1 files changed, 247 insertions, 65 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index ff774a06c89..62435ffc618 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>
@@ -55,21 +60,29 @@
 #include <net/scm.h>
 
 #define Nprintk(a...)
+#define NLGRPSZ(x)	(ALIGN(x, sizeof(unsigned long) * 8) / 8)
 
 struct netlink_sock {
 	/* struct sock has to be the first member of netlink_sock */
 	struct sock		sk;
 	u32			pid;
-	unsigned int		groups;
 	u32			dst_pid;
-	unsigned int		dst_groups;
+	u32			dst_group;
+	u32			flags;
+	u32			subscriptions;
+	u32			ngroups;
+	unsigned long		*groups;
 	unsigned long		state;
 	wait_queue_head_t	wait;
 	struct netlink_callback	*cb;
 	spinlock_t		cb_lock;
 	void			(*data_ready)(struct sock *sk, int bytes);
+	struct module		*module;
 };
 
+#define NETLINK_KERNEL_SOCKET	0x1
+#define NETLINK_RECV_PKTINFO	0x2
+
 static inline struct netlink_sock *nlk_sk(struct sock *sk)
 {
 	return (struct netlink_sock *)sk;
@@ -92,6 +105,9 @@ struct netlink_table {
 	struct nl_pid_hash hash;
 	struct hlist_head mc_list;
 	unsigned int nl_nonroot;
+	unsigned int groups;
+	struct module *module;
+	int registered;
 };
 
 static struct netlink_table *nl_table;
@@ -106,6 +122,11 @@ static atomic_t nl_table_users = ATOMIC_INIT(0);
 
 static struct notifier_block *netlink_chain;
 
+static u32 netlink_group_mask(u32 group)
+{
+	return group ? 1 << (group - 1) : 0;
+}
+
 static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
 {
 	return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
@@ -122,6 +143,7 @@ static void netlink_sock_destruct(struct sock *sk)
 	BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
 	BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
 	BUG_TRAP(!nlk_sk(sk)->cb);
+	BUG_TRAP(!nlk_sk(sk)->groups);
 }
 
 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on SMP.
@@ -317,7 +339,7 @@ static void netlink_remove(struct sock *sk)
 	netlink_table_grab();
 	if (sk_del_node_init(sk))
 		nl_table[sk->sk_protocol].hash.entries--;
-	if (nlk_sk(sk)->groups)
+	if (nlk_sk(sk)->subscriptions)
 		__sk_del_bind_node(sk);
 	netlink_table_ungrab();
 }
@@ -328,19 +350,11 @@ static struct proto netlink_proto = {
 	.obj_size = sizeof(struct netlink_sock),
 };
 
-static int netlink_create(struct socket *sock, int protocol)
+static int __netlink_create(struct socket *sock, int protocol)
 {
 	struct sock *sk;
 	struct netlink_sock *nlk;
 
-	sock->state = SS_UNCONNECTED;
-
-	if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
-		return -ESOCKTNOSUPPORT;
-
-	if (protocol<0 || protocol >= MAX_LINKS)
-		return -EPROTONOSUPPORT;
-
 	sock->ops = &netlink_ops;
 
 	sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1);
@@ -350,15 +364,67 @@ static int netlink_create(struct socket *sock, int protocol)
 	sock_init_data(sock, sk);
 
 	nlk = nlk_sk(sk);
-
 	spin_lock_init(&nlk->cb_lock);
 	init_waitqueue_head(&nlk->wait);
-	sk->sk_destruct = netlink_sock_destruct;
 
+	sk->sk_destruct = netlink_sock_destruct;
 	sk->sk_protocol = protocol;
 	return 0;
 }
 
