clnt_unix.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

static void
clntunix_geterr(h, errp)
	CLIENT *h;
	struct rpc_err *errp;
{
	register struct ct_data *ct =
	    (struct ct_data *) h->cl_private;

	*errp = ct->ct_error;
}

static bool_t
clntunix_freeres(cl, xdr_res, res_ptr)
	CLIENT *cl;
	xdrproc_t xdr_res;
	caddr_t res_ptr;
{
	register struct ct_data *ct = (struct ct_data *)cl->cl_private;
	register XDR *xdrs = &(ct->ct_xdrs);

	xdrs->x_op = XDR_FREE;
	return ((*xdr_res)(xdrs, res_ptr));
}

static void
clntunix_abort()
{
}


static bool_t
clntunix_control(cl, request, info)
	CLIENT *cl;
	int request;
	char *info;
{
	register struct ct_data *ct = (struct ct_data *)cl->cl_private;
	register struct timeval *tv;
	int len;

	switch (request) {
	case CLSET_FD_CLOSE:
		ct->ct_closeit = TRUE;
		break;
	case CLSET_FD_NCLOSE:
		ct->ct_closeit = FALSE;
		break;
	case CLSET_TIMEOUT:
		if (info == NULL)
			return(FALSE);
		tv = (struct timeval *)info;
		ct->ct_wait.tv_sec = tv->tv_sec;
		ct->ct_wait.tv_usec = tv->tv_usec;
		ct->ct_waitset = TRUE;
		break;
	case CLGET_TIMEOUT:
		if (info == NULL)
			return(FALSE);
		*(struct timeval *)info = ct->ct_wait;
		break;
	case CLGET_SERVER_ADDR:
		if (info == NULL)
			return(FALSE);
		*(struct sockaddr_un *)info = ct->ct_addr;
		break;
	case CLGET_FD:
		if (info == NULL)
			return(FALSE);
		*(int *)info = ct->ct_sock;
		break;
	case CLGET_XID:
		/*
		 * use the knowledge that xid is the
		 * first element in the call structure *.
		 * This will get the xid of the PREVIOUS call
		 */
		if (info == NULL)
			return(FALSE);
		*(u_long *)info = ntohl(*(u_long *)ct->ct_mcall);
		break;
	case CLSET_XID:
		/* This will set the xid of the NEXT call */
		if (info == NULL)
			return(FALSE);
		*(u_long *)ct->ct_mcall =  htonl(*(u_long *)info - 1);
		/* decrement by 1 as clntunix_call() increments once */
	case CLGET_VERS:
		/*
		 * This RELIES on the information that, in the call body,
		 * the version number field is the fifth field from the
		 * begining of the RPC header. MUST be changed if the
		 * call_struct is changed
		 */
		if (info == NULL)
			return(FALSE);
		*(u_long *)info = ntohl(*(u_long *)(ct->ct_mcall +
						4 * BYTES_PER_XDR_UNIT));
		break;
	case CLSET_VERS:
		if (info == NULL)
			return(FALSE);
		*(u_long *)(ct->ct_mcall + 4 * BYTES_PER_XDR_UNIT)
				= htonl(*(u_long *)info);
		break;
	case CLGET_PROG:
		/*
		 * This RELIES on the information that, in the call body,
		 * the program number field is the  field from the
		 * begining of the RPC header. MUST be changed if the
		 * call_struct is changed
		 */
		if (info == NULL)
			return(FALSE);
		*(u_long *)info = ntohl(*(u_long *)(ct->ct_mcall +
						3 * BYTES_PER_XDR_UNIT));
		break;
	case CLSET_PROG:
		if (info == NULL)
			return(FALSE);
		*(u_long *)(ct->ct_mcall + 3 * BYTES_PER_XDR_UNIT)
				= htonl(*(u_long *)info);
		break;
	case CLGET_LOCAL_ADDR:
		len = sizeof(struct sockaddr);
		if (getsockname(ct->ct_sock, (struct sockaddr *)info, &len) <0)
			return(FALSE);
		break;
	case CLGET_RETRY_TIMEOUT:
	case CLSET_RETRY_TIMEOUT:
	case CLGET_SVC_ADDR:
	case CLSET_SVC_ADDR:
	case CLSET_PUSH_TIMOD:
	case CLSET_POP_TIMOD:
	default:
		return (FALSE);
	}
	return (TRUE);
}


static void
clntunix_destroy(h)
	CLIENT *h;
{
	register struct ct_data *ct =
	    (struct ct_data *) h->cl_private;

	if (ct->ct_closeit) {
		(void)_RPC_close(ct->ct_sock);
	}
	XDR_DESTROY(&(ct->ct_xdrs));
	mem_free((caddr_t)ct, sizeof(struct ct_data));
	mem_free((caddr_t)h, sizeof(CLIENT));
}

