[mirror_ubuntu-artful-kernel.git] / net / netlink / attr.c

/*
 * 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);
Commit	Line	Data
bfa83a9e TG	1	/*
	2	* NETLINK Netlink attributes
	3	*
	4	* Authors: Thomas Graf <tgraf@suug.ch>
	5	* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
	6	*/
	7
bfa83a9e TG	8	#include <linux/module.h>
	9	#include <linux/kernel.h>
	10	#include <linux/errno.h>
	11	#include <linux/jiffies.h>
	12	#include <linux/netdevice.h>
	13	#include <linux/skbuff.h>
	14	#include <linux/string.h>
	15	#include <linux/types.h>
	16	#include <net/netlink.h>
	17
	18	static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = {
	19	[NLA_U8] = sizeof(u8),
	20	[NLA_U16] = sizeof(u16),
	21	[NLA_U32] = sizeof(u32),
	22	[NLA_U64] = sizeof(u64),
bfa83a9e TG	23	[NLA_NESTED] = NLA_HDRLEN,
	24	};
	25
	26	static int validate_nla(struct nlattr *nla, int maxtype,
	27	struct nla_policy *policy)
	28	{
	29	struct nla_policy *pt;
a5531a5d	30	int minlen = 0, attrlen = nla_len(nla);
bfa83a9e TG	31
	32	if (nla->nla_type <= 0 \|\| nla->nla_type > maxtype)
	33	return 0;
	34
	35	pt = &policy[nla->nla_type];
	36
	37	BUG_ON(pt->type > NLA_TYPE_MAX);
	38
a5531a5d TG	39	switch (pt->type) {
	40	case NLA_FLAG:
	41	if (attrlen > 0)
	42	return -ERANGE;
	43	break;
bfa83a9e	44
a5531a5d TG	45	case NLA_NUL_STRING:
	46	if (pt->len)
	47	minlen = min_t(int, attrlen, pt->len + 1);
	48	else
	49	minlen = attrlen;
bfa83a9e	50
a5531a5d TG	51	if (!minlen \|\| memchr(nla_data(nla), '\0', minlen) == NULL)
	52	return -EINVAL;
	53	/* fall through */
	54
	55	case NLA_STRING:
	56	if (attrlen < 1)
	57	return -ERANGE;
	58
	59	if (pt->len) {
	60	char *buf = nla_data(nla);
	61
	62	if (buf[attrlen - 1] == '\0')
	63	attrlen--;
	64
	65	if (attrlen > pt->len)
	66	return -ERANGE;
	67	}
	68	break;
	69
	70	default:
	71	if (pt->len)
	72	minlen = pt->len;
	73	else if (pt->type != NLA_UNSPEC)
	74	minlen = nla_attr_minlen[pt->type];
	75
	76	if (attrlen < minlen)
	77	return -ERANGE;
	78	}
bfa83a9e TG	79
	80	return 0;
	81	}
	82
	83	/**
	84	* nla_validate - Validate a stream of attributes
	85	* @head: head of attribute stream
	86	* @len: length of attribute stream
	87	* @maxtype: maximum attribute type to be expected
	88	* @policy: validation policy
	89	*
	90	* Validates all attributes in the specified attribute stream against the
	91	* specified policy. Attributes with a type exceeding maxtype will be
	92	* ignored. See documenation of struct nla_policy for more details.
	93	*
	94	* Returns 0 on success or a negative error code.
	95	*/
	96	int nla_validate(struct nlattr *head, int len, int maxtype,
	97	struct nla_policy *policy)
	98	{
	99	struct nlattr *nla;
	100	int rem, err;
	101
	102	nla_for_each_attr(nla, head, len, rem) {
	103	err = validate_nla(nla, maxtype, policy);
	104	if (err < 0)
	105	goto errout;
	106	}
	107
	108	err = 0;
	109	errout:
	110	return err;
	111	}
	112
	113	/**
	114	* nla_parse - Parse a stream of attributes into a tb buffer
	115	* @tb: destination array with maxtype+1 elements
	116	* @maxtype: maximum attribute type to be expected
	117	* @head: head of attribute stream
	118	* @len: length of attribute stream
	119	*
	120	* Parses a stream of attributes and stores a pointer to each attribute in
	121	* the tb array accessable via the attribute type. Attributes with a type
	122	* exceeding maxtype will be silently ignored for backwards compatibility
	123	* reasons. policy may be set to NULL if no validation is required.
	124	*
	125	* Returns 0 on success or a negative error code.
