123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379 |
- /* L3/L4 protocol support for nf_conntrack. */
- /* (C) 1999-2001 Paul `Rusty' Russell
- * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
- * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
- #include <linux/types.h>
- #include <linux/netfilter.h>
- #include <linux/module.h>
- #include <linux/mutex.h>
- #include <linux/skbuff.h>
- #include <linux/vmalloc.h>
- #include <linux/stddef.h>
- #include <linux/err.h>
- #include <linux/percpu.h>
- #include <linux/moduleparam.h>
- #include <linux/notifier.h>
- #include <linux/kernel.h>
- #include <linux/netdevice.h>
- #include <net/netfilter/nf_conntrack.h>
- #include <net/netfilter/nf_conntrack_l3proto.h>
- #include <net/netfilter/nf_conntrack_l4proto.h>
- #include <net/netfilter/nf_conntrack_core.h>
- struct nf_conntrack_l4proto **nf_ct_protos[PF_MAX] __read_mostly;
- struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX] __read_mostly;
- EXPORT_SYMBOL_GPL(nf_ct_l3protos);
- #ifdef CONFIG_SYSCTL
- static DEFINE_MUTEX(nf_ct_proto_sysctl_mutex);
- static int
- nf_ct_register_sysctl(struct ctl_table_header **header, struct ctl_table *path,
- struct ctl_table *table, unsigned int *users)
- {
- if (*header == NULL) {
- *header = nf_register_sysctl_table(path, table);
- if (*header == NULL)
- return -ENOMEM;
- }
- if (users != NULL)
- (*users)++;
- return 0;
- }
- static void
- nf_ct_unregister_sysctl(struct ctl_table_header **header,
- struct ctl_table *table, unsigned int *users)
- {
- if (users != NULL && --*users > 0)
- return;
- nf_unregister_sysctl_table(*header, table);
- *header = NULL;
- }
- #endif
- struct nf_conntrack_l4proto *
- __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
- {
- if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL))
- return &nf_conntrack_l4proto_generic;
- return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
- }
- EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);
- /* this is guaranteed to always return a valid protocol helper, since
- * it falls back to generic_protocol */
- struct nf_conntrack_l4proto *
- nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t l4proto)
- {
- struct nf_conntrack_l4proto *p;
- rcu_read_lock();
- p = __nf_ct_l4proto_find(l3proto, l4proto);
- if (!try_module_get(p->me))
- p = &nf_conntrack_l4proto_generic;
- rcu_read_unlock();
- return p;
- }
- EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get);
- void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p)
- {
- module_put(p->me);
- }
- EXPORT_SYMBOL_GPL(nf_ct_l4proto_put);
- struct nf_conntrack_l3proto *
- nf_ct_l3proto_find_get(u_int16_t l3proto)
- {
- struct nf_conntrack_l3proto *p;
- rcu_read_lock();
- p = __nf_ct_l3proto_find(l3proto);
- if (!try_module_get(p->me))
- p = &nf_conntrack_l3proto_generic;
- rcu_read_unlock();
- return p;
- }
- EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);
- void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p)
- {
- module_put(p->me);
- }
- EXPORT_SYMBOL_GPL(nf_ct_l3proto_put);
- int
- nf_ct_l3proto_try_module_get(unsigned short l3proto)
- {
- int ret;
- struct nf_conntrack_l3proto *p;
- retry: p = nf_ct_l3proto_find_get(l3proto);
- if (p == &nf_conntrack_l3proto_generic) {
- ret = request_module("nf_conntrack-%d", l3proto);
- if (!ret)
- goto retry;
- return -EPROTOTYPE;
- }
- return 0;
- }
- EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);
- void nf_ct_l3proto_module_put(unsigned short l3proto)
- {
- struct nf_conntrack_l3proto *p;
- /* rcu_read_lock not necessary since the caller holds a reference */
- p = __nf_ct_l3proto_find(l3proto);
- module_put(p->me);
- }
- EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
- static int kill_l3proto(struct nf_conn *i, void *data)
- {
- return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num ==
- ((struct nf_conntrack_l3proto *)data)->l3proto);
- }
- static int kill_l4proto(struct nf_conn *i, void *data)
- {
- struct nf_conntrack_l4proto *l4proto;
- l4proto = (struct nf_conntrack_l4proto *)data;
- return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum ==
- l4proto->l4proto) &&
- (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num ==
- l4proto->l3proto);
- }
- static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
- {
- int err = 0;
- #ifdef CONFIG_SYSCTL
- mutex_lock(&nf_ct_proto_sysctl_mutex);
- if (l3proto->ctl_table != NULL) {
- err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
- l3proto->ctl_table_path,
- l3proto->ctl_table, NULL);
- }
- mutex_unlock(&nf_ct_proto_sysctl_mutex);
- #endif
- return err;
- }
- static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto)
- {
- #ifdef CONFIG_SYSCTL
- mutex_lock(&nf_ct_proto_sysctl_mutex);
- if (l3proto->ctl_table_header != NULL)
- nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
- l3proto->ctl_table, NULL);
- mutex_unlock(&nf_ct_proto_sysctl_mutex);
- #endif
- }
- int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
- {
- int ret = 0;
