srvr_nfs.c

早期freebsd实现

/*
 * Copyright (c) 1990 Jan-Simon Pendry
 * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Jan-Simon Pendry at Imperial College, London.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)srvr_nfs.c	8.1 (Berkeley) 6/6/93
 *
 * $Id: srvr_nfs.c,v 5.2.2.1 1992/02/09 15:09:06 jsp beta $
 *
 */

/*
 * NFS server modeling
 */

#include "am.h"
#include <netdb.h>
#include <rpc/pmap_prot.h>
#include "mount.h"

extern qelem nfs_srvr_list;
qelem nfs_srvr_list = { &nfs_srvr_list, &nfs_srvr_list };

typedef struct nfs_private {
	u_short np_mountd;	/* Mount daemon port number */
	char np_mountd_inval;	/* Port *may* be invalid */
	int np_ping;		/* Number of failed ping attempts */
	time_t np_ttl;		/* Time when server is thought dead */
	int np_xid;		/* RPC transaction id for pings */
	int np_error;		/* Error during portmap request */
} nfs_private;

static int np_xid;	/* For NFS pings */
#define	NPXID_ALLOC()	(++np_xid)
/*#define	NPXID_ALLOC()	((++np_xid&0x0fffffff) == 0 ? npxid_gc() : np_xid)*/

/*
 * Number of pings allowed to fail before host is declared down
 * - three-fifths of the allowed mount time...
#define	MAX_ALLOWED_PINGS	((((ALLOWED_MOUNT_TIME + 5 * AM_PINGER - 1) * 3) / 5) / AM_PINGER)
 */
#define	MAX_ALLOWED_PINGS	(3 + /* for luck ... */ 1)

/*
 * How often to ping when starting a new server
 */
#define	FAST_NFS_PING		3

#if (FAST_NFS_PING * MAX_ALLOWED_PINGS) >= ALLOWED_MOUNT_TIME
 #error: sanity check failed
/*
 you cannot do things this way...
 sufficient fast pings must be given the chance to fail
 within the allowed mount time
 */
#endif /* (FAST_NFS_PING * MAX_ALLOWED_PINGS) >= ALLOWED_MOUNT_TIME */

static int ping_len;
static char ping_buf[sizeof(struct rpc_msg) + 32];

/*
 * Flush any cached data
 */
void flush_srvr_nfs_cache P((void));
void flush_srvr_nfs_cache()
{
	fserver *fs = 0;

	ITER(fs, fserver, &nfs_srvr_list) {
		nfs_private *np = (nfs_private *) fs->fs_private;
		if (np) {
			np->np_mountd_inval = TRUE;
			np->np_error = -1;
		}
	}
}

/*
 * Startup the NFS ping
 */
static void start_ping(P_void);
static void start_ping()
{
	XDR ping_xdr;
	struct rpc_msg ping_msg;

	rpc_msg_init(&ping_msg, NFS_PROGRAM, NFS_VERSION, NFSPROC_NULL);

	/*
	 * Create an XDR endpoint
	 */
	xdrmem_create(&ping_xdr, ping_buf, sizeof(ping_buf), XDR_ENCODE);

	/*
	 * Create the NFS ping message
	 */
	if (!xdr_callmsg(&ping_xdr, &ping_msg)) {
		plog(XLOG_ERROR, "Couldn't create ping RPC message");
		going_down(3);
	}

	/*
	 * Find out how long it is
	 */
	ping_len = xdr_getpos(&ping_xdr);

	/*
	 * Destroy the XDR endpoint - we don't need it anymore
	 */
	xdr_destroy(&ping_xdr);
}


/*
 * Called when a portmap reply arrives
 */
/*ARGSUSED*/
static void got_portmap P((voidp pkt, int len, struct sockaddr_in *sa, struct sockaddr_in *ia, voidp idv, int done));
static void got_portmap(pkt, len, sa, ia, idv, done)
voidp pkt;
int len;
struct sockaddr_in *sa;
struct sockaddr_in *ia;
voidp idv;
int done;
{
	fserver *fs2 = (fserver *) idv;
	fserver *fs = 0;

	/*
	 * Find which fileserver we are talking about
	 */
	ITER(fs, fserver, &nfs_srvr_list)
		if (fs == fs2)
			break;

	if (fs == fs2) {
		u_long port = 0;	/* XXX - should be short but protocol is naff */
		int error = done ? pickup_rpc_reply(pkt, len, (voidp) &port, xdr_u_long) : -1;
		nfs_private *np = (nfs_private *) fs->fs_private;
		if (!error && port) {
#ifdef DEBUG
			dlog("got port (%d) for mountd on %s", port, fs->fs_host);
#endif /* DEBUG */
			/*
			 * Grab the port number.  Portmap sends back
			 * an unsigned long in native ordering, so it
			 * needs converting to a unsigned short in
			 * network ordering.
			 */
			np->np_mountd = htons((u_short) port);
			np->np_mountd_inval = FALSE;
			np->np_error = 0;
		} else {
#ifdef DEBUG
			dlog("Error fetching port for mountd on %s", fs->fs_host);
#endif /* DEBUG */
			/*
			 * Almost certainly no mountd running on remote host
			 */
			np->np_error = error ? error : ETIMEDOUT;
		}
		if (fs->fs_flags & FSF_WANT)
			wakeup_srvr(fs);
	} else if (done) {
#ifdef DEBUG
		dlog("Got portmap for old port request");
#endif /* DEBUG */
	} else {
#ifdef DEBUG
		dlog("portmap request timed out");
#endif /* DEBUG */
	}
}

