diff options
Diffstat (limited to 'net/sched/act_ipt.c')
-rw-r--r-- | net/sched/act_ipt.c | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/net/sched/act_ipt.c b/net/sched/act_ipt.c new file mode 100644 index 0000000..39a22a3 --- /dev/null +++ b/net/sched/act_ipt.c @@ -0,0 +1,328 @@ +/* + * net/sched/ipt.c iptables target interface + * + *TODO: Add other tables. For now we only support the ipv4 table targets + * + * 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. + * + * Copyright: Jamal Hadi Salim (2002-4) + */ + +#include <asm/uaccess.h> +#include <asm/system.h> +#include <asm/bitops.h> +#include <linux/config.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/in.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <linux/rtnetlink.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/proc_fs.h> +#include <linux/kmod.h> +#include <net/sock.h> +#include <net/pkt_sched.h> +#include <linux/tc_act/tc_ipt.h> +#include <net/tc_act/tc_ipt.h> + +#include <linux/netfilter_ipv4/ip_tables.h> + +/* use generic hash table */ +#define MY_TAB_SIZE 16 +#define MY_TAB_MASK 15 + +static u32 idx_gen; +static struct tcf_ipt *tcf_ipt_ht[MY_TAB_SIZE]; +/* ipt hash table lock */ +static DEFINE_RWLOCK(ipt_lock); + +/* ovewrride the defaults */ +#define tcf_st tcf_ipt +#define tcf_t_lock ipt_lock +#define tcf_ht tcf_ipt_ht + +#define CONFIG_NET_ACT_INIT +#include <net/pkt_act.h> + +static int +ipt_init_target(struct ipt_entry_target *t, char *table, unsigned int hook) +{ + struct ipt_target *target; + int ret = 0; + + target = xt_find_target(AF_INET, t->u.user.name, t->u.user.revision); + if (!target) + return -ENOENT; + + DPRINTK("ipt_init_target: found %s\n", target->name); + t->u.kernel.target = target; + + if (t->u.kernel.target->checkentry + && !t->u.kernel.target->checkentry(table, NULL, t->data, + t->u.target_size - sizeof(*t), + hook)) { + DPRINTK("ipt_init_target: check failed for `%s'.\n", + t->u.kernel.target->name); + module_put(t->u.kernel.target->me); + ret = -EINVAL; + } + + return ret; +} + +static void +ipt_destroy_target(struct ipt_entry_target *t) +{ + if (t->u.kernel.target->destroy) + t->u.kernel.target->destroy(t->data, + t->u.target_size - sizeof(*t)); + module_put(t->u.kernel.target->me); +} + +static int +tcf_ipt_release(struct tcf_ipt *p, int bind) +{ + int ret = 0; + if (p) { + if (bind) + p->bindcnt--; + p->refcnt--; + if (p->bindcnt <= 0 && p->refcnt <= 0) { + ipt_destroy_target(p->t); + kfree(p->tname); + kfree(p->t); + tcf_hash_destroy(p); + ret = ACT_P_DELETED; + } + } + return ret; +} + +static int +tcf_ipt_init(struct rtattr *rta, struct rtattr *est, struct tc_action *a, + int ovr, int bind) +{ + struct rtattr *tb[TCA_IPT_MAX]; + struct tcf_ipt *p; + struct ipt_entry_target *td, *t; + char *tname; + int ret = 0, err; + u32 hook = 0; + u32 index = 0; + + if (rta == NULL || rtattr_parse_nested(tb, TCA_IPT_MAX, rta) < 0) + return -EINVAL; + + if (tb[TCA_IPT_HOOK-1] == NULL || + RTA_PAYLOAD(tb[TCA_IPT_HOOK-1]) < sizeof(u32)) + return -EINVAL; + if (tb[TCA_IPT_TARG-1] == NULL || + RTA_PAYLOAD(tb[TCA_IPT_TARG-1]) < sizeof(*t)) + return -EINVAL; + td = (struct ipt_entry_target *)RTA_DATA(tb[TCA_IPT_TARG-1]); + if (RTA_PAYLOAD(tb[TCA_IPT_TARG-1]) < td->u.target_size) + return -EINVAL; + + if (tb[TCA_IPT_INDEX-1] != NULL && + RTA_PAYLOAD(tb[TCA_IPT_INDEX-1]) >= sizeof(u32)) + index = *(u32 *)RTA_DATA(tb[TCA_IPT_INDEX-1]); + + p = tcf_hash_check(index, a, ovr, bind); + if (p == NULL) { + p = tcf_hash_create(index, est, a, sizeof(*p), ovr, bind); + if (p == NULL) + return -ENOMEM; + ret = ACT_P_CREATED; + } else { + if (!ovr) { + tcf_ipt_release(p, bind); + return -EEXIST; + } + } + + hook = *(u32 *)RTA_DATA(tb[TCA_IPT_HOOK-1]); + + err = -ENOMEM; + tname = kmalloc(IFNAMSIZ, GFP_KERNEL); + if (tname == NULL) + goto err1; + if (tb[TCA_IPT_TABLE - 1] == NULL || + rtattr_strlcpy(tname, tb[TCA_IPT_TABLE-1], IFNAMSIZ) >= IFNAMSIZ) + strcpy(tname, "mangle"); + + t = kmalloc(td->u.target_size, GFP_KERNEL); + if (t == NULL) + goto err2; + memcpy(t, td, td->u.target_size); + + if ((err = ipt_init_target(t, tname, hook)) < 0) + goto err3; + + spin_lock_bh(&p->lock); + if (ret != ACT_P_CREATED) { + ipt_destroy_target(p->t); + kfree(p->tname); + kfree(p->t); + } + p->tname = tname; + p->t = t; + p->hook = hook; + spin_unlock_bh(&p->lock); + if (ret == ACT_P_CREATED) + tcf_hash_insert(p); + return ret; + +err3: + kfree(t); +err2: + kfree(tname); +err1: + kfree(p); + return err; +} + +static int +tcf_ipt_cleanup(struct tc_action *a, int bind) +{ + struct tcf_ipt *p = PRIV(a, ipt); + return tcf_ipt_release(p, bind); +} + +static int +tcf_ipt(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res) +{ + int ret = 0, result = 0; + struct tcf_ipt *p = PRIV(a, ipt); + + if (skb_cloned(skb)) { + if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) + return TC_ACT_UNSPEC; + } + + spin_lock(&p->lock); + + p->tm.lastuse = jiffies; + p->bstats.bytes += skb->len; + p->bstats.packets++; + + /* yes, we have to worry about both in and out dev + worry later - danger - this API seems to have changed + from earlier kernels */ + + /* iptables targets take a double skb pointer in case the skb + * needs to be replaced. We don't own the skb, so this must not + * happen. The pskb_expand_head above should make sure of this */ + ret = p->t->u.kernel.target->target(&skb, skb->dev, NULL, + p->hook, p->t->data, NULL); + switch (ret) { + case NF_ACCEPT: + result = TC_ACT_OK; + break; + case NF_DROP: + result = TC_ACT_SHOT; + p->qstats.drops++; + break; + case IPT_CONTINUE: + result = TC_ACT_PIPE; + break; + default: + if (net_ratelimit()) + printk("Bogus netfilter code %d assume ACCEPT\n", ret); + result = TC_POLICE_OK; + break; + } + spin_unlock(&p->lock); + return result; + +} + +static int +tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) +{ + struct ipt_entry_target *t; + struct tcf_t tm; + struct tc_cnt c; + unsigned char *b = skb->tail; + struct tcf_ipt *p = PRIV(a, ipt); + + /* for simple targets kernel size == user size + ** user name = target name + ** for foolproof you need to not assume this + */ + + t = kmalloc(p->t->u.user.target_size, GFP_ATOMIC); + if (t == NULL) + goto rtattr_failure; + + c.bindcnt = p->bindcnt - bind; + c.refcnt = p->refcnt - ref; + memcpy(t, p->t, p->t->u.user.target_size); + strcpy(t->u.user.name, p->t->u.kernel.target->name); + + DPRINTK("\ttcf_ipt_dump tablename %s length %d\n", p->tname, + strlen(p->tname)); + DPRINTK("\tdump target name %s size %d size user %d " + "data[0] %x data[1] %x\n", p->t->u.kernel.target->name, + p->t->u.target_size, p->t->u.user.target_size, + p->t->data[0], p->t->data[1]); + RTA_PUT(skb, TCA_IPT_TARG, p->t->u.user.target_size, t); + RTA_PUT(skb, TCA_IPT_INDEX, 4, &p->index); + RTA_PUT(skb, TCA_IPT_HOOK, 4, &p->hook); + RTA_PUT(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c); + RTA_PUT(skb, TCA_IPT_TABLE, IFNAMSIZ, p->tname); + tm.install = jiffies_to_clock_t(jiffies - p->tm.install); + tm.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse); + tm.expires = jiffies_to_clock_t(p->tm.expires); + RTA_PUT(skb, TCA_IPT_TM, sizeof (tm), &tm); + kfree(t); + return skb->len; + + rtattr_failure: + skb_trim(skb, b - skb->data); + kfree(t); + return -1; +} + +static struct tc_action_ops act_ipt_ops = { + .kind = "ipt", + .type = TCA_ACT_IPT, + .capab = TCA_CAP_NONE, + .owner = THIS_MODULE, + .act = tcf_ipt, + .dump = tcf_ipt_dump, + .cleanup = tcf_ipt_cleanup, + .lookup = tcf_hash_search, + .init = tcf_ipt_init, + .walk = tcf_generic_walker +}; + +MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); +MODULE_DESCRIPTION("Iptables target actions"); +MODULE_LICENSE("GPL"); + +static int __init +ipt_init_module(void) +{ + return tcf_register_action(&act_ipt_ops); +} + +static void __exit +ipt_cleanup_module(void) +{ + tcf_unregister_action(&act_ipt_ops); +} + +module_init(ipt_init_module); +module_exit(ipt_cleanup_module); |