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