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 u32 simp_idx_gen; 29 static struct tcf_hashinfo simp_hash_info; 30 31 #define SIMP_MAX_DATA 32 32 static int tcf_simp(struct sk_buff *skb, const struct tc_action *a, 33 struct tcf_result *res) 34 { 35 struct tcf_defact *d = a->priv; 36 37 spin_lock(&d->tcf_lock); 38 d->tcf_tm.lastuse = jiffies; 39 bstats_update(&d->tcf_bstats, skb); 40 41 /* print policy string followed by _ then packet count 42 * Example if this was the 3rd packet and the string was "hello" 43 * then it would look like "hello_3" (without quotes) 44 */ 45 pr_info("simple: %s_%d\n", 46 (char *)d->tcfd_defdata, d->tcf_bstats.packets); 47 spin_unlock(&d->tcf_lock); 48 return d->tcf_action; 49 } 50 51 static int tcf_simp_release(struct tcf_defact *d, int bind) 52 { 53 int ret = 0; 54 if (d) { 55 if (bind) 56 d->tcf_bindcnt--; 57 d->tcf_refcnt--; 58 if (d->tcf_bindcnt <= 0 && d->tcf_refcnt <= 0) { 59 kfree(d->tcfd_defdata); 60 tcf_hash_destroy(&d->common, &simp_hash_info); 61 ret = 1; 62 } 63 } 64 return ret; 65 } 66 67 static int alloc_defdata(struct tcf_defact *d, char *defdata) 68 { 69 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL); 70 if (unlikely(!d->tcfd_defdata)) 71 return -ENOMEM; 72 strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 73 return 0; 74 } 75 76 static void reset_policy(struct tcf_defact *d, char *defdata, 77 struct tc_defact *p) 78 { 79 spin_lock_bh(&d->tcf_lock); 80 d->tcf_action = p->action; 81 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); 82 strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 83 spin_unlock_bh(&d->tcf_lock); 84 } 85 86 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { 87 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, 88 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA }, 89 }; 90 91 static int tcf_simp_init(struct net *net, struct nlattr *nla, 92 struct nlattr *est, struct tc_action *a, 93 int ovr, int bind) 94 { 95 struct nlattr *tb[TCA_DEF_MAX + 1]; 96 struct tc_defact *parm; 97 struct tcf_defact *d; 98 struct tcf_common *pc; 99 char *defdata; 100 int ret = 0, err; 101 102 if (nla == NULL) 103 return -EINVAL; 104 105 err = nla_parse_nested(tb, TCA_DEF_MAX, nla, simple_policy); 106 if (err < 0) 107 return err; 108 109 if (tb[TCA_DEF_PARMS] == NULL) 110 return -EINVAL; 111 112 if (tb[TCA_DEF_DATA] == NULL) 113 return -EINVAL; 114 115 parm = nla_data(tb[TCA_DEF_PARMS]); 116 defdata = nla_data(tb[TCA_DEF_DATA]); 117 118 pc = tcf_hash_check(parm->index, a, bind, &simp_hash_info); 119 if (!pc) { 120 pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind, 121 &simp_idx_gen, &simp_hash_info); 122 if (IS_ERR(pc)) 123 return PTR_ERR(pc); 124 125 d = to_defact(pc); 126 ret = alloc_defdata(d, defdata); 127 if (ret < 0) { 128 if (est) 129 gen_kill_estimator(&pc->tcfc_bstats, 130 &pc->tcfc_rate_est); 131 kfree_rcu(pc, tcfc_rcu); 132 return ret; 133 } 134 d->tcf_action = parm->action; 135 ret = ACT_P_CREATED; 136 } else { 137 d = to_defact(pc); 138 if (!ovr) { 139 tcf_simp_release(d, bind); 140 return -EEXIST; 141 } 142 reset_policy(d, defdata, parm); 143 } 144 145 if (ret == ACT_P_CREATED) 146 tcf_hash_insert(pc, &simp_hash_info); 147 return ret; 148 } 149 150 static int tcf_simp_cleanup(struct tc_action *a, int bind) 151 { 152 struct tcf_defact *d = a->priv; 153 154 if (d) 155 return tcf_simp_release(d, bind); 156 return 0; 157 } 158 159 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 160 int bind, int ref) 161 { 162 unsigned char *b = skb_tail_pointer(skb); 163 struct tcf_defact *d = a->priv; 164 struct tc_defact opt = { 165 .index = d->tcf_index, 166 .refcnt = d->tcf_refcnt - ref, 167 .bindcnt = d->tcf_bindcnt - bind, 168 .action = d->tcf_action, 169 }; 170 struct tcf_t t; 171 172 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) || 173 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata)) 174 goto nla_put_failure; 175 t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install); 176 t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse); 177 t.expires = jiffies_to_clock_t(d->tcf_tm.expires); 178 if (nla_put(skb, TCA_DEF_TM, sizeof(t), &t)) 179 goto nla_put_failure; 180 return skb->len; 181 182 nla_put_failure: 183 nlmsg_trim(skb, b); 184 return -1; 185 } 186 187 static struct tc_action_ops act_simp_ops = { 188 .kind = "simple", 189 .hinfo = &simp_hash_info, 190 .type = TCA_ACT_SIMP, 191 .capab = TCA_CAP_NONE, 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