/****************************************************************************
* net/udp/udp_conn.c
*
* Copyright (C) 2007-2009, 2011-2012, 2016, 2018 Gregory Nutt. All rights
* reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Large parts of this file were leveraged from uIP logic:
*
* Copyright (c) 2001-2003, Adam Dunkels.
* All rights reserved.
*
* 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. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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>
#if defined(CONFIG_NET) && defined(CONFIG_NET_UDP)
#include <stdint.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <netinet/in.h>
#include <arch/irq.h>
#include <nuttx/clock.h>
#include <nuttx/semaphore.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/net.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/ip.h>
#include <nuttx/net/udp.h>
#include "devif/devif.h"
#include "netdev/netdev.h"
#include "inet/inet.h"
#include "udp/udp.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define IPv4BUF ((struct ipv4_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
#define IPv6BUF ((struct ipv6_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
/****************************************************************************
* Private Data
****************************************************************************/
/* The array containing all UDP connections. */
struct udp_conn_s g_udp_connections[CONFIG_NET_UDP_CONNS];
/* A list of all free UDP connections */
static dq_queue_t g_free_udp_connections;
static sem_t g_free_sem;
/* A list of all allocated UDP connections */
static dq_queue_t g_active_udp_connections;
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: _udp_semtake() and _udp_semgive()
*
* Description:
* Take/give semaphore
*
****************************************************************************/
static inline void _udp_semtake(FAR sem_t *sem)
{
net_lockedwait_uninterruptible(sem);
}
#define _udp_semgive(sem) nxsem_post(sem)
/****************************************************************************
* Name: udp_find_conn()
*
* Description:
* Find the UDP connection that uses this local port number.
*
* Assumptions:
* This function must be called with the network locked.
*
****************************************************************************/
static FAR struct udp_conn_s *udp_find_conn(uint8_t domain,
FAR union ip_binding_u *ipaddr,
uint16_t portno)
{
FAR struct udp_conn_s *conn;
int i;
/* Now search each connection structure. */
for (i = 0; i < CONFIG_NET_UDP_CONNS; i++)
{
conn = &g_udp_connections[i];
/* If the port local port number assigned to the connections matches
* AND the IP address of the connection matches, then return a
* reference to the connection structure. INADDR_ANY is a special
* case: There can only be instance of a port number with INADDR_ANY.
*/
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (domain == PF_INET)
#endif
{
if (conn->lport == portno &&
(net_ipv4addr_cmp(conn->u.ipv4.laddr, ipaddr->ipv4.laddr) ||
net_ipv4addr_cmp(conn->u.ipv4.laddr, INADDR_ANY)))
{
return conn;
}
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
if (conn->lport == portno &&
(net_ipv6addr_cmp(conn->u.ipv6.laddr, ipaddr->ipv6.laddr) ||
net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr)))
{
return conn;
}
}
#endif /* CONFIG_NET_IPv6 */
}
return NULL;
}
/****************************************************************************
* Name: udp_select_port
*
* Description:
* Select an unused port number.
*
* NOTE that in principle this function could fail if there is no available
* port number. There is no check for that case and it would actually
* in an infinite loop if that were the case. In this simple, small UDP
* implementation, it is reasonable to assume that that error cannot happen
* and that a port number will always be available.
*
* Input Parameters:
* None
*
* Returned Value:
* Next available port number
*
****************************************************************************/
static uint16_t udp_select_port(uint8_t domain, FAR union ip_binding_u *u)
{
static uint16_t g_last_udp_port;
uint16_t portno;
net_lock();
/* Generate port base dynamically */
if (g_last_udp_port == 0)
{
g_last_udp_port = clock_systime_ticks() % 32000;
if (g_last_udp_port < 4096)
{
g_last_udp_port += 4096;
}
}
/* Find an unused local port number. Loop until we find a valid
* listen port number that is not being used by any other connection.
*/
do
{
/* Guess that the next available port number will be the one after
* the last port number assigned.
