/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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. 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.
 *
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/*
 * 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 <fs/nfs/nfsport.h>

extern struct nfsstatsv1 nfsstatsv1;
extern int ncl_mbuf_mlen;
extern enum vtype newnv2tov_type[8];
extern enum vtype nv34tov_type[8];
NFSCLSTATEMUTEX;

static nfsuint64 nfs_nullcookie = {{ 0, 0 }};

/*
 * copies a uio scatter/gather list to an mbuf chain.
 * NOTE: can ony handle iovcnt == 1
 */
void
nfsm_uiombuf(struct nfsrv_descript *nd, struct uio *uiop, int siz)
{
	char *uiocp;
	struct mbuf *mp, *mp2;
	int xfer, left, mlen;
	int uiosiz, clflg, rem;
	char *mcp, *tcp;

	KASSERT(uiop->uio_iovcnt == 1, ("nfsm_uiotombuf: iovcnt != 1"));

	if (siz > ncl_mbuf_mlen)	/* or should it >= MCLBYTES ?? */
		clflg = 1;
	else
		clflg = 0;
	rem = NFSM_RNDUP(siz) - siz;
	mp = mp2 = nd->nd_mb;
	mcp = nd->nd_bpos;
	while (siz > 0) {
		KASSERT((nd->nd_flag & ND_EXTPG) != 0 || mcp ==
		    mtod(mp, char *) + mp->m_len, ("nfsm_uiombuf: mcp wrong"));
		left = uiop->uio_iov->iov_len;
		uiocp = uiop->uio_iov->iov_base;
		if (left > siz)
			left = siz;
		uiosiz = left;
		while (left > 0) {
			if ((nd->nd_flag & ND_EXTPG) != 0)
				mlen = nd->nd_bextpgsiz;
			else
				mlen = M_TRAILINGSPACE(mp);
			if (mlen == 0) {
				if ((nd->nd_flag & ND_EXTPG) != 0) {
					mp = nfsm_add_ext_pgs(mp,
					    nd->nd_maxextsiz, &nd->nd_bextpg);
					mcp = (char *)(void *)PHYS_TO_DMAP(
					  mp->m_epg_pa[nd->nd_bextpg]);
					nd->nd_bextpgsiz = mlen = PAGE_SIZE;
				} else {
					if (clflg)
						NFSMCLGET(mp, M_WAITOK);
					else
						NFSMGET(mp);
					mp->m_len = 0;
					mlen = M_TRAILINGSPACE(mp);
					mcp = mtod(mp, char *);
					mp2->m_next = mp;
					mp2 = mp;
				}
			}
			xfer = (left > mlen) ? mlen : left;
			if (uiop->uio_segflg == UIO_SYSSPACE)
				NFSBCOPY(uiocp, mcp, xfer);
			else
				copyin(uiocp, mcp, xfer);
			mp->m_len += xfer;
			left -= xfer;
			uiocp += xfer;
			mcp += xfer;
			if ((nd->nd_flag & ND_EXTPG) != 0) {
				nd->nd_bextpgsiz -= xfer;
				mp->m_epg_last_len += xfer;
			}
			uiop->uio_offset += xfer;
			uiop->uio_resid -= xfer;
		}
		tcp = (char *)uiop->uio_iov->iov_base;
		tcp += uiosiz;
		uiop->uio_iov->iov_base = (void *)tcp;
		uiop->uio_iov->iov_len -= uiosiz;
		siz -= uiosiz;
	}
	if (rem > 0) {
		if ((nd->nd_flag & ND_EXTPG) == 0 && rem >
		    M_TRAILINGSPACE(mp)) {
			NFSMGET(mp);
			mp->m_len = 0;
			mp2->m