net/sched/act_vlan.c

   1 /*
   2  * Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/rtnetlink.h>
  15 #include <linux/if_vlan.h>
  16 #include <net/netlink.h>
  17 #include <net/pkt_sched.h>
  18 #include <net/pkt_cls.h>
  19
  20 #include <linux/tc_act/tc_vlan.h>
  21 #include <net/tc_act/tc_vlan.h>
  22
  23 static unsigned int vlan_net_id;
  24 static struct tc_action_ops act_vlan_ops;
  25
  26 static int tcf_vlan_act(struct sk_buff *skb, const struct tc_action *a,
  27                         struct tcf_result *res)
  28 {
  29         struct tcf_vlan *v = to_vlan(a);
  30         struct tcf_vlan_params *p;
  31         int action;
  32         int err;
  33         u16 tci;
  34
  35         tcf_lastuse_update(&v->tcf_tm);
  36         bstats_cpu_update(this_cpu_ptr(v->common.cpu_bstats), skb);
  37
  38         /* Ensure 'data' points at mac_header prior calling vlan manipulating
  39          * functions.
  40          */
  41         if (skb_at_tc_ingress(skb))
  42                 skb_push_rcsum(skb, skb->mac_len);
  43
  44         action = READ_ONCE(v->tcf_action);
  45
  46         p = rcu_dereference_bh(v->vlan_p);
  47
  48         switch (p->tcfv_action) {
  49         case TCA_VLAN_ACT_POP:
  50                 err = skb_vlan_pop(skb);
  51                 if (err)
  52                         goto drop;
  53                 break;
  54         case TCA_VLAN_ACT_PUSH:
  55                 err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
  56                                     (p->tcfv_push_prio << VLAN_PRIO_SHIFT));
  57                 if (err)
  58                         goto drop;
  59                 break;
  60         case TCA_VLAN_ACT_MODIFY:
  61                 /* No-op if no vlan tag (either hw-accel or in-payload) */
  62                 if (!skb_vlan_tagged(skb))
  63                         goto out;
  64                 /* extract existing tag (and guarantee no hw-accel tag) */
  65                 if (skb_vlan_tag_present(skb)) {
  66                         tci = skb_vlan_tag_get(skb);
  67                         __vlan_hwaccel_clear_tag(skb);
  68                 } else {
  69                         /* in-payload vlan tag, pop it */
  70                         err = __skb_vlan_pop(skb, &tci);
  71                         if (err)
  72                                 goto drop;
  73                 }
  74                 /* replace the vid */
  75                 tci = (tci & ~VLAN_VID_MASK) | p->tcfv_push_vid;
  76                 /* replace prio bits, if tcfv_push_prio specified */
  77                 if (p->tcfv_push_prio) {
  78                         tci &= ~VLAN_PRIO_MASK;
  79                         tci |= p->tcfv_push_prio << VLAN_PRIO_SHIFT;
  80                 }
  81                 /* put updated tci as hwaccel tag */
  82                 __vlan_hwaccel_put_tag(skb, p->tcfv_push_proto, tci);
  83                 break;
  84         default:
  85                 BUG();
  86         }
  87
  88 out:
  89         if (skb_at_tc_ingress(skb))
  90                 skb_pull_rcsum(skb, skb->mac_len);
  91
  92         return action;
  93
  94 drop:
  95         qstats_drop_inc(this_cpu_ptr(v->common.cpu_qstats));
  96         return TC_ACT_SHOT;
  97 }
  98
  99 static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
 100         [TCA_VLAN_PARMS]                = { .len = sizeof(struct tc_vlan) },
 101         [TCA_VLAN_PUSH_VLAN_ID]         = { .type = NLA_U16 },
 102         [TCA_VLAN_PUSH_VLAN_PROTOCOL]   = { .type = NLA_U16 },
 103         [TCA_VLAN_PUSH_VLAN_PRIORITY]   = { .type = NLA_U8 },
 104 };
 105
 106 static int tcf_vlan_init(struct net *net, struct nlattr *nla,
 107                          struct nlattr *est, struct tc_action **a,
 108                          int ovr, int bind, bool rtnl_held,
 109                          struct tcf_proto *tp, struct netlink_ext_ack *extack)
 110 {
 111         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 112         struct nlattr *tb[TCA_VLAN_MAX + 1];
 113         struct tcf_chain *goto_ch = NULL;
 114         struct tcf_vlan_params *p;
 115         struct tc_vlan *parm;
 116         struct tcf_vlan *v;
 117         int action;
 118         u16 push_vid = 0;
 119         __be16 push_proto = 0;
 120         u8 push_prio = 0;
 121         bool exists = false;
 122         int ret = 0, err;
 123
 124         if (!nla)
 125                 return -EINVAL;
