net/sched/act_gact.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/act_gact.c         Generic actions
   4  *
   5  * copyright    Jamal Hadi Salim (2002-4)
   6  */
   7
   8 #include <linux/types.h>
   9 #include <linux/kernel.h>
  10 #include <linux/string.h>
  11 #include <linux/errno.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/rtnetlink.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <net/netlink.h>
  17 #include <net/pkt_sched.h>
  18 #include <net/pkt_cls.h>
  19 #include <linux/tc_act/tc_gact.h>
  20 #include <net/tc_act/tc_gact.h>
  21
  22 static struct tc_action_ops act_gact_ops;
  23
  24 #ifdef CONFIG_GACT_PROB
  25 static int gact_net_rand(struct tcf_gact *gact)
  26 {
  27         smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
  28         if (prandom_u32_max(gact->tcfg_pval))
  29                 return gact->tcf_action;
  30         return gact->tcfg_paction;
  31 }
  32
  33 static int gact_determ(struct tcf_gact *gact)
  34 {
  35         u32 pack = atomic_inc_return(&gact->packets);
  36
  37         smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
  38         if (pack % gact->tcfg_pval)
  39                 return gact->tcf_action;
  40         return gact->tcfg_paction;
  41 }
  42
  43 typedef int (*g_rand)(struct tcf_gact *gact);
  44 static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ };
  45 #endif /* CONFIG_GACT_PROB */
  46
  47 static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = {
  48         [TCA_GACT_PARMS]        = { .len = sizeof(struct tc_gact) },
  49         [TCA_GACT_PROB]         = { .len = sizeof(struct tc_gact_p) },
  50 };
  51
  52 static int tcf_gact_init(struct net *net, struct nlattr *nla,
  53                          struct nlattr *est, struct tc_action **a,
  54                          struct tcf_proto *tp, u32 flags,
  55                          struct netlink_ext_ack *extack)
  56 {
  57         struct tc_action_net *tn = net_generic(net, act_gact_ops.net_id);
  58         bool bind = flags & TCA_ACT_FLAGS_BIND;
  59         struct nlattr *tb[TCA_GACT_MAX + 1];
  60         struct tcf_chain *goto_ch = NULL;
  61         struct tc_gact *parm;
  62         struct tcf_gact *gact;
  63         int ret = 0;
  64         u32 index;
  65         int err;
  66 #ifdef CONFIG_GACT_PROB
  67         struct tc_gact_p *p_parm = NULL;
  68 #endif
  69
  70         if (nla == NULL)
  71                 return -EINVAL;
  72
  73         err = nla_parse_nested_deprecated(tb, TCA_GACT_MAX, nla, gact_policy,
  74                                           NULL);
  75         if (err < 0)
  76                 return err;
  77
  78         if (tb[TCA_GACT_PARMS] == NULL)
  79                 return -EINVAL;
  80         parm = nla_data(tb[TCA_GACT_PARMS]);
  81         index = parm->index;
  82
  83 #ifndef CONFIG_GACT_PROB
  84         if (tb[TCA_GACT_PROB] != NULL)
  85                 return -EOPNOTSUPP;
  86 #else
  87         if (tb[TCA_GACT_PROB]) {
  88                 p_parm = nla_data(tb[TCA_GACT_PROB]);
  89                 if (p_parm->ptype >= MAX_RAND)
  90                         return -EINVAL;
  91                 if (TC_ACT_EXT_CMP(p_parm->paction, TC_ACT_GOTO_CHAIN)) {
  92                         NL_SET_ERR_MSG(extack,
  93                                        "goto chain not allowed on fallback");
  94                         return -EINVAL;
  95                 }
  96         }
  97 #endif
  98
  99         err = tcf_idr_check_alloc(tn, &index, a, bind);
 100         if (!err) {
 101                 ret = tcf_idr_create_from_flags(tn, index, est, a,
 102                                                 &act_gact_ops, bind, flags);
 103                 if (ret) {
 104                         tcf_idr_cleanup(tn, index);
 105                         return ret;
 106                 }
 107                 ret = ACT_P_CREATED;
 108         } else if (err > 0) {
 109                 if (bind)/* dont override defaults */
 110                         return 0;
 111                 if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
 112                         tcf_idr_release(*a, bind);
 113                         return -EEXIST;
 114                 }
 115         } else {
 116                 return err;
