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nuttx/net/udp/udp_sendto_buffered.c
Alin Jerpelea 67d02a45eb net: migrate to SPDX identifier 
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2024-09-12 01:08:11 +08:00

980 lines
27 KiB
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/****************************************************************************
* net/udp/udp_sendto_buffered.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#if defined(CONFIG_NET) && defined(CONFIG_NET_UDP) && \
defined(CONFIG_NET_UDP_WRITE_BUFFERS)
#if defined(CONFIG_DEBUG_FEATURES) && defined(CONFIG_NET_UDP_WRBUFFER_DEBUG)
/* Force debug output (from this file only) */
# undef CONFIG_DEBUG_NET
# define CONFIG_DEBUG_NET 1
#endif
#include <sys/types.h>
#include <sys/socket.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <arch/irq.h>
#include <nuttx/net/net.h>
#include <nuttx/mm/iob.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/udp.h>
#include "netdev/netdev.h"
#include "socket/socket.h"
#include "inet/inet.h"
#include "arp/arp.h"
#include "icmpv6/icmpv6.h"
#include "neighbor/neighbor.h"
#include "udp/udp.h"
#include "devif/devif.h"
#include "utils/utils.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* If both IPv4 and IPv6 support are both enabled, then we will need to build
* in some additional domain selection support.
*/
#if defined(CONFIG_NET_IPv4) && defined(CONFIG_NET_IPv6)
# define NEED_IPDOMAIN_SUPPORT 1
#endif
/* Debug */
#ifdef CONFIG_NET_UDP_WRBUFFER_DUMP
# define BUF_DUMP(msg,buf,len) lib_dumpbuffer(msg,buf,len)
#else
# define BUF_DUMP(msg,buf,len)
# undef UDP_WBDUMP
# define UDP_WBDUMP(msg,wrb,len,offset)
#endif
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
#ifdef NEED_IPDOMAIN_SUPPORT
static inline void sendto_ipselect(FAR struct net_driver_s *dev,
FAR struct udp_conn_s *conn);
#endif
static int sendto_next_transfer(FAR struct udp_conn_s *conn);
static uint16_t sendto_eventhandler(FAR struct net_driver_s *dev,
FAR void *pvpriv, uint16_t flags);
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: sendto_writebuffer_release
*
* Description:
* Release the write buffer at the head of the write buffer queue.
*
* Input Parameters:
* conn - The UDP connection of interest
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked
*
****************************************************************************/
static void sendto_writebuffer_release(FAR struct udp_conn_s *conn)
{
FAR struct udp_wrbuffer_s *wrb;
int ret = OK;
do
{
/* Check if the write queue became empty */
if (sq_empty(&conn->write_q))
{
/* Yes.. stifle any further callbacks until more write data is
* enqueued.
*/
conn->sndcb->flags = 0;
conn->sndcb->priv = NULL;
conn->sndcb->event = NULL;
wrb = NULL;
#ifdef CONFIG_NET_UDP_NOTIFIER
/* Notify any waiters that the write buffers have been drained. */
udp_writebuffer_signal(conn);
#endif
}
else
{
/* Remove the write buffer from the head of the write buffer queue
* and release it.
*/
wrb = (FAR struct udp_wrbuffer_s *)sq_remfirst(&conn->write_q);
DEBUGASSERT(wrb != NULL);
udp_wrbuffer_release(wrb);
/* Set up for the next packet transfer by setting the connection
* address to the address of the next packet now at the header of
* the write buffer queue.
*/
ret = sendto_next_transfer(conn);
}
}
while (wrb != NULL && ret < 0);
#if CONFIG_NET_SEND_BUFSIZE > 0
/* Notify the send buffer available if wrbbuffer drained */
udp_sendbuffer_notify(conn);
#endif /* CONFIG_NET_SEND_BUFSIZE */
}
/****************************************************************************
* Name: sendto_ipselect
*
* Description:
* If both IPv4 and IPv6 support are enabled, then we will need to select
* which one to use when generating the outgoing packet. If only one
* domain is selected, then the setup is already in place and we need do
* nothing.
