nuttx/net/netlink/netlink_sockif.c
Xiang Xiao 581dbb22fe netlink: Fix nxstyle issue
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
2020-04-10 08:18:07 -06:00

906 lines
29 KiB
C

/****************************************************************************
* net/netlink/netlink_sockif.c
*
* Copyright (C) 2018-2019 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <stdbool.h>
#include <string.h>
#include <poll.h>
#include <sched.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/semaphore.h>
#include <nuttx/wqueue.h>
#include <nuttx/net/net.h>
#include "netlink/netlink.h"
#ifdef CONFIG_NET_NETLINK
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int netlink_setup(FAR struct socket *psock, int protocol);
static sockcaps_t netlink_sockcaps(FAR struct socket *psock);
static void netlink_addref(FAR struct socket *psock);
static int netlink_bind(FAR struct socket *psock,
FAR const struct sockaddr *addr, socklen_t addrlen);
static int netlink_getsockname(FAR struct socket *psock,
FAR struct sockaddr *addr, FAR socklen_t *addrlen);
static int netlink_getpeername(FAR struct socket *psock,
FAR struct sockaddr *addr, FAR socklen_t *addrlen);
static int netlink_listen(FAR struct socket *psock, int backlog);
static int netlink_connect(FAR struct socket *psock,
FAR const struct sockaddr *addr, socklen_t addrlen);
static int netlink_accept(FAR struct socket *psock,
FAR struct sockaddr *addr, FAR socklen_t *addrlen,
FAR struct socket *newsock);
static int netlink_poll(FAR struct socket *psock, FAR struct pollfd *fds,
bool setup);
static ssize_t netlink_send(FAR struct socket *psock,
FAR const void *buf, size_t len, int flags);
static ssize_t netlink_sendto(FAR struct socket *psock, FAR const void *buf,
size_t len, int flags, FAR const struct sockaddr *to,
socklen_t tolen);
static ssize_t netlink_recvfrom(FAR struct socket *psock, FAR void *buf,
size_t len, int flags, FAR struct sockaddr *from,
FAR socklen_t *fromlen);
static int netlink_close(FAR struct socket *psock);
/****************************************************************************
* Public Data
****************************************************************************/
const struct sock_intf_s g_netlink_sockif =
{
netlink_setup, /* si_setup */
netlink_sockcaps, /* si_sockcaps */
netlink_addref, /* si_addref */
netlink_bind, /* si_bind */
netlink_getsockname, /* si_getsockname */
netlink_getpeername, /* si_getpeername */
netlink_listen, /* si_listen */
netlink_connect, /* si_connect */
netlink_accept, /* si_accept */
netlink_poll, /* si_poll */
netlink_send, /* si_send */
netlink_sendto, /* si_sendto */
#ifdef CONFIG_NET_SENDFILE
NULL, /* si_sendfile */
#endif
netlink_recvfrom, /* si_recvfrom */
netlink_close /* si_close */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: netlink_setup
*
* Description:
* Called for socket() to verify that the provided socket type and
* protocol are usable by this address family. Perform any family-
* specific socket fields.
*
* Input Parameters:
* psock - A pointer to a user allocated socket structure to be
* initialized.
* protocol - NetLink socket protocol (see sys/socket.h)
*
* Returned Value:
* Zero (OK) is returned on success. Otherwise, a negated errno value is
* returned.
*
****************************************************************************/
static int netlink_setup(FAR struct socket *psock, int protocol)
{
int domain = psock->s_domain;
int type = psock->s_type;
/* Verify that the protocol is supported */
DEBUGASSERT((unsigned int)protocol <= UINT8_MAX);
switch (protocol)
{
#ifdef CONFIG_NETLINK_ROUTE
case NETLINK_ROUTE:
break;
#endif
default:
return -EPROTONOSUPPORT;
}
/* Verify the socket type (domain should always be PF_NETLINK here) */
if (domain == PF_NETLINK && (type == SOCK_RAW || type == SOCK_DGRAM))
{
/* Allocate the NetLink socket connection structure and save it in the
* new socket instance.
