Attributes

Netlink Attributes Construction/Parsing Interface. More...

Data Structures
struct	nla_policy
	attribute validation policy More...

Validation Policy Types
enum	{   NLA_UNSPEC , NLA_U8 , NLA_U16 , NLA_U32 ,   NLA_U64 , NLA_STRING , NLA_FLAG , NLA_MSECS ,   NLA_NESTED , __NLA_TYPE_MAX }
	Standard attribute types to specify validation policy. More...
#define	NLA_TYPE_MAX   (__NLA_TYPE_MAX - 1)
	Maximum netlink validation policy type.

Attribute Parsing
int	nla_ok (const struct nlattr *nla, int remaining)
	check if the netlink attribute fits into the remaining bytes
struct nlattr *	nla_next (const struct nlattr *nla, int *remaining)
	next netlink attribte in attribute stream
int	nla_parse (struct nlattr *tb[], int maxtype, struct nlattr *head, int len, struct nla_policy *policy)
	Parse a stream of attributes into a tb buffer.
int	nla_parse_nested (struct nlattr *tb[], int maxtype, struct nlattr *nla, struct nla_policy *policy)
	parse nested attributes
int	nla_validate (struct nlattr *head, int len, int maxtype, struct nla_policy *policy)
	Validate a stream of attributes.
struct nlattr *	nla_find (struct nlattr *head, int len, int attrtype)
	Find a specific attribute in a stream of attributes.

Size Calculations
int	nla_attr_size (int payload)
	length of attribute not including padding
int	nla_total_size (int payload)
	total length of attribute including padding
int	nla_padlen (int payload)
	length of padding at the tail of the attribute

Payload Access
int	nla_type (const struct nlattr *nla)
	attribute type
void *	nla_data (const struct nlattr *nla)
	head of payload
int	nla_len (const struct nlattr *nla)
	length of payload

Utilities
int	nla_memcpy (void *dest, struct nlattr *src, int count)
	Copy a netlink attribute into another memory area.
size_t	nla_strlcpy (char *dst, const struct nlattr *nla, size_t dstsize)
	Copy string attribute payload into a sized buffer.
int	nla_memcmp (const struct nlattr *nla, const void *data, size_t size)
	Compare an attribute with sized memory area.
int	nla_strcmp (const struct nlattr *nla, const char *str)
	Compare a string attribute against a string.

Attribute Construction
struct nlattr *	nla_reserve (struct nl_msg *n, int attrtype, int attrlen)
	reserve room for attribute on the skb
int	nla_put (struct nl_msg *n, int attrtype, int attrlen, const void *data)
	Add a netlink attribute to a netlink message.
int	nla_put_nested (struct nl_msg *n, int attrtype, struct nl_msg *nested)
	Add a nested netlink attribute to a netlink message.
int	nla_put_u8 (struct nl_msg *n, int attrtype, uint8_t value)
	Add a u16 netlink attribute to a netlink message.
int	nla_put_u16 (struct nl_msg *n, int attrtype, uint16_t value)
	Add a u16 netlink attribute to a netlink message.
int	nla_put_u32 (struct nl_msg *n, int attrtype, uint32_t value)
	Add a u32 netlink attribute to a netlink message.
int	nla_put_u64 (struct nl_msg *n, int attrtype, uint64_t value)
	Add a u64 netlink attribute to a netlink message.
int	nla_put_string (struct nl_msg *n, int attrtype, const char *str)
	Add a string netlink attribute to a netlink message.
int	nla_put_flag (struct nl_msg *n, int attrtype)
	Add a flag netlink attribute to a netlink message.
int	nla_put_msecs (struct nl_msg *n, int attrtype, unsigned long msecs)
	Add a msecs netlink attribute to a netlink message.
int	nla_put_data (struct nl_msg *n, int attrtype, struct nl_data *data)
	Add an abstract data netlink attribute to a netlink message.
int	nla_put_addr (struct nl_msg *n, int attrtype, struct nl_addr *addr)
	Add an abstract address netlink attribute to a netlink message.

