/* * 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 <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 struct tcf_hashinfo mirred_hash_info = { .htab = tcf_mirred_ht, .hmask = MIRRED_TAB_MASK, .lock = &mirred_lock, }; static inline 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) { 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 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 = NULL; int ret = 0, err; int ok_push = 0; if (nla == NULL) return -EINVAL; err = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy); if (err < 0) return err; if (tb[TCA_MIRRED_PARMS] == NULL) return -EINVAL; parm = nla_data(tb[TCA_MIRRED_PARMS]); if (parm->ifindex) { dev = __dev_get_by_index(&init_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; } } pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info); if (!pc) { if (!parm->ifindex) return -EINVAL; pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind, &mirred_idx_gen, &mirred_hash_info); if (unlikely(!pc)) return -ENOMEM; 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 (parm->ifindex) { m->tcfm_ifindex = parm->ifindex; if (ret != ACT_P_CREATED) dev_put(m->tcfm_dev); m->tcfm_dev = dev; dev_hold(dev); m->tcfm_ok_push = ok_push; } spin_unlock_bh(&m->tcf_lock); if (ret == ACT_P_CREATED) 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, struct tc_action *a, struct tcf_result *res) { struct tcf_mirred *m = a->priv; struct net_device *dev; struct sk_buff *skb2 = NULL; u32 at = G_TC_AT(skb->tc_verd); spin_lock(&m->tcf_lock); dev = m->tcfm_dev; m->tcf_tm.lastuse = jiffies; if (!(dev->flags&IFF_UP) ) { if (net_ratelimit()) printk("mirred to Houston: device %s is gone!\n", dev->name); bad_mirred: if (skb2 != NULL) kfree_skb(skb2); m->tcf_qstats.overlimits++; m->tcf_bstats.bytes += qdisc_pkt_len(skb); m->tcf_bstats.packets++; spin_unlock(&m->tcf_lock); /* should we be asking for packet to be dropped? * may make sense for redirect case only */ return TC_ACT_SHOT; } skb2 = skb_act_clone(skb, GFP_ATOMIC); if (skb2 == NULL) goto bad_mirred; if (m->tcfm_eaction != TCA_EGRESS_MIRROR && m->tcfm_eaction != TCA_EGRESS_REDIR) { if (net_ratelimit()) printk("tcf_mirred unknown action %d\n", m->tcfm_eaction); goto bad_mirred; } m->tcf_bstats.bytes += qdisc_pkt_len(skb2); m->tcf_bstats.packets++; 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->dev = dev; skb2->iif = skb->dev->ifindex; dev_queue_xmit(skb2); spin_unlock(&m->tcf_lock); return m->tcf_action; } 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; struct tcf_t t; opt.index = m->tcf_index; opt.action = m->tcf_action; opt.refcnt = m->tcf_refcnt - ref; opt.bindcnt = m->tcf_bindcnt - bind; opt.eaction = m->tcfm_eaction; opt.ifindex = m->tcfm_ifindex; NLA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt); 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); NLA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t); return skb->len; nla_put_failure: nlmsg_trim(skb, b); return -1; } 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) { printk("Mirror/redirect action on\n"); return tcf_register_action(&act_mirred_ops); } static void __exit mirred_cleanup_module(void) { tcf_unregister_action(&act_mirred_ops); } module_init(mirred_init_module); module_exit(mirred_cleanup_module);