/**************************************************************************** * net/socket/net_dup2.c * * Copyright (C) 2009, 2011-2015, 2017 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include #include "inet/inet.h" #include "tcp/tcp.h" #include "socket/socket.h" /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: psock_dup2 * * Description: * Performs the low level, common portion of net_dup() and net_dup2() * * Input Parameters: * psock1 - The existing socket that is being cloned. * psock2 - A reference to an uninitialized socket structure allocated by * the caller. * * Returned Value: * Zero (OK) is returned on success; a negated errno value is returned on * any failure. * ****************************************************************************/ int psock_dup2(FAR struct socket *psock1, FAR struct socket *psock2) { int ret = OK; /* Parts of this operation need to be atomic */ net_lock(); /* Duplicate the relevant socket state (zeroing everything else) */ memset(psock2, 0, sizeof(struct socket)); psock2->s_domain = psock1->s_domain; /* IP domain: PF_INET, PF_INET6, or PF_PACKET */ psock2->s_type = psock1->s_type; /* Protocol type: Only SOCK_STREAM or SOCK_DGRAM */ psock2->s_sockif = psock1->s_sockif; /* Socket interface */ psock2->s_flags = psock1->s_flags; /* See _SF_* definitions */ #ifdef CONFIG_NET_SOCKOPTS psock2->s_options = psock1->s_options; /* Selected socket options */ psock2->s_rcvtimeo = psock1->s_rcvtimeo; /* Receive timeout value (in deciseconds) */ psock2->s_sndtimeo = psock1->s_sndtimeo; /* Send timeout value (in deciseconds) */ #ifdef CONFIG_NET_SOLINGER psock2->s_linger = psock1->s_linger; /* Linger timeout value (in deciseconds) */ #endif #endif psock2->s_conn = psock1->s_conn; /* UDP or TCP connection structure */ /* Increment the reference count on the socket */ psock2->s_crefs = 1; /* One reference on the new socket itself */ /* Increment the reference count on the underlying connection structure * for this address family type. */ DEBUGASSERT(psock2->s_sockif != NULL && psock2->s_sockif->si_addref != NULL); psock2->s_sockif->si_addref(psock2); #ifdef NET_TCP_HAVE_STACK /* For connected socket types, it is necessary to also start the network * monitor so that the newly cloned socket can receive a notification if * the network connection is lost. */ if (psock2->s_type == SOCK_STREAM) { ret = tcp_start_monitor(psock2); /* On failure, back out the reference count on the TCP connection * structure. tcp_start_monitor() will fail only in the race condition * where the TCP connection has been lost. */ if (ret < 0) { /* There should be at least two reference counts on the connection * structure: At least one from the original socket and the one * from above where we incremented the reference count. * inet_close() will handle all cases. * * NOTE: As a side-effect, inet_close()will also call * tcp_stop_monitor() which could inform the loss of connection to * all open sockets on the connection structure if the reference * count decrements to zero. */ inet_close(psock2); /* Then release our reference on the socket structure containing * the connection. */ psock_release(psock2); } } #endif net_unlock(); return ret; } /**************************************************************************** * Name: net_dup2 * * Description: * Clone a socket descriptor to an arbitrary descriptor number. * * Returned Value: * Zero (OK) is returned on success; a negated errno value is returned on * any failure. * ****************************************************************************/ int net_dup2(int sockfd1, int sockfd2) { FAR struct socket *psock1; FAR struct socket *psock2; int ret; /* Lock the scheduler throughout the following */ sched_lock(); /* Get the socket structures underly both descriptors */ psock1 = sockfd_socket(sockfd1); psock2 = sockfd_socket(sockfd2); /* Verify that the sockfd1 and sockfd2 both refer to valid socket * descriptors and that sockfd2 corresponds to an allocated socket */ if (psock1 == NULL || psock2 == NULL || psock1->s_crefs <= 0) { ret = -EBADF; goto errout; } /* If sockfd2 also valid, allocated socket, then we will have to * close it! */ if (psock2->s_crefs > 0) { net_close(sockfd2); } /* Duplicate the socket state */ ret = psock_dup2(psock1, psock2); errout: sched_unlock(); return ret; }