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 29 #define SIMP_MAX_DATA 32 30 static int tcf_simp(struct sk_buff *skb, const struct tc_action *a, 31 struct tcf_result *res) 32 { 33 struct tcf_defact *d = a->priv; 34 35 spin_lock(&d->tcf_lock); 36 d->tcf_tm.lastuse = jiffies; 37 bstats_update(&d->tcf_bstats, skb); 38 39 /* print policy string followed by _ then packet count 40 * Example if this was the 3rd packet and the string was "hello" 41 * then it would look like "hello_3" (without quotes) 42 */ 43 pr_info("simple: %s_%d\n", 44 (char *)d->tcfd_defdata, d->tcf_bstats.packets); 45 spin_unlock(&d->tcf_lock); 46 return d->tcf_action; 47 } 48 49 static void tcf_simp_release(struct tc_action *a, int bind) 50 { 51 struct tcf_defact *d = to_defact(a); 52 kfree(d->tcfd_defdata); 53 } 54 55 static int alloc_defdata(struct tcf_defact *d, char *defdata) 56 { 57 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL); 58 if (unlikely(!d->tcfd_defdata)) 59 return -ENOMEM; 60 strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 61 return 0; 62 } 63 64 static void reset_policy(struct tcf_defact *d, char *defdata, 65 struct tc_defact *p) 66 { 67 spin_lock_bh(&d->tcf_lock); 68 d->tcf_action = p->action; 69 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); 70 strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 71 spin_unlock_bh(&d->tcf_lock); 72 } 73 74 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { 75 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, 76 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA }, 77 }; 78 79 static int tcf_simp_init(struct net *net, struct nlattr *nla, 80 struct nlattr *est, struct tc_action *a, 81 int ovr, int bind) 82 { 83 struct nlattr *tb[TCA_DEF_MAX + 1]; 84 struct tc_defact *parm; 85 struct tcf_defact *d; 86 char *defdata; 87 int ret = 0, err; 88 89 if (nla == NULL) 90 return -EINVAL; 91 92 err = nla_parse_nested(tb, TCA_DEF_MAX, nla, simple_policy); 93 if (err < 0) 94 return err; 95 96 if (tb[TCA_DEF_PARMS] == NULL) 97 return -EINVAL; 98 99 if (tb[TCA_DEF_DATA] == NULL) 100 return -EINVAL; 101 102 parm = nla_data(tb[TCA_DEF_PARMS]); 103 defdata = nla_data(tb[TCA_DEF_DATA]); 104 105 if (!tcf_hash_check(parm->index, a, bind)) { 106 ret = tcf_hash_create(parm->index, est, a, sizeof(*d), bind); 107 if (ret) 108 return ret; 109 110 d = to_defact(a); 111 ret = alloc_defdata(d, defdata); 112 if (ret < 0) { 113 tcf_hash_cleanup(a, est); 114 return ret; 115 } 116 d->tcf_action = parm->action; 117 ret = ACT_P_CREATED; 118 } else { 119 d = to_defact(a); 120 121 if (bind) 122 return 0; 123 tcf_hash_release(a, bind); 124 if (!ovr) 125 return -EEXIST; 126 127 reset_policy(d, defdata, parm); 128 } 129 130 if (ret == ACT_P_CREATED) 131 tcf_hash_insert(a); 132 return ret; 133 } 134 135 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 136 int bind, int ref) 137 { 138 unsigned char *b = skb_tail_pointer(skb); 139 struct tcf_defact *d = a->priv; 140 struct tc_defact opt = { 141 .index = d->tcf_index, 142 .refcnt = d->tcf_refcnt - ref, 143 .bindcnt = d->tcf_bindcnt - bind, 144 .action = d->tcf_action, 145 }; 146 struct tcf_t t; 147 148 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) || 149 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata)) 150 goto nla_put_failure; 151 t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install); 152 t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse); 153 t.expires = jiffies_to_clock_t(d->tcf_tm.expires); 154 if (nla_put(skb, TCA_DEF_TM, sizeof(t), &t)) 155 goto nla_put_failure; 156 return skb->len; 157 158 nla_put_failure: 159 nlmsg_trim(skb, b); 160 return -1; 161 } 162 163 static struct tc_action_ops act_simp_ops = { 164 .kind = "simple", 165 .type = TCA_ACT_SIMP, 166 .owner = THIS_MODULE, 167 .act = tcf_simp, 168 .dump = tcf_simp_dump, 169 .cleanup = tcf_simp_release, 170 .init = tcf_simp_init, 171 }; 172 173 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 174 MODULE_DESCRIPTION("Simple example action"); 175 MODULE_LICENSE("GPL"); 176 177 static int __init simp_init_module(void) 178 { 179 int ret; 180 ret = tcf_register_action(&act_simp_ops, SIMP_TAB_MASK); 181 if (!ret) 182 pr_info("Simple TC action Loaded\n"); 183 return ret; 184 } 185 186 static void __exit simp_cleanup_module(void) 187 { 188 tcf_unregister_action(&act_simp_ops); 189 } 190 191 module_init(simp_init_module); 192 module_exit(simp_cleanup_module); 193