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, 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 bstats_update(&d->tcf_bstats, skb); 46 47 /* print policy string followed by _ then packet count 48 * Example if this was the 3rd packet and the string was "hello" 49 * then it would look like "hello_3" (without quotes) 50 */ 51 pr_info("simple: %s_%d\n", 52 (char *)d->tcfd_defdata, d->tcf_bstats.packets); 53 spin_unlock(&d->tcf_lock); 54 return d->tcf_action; 55 } 56 57 static int tcf_simp_release(struct tcf_defact *d, int bind) 58 { 59 int ret = 0; 60 if (d) { 61 if (bind) 62 d->tcf_bindcnt--; 63 d->tcf_refcnt--; 64 if (d->tcf_bindcnt <= 0 && d->tcf_refcnt <= 0) { 65 kfree(d->tcfd_defdata); 66 tcf_hash_destroy(&d->common, &simp_hash_info); 67 ret = 1; 68 } 69 } 70 return ret; 71 } 72 73 static int alloc_defdata(struct tcf_defact *d, char *defdata) 74 { 75 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL); 76 if (unlikely(!d->tcfd_defdata)) 77 return -ENOMEM; 78 strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 79 return 0; 80 } 81 82 static void reset_policy(struct tcf_defact *d, char *defdata, 83 struct tc_defact *p) 84 { 85 spin_lock_bh(&d->tcf_lock); 86 d->tcf_action = p->action; 87 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); 88 strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 89 spin_unlock_bh(&d->tcf_lock); 90 } 91 92 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { 93 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, 94 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA }, 95 }; 96 97 static int tcf_simp_init(struct nlattr *nla, struct nlattr *est, 98 struct tc_action *a, int ovr, int bind) 99 { 100 struct nlattr *tb[TCA_DEF_MAX + 1]; 101 struct tc_defact *parm; 102 struct tcf_defact *d; 103 struct tcf_common *pc; 104 char *defdata; 105 int ret = 0, err; 106 107 if (nla == NULL) 108 return -EINVAL; 109 110 err = nla_parse_nested(tb, TCA_DEF_MAX, nla, simple_policy); 111 if (err < 0) 112 return err; 113 114 if (tb[TCA_DEF_PARMS] == NULL) 115 return -EINVAL; 116 117 if (tb[TCA_DEF_DATA] == NULL) 118 return -EINVAL; 119 120 parm = nla_data(tb[TCA_DEF_PARMS]); 121 defdata = nla_data(tb[TCA_DEF_DATA]); 122 123 pc = tcf_hash_check(parm->index, a, bind, &simp_hash_info); 124 if (!pc) { 125 pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind, 126 &simp_idx_gen, &simp_hash_info); 127 if (IS_ERR(pc)) 128 return PTR_ERR(pc); 129 130 d = to_defact(pc); 131 ret = alloc_defdata(d, defdata); 132 if (ret < 0) { 133 kfree(pc); 134 return ret; 135 } 136 d->tcf_action = parm->action; 137 ret = ACT_P_CREATED; 138 } else { 139 d = to_defact(pc); 140 if (!ovr) { 141 tcf_simp_release(d, bind); 142 return -EEXIST; 143 } 144 reset_policy(d, defdata, parm); 145 } 146 147 if (ret == ACT_P_CREATED) 148 tcf_hash_insert(pc, &simp_hash_info); 149 return ret; 150 } 151 152 static int tcf_simp_cleanup(struct tc_action *a, int bind) 153 { 154 struct tcf_defact *d = a->priv; 155 156 if (d) 157 return tcf_simp_release(d, bind); 158 return 0; 159 } 160 161 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 162 int bind, int ref) 163 { 164 unsigned char *b = skb_tail_pointer(skb); 165 struct tcf_defact *d = a->priv; 166 struct tc_defact opt = { 167 .index = d->tcf_index, 168 .refcnt = d->tcf_refcnt - ref, 169 .bindcnt = d->tcf_bindcnt - bind, 170 .action = d->tcf_action, 171 }; 172 struct tcf_t t; 173 174 NLA_PUT(skb, TCA_DEF_PARMS, sizeof(opt), &opt); 175 NLA_PUT_STRING(skb, TCA_DEF_DATA, 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 pr_info("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