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 int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 152 { 153 unsigned char *b = skb_tail_pointer(skb); 154 struct tcf_gact *gact = a->priv; 155 struct tc_gact opt = { 156 .index = gact->tcf_index, 157 .refcnt = gact->tcf_refcnt - ref, 158 .bindcnt = gact->tcf_bindcnt - bind, 159 .action = gact->tcf_action, 160 }; 161 struct tcf_t t; 162 163 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt)) 164 goto nla_put_failure; 165 #ifdef CONFIG_GACT_PROB 166 if (gact->tcfg_ptype) { 167 struct tc_gact_p p_opt = { 168 .paction = gact->tcfg_paction, 169 .pval = gact->tcfg_pval, 170 .ptype = gact->tcfg_ptype, 171 }; 172 173 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt)) 174 goto nla_put_failure; 175 } 176 #endif 177 t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install); 178 t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse); 179 t.expires = jiffies_to_clock_t(gact->tcf_tm.expires); 180 if (nla_put(skb, TCA_GACT_TM, sizeof(t), &t)) 181 goto nla_put_failure; 182 return skb->len; 183 184 nla_put_failure: 185 nlmsg_trim(skb, b); 186 return -1; 187 } 188 189 static int tcf_gact_walker(struct net *net, struct sk_buff *skb, 190 struct netlink_callback *cb, int type, 191 struct tc_action *a) 192 { 193 struct tc_action_net *tn = net_generic(net, gact_net_id); 194 195 return tcf_generic_walker(tn, skb, cb, type, a); 196 } 197 198 static int tcf_gact_search(struct net *net, struct tc_action *a, u32 index) 199 { 200 struct tc_action_net *tn = net_generic(net, gact_net_id); 201 202 return tcf_hash_search(tn, a, index); 203 } 204 205 static struct tc_action_ops act_gact_ops = { 206 .kind = "gact", 207 .type = TCA_ACT_GACT, 208 .owner = THIS_MODULE, 209 .act = tcf_gact, 210 .dump = tcf_gact_dump, 211 .init = tcf_gact_init, 212 .walk = tcf_gact_walker, 213 .lookup = tcf_gact_search, 214 }; 215 216 static __net_init int gact_init_net(struct net *net) 217 { 218 struct tc_action_net *tn = net_generic(net, gact_net_id); 219 220 return tc_action_net_init(tn, &act_gact_ops, GACT_TAB_MASK); 221 } 222 223 static void __net_exit gact_exit_net(struct net *net) 224 { 225 struct tc_action_net *tn = net_generic(net, gact_net_id); 226 227 tc_action_net_exit(tn); 228 } 229 230 static struct pernet_operations gact_net_ops = { 231 .init = gact_init_net, 232 .exit = gact_exit_net, 233 .id = &gact_net_id, 234 .size = sizeof(struct tc_action_net), 235 }; 236 237 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 238 MODULE_DESCRIPTION("Generic Classifier actions"); 239 MODULE_LICENSE("GPL"); 240 241 static int __init gact_init_module(void) 242 { 243 #ifdef CONFIG_GACT_PROB 244 pr_info("GACT probability on\n"); 245 #else 246 pr_info("GACT probability NOT on\n"); 247 #endif 248 249 return tcf_register_action(&act_gact_ops, &gact_net_ops); 250 } 251 252 static void __exit gact_cleanup_module(void) 253 { 254 tcf_unregister_action(&act_gact_ops, &gact_net_ops); 255 } 256 257 module_init(gact_init_module); 258 module_exit(gact_cleanup_module); 259