- if (proto->l3proto >= AF_MAX) {
- ret = -EBUSY;
- goto out;
- }
- write_lock_bh(&nf_conntrack_lock);
- if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
- ret = -EBUSY;
- goto out_unlock;
- }
- rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
- write_unlock_bh(&nf_conntrack_lock);
- ret = nf_ct_l3proto_register_sysctl(proto);
- if (ret < 0)
- nf_conntrack_l3proto_unregister(proto);
- return ret;
- out_unlock:
- write_unlock_bh(&nf_conntrack_lock);
- out:
- return ret;
- }
- EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);
- void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
- {
- BUG_ON(proto->l3proto >= AF_MAX);
- write_lock_bh(&nf_conntrack_lock);
- BUG_ON(nf_ct_l3protos[proto->l3proto] != proto);
- rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
- &nf_conntrack_l3proto_generic);
- write_unlock_bh(&nf_conntrack_lock);
- synchronize_rcu();
- nf_ct_l3proto_unregister_sysctl(proto);
- /* Remove all contrack entries for this protocol */
- nf_ct_iterate_cleanup(kill_l3proto, proto);
- }
- EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
- static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
- {
- int err = 0;
- #ifdef CONFIG_SYSCTL
- mutex_lock(&nf_ct_proto_sysctl_mutex);
- if (l4proto->ctl_table != NULL) {
- err = nf_ct_register_sysctl(l4proto->ctl_table_header,
- nf_net_netfilter_sysctl_path,
- l4proto->ctl_table,
- l4proto->ctl_table_users);
- if (err < 0)
- goto out;
- }
- #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
- if (l4proto->ctl_compat_table != NULL) {
- err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header,
- nf_net_ipv4_netfilter_sysctl_path,
- l4proto->ctl_compat_table, NULL);
- if (err == 0)
- goto out;
- nf_ct_unregister_sysctl(l4proto->ctl_table_header,
- l4proto->ctl_table,
- l4proto->ctl_table_users);
- }
- #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
- out:
- mutex_unlock(&nf_ct_proto_sysctl_mutex);
- #endif /* CONFIG_SYSCTL */
- return err;
- }
- static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
- {
- #ifdef CONFIG_SYSCTL
- mutex_lock(&nf_ct_proto_sysctl_mutex);
- if (l4proto->ctl_table_header != NULL &&
- *l4proto->ctl_table_header != NULL)
- nf_ct_unregister_sysctl(l4proto->ctl_table_header,
- l4proto->ctl_table,
- l4proto->ctl_table_users);
- #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
- if (l4proto->ctl_compat_table_header != NULL)
- nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header,
- l4proto->ctl_compat_table, NULL);
- #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
- mutex_unlock(&nf_ct_proto_sysctl_mutex);
- #endif /* CONFIG_SYSCTL */
- }
- /* FIXME: Allow NULL functions and sub in pointers to generic for
- them. --RR */
- int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
- {
- int ret = 0;
- if (l4proto->l3proto >= PF_MAX) {
- ret = -EBUSY;
- goto out;
- }
- if (l4proto == &nf_conntrack_l4proto_generic)
- return nf_ct_l4proto_register_sysctl(l4proto);
- retry:
- write_lock_bh(&nf_conntrack_lock);
- if (nf_ct_protos[l4proto->l3proto]) {
- if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
- != &nf_conntrack_l4proto_generic) {
- ret = -EBUSY;
- goto out_unlock;
- }
- } else {
- /* l3proto may be loaded latter. */
- struct nf_conntrack_l4proto **proto_array;
- int i;
- write_unlock_bh(&nf_conntrack_lock);
- proto_array = (struct nf_conntrack_l4proto **)
- kmalloc(MAX_NF_CT_PROTO *
- sizeof(struct nf_conntrack_l4proto *),
- GFP_KERNEL);
- if (proto_array == NULL) {
- ret = -ENOMEM;
- goto out;
- }
- for (i = 0; i < MAX_NF_CT_PROTO; i++)
- proto_array[i] = &nf_conntrack_l4proto_generic;
- write_lock_bh(&nf_conntrack_lock);
- if (nf_ct_protos[l4proto->l3proto]) {
- /* bad timing, but no problem */
- write_unlock_bh(&nf_conntrack_lock);
- kfree(proto_array);
- } else {
- nf_ct_protos[l4proto->l3proto] = proto_array;
- write_unlock_bh(&nf_conntrack_lock);
- }
- /*
- * Just once because array is never freed until unloading
- * nf_conntrack.ko
- */
- goto retry;
- }
- rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], l4proto);
- write_unlock_bh(&nf_conntrack_lock);
- ret = nf_ct_l4proto_register_sysctl(l4proto);
- if (ret < 0)
- nf_conntrack_l4proto_unregister(l4proto);
- return ret;
- out_unlock:
- write_unlock_bh(&nf_conntrack_lock);
- out:
- return ret;
- }
- EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);
- void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
- {
- BUG_ON(l4proto->l3proto >= PF_MAX);
- if (l4proto == &nf_conntrack_l4proto_generic) {
- nf_ct_l4proto_unregister_sysctl(l4proto);
- return;
- }
- write_lock_bh(&nf_conntrack_lock);
- BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto);
- rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
- &nf_conntrack_l4proto_generic);
- write_unlock_bh(&nf_conntrack_lock);
- synchronize_rcu();
- nf_ct_l4proto_unregister_sysctl(l4proto);
- /* Remove all contrack entries for this protocol */
- nf_ct_iterate_cleanup(kill_l4proto, l4proto);
- }
- EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
|