Attribute Nesting
struct nlattr *	nla_nest_start (struct nl_msg *n, int attrtype)
	Start a new level of nested attributes.
int	nla_nest_end (struct nl_msg *n, struct nlattr *start)
	Finalize nesting of attributes.

Attribute Reading
uint32_t	nla_get_u32 (struct nlattr *nla)
	Return payload of u32 attribute.
uint16_t	nla_get_u16 (struct nlattr *nla)
	Return payload of u16 attribute.
uint8_t	nla_get_u8 (struct nlattr *nla)
	Return payload of u8 attribute.
uint64_t	nla_get_u64 (struct nlattr *nla)
	Return payload of u64 attribute.
char *	nla_get_string (struct nlattr *nla)
	return payload of string attribute
int	nla_get_flag (struct nlattr *nla)
	Return payload of flag attribute.
unsigned long	nla_get_msecs (struct nlattr *nla)
	Return payload of msecs attribute.
struct nl_addr *	nla_get_addr (struct nlattr *nla, int family)
	Return payload of address attribute.
struct nl_data *	nla_get_data (struct nlattr *nla)
	Return payload of abstract data attribute.

Attribute Construction (Exception Based)
All these functions jump to nla_put_failure in case of a failure instead of returning an error code.
#define	NLA_PUT(n, attrtype, attrlen, data)
	Add a netlink attribute to a netlink message.
#define	NLA_PUT_TYPE(n, type, attrtype, value)
	Add a basic netlink attribute to a netlink message.
#define	NLA_PUT_U8(n, attrtype, value)    NLA_PUT_TYPE(n, uint8_t, attrtype, value)
	Add a u8 netlink attribute to a netlink message.
#define	NLA_PUT_U16(n, attrtype, value)    NLA_PUT_TYPE(n, uint16_t, attrtype, value)
	Add a u16 netlink attribute to a netlink message.
#define	NLA_PUT_U32(n, attrtype, value)    NLA_PUT_TYPE(n, uint32_t, attrtype, value)
	Add a u32 netlink attribute to a netlink message.
#define	NLA_PUT_U64(n, attrtype, value)    NLA_PUT_TYPE(n, uint64_t, attrtype, value)
	Add a u64 netlink attribute to a netlink message.
#define	NLA_PUT_STRING(n, attrtype, value)    NLA_PUT(n, attrtype, strlen(value) + 1, value)
	Add a character string netlink attribute to a netlink message.
#define	NLA_PUT_FLAG(n, attrtype)    NLA_PUT(n, attrtype, 0, NULL)
	Add a flag netlink attribute to a netlink message.
#define	NLA_PUT_MSECS(n, attrtype, msecs)    NLA_PUT_U64(n, attrtype, msecs)
	Add a msecs netlink attribute to a netlink message.
#define	NLA_PUT_ADDR(n, attrtype, addr)
	Add a address attribute to a netlink message.

Iterators
#define	nla_for_each_attr(pos, head, len, rem)
	iterate over a stream of attributes
#define	nla_for_each_nested(pos, nla, rem)
	iterate over a stream of nested attributes

Detailed Description

0) Introduction

Netlink attributes are chained together following each other:

 <------- nla_total_size(payload) ------->
 <---- nla_attr_size(payload) ----->
+----------+- - -+- - - - - - - - - +- - -+-------- - -
|  Header  | Pad |     Payload      | Pad |  Header
+----------+- - -+- - - - - - - - - +- - -+-------- - -
                  <- nla_len(nla) ->      ^
nla_data(nla)----^                        |
nla_next(nla)-----------------------------'

The attribute header and payload must be aligned properly:

 <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
+---------------------+- - -+- - - - - - - - - -+- - -+
|        Header       | Pad |     Payload       | Pad |
|   (struct nlattr)   | ing |                   | ing |
+---------------------+- - -+- - - - - - - - - -+- - -+
 <-------------- nlattr->nla_len -------------->

Nested TLVs:

Nested TLVs are an array of TLVs nested into another TLV. This can be useful to allow subsystems to have their own formatting rules without the need to make the underlying layer be aware of it. It can also be useful to transfer arrays, lists and flattened trees.