*/
++g_last_udp_port;
/* Make sure that the port number is within range */
if (g_last_udp_port >= 32000)
{
g_last_udp_port = 4096;
}
}
while (udp_find_conn(domain, u, htons(g_last_udp_port)) != NULL);
/* Initialize and return the connection structure, bind it to the
* port number
*/
portno = g_last_udp_port;
net_unlock();
return portno;
}
/****************************************************************************
* Name: udp_ipv4_active
*
* Description:
* Find a connection structure that is the appropriate connection to be
* used within the provided UDP header
*
* Assumptions:
* This function must be called with the network locked.
*
****************************************************************************/
#ifdef CONFIG_NET_IPv4
static inline FAR struct udp_conn_s *
udp_ipv4_active(FAR struct net_driver_s *dev, FAR struct udp_hdr_s *udp)
{
#ifdef CONFIG_NET_BROADCAST
static const in_addr_t bcast = INADDR_BROADCAST;
#endif
FAR struct ipv4_hdr_s *ip = IPv4BUF;
FAR struct udp_conn_s *conn;
conn = (FAR struct udp_conn_s *)g_active_udp_connections.head;
while (conn)
{
/* If the local UDP port is non-zero, the connection is considered
* to be used. If so, then the following checks are performed:
*
* 1. The destination address is verified against the bound address
* of the connection.
*
* - The local port number is checked against the destination port
* number in the received packet.
* - If multiple network interfaces are supported, then the local
* IP address is available and we will insist that the
* destination IP matches the bound address (or the destination
* IP address is a broadcast address). If a socket is bound to
* INADDRY_ANY (laddr), then it should receive all packets
* directed to the port.
*
* 2. If this is a connection mode UDP socket, then the source address
* is verified against the connected remote address.
*
* - The remote port number is checked if the connection is bound
* to a remote port.
* - Finally, if the connection is bound to a remote IP address,
* the source IP address of the packet is checked. Broadcast
* addresses are also accepted.
*
* If all of the above are true then the newly received UDP packet
* is destined for this UDP connection.
*
* To send and receive multicast packets, the application should:
*
* - Bind socket to INADDR6_ANY (for the all-nodes multicast address)
* or to a specific <multicast-address>
* - setsockopt to SO_BROADCAST (for all-nodes address)
*
* For connection-less UDP sockets:
*
* - call sendto with sendaddr.sin_addr.s_addr = <multicast-address>
* - call recvfrom.
*
* For connection-mode UDP sockets:
*
* - call connect() to connect the UDP socket to a specific remote
* address, then
* - Call send() with no address address information
* - call recv() (from address information should not be needed)
*
* REVIST: SO_BROADCAST flag is currently ignored.
*/
/* Check that there is a local port number and this is matches
* the port number in the destination address.
*/
if (conn->lport != 0 && udp->destport == conn->lport &&
/* Local port accepts any address on this port or there
* is an exact match in destipaddr and the bound local
* address. This catches the receipt of a broadcast when
* the socket is bound to INADDR_ANY.
*/
(net_ipv4addr_cmp(conn->u.ipv4.laddr, INADDR_ANY) ||
net_ipv4addr_hdrcmp(ip->destipaddr, &conn->u.ipv4.laddr)))
{
/* Check if the socket is connection mode. In this case, only
* packets with source addresses from the connected remote peer
* will be accepted.
*/
if (_UDP_ISCONNECTMODE(conn->flags))
{
/* Check if the UDP connection is either (1) accepting packets
* from any port or (2) the packet srcport matches the local
* bound port number.
*/
if ((conn->rport == 0 || udp->srcport == conn->rport) &&
/* If (1) not connected to a remote address, or (2) a
* broadcast destipaddr was received, or (3) there is an
* exact match between the srcipaddr and the bound remote IP
* address, then accept the packet.
*/
(net_ipv4addr_cmp(conn->u.ipv4.raddr, INADDR_ANY) ||
#ifdef CONFIG_NET_BROADCAST
net_ipv4addr_hdrcmp(ip->destipaddr, &bcast) ||
#endif
net_ipv4addr_hdrcmp(ip->srcipaddr, &conn->u.ipv4.raddr)))
{
/* Matching connection found.. Break out of the loop and
* return this reference to it.
*/
break;
}
}
else
{
/* This UDP socket is not connected. We need to match only
* the destination address with the bound socket address.
* Break out out of the loop and return this reference to
* the matching connection structure.
