1 /* L3/L4 protocol support for nf_conntrack. */
3 /* (C) 1999-2001 Paul `Rusty' Russell
4 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
5 * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/types.h>
13 #include <linux/netfilter.h>
14 #include <linux/module.h>
15 #include <linux/skbuff.h>
16 #include <linux/vmalloc.h>
17 #include <linux/stddef.h>
18 #include <linux/err.h>
19 #include <linux/percpu.h>
20 #include <linux/moduleparam.h>
21 #include <linux/notifier.h>
22 #include <linux/kernel.h>
23 #include <linux/netdevice.h>
25 #include <net/netfilter/nf_conntrack.h>
26 #include <net/netfilter/nf_conntrack_l3proto.h>
27 #include <net/netfilter/nf_conntrack_l4proto.h>
28 #include <net/netfilter/nf_conntrack_core.h>
30 struct nf_conntrack_l4proto **nf_ct_protos[PF_MAX] __read_mostly;
31 struct nf_conntrack_l3proto *nf_ct_l3protos[PF_MAX] __read_mostly;
33 struct nf_conntrack_l4proto *
34 __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
36 if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL))
37 return &nf_conntrack_l4proto_generic;
39 return nf_ct_protos[l3proto][l4proto];
42 /* this is guaranteed to always return a valid protocol helper, since
43 * it falls back to generic_protocol */
44 struct nf_conntrack_l4proto *
45 nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t l4proto)
47 struct nf_conntrack_l4proto *p;
50 p = __nf_ct_l4proto_find(l3proto, l4proto);
51 if (!try_module_get(p->me))
52 p = &nf_conntrack_l4proto_generic;
58 void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p)
63 struct nf_conntrack_l3proto *
64 nf_ct_l3proto_find_get(u_int16_t l3proto)
66 struct nf_conntrack_l3proto *p;
69 p = __nf_ct_l3proto_find(l3proto);
70 if (!try_module_get(p->me))
71 p = &nf_conntrack_l3proto_generic;
77 void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p)
83 nf_ct_l3proto_try_module_get(unsigned short l3proto)
86 struct nf_conntrack_l3proto *p;
88 retry: p = nf_ct_l3proto_find_get(l3proto);
89 if (p == &nf_conntrack_l3proto_generic) {
90 ret = request_module("nf_conntrack-%d", l3proto);
100 void nf_ct_l3proto_module_put(unsigned short l3proto)
102 struct nf_conntrack_l3proto *p;
105 p = __nf_ct_l3proto_find(l3proto);
111 static int kill_l3proto(struct nf_conn *i, void *data)
113 return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num ==
114 ((struct nf_conntrack_l3proto *)data)->l3proto);
117 static int kill_l4proto(struct nf_conn *i, void *data)
119 struct nf_conntrack_l4proto *l4proto;
120 l4proto = (struct nf_conntrack_l4proto *)data;
121 return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum ==
123 (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num ==
127 int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
131 write_lock_bh(&nf_conntrack_lock);
132 if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
136 nf_ct_l3protos[proto->l3proto] = proto;
138 write_unlock_bh(&nf_conntrack_lock);
143 void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
145 write_lock_bh(&nf_conntrack_lock);
146 nf_ct_l3protos[proto->l3proto] = &nf_conntrack_l3proto_generic;
147 write_unlock_bh(&nf_conntrack_lock);
149 /* Somebody could be still looking at the proto in bh. */
152 /* Remove all contrack entries for this protocol */
153 nf_ct_iterate_cleanup(kill_l3proto, proto);
156 /* FIXME: Allow NULL functions and sub in pointers to generic for
158 int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
163 write_lock_bh(&nf_conntrack_lock);
164 if (nf_ct_protos[l4proto->l3proto]) {
165 if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
166 != &nf_conntrack_l4proto_generic) {
171 /* l3proto may be loaded latter. */
172 struct nf_conntrack_l4proto **proto_array;
175 write_unlock_bh(&nf_conntrack_lock);
177 proto_array = (struct nf_conntrack_l4proto **)
178 kmalloc(MAX_NF_CT_PROTO *
179 sizeof(struct nf_conntrack_l4proto *),
181 if (proto_array == NULL) {
185 for (i = 0; i < MAX_NF_CT_PROTO; i++)
186 proto_array[i] = &nf_conntrack_l4proto_generic;
188 write_lock_bh(&nf_conntrack_lock);
189 if (nf_ct_protos[l4proto->l3proto]) {
190 /* bad timing, but no problem */
191 write_unlock_bh(&nf_conntrack_lock);
194 nf_ct_protos[l4proto->l3proto] = proto_array;
195 write_unlock_bh(&nf_conntrack_lock);
199 * Just once because array is never freed until unloading
205 nf_ct_protos[l4proto->l3proto][l4proto->l4proto] = l4proto;
208 write_unlock_bh(&nf_conntrack_lock);
213 void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
215 write_lock_bh(&nf_conntrack_lock);
216 nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
217 = &nf_conntrack_l4proto_generic;
218 write_unlock_bh(&nf_conntrack_lock);
220 /* Somebody could be still looking at the proto in bh. */
223 /* Remove all contrack entries for this protocol */
224 nf_ct_iterate_cleanup(kill_l4proto, l4proto);