/* * net/sched/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 struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1]; static u32 mirred_idx_gen; static DEFINE_RWLOCK(mirred_lock); static LIST_HEAD(mirred_list); static struct tcf_hashinfo mirred_hash_info = { .htab = tcf_mirred_ht, .hmask = MIRRED_TAB_MASK, .lock = &mirred_lock, }; static int tcf_mirred_release(struct tcf_mirred *m, int bind) { if (m) { if (bind) m->tcf_bindcnt--; m->tcf_refcnt--; if (!m->tcf_bindcnt && m->tcf_refcnt <= 0) { list_del(&m->tcfm_list); if (m->tcfm_dev) dev_put(m->tcfm_dev); tcf_hash_destroy(&m->common, &mirred_hash_info); return 1; } } return 0; } static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = { [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) }, }; static int tcf_mirred_init(struct net *net, struct nlattr *nla, struct nlattr *est, struct tc_action *a, int ovr, int bind) { struct nlattr *tb[TCA_MIRRED_MAX + 1]; struct tc_mirred *parm; struct tcf_mirred *m; struct tcf_common *pc; struct net_device *dev; int ret, ok_push = 0; 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]); switch (parm->eaction) { case TCA_EGRESS_MIRROR: case TCA_EGRESS_REDIR: break; default: return -EINVAL; } if (parm->ifindex) { dev = __dev_get_by_index(net, parm->ifindex); if (dev == NULL) 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; } pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info); if (!pc) { if (dev == NULL) return -EINVAL; pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind, &mirred_idx_gen, &mirred_hash_info); if (IS_ERR(pc)) return PTR_ERR(pc); ret = ACT_P_CREATED; } else { if (!ovr) { tcf_mirred_release(to_mirred(pc), bind); return -EEXIST; } } m = to_mirred(pc); spin_lock_bh(&m->tcf_lock); 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(m->tcfm_dev); dev_hold(dev); m->tcfm_dev = dev; m->tcfm_ok_push = ok_push; } spin_unlock_bh(&m->tcf_lock); if (ret == ACT_P_CREATED) { list_add(&m->tcfm_list, &mirred_list); tcf_hash_insert(pc, &mirred_hash_info); } return ret; } static int tcf_mirred_cleanup(struct tc_action *a, int bind) { struct tcf_mirred *m = a->priv; if (m) return tcf_mirred_release(m, bind); return 0; } 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; u32 at; int retval, err = 1; spin_lock(&m->tcf_lock); m->tcf_tm.lastuse = jiffies; bstats_update(&m->tcf_bstats, skb); dev = m->tcfm_dev; if (!dev) { printk_once(KERN_NOTICE "tc mirred: target device is gone\n"); goto out; } if (!(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_act_clone(skb, GFP_ATOMIC, m->tcf_action); if (skb2 == NULL) goto out; if (!(at & AT_EGRESS)) { if (m->tcfm_ok_push) skb_push(skb2, skb2->dev->hard_header_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); out: if (err) { m->tcf_qstats.overlimits++; if (m->tcfm_eaction != TCA_EGRESS_MIRROR) retval = TC_ACT_SHOT; else retval = m->tcf_action; } else retval = m->tcf_action; spin_unlock(&m->tcf_lock); 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; t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install); t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse); t.expires = jiffies_to_clock_t(m->tcf_tm.expires); if (nla_put(skb, TCA_MIRRED_TM, sizeof(t), &t)) goto nla_put_failure; return skb->len; nla_put_failure: nlmsg_trim(skb, b); return -1; } 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; if (event == NETDEV_UNREGISTER) list_for_each_entry(m, &mirred_list, tcfm_list) { if (m->tcfm_dev == dev) { dev_put(dev); m->tcfm_dev = NULL; } } 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", .hinfo = &mirred_hash_info, .type = TCA_ACT_MIRRED, .capab = TCA_CAP_NONE, .owner = THIS_MODULE, .act = tcf_mirred, .dump = tcf_mirred_dump, .cleanup = tcf_mirred_cleanup, .lookup = tcf_hash_search, .init = tcf_mirred_init, .walk = tcf_generic_walker }; 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); } static void __exit mirred_cleanup_module(void) { unregister_netdevice_notifier(&mirred_device_notifier); tcf_unregister_action(&act_mirred_ops); } module_init(mirred_init_module); module_exit(mirred_cleanup_module);