1 /* 2 * net/sched/mirred.c packet mirroring and redirect actions 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 (2002-4) 10 * 11 * TODO: Add ingress support (and socket redirect support) 12 * 13 */ 14 15 #include <linux/types.h> 16 #include <linux/kernel.h> 17 #include <linux/string.h> 18 #include <linux/errno.h> 19 #include <linux/skbuff.h> 20 #include <linux/rtnetlink.h> 21 #include <linux/module.h> 22 #include <linux/init.h> 23 #include <linux/gfp.h> 24 #include <net/net_namespace.h> 25 #include <net/netlink.h> 26 #include <net/pkt_sched.h> 27 #include <linux/tc_act/tc_mirred.h> 28 #include <net/tc_act/tc_mirred.h> 29 30 #include <linux/if_arp.h> 31 32 #define MIRRED_TAB_MASK 7 33 static LIST_HEAD(mirred_list); 34 static struct tcf_hashinfo mirred_hash_info; 35 36 static int tcf_mirred_release(struct tcf_mirred *m, int bind) 37 { 38 if (m) { 39 if (bind) 40 m->tcf_bindcnt--; 41 m->tcf_refcnt--; 42 if (!m->tcf_bindcnt && m->tcf_refcnt <= 0) { 43 list_del(&m->tcfm_list); 44 if (m->tcfm_dev) 45 dev_put(m->tcfm_dev); 46 tcf_hash_destroy(&m->common, &mirred_hash_info); 47 return 1; 48 } 49 } 50 return 0; 51 } 52 53 static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = { 54 [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) }, 55 }; 56 57 static int tcf_mirred_init(struct net *net, struct nlattr *nla, 58 struct nlattr *est, struct tc_action *a, int ovr, 59 int bind) 60 { 61 struct nlattr *tb[TCA_MIRRED_MAX + 1]; 62 struct tc_mirred *parm; 63 struct tcf_mirred *m; 64 struct tcf_common *pc; 65 struct net_device *dev; 66 int ret, ok_push = 0; 67 68 if (nla == NULL) 69 return -EINVAL; 70 ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy); 71 if (ret < 0) 72 return ret; 73 if (tb[TCA_MIRRED_PARMS] == NULL) 74 return -EINVAL; 75 parm = nla_data(tb[TCA_MIRRED_PARMS]); 76 switch (parm->eaction) { 77 case TCA_EGRESS_MIRROR: 78 case TCA_EGRESS_REDIR: 79 break; 80 default: 81 return -EINVAL; 82 } 83 if (parm->ifindex) { 84 dev = __dev_get_by_index(net, parm->ifindex); 85 if (dev == NULL) 86 return -ENODEV; 87 switch (dev->type) { 88 case ARPHRD_TUNNEL: 89 case ARPHRD_TUNNEL6: 90 case ARPHRD_SIT: 91 case ARPHRD_IPGRE: 92 case ARPHRD_VOID: 93 case ARPHRD_NONE: 94 ok_push = 0; 95 break; 96 default: 97 ok_push = 1; 98 break; 99 } 100 } else { 101 dev = NULL; 102 } 103 104 pc = tcf_hash_check(parm->index, a, bind); 105 if (!pc) { 106 if (dev == NULL) 107 return -EINVAL; 108 pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind); 109 if (IS_ERR(pc)) 110 return PTR_ERR(pc); 111 ret = ACT_P_CREATED; 112 } else { 113 if (!ovr) { 114 tcf_mirred_release(to_mirred(pc), bind); 115 return -EEXIST; 116 } 117 } 118 m = to_mirred(pc); 119 120 spin_lock_bh(&m->tcf_lock); 121 m->tcf_action = parm->action; 122 m->tcfm_eaction = parm->eaction; 123 if (dev != NULL) { 124 m->tcfm_ifindex = parm->ifindex; 125 if (ret != ACT_P_CREATED) 126 dev_put(m->tcfm_dev); 127 dev_hold(dev); 128 m->tcfm_dev = dev; 129 m->tcfm_ok_push = ok_push; 130 } 131 spin_unlock_bh(&m->tcf_lock); 132 if (ret == ACT_P_CREATED) { 133 list_add(&m->tcfm_list, &mirred_list); 134 tcf_hash_insert(pc, a->ops->hinfo); 135 } 136 137 return ret; 138 } 139 140 static int tcf_mirred_cleanup(struct tc_action *a, int bind) 141 { 142 struct tcf_mirred *m = a->priv; 143 144 if (m) 145 return tcf_mirred_release(m, bind); 146 return 0; 147 } 148 149 static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a, 150 struct tcf_result *res) 151 { 152 struct tcf_mirred *m = a->priv; 153 struct net_device *dev; 154 struct sk_buff *skb2; 155 u32 at; 156 int retval, err = 1; 157 158 spin_lock(&m->tcf_lock); 159 m->tcf_tm.lastuse = jiffies; 160 bstats_update(&m->tcf_bstats, skb); 161 162 dev = m->tcfm_dev; 163 if (!dev) { 164 printk_once(KERN_NOTICE "tc mirred: target device is gone\n"); 165 goto out; 166 } 167 168 if (!