nfs_subs.c

早期freebsd实现

/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Rick Macklem at The University of Guelph.
 *
 * 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.
 *
 *	@(#)nfs_subs.c	8.3 (Berkeley) 1/4/94
 */

/*
 * These functions support the macros and help fiddle mbuf chains for
 * the nfs op functions. They do things like create the rpc header and
 * copy data between mbuf chains and uio lists.
 */
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/namei.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/stat.h>

#include <nfs/rpcv2.h>
#include <nfs/nfsv2.h>
#include <nfs/nfsnode.h>
#include <nfs/nfs.h>
#include <nfs/xdr_subs.h>
#include <nfs/nfsm_subs.h>
#include <nfs/nfsmount.h>
#include <nfs/nqnfs.h>
#include <nfs/nfsrtt.h>

#include <miscfs/specfs/specdev.h>

#include <netinet/in.h>
#ifdef ISO
#include <netiso/iso.h>
#endif

#define TRUE	1
#define	FALSE	0

/*
 * Data items converted to xdr at startup, since they are constant
 * This is kinda hokey, but may save a little time doing byte swaps
 */
u_long nfs_procids[NFS_NPROCS];
u_long nfs_xdrneg1;
u_long rpc_call, rpc_vers, rpc_reply, rpc_msgdenied, rpc_autherr,
	rpc_mismatch, rpc_auth_unix, rpc_msgaccepted, rpc_rejectedcred,
	rpc_auth_kerb;
u_long nfs_vers, nfs_prog, nfs_true, nfs_false;

/* And other global data */
static u_long nfs_xid = 0;
enum vtype ntov_type[7] = { VNON, VREG, VDIR, VBLK, VCHR, VLNK, VNON };
extern struct proc *nfs_iodwant[NFS_MAXASYNCDAEMON];
extern struct nfsreq nfsreqh;
extern int nqnfs_piggy[NFS_NPROCS];
extern struct nfsrtt nfsrtt;
extern time_t nqnfsstarttime;
extern u_long nqnfs_prog, nqnfs_vers;
extern int nqsrv_clockskew;
extern int nqsrv_writeslack;
extern int nqsrv_maxlease;

/*
 * Create the header for an rpc request packet
 * The hsiz is the size of the rest of the nfs request header.
 * (just used to decide if a cluster is a good idea)
 */
struct mbuf *
nfsm_reqh(vp, procid, hsiz, bposp)
	struct vnode *vp;
	u_long procid;
	int hsiz;
	caddr_t *bposp;
{
	register struct mbuf *mb;
	register u_long *tl;
	register caddr_t bpos;
	struct mbuf *mb2;
	struct nfsmount *nmp;
	int nqflag;

	MGET(mb, M_WAIT, MT_DATA);
	if (hsiz >= MINCLSIZE)
		MCLGET(mb, M_WAIT);
	mb->m_len = 0;
	bpos = mtod(mb, caddr_t);
	
	/*
	 * For NQNFS, add lease request.
	 */
	if (vp) {
		nmp = VFSTONFS(vp->v_mount);
		if (nmp->nm_flag & NFSMNT_NQNFS) {
			nqflag = NQNFS_NEEDLEASE(vp, procid);
			if (nqflag) {
				nfsm_build(tl, u_long *, 2*NFSX_UNSIGNED);
				*tl++ = txdr_unsigned(nqflag);
				*tl = txdr_unsigned(nmp->nm_leaseterm);
			} else {
				nfsm_build(tl, u_long *, NFSX_UNSIGNED);
				*tl = 0;
			}
		}
	}
	/* Finally, return values */
	*bposp = bpos;
	return (mb);
}

/*
 * Build the RPC header and fill in the authorization info.
 * The authorization string argument is only used when the credentials
 * come from outside of the kernel.
 * Returns the head of the mbuf list.
 */
struct mbuf *
nfsm_rpchead(cr, nqnfs, procid, auth_type, auth_len, auth_str, mrest,
	mrest_len, mbp, xidp)
	register struct ucred *cr;
	int nqnfs;
	int procid;
	int auth_type;
	int auth_len;
	char *auth_str;
	struct mbuf *mrest;
	int mrest_len;
	struct mbuf **mbp;
	u_long *xidp;
{
	register struct mbuf *mb;
	register u_long *tl;
	register caddr_t bpos;
	register int i;
	struct mbuf *mreq, *mb2;
	int siz, grpsiz, authsiz;

