1 /* 2 * net/sched/act_simple.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 static unsigned int simp_net_id; 30 static struct tc_action_ops act_simp_ops; 31 32 #define SIMP_MAX_DATA 32 33 static int tcf_simp(struct sk_buff *skb, const struct tc_action *a, 34 struct tcf_result *res) 35 { 36 struct tcf_defact *d = to_defact(a); 37 38 spin_lock(&d->tcf_lock); 39 tcf_lastuse_update(&d->tcf_tm); 40 bstats_update(&d->tcf_bstats, skb); 41 42 /* print policy string followed by _ then packet count 43 * Example if this was the 3rd packet and the string was "hello" 44 * then it would look like "hello_3" (without quotes) 45 */ 46 pr_info("simple: %s_%d\n", 47 (char *)d->tcfd_defdata, d->tcf_bstats.packets); 48 spin_unlock(&d->tcf_lock); 49 return d->tcf_action; 50 } 51 52 static void tcf_simp_release(struct tc_action *a, int bind) 53 { 54 struct tcf_defact *d = to_defact(a); 55 kfree(d->tcfd_defdata); 56 } 57 58 static int alloc_defdata(struct tcf_defact *d, char *defdata) 59 { 60 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL); 61 if (unlikely(!d->tcfd_defdata)) 62 return -ENOMEM; 63 strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 64 return 0; 65 } 66 67 static void reset_policy(struct tcf_defact *d, char *defdata, 68 struct tc_defact *p) 69 { 70 spin_lock_bh(&d->tcf_lock); 71 d->tcf_action = p->action; 72 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); 73 strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 74 spin_unlock_bh(&d->tcf_lock); 75 } 76 77 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { 78 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, 79 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA }, 80 }; 81 82 static int tcf_simp_init(struct net *net, struct nlattr *nla, 83 struct nlattr *est, struct tc_action **a, 84 int ovr, int bind) 85 { 86 struct tc_action_net *tn = net_generic(net, simp_net_id); 87 struct nlattr *tb[TCA_DEF_MAX + 1]; 88 struct tc_defact *parm; 89 struct tcf_defact *d; 90 bool exists = false; 91 int ret = 0, err; 92 char *defdata; 93 94 if (nla == NULL) 95 return -EINVAL; 96 97 err = nla_parse_nested(tb, TCA_DEF_MAX, nla, simple_policy, NULL); 98 if (err < 0) 99 return err; 100 101 if (tb[TCA_DEF_PARMS] == NULL) 102 return -EINVAL; 103 104 parm = nla_data(tb[TCA_DEF_PARMS]); 105 exists = tcf_hash_check(tn, parm->index, a, bind); 106 if (exists && bind) 107 return 0; 108 109 if (tb[TCA_DEF_DATA] == NULL) { 110 if (exists) 111 tcf_hash_release(*a, bind); 112 return -EINVAL; 113 } 114 115 defdata = nla_data(tb[TCA_DEF_DATA]); 116 117 if (!exists) { 118 ret = tcf_hash_create(tn, parm->index, est, a, 119 &act_simp_ops, bind, false); 120 if (ret) 121 return ret; 122 123 d = to_defact(*a); 124 ret = alloc_defdata(d, defdata); 125 if (ret < 0) { 126 tcf_hash_cleanup(*a, est); 127 return ret; 128 } 129 d->tcf_action = parm->action; 130 ret = ACT_P_CREATED; 131 } else { 132 d = to_defact(*a); 133 134 tcf_hash_release(*a, bind); 135 if (!ovr) 136 return -EEXIST; 137 138 reset_policy(d, defdata, parm); 139 } 140 141 if (ret == ACT_P_CREATED) 142 tcf_hash_insert(tn, *a); 143 return ret; 144 } 145 146 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 147 int bind, int ref) 148 { 149 unsigned char *b = skb_tail_pointer(skb); 150 struct tcf_defact *d = to_defact(a); 151 struct tc_defact opt = { 152 .index = d->tcf_index, 153 .refcnt = d->tcf_refcnt - ref, 154 .bindcnt = d->tcf_bindcnt - bind, 155 .action = d->tcf_action, 156 }; 157 struct tcf_t t; 158 159 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) || 160 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata)) 161 goto nla_put_failure; 162 163 tcf_tm_dump(&t, &d->tcf_tm); 164 if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD)) 165 goto nla_put_failure; 166 return skb->len; 167 168 nla_put_failure: 169 nlmsg_trim(skb, b); 170 return -1; 171 } 172 173 static int tcf_simp_walker(struct net *net, struct sk_buff *skb, 174 struct netlink_callback *cb, int type, 175 const struct tc_action_ops *ops) 176 { 177 struct tc_action_net *tn = net_generic(net, simp_net_id); 178 179 return tcf_generic_walker(tn, skb, cb, type, ops); 180 } 181 182 static int tcf_simp_search(struct net *net, struct tc_action **a, u32 index) 183 { 184 struct tc_action_net *tn = net_generic(net, simp_net_id); 185 186 return tcf_hash_search(tn, a, index); 187 } 188 189 static struct tc_action_ops act_simp_ops = { 190 .kind = "simple", 191 .type = TCA_ACT_SIMP, 192 .owner = THIS_MODULE, 193 .act = tcf_simp, 194 .dump = tcf_simp_dump, 195 .cleanup = tcf_simp_release, 196 .init = tcf_simp_init, 197 .walk = tcf_simp_walker, 198 .lookup = tcf_simp_search, 199 .size = sizeof(struct tcf_defact), 200 }; 201 202 static __net_init int simp_init_net(struct net *net) 203 { 204 struct tc_action_net *tn = net_generic(net, simp_net_id); 205 206 return tc_action_net_init(tn, &act_simp_ops, SIMP_TAB_MASK); 207 } 208 209 static void __net_exit simp_exit_net(struct net *net) 210 { 211 struct tc_action_net *tn = net_generic(net, simp_net_id); 212 213 tc_action_net_exit(tn); 214 } 215 216 static struct pernet_operations simp_net_ops = { 217 .init = simp_init_net, 218 .exit = simp_exit_net, 219 .id = &simp_net_id, 220 .size = sizeof(struct tc_action_net), 221 }; 222 223 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 224 MODULE_DESCRIPTION("Simple example action"); 225 MODULE_LICENSE("GPL"); 226 227 static int __init simp_init_module(void) 228 { 229 int ret = tcf_register_action(&act_simp_ops, &simp_net_ops); 230 if (!ret) 231 pr_info("Simple TC action Loaded\n"); 232 return ret; 233 } 234 235 static void __exit simp_cleanup_module(void) 236 { 237 tcf_unregister_action(&act_simp_ops, &simp_net_ops); 238 } 239 240 module_init(simp_init_module); 241 module_exit(simp_cleanup_module); 242