*/
FAR struct netlink_conn_s *conn = netlink_alloc();
if (conn == NULL)
{
/* Failed to reserve a connection structure */
return -ENOMEM;
}
/* Initialize the connection instance */
conn->protocol = (uint8_t)protocol;
/* Set the reference count on the connection structure. This
* reference count will be incremented only if the socket is
* dup'ed
*/
conn->crefs = 1;
/* Attach the connection instance to the socket */
psock->s_conn = conn;
return OK;
}
return -EPROTONOSUPPORT;
}
/****************************************************************************
* Name: netlink_sockcaps
*
* Description:
* Return the bit encoded capabilities of this socket.
*
* Input Parameters:
* psock - Socket structure of the socket whose capabilities are being
* queried.
*
* Returned Value:
* The non-negative set of socket capabilities is returned.
*
****************************************************************************/
static sockcaps_t netlink_sockcaps(FAR struct socket *psock)
{
/* Permit vfcntl to set socket to non-blocking */
return SOCKCAP_NONBLOCKING;
}
/****************************************************************************
* Name: netlink_addref
*
* Description:
* Increment the reference count on the underlying connection structure.
*
* Input Parameters:
* psock - Socket structure of the socket whose reference count will be
* incremented.
*
* Returned Value:
* None
*
****************************************************************************/
static void netlink_addref(FAR struct socket *psock)
{
FAR struct netlink_conn_s *conn;
DEBUGASSERT(psock != NULL && psock->s_conn != NULL);
conn = psock->s_conn;
DEBUGASSERT(conn->crefs > 0 && conn->crefs < 255);
conn->crefs++;
}
/****************************************************************************
* Name: netlink_bind
*
* Description:
* netlink_bind() gives the socket 'conn' the local address 'addr'. 'addr'
* is 'addrlen' bytes long. Traditionally, this is called "assigning a name
* to a socket." When a socket is created with socket, it exists in a name
* space (address family) but has no name assigned.
*
* Input Parameters:
* conn NetLink socket connection structure
* addr Socket local address
* addrlen Length of 'addr'
*
* Returned Value:
* 0 on success; -1 on error with errno set appropriately
*
* EACCES
* The address is protected, and the user is not the superuser.
* EADDRINUSE
* The given address is already in use.
* EINVAL
* The socket is already bound to an address.
* ENOTSOCK
* psock is a descriptor for a file, not a socket.
*
* Assumptions:
*
****************************************************************************/
static int netlink_bind(FAR struct socket *psock,
FAR const struct sockaddr *addr, socklen_t addrlen)
{
FAR struct sockaddr_nl *nladdr;
FAR struct netlink_conn_s *conn;
DEBUGASSERT(psock != NULL && psock->s_conn != NULL && addr != NULL &&
addrlen >= sizeof(struct sockaddr_nl));
/* Save the address information in the connection structure */
nladdr = (FAR struct sockaddr_nl *)addr;
conn = (FAR struct netlink_conn_s *)psock->s_conn;
conn->pid = nladdr->nl_pid ? nladdr->nl_pid : getpid();
conn->groups = nladdr->nl_groups;
return OK;
}
/****************************************************************************
* Name: netlink_getsockname
*
* Description:
* The getsockname() function retrieves the locally-bound name of the
* specified socket, stores this address in the sockaddr structure pointed
* to by the 'addr' argument, and stores the length of this address in the
* object pointed to by the 'addrlen' argument.
*
* If the actual length of the address is greater than the length of the
* supplied sockaddr structure, the stored address will be truncated.
*
* If the socket has not been bound to a local name, the value stored in
* the object pointed to by address is unspecified.