	126	*/
	127	int nla_parse(struct nlattr tb[], int maxtype, struct nlattr head, int len,
	128	struct nla_policy *policy)
	129	{
	130	struct nlattr *nla;
	131	int rem, err;
	132
	133	memset(tb, 0, sizeof(struct nlattr ) (maxtype + 1));
	134
	135	nla_for_each_attr(nla, head, len, rem) {
	136	u16 type = nla->nla_type;
	137
	138	if (type > 0 && type <= maxtype) {
	139	if (policy) {
	140	err = validate_nla(nla, maxtype, policy);
	141	if (err < 0)
	142	goto errout;
143	}
144
145	tb[type] = nla;
146	}
147	}
148
149	if (unlikely(rem > 0))
150	printk(KERN_WARNING "netlink: %d bytes leftover after parsing "
151	"attributes.\n", rem);
152
153	err = 0;
154	errout:
155	return err;
156	}
157
158	/**
159	* nla_find - Find a specific attribute in a stream of attributes
160	* @head: head of attribute stream
161	* @len: length of attribute stream
162	* @attrtype: type of attribute to look for
163	*
164	* Returns the first attribute in the stream matching the specified type.
165	*/
166	struct nlattr nla_find(struct nlattr head, int len, int attrtype)
167	{
168	struct nlattr *nla;
169	int rem;
170
171	nla_for_each_attr(nla, head, len, rem)
172	if (nla->nla_type == attrtype)
173	return nla;
174
175	return NULL;
176	}
177
178	/**
179	* nla_strlcpy - Copy string attribute payload into a sized buffer
180	* @dst: where to copy the string to
181	* @src: attribute to copy the string from
182	* @dstsize: size of destination buffer
183	*
184	* Copies at most dstsize - 1 bytes into the destination buffer.
185	* The result is always a valid NUL-terminated string. Unlike
186	* strlcpy the destination buffer is always padded out.
187	*
188	* Returns the length of the source buffer.
189	*/
190	size_t nla_strlcpy(char dst, const struct nlattr nla, size_t dstsize)
191	{
192	size_t srclen = nla_len(nla);
193	char *src = nla_data(nla);
194
195	if (srclen > 0 && src[srclen - 1] == '\0')
196	srclen--;
197
198	if (dstsize > 0) {
199	size_t len = (srclen >= dstsize) ? dstsize - 1 : srclen;
200
201	memset(dst, 0, dstsize);
202	memcpy(dst, src, len);
203	}
204
205	return srclen;
206	}
207
208	/**
209	* nla_memcpy - Copy a netlink attribute into another memory area
210	* @dest: where to copy to memcpy
211	* @src: netlink attribute to copy from
212	* @count: size of the destination area
213	*
214	* Note: The number of bytes copied is limited by the length of
215	* attribute's payload. memcpy
216	*
217	* Returns the number of bytes copied.
218	*/
219	int nla_memcpy(void dest, struct nlattr src, int count)
220	{
221	int minlen = min_t(int, count, nla_len(src));
222
223	memcpy(dest, nla_data(src), minlen);
224
225	return minlen;
226	}
227
228	/**
229	* nla_memcmp - Compare an attribute with sized memory area
230	* @nla: netlink attribute
231	* @data: memory area
232	* @size: size of memory area
233	*/
234	int nla_memcmp(const struct nlattr nla, const void data,
235	size_t size)
236	{
237	int d = nla_len(nla) - size;
238
239	if (d == 0)
240	d = memcmp(nla_data(nla), data, size);
241
242	return d;
243	}
244
245	/**
246	* nla_strcmp - Compare a string attribute against a string
247	* @nla: netlink string attribute
248	* @str: another string
249	*/
250	int nla_strcmp(const struct nlattr nla, const char str)
251	{
252	int len = strlen(str) + 1;
253	int d = nla_len(nla) - len;
254
255	if (d == 0)
256	d = memcmp(nla_data(nla), str, len);
257
258	return d;
259	}
260
261	/**
262	* __nla_reserve - reserve room for attribute on the skb
263	* @skb: socket buffer to reserve room on
264	* @attrtype: attribute type
265	* @attrlen: length of attribute payload
266	*
267	* Adds a netlink attribute header to a socket buffer and reserves
268	* room for the payload but does not copy it.
269	*
270	* The caller is responsible to ensure that the skb provides enough
271	* tailroom for the attribute header and payload.
272	*/
273	struct nlattr __nla_reserve(struct sk_buff skb, int attrtype, int attrlen)
274	{
275	struct nlattr *nla;
276
277	nla = (struct nlattr *) skb_put(skb, nla_total_size(attrlen));
278	nla->nla_type = attrtype;
279	nla->nla_len = nla_attr_size(attrlen);
280
281	memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen));
282
283	return nla;
284	}
285
fe4944e5 TG	286	/**
	287	* __nla_reserve_nohdr - reserve room for attribute without header
	288	* @skb: socket buffer to reserve room on
	289	* @attrlen: length of attribute payload
	290	*
	291	* Reserves room for attribute payload without a header.
	292	*
	293	* The caller is responsible to ensure that the skb provides enough
	294	* tailroom for the payload.
