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/netdevice.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 static int tcf_simp(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res) 39 { 40 struct tcf_defact *d = a->priv; 41 42 spin_lock(&d->tcf_lock); 43 d->tcf_tm.lastuse = jiffies; 44 d->tcf_bstats.bytes += skb->len; 45 d->tcf_bstats.packets++; 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 printk("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, u32 datalen, void *defdata) 74 { 75 d->tcfd_defdata = kmemdup(defdata, datalen, GFP_KERNEL); 76 if (unlikely(!d->tcfd_defdata)) 77 return -ENOMEM; 78 d->tcfd_datalen = datalen; 79 return 0; 80 } 81 82 static int realloc_defdata(struct tcf_defact *d, u32 datalen, void *defdata) 83 { 84 kfree(d->tcfd_defdata); 85 return alloc_defdata(d, datalen, defdata); 86 } 87 88 static int tcf_simp_init(struct rtattr *rta, struct rtattr *est, 89 struct tc_action *a, int ovr, int bind) 90 { 91 struct rtattr *tb[TCA_DEF_MAX]; 92 struct tc_defact *parm; 93 struct tcf_defact *d; 94 struct tcf_common *pc; 95 void *defdata; 96 u32 datalen = 0; 97 int ret = 0; 98 99 if (rta == NULL || rtattr_parse_nested(tb, TCA_DEF_MAX, rta) < 0) 100 return -EINVAL; 101 102 if (tb[TCA_DEF_PARMS - 1] == NULL || 103 RTA_PAYLOAD(tb[TCA_DEF_PARMS - 1]) < sizeof(*parm)) 104 return -EINVAL; 105 106 parm = RTA_DATA(tb[TCA_DEF_PARMS - 1]); 107 defdata = RTA_DATA(tb[TCA_DEF_DATA - 1]); 108 if (defdata == NULL) 109 return -EINVAL; 110 111 datalen = RTA_PAYLOAD(tb[TCA_DEF_DATA - 1]); 112 if (datalen <= 0) 113 return -EINVAL; 114 115 pc = tcf_hash_check(parm->index, a, bind, &simp_hash_info); 116 if (!pc) { 117 pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind, 118 &simp_idx_gen, &simp_hash_info); 119 if (unlikely(!pc)) 120 return -ENOMEM; 121 122 d = to_defact(pc); 123 ret = alloc_defdata(d, datalen, defdata); 124 if (ret < 0) { 125 kfree(pc); 126 return ret; 127 } 128 ret = ACT_P_CREATED; 129 } else { 130 d = to_defact(pc); 131 if (!ovr) { 132 tcf_simp_release(d, bind); 133 return -EEXIST; 134 } 135 realloc_defdata(d, datalen, defdata); 136 } 137 138 spin_lock_bh(&d->tcf_lock); 139 d->tcf_action = parm->action; 140 spin_unlock_bh(&d->tcf_lock); 141 142 if (ret == ACT_P_CREATED) 143 tcf_hash_insert(pc, &simp_hash_info); 144 return ret; 145 } 146 147 static inline int tcf_simp_cleanup(struct tc_action *a, int bind) 148 { 149 struct tcf_defact *d = a->priv; 150 151 if (d) 152 return tcf_simp_release(d, bind); 153 return 0; 154 } 155 156 static inline int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 157 int bind, int ref) 158 { 159 unsigned char *b = skb_tail_pointer(skb); 160 struct tcf_defact *d = a->priv; 161 struct tc_defact opt; 162 struct tcf_t t; 163 164 opt.index = d->tcf_index; 165 opt.refcnt = d->tcf_refcnt - ref; 166 opt.bindcnt = d->tcf_bindcnt - bind; 167 opt.action = d->tcf_action; 168 RTA_PUT(skb, TCA_DEF_PARMS, sizeof(opt), &opt); 169 RTA_PUT(skb, TCA_DEF_DATA, d->tcfd_datalen, d->tcfd_defdata); 170 t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install); 171 t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse); 172 t.expires = jiffies_to_clock_t(d->tcf_tm.expires); 173 RTA_PUT(skb, TCA_DEF_TM, sizeof(t), &t); 174 return skb->len; 175 176 rtattr_failure: 177 nlmsg_trim(skb, b); 178 return -1; 179 } 180 181 static struct tc_action_ops act_simp_ops = { 182 .kind = "simple", 183 .hinfo = &simp_hash_info, 184 .type = TCA_ACT_SIMP, 185 .capab = TCA_CAP_NONE, 186 .owner = THIS_MODULE, 187 .act = tcf_simp, 188 .dump = tcf_simp_dump, 189 .cleanup = tcf_simp_cleanup, 190 .init = tcf_simp_init, 191 .walk = tcf_generic_walker, 192 }; 193 194 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 195 MODULE_DESCRIPTION("Simple example action"); 196 MODULE_LICENSE("GPL"); 197 198 static int __init simp_init_module(void) 199 { 200 int ret = tcf_register_action(&act_simp_ops); 201 if (!ret) 202 printk("Simple TC action Loaded\n"); 203 return ret; 204 } 205 206 static void __exit simp_cleanup_module(void) 207 { 208 tcf_unregister_action(&act_simp_ops); 209 } 210 211 module_init(simp_init_module); 212 module_exit(simp_cleanup_module); 213