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 spin_lock_bh(&gact->tcf_lock); 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 spin_unlock_bh(&gact->tcf_lock); 130 131 if (ret == ACT_P_CREATED) 132 tcf_idr_insert(tn, *a); 133 return ret; 134 } 135 136 static int tcf_gact_act(struct sk_buff *skb, const struct tc_action *a, 137 struct tcf_result *res) 138 { 139 struct tcf_gact *gact = to_gact(a); 140 int action = READ_ONCE(gact->tcf_action); 141 142 #ifdef CONFIG_GACT_PROB 143 { 144 u32 ptype = READ_ONCE(gact->tcfg_ptype); 145 146 if (ptype) 147 action = gact_rand[ptype](gact); 148 } 149 #endif 150 bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), skb); 151 if (action == TC_ACT_SHOT) 152 qstats_drop_inc(this_cpu_ptr(gact->common.cpu_qstats)); 153 154 tcf_lastuse_update(&gact->tcf_tm); 155 156 return action; 157 } 158 159 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u32 packets, 160 u64 lastuse) 161 { 162 struct tcf_gact *gact = to_gact(a); 163 int action = READ_ONCE(gact->tcf_action); 164 struct tcf_t *tm = &gact->tcf_tm; 165 166 _bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), bytes, 167 packets); 168 if (action == TC_ACT_SHOT) 169 this_cpu_ptr(gact->common.cpu_qstats)->drops += packets; 170 171 tm->lastuse = max_t(u64, tm->lastuse, lastuse); 172 } 173 174 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, 175 int bind, int ref) 176 { 177 unsigned char *b = skb_tail_pointer(skb); 178 struct tcf_gact *gact = to_gact(a); 179 struct tc_gact opt = { 180 .index = gact->tcf_index, 181 .refcnt = refcount_read(&gact->tcf_refcnt) - ref, 182 .bindcnt = atomic_read(&gact->tcf_bindcnt) - bind, 183 }; 184 struct tcf_t t; 185 186 spin_lock_bh(&gact->tcf_lock); 187 opt.action = gact->tcf_action; 188 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt)) 189 goto nla_put_failure; 190 #ifdef CONFIG_GACT_PROB 191 if (gact->tcfg_ptype) { 192 struct tc_gact_p p_opt = { 193 .paction = gact->tcfg_paction, 194 .pval = gact->tcfg_pval, 195 .ptype = gact->tcfg_ptype, 196 }; 197 198 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt)) 199 goto nla_put_failure; 200 } 201 #endif 202 tcf_tm_dump(&t, &gact->tcf_tm); 203 if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD)) 204 goto nla_put_failure; 205 spin_unlock_bh(&gact->tcf_lock); 206 207 return skb->len; 208 209 nla_put_failure: 210 spin_unlock_bh(&gact->tcf_lock); 211 nlmsg_trim(skb, b); 212 return -1; 213 } 214 215 static int tcf_gact_walker(struct net *net, struct sk_buff *skb, 216 struct netlink_callback *cb, int type, 217 const struct tc_action_ops *ops, 218 struct netlink_ext_ack *extack) 219 { 220 struct tc_action_net *tn = net_generic(net, gact_net_id); 221 222 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 223 } 224 225 static int tcf_gact_search(struct net *net, struct tc_action **a, u32 index, 226 struct netlink_ext_ack *extack) 227 { 228 struct tc_action_net *tn = net_generic(net, gact_net_id); 229 230 return tcf_idr_search(tn, a, index); 231 } 232 233 static size_t tcf_gact_get_fill_size(const struct tc_action *act) 234 { 235 size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */ 236 237 #ifdef CONFIG_GACT_PROB 238 if (to_gact(act)->tcfg_ptype) 239 /* TCA_GACT_PROB */ 240 sz += nla_total_size(sizeof(struct tc_gact_p)); 241 #endif 242 243 return sz; 244 } 245 246 static int tcf_gact_delete(struct net *net, u32 index) 247 { 248 struct tc_action_net *tn = net_generic(net, gact_net_id); 249 250 return tcf_idr_delete_index(tn, index); 251 } 252 253 static struct tc_action_ops act_gact_ops = { 254 .kind = "gact", 255 .type = TCA_ACT_GACT, 256 .owner = THIS_MODULE, 257 .act = tcf_gact_act, 258 .stats_update = tcf_gact_stats_update, 259 .dump = tcf_gact_dump, 260 .init = tcf_gact_init, 261 .walk = tcf_gact_walker, 262 .lookup = tcf_gact_search, 263 .get_fill_size = tcf_gact_get_fill_size, 264 .delete = tcf_gact_delete, 265 .size = sizeof(struct tcf_gact), 266 }; 267 268 static __net_init int gact_init_net(struct net *net) 269 { 270 struct tc_action_net *tn = net_generic(net, gact_net_id); 271 272 return tc_action_net_init(tn, &act_gact_ops); 273 } 274 275 static void __net_exit gact_exit_net(struct list_head *net_list) 276 { 277 tc_action_net_exit(net_list, gact_net_id); 278 } 279 280 static struct pernet_operations gact_net_ops = { 281 .init = gact_init_net, 282 .exit_batch = gact_exit_net, 283 .id = &gact_net_id, 284 .size = sizeof(struct tc_action_net), 285 }; 286 287 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 288 MODULE_DESCRIPTION("Generic Classifier actions"); 289 MODULE_LICENSE("GPL"); 290 291 static int __init gact_init_module(void) 292 { 293 #ifdef CONFIG_GACT_PROB 294 pr_info("GACT probability on\n"); 295 #else 296 pr_info("GACT probability NOT on\n"); 297 #endif 298 299 return tcf_register_action(&act_gact_ops, &gact_net_ops); 300 } 301 302 static void __exit gact_cleanup_module(void) 303 { 304 tcf_unregister_action(&act_gact_ops, &gact_net_ops); 305 } 306 307 module_init(gact_init_module); 308 module_exit(gact_cleanup_module); 309