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
  19 #include <linux/tc_act/tc_vlan.h>
  20 #include <net/tc_act/tc_vlan.h>
  21
  22 static unsigned int vlan_net_id;
  23 static struct tc_action_ops act_vlan_ops;
  24
  25 static int tcf_vlan_act(struct sk_buff *skb, const struct tc_action *a,
  26                         struct tcf_result *res)
  27 {
  28         struct tcf_vlan *v = to_vlan(a);
  29         struct tcf_vlan_params *p;
  30         int action;
  31         int err;
  32         u16 tci;
  33
  34         tcf_lastuse_update(&v->tcf_tm);
  35         bstats_cpu_update(this_cpu_ptr(v->common.cpu_bstats), skb);
  36
  37         /* Ensure 'data' points at mac_header prior calling vlan manipulating
  38          * functions.
  39          */
  40         if (skb_at_tc_ingress(skb))
  41                 skb_push_rcsum(skb, skb->mac_len);
  42
  43         action = READ_ONCE(v->tcf_action);
  44
  45         p = rcu_dereference_bh(v->vlan_p);
  46
  47         switch (p->tcfv_action) {
  48         case TCA_VLAN_ACT_POP:
  49                 err = skb_vlan_pop(skb);
  50                 if (err)
  51                         goto drop;
  52                 break;
  53         case TCA_VLAN_ACT_PUSH:
  54                 err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
  55                                     (p->tcfv_push_prio << VLAN_PRIO_SHIFT));
  56                 if (err)
  57                         goto drop;
  58                 break;
  59         case TCA_VLAN_ACT_MODIFY:
  60                 /* No-op if no vlan tag (either hw-accel or in-payload) */
  61                 if (!skb_vlan_tagged(skb))
  62                         goto out;
  63                 /* extract existing tag (and guarantee no hw-accel tag) */
  64                 if (skb_vlan_tag_present(skb)) {
  65                         tci = skb_vlan_tag_get(skb);
  66                         skb->vlan_tci = 0;
  67                 } else {
  68                         /* in-payload vlan tag, pop it */
  69                         err = __skb_vlan_pop(skb, &tci);
  70                         if (err)
  71                                 goto drop;
  72                 }
  73                 /* replace the vid */
  74                 tci = (tci & ~VLAN_VID_MASK) | p->tcfv_push_vid;
  75                 /* replace prio bits, if tcfv_push_prio specified */
  76                 if (p->tcfv_push_prio) {
  77                         tci &= ~VLAN_PRIO_MASK;
  78                         tci |= p->tcfv_push_prio << VLAN_PRIO_SHIFT;
  79                 }
  80                 /* put updated tci as hwaccel tag */
  81                 __vlan_hwaccel_put_tag(skb, p->tcfv_push_proto, tci);
  82                 break;
  83         default:
  84                 BUG();
  85         }
  86
  87 out:
  88         if (skb_at_tc_ingress(skb))
  89                 skb_pull_rcsum(skb, skb->mac_len);
  90
  91         return action;
  92
  93 drop:
  94         qstats_drop_inc(this_cpu_ptr(v->common.cpu_qstats));
  95         return TC_ACT_SHOT;
  96 }
  97
  98 static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
  99         [TCA_VLAN_PARMS]                = { .len = sizeof(struct tc_vlan) },
 100         [TCA_VLAN_PUSH_VLAN_ID]         = { .type = NLA_U16 },
 101         [TCA_VLAN_PUSH_VLAN_PROTOCOL]   = { .type = NLA_U16 },
 102         [TCA_VLAN_PUSH_VLAN_PRIORITY]   = { .type = NLA_U8 },
 103 };
 104
 105 static int tcf_vlan_init(struct net *net, struct nlattr *nla,
 106                          struct nlattr *est, struct tc_action **a,
 107                          int ovr, int bind, bool rtnl_held,
 108                          struct netlink_ext_ack *extack)
 109 {
 110         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 111         struct nlattr *tb[TCA_VLAN_MAX + 1];
 112         struct tcf_vlan_params *p;
 113         struct tc_vlan *parm;
 114         struct tcf_vlan *v;
 115         int action;
 116         u16 push_vid = 0;
 117         __be16 push_proto = 0;
 118         u8 push_prio = 0;
 119         bool exists = false;
 120         int ret = 0, err;
 121         u32 index;
 122
 123         if (!nla)
 124                 return -EINVAL;
 125
 126         err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy, NULL);
 127         if (err < 0)
 128                 return err;
 129
 130         if (!tb[TCA_VLAN_PARMS])
 131                 return -EINVAL;
 132         parm = nla_data(tb[TCA_VLAN_PARMS]);
 133         index = parm->index;
 134         err = tcf_idr_check_alloc(tn, &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, 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, 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, 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, index);
 187                 return -EINVAL;
 188         }
 189         action = parm->v_action;
 190
 191         if (!exists) {
 192                 ret = tcf_idr_create(tn, index, est, a,
 193                                      &act_vlan_ops, bind, true);
 194                 if (ret) {
 195                         tcf_idr_cleanup(tn, 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         v = to_vlan(*a);
 206
 207         p = kzalloc(sizeof(*p), GFP_KERNEL);
 208         if (!p) {
