#ifndef __NET_NETLINK_H#define __NET_NETLINK_H #include <linux/types.h>#include <linux/netlink.h> /* ======================================================================== *         Netlink Messages and Attributes Interface (As Seen On TV) * ------------------------------------------------------------------------ *                          Messages Interface * ------------------------------------------------------------------------ * * Message Format: *    <--- nlmsg_total_size(payload)  ---> *    <-- nlmsg_msg_size(payload) -> *   +----------+- - -+-------------+- - -+-------- - - *   | nlmsghdr | Pad |   Payload   | Pad | nlmsghdr *   +----------+- - -+-------------+- - -+-------- - - *   nlmsg_data(nlh)---^                   ^ *   nlmsg_next(nlh)-----------------------+ * * Payload Format: *    <---------------------- nlmsg_len(nlh) ---------------------> *    <------ hdrlen ------>       <- nlmsg_attrlen(nlh, hdrlen) -> *   +----------------------+- - -+--------------------------------+ *   |     Family Header    | Pad |           Attributes           | *   +----------------------+- - -+--------------------------------+ *   nlmsg_attrdata(nlh, hdrlen)---^ * * Data Structures: *   struct nlmsghdr			netlink message header * * Message Construction: *   nlmsg_new()			create a new netlink message *   nlmsg_put()			add a netlink message to an skb *   nlmsg_put_answer()			callback based nlmsg_put() *   nlmsg_end()			finanlize netlink message *   nlmsg_cancel()			cancel message construction *   nlmsg_free()			free a netlink message * * Message Sending: *   nlmsg_multicast()			multicast message to several groups *   nlmsg_unicast()			unicast a message to a single socket * * Message Length Calculations: *   nlmsg_msg_size(payload)		length of message w/o padding *   nlmsg_total_size(payload)		length of message w/ padding *   nlmsg_padlen(payload)		length of padding at tail * * Message Payload Access: *   nlmsg_data(nlh)			head of message payload *   nlmsg_len(nlh)			length of message payload *   nlmsg_attrdata(nlh, hdrlen)	head of attributes data *   nlmsg_attrlen(nlh, hdrlen)		length of attributes data * * Message Parsing: *   nlmsg_ok(nlh, remaining)		does nlh fit into remaining bytes? *   nlmsg_next(nlh, remaining)		get next netlink message *   nlmsg_parse()			parse attributes of a message *   nlmsg_find_attr()			find an attribute in a message *   nlmsg_for_each_msg()		loop over all messages *   nlmsg_validate()			validate netlink message incl. attrs *   nlmsg_for_each_attr()		loop over all attributes * * ------------------------------------------------------------------------ *                          Attributes Interface * ------------------------------------------------------------------------ * * Attribute Format: *    <------- nla_total_size(payload) -------> *    <---- nla_attr_size(payload) -----> *   +----------+- - -+- - - - - - - - - +- - -+-------- - - *   |  Header  | Pad |     Payload      | Pad |  Header *   +----------+- - -+- - - - - - - - - +- - -+-------- - - *                     <- nla_len(nla) ->      ^ *   nla_data(nla)----^                        | *   nla_next(nla)-----------------------------' * * Data Structures: *   struct nlattr			netlink attribtue header * * Attribute Construction: *   nla_reserve(skb, type, len)	reserve skb tailroom for an attribute *   nla_put(skb, type, len, data)	add attribute to skb * * Attribute Construction for Basic Types: *   nla_put_u8(skb, type, value)	add u8 attribute to skb *   nla_put_u16(skb, type, value)	add u16 attribute to skb *   nla_put_u32(skb, type, value)	add u32 attribute to skb *   nla_put_u64(skb, type, value)	add u64 attribute to skb *   nla_put_string(skb, type, str)	add string attribute to skb *   nla_put_flag(skb, type)		add flag attribute to skb *   nla_put_msecs(skb, type, jiffies)	add msecs attribute to skb * * Exceptions Based Attribute Construction: *   NLA_PUT(skb, type, len, data)	add attribute to skb *   NLA_PUT_U8(skb, type, value)	add u8 attribute to skb *   NLA_PUT_U16(skb, type, value)	add u16 attribute to skb *   NLA_PUT_U32(skb, type, value)	add u32 attribute to skb *   NLA_PUT_U64(skb, type, value)	add u64 attribute to skb *   NLA_PUT_STRING(skb, type, str)	add string attribute to skb *   NLA_PUT_FLAG(skb, type)		add flag attribute to skb *   NLA_PUT_MSECS(skb, type, jiffies)	add msecs attribute to skb * *   The meaning of these functions is equal to their lower case *   variants but they jump to the label nla_put_failure in case *   of a failure. * * Nested Attributes Construction: *   nla_nest_start(skb, type)		start a nested attribute *   nla_nest_end(skb, nla)		finalize a nested attribute *   nla_nest_cancel(skb, nla)		cancel nested attribute construction * * Attribute Length Calculations: *   nla_attr_size(payload)		length of attribute w/o padding *   nla_total_size(payload)		length of attribute w/ padding *   nla_padlen(payload)		length of padding * * Attribute Payload Access: *   nla_data(nla)			head of attribute payload *   nla_len(nla)			length of attribute payload * * Attribute Payload Access for Basic Types: *   nla_get_u8(nla)			get payload for a u8 attribute *   nla_get_u16(nla)			get payload for a u16 attribute *   nla_get_u32(nla)			get payload for a u32 attribute *   nla_get_u64(nla)			