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 nlattr *nla, struct nlattr *est, 62 struct tc_action *a, int ovr, int bind) 63 { 64 struct nlattr *tb[TCA_GACT_MAX + 1]; 65 struct tc_gact *parm; 66 struct tcf_gact *gact; 67 struct tcf_common *pc; 68 int ret = 0; 69 int err; 70 71 if (nla == NULL) 72 return -EINVAL; 73 74 err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy); 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 #endif 86 87 pc = tcf_hash_check(parm->index, a, bind, &gact_hash_info); 88 if (!pc) { 89 pc = tcf_hash_create(parm->index, est, a, sizeof(*gact), 90 bind, &gact_idx_gen, &gact_hash_info); 91 if (IS_ERR(pc)) 92 return PTR_ERR(pc); 93 ret = ACT_P_CREATED; 94 } else { 95 if (!ovr) { 96 tcf_hash_release(pc, bind, &gact_hash_info); 97 return -EEXIST; 98 } 99 } 100 101 gact = to_gact(pc); 102 103 spin_lock_bh(&gact->tcf_lock); 104 gact->tcf_action = parm->action; 105 #ifdef CONFIG_GACT_PROB 106 if (tb[TCA_GACT_PROB] != NULL) { 107 struct tc_gact_p *p_parm = nla_data(tb[TCA_GACT_PROB]); 108 gact->tcfg_paction = p_parm->paction; 109 gact->tcfg_pval = p_parm->pval; 110 gact->tcfg_ptype = p_parm->ptype; 111 } 112 #endif 113 spin_unlock_bh(&gact->tcf_lock); 114 if (ret == ACT_P_CREATED) 115 tcf_hash_insert(pc, &gact_hash_info); 116 return ret; 117 } 118 119 static int tcf_gact_cleanup(struct tc_action *a, int bind) 120 { 121 struct tcf_gact *gact = a->priv; 122 123 if (gact) 124 return tcf_hash_release(&gact->common, bind, &gact_hash_info); 125 return 0; 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 = TC_ACT_SHOT; 133 134 spin_lock(&gact->tcf_lock); 135 #ifdef CONFIG_GACT_PROB 136 if (gact->tcfg_ptype && gact_rand[gact->tcfg_ptype] != NULL) 137 action = gact_rand[gact->tcfg_ptype](gact); 138 else 139 action = gact->tcf_action; 140 #else 141 action = gact->tcf_action; 142 #endif 143 gact->tcf_bstats.bytes += qdisc_pkt_len(skb); 144 gact->tcf_bstats.packets++; 145 if (action == TC_ACT_SHOT) 146 gact->tcf_qstats.drops++; 147 gact->tcf_tm.lastuse = jiffies; 148 spin_unlock(&gact->tcf_lock); 149 150 return action; 151 } 152 153 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 154 { 155 unsigned char *b = skb_tail_pointer(skb); 156 struct tcf_gact *gact = a->priv; 157 struct tc_gact opt = { 158 .index = gact->tcf_index, 159 .refcnt = gact->tcf_refcnt - ref, 160 .bindcnt = gact->tcf_bindcnt - bind, 161 .action = gact->tcf_action, 162 }; 163 struct tcf_t t; 164 165 NLA_PUT(skb, TCA_GACT_PARMS, sizeof(opt), &opt); 166 #ifdef CONFIG_GACT_PROB 167 if (gact->tcfg_ptype) { 168 struct tc_gact_p p_opt = { 169 .paction = gact->tcfg_paction, 170 .pval = gact->tcfg_pval, 171 .ptype = gact->tcfg_ptype, 172 }; 173 174 NLA_PUT(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt); 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 NLA_PUT(skb, TCA_GACT_TM, sizeof(t), &t); 181 return skb->len; 182 183 nla_put_failure: 184 nlmsg_trim(skb, b); 185 return -1; 186 } 187 188 static struct tc_action_ops act_gact_ops = { 189 .kind = "gact", 190 .hinfo = &gact_hash_info, 191 .type = TCA_ACT_GACT, 192 .capab = TCA_CAP_NONE, 193 .owner = THIS_MODULE, 194 .act = tcf_gact, 195 .dump = tcf_gact_dump, 196 .cleanup = tcf_gact_cleanup, 197 .lookup = tcf_hash_search, 198 .init = tcf_gact_init, 199 .walk = tcf_generic_walker 200 }; 201 202 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 203 MODULE_DESCRIPTION("Generic Classifier actions"); 204 MODULE_LICENSE("GPL"); 205 206 static int __init gact_init_module(void) 207 { 208 #ifdef CONFIG_GACT_PROB 209 pr_info("GACT probability on\n"); 210 #else 211 pr_info("GACT probability NOT on\n"); 212 #endif 213 return tcf_register_action(&act_gact_ops); 214 } 215 216 static void __exit gact_cleanup_module(void) 217 { 218 tcf_unregister_action(&act_gact_ops); 219 } 220 221 module_init(gact_init_module); 222 module_exit(gact_cleanup_module); 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