+static int netlink_create(struct socket *sock, int protocol)
+{
+	struct module *module = NULL;
+	struct netlink_sock *nlk;
+	unsigned int groups;
+	int err = 0;
+
+	sock->state = SS_UNCONNECTED;
+
+	if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
+		return -ESOCKTNOSUPPORT;
+
+	if (protocol<0 || protocol >= MAX_LINKS)
+		return -EPROTONOSUPPORT;
+
+	netlink_lock_table();
+#ifdef CONFIG_KMOD
+	if (!nl_table[protocol].registered) {
+		netlink_unlock_table();
+		request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
+		netlink_lock_table();
+	}
+#endif
+	if (nl_table[protocol].registered &&
+	    try_module_get(nl_table[protocol].module))
+		module = nl_table[protocol].module;
+	else
+		err = -EPROTONOSUPPORT;
+	groups = nl_table[protocol].groups;
+	netlink_unlock_table();
+
+	if (err || (err = __netlink_create(sock, protocol) < 0))
+		goto out_module;
+
+	nlk = nlk_sk(sock->sk);
+
+	nlk->groups = kmalloc(NLGRPSZ(groups), GFP_KERNEL);
+	if (nlk->groups == NULL) {
+		err = -ENOMEM;
+		goto out_module;
+	}
+	memset(nlk->groups, 0, NLGRPSZ(groups));
+	nlk->ngroups = groups;
+
+	nlk->module = module;
+out:
+	return err;
+
+out_module:
+	module_put(module);
+	goto out;
+}
+
 static int netlink_release(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
@@ -387,14 +453,27 @@ static int netlink_release(struct socket *sock)
 
 	skb_queue_purge(&sk->sk_write_queue);
 
-	if (nlk->pid && !nlk->groups) {
+	if (nlk->pid && !nlk->subscriptions) {
 		struct netlink_notify n = {
 						.protocol = sk->sk_protocol,
 						.pid = nlk->pid,
 					  };
 		notifier_call_chain(&netlink_chain, NETLINK_URELEASE, &n);
 	}	
-	
+
+	if (nlk->module)
+		module_put(nlk->module);
+
+	if (nlk->flags & NETLINK_KERNEL_SOCKET) {
+		netlink_table_grab();
+		nl_table[sk->sk_protocol].module = NULL;
+		nl_table[sk->sk_protocol].registered = 0;
+		netlink_table_ungrab();
+	}
+
+	kfree(nlk->groups);
+	nlk->groups = NULL;
+
 	sock_put(sk);
 	return 0;
 }
@@ -443,6 +522,18 @@ static inline int netlink_capable(struct socket *sock, unsigned int flag)
 	       capable(CAP_NET_ADMIN);
 } 
 
+static void
+netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
+{
+	struct netlink_sock *nlk = nlk_sk(sk);
+
+	if (nlk->subscriptions && !subscriptions)
+		__sk_del_bind_node(sk);
+	else if (!nlk->subscriptions && subscriptions)
+		sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
+	nlk->subscriptions = subscriptions;
+}
+
 static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 {
 	struct sock *sk = sock->sk;
@@ -468,15 +559,14 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len
 			return err;
 	}
 
-	if (!nladdr->nl_groups && !nlk->groups)
+	if (!nladdr->nl_groups && !(u32)nlk->groups[0])
 		return 0;
 
 	netlink_table_grab();
-	if (nlk->groups && !nladdr->nl_groups)
-		__sk_del_bind_node(sk);
-	else if (!nlk->groups && nladdr->nl_groups)
-		sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
-	nlk->groups = nladdr->nl_groups;
+	netlink_update_subscriptions(sk, nlk->subscriptions +
+	                                 hweight32(nladdr->nl_groups) -
+	                                 hweight32(nlk->groups[0]));
+	nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; 
 	netlink_table_ungrab();
 
 	return 0;
@@ -493,7 +583,7 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
 	if (addr->sa_family == AF_UNSPEC) {
 		sk->sk_state	= NETLINK_UNCONNECTED;
 		nlk->dst_pid	= 0;
-		nlk->dst_groups = 0;
+		nlk->dst_group  = 0;
 		return 0;
 	}
 	if (addr->sa_family != AF_NETLINK)
@@ -509,7 +599,7 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
 	if (err == 0) {
 		sk->sk_state	= NETLINK_CONNECTED;
 		nlk->dst_pid 	= nladdr->nl_pid;
-		nlk->dst_groups = nladdr->nl_groups;
+		nlk->dst_group  = ffs(nladdr->nl_groups);
 	}
 
 	return err;
@@ -527,10 +617,10 @@ static int netlink_getname(struct socket *sock, struct sockaddr *addr, int *addr
 
 	if (peer) {
 		nladdr->nl_pid = nlk->dst_pid;
-		nladdr->nl_groups = nlk->dst_groups;
+		nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
 	} else {
 		nladdr->nl_pid = nlk->pid;
-		nladdr->nl_groups = nlk->groups;
+		nladdr->nl_groups = nlk->groups[0];
 	}
 	return 0;
 }
@@ -731,7 +821,8 @@ static inline int do_one_broadcast(struct sock *sk,
 	if (p->exclude_sk == sk)
 		goto out;
 
