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authorHarald Welte <laforge@netfilter.org>2005-08-09 19:40:55 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2005-08-29 15:35:08 -0700
commit4fdb3bb723db469717c6d38fda667d8b0fa86ebd (patch)
tree43d82e717922e6319cf8a8f9dc5ee902c651b491
parent020b4c12dbe3868d792a01d7c1470cd837abe10f (diff)
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[NETLINK]: Add properly module refcounting for kernel netlink sockets.
- Remove bogus code for compiling netlink as module - Add module refcounting support for modules implementing a netlink protocol - Add support for autoloading modules that implement a netlink protocol as soon as someone opens a socket for that protocol Signed-off-by: Harald Welte <laforge@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/w1/w1_int.c4
-rw-r--r--include/linux/net.h3
-rw-r--r--include/linux/netlink.h2
-rw-r--r--kernel/audit.c3
-rw-r--r--lib/kobject_uevent.c3
-rw-r--r--net/bridge/netfilter/ebt_ulog.c2
-rw-r--r--net/core/rtnetlink.c2
-rw-r--r--net/decnet/netfilter/dn_rtmsg.c4
-rw-r--r--net/ipv4/fib_frontend.c2
-rw-r--r--net/ipv4/netfilter/ip_queue.c3
-rw-r--r--net/ipv4/netfilter/ipt_ULOG.c3
-rw-r--r--net/ipv4/tcp_diag.c3
-rw-r--r--net/ipv6/netfilter/ip6_queue.c2
-rw-r--r--net/netfilter/nfnetlink.c5
-rw-r--r--net/netlink/af_netlink.c108
-rw-r--r--net/xfrm/xfrm_user.c4
-rw-r--r--security/selinux/netlink.c2
17 files changed, 119 insertions, 36 deletions
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
index b5a5e04b6d3..8809788dac2 100644
--- a/drivers/w1/w1_int.c
+++ b/drivers/w1/w1_int.c
@@ -88,7 +88,7 @@ static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
dev->groups = 23;
dev->seq = 1;
- dev->nls = netlink_kernel_create(NETLINK_W1, NULL);
+ dev->nls = netlink_kernel_create(NETLINK_W1, NULL, THIS_MODULE);
if (!dev->nls) {
printk(KERN_ERR "Failed to create new netlink socket(%u) for w1 master %s.\n",
NETLINK_NFLOG, dev->dev.bus_id);
@@ -225,3 +225,5 @@ void w1_remove_master_device(struct w1_bus_master *bm)
EXPORT_SYMBOL(w1_add_master_device);
EXPORT_SYMBOL(w1_remove_master_device);
+
+MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_W1);
diff --git a/include/linux/net.h b/include/linux/net.h
index 20cb226b226..39906619b9d 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -282,5 +282,8 @@ static struct proto_ops name##_ops = { \
#define MODULE_ALIAS_NETPROTO(proto) \
MODULE_ALIAS("net-pf-" __stringify(proto))
+#define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
+ MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
+
#endif /* __KERNEL__ */
#endif /* _LINUX_NET_H */
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 6552b71bfa7..1c50fea8995 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -117,7 +117,7 @@ struct netlink_skb_parms
#define NETLINK_CREDS(skb) (&NETLINK_CB((skb)).creds)
-extern struct sock *netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len));
+extern struct sock *netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len), struct module *module);
extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 pid, int nonblock);
extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 pid,
diff --git a/kernel/audit.c b/kernel/audit.c
index ef35166fdc2..ed4019563d5 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -514,7 +514,8 @@ static int __init audit_init(void)
{
printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
audit_default ? "enabled" : "disabled");
- audit_sock = netlink_kernel_create(NETLINK_AUDIT, audit_receive);
+ audit_sock = netlink_kernel_create(NETLINK_AUDIT, audit_receive,
+ THIS_MODULE);
if (!audit_sock)
audit_panic("cannot initialize netlink socket");
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 8e49d21057e..88f4d746aa0 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -153,7 +153,8 @@ EXPORT_SYMBOL_GPL(kobject_uevent_atomic);
static int __init kobject_uevent_init(void)
{
- uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, NULL);
+ uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, NULL,
+ THIS_MODULE);
if (!uevent_sock) {
printk(KERN_ERR
diff --git a/net/bridge/netfilter/ebt_ulog.c b/net/bridge/netfilter/ebt_ulog.c
index 01af4fcef26..561d75c8ed5 100644
--- a/net/bridge/netfilter/ebt_ulog.c
+++ b/net/bridge/netfilter/ebt_ulog.c
@@ -258,7 +258,7 @@ static int __init init(void)
spin_lock_init(&ulog_buffers[i].lock);
}
- ebtulognl = netlink_kernel_create(NETLINK_NFLOG, NULL);
+ ebtulognl = netlink_kernel_create(NETLINK_NFLOG, NULL, THIS_MODULE);
if (!ebtulognl)
ret = -ENOMEM;
else if ((ret = ebt_register_watcher(&ulog)))
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 4b1bb30e638..9b3c61f1a37 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -708,7 +708,7 @@ void __init rtnetlink_init(void)
if (!rta_buf)
panic("rtnetlink_init: cannot allocate rta_buf\n");
- rtnl = netlink_kernel_create(NETLINK_ROUTE, rtnetlink_rcv);
+ rtnl = netlink_kernel_create(NETLINK_ROUTE, rtnetlink_rcv, THIS_MODULE);
if (rtnl == NULL)
panic("rtnetlink_init: cannot initialize rtnetlink\n");
netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
diff --git a/net/decnet/netfilter/dn_rtmsg.c b/net/decnet/netfilter/dn_rtmsg.c
index 284a9998e53..3068fddb2da 100644
--- a/net/decnet/netfilter/dn_rtmsg.c
+++ b/net/decnet/netfilter/dn_rtmsg.c
@@ -138,7 +138,8 @@ static int __init init(void)
{
int rv = 0;
- dnrmg = netlink_kernel_create(NETLINK_DNRTMSG, dnrmg_receive_user_sk);
+ dnrmg = netlink_kernel_create(NETLINK_DNRTMSG, dnrmg_receive_user_sk,
+ THIS_MODULE);
if (dnrmg == NULL) {
printk(KERN_ERR "dn_rtmsg: Cannot create netlink socket");
return -ENOMEM;
@@ -162,6 +163,7 @@ static void __exit fini(void)
MODULE_DESCRIPTION("DECnet Routing Message Grabulator");
MODULE_AUTHOR("Steven Whitehouse <steve@chygwyn.com>");
MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_DNRTMSG);
module_init(init);
module_exit(fini);
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index e5722084239..b5e2f1550c9 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -567,7 +567,7 @@ static void nl_fib_input(struct sock *sk, int len)
static void nl_fib_lookup_init(void)
{
- netlink_kernel_create(NETLINK_FIB_LOOKUP, nl_fib_input);
+ netlink_kernel_create(NETLINK_FIB_LOOKUP, nl_fib_input, THIS_MODULE);
}
static void fib_disable_ip(struct net_device *dev, int force)
diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
index ae975ac59c6..b237f7fcad9 100644
--- a/net/ipv4/netfilter/ip_queue.c
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -692,7 +692,8 @@ init_or_cleanup(int init)
goto cleanup;
netlink_register_notifier(&ipq_nl_notifier);
- ipqnl = netlink_kernel_create(NETLINK_FIREWALL, ipq_rcv_sk);
+ ipqnl = netlink_kernel_create(NETLINK_FIREWALL, ipq_rcv_sk,
+ THIS_MODULE);
if (ipqnl == NULL) {
printk(KERN_ERR "ip_queue: failed to create netlink socket\n");
goto cleanup_netlink_notifier;
diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c
index 52a0076302a..4ea8371ab27 100644
--- a/net/ipv4/netfilter/ipt_ULOG.c
+++ b/net/ipv4/netfilter/ipt_ULOG.c
@@ -62,6 +62,7 @@
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
MODULE_DESCRIPTION("iptables userspace logging module");
+MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NFLOG);
#define ULOG_NL_EVENT 111 /* Harald's favorite number */
#define ULOG_MAXNLGROUPS 32 /* numer of nlgroups */
@@ -372,7 +373,7 @@ static int __init init(void)
ulog_buffers[i].timer.data = i;
}
- nflognl = netlink_kernel_create(NETLINK_NFLOG, NULL);
+ nflognl = netlink_kernel_create(NETLINK_NFLOG, NULL, THIS_MODULE);
if (!nflognl)
return -ENOMEM;
diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
index f66945cb158..f79bd11a470 100644
--- a/net/ipv4/tcp_diag.c
+++ b/net/ipv4/tcp_diag.c
@@ -774,7 +774,8 @@ static void tcpdiag_rcv(struct sock *sk, int len)
static int __init tcpdiag_init(void)
{
- tcpnl = netlink_kernel_create(NETLINK_TCPDIAG, tcpdiag_rcv);
