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 struct tcf_proto *tp, u32 flags, 56 struct netlink_ext_ack *extack) 57 { 58 struct tc_action_net *tn = net_generic(net, gact_net_id); 59 bool bind = flags & TCA_ACT_FLAGS_BIND; 60 struct nlattr *tb[TCA_GACT_MAX + 1]; 61 struct tcf_chain *goto_ch = NULL; 62 struct tc_gact *parm; 63 struct tcf_gact *gact; 64 int ret = 0; 65 u32 index; 66 int err; 67 #ifdef CONFIG_GACT_PROB 68 struct tc_gact_p *p_parm = NULL; 69 #endif 70 71 if (nla == NULL) 72 return -EINVAL; 73 74 err = nla_parse_nested_deprecated(tb, TCA_GACT_MAX, nla, gact_policy, 75 NULL); 76 if (err < 0) 77 return err; 78 79 if (tb[TCA_GACT_PARMS] == NULL) 80 return -EINVAL; 81 parm = nla_data(tb[TCA_GACT_PARMS]); 82 index = parm->index; 83 84 #ifndef CONFIG_GACT_PROB 85 if (tb[TCA_GACT_PROB] != NULL) 86 return -EOPNOTSUPP; 87 #else 88 if (tb[TCA_GACT_PROB]) { 89 p_parm = nla_data(tb[TCA_GACT_PROB]); 90 if (p_parm->ptype >= MAX_RAND) 91 return -EINVAL; 92 if (TC_ACT_EXT_CMP(p_parm->paction, TC_ACT_GOTO_CHAIN)) { 93 NL_SET_ERR_MSG(extack, 94 "goto chain not allowed on fallback"); 95 return -EINVAL; 96 } 97 } 98 #endif 99 100 err = tcf_idr_check_alloc(tn, &index, a, bind); 101 if (!err) { 102 ret = tcf_idr_create_from_flags(tn, index, est, a, 103 &act_gact_ops, bind, flags); 104 if (ret) { 105 tcf_idr_cleanup(tn, index); 106 return ret; 107 } 108 ret = ACT_P_CREATED; 109 } else if (err > 0) { 110 if (bind)/* dont override defaults */ 111 return 0; 112 if (!(flags & TCA_ACT_FLAGS_REPLACE)) { 113 tcf_idr_release(*a, bind); 114 return -EEXIST; 115 } 116 } else { 117 return err; 118 } 119 120 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); 121 if (err < 0) 122 goto release_idr; 123 gact = to_gact(*a); 124 125 spin_lock_bh(&gact->tcf_lock); 126 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 127 #ifdef CONFIG_GACT_PROB 128 if (p_parm) { 129 gact->tcfg_paction = p_parm->paction; 130 gact->tcfg_pval = max_t(u16, 1, p_parm->pval); 131 /* Make sure tcfg_pval is written before tcfg_ptype 132 * coupled with smp_rmb() in gact_net_rand() & gact_determ() 133 */ 134 smp_wmb(); 135 gact->tcfg_ptype = p_parm->ptype; 136 } 137 #endif 138 spin_unlock_bh(&gact->tcf_lock); 139 140 if (goto_ch) 141 tcf_chain_put_by_act(goto_ch); 142 143 return ret; 144 release_idr: 145 tcf_idr_release(*a, bind); 146 return err; 147 } 148 149 static int tcf_gact_act(struct sk_buff *skb, const struct tc_action *a, 150 struct tcf_result *res) 151 { 152 struct tcf_gact *gact = to_gact(a); 153 int action = READ_ONCE(gact->tcf_action); 154 155 #ifdef CONFIG_GACT_PROB 156 { 157 u32 ptype = READ_ONCE(gact->tcfg_ptype); 158 159 if (ptype) 160 action = gact_rand[ptype](gact); 161 } 162 #endif 163 tcf_action_update_bstats(&gact->common, skb); 164 if (action == TC_ACT_SHOT) 165 tcf_action_inc_drop_qstats(&gact->common); 166 167 tcf_lastuse_update(&gact->tcf_tm); 168 169 return action; 170 } 171 172 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u64 packets, 173 u64 drops, u64 lastuse, bool hw) 174 { 175 struct tcf_gact *gact = to_gact(a); 176 int action = READ_ONCE(gact->tcf_action); 177 struct tcf_t *tm = &gact->tcf_tm; 178 179 tcf_action_update_stats(a, bytes, packets, 180 action == TC_ACT_SHOT ? packets : drops, hw); 181 tm->lastuse = max_t(u64, tm->lastuse, lastuse); 182 } 183 184 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, 185 int bind, int ref) 