*
* Input Parameters:
* dev - The structure of the network driver that caused the event
* conn - The UDP connection of interest
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked
*
****************************************************************************/
#ifdef NEED_IPDOMAIN_SUPPORT
static inline void sendto_ipselect(FAR struct net_driver_s *dev,
FAR struct udp_conn_s *conn)
{
/* Which domain the socket support */
if (conn->domain == PF_INET ||
(conn->domain == PF_INET6 &&
ip6_is_ipv4addr((FAR struct in6_addr *)conn->u.ipv6.raddr)))
{
/* Select the IPv4 domain */
udp_ipv4_select(dev);
}
else /* if (conn->domain == PF_INET6) */
{
/* Select the IPv6 domain */
udp_ipv6_select(dev);
}
}
#endif
/****************************************************************************
* Name: sendto_next_transfer
*
* Description:
* Setup for the next packet transfer. That function is called (1)
* psock_udp_sendto() by when the new UDP packet is buffered at the head of
* the write queue and (2) by sendto_writebuffer_release() when that
* previously queued write buffer was sent and a new write buffer lies at
* the head of the write queue.
*
* Input Parameters:
* conn - The UDP connection structure
*
* Returned Value:
* None
*
****************************************************************************/
static int sendto_next_transfer(FAR struct udp_conn_s *conn)
{
FAR struct udp_wrbuffer_s *wrb;
FAR struct net_driver_s *dev;
/* Set the UDP "connection" to the destination address of the write buffer
* at the head of the queue.
*/
wrb = (FAR struct udp_wrbuffer_s *)sq_peek(&conn->write_q);
if (wrb == NULL)
{
ninfo("Write buffer queue is empty\n");
return -ENOENT;
}
/* Has this address already been bound to a local port (lport)? */
if (!conn->lport)
{
/* No.. Find an unused local port number and bind it to the
* connection structure.
*/
conn->lport = HTONS(udp_select_port(conn->domain, &conn->u));
if (!conn->lport)
{
nerr("ERROR: Failed to get a local port!\n");
return -EADDRINUSE;
}
}
/* Get the device that will handle the remote packet transfers. This
* should never be NULL.
*
* REVISIT: There is a logical error here for the case where there are
* multiple network devices. In that case, the packets may need to be sent
* in a different order than they were queued. Forcing FIFO packet
* transmission could harm performance.
*/
dev = udp_find_raddr_device(conn, &wrb->wb_dest);
if (dev == NULL)
{
nerr("ERROR: udp_find_raddr_device failed\n");
return -ENETUNREACH;
}
/* Make sure that the device is in the UP state */
if ((dev->d_flags & IFF_UP) == 0)
{
nwarn("WARNING: device is DOWN\n");
return -EHOSTUNREACH;
}
#ifndef CONFIG_NET_IPFRAG
/* Sanity check if the packet len (with IP hdr) is greater than the MTU */
if (wrb->wb_iob->io_pktlen > devif_get_mtu(dev))
{
nerr("ERROR: Packet too long to send!\n");
return -EMSGSIZE;
}
#endif
/* If this is not the same device that we used in the last call to
* udp_callback_alloc(), then we need to release and reallocate the old
* callback instance.
*/
if (conn->sndcb != NULL && conn->dev != dev)
{
udp_callback_free(conn->dev, conn, conn->sndcb);
conn->sndcb = NULL;
}
/* Allocate resources to receive a callback from this device if the
* callback is not already in place.
*/
if (conn->sndcb == NULL)
{
conn->sndcb = udp_callback_alloc(dev, conn);
}
/* Test if the callback has been allocated */
if (conn->sndcb == NULL)
{
/* A buffer allocation error occurred */
nerr("ERROR: Failed to allocate callback\n");
return -ENOMEM;
}
conn->dev = dev;
/* Set up the callback in the connection */
conn->sndcb->flags = (UDP_POLL | NETDEV_DOWN);
conn->sndcb->priv = (FAR void *)conn;
conn->sndcb->event = sendto_eventhandler;
/* Notify the device driver of the availability of TX data */
netdev_txnotify_dev(dev);
return OK;
}
/****************************************************************************
* Name: sendto_eventhandler
*
* Description:
* This function is called to perform the actual send operation when
* polled by the lower, device interfacing layer.
