Creation of Cybook 2416 (actually Gen4) repository

net/netlink/Makefile

@@ -0,0 +1,5 @@
+#
+# Makefile for the netlink driver.
+#
+
+obj-y  				:= af_netlink.o attr.o genetlink.o

net/netlink/attr.c

@@ -0,0 +1,431 @@
+/*
+ * NETLINK      Netlink attributes
+ *
+ * 		Authors:	Thomas Graf <tgraf@suug.ch>
+ * 				Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/jiffies.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <net/netlink.h>
+
+static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = {
+	[NLA_U8]	= sizeof(u8),
+	[NLA_U16]	= sizeof(u16),
+	[NLA_U32]	= sizeof(u32),
+	[NLA_U64]	= sizeof(u64),
+	[NLA_NESTED]	= NLA_HDRLEN,
+};
+
+static int validate_nla(struct nlattr *nla, int maxtype,
+			struct nla_policy *policy)
+{
+	struct nla_policy *pt;
+	int minlen = 0, attrlen = nla_len(nla);
+
+	if (nla->nla_type <= 0 || nla->nla_type > maxtype)
+		return 0;
+
+	pt = &policy[nla->nla_type];
+
+	BUG_ON(pt->type > NLA_TYPE_MAX);
+
+	switch (pt->type) {
+	case NLA_FLAG:
+		if (attrlen > 0)
+			return -ERANGE;
+		break;
+
+	case NLA_NUL_STRING:
+		if (pt->len)
+			minlen = min_t(int, attrlen, pt->len + 1);
+		else
+			minlen = attrlen;
+
+		if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL)
+			return -EINVAL;
+		/* fall through */
+
+	case NLA_STRING:
+		if (attrlen < 1)
+			return -ERANGE;
+
+		if (pt->len) {
+			char *buf = nla_data(nla);
+
+			if (buf[attrlen - 1] == '\0')
+				attrlen--;
+
+			if (attrlen > pt->len)
+				return -ERANGE;
+		}
+		break;
+
+	default:
+		if (pt->len)
+			minlen = pt->len;
+		else if (pt->type != NLA_UNSPEC)
+			minlen = nla_attr_minlen[pt->type];
+
+		if (attrlen < minlen)
+			return -ERANGE;
+	}
+
+	return 0;
+}
+
+/**
+ * nla_validate - Validate a stream of attributes
+ * @head: head of attribute stream
+ * @len: length of attribute stream
+ * @maxtype: maximum attribute type to be expected
+ * @policy: validation policy
+ *
+ * Validates all attributes in the specified attribute stream against the
+ * specified policy. Attributes with a type exceeding maxtype will be
+ * ignored. See documenation of struct nla_policy for more details.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int nla_validate(struct nlattr *head, int len, int maxtype,
+		 struct nla_policy *policy)
+{
+	struct nlattr *nla;
+	int rem, err;
+
+	nla_for_each_attr(nla, head, len, rem) {
+		err = validate_nla(nla, maxtype, policy);
+		if (err < 0)
+			goto errout;
+	}
+
+	err = 0;
+errout:
+	return err;
+}
+
+/**
+ * nla_parse - Parse a stream of attributes into a tb buffer
+ * @tb: destination array with maxtype+1 elements
+ * @maxtype: maximum attribute type to be expected
+ * @head: head of attribute stream
+ * @len: length of attribute stream
+ *
+ * Parses a stream of attributes and stores a pointer to each attribute in
+ * the tb array accessable via the attribute type. Attributes with a type
+ * exceeding maxtype will be silently ignored for backwards compatibility
+ * reasons. policy may be set to NULL if no validation is required.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len,
+	      struct nla_policy *policy)
+{
+	struct nlattr *nla;
+	int rem, err;
+
+	memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
+
+	nla_for_each_attr(nla, head, len, rem) {
+		u16 type = nla->nla_type;
+
+		if (type > 0 && type <= maxtype) {
+			if (policy) {
+				err = validate_nla(nla, maxtype, policy);
+				if (err < 0)
+					goto errout;
+			}
+
+			tb[type] = nla;
+		}
+	}
+
+	if (unlikely(rem > 0))
+		printk(KERN_WARNING "netlink: %d bytes leftover after parsing "
+		       "attributes.\n", rem);
+
+	err = 0;
+errout:
+	return err;
+}
+
+/**
+ * nla_find - Find a specific attribute in a stream of attributes
+ * @head: head of attribute stream
+ * @len: length of attribute stream
+ * @attrtype: type of attribute to look for
+ *
+ * Returns the first attribute in the stream matching the specified type.
