/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2018 Red Hat, Inc.
*/
#ifndef __NM_NETLINK_H__
#define __NM_NETLINK_H__
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/genetlink.h>
#include "libnm-std-aux/unaligned.h"
/*****************************************************************************/
#define NLMSGERR_ATTR_UNUSED 0
#define NLMSGERR_ATTR_MSG 1
#define NLMSGERR_ATTR_OFFS 2
#define NLMSGERR_ATTR_COOKIE 3
#define NLMSGERR_ATTR_MAX 3
#ifndef NLM_F_ACK_TLVS
#define NLM_F_ACK_TLVS 0x200
#endif
/*****************************************************************************/
/* Basic attribute data types */
enum {
NLA_UNSPEC, /* Unspecified type, binary data chunk */
NLA_U8, /* 8 bit integer */
NLA_U16, /* 16 bit integer */
NLA_U32, /* 32 bit integer */
NLA_U64, /* 64 bit integer */
NLA_STRING, /* NUL terminated character string */
NLA_FLAG, /* Flag */
NLA_MSECS, /* Micro seconds (64bit) */
NLA_NESTED, /* Nested attributes */
NLA_NESTED_COMPAT,
NLA_NUL_STRING,
NLA_BINARY,
NLA_S8,
NLA_S16,
NLA_S32,
NLA_S64,
__NLA_TYPE_MAX,
};
#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
struct nl_msg;
/*****************************************************************************/
const char *nl_nlmsgtype2str(int type, char *buf, size_t size);
const char *nl_nlmsg_flags2str(int flags, char *buf, size_t len);
const char *nl_nlmsghdr_to_str(const struct nlmsghdr *hdr, char *buf, gsize len);
/*****************************************************************************/
struct nla_policy {
/* Type of attribute or NLA_UNSPEC */
uint16_t type;
/* Minimal length of payload required */
uint16_t minlen;
/* Maximal length of payload allowed */
uint16_t maxlen;
};
/*****************************************************************************/
/* static asserts that @tb and @policy are suitable arguments to nla_parse(). */
#define _nl_static_assert_tb(tb, policy) \
G_STMT_START \
{ \
G_STATIC_ASSERT_EXPR(G_N_ELEMENTS(tb) > 0); \
\
/* We allow @policy to be either a C array or NULL. The sizeof()
* must either match the expected array size or the sizeof(NULL),
* but not both. */ \
G_STATIC_ASSERT_EXPR((sizeof(policy) == G_N_ELEMENTS(tb) * sizeof(struct nla_policy)) \
^ (sizeof(policy) == sizeof(NULL))); \
} \
G_STMT_END
/*****************************************************************************/
static inline int
nla_attr_size(int payload)
{
nm_assert(payload >= 0);
return NLA_HDRLEN + payload;
}
static inline int
nla_total_size(int payload)
{
return NLA_ALIGN(nla_attr_size(payload));
}
static inline int
nla_padlen(int payload)
{
return nla_total_size(payload) - nla_attr_size(payload);
}
struct nlattr *nla_reserve(struct nl_msg *msg, int attrtype, int attrlen);
static inline int
nla_len(const struct nlattr *nla)
{
nm_assert(nla);
nm_assert(nla->nla_len >= NLA_HDRLEN);
return ((int) nla->nla_len) - NLA_HDRLEN;
}
static inline int
nla_type(const struct nlattr *nla)
{
nm_assert(nla_len(nla) >= 0);
return nla->nla_type & NLA_TYPE_MASK;
}
static inline void *
nla_data(const struct nlattr *nla)
{
nm_assert(nla_len(nla) >= 0);
return &(((char *) nla)[NLA_HDRLEN]);
}
#define nla_data_as(type, nla) \
({ \
const struct nlattr *_nla = (nla); \
\
nm_assert(nla_len(_nla) >= sizeof(type)); \
\
/* note that casting the pointer is undefined behavior in C, if
* the data has wrong alignment. Netlink data is aligned to 4 bytes,
* that means, if the alignment is larger than 4, this is invalid. */ \
G_STATIC_ASSERT_EXPR(_nm_alignof(type) <= NLA_ALIGNTO); \
\
(type *) nla_data(_nla); \
})
static inline uint8_t
nla_get_u8(const struct nlattr *nla)
{
nm_assert(nla_len(nla) >= sizeof(uint8_t));
return *((const uint8_t *) nla_data(nla));
}
static inline int8_t
