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(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, char *defdata) 57 { 58 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL); 59 if (unlikely(!d->tcfd_defdata)) 60 return -ENOMEM; 61 strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 62 return 0; 63 } 64 65 static void reset_policy(struct tcf_defact *d, char *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 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, struct netlink_ext_ack *extack) 83 { 84 struct tc_action_net *tn = net_generic(net, simp_net_id); 85 struct nlattr *tb[TCA_DEF_MAX + 1]; 86 struct tc_defact *parm; 87 struct tcf_defact *d; 88 bool exists = false; 89 int ret = 0, err; 90 char *defdata; 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 exists = tcf_idr_check(tn, parm->index, a, bind); 104 if (exists && bind) 105 return 0; 106 107 if (tb[TCA_DEF_DATA] == NULL) { 108 if (exists) 109 tcf_idr_release(*a, bind); 110 return -EINVAL; 111 } 112 113 defdata = nla_data(tb[TCA_DEF_DATA]); 114 115 if (!exists) { 116 ret = tcf_idr_create(tn, parm->index, est, a, 117 &act_simp_ops, bind, false); 118 if (ret) 119 return ret; 120 121 d = to_defact(*a); 122 ret = alloc_defdata(d, defdata); 123 if (ret < 0) { 124 tcf_idr_release(*a, bind); 125 return ret; 126 } 127 d->tcf_action = parm->action; 128 ret = ACT_P_CREATED; 129 } else { 130 d = to_defact(*a); 131 132 tcf_idr_release(*a, bind); 133 if (!ovr) 134 return -EEXIST; 135 136 reset_policy(d, defdata, parm); 137 } 138 139 if (ret == ACT_P_CREATED) 140 tcf_idr_insert(tn, *a); 141 return ret; 142 } 143 144 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 145 int bind, int ref) 146 { 147 unsigned char *b = skb_tail_pointer(skb); 148 struct tcf_defact *d = to_defact(a); 149 struct tc_defact opt = { 150 .index = d->tcf_index, 151 .refcnt = d->tcf_refcnt - ref, 152 .bindcnt = d->tcf_bindcnt - bind, 153 .action = d->tcf_action, 154 }; 155 struct tcf_t t; 156 157 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) || 158 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata)) 159 goto nla_put_failure; 160 161 tcf_tm_dump(&t, &d->tcf_tm); 162 if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD)) 163 goto nla_put_failure; 164 return skb->len; 165 166 nla_put_failure: 167 nlmsg_trim(skb, b); 168 return -1; 169 } 170 171 static int tcf_simp_walker(struct net *net, struct sk_buff *skb, 172 struct netlink_callback *cb, int type, 173 const struct tc_action_ops *ops, 174 struct netlink_ext_ack *extack) 175 { 176 struct tc_action_net *tn = net_generic(net, simp_net_id); 177 178 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 179 } 180 181 static int tcf_simp_search(struct net *net, struct tc_action **a, u32 index, 182 struct netlink_ext_ack *extack) 183 { 184 struct tc_action_net *tn = net_generic(net, simp_net_id); 185 186 return tcf_idr_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); 207 } 208 209 static void __net_exit simp_exit_net(struct list_head *net_list) 210 { 211 tc_action_net_exit(net_list, simp_net_id); 212 } 213 214 static struct pernet_operations simp_net_ops = { 215 .init = simp_init_net, 216 .exit_batch = simp_exit_net, 217 .id = &simp_net_id, 218 .size = sizeof(struct tc_action_net), 219 }; 220 221 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 222 MODULE_DESCRIPTION("Simple example action"); 223 MODULE_LICENSE("GPL"); 224 225 static int __init simp_init_module(void) 226 { 227 int ret = tcf_register_action(&act_simp_ops, &simp_net_ops); 228 if (!ret) 229 pr_info("Simple TC action Loaded\n"); 230 return ret; 231 } 232 233 static void __exit simp_cleanup_module(void) 234 { 235 tcf_unregister_action(&act_simp_ops, &simp_net_ops); 236 } 237 238 module_init(simp_init_module); 239 module_exit(simp_cleanup_module); 240