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 #define GACT_TAB_MASK 15 27 28 static int gact_net_id; 29 static struct tc_action_ops act_gact_ops; 30 31 #ifdef CONFIG_GACT_PROB 32 static int gact_net_rand(struct tcf_gact *gact) 33 { 34 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */ 35 if (prandom_u32() % gact->tcfg_pval) 36 return gact->tcf_action; 37 return gact->tcfg_paction; 38 } 39 40 static int gact_determ(struct tcf_gact *gact) 41 { 42 u32 pack = atomic_inc_return(&gact->packets); 43 44 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */ 45 if (pack % gact->tcfg_pval) 46 return gact->tcf_action; 47 return gact->tcfg_paction; 48 } 49 50 typedef int (*g_rand)(struct tcf_gact *gact); 51 static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ }; 52 #endif /* CONFIG_GACT_PROB */ 53 54 static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = { 55 [TCA_GACT_PARMS] = { .len = sizeof(struct tc_gact) }, 56 [TCA_GACT_PROB] = { .len = sizeof(struct tc_gact_p) }, 57 }; 58 59 static int tcf_gact_init(struct net *net, struct nlattr *nla, 60 struct nlattr *est, struct tc_action **a, 61 int ovr, int bind) 62 { 63 struct tc_action_net *tn = net_generic(net, gact_net_id); 64 struct nlattr *tb[TCA_GACT_MAX + 1]; 65 struct tc_gact *parm; 66 struct tcf_gact *gact; 67 int ret = 0; 68 int err; 69 #ifdef CONFIG_GACT_PROB 70 struct tc_gact_p *p_parm = NULL; 71 #endif 72 73 if (nla == NULL) 74 return -EINVAL; 75 76 err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy); 77 if (err < 0) 78 return err; 79 80 if (tb[TCA_GACT_PARMS] == NULL) 81 return -EINVAL; 82 parm = nla_data(tb[TCA_GACT_PARMS]); 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 } 93 #endif 94 95 if (!tcf_hash_check(tn, parm->index, a, bind)) { 96 ret = tcf_hash_create(tn, parm->index, est, a, 97 &act_gact_ops, bind, true); 98 if (ret) 99 return ret; 100 ret = ACT_P_CREATED; 101 } else { 102 if (bind)/* dont override defaults */ 103 return 0; 104 tcf_hash_release(*a, bind); 105 if (!ovr) 106 return -EEXIST; 107 } 108 109 gact = to_gact(*a); 110 111 ASSERT_RTNL(); 112 gact->tcf_action = parm->action; 113 #ifdef CONFIG_GACT_PROB 114 if (p_parm) { 115 gact->tcfg_paction = p_parm->paction; 116 gact->tcfg_pval = max_t(u16, 1, p_parm->pval); 117 /* Make sure tcfg_pval is written before tcfg_ptype 118 * coupled with smp_rmb() in gact_net_rand() & gact_determ() 119 */ 120 smp_wmb(); 121 gact->tcfg_ptype = p_parm->ptype; 122 } 123 #endif 124 if (ret == ACT_P_CREATED) 125 tcf_hash_insert(tn, *a); 126 return ret; 127 } 128 129 static int tcf_gact(struct sk_buff *skb, const struct tc_action *a, 130 struct tcf_result *res) 131 { 132 struct tcf_gact *gact = to_gact(a); 133 int action = READ_ONCE(gact->tcf_action); 134 135 #ifdef CONFIG_GACT_PROB 136 { 137 u32 ptype = READ_ONCE(gact->tcfg_ptype); 138 139 if (ptype) 140 action = gact_rand[ptype](gact); 141 } 142 #endif 143 bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), skb); 144 if (action == TC_ACT_SHOT) 145 qstats_drop_inc(this_cpu_ptr(gact->common.cpu_qstats)); 146 147 tcf_lastuse_update(&gact->tcf_tm); 148 149 return action; 150 } 151 152 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u32 packets, 153 u64 lastuse) 154 { 155 struct tcf_gact *gact = to_gact(a); 156 int