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