+ tcpnl = netlink_kernel_create(NETLINK_TCPDIAG, tcpdiag_rcv,
+ THIS_MODULE);
if (tcpnl == NULL)
return -ENOMEM;
return 0;
diff --git a/net/ipv6/netfilter/ip6_queue.c b/net/ipv6/netfilter/ip6_queue.c
index 7130603a32c..1c3d247a22c 100644
--- a/net/ipv6/netfilter/ip6_queue.c
+++ b/net/ipv6/netfilter/ip6_queue.c
@@ -685,7 +685,7 @@ init_or_cleanup(int init)
goto cleanup;
netlink_register_notifier(&ipq_nl_notifier);
- ipqnl = netlink_kernel_create(NETLINK_IP6_FW, ipq_rcv_sk);
+ ipqnl = netlink_kernel_create(NETLINK_IP6_FW, ipq_rcv_sk, THIS_MODULE);
if (ipqnl == NULL) {
printk(KERN_ERR "ip6_queue: failed to create netlink socket\n");
goto cleanup_netlink_notifier;
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index b0ed5798184..6210ca42166 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -38,6 +38,8 @@
#include <linux/netfilter/nfnetlink.h>
MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
+MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER);
static char __initdata nfversion[] = "0.30";
@@ -324,7 +326,8 @@ int __init nfnetlink_init(void)
{
printk("Netfilter messages via NETLINK v%s.\n", nfversion);
- nfnl = netlink_kernel_create(NETLINK_NETFILTER, nfnetlink_rcv);
+ nfnl = netlink_kernel_create(NETLINK_NETFILTER, nfnetlink_rcv,
+ THIS_MODULE);
if (!nfnl) {
printk(KERN_ERR "cannot initialize nfnetlink!\n");
return -1;
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index ff774a06c89..5d487cd69c8 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -13,7 +13,12 @@
* added netlink_proto_exit
* Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
* use nlk_sk, as sk->protinfo is on a diet 8)
- *
+ * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org>
+ * - inc module use count of module that owns
+ * the kernel socket in case userspace opens
+ * socket of same protocol
+ * - remove all module support, since netlink is
+ * mandatory if CONFIG_NET=y these days
*/
#include <linux/config.h>
@@ -92,6 +97,7 @@ struct netlink_table {
struct nl_pid_hash hash;
struct hlist_head mc_list;
unsigned int nl_nonroot;
+ struct proto_ops *p_ops;
};
static struct netlink_table *nl_table;
@@ -341,7 +347,21 @@ static int netlink_create(struct socket *sock, int protocol)
if (protocol<0 || protocol >= MAX_LINKS)
return -EPROTONOSUPPORT;
- sock->ops = &netlink_ops;
+ netlink_table_grab();
+ if (!nl_table[protocol].hash.entries) {
+#ifdef CONFIG_KMOD
+ /* We do 'best effort'. If we find a matching module,
+ * it is loaded. If not, we don't return an error to
+ * allow pure userspace<->userspace communication. -HW
+ */
+ netlink_table_ungrab();
+ request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
+ netlink_table_grab();
+#endif
+ }
+ netlink_table_ungrab();
+
+ sock->ops = nl_table[protocol].p_ops;
sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1);
if (!sk)
@@ -394,6 +414,22 @@ static int netlink_release(struct socket *sock)
};
notifier_call_chain(&netlink_chain, NETLINK_URELEASE, &n);
}
+
+ /* When this is a kernel socket, we need to remove the owner pointer,
+ * since we don't know whether the module will be dying at any given
+ * point - HW
+ */
+ if (!nlk->pid) {
+ struct proto_ops *p_tmp;
+
+ netlink_table_grab();
+ p_tmp = nl_table[sk->sk_protocol].p_ops;
+ if (p_tmp != &netlink_ops) {
+ nl_table[sk->sk_protocol].p_ops = &netlink_ops;
+ kfree(p_tmp);
+ }
+ netlink_table_ungrab();
+ }
sock_put(sk);
return 0;
@@ -1023,8 +1059,9 @@ static void netlink_data_ready(struct sock *sk, int len)
*/
struct sock *
-netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len))
+netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len), struct module *module)
{
+ struct proto_ops *p_ops;
struct socket *sock;
struct sock *sk;
@@ -1034,22 +1071,63 @@ netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len))
if (unit<0 || unit>=MAX_LINKS)
return NULL;
+ /* Do a quick check, to make us not go down to netlink_insert()
+ * if protocol already has kernel socket.