 <-------------------- NLA_ALIGN(...) ------------------->
+---------------+- - - - - - - - - - - - - - - - - -+- - -+
|               |+---------+---------+- - -+-------+|     |
|  TLV Header   ||  TLV 1  |  TLV 2  |     | TLV n || Pad |
|               |+---------+---------+- - -+-------+|     |
+---------------+- - - - - - - - - - - - - - - - - -+- - -+
                 <--------- nla_data(nla) --------->

1) Constructing a message with attributes

int param1 = 10;
char *param2 = "parameter text";
 
struct nl_msg *msg = nlmsg_alloc();
nla_put_u32(msg, 1, param1);
nla_put_string(msg, 2, param2);
 
nl_send_auto_complete(handle, nl_msg_get(msg));
nlmsg_free(msg);

2) Constructing nested attributes

struct nl_msg * nested_config(void)
{
        int a = 5, int b = 10;
        struct nl_msg *n = nlmsg_alloc();
        nla_put_u32(n, 10, a);
        nla_put_u32(n, 20, b);
        return n;
}
 
...
struct nl_msg *m = nlmsg_alloc();
struct nl_msg *nest = nested_config();
nla_put_nested(m, 1, nest);
 
nl_send_auto_complete(handle, nl_msg_get(m));
nlmsg_free(nest);
nlmsg_free(m);

Macro Definition Documentation

NLA_TYPE_MAX

#define NLA_TYPE_MAX   (__NLA_TYPE_MAX - 1)

Definition at line 52 of file attr.h.

NLA_PUT

#define NLA_PUT	(		n,
			attrtype,
			attrlen,
			data
	)

Value:

        do { \
                if (nla_put(n, attrtype, attrlen, data) < 0) \
                        goto nla_put_failure; \
        } while(0)

Parameters

n	netlink message
attrtype	attribute type
attrlen	length of attribute payload
data	head of attribute payload

Definition at line 157 of file attr.h.

NLA_PUT_TYPE

#define NLA_PUT_TYPE	(		n,
			type,
			attrtype,
			value
	)

Value:

        do { \
                type __tmp = value; \
                NLA_PUT(n, attrtype, sizeof(type), &__tmp); \
        } while(0)

Parameters

n	netlink message
type	atomic type
attrtype	attribute type
value	head of attribute payload

Definition at line 171 of file attr.h.

nla_for_each_attr

#define nla_for_each_attr	(		pos,
			head,
			len,
			rem
	)

Value:

        for (pos = head, rem = len; \
             nla_ok(pos, rem); \
             pos = nla_next(pos, &(rem)))

Parameters

pos	loop counter, set to current attribute
head	head of attribute stream
len	length of attribute stream
rem	initialized to len, holds bytes currently remaining in stream

Definition at line 264 of file attr.h.

nla_for_each_nested

#define nla_for_each_nested	(		pos,
			nla,
			rem
	)

Value:

        for (pos = nla_data(nla), rem = nla_len(nla); \
             nla_ok(pos, rem); \
             pos = nla_next(pos, &(rem)))

Parameters

pos	loop counter, set to current attribute
nla	attribute containing the nested attributes
rem	initialized to len, holds bytes currently remaining in stream

Definition at line 276 of file attr.h.

NLA_PUT_U8

#define NLA_PUT_U8	(		n,
			attrtype,
			value
	)		NLA_PUT_TYPE(n, uint8_t, attrtype, value)

Parameters

n	netlink message
attrtype	attribute type
value	numeric value

Definition at line 183 of file attr.h.

NLA_PUT_U16

#define NLA_PUT_U16	(		n,
			attrtype,
			value
	)		NLA_PUT_TYPE(n, uint16_t, attrtype, value)

Parameters

n	netlink message
attrtype	attribute type
value	numeric value

Definition at line 192 of file attr.h.

