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 #define VLAN_TAB_MASK     15
  23
  24 static unsigned int vlan_net_id;
  25 static struct tc_action_ops act_vlan_ops;
  26
  27 static int tcf_vlan(struct sk_buff *skb, const struct tc_action *a,
  28                     struct tcf_result *res)
  29 {
  30         struct tcf_vlan *v = to_vlan(a);
  31         int action;
  32         int err;
  33         u16 tci;
  34
  35         spin_lock(&v->tcf_lock);
  36         tcf_lastuse_update(&v->tcf_tm);
  37         bstats_update(&v->tcf_bstats, skb);
  38         action = v->tcf_action;
  39
  40         /* Ensure 'data' points at mac_header prior calling vlan manipulating
  41          * functions.
  42          */
  43         if (skb_at_tc_ingress(skb))
  44                 skb_push_rcsum(skb, skb->mac_len);
  45
  46         switch (v->tcfv_action) {
  47         case TCA_VLAN_ACT_POP:
  48                 err = skb_vlan_pop(skb);
  49                 if (err)
  50                         goto drop;
  51                 break;
  52         case TCA_VLAN_ACT_PUSH:
  53                 err = skb_vlan_push(skb, v->tcfv_push_proto, v->tcfv_push_vid |
  54                                     (v->tcfv_push_prio << VLAN_PRIO_SHIFT));
  55                 if (err)
  56                         goto drop;
  57                 break;
  58         case TCA_VLAN_ACT_MODIFY:
  59                 /* No-op if no vlan tag (either hw-accel or in-payload) */
  60                 if (!skb_vlan_tagged(skb))
  61                         goto unlock;
  62                 /* extract existing tag (and guarantee no hw-accel tag) */
  63                 if (skb_vlan_tag_present(skb)) {
  64                         tci = skb_vlan_tag_get(skb);
  65                         skb->vlan_tci = 0;
  66                 } else {
  67                         /* in-payload vlan tag, pop it */
  68                         err = __skb_vlan_pop(skb, &tci);
  69                         if (err)
  70                                 goto drop;
  71                 }
  72                 /* replace the vid */
  73                 tci = (tci & ~VLAN_VID_MASK) | v->tcfv_push_vid;
  74                 /* replace prio bits, if tcfv_push_prio specified */
  75                 if (v->tcfv_push_prio) {
  76                         tci &= ~VLAN_PRIO_MASK;
  77                         tci |= v->tcfv_push_prio << VLAN_PRIO_SHIFT;
  78                 }
  79                 /* put updated tci as hwaccel tag */
  80                 __vlan_hwaccel_put_tag(skb, v->tcfv_push_proto, tci);
  81                 break;
  82         default:
  83                 BUG();
  84         }
  85
  86         goto unlock;
  87
  88 drop:
  89         action = TC_ACT_SHOT;
  90         v->tcf_qstats.drops++;
  91 unlock:
  92         if (skb_at_tc_ingress(skb))
  93                 skb_pull_rcsum(skb, skb->mac_len);
  94
  95         spin_unlock(&v->tcf_lock);
  96         return action;
  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)
 109 {
 110         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 111         struct nlattr *tb[TCA_VLAN_MAX + 1];
 112         struct tc_vlan *parm;
 113         struct tcf_vlan *v;
 114         int action;
 115         __be16 push_vid = 0;
 116         __be16 push_proto = 0;
 117         u8 push_prio = 0;
 118         bool exists = false;
 119         int ret = 0, err;
 120
 121         if (!nla)
 122                 return -EINVAL;
 123
 124         err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy, 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         exists = tcf_hash_check(tn, parm->index, a, bind);
 132         if (exists && bind)
 133                 return 0;
 134
 135         switch (parm->v_action) {
 136         case TCA_VLAN_ACT_POP:
 137                 break;
 138         case TCA_VLAN_ACT_PUSH:
 139         case TCA_VLAN_ACT_MODIFY:
 140                 if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
 141                         if (exists)
 142                                 tcf_hash_release(*a, bind);
 143                         return -EINVAL;
 144                 }
 145                 push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
 146                 if (push_vid >= VLAN_VID_MASK) {
 147                         if (exists)
 148                                 tcf_hash_release(*a, bind);
 149                         return -ERANGE;
 150                 }
 151
 152                 if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
 153                         push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
 154                         switch (push_proto) {
 155                         case htons(ETH_P_8021Q):
 156                         case htons(ETH_P_8021AD):
 157                                 break;
 158                         default:
 159                                 return -EPROTONOSUPPORT;
 160                         }
 161                 } else {
 162                         push_proto = htons(ETH_P_8021Q);
 163                 }