action = READ_ONCE(gact->tcf_action); 157 struct tcf_t *tm = &gact->tcf_tm; 158 159 _bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), bytes, packets); 160 if (action == TC_ACT_SHOT) 161 this_cpu_ptr(gact->common.cpu_qstats)->drops += packets; 162 163 tm->lastuse = lastuse; 164 } 165 166 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, 167 int bind, int ref) 168 { 169 unsigned char *b = skb_tail_pointer(skb); 170 struct tcf_gact *gact = to_gact(a); 171 struct tc_gact opt = { 172 .index = gact->tcf_index, 173 .refcnt = gact->tcf_refcnt - ref, 174 .bindcnt = gact->tcf_bindcnt - bind, 175 .action = gact->tcf_action, 176 }; 177 struct tcf_t t; 178 179 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt)) 180 goto nla_put_failure; 181 #ifdef CONFIG_GACT_PROB 182 if (gact->tcfg_ptype) { 183 struct tc_gact_p p_opt = { 184 .paction = gact->tcfg_paction, 185 .pval = gact->tcfg_pval, 186 .ptype = gact->tcfg_ptype, 187 }; 188 189 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt)) 190 goto nla_put_failure; 191 } 192 #endif 193 tcf_tm_dump(&t, &gact->tcf_tm); 194 if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD)) 195 goto nla_put_failure; 196 return skb->len; 197 198 nla_put_failure: 199 nlmsg_trim(skb, b); 200 return -1; 201 } 202 203 static int tcf_gact_walker(struct net *net, struct sk_buff *skb, 204 struct netlink_callback *cb, int type, 205 const struct tc_action_ops *ops) 206 { 207 struct tc_action_net *tn = net_generic(net, gact_net_id); 208 209 return tcf_generic_walker(tn, skb, cb, type, ops); 210 } 211 212 static int tcf_gact_search(struct net *net, struct tc_action **a, u32 index) 213 { 214 struct tc_action_net *tn = net_generic(net, gact_net_id); 215 216 return tcf_hash_search(tn, a, index); 217 } 218 219 static struct tc_action_ops act_gact_ops = { 220 .kind = "gact", 221 .type = TCA_ACT_GACT, 222 .owner = THIS_MODULE, 223 .act = tcf_gact, 224 .stats_update = tcf_gact_stats_update, 225 .dump = tcf_gact_dump, 226 .init = tcf_gact_init, 227 .walk = tcf_gact_walker, 228 .lookup = tcf_gact_search, 229 .size = sizeof(struct tcf_gact), 230 }; 231 232 static __net_init int gact_init_net(struct net *net) 233 { 234 struct tc_action_net *tn = net_generic(net, gact_net_id); 235 236 return tc_action_net_init(tn, &act_gact_ops, GACT_TAB_MASK); 237 } 238 239 static void __net_exit gact_exit_net(struct net *net) 240 { 241 struct tc_action_net *tn = net_generic(net, gact_net_id); 242 243 tc_action_net_exit(tn); 244 } 245 246 static struct pernet_operations gact_net_ops = { 247 .init = gact_init_net, 248 .exit = gact_exit_net, 249 .id = &gact_net_id, 250 .size = sizeof(struct tc_action_net), 251 }; 252 253 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 254 MODULE_DESCRIPTION("Generic Classifier actions"); 255 MODULE_LICENSE("GPL"); 256 257 static int __init gact_init_module(void) 258 { 259 #ifdef CONFIG_GACT_PROB 260 pr_info("GACT probability on\n"); 261 #else 262 pr_info("GACT probability NOT on\n"); 263 #endif 264 265 return tcf_register_action(&act_gact_ops, &gact_net_ops); 266 } 267 268 static void __exit gact_cleanup_module(void) 269 { 270 tcf_unregister_action(&act_gact_ops, &gact_net_ops); 271 } 272 273 module_init(gact_init_module); 274 module_exit(gact_cleanup_module); 275