186 { 187 unsigned char *b = skb_tail_pointer(skb); 188 struct tcf_gact *gact = to_gact(a); 189 struct tc_gact opt = { 190 .index = gact->tcf_index, 191 .refcnt = refcount_read(&gact->tcf_refcnt) - ref, 192 .bindcnt = atomic_read(&gact->tcf_bindcnt) - bind, 193 }; 194 struct tcf_t t; 195 196 spin_lock_bh(&gact->tcf_lock); 197 opt.action = gact->tcf_action; 198 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt)) 199 goto nla_put_failure; 200 #ifdef CONFIG_GACT_PROB 201 if (gact->tcfg_ptype) { 202 struct tc_gact_p p_opt = { 203 .paction = gact->tcfg_paction, 204 .pval = gact->tcfg_pval, 205 .ptype = gact->tcfg_ptype, 206 }; 207 208 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt)) 209 goto nla_put_failure; 210 } 211 #endif 212 tcf_tm_dump(&t, &gact->tcf_tm); 213 if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD)) 214 goto nla_put_failure; 215 spin_unlock_bh(&gact->tcf_lock); 216 217 return skb->len; 218 219 nla_put_failure: 220 spin_unlock_bh(&gact->tcf_lock); 221 nlmsg_trim(skb, b); 222 return -1; 223 } 224 225 static int tcf_gact_walker(struct net *net, struct sk_buff *skb, 226 struct netlink_callback *cb, int type, 227 const struct tc_action_ops *ops, 228 struct netlink_ext_ack *extack) 229 { 230 struct tc_action_net *tn = net_generic(net, gact_net_id); 231 232 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 233 } 234 235 static int tcf_gact_search(struct net *net, struct tc_action **a, u32 index) 236 { 237 struct tc_action_net *tn = net_generic(net, gact_net_id); 238 239 return tcf_idr_search(tn, a, index); 240 } 241 242 static size_t tcf_gact_get_fill_size(const struct tc_action *act) 243 { 244 size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */ 245 246 #ifdef CONFIG_GACT_PROB 247 if (to_gact(act)->tcfg_ptype) 248 /* TCA_GACT_PROB */ 249 sz += nla_total_size(sizeof(struct tc_gact_p)); 250 #endif 251 252 return sz; 253 } 254 255 static struct tc_action_ops act_gact_ops = { 256 .kind = "gact", 257 .id = TCA_ID_GACT, 258 .owner = THIS_MODULE, 259 .act = tcf_gact_act, 260 .stats_update = tcf_gact_stats_update, 261 .dump = tcf_gact_dump, 262 .init = tcf_gact_init, 263 .walk = tcf_gact_walker, 264 .lookup = tcf_gact_search, 265 .get_fill_size = tcf_gact_get_fill_size, 266 .size = sizeof(struct tcf_gact), 267 }; 268 269 static __net_init int gact_init_net(struct net *net) 270 { 271 struct tc_action_net *tn = net_generic(net, gact_net_id); 272 273 return tc_action_net_init(net, tn, &act_gact_ops); 274 } 275 276 static void __net_exit gact_exit_net(struct list_head *net_list) 277 { 278 tc_action_net_exit(net_list, gact_net_id); 279 } 280 281 static struct pernet_operations gact_net_ops = { 282 .init = gact_init_net, 283 .exit_batch = gact_exit_net, 284 .id = &gact_net_id, 285 .size = sizeof(struct tc_action_net), 286 }; 287 288 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 289 MODULE_DESCRIPTION("Generic Classifier actions"); 290 MODULE_LICENSE("GPL"); 291 292 static int __init gact_init_module(void) 293 { 294 #ifdef CONFIG_GACT_PROB 295 pr_info("GACT probability on\n"); 296 #else 297 pr_info("GACT probability NOT on\n"); 298 #endif 299 300 return tcf_register_action(&act_gact_ops, &gact_net_ops); 301 } 302 303 static void __exit gact_cleanup_module(void) 304 { 305 tcf_unregister_action(&act_gact_ops, &gact_net_ops); 306 } 307 308 module_init(gact_init_module); 309 module_exit(gact_cleanup_module); 310