*
* Input Parameters:
* dev The structure of the network driver that caused the event
* conn The connection structure associated with the socket
* flags Set of events describing why the callback was invoked
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked
*
****************************************************************************/
static uint16_t sendto_eventhandler(FAR struct net_driver_s *dev,
FAR void *pvpriv, uint16_t flags)
{
FAR struct udp_conn_s *conn = pvpriv;
DEBUGASSERT(dev != NULL && conn != NULL);
ninfo("flags: %04x\n", flags);
/* Check if the network device has gone down */
if ((flags & NETDEV_DOWN) != 0)
{
ninfo("Device down: %04x\n", flags);
/* Free the write buffer at the head of the queue and attempt to setup
* the next transfer.
*/
sendto_writebuffer_release(conn);
return flags;
}
/* The UDP socket should be bound to a device. Make sure that the polling
* device is the one that we are bound to.
*
* REVISIT: There is a logical error here for the case where there are
* multiple network devices. In that case, the packets may need to be sent
* in a different order than they were queued. The packet we may need to
* send on this device may not be at the head of the list. Forcing FIFO
* packet transmission could degrade performance!
*/
DEBUGASSERT(conn != NULL);
DEBUGASSERT(conn->dev != NULL);
if (dev != conn->dev)
{
return flags;
}
/* Check for a normal polling cycle and if the outgoing packet is
* available. It would not be available if it has been claimed by a send
* event serving a different thread -OR- if the output buffer currently
* contains unprocessed incoming data. In these cases we will just have
* to wait for the next polling cycle.
*
* And, of course, we can do nothing if we have no data in the write
* buffers to send.
*/
if (dev->d_sndlen <= 0 && (flags & UDP_NEWDATA) == 0 &&
(flags & UDP_POLL) != 0 && !sq_empty(&conn->write_q))
{
uint16_t udpiplen = udpip_hdrsize(conn);
FAR struct udp_wrbuffer_s *wrb;
/* Peek at the head of the write queue (but don't remove anything
* from the write queue yet). We know from the above test that
* the write_q is not empty.
*/
wrb = (FAR struct udp_wrbuffer_s *)sq_peek(&conn->write_q);
DEBUGASSERT(wrb != NULL);
/* If the udp socket not connected, it is possible to have
* multi-different destination address in each iob entry,
* update the remote address every time to avoid sent to the
* incorrect destination.
*/
udp_connect(conn, (FAR const struct sockaddr *)&wrb->wb_dest);
/* Then set-up to send that amount of data with the offset
* corresponding to the size of the IP-dependent address structure.
*/
netdev_iob_replace(dev, wrb->wb_iob);
/* Get the amount of data that we can send in the next packet.
* We will send either the remaining data in the buffer I/O
* buffer chain, or as much as will fit given the MSS and current
* window size.
*/
dev->d_sndlen = wrb->wb_iob->io_pktlen - udpiplen;
ninfo("wrb=%p sndlen=%d\n", wrb, dev->d_sndlen);
/* Do not need to release wb_iob, the life cycle of wb_iob is
* handed over to the network device
*/
wrb->wb_iob = NULL;
#ifdef NEED_IPDOMAIN_SUPPORT
/* If both IPv4 and IPv6 support are enabled, then we will need to
* select which one to use when generating the outgoing packet.
* If only one domain is selected, then the setup is already in
* place and we need do nothing.
*/
sendto_ipselect(dev, conn);
#endif
/* Free the write buffer at the head of the queue and attempt to
* setup the next transfer.
*/
sendto_writebuffer_release(conn);
/* Only one data can be sent by low level driver at once,
* tell the caller stop polling the other connections.