+ */
+struct nlattr *nla_find(struct nlattr *head, int len, int attrtype)
+{
+	struct nlattr *nla;
+	int rem;
+
+	nla_for_each_attr(nla, head, len, rem)
+		if (nla->nla_type == attrtype)
+			return nla;
+
+	return NULL;
+}
+
+/**
+ * nla_strlcpy - Copy string attribute payload into a sized buffer
+ * @dst: where to copy the string to
+ * @src: attribute to copy the string from
+ * @dstsize: size of destination buffer
+ *
+ * Copies at most dstsize - 1 bytes into the destination buffer.
+ * The result is always a valid NUL-terminated string. Unlike
+ * strlcpy the destination buffer is always padded out.
+ *
+ * Returns the length of the source buffer.
+ */
+size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize)
+{
+	size_t srclen = nla_len(nla);
+	char *src = nla_data(nla);
+
+	if (srclen > 0 && src[srclen - 1] == '\0')
+		srclen--;
+
+	if (dstsize > 0) {
+		size_t len = (srclen >= dstsize) ? dstsize - 1 : srclen;
+
+		memset(dst, 0, dstsize);
+		memcpy(dst, src, len);
+	}
+
+	return srclen;
+}
+
+/**
+ * nla_memcpy - Copy a netlink attribute into another memory area
+ * @dest: where to copy to memcpy
+ * @src: netlink attribute to copy from
+ * @count: size of the destination area
+ *
+ * Note: The number of bytes copied is limited by the length of
+ *       attribute's payload. memcpy
+ *
+ * Returns the number of bytes copied.
+ */
+int nla_memcpy(void *dest, struct nlattr *src, int count)
+{
+	int minlen = min_t(int, count, nla_len(src));
+
+	memcpy(dest, nla_data(src), minlen);
+
+	return minlen;
+}
+
+/**
+ * nla_memcmp - Compare an attribute with sized memory area
+ * @nla: netlink attribute
+ * @data: memory area
+ * @size: size of memory area
+ */
+int nla_memcmp(const struct nlattr *nla, const void *data,
+			     size_t size)
+{
+	int d = nla_len(nla) - size;
+
+	if (d == 0)
+		d = memcmp(nla_data(nla), data, size);
+
+	return d;
+}
+
+/**
+ * nla_strcmp - Compare a string attribute against a string
+ * @nla: netlink string attribute
+ * @str: another string
+ */
+int nla_strcmp(const struct nlattr *nla, const char *str)
+{
+	int len = strlen(str) + 1;
+	int d = nla_len(nla) - len;
+
+	if (d == 0)
+		d = memcmp(nla_data(nla), str, len);
+
+	return d;
+}
+
+/**
+ * __nla_reserve - reserve room for attribute on the skb
+ * @skb: socket buffer to reserve room on
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ *
+ * Adds a netlink attribute header to a socket buffer and reserves
+ * room for the payload but does not copy it.
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the attribute header and payload.
+ */
+struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
+{
+	struct nlattr *nla;
+
+	nla = (struct nlattr *) skb_put(skb, nla_total_size(attrlen));
+	nla->nla_type = attrtype;
+	nla->nla_len = nla_attr_size(attrlen);
+
+	memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen));
+
+	return nla;
+}
+
+/**
+ * __nla_reserve_nohdr - reserve room for attribute without header
+ * @skb: socket buffer to reserve room on
+ * @attrlen: length of attribute payload
+ *
+ * Reserves room for attribute payload without a header.
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the payload.