/*
 * Obtain portmap information
 */
static int call_portmap P((fserver *fs, AUTH *auth, unsigned long prog, unsigned long vers, unsigned long prot));
static int call_portmap(fs, auth, prog, vers, prot)
fserver *fs;
AUTH *auth;
unsigned long prog, vers, prot;
{
	struct rpc_msg pmap_msg;
	int len;
	char iobuf[UDPMSGSIZE];
	int error;
	struct pmap pmap;

	rpc_msg_init(&pmap_msg, PMAPPROG, PMAPVERS, (unsigned long) 0);
	pmap.pm_prog = prog;
	pmap.pm_vers = vers;
	pmap.pm_prot = prot;
	pmap.pm_port = 0;
	len = make_rpc_packet(iobuf, sizeof(iobuf), PMAPPROC_GETPORT,
			&pmap_msg, (voidp) &pmap, xdr_pmap, auth);
	if (len > 0) {
		struct sockaddr_in sin;
		bzero((voidp) &sin, sizeof(sin));
		sin = *fs->fs_ip;
		sin.sin_port = htons(PMAPPORT);
		error = fwd_packet(RPC_XID_PORTMAP, (voidp) iobuf, len,
				&sin, &sin, (voidp) fs, got_portmap);
	} else {
		error = -len;
	}
	return error;
}

static void nfs_keepalive P((fserver*));

static void recompute_portmap P((fserver *fs));
static void recompute_portmap(fs)
fserver *fs;
{				
	int error;

	if (nfs_auth)
		error = 0;
	else
		error = make_nfs_auth();

	if (error) {
		nfs_private *np = (nfs_private *) fs->fs_private;
		np->np_error = error;
	} else {
		call_portmap(fs, nfs_auth, MOUNTPROG,
			MOUNTVERS, (unsigned long) IPPROTO_UDP);
	}
}

/*
 * This is called when we get a reply to an RPC ping.
 * The value of id was taken from the nfs_private
 * structure when the ping was transmitted.
 */
/*ARGSUSED*/
static void nfs_pinged P((voidp pkt, int len, struct sockaddr_in *sp, struct sockaddr_in *tsp, voidp idv, int done));
static void nfs_pinged(pkt, len, sp, tsp, idv, done)
voidp pkt;
int len;
struct sockaddr_in *sp;
struct sockaddr_in *tsp;
voidp idv;
int done;
{
	int xid = (int) idv;
	fserver *fs;
#ifdef DEBUG
	int found_map = 0;
#endif /* DEBUG */

	if (!done)
		return;

	/*
	 * For each node...
	 */
	ITER(fs, fserver, &nfs_srvr_list) {
		nfs_private *np = (nfs_private *) fs->fs_private;
		if (np->np_xid == xid) {
			/*
			 * Reset the ping counter.
			 * Update the keepalive timer.
			 * Log what happened.
			 */
			if (fs->fs_flags & FSF_DOWN) {
				fs->fs_flags &= ~FSF_DOWN;
				if (fs->fs_flags & FSF_VALID) {
					srvrlog(fs, "is up");
				} else {
					if (np->np_ping > 1)
						srvrlog(fs, "ok");
#ifdef DEBUG
					else
						srvrlog(fs, "starts up");
#endif
					fs->fs_flags |= FSF_VALID;
				}

#ifdef notdef
				/* why ??? */
				if (fs->fs_flags & FSF_WANT)
					wakeup_srvr(fs);
#endif /* notdef */
				map_flush_srvr(fs);
			} else {
				if (fs->fs_flags & FSF_VALID) {
#ifdef DEBUG
					dlog("file server %s type nfs is still up", fs->fs_host);
#endif /* DEBUG */
				} else {
					if (np->np_ping > 1)
						srvrlog(fs, "ok");
					fs->fs_flags |= FSF_VALID;
				}
			}

			/*
			 * Adjust ping interval
			 */
			untimeout(fs->fs_cid);
			fs->fs_cid = timeout(fs->fs_pinger, nfs_keepalive, (voidp) fs);

			/*
			 * Update ttl for this server
			 */
			np->np_ttl = clocktime() +
				(MAX_ALLOWED_PINGS - 1) * FAST_NFS_PING + fs->fs_pinger - 1;

			/*
			 * New RPC xid...
			 */
			np->np_xid = NPXID_ALLOC();

			/*
			 * Failed pings is zero...
			 */
			np->np_ping = 0;

			/*
			 * Recompute portmap information if not known
			 */
			if (np->np_mountd_inval)
				recompute_portmap(fs);

#ifdef DEBUG