net/sched/act_vlan.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
   4  */
   5
   6 #include <linux/module.h>
   7 #include <linux/init.h>
   8 #include <linux/kernel.h>
   9 #include <linux/skbuff.h>
  10 #include <linux/rtnetlink.h>
  11 #include <linux/if_vlan.h>
  12 #include <net/netlink.h>
  13 #include <net/pkt_sched.h>
  14 #include <net/pkt_cls.h>
  15
  16 #include <linux/tc_act/tc_vlan.h>
  17 #include <net/tc_act/tc_vlan.h>
  18
  19 static unsigned int vlan_net_id;
  20 static struct tc_action_ops act_vlan_ops;
  21
  22 static int tcf_vlan_act(struct sk_buff *skb, const struct tc_action *a,
  23                         struct tcf_result *res)
  24 {
  25         struct tcf_vlan *v = to_vlan(a);
  26         struct tcf_vlan_params *p;
  27         int action;
  28         int err;
  29         u16 tci;
  30
  31         tcf_lastuse_update(&v->tcf_tm);
  32         bstats_cpu_update(this_cpu_ptr(v->common.cpu_bstats), skb);
  33
  34         /* Ensure 'data' points at mac_header prior calling vlan manipulating
  35          * functions.
  36          */
  37         if (skb_at_tc_ingress(skb))
  38                 skb_push_rcsum(skb, skb->mac_len);
  39
  40         action = READ_ONCE(v->tcf_action);
  41
  42         p = rcu_dereference_bh(v->vlan_p);
  43
  44         switch (p->tcfv_action) {
  45         case TCA_VLAN_ACT_POP:
  46                 err = skb_vlan_pop(skb);
  47                 if (err)
  48                         goto drop;
  49                 break;
  50         case TCA_VLAN_ACT_PUSH:
  51                 err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
  52                                     (p->tcfv_push_prio << VLAN_PRIO_SHIFT));
  53                 if (err)
  54                         goto drop;
  55                 break;
  56         case TCA_VLAN_ACT_MODIFY:
  57                 /* No-op if no vlan tag (either hw-accel or in-payload) */
  58                 if (!skb_vlan_tagged(skb))
  59                         goto out;
  60                 /* extract existing tag (and guarantee no hw-accel tag) */
  61                 if (skb_vlan_tag_present(skb)) {
  62                         tci = skb_vlan_tag_get(skb);
  63                         __vlan_hwaccel_clear_tag(skb);
  64                 } else {
  65                         /* in-payload vlan tag, pop it */
  66                         err = __skb_vlan_pop(skb, &tci);
  67                         if (err)
  68                                 goto drop;
  69                 }
  70                 /* replace the vid */
  71                 tci = (tci & ~VLAN_VID_MASK) | p->tcfv_push_vid;
  72                 /* replace prio bits, if tcfv_push_prio specified */
  73                 if (p->tcfv_push_prio) {
  74                         tci &= ~VLAN_PRIO_MASK;
  75                         tci |= p->tcfv_push_prio << VLAN_PRIO_SHIFT;
  76                 }
  77                 /* put updated tci as hwaccel tag */
  78                 __vlan_hwaccel_put_tag(skb, p->tcfv_push_proto, tci);
  79                 break;
  80         default:
  81                 BUG();
  82         }
  83
  84 out:
  85         if (skb_at_tc_ingress(skb))
  86                 skb_pull_rcsum(skb, skb->mac_len);
  87
  88         return action;
  89
  90 drop:
  91         qstats_drop_inc(this_cpu_ptr(v->common.cpu_qstats));
  92         return TC_ACT_SHOT;
  93 }
  94
  95 static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
  96         [TCA_VLAN_PARMS]                = { .len = sizeof(struct tc_vlan) },
  97         [TCA_VLAN_PUSH_VLAN_ID]         = { .type = NLA_U16 },
  98         [TCA_VLAN_PUSH_VLAN_PROTOCOL]   = { .type = NLA_U16 },
  99         [TCA_VLAN_PUSH_VLAN_PRIORITY]   = { .type = NLA_U8 },
 100 };
 101
 102 static int tcf_vlan_init(struct net *net, struct nlattr *nla,
 103                          struct nlattr *est, struct tc_action **a,
 104                          int ovr, int bind, bool rtnl_held,
 105                          struct tcf_proto *tp, struct netlink_ext_ack *extack)
 106 {
 107         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 108         struct nlattr *tb[TCA_VLAN_MAX + 1];
 109         struct tcf_chain *goto_ch = NULL;
 110         struct tcf_vlan_params *p;
 111         struct tc_vlan *parm;
 112         struct tcf_vlan *v;
 113         int action;
 114         u16 push_vid = 0;
 115         __be16 push_proto = 0;
