#include <stdio.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <linux/un.h>

int main(int argc, char* argv[]) {
	int fd_unix;
	int fd_inet;
	struct sockaddr_un unaddr;
	struct sockaddr_in inetaddr;
	struct sockaddr_un clnt;
	socklen_t clntlen;
	int err;

	clnt.sun_family = AF_UNIX;
	strcpy(clnt.sun_path, "/tmp/ncpfsdir");
	clntlen = sizeof(clnt);

	fd_unix = socket(PF_UNIX, SOCK_DGRAM, 0);
	if (fd_unix == -1) {
		perror("socket(PF_UNIX, SOCK_DGRAM, 0)");
		return 1;
	}
	fd_inet = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
	if (fd_inet == -1) {
		perror("socket(PF_INET, SOCK_DGRAM, 0)");
		return 1;
	}
	{
		int val = 1;
		
		if (setsockopt(fd_unix, SOL_SOCKET, SO_PASSCRED, &val, sizeof(val)) == -1) {
			perror("setsockopt(unix, SOL_SOCKET, SO_PASSCRED, &1, sizeof(int))");
			return 1;
		}
	}
	unaddr.sun_family = AF_UNIX;
	memcpy(unaddr.sun_path, "\000ncpfs", 2 + 1 + 5);
	err = bind(fd_unix, (struct sockaddr*)&unaddr, 2 + 1 + 5);
	if (err) {
		perror("bind(unix, &(@ncpfs), x)");
		return 1;
	}
	inetaddr.sin_family = AF_INET;
	inetaddr.sin_port = htons(0);
	inetaddr.sin_addr.s_addr = htonl(INADDR_ANY);
	err = bind(fd_inet, (struct sockaddr*)&inetaddr, sizeof(inetaddr));
	if (err) {
		perror("bind(inet, &INADDR_ANY, x)");
		return 1;
	}
	inetaddr.sin_port = htons(524);
	inetaddr.sin_addr.s_addr = htonl(0xC0A81A05);
	err = connect(fd_inet, (struct sockaddr*)&inetaddr, sizeof(inetaddr));
	if (err) {
		perror("connect(inet, &192.168.26.5, x)");
		return 1;
	}
	while (1) {
		fd_set rset;
		int ret;

		FD_ZERO(&rset);
		FD_SET(fd_unix, &rset);
		FD_SET(fd_inet, &rset);
		ret = select(fd_inet + 1, &rset, NULL, NULL, NULL);
		printf("Select returned %d\n", ret);
		if (ret < 0) {
			perror("Select");
		} else if (ret > 0) {
			if (FD_ISSET(fd_unix, &rset)) {
				unsigned char buffer[2000];
				struct msghdr msg;
				unsigned char ctrl[2000];
				struct iovec io[1];
				
				msg.msg_name = &clnt;
				msg.msg_namelen = sizeof(clnt);
				msg.msg_control = ctrl;
				msg.msg_controllen = sizeof(ctrl);
				msg.msg_flags = 0;
				msg.msg_iovlen = 1;
				msg.msg_iov = io;
				io[0].iov_base = buffer;
				io[0].iov_len = sizeof(buffer);
				
				ret = recvmsg(fd_unix, &msg, MSG_DONTWAIT);
				if (ret < 0) {
					perror("UNIX false alarm");
				} else if (ret == 0) {
					perror("UNIX zero data");
				} else {
					struct cmsghdr* cmsg;
					
					clntlen = msg.msg_namelen;
					printf("%d bytes received from UNIX...\n", ret);
					printf("%d bytes cmsg data\n", msg.msg_controllen);
					printf("%d bytes name data\n", msg.msg_namelen);
					printf("%08X flags\n", msg.msg_flags);
					
					for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
						printf("cmsg len/level/type: %d/%d/%d\n",
							cmsg->cmsg_len, cmsg->cmsg_level, cmsg->cmsg_type);
						if ((cmsg->cmsg_level == SOL_SOCKET) && (cmsg->cmsg_type == SCM_CREDENTIALS)) {
							struct ucred * cred = (struct ucred*)CMSG_DATA(cmsg);
							
							printf("PID=%u, UID=%u, GID=%u\n", cred->pid, cred->uid, cred->gid);
						}
					}
					
					ret = send(fd_inet, buffer, ret, 0);
					if (ret < 0)
						perror("INET send");
				}
			}
			if (FD_ISSET(fd_inet, &rset)) {
				struct sockaddr_in unaddr2;
				socklen_t alen;
				unsigned char buffer[2000];

				alen = sizeof(unaddr2);
				ret = recvfrom(fd_inet, buffer, sizeof(buffer), MSG_DONTWAIT, (struct sockaddr*)&unaddr, &alen);
				if (ret < 0) {
					perror("INET false alarm");
				} else if (ret == 0) {
					perror("INET zero data");
				} else {
					printf("%d bytes received from network...\n", ret);
					ret = sendto(fd_unix, buffer, ret, 0, (struct sockaddr*)&clnt, clntlen);
					if (ret < 0)
						perror("UNIX send");
				}
			}
		}
	}

}