*/
break;
}
}
/* Look at the next active connection */
conn = (FAR struct udp_conn_s *)conn->node.flink;
}
return conn;
}
#endif /* CONFIG_NET_IPv4 */
/****************************************************************************
* Name: udp_ipv6_active
*
* Description:
* Find a connection structure that is the appropriate connection to be
* used within the provided UDP header
*
* Assumptions:
* This function must be called with the network locked.
*
****************************************************************************/
#ifdef CONFIG_NET_IPv6
static inline FAR struct udp_conn_s *
udp_ipv6_active(FAR struct net_driver_s *dev, FAR struct udp_hdr_s *udp)
{
FAR struct ipv6_hdr_s *ip = IPv6BUF;
FAR struct udp_conn_s *conn;
conn = (FAR struct udp_conn_s *)g_active_udp_connections.head;
while (conn != NULL)
{
/* If the local UDP port is non-zero, the connection is considered
* to be used. If so, then the following checks are performed:
*
* 1. The destination address is verified against the bound address
* of the connection.
*
* - The local port number is checked against the destination port
* number in the received packet.
* - If multiple network interfaces are supported, then the local
* IP address is available and we will insist that the
* destination IP matches the bound address. If a socket is bound
* to INADDR6_ANY (laddr), then it should receive all packets
* directed to the port. REVISIT: Should also depend on
* SO_BROADCAST.
*
* 2. If this is a connection mode UDP socket, then the source address
* is verified against the connected remote address.
*
* - The remote port number is checked if the connection is bound
* to a remote port.
* - Finally, if the connection is bound to a remote IP address,
* the source IP address of the packet is checked.
*
* If all of the above are true then the newly received UDP packet
* is destined for this UDP connection.
*
* To send and receive multicast packets, the application should:
*
* - Bind socket to INADDR6_ANY (for the all-nodes multicast address)
* or to a specific <multicast-address>
* - setsockopt to SO_BROADCAST (for all-nodes address)
*
* For connection-less UDP sockets:
*
* - call sendto with sendaddr.sin_addr.s_addr = <multicast-address>
* - call recvfrom.
*
* For connection-mode UDP sockets:
*
* - call connect() to connect the UDP socket to a specific remote
* address, then
* - Call send() with no address address information
* - call recv() (from address information should not be needed)
*
* REVIST: SO_BROADCAST flag is currently ignored.
*/
/* Check that there is a local port number and this is matches
* the port number in the destination address.
*/
if ((conn->lport != 0 && udp->destport == conn->lport &&
/* Check if the local port accepts any address on this port or
* that there is an exact match between the destipaddr and the
* bound local address. This catches the case of the all nodes
* multicast when the socket is bound to the IPv6 unspecified
* address.
*/
(net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr) ||
net_ipv6addr_hdrcmp(ip->destipaddr, conn->u.ipv6.laddr))))
{
/* Check if the socket is connection mode. In this case, only
* packets with source addresses from the connected remote peer
* will be accepted.
*/
if (_UDP_ISCONNECTMODE(conn->flags))
{
/* Check if the UDP connection is either (1) accepting packets
* from any port or (2) the packet srcport matches the local
* bound port number.
*/
if ((conn->rport == 0 || udp->srcport == conn->rport) &&
/* If (1) not connected to a remote address, or (2) a all-
* nodes multicast destipaddr was received, or (3) there is an
* exact match between the srcipaddr and the bound remote IP
* address, then accept the packet.
*/
(net_ipv6addr_cmp(conn->u.ipv6.raddr, g_ipv6_unspecaddr) ||
#ifdef CONFIG_NET_BROADCAST
net_ipv6addr_hdrcmp(ip->destipaddr, g_ipv6_allnodes) ||
#endif
net_ipv6addr_hdrcmp(ip->srcipaddr, conn->u.ipv6.raddr)))
{
/* Matching connection found.. Break out of the loop and
* return this reference to it.
*/
break;
}
}
else
{
/* This UDP socket is not connected. We need to match only
* the destination address with the bound socket address.
* Break out out of the loop and return this reference to
* the matching connection structure.
*/
break;
}
}
/* Look at the next active connection */
conn = (FAR struct udp_conn_s *)conn->node.flink;
}
return conn;
}
#endif /* CONFIG_NET_IPv6 */
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: udp_initialize
*
* Description:
* Initialize the UDP connection structures. Called once and only from
* the UIP layer.