+ */
+void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
+{
+	void *start;
+
+	start = skb_put(skb, NLA_ALIGN(attrlen));
+	memset(start, 0, NLA_ALIGN(attrlen));
+
+	return start;
+}
+
+/**
+ * nla_reserve - reserve room for attribute on the skb
+ * @skb: socket buffer to reserve room on
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ *
+ * Adds a netlink attribute header to a socket buffer and reserves
+ * room for the payload but does not copy it.
+ *
+ * Returns NULL if the tailroom of the skb is insufficient to store
+ * the attribute header and payload.
+ */
+struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
+{
+	if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
+		return NULL;
+
+	return __nla_reserve(skb, attrtype, attrlen);
+}
+
+/**
+ * nla_reserve - reserve room for attribute without header
+ * @skb: socket buffer to reserve room on
+ * @len: length of attribute payload
+ *
+ * Reserves room for attribute payload without a header.
+ *
+ * Returns NULL if the tailroom of the skb is insufficient to store
+ * the attribute payload.
+ */
+void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
+{
+	if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
+		return NULL;
+
+	return __nla_reserve_nohdr(skb, attrlen);
+}
+
+/**
+ * __nla_put - Add a netlink attribute to a socket buffer
+ * @skb: socket buffer to add attribute to
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the attribute header and payload.
+ */
+void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
+			     const void *data)
+{
+	struct nlattr *nla;
+
+	nla = __nla_reserve(skb, attrtype, attrlen);
+	memcpy(nla_data(nla), data, attrlen);
+}
+
+/**
+ * __nla_put_nohdr - Add a netlink attribute without header
+ * @skb: socket buffer to add attribute to
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the attribute payload.
+ */
+void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
+{
+	void *start;
+
+	start = __nla_reserve_nohdr(skb, attrlen);
+	memcpy(start, data, attrlen);
+}
+
+/**
+ * nla_put - Add a netlink attribute to a socket buffer
+ * @skb: socket buffer to add attribute to
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * Returns -1 if the tailroom of the skb is insufficient to store
+ * the attribute header and payload.
+ */
+int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
+{
+	if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
+		return -1;
+
+	__nla_put(skb, attrtype, attrlen, data);
+	return 0;
+}
+
+/**
+ * nla_put_nohdr - Add a netlink attribute without header
+ * @skb: socket buffer to add attribute to
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * Returns -1 if the tailroom of the skb is insufficient to store
+ * the attribute payload.
+ */
+int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
+{
+	if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
+		return -1;
+
+	__nla_put_nohdr(skb, attrlen, data);
+	return 0;
+}
+
+EXPORT_SYMBOL(nla_validate);
+EXPORT_SYMBOL(nla_parse);
+EXPORT_SYMBOL(nla_find);
+EXPORT_SYMBOL(nla_strlcpy);
+EXPORT_SYMBOL(__nla_reserve);
+EXPORT_SYMBOL(__nla_reserve_nohdr);
+EXPORT_SYMBOL(nla_reserve);
+EXPORT_SYMBOL(nla_reserve_nohdr);
+EXPORT_SYMBOL(__nla_put);
+EXPORT_SYMBOL(__nla_put_nohdr);
+EXPORT_SYMBOL(nla_put);
+EXPORT_SYMBOL(nla_put_nohdr);
+EXPORT_SYMBOL(nla_memcpy);
+EXPORT_SYMBOL(nla_memcmp);
+EXPORT_SYMBOL(nla_strcmp);

net/netlink/genetlink.c

@@ -0,0 +1,607 @@
+/*
+ * NETLINK      Generic Netlink Family
+ *
+ * 		Authors:	Jamal Hadi Salim
+ * 				Thomas Graf <tgraf@suug.ch>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/string.h>
+#include <linux/skbuff.h>
