clnt.c

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		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;
	unsigned int	bufsiz;
	kxdrproc_t	encode;
	int		status;
	u32		*p;

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

	task->tk_action = call_bind;

	/* Default buffer setup */
	bufsiz = rpcproc_bufsiz(clnt, task->tk_msg.rpc_proc)+RPC_SLACK_SPACE;
	req->rq_svec[0].iov_base = (void *)task->tk_buffer;
	req->rq_svec[0].iov_len  = bufsiz;
	req->rq_slen		 = 0;
	req->rq_snr		 = 1;
	req->rq_rvec[0].iov_base = (void *)((char *)task->tk_buffer + bufsiz);
	req->rq_rvec[0].iov_len  = bufsiz;
	req->rq_rlen		 = bufsiz;
	req->rq_rnr		 = 1;

	/* Zero buffer so we have automatic zero-padding of opaque & string */
	memset(task->tk_buffer, 0, bufsiz);

	/* Encode header and provided arguments */
	encode = rpcproc_encode(clnt, task->tk_msg.rpc_proc);
	if (!(p = call_header(task))) {
		printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
		rpc_exit(task, -EIO);
	} else
	if (encode && (status = 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;

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

	if (!clnt->cl_port) {
		task->tk_action = call_reconnect;
		task->tk_timeout = clnt->cl_timeout.to_maxval;
		rpc_getport(task, clnt);
	}
}

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

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

	task->tk_action = call_transmit;
	if (task->tk_status < 0 || !clnt->cl_xprt->stream)
		return;

	/* Run as a child to ensure it runs as an rpciod task */
	child = rpc_new_child(clnt, task);
	if (child) {
		child->tk_action = child_reconnect;
		rpc_run_child(task, child, NULL);
	}
}

static void child_reconnect(struct rpc_task *task)
{
	task->tk_client->cl_stats->netreconn++;
	task->tk_status = 0;
	task->tk_action = child_reconnect_status;
	xprt_reconnect(task);
}

static void child_reconnect_status(struct rpc_task *task)
{
	if (task->tk_status == -EAGAIN)
		task->tk_action = child_reconnect;
	else
		task->tk_action = NULL;
}

/*
 * 5.	Transmit the RPC request, and wait for reply
 */
static void
call_transmit(struct rpc_task *task)
{
	struct rpc_clnt	*clnt = task->tk_client;

	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;
	xprt_transmit(task);
	if (!rpcproc_decode(clnt, task->tk_msg.rpc_proc)) {
		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_xprt *xprt = clnt->cl_xprt;
	struct rpc_rqst	*req;
	int		status = task->tk_status;

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

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

	task->tk_status = 0;
	req = task->tk_rqstp;
	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) {
			clnt->cl_port = 0;
			task->tk_action = call_bind;
			break;
		}
		if (xprt->stream) {
			task->tk_action = call_reconnect;
			break;
		}
		/*
		 * Sleep and dream of an open connection
		 */
		task->tk_timeout = 5 * HZ;
		rpc_sleep_on(&xprt->sending, task, NULL, NULL);
	case -ENOMEM:
	case -EAGAIN:
		task->tk_action = call_transmit;
		clnt->cl_stats->rpcretrans++;
		break;
	default:
		if (clnt->cl_chatty)
			printk("%s: RPC call returned error %d\n",
			       clnt->cl_protname, -status);
		rpc_exit(task, status);
	}
}

/*
 * 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;
	struct rpc_rqst	*req = task->tk_rqstp;

	if (req) {
		struct rpc_timeout *to = &req->rq_timeout;

		if (xprt_adjust_timeout(to)) {
			dprintk("RPC: %4d call_timeout (minor timeo)\n",
				task->tk_pid);
			goto minor_timeout;
		}
		to->to_retries = clnt->cl_timeout.to_retries;
	}

	dprintk("RPC: %4d call_timeout (major timeo)\n", task->tk_pid);
	if (clnt->cl_softrtry) {
		if (clnt->cl_chatty && !task->tk_exit)
			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;
		if (req)
			printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
				clnt->cl_protname, clnt->cl_server);
#ifdef RPC_DEBUG				
		else
			printk(KERN_NOTICE "%s: task %d can't get a request slot\n",
				clnt->cl_protname, task->tk_pid);
#endif				
	}
	if (clnt->cl_autobind)
		clnt->cl_port = 0;

minor_timeout:
	if (!req)
		task->tk_action = call_reserve;
	else if (!clnt->cl_port) {
		task->tk_action = call_bind;
		clnt->cl_stats->rpcretrans++;
	} else if (!xprt_connected(clnt->cl_xprt)) {
		task->tk_action = call_reconnect;
		clnt->cl_stats->rpcretrans++;
	} else {
		task->tk_action = call_transmit;
		clnt->cl_stats->rpcretrans++;
	}
	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 = rpcproc_decode(clnt, task->tk_msg.rpc_proc);
	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 (!clnt->cl_softrtry) {
			task->tk_action = call_transmit;
			clnt->cl_stats->rpcretrans++;
		} else {
			printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
				clnt->cl_protname, task->tk_status);
			rpc_exit(task, -EIO);
		}
		return;
	}

	/* Verify the RPC header */
	if (!(p = call_verify(task)))
		return;

	/*
	 * 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_encode;
			task->tk_suid_retry--;
			return;
		}
	}

	task->tk_action = NULL;

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

/*
 * 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)
{
	dprintk("RPC: %4d call_refreshresult (status %d)\n", 
				task->tk_pid, task->tk_status);

	if (task->tk_status < 0)
		rpc_exit(task, -EACCES);
	else
		task->tk_action = call_reserve;
}

/*
 * 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);	/* procedure */
	return rpcauth_marshcred(task, p);
}

/*
 * Reply header verification
 */
static u32 *
call_verify(struct rpc_task *task)
{
	u32	*p = task->tk_rqstp->rq_rvec[0].iov_base, n;

	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 ((n = ntohl(*p++)) != RPC_AUTH_ERROR) {
			printk(KERN_WARNING "call_verify: RPC call rejected: %x\n", n);
		} else
		switch ((n = ntohl(*p++))) {
		case RPC_AUTH_REJECTEDCRED:
		case RPC_AUTH_REJECTEDVERF:
			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_encode;
			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;
		}
		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 */
	}
	switch ((n = ntohl(*p++))) {
	case RPC_SUCCESS:
		return p;
	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_encode;
		return NULL;
	}
	printk(KERN_WARNING "RPC: garbage, exit EIO\n");
	rpc_exit(task, -EIO);
	return NULL;
}