*
****************************************************************************/
void udp_initialize(void)
{
int i;
/* Initialize the queues */
dq_init(&g_free_udp_connections);
dq_init(&g_active_udp_connections);
nxsem_init(&g_free_sem, 0, 1);
for (i = 0; i < CONFIG_NET_UDP_CONNS; i++)
{
/* Mark the connection closed and move it to the free list */
g_udp_connections[i].lport = 0;
dq_addlast(&g_udp_connections[i].node, &g_free_udp_connections);
}
}
/****************************************************************************
* Name: udp_alloc
*
* Description:
* Allocate a new, uninitialized UDP connection structure. This is
* normally something done by the implementation of the socket() API
*
****************************************************************************/
FAR struct udp_conn_s *udp_alloc(uint8_t domain)
{
FAR struct udp_conn_s *conn;
/* The free list is protected by a semaphore (that behaves like a mutex). */
_udp_semtake(&g_free_sem);
conn = (FAR struct udp_conn_s *)dq_remfirst(&g_free_udp_connections);
if (conn)
{
/* Make sure that the connection is marked as uninitialized */
conn->flags = 0;
#if defined(CONFIG_NET_IPv4) && defined(CONFIG_NET_IPv6)
conn->domain = domain;
#endif
#ifdef CONFIG_NET_UDP_BINDTODEVICE
conn->boundto = 0; /* Not bound to any interface */
#endif
conn->lport = 0;
conn->ttl = IP_TTL;
#ifdef CONFIG_NET_UDP_WRITE_BUFFERS
/* Initialize the write buffer lists */
sq_init(&conn->write_q);
#endif
/* Enqueue the connection into the active list */
dq_addlast(&conn->node, &g_active_udp_connections);
}
_udp_semgive(&g_free_sem);
return conn;
}
/****************************************************************************
* Name: udp_free
*
* Description:
* Free a UDP connection structure that is no longer in use. This should be
* done by the implementation of close().
*
****************************************************************************/
void udp_free(FAR struct udp_conn_s *conn)
{
#ifdef CONFIG_NET_UDP_WRITE_BUFFERS
FAR struct udp_wrbuffer_s *wrbuffer;
#endif
/* The free list is protected by a semaphore (that behaves like a mutex). */
DEBUGASSERT(conn->crefs == 0);
_udp_semtake(&g_free_sem);
conn->lport = 0;
/* Remove the connection from the active list */
dq_rem(&conn->node, &g_active_udp_connections);
/* Release any read-ahead buffers attached to the connection */
iob_free_queue(&conn->readahead, IOBUSER_NET_UDP_READAHEAD);
#ifdef CONFIG_NET_UDP_WRITE_BUFFERS
/* Release any write buffers attached to the connection */
while ((wrbuffer = (struct udp_wrbuffer_s *)
sq_remfirst(&conn->write_q)) != NULL)
{
udp_wrbuffer_release(wrbuffer);
}
#endif
/* Free the connection */
dq_addlast(&conn->node, &g_free_udp_connections);
_udp_semgive(&g_free_sem);
}
/****************************************************************************
* Name: udp_active
*
* Description:
* Find a connection structure that is the appropriate
* connection to be used within the provided UDP header
*
* Assumptions:
* This function must be called with the network locked.
*
****************************************************************************/
FAR struct udp_conn_s *udp_active(FAR struct net_driver_s *dev,
FAR struct udp_hdr_s *udp)
{
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (IFF_IS_IPv6(dev->d_flags))
#endif
{
return udp_ipv6_active(dev, udp);
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
return udp_ipv4_active(dev, udp);
}
#endif /* CONFIG_NET_IPv4 */
}
/****************************************************************************
* Name: udp_nextconn
*
* Description:
* Traverse the list of allocated UDP connections
*
* Assumptions:
* This function must be called with the network locked.
*
****************************************************************************/
FAR struct udp_conn_s *udp_nextconn(FAR struct udp_conn_s *conn)
{
if (!conn)
{
return (FAR struct udp_conn_s *)g_active_udp_connections.head;
}
else
{
return (FAR struct udp_conn_s *)conn->node.flink;
}
}
/****************************************************************************
* Name: udp_bind
*
* Description:
* This function implements the low level parts of the standard UDP
* bind() operation.