NLA_PUT_U32

#define NLA_PUT_U32	(		n,
			attrtype,
			value
	)		NLA_PUT_TYPE(n, uint32_t, attrtype, value)

Parameters

n	netlink message
attrtype	attribute type
value	numeric value

Definition at line 201 of file attr.h.

NLA_PUT_U64

#define NLA_PUT_U64	(		n,
			attrtype,
			value
	)		NLA_PUT_TYPE(n, uint64_t, attrtype, value)

Parameters

n	netlink message
attrtype	attribute type
value	numeric value

Definition at line 210 of file attr.h.

NLA_PUT_STRING

#define NLA_PUT_STRING	(		n,
			attrtype,
			value
	)		NLA_PUT(n, attrtype, strlen(value) + 1, value)

Parameters

n	netlink message
attrtype	attribute type
value	character string

Definition at line 219 of file attr.h.

NLA_PUT_FLAG

#define NLA_PUT_FLAG	(		n,
			attrtype
	)		NLA_PUT(n, attrtype, 0, NULL)

Parameters

n	netlink message
attrtype	attribute type

Definition at line 227 of file attr.h.

NLA_PUT_MSECS

#define NLA_PUT_MSECS	(		n,
			attrtype,
			msecs
	)		NLA_PUT_U64(n, attrtype, msecs)

Parameters

n	netlink message
attrtype	attribute type
msecs	numeric value in micro seconds

Definition at line 236 of file attr.h.

NLA_PUT_ADDR

#define NLA_PUT_ADDR	(		n,
			attrtype,
			addr
	)

Value:

        NLA_PUT(n, attrtype, nl_addr_get_len(addr), \
                nl_addr_get_binary_addr(addr))

Parameters

n	netlink message
attrtype	attribute type
addr	abstract address object

Definition at line 245 of file attr.h.

Enumeration Type Documentation

anonymous enum

anonymous enum

Enumerator
NLA_UNSPEC	Unspecified type.
NLA_U8	8bit integer
NLA_U16	16bit integer
NLA_U32	32bit integer
NLA_U64	64bit integer
NLA_STRING	character string
NLA_FLAG	flag
NLA_MSECS	micro seconds (64bit)
NLA_NESTED	nested attributes

Definition at line 35 of file attr.h.

     {
        NLA_UNSPEC,     /**< Unspecified type */
        NLA_U8,         /**< 8bit integer */
        NLA_U16,        /**< 16bit integer */
        NLA_U32,        /**< 32bit integer */
        NLA_U64,        /**< 64bit integer */
        NLA_STRING,     /**< character string */
        NLA_FLAG,       /**< flag */
        NLA_MSECS,      /**< micro seconds (64bit) */
        NLA_NESTED,     /**< nested attributes */
        __NLA_TYPE_MAX,
};

Function Documentation

nla_attr_size()

int nla_attr_size

(

int

payload

)

Parameters

payload

length of payload

Definition at line 108 of file attr.c.

{
        return NLA_HDRLEN + payload;
}

Referenced by nla_padlen(), nla_reserve(), and nla_total_size().

nla_total_size()

int nla_total_size

(

int

payload

)

Parameters

payload

length of payload

Definition at line 117 of file attr.c.

{
        return NLA_ALIGN(nla_attr_size(payload));
}

References nla_attr_size().

Referenced by nla_padlen(), and nla_reserve().

nla_padlen()

int nla_padlen

(

int

payload

)

Parameters

payload

length of payload

Definition at line 126 of file attr.c.

{
        return nla_total_size(payload) - nla_attr_size(payload);
}

References nla_attr_size(), and nla_total_size().

Referenced by nla_reserve().

nla_type()

int nla_type

(

const struct nlattr *

nla

)

Parameters

nla	netlink attribute

Definition at line 142 of file attr.c.

