/**************************************************************************** * net/udp/udp_conn.c * * Copyright (C) 2007-2009, 2011-2012, 2016, 2018 Gregory Nutt. All rights * reserved. * Author: Gregory Nutt * * 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 #if defined(CONFIG_NET) && defined(CONFIG_NET_UDP) #include #include #include #include #include #include #include #include #include #include #include #include #include #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; /* Last port used by a UDP connection connection. */ static uint16_t g_last_udp_port; /**************************************************************************** * 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) { uint16_t portno; /* Find an unused local port number. Loop until we find a valid * listen port number that is not being used by any other connection. */ net_lock(); 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 * - setsockopt to SO_BROADCAST (for all-nodes address) * * For connection-less UDP sockets: * * - call sendto with sendaddr.sin_addr.s_addr = * - 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 * - setsockopt to SO_BROADCAST (for all-nodes address) * * For connection-less UDP sockets: * * - call sendto with sendaddr.sin_addr.s_addr = * - 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); } g_last_udp_port = 1024; } /**************************************************************************** * 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 */