 209                 tcf_idr_release(*a, bind);
 210                 return -ENOMEM;
 211         }
 212
 213         p->tcfv_action = action;
 214         p->tcfv_push_vid = push_vid;
 215         p->tcfv_push_prio = push_prio;
 216         p->tcfv_push_proto = push_proto;
 217
 218         spin_lock_bh(&v->tcf_lock);
 219         v->tcf_action = parm->action;
 220         rcu_swap_protected(v->vlan_p, p, lockdep_is_held(&v->tcf_lock));
 221         spin_unlock_bh(&v->tcf_lock);
 222
 223         if (p)
 224                 kfree_rcu(p, rcu);
 225
 226         if (ret == ACT_P_CREATED)
 227                 tcf_idr_insert(tn, *a);
 228         return ret;
 229 }
 230
 231 static void tcf_vlan_cleanup(struct tc_action *a)
 232 {
 233         struct tcf_vlan *v = to_vlan(a);
 234         struct tcf_vlan_params *p;
 235
 236         p = rcu_dereference_protected(v->vlan_p, 1);
 237         if (p)
 238                 kfree_rcu(p, rcu);
 239 }
 240
 241 static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
 242                          int bind, int ref)
 243 {
 244         unsigned char *b = skb_tail_pointer(skb);
 245         struct tcf_vlan *v = to_vlan(a);
 246         struct tcf_vlan_params *p;
 247         struct tc_vlan opt = {
 248                 .index    = v->tcf_index,
 249                 .refcnt   = refcount_read(&v->tcf_refcnt) - ref,
 250                 .bindcnt  = atomic_read(&v->tcf_bindcnt) - bind,
 251         };
 252         struct tcf_t t;
 253
 254         spin_lock_bh(&v->tcf_lock);
 255         opt.action = v->tcf_action;
 256         p = rcu_dereference_protected(v->vlan_p, lockdep_is_held(&v->tcf_lock));
 257         opt.v_action = p->tcfv_action;
 258         if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
 259                 goto nla_put_failure;
 260
 261         if ((p->tcfv_action == TCA_VLAN_ACT_PUSH ||
 262              p->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
 263             (nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, p->tcfv_push_vid) ||
 264              nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
 265                           p->tcfv_push_proto) ||
 266              (nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
 267                                               p->tcfv_push_prio))))
 268                 goto nla_put_failure;
 269
 270         tcf_tm_dump(&t, &v->tcf_tm);
 271         if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
 272                 goto nla_put_failure;
 273         spin_unlock_bh(&v->tcf_lock);
 274
 275         return skb->len;
 276
 277 nla_put_failure:
 278         spin_unlock_bh(&v->tcf_lock);
 279         nlmsg_trim(skb, b);
 280         return -1;
 281 }
 282
 283 static int tcf_vlan_walker(struct net *net, struct sk_buff *skb,
 284                            struct netlink_callback *cb, int type,
 285                            const struct tc_action_ops *ops,
 286                            struct netlink_ext_ack *extack)
 287 {
 288         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 289
 290         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 291 }
 292
 293 static int tcf_vlan_search(struct net *net, struct tc_action **a, u32 index,
 294                            struct netlink_ext_ack *extack)
 295 {
 296         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 297
 298         return tcf_idr_search(tn, a, index);
 299 }
 300
 301 static size_t tcf_vlan_get_fill_size(const struct tc_action *act)
 302 {
 303         return nla_total_size(sizeof(struct tc_vlan))
 304                 + nla_total_size(sizeof(u16)) /* TCA_VLAN_PUSH_VLAN_ID */
 305                 + nla_total_size(sizeof(u16)) /* TCA_VLAN_PUSH_VLAN_PROTOCOL */
 306                 + nla_total_size(sizeof(u8)); /* TCA_VLAN_PUSH_VLAN_PRIORITY */
 307 }
 308
 309 static struct tc_action_ops act_vlan_ops = {
 310         .kind           =       "vlan",
 311         .type           =       TCA_ACT_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         .get_fill_size  =       tcf_vlan_get_fill_size,
 319         .lookup         =       tcf_vlan_search,
 320         .size           =       sizeof(struct tcf_vlan),
 321 };
 322
 323 static __net_init int vlan_init_net(struct net *net)
 324 {
 325         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 326
 327         return tc_action_net_init(net, tn, &act_vlan_ops);
 328 }
 329
 330 static void __net_exit vlan_exit_net(struct list_head *net_list)
 331 {
 332         tc_action_net_exit(net_list, vlan_net_id);
 333 }
 334
 335 static struct pernet_operations vlan_net_ops = {
 336         .init = vlan_init_net,
 337         .exit_batch = vlan_exit_net,
 338         .id   = &vlan_net_id,
 339         .size = sizeof(struct tc_action_net),
 340 };
 341
 342 static int __init vlan_init_module(void)
 343 {
 344         return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
 345 }
 346
 347 static void __exit vlan_cleanup_module(void)
 348 {
 349         tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
 350 }
 351
 352 module_init(vlan_init_module);
 353 module_exit(vlan_cleanup_module);
 354
 355 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
 356 MODULE_DESCRIPTION("vlan manipulation actions");
 357 MODULE_LICENSE("GPL v2");