nla_get_s8(const struct nlattr *nla)
{
nm_assert(nla_len(nla) >= sizeof(int8_t));
return *((const int8_t *) nla_data(nla));
}
static inline uint8_t
nla_get_u8_cond(/*const*/ struct nlattr *const *tb, int attr, uint8_t default_val)
{
nm_assert(tb);
nm_assert(attr >= 0);
return tb[attr] ? nla_get_u8(tb[attr]) : default_val;
}
static inline uint16_t
nla_get_u16(const struct nlattr *nla)
{
nm_assert(nla_len(nla) >= sizeof(uint16_t));
return *((const uint16_t *) nla_data(nla));
}
static inline uint32_t
nla_get_u32(const struct nlattr *nla)
{
nm_assert(nla_len(nla) >= sizeof(uint32_t));
return *((const uint32_t *) nla_data(nla));
}
static inline int32_t
nla_get_s32(const struct nlattr *nla)
{
nm_assert(nla_len(nla) >= sizeof(int32_t));
return *((const int32_t *) nla_data(nla));
}
static inline uint64_t
nla_get_u64(const struct nlattr *nla)
{
nm_assert(nla_len(nla) >= sizeof(uint64_t));
return unaligned_read_ne64(nla_data(nla));
}
static inline uint64_t
nla_get_be64(const struct nlattr *nla)
{
nm_assert(nla_len(nla) >= sizeof(uint64_t));
return unaligned_read_be64(nla_data(nla));
}
static inline char *
nla_get_string(const struct nlattr *nla)
{
nm_assert(nla_len(nla) >= 0);
return (char *) nla_data(nla);
}
size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
size_t nla_memcpy(void *dst, const struct nlattr *nla, size_t dstsize);
#define nla_memcpy_checked_size(dst, nla, dstsize) \
G_STMT_START \
{ \
void *const _dst = (dst); \
const struct nlattr *const _nla = (nla); \
const size_t _dstsize = (dstsize); \
size_t _srcsize; \
\
/* assert that, if @nla is given, that it has the exact expected
* size. This implies that the caller previously verified the length
* of the attribute (via minlen/maxlen at nla_parse()). */ \
\
if (_nla) { \
_srcsize = nla_memcpy(_dst, _nla, _dstsize); \
nm_assert(_srcsize == _dstsize); \
} \
} \
G_STMT_END
int nla_put(struct nl_msg *msg, int attrtype, int datalen, const void *data);
static inline int
nla_put_string(struct nl_msg *msg, int attrtype, const char *str)
{
nm_assert(str);
return nla_put(msg, attrtype, strlen(str) + 1, str);
}
static inline int
nla_put_uint8(struct nl_msg *msg, int attrtype, uint8_t val)
{
return nla_put(msg, attrtype, sizeof(val), &val);
}
static inline int
nla_put_uint16(struct nl_msg *msg, int attrtype, uint16_t val)
{
return nla_put(msg, attrtype, sizeof(val), &val);
}
static inline int
nla_put_uint32(struct nl_msg *msg, int attrtype, uint32_t val)
{
return nla_put(msg, attrtype, sizeof(val), &val);
}
#define NLA_PUT(msg, attrtype, attrlen, data) \
G_STMT_START \
{ \
if (nla_put(msg, attrtype, attrlen, data) < 0) \
goto nla_put_failure; \
} \
G_STMT_END
#define NLA_PUT_TYPE(msg, type, attrtype, value) \
G_STMT_START \
{ \
type __nla_tmp = value; \
NLA_PUT(msg, attrtype, sizeof(type), &__nla_tmp); \
} \
G_STMT_END
#define NLA_PUT_U8(msg, attrtype, value) NLA_PUT_TYPE(msg, uint8_t, attrtype, value)
#define NLA_PUT_S8(msg, attrtype, value) NLA_PUT_TYPE(msg, int8_t, attrtype, value)
#define NLA_PUT_U16(msg, attrtype, value) NLA_PUT_TYPE(msg, uint16_t, attrtype, value)
#define NLA_PUT_U32(msg, attrtype, value) NLA_PUT_TYPE(msg, uint32_t, attrtype, value)
#define NLA_PUT_S32(msg, attrtype, value) NLA_PUT_TYPE(msg, int32_t, attrtype, value)
#define NLA_PUT_U64(msg, attrtype, value) NLA_PUT_TYPE(msg, uint64_t, attrtype, value)
#define NLA_PUT_STRING(msg, attrtype, value) NLA_PUT(msg, attrtype, (int) strlen(value) + 1, value)
#define NLA_PUT_FLAG(msg, attrtype) NLA_PUT(msg, attrtype, 0, NULL)
struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
static inline int
nla_ok(const struct nlattr *nla, int remaining)
{
return remaining >= (int) sizeof(*nla) && nla->nla_len >= sizeof(*nla)
