io.cpp

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/*
 * Software License Agreement (BSD License)
 *
 *  Copyright (c) 2008, Willow Garage, Inc.
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * 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.
 *   * Neither the name of Willow Garage, Inc. 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.
 */
/*****************************************************************************
** Includes
*****************************************************************************/

#include <ros/io.h>
#include <ros/assert.h> // don't need if we dont call the pipe functions.
#include <errno.h> // for EFAULT and co.
#include <iostream>
#include <sstream>
#ifdef WIN32
#else
  #include <cstring> // strerror
  #include <fcntl.h> // for non-blocking configuration
#endif

/*****************************************************************************
** Namespaces
*****************************************************************************/

namespace ros {

int last_socket_error() {
        #ifdef WIN32
                return WSAGetLastError();
        #else
                return errno;
        #endif
}
const char* last_socket_error_string() {
        #ifdef WIN32
                // could fix this to use FORMAT_MESSAGE and print a real string later,
                // but not high priority.
                std::stringstream ostream;
                ostream << "WSA Error: " << WSAGetLastError();
                return ostream.str().c_str();
        #else
                return strerror(errno);
        #endif
}

bool last_socket_error_is_would_block() {
#if defined(WIN32)
        if ( WSAGetLastError() == WSAEWOULDBLOCK ) {
                return true;
        } else {
                return false;
        }
#else
        if ( ( errno == EAGAIN  ) || ( errno == EWOULDBLOCK ) ) { // posix permits either
                return true;
        } else {
                return false;
        }
#endif
}

/*****************************************************************************
** Service Robotics/Libssh Functions
*****************************************************************************/
int poll_sockets(socket_pollfd *fds, nfds_t nfds, int timeout) {
#if defined(WIN32)
        fd_set readfds, writefds, exceptfds;
        struct timeval tv, *ptv;
        socket_fd_t max_fd;
        int rc;
        nfds_t i;

        if (fds == NULL) {
                errno = EFAULT;
                return -1;
        }

        FD_ZERO (&readfds);
        FD_ZERO (&writefds);
        FD_ZERO (&exceptfds);

        /*********************
        ** Compute fd sets
        **********************/
        // also find the largest descriptor.
        for (rc = -1, max_fd = 0, i = 0; i < nfds; i++) {
                if (fds[i].fd == INVALID_SOCKET) {
                        continue;
                }
                if (fds[i].events & (POLLIN | POLLRDNORM)) {
                        FD_SET (fds[i].fd, &readfds);
                }
                if (fds[i].events & (POLLOUT | POLLWRNORM | POLLWRBAND)) {
                        FD_SET (fds[i].fd, &writefds);
                }
                if (fds[i].events & (POLLPRI | POLLRDBAND)) {
                        FD_SET (fds[i].fd, &exceptfds);
                }
                if (fds[i].fd > max_fd &&
                          (fds[i].events & (POLLIN | POLLOUT | POLLPRI |
                                                                POLLRDNORM | POLLRDBAND |
                                                                POLLWRNORM | POLLWRBAND))) {
                        max_fd = fds[i].fd;
                        rc = 0;
                }
        }

        if (rc == -1) {
                errno = EINVAL;
                return -1;
        }
        /*********************
        ** Setting the timeout
        **********************/
        if (timeout < 0) {
                ptv = NULL;
        } else {
                ptv = &tv;
                if (timeout == 0) {
                        tv.tv_sec = 0;
                        tv.tv_usec = 0;
                } else {
                        tv.tv_sec = timeout / 1000;
                        tv.tv_usec = (timeout % 1000) * 1000;
                }
        }

        rc = select (max_fd + 1, &readfds, &writefds, &exceptfds, ptv);
        if (rc < 0) {
                return -1;
        } else if ( rc == 0 ) {
                return 0;
        }

        for (rc = 0, i = 0; i < nfds; i++) {
                if (fds[i].fd != INVALID_SOCKET) {
                        fds[i].revents = 0;

                        if (FD_ISSET(fds[i].fd, &readfds)) {
                                int save_errno = errno;
                                char data[64] = {0};
                                int ret;

                                /* support for POLLHUP */
                                // just check if there's incoming data, without removing it from the queue.
                                ret = recv(fds[i].fd, data, 64, MSG_PEEK);
                                #ifdef WIN32
                                if ((ret == -1) &&
                                                (errno == WSAESHUTDOWN || errno == WSAECONNRESET ||
                                                (errno == WSAECONNABORTED) || errno == WSAENETRESET))
                                #else
                                if ((ret == -1) &&
                                                (errno == ESHUTDOWN || errno == ECONNRESET ||
                                                (errno == ECONNABORTED) || errno == ENETRESET))
                                #endif
                                {
                                        fds[i].revents |= POLLHUP;
                                } else {
                                        fds[i].revents |= fds[i].events & (POLLIN | POLLRDNORM);
                                }
                                errno = save_errno;
                        }
                        if (FD_ISSET(fds[i].fd, &writefds)) {
                                fds[i].revents |= fds[i].events & (POLLOUT | POLLWRNORM | POLLWRBAND);
                        }

                        if (FD_ISSET(fds[i].fd, &exceptfds)) {
                                fds[i].revents |= fds[i].events & (POLLPRI | POLLRDBAND);
                        }

