[NETFILTER]: nf_conntrack: support for layer 3 protocol load on demand
x_tables matches and targets that require nf_conntrack_ipv[4|6] to work
don't have enough information to load on demand these modules. This
patch introduces the following changes to solve this issue:
o nf_ct_l3proto_try_module_get: try to load the layer 3 connection
tracker module and increases the refcount.
o nf_ct_l3proto_module put: drop the refcount of the module.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index 2743c15..b6f0905 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -195,6 +195,10 @@
nf_conntrack_put(&ct->ct_general);
}
+/* Protocol module loading */
+extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
+extern void nf_ct_l3proto_module_put(unsigned short l3proto);
+
extern struct nf_conntrack_tuple_hash *
__nf_conntrack_find(const struct nf_conntrack_tuple *tuple,
const struct nf_conn *ignored_conntrack);
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index cb9c661..c8abc9d 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -568,6 +568,7 @@
return ret;
}
+MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET));
MODULE_LICENSE("GPL");
static int __init init(void)
diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
index ac35f95..c16f629 100644
--- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
@@ -584,6 +584,7 @@
return ret;
}
+MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6));
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>");
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index c288406..0ae281d 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -23,6 +23,8 @@
* 26 Jan 2006: Harald Welte <laforge@netfilter.org>
* - restructure nf_conn (introduce nf_conn_help)
* - redesign 'features' how they were originally intended
+ * 26 Feb 2006: Pablo Neira Ayuso <pablo@eurodev.net>
+ * - add support for L3 protocol module load on demand.
*
* Derived from net/ipv4/netfilter/ip_conntrack_core.c
*/
@@ -241,6 +243,35 @@
module_put(p->me);
}
+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_generic_l3proto) {
+ ret = request_module("nf_conntrack-%d", l3proto);
+ if (!ret)
+ goto retry;
+
+ return -EPROTOTYPE;
+ }
+
+ return 0;
+}
+
+void nf_ct_l3proto_module_put(unsigned short l3proto)
+{
+ struct nf_conntrack_l3proto *p;
+
+ preempt_disable();
+ p = __nf_ct_l3proto_find(l3proto);
+ preempt_enable();
+
+ module_put(p->me);
+}
+
static int nf_conntrack_hash_rnd_initted;
static unsigned int nf_conntrack_hash_rnd;
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 290d5a0..75577e1 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -834,6 +834,8 @@
EXPORT_PER_CPU_SYMBOL_GPL(nf_conntrack_ecache);
EXPORT_SYMBOL_GPL(nf_ct_deliver_cached_events);
#endif
+EXPORT_SYMBOL(nf_ct_l3proto_try_module_get);
+EXPORT_SYMBOL(nf_ct_l3proto_module_put);
EXPORT_SYMBOL(nf_conntrack_l3proto_register);
EXPORT_SYMBOL(nf_conntrack_l3proto_unregister);
EXPORT_SYMBOL(nf_conntrack_protocol_register);
diff --git a/net/netfilter/xt_connmark.c b/net/netfilter/xt_connmark.c
index e810600..7b16f1e 100644
--- a/net/netfilter/xt_connmark.c
+++ b/net/netfilter/xt_connmark.c
@@ -64,14 +64,30 @@
printk(KERN_WARNING "connmark: only support 32bit mark\n");
return 0;
}
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ if (nf_ct_l3proto_try_module_get(match->family) < 0) {
+ printk(KERN_WARNING "can't load nf_conntrack support for "
+ "proto=%d\n", match->family);
+ return 0;
+ }
+#endif
return 1;
}
+static void
+destroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize)
+{
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ nf_ct_l3proto_module_put(match->family);
+#endif
+}
+
static struct xt_match connmark_match = {