&& nla->nla_len <= remaining;
}
static inline struct nlattr *
nla_next(const struct nlattr *nla, int *remaining)
{
int totlen = NLA_ALIGN(nla->nla_len);
*remaining -= totlen;
return (struct nlattr *) ((char *) nla + totlen);
}
#define nla_for_each_attr(pos, head, len, rem) \
for (pos = head, rem = len; nla_ok(pos, rem); pos = nla_next(pos, &(rem)))
#define nla_for_each_nested(pos, nla, rem) \
for (pos = (struct nlattr *) nla_data(nla), rem = nla_len(nla); nla_ok(pos, rem); \
pos = nla_next(pos, &(rem)))
void nla_nest_cancel(struct nl_msg *msg, const struct nlattr *attr);
struct nlattr *nla_nest_start(struct nl_msg *msg, int attrtype);
int nla_nest_end(struct nl_msg *msg, struct nlattr *start);
int nla_parse(struct nlattr * tb[],
int maxtype,
struct nlattr * head,
int len,
const struct nla_policy *policy);
#define nla_parse_arr(tb, head, len, policy) \
({ \
_nl_static_assert_tb((tb), (policy)); \
\
nla_parse((tb), G_N_ELEMENTS(tb) - 1, (head), (len), (policy)); \
})
static inline int
nla_parse_nested(struct nlattr * tb[],
int maxtype,
struct nlattr * nla,
const struct nla_policy *policy)
{
return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
}
#define nla_parse_nested_arr(tb, nla, policy) \
({ \
_nl_static_assert_tb((tb), (policy)); \
\
nla_parse_nested((tb), G_N_ELEMENTS(tb) - 1, (nla), (policy)); \
})
/*****************************************************************************/
struct nl_msg *nlmsg_alloc(void);
struct nl_msg *nlmsg_alloc_size(size_t max);
struct nl_msg *nlmsg_alloc_convert(struct nlmsghdr *hdr);
struct nl_msg *nlmsg_alloc_simple(int nlmsgtype, int flags);
void *nlmsg_reserve(struct nl_msg *n, size_t len, int pad);
int nlmsg_append(struct nl_msg *n, const void *data, size_t len, int pad);
#define nlmsg_append_struct(n, data) nlmsg_append(n, (data), sizeof(*(data)), NLMSG_ALIGNTO)
void nlmsg_free(struct nl_msg *msg);
static inline int
nlmsg_size(int payload)
{
nm_assert(payload >= 0 && payload < G_MAXINT - NLMSG_HDRLEN - 4);
return NLMSG_HDRLEN + payload;
}
static inline int
nlmsg_total_size(int payload)
{
return NLMSG_ALIGN(nlmsg_size(payload));
}
static inline int
nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
{
return (remaining >= (int) sizeof(struct nlmsghdr) && nlh->nlmsg_len >= sizeof(struct nlmsghdr)
&& nlh->nlmsg_len <= remaining);
}
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);
}
int nlmsg_get_proto(struct nl_msg *msg);
void nlmsg_set_proto(struct nl_msg *msg, int protocol);
void nlmsg_set_src(struct nl_msg *msg, struct sockaddr_nl *addr);
struct ucred *nlmsg_get_creds(struct nl_msg *msg);
void nlmsg_set_creds(struct nl_msg *msg, struct ucred *creds);
static inline void
_nm_auto_nl_msg_cleanup(struct nl_msg **ptr)
{
nlmsg_free(*ptr);
}
#define nm_auto_nlmsg nm_auto(_nm_auto_nl_msg_cleanup)
static inline void *
nlmsg_data(const struct nlmsghdr *nlh)
{
return (unsigned char *) nlh + NLMSG_HDRLEN;
}
static inline void *
nlmsg_tail(const struct nlmsghdr *nlh)
{
return (unsigned char *) nlh + NLMSG_ALIGN(nlh->nlmsg_len);
}
struct nlmsghdr *nlmsg_hdr(struct nl_msg *n);
static inline int
nlmsg_valid_hdr(const struct nlmsghdr *nlh, int hdrlen)
{
if (nlh->nlmsg_len < nlmsg_size(hdrlen))
return 0;
return 1;
}
static inline int
nlmsg_datalen(const struct nlmsghdr *nlh)
{
return nlh->nlmsg_len - NLMSG_HDRLEN;
}
static inline int
nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
{
return NM_MAX((int) (nlmsg_datalen(nlh) - NLMSG_ALIGN(hdrlen)), 0);
}
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));
}
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);
}
int nlmsg_parse(struct nlmsghdr * nlh,
int hdrlen,
struct nlattr * tb[],
int maxtype,
const struct nla_policy *policy);