 126
 127         err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy, NULL);
 128         if (err < 0)
 129                 return err;
 130
 131         if (!tb[TCA_VLAN_PARMS])
 132                 return -EINVAL;
 133         parm = nla_data(tb[TCA_VLAN_PARMS]);
 134         err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
 135         if (err < 0)
 136                 return err;
 137         exists = err;
 138         if (exists && bind)
 139                 return 0;
 140
 141         switch (parm->v_action) {
 142         case TCA_VLAN_ACT_POP:
 143                 break;
 144         case TCA_VLAN_ACT_PUSH:
 145         case TCA_VLAN_ACT_MODIFY:
 146                 if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
 147                         if (exists)
 148                                 tcf_idr_release(*a, bind);
 149                         else
 150                                 tcf_idr_cleanup(tn, parm->index);
 151                         return -EINVAL;
 152                 }
 153                 push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
 154                 if (push_vid >= VLAN_VID_MASK) {
 155                         if (exists)
 156                                 tcf_idr_release(*a, bind);
 157                         else
 158                                 tcf_idr_cleanup(tn, parm->index);
 159                         return -ERANGE;
 160                 }
 161
 162                 if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
 163                         push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
 164                         switch (push_proto) {
 165                         case htons(ETH_P_8021Q):
 166                         case htons(ETH_P_8021AD):
 167                                 break;
 168                         default:
 169                                 if (exists)
 170                                         tcf_idr_release(*a, bind);
 171                                 else
 172                                         tcf_idr_cleanup(tn, parm->index);
 173                                 return -EPROTONOSUPPORT;
 174                         }
 175                 } else {
 176                         push_proto = htons(ETH_P_8021Q);
 177                 }
 178
 179                 if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
 180                         push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
 181                 break;
 182         default:
 183                 if (exists)
 184                         tcf_idr_release(*a, bind);
 185                 else
 186                         tcf_idr_cleanup(tn, parm->index);
 187                 return -EINVAL;
 188         }
 189         action = parm->v_action;
 190
 191         if (!exists) {
 192                 ret = tcf_idr_create(tn, parm->index, est, a,
 193                                      &act_vlan_ops, bind, true);
 194                 if (ret) {
 195                         tcf_idr_cleanup(tn, parm->index);
 196                         return ret;
 197                 }
 198
 199                 ret = ACT_P_CREATED;
 200         } else if (!ovr) {
 201                 tcf_idr_release(*a, bind);
 202                 return -EEXIST;
 203         }
 204
 205         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
 206         if (err < 0)
 207                 goto release_idr;
 208
 209         v = to_vlan(*a);
 210
 211         p = kzalloc(sizeof(*p), GFP_KERNEL);
 212         if (!p) {
 213                 err = -ENOMEM;
 214                 goto put_chain;
 215         }
 216
 217         p->tcfv_action = action;
 218         p->tcfv_push_vid = push_vid;
 219         p->tcfv_push_prio = push_prio;
 220         p->tcfv_push_proto = push_proto;
 221
 222         spin_lock_bh(&v->tcf_lock);
 223         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 224         rcu_swap_protected(v->vlan_p, p, lockdep_is_held(&v->tcf_lock));
 225         spin_unlock_bh(&v->tcf_lock);
 226
 227         if (goto_ch)
 228                 tcf_chain_put_by_act(goto_ch);
 229         if (p)
 230                 kfree_rcu(p, rcu);
 231
 232         if (ret == ACT_P_CREATED)
 233                 tcf_idr_insert(tn, *a);
 234         return ret;
 235 put_chain:
 236         if (goto_ch)
 237                 tcf_chain_put_by_act(goto_ch);
 238 release_idr:
 239         tcf_idr_release(*a, bind);
 240         return err;
 241 }
 242
 243 static void tcf_vlan_cleanup(struct tc_action *a)
 244 {
 245         struct tcf_vlan *v = to_vlan(a);
 246         struct tcf_vlan_params *p;
 247
 248         p = rcu_dereference_protected(v->vlan_p, 1);
 249         if (p)
 250                 kfree_rcu(p, rcu);
 251 }
 252
 253 static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
 254                          int bind, int ref)
 255 {
 256         unsigned char *b = skb_tail_pointer(skb);
 257         struct tcf_vlan *v = to_vlan(a);
 258         struct tcf_vlan_params *p;
 259         struct tc_vlan opt = {
 260                 .index    = v->tcf_index,
 261                 .refcnt   = refcount_read(&v->tcf_refcnt) - ref,
 262                 .bindcnt  = atomic_read(&v->tcf_bindcnt) - bind,
 263         };
 264         struct tcf_t t;
 265
 266         spin_lock_bh(&v->tcf_lock);
 267         opt.action = v->tcf_action;
 268         p = rcu_dereference_protected(v->vlan_p, lockdep_is_held(&v->tcf_lock));
 269         opt.v_action = p->tcfv_action;
 270         if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
 271                 goto nla_put_failure;
 272
 273         if ((p->tcfv_action == TCA_VLAN_ACT_PUSH ||
 274              p->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
 275             (nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, p->tcfv_push_vid) ||
 276              nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
 277                           p->tcfv_push_proto) ||
 278              (nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
 279                                               p->tcfv_push_prio))))
 280                 goto nla_put_failure;
 281
 282         tcf_tm_dump(&t, &v->tcf_tm);
 283         if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
 284                 goto nla_put_failure;
 285         spin_unlock_bh(&v->tcf_lock);
 286
 287         return skb->len;
 288
 289 nla_put_failure:
 290         spin_unlock_bh(&v->tcf_lock);
 291         nlmsg_trim(skb, b);
 292         return -1;
 293 }
 294
 295 static int tcf_vlan_walker(struct net *net, struct sk_buff *skb,
 296                            struct netlink_callback *cb, int type,
 297                            const struct tc_action_ops *ops,
 298                            struct netlink_ext_ack *extack)
 299 {
 300         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 301
 302         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 303 }
 304
 305 static int tcf_vlan_search(struct net *net, struct tc_action **a, u32 index)
 306 {
 307         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 308
 309         return tcf_idr_search(tn, a, index);
 310 }
 311
 312 static struct tc_action_ops act_vlan_ops = {
 313         .kind           =       "vlan",
 314         .id             =       TCA_ID_VLAN,
 315         .owner          =       THIS_MODULE,
 316         .act            =       tcf_vlan_act,
 317         .dump           =       tcf_vlan_dump,
 318         .init           =       tcf_vlan_init,
 319         .cleanup        =       tcf_vlan_cleanup,
 320         .walk           =       tcf_vlan_walker,
 321         .lookup         =       tcf_vlan_search,
 322         .size           =       sizeof(struct tcf_vlan),
 323 };
 324
 325 static __net_init int vlan_init_net(struct net *net)
 326 {
 327         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 328
 329         return tc_action_net_init(tn, &act_vlan_ops);
 330 }
 331
 332 static void __net_exit vlan_exit_net(struct list_head *net_list)
 333 {
 334         tc_action_net_exit(net_list, vlan_net_id);
 335 }
 336
 337 static struct pernet_operations vlan_net_ops = {
 338         .init = vlan_init_net,
 339         .exit_batch = vlan_exit_net,
 340         .id   = &vlan_net_id,
 341         .size = sizeof(struct tc_action_net),
 342 };
 343
 344 static int __init vlan_init_module(void)
 345 {
 346         return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
 347 }
 348
 349 static void __exit vlan_cleanup_module(void)
 350 {
 351         tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
 352 }
 353
 354 module_init(vlan_init_module);
 355 module_exit(vlan_cleanup_module);
 356
 357 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
 358 MODULE_DESCRIPTION("vlan manipulation actions");
 359 MODULE_LICENSE("GPL v2");