1 /* 2 * net/sched/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 static struct tcf_common *tcf_gact_ht[GACT_TAB_MASK + 1]; 28 static u32 gact_idx_gen; 29 static DEFINE_RWLOCK(gact_lock); 30 31 static struct tcf_hashinfo gact_hash_info = { 32 .htab = tcf_gact_ht, 33 .hmask = GACT_TAB_MASK, 34 .lock = &gact_lock, 35 }; 36 37 #ifdef CONFIG_GACT_PROB 38 static int gact_net_rand(struct tcf_gact *gact) 39 { 40 if (!gact->tcfg_pval || net_random() % gact->tcfg_pval) 41 return gact->tcf_action; 42 return gact->tcfg_paction; 43 } 44 45 static int gact_determ(struct tcf_gact *gact) 46 { 47 if (!gact->tcfg_pval || gact->tcf_bstats.packets % gact->tcfg_pval) 48 return gact->tcf_action; 49 return gact->tcfg_paction; 50 } 51 52 typedef int (*g_rand)(struct tcf_gact *gact); 53 static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ }; 54 #endif /* CONFIG_GACT_PROB */ 55 56 static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = { 57 [TCA_GACT_PARMS] = { .len = sizeof(struct tc_gact) }, 58 [TCA_GACT_PROB] = { .len = sizeof(struct tc_gact_p) }, 59 }; 60 61 static int tcf_gact_init(struct net *net, struct nlattr *nla, 62 struct nlattr *est, struct tc_action *a, 63 int ovr, int bind) 64 { 65 struct nlattr *tb[TCA_GACT_MAX + 1]; 66 struct tc_gact *parm; 67 struct tcf_gact *gact; 68 struct tcf_common *pc; 69 int ret = 0; 70 int err; 71 #ifdef CONFIG_GACT_PROB 72 struct tc_gact_p *p_parm = NULL; 73 #endif 74 75 if (nla == NULL) 76 return -EINVAL; 77 78 err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy); 79 if (err < 0) 80 return err; 81 82 if (tb[TCA_GACT_PARMS] == NULL) 83 return -EINVAL; 84 parm = nla_data(tb[TCA_GACT_PARMS]); 85 86 #ifndef CONFIG_GACT_PROB 87 if (tb[TCA_GACT_PROB] != NULL) 88 return -EOPNOTSUPP; 89 #else 90 if (tb[TCA_GACT_PROB]) { 91 p_parm = nla_data(tb[TCA_GACT_PROB]); 92 if (p_parm->ptype >= MAX_RAND) 93 return -EINVAL; 94 } 95 #endif 96 97 pc = tcf_hash_check(parm->index, a, bind, &gact_hash_info); 98 if (!pc) { 99 pc = tcf_hash_create(parm->index, est, a, sizeof(*gact), 100 bind, &gact_idx_gen, &gact_hash_info); 101 if (IS_ERR(pc)) 102 return PTR_ERR(pc); 103 ret = ACT_P_CREATED; 104 } else { 105 if (!ovr) { 106 tcf_hash_release(pc, bind, &gact_hash_info); 107 return -EEXIST; 108 } 109 } 110 111 gact = to_gact(pc); 112 113 spin_lock_bh(&gact->tcf_lock); 114 gact->tcf_action = parm->action; 115 #ifdef CONFIG_GACT_PROB 116 if (p_parm) { 117 gact->tcfg_paction = p_parm->paction; 118 gact->tcfg_pval = p_parm->pval; 119 gact->tcfg_ptype = p_parm->ptype; 120 } 121 #endif 122 spin_unlock_bh(&gact->tcf_lock); 123 if (ret == ACT_P_CREATED) 124 tcf_hash_insert(pc, &gact_hash_info); 125 return ret; 126 } 127 128 static int tcf_gact_cleanup(struct tc_action *a, int bind) 129 { 130 struct tcf_gact *gact = a->priv; 131 132 if (gact) 133 return tcf_hash_release(&gact->common, bind, &gact_hash_info); 134 return 0; 135 } 136 137 static int tcf_gact(struct sk_buff *skb, const struct tc_action *a, 138 struct tcf_result *res) 139 { 140 struct tcf_gact *gact = a->priv; 141 int action = TC_ACT_SHOT; 142 143 spin_lock(&gact->tcf_lock); 144 #ifdef CONFIG_GACT_PROB 145 if (gact->tcfg_ptype) 146 action = gact_rand[gact->tcfg_ptype](gact); 147 else 148 action = gact->tcf_action; 149 #else 150 action = gact->tcf_action; 151 #endif 152 gact->tcf_bstats.bytes += qdisc_pkt_len(skb); 153 gact->tcf_bstats.packets++; 154 if (action == TC_ACT_SHOT) 155 gact->tcf_qstats.drops++; 156 gact->tcf_tm.lastuse = jiffies; 157 spin_unlock(&gact->tcf_lock); 158 159 return action; 160 } 161 162 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 163 { 164 unsigned char *b = skb_tail_pointer(skb); 165 struct tcf_gact *gact = a->priv; 166 struct tc_gact opt = { 167 .index = gact->tcf_index, 168 .refcnt = gact->tcf_refcnt - ref, 169 .bindcnt = gact->tcf_bindcnt - bind, 170 .action = gact->tcf_action, 171 }; 172 struct tcf_t t; 173 174 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt)) 175 goto nla_put_failure; 176 #ifdef CONFIG_GACT_PROB 177 if (gact->tcfg_ptype) { 178 struct tc_gact_p p_opt = { 179 .paction = gact->tcfg_paction, 180 .pval = gact->tcfg_pval, 181 .ptype = gact->tcfg_ptype, 182 }; 183 184 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt)) 185 goto nla_put_failure; 186 } 187 #endif 188 t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install); 189 t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse); 190 t.expires = jiffies_to_clock_t(gact->tcf_tm.expires); 191 if (nla_put(skb, TCA_GACT_TM, sizeof(t), &t)) 192 goto nla_put_failure; 193 return skb->len; 194 195 nla_put_failure: 196 nlmsg_trim(skb, b); 197 return -1; 198 } 199 200 static struct tc_action_ops act_gact_ops = { 201 .kind = "gact", 202 .hinfo = &gact_hash_info, 203 .type = TCA_ACT_GACT, 204 .capab = TCA_CAP_NONE, 205 .owner = THIS_MODULE, 206 .act = tcf_gact, 207 .dump = tcf_gact_dump, 208 .cleanup = tcf_gact_cleanup, 209 .init = tcf_gact_init, 210 }; 211 212 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 213 MODULE_DESCRIPTION("Generic Classifier actions"); 214 MODULE_LICENSE("GPL"); 215 216 static int __init gact_init_module(void) 217 { 218 #ifdef CONFIG_GACT_PROB 219 pr_info("GACT probability on\n"); 220 #else 221 pr_info("GACT probability NOT on\n"); 222 #endif 223 return tcf_register_action(&act_gact_ops); 224 } 225 226 static void __exit gact_cleanup_module(void) 227 { 228 tcf_unregister_action(&act_gact_ops); 229 } 230 231 module_init(gact_init_module); 232 module_exit(gact_cleanup_module); 233