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 #ifdef CONFIG_GACT_PROB 71 struct tc_gact_p *p_parm = NULL; 72 #endif 73 74 if (nla == NULL) 75 return -EINVAL; 76 77 err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy); 78 if (err < 0) 79 return err; 80 81 if (tb[TCA_GACT_PARMS] == NULL) 82 return -EINVAL; 83 parm = nla_data(tb[TCA_GACT_PARMS]); 84 85 #ifndef CONFIG_GACT_PROB 86 if (tb[TCA_GACT_PROB] != NULL) 87 return -EOPNOTSUPP; 88 #else 89 if (tb[TCA_GACT_PROB]) { 90 p_parm = nla_data(tb[TCA_GACT_PROB]); 91 if (p_parm->ptype >= MAX_RAND) 92 return -EINVAL; 93 } 94 #endif 95 96 pc = tcf_hash_check(parm->index, a, bind, &gact_hash_info); 97 if (!pc) { 98 pc = tcf_hash_create(parm->index, est, a, sizeof(*gact), 99 bind, &gact_idx_gen, &gact_hash_info); 100 if (IS_ERR(pc)) 101 return PTR_ERR(pc); 102 ret = ACT_P_CREATED; 103 } else { 104 if (!ovr) { 105 tcf_hash_release(pc, bind, &gact_hash_info); 106 return -EEXIST; 107 } 108 } 109 110 gact = to_gact(pc); 111 112 spin_lock_bh(&gact->tcf_lock); 113 gact->tcf_action = parm->action; 114 #ifdef CONFIG_GACT_PROB 115 if (p_parm) { 116 gact->tcfg_paction = p_parm->paction; 117 gact->tcfg_pval = p_parm->pval; 118 gact->tcfg_ptype = p_parm->ptype; 119 } 120 #endif 121 spin_unlock_bh(&gact->tcf_lock); 122 if (ret == ACT_P_CREATED) 123 tcf_hash_insert(pc, &gact_hash_info); 124 return ret; 125 } 126 127 static int tcf_gact_cleanup(struct tc_action *a, int bind) 128 { 129 struct tcf_gact *gact = a->priv; 130 131 if (gact) 132 return tcf_hash_release(&gact->common, bind, &gact_hash_info); 133 return 0; 134 } 135 136 static int tcf_gact(struct sk_buff *skb, const struct tc_action *a, 137 struct tcf_result *res) 138 { 139 struct tcf_gact *gact = a->priv; 140 int action = TC_ACT_SHOT; 141 142 spin_lock(&gact->tcf_lock); 143 #ifdef CONFIG_GACT_PROB 144 if (gact->tcfg_ptype) 145 action = gact_rand[gact->tcfg_ptype](gact); 146 else 147 action = gact->tcf_action; 148 #else 149 action = gact->tcf_action; 150 #endif 151 gact->tcf_bstats.bytes += qdisc_pkt_len(skb); 152 gact->tcf_bstats.packets++; 153 if (action == TC_ACT_SHOT) 154 gact->tcf_qstats.drops++; 155 gact->tcf_tm.lastuse = jiffies; 156 spin_unlock(&gact->tcf_lock); 157 158 return action; 159 } 160 161 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 162 { 163 unsigned char *b = skb_tail_pointer(skb); 164 struct tcf_gact *gact = a->priv; 165 struct tc_gact opt = { 166 .index = gact->tcf_index, 167 .refcnt = gact->tcf_refcnt - ref, 168 .bindcnt = gact->tcf_bindcnt - bind, 169 .action = gact->tcf_action, 170 }; 171 struct tcf_t t; 172 173 if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt)) 174 goto nla_put_failure; 175 #ifdef CONFIG_GACT_PROB 176 if (gact->tcfg_ptype) { 177 struct tc_gact_p p_opt = { 178 .paction = gact->tcfg_paction, 179 .pval = gact->tcfg_pval, 180 .ptype = gact->tcfg_ptype, 181 }; 182 183 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt)) 184 goto nla_put_failure; 185 } 186 #endif 187 t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install); 188 t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse); 189 t.expires = jiffies_to_clock_t(gact->tcf_tm.expires); 190 if (nla_put(skb, TCA_GACT_TM, sizeof(t), &t)) 191 goto nla_put_failure; 192 return skb->len; 193 194 nla_put_failure: 195 nlmsg_trim(skb, b); 196 return -1; 197 } 198 199 static struct tc_action_ops act_gact_ops = { 200 .kind = "gact", 201 .hinfo = &gact_hash_info, 202 .type = TCA_ACT_GACT, 203 .capab = TCA_CAP_NONE, 204 .owner = THIS_MODULE, 205 .act = tcf_gact, 206 .dump = tcf_gact_dump, 207 .cleanup = tcf_gact_cleanup, 208 .lookup = tcf_hash_search, 209 .init = tcf_gact_init, 210 .walk = tcf_generic_walker 211 }; 212 213 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 214 MODULE_DESCRIPTION("Generic Classifier actions"); 215 MODULE_LICENSE("GPL"); 216 217 static int __init gact_init_module(void) 218 { 219 #ifdef CONFIG_GACT_PROB 220 pr_info("GACT probability on\n"); 221 #else 222 pr_info("GACT probability NOT on\n"); 223 #endif 224 return tcf_register_action(&act_gact_ops); 225 } 226 227 static void __exit gact_cleanup_module(void) 228 { 229 tcf_unregister_action(&act_gact_ops); 230 } 231 232 module_init(gact_init_module); 233 module_exit(gact_cleanup_module); 234