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- /*
- * net/sched/act_mirred.c packet mirroring and redirect actions
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
- * Authors: Jamal Hadi Salim (2002-4)
- *
- * TODO: Add ingress support (and socket redirect support)
- *
- */
- #include <linux/types.h>
- #include <linux/kernel.h>
- #include <linux/string.h>
- #include <linux/errno.h>
- #include <linux/skbuff.h>
- #include <linux/rtnetlink.h>
- #include <linux/module.h>
- #include <linux/init.h>
- #include <linux/gfp.h>
- #include <net/net_namespace.h>
- #include <net/netlink.h>
- #include <net/pkt_sched.h>
- #include <linux/tc_act/tc_mirred.h>
- #include <net/tc_act/tc_mirred.h>
- #include <linux/if_arp.h>
- #define MIRRED_TAB_MASK 7
- static LIST_HEAD(mirred_list);
- static DEFINE_SPINLOCK(mirred_list_lock);
- static void tcf_mirred_release(struct tc_action *a, int bind)
- {
- struct tcf_mirred *m = to_mirred(a);
- struct net_device *dev;
- /* We could be called either in a RCU callback or with RTNL lock held. */
- spin_lock_bh(&mirred_list_lock);
- list_del(&m->tcfm_list);
- dev = rcu_dereference_protected(m->tcfm_dev, 1);
- if (dev)
- dev_put(dev);
- spin_unlock_bh(&mirred_list_lock);
- }
- static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
- [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
- };
- static int mirred_net_id;
- static struct tc_action_ops act_mirred_ops;
- static int tcf_mirred_init(struct net *net, struct nlattr *nla,
- struct nlattr *est, struct tc_action **a, int ovr,
- int bind)
- {
- struct tc_action_net *tn = net_generic(net, mirred_net_id);
- struct nlattr *tb[TCA_MIRRED_MAX + 1];
- struct tc_mirred *parm;
- struct tcf_mirred *m;
- struct net_device *dev;
- int ret, ok_push = 0;
- bool exists = false;
- if (nla == NULL)
- return -EINVAL;
- ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
- if (ret < 0)
- return ret;
- if (tb[TCA_MIRRED_PARMS] == NULL)
- return -EINVAL;
- parm = nla_data(tb[TCA_MIRRED_PARMS]);
- exists = tcf_hash_check(tn, parm->index, a, bind);
- if (exists && bind)
- return 0;
- switch (parm->eaction) {
- case TCA_EGRESS_MIRROR:
- case TCA_EGRESS_REDIR:
- break;
- default:
- if (exists)
- tcf_hash_release(*a, bind);
- return -EINVAL;
- }
- if (parm->ifindex) {
- dev = __dev_get_by_index(net, parm->ifindex);
- if (dev == NULL) {
- if (exists)
- tcf_hash_release(*a, bind);
- return -ENODEV;
- }
- switch (dev->type) {
- case ARPHRD_TUNNEL:
- case ARPHRD_TUNNEL6:
- case ARPHRD_SIT:
- case ARPHRD_IPGRE:
- case ARPHRD_VOID:
- case ARPHRD_NONE:
- ok_push = 0;
- break;
- default:
- ok_push = 1;
- break;
- }
- } else {
- dev = NULL;
- }
- if (!exists) {
- if (dev == NULL)
- return -EINVAL;
- ret = tcf_hash_create(tn, parm->index, est, a,
- &act_mirred_ops, bind, true);
- if (ret)
- return ret;
- ret = ACT_P_CREATED;
- } else {
- tcf_hash_release(*a, bind);
- if (!ovr)
- return -EEXIST;
- }
- m = to_mirred(*a);
- ASSERT_RTNL();
- m->tcf_action = parm->action;
- m->tcfm_eaction = parm->eaction;
- if (dev != NULL) {
- m->tcfm_ifindex = parm->ifindex;
- if (ret != ACT_P_CREATED)
- dev_put(rcu_dereference_protected(m->tcfm_dev, 1));
- dev_hold(dev);
- rcu_assign_pointer(m->tcfm_dev, dev);
- m->tcfm_ok_push = ok_push;
- }
- if (ret == ACT_P_CREATED) {
- spin_lock_bh(&mirred_list_lock);
- list_add(&m->tcfm_list, &mirred_list);
- spin_unlock_bh(&mirred_list_lock);
- tcf_hash_insert(tn, *a);
- }
- return ret;
- }
- static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
- struct tcf_result *res)
- {
- struct tcf_mirred *m = to_mirred(a);
- struct net_device *dev;
- struct sk_buff *skb2;
- int retval, err;
- u32 at;
- tcf_lastuse_update(&m->tcf_tm);
- bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);
- rcu_read_lock();
- retval = READ_ONCE(m->tcf_action);
- dev = rcu_dereference(m->tcfm_dev);
- if (unlikely(!dev)) {
- pr_notice_once("tc mirred: target device is gone\n");
- goto out;
- }
- if (unlikely(!(dev->flags & IFF_UP))) {
- net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
- dev->name);
- goto out;
- }
- at = G_TC_AT(skb->tc_verd);
- skb2 = skb_clone(skb, GFP_ATOMIC);
- if (!skb2)
- goto out;
- if (!(at & AT_EGRESS)) {
