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) 10 * 11 */ 12 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/kernel.h> 16 #include <linux/skbuff.h> 17 #include <linux/rtnetlink.h> 18 #include <net/netlink.h> 19 #include <net/pkt_sched.h> 20 21 #define TCA_ACT_SIMP 22 22 23 #include <linux/tc_act/tc_defact.h> 24 #include <net/tc_act/tc_defact.h> 25 26 #define SIMP_TAB_MASK 7 27 static struct tcf_common *tcf_simp_ht[SIMP_TAB_MASK + 1]; 28 static u32 simp_idx_gen; 29 static DEFINE_RWLOCK(simp_lock); 30 31 static struct tcf_hashinfo simp_hash_info = { 32 .htab = tcf_simp_ht, 33 .hmask = SIMP_TAB_MASK, 34 .lock = &simp_lock, 35 }; 36 37 static int tcf_simp(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res) 38 { 39 struct tcf_defact *d = a->priv; 40 41 spin_lock(&d->tcf_lock); 42 d->tcf_tm.lastuse = jiffies; 43 d->tcf_bstats.bytes += skb->len; 44 d->tcf_bstats.packets++; 45 46 /* print policy string followed by _ then packet count 47 * Example if this was the 3rd packet and the string was "hello" 48 * then it would look like "hello_3" (without quotes) 49 **/ 50 printk("simple: %s_%d\n", 51 (char *)d->tcfd_defdata, d->tcf_bstats.packets); 52 spin_unlock(&d->tcf_lock); 53 return d->tcf_action; 54 } 55 56 static int tcf_simp_release(struct tcf_defact *d, int bind) 57 { 58 int ret = 0; 59 if (d) { 60 if (bind) 61 d->tcf_bindcnt--; 62 d->tcf_refcnt--; 63 if (d->tcf_bindcnt <= 0 && d->tcf_refcnt <= 0) { 64 kfree(d->tcfd_defdata); 65 tcf_hash_destroy(&d->common, &simp_hash_info); 66 ret = 1; 67 } 68 } 69 return ret; 70 } 71 72 static int alloc_defdata(struct tcf_defact *d, u32 datalen, void *defdata) 73 { 74 d->tcfd_defdata = kmemdup(defdata, datalen, GFP_KERNEL); 75 if (unlikely(!d->tcfd_defdata)) 76 return -ENOMEM; 77 d->tcfd_datalen = datalen; 78 return 0; 79 } 80 81 static int realloc_defdata(struct tcf_defact *d, u32 datalen, void *defdata) 82 { 83 kfree(d->tcfd_defdata); 84 return alloc_defdata(d, datalen, defdata); 85 } 86 87 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { 88 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, 89 }; 90 91 static int tcf_simp_init(struct nlattr *nla, struct nlattr *est, 92 struct tc_action *a, 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 void *defdata; 99 u32 datalen = 0; 100 int ret = 0, err; 101 102 if (nla == NULL) 103 return -EINVAL; 104 105 err = nla_parse_nested(tb, TCA_DEF_MAX, nla, NULL); 106 if (err < 0) 107 return err; 108 109 if (tb[TCA_DEF_PARMS] == NULL) 110 return -EINVAL; 111 112 parm = nla_data(tb[TCA_DEF_PARMS]); 113 defdata = nla_data(tb[TCA_DEF_DATA]); 114 if (defdata == NULL) 115 return -EINVAL; 116 117 datalen = nla_len(tb[TCA_DEF_DATA]); 118 if (datalen <= 0) 119 return -EINVAL; 120 121 pc = tcf_hash_check(parm->index, a, bind, &simp_hash_info); 122 if (!pc) { 123 pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind, 124 &simp_idx_gen, &simp_hash_info); 125 if (unlikely(!pc)) 126 return -ENOMEM; 127 128 d = to_defact(pc); 129 ret = alloc_defdata(d, datalen, defdata); 130 if (ret < 0) { 131 kfree(pc); 132 return ret; 133 } 134 ret = ACT_P_CREATED; 135 } else { 136 d = to_defact(pc); 137 if (!ovr) { 138 tcf_simp_release(d, bind); 139 return -EEXIST; 140 } 141 realloc_defdata(d, datalen, defdata); 142 } 143 144 spin_lock_bh(&d->tcf_lock); 145 d->tcf_action = parm->action; 146 spin_unlock_bh(&d->tcf_lock); 147 148 if (ret == ACT_P_CREATED) 149 tcf_hash_insert(pc, &simp_hash_info); 150 return ret; 151 } 152 153 static 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 } 161 162 static 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 struct tcf_t t; 169 170 opt.index = d->tcf_index; 171 opt.refcnt = d->tcf_refcnt - ref; 172 opt.bindcnt = d->tcf_bindcnt - bind; 173 opt.action = d->tcf_action; 174 NLA_PUT(skb, TCA_DEF_PARMS, sizeof(opt), &opt); 175 NLA_PUT(skb, TCA_DEF_DATA, d->tcfd_datalen, d->tcfd_defdata); 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 NLA_PUT(skb, TCA_DEF_TM, sizeof(t), &t); 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 .walk = tcf_generic_walker, 198 }; 199 200 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 201 MODULE_DESCRIPTION("Simple example action"); 202 MODULE_LICENSE("GPL"); 203 204 static int __init simp_init_module(void) 205 { 206 int ret = tcf_register_action(&act_simp_ops); 207 if (!ret) 208 printk("Simple TC action Loaded\n"); 209 return ret; 210 } 211 212 static void __exit simp_cleanup_module(void) 213 { 214 tcf_unregister_action(&act_simp_ops); 215 } 216 217 module_init(simp_init_module); 218 module_exit(simp_cleanup_module); 219