+#include <linux/mutex.h>
+#include <net/sock.h>
+#include <net/genetlink.h>
+
+struct sock *genl_sock = NULL;
+
+static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
+
+static void genl_lock(void)
+{
+	mutex_lock(&genl_mutex);
+}
+
+static int genl_trylock(void)
+{
+	return !mutex_trylock(&genl_mutex);
+}
+
+static void genl_unlock(void)
+{
+	mutex_unlock(&genl_mutex);
+
+	if (genl_sock && genl_sock->sk_receive_queue.qlen)
+		genl_sock->sk_data_ready(genl_sock, 0);
+}
+
+#define GENL_FAM_TAB_SIZE	16
+#define GENL_FAM_TAB_MASK	(GENL_FAM_TAB_SIZE - 1)
+
+static struct list_head family_ht[GENL_FAM_TAB_SIZE];
+
+static int genl_ctrl_event(int event, void *data);
+
+static inline unsigned int genl_family_hash(unsigned int id)
+{
+	return id & GENL_FAM_TAB_MASK;
+}
+
+static inline struct list_head *genl_family_chain(unsigned int id)
+{
+	return &family_ht[genl_family_hash(id)];
+}
+
+static struct genl_family *genl_family_find_byid(unsigned int id)
+{
+	struct genl_family *f;
+
+	list_for_each_entry(f, genl_family_chain(id), family_list)
+		if (f->id == id)
+			return f;
+
+	return NULL;
+}
+
+static struct genl_family *genl_family_find_byname(char *name)
+{
+	struct genl_family *f;
+	int i;
+
+	for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
+		list_for_each_entry(f, genl_family_chain(i), family_list)
+			if (strcmp(f->name, name) == 0)
+				return f;
+
+	return NULL;
+}
+
+static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family)
+{
+	struct genl_ops *ops;
+
+	list_for_each_entry(ops, &family->ops_list, ops_list)
+		if (ops->cmd == cmd)
+			return ops;
+
+	return NULL;
+}
+
+/* Of course we are going to have problems once we hit
+ * 2^16 alive types, but that can only happen by year 2K
+*/
+static inline u16 genl_generate_id(void)
+{
+	static u16 id_gen_idx;
+	int overflowed = 0;
+
+	do {
+		if (id_gen_idx == 0)
+			id_gen_idx = GENL_MIN_ID;
+
+		if (++id_gen_idx > GENL_MAX_ID) {
+			if (!overflowed) {
+				overflowed = 1;
+				id_gen_idx = 0;
+				continue;
+			} else
+				return 0;
+		}
+
+	} while (genl_family_find_byid(id_gen_idx));
+
+	return id_gen_idx;
+}
+
+/**
+ * genl_register_ops - register generic netlink operations
+ * @family: generic netlink family
+ * @ops: operations to be registered
+ *
+ * Registers the specified operations and assigns them to the specified
+ * family. Either a doit or dumpit callback must be specified or the
+ * operation will fail. Only one operation structure per command
+ * identifier may be registered.
+ *
+ * See include/net/genetlink.h for more documenation on the operations
+ * structure.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int genl_register_ops(struct genl_family *family, struct genl_ops *ops)
+{
+	int err = -EINVAL;
+
+	if (ops->dumpit == NULL && ops->doit == NULL)
+		goto errout;
+
+	if (genl_get_cmd(ops->cmd, family)) {
+		err = -EEXIST;
+		goto errout;
+	}
+
+	if (ops->dumpit)
+		ops->flags |= GENL_CMD_CAP_DUMP;
+	if (ops->doit)
+		ops->flags |= GENL_CMD_CAP_DO;
+	if (ops->policy)
+		ops->flags |= GENL_CMD_CAP_HASPOL;
+
+	genl_lock();
+	list_add_tail(&ops->ops_list, &family->ops_list);
+	genl_unlock();
+
+	genl_ctrl_event(CTRL_CMD_NEWOPS, ops);
+	err = 0;
+errout:
+	return err;
+}
+
+/**
+ * genl_unregister_ops - unregister generic netlink operations
+ * @family: generic netlink family
+ * @ops: operations to be unregistered
+ *
+ * Unregisters the specified operations and unassigns them from the
+ * specified family. The operation blocks until the current message
+ * processing has finished and doesn't start again until the
+ * unregister process has finished.
