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group-ipc.cc

/*
 * Copyright (c) 1991-1994 Regents of the University of California.
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and the Network Research Group at
 *      Lawrence Berkeley Laboratory.
 * 4. Neither the name of the University nor of the Laboratory may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 lint
static const char rcsid[] =
    "@(#) $Header: group-ipc.cc,v 1.21 96/02/06 14:43:30 mccanne Exp $ (LBL)";
#endif

#ifndef WIN32
#include <unistd.h>
#endif
#include <stdlib.h>
#include <string.h>
#ifdef WIN32
#include <winsock.h>
#define close closesocket
#else
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/uio.h>
#endif
#include <fcntl.h>

#include "group-ipc.h"

#define GROUP_IPC_ADDR 0xe0ffdeef
#define GROUP_IPC_PORT 0xdeaf

static void nonblock(int fd)
{       
#ifdef WIN32
      u_long flag = 1;
      if (ioctlsocket(fd, FIONBIO, &flag) == -1) {
            fprintf(stderr, "ioctlsocket: FIONBIO: %lu\n", GetLastError());
            exit(1);
      }
#else
       int flags = fcntl(fd, F_GETFL, 0);
#if defined(hpux) || defined(__hpux)
        flags |= O_NONBLOCK;
#else
        flags |= O_NONBLOCK|O_NDELAY;
#endif
        if (fcntl(fd, F_SETFL, flags) == -1) {
                perror("fcntl: F_SETFL");
                exit(1);
        }
#endif
}

IPCHandler::IPCHandler(int mask) : mask_(mask) { }

#ifdef IP_ADD_MEMBERSHIP
GroupIPC::GroupIPC(int channel) : handlers_(0)
{
      rsock_ = socket(AF_INET, SOCK_DGRAM, 0);
      if (rsock_ < 0) {
            perror("socket");
            exit(1);
      }
      int on = 1;
      if (setsockopt(rsock_, SOL_SOCKET, SO_REUSEADDR, (char *)&on,
                   sizeof(on)) < 0) {
            perror("SO_REUSEADDR");
            exit(1);
      }
#ifdef SO_REUSEPORT
      on = 1;
      if (setsockopt(rsock_, SOL_SOCKET, SO_REUSEPORT, (char *)&on,
                   sizeof(on)) < 0) {
            perror("SO_REUSEPORT");
            exit(1);
      }
#endif
      sockaddr_in sin;
      memset((char *)&sin, 0, sizeof(sin));
      sin.sin_family = AF_INET;
      int port = htons(GROUP_IPC_PORT + channel);
      sin.sin_port = port;
      sin.sin_addr.s_addr = htonl(GROUP_IPC_ADDR);
      if (bind(rsock_, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
            sin.sin_addr.s_addr = INADDR_ANY;
            if (bind(rsock_, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
                  perror("GroupIPC bind");
                  close(rsock_);
                  rsock_ = -1;
                  ssock_ = -1;
            }
      }
      if (rsock_ >= 0) {
            nonblock(rsock_);

            struct ip_mreq mr;
            mr.imr_multiaddr.s_addr = htonl(GROUP_IPC_ADDR);
            mr.imr_interface.s_addr = htonl(INADDR_LOOPBACK);
            if (setsockopt(rsock_, IPPROTO_IP, IP_ADD_MEMBERSHIP, 
                         (char *)&mr, sizeof(mr)) < 0) {
                  /*
                   * host probably doesn't have multicast
                   */
                  close(rsock_);
                  rsock_ = -1;
                  ssock_ = -1;
            }
      } 
      if (rsock_ >= 0) {
            link(rsock_, TK_READABLE);
            ssock_ = socket(AF_INET, SOCK_DGRAM, 0);
            if (ssock_ < 0) {
                  perror("GroupIPC socket");
                  exit(1);
            }
            sin.sin_port = 0;
            sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
            if (bind(ssock_, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
                  perror("GroupIPC bind");
                  exit(1);
            }
            sin.sin_port = port;
            sin.sin_addr.s_addr = htonl(GROUP_IPC_ADDR);
            if (connect(ssock_, (struct sockaddr*)&sin, sizeof(sin)) < 0) {
                  perror("GroupIPC connect");
                  exit(1);
            }
            char ttl = 0;
            if (setsockopt(ssock_, IPPROTO_IP, IP_MULTICAST_TTL,
                         &ttl, 1) < 0) {
                  perror("GroupIPC: IP_MULTICAST_TTL");
                  exit(1);
            }
            u_int32_t addr = htonl(INADDR_LOOPBACK);
            if (setsockopt(ssock_, IPPROTO_IP, IP_MULTICAST_IF,
                        (char *)&addr, 4) < 0) {
                  perror("GroupIPC: IP_MULTICAST_IF");
                  exit(1);
            }
#ifdef ultrix
            ttl = 1;
            if (setsockopt(ssock_, IPPROTO_IP, IP_MULTICAST_LOOP,
                        &ttl, 1) < 0) {
                  perror("GroupIPC: IP_MULTICAST_LOOP");
                  exit(1);
            }
#endif
      }
      pid_ = getpid();
}
#else
GroupIPC::GroupIPC(int channel) : handlers_(0), rsock_(-1), ssock_(-1)
{
}
#endif

GroupIPC::~GroupIPC()
{
      if (rsock_ >= 0)
            (void)close(rsock_);
      if (ssock_ >= 0)
            (void)close(ssock_);
}

void GroupIPC::send(int type, int len)
{
      ipchdr* h = (ipchdr*)buffer_;
      h->type = type;
      h->pid = pid_;
      h->magic = GIPC_MAGIC;
      len += sizeof(*h);
      if (ssock_ >= 0 && ::send(ssock_, (char*)buffer_, len, 0) < 0)
            perror("GroupIPC send");
}

void GroupIPC::send(int type, const char* msg)
{
      strcpy((char*)buffer(), msg);
      /* include null terminator */
      send(type, strlen(msg) + 1);
}

void GroupIPC::attach(IPCHandler *h)
{
      h->next_ = handlers_;
      handlers_ = h;
}

void GroupIPC::dispatch(int)
{
      int cc = recv(rsock_, (char*)buffer_, sizeof(buffer_), 0);
      if (cc < 0) {
            perror("GroupIPC: recv");
            return;
      }
      cc -= sizeof(ipchdr);
      if (cc < 0)
            return;

      ipchdr* h = (ipchdr*)buffer_;
      if (h->pid == pid_)
            return;
            
      int bit = 1 << h->type;
      for (IPCHandler* p = handlers_; p != 0; p = p->next_) {
            if (p->mask() & bit)
                  p->ipc_input(h->type, h->pid, (u_char*)(h + 1), cc);
      }
}

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