clnt.c

Linux Kernel 2.6.9 for OMAP1710

	if (task->tk_rqstp) {
		printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
				__FUNCTION__, status);
		xprt_release(task);
	}

	switch (status) {
	case -EAGAIN:	/* woken up; retry */
		task->tk_action = call_reserve;
		return;
	case -EIO:	/* probably a shutdown */
		break;
	default:
		printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
				__FUNCTION__, status);
		break;
	}
	rpc_exit(task, status);
}

/*
 * 2.	Allocate the buffer. For details, see sched.c:rpc_malloc.
 *	(Note: buffer memory is freed in rpc_task_release).
 */
static void
call_allocate(struct rpc_task *task)
{
	unsigned int	bufsiz;

	dprintk("RPC: %4d call_allocate (status %d)\n", 
				task->tk_pid, task->tk_status);
	task->tk_action = call_bind;
	if (task->tk_buffer)
		return;

	/* FIXME: compute buffer requirements more exactly using
	 * auth->au_wslack */
	bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;

	if (rpc_malloc(task, bufsiz << 1) != NULL)
		return;
	printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task); 

	if (RPC_IS_ASYNC(task) || !(task->tk_client->cl_intr && signalled())) {
		xprt_release(task);
		task->tk_action = call_reserve;
		rpc_delay(task, HZ>>4);
		return;
	}

	rpc_exit(task, -ERESTARTSYS);
}

/*
 * 3.	Encode arguments of an RPC call
 */
static void
call_encode(struct rpc_task *task)
{
	struct rpc_clnt	*clnt = task->tk_client;
	struct rpc_rqst	*req = task->tk_rqstp;
	struct xdr_buf *sndbuf = &req->rq_snd_buf;
	struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
	unsigned int	bufsiz;
	kxdrproc_t	encode;
	int		status;
	u32		*p;

	dprintk("RPC: %4d call_encode (status %d)\n", 
				task->tk_pid, task->tk_status);

	/* Default buffer setup */
	bufsiz = task->tk_bufsize >> 1;
	sndbuf->head[0].iov_base = (void *)task->tk_buffer;
	sndbuf->head[0].iov_len  = bufsiz;
	sndbuf->tail[0].iov_len  = 0;
	sndbuf->page_len	 = 0;
	sndbuf->len		 = 0;
	sndbuf->buflen		 = bufsiz;
	rcvbuf->head[0].iov_base = (void *)((char *)task->tk_buffer + bufsiz);
	rcvbuf->head[0].iov_len  = bufsiz;
	rcvbuf->tail[0].iov_len  = 0;
	rcvbuf->page_len	 = 0;
	rcvbuf->len		 = 0;
	rcvbuf->buflen		 = bufsiz;

	/* Encode header and provided arguments */
	encode = task->tk_msg.rpc_proc->p_encode;
	if (!(p = call_header(task))) {
		printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
		rpc_exit(task, -EIO);
		return;
	}
	if (encode && (status = rpcauth_wrap_req(task, encode, req, p,
						 task->tk_msg.rpc_argp)) < 0) {
		printk(KERN_WARNING "%s: can't encode arguments: %d\n",
				clnt->cl_protname, -status);
		rpc_exit(task, status);
	}
}

/*
 * 4.	Get the server port number if not yet set
 */
static void
call_bind(struct rpc_task *task)
{
	struct rpc_clnt	*clnt = task->tk_client;
	struct rpc_xprt *xprt = clnt->cl_xprt;

	dprintk("RPC: %4d call_bind xprt %p %s connected\n", task->tk_pid,
			xprt, (xprt_connected(xprt) ? "is" : "is not"));

	task->tk_action = (xprt_connected(xprt)) ? call_transmit : call_connect;

	if (!clnt->cl_port) {
		task->tk_action = call_connect;
		task->tk_timeout = RPC_CONNECT_TIMEOUT;
		rpc_getport(task, clnt);
	}
}

