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(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         rcu_read_lock();
  44
  45         action = READ_ONCE(v->tcf_action);
  46
  47         p = rcu_dereference(v->vlan_p);
  48
  49         switch (p->tcfv_action) {
  50         case TCA_VLAN_ACT_POP:
  51                 err = skb_vlan_pop(skb);
  52                 if (err)
  53                         goto drop;
  54                 break;
  55         case TCA_VLAN_ACT_PUSH:
  56                 err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
  57                                     (p->tcfv_push_prio << VLAN_PRIO_SHIFT));
  58                 if (err)
  59                         goto drop;
  60                 break;
  61         case TCA_VLAN_ACT_MODIFY:
  62                 /* No-op if no vlan tag (either hw-accel or in-payload) */
  63                 if (!skb_vlan_tagged(skb))
  64                         goto unlock;
  65                 /* extract existing tag (and guarantee no hw-accel tag) */
  66                 if (skb_vlan_tag_present(skb)) {
  67                         tci = skb_vlan_tag_get(skb);
  68                         skb->vlan_tci = 0;
  69                 } else {
  70                         /* in-payload vlan tag, pop it */
  71                         err = __skb_vlan_pop(skb, &tci);
  72                         if (err)
  73                                 goto drop;
  74                 }
  75                 /* replace the vid */
  76                 tci = (tci & ~VLAN_VID_MASK) | p->tcfv_push_vid;
  77                 /* replace prio bits, if tcfv_push_prio specified */
  78                 if (p->tcfv_push_prio) {
  79                         tci &= ~VLAN_PRIO_MASK;
  80                         tci |= p->tcfv_push_prio << VLAN_PRIO_SHIFT;
  81                 }
  82                 /* put updated tci as hwaccel tag */
  83                 __vlan_hwaccel_put_tag(skb, p->tcfv_push_proto, tci);
  84                 break;
  85         default:
  86                 BUG();
  87         }
  88
  89         goto unlock;
  90
  91 drop:
  92         action = TC_ACT_SHOT;
  93         qstats_drop_inc(this_cpu_ptr(v->common.cpu_qstats));
  94
  95 unlock:
  96         rcu_read_unlock();
  97         if (skb_at_tc_ingress(skb))
  98                 skb_pull_rcsum(skb, skb->mac_len);
  99
 100         return action;
 101 }
 102
 103 static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
 104         [TCA_VLAN_PARMS]                = { .len = sizeof(struct tc_vlan) },
 105         [TCA_VLAN_PUSH_VLAN_ID]         = { .type = NLA_U16 },
 106         [TCA_VLAN_PUSH_VLAN_PROTOCOL]   = { .type = NLA_U16 },
 107         [TCA_VLAN_PUSH_VLAN_PRIORITY]   = { .type = NLA_U8 },
 108 };
 109
 110 static int tcf_vlan_init(struct net *net, struct nlattr *nla,
 111                          struct nlattr *est, struct tc_action **a,
 112                          int ovr, int bind, bool rtnl_held,
 113                          struct netlink_ext_ack *extack)
 114 {
 115         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 116         struct nlattr *tb[TCA_VLAN_MAX + 1];
 117         struct tcf_vlan_params *p, *p_old;
 118         struct tc_vlan *parm;
 119         struct tcf_vlan *v;
 120         int action;
 121         u16 push_vid = 0;
 122         __be16 push_proto = 0;
 123         u8 push_prio = 0;
 124         bool exists = false;
 125         int ret = 0, err;
 126
 127         if (!nla)
 128                 return -EINVAL;
 129
 130         err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy, NULL);
 131         if (err < 0)
 132                 return err;
 133
 134         if (!tb[TCA_VLAN_PARMS])
 135                 return -EINVAL;
 136         parm = nla_data(tb[TCA_VLAN_PARMS]);
 137         err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
 138         if (err < 0)
 139                 return err;
 140         exists = err;
 141         if (exists && bind)
 142                 return 0;
 143
 144         switch (parm->v_action) {
 145         case TCA_VLAN_ACT_POP:
 146                 break;
 147         case TCA_VLAN_ACT_PUSH:
 148         case TCA_VLAN_ACT_MODIFY:
 149                 if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
 150                         if (exists)
 151                                 tcf_idr_release(*a, bind);
 152                         else
 153                                 tcf_idr_cleanup(tn, parm->index);
 154                         return -EINVAL;
 155                 }
 156                 push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
 157                 if (push_vid >= VLAN_VID_MASK) {
 158                         if (exists)
 159                                 tcf_idr_release(*a, bind);
 160                         else
 161                                 tcf_idr_cleanup(tn, parm->index);
 162                         return -ERANGE;
 163                 }
 164
 165                 if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
 166                         push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