*
* Input Parameters:
* conn NetLink socket connection structure
* addr sockaddr structure to receive data [out]
* addrlen Length of sockaddr structure [in/out]
*
****************************************************************************/
static int netlink_getsockname(FAR struct socket *psock,
FAR struct sockaddr *addr,
FAR socklen_t *addrlen)
{
FAR struct sockaddr_nl *nladdr;
FAR struct netlink_conn_s *conn;
DEBUGASSERT(psock != NULL && psock->s_conn != NULL && addr != NULL &&
addrlen != NULL && *addrlen >= sizeof(struct sockaddr_nl));
conn = (FAR struct netlink_conn_s *)psock->s_conn;
/* Return the address information in the address structure */
nladdr = (FAR struct sockaddr_nl *)addr;
memset(nladdr, 0, sizeof(struct sockaddr_nl));
nladdr->nl_family = AF_NETLINK;
nladdr->nl_pid = conn->pid;
nladdr->nl_groups = conn->groups;
*addrlen = sizeof(struct sockaddr_nl);
return OK;
}
/****************************************************************************
* Name: netlink_getpeername
*
* Description:
* The netlink_getpeername() function retrieves the remote-connected name
* of the specified packet socket, stores this address in the sockaddr
* structure pointed to by the 'addr' argument, and stores the length of
* this address in the object pointed to by the 'addrlen' argument.
*
* If the actual length of the address is greater than the length of the
* supplied sockaddr structure, the stored address will be truncated.
*
* If the socket has not been bound to a local name, the value stored in
* the object pointed to by address is unspecified.
*
* Parameters:
* psock Socket structure of the socket to be queried
* addr sockaddr structure to receive data [out]
* addrlen Length of sockaddr structure [in/out]
*
* Returned Value:
* On success, 0 is returned, the 'addr' argument points to the address
* of the socket, and the 'addrlen' argument points to the length of the
* address. Otherwise, a negated errno value is returned. See
* getpeername() for the list of appropriate error numbers.
*
****************************************************************************/
static int netlink_getpeername(FAR struct socket *psock,
FAR struct sockaddr *addr,
FAR socklen_t *addrlen)
{
FAR struct sockaddr_nl *nladdr;
FAR struct netlink_conn_s *conn;
DEBUGASSERT(psock != NULL && psock->s_conn != NULL && addr != NULL &&
addrlen != NULL && *addrlen >= sizeof(struct sockaddr_nl));
conn = (FAR struct netlink_conn_s *)psock->s_conn;
/* Return the address information in the address structure */
nladdr = (FAR struct sockaddr_nl *)addr;
memset(nladdr, 0, sizeof(struct sockaddr_nl));
nladdr->nl_family = AF_NETLINK;
nladdr->nl_pid = conn->dst_pid;
nladdr->nl_groups = conn->dst_groups;
*addrlen = sizeof(struct sockaddr_nl);
return OK;
}
/****************************************************************************
* Name: netlink_listen
*
* Description:
* To accept connections, a socket is first created with psock_socket(), a
* willingness to accept incoming connections and a queue limit for
* incoming connections are specified with psock_listen(), and then the
* connections are accepted with psock_accept(). For the case of AFINET
* and AFINET6 sockets, psock_listen() calls this function. The
* psock_listen() call applies only to sockets of type SOCK_STREAM or
* SOCK_SEQPACKET.
*
* Input Parameters:
* psock Reference to an internal, bound socket structure.
* backlog The maximum length the queue of pending connections may grow.
* If a connection request arrives with the queue full, the client
* may receive an error with an indication of ECONNREFUSED or,
* if the underlying protocol supports retransmission, the request
* may be ignored so that retries succeed.
*
* Returned Value:
* On success, zero is returned. On error, a negated errno value is
* returned. See list() for the set of appropriate error values.