                        if (fds[i].revents & ~POLLHUP) {
                                rc++;
                        }
                } else {
                                fds[i].revents = POLLNVAL;
                }
        }
        return rc;
#else
        // use an existing poll implementation
        int result = poll(fds, nfds, timeout);
        if ( result < 0 ) {
                // EINTR means that we got interrupted by a signal, and is not an error
                if(errno == EINTR) {
                        result = 0;
                }
        }
        return result;
#endif // poll_sockets functions
}
/*****************************************************************************
** Socket Utilities
*****************************************************************************/
int set_non_blocking(socket_fd_t &socket) {
#ifdef WIN32
    u_long non_blocking = 1;
        if(ioctlsocket( socket, FIONBIO, &non_blocking ) != 0 )
        {
      return WSAGetLastError();
        }
#else
    if(fcntl(socket, F_SETFL, O_NONBLOCK) == -1)
    {
      return errno;
    }
#endif
    return 0;
}

int close_socket(socket_fd_t &socket) {
#ifdef WIN32
        if(::closesocket(socket) == SOCKET_ERROR ) {
                return -1;
        } else {
                return 0;
        }
#else
        if (::close(socket) < 0) {
                return -1;
        } else {
                return 0;
        }
#endif //WIN32
}

/*****************************************************************************
** Signal Pair
*****************************************************************************/
int create_signal_pair(signal_fd_t signal_pair[2]) {
#ifdef WIN32 // use a socket pair
        signal_pair[0] = INVALID_SOCKET;
        signal_pair[1] = INVALID_SOCKET;

    union {
       struct sockaddr_in inaddr;
       struct sockaddr addr;
    } a;
    socklen_t addrlen = sizeof(a.inaddr);

    /*********************
        ** Listen Socket
        **********************/
        socket_fd_t listen_socket = INVALID_SOCKET;
    listen_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
        if (listen_socket == INVALID_SOCKET) {
                return -1;
        }

    // allow it to be bound to an address already in use - do we actually need this?
    int reuse = 1;
    if (setsockopt(listen_socket, SOL_SOCKET, SO_REUSEADDR, (char*) &reuse, (socklen_t) sizeof(reuse)) == SOCKET_ERROR ) {
        ::closesocket(listen_socket);
                return -1;
    }

    memset(&a, 0, sizeof(a));
    a.inaddr.sin_family = AF_INET;
    a.inaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
    // For TCP/IP, if the port is specified as zero, the service provider assigns
    // a unique port to the application from the dynamic client port range.
    a.inaddr.sin_port = 0;

    if  (bind(listen_socket, &a.addr, sizeof(a.inaddr)) == SOCKET_ERROR) {
        ::closesocket(listen_socket);
                return -1;
    }
    // we need this below because the system auto filled in some entries, e.g. port #
    if  (getsockname(listen_socket, &a.addr, &addrlen) == SOCKET_ERROR) {
        ::closesocket(listen_socket);
                return -1;
    }
    // max 1 connection permitted
    if (listen(listen_socket, 1) == SOCKET_ERROR) {
        ::closesocket(listen_socket);
                return -1;
    }

    /*********************
        ** Connection
        **********************/
    // do we need io overlapping?
    // DWORD flags = (make_overlapped ? WSA_FLAG_OVERLAPPED : 0);
    DWORD overlapped_flag = 0;
    signal_pair[0] = WSASocket(AF_INET, SOCK_STREAM, 0, NULL, 0, overlapped_flag);
    if (signal_pair[0] == INVALID_SOCKET) {
        ::closesocket(listen_socket);
        ::closesocket(signal_pair[0]);
        return -1;
    }
    // reusing the information from above to connect to the listener
    if (connect(signal_pair[0], &a.addr, sizeof(a.inaddr)) == SOCKET_ERROR) {
        ::closesocket(listen_socket);
        ::closesocket(signal_pair[0]);
        return -1;
    }
    /*********************
        ** Accept
        **********************/
    signal_pair[1] = accept(listen_socket, NULL, NULL);
    if (signal_pair[1] == INVALID_SOCKET) {
        ::closesocket(listen_socket);
        ::closesocket(signal_pair[0]);
        ::closesocket(signal_pair[1]);
        return -1;
    }
        /*********************
        ** Nonblocking
        **********************/
    // should we do this or should we set io overlapping?
    if ( (set_non_blocking(signal_pair[0]) != 0) || (set_non_blocking(signal_pair[1]) != 0)  ) {
                ::closesocket(listen_socket);
                ::closesocket(signal_pair[0]);
                ::closesocket(signal_pair[1]);
        return -1;
    }
        /*********************
        ** Cleanup
        **********************/
    ::closesocket(listen_socket);  // the listener has done its job.
    return 0;
#else // use a pipe pair
        // initialize
        signal_pair[0] = -1;
        signal_pair[1] = -1;

        if(pipe(signal_pair) != 0) {
                ROS_FATAL( "pipe() failed");
                return -1;
        }
        if(fcntl(signal_pair[0], F_SETFL, O_NONBLOCK) == -1) {
                ROS_FATAL( "fcntl() failed");
                return -1;
        }
        if(fcntl(signal_pair[1], F_SETFL, O_NONBLOCK) == -1) {
                ROS_FATAL( "fcntl() failed");
                return -1;
        }
        return 0;
#endif // create_pipe
}

} // namespace ros