| /* |
| * 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 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, |
| sizeof(*m), 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 = a->priv; |
| 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 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 = a->priv; |
| 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, |
| struct tc_action *a) |
| { |
| struct tc_action_net *tn = net_generic(net, mirred_net_id); |
| |
| return tcf_generic_walker(tn, skb, cb, type, a); |
| } |
| |
| 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, |
| .dump = tcf_mirred_dump, |
| .cleanup = tcf_mirred_release, |
| .init = tcf_mirred_init, |
| .walk = tcf_mirred_walker, |
| .lookup = tcf_mirred_search, |
| }; |
| |
| 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); |