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 unsigned int gact_net_id; 23 static struct tc_action_ops act_gact_ops; 24 25 #ifdef CONFIG_GACT_PROB 26 static int gact_net_rand(struct tcf_gact *gact) 27 { 28 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */ 29 if (prandom_u32() % gact->tcfg_pval) 30 return gact->tcf_action; 31 return gact->tcfg_paction; 32 } 33 34 static int gact_determ(struct tcf_gact *gact) 35 { 36 u32 pack = atomic_inc_return(&gact->packets); 37 38 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */ 39 if (pack % gact->tcfg_pval) 40 return gact->tcf_action; 41 return gact->tcfg_paction; 42 } 43 44 typedef int (*g_rand)(struct tcf_gact *gact); 45 static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ }; 46 #endif /* CONFIG_GACT_PROB */ 47 48 static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = { 49 [TCA_GACT_PARMS] = { .len = sizeof(struct tc_gact) }, 50 [TCA_GACT_PROB] = { .len = sizeof(struct tc_gact_p) }, 51 }; 52 53 static int tcf_gact_init(struct net *net, struct nlattr *nla, 54 struct nlattr *est, struct tc_action **a, 55 int ovr, int bind, bool rtnl_held, 56 struct tcf_proto *tp, struct netlink_ext_ack *extack) 57 { 58 struct tc_action_net *tn = net_generic(net, gact_net_id); 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(tn, index, est, a, 102 &act_gact_ops, bind, true); 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 (!ovr) { 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 if (ret == ACT_P_CREATED) 143 tcf_idr_insert(tn, *a); 144 return ret; 145 release_idr: 146 tcf_idr_release(*a, bind); 147 return err; 148 } 149 150 static int tcf_gact_act(struct sk_buff *skb, const struct tc_action *a, 151 struct tcf_result *res) 152 { 153 struct tcf_gact *gact = to_gact(a); 154 int action = READ_ONCE(gact->tcf_action); 155 156 #ifdef CONFIG_GACT_PROB 157 { 158 u32 ptype = READ_ONCE(gact->tcfg_ptype); 159 160 if (ptype) 161 action = gact_rand[ptype](gact); 162 } 163 #endif 164 bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), skb); 165 if (action == TC_ACT_SHOT) 166 qstats_drop_inc(this_cpu_ptr(gact->common.cpu_qstats)); 167 168 tcf_lastuse_update(&gact->tcf_tm); 169 170 return action; 171 } 172 173 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u32 packets, 174 u64 lastuse, bool hw) 175 { 176 struct tcf_gact *gact = to_gact(a); 177 int action = READ_ONCE(gact->tcf_action); 178 struct tcf_t *tm = &gact->tcf_tm; 179 180 _bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), bytes, 181 packets); 182 if (action == TC_ACT_SHOT) 183 this_cpu_ptr(gact->common.cpu_qstats)->drops += packets; 184 185 if (hw) 186 _bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats_hw), 187 bytes, packets); 188 189 tm->lastuse = max_t(u64, tm->lastuse, lastuse); 190 } 191 192 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, 193 int bind, int ref) 194 { 195 unsigned char *b = skb_tail_pointer(skb); 196 struct tcf_gact *gact = to_gact(a); 197 struct tc_gact opt = { 198 .index = gact->tcf_index, 199 .refcnt = refcount_read(&gact->tcf_refcnt) - ref, 200 .bindcnt = atomic_read(&gact->tcf_bindcnt) - bind, 201 }; 202 struct tcf_t t; 203 204 spin_lock_bh(&gact->tcf_lock); 205 opt.action = gact->tcf_action; 206 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt)) 207 goto nla_put_failure; 208 #ifdef CONFIG_GACT_PROB 209 if (gact->tcfg_ptype) { 210 struct tc_gact_p p_opt = { 211 .paction = gact->tcfg_paction, 212 .pval = gact->tcfg_pval, 213 .ptype = gact->tcfg_ptype, 214 }; 215 216 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt)) 217 goto nla_put_failure; 218 } 219 #endif 220 tcf_tm_dump(&t, &gact->tcf_tm); 221 if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD)) 222 goto nla_put_failure; 223 spin_unlock_bh(&gact->tcf_lock); 224 225 return skb->len; 226 227 nla_put_failure: 228 spin_unlock_bh(&gact->tcf_lock); 229 nlmsg_trim(skb, b); 230 return -1; 231 } 232 233 static int tcf_gact_walker(struct net *net, struct sk_buff *skb, 234 struct netlink_callback *cb, int type, 235 const struct tc_action_ops *ops, 236 struct netlink_ext_ack *extack) 237 { 238 struct tc_action_net *tn = net_generic(net, gact_net_id); 239 240 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 241 } 242 243 static int tcf_gact_search(struct net *net, struct tc_action **a, u32 index) 244 { 245 struct tc_action_net *tn = net_generic(net, gact_net_id); 246 247 return tcf_idr_search(tn, a, index); 248 } 249 250 static size_t tcf_gact_get_fill_size(const struct tc_action *act) 251 { 252 size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */ 253 254 #ifdef CONFIG_GACT_PROB 255 if (to_gact(act)->tcfg_ptype) 256 /* TCA_GACT_PROB */ 257 sz += nla_total_size(sizeof(struct tc_gact_p)); 258 #endif 259 260 return sz; 261 } 262 263 static struct tc_action_ops act_gact_ops = { 264 .kind = "gact", 265 .id = TCA_ID_GACT, 266 .owner = THIS_MODULE, 267 .act = tcf_gact_act, 268 .stats_update = tcf_gact_stats_update, 269 .dump = tcf_gact_dump, 270 .init = tcf_gact_init, 271 .walk = tcf_gact_walker, 272 .lookup = tcf_gact_search, 273 .get_fill_size = tcf_gact_get_fill_size, 274 .size = sizeof(struct tcf_gact), 275 }; 276 277 static __net_init int gact_init_net(struct net *net) 278 { 279 struct tc_action_net *tn = net_generic(net, gact_net_id); 280 281 return tc_action_net_init(net, tn, &act_gact_ops); 282 } 283 284 static void __net_exit gact_exit_net(struct list_head *net_list) 285 { 286 tc_action_net_exit(net_list, gact_net_id); 287 } 288 289 static struct pernet_operations gact_net_ops = { 290 .init = gact_init_net, 291 .exit_batch = gact_exit_net, 292 .id = &gact_net_id, 293 .size = sizeof(struct tc_action_net), 294 }; 295 296 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 297 MODULE_DESCRIPTION("Generic Classifier actions"); 298 MODULE_LICENSE("GPL"); 299 300 static int __init gact_init_module(void) 301 { 302 #ifdef CONFIG_GACT_PROB 303 pr_info("GACT probability on\n"); 304 #else 305 pr_info("GACT probability NOT on\n"); 306 #endif 307 308 return tcf_register_action(&act_gact_ops, &gact_net_ops); 309 } 310 311 static void __exit gact_cleanup_module(void) 312 { 313 tcf_unregister_action(&act_gact_ops, &gact_net_ops); 314 } 315 316 module_init(gact_init_module); 317 module_exit(gact_cleanup_module); 318