 164
 165                 if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
 166                         push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
 167                 break;
 168         default:
 169                 if (exists)
 170                         tcf_hash_release(*a, bind);
 171                 return -EINVAL;
 172         }
 173         action = parm->v_action;
 174
 175         if (!exists) {
 176                 ret = tcf_hash_create(tn, parm->index, est, a,
 177                                       &act_vlan_ops, bind, false);
 178                 if (ret)
 179                         return ret;
 180
 181                 ret = ACT_P_CREATED;
 182         } else {
 183                 tcf_hash_release(*a, bind);
 184                 if (!ovr)
 185                         return -EEXIST;
 186         }
 187
 188         v = to_vlan(*a);
 189
 190         spin_lock_bh(&v->tcf_lock);
 191
 192         v->tcfv_action = action;
 193         v->tcfv_push_vid = push_vid;
 194         v->tcfv_push_prio = push_prio;
 195         v->tcfv_push_proto = push_proto;
 196
 197         v->tcf_action = parm->action;
 198
 199         spin_unlock_bh(&v->tcf_lock);
 200
 201         if (ret == ACT_P_CREATED)
 202                 tcf_hash_insert(tn, *a);
 203         return ret;
 204 }
 205
 206 static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
 207                          int bind, int ref)
 208 {
 209         unsigned char *b = skb_tail_pointer(skb);
 210         struct tcf_vlan *v = to_vlan(a);
 211         struct tc_vlan opt = {
 212                 .index    = v->tcf_index,
 213                 .refcnt   = v->tcf_refcnt - ref,
 214                 .bindcnt  = v->tcf_bindcnt - bind,
 215                 .action   = v->tcf_action,
 216                 .v_action = v->tcfv_action,
 217         };
 218         struct tcf_t t;
 219
 220         if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
 221                 goto nla_put_failure;
 222
 223         if ((v->tcfv_action == TCA_VLAN_ACT_PUSH ||
 224              v->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
 225             (nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, v->tcfv_push_vid) ||
 226              nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
 227                           v->tcfv_push_proto) ||
 228              (nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
 229                                               v->tcfv_push_prio))))
 230                 goto nla_put_failure;
 231
 232         tcf_tm_dump(&t, &v->tcf_tm);
 233         if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
 234                 goto nla_put_failure;
 235         return skb->len;
 236
 237 nla_put_failure:
 238         nlmsg_trim(skb, b);
 239         return -1;
 240 }
 241
 242 static int tcf_vlan_walker(struct net *net, struct sk_buff *skb,
 243                            struct netlink_callback *cb, int type,
 244                            const struct tc_action_ops *ops)
 245 {
 246         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 247
 248         return tcf_generic_walker(tn, skb, cb, type, ops);
 249 }
 250
 251 static int tcf_vlan_search(struct net *net, struct tc_action **a, u32 index)
 252 {
 253         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 254
 255         return tcf_hash_search(tn, a, index);
 256 }
 257
 258 static struct tc_action_ops act_vlan_ops = {
 259         .kind           =       "vlan",
 260         .type           =       TCA_ACT_VLAN,
 261         .owner          =       THIS_MODULE,
 262         .act            =       tcf_vlan,
 263         .dump           =       tcf_vlan_dump,
 264         .init           =       tcf_vlan_init,
 265         .walk           =       tcf_vlan_walker,
 266         .lookup         =       tcf_vlan_search,
 267         .size           =       sizeof(struct tcf_vlan),
 268 };
 269
 270 static __net_init int vlan_init_net(struct net *net)
 271 {
 272         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 273
 274         return tc_action_net_init(tn, &act_vlan_ops, VLAN_TAB_MASK);
 275 }
 276
 277 static void __net_exit vlan_exit_net(struct net *net)
 278 {
 279         struct tc_action_net *tn = net_generic(net, vlan_net_id);
 280
 281         tc_action_net_exit(tn);
 282 }
 283
 284 static struct pernet_operations vlan_net_ops = {
 285         .init = vlan_init_net,
 286         .exit = vlan_exit_net,
 287         .id   = &vlan_net_id,
 288         .size = sizeof(struct tc_action_net),
 289 };
 290
 291 static int __init vlan_init_module(void)
 292 {
 293         return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
 294 }
 295
 296 static void __exit vlan_cleanup_module(void)
 297 {
 298         tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
 299 }
 300
 301 module_init(vlan_init_module);
 302 module_exit(vlan_cleanup_module);
 303
 304 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
 305 MODULE_DESCRIPTION("vlan manipulation actions");
 306 MODULE_LICENSE("GPL v2");