	authsiz = nfsm_rndup(auth_len);
	if (auth_type == RPCAUTH_NQNFS)
		authsiz += 2 * NFSX_UNSIGNED;
	MGETHDR(mb, M_WAIT, MT_DATA);
	if ((authsiz + 10*NFSX_UNSIGNED) >= MINCLSIZE) {
		MCLGET(mb, M_WAIT);
	} else if ((authsiz + 10*NFSX_UNSIGNED) < MHLEN) {
		MH_ALIGN(mb, authsiz + 10*NFSX_UNSIGNED);
	} else {
		MH_ALIGN(mb, 8*NFSX_UNSIGNED);
	}
	mb->m_len = 0;
	mreq = mb;
	bpos = mtod(mb, caddr_t);

	/*
	 * First the RPC header.
	 */
	nfsm_build(tl, u_long *, 8*NFSX_UNSIGNED);
	if (++nfs_xid == 0)
		nfs_xid++;
	*tl++ = *xidp = txdr_unsigned(nfs_xid);
	*tl++ = rpc_call;
	*tl++ = rpc_vers;
	if (nqnfs) {
		*tl++ = txdr_unsigned(NQNFS_PROG);
		*tl++ = txdr_unsigned(NQNFS_VER1);
	} else {
		*tl++ = txdr_unsigned(NFS_PROG);
		*tl++ = txdr_unsigned(NFS_VER2);
	}
	*tl++ = txdr_unsigned(procid);

	/*
	 * And then the authorization cred.
	 */
	*tl++ = txdr_unsigned(auth_type);
	*tl = txdr_unsigned(authsiz);
	switch (auth_type) {
	case RPCAUTH_UNIX:
		nfsm_build(tl, u_long *, auth_len);
		*tl++ = 0;		/* stamp ?? */
		*tl++ = 0;		/* NULL hostname */
		*tl++ = txdr_unsigned(cr->cr_uid);
		*tl++ = txdr_unsigned(cr->cr_groups[0]);
		grpsiz = (auth_len >> 2) - 5;
		*tl++ = txdr_unsigned(grpsiz);
		for (i = 1; i <= grpsiz; i++)
			*tl++ = txdr_unsigned(cr->cr_groups[i]);
		break;
	case RPCAUTH_NQNFS:
		nfsm_build(tl, u_long *, 2*NFSX_UNSIGNED);
		*tl++ = txdr_unsigned(cr->cr_uid);
		*tl = txdr_unsigned(auth_len);
		siz = auth_len;
		while (siz > 0) {
			if (M_TRAILINGSPACE(mb) == 0) {
				MGET(mb2, M_WAIT, MT_DATA);
				if (siz >= MINCLSIZE)
					MCLGET(mb2, M_WAIT);
				mb->m_next = mb2;
				mb = mb2;
				mb->m_len = 0;
				bpos = mtod(mb, caddr_t);
			}
			i = min(siz, M_TRAILINGSPACE(mb));
			bcopy(auth_str, bpos, i);
			mb->m_len += i;
			auth_str += i;
			bpos += i;
			siz -= i;
		}
		if ((siz = (nfsm_rndup(auth_len) - auth_len)) > 0) {
			for (i = 0; i < siz; i++)
				*bpos++ = '\0';
			mb->m_len += siz;
		}
		break;
	};
	nfsm_build(tl, u_long *, 2*NFSX_UNSIGNED);
	*tl++ = txdr_unsigned(RPCAUTH_NULL);
	*tl = 0;
	mb->m_next = mrest;
	mreq->m_pkthdr.len = authsiz + 10*NFSX_UNSIGNED + mrest_len;
	mreq->m_pkthdr.rcvif = (struct ifnet *)0;
	*mbp = mb;
	return (mreq);
}