*/
flags &= ~UDP_POLL;
}
/* Continue waiting */
return flags;
}
/****************************************************************************
* Name: udp_send_gettimeout
*
* Description:
* Calculate the send timeout
*
****************************************************************************/
static unsigned int udp_send_gettimeout(clock_t start, unsigned int timeout)
{
unsigned int elapse;
if (timeout != UINT_MAX)
{
elapse = TICK2MSEC(clock_systime_ticks() - start);
if (elapse >= timeout)
{
timeout = 0;
}
else
{
timeout -= elapse;
}
}
return timeout;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: psock_udp_sendto
*
* Description:
* This function implements the UDP-specific logic of the standard
* sendto() socket operation.
*
* Input Parameters:
* psock A pointer to a NuttX-specific, internal socket structure
* buf Data to send
* len Length of data to send
* flags Send flags
* to Address of recipient
* tolen The length of the address structure
*
* NOTE: All input parameters were verified by sendto() before this
* function was called.
*
* Returned Value:
* On success, returns the number of characters sent. On error,
* a negated errno value is returned. See the description in
* net/socket/sendto.c for the list of appropriate return value.
*
****************************************************************************/
ssize_t psock_udp_sendto(FAR struct socket *psock, FAR const void *buf,
size_t len, int flags,
FAR const struct sockaddr *to, socklen_t tolen)
{
FAR struct udp_wrbuffer_s *wrb;
FAR struct udp_conn_s *conn;
unsigned int timeout;
uint16_t udpiplen;
bool nonblock;
bool empty;
int ret = OK;
clock_t start;
/* Get the underlying the UDP connection structure. */
conn = psock->s_conn;
/* The length of a datagram to be up to 65,535 octets */
if (len > 65535)
{
return -EMSGSIZE;
}
/* If the UDP socket was previously assigned a remote peer address via
* connect(), then as with connection-mode socket, sendto() may not be
* used with a non-NULL destination address. Normally send() would be
* used with such connected UDP sockets.
*/
if (to != NULL && _SS_ISCONNECTED(conn->sconn.s_flags))
{
/* EISCONN - A destination address was specified and the socket is
* already connected.
*/
return -EISCONN;
}
/* Otherwise, if the socket is not connected, then a destination address
* must be provided.
*/
else if (to == NULL && !_SS_ISCONNECTED(conn->sconn.s_flags))
{
/* EDESTADDRREQ - The socket is not connection-mode and no peer
* address is set.
*/
return -EDESTADDRREQ;
}
#if defined(CONFIG_NET_ARP_SEND) || defined(CONFIG_NET_ICMPv6_NEIGHBOR)
#ifdef CONFIG_NET_ARP_SEND
/* Assure the the IPv4 destination address maps to a valid MAC address in
* the ARP table.
*/
if (psock->s_domain == PF_INET)
{
in_addr_t destipaddr;
/* Check if the socket is connection mode */
if (_SS_ISCONNECTED(conn->sconn.s_flags))
{
/* Yes.. use the connected remote address (the 'to' address is
* null).
*/
destipaddr = conn->u.ipv4.raddr;
}
else
{
FAR const struct sockaddr_in *into;
/* No.. use the destination address provided by the non-NULL 'to'
* argument.
*/
into = (FAR const struct sockaddr_in *)to;
destipaddr = into->sin_addr.s_addr;
}
/* Make sure that the IP address mapping is in the ARP table */
ret = arp_send(destipaddr);
}
#endif /* CONFIG_NET_ARP_SEND */
#ifdef CONFIG_NET_ICMPv6_NEIGHBOR
/* Assure the the IPv6 destination address maps to a valid MAC address in
* the neighbor table.
*/
if (psock->s_domain == PF_INET6)
{
FAR const uint16_t *destipaddr;
/* Check if the socket is connection mode */
if (_SS_ISCONNECTED(conn->sconn.s_flags))
{
/* Yes.. use the connected remote address (the 'to' address is
* null).
*/
destipaddr = conn->u.ipv6.raddr;
}
else
{
FAR const struct sockaddr_in6 *into;
/* No.. use the destination address provided by the non-NULL 'to'
* argument.