{
        return nla->nla_type & NLA_TYPE_MASK;
}

Referenced by nla_find(), and nla_parse().

nla_data()

void * nla_data

(

const struct nlattr *

nla

)

Parameters

nla	netlink attribute

Definition at line 151 of file attr.c.

{
        return (char *) nla + NLA_HDRLEN;
}

Referenced by nla_get_addr(), nla_get_data(), nla_get_string(), nla_get_u16(), nla_get_u32(), nla_get_u8(), nla_memcmp(), nla_memcpy(), nla_parse_nested(), nla_put(), nla_strcmp(), and nla_strlcpy().

nla_len()

int nla_len

(

const struct nlattr *

nla

)

Parameters

nla	netlink attribute

Definition at line 160 of file attr.c.

{
        return nla->nla_len - NLA_HDRLEN;
}

Referenced by nla_get_addr(), nla_get_data(), nla_memcmp(), nla_memcpy(), nla_parse_nested(), nla_strcmp(), and nla_strlcpy().

nla_ok()

int nla_ok	(	const struct nlattr *	nla,
		int	remaining
	)

Parameters

nla	netlink attribute
remaining	number of bytes remaining in attribute stream

Definition at line 177 of file attr.c.

{
        return remaining >= sizeof(*nla) &&
               nla->nla_len >= sizeof(*nla) &&
               nla->nla_len <= remaining;
}

nla_next()

struct nlattr * nla_next	(	const struct nlattr *	nla,
		int *	remaining
	)

Parameters

nla	netlink attribute
remaining	number of bytes remaining in attribute stream

Returns

the next netlink attribute in the attribute stream and decrements remaining by the size of the current attribute.

Definition at line 192 of file attr.c.

{
        int totlen = NLA_ALIGN(nla->nla_len);
 
        *remaining -= totlen;
        return (struct nlattr *) ((char *) nla + totlen);
}

nla_parse()

int nla_parse	(	struct nlattr *	tb[],
		int	maxtype,
		struct nlattr *	head,
		int	len,
		struct nla_policy *	policy
	)

Parameters

tb	destination array with maxtype+1 elements
maxtype	maximum attribute type to be expected
head	head of attribute stream
len	length of attribute stream
policy	validation policy

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.

Definition at line 262 of file attr.c.

{
        struct nlattr *nla;
        int rem, err;
 
        memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
 
        nla_for_each_attr(nla, head, len, rem) {
                int type = nla_type(nla);
 
                /* Padding attributes */
                if (type == 0)
                        continue;
 
                if (type <= maxtype) {
                        if (policy) {
                                err = validate_nla(nla, maxtype, policy);
                                if (err < 0)
                                        goto errout;
                        }
 
                        tb[type] = nla;
                }
        }
 
        if (rem > 0)
                fprintf(stderr, "netlink: %d bytes leftover after parsing "
                       "attributes.\n", rem);
 
        err = 0;
errout:
        return err;
}

References nla_for_each_attr, and nla_type().

Referenced by nla_parse_nested(), and nlmsg_parse().

nla_parse_nested()

int nla_parse_nested	(	struct nlattr *	tb[],
		int	maxtype,
		struct nlattr *	nla,
		struct nla_policy *	policy
	)

Parameters

tb	destination array with maxtype+1 elements
maxtype	maximum attribute type to be expected
nla	attribute containing the nested attributes
policy	validation policy

See also

nla_parse()

Definition at line 307 of file attr.c.

{
        return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
}

References nla_data(), nla_len(), and nla_parse().

nla_validate()

int nla_validate	(	struct nlattr *	head,
		int	len,
		int	maxtype,
		struct nla_policy *	policy
	)

Parameters

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.

Definition at line 327 of file attr.c.

{
        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;
}

References nla_for_each_attr.

Referenced by nlmsg_validate().

nla_find()

struct nlattr * nla_find	(	struct nlattr *	head,
		int	len,
		int	attrtype
	)

Parameters

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.

Definition at line 352 of file attr.c.