-	if (nlk->pid == p->pid || !(nlk->groups & p->group))
+	if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
+	    !test_bit(p->group - 1, nlk->groups))
 		goto out;
 
 	if (p->failure) {
@@ -770,7 +861,7 @@ out:
 }
 
 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
-		      u32 group, int allocation)
+		      u32 group, unsigned int __nocast allocation)
 {
 	struct netlink_broadcast_data info;
 	struct hlist_node *node;
@@ -827,7 +918,8 @@ static inline int do_one_set_err(struct sock *sk,
 	if (sk == p->exclude_sk)
 		goto out;
 
-	if (nlk->pid == p->pid || !(nlk->groups & p->group))
+	if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
+	    !test_bit(p->group - 1, nlk->groups))
 		goto out;
 
 	sk->sk_err = p->code;
@@ -855,6 +947,94 @@ void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
 	read_unlock(&nl_table_lock);
 }
 
+static int netlink_setsockopt(struct socket *sock, int level, int optname,
+                              char __user *optval, int optlen)
+{
+	struct sock *sk = sock->sk;
+	struct netlink_sock *nlk = nlk_sk(sk);
+	int val = 0, err;
+
+	if (level != SOL_NETLINK)
+		return -ENOPROTOOPT;
+
+	if (optlen >= sizeof(int) &&
+	    get_user(val, (int __user *)optval))
+		return -EFAULT;
+
+	switch (optname) {
+	case NETLINK_PKTINFO:
+		if (val)
+			nlk->flags |= NETLINK_RECV_PKTINFO;
+		else
+			nlk->flags &= ~NETLINK_RECV_PKTINFO;
+		err = 0;
+		break;
+	case NETLINK_ADD_MEMBERSHIP:
+	case NETLINK_DROP_MEMBERSHIP: {
+		unsigned int subscriptions;
+		int old, new = optname == NETLINK_ADD_MEMBERSHIP ? 1 : 0;
+
+		if (!netlink_capable(sock, NL_NONROOT_RECV))
+			return -EPERM;
+		if (!val || val - 1 >= nlk->ngroups)
+			return -EINVAL;
+		netlink_table_grab();
+		old = test_bit(val - 1, nlk->groups);
+		subscriptions = nlk->subscriptions - old + new;
+		if (new)
+			__set_bit(val - 1, nlk->groups);
+		else
+			__clear_bit(val - 1, nlk->groups);
+		netlink_update_subscriptions(sk, subscriptions);
+		netlink_table_ungrab();
+		err = 0;
+		break;
+	}
+	default:
+		err = -ENOPROTOOPT;
+	}
+	return err;
+}
+
+static int netlink_getsockopt(struct socket *sock, int level, int optname,
+                              char __user *optval, int __user *optlen)
+{
+	struct sock *sk = sock->sk;
+	struct netlink_sock *nlk = nlk_sk(sk);
+	int len, val, err;
+
+	if (level != SOL_NETLINK)
+		return -ENOPROTOOPT;
+
+	if (get_user(len, optlen))
+		return -EFAULT;
+	if (len < 0)
+		return -EINVAL;
+
+	switch (optname) {
+	case NETLINK_PKTINFO:
+		if (len < sizeof(int))
+			return -EINVAL;
+		len = sizeof(int);
+		val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
+		put_user(len, optlen);
+		put_user(val, optval);
+		err = 0;
+		break;
+	default:
+		err = -ENOPROTOOPT;
+	}
+	return err;
+}
+
+static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
+{
+	struct nl_pktinfo info;
+
+	info.group = NETLINK_CB(skb).dst_group;
+	put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
+}
+
 static inline void netlink_rcv_wake(struct sock *sk)
 {
 	struct netlink_sock *nlk = nlk_sk(sk);
@@ -873,7 +1053,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
 	struct netlink_sock *nlk = nlk_sk(sk);
 	struct sockaddr_nl *addr=msg->msg_name;
 	u32 dst_pid;
-	u32 dst_groups;
+	u32 dst_group;
 	struct sk_buff *skb;
 	int err;
 	struct scm_cookie scm;
@@ -891,12 +1071,12 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
 		if (addr->nl_family != AF_NETLINK)
 			return -EINVAL;
 		dst_pid = addr->nl_pid;
-		dst_groups = addr->nl_groups;
-		if (dst_groups && !netlink_capable(sock, NL_NONROOT_SEND))
+		dst_group = ffs(addr->nl_groups);
+		if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND))
 			return -EPERM;
 	} else {
 		dst_pid = nlk->dst_pid;
-		dst_groups = nlk->dst_groups;
+		dst_group = nlk->dst_group;
 	}
 
 	if (!nlk->pid) {
@@ -914,9 +1094,8 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
 		goto out;
 