*/
into = (FAR const struct sockaddr_in6 *)to;
destipaddr = into->sin6_addr.s6_addr16;
}
/* Make sure that the IP address mapping is in the Neighbor Table */
ret = icmpv6_neighbor(NULL, destipaddr);
}
#endif /* CONFIG_NET_ICMPv6_NEIGHBOR */
/* Did we successfully get the address mapping? */
if (ret < 0)
{
nerr("ERROR: Not reachable\n");
return -ENETUNREACH;
}
#endif /* CONFIG_NET_ARP_SEND || CONFIG_NET_ICMPv6_NEIGHBOR */
nonblock = _SS_ISNONBLOCK(conn->sconn.s_flags) ||
(flags & MSG_DONTWAIT) != 0;
start = clock_systime_ticks();
timeout = _SO_TIMEOUT(conn->sconn.s_sndtimeo);
/* Dump the incoming buffer */
BUF_DUMP("psock_udp_sendto", buf, len);
if (len > 0)
{
net_lock();
#if CONFIG_NET_SEND_BUFSIZE > 0
/* If the send buffer size exceeds the send limit,
* wait for the write buffer to be released
*/
while (udp_wrbuffer_inqueue_size(conn) + len > conn->sndbufs)
{
if (nonblock)
{
ret = -EAGAIN;
goto errout_with_lock;
}
ret = net_sem_timedwait_uninterruptible(&conn->sndsem,
udp_send_gettimeout(start, timeout));
if (ret < 0)
{
if (ret == -ETIMEDOUT)
{
ret = -EAGAIN;
}
goto errout_with_lock;
}
}
#endif /* CONFIG_NET_SEND_BUFSIZE */
/* Allocate a write buffer. Careful, the network will be momentarily
* unlocked here.
*/
#ifdef CONFIG_NET_JUMBO_FRAME
/* alloc iob of gso pkt for udp data */
wrb = udp_wrbuffer_tryalloc(len + udpip_hdrsize(conn) +
CONFIG_NET_LL_GUARDSIZE);
#else
if (nonblock)
{
wrb = udp_wrbuffer_tryalloc();
}
else
{
wrb = udp_wrbuffer_timedalloc(udp_send_gettimeout(start,
timeout));
}
#endif
if (wrb == NULL)
{
/* A buffer allocation error occurred */
nerr("ERROR: Failed to allocate write buffer\n");
if (nonblock || timeout != UINT_MAX)
{
ret = -EAGAIN;
}
else
{
ret = -ENOMEM;
}
goto errout_with_lock;
}
/* Initialize the write buffer
*
* Check if the socket is connected
*/
if (_SS_ISCONNECTED(conn->sconn.s_flags))
{
/* Yes.. get the connection address from the connection structure */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (conn->domain == PF_INET)
#endif
{
FAR struct sockaddr_in *addr4 =
(FAR struct sockaddr_in *)&wrb->wb_dest;
addr4->sin_family = AF_INET;
addr4->sin_port = conn->rport;
net_ipv4addr_copy(addr4->sin_addr.s_addr, conn->u.ipv4.raddr);
memset(addr4->sin_zero, 0, sizeof(addr4->sin_zero));
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
FAR struct sockaddr_in6 *addr6 =
(FAR struct sockaddr_in6 *)&wrb->wb_dest;
addr6->sin6_family = AF_INET6;
addr6->sin6_port = conn->rport;
net_ipv6addr_copy(addr6->sin6_addr.s6_addr,
conn->u.ipv6.raddr);
}
#endif /* CONFIG_NET_IPv6 */
}
/* Not connected. Use the provided destination address */
else
{
memcpy(&wrb->wb_dest, to, tolen);
udp_connect(conn, to);
}
/* Skip l2/l3/l4 offset before copy */
udpiplen = udpip_hdrsize(conn);
iob_reserve(wrb->wb_iob, CONFIG_NET_LL_GUARDSIZE);
iob_update_pktlen(wrb->wb_iob, udpiplen, false);
/* Copy the user data into the write buffer. We cannot wait for
* buffer space if the socket was opened non-blocking.
