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                         __vlan_hwaccel_clear_tag(skb);
  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
 122         if (!nla)
 123                 return -EINVAL;
 124
 125         err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy, NULL);
 126         if (err < 0)
 127                 return err;
 128
 129         if (!tb[TCA_VLAN_PARMS])
 130                 return -EINVAL;
 131         parm = nla_data(tb[TCA_VLAN_PARMS]);
 132         err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
 133         if (err < 0)
 134                 return err;
 135         exists = err;
 136         if (exists && bind)
 137                 return 0;
 138
 139         switch (parm->v_action) {
 140         case TCA_VLAN_ACT_POP:
 141                 break;
 142         case TCA_VLAN_ACT_PUSH:
 143         case TCA_VLAN_ACT_MODIFY:
 144                 if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
 145                         if (exists)
 146                                 tcf_idr_release(*a, bind);
 147                         else
 148                                 tcf_idr_cleanup(tn, parm->index);
 149                         return -EINVAL;
 150                 }
 151                 push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
 152                 if (push_vid >= VLAN_VID_MASK) {
 153                         if (exists)
 154                                 tcf_idr_release(*a, bind);
 155                         else
 156                                 tcf_idr_cleanup(tn, parm->index);
 157                         return -ERANGE;
 158                 }
 159
 160                 if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
 161                         push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
 162                         switch (push_proto) {
 163                         case htons(ETH_P_8021Q):
 164                         case htons(ETH_P_8021AD):
 165                                 break;
 166                         default:
 167                                 if (exists)
 168                                         tcf_idr_release(*a, bind);
 169                                 else
 170                                         tcf_idr_cleanup(tn, parm->index);
 171                                 return -EPROTONOSUPPORT;
 172                         }
 173                 } else {
 174                         push_proto = htons(ETH_P_8021Q);
 175                 }
 176
 177                 if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
 178                         push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
 179                 break;
 180         default:
 181                 if (exists)
 182                         tcf_idr_release(*a, bind);
 183                 else
 184                         tcf_idr_cleanup(tn, parm->index);
 185                 return -EINVAL;
 186         }
 187         action = parm->v_action;
 188
 189         if (!exists) {
 190                 ret = tcf_idr_create(tn, parm->index, est, a,
 191                                      &act_vlan_ops, bind, true);
 192                 if (ret) {
 193                         tcf_idr_cleanup(tn, parm->index);
 194                         return ret;
 195                 }
 196
 197                 ret = ACT_P_CREATED;
 198         } else if (!ovr) {
 199                 tcf_idr_release(*a, bind);
 200                 return -EEXIST;
 201         }
 202
 203         v = to_vlan(*a);
 204
 205         p = kzalloc(sizeof(*p), GFP_KERNEL);
 206         if (!p) {
 207                 tcf_idr_release(*a, bind);
 208                 return -ENOMEM;
 209         }
 210
 211         p->tcfv_action = action;
 212         p->tcfv_push_vid = push_vid;
 213         p->tcfv_push_prio = push_prio;
 214         p->tcfv_push_proto = push_proto;
 215
 216         spin_lock_bh(&v->tcf_lock);
 217         v->tcf_action = parm->action;
 218         rcu_swap_protected(v->vlan_p, p, lockdep_is_held(&v->tcf_lock));
 219         spin_unlock_bh(&v->tcf_lock);
 220
 221         if (p)
 222                 kfree_rcu(p, rcu);
 223
 224         if (ret == ACT_P_CREATED)
 225                 tcf_idr_insert(tn, *a);
 226         return ret;
 227 }
 228
 229 static void tcf_vlan_cleanup(struct tc_action *a)
 230 {
 231         struct tcf_vlan *v = to_vlan(a);
 232         struct tcf_vlan_params *p;
 233
 234         p = rcu_dereference_protected(v->vlan_p, 1);
 235         if (p)
 236                 kfree_rcu(p, rcu);
 237 }
 238
 239 static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
 240                          int bind, int ref)
 241 {
 242         unsigned char *b = skb_tail_pointer(skb);
 243         struct tcf_vlan *v = to_vlan(a);
 244         struct tcf_vlan_params *p;
 245         struct tc_vlan opt = {
 246                 .index    = v->tcf_index,
 247                 .refcnt   = refcount_read(&v->tcf_refcnt) - ref,
 248                 .bindcnt  = atomic_read(&v->tcf_bindcnt) - bind,
 249         };
 250         struct tcf_t t;
 251
 252         spin_lock_bh(&v->tcf_lock);
 253         opt.action = v->tcf_action;
 254         p = rcu_dereference_protected(v->vlan_p, lockdep_is_held(&v->tcf_lock));
 255         opt.v_action = p->tcfv_action;
 256         if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
 257                 goto nla_put_failure;
 258
 259         if ((p->tcfv_action == TCA_VLAN_ACT_PUSH ||
 260              p->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
 261             (nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, p->tcfv_push_vid) ||
 262              nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
 263                           p->tcfv_push_proto) ||
 264              (nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
 265                                               p->tcfv_push_prio))))
 266                 goto nla_put_failure;
 267
 268         tcf_tm_dump(&t, &v->tcf_tm);
 269         if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
 270                 goto nla_put_failure;
 271         spin_unlock_bh(&v->tcf_lock);
 272
 273         return skb->len;
 274
 275 nla_put_failure:
 276         spin_unlock_bh(&v->tcf_lock);
 277         nlmsg_trim(skb, b);
 278         return -1;
 279 }
 280
 281 static int tcf_vlan_walker(struct net *net, struct sk_buff *skb,
 282                            struct netlink_callback *cb, int type,
 283                            const struct tc_action_ops *ops,
 284                            struct netlink_ext_ack *extack)
 285 {
 286         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 287
 288         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 289 }
 290
 291 static int tcf_vlan_search(struct net *net, struct tc_action **a, u32 index)
 292 {
 293         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 294
 295         return tcf_idr_search(tn, a, index);
 296 }
 297
 298 static struct tc_action_ops act_vlan_ops = {
 299         .kind           =       "vlan",
 300         .id             =       TCA_ID_VLAN,
 301         .owner          =       THIS_MODULE,
 302         .act            =       tcf_vlan_act,
 303         .dump           =       tcf_vlan_dump,
 304         .init           =       tcf_vlan_init,
 305         .cleanup        =       tcf_vlan_cleanup,
 306         .walk           =       tcf_vlan_walker,
 307         .lookup         =       tcf_vlan_search,
 308         .size           =       sizeof(struct tcf_vlan),
 309 };
 310
 311 static __net_init int vlan_init_net(struct net *net)
 312 {
 313         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 314
 315         return tc_action_net_init(tn, &act_vlan_ops);
 316 }
 317
 318 static void __net_exit vlan_exit_net(struct list_head *net_list)
 319 {
 320         tc_action_net_exit(net_list, vlan_net_id);
 321 }
 322
 323 static struct pernet_operations vlan_net_ops = {
 324         .init = vlan_init_net,
 325         .exit_batch = vlan_exit_net,
 326         .id   = &vlan_net_id,
 327         .size = sizeof(struct tc_action_net),
 328 };
 329
 330 static int __init vlan_init_module(void)
 331 {
 332         return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
 333 }
 334
 335 static void __exit vlan_cleanup_module(void)
 336 {
 337         tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
 338 }
 339
 340 module_init(vlan_init_module);
 341 module_exit(vlan_cleanup_module);
 342
 343 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
 344 MODULE_DESCRIPTION("vlan manipulation actions");
 345 MODULE_LICENSE("GPL v2");