	295	*/
	296	void __nla_reserve_nohdr(struct sk_buff skb, int attrlen)
	297	{
	298	void *start;
	299
	300	start = skb_put(skb, NLA_ALIGN(attrlen));
	301	memset(start, 0, NLA_ALIGN(attrlen));
	302
	303	return start;
	304	}
	305
bfa83a9e TG	306	/**
	307	* nla_reserve - reserve room for attribute on the skb
	308	* @skb: socket buffer to reserve room on
	309	* @attrtype: attribute type
	310	* @attrlen: length of attribute payload
	311	*
	312	* Adds a netlink attribute header to a socket buffer and reserves
	313	* room for the payload but does not copy it.
	314	*
	315	* Returns NULL if the tailroom of the skb is insufficient to store
	316	* the attribute header and payload.
	317	*/
	318	struct nlattr nla_reserve(struct sk_buff skb, int attrtype, int attrlen)
	319	{
	320	if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
	321	return NULL;
	322
	323	return __nla_reserve(skb, attrtype, attrlen);
	324	}
	325
fe4944e5 TG	326	/**
	327	* nla_reserve - reserve room for attribute without header
	328	* @skb: socket buffer to reserve room on
	329	* @len: length of attribute payload
	330	*
	331	* Reserves room for attribute payload without a header.
	332	*
	333	* Returns NULL if the tailroom of the skb is insufficient to store
	334	* the attribute payload.
	335	*/
	336	void nla_reserve_nohdr(struct sk_buff skb, int attrlen)
	337	{
	338	if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
	339	return NULL;
	340
	341	return __nla_reserve_nohdr(skb, attrlen);
	342	}
	343
bfa83a9e TG	344	/**
	345	* __nla_put - Add a netlink attribute to a socket buffer
	346	* @skb: socket buffer to add attribute to
	347	* @attrtype: attribute type
	348	* @attrlen: length of attribute payload
	349	* @data: head of attribute payload
	350	*
	351	* The caller is responsible to ensure that the skb provides enough
	352	* tailroom for the attribute header and payload.
	353	*/
	354	void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
	355	const void *data)
	356	{
	357	struct nlattr *nla;
	358
	359	nla = __nla_reserve(skb, attrtype, attrlen);
	360	memcpy(nla_data(nla), data, attrlen);
	361	}
	362
fe4944e5 TG	363	/**
	364	* __nla_put_nohdr - Add a netlink attribute without header
	365	* @skb: socket buffer to add attribute to
	366	* @attrlen: length of attribute payload
	367	* @data: head of attribute payload
	368	*
	369	* The caller is responsible to ensure that the skb provides enough
	370	* tailroom for the attribute payload.
	371	*/
	372	void __nla_put_nohdr(struct sk_buff skb, int attrlen, const void data)
	373	{
	374	void *start;
	375
	376	start = __nla_reserve_nohdr(skb, attrlen);
	377	memcpy(start, data, attrlen);
	378	}
bfa83a9e TG	379
	380	/**
	381	* nla_put - Add a netlink attribute to a socket buffer
	382	* @skb: socket buffer to add attribute to
	383	* @attrtype: attribute type
	384	* @attrlen: length of attribute payload
	385	* @data: head of attribute payload
	386	*
	387	* Returns -1 if the tailroom of the skb is insufficient to store
	388	* the attribute header and payload.
	389	*/
	390	int nla_put(struct sk_buff skb, int attrtype, int attrlen, const void data)
	391	{
	392	if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
	393	return -1;
	394
	395	__nla_put(skb, attrtype, attrlen, data);
	396	return 0;
	397	}
	398
fe4944e5 TG	399	/**
	400	* nla_put_nohdr - Add a netlink attribute without header
	401	* @skb: socket buffer to add attribute to
	402	* @attrlen: length of attribute payload
	403	* @data: head of attribute payload
	404	*
	405	* Returns -1 if the tailroom of the skb is insufficient to store
	406	* the attribute payload.
	407	*/
	408	int nla_put_nohdr(struct sk_buff skb, int attrlen, const void data)
	409	{
	410	if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
	411	return -1;
	412
	413	__nla_put_nohdr(skb, attrlen, data);
	414	return 0;
	415	}
bfa83a9e TG	416
	417	EXPORT_SYMBOL(nla_validate);
	418	EXPORT_SYMBOL(nla_parse);
	419	EXPORT_SYMBOL(nla_find);
	420	EXPORT_SYMBOL(nla_strlcpy);
	421	EXPORT_SYMBOL(__nla_reserve);
fe4944e5	422	EXPORT_SYMBOL(__nla_reserve_nohdr);
bfa83a9e	423	EXPORT_SYMBOL(nla_reserve);
fe4944e5	424	EXPORT_SYMBOL(nla_reserve_nohdr);
bfa83a9e	425	EXPORT_SYMBOL(__nla_put);
fe4944e5	426	EXPORT_SYMBOL(__nla_put_nohdr);
bfa83a9e	427	EXPORT_SYMBOL(nla_put);
fe4944e5	428	EXPORT_SYMBOL(nla_put_nohdr);
bfa83a9e TG	429	EXPORT_SYMBOL(nla_memcpy);
	430	EXPORT_SYMBOL(nla_memcmp);
	431	EXPORT_SYMBOL(nla_strcmp);