/*
 * 4a.	Connect to the RPC server (TCP case)
 */
static void
call_connect(struct rpc_task *task)
{
	struct rpc_clnt *clnt = task->tk_client;

	dprintk("RPC: %4d call_connect status %d\n",
				task->tk_pid, task->tk_status);

	if (xprt_connected(clnt->cl_xprt)) {
		task->tk_action = call_transmit;
		return;
	}
	task->tk_action = call_connect_status;
	if (task->tk_status < 0)
		return;
	xprt_connect(task);
}

/*
 * 4b. Sort out connect result
 */
static void
call_connect_status(struct rpc_task *task)
{
	struct rpc_clnt *clnt = task->tk_client;
	int status = task->tk_status;

	task->tk_status = 0;
	if (status >= 0) {
		clnt->cl_stats->netreconn++;
		task->tk_action = call_transmit;
		return;
	}

	/* Something failed: we may have to rebind */
	if (clnt->cl_autobind)
		clnt->cl_port = 0;
	switch (status) {
	case -ENOTCONN:
	case -ETIMEDOUT:
	case -EAGAIN:
		task->tk_action = (clnt->cl_port == 0) ? call_bind : call_connect;
		break;
	default:
		rpc_exit(task, -EIO);
	}
}

/*
 * 5.	Transmit the RPC request, and wait for reply
 */
static void
call_transmit(struct rpc_task *task)
{
	dprintk("RPC: %4d call_transmit (status %d)\n", 
				task->tk_pid, task->tk_status);

	task->tk_action = call_status;
	if (task->tk_status < 0)
		return;
	task->tk_status = xprt_prepare_transmit(task);
	if (task->tk_status != 0)
		return;
	/* Encode here so that rpcsec_gss can use correct sequence number. */
	if (!task->tk_rqstp->rq_bytes_sent)
		call_encode(task);
	if (task->tk_status < 0)
		return;
	xprt_transmit(task);
	if (task->tk_status < 0)
		return;
	if (!task->tk_msg.rpc_proc->p_decode) {
		task->tk_action = NULL;
		rpc_wake_up_task(task);
	}
}

/*
 * 6.	Sort out the RPC call status
 */
static void
call_status(struct rpc_task *task)
{
	struct rpc_clnt	*clnt = task->tk_client;
	struct rpc_rqst	*req = task->tk_rqstp;
	int		status;

	if (req->rq_received > 0 && !req->rq_bytes_sent)
		task->tk_status = req->rq_received;

	dprintk("RPC: %4d call_status (status %d)\n", 
				task->tk_pid, task->tk_status);

	status = task->tk_status;
	if (status >= 0) {
		task->tk_action = call_decode;
		return;
	}

	task->tk_status = 0;
	switch(status) {
	case -ETIMEDOUT:
		task->tk_action = call_timeout;
		break;
	case -ECONNREFUSED:
	case -ENOTCONN:
		req->rq_bytes_sent = 0;
		if (clnt->cl_autobind)
			clnt->cl_port = 0;
		task->tk_action = call_bind;
		break;
	case -EAGAIN:
		task->tk_action = call_transmit;
		break;
	case -EIO:
		/* shutdown or soft timeout */
		rpc_exit(task, status);
		break;
	default:
		if (clnt->cl_chatty)
			printk("%s: RPC call returned error %d\n",
			       clnt->cl_protname, -status);
		rpc_exit(task, status);
		break;
	}
}

/*
 * 6a.	Handle RPC timeout
 * 	We do not release the request slot, so we keep using the
 *	same XID for all retransmits.
 */
static void
call_timeout(struct rpc_task *task)
{
	struct rpc_clnt	*clnt = task->tk_client;

	if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
		dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
		goto retry;
	}

	dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
	if (RPC_IS_SOFT(task)) {
		if (clnt->cl_chatty)
			printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
				clnt->cl_protname, clnt->cl_server);
		rpc_exit(task, -EIO);
		return;
	}

	if (clnt->cl_chatty && !(task->tk_flags & RPC_CALL_MAJORSEEN)) {
		task->tk_flags |= RPC_CALL_MAJORSEEN;
		printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
			clnt->cl_protname, clnt->cl_server);
	}
	if (clnt->cl_autobind)
		clnt->cl_port = 0;

retry:
	clnt->cl_stats->rpcretrans++;
	task->tk_action = call_bind;
	task->tk_status = 0;
}