{
        struct nlattr *nla;
        int rem;
 
        nla_for_each_attr(nla, head, len, rem)
                if (nla_type(nla) == attrtype)
                        return nla;
 
        return NULL;
}

References nla_for_each_attr, and nla_type().

Referenced by nlmsg_find_attr().

nla_memcpy()

int nla_memcpy	(	void *	dest,
		struct nlattr *	src,
		int	count
	)

Parameters

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.

Definition at line 382 of file attr.c.

{
        int minlen;
 
        if (!src)
                return 0;
        
        minlen = min_t(int, count, nla_len(src));
        memcpy(dest, nla_data(src), minlen);
 
        return minlen;
}

References nla_data(), and nla_len().

Referenced by nla_get_u64().

nla_strlcpy()

size_t nla_strlcpy	(	char *	dst,
		const struct nlattr *	nla,
		size_t	dstsize
	)

Parameters

dst	where to copy the string to
nla	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.

Definition at line 407 of file attr.c.

{
        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;
}

References nla_data(), and nla_len().

nla_memcmp()

int nla_memcmp	(	const struct nlattr *	nla,
		const void *	data,
		size_t	size
	)

Parameters

nla	netlink attribute
data	memory area
size	size of memory area

Definition at line 431 of file attr.c.

{
        int d = nla_len(nla) - size;
 
        if (d == 0)
                d = memcmp(nla_data(nla), data, size);
 
        return d;
}

References nla_data(), and nla_len().

nla_strcmp()

int nla_strcmp	(	const struct nlattr *	nla,
		const char *	str
	)

Parameters

nla	netlink string attribute
str	another string

Definition at line 447 of file attr.c.

{
        int len = strlen(str) + 1;
        int d = nla_len(nla) - len;
 
        if (d == 0)
                d = memcmp(nla_data(nla), str, len);
 
        return d;
}

References nla_data(), and nla_len().

nla_reserve()

struct nlattr * nla_reserve	(	struct nl_msg *	n,
		int	attrtype,
		int	attrlen
	)

Parameters

n	netlink message
attrtype	attribute type
attrlen	length of attribute payload

Adds a netlink attribute header to a netlink message and reserves room for the payload but does not copy it.

Definition at line 474 of file attr.c.

{
        struct nlattr *nla;
        int tlen;
        
        tlen = NLMSG_ALIGN(n->nm_nlh->nlmsg_len) + nla_total_size(attrlen);
 
        if (tlen > n->nm_size) {
                nl_errno(ENOBUFS);
                return NULL;
        }
 
        nla = (struct nlattr *) nlmsg_tail(n->nm_nlh);
        nla->nla_type = attrtype;
        nla->nla_len = nla_attr_size(attrlen);
 
        memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen));
        n->nm_nlh->nlmsg_len = tlen;
 
        NL_DBG(2, "msg %p: Reserved %d bytes at offset +%td for attr %d "
                  "nlmsg_len=%d\n", n, attrlen,
                  (void *) nla - nlmsg_data(n->nm_nlh),
                  attrtype, n->nm_nlh->nlmsg_len);
 
        return nla;
}

References nla_attr_size(), nla_padlen(), nla_total_size(), and nlmsg_data().

Referenced by nla_put().

nla_put()

int nla_put	(	struct nl_msg *	n,
		int	attrtype,
		int	attrlen,
		const void *	data
	)

Parameters

n	netlink message
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.

Definition at line 511 of file attr.c.

{
        struct nlattr *nla;
 
        nla = nla_reserve(n, attrtype, attrlen);
        if (!nla)
                return nl_errno(ENOMEM);
 
        memcpy(nla_data(nla), data, attrlen);
        NL_DBG(2, "msg %p: Wrote %d bytes at offset +%td for attr %d\n",
               n, attrlen, (void *) nla - nlmsg_data(n->nm_nlh), attrtype);
 
        return 0;
}

References nla_data(), nla_reserve(), and nlmsg_data().

