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 if (!ovr) { 146 tcf_simp_release(d, bind); 147 return -EEXIST; 148 } 149 reset_policy(d, defdata, parm); 150 } 151 152 if (ret == ACT_P_CREATED) 153 tcf_hash_insert(pc, &simp_hash_info); 154 return ret; 155 } 156 157 static int tcf_simp_cleanup(struct tc_action *a, int bind) 158 { 159 struct tcf_defact *d = a->priv; 160 161 if (d) 162 return tcf_simp_release(d, bind); 163 return 0; 164 } 165 166 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 167 int bind, int ref) 168 { 169 unsigned char *b = skb_tail_pointer(skb); 170 struct tcf_defact *d = a->priv; 171 struct tc_defact opt = { 172 .index = d->tcf_index, 173 .refcnt = d->tcf_refcnt - ref, 174 .bindcnt = d->tcf_bindcnt - bind, 175 .action = d->tcf_action, 176 }; 177 struct tcf_t t; 178 179 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) || 180 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata)) 181 goto nla_put_failure; 182 t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install); 183 t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse); 184 t.expires = jiffies_to_clock_t(d->tcf_tm.expires); 185 if (nla_put(skb, TCA_DEF_TM, sizeof(t), &t)) 186 goto nla_put_failure; 187 return skb->len; 188 189 nla_put_failure: 190 nlmsg_trim(skb, b); 191 return -1; 192 } 193 194 static struct tc_action_ops act_simp_ops = { 195 .kind = "simple", 196 .hinfo = &simp_hash_info, 197 .type = TCA_ACT_SIMP, 198 .capab = TCA_CAP_NONE, 199 .owner = THIS_MODULE, 200 .act = tcf_simp, 201 .dump = tcf_simp_dump, 202 .cleanup = tcf_simp_cleanup, 203 .init = tcf_simp_init, 204 .walk = tcf_generic_walker, 205 }; 206 207 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 208 MODULE_DESCRIPTION("Simple example action"); 209 MODULE_LICENSE("GPL"); 210 211 static int __init simp_init_module(void) 212 { 213 int ret = tcf_register_action(&act_simp_ops); 214 if (!ret) 215 pr_info("Simple TC action Loaded\n"); 216 return ret; 217 } 218 219 static void __exit simp_cleanup_module(void) 220 { 221 tcf_unregister_action(&act_simp_ops); 222 } 223 224 module_init(simp_init_module); 225 module_exit(simp_cleanup_module); 226