/*
 * 7.	Decode the RPC reply
 */
static void
call_decode(struct rpc_task *task)
{
	struct rpc_clnt	*clnt = task->tk_client;
	struct rpc_rqst	*req = task->tk_rqstp;
	kxdrproc_t	decode = task->tk_msg.rpc_proc->p_decode;
	u32		*p;

	dprintk("RPC: %4d call_decode (status %d)\n", 
				task->tk_pid, task->tk_status);

	if (clnt->cl_chatty && (task->tk_flags & RPC_CALL_MAJORSEEN)) {
		printk(KERN_NOTICE "%s: server %s OK\n",
			clnt->cl_protname, clnt->cl_server);
		task->tk_flags &= ~RPC_CALL_MAJORSEEN;
	}

	if (task->tk_status < 12) {
		if (!RPC_IS_SOFT(task)) {
			task->tk_action = call_bind;
			clnt->cl_stats->rpcretrans++;
			goto out_retry;
		}
		printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
			clnt->cl_protname, task->tk_status);
		rpc_exit(task, -EIO);
		return;
	}

	req->rq_rcv_buf.len = req->rq_private_buf.len;

	/* Check that the softirq receive buffer is valid */
	WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
				sizeof(req->rq_rcv_buf)) != 0);

	/* Verify the RPC header */
	if (!(p = call_verify(task))) {
		if (task->tk_action == NULL)
			return;
		goto out_retry;
	}

	/*
	 * The following is an NFS-specific hack to cater for setuid
	 * processes whose uid is mapped to nobody on the server.
	 */
	if (task->tk_client->cl_droppriv && 
            (ntohl(*p) == NFSERR_ACCES || ntohl(*p) == NFSERR_PERM)) {
		if (RPC_IS_SETUID(task) && task->tk_suid_retry) {
			dprintk("RPC: %4d retry squashed uid\n", task->tk_pid);
			task->tk_flags ^= RPC_CALL_REALUID;
			task->tk_action = call_bind;
			task->tk_suid_retry--;
			goto out_retry;
		}
	}

	task->tk_action = NULL;

	if (decode)
		task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
						      task->tk_msg.rpc_resp);
	dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
					task->tk_status);
	return;
out_retry:
	req->rq_received = req->rq_private_buf.len = 0;
	task->tk_status = 0;
}

/*
 * 8.	Refresh the credentials if rejected by the server
 */
static void
call_refresh(struct rpc_task *task)
{
	dprintk("RPC: %4d call_refresh\n", task->tk_pid);

	xprt_release(task);	/* Must do to obtain new XID */
	task->tk_action = call_refreshresult;
	task->tk_status = 0;
	task->tk_client->cl_stats->rpcauthrefresh++;
	rpcauth_refreshcred(task);
}

/*
 * 8a.	Process the results of a credential refresh
 */
static void
call_refreshresult(struct rpc_task *task)
{
	int status = task->tk_status;
	dprintk("RPC: %4d call_refreshresult (status %d)\n", 
				task->tk_pid, task->tk_status);

	task->tk_status = 0;
	task->tk_action = call_reserve;
	if (status >= 0 && rpcauth_uptodatecred(task))
		return;
	if (rpcauth_deadcred(task)) {
		rpc_exit(task, -EACCES);
		return;
	}
	task->tk_action = call_refresh;
	if (status != -ETIMEDOUT)
		rpc_delay(task, 3*HZ);
	return;
}

/*
 * Call header serialization
 */
static u32 *
call_header(struct rpc_task *task)
{
	struct rpc_clnt *clnt = task->tk_client;
	struct rpc_xprt *xprt = clnt->cl_xprt;
	struct rpc_rqst	*req = task->tk_rqstp;
	u32		*p = req->rq_svec[0].iov_base;

	/* FIXME: check buffer size? */
	if (xprt->stream)
		*p++ = 0;		/* fill in later */
	*p++ = req->rq_xid;		/* XID */
	*p++ = htonl(RPC_CALL);		/* CALL */
	*p++ = htonl(RPC_VERSION);	/* RPC version */
	*p++ = htonl(clnt->cl_prog);	/* program number */
	*p++ = htonl(clnt->cl_vers);	/* program version */
	*p++ = htonl(task->tk_msg.rpc_proc->p_proc);	/* procedure */
	return rpcauth_marshcred(task, p);
}