- if (m->tcfm_ok_push)
- skb_push_rcsum(skb2, skb->mac_len);
- }
- /* mirror is always swallowed */
- if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
- skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
- skb2->skb_iif = skb->dev->ifindex;
- skb2->dev = dev;
- err = dev_queue_xmit(skb2);
- if (err) {
- out:
- qstats_overlimit_inc(this_cpu_ptr(m->common.cpu_qstats));
- if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
- retval = TC_ACT_SHOT;
- }
- rcu_read_unlock();
- return retval;
- }
- static void tcf_stats_update(struct tc_action *a, u64 bytes, u32 packets,
- u64 lastuse)
- {
- struct tcf_mirred *m = to_mirred(a);
- struct tcf_t *tm = &m->tcf_tm;
- _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
- tm->lastuse = max_t(u64, tm->lastuse, lastuse);
- }
- static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind,
- int ref)
- {
- unsigned char *b = skb_tail_pointer(skb);
- struct tcf_mirred *m = to_mirred(a);
- struct tc_mirred opt = {
- .index = m->tcf_index,
- .action = m->tcf_action,
- .refcnt = m->tcf_refcnt - ref,
- .bindcnt = m->tcf_bindcnt - bind,
- .eaction = m->tcfm_eaction,
- .ifindex = m->tcfm_ifindex,
- };
- struct tcf_t t;
- if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
- goto nla_put_failure;
- tcf_tm_dump(&t, &m->tcf_tm);
- if (nla_put_64bit(skb, TCA_MIRRED_TM, sizeof(t), &t, TCA_MIRRED_PAD))
- goto nla_put_failure;
- return skb->len;
- nla_put_failure:
- nlmsg_trim(skb, b);
- return -1;
- }
- static int tcf_mirred_walker(struct net *net, struct sk_buff *skb,
- struct netlink_callback *cb, int type,
- const struct tc_action_ops *ops)
- {
- struct tc_action_net *tn = net_generic(net, mirred_net_id);
- return tcf_generic_walker(tn, skb, cb, type, ops);
- }
- static int tcf_mirred_search(struct net *net, struct tc_action **a, u32 index)
- {
- struct tc_action_net *tn = net_generic(net, mirred_net_id);
- return tcf_hash_search(tn, a, index);
- }
- static int mirred_device_event(struct notifier_block *unused,
- unsigned long event, void *ptr)
- {
- struct net_device *dev = netdev_notifier_info_to_dev(ptr);
- struct tcf_mirred *m;
- ASSERT_RTNL();
- if (event == NETDEV_UNREGISTER) {
- spin_lock_bh(&mirred_list_lock);
- list_for_each_entry(m, &mirred_list, tcfm_list) {
- if (rcu_access_pointer(m->tcfm_dev) == dev) {
- dev_put(dev);
- /* Note : no rcu grace period necessary, as
- * net_device are already rcu protected.
- */
- RCU_INIT_POINTER(m->tcfm_dev, NULL);
- }
- }
- spin_unlock_bh(&mirred_list_lock);
- }
- return NOTIFY_DONE;
- }
- static struct notifier_block mirred_device_notifier = {
- .notifier_call = mirred_device_event,
- };
- static struct tc_action_ops act_mirred_ops = {
- .kind = "mirred",
- .type = TCA_ACT_MIRRED,
- .owner = THIS_MODULE,
- .act = tcf_mirred,
- .stats_update = tcf_stats_update,
- .dump = tcf_mirred_dump,
- .cleanup = tcf_mirred_release,
- .init = tcf_mirred_init,
- .walk = tcf_mirred_walker,
- .lookup = tcf_mirred_search,
- .size = sizeof(struct tcf_mirred),
- };
- static __net_init int mirred_init_net(struct net *net)
- {
- struct tc_action_net *tn = net_generic(net, mirred_net_id);
- return tc_action_net_init(tn, &act_mirred_ops, MIRRED_TAB_MASK);
- }
- static void __net_exit mirred_exit_net(struct net *net)
- {
- struct tc_action_net *tn = net_generic(net, mirred_net_id);
- tc_action_net_exit(tn);
- }
- static struct pernet_operations mirred_net_ops = {
- .init = mirred_init_net,
- .exit = mirred_exit_net,
- .id = &mirred_net_id,
- .size = sizeof(struct tc_action_net),
- };
- MODULE_AUTHOR("Jamal Hadi Salim(2002)");
- MODULE_DESCRIPTION("Device Mirror/redirect actions");
- MODULE_LICENSE("GPL");
- static int __init mirred_init_module(void)
- {
- int err = register_netdevice_notifier(&mirred_device_notifier);
- if (err)
- return err;
- pr_info("Mirror/redirect action on\n");
- return tcf_register_action(&act_mirred_ops, &mirred_net_ops);
- }
- static void __exit mirred_cleanup_module(void)
- {
- tcf_unregister_action(&act_mirred_ops, &mirred_net_ops);
- unregister_netdevice_notifier(&mirred_device_notifier);
- }
- module_init(mirred_init_module);
- module_exit(mirred_cleanup_module);
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