net/sched/act_tunnel_key.c

   1 /*
   2  * Copyright (c) 2016, Amir Vadai <amir@vadai.me>
   3  * Copyright (c) 2016, Mellanox Technologies. All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/rtnetlink.h>
  16 #include <net/netlink.h>
  17 #include <net/pkt_sched.h>
  18 #include <net/dst.h>
  19 #include <net/dst_metadata.h>
  20
  21 #include <linux/tc_act/tc_tunnel_key.h>
  22 #include <net/tc_act/tc_tunnel_key.h>
  23
  24 #define TUNNEL_KEY_TAB_MASK     15
  25
  26 static int tunnel_key_net_id;
  27 static struct tc_action_ops act_tunnel_key_ops;
  28
  29 static int tunnel_key_act(struct sk_buff *skb, const struct tc_action *a,
  30                           struct tcf_result *res)
  31 {
  32         struct tcf_tunnel_key *t = to_tunnel_key(a);
  33         struct tcf_tunnel_key_params *params;
  34         int action;
  35
  36         rcu_read_lock();
  37
  38         params = rcu_dereference(t->params);
  39
  40         tcf_lastuse_update(&t->tcf_tm);
  41         bstats_cpu_update(this_cpu_ptr(t->common.cpu_bstats), skb);
  42         action = READ_ONCE(t->tcf_action);
  43
  44         switch (params->tcft_action) {
  45         case TCA_TUNNEL_KEY_ACT_RELEASE:
  46                 skb_dst_drop(skb);
  47                 break;
  48         case TCA_TUNNEL_KEY_ACT_SET:
  49                 skb_dst_drop(skb);
  50                 skb_dst_set(skb, dst_clone(&params->tcft_enc_metadata->dst));
  51                 break;
  52         default:
  53                 WARN_ONCE(1, "Bad tunnel_key action %d.\n",
  54                           params->tcft_action);
  55                 break;
  56         }
  57
  58         rcu_read_unlock();
  59
  60         return action;
  61 }
  62
  63 static const struct nla_policy tunnel_key_policy[TCA_TUNNEL_KEY_MAX + 1] = {
  64         [TCA_TUNNEL_KEY_PARMS]      = { .len = sizeof(struct tc_tunnel_key) },
  65         [TCA_TUNNEL_KEY_ENC_IPV4_SRC] = { .type = NLA_U32 },
  66         [TCA_TUNNEL_KEY_ENC_IPV4_DST] = { .type = NLA_U32 },
  67         [TCA_TUNNEL_KEY_ENC_IPV6_SRC] = { .len = sizeof(struct in6_addr) },
  68         [TCA_TUNNEL_KEY_ENC_IPV6_DST] = { .len = sizeof(struct in6_addr) },
  69         [TCA_TUNNEL_KEY_ENC_KEY_ID]   = { .type = NLA_U32 },
  70 };
  71
  72 static int tunnel_key_init(struct net *net, struct nlattr *nla,
  73                            struct nlattr *est, struct tc_action **a,
  74                            int ovr, int bind)
  75 {
  76         struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
  77         struct nlattr *tb[TCA_TUNNEL_KEY_MAX + 1];
  78         struct tcf_tunnel_key_params *params_old;
  79         struct tcf_tunnel_key_params *params_new;
  80         struct metadata_dst *metadata = NULL;
  81         struct tc_tunnel_key *parm;
  82         struct tcf_tunnel_key *t;
  83         bool exists = false;
  84         __be64 key_id;
  85         int ret = 0;
  86         int err;
  87
  88         if (!nla)
  89                 return -EINVAL;
  90
  91         err = nla_parse_nested(tb, TCA_TUNNEL_KEY_MAX, nla, tunnel_key_policy);
  92         if (err < 0)
  93                 return err;
  94
  95         if (!tb[TCA_TUNNEL_KEY_PARMS])
  96                 return -EINVAL;
  97
  98         parm = nla_data(tb[TCA_TUNNEL_KEY_PARMS]);
  99         exists = tcf_hash_check(tn, parm->index, a, bind);
 100         if (exists && bind)
 101                 return 0;
 102
 103         switch (parm->t_action) {
 104         case TCA_TUNNEL_KEY_ACT_RELEASE:
 105                 break;
 106         case TCA_TUNNEL_KEY_ACT_SET:
 107                 if (!tb[TCA_TUNNEL_KEY_ENC_KEY_ID]) {
 108                         ret = -EINVAL;
 109                         goto err_out;
 110                 }
 111
 112                 key_id = key32_to_tunnel_id(nla_get_be32(tb[TCA_TUNNEL_KEY_ENC_KEY_ID]));
 113
 114                 if (tb[TCA_TUNNEL_KEY_ENC_IPV4_SRC] &&
 115                     tb[TCA_TUNNEL_KEY_ENC_IPV4_DST]) {
 116                         __be32 saddr;
 117                         __be32 daddr;
 118
 119                         saddr = nla_get_in_addr(tb[TCA_TUNNEL_KEY_ENC_IPV4_SRC]);
 120                         daddr = nla_get_in_addr(tb[TCA_TUNNEL_KEY_ENC_IPV4_DST]);