 116         u8 push_prio = 0;
 117         bool exists = false;
 118         int ret = 0, err;
 119
 120         if (!nla)
 121                 return -EINVAL;
 122
 123         err = nla_parse_nested_deprecated(tb, TCA_VLAN_MAX, nla, vlan_policy,
 124                                           NULL);
 125         if (err < 0)
 126                 return err;
 127
 128         if (!tb[TCA_VLAN_PARMS])
 129                 return -EINVAL;
 130         parm = nla_data(tb[TCA_VLAN_PARMS]);
 131         err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
 132         if (err < 0)
 133                 return err;
 134         exists = err;
 135         if (exists && bind)
 136                 return 0;
 137
 138         switch (parm->v_action) {
 139         case TCA_VLAN_ACT_POP:
 140                 break;
 141         case TCA_VLAN_ACT_PUSH:
 142         case TCA_VLAN_ACT_MODIFY:
 143                 if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
 144                         if (exists)
 145                                 tcf_idr_release(*a, bind);
 146                         else
 147                                 tcf_idr_cleanup(tn, parm->index);
 148                         return -EINVAL;
 149                 }
 150                 push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
 151                 if (push_vid >= VLAN_VID_MASK) {
 152                         if (exists)
 153                                 tcf_idr_release(*a, bind);
 154                         else
 155                                 tcf_idr_cleanup(tn, parm->index);
 156                         return -ERANGE;
 157                 }
 158
 159                 if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
 160                         push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
 161                         switch (push_proto) {
 162                         case htons(ETH_P_8021Q):
 163                         case htons(ETH_P_8021AD):
 164                                 break;
 165                         default:
 166                                 if (exists)
 167                                         tcf_idr_release(*a, bind);
 168                                 else
 169                                         tcf_idr_cleanup(tn, parm->index);
 170                                 return -EPROTONOSUPPORT;
 171                         }
 172                 } else {
 173                         push_proto = htons(ETH_P_8021Q);
 174                 }
 175
 176                 if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
 177                         push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
 178                 break;
 179         default:
 180                 if (exists)
 181                         tcf_idr_release(*a, bind);
 182                 else
 183                         tcf_idr_cleanup(tn, parm->index);
 184                 return -EINVAL;
 185         }
 186         action = parm->v_action;
 187
 188         if (!exists) {
 189                 ret = tcf_idr_create(tn, parm->index, est, a,
 190                                      &act_vlan_ops, bind, true);
 191                 if (ret) {
 192                         tcf_idr_cleanup(tn, parm->index);
 193                         return ret;
 194                 }
 195
 196                 ret = ACT_P_CREATED;
 197         } else if (!ovr) {
 198                 tcf_idr_release(*a, bind);
 199                 return -EEXIST;
 200         }
 201
 202         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
 203         if (err < 0)
 204                 goto release_idr;
 205
 206         v = to_vlan(*a);
 207
 208         p = kzalloc(sizeof(*p), GFP_KERNEL);
 209         if (!p) {
 210                 err = -ENOMEM;
 211                 goto put_chain;
 212         }
 213
 214         p->tcfv_action = action;
 215         p->tcfv_push_vid = push_vid;
 216         p->tcfv_push_prio = push_prio;
 217         p->tcfv_push_proto = push_proto;
 218
 219         spin_lock_bh(&v->tcf_lock);
 220         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 221         rcu_swap_protected(v->vlan_p, p, lockdep_is_held(&v->tcf_lock));
 222         spin_unlock_bh(&v->tcf_lock);
 223
 224         if (goto_ch)
 225                 tcf_chain_put_by_act(goto_ch);
 226         if (p)
 227                 kfree_rcu(p, rcu);
 228
