct tc_action_ops act_skbedit_ops = {
 310         .kind           =       "skbedit",
 311         .id             =       TCA_ID_SKBEDIT,
 312         .owner          =       THIS_MODULE,
 313         .act            =       tcf_skbedit_act,
 314         .dump           =       tcf_skbedit_dump,
 315         .init           =       tcf_skbedit_init,
 316         .cleanup        =       tcf_skbedit_cleanup,
 317         .walk           =       tcf_skbedit_walker,
 318         .lookup         =       tcf_skbedit_search,
 319         .size           =       sizeof(struct tcf_skbedit),
 320 };
 321
 322 static __net_init int skbedit_init_net(struct net *net)
 323 {
 324         struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 325
 326         return tc_action_net_init(tn, &act_skbedit_ops);
 327 }
 328
 329 static void __net_exit skbedit_exit_net(struct list_head *net_list)
 330 {
 331         tc_action_net_exit(net_list, skbedit_net_id);
 332 }
 333
 334 static struct pernet_operations skbedit_net_ops = {
 335         .init = skbedit_init_net,
 336         .exit_batch = skbedit_exit_net,
 337         .id   = &skbedit_net_id,
 338         .size = sizeof(struct tc_action_net),
 339 };
 340
 341 MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>");
 342 MODULE_DESCRIPTION("SKB Editing");
 343 MODULE_LICENSE("GPL");
 344
 345 static int __init skbedit_init_module(void)
 346 {
 347         return tcf_register_action(&act_skbedit_ops, &skbedit_net_ops);
 348 }
 349
 350 static void __exit skbedit_cleanup_module(void)
 351 {
 352         tcf_unregister_action(&act_skbedit_ops, &skbedit_net_ops);
 353 }
 354
 355 module_init(skbedit_init_module);
 356 module_exit(skbedit_cleanup_module);