1 /* 2 * net/sched/act_gact.c Generic actions 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * copyright Jamal Hadi Salim (2002-4) 10 * 11 */ 12 13 #include <linux/types.h> 14 #include <linux/kernel.h> 15 #include <linux/string.h> 16 #include <linux/errno.h> 17 #include <linux/skbuff.h> 18 #include <linux/rtnetlink.h> 19 #include <linux/module.h> 20 #include <linux/init.h> 21 #include <net/netlink.h> 22 #include <net/pkt_sched.h> 23 #include <linux/tc_act/tc_gact.h> 24 #include <net/tc_act/tc_gact.h> 25 26 static unsigned int gact_net_id; 27 static struct tc_action_ops act_gact_ops; 28 29 #ifdef CONFIG_GACT_PROB 30 static int gact_net_rand(struct tcf_gact *gact) 31 { 32 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */ 33 if (prandom_u32() % gact->tcfg_pval) 34 return gact->tcf_action; 35 return gact->tcfg_paction; 36 } 37 38 static int gact_determ(struct tcf_gact *gact) 39 { 40 u32 pack = atomic_inc_return(&gact->packets); 41 42 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */ 43 if (pack % gact->tcfg_pval) 44 return gact->tcf_action; 45 return gact->tcfg_paction; 46 } 47 48 typedef int (*g_rand)(struct tcf_gact *gact); 49 static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ }; 50 #endif /* CONFIG_GACT_PROB */ 51 52 static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = { 53 [TCA_GACT_PARMS] = { .len = sizeof(struct tc_gact) }, 54 [TCA_GACT_PROB] = { .len = sizeof(struct tc_gact_p) }, 55 }; 56 57 static int tcf_gact_init(struct net *net, struct nlattr *nla, 58 struct nlattr *est, struct tc_action **a, 59 int ovr, int bind, bool rtnl_held, 60 struct netlink_ext_ack *extack) 61 { 62 struct tc_action_net *tn = net_generic(net, gact_net_id); 63 struct nlattr *tb[TCA_GACT_MAX + 1]; 64 struct tc_gact *parm; 65 struct tcf_gact *gact; 66 int ret = 0; 67 int err; 68 #ifdef CONFIG_GACT_PROB 69 struct tc_gact_p *p_parm = NULL; 70 #endif 71 72 if (nla == NULL) 73 return -EINVAL; 74 75 err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy, 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 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 } 92 #endif 93 94 err = tcf_idr_check_alloc(tn, &parm->index, a, bind); 95 if (!err) { 96 ret = tcf_idr_create(tn, parm->index, est, a, 97 &act_gact_ops, bind, true); 98 if (ret) { 99 tcf_idr_cleanup(tn, parm->index); 100 return ret; 101 } 102 ret = ACT_P_CREATED; 103 } else if (err > 0) { 104 if (bind)/* dont override defaults */ 105 return 0; 106 if (!ovr) { 107 tcf_idr_release(*a, bind); 108 return -EEXIST; 109 } 110 } else { 111 return err; 112 } 113 114 gact = to_gact(*a); 115 116 ASSERT_RTNL(); 117 gact->tcf_action = parm->action; 118 #ifdef CONFIG_GACT_PROB 119 if (p_parm) { 120 gact->tcfg_paction = p_parm->paction; 121 gact->tcfg_pval = max_t(u16, 1, p_parm->pval); 122 /* Make sure tcfg_pval is written before tcfg_ptype 123 * coupled with smp_rmb() in gact_net_rand() & gact_determ() 124 */ 125 smp_wmb(); 126 gact->tcfg_ptype = p_parm->ptype; 127 } 128 #endif 129 if (ret == ACT_P_CREATED) 130 tcf_idr_insert(tn, *a); 131 return ret; 132 } 133 134 static int tcf_gact(struct sk_buff *skb, const struct tc_action *a, 135 struct tcf_result *res) 136 { 137 struct tcf_gact *gact = to_gact(a); 138 int action = READ_ONCE(gact->tcf_action); 139 140 #ifdef CONFIG_GACT_PROB 141 { 142 u32 ptype = READ_ONCE(gact->tcfg_ptype); 143 144 if (ptype) 145 action = gact_rand[ptype](gact); 146 } 147 #endif 148 bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), skb); 149 if (action == TC_ACT_SHOT) 150 qstats_drop_inc(this_cpu_ptr(gact->common.cpu_qstats)); 151 152 tcf_lastuse_update(&gact->tcf_tm); 153 154 return action; 155 } 156 157 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u32 packets, 158 u64 lastuse) 159 { 160 struct tcf_gact *gact = to_gact(a); 161 int action = READ_ONCE(gact->tcf_action); 162 struct tcf_t *tm = &gact->tcf_tm; 