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); 339