.name = "connmark",
.match = match,
.matchsize = sizeof(struct xt_connmark_info),
.checkentry = checkentry,
+ .destroy = destroy,
.family = AF_INET,
.me = THIS_MODULE
};
@@ -81,6 +97,7 @@
.match = match,
.matchsize = sizeof(struct xt_connmark_info),
.checkentry = checkentry,
+ .destroy = destroy,
.family = AF_INET6,
.me = THIS_MODULE
};
diff --git a/net/netfilter/xt_conntrack.c b/net/netfilter/xt_conntrack.c
index 7d20caa..65a8480 100644
--- a/net/netfilter/xt_conntrack.c
+++ b/net/netfilter/xt_conntrack.c
@@ -203,9 +203,37 @@
#endif /* CONFIG_NF_IP_CONNTRACK */
+static int
+checkentry(const char *tablename,
+ const void *ip,
+ const struct xt_match *match,
+ void *matchinfo,
+ unsigned int matchsize,
+ unsigned int hook_mask)
+{
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ if (nf_ct_l3proto_try_module_get(match->family) < 0) {
+ printk(KERN_WARNING "can't load nf_conntrack support for "
+ "proto=%d\n", match->family);
+ return 0;
+ }
+#endif
+ return 1;
+}
+
+static void
+destroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize)
+{
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ nf_ct_l3proto_module_put(match->family);
+#endif
+}
+
static struct xt_match conntrack_match = {
.name = "conntrack",
.match = match,
+ .checkentry = checkentry,
+ .destroy = destroy,
.matchsize = sizeof(struct xt_conntrack_info),
.family = AF_INET,
.me = THIS_MODULE,
diff --git a/net/netfilter/xt_helper.c b/net/netfilter/xt_helper.c
index 7d2d68b..101f000 100644
--- a/net/netfilter/xt_helper.c
+++ b/net/netfilter/xt_helper.c
@@ -144,15 +144,31 @@
{
struct xt_helper_info *info = matchinfo;
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ if (nf_ct_l3proto_try_module_get(match->family) < 0) {
+ printk(KERN_WARNING "can't load nf_conntrack support for "
+ "proto=%d\n", match->family);
+ return 0;
+ }
+#endif
info->name[29] = '\0';
return 1;
}
+static void
+destroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize)
+{
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ nf_ct_l3proto_module_put(match->family);
+#endif
+}
+
static struct xt_match helper_match = {
.name = "helper",
.match = match,
.matchsize = sizeof(struct xt_helper_info),
.checkentry = check,
+ .destroy = destroy,
.family = AF_INET,
.me = THIS_MODULE,
};
@@ -161,6 +177,7 @@
.match = match,
.matchsize = sizeof(struct xt_helper_info),
.checkentry = check,
+ .destroy = destroy,
.family = AF_INET6,
.me = THIS_MODULE,
};
diff --git a/net/netfilter/xt_state.c b/net/netfilter/xt_state.c
index 7cd557c..e6c0be9 100644
--- a/net/netfilter/xt_state.c
+++ b/net/netfilter/xt_state.c
@@ -44,9 +44,36 @@
return (sinfo->statemask & statebit);
}
+static int check(const char *tablename,
+ const void *inf,
+ const struct xt_match *match,
+ void *matchinfo,
+ unsigned int matchsize,
+ unsigned int hook_mask)
+{
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ if (nf_ct_l3proto_try_module_get(match->family) < 0) {
+ printk(KERN_WARNING "can't load nf_conntrack support for "
+ "proto=%d\n", match->family);
+ return 0;
+ }
+#endif
+ return 1;
+}
+
+static void
+destroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize)
+{
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ nf_ct_l3proto_module_put(match->family);
+#endif
+}
+
static struct xt_match state_match = {
.name = "state",
.match = match,
+ .checkentry = check,
+ .destroy = destroy,
.matchsize = sizeof(struct xt_state_info),
.family = AF_INET,
.me = THIS_MODULE,
@@ -55,6 +82,8 @@
static struct xt_match state6_match = {
.name = "state",
.match = match,
+ .checkentry = check,
+ .destroy = destroy,
.matchsize = sizeof(struct xt_state_info),
.family = AF_INET6,
.me = THIS_MODULE,
