text: // Copyright 2017-2019 VMware, Inc.
  // SPDX-License-Identifier: BSD-2-Clause
  //
  // The BSD-2 license (the License) set forth below applies to all parts of the
  // Cascade project.  You may not use this file except in compliance with the
  // License.
  //
  // BSD-2 License
  //
  // 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.
  //
  // 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 HOLDER 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.
  
  #ifndef CASCADE_SRC_COMMON_SOCKSTREAM_H
  #define CASCADE_SRC_COMMON_SOCKSTREAM_H
  
  #include <arpa/inet.h>
  #include <cstring>
  #include <fcntl.h>
  #include <netinet/in.h>
  #include <sys/socket.h>
  #include <sys/un.h>
  #include <unistd.h>
  #include "common/fdstream.h"
  
  namespace cascade {
  
  // This class is a specialized instance of an fdsrream which is used to
  // encapsulate the behavior of a TCP or UNIX Domain socket.
  
  class sockstream : public fdstream {
    public:
      sockstream(int fd, uint32_t gid = 0);
      sockstream(uint32_t gid, const char* path);
      sockstream(const char* host, uint32_t port, uint32_t gid = 0);
      ~sockstream() override;
  
      // Returns true if an error occurred while creating this socket
      bool error() const;
      // Returns true if the file descriptor underlying this socket is valid
      bool valid() const;
      // Returns the file descriptor underlying this socket
      int descriptor() const;
  
    private:
      int raw_fd(int fd);
      int unix_sock(const char* path);
      int inet_sock(const char* host, uint32_t port);
      int fd_;
  };
  
  inline sockstream::sockstream(int fd, uint32_t gid) : fdstream(raw_fd(fd), gid) { }
  
  inline sockstream::sockstream(uint32_t gid, const char* path) : fdstream(unix_sock(path), gid) { }
  
  inline sockstream::sockstream(const char* host, uint32_t port, uint32_t gid) : fdstream(inet_sock(host, port), gid) { }
  
  inline sockstream::~sockstream() {
    if (fd_ != -1) {
      flush();
      ::close(fd_);
    }
  }
  
  inline bool sockstream::error() const {
    return fd_ == -1;
  }
  
  inline bool sockstream::valid() const {
    errno = 0;
    return (fcntl(fd_, F_GETFD) != -1) || (errno != EBADF);
  }
  
  inline int sockstream::descriptor() const {
    return fd_;
  }
  
  inline int sockstream::raw_fd(int fd) {
    fd_ = fd;
    return fd_;
  }
  
  inline int sockstream::unix_sock(const char* path) {
    struct sockaddr_un dest;
    bzero(&dest, sizeof(dest));
    dest.sun_family = AF_UNIX;
    strncpy(dest.sun_path, path, sizeof(dest.sun_path)-1);
  
    fd_ = socket(AF_UNIX, SOCK_STREAM, 0);
    if ((fd_ != -1) && (::connect(fd_, (struct sockaddr*)&dest, sizeof(dest)) != 0)) {
      ::close(fd_);
      fd_ = -1;
    }
    return fd_;
  }
  
  inline int sockstream::inet_sock(const char* host, uint32_t port) {
    struct sockaddr_in dest;
    bzero(&dest, sizeof(dest));
    dest.sin_family = AF_INET;
    dest.sin_port = htons(port);
    inet_aton(host, (in_addr*) &dest.sin_addr.s_addr);
  
    fd_ = socket(AF_INET, SOCK_STREAM, 0);
    if ((fd_ != -1) && (::connect(fd_, (struct sockaddr*)&dest, sizeof(dest)) != 0)) {
      ::close(fd_);
      fd_ = -1;
    }
    return fd_;
  }
  
  } // namespace cascade
  
  #endif
  