Referenced by nla_nest_start(), nla_put_addr(), nla_put_data(), nla_put_flag(), nla_put_nested(), nla_put_string(), nla_put_u16(), nla_put_u32(), nla_put_u64(), and nla_put_u8().

nla_put_nested()

int nla_put_nested	(	struct nl_msg *	n,
		int	attrtype,
		struct nl_msg *	nested
	)

Parameters

n	netlink message
attrtype	attribute type
nested	netlink attribute to nest

Returns

-1 if the tailroom of the skb is insufficient to store the attribute header and payload.

Definition at line 535 of file attr.c.

{
        return nla_put(n, attrtype, nlmsg_len(nested->nm_nlh),
                       nlmsg_data(nested->nm_nlh));
}

References nla_put(), nlmsg_data(), and nlmsg_len().

Referenced by rtnl_neightbl_build_change_request().

nla_put_u8()

int nla_put_u8	(	struct nl_msg *	n,
		int	attrtype,
		uint8_t	value
	)

Parameters

n	netlink message
attrtype	attribute type
value	numeric value

Definition at line 547 of file attr.c.

{
        return nla_put(n, attrtype, sizeof(uint8_t), &value);
}

References nla_put().

nla_put_u16()

int nla_put_u16	(	struct nl_msg *	n,
		int	attrtype,
		uint16_t	value
	)

Parameters

n	netlink message
attrtype	attribute type
value	numeric value

Definition at line 558 of file attr.c.

{
        return nla_put(n, attrtype, sizeof(uint16_t), &value);
}

References nla_put().

nla_put_u32()

int nla_put_u32	(	struct nl_msg *	n,
		int	attrtype,
		uint32_t	value
	)

Parameters

n	netlink message
attrtype	attribute type
value	numeric value

Definition at line 569 of file attr.c.

{
        return nla_put(n, attrtype, sizeof(uint32_t), &value);
}

References nla_put().

Referenced by rtnl_neightbl_build_change_request().

nla_put_u64()

int nla_put_u64	(	struct nl_msg *	n,
		int	attrtype,
		uint64_t	value
	)

Parameters

n	netlink message
attrtype	attribute type
value	numeric value

Definition at line 580 of file attr.c.

{
        return nla_put(n, attrtype, sizeof(uint64_t), &value);
}

References nla_put().

Referenced by nla_put_msecs(), and rtnl_neightbl_build_change_request().

nla_put_string()

int nla_put_string	(	struct nl_msg *	n,
		int	attrtype,
		const char *	str
	)

Parameters

n	netlink message
attrtype	attribute type
str	NUL terminated string

Definition at line 591 of file attr.c.

{
        return nla_put(n, attrtype, strlen(str) + 1, str);
}

References nla_put().

Referenced by rtnl_neightbl_build_change_request().

nla_put_flag()

int nla_put_flag	(	struct nl_msg *	n,
		int	attrtype
	)

Parameters

n	netlink message
attrtype	attribute type

Definition at line 601 of file attr.c.

{
        return nla_put(n, attrtype, 0, NULL);
}

References nla_put().

nla_put_msecs()

int nla_put_msecs	(	struct nl_msg *	n,
		int	attrtype,
		unsigned long	msecs
	)

Parameters

n	netlink message
attrtype	attribute type
msecs	number of msecs

Definition at line 612 of file attr.c.

{
        return nla_put_u64(n, attrtype, msecs);
}

References nla_put_u64().

nla_put_data()

int nla_put_data	(	struct nl_msg *	n,
		int	attrtype,
		struct nl_data *	data
	)

Parameters

n	netlink message
attrtype	attribute type
data	abstract data

Definition at line 623 of file attr.c.

{
        return nla_put(n, attrtype, nl_data_get_size(data),
                       nl_data_get(data));
}

References nl_data_get(), nl_data_get_size(), and nla_put().

nla_put_addr()

int nla_put_addr	(	struct nl_msg *	n,
		int	attrtype,
		struct nl_addr *	addr
	)

Parameters

n	netlink message
attrtype	attribute type
addr	abstract address

Definition at line 635 of file attr.c.

