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 28static struct tcf_common *tcf_simp_ht[SIMP_TAB_MASK + 1]; 29static u32 simp_idx_gen; 30static DEFINE_RWLOCK(simp_lock); 31 32static 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 39static int tcf_simp(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res) 40{ 41 struct tcf_defact *d = a->priv; 42 43 spin_lock(&d->tcf_lock); 44 d->tcf_tm.lastuse = jiffies; 45 d->tcf_bstats.bytes += qdisc_pkt_len(skb); 46 d->tcf_bstats.packets++; 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 58static 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 74static 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 83static 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 93static 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 98static int tcf_simp_init(struct nlattr *nla, struct nlattr *est, 99 struct tc_action *a, int ovr, int bind) 100{ 101 struct nlattr *tb[TCA_DEF_MAX + 1]; 102 struct tc_defact *parm; 103 struct tcf_defact *d; 104 struct tcf_common *pc; 105 char *defdata; 106 int ret = 0, err; 107 108 if (nla == NULL) 109 return -EINVAL; 110 111 err = nla_parse_nested(tb, TCA_DEF_MAX, nla, simple_policy); 112 if (err < 0) 113 return err; 114 115 if (tb[TCA_DEF_PARMS] == NULL) 116 return -EINVAL; 117 118 if (tb[TCA_DEF_DATA] == NULL) 119 return -EINVAL; 120 121 parm = nla_data(tb[TCA_DEF_PARMS]); 122 defdata = nla_data(tb[TCA_DEF_DATA]); 123 124 pc = tcf_hash_check(parm->index, a, bind, &simp_hash_info); 125 if (!pc) { 126 pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind, 127 &simp_idx_gen, &simp_hash_info); 128 if (IS_ERR(pc)) 129 return PTR_ERR(pc); 130 131 d = to_defact(pc); 132 ret = alloc_defdata(d, defdata); 133 if (ret < 0) { 134 kfree(pc); 135 return ret; 136 } 137 d->tcf_action = parm->action; 138 ret = ACT_P_CREATED; 139 } else { 140 d = to_defact(pc); 141 if (!ovr) { 142 tcf_simp_release(d, bind); 143 return -EEXIST; 144 } 145 reset_policy(d, defdata, parm); 146 } 147 148 if (ret == ACT_P_CREATED) 149 tcf_hash_insert(pc, &simp_hash_info); 150 return ret; 151} 152 153static inline int tcf_simp_cleanup(struct tc_action *a, int bind) 154{ 155 struct tcf_defact *d = a->priv; 156 157 if (d) 158 return tcf_simp_release(d, bind); 159 return 0; 160} 161 162static inline int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 163 int bind, int ref) 164{ 165 unsigned char *b = skb_tail_pointer(skb); 166 struct tcf_defact *d = a->priv; 167 struct tc_defact opt = { 168 .index = d->tcf_index, 169 .refcnt = d->tcf_refcnt - ref, 170 .bindcnt = d->tcf_bindcnt - bind, 171 .action = d->tcf_action, 172 }; 173 struct tcf_t t; 174 175 NLA_PUT(skb, TCA_DEF_PARMS, sizeof(opt), &opt); 176 NLA_PUT_STRING(skb, TCA_DEF_DATA, d->tcfd_defdata); 177 t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install); 178 t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse); 179 t.expires = jiffies_to_clock_t(d->tcf_tm.expires); 180 NLA_PUT(skb, TCA_DEF_TM, sizeof(t), &t); 181 return skb->len; 182 183nla_put_failure: 184 nlmsg_trim(skb, b); 185 return -1; 186} 187 188static struct tc_action_ops act_simp_ops = { 189 .kind = "simple", 190 .hinfo = &simp_hash_info, 191 .type = TCA_ACT_SIMP, 192 .capab = TCA_CAP_NONE, 193 .owner = THIS_MODULE, 194 .act = tcf_simp, 195 .dump = tcf_simp_dump, 196 .cleanup = tcf_simp_cleanup, 197 .init = tcf_simp_init, 198 .walk = tcf_generic_walker, 199}; 200 201MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 202MODULE_DESCRIPTION("Simple example action"); 203MODULE_LICENSE("GPL"); 204 205static int __init simp_init_module(void) 206{ 207 int ret = tcf_register_action(&act_simp_ops); 208 if (!ret) 209 pr_info("Simple TC action Loaded\n"); 210 return ret; 211} 212 213static void __exit simp_cleanup_module(void) 214{ 215 tcf_unregister_action(&act_simp_ops); 216} 217 218module_init(simp_init_module); 219module_exit(simp_cleanup_module); 220