+ *
+ * Note: It is not necessary to unregister all operations before
+ *       unregistering the family, unregistering the family will cause
+ *       all assigned operations to be unregistered automatically.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int genl_unregister_ops(struct genl_family *family, struct genl_ops *ops)
+{
+	struct genl_ops *rc;
+
+	genl_lock();
+	list_for_each_entry(rc, &family->ops_list, ops_list) {
+		if (rc == ops) {
+			list_del(&ops->ops_list);
+			genl_unlock();
+			genl_ctrl_event(CTRL_CMD_DELOPS, ops);
+			return 0;
+		}
+	}
+	genl_unlock();
+
+	return -ENOENT;
+}
+
+/**
+ * genl_register_family - register a generic netlink family
+ * @family: generic netlink family
+ *
+ * Registers the specified family after validating it first. Only one
+ * family may be registered with the same family name or identifier.
+ * The family id may equal GENL_ID_GENERATE causing an unique id to
+ * be automatically generated and assigned.
+ *
+ * Return 0 on success or a negative error code.
+ */
+int genl_register_family(struct genl_family *family)
+{
+	int err = -EINVAL;
+
+	if (family->id && family->id < GENL_MIN_ID)
+		goto errout;
+
+	if (family->id > GENL_MAX_ID)
+		goto errout;
+
+	INIT_LIST_HEAD(&family->ops_list);
+
+	genl_lock();
+
+	if (genl_family_find_byname(family->name)) {
+		err = -EEXIST;
+		goto errout_locked;
+	}
+
+	if (genl_family_find_byid(family->id)) {
+		err = -EEXIST;
+		goto errout_locked;
+	}
+
+	if (family->id == GENL_ID_GENERATE) {
+		u16 newid = genl_generate_id();
+
+		if (!newid) {
+			err = -ENOMEM;
+			goto errout_locked;
+		}
+
+		family->id = newid;
+	}
+
+	if (family->maxattr) {
+		family->attrbuf = kmalloc((family->maxattr+1) *
+					sizeof(struct nlattr *), GFP_KERNEL);
+		if (family->attrbuf == NULL) {
+			err = -ENOMEM;
+			goto errout_locked;
+		}
+	} else
+		family->attrbuf = NULL;
+
+	list_add_tail(&family->family_list, genl_family_chain(family->id));
+	genl_unlock();
+
+	genl_ctrl_event(CTRL_CMD_NEWFAMILY, family);
+
+	return 0;
+
+errout_locked:
+	genl_unlock();
+errout:
+	return err;
+}
+
+/**
+ * genl_unregister_family - unregister generic netlink family
+ * @family: generic netlink family
+ *
+ * Unregisters the specified family.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int genl_unregister_family(struct genl_family *family)
+{
+	struct genl_family *rc;
+
+	genl_lock();
+
+	list_for_each_entry(rc, genl_family_chain(family->id), family_list) {
+		if (family->id != rc->id || strcmp(rc->name, family->name))
+			continue;
+
+		list_del(&rc->family_list);
+		INIT_LIST_HEAD(&family->ops_list);
+		genl_unlock();
+
+		kfree(family->attrbuf);
+		genl_ctrl_event(CTRL_CMD_DELFAMILY, family);
+		return 0;
+	}
+
+	genl_unlock();
+
+	return -ENOENT;
+}
+
+static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+			       int *errp)
+{
+	struct genl_ops *ops;
+	struct genl_family *family;
+	struct genl_info info;
+	struct genlmsghdr *hdr = nlmsg_data(nlh);
+	int hdrlen, err = -EINVAL;
+
+	if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
+		goto ignore;
+
+	if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
+		goto ignore;
+
+	family = genl_family_find_byid(nlh->nlmsg_type);
+	if (family == NULL) {
+		err = -ENOENT;
+		goto errout;
+	}
+