*
****************************************************************************/
static int netlink_listen(FAR struct socket *psock, int backlog)
{
return -EOPNOTSUPP;
}
/****************************************************************************
* Name: netlink_connect
*
* Description:
* Perform a netlink connection
*
* Input Parameters:
* psock A reference to the structure of the socket to be connected
* addr The address of the remote server to connect to
* addrlen Length of address buffer
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
static int netlink_connect(FAR struct socket *psock,
FAR const struct sockaddr *addr,
socklen_t addrlen)
{
FAR struct sockaddr_nl *nladdr;
FAR struct netlink_conn_s *conn;
DEBUGASSERT(psock != NULL && psock->s_conn != NULL && addr != NULL &&
addrlen >= sizeof(struct sockaddr_nl));
/* Save the address information in the connection structure */
nladdr = (FAR struct sockaddr_nl *)addr;
conn = (FAR struct netlink_conn_s *)psock->s_conn;
conn->dst_pid = nladdr->nl_pid;
conn->dst_groups = nladdr->nl_groups;
return OK;
}
/****************************************************************************
* Name: netlink_accept
*
* Description:
* The netlink_accept function is used with connection-based socket
* types (SOCK_STREAM, SOCK_SEQPACKET and SOCK_RDM). It extracts the first
* connection request on the queue of pending connections, creates a new
* connected socket with mostly the same properties as 'sockfd', and
* allocates a new socket descriptor for the socket, which is returned. The
* newly created socket is no longer in the listening state. The original
* socket 'sockfd' is unaffected by this call. Per file descriptor flags
* are not inherited across an inet_accept.
*
* The 'sockfd' argument is a socket descriptor that has been created with
* socket(), bound to a local address with bind(), and is listening for
* connections after a call to listen().
*
* On return, the 'addr' structure is filled in with the address of the
* connecting entity. The 'addrlen' argument initially contains the size
* of the structure pointed to by 'addr'; on return it will contain the
* actual length of the address returned.
*
* If no pending connections are present on the queue, and the socket is
* not marked as non-blocking, accept blocks the caller until a
* connection is present. If the socket is marked non-blocking and no
* pending connections are present on the queue, inet_accept returns
* EAGAIN.
*
* Input Parameters:
* psock Reference to the listening socket structure
* addr Receives the address of the connecting client
* addrlen Input: Allocated size of 'addr'
* Return: Actual size returned size of 'addr'
* newsock Location to return the accepted socket information.
*
* Returned Value:
* Returns 0 (OK) on success. On failure, it returns a negated errno
* value. See accept() for a description of the appropriate error value.
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
static int netlink_accept(FAR struct socket *psock,
FAR struct sockaddr *addr, FAR socklen_t *addrlen,
FAR struct socket *newsock)
{
return -EOPNOTSUPP;
}
/****************************************************************************
* Name: netlink_response_available
*
* Description:
* Handle a Netlink response available notification.
*
* Input Parameters:
* Standard work handler parameters
*
* Returned Value:
* None
*
****************************************************************************/
static void netlink_response_available(FAR void *arg)
{
FAR struct netlink_conn_s *conn = arg;
DEBUGASSERT(conn != NULL);
/* The following should always be true ... but maybe not in some race
* condition?
*/
sched_lock();
net_lock();
if (conn->pollsem != NULL && conn->pollevent != NULL)
{
/* Wake up the poll() with POLLIN */
*conn->pollevent |= POLLIN;
nxsem_post(conn->pollsem);
}
else
{
nwarn("WARNING: Missing references in connection.\n");
}
/* Allow another poll() */
conn->pollsem = NULL;
conn->pollevent = NULL;
net_unlock();
sched_unlock();
}
/****************************************************************************
* Name: netlink_poll
*
* Description:
* The standard poll() operation redirects operations on socket descriptors
* to this function.
*
* POLLUP: Will never be reported
* POLLERR: Reported in the event of any failure.
* POLLOUT: Always reported if requested.
* POLLIN: Reported if requested but only when pending response data is
* available
*
* Input Parameters:
* psock - An instance of the internal socket structure.
* fds - The structure describing the events to be monitored.