 121
 122                         metadata = __ip_tun_set_dst(saddr, daddr, 0, 0,
 123                                                     TUNNEL_KEY, key_id, 0);
 124                 } else if (tb[TCA_TUNNEL_KEY_ENC_IPV6_SRC] &&
 125                            tb[TCA_TUNNEL_KEY_ENC_IPV6_DST]) {
 126                         struct in6_addr saddr;
 127                         struct in6_addr daddr;
 128
 129                         saddr = nla_get_in6_addr(tb[TCA_TUNNEL_KEY_ENC_IPV6_SRC]);
 130                         daddr = nla_get_in6_addr(tb[TCA_TUNNEL_KEY_ENC_IPV6_DST]);
 131
 132                         metadata = __ipv6_tun_set_dst(&saddr, &daddr, 0, 0, 0,
 133                                                       TUNNEL_KEY, key_id, 0);
 134                 }
 135
 136                 if (!metadata) {
 137                         ret = -EINVAL;
 138                         goto err_out;
 139                 }
 140
 141                 metadata->u.tun_info.mode |= IP_TUNNEL_INFO_TX;
 142                 break;
 143         default:
 144                 ret = -EINVAL;
 145                 goto err_out;
 146         }
 147
 148         if (!exists) {
 149                 ret = tcf_hash_create(tn, parm->index, est, a,
 150                                       &act_tunnel_key_ops, bind, true);
 151                 if (ret)
 152                         return ret;
 153
 154                 ret = ACT_P_CREATED;
 155         } else {
 156                 tcf_hash_release(*a, bind);
 157                 if (!ovr)
 158                         return -EEXIST;
 159         }
 160
 161         t = to_tunnel_key(*a);
 162
 163         ASSERT_RTNL();
 164         params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
 165         if (unlikely(!params_new)) {
 166                 if (ret == ACT_P_CREATED)
 167                         tcf_hash_release(*a, bind);
 168                 return -ENOMEM;
 169         }
 170
 171         params_old = rtnl_dereference(t->params);
 172
 173         t->tcf_action = parm->action;
 174         params_new->tcft_action = parm->t_action;
 175         params_new->tcft_enc_metadata = metadata;
 176
 177         rcu_assign_pointer(t->params, params_new);
 178
 179         if (params_old)
 180                 kfree_rcu(params_old, rcu);
 181
 182         if (ret == ACT_P_CREATED)
 183                 tcf_hash_insert(tn, *a);
 184
 185         return ret;
 186
 187 err_out:
 188         if (exists)
 189                 tcf_hash_release(*a, bind);
 190         return ret;
 191 }
 192
 193 static void tunnel_key_release(struct tc_action *a, int bind)
 194 {
 195         struct tcf_tunnel_key *t = to_tunnel_key(a);
 196         struct tcf_tunnel_key_params *params;
 197
 198         params = rcu_dereference_protected(t->params, 1);
 199         if (params) {
 200                 if (params->tcft_action == TCA_TUNNEL_KEY_ACT_SET)
 201                         dst_release(&params->tcft_enc_metadata->dst);
 202
 203                 kfree_rcu(params, rcu);
 204         }
 205 }
 206
 207 static int tunnel_key_dump_addresses(struct sk_buff *skb,
 208                                      const struct ip_tunnel_info *info)
 209 {
 210         unsigned short family = ip_tunnel_info_af(info);
 211
 212         if (family == AF_INET) {
 213                 __be32 saddr = info->key.u.ipv4.src;
 214                 __be32 daddr = info->key.u.ipv4.dst;
 215
 216                 if (!nla_put_in_addr(skb, TCA_TUNNEL_KEY_ENC_IPV4_SRC, saddr) &&
 217                     !nla_put_in_addr(skb, TCA_TUNNEL_KEY_ENC_IPV4_DST, daddr))
 218                         return 0;
 219         }
 220
 221         if (family == AF_INET6) {
 222                 const struct in6_addr *saddr6 = &info->key.u.ipv6.src;
 223                 const struct in6_addr *daddr6 = &info->key.u.ipv6.dst;
 224
 225                 if (!nla_put_in6_addr(skb,
 226                                       TCA_TUNNEL_KEY_ENC_IPV6_SRC, saddr6) &&
 227                     !nla_put_in6_addr(skb,
 228                                       TCA_TUNNEL_KEY_ENC_IPV6_DST, daddr6))
 229                         return 0;
 230         }
 231