+	hdrlen = GENL_HDRLEN + family->hdrsize;
+	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
+		goto errout;
+
+	ops = genl_get_cmd(hdr->cmd, family);
+	if (ops == NULL) {
+		err = -EOPNOTSUPP;
+		goto errout;
+	}
+
+	if ((ops->flags & GENL_ADMIN_PERM) && security_netlink_recv(skb, CAP_NET_ADMIN)) {
+		err = -EPERM;
+		goto errout;
+	}
+
+	if (nlh->nlmsg_flags & NLM_F_DUMP) {
+		if (ops->dumpit == NULL) {
+			err = -EOPNOTSUPP;
+			goto errout;
+		}
+
+		*errp = err = netlink_dump_start(genl_sock, skb, nlh,
+						 ops->dumpit, ops->done);
+		if (err == 0)
+			skb_pull(skb, min(NLMSG_ALIGN(nlh->nlmsg_len),
+					  skb->len));
+		return -1;
+	}
+
+	if (ops->doit == NULL) {
+		err = -EOPNOTSUPP;
+		goto errout;
+	}
+
+	if (family->attrbuf) {
+		err = nlmsg_parse(nlh, hdrlen, family->attrbuf, family->maxattr,
+				  ops->policy);
+		if (err < 0)
+			goto errout;
+	}
+
+	info.snd_seq = nlh->nlmsg_seq;
+	info.snd_pid = NETLINK_CB(skb).pid;
+	info.nlhdr = nlh;
+	info.genlhdr = nlmsg_data(nlh);
+	info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
+	info.attrs = family->attrbuf;
+
+	*errp = err = ops->doit(skb, &info);
+	return err;
+
+ignore:
+	return 0;
+
+errout:
+	*errp = err;
+	return -1;
+}
+
+static void genl_rcv(struct sock *sk, int len)
+{
+	unsigned int qlen = 0;
+
+	do {
+		if (genl_trylock())
+			return;
+		netlink_run_queue(sk, &qlen, genl_rcv_msg);
+		genl_unlock();
+	} while (qlen && genl_sock && genl_sock->sk_receive_queue.qlen);
+}
+
+/**************************************************************************
+ * Controller
+ **************************************************************************/
+
+static struct genl_family genl_ctrl = {
+	.id = GENL_ID_CTRL,
+	.name = "nlctrl",
+	.version = 0x2,
+	.maxattr = CTRL_ATTR_MAX,
+};
+
+static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq,
+			  u32 flags, struct sk_buff *skb, u8 cmd)
+{
+	void *hdr;
+
+	hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
+	if (hdr == NULL)
+		return -1;
+
+	NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, family->name);
+	NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, family->id);
+	NLA_PUT_U32(skb, CTRL_ATTR_VERSION, family->version);
+	NLA_PUT_U32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize);
+	NLA_PUT_U32(skb, CTRL_ATTR_MAXATTR, family->maxattr);
+
+	if (!list_empty(&family->ops_list)) {
+		struct nlattr *nla_ops;
+		struct genl_ops *ops;
+		int idx = 1;
+
+		nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
+		if (nla_ops == NULL)
+			goto nla_put_failure;
+
+		list_for_each_entry(ops, &family->ops_list, ops_list) {
+			struct nlattr *nest;
+
+			nest = nla_nest_start(skb, idx++);
+			if (nest == NULL)
+				goto nla_put_failure;
+
+			NLA_PUT_U32(skb, CTRL_ATTR_OP_ID, ops->cmd);
+			NLA_PUT_U32(skb, CTRL_ATTR_OP_FLAGS, ops->flags);
+
+			nla_nest_end(skb, nest);
+		}
+
+		nla_nest_end(skb, nla_ops);
+	}
+
+	return genlmsg_end(skb, hdr);
+
+nla_put_failure:
+	return genlmsg_cancel(skb, hdr);
+}
+
+static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
+{
+
+	int i, n = 0;
+	struct genl_family *rt;
+	int chains_to_skip = cb->args[0];
+	int fams_to_skip = cb->args[1];
+
+	if (chains_to_skip != 0)
+		genl_lock();
+
+	for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
