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, 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, 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 91 if (nla == NULL) 92 return -EINVAL; 93 94 err = nla_parse_nested(tb, TCA_DEF_MAX, nla, simple_policy, NULL); 95 if (err < 0) 96 return err; 97 98 if (tb[TCA_DEF_PARMS] == NULL) 99 return -EINVAL; 100 101 parm = nla_data(tb[TCA_DEF_PARMS]); 102 exists = tcf_idr_check(tn, parm->index, a, bind); 103 if (exists && bind) 104 return 0; 105 106 if (tb[TCA_DEF_DATA] == NULL) { 107 if (exists) 108 tcf_idr_release(*a, bind); 109 return -EINVAL; 110 } 111 112 if (!exists) { 113 ret = tcf_idr_create(tn, parm->index, est, a, 114 &act_simp_ops, bind, false); 115 if (ret) 116 return ret; 117 118 d = to_defact(*a); 119 ret = alloc_defdata(d, tb[TCA_DEF_DATA]); 120 if (ret < 0) { 121 tcf_idr_release(*a, bind); 122 return ret; 123 } 124 d->tcf_action = parm->action; 125 ret = ACT_P_CREATED; 126 } else { 127 d = to_defact(*a); 128 129 tcf_idr_release(*a, bind); 130 if (!ovr) 131 return -EEXIST; 132 133 reset_policy(d, tb[TCA_DEF_DATA], parm); 134 } 135 136 if (ret == ACT_P_CREATED) 137 tcf_idr_insert(tn, *a); 138 return ret; 139 } 140 141 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 142 int bind, int ref) 143 { 144 unsigned char *b = skb_tail_pointer(skb); 145 struct tcf_defact *d = to_defact(a); 146 struct tc_defact opt = { 147 .index = d->tcf_index, 148 .refcnt = d->tcf_refcnt - ref, 149 .bindcnt = d->tcf_bindcnt - bind, 150 .action = d->tcf_action, 151 }; 152 struct tcf_t t; 153 154 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) || 155 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata)) 156 goto nla_put_failure; 157 158 tcf_tm_dump(&t, &d->tcf_tm); 159 if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD)) 160 goto nla_put_failure; 161 return skb->len; 162 163 nla_put_failure: 164 nlmsg_trim(skb, b); 165 return -1; 166 } 167 168 static int tcf_simp_walker(struct net *net, struct sk_buff *skb, 169 struct netlink_callback *cb, int type, 170 const struct tc_action_ops *ops, 171 struct netlink_ext_ack *extack) 172 { 173 struct tc_action_net *tn = net_generic(net, simp_net_id); 174 175 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 176 } 177 178 static int tcf_simp_search(struct net *net, struct tc_action **a, u32 index, 179 struct netlink_ext_ack *extack) 180 { 181 struct tc_action_net *tn = net_generic(net, simp_net_id); 182 183 return tcf_idr_search(tn, a, index); 184 } 185 186 static struct tc_action_ops act_simp_ops = { 187 .kind = "simple", 188 .type = TCA_ACT_SIMP, 189 .owner = THIS_MODULE, 190 .act = tcf_simp, 191 .dump = tcf_simp_dump, 192 .cleanup = tcf_simp_release, 193 .init = tcf_simp_init, 194 .walk = tcf_simp_walker, 195 .lookup = tcf_simp_search, 196 .size = sizeof(struct tcf_defact), 197 }; 198 199 static __net_init int simp_init_net(struct net *net) 200 { 201 struct tc_action_net *tn = net_generic(net, simp_net_id); 202 203 return tc_action_net_init(tn, &act_simp_ops); 204 } 205 206 static void __net_exit simp_exit_net(struct list_head *net_list) 207 { 208 tc_action_net_exit(net_list, simp_net_id); 209 } 210 211 static struct pernet_operations simp_net_ops = { 212 .init = simp_init_net, 213 .exit_batch = simp_exit_net, 214 .id = &simp_net_id, 215 .size = sizeof(struct tc_action_net), 216 }; 217 218 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 219 MODULE_DESCRIPTION("Simple example action"); 220 MODULE_LICENSE("GPL"); 221 222 static int __init simp_init_module(void) 223 { 224 int ret = tcf_register_action(&act_simp_ops, &simp_net_ops); 225 if (!ret) 226 pr_info("Simple TC action Loaded\n"); 227 return ret; 228 } 229 230 static void __exit simp_cleanup_module(void) 231 { 232 tcf_unregister_action(&act_simp_ops, &simp_net_ops); 233 } 234 235 module_init(simp_init_module); 236 module_exit(simp_cleanup_module); 237