#define nlmsg_parse_arr(nlh, hdrlen, tb, policy) \
({ \
_nl_static_assert_tb((tb), (policy)); \
G_STATIC_ASSERT_EXPR((hdrlen) >= 0); \
\
nlmsg_parse((nlh), (hdrlen), (tb), G_N_ELEMENTS(tb) - 1, (policy)); \
})
struct nlmsghdr *
nlmsg_put(struct nl_msg *n, uint32_t pid, uint32_t seq, int type, int payload, int flags);
/*****************************************************************************/
#define NL_AUTO_PORT 0
#define NL_AUTO_SEQ 0
struct nl_sock;
struct nl_sock *nl_socket_alloc(void);
void nl_socket_free(struct nl_sock *sk);
int nl_socket_get_fd(const struct nl_sock *sk);
struct sockaddr_nl *nlmsg_get_dst(struct nl_msg *msg);
size_t nl_socket_get_msg_buf_size(struct nl_sock *sk);
int nl_socket_set_msg_buf_size(struct nl_sock *sk, size_t bufsize);
int nl_socket_set_buffer_size(struct nl_sock *sk, int rxbuf, int txbuf);
int nl_socket_set_passcred(struct nl_sock *sk, int state);
int nl_socket_set_nonblocking(const struct nl_sock *sk);
void nl_socket_disable_msg_peek(struct nl_sock *sk);
uint32_t nl_socket_get_local_port(const struct nl_sock *sk);
int nl_socket_add_memberships(struct nl_sock *sk, int group, ...);
int nl_connect(struct nl_sock *sk, int protocol);
int nl_recv(struct nl_sock * sk,
struct sockaddr_nl *nla,
unsigned char ** buf,
struct ucred * out_creds,
gboolean * out_creds_has);
int nl_send(struct nl_sock *sk, struct nl_msg *msg);
int nl_send_auto(struct nl_sock *sk, struct nl_msg *msg);
/*****************************************************************************/
enum nl_cb_action {
/* Proceed with wathever would come next */
NL_OK,
/* Skip this message */
NL_SKIP,
/* Stop parsing altogether and discard remaining messages */
NL_STOP,
};
typedef int (*nl_recvmsg_msg_cb_t)(struct nl_msg *msg, void *arg);
typedef int (*nl_recvmsg_err_cb_t)(struct sockaddr_nl *nla, struct nlmsgerr *nlerr, void *arg);
struct nl_cb {
nl_recvmsg_msg_cb_t valid_cb;
void * valid_arg;
nl_recvmsg_msg_cb_t finish_cb;
void * finish_arg;
nl_recvmsg_msg_cb_t ack_cb;
void * ack_arg;
nl_recvmsg_err_cb_t err_cb;
void * err_arg;
};
int nl_sendmsg(struct nl_sock *sk, struct nl_msg *msg, struct msghdr *hdr);
int nl_send_iovec(struct nl_sock *sk, struct nl_msg *msg, struct iovec *iov, unsigned iovlen);
void nl_complete_msg(struct nl_sock *sk, struct nl_msg *msg);
int nl_recvmsgs(struct nl_sock *sk, const struct nl_cb *cb);
int nl_wait_for_ack(struct nl_sock *sk, const struct nl_cb *cb);
int nl_socket_set_ext_ack(struct nl_sock *sk, gboolean enable);
/*****************************************************************************/
void * genlmsg_put(struct nl_msg *msg,
uint32_t port,
uint32_t seq,
int family,
int hdrlen,
int flags,
uint8_t cmd,
uint8_t version);
void * genlmsg_data(const struct genlmsghdr *gnlh);
void * genlmsg_user_hdr(const struct genlmsghdr *gnlh);
struct genlmsghdr *genlmsg_hdr(struct nlmsghdr *nlh);
void * genlmsg_user_data(const struct genlmsghdr *gnlh, const int hdrlen);
struct nlattr * genlmsg_attrdata(const struct genlmsghdr *gnlh, int hdrlen);
int genlmsg_len(const struct genlmsghdr *gnlh);
int genlmsg_attrlen(const struct genlmsghdr *gnlh, int hdrlen);
int genlmsg_valid_hdr(struct nlmsghdr *nlh, int hdrlen);
int genlmsg_parse(struct nlmsghdr * nlh,
int hdrlen,
struct nlattr * tb[],
int maxtype,
const struct nla_policy *policy);
#define genlmsg_parse_arr(nlh, hdrlen, tb, policy) \
({ \
_nl_static_assert_tb((tb), (policy)); \
G_STATIC_ASSERT_EXPR((hdrlen) >= 0); \
\
genlmsg_parse((nlh), (hdrlen), (tb), G_N_ELEMENTS(tb) - 1, (policy)); \
})
int genl_ctrl_resolve(struct nl_sock *sk, const char *name);
/*****************************************************************************/
#endif /* __NM_NETLINK_H__ */