+		if (i < chains_to_skip)
+			continue;
+		n = 0;
+		list_for_each_entry(rt, genl_family_chain(i), family_list) {
+			if (++n < fams_to_skip)
+				continue;
+			if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).pid,
+					   cb->nlh->nlmsg_seq, NLM_F_MULTI,
+					   skb, CTRL_CMD_NEWFAMILY) < 0)
+				goto errout;
+		}
+
+		fams_to_skip = 0;
+	}
+
+errout:
+	if (chains_to_skip != 0)
+		genl_unlock();
+
+	cb->args[0] = i;
+	cb->args[1] = n;
+
+	return skb->len;
+}
+
+static struct sk_buff *ctrl_build_msg(struct genl_family *family, u32 pid,
+				      int seq, u8 cmd)
+{
+	struct sk_buff *skb;
+	int err;
+
+	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (skb == NULL)
+		return ERR_PTR(-ENOBUFS);
+
+	err = ctrl_fill_info(family, pid, seq, 0, skb, cmd);
+	if (err < 0) {
+		nlmsg_free(skb);
+		return ERR_PTR(err);
+	}
+
+	return skb;
+}
+
+static struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] __read_mostly = {
+	[CTRL_ATTR_FAMILY_ID]	= { .type = NLA_U16 },
+	[CTRL_ATTR_FAMILY_NAME]	= { .type = NLA_NUL_STRING,
+				    .len = GENL_NAMSIZ - 1 },
+};
+
+static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
+{
+	struct sk_buff *msg;
+	struct genl_family *res = NULL;
+	int err = -EINVAL;
+
+	if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
+		u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
+		res = genl_family_find_byid(id);
+	}
+
+	if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
+		char *name;
+
+		name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
+		res = genl_family_find_byname(name);
+	}
+
+	if (res == NULL) {
+		err = -ENOENT;
+		goto errout;
+	}
+
+	msg = ctrl_build_msg(res, info->snd_pid, info->snd_seq,
+			     CTRL_CMD_NEWFAMILY);
+	if (IS_ERR(msg)) {
+		err = PTR_ERR(msg);
+		goto errout;
+	}
+
+	err = genlmsg_reply(msg, info);
+errout:
+	return err;
+}
+
+static int genl_ctrl_event(int event, void *data)
+{
+	struct sk_buff *msg;
+
+	if (genl_sock == NULL)
+		return 0;
+
+	switch (event) {
+	case CTRL_CMD_NEWFAMILY:
+	case CTRL_CMD_DELFAMILY:
+		msg = ctrl_build_msg(data, 0, 0, event);
+		if (IS_ERR(msg))
+			return PTR_ERR(msg);
+
+		genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL);
+		break;
+	}
+
+	return 0;
+}
+
+static struct genl_ops genl_ctrl_ops = {
+	.cmd		= CTRL_CMD_GETFAMILY,
+	.doit		= ctrl_getfamily,
+	.dumpit		= ctrl_dumpfamily,
+	.policy		= ctrl_policy,
+};
+
+static int __init genl_init(void)
+{
+	int i, err;
+
+	for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
+		INIT_LIST_HEAD(&family_ht[i]);
+
+	err = genl_register_family(&genl_ctrl);
+	if (err < 0)
+		goto errout;
+
+	err = genl_register_ops(&genl_ctrl, &genl_ctrl_ops);
+	if (err < 0)
+		goto errout_register;
+
+	netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV);
+	genl_sock = netlink_kernel_create(NETLINK_GENERIC, GENL_MAX_ID,
+					  genl_rcv, THIS_MODULE);
+	if (genl_sock == NULL)
+		panic("GENL: Cannot initialize generic netlink\n");
+
+	return 0;
+
+errout_register:
+	genl_unregister_family(&genl_ctrl);
+errout:
+	panic("GENL: Cannot register controller: %d\n", err);
+}
+
+subsys_initcall(genl_init);
+
+EXPORT_SYMBOL(genl_sock);
+EXPORT_SYMBOL(genl_register_ops);
+EXPORT_SYMBOL(genl_unregister_ops);
+EXPORT_SYMBOL(genl_register_family);
+EXPORT_SYMBOL(genl_unregister_family);