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 30 #ifdef CONFIG_GACT_PROB 31 static int gact_net_rand(struct tcf_gact *gact) 32 { 33 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */ 34 if (prandom_u32() % gact->tcfg_pval) 35 return gact->tcf_action; 36 return gact->tcfg_paction; 37 } 38 39 static int gact_determ(struct tcf_gact *gact) 40 { 41 u32 pack = atomic_inc_return(&gact->packets); 42 43 smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */ 44 if (pack % gact->tcfg_pval) 45 return gact->tcf_action; 46 return gact->tcfg_paction; 47 } 48 49 typedef int (*g_rand)(struct tcf_gact *gact); 50 static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ }; 51 #endif /* CONFIG_GACT_PROB */ 52 53 static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = { 54 [TCA_GACT_PARMS] = { .len = sizeof(struct tc_gact) }, 55 [TCA_GACT_PROB] = { .len = sizeof(struct tc_gact_p) }, 56 }; 57 58 static int tcf_gact_init(struct net *net, struct nlattr *nla, 59 struct nlattr *est, struct tc_action *a, 60 int ovr, int bind) 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); 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 if (!tcf_hash_check(tn, parm->index, a, bind)) { 95 ret = tcf_hash_create(tn, parm->index, est, a, 96 sizeof(*gact), bind, true); 97 if (ret) 98 return ret; 99 ret = ACT_P_CREATED; 100 } else { 101 if (bind)/* dont override defaults */ 102 return 0; 103 tcf_hash_release(a, bind); 104 if (!ovr) 105 return -EEXIST; 106 } 107 108 gact = to_gact(a); 109 110 ASSERT_RTNL(); 111 gact->tcf_action = parm->action; 112 #ifdef CONFIG_GACT_PROB 113 if (p_parm) { 114 gact->tcfg_paction = p_parm->paction; 115 gact->tcfg_pval = max_t(u16, 1, p_parm->pval); 116 /* Make sure tcfg_pval is written before tcfg_ptype 117 * coupled with smp_rmb() in gact_net_rand() & gact_determ() 118 */ 119 smp_wmb(); 120 gact->tcfg_ptype = p_parm->ptype; 121 } 122 #endif 123 if (ret == ACT_P_CREATED) 124 tcf_hash_insert(tn, a); 125 return ret; 126 } 127 128 static int tcf_gact(struct sk_buff *skb, const struct tc_action *a, 129 struct tcf_result *res) 130 { 131 struct tcf_gact *gact = a->priv; 132 int action = READ_ONCE(gact->tcf_action); 133 134 #ifdef CONFIG_GACT_PROB 135 { 136 u32 ptype = READ_ONCE(gact->tcfg_ptype); 137 138 if (ptype) 139 action = gact_rand[ptype](gact); 140 } 141 #endif 142 bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), skb); 143 if (action == TC_ACT_SHOT) 144 qstats_drop_inc(this_cpu_ptr(gact->common.cpu_qstats)); 145 146 tcf_lastuse_update(&gact->tcf_tm); 147 148 return action; 149 } 150 151 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u32 packets, 152 u64 lastuse) 153 { 154 struct tcf_gact *gact = a->priv; 155 int action = READ_ONCE(gact->tcf_action); 156 struct tcf_t *tm = &gact->tcf_tm; 157 158 _bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), bytes, packets); 159 if (action == TC_ACT_SHOT) 160 this_cpu_ptr(gact->common.cpu_qstats)->drops += packets; 161 162 tm->lastuse = lastuse; 163 } 164 165 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 166 { 167 unsigned char *b = skb_tail_pointer(skb); 168 struct tcf_gact *gact = a->priv; 169 struct tc_gact opt = { 170 .index = gact->tcf_index, 171 .refcnt = gact->tcf_refcnt - ref, 172 .bindcnt = gact->tcf_bindcnt - bind, 173 .action = gact->tcf_action, 174 }; 175 struct tcf_t t; 176 177 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt)) 178 goto nla_put_failure; 179 #ifdef CONFIG_GACT_PROB 180 if (gact->tcfg_ptype) { 181 struct tc_gact_p p_opt = { 182 .paction = gact->tcfg_paction, 183 .pval = gact->tcfg_pval, 184 .ptype = gact->tcfg_ptype, 185 }; 186 187 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt)) 188 goto nla_put_failure; 189 } 190 #endif 191 t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install); 192 t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse); 193 t.expires = jiffies_to_clock_t(gact->tcf_tm.expires); 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 struct tc_action *a) 206 { 207 struct tc_action_net *tn = net_generic(net, gact_net_id); 208 209 return tcf_generic_walker(tn, skb, cb, type, a); 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 }; 230 231 static __net_init int gact_init_net(struct net *net) 232 { 233 struct tc_action_net *tn = net_generic(net, gact_net_id); 234 235 return tc_action_net_init(tn, &act_gact_ops, GACT_TAB_MASK); 236 } 237 238 static void __net_exit gact_exit_net(struct net *net) 239 { 240 struct tc_action_net *tn = net_generic(net, gact_net_id); 241 242 tc_action_net_exit(tn); 243 } 244 245 static struct pernet_operations gact_net_ops = { 246 .init = gact_init_net, 247 .exit = gact_exit_net, 248 .id = &gact_net_id, 249 .size = sizeof(struct tc_action_net), 250 }; 251 252 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 253 MODULE_DESCRIPTION("Generic Classifier actions"); 254 MODULE_LICENSE("GPL"); 255 256 static int __init gact_init_module(void) 257 { 258 #ifdef CONFIG_GACT_PROB 259 pr_info("GACT probability on\n"); 260 #else 261 pr_info("GACT probability NOT on\n"); 262 #endif 263 264 return tcf_register_action(&act_gact_ops, &gact_net_ops); 265 } 266 267 static void __exit gact_cleanup_module(void) 268 { 269 tcf_unregister_action(&act_gact_ops, &gact_net_ops); 270 } 271 272 module_init(gact_init_module); 273 module_exit(gact_cleanup_module); 274