/*
 * copies mbuf chain to the uio scatter/gather list
 */
nfsm_mbuftouio(mrep, uiop, siz, dpos)
	struct mbuf **mrep;
	register struct uio *uiop;
	int siz;
	caddr_t *dpos;
{
	register char *mbufcp, *uiocp;
	register int xfer, left, len;
	register struct mbuf *mp;
	long uiosiz, rem;
	int error = 0;

	mp = *mrep;
	mbufcp = *dpos;
	len = mtod(mp, caddr_t)+mp->m_len-mbufcp;
	rem = nfsm_rndup(siz)-siz;
	while (siz > 0) {
		if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
			return (EFBIG);
		left = uiop->uio_iov->iov_len;
		uiocp = uiop->uio_iov->iov_base;
		if (left > siz)
			left = siz;
		uiosiz = left;
		while (left > 0) {
			while (len == 0) {
				mp = mp->m_next;
				if (mp == NULL)
					return (EBADRPC);
				mbufcp = mtod(mp, caddr_t);
				len = mp->m_len;
			}
			xfer = (left > len) ? len : left;
#ifdef notdef
			/* Not Yet.. */
			if (uiop->uio_iov->iov_op != NULL)
				(*(uiop->uio_iov->iov_op))
				(mbufcp, uiocp, xfer);
			else
#endif
			if (uiop->uio_segflg == UIO_SYSSPACE)
				bcopy(mbufcp, uiocp, xfer);
			else
				copyout(mbufcp, uiocp, xfer);
			left -= xfer;
			len -= xfer;
			mbufcp += xfer;
			uiocp += xfer;
			uiop->uio_offset += xfer;
			uiop->uio_resid -= xfer;
		}
		if (uiop->uio_iov->iov_len <= siz) {
			uiop->uio_iovcnt--;
			uiop->uio_iov++;
		} else {
			uiop->uio_iov->iov_base += uiosiz;
			uiop->uio_iov->iov_len -= uiosiz;
		}
		siz -= uiosiz;
	}
	*dpos = mbufcp;
	*mrep = mp;
	if (rem > 0) {
		if (len < rem)
			error = nfs_adv(mrep, dpos, rem, len);
		else
			*dpos += rem;
	}
	return (error);
}

/*
 * copies a uio scatter/gather list to an mbuf chain...
 */
nfsm_uiotombuf(uiop, mq, siz, bpos)
	register struct uio *uiop;
	struct mbuf **mq;
	int siz;
	caddr_t *bpos;
{
	register char *uiocp;
	register struct mbuf *mp, *mp2;
	register int xfer, left, mlen;
	int uiosiz, clflg, rem;
	char *cp;

	if (siz > MLEN)		/* or should it >= MCLBYTES ?? */
		clflg = 1;
	else
		clflg = 0;
	rem = nfsm_rndup(siz)-siz;
	mp = mp2 = *mq;
	while (siz > 0) {
		if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
			return (EINVAL);
		left = uiop->uio_iov->iov_len;
		uiocp = uiop->uio_iov->iov_base;
		if (left > siz)
			left = siz;
		uiosiz = left;
		while (left > 0) {
			mlen = M_TRAILINGSPACE(mp);
			if (mlen == 0) {
				MGET(mp, M_WAIT, MT_DATA);
				if (clflg)
					MCLGET(mp, M_WAIT);
				mp->m_len = 0;
				mp2->m_next = mp;
				mp2 = mp;
				mlen = M_TRAILINGSPACE(mp);
			}
			xfer = (left > mlen) ? mlen : left;
#ifdef notdef
			/* Not Yet.. */
			if (uiop->uio_iov->iov_op != NULL)
				(*(uiop->uio_iov->iov_op))
				(uiocp, mtod(mp, caddr_t)+mp->m_len, xfer);
			else
#endif
			if (uiop->uio_segflg == UIO_SYSSPACE)
				bcopy(uiocp, mtod(mp, caddr_t)+mp->m_len, xfer);
			else
				copyin(uiocp, mtod(mp, caddr_t)+mp->m_len, xfer);
			mp->m_len += xfer;
			left -= xfer;
			uiocp += xfer;
			uiop->uio_offset += xfer;
			uiop->uio_resid -= xfer;
		}
		if (uiop->uio_iov->iov_len <= siz) {
			uiop->uio_iovcnt--;
			uiop->uio_iov++;
		} else {
			uiop->uio_iov->iov_base += uiosiz;
			uiop->uio_iov->iov_len -= uiosiz;
		}
		siz -= uiosiz;
	}
	if (rem > 0) {
		if (rem > M_TRAILINGSPACE(mp)) {
			MGET(mp, M_WAIT, MT_DATA);
			mp->m_len = 0;
			mp2->m_next = mp;
		}
		cp = mtod(mp, caddr_t)+mp->m_len;
		for (left = 0; left < rem; left++)
			*cp++ = '\0';
		mp->m_len += rem;
		*bpos = cp;
	} else
		*bpos = mtod(mp, caddr_t)+mp->m_len;
	*mq = mp;
	return (0);
}