+ */
+ sk = netlink_lookup(unit, 0);
+ if (unlikely(sk)) {
+ sock_put(sk);
+ return NULL;
+ }
+
if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
return NULL;
+ sk = NULL;
+ if (module) {
+ /* Every registering protocol implemented in a module needs
+ * it's own p_ops, since the socket code cannot deal with
+ * module refcounting otherwise. -HW
+ */
+ p_ops = kmalloc(sizeof(*p_ops), GFP_KERNEL);
+ if (!p_ops)
+ goto out_sock_release;
+
+ memcpy(p_ops, &netlink_ops, sizeof(*p_ops));
+ p_ops->owner = module;
+ } else
+ p_ops = &netlink_ops;
+
+ netlink_table_grab();
+ nl_table[unit].p_ops = p_ops;
+ netlink_table_ungrab();
+
if (netlink_create(sock, unit) < 0) {
- sock_release(sock);
- return NULL;
+ sk = NULL;
+ goto out_kfree_p_ops;
}
+
sk = sock->sk;
sk->sk_data_ready = netlink_data_ready;
if (input)
nlk_sk(sk)->data_ready = input;
if (netlink_insert(sk, 0)) {
- sock_release(sock);
- return NULL;
+ sk = NULL;
+ goto out_kfree_p_ops;
+ }
+
+ return sk;
+
+out_kfree_p_ops:
+ netlink_table_grab();
+ if (nl_table[unit].p_ops != &netlink_ops) {
+ kfree(nl_table[unit].p_ops);
+ nl_table[unit].p_ops = &netlink_ops;
}
+ netlink_table_ungrab();
+out_sock_release:
+ sock_release(sock);
return sk;
}
@@ -1413,6 +1491,8 @@ enomem:
for (i = 0; i < MAX_LINKS; i++) {
struct nl_pid_hash *hash = &nl_table[i].hash;
+ nl_table[i].p_ops = &netlink_ops;
+
hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table));
if (!hash->table) {
while (i-- > 0)
@@ -1438,21 +1518,7 @@ out:
return err;
}
-static void __exit netlink_proto_exit(void)
-{
- sock_unregister(PF_NETLINK);
- proc_net_remove("netlink");
- kfree(nl_table);
- nl_table = NULL;
- proto_unregister(&netlink_proto);
-}
-
core_initcall(netlink_proto_init);
-module_exit(netlink_proto_exit);
-
-MODULE_LICENSE("GPL");
-
-MODULE_ALIAS_NETPROTO(PF_NETLINK);
EXPORT_SYMBOL(netlink_ack);
EXPORT_SYMBOL(netlink_broadcast);
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 8da3e25b2c4..33ceeea783b 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1519,7 +1519,8 @@ static int __init xfrm_user_init(void)
{
printk(KERN_INFO "Initializing IPsec netlink socket\n");
- xfrm_nl = netlink_kernel_create(NETLINK_XFRM, xfrm_netlink_rcv);
+ xfrm_nl = netlink_kernel_create(NETLINK_XFRM, xfrm_netlink_rcv,
+ THIS_MODULE);
if (xfrm_nl == NULL)
return -ENOMEM;
@@ -1537,3 +1538,4 @@ static void __exit xfrm_user_exit(void)
module_init(xfrm_user_init);
module_exit(xfrm_user_exit);
MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_XFRM);
diff --git a/security/selinux/netlink.c b/security/selinux/netlink.c
index 18d08acafa7..341dbe2579b 100644
--- a/security/selinux/netlink.c
+++ b/security/selinux/netlink.c
@@ -103,7 +103,7 @@ void selnl_notify_policyload(u32 seqno)
static int __init selnl_init(void)
{
- selnl = netlink_kernel_create(NETLINK_SELINUX, NULL);
+ selnl = netlink_kernel_create(NETLINK_SELINUX, NULL, THIS_MODULE);
if (selnl == NULL)
panic("SELinux: Cannot create netlink socket.");
netlink_set_nonroot(NETLINK_SELINUX, NL_NONROOT_RECV);