(dev->flags & IFF_UP)) { 169 net_notice_ratelimited("tc mirred to Houston: device %s is down\n", 170 dev->name); 171 goto out; 172 } 173 174 at = G_TC_AT(skb->tc_verd); 175 skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action); 176 if (skb2 == NULL) 177 goto out; 178 179 if (!(at & AT_EGRESS)) { 180 if (m->tcfm_ok_push) 181 skb_push(skb2, skb2->dev->hard_header_len); 182 } 183 184 /* mirror is always swallowed */ 185 if (m->tcfm_eaction != TCA_EGRESS_MIRROR) 186 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at); 187 188 skb2->skb_iif = skb->dev->ifindex; 189 skb2->dev = dev; 190 err = dev_queue_xmit(skb2); 191 192 out: 193 if (err) { 194 m->tcf_qstats.overlimits++; 195 if (m->tcfm_eaction != TCA_EGRESS_MIRROR) 196 retval = TC_ACT_SHOT; 197 else 198 retval = m->tcf_action; 199 } else 200 retval = m->tcf_action; 201 spin_unlock(&m->tcf_lock); 202 203 return retval; 204 } 205 206 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 207 { 208 unsigned char *b = skb_tail_pointer(skb); 209 struct tcf_mirred *m = a->priv; 210 struct tc_mirred opt = { 211 .index = m->tcf_index, 212 .action = m->tcf_action, 213 .refcnt = m->tcf_refcnt - ref, 214 .bindcnt = m->tcf_bindcnt - bind, 215 .eaction = m->tcfm_eaction, 216 .ifindex = m->tcfm_ifindex, 217 }; 218 struct tcf_t t; 219 220 if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt)) 221 goto nla_put_failure; 222 t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install); 223 t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse); 224 t.expires = jiffies_to_clock_t(m->tcf_tm.expires); 225 if (nla_put(skb, TCA_MIRRED_TM, sizeof(t), &t)) 226 goto nla_put_failure; 227 return skb->len; 228 229 nla_put_failure: 230 nlmsg_trim(skb, b); 231 return -1; 232 } 233 234 static int mirred_device_event(struct notifier_block *unused, 235 unsigned long event, void *ptr) 236 { 237 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 238 struct tcf_mirred *m; 239 240 if (event == NETDEV_UNREGISTER) 241 list_for_each_entry(m, &mirred_list, tcfm_list) { 242 if (m->tcfm_dev == dev) { 243 dev_put(dev); 244 m->tcfm_dev = NULL; 245 } 246 } 247 248 return NOTIFY_DONE; 249 } 250 251 static struct notifier_block mirred_device_notifier = { 252 .notifier_call = mirred_device_event, 253 }; 254 255 static struct tc_action_ops act_mirred_ops = { 256 .kind = "mirred", 257 .hinfo = &mirred_hash_info, 258 .type = TCA_ACT_MIRRED, 259 .owner = THIS_MODULE, 260 .act = tcf_mirred, 261 .dump = tcf_mirred_dump, 262 .cleanup = tcf_mirred_cleanup, 263 .init = tcf_mirred_init, 264 }; 265 266 MODULE_AUTHOR("Jamal Hadi Salim(2002)"); 267 MODULE_DESCRIPTION("Device Mirror/redirect actions"); 268 MODULE_LICENSE("GPL"); 269 270 static int __init mirred_init_module(void) 271 { 272 int err = register_netdevice_notifier(&mirred_device_notifier); 273 if (err) 274 return err; 275 276 err = tcf_hashinfo_init(&mirred_hash_info, MIRRED_TAB_MASK); 277 if (err) { 278 unregister_netdevice_notifier(&mirred_device_notifier); 279 return err; 280 } 281 pr_info("Mirror/redirect action on\n"); 282 return tcf_register_action(&act_mirred_ops); 283 } 284 285 static void __exit mirred_cleanup_module(void) 286 { 287 tcf_unregister_action(&act_mirred_ops); 288 tcf_hashinfo_destroy(&mirred_hash_info); 289 unregister_netdevice_notifier(&mirred_device_notifier); 290 } 291 292 module_init(mirred_init_module); 293 module_exit(mirred_cleanup_module); 294