tools/lib/bpf/nlattr.h

Source file repositories/reference/linux-study-clean/tools/lib/bpf/nlattr.h

File Facts

System
Linux kernel
Corpus path
tools/lib/bpf/nlattr.h
Extension
.h
Size
4336 bytes
Lines
177
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

struct libbpf_nla_policy {
	/** Type of attribute or LIBBPF_NLA_UNSPEC */
	uint16_t	type;

	/** Minimal length of payload required */
	uint16_t	minlen;

	/** Maximal length of payload allowed */
	uint16_t	maxlen;
};

struct libbpf_nla_req {
	struct nlmsghdr nh;
	union {
		struct ifinfomsg ifinfo;
		struct tcmsg tc;
		struct genlmsghdr gnl;
	};
	char buf[128];
};

/**
 * @ingroup attr
 * Iterate over a stream of attributes
 * @arg pos	loop counter, set to current attribute
 * @arg head	head of attribute stream
 * @arg len	length of attribute stream
 * @arg rem	initialized to len, holds bytes currently remaining in stream
 */
#define libbpf_nla_for_each_attr(pos, head, len, rem) \
	for (pos = head, rem = len; \
	     nla_ok(pos, rem); \
	     pos = nla_next(pos, &(rem)))

/**
 * libbpf_nla_data - head of payload
 * @nla: netlink attribute
 */
static inline void *libbpf_nla_data(const struct nlattr *nla)
{
	return (void *)nla + NLA_HDRLEN;
}

static inline uint8_t libbpf_nla_getattr_u8(const struct nlattr *nla)
{
	return *(uint8_t *)libbpf_nla_data(nla);
}

static inline uint16_t libbpf_nla_getattr_u16(const struct nlattr *nla)
{
	return *(uint16_t *)libbpf_nla_data(nla);
}

static inline uint32_t libbpf_nla_getattr_u32(const struct nlattr *nla)
{
	return *(uint32_t *)libbpf_nla_data(nla);
}

static inline uint64_t libbpf_nla_getattr_u64(const struct nlattr *nla)
{
	return *(uint64_t *)libbpf_nla_data(nla);
}

static inline const char *libbpf_nla_getattr_str(const struct nlattr *nla)
{
	return (const char *)libbpf_nla_data(nla);
}

/**
 * libbpf_nla_len - length of payload
 * @nla: netlink attribute
 */
static inline int libbpf_nla_len(const struct nlattr *nla)
{
	return nla->nla_len - NLA_HDRLEN;
}

int libbpf_nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head,
		     int len, struct libbpf_nla_policy *policy);
int libbpf_nla_parse_nested(struct nlattr *tb[], int maxtype,
			    struct nlattr *nla,
			    struct libbpf_nla_policy *policy);

int libbpf_nla_dump_errormsg(struct nlmsghdr *nlh);

static inline struct nlattr *nla_data(struct nlattr *nla)
{
	return (struct nlattr *)((void *)nla + NLA_HDRLEN);
}

Annotation

Implementation Notes