{
        return nla_put(n, attrtype, nl_addr_get_len(addr),
                       nl_addr_get_binary_addr(addr));
}

References nl_addr_get_binary_addr(), nl_addr_get_len(), and nla_put().

nla_nest_start()

struct nlattr * nla_nest_start	(	struct nl_msg *	n,
		int	attrtype
	)

Parameters

n	netlink message
attrtype	attribute type of container

Returns

the container attribute

Definition at line 655 of file attr.c.

{
        struct nlattr *start = (struct nlattr *) nlmsg_tail(n->nm_nlh);
 
        if (nla_put(n, attrtype, 0, NULL) < 0)
                return NULL;
 
        return start;
}

References nla_put().

Referenced by rtnl_link_build_change_request().

nla_nest_end()

int nla_nest_end	(	struct nl_msg *	n,
		struct nlattr *	start
	)

Parameters

n	netlink message
start	container attribute

Corrects the container attribute header to include the all appeneded attributes.

Returns

the total data length of the skb.

Definition at line 675 of file attr.c.

{
        start->nla_len = (unsigned char *) nlmsg_tail(n->nm_nlh) -
                                (unsigned char *) start;
        return 0;
}

Referenced by rtnl_link_build_change_request().

nla_get_u32()

uint32_t nla_get_u32

(

struct nlattr *

nla

)

Parameters

nla	u32 netlink attribute

Definition at line 693 of file attr.c.

{
        return *(uint32_t *) nla_data(nla);
}

References nla_data().

nla_get_u16()

uint16_t nla_get_u16

(

struct nlattr *

nla

)

Parameters

nla	u16 netlink attribute

Definition at line 702 of file attr.c.

{
        return *(uint16_t *) nla_data(nla);
}

References nla_data().

nla_get_u8()

uint8_t nla_get_u8

(

struct nlattr *

nla

)

Parameters

nla	u8 netlink attribute

Definition at line 711 of file attr.c.

{
        return *(uint8_t *) nla_data(nla);
}

References nla_data().

nla_get_u64()

uint64_t nla_get_u64

(

struct nlattr *

nla

)

Parameters

nla	u64 netlink attribute

Definition at line 720 of file attr.c.

{
        uint64_t tmp;
 
        nla_memcpy(&tmp, nla, sizeof(tmp));
 
        return tmp;
}

References nla_memcpy().

Referenced by nla_get_msecs().

nla_get_string()

char * nla_get_string

(

struct nlattr *

nla

)

Parameters

nla	string netlink attribute

Definition at line 733 of file attr.c.

{
        return (char *) nla_data(nla);
}

References nla_data().

nla_get_flag()

int nla_get_flag

(

struct nlattr *

nla

)

Parameters

nla	flag netlink attribute

Definition at line 742 of file attr.c.

{
        return !!nla;
}

nla_get_msecs()

unsigned long nla_get_msecs

(

struct nlattr *

nla

)

Parameters

nla	msecs netlink attribute

Returns

the number of milliseconds.

Definition at line 753 of file attr.c.

{
        return nla_get_u64(nla);
}

References nla_get_u64().

nla_get_addr()

struct nl_addr * nla_get_addr	(	struct nlattr *	nla,
		int	family
	)

Parameters

nla	address netlink attribute
family	address family

Returns

Newly allocated address handle or NULL

Definition at line 765 of file attr.c.

{
        return nl_addr_build(family, nla_data(nla), nla_len(nla));
}

References nl_addr_build(), nla_data(), and nla_len().

nla_get_data()

struct nl_data * nla_get_data

(

struct nlattr *

nla

)

Parameters

nla	abstract data netlink attribute

Returns

Newly allocated abstract data handle or NULL

Definition at line 776 of file attr.c.

{
        return nl_data_alloc(nla_data(nla), nla_len(nla));
}

References nl_data_alloc(), nla_data(), and nla_len().