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 <net/net_namespace.h> 24 #include <net/netlink.h> 25 #include <net/pkt_sched.h> 26 #include <linux/tc_act/tc_mirred.h> 27 #include <net/tc_act/tc_mirred.h> 28 29 #include <linux/if_arp.h> 30 31 #define MIRRED_TAB_MASK 7 32 static struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1]; 33 static u32 mirred_idx_gen; 34 static DEFINE_RWLOCK(mirred_lock); 35 36 static struct tcf_hashinfo mirred_hash_info = { 37 .htab = tcf_mirred_ht, 38 .hmask = MIRRED_TAB_MASK, 39 .lock = &mirred_lock, 40 }; 41 42 static inline int tcf_mirred_release(struct tcf_mirred *m, int bind) 43 { 44 if (m) { 45 if (bind) 46 m->tcf_bindcnt--; 47 m->tcf_refcnt--; 48 if(!m->tcf_bindcnt && m->tcf_refcnt <= 0) { 49 dev_put(m->tcfm_dev); 50 tcf_hash_destroy(&m->common, &mirred_hash_info); 51 return 1; 52 } 53 } 54 return 0; 55 } 56 57 static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = { 58 [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) }, 59 }; 60 61 static int tcf_mirred_init(struct nlattr *nla, struct nlattr *est, 62 struct tc_action *a, int ovr, int bind) 63 { 64 struct nlattr *tb[TCA_MIRRED_MAX + 1]; 65 struct tc_mirred *parm; 66 struct tcf_mirred *m; 67 struct tcf_common *pc; 68 struct net_device *dev; 69 int ret, ok_push = 0; 70 71 if (nla == NULL) 72 return -EINVAL; 73 ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy); 74 if (ret < 0) 75 return ret; 76 if (tb[TCA_MIRRED_PARMS] == NULL) 77 return -EINVAL; 78 parm = nla_data(tb[TCA_MIRRED_PARMS]); 79 switch (parm->eaction) { 80 case TCA_EGRESS_MIRROR: 81 case TCA_EGRESS_REDIR: 82 break; 83 default: 84 return -EINVAL; 85 } 86 if (parm->ifindex) { 87 dev = __dev_get_by_index(&init_net, parm->ifindex); 88 if (dev == NULL) 89 return -ENODEV; 90 switch (dev->type) { 91 case ARPHRD_TUNNEL: 92 case ARPHRD_TUNNEL6: 93 case ARPHRD_SIT: 94 case ARPHRD_IPGRE: 95 case ARPHRD_VOID: 96 case ARPHRD_NONE: 97 ok_push = 0; 98 break; 99 default: 100 ok_push = 1; 101 break; 102 } 103 } else { 104 dev = NULL; 105 } 106 107 pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info); 108 if (!pc) { 109 if (dev == NULL) 110 return -EINVAL; 111 pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind, 112 &mirred_idx_gen, &mirred_hash_info); 113 if (IS_ERR(pc)) 114 return PTR_ERR(pc); 115 ret = ACT_P_CREATED; 116 } else { 117 if (!ovr) { 118 tcf_mirred_release(to_mirred(pc), bind); 119 return -EEXIST; 120 } 121 } 122 m = to_mirred(pc); 123 124 spin_lock_bh(&m->tcf_lock); 125 m->tcf_action = parm->action; 126 m->tcfm_eaction = parm->eaction; 127 if (dev != NULL) { 128 m->tcfm_ifindex = parm->ifindex; 129 if (ret != ACT_P_CREATED) 130 dev_put(m->tcfm_dev); 131 dev_hold(dev); 132 m->tcfm_dev = dev; 133 m->tcfm_ok_push = ok_push; 134 } 135 spin_unlock_bh(&m->tcf_lock); 136 if (ret == ACT_P_CREATED) 137 tcf_hash_insert(pc, &mirred_hash_info); 138 139 return ret; 140 } 141 142 static int tcf_mirred_cleanup(struct tc_action *a, int bind) 143 { 144 struct tcf_mirred *m = a->priv; 145 146 if (m) 147 return tcf_mirred_release(m, bind); 148 return 0; 149 } 150 151 static int tcf_mirred(struct sk_buff *skb, struct tc_action *a, 152 struct tcf_result *res) 153 { 154 struct tcf_mirred *m = a->priv; 155 struct net_device *dev; 156 struct sk_buff *skb2; 157 u32 at; 158 int retval, err = 1; 159 160 spin_lock(&m->tcf_lock); 161 m->tcf_tm.lastuse = jiffies; 162 163 dev = m->tcfm_dev; 164 if (!