 	NETLINK_CB(skb).pid	= nlk->pid;
-	NETLINK_CB(skb).groups	= nlk->groups;
 	NETLINK_CB(skb).dst_pid = dst_pid;
-	NETLINK_CB(skb).dst_groups = dst_groups;
+	NETLINK_CB(skb).dst_group = dst_group;
 	NETLINK_CB(skb).loginuid = audit_get_loginuid(current->audit_context);
 	memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
 
@@ -938,9 +1117,9 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
 		goto out;
 	}
 
-	if (dst_groups) {
+	if (dst_group) {
 		atomic_inc(&skb->users);
-		netlink_broadcast(sk, skb, dst_pid, dst_groups, GFP_KERNEL);
+		netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
 	}
 	err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
 
@@ -986,7 +1165,7 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
 		addr->nl_family = AF_NETLINK;
 		addr->nl_pad    = 0;
 		addr->nl_pid	= NETLINK_CB(skb).pid;
-		addr->nl_groups	= NETLINK_CB(skb).dst_groups;
+		addr->nl_groups	= netlink_group_mask(NETLINK_CB(skb).dst_group);
 		msg->msg_namelen = sizeof(*addr);
 	}
 
@@ -1001,6 +1180,8 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
 		netlink_dump(sk);
 
 	scm_recv(sock, msg, siocb->scm, flags);
+	if (nlk->flags & NETLINK_RECV_PKTINFO)
+		netlink_cmsg_recv_pktinfo(msg, skb);
 
 out:
 	netlink_rcv_wake(sk);
@@ -1023,10 +1204,13 @@ 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, unsigned int groups,
+                      void (*input)(struct sock *sk, int len),
+                      struct module *module)
 {
 	struct socket *sock;
 	struct sock *sk;
+	struct netlink_sock *nlk;
 
 	if (!nl_table)
 		return NULL;
@@ -1037,20 +1221,31 @@ netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len))
 	if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
 		return NULL;
 
-	if (netlink_create(sock, unit) < 0) {
-		sock_release(sock);
-		return NULL;
-	}
+	if (__netlink_create(sock, unit) < 0)
+		goto out_sock_release;
+
 	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;
-	}
+	if (netlink_insert(sk, 0))
+		goto out_sock_release;
+
+	nlk = nlk_sk(sk);
+	nlk->flags |= NETLINK_KERNEL_SOCKET;
+
+	netlink_table_grab();
+	nl_table[unit].groups = groups < 32 ? 32 : groups;
+	nl_table[unit].module = module;
+	nl_table[unit].registered = 1;
+	netlink_table_ungrab();
+
 	return sk;
+
+out_sock_release:
+	sock_release(sock);
+	return NULL;
 }
 
 void netlink_set_nonroot(int protocol, unsigned int flags)
@@ -1288,7 +1483,8 @@ static int netlink_seq_show(struct seq_file *seq, void *v)
 			   s,
 			   s->sk_protocol,
 			   nlk->pid,
-			   nlk->groups,
+			   nlk->flags & NETLINK_KERNEL_SOCKET ?
+				0 : (unsigned int)nlk->groups[0],
 			   atomic_read(&s->sk_rmem_alloc),
 			   atomic_read(&s->sk_wmem_alloc),
 			   nlk->cb,
@@ -1362,8 +1558,8 @@ static struct proto_ops netlink_ops = {
 	.ioctl =	sock_no_ioctl,
 	.listen =	sock_no_listen,
 	.shutdown =	sock_no_shutdown,
-	.setsockopt =	sock_no_setsockopt,
-	.getsockopt =	sock_no_getsockopt,
+	.setsockopt =	netlink_setsockopt,
+	.getsockopt =	netlink_getsockopt,
 	.sendmsg =	netlink_sendmsg,
 	.recvmsg =	netlink_recvmsg,
 	.mmap =		sock_no_mmap,
@@ -1438,21 +1634,7 @@ 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);