1 /* 2 * net/sched/simp.c Simple example of an action 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 * Authors: Jamal Hadi Salim (2005-8) 10 * 11 */ 12 13 #include <linux/module.h> 14 #include <linux/slab.h> 15 #include <linux/init.h> 16 #include <linux/kernel.h> 17 #include <linux/skbuff.h> 18 #include <linux/rtnetlink.h> 19 #include <net/netlink.h> 20 #include <net/pkt_sched.h> 21 22 #define TCA_ACT_SIMP 22 23 24 #include <linux/tc_act/tc_defact.h> 25 #include <net/tc_act/tc_defact.h> 26 27 #define SIMP_TAB_MASK 7 28 static struct tcf_common *tcf_simp_ht[SIMP_TAB_MASK + 1]; 29 static u32 simp_idx_gen; 30 static DEFINE_RWLOCK(simp_lock); 31 32 static struct tcf_hashinfo simp_hash_info = { 33 .htab = tcf_simp_ht, 34 .hmask = SIMP_TAB_MASK, 35 .lock = &simp_lock, 36 }; 37 38 #define SIMP_MAX_DATA 32 39 static int tcf_simp(struct sk_buff *skb, const struct tc_action *a, 40 struct tcf_result *res) 41 { 42 struct tcf_defact *d = a->priv; 43 44 spin_lock(&d->tcf_lock); 45 d->tcf_tm.lastuse = jiffies; 46 bstats_update(&d->tcf_bstats, skb); 47 48 /* print policy string followed by _ then packet count 49 * Example if this was the 3rd packet and the string was "hello" 50 * then it would look like "hello_3" (without quotes) 51 */ 52 pr_info("simple: %s_%d\n", 53 (char *)d->tcfd_defdata, d->tcf_bstats.packets); 54 spin_unlock(&d->tcf_lock); 55 return d->tcf_action; 56 } 57 58 static int tcf_simp_release(struct tcf_defact *d, int bind) 59 { 60 int ret = 0; 61 if (d) { 62 if (bind) 63 d->tcf_bindcnt--; 64 d->tcf_refcnt--; 65 if (d->tcf_bindcnt <= 0 && d->tcf_refcnt <= 0) { 66 kfree(d->tcfd_defdata); 67 tcf_hash_destroy(&d->common, &simp_hash_info); 68 ret = 1; 69 } 70 } 71 return ret; 72 } 73 74 static int alloc_defdata(struct tcf_defact *d, char *defdata) 75 { 76 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL); 77 if (unlikely(!d->tcfd_defdata)) 78 return -ENOMEM; 79 strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 80 return 0; 81 } 82 83 static void reset_policy(struct tcf_defact *d, char *defdata, 84 struct tc_defact *p) 85 { 86 spin_lock_bh(&d->tcf_lock); 87 d->tcf_action = p->action; 88 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); 89 strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 90 spin_unlock_bh(&d->tcf_lock); 91 } 92 93 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { 94 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, 95 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA }, 96 }; 97 98 static int tcf_simp_init(struct net *net, struct nlattr *nla, 99 struct nlattr *est, struct tc_action *a, 100 int ovr, int bind) 101 { 102 struct nlattr *tb[TCA_DEF_MAX + 1]; 103 struct tc_defact *parm; 104 struct tcf_defact *d; 105 struct tcf_common *pc; 106 char *defdata; 107 int ret = 0, err; 108 109 if (nla == NULL) 110 return -EINVAL; 111 112 err = nla_parse_nested(tb, TCA_DEF_MAX, nla, simple_policy); 113 if (err < 0) 114 return err; 115 116 if (tb[TCA_DEF_PARMS] == NULL) 117 return -EINVAL; 118 119 if (tb[TCA_DEF_DATA] == NULL) 120 return -EINVAL; 121 122 parm = nla_data(tb[TCA_DEF_PARMS]); 123 defdata = nla_data(tb[TCA_DEF_DATA]); 124 125 pc = tcf_hash_check(parm->index, a, bind, &simp_hash_info); 126 if (!pc) { 127 pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind, 128 &simp_idx_gen, &simp_hash_info); 129 if (IS_ERR(pc)) 130 return PTR_ERR(pc); 131 132 d = to_defact(pc); 133 ret = alloc_defdata(d, defdata); 134 if (ret < 0) { 135 if (est) 136 gen_kill_estimator(&pc->tcfc_bstats, 137 &pc->tcfc_rate_est); 138 kfree_rcu(pc, tcfc_rcu); 139 return ret; 140 } 141 d->tcf_action = parm->action; 142 ret = ACT_P_CREATED; 143 } else { 144 d = to_defact(pc); 145 146 if (bind) 147 return 0; 148 tcf_simp_release(d, bind); 149 if (!ovr) 150 return -EEXIST; 151 152 reset_policy(d, defdata, parm); 153 } 154 155 if (ret == ACT_P_CREATED) 156 tcf_hash_insert(pc, &simp_hash_info); 157 return ret; 158 } 159 160 static int tcf_simp_cleanup(struct tc_action *a, int bind) 161 { 162 struct tcf_defact *d = a->priv; 163 164 if (d) 165 return tcf_simp_release(d, bind); 166 return 0; 167 } 168 169 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 170 int bind, int ref) 171 { 172 unsigned char *b = skb_tail_pointer(skb); 173 struct tcf_defact *d = a->priv; 174 struct tc_defact opt = { 175 .index = d->tcf_index, 176 .refcnt = d->tcf_refcnt - ref, 177 .bindcnt = d->tcf_bindcnt - bind, 178 .action = d->tcf_action, 179 }; 180 struct tcf_t t; 181 182 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) || 183 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata)) 184 goto nla_put_failure; 185 t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install); 186 t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse); 187 t.expires = jiffies_to_clock_t(d->tcf_tm.expires); 188 if (nla_put(skb, TCA_DEF_TM, sizeof(t), &t)) 189 goto nla_put_failure; 190 return skb->len; 191 192 nla_put_failure: 193 nlmsg_trim(skb, b); 194 return -1; 195 } 196 197 static struct tc_action_ops act_simp_ops = { 198 .kind = "simple", 199 .hinfo = &simp_hash_info, 200 .type = TCA_ACT_SIMP, 201 .capab = TCA_CAP_NONE, 202 .owner = THIS_MODULE, 203 .act = tcf_simp, 204 .dump = tcf_simp_dump, 205 .cleanup = tcf_simp_cleanup, 206 .init = tcf_simp_init, 207 }; 208 209 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 210 MODULE_DESCRIPTION("Simple example action"); 211 MODULE_LICENSE("GPL"); 212 213 static int __init simp_init_module(void) 214 { 215 int ret = tcf_register_action(&act_simp_ops); 216 if (!ret) 217 pr_info("Simple TC action Loaded\n"); 218 return ret; 219 } 220 221 static void __exit simp_cleanup_module(void) 222 { 223 tcf_unregister_action(&act_simp_ops); 224 } 225 226 module_init(simp_init_module); 227 module_exit(simp_cleanup_module); 228