|
#include <sys/socket.h>
|
|
#include <sys/uio.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
|
|
main(argc, argv)
|
|
int argc;
|
|
char **argv;
|
|
{
|
|
int i;
|
|
int j[2];
|
|
|
|
socketpair(AF_UNIX, SOCK_STREAM, 0, j);
|
|
|
|
i = fork();
|
|
if (i == 0) {
|
|
close(0);
|
|
close(1);
|
|
close(2);
|
|
|
|
int mysecretfd = recvfd(j[0]);
|
|
write(mysecretfd, "hello\n", 7);
|
|
} else {
|
|
sendfd(j[1], 1);
|
|
|
|
pause();
|
|
}
|
|
|
|
}
|
|
|
|
int
|
|
sendfd(int s, int fd)
|
|
{
|
|
char buf[1];
|
|
struct iovec iov;
|
|
struct msghdr msg;
|
|
struct cmsghdr *cmsg;
|
|
int n;
|
|
char cms[CMSG_SPACE(sizeof(int))];
|
|
|
|
buf[0] = 0;
|
|
iov.iov_base = buf;
|
|
iov.iov_len = 1;
|
|
|
|
memset(&msg, 0, sizeof msg);
|
|
msg.msg_iov = &iov;
|
|
msg.msg_iovlen = 1;
|
|
msg.msg_control = (caddr_t)cms;
|
|
msg.msg_controllen = CMSG_LEN(sizeof(int));
|
|
|
|
cmsg = CMSG_FIRSTHDR(&msg);
|
|
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
|
|
cmsg->cmsg_level = SOL_SOCKET;
|
|
cmsg->cmsg_type = SCM_RIGHTS;
|
|
memmove(CMSG_DATA(cmsg), &fd, sizeof(int));
|
|
|
|
if((n=sendmsg(s, &msg, 0)) != iov.iov_len)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
recvfd(int s)
|
|
{
|
|
int n;
|
|
int fd;
|
|
char buf[1];
|
|
struct iovec iov;
|
|
struct msghdr msg;
|
|
struct cmsghdr *cmsg;
|
|
char cms[CMSG_SPACE(sizeof(int))];
|
|
|
|
iov.iov_base = buf;
|
|
iov.iov_len = 1;
|
|
|
|
memset(&msg, 0, sizeof msg);
|
|
msg.msg_name = 0;
|
|
msg.msg_namelen = 0;
|
|
msg.msg_iov = &iov;
|
|
msg.msg_iovlen = 1;
|
|
|
|
msg.msg_control = (caddr_t)cms;
|
|
msg.msg_controllen = sizeof cms;
|
|
|
|
if((n=recvmsg(s, &msg, 0)) < 0)
|
|
return -1;
|
|
if(n == 0){
|
|
return -1;
|
|
}
|
|
cmsg = CMSG_FIRSTHDR(&msg);
|
|
memmove(&fd, CMSG_DATA(cmsg), sizeof(int));
|
|
return fd;
|
|
}
|