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