/*
 * read() and write() are replaced with recvmsg()/sendmsg() so that
 * we can pass ancillary control data. In this case, the data constists
 * of credential information which the kernel will fill in for us.
 * XXX: This code is specific to FreeBSD and will not work on other
 * platforms without the requisite kernel modifications.
 */
struct cmessage {
	struct cmsghdr cmsg;
	struct cmsgcred cmcred;
};

static int __msgread(sock, buf, cnt)
	int sock;
	void *buf;
	size_t cnt;
{
	struct iovec iov[1];
	struct msghdr msg;
	struct cmessage cm;

	bzero((char *)&cm, sizeof(cm));
	iov[0].iov_base = buf;
	iov[0].iov_len = cnt;

	msg.msg_iov = iov;
	msg.msg_iovlen = 1;
	msg.msg_name = NULL;
	msg.msg_namelen = 0;
	msg.msg_control = (caddr_t)&cm;
	msg.msg_controllen = sizeof(struct cmessage);
	msg.msg_flags = 0;

	return(recvmsg(sock, &msg, 0));
}

static int __msgwrite(sock, buf, cnt)
	int sock;
	void *buf;
	size_t cnt;
{
	struct iovec iov[1];
	struct msghdr msg;
	struct cmessage cm;

	bzero((char *)&cm, sizeof(cm));
	iov[0].iov_base = buf;
	iov[0].iov_len = cnt;

	cm.cmsg.cmsg_type = SCM_CREDS;
	cm.cmsg.cmsg_level = SOL_SOCKET;
	cm.cmsg.cmsg_len = sizeof(struct cmessage);

	msg.msg_iov = iov;
	msg.msg_iovlen = 1;
	msg.msg_name = NULL;
	msg.msg_namelen = 0;
	msg.msg_control = (caddr_t)&cm;
	msg.msg_controllen = sizeof(struct cmessage);
	msg.msg_flags = 0;

	return(sendmsg(sock, &msg, 0));
}

/*
 * Interface between xdr serializer and unix connection.
 * Behaves like the system calls, read & write, but keeps some error state
 * around for the rpc level.
 */
static int
readunix(ct, buf, len)
	register struct ct_data *ct;
	caddr_t buf;
	register int len;
{
	fd_set *fds, readfds;
	struct timeval start, after, duration, delta, tmp, tv;
	int r, save_errno;

	if (len == 0)
		return (0);

	if (ct->ct_sock + 1 > FD_SETSIZE) {
		int bytes = howmany(ct->ct_sock + 1, NFDBITS) * sizeof(fd_mask);
		fds = (fd_set *)malloc(bytes);
		if (fds == NULL)
			return (-1);
		memset(fds, 0, bytes);
	} else {
		fds = &readfds;
		FD_ZERO(fds);
	}

	gettimeofday(&start, NULL);
	delta = ct->ct_wait;
	while (TRUE) {
		/* XXX we know the other bits are still clear */
		FD_SET(ct->ct_sock, fds);
		tv = delta;	/* in case select writes back */
		r = select(ct->ct_sock+1, fds, NULL, NULL, &tv);
		save_errno = errno;

		gettimeofday(&after, NULL);
		timersub(&start, &after, &duration);
		timersub(&delta, &duration, &tmp);
		delta = tmp;
		if (delta.tv_sec < 0 || !timerisset(&delta))
			r = 0;

		switch (r) {
		case 0:
			if (fds != &readfds)
				free(fds);
			ct->ct_error.re_status = RPC_TIMEDOUT;
			return (-1);

		case -1:
			if (errno == EINTR)
				continue;
			if (fds != &readfds)
				free(fds);
			ct->ct_error.re_status = RPC_CANTRECV;
			ct->ct_error.re_errno = save_errno;
			return (-1);
		}
		break;
	}
	switch (len = __msgread(ct->ct_sock, buf, len)) {

	case 0:
		/* premature eof */
		ct->ct_error.re_errno = ECONNRESET;
		ct->ct_error.re_status = RPC_CANTRECV;
		len = -1;  /* it's really an error */
		break;

	case -1:
		ct->ct_error.re_errno = errno;
		ct->ct_error.re_status = RPC_CANTRECV;
		break;
	}
	return (len);
}

static int
writeunix(ct, buf, len)
	struct ct_data *ct;
	caddr_t buf;
	int len;
{
	register int i, cnt;

	for (cnt = len; cnt > 0; cnt -= i, buf += i) {
		if ((i = __msgwrite(ct->ct_sock, buf, cnt)) == -1) {
			ct->ct_error.re_errno = errno;
			ct->ct_error.re_status = RPC_CANTSEND;
			return (-1);
		}
	}
	return (len);
}