/*
 * Reply header verification
 */
static u32 *
call_verify(struct rpc_task *task)
{
	struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
	int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
	u32	*p = iov->iov_base, n;

	if ((len -= 3) < 0)
		goto garbage;
	p += 1;	/* skip XID */

	if ((n = ntohl(*p++)) != RPC_REPLY) {
		printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
		goto garbage;
	}
	if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
		int	error = -EACCES;

		if (--len < 0)
			goto garbage;
		if ((n = ntohl(*p++)) != RPC_AUTH_ERROR) {
			printk(KERN_WARNING "call_verify: RPC call rejected: %x\n", n);
		} else if (--len < 0)
		switch ((n = ntohl(*p++))) {
		case RPC_AUTH_REJECTEDCRED:
		case RPC_AUTH_REJECTEDVERF:
		case RPCSEC_GSS_CREDPROBLEM:
		case RPCSEC_GSS_CTXPROBLEM:
			if (!task->tk_cred_retry)
				break;
			task->tk_cred_retry--;
			dprintk("RPC: %4d call_verify: retry stale creds\n",
							task->tk_pid);
			rpcauth_invalcred(task);
			task->tk_action = call_refresh;
			return NULL;
		case RPC_AUTH_BADCRED:
		case RPC_AUTH_BADVERF:
			/* possibly garbled cred/verf? */
			if (!task->tk_garb_retry)
				break;
			task->tk_garb_retry--;
			dprintk("RPC: %4d call_verify: retry garbled creds\n",
							task->tk_pid);
			task->tk_action = call_bind;
			return NULL;
		case RPC_AUTH_TOOWEAK:
			printk(KERN_NOTICE "call_verify: server requires stronger "
			       "authentication.\n");
			break;
		default:
			printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
			error = -EIO;
		} else
			goto garbage;
		dprintk("RPC: %4d call_verify: call rejected %d\n",
						task->tk_pid, n);
		rpc_exit(task, error);
		return NULL;
	}
	if (!(p = rpcauth_checkverf(task, p))) {
		printk(KERN_WARNING "call_verify: auth check failed\n");
		goto garbage;		/* bad verifier, retry */
	}
	len = p - (u32 *)iov->iov_base - 1;
	if (len < 0)
		goto garbage;
	switch ((n = ntohl(*p++))) {
	case RPC_SUCCESS:
		return p;
	case RPC_PROG_UNAVAIL:
		printk(KERN_WARNING "RPC: call_verify: program %u is unsupported by server %s\n",
				(unsigned int)task->tk_client->cl_prog,
				task->tk_client->cl_server);
		goto out_eio;
	case RPC_PROG_MISMATCH:
		printk(KERN_WARNING "RPC: call_verify: program %u, version %u unsupported by server %s\n",
				(unsigned int)task->tk_client->cl_prog,
				(unsigned int)task->tk_client->cl_vers,
				task->tk_client->cl_server);
		goto out_eio;
	case RPC_PROC_UNAVAIL:
		printk(KERN_WARNING "RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
				task->tk_msg.rpc_proc,
				task->tk_client->cl_prog,
				task->tk_client->cl_vers,
				task->tk_client->cl_server);
		goto out_eio;
	case RPC_GARBAGE_ARGS:
		break;			/* retry */
	default:
		printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
		/* Also retry */
	}

garbage:
	dprintk("RPC: %4d call_verify: server saw garbage\n", task->tk_pid);
	task->tk_client->cl_stats->rpcgarbage++;
	if (task->tk_garb_retry) {
		task->tk_garb_retry--;
		dprintk(KERN_WARNING "RPC: garbage, retrying %4d\n", task->tk_pid);
		task->tk_action = call_bind;
		return NULL;
	}
	printk(KERN_WARNING "RPC: garbage, exit EIO\n");
out_eio:
	rpc_exit(task, -EIO);
	return NULL;
}