 229         if (ret == ACT_P_CREATED)
 230                 tcf_idr_insert(tn, *a);
 231         return ret;
 232 put_chain:
 233         if (goto_ch)
 234                 tcf_chain_put_by_act(goto_ch);
 235 release_idr:
 236         tcf_idr_release(*a, bind);
 237         return err;
 238 }
 239
 240 static void tcf_vlan_cleanup(struct tc_action *a)
 241 {
 242         struct tcf_vlan *v = to_vlan(a);
 243         struct tcf_vlan_params *p;
 244
 245         p = rcu_dereference_protected(v->vlan_p, 1);
 246         if (p)
 247                 kfree_rcu(p, rcu);
 248 }
 249
 250 static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
 251                          int bind, int ref)
 252 {
 253         unsigned char *b = skb_tail_pointer(skb);
 254         struct tcf_vlan *v = to_vlan(a);
 255         struct tcf_vlan_params *p;
 256         struct tc_vlan opt = {
 257                 .index    = v->tcf_index,
 258                 .refcnt   = refcount_read(&v->tcf_refcnt) - ref,
 259                 .bindcnt  = atomic_read(&v->tcf_bindcnt) - bind,
 260         };
 261         struct tcf_t t;
 262
 263         spin_lock_bh(&v->tcf_lock);
 264         opt.action = v->tcf_action;
 265         p = rcu_dereference_protected(v->vlan_p, lockdep_is_held(&v->tcf_lock));
 266         opt.v_action = p->tcfv_action;
 267         if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
 268                 goto nla_put_failure;
 269
 270         if ((p->tcfv_action == TCA_VLAN_ACT_PUSH ||
 271              p->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
 272             (nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, p->tcfv_push_vid) ||
 273              nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
 274                           p->tcfv_push_proto) ||
 275              (nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
 276                                               p->tcfv_push_prio))))
 277                 goto nla_put_failure;
 278
 279         tcf_tm_dump(&t, &v->tcf_tm);
 280         if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
 281                 goto nla_put_failure;
 282         spin_unlock_bh(&v->tcf_lock);
 283
 284         return skb->len;
 285
 286 nla_put_failure:
 287         spin_unlock_bh(&v->tcf_lock);
 288         nlmsg_trim(skb, b);
 289         return -1;
 290 }
 291
 292 static int tcf_vlan_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, vlan_net_id);
 298
 299         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 300 }
 301
 302 static int tcf_vlan_search(struct net *net, struct tc_action **a, u32 index)
 303 {
 304         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 305
 306         return tcf_idr_search(tn, a, index);
 307 }
 308
 309 static struct tc_action_ops act_vlan_ops = {
 310         .kind           =       "vlan",
 311         .id             =       TCA_ID_VLAN,
 312         .owner          =       THIS_MODULE,
 313         .act            =       tcf_vlan_act,
 314         .dump           =       tcf_vlan_dump,
 315         .init           =       tcf_vlan_init,
 316         .cleanup        =       tcf_vlan_cleanup,
 317         .walk           =       tcf_vlan_walker,
 318         .lookup         =       tcf_vlan_search,
 319         .size           =       sizeof(struct tcf_vlan),
 320 };
 321
 322 static __net_init int vlan_init_net(struct net *net)
 323 {
 324         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 325
 326         return tc_action_net_init(tn, &act_vlan_ops);
 327 }
 328
 329 static void __net_exit vlan_exit_net(struct list_head *net_list)
 330 {
 331         tc_action_net_exit(net_list, vlan_net_id);
 332 }
 333
 334 static struct pernet_operations vlan_net_ops = {
 335         .init = vlan_init_net,
 336         .exit_batch = vlan_exit_net,
 337         .id   = &vlan_net_id,
 338         .size = sizeof(struct tc_action_net),
 339 };
 340
 341 static int __init vlan_init_module(void)
 342 {
 343         return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
 344 }
 345
 346 static void __exit vlan_cleanup_module(void)
 347 {
 348         tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
 349 }
 350
 351 module_init(vlan_init_module);
 352 module_exit(vlan_cleanup_module);
 353
 354 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
 355 MODULE_DESCRIPTION("vlan manipulation actions");
 356 MODULE_LICENSE("GPL v2");