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author | Martin Josefsson <gandalf@wlug.westbo.se> | 2006-11-29 02:34:59 +0100 |
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committer | David S. Miller <davem@sunset.davemloft.net> | 2006-12-02 21:31:05 -0800 |
commit | 7e5d03bb9d2b96fdeab0cb0c98b93e6cf7130c96 (patch) | |
tree | 8214d124da1d3c098b3fcf67f46ef1ec7529cf5d /net/netfilter/nf_conntrack_helper.c | |
parent | 77ab9cff0f4112703df3ef7903c1a15adb967114 (diff) | |
download | linux-stable-7e5d03bb9d2b96fdeab0cb0c98b93e6cf7130c96.tar.gz linux-stable-7e5d03bb9d2b96fdeab0cb0c98b93e6cf7130c96.tar.bz2 linux-stable-7e5d03bb9d2b96fdeab0cb0c98b93e6cf7130c96.zip |
[NETFILTER]: nf_conntrack: split out helper handling
This patch splits out handling of helpers into its own file
nf_conntrack_helper.c
Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/netfilter/nf_conntrack_helper.c')
-rw-r--r-- | net/netfilter/nf_conntrack_helper.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c new file mode 100644 index 000000000000..ca044875a561 --- /dev/null +++ b/net/netfilter/nf_conntrack_helper.c @@ -0,0 +1,151 @@ +/* Helper handling for netfilter. */ + +/* (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/skbuff.h> +#include <linux/vmalloc.h> +#include <linux/stddef.h> +#include <linux/slab.h> +#include <linux/random.h> +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/netdevice.h> + +#define ASSERT_READ_LOCK(x) +#define ASSERT_WRITE_LOCK(x) + +#include <net/netfilter/nf_conntrack.h> +#include <net/netfilter/nf_conntrack_l3proto.h> +#include <net/netfilter/nf_conntrack_protocol.h> +#include <net/netfilter/nf_conntrack_helper.h> +#include <net/netfilter/nf_conntrack_core.h> + +static LIST_HEAD(helpers); + +struct nf_conntrack_helper * +__nf_ct_helper_find(const struct nf_conntrack_tuple *tuple) +{ + struct nf_conntrack_helper *h; + + list_for_each_entry(h, &helpers, list) { + if (nf_ct_tuple_mask_cmp(tuple, &h->tuple, &h->mask)) + return h; + } + return NULL; +} + +struct nf_conntrack_helper * +nf_ct_helper_find_get( const struct nf_conntrack_tuple *tuple) +{ + struct nf_conntrack_helper *helper; + + /* need nf_conntrack_lock to assure that helper exists until + * try_module_get() is called */ + read_lock_bh(&nf_conntrack_lock); + + helper = __nf_ct_helper_find(tuple); + if (helper) { + /* need to increase module usage count to assure helper will + * not go away while the caller is e.g. busy putting a + * conntrack in the hash that uses the helper */ + if (!try_module_get(helper->me)) + helper = NULL; + } + + read_unlock_bh(&nf_conntrack_lock); + + return helper; +} + +void nf_ct_helper_put(struct nf_conntrack_helper *helper) +{ + module_put(helper->me); +} + +struct nf_conntrack_helper * +__nf_conntrack_helper_find_byname(const char *name) +{ + struct nf_conntrack_helper *h; + + list_for_each_entry(h, &helpers, list) { + if (!strcmp(h->name, name)) + return h; + } + + return NULL; +} + +static inline int unhelp(struct nf_conntrack_tuple_hash *i, + const struct nf_conntrack_helper *me) +{ + struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i); + struct nf_conn_help *help = nfct_help(ct); + + if (help && help->helper == me) { + nf_conntrack_event(IPCT_HELPER, ct); + help->helper = NULL; + } + return 0; +} + +int nf_conntrack_helper_register(struct nf_conntrack_helper *me) +{ + int ret; + BUG_ON(me->timeout == 0); + + ret = nf_conntrack_register_cache(NF_CT_F_HELP, "nf_conntrack:help", + sizeof(struct nf_conn) + + sizeof(struct nf_conn_help) + + __alignof__(struct nf_conn_help)); + if (ret < 0) { + printk(KERN_ERR "nf_conntrack_helper_register: Unable to create slab cache for conntracks\n"); + return ret; + } + write_lock_bh(&nf_conntrack_lock); + list_add(&me->list, &helpers); + write_unlock_bh(&nf_conntrack_lock); + + return 0; +} + +void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me) +{ + unsigned int i; + struct nf_conntrack_tuple_hash *h; + struct nf_conntrack_expect *exp, *tmp; + + /* Need write lock here, to delete helper. */ + write_lock_bh(&nf_conntrack_lock); + list_del(&me->list); + + /* Get rid of expectations */ + list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list, list) { + struct nf_conn_help *help = nfct_help(exp->master); + if (help->helper == me && del_timer(&exp->timeout)) { + nf_ct_unlink_expect(exp); + nf_conntrack_expect_put(exp); + } + } + + /* Get rid of expecteds, set helpers to NULL. */ + list_for_each_entry(h, &unconfirmed, list) + unhelp(h, me); + for (i = 0; i < nf_conntrack_htable_size; i++) { + list_for_each_entry(h, &nf_conntrack_hash[i], list) + unhelp(h, me); + } + write_unlock_bh(&nf_conntrack_lock); + + /* Someone could be still looking at the helper in a bh. */ + synchronize_net(); +} |