1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * net/sched/act_simple.c Simple example of an action 4 * 5 * Authors: Jamal Hadi Salim (2005-8) 6 */ 7 8 #include <linux/module.h> 9 #include <linux/slab.h> 10 #include <linux/init.h> 11 #include <linux/kernel.h> 12 #include <linux/skbuff.h> 13 #include <linux/rtnetlink.h> 14 #include <net/netlink.h> 15 #include <net/pkt_sched.h> 16 #include <net/pkt_cls.h> 17 18 #include <linux/tc_act/tc_defact.h> 19 #include <net/tc_act/tc_defact.h> 20 21 static unsigned int simp_net_id; 22 static struct tc_action_ops act_simp_ops; 23 24 #define SIMP_MAX_DATA 32 25 static int tcf_simp_act(struct sk_buff *skb, const struct tc_action *a, 26 struct tcf_result *res) 27 { 28 struct tcf_defact *d = to_defact(a); 29 30 spin_lock(&d->tcf_lock); 31 tcf_lastuse_update(&d->tcf_tm); 32 bstats_update(&d->tcf_bstats, skb); 33 34 /* print policy string followed by _ then packet count 35 * Example if this was the 3rd packet and the string was "hello" 36 * then it would look like "hello_3" (without quotes) 37 */ 38 pr_info("simple: %s_%llu\n", 39 (char *)d->tcfd_defdata, d->tcf_bstats.packets); 40 spin_unlock(&d->tcf_lock); 41 return d->tcf_action; 42 } 43 44 static void tcf_simp_release(struct tc_action *a) 45 { 46 struct tcf_defact *d = to_defact(a); 47 kfree(d->tcfd_defdata); 48 } 49 50 static int alloc_defdata(struct tcf_defact *d, const struct nlattr *defdata) 51 { 52 d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL); 53 if (unlikely(!d->tcfd_defdata)) 54 return -ENOMEM; 55 nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 56 return 0; 57 } 58 59 static int reset_policy(struct tc_action *a, const struct nlattr *defdata, 60 struct tc_defact *p, struct tcf_proto *tp, 61 struct netlink_ext_ack *extack) 62 { 63 struct tcf_chain *goto_ch = NULL; 64 struct tcf_defact *d; 65 int err; 66 67 err = tcf_action_check_ctrlact(p->action, tp, &goto_ch, extack); 68 if (err < 0) 69 return err; 70 d = to_defact(a); 71 spin_lock_bh(&d->tcf_lock); 72 goto_ch = tcf_action_set_ctrlact(a, p->action, goto_ch); 73 memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); 74 nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); 75 spin_unlock_bh(&d->tcf_lock); 76 if (goto_ch) 77 tcf_chain_put_by_act(goto_ch); 78 return 0; 79 } 80 81 static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = { 82 [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, 83 [TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA }, 84 }; 85 86 static int tcf_simp_init(struct net *net, struct nlattr *nla, 87 struct nlattr *est, struct tc_action **a, 88 int ovr, int bind, bool rtnl_held, 89 struct tcf_proto *tp, u32 flags, 90 struct netlink_ext_ack *extack) 91 { 92 struct tc_action_net *tn = net_generic(net, simp_net_id); 93 struct nlattr *tb[TCA_DEF_MAX + 1]; 94 struct tcf_chain *goto_ch = NULL; 95 struct tc_defact *parm; 96 struct tcf_defact *d; 97 bool exists = false; 98 int ret = 0, err; 99 u32 index; 100 101 if (nla == NULL) 102 return -EINVAL; 103 104 err = nla_parse_nested_deprecated(tb, TCA_DEF_MAX, nla, simple_policy, 105 NULL); 106 if (err < 0) 107 return err; 108 109 if (tb[TCA_DEF_PARMS] == NULL) 110 return -EINVAL; 111 112 parm = nla_data(tb[TCA_DEF_PARMS]); 113 index = parm->index; 114 err = tcf_idr_check_alloc(tn, &index, a, bind); 115 if (err < 0) 116 return err; 117 exists = err; 118 if (exists && bind) 119 return 0; 120 121 if (tb[TCA_DEF_DATA] == NULL) { 122 if (exists) 123 tcf_idr_release(*a, bind); 124 else 125 tcf_idr_cleanup(tn, index); 126 return -EINVAL; 127 } 128 129 if (!exists) { 130 ret = tcf_idr_create(tn, index, est, a, 131 &act_simp_ops, bind, false, 0); 132 if (ret) { 133 tcf_idr_cleanup(tn, index); 134 return ret; 135 } 136 137 d = to_defact(*a); 138 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, 139 extack); 140 if (err < 0) 141 goto release_idr; 142 143 err = alloc_defdata(d, tb[TCA_DEF_DATA]); 144 if (err < 0) 145 goto put_chain; 146 147 tcf_action_set_ctrlact(*a, parm->action, goto_ch); 148 ret = ACT_P_CREATED; 149 } else { 150 if (!ovr) { 151 err = -EEXIST; 152 goto release_idr; 153 } 154 155 err = reset_policy(*a, tb[TCA_DEF_DATA], parm, tp, extack); 156 if (err) 157 goto release_idr; 158 } 159 160 return ret; 161 put_chain: 162 if (goto_ch) 163 tcf_chain_put_by_act(goto_ch); 164 release_idr: 165 tcf_idr_release(*a, bind); 166 return err; 167 } 168 169 static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a, 170 int bind, int ref) 171 { 172 unsigned char *b = skb_tail_pointer(skb); 173 struct tcf_defact *d = to_defact(a); 174 struct tc_defact opt = { 175 .index = d->tcf_index, 176 .refcnt = refcount_read(&d->tcf_refcnt) - ref, 177 .bindcnt = atomic_read(&d->tcf_bindcnt) - bind, 178 }; 179 struct tcf_t t; 180 181 spin_lock_bh(&d->tcf_lock); 182 opt.action = d->tcf_action; 183 if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) || 184 nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata)) 185 goto nla_put_failure; 186 187 tcf_tm_dump(&t, &d->tcf_tm); 188 if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD)) 189 goto nla_put_failure; 190 spin_unlock_bh(&d->tcf_lock); 191 192 return skb->len; 193 194 nla_put_failure: 195 spin_unlock_bh(&d->tcf_lock); 196 nlmsg_trim(skb, b); 197 return -1; 198 } 199 200 static int tcf_simp_walker(struct net *net, struct sk_buff *skb, 201 struct netlink_callback *cb, int type, 202 const struct tc_action_ops *ops, 203 struct netlink_ext_ack *extack) 204 { 205 struct tc_action_net *tn = net_generic(net, simp_net_id); 206 207 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 208 } 209 210 static int tcf_simp_search(struct net *net, struct tc_action **a, u32 index) 211 { 212 struct tc_action_net *tn = net_generic(net, simp_net_id); 213 214 return tcf_idr_search(tn, a, index); 215 } 216 217 static struct tc_action_ops act_simp_ops = { 218 .kind = "simple", 219 .id = TCA_ID_SIMP, 220 .owner = THIS_MODULE, 221 .act = tcf_simp_act, 222 .dump = tcf_simp_dump, 223 .cleanup = tcf_simp_release, 224 .init = tcf_simp_init, 225 .walk = tcf_simp_walker, 226 .lookup = tcf_simp_search, 227 .size = sizeof(struct tcf_defact), 228 }; 229 230 static __net_init int simp_init_net(struct net *net) 231 { 232 struct tc_action_net *tn = net_generic(net, simp_net_id); 233 234 return tc_action_net_init(net, tn, &act_simp_ops); 235 } 236 237 static void __net_exit simp_exit_net(struct list_head *net_list) 238 { 239 tc_action_net_exit(net_list, simp_net_id); 240 } 241 242 static struct pernet_operations simp_net_ops = { 243 .init = simp_init_net, 244 .exit_batch = simp_exit_net, 245 .id = &simp_net_id, 246 .size = sizeof(struct tc_action_net), 247 }; 248 249 MODULE_AUTHOR("Jamal Hadi Salim(2005)"); 250 MODULE_DESCRIPTION("Simple example action"); 251 MODULE_LICENSE("GPL"); 252 253 static int __init simp_init_module(void) 254 { 255 int ret = tcf_register_action(&act_simp_ops, &simp_net_ops); 256 if (!ret) 257 pr_info("Simple TC action Loaded\n"); 258 return ret; 259 } 260 261 static void __exit simp_cleanup_module(void) 262 { 263 tcf_unregister_action(&act_simp_ops, &simp_net_ops); 264 } 265 266 module_init(simp_init_module); 267 module_exit(simp_cleanup_module); 268