(dev->flags & IFF_UP)) { 165 if (net_ratelimit()) 166 printk("mirred to Houston: device %s is gone!\n", 167 dev->name); 168 goto out; 169 } 170 171 skb2 = skb_act_clone(skb, GFP_ATOMIC); 172 if (skb2 == NULL) 173 goto out; 174 175 m->tcf_bstats.bytes += qdisc_pkt_len(skb2); 176 m->tcf_bstats.packets++; 177 at = G_TC_AT(skb->tc_verd); 178 if (!(at & AT_EGRESS)) { 179 if (m->tcfm_ok_push) 180 skb_push(skb2, skb2->dev->hard_header_len); 181 } 182 183 /* mirror is always swallowed */ 184 if (m->tcfm_eaction != TCA_EGRESS_MIRROR) 185 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at); 186 187 skb2->dev = dev; 188 skb2->skb_iif = skb->dev->ifindex; 189 dev_queue_xmit(skb2); 190 err = 0; 191 192 out: 193 if (err) { 194 m->tcf_qstats.overlimits++; 195 m->tcf_bstats.bytes += qdisc_pkt_len(skb); 196 m->tcf_bstats.packets++; 197 /* should we be asking for packet to be dropped? 198 * may make sense for redirect case only 199 */ 200 retval = TC_ACT_SHOT; 201 } else { 202 retval = m->tcf_action; 203 } 204 spin_unlock(&m->tcf_lock); 205 206 return retval; 207 } 208 209 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 210 { 211 unsigned char *b = skb_tail_pointer(skb); 212 struct tcf_mirred *m = a->priv; 213 struct tc_mirred opt; 214 struct tcf_t t; 215 216 opt.index = m->tcf_index; 217 opt.action = m->tcf_action; 218 opt.refcnt = m->tcf_refcnt - ref; 219 opt.bindcnt = m->tcf_bindcnt - bind; 220 opt.eaction = m->tcfm_eaction; 221 opt.ifindex = m->tcfm_ifindex; 222 NLA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt); 223 t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install); 224 t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse); 225 t.expires = jiffies_to_clock_t(m->tcf_tm.expires); 226 NLA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t); 227 return skb->len; 228 229 nla_put_failure: 230 nlmsg_trim(skb, b); 231 return -1; 232 } 233 234 static struct tc_action_ops act_mirred_ops = { 235 .kind = "mirred", 236 .hinfo = &mirred_hash_info, 237 .type = TCA_ACT_MIRRED, 238 .capab = TCA_CAP_NONE, 239 .owner = THIS_MODULE, 240 .act = tcf_mirred, 241 .dump = tcf_mirred_dump, 242 .cleanup = tcf_mirred_cleanup, 243 .lookup = tcf_hash_search, 244 .init = tcf_mirred_init, 245 .walk = tcf_generic_walker 246 }; 247 248 MODULE_AUTHOR("Jamal Hadi Salim(2002)"); 249 MODULE_DESCRIPTION("Device Mirror/redirect actions"); 250 MODULE_LICENSE("GPL"); 251 252 static int __init mirred_init_module(void) 253 { 254 printk("Mirror/redirect action on\n"); 255 return tcf_register_action(&act_mirred_ops); 256 } 257 258 static void __exit mirred_cleanup_module(void) 259 { 260 tcf_unregister_action(&act_mirred_ops); 261 } 262 263 module_init(mirred_init_module); 264 module_exit(mirred_cleanup_module); 265