 117         }
 118
 119         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
 120         if (err < 0)
 121                 goto release_idr;
 122         gact = to_gact(*a);
 123
 124         spin_lock_bh(&gact->tcf_lock);
 125         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 126 #ifdef CONFIG_GACT_PROB
 127         if (p_parm) {
 128                 gact->tcfg_paction = p_parm->paction;
 129                 gact->tcfg_pval    = max_t(u16, 1, p_parm->pval);
 130                 /* Make sure tcfg_pval is written before tcfg_ptype
 131                  * coupled with smp_rmb() in gact_net_rand() & gact_determ()
 132                  */
 133                 smp_wmb();
 134                 gact->tcfg_ptype   = p_parm->ptype;
 135         }
 136 #endif
 137         spin_unlock_bh(&gact->tcf_lock);
 138
 139         if (goto_ch)
 140                 tcf_chain_put_by_act(goto_ch);
 141
 142         return ret;
 143 release_idr:
 144         tcf_idr_release(*a, bind);
 145         return err;
 146 }
 147
 148 static int tcf_gact_act(struct sk_buff *skb, const struct tc_action *a,
 149                         struct tcf_result *res)
 150 {
 151         struct tcf_gact *gact = to_gact(a);
 152         int action = READ_ONCE(gact->tcf_action);
 153
 154 #ifdef CONFIG_GACT_PROB
 155         {
 156         u32 ptype = READ_ONCE(gact->tcfg_ptype);
 157
 158         if (ptype)
 159                 action = gact_rand[ptype](gact);
 160         }
 161 #endif
 162         tcf_action_update_bstats(&gact->common, skb);
 163         if (action == TC_ACT_SHOT)
 164                 tcf_action_inc_drop_qstats(&gact->common);
 165
 166         tcf_lastuse_update(&gact->tcf_tm);
 167
 168         return action;
 169 }
 170
 171 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u64 packets,
 172                                   u64 drops, u64 lastuse, bool hw)
 173 {
 174         struct tcf_gact *gact = to_gact(a);
 175         int action = READ_ONCE(gact->tcf_action);
 176         struct tcf_t *tm = &gact->tcf_tm;
 177
 178         tcf_action_update_stats(a, bytes, packets,
 179                                 action == TC_ACT_SHOT ? packets : drops, hw);
 180         tm->lastuse = max_t(u64, tm->lastuse, lastuse);
 181 }
 182
 183 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a,
 184                          int bind, int ref)
 185 {
 186         unsigned char *b = skb_tail_pointer(skb);
 187         struct tcf_gact *gact = to_gact(a);
 188         struct tc_gact opt = {
 189                 .index   = gact->tcf_index,
 190                 .refcnt  = refcount_read(&gact->tcf_refcnt) - ref,
 191                 .bindcnt = atomic_read(&gact->tcf_bindcnt) - bind,
 192         };
 193         struct tcf_t t;
 194
 195         spin_lock_bh(&gact->tcf_lock);
 196         opt.action = gact->tcf_action;
 197         if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
 198                 goto nla_put_failure;
 199 #ifdef CONFIG_GACT_PROB
 200         if (gact->tcfg_ptype) {
 201                 struct tc_gact_p p_opt = {
 202                         .paction = gact->tcfg_paction,
 203                         .pval    = gact->tcfg_pval,
 204                         .ptype   = gact->tcfg_ptype,
 205                 };
 206
 207                 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
 208                         goto nla_put_failure;
 209         }
 210 #endif
 211         tcf_tm_dump(&t, &gact->tcf_tm);
 212         if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD))
 213                 goto nla_put_failure;
 214         spin_unlock_bh(&gact->tcf_lock);
 215
 216         return skb->len;
 217
 218 nla_put_failure:
 219         spin_unlock_bh(&gact->tcf_lock);
 220         nlmsg_trim(skb, b);
 221         return -1;
 222 }
 223
 224 static size_t tcf_gact_get_fill_size(const struct tc_action *act)
 225 {
 226         size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */
 227
 228 #ifdef CONFIG_GACT_PROB
 229         if (to_gact(act)->tcfg_ptype)
 230                 /* TCA_GACT_PROB */
 231                 sz += nla_total_size(sizeof(struct tc_gact_p));
 232 #endif
 233
 234         return sz;
 235 }
 236
 237 static int tcf_gact_offload_act_setup(struct tc_action *act, void *entry_data,