163 164 _bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), bytes, 165 packets); 166 if (action == TC_ACT_SHOT) 167 this_cpu_ptr(gact->common.cpu_qstats)->drops += packets; 168 169 tm->lastuse = max_t(u64, tm->lastuse, lastuse); 170 } 171 172 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, 173 int bind, int ref) 174 { 175 unsigned char *b = skb_tail_pointer(skb); 176 struct tcf_gact *gact = to_gact(a); 177 struct tc_gact opt = { 178 .index = gact->tcf_index, 179 .refcnt = refcount_read(&gact->tcf_refcnt) - ref, 180 .bindcnt = atomic_read(&gact->tcf_bindcnt) - bind, 181 .action = gact->tcf_action, 182 }; 183 struct tcf_t t; 184 185 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt)) 186 goto nla_put_failure; 187 #ifdef CONFIG_GACT_PROB 188 if (gact->tcfg_ptype) { 189 struct tc_gact_p p_opt = { 190 .paction = gact->tcfg_paction, 191 .pval = gact->tcfg_pval, 192 .ptype = gact->tcfg_ptype, 193 }; 194 195 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt)) 196 goto nla_put_failure; 197 } 198 #endif 199 tcf_tm_dump(&t, &gact->tcf_tm); 200 if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD)) 201 goto nla_put_failure; 202 return skb->len; 203 204 nla_put_failure: 205 nlmsg_trim(skb, b); 206 return -1; 207 } 208 209 static int tcf_gact_walker(struct net *net, struct sk_buff *skb, 210 struct netlink_callback *cb, int type, 211 const struct tc_action_ops *ops, 212 struct netlink_ext_ack *extack) 213 { 214 struct tc_action_net *tn = net_generic(net, gact_net_id); 215 216 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 217 } 218 219 static int tcf_gact_search(struct net *net, struct tc_action **a, u32 index, 220 struct netlink_ext_ack *extack) 221 { 222 struct tc_action_net *tn = net_generic(net, gact_net_id); 223 224 return tcf_idr_search(tn, a, index); 225 } 226 227 static size_t tcf_gact_get_fill_size(const struct tc_action *act) 228 { 229 size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */ 230 231 #ifdef CONFIG_GACT_PROB 232 if (to_gact(act)->tcfg_ptype) 233 /* TCA_GACT_PROB */ 234 sz += nla_total_size(sizeof(struct tc_gact_p)); 235 #endif 236 237 return sz; 238 } 239 240 static int tcf_gact_delete(struct net *net, u32 index) 241 { 242 struct tc_action_net *tn = net_generic(net, gact_net_id); 243 244 return tcf_idr_delete_index(tn, index); 245 } 246 247 static struct tc_action_ops act_gact_ops = { 248 .kind = "gact", 249 .type = TCA_ACT_GACT, 250 .owner = THIS_MODULE, 251 .act = tcf_gact, 252 .stats_update = tcf_gact_stats_update, 253 .dump = tcf_gact_dump, 254 .init = tcf_gact_init, 255 .walk = tcf_gact_walker, 256 .lookup = tcf_gact_search, 257 .get_fill_size = tcf_gact_get_fill_size, 258 .delete = tcf_gact_delete, 259 .size = sizeof(struct tcf_gact), 260 }; 261 262 static __net_init int gact_init_net(struct net *net) 263 { 264 struct tc_action_net *tn = net_generic(net, gact_net_id); 265 266 return tc_action_net_init(tn, &act_gact_ops); 267 } 268 269 static void __net_exit gact_exit_net(struct list_head *net_list) 270 { 271 tc_action_net_exit(net_list, gact_net_id); 272 } 273 274 static struct pernet_operations gact_net_ops = { 275 .init = gact_init_net, 276 .exit_batch = gact_exit_net, 277 .id = &gact_net_id, 278 .size = sizeof(struct tc_action_net), 279 }; 280 281 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 282 MODULE_DESCRIPTION("Generic Classifier actions"); 283 MODULE_LICENSE("GPL"); 284 285 static int __init gact_init_module(void) 286 { 287 #ifdef CONFIG_GACT_PROB 288 pr_info("GACT probability on\n"); 289 #else 290 pr_info("GACT probability NOT on\n"); 291 #endif 292 293 return tcf_register_action(&act_gact_ops, &gact_net_ops); 294 } 295 296 static void __exit gact_cleanup_module(void) 297 { 298 tcf_unregister_action(&act_gact_ops, &gact_net_ops); 299 } 300 301 module_init(gact_init_module); 302 module_exit(gact_cleanup_module); 303