* setup - true: Setup up the poll; false: Tear down the poll
*
* Returned Value:
* 0: Success; Negated errno on failure
*
****************************************************************************/
static int netlink_poll(FAR struct socket *psock, FAR struct pollfd *fds,
bool setup)
{
FAR struct netlink_conn_s *conn;
int ret = OK;
DEBUGASSERT(psock != NULL && psock->s_conn != NULL);
conn = (FAR struct netlink_conn_s *)psock->s_conn;
/* Check if we are setting up or tearing down the poll */
if (setup)
{
/* If POLLOUT is selected, return immediately (maybe) */
pollevent_t revents = POLLOUT;
/* If POLLIN is selected and a response is available, return
* immediately (maybe).
*/
net_lock();
if (netlink_check_response(psock))
{
revents |= POLLIN;
}
/* But return ONLY if POLLIN and/or POLLIN are included in the
* requested event set.
*/
revents &= fds->events;
if (revents != 0)
{
fds->revents = revents;
nxsem_post(fds->sem);
net_unlock();
return OK;
}
/* Set up to be notified when a response is available if POLLIN is
* requested.
*/
if ((fds->events & POLLIN) != 0)
{
/* Some limitations: There can be only a single outstanding POLLIN
* on the Netlink connection.
*/
if (conn->pollsem != NULL || conn->pollevent != NULL)
{
nerr("ERROR: Multiple polls() on socket not supported.\n");
net_unlock();
return -EBUSY;
}
/* Set up the notification */
conn->pollsem = fds->sem;
conn->pollevent = &fds->revents;
ret = netlink_notifier_setup(netlink_response_available,
conn, conn);
if (ret < 0)
{
nerr("ERROR: netlink_notifier_setup() failed: %d\n", ret);
conn->pollsem = NULL;
conn->pollevent = NULL;
}
}
net_unlock();
}
else
{
/* Cancel any response notifications */
ret = netlink_notifier_teardown(conn);
conn->pollsem = NULL;
conn->pollevent = NULL;
}
return ret;
}
/****************************************************************************
* Name: netlink_send
*
* Description:
* The netlink_send() call may be used only when the socket is in
* a connected state (so that the intended recipient is known).
*
* Input Parameters:
* psock - An instance of the internal socket structure.
* buf - Data to send
* len - Length of data to send
* flags - Send flags (ignored)
*
* Returned Value:
* On success, returns the number of characters sent. On error, a negated
* errno value is returned (see send() for the list of appropriate error
* values.
*
****************************************************************************/
static ssize_t netlink_send(FAR struct socket *psock, FAR const void *buf,
size_t len, int flags)
{
FAR struct netlink_conn_s *conn;
struct sockaddr_nl nladdr;
DEBUGASSERT(psock != NULL && psock->s_conn != NULL && buf != NULL);
/* Get the underlying connection structure */
conn = (FAR struct netlink_conn_s *)psock->s_conn;
/* Format the address */
nladdr.nl_family = AF_NETLINK;
nladdr.nl_pad = 0;
nladdr.nl_pid = conn->dst_pid;
nladdr.nl_groups = conn->dst_groups;
/* Then let sendto() perform the actual send operation */
return netlink_sendto(psock, buf, len, flags,
(FAR const struct sockaddr *)&nladdr,
sizeof(struct sockaddr_nl));
}
/****************************************************************************
* Name: netlink_sendto
*
* Description:
* If sendto() is used on a connection-mode (SOCK_STREAM, SOCK_SEQPACKET)
* socket, the parameters to and 'tolen' are ignored (and the error EISCONN
* may be returned when they are not NULL and 0), and the error ENOTCONN is
* returned when the socket was not actually connected.