 232         return -EINVAL;
 233 }
 234
 235 static int tunnel_key_dump(struct sk_buff *skb, struct tc_action *a,
 236                            int bind, int ref)
 237 {
 238         unsigned char *b = skb_tail_pointer(skb);
 239         struct tcf_tunnel_key *t = to_tunnel_key(a);
 240         struct tcf_tunnel_key_params *params;
 241         struct tc_tunnel_key opt = {
 242                 .index    = t->tcf_index,
 243                 .refcnt   = t->tcf_refcnt - ref,
 244                 .bindcnt  = t->tcf_bindcnt - bind,
 245                 .action   = t->tcf_action,
 246         };
 247         struct tcf_t tm;
 248
 249         params = rtnl_dereference(t->params);
 250
 251         opt.t_action = params->tcft_action;
 252
 253         if (nla_put(skb, TCA_TUNNEL_KEY_PARMS, sizeof(opt), &opt))
 254                 goto nla_put_failure;
 255
 256         if (params->tcft_action == TCA_TUNNEL_KEY_ACT_SET) {
 257                 struct ip_tunnel_key *key =
 258                         &params->tcft_enc_metadata->u.tun_info.key;
 259                 __be32 key_id = tunnel_id_to_key32(key->tun_id);
 260
 261                 if (nla_put_be32(skb, TCA_TUNNEL_KEY_ENC_KEY_ID, key_id) ||
 262                     tunnel_key_dump_addresses(skb,
 263                                               &params->tcft_enc_metadata->u.tun_info))
 264                         goto nla_put_failure;
 265         }
 266
 267         tcf_tm_dump(&tm, &t->tcf_tm);
 268         if (nla_put_64bit(skb, TCA_TUNNEL_KEY_TM, sizeof(tm),
 269                           &tm, TCA_TUNNEL_KEY_PAD))
 270                 goto nla_put_failure;
 271
 272         return skb->len;
 273
 274 nla_put_failure:
 275         nlmsg_trim(skb, b);
 276         return -1;
 277 }
 278
 279 static int tunnel_key_walker(struct net *net, struct sk_buff *skb,
 280                              struct netlink_callback *cb, int type,
 281                              const struct tc_action_ops *ops)
 282 {
 283         struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
 284
 285         return tcf_generic_walker(tn, skb, cb, type, ops);
 286 }
 287
 288 static int tunnel_key_search(struct net *net, struct tc_action **a, u32 index)
 289 {
 290         struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
 291
 292         return tcf_hash_search(tn, a, index);
 293 }
 294
 295 static struct tc_action_ops act_tunnel_key_ops = {
 296         .kind           =       "tunnel_key",
 297         .type           =       TCA_ACT_TUNNEL_KEY,
 298         .owner          =       THIS_MODULE,
 299         .act            =       tunnel_key_act,
 300         .dump           =       tunnel_key_dump,
 301         .init           =       tunnel_key_init,
 302         .cleanup        =       tunnel_key_release,
 303         .walk           =       tunnel_key_walker,
 304         .lookup         =       tunnel_key_search,
 305         .size           =       sizeof(struct tcf_tunnel_key),
 306 };
 307
 308 static __net_init int tunnel_key_init_net(struct net *net)
 309 {
 310         struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
 311
 312         return tc_action_net_init(tn, &act_tunnel_key_ops, TUNNEL_KEY_TAB_MASK);
 313 }
 314
 315 static void __net_exit tunnel_key_exit_net(struct net *net)
 316 {
 317         struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
 318
 319         tc_action_net_exit(tn);
 320 }
 321
 322 static struct pernet_operations tunnel_key_net_ops = {
 323         .init = tunnel_key_init_net,
 324         .exit = tunnel_key_exit_net,
 325         .id   = &tunnel_key_net_id,
 326         .size = sizeof(struct tc_action_net),
 327 };
 328
 329 static int __init tunnel_key_init_module(void)
 330 {
 331         return tcf_register_action(&act_tunnel_key_ops, &tunnel_key_net_ops);
 332 }
 333
 334 static void __exit tunnel_key_cleanup_module(void)
 335 {
 336         tcf_unregister_action(&act_tunnel_key_ops, &tunnel_key_net_ops);
 337 }
 338
 339 module_init(tunnel_key_init_module);
 340 module_exit(tunnel_key_cleanup_module);
 341
 342 MODULE_AUTHOR("Amir Vadai <amir@vadai.me>");
 343 MODULE_DESCRIPTION("ip tunnel manipulation actions");
 344 MODULE_LICENSE("GPL v2");