get payload for a u64 attribute *   nla_get_flag(nla)			return 1 if flag is true *   nla_get_msecs(nla)			get payload for a msecs attribute * * Attribute Misc: *   nla_memcpy(dest, nla, count)	copy attribute into memory *   nla_memcmp(nla, data, size)	compare attribute with memory area *   nla_strlcpy(dst, nla, size)	copy attribute to a sized string *   nla_strcmp(nla, str)		compare attribute with string * * Attribute Parsing: *   nla_ok(nla, remaining)		does nla fit into remaining bytes? *   nla_next(nla, remaining)		get next netlink attribute *   nla_validate()			validate a stream of attributes *   nla_find()				find attribute in stream of attributes *   nla_parse()			parse and validate stream of attrs *   nla_parse_nested()			parse nested attribuets *   nla_for_each_attr()		loop over all attributes *========================================================================= */  /**  * Standard attribute types to specify validation policy  */enum {	NLA_UNSPEC,	NLA_U8,	NLA_U16,	NLA_U32,	NLA_U64,	NLA_STRING,	NLA_FLAG,	NLA_MSECS,	NLA_NESTED,	__NLA_TYPE_MAX,}; #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) /** * struct nla_policy - attribute validation policy * @type: Type of attribute or NLA_UNSPEC * @minlen: Minimal length of payload required to be available * * Policies are defined as arrays of this struct, the array must be * accessible by attribute type up to the highest identifier to be expected. * * Example: * static struct nla_policy my_policy[ATTR_MAX+1] __read_mostly = { * 	[ATTR_FOO] = { .type = NLA_U16 }, *	[ATTR_BAR] = { .type = NLA_STRING }, *	[ATTR_BAZ] = { .minlen = sizeof(struct mystruct) }, * }; */struct nla_policy {	u16		type;	u16		minlen;}; extern void		netlink_run_queue(struct sock *sk, unsigned int *qlen,					  int (*cb)(struct sk_buff *,						    struct nlmsghdr *, int *));extern void		netlink_queue_skip(struct nlmsghdr *nlh,					   struct sk_buff *skb); extern int		nla_validate(struct nlattr *head, int len, int maxtype,				     struct nla_policy *policy);extern int		nla_parse(struct nlattr *tb[], int maxtype,				  struct nlattr *head, int len,				  struct nla_policy *policy);extern struct nlattr *	nla_find(struct nlattr *head, int len, int attrtype);extern size_t		nla_strlcpy(char *dst, const struct nlattr *nla,				    size_t dstsize);extern int		nla_memcpy(void *dest, struct nlattr *src, int count);extern int		nla_memcmp(const struct nlattr *nla, const void *data,				   size_t size);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 struct nlattr *	nla_reserve(struct sk_buff *skb, int attrtype,				    int attrlen);extern void		__nla_put(struct sk_buff *skb, int attrtype,				  int attrlen, const void *data);extern int		nla_put(struct sk_buff *skb, int attrtype,				int attrlen, const void *data); /************************************************************************** * Netlink Messages **************************************************************************/ /** * nlmsg_msg_size - length of netlink message not including padding * @payload: length of message payload */static inline int nlmsg_msg_size(int payload){	return NLMSG_HDRLEN + payload;} /** * nlmsg_total_size - length of netlink message including padding * @payload: length of message payload */static inline int nlmsg_total_size(int payload){	return NLMSG_ALIGN(nlmsg_msg_size(payload));} /** * nlmsg_padlen - length of padding at the message's tail * @payload: length of message payload */static inline int nlmsg_padlen(int payload){	return nlmsg_total_size(payload) - nlmsg_msg_size(payload);} /** * nlmsg_data - head of message payload * @nlh: netlink messsage header */static inline void *nlmsg_data(const struct nlmsghdr *nlh){	return (unsigned char *) nlh + NLMSG_HDRLEN;} /** * nlmsg_len - length of message payload * @nlh: netlink message header */static inline int nlmsg_len(const struct nlmsghdr *nlh){	return nlh->nlmsg_len - NLMSG_HDRLEN;} /** * nlmsg_attrdata - head of attributes data * @nlh: netlink message header * @hdrlen: length of family specific header */static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,					    int hdrlen){	unsigned char *data = nlmsg_data(nlh);	return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));} /** * nlmsg_attrlen - length of attributes data * @nlh: netlink message header * @hdrlen: length of family specific header */static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen){	return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);} /** * nlmsg_ok - check if the netlink message fits into the remaining bytes * @nlh: netlink message header * @remaining: number of bytes remaining in message stream */static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining){	return (remaining >= sizeof(struct nlmsghdr) &&		nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&		nlh->nlmsg_len <= remaining);} /** * nlmsg_next - next netlink message in message stream * @nlh: netlink message header * @remaining: number of bytes remaining in message stream * * Returns the next netlink message in the message stream and * decrements remaining by the size of the current message. */static inline struct nlmsghdr *nlmsg_next(struct nlmsghdr *nlh, int *remaining){	int totlen = NLMSG_ALIGN(nlh->nlmsg_len); 	*remaining -= totlen; 	