*
* Input Parameters:
* psock A reference to the structure of the socket to be connected
* buf Data to send
* len Length of data to send
* flags Send flags (ignored)
* to Address of recipient
* tolen The length of the address structure
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
static ssize_t netlink_sendto(FAR struct socket *psock, FAR const void *buf,
size_t len, int flags,
FAR const struct sockaddr *to, socklen_t tolen)
{
FAR struct netlink_conn_s *conn;
FAR struct nlmsghdr *nlmsg;
int ret;
DEBUGASSERT(psock != NULL && psock->s_conn != NULL && buf != NULL &&
to != NULL && tolen >= sizeof(struct sockaddr_nl));
conn = (FAR struct netlink_conn_s *)psock->s_conn;
/* Get a reference to the netlink message */
nlmsg = (FAR struct nlmsghdr *)buf;
DEBUGASSERT(nlmsg->nlmsg_len >= sizeof(struct nlmsghdr));
switch (conn->protocol)
{
#ifdef CONFIG_NETLINK_ROUTE
case NETLINK_ROUTE:
ret = netlink_route_sendto(psock, nlmsg, len, flags,
(FAR struct sockaddr_nl *)to,
tolen);
break;
#endif
default:
ret = -EOPNOTSUPP;
break;
}
return ret;
}
/****************************************************************************
* Name: netlink_recvfrom
*
* Description:
* recvfrom() receives messages from a socket, and may be used to receive
* data on a socket whether or not it is connection-oriented.
*
* If from is not NULL, and the underlying protocol provides the source
* address, this source address is filled in. The argument 'fromlen'
* initialized to the size of the buffer associated with from, and modified
* on return to indicate the actual size of the address stored there.
*
* Input Parameters:
* psock A pointer to a NuttX-specific, internal socket structure
* buf Buffer to receive data
* len Length of buffer
* flags Receive flags (ignored)
* from Address of source (may be NULL)
* fromlen The length of the address structure
*
****************************************************************************/
static ssize_t netlink_recvfrom(FAR struct socket *psock, FAR void *buf,
size_t len, int flags,
FAR struct sockaddr *from,
FAR socklen_t *fromlen)
{
FAR struct netlink_response_s *entry;
DEBUGASSERT(psock != NULL && psock->s_conn != NULL && buf != NULL);
DEBUGASSERT(from == NULL ||
(fromlen != NULL && *fromlen >= sizeof(struct sockaddr_nl)));
/* Find the response to this message. The return value */
entry = (FAR struct netlink_response_s *)netlink_tryget_response(psock);
if (entry == NULL)
{
/* No response is variable, but presumably, one is expected. Check
* if the socket has been configured for non-blocking operation.
*/
if (_SS_ISNONBLOCK(psock->s_flags) || (flags & MSG_DONTWAIT) != 0)
{
return -EAGAIN;
}
/* Wait for the response. This should always succeed. */
entry = (FAR struct netlink_response_s *)netlink_get_response(psock);
DEBUGASSERT(entry != NULL);
if (entry == NULL)
{
return -EPIPE;
}
}
if (len > entry->msg.nlmsg_len)
{
len = entry->msg.nlmsg_len;
}
/* Copy the payload to the user buffer */
memcpy(buf, &entry->msg, len);
kmm_free(entry);
if (from != NULL)
{
netlink_getpeername(psock, from, fromlen);
}
return len;
}
/****************************************************************************
* Name: netlink_close
*
* Description:
* Performs the close operation on a NetLink socket instance
*
* Input Parameters:
* psock Socket instance
*
* Returned Value:
* 0 on success; -1 on error with errno set appropriately.
*
* Assumptions:
*
****************************************************************************/
static int netlink_close(FAR struct socket *psock)
{
FAR struct netlink_conn_s *conn = psock->s_conn;
int ret = OK;
/* Perform some pre-close operations for the NETLINK socket type. */
/* Is this the last reference to the connection structure (there
* could be more if the socket was dup'ed).
*/
if (conn->crefs <= 1)
{
/* Free the connection structure */
conn->crefs = 0;
netlink_free(psock->s_conn);
if (ret < 0)
{
/* Return with error code, but free resources. */
nerr("ERROR: netlink_close failed: %d\n", ret);
return ret;
}
}
else
{
/* No.. Just decrement the reference count */
conn->crefs--;
}
return ret;
}
#endif /* CONFIG_NET_NETLINK */