#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <sys/un.h>
#include <sys/socket.h>
#include <errno.h>
#include <signal.h>
#include <assert.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <fcntl.h>
#include <sys/time.h>

#define TESTSTRING "This is a test string write into the file\n"

int write_fd(int socketfd, int sendfd) 
{
	struct msghdr msg;
	struct iovec  iov[1];
	char          c;
	union {
		struct cmsghdr cm;
		char           control[CMSG_SPACE(sizeof(int))];
	} control_un;
	struct cmsghdr *cmptr;
	
	msg.msg_control = control_un.control;
	msg.msg_controllen = sizeof(control_un.control);
	
	cmptr = CMSG_FIRSTHDR(&msg);
	cmptr->cmsg_len = CMSG_LEN(sizeof(int));
	cmptr->cmsg_level = SOL_SOCKET;
	cmptr->cmsg_type = SCM_RIGHTS;
	*((int *) CMSG_DATA(cmptr)) = sendfd;
	
	msg.msg_name = NULL;
	msg.msg_namelen = 0;
	c = 'T';
	
	iov[0].iov_base = &c;
	iov[0].iov_len = sizeof(c);
	msg.msg_iov = iov;
	msg.msg_iovlen = 1;
	
	return sendmsg(socketfd, &msg, 0);
}

int read_fd(int socketfd, int *recvfd)
{
	struct msghdr msg;
	struct iovec iov[1];
	ssize_t      n;
	char         c;
	union {
		struct cmsghdr cm;
//		char           control[CMSG_SPACE(sizeof(int))];
		char           control[256];
	} control_un;
	struct cmsghdr *cmptr;
	
	msg.msg_control = control_un.control;
	msg.msg_controllen = sizeof(control_un.control);
	msg.msg_name = NULL;
	msg.msg_namelen = 0;
	/* XXX Do we have to stuff this? */
	iov[0].iov_base = &c;
	iov[0].iov_len  = sizeof(c);
	msg.msg_iov = iov;
	msg.msg_iovlen = 1;
	
	if ((n = recvmsg(socketfd, &msg, 0)) <= 0) {
		printf("n = %d, errno=%d\n", n, errno);
		return n;
	}
	
	if ((cmptr = CMSG_FIRSTHDR(&msg)) != NULL &&
		(cmptr->cmsg_len == CMSG_LEN(sizeof(int)))) {
		if(cmptr->cmsg_level != SOL_SOCKET) {
			printf("cmsg_level != SOL_SOCKET");
			return -1;
		}
		if(cmptr->cmsg_type != SCM_RIGHTS) {
			printf("cmsg_level != SOL_SOCKET");
			return -1;
		}
	
		*recvfd = *((int *)CMSG_DATA(cmptr));
	} else {
		printf("cmptr = %p\n", cmptr);
		if (cmptr) {
			printf("cmptr->cmsg_len = %d\n", cmptr->cmsg_len);
		}
		*recvfd = -1;
	}	
	
	return n;
}

int main(int argc, char *argv[], char* envp[])
{
	struct sockaddr_un  servaddr,cliaddr;
	int                 len,rc,status,len1,len2;
	int                 sockfd,sockfd2,connfd,filefd,child,fail,errsave;
	char                *path="/tmp/tfsocket";
	char 				*filepath="/dev/shmem/tmp";
	unsigned char buf[128];

	memset(buf,0,sizeof(buf));
	
	sockfd = socket(AF_LOCAL, SOCK_STREAM, 0);
	assert(sockfd >= 0);
	
	unlink(path);
	memset(&servaddr, 0, sizeof(servaddr));
	servaddr.sun_family = AF_LOCAL;
	strncpy(servaddr.sun_path, path, sizeof(servaddr.sun_path) - 1);
	
	rc=bind(sockfd, (struct sockaddr *)&servaddr, SUN_LEN(&servaddr));
	assert(rc==0);
	
	rc=listen(sockfd, 4);	
	assert(rc!=-1);
	
	child=fork();
	assert(child!=-1);
	if (child == 0) 
	{
		fail=0;
		filefd=-1;
		
		// children connect to UDS and receive
		sockfd2 = socket(AF_LOCAL, SOCK_STREAM, 0);
		assert(sockfd2>=0);
		
		memset(&servaddr, 0, sizeof(servaddr));
		servaddr.sun_family = AF_LOCAL;
		strncpy(servaddr.sun_path, path, sizeof(servaddr.sun_path) - 1);
		rc=connect(sockfd2, (struct sockaddr *)&servaddr, SUN_LEN(&servaddr));
		assert(rc!=-1);

		//Once we have a connection try to read in a fd
		rc=read_fd(sockfd2,&filefd);
		if (rc==-1) {
			printf("read_fd() failed\n");
			exit(1);
		}
		if (filefd==-1) {
			printf("Returned -1 for fd\n");
			exit(1);
		}
		
		if (write(filefd,TESTSTRING,strlen(TESTSTRING)+1)!=-1) {
			fail++;
		}
		if (read(filefd,buf,10)==-1) {
			fail++;
		}

		exit(fail);
	}
	
	//the parent
	unlink(filepath);
	filefd=open("/dev/shmem/test", O_RDONLY|O_CREAT,S_IRUSR|S_IWUSR);
	assert(filefd!=-1);

	len=sizeof(cliaddr);
	connfd=accept(sockfd,(struct sockaddr *)&cliaddr, &len);
	
	//once we have a connetion, write the fd out to it
	write_fd(connfd,filefd);

	//Now wait fo r the child	
	rc=waitpid(child, &status, 0);
	assert(rc==child);
	
	if ((WIFEXITED(status)) && (WEXITSTATUS(status)==0)){
		printf("The test is passed\n");
	} else {
		printf("The test is failed\n");
	}
	
	//And close the fds
	close(sockfd);
	close(connfd);
	close(filefd);
	
	exit(0);
}