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 int err; 65 #ifdef CONFIG_GACT_PROB 66 struct tc_gact_p *p_parm = NULL; 67 #endif 68 69 if (nla == NULL) 70 return -EINVAL; 71 72 err = nla_parse_nested_deprecated(tb, TCA_GACT_MAX, nla, gact_policy, 73 NULL); 74 if (err < 0) 75 return err; 76 77 if (tb[TCA_GACT_PARMS] == NULL) 78 return -EINVAL; 79 parm = nla_data(tb[TCA_GACT_PARMS]); 80 81 #ifndef CONFIG_GACT_PROB 82 if (tb[TCA_GACT_PROB] != NULL) 83 return -EOPNOTSUPP; 84 #else 85 if (tb[TCA_GACT_PROB]) { 86 p_parm = nla_data(tb[TCA_GACT_PROB]); 87 if (p_parm->ptype >= MAX_RAND) 88 return -EINVAL; 89 if (TC_ACT_EXT_CMP(p_parm->paction, TC_ACT_GOTO_CHAIN)) { 90 NL_SET_ERR_MSG(extack, 91 "goto chain not allowed on fallback"); 92 return -EINVAL; 93 } 94 } 95 #endif 96 97 err = tcf_idr_check_alloc(tn, &parm->index, a, bind); 98 if (!err) { 99 ret = tcf_idr_create(tn, parm->index, est, a, 100 &act_gact_ops, bind, true); 101 if (ret) { 102 tcf_idr_cleanup(tn, parm->index); 103 return ret; 104 } 105 ret = ACT_P_CREATED; 106 } else if (err > 0) { 107 if (bind)/* dont override defaults */ 108 return 0; 109 if (!ovr) { 110 tcf_idr_release(*a, bind); 111 return -EEXIST; 112 } 113 } else { 114 return err; 115 } 116 117 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); 118 if (err < 0) 119 goto release_idr; 120 gact = to_gact(*a); 121 122 spin_lock_bh(&gact->tcf_lock); 123 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 124 #ifdef CONFIG_GACT_PROB 125 if (p_parm) { 126 gact->tcfg_paction = p_parm->paction; 127 gact->tcfg_pval = max_t(u16, 1, p_parm->pval); 128 /* Make sure tcfg_pval is written before tcfg_ptype 129 * coupled with smp_rmb() in gact_net_rand() & gact_determ() 130 */ 131 smp_wmb(); 132 gact->tcfg_ptype = p_parm->ptype; 133 } 134 #endif 135 spin_unlock_bh(&gact->tcf_lock); 136 137 if (goto_ch) 138 tcf_chain_put_by_act(goto_ch); 139 140 if (ret == ACT_P_CREATED) 141 tcf_idr_insert(tn, *a); 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 bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), skb); 163 if (action == TC_ACT_SHOT) 164 qstats_drop_inc(this_cpu_ptr(gact->common.cpu_qstats)); 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, u32 packets, 172 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 _bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), bytes, 179 packets); 180 if (action == TC_ACT_SHOT) 181 this_cpu_ptr(gact->common.cpu_qstats)->drops += packets; 182 183 if (hw) 184 _bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats_hw), 185 bytes, packets); 186 187 tm->lastuse = max_t(u64, tm->lastuse, lastuse); 188 } 189 190 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, 191 int bind, int ref) 192 { 193 unsigned char *b = skb_tail_pointer(skb); 194 struct tcf_gact *gact = to_gact(a); 195 struct tc_gact opt = { 196 .index = gact->tcf_index, 197 .refcnt = refcount_read(&gact->tcf_refcnt) - ref, 198 .bindcnt = atomic_read(&gact->tcf_bindcnt) - bind, 199 }; 200 struct tcf_t t; 201 202 spin_lock_bh(&gact->tcf_lock); 203 opt.action = gact->tcf_action; 204 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt)) 205 goto nla_put_failure; 206 #ifdef CONFIG_GACT_PROB 207 if (gact->tcfg_ptype) { 208 struct tc_gact_p p_opt = { 209 .paction = gact->tcfg_paction, 210 .pval = gact->tcfg_pval, 211 .ptype = gact->tcfg_ptype, 212 }; 213 214 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt)) 215 goto nla_put_failure; 216 } 217 #endif 218 tcf_tm_dump(&t, &gact->tcf_tm); 219 if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD)) 220 goto nla_put_failure; 221 spin_unlock_bh(&gact->tcf_lock); 222 223 return skb->len; 224 225 nla_put_failure: 226 spin_unlock_bh(&gact->tcf_lock); 227 nlmsg_trim(skb, b); 228 return -1; 229 } 230 231 static int tcf_gact_walker(struct net *net, struct sk_buff *skb, 232 struct netlink_callback *cb, int type, 233 const struct tc_action_ops *ops, 234 struct netlink_ext_ack *extack) 235 { 236 struct tc_action_net *tn = net_generic(net, gact_net_id); 237 238 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 239 } 240 241 static int tcf_gact_search(struct net *net, struct tc_action **a, u32 index) 242 { 243 struct tc_action_net *tn = net_generic(net, gact_net_id); 244 245 return tcf_idr_search(tn, a, index); 246 } 247 248 static size_t tcf_gact_get_fill_size(const struct tc_action *act) 249 { 250 size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */ 251 252 #ifdef CONFIG_GACT_PROB 253 if (to_gact(act)->tcfg_ptype) 254 /* TCA_GACT_PROB */ 255 sz += nla_total_size(sizeof(struct tc_gact_p)); 256 #endif 257 258 return sz; 259 } 260 261 static struct tc_action_ops act_gact_ops = { 262 .kind = "gact", 263 .id = TCA_ID_GACT, 264 .owner = THIS_MODULE, 265 .act = tcf_gact_act, 266 .stats_update = tcf_gact_stats_update, 267 .dump = tcf_gact_dump, 268 .init = tcf_gact_init, 269 .walk = tcf_gact_walker, 270 .lookup = tcf_gact_search, 271 .get_fill_size = tcf_gact_get_fill_size, 272 .size = sizeof(struct tcf_gact), 273 }; 274 275 static __net_init int gact_init_net(struct net *net) 276 { 277 struct tc_action_net *tn = net_generic(net, gact_net_id); 278 279 return tc_action_net_init(tn, &act_gact_ops); 280 } 281 282 static void __net_exit gact_exit_net(struct list_head *net_list) 283 { 284 tc_action_net_exit(net_list, gact_net_id); 285 } 286 287 static struct pernet_operations gact_net_ops = { 288 .init = gact_init_net, 289 .exit_batch = gact_exit_net, 290 .id = &gact_net_id, 291 .size = sizeof(struct tc_action_net), 292 }; 293 294 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 295 MODULE_DESCRIPTION("Generic Classifier actions"); 296 MODULE_LICENSE("GPL"); 297 298 static int __init gact_init_module(void) 299 { 300 #ifdef CONFIG_GACT_PROB 301 pr_info("GACT probability on\n"); 302 #else 303 pr_info("GACT probability NOT on\n"); 304 #endif 305 306 return tcf_register_action(&act_gact_ops, &gact_net_ops); 307 } 308 309 static void __exit gact_cleanup_module(void) 310 { 311 tcf_unregister_action(&act_gact_ops, &gact_net_ops); 312 } 313 314 module_init(gact_init_module); 315 module_exit(gact_cleanup_module); 316