*/
if (nonblock)
{
ret = iob_trycopyin(wrb->wb_iob, (FAR uint8_t *)buf,
len, udpiplen, false);
}
else
{
unsigned int count;
int blresult;
/* iob_copyin might wait for buffers to be freed, but if
* network is locked this might never happen, since network
* driver is also locked, therefore we need to break the lock
*/
blresult = net_breaklock(&count);
ret = iob_copyin(wrb->wb_iob, (FAR uint8_t *)buf,
len, udpiplen, false);
if (blresult >= 0)
{
net_restorelock(count);
}
}
if (ret < 0)
{
goto errout_with_wrb;
}
/* Dump I/O buffer chain */
UDP_WBDUMP("I/O buffer chain", wrb, wrb->wb_iob->io_pktlen, 0);
/* sendto_eventhandler() will send data in FIFO order from the
* conn->write_q.
*
* REVISIT: Why FIFO order? Because it is easy. In a real world
* environment where there are multiple network devices this might
* be inefficient because we could be sending data to different
* device out-of-queued-order to optimize performance. Sending
* data to different networks from a single UDP socket is probably
* not a very common use case, however.
*/
empty = sq_empty(&conn->write_q);
sq_addlast(&wrb->wb_node, &conn->write_q);
ninfo("Queued WRB=%p pktlen=%u write_q(%p,%p)\n",
wrb, wrb->wb_iob->io_pktlen,
conn->write_q.head, conn->write_q.tail);
if (empty)
{
/* The new write buffer lies at the head of the write queue. Set
* up for the next packet transfer by setting the connection
* address to the address of the next packet now at the header of
* the write buffer queue.
*/
ret = sendto_next_transfer(conn);
if (ret < 0)
{
sq_remlast(&conn->write_q);
goto errout_with_wrb;
}
}
net_unlock();
}
/* Return the number of bytes that will be sent */
return len;
errout_with_wrb:
udp_wrbuffer_release(wrb);
errout_with_lock:
net_unlock();
return ret;
}
/****************************************************************************
* Name: psock_udp_cansend
*
* Description:
* psock_udp_cansend() returns a value indicating if a write to the socket
* would block. No space in the buffer is actually reserved, so it is
* possible that the write may still block if the buffer is filled by
* another means.
*
* Input Parameters:
* conn A reference to UDP connection structure.
*
* Returned Value:
* OK
* At least one byte of data could be successfully written.
* -EWOULDBLOCK
* There is no room in the output buffer.
* -EBADF
* An invalid descriptor was specified.
*
****************************************************************************/
int psock_udp_cansend(FAR struct udp_conn_s *conn)
{
/* Verify that we received a valid socket */
if (conn == NULL)
{
nerr("ERROR: Invalid socket\n");
return -EBADF;
}
/* In order to setup the send, we need to have at least one free write
* buffer head and at least one free IOB to initialize the write buffer
* head.
*
* REVISIT: The send will still block if we are unable to buffer the
* entire user-provided buffer which may be quite large. We will almost
* certainly need to have more than one free IOB, but we don't know how
* many more.
*/
if (udp_wrbuffer_test() < 0 || iob_navail(false) <= 0)
{
return -EWOULDBLOCK;
}
return OK;
}
/****************************************************************************
* Name: udp_sendbuffer_notify
*
* Description:
* Notify the send buffer semaphore
*
* Input Parameters:
* conn - The UDP connection of interest
*
* Assumptions:
* Called from user logic with the network locked.
*
****************************************************************************/
#if CONFIG_NET_SEND_BUFSIZE > 0
void udp_sendbuffer_notify(FAR struct udp_conn_s *conn)
{
int val = 0;
nxsem_get_value(&conn->sndsem, &val);
if (val < 0)
{
nxsem_post(&conn->sndsem);
}
}
#endif /* CONFIG_NET_SEND_BUFSIZE */
#endif /* CONFIG_NET && CONFIG_NET_UDP && CONFIG_NET_UDP_WRITE_BUFFERS */
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