 238                                       u32 *index_inc, bool bind,
 239                                       struct netlink_ext_ack *extack)
 240 {
 241         if (bind) {
 242                 struct flow_action_entry *entry = entry_data;
 243
 244                 if (is_tcf_gact_ok(act)) {
 245                         entry->id = FLOW_ACTION_ACCEPT;
 246                 } else if (is_tcf_gact_shot(act)) {
 247                         entry->id = FLOW_ACTION_DROP;
 248                 } else if (is_tcf_gact_trap(act)) {
 249                         entry->id = FLOW_ACTION_TRAP;
 250                 } else if (is_tcf_gact_goto_chain(act)) {
 251                         entry->id = FLOW_ACTION_GOTO;
 252                         entry->chain_index = tcf_gact_goto_chain_index(act);
 253                 } else if (is_tcf_gact_continue(act)) {
 254                         NL_SET_ERR_MSG_MOD(extack, "Offload of \"continue\" action is not supported");
 255                         return -EOPNOTSUPP;
 256                 } else if (is_tcf_gact_reclassify(act)) {
 257                         NL_SET_ERR_MSG_MOD(extack, "Offload of \"reclassify\" action is not supported");
 258                         return -EOPNOTSUPP;
 259                 } else if (is_tcf_gact_pipe(act)) {
 260                         NL_SET_ERR_MSG_MOD(extack, "Offload of \"pipe\" action is not supported");
 261                         return -EOPNOTSUPP;
 262                 } else {
 263                         NL_SET_ERR_MSG_MOD(extack, "Unsupported generic action offload");
 264                         return -EOPNOTSUPP;
 265                 }
 266                 *index_inc = 1;
 267         } else {
 268                 struct flow_offload_action *fl_action = entry_data;
 269
 270                 if (is_tcf_gact_ok(act))
 271                         fl_action->id = FLOW_ACTION_ACCEPT;
 272                 else if (is_tcf_gact_shot(act))
 273                         fl_action->id = FLOW_ACTION_DROP;
 274                 else if (is_tcf_gact_trap(act))
 275                         fl_action->id = FLOW_ACTION_TRAP;
 276                 else if (is_tcf_gact_goto_chain(act))
 277                         fl_action->id = FLOW_ACTION_GOTO;
 278                 else
 279                         return -EOPNOTSUPP;
 280         }
 281
 282         return 0;
 283 }
 284
 285 static struct tc_action_ops act_gact_ops = {
 286         .kind           =       "gact",
 287         .id             =       TCA_ID_GACT,
 288         .owner          =       THIS_MODULE,
 289         .act            =       tcf_gact_act,
 290         .stats_update   =       tcf_gact_stats_update,
 291         .dump           =       tcf_gact_dump,
 292         .init           =       tcf_gact_init,
 293         .get_fill_size  =       tcf_gact_get_fill_size,
 294         .offload_act_setup =    tcf_gact_offload_act_setup,
 295         .size           =       sizeof(struct tcf_gact),
 296 };
 297
 298 static __net_init int gact_init_net(struct net *net)
 299 {
 300         struct tc_action_net *tn = net_generic(net, act_gact_ops.net_id);
 301
 302         return tc_action_net_init(net, tn, &act_gact_ops);
 303 }
 304
 305 static void __net_exit gact_exit_net(struct list_head *net_list)
 306 {
 307         tc_action_net_exit(net_list, act_gact_ops.net_id);
 308 }
 309
 310 static struct pernet_operations gact_net_ops = {
 311         .init = gact_init_net,
 312         .exit_batch = gact_exit_net,
 313         .id   = &act_gact_ops.net_id,
 314         .size = sizeof(struct tc_action_net),
 315 };
 316
 317 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
 318 MODULE_DESCRIPTION("Generic Classifier actions");
 319 MODULE_LICENSE("GPL");
 320
 321 static int __init gact_init_module(void)
 322 {
 323 #ifdef CONFIG_GACT_PROB
 324         pr_info("GACT probability on\n");
 325 #else
 326         pr_info("GACT probability NOT on\n");
 327 #endif
 328
 329         return tcf_register_action(&act_gact_ops, &gact_net_ops);
 330 }
 331
 332 static void __exit gact_cleanup_module(void)
 333 {
 334         tcf_unregister_action(&act_gact_ops, &gact_net_ops);
 335 }
 336
 337 module_init(gact_init_module);
 338 module_exit(gact_cleanup_module);