return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);} /** * nlmsg_parse - parse attributes of a netlink message * @nlh: netlink message header * @hdrlen: length of family specific header * @tb: destination array with maxtype+1 elements * @maxtype: maximum attribute type to be expected * @policy: validation policy * * See nla_parse() */static inline int nlmsg_parse(struct nlmsghdr *nlh, int hdrlen,			      struct nlattr *tb[], int maxtype,			      struct nla_policy *policy){	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))		return -EINVAL; 	return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),			 nlmsg_attrlen(nlh, hdrlen), policy);} /** * nlmsg_find_attr - find a specific attribute in a netlink message * @nlh: netlink message header * @hdrlen: length of familiy specific header * @attrtype: type of attribute to look for * * Returns the first attribute which matches the specified type. */static inline struct nlattr *nlmsg_find_attr(struct nlmsghdr *nlh,					     int hdrlen, int attrtype){	return nla_find(nlmsg_attrdata(nlh, hdrlen),			nlmsg_attrlen(nlh, hdrlen), attrtype);} /** * nlmsg_validate - validate a netlink message including attributes * @nlh: netlinket message header * @hdrlen: length of familiy specific header * @maxtype: maximum attribute type to be expected * @policy: validation policy */static inline int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype,				 struct nla_policy *policy){	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))		return -EINVAL; 	return nla_validate(nlmsg_attrdata(nlh, hdrlen),			    nlmsg_attrlen(nlh, hdrlen), maxtype, policy);} /** * nlmsg_for_each_attr - iterate over a stream of attributes * @pos: loop counter, set to current attribute * @nlh: netlink message header * @hdrlen: length of familiy specific header * @rem: initialized to len, holds bytes currently remaining in stream */#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \	nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \			  nlmsg_attrlen(nlh, hdrlen), rem) #if 0/* FIXME: Enable once all users have been converted */ /** * __nlmsg_put - Add a new netlink message to an skb * @skb: socket buffer to store message in * @pid: netlink process id * @seq: sequence number of message * @type: message type * @payload: length of message payload * @flags: message flags * * The caller is responsible to ensure that the skb provides enough * tailroom for both the netlink header and payload. */static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid,					   u32 seq, int type, int payload,					   int flags){	struct nlmsghdr *nlh; 	nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload));	nlh->nlmsg_type = type;	nlh->nlmsg_len = nlmsg_msg_size(payload);	nlh->nlmsg_flags = flags;	nlh->nlmsg_pid = pid;	nlh->nlmsg_seq = seq; 	memset((unsigned char *) nlmsg_data(nlh) + payload, 0,	       nlmsg_padlen(payload)); 	return nlh;}#endif /** * nlmsg_put - Add a new netlink message to an skb * @skb: socket buffer to store message in * @pid: netlink process id * @seq: sequence number of message * @type: message type * @payload: length of message payload * @flags: message flags * * Returns NULL if the tailroom of the skb is insufficient to store * the message header and payload. */static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,					 int type, int payload, int flags){	if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))		return NULL; 	return __nlmsg_put(skb, pid, seq, type, payload, flags);} /** * nlmsg_put_answer - Add a new callback based netlink message to an skb * @skb: socket buffer to store message in * @cb: netlink callback * @type: message type * @payload: length of message payload * @flags: message flags * * Returns NULL if the tailroom of the skb is insufficient to store * the message header and payload. */static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,						struct netlink_callback *cb,						int type, int payload,						int flags){	return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,			 type, payload, flags);} /** * nlmsg_new - Allocate a new netlink message * @size: maximum size of message * * Use NLMSG_GOODSIZE if size isn't know and you need a good default size. */static inline struct sk_buff *nlmsg_new(int size){	return alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);} /** * nlmsg_end - Finalize a netlink message * @skb: socket buffer the message is stored in * @nlh: netlink message header * * Corrects the netlink message header to include the appeneded * attributes. Only necessary if attributes have been added to * the message. * * Returns the total data length of the skb. */static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh){	nlh->nlmsg_len = skb->tail - (unsigned char *) nlh; 	return skb->len;} /** * nlmsg_cancel - Cancel construction of a netlink message * @skb: socket buffer the message is stored in * @nlh: netlink message header * * Removes the complete netlink message including all * attributes from the socket buffer again. Returns -1. */static inline int nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh){	skb_trim(skb, (unsigned char *) nlh - skb->data); 	return -1;} /** * nlmsg_free - free a netlink message * @skb: socket buffer of netlink message */

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