/*
 * Help break down an mbuf chain by setting the first siz bytes contiguous
 * pointed to by returned val.
 * This is used by the macros nfsm_dissect and nfsm_dissecton for tough
 * cases. (The macros use the vars. dpos and dpos2)
 */
nfsm_disct(mdp, dposp, siz, left, cp2)
	struct mbuf **mdp;
	caddr_t *dposp;
	int siz;
	int left;
	caddr_t *cp2;
{
	register struct mbuf *mp, *mp2;
	register int siz2, xfer;
	register caddr_t p;

	mp = *mdp;
	while (left == 0) {
		*mdp = mp = mp->m_next;
		if (mp == NULL)
			return (EBADRPC);
		left = mp->m_len;
		*dposp = mtod(mp, caddr_t);
	}
	if (left >= siz) {
		*cp2 = *dposp;
		*dposp += siz;
	} else if (mp->m_next == NULL) {
		return (EBADRPC);
	} else if (siz > MHLEN) {
		panic("nfs S too big");
	} else {
		MGET(mp2, M_WAIT, MT_DATA);
		mp2->m_next = mp->m_next;
		mp->m_next = mp2;
		mp->m_len -= left;
		mp = mp2;
		*cp2 = p = mtod(mp, caddr_t);
		bcopy(*dposp, p, left);		/* Copy what was left */
		siz2 = siz-left;
		p += left;
		mp2 = mp->m_next;
		/* Loop around copying up the siz2 bytes */
		while (siz2 > 0) {
			if (mp2 == NULL)
				return (EBADRPC);
			xfer = (siz2 > mp2->m_len) ? mp2->m_len : siz2;
			if (xfer > 0) {
				bcopy(mtod(mp2, caddr_t), p, xfer);
				NFSMADV(mp2, xfer);
				mp2->m_len -= xfer;
				p += xfer;
				siz2 -= xfer;
			}
			if (siz2 > 0)
				mp2 = mp2->m_next;
		}
		mp->m_len = siz;
		*mdp = mp2;
		*dposp = mtod(mp2, caddr_t);
	}
	return (0);
}

/*
 * Advance the position in the mbuf chain.
 */
nfs_adv(mdp, dposp, offs, left)
	struct mbuf **mdp;
	caddr_t *dposp;
	int offs;
	int left;
{
	register struct mbuf *m;
	register int s;

	m = *mdp;
	s = left;
	while (s < offs) {
		offs -= s;
		m = m->m_next;
		if (m == NULL)
			return (EBADRPC);
		s = m->m_len;
	}
	*mdp = m;
	*dposp = mtod(m, caddr_t)+offs;
	return (0);
}

/*
 * Copy a string into mbufs for the hard cases...
 */
nfsm_strtmbuf(mb, bpos, cp, siz)
	struct mbuf **mb;
	char **bpos;
	char *cp;
	long siz;
{
	register struct mbuf *m1, *m2;
	long left, xfer, len, tlen;
	u_long *tl;
	int putsize;

	putsize = 1;
	m2 = *mb;
	left = M_TRAILINGSPACE(m2);
	if (left > 0) {
		tl = ((u_long *)(*bpos));
		*tl++ = txdr_unsigned(siz);
		putsize = 0;
		left -= NFSX_UNSIGNED;
		m2->m_len += NFSX_UNSIGNED;
		if (left > 0) {
			bcopy(cp, (caddr_t) tl, left);
			siz -= left;
			cp += left;
			m2->m_len += left;
			left = 0;
		}
	}
	/* Loop around adding mbufs */
	while (siz > 0) {
		MGET(m1, M_WAIT, MT_DATA);
		if (siz > MLEN)
			MCLGET(m1, M_WAIT);
		m1->m_len = NFSMSIZ(m1);
		m2->m_next = m1;
		m2 = m1;
		tl = mtod(m1, u_long *);
		tlen = 0;
		if (putsize) {
			*tl++ = txdr_unsigned(siz);
			m1->m_len -= NFSX_UNSIGNED;
			tlen = NFSX_UNSIGNED;
			putsize = 0;
		}
		if (siz < m1->m_len) {
			len = nfsm_rndup(siz);
			xfer = siz;
			if (xfer < len)
				*(tl+(xfer>>2)) = 0;
		} else {
			xfer = len = m1->m_len;
		}
		bcopy(cp, (caddr_t) tl, xfer);