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) 60 { 61 struct tc_action_net *tn = net_generic(net, gact_net_id); 62 struct nlattr *tb[TCA_GACT_MAX + 1]; 63 struct tc_gact *parm; 64 struct tcf_gact *gact; 65 int ret = 0; 66 int err; 67 #ifdef CONFIG_GACT_PROB 68 struct tc_gact_p *p_parm = NULL; 69 #endif 70 71 if (nla == NULL) 72 return -EINVAL; 73 74 err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy, NULL); 75 if (err < 0) 76 return err; 77 78 if (tb[TCA_GACT_PARMS] == NULL) 79 return -EINVAL; 80 parm = nla_data(tb[TCA_GACT_PARMS]); 81 82 #ifndef CONFIG_GACT_PROB 83 if (tb[TCA_GACT_PROB] != NULL) 84 return -EOPNOTSUPP; 85 #else 86 if (tb[TCA_GACT_PROB]) { 87 p_parm = nla_data(tb[TCA_GACT_PROB]); 88 if (p_parm->ptype >= MAX_RAND) 89 return -EINVAL; 90 } 91 #endif 92 93 if (!tcf_idr_check(tn, parm->index, a, bind)) { 94 ret = tcf_idr_create(tn, parm->index, est, a, 95 &act_gact_ops, bind, true); 96 if (ret) 97 return ret; 98 ret = ACT_P_CREATED; 99 } else { 100 if (bind)/* dont override defaults */ 101 return 0; 102 tcf_idr_release(*a, bind); 103 if (!ovr) 104 return -EEXIST; 105 } 106 107 gact = to_gact(*a); 108 109 ASSERT_RTNL(); 110 gact->tcf_action = parm->action; 111 #ifdef CONFIG_GACT_PROB 112 if (p_parm) { 113 gact->tcfg_paction = p_parm->paction; 114 gact->tcfg_pval = max_t(u16, 1, p_parm->pval); 115 /* Make sure tcfg_pval is written before tcfg_ptype 116 * coupled with smp_rmb() in gact_net_rand() & gact_determ() 117 */ 118 smp_wmb(); 119 gact->tcfg_ptype = p_parm->ptype; 120 } 121 #endif 122 if (ret == ACT_P_CREATED) 123 tcf_idr_insert(tn, *a); 124 return ret; 125 } 126 127 static int tcf_gact(struct sk_buff *skb, const struct tc_action *a, 128 struct tcf_result *res) 129 { 130 struct tcf_gact *gact = to_gact(a); 131 int action = READ_ONCE(gact->tcf_action); 132 133 #ifdef CONFIG_GACT_PROB 134 { 135 u32 ptype = READ_ONCE(gact->tcfg_ptype); 136 137 if (ptype) 138 action = gact_rand[ptype](gact); 139 } 140 #endif 141 bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), skb); 142 if (action == TC_ACT_SHOT) 143 qstats_drop_inc(this_cpu_ptr(gact->common.cpu_qstats)); 144 145 tcf_lastuse_update(&gact->tcf_tm); 146 147 return action; 148 } 149 150 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u32 packets, 151 u64 lastuse) 152 { 153 struct tcf_gact *gact = to_gact(a); 154 int action = READ_ONCE(gact->tcf_action); 155 struct tcf_t *tm = &gact->tcf_tm; 156 157 _bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), bytes, 158 packets); 159 if (action == TC_ACT_SHOT) 160 this_cpu_ptr(gact->common.cpu_qstats)->drops += packets; 161 162 tm->lastuse = max_t(u64, tm->lastuse, lastuse); 163 } 164 165 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, 166 int bind, int ref) 167 { 168 unsigned char *b = skb_tail_pointer(skb); 169 struct tcf_gact *gact = to_gact(a); 170 struct tc_gact opt = { 171 .index = gact->tcf_index, 172 .refcnt = gact->tcf_refcnt - ref, 173 .bindcnt = gact->tcf_bindcnt - bind, 174 .action = gact->tcf_action, 175 }; 176 struct tcf_t t; 177 178 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt)) 179 goto nla_put_failure; 180 #ifdef CONFIG_GACT_PROB 181 if (gact->tcfg_ptype) { 182 struct tc_gact_p p_opt = { 183 .paction = gact->tcfg_paction, 184 .pval = gact->tcfg_pval, 185 .ptype = gact->tcfg_ptype, 186 }; 187 188 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt)) 189 goto nla_put_failure; 190 } 191 #endif 192 tcf_tm_dump(&t, &gact->tcf_tm); 193 if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD)) 194 goto nla_put_failure; 195 return skb->len; 196 197 nla_put_failure: 198 nlmsg_trim(skb, b); 199 return -1; 200 } 201 202 static int tcf_gact_walker(struct net *net, struct sk_buff *skb, 203 struct netlink_callback *cb, int type, 204 const struct tc_action_ops *ops) 205 { 206 struct tc_action_net *tn = net_generic(net, gact_net_id); 207 208 return tcf_generic_walker(tn, skb, cb, type, ops); 209 } 210 211 static int tcf_gact_search(struct net *net, struct tc_action **a, u32 index) 212 { 213 struct tc_action_net *tn = net_generic(net, gact_net_id); 214 215 return tcf_idr_search(tn, a, index); 216 } 217 218 static struct tc_action_ops act_gact_ops = { 219 .kind = "gact", 220 .type = TCA_ACT_GACT, 221 .owner = THIS_MODULE, 222 .act = tcf_gact, 223 .stats_update = tcf_gact_stats_update, 224 .dump = tcf_gact_dump, 225 .init = tcf_gact_init, 226 .walk = tcf_gact_walker, 227 .lookup = tcf_gact_search, 228 .size = sizeof(struct tcf_gact), 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); 236 } 237 238 static void __net_exit gact_exit_net(struct list_head *net_list) 239 { 240 tc_action_net_exit(net_list, gact_net_id); 241 } 242 243 static struct pernet_operations gact_net_ops = { 244 .init = gact_init_net, 245 .exit_batch = gact_exit_net, 246 .id = &gact_net_id, 247 .size = sizeof(struct tc_action_net), 248 }; 249 250 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 251 MODULE_DESCRIPTION("Generic Classifier actions"); 252 MODULE_LICENSE("GPL"); 253 254 static int __init gact_init_module(void) 255 { 256 #ifdef CONFIG_GACT_PROB 257 pr_info("GACT probability on\n"); 258 #else 259 pr_info("GACT probability NOT on\n"); 260 #endif 261 262 return tcf_register_action(&act_gact_ops, &gact_net_ops); 263 } 264 265 static void __exit gact_cleanup_module(void) 266 { 267 tcf_unregister_action(&act_gact_ops, &gact_net_ops); 268 } 269 270 module_init(gact_init_module); 271 module_exit(gact_cleanup_module); 272