[NETLINK]: Extend netlink messaging interface (fe4944e5) · Commits · 戴 / test

include/net/netlink.h

+64 −10

Original line number	Diff line number	Diff line
		@@ -35,6 +35,8 @@
		* nlmsg_put() add a netlink message to an skb
		* nlmsg_put_answer() callback based nlmsg_put()
		* nlmsg_end() finanlize netlink message
		* nlmsg_get_pos() return current position in message
		* nlmsg_trim() trim part of message
		* nlmsg_cancel() cancel message construction
		* nlmsg_free() free a netlink message
		*
		@@ -80,8 +82,10 @@
		* struct nlattr netlink attribtue header
		*
		* Attribute Construction:
		* nla_reserve(skb, type, len) reserve skb tailroom for an attribute
		* nla_reserve(skb, type, len) reserve room for an attribute
		* nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
		* nla_put(skb, type, len, data) add attribute to skb
		* nla_put_nohdr(skb, len, data) add attribute w/o hdr
		*
		* Attribute Construction for Basic Types:
		* nla_put_u8(skb, type, value) add u8 attribute to skb
		@@ -139,6 +143,7 @@
		* nla_next(nla, remaining) get next netlink attribute
		* nla_validate() validate a stream of attributes
		* nla_find() find attribute in stream of attributes
		* nla_find_nested() find attribute in nested attributes
		* nla_parse() parse and validate stream of attrs
		* nla_parse_nested() parse nested attribuets
		* nla_for_each_attr() loop over all attributes
		@@ -203,12 +208,18 @@ extern int nla_memcmp(const struct nlattr nla, const void data,
		extern int nla_strcmp(const struct nlattr nla, const char str);
		extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype,
		int attrlen);
		extern void * __nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
		extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype,
		int attrlen);
		extern void * nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
		extern void __nla_put(struct sk_buff *skb, int attrtype,
		int attrlen, const void *data);
		extern void __nla_put_nohdr(struct sk_buff *skb, int attrlen,
		const void *data);
		extern int nla_put(struct sk_buff *skb, int attrtype,
		int attrlen, const void *data);
		extern int nla_put_nohdr(struct sk_buff *skb, int attrlen,
		const void *data);

		/**************************************************************************
		* Netlink Messages
		@@ -453,12 +464,13 @@ static inline struct nlmsghdr nlmsg_put_answer(struct sk_buff skb,
		/**
		* nlmsg_new - Allocate a new netlink message
		* @size: maximum size of message
		* @flags: the type of memory to allocate.
		*
		* Use NLMSG_GOODSIZE if size isn't know and you need a good default size.
		*/
		static inline struct sk_buff *nlmsg_new(int size)
		static inline struct sk_buff *nlmsg_new(int size, gfp_t flags)
		{
		return alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
		return alloc_skb(size, flags);
		}

		/**
		@@ -479,6 +491,32 @@ static inline int nlmsg_end(struct sk_buff skb, struct nlmsghdr nlh)
		return skb->len;
		}

		/**
		* nlmsg_get_pos - return current position in netlink message
		* @skb: socket buffer the message is stored in
		*
		* Returns a pointer to the current tail of the message.
		*/
		static inline void nlmsg_get_pos(struct sk_buff skb)
		{
		return skb->tail;
		}

		/**
		* nlmsg_trim - Trim message to a mark
		* @skb: socket buffer the message is stored in
		* @mark: mark to trim to
		*
		* Trims the message to the provided mark. Returns -1.
		*/
		static inline int nlmsg_trim(struct sk_buff skb, void mark)
		{
		if (mark)
		skb_trim(skb, (unsigned char *) mark - skb->data);

		return -1;
		}

		/**
		* nlmsg_cancel - Cancel construction of a netlink message
		* @skb: socket buffer the message is stored in
		@@ -489,9 +527,7 @@ static inline int nlmsg_end(struct sk_buff skb, struct nlmsghdr nlh)
		*/
		static inline int nlmsg_cancel(struct sk_buff skb, struct nlmsghdr nlh)
		{
		skb_trim(skb, (unsigned char *) nlh - skb->data);

		return -1;
		return nlmsg_trim(skb, nlh);
		}

		/**
		@@ -630,6 +666,18 @@ static inline struct nlattr nla_next(const struct nlattr nla, int *remaining)
		return (struct nlattr ) ((char ) nla + totlen);
		}

		/**
		* nla_find_nested - find attribute in a set of nested attributes
		* @nla: attribute containing the nested attributes
		* @attrtype: type of attribute to look for
		*
		* Returns the first attribute which matches the specified type.
		*/
		static inline struct nlattr nla_find_nested(struct nlattr nla, int attrtype)
		{
		return nla_find(nla_data(nla), nla_len(nla), attrtype);
		}

		/**
		* nla_parse_nested - parse nested attributes
		* @tb: destination array with maxtype+1 elements
		@@ -862,10 +910,7 @@ static inline int nla_nest_end(struct sk_buff skb, struct nlattr start)
		*/
		static inline int nla_nest_cancel(struct sk_buff skb, struct nlattr start)
		{
		if (start)
		skb_trim(skb, (unsigned char *) start - skb->data);

		return -1;
		return nlmsg_trim(skb, start);
		}

		/**
		@@ -880,4 +925,13 @@ static inline int nla_nest_cancel(struct sk_buff skb, struct nlattr start)
		nla_ok(pos, rem); \
		pos = nla_next(pos, &(rem)))

		/**
		* nla_for_each_nested - iterate over nested attributes
		* @pos: loop counter, set to current attribute
		* @nla: attribute containing the nested attributes
		* @rem: initialized to len, holds bytes currently remaining in stream
		*/
		#define nla_for_each_nested(pos, nla, rem) \
		nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)

		#endif

kernel/taskstats.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -75,7 +75,7 @@ static int prepare_reply(struct genl_info info, u8 cmd, struct sk_buff *skbp,
		/*
		* If new attributes are added, please revisit this allocation
		*/
		skb = nlmsg_new(size);
		skb = nlmsg_new(size, GFP_KERNEL);
		if (!skb)
		return -ENOMEM;

net/netlink/attr.c

+75 −0

Original line number	Diff line number	Diff line
		@@ -254,6 +254,26 @@ struct nlattr __nla_reserve(struct sk_buff skb, int attrtype, int 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
		@@ -274,6 +294,24 @@ struct nlattr nla_reserve(struct sk_buff skb, int attrtype, int attrlen)
		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
		@@ -293,6 +331,22 @@ void __nla_put(struct sk_buff *skb, int attrtype, int 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
		@@ -313,15 +367,36 @@ int nla_put(struct sk_buff skb, int attrtype, int attrlen, const void 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

+1 −1

Original line number	Diff line number	Diff line
		@@ -440,7 +440,7 @@ static struct sk_buff ctrl_build_msg(struct genl_family family, u32 pid,
		struct sk_buff *skb;
		int err;

		skb = nlmsg_new(NLMSG_GOODSIZE);
		skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
		if (skb == NULL)
		return ERR_PTR(-ENOBUFS);

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