Unix进程间SOCKET句柄传递-进程池应用

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/* test_fdpass.c */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include <unistd.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>

#include <sys/socket.h> /* for socketpair */

#define MY_LOGO       "-- Tony Bai"

static int send_fd(int fd, int fd_to_send)
{
      struct iovec iov[1];
      struct msghdr msg;
      char          buf[1];

      if (fd_to_send >= 0) {
            msg.msg_accrights    = (caddr_t)&fd_to_send;
            msg.msg_accrightslen = sizeof(int);
      } else {
            msg.msg_accrights    = (caddr_t)NULL;
            msg.msg_accrightslen = 0;
      }

      msg.msg_name = NULL;
      msg.msg_namelen = 0;

      iov[0].iov_base = buf;
      iov[0].iov_len  = 1;
      msg.msg_iov    = iov;
      msg.msg_iovlen  = 1;

      if(sendmsg(fd, &msg, 0) < 0) {
            printf("sendmsg error, errno is %d/n", errno);
            return errno;
      }

      return 0;
}

static int recv_fd(int fd, int *fd_to_recv)
{
      struct iovec iov[1];
      struct msghdr msg;
      char          buf[1];

      msg.msg_accrights    = (caddr_t)fd_to_recv;
      msg.msg_accrightslen = sizeof(int);

      msg.msg_name = NULL;
      msg.msg_namelen = 0;

      iov[0].iov_base = buf;
      iov[0].iov_len  = 1;
      msg.msg_iov    = iov;
      msg.msg_iovlen  = 1;

      if (recvmsg(fd, &msg, 0) < 0) {
            return errno;
      }

      if(msg.msg_accrightslen != sizeof(int)) {
            *fd_to_recv = -1;
      }

      return 0;
}

int x_sock_set_block(int sock, int on)
{
      int          val;
      int          rv;

      val = fcntl(sock, F_GETFL, 0);
      if (on) {
            rv = fcntl(sock, F_SETFL, ~O_NONBLOCK&val);
      } else {
            rv = fcntl(sock, F_SETFL, O_NONBLOCK|val);
      }

      if (rv) {
            return errno;
      }

      return 0;
}

int main() {
      pid_t pid;
      int    sockpair[2];
      int    rv;
      char fname[256];
      int    fd;

      rv = socketpair(AF_UNIX, SOCK_STREAM, 0, sockpair);
      if (rv < 0) {
            printf("Call socketpair error, errno is %d/n", errno);
            return errno;
      }

      pid = fork();
      if (pid == 0) {
            /* in child */
            close(sockpair[1]);

            for ( ; ; ) {
                     rv = x_sock_set_block(sockpair[0], 1);
                     if (rv != 0) {
                              printf("[CHILD]: x_sock_set_block error, errno is %d/n", rv);
                              break;
                     }

                     rv = recv_fd(sockpair[0], &fd);
                     if (rv < 0) {
                              printf("[CHILD]: recv_fd error, errno is %d/n", rv);
                              break;
                     }

                     if (fd < 0) {
                              printf("[CHILD]: child process exit normally!/n");
                              break;
                     }

                     /* 处理fd描述符对应的文件 */
                     rv = write(fd, MY_LOGO, strlen(MY_LOGO));
                     if (rv < 0) {
                              printf("[CHILD]: write error, errno is %d/n", rv);
                     } else {
                              printf("[CHILD]: append logo successfully/n");
                     }
                     close(fd);
            }

            exit(0);
      }

      /* in parent */
      for ( ; ; ) {
            memset(fname, 0, sizeof(fname));
            printf("[PARENT]: please enter filename:/n");
            scanf("%s", fname);

            if (strcmp(fname, "exit") == 0) {
                     rv = send_fd(sockpair[1], -1);
                     if (rv < 0) {
                              printf("[PARENT]: send_fd error, errno is %d/n", rv);
                     }
                     break;
            }

            fd = open(fname, O_RDWR | O_APPEND);
            if (fd < 0) {
                     if (errno == ENOENT) {
                              printf("[PARENT]: can't find file '%s'/n", fname);
                              continue;
                     }
                     printf("[PARENT]: open file error, errno is %d/n", errno);
            }

            rv = send_fd(sockpair[1], fd);
            if (rv != 0) {
                     printf("[PARENT]: send_fd error, errno is %d/n", rv);
            }

            close(fd);
      }

      wait(NULL);
      return 0;
}

=================================================================

Under Windows

int CSocketFunc::socketpair(int family, int socktype, int protocol, int fd[2])
{
#ifndef WIN32 //uninx/linux平台
return ::socketpair(AF_LOCAL, socktype, 0, fd);
#else //WIN32 平台
int listener;
struct sockaddr_in sockAdd = {0};
struct sockaddr_in sockAdd2 = {0};
int socklen = sizeof(sockAdd2);
long ltemp =1;

fd[0] = fd[1] = listener = -1;

if ((listener = (int)socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
goto FAILED;
memset(&sockAdd2, 0, sizeof(sockAdd2));
//sockAdd2.sin_addr.s_addr = ::htonl(INADDR_LOOPBACK);
sockAdd2.sin_family = family;

if(bind(listener, (struct sockaddr *)&sockAdd2, sizeof(sockAdd2)) !=0)
goto FAILED;

if (listen(listener, 1) != 0)
goto FAILED;

if (::getsockname(listener, (struct sockaddr *)&sockAdd, &socklen) != 0)
goto FAILED;

if ((fd[1] = (int)socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
goto FAILED;

//设置为非阻塞模式
ltemp =1;
ioctlsocket(fd[1], FIONBIO, (u_long *)&ltemp);

sockAdd.sin_addr.s_addr = ::htonl(INADDR_LOOPBACK);

if (connect(fd[1], (struct sockaddr *)&sockAdd, sizeof(sockAdd)) == -1)
{
if ((ltemp = WSAGetLastError()) != WSAEWOULDBLOCK
&& ltemp != WSAEINPROGRESS )
goto FAILED;
}

if ((fd[0] =(int)accept(listener, (struct sockaddr *)&sockAdd2, &socklen)) == -1)
goto FAILED;

//设置回为阻塞模式
ltemp =0;
ioctlsocket(fd[1], FIONBIO, (u_long *)&ltemp);

closesocket(listener);

// all OK!
return 0;

FAILED:
if (fd[0] != -1) closesocket(fd[0]);
if (fd[1] != -1) closesocket(fd[1]);
if (listener != -1) closesocket(listener);
return -1;

#endif // WIN32
}