 167                         switch (push_proto) {
 168                         case htons(ETH_P_8021Q):
 169                         case htons(ETH_P_8021AD):
 170                                 break;
 171                         default:
 172                                 if (exists)
 173                                         tcf_idr_release(*a, bind);
 174                                 else
 175                                         tcf_idr_cleanup(tn, parm->index);
 176                                 return -EPROTONOSUPPORT;
 177                         }
 178                 } else {
 179                         push_proto = htons(ETH_P_8021Q);
 180                 }
 181
 182                 if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
 183                         push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
 184                 break;
 185         default:
 186                 if (exists)
 187                         tcf_idr_release(*a, bind);
 188                 else
 189                         tcf_idr_cleanup(tn, parm->index);
 190                 return -EINVAL;
 191         }
 192         action = parm->v_action;
 193
 194         if (!exists) {
 195                 ret = tcf_idr_create(tn, parm->index, est, a,
 196                                      &act_vlan_ops, bind, true);
 197                 if (ret) {
 198                         tcf_idr_cleanup(tn, parm->index);
 199                         return ret;
 200                 }
 201
 202                 ret = ACT_P_CREATED;
 203         } else if (!ovr) {
 204                 tcf_idr_release(*a, bind);
 205                 return -EEXIST;
 206         }
 207
 208         v = to_vlan(*a);
 209
 210         ASSERT_RTNL();
 211         p = kzalloc(sizeof(*p), GFP_KERNEL);
 212         if (!p) {
 213                 tcf_idr_release(*a, bind);
 214                 return -ENOMEM;
 215         }
 216
 217         v->tcf_action = parm->action;
 218
 219         p_old = rtnl_dereference(v->vlan_p);
 220
 221         p->tcfv_action = action;
 222         p->tcfv_push_vid = push_vid;
 223         p->tcfv_push_prio = push_prio;
 224         p->tcfv_push_proto = push_proto;
 225
 226         rcu_assign_pointer(v->vlan_p, p);
 227
 228         if (p_old)
 229                 kfree_rcu(p_old, rcu);
 230
 231         if (ret == ACT_P_CREATED)
 232                 tcf_idr_insert(tn, *a);
 233         return ret;
 234 }
 235
 236 static void tcf_vlan_cleanup(struct tc_action *a)
 237 {
 238         struct tcf_vlan *v = to_vlan(a);
 239         struct tcf_vlan_params *p;
 240
 241         p = rcu_dereference_protected(v->vlan_p, 1);
 242         if (p)
 243                 kfree_rcu(p, rcu);
 244 }
 245
 246 static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
 247                          int bind, int ref)
 248 {
 249         unsigned char *b = skb_tail_pointer(skb);
 250         struct tcf_vlan *v = to_vlan(a);
 251         struct tcf_vlan_params *p = rtnl_dereference(v->vlan_p);
 252         struct tc_vlan opt = {
 253                 .index    = v->tcf_index,
 254                 .refcnt   = refcount_read(&v->tcf_refcnt) - ref,
 255                 .bindcnt  = atomic_read(&v->tcf_bindcnt) - bind,
 256                 .action   = v->tcf_action,
 257                 .v_action = p->tcfv_action,
 258         };
 259         struct tcf_t t;
 260
 261         if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
 262                 goto nla_put_failure;
 263
 264         if ((p->tcfv_action == TCA_VLAN_ACT_PUSH ||
 265              p->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
 266             (nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, p->tcfv_push_vid) ||
 267              nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
 268                           p->tcfv_push_proto) ||
 269              (nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
 270                                               p->tcfv_push_prio))))
 271                 goto nla_put_failure;
 272
 273         tcf_tm_dump(&t, &v->tcf_tm);
 274         if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
 275                 goto nla_put_failure;
 276         return skb->len;
 277
 278 nla_put_failure:
 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 int tcf_vlan_delete(struct net *net, u32 index)
 302 {
 303         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 304
 305         return tcf_idr_delete_index(tn, index);
 306 }
 307
 308 static struct tc_action_ops act_vlan_ops = {
 309         .kind           =       "vlan",
 310         .type           =       TCA_ACT_VLAN,
 311         .owner          =       THIS_MODULE,
 312         .act            =       tcf_vlan,
 313         .dump           =       tcf_vlan_dump,
 314         .init           =       tcf_vlan_init,
 315         .cleanup        =       tcf_vlan_cleanup,
 316         .walk           =       tcf_vlan_walker,
 317         .lookup         =       tcf_vlan_search,
 318         .delete         =       tcf_vlan_delete,
 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");