*
* Assumptions:
* This function is called from normal user level code.
*
****************************************************************************/
int udp_bind(FAR struct udp_conn_s *conn, FAR const struct sockaddr *addr)
{
uint16_t portno;
int ret;
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (conn->domain == PF_INET)
#endif
{
FAR const struct sockaddr_in *inaddr =
(FAR const struct sockaddr_in *)addr;
/* Get the port number that we are binding to */
portno = inaddr->sin_port;
/* Bind the local IP address to the connection. NOTE this address may
* be INADDR_ANY meaning, essentially, that we are binding to all
* interfaces for receiving (Sending will use the default port).
*/
net_ipv4addr_copy(conn->u.ipv4.laddr, inaddr->sin_addr.s_addr);
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
FAR const struct sockaddr_in6 *inaddr =
(FAR const struct sockaddr_in6 *)addr;
/* Get the port number that we are binding to */
portno = inaddr->sin6_port;
/* Bind the local IP address to the connection. NOTE this address may
* be INADDR_ANY meaning, essentially, that we are binding to all
* interfaces for receiving (Sending will use the default port).
*/
net_ipv6addr_copy(conn->u.ipv6.laddr,
inaddr->sin6_addr.in6_u.u6_addr16);
}
#endif /* CONFIG_NET_IPv6 */
/* Is the user requesting to bind to any port? */
if (portno == 0)
{
/* Yes.. Select any unused local port number */
conn->lport = htons(udp_select_port(conn->domain, &conn->u));
ret = OK;
}
else
{
/* Interrupts must be disabled while access the UDP connection list */
net_lock();
/* Is any other UDP connection already bound to this address
* and port ?
*/
if (udp_find_conn(conn->domain, &conn->u, portno) == NULL)
{
/* No.. then bind the socket to the port */
conn->lport = portno;
ret = OK;
}
else
{
ret = -EADDRINUSE;
}
net_unlock();
}
return ret;
}
/****************************************************************************
* Name: udp_connect
*
* Description:
* This function simply assigns a remote address to UDP "connection"
* structure. This function is called as part of the implementation of:
*
* - connect(). If connect() is called for a SOCK_DGRAM socket, then
* this logic performs the moral equivalent of connect() operation
* for the UDP socket.
* - recvfrom() and sendto(). This function is called to set the
* remote address of the peer.
*
* The function will automatically allocate an unused local port for the
* new connection if the socket is not yet bound to a local address.
* However, another port can be chosen by using the udp_bind() call,
* after the udp_connect() function has been called.
*
* Input Parameters:
* conn - A reference to UDP connection structure. A value of NULL will
* disconnect from any previously connected address.
* addr - The address of the remote host.
*
* Assumptions:
* This function is called (indirectly) from user code. Interrupts may
* be enabled.
*
****************************************************************************/
int udp_connect(FAR struct udp_conn_s *conn, FAR const struct sockaddr *addr)
{
/* 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));
}
/* Is there a remote port (rport)? */
if (addr != NULL)
{
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (conn->domain == PF_INET)
#endif
{
FAR const struct sockaddr_in *inaddr =
(FAR const struct sockaddr_in *)addr;
conn->rport = inaddr->sin_port;
net_ipv4addr_copy(conn->u.ipv4.raddr, inaddr->sin_addr.s_addr);
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
FAR const struct sockaddr_in6 *inaddr =
(FAR const struct sockaddr_in6 *)addr;
conn->rport = inaddr->sin6_port;
net_ipv6addr_copy(conn->u.ipv6.raddr, inaddr->sin6_addr.s6_addr16);
}
#endif /* CONFIG_NET_IPv6 */
}
else
{
conn->rport = 0;
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (conn->domain == PF_INET)
#endif
{
net_ipv4addr_copy(conn->u.ipv4.raddr, INADDR_ANY);
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
net_ipv6addr_copy(conn->u.ipv6.raddr, g_ipv6_unspecaddr);
}
#endif /* CONFIG_NET_IPv6 */
}
return OK;
}
#endif /* CONFIG_NET && CONFIG_NET_UDP */