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 static unsigned int simp_net_id; 28 static struct tc_action_ops act_simp_ops; 29 30 #define SIMP_MAX_DATA 32 31 static int tcf_simp_act(struct sk_buff *skb, const struct tc_action *a, 32 struct tcf_result *res) 33 { 34 struct tcf_defact *d = to_defact(a); 35 36 spin_lock(&d->tcf_lock); 37 tcf_lastuse_update(&d->tcf_tm); 38 bstats_update(&d->tcf_bstats, skb); 39 40 /* print policy string followed by _ then packet count 41 * Example if this was the 3rd packet and the string was "hello" 42 * then it would look like "hello_3" (without quotes) 43 */ 44 pr_info("simple: %s_%d\n", 45 (char *)d->tcfd_defdata, d->tcf_bstats.packets); 46 spin_unlock(&d->tcf_lock); 47 return d->tcf_action; 48 } 49 50 static void tcf_simp_release(struct tc_action *a) 51 { 52 struct tcf_defact *d = to_defact(a); 53 kfree(d->tcfd_defdata); 54 } 55 56 static int alloc_defdata(struct tcf_defact *d, const struct nlattr *defdata) 57 { 58 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL); 59 if (unlikely(!d->tcfd_defdata)) 60 return -ENOMEM; 61 nla_strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 62 return 0; 63 } 64 65 static void reset_policy(struct tcf_defact *d, const struct nlattr *defdata, 66 struct tc_defact *p) 67 { 68 spin_lock_bh(&d->tcf_lock); 69 d->tcf_action = p->action; 70 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); 71 nla_strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 72 spin_unlock_bh(&d->tcf_lock); 73 } 74 75 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { 76 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, 77 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA }, 78 }; 79 80 static int tcf_simp_init(struct net *net, struct nlattr *nla, 81 struct nlattr *est, struct tc_action **a, 82 int ovr, int bind, bool rtnl_held, 83 struct netlink_ext_ack *extack) 84 { 85 struct tc_action_net *tn = net_generic(net, simp_net_id); 86 struct nlattr *tb[TCA_DEF_MAX + 1]; 87 struct tc_defact *parm; 88 struct tcf_defact *d; 89 bool exists = false; 90 int ret = 0, err; 91 92 if (nla == NULL) 93 return -EINVAL; 94 95 err = nla_parse_nested(tb, TCA_DEF_MAX, nla, simple_policy, NULL); 96 if (err < 0) 97 return err; 98 99 if (tb[TCA_DEF_PARMS] == NULL) 100 return -EINVAL; 101 102 parm = nla_data(tb[TCA_DEF_PARMS]); 103 err = tcf_idr_check_alloc(tn, &parm->index, a, bind); 104 if (err < 0) 105 return err; 106 exists = err; 107 if (exists && bind) 108 return 0; 109 110 if (tb[TCA_DEF_DATA] == NULL) { 111 if (exists) 112 tcf_idr_release(*a, bind); 113 else 114 tcf_idr_cleanup(tn, parm->index); 115 return -EINVAL; 116 } 117 118 if (!exists) { 119 ret = tcf_idr_create(tn, parm->index, est, a, 120 &act_simp_ops, bind, false); 121 if (ret) { 122 tcf_idr_cleanup(tn, parm->index); 123 return ret; 124 } 125 126 d = to_defact(*a); 127 ret = alloc_defdata(d, tb[TCA_DEF_DATA]); 128 if (ret < 0) { 129 tcf_idr_release(*a, bind); 130 return ret; 131 } 132 d->tcf_action = parm->action; 133 ret = ACT_P_CREATED; 134 } else { 135 d = to_defact(*a); 136 137 if (!ovr) { 138 tcf_idr_release(*a, bind); 139 return -EEXIST; 140 } 141 142 reset_policy(d, tb[TCA_DEF_DATA], parm); 143 } 144 145 if (ret == ACT_P_CREATED) 146 tcf_idr_insert(tn, *a); 147 return ret; 148 } 149 150 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 151 int bind, int ref) 152 { 153 unsigned char *b = skb_tail_pointer(skb); 154 struct tcf_defact *d = to_defact(a); 155 struct tc_defact opt = { 156 .index = d->tcf_index, 157 .refcnt = refcount_read(&d->tcf_refcnt) - ref, 158 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind, 159 }; 160 struct tcf_t t; 161 162 spin_lock_bh(&d->tcf_lock); 163 opt.action = d->tcf_action; 164 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) || 165 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata)) 166 goto nla_put_failure; 167 168 tcf_tm_dump(&t, &d->tcf_tm); 169 if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD)) 170 goto nla_put_failure; 171 spin_unlock_bh(&d->tcf_lock); 172 173 return skb->len; 174 175 nla_put_failure: 176 spin_unlock_bh(&d->tcf_lock); 177 nlmsg_trim(skb, b); 178 return -1; 179 } 180 181 static int tcf_simp_walker(struct net *net, struct sk_buff *skb, 182 struct netlink_callback *cb, int type, 183 const struct tc_action_ops *ops, 184 struct netlink_ext_ack *extack) 185 { 186 struct tc_action_net *tn = net_generic(net, simp_net_id); 187 188 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 189 } 190 191 static int tcf_simp_search(struct net *net, struct tc_action **a, u32 index, 192 struct netlink_ext_ack *extack) 193 { 194 struct tc_action_net *tn = net_generic(net, simp_net_id); 195 196 return tcf_idr_search(tn, a, index); 197 } 198 199 static struct tc_action_ops act_simp_ops = { 200 .kind = "simple", 201 .type = TCA_ACT_SIMP, 202 .owner = THIS_MODULE, 203 .act = tcf_simp_act, 204 .dump = tcf_simp_dump, 205 .cleanup = tcf_simp_release, 206 .init = tcf_simp_init, 207 .walk = tcf_simp_walker, 208 .lookup = tcf_simp_search, 209 .size = sizeof(struct tcf_defact), 210 }; 211 212 static __net_init int simp_init_net(struct net *net) 213 { 214 struct tc_action_net *tn = net_generic(net, simp_net_id); 215 216 return tc_action_net_init(tn, &act_simp_ops); 217 } 218 219 static void __net_exit simp_exit_net(struct list_head *net_list) 220 { 221 tc_action_net_exit(net_list, simp_net_id); 222 } 223 224 static struct pernet_operations simp_net_ops = { 225 .init = simp_init_net, 226 .exit_batch = simp_exit_net, 227 .id = &simp_net_id, 228 .size = sizeof(struct tc_action_net), 229 }; 230 231 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 232 MODULE_DESCRIPTION("Simple example action"); 233 MODULE_LICENSE("GPL"); 234 235 static int __init simp_init_module(void) 236 { 237 int ret = tcf_register_action(&act_simp_ops, &simp_net_ops); 238 if (!ret) 239 pr_info("Simple TC action Loaded\n"); 240 return ret; 241 } 242 243 static void __exit simp_cleanup_module(void) 244 { 245 tcf_unregister_action(&act_simp_ops, &simp_net_ops); 246 } 247 248 module_init(simp_init_module); 249 module_exit(simp_cleanup_module); 250