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 #include <net/pkt_cls.h> 22 23 #include <linux/tc_act/tc_defact.h> 24 #include <net/tc_act/tc_defact.h> 25 26 static unsigned int simp_net_id; 27 static struct tc_action_ops act_simp_ops; 28 29 #define SIMP_MAX_DATA 32 30 static int tcf_simp_act(struct sk_buff *skb, const struct tc_action *a, 31 struct tcf_result *res) 32 { 33 struct tcf_defact *d = to_defact(a); 34 35 spin_lock(&d->tcf_lock); 36 tcf_lastuse_update(&d->tcf_tm); 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) 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, const struct nlattr *defdata) 56 { 57 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL); 58 if (unlikely(!d->tcfd_defdata)) 59 return -ENOMEM; 60 nla_strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 61 return 0; 62 } 63 64 static int reset_policy(struct tc_action *a, const struct nlattr *defdata, 65 struct tc_defact *p, struct tcf_proto *tp, 66 struct netlink_ext_ack *extack) 67 { 68 struct tcf_chain *goto_ch = NULL; 69 struct tcf_defact *d; 70 int err; 71 72 err = tcf_action_check_ctrlact(p->action, tp, &goto_ch, extack); 73 if (err < 0) 74 return err; 75 d = to_defact(a); 76 spin_lock_bh(&d->tcf_lock); 77 goto_ch = tcf_action_set_ctrlact(a, p->action, goto_ch); 78 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); 79 nla_strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 80 spin_unlock_bh(&d->tcf_lock); 81 if (goto_ch) 82 tcf_chain_put_by_act(goto_ch); 83 return 0; 84 } 85 86 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { 87 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, 88 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA }, 89 }; 90 91 static int tcf_simp_init(struct net *net, struct nlattr *nla, 92 struct nlattr *est, struct tc_action **a, 93 int ovr, int bind, bool rtnl_held, 94 struct tcf_proto *tp, struct netlink_ext_ack *extack) 95 { 96 struct tc_action_net *tn = net_generic(net, simp_net_id); 97 struct nlattr *tb[TCA_DEF_MAX + 1]; 98 struct tcf_chain *goto_ch = NULL; 99 struct tc_defact *parm; 100 struct tcf_defact *d; 101 bool exists = false; 102 int ret = 0, err; 103 104 if (nla == NULL) 105 return -EINVAL; 106 107 err = nla_parse_nested_deprecated(tb, TCA_DEF_MAX, nla, simple_policy, 108 NULL); 109 if (err < 0) 110 return err; 111 112 if (tb[TCA_DEF_PARMS] == NULL) 113 return -EINVAL; 114 115 parm = nla_data(tb[TCA_DEF_PARMS]); 116 err = tcf_idr_check_alloc(tn, &parm->index, a, bind); 117 if (err < 0) 118 return err; 119 exists = err; 120 if (exists && bind) 121 return 0; 122 123 if (tb[TCA_DEF_DATA] == NULL) { 124 if (exists) 125 tcf_idr_release(*a, bind); 126 else 127 tcf_idr_cleanup(tn, parm->index); 128 return -EINVAL; 129 } 130 131 if (!exists) { 132 ret = tcf_idr_create(tn, parm->index, est, a, 133 &act_simp_ops, bind, false); 134 if (ret) { 135 tcf_idr_cleanup(tn, parm->index); 136 return ret; 137 } 138 139 d = to_defact(*a); 140 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, 141 extack); 142 if (err < 0) 143 goto release_idr; 144 145 err = alloc_defdata(d, tb[TCA_DEF_DATA]); 146 if (err < 0) 147 goto put_chain; 148 149 tcf_action_set_ctrlact(*a, parm->action, goto_ch); 150 ret = ACT_P_CREATED; 151 } else { 152 if (!ovr) { 153 err = -EEXIST; 154 goto release_idr; 155 } 156 157 err = reset_policy(*a, tb[TCA_DEF_DATA], parm, tp, extack); 158 if (err) 159 goto release_idr; 160 } 161 162 if (ret == ACT_P_CREATED) 163 tcf_idr_insert(tn, *a); 164 return ret; 165 put_chain: 166 if (goto_ch) 167 tcf_chain_put_by_act(goto_ch); 168 release_idr: 169 tcf_idr_release(*a, bind); 170 return err; 171 } 172 173 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 174 int bind, int ref) 175 { 176 unsigned char *b = skb_tail_pointer(skb); 177 struct tcf_defact *d = to_defact(a); 178 struct tc_defact opt = { 179 .index = d->tcf_index, 180 .refcnt = refcount_read(&d->tcf_refcnt) - ref, 181 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind, 182 }; 183 struct tcf_t t; 184 185 spin_lock_bh(&d->tcf_lock); 186 opt.action = d->tcf_action; 187 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) || 188 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata)) 189 goto nla_put_failure; 190 191 tcf_tm_dump(&t, &d->tcf_tm); 192 if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD)) 193 goto nla_put_failure; 194 spin_unlock_bh(&d->tcf_lock); 195 196 return skb->len; 197 198 nla_put_failure: 199 spin_unlock_bh(&d->tcf_lock); 200 nlmsg_trim(skb, b); 201 return -1; 202 } 203 204 static int tcf_simp_walker(struct net *net, struct sk_buff *skb, 205 struct netlink_callback *cb, int type, 206 const struct tc_action_ops *ops, 207 struct netlink_ext_ack *extack) 208 { 209 struct tc_action_net *tn = net_generic(net, simp_net_id); 210 211 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 212 } 213 214 static int tcf_simp_search(struct net *net, struct tc_action **a, u32 index) 215 { 216 struct tc_action_net *tn = net_generic(net, simp_net_id); 217 218 return tcf_idr_search(tn, a, index); 219 } 220 221 static struct tc_action_ops act_simp_ops = { 222 .kind = "simple", 223 .id = TCA_ID_SIMP, 224 .owner = THIS_MODULE, 225 .act = tcf_simp_act, 226 .dump = tcf_simp_dump, 227 .cleanup = tcf_simp_release, 228 .init = tcf_simp_init, 229 .walk = tcf_simp_walker, 230 .lookup = tcf_simp_search, 231 .size = sizeof(struct tcf_defact), 232 }; 233 234 static __net_init int simp_init_net(struct net *net) 235 { 236 struct tc_action_net *tn = net_generic(net, simp_net_id); 237 238 return tc_action_net_init(tn, &act_simp_ops); 239 } 240 241 static void __net_exit simp_exit_net(struct list_head *net_list) 242 { 243 tc_action_net_exit(net_list, simp_net_id); 244 } 245 246 static struct pernet_operations simp_net_ops = { 247 .init = simp_init_net, 248 .exit_batch = simp_exit_net, 249 .id = &simp_net_id, 250 .size = sizeof(struct tc_action_net), 251 }; 252 253 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 254 MODULE_DESCRIPTION("Simple example action"); 255 MODULE_LICENSE("GPL"); 256 257 static int __init simp_init_module(void) 258 { 259 int ret = tcf_register_action(&act_simp_ops, &simp_net_ops); 260 if (!ret) 261 pr_info("Simple TC action Loaded\n"); 262 return ret; 263 } 264 265 static void __exit simp_cleanup_module(void) 266 { 267 tcf_unregister_action(&act_simp_ops, &simp_net_ops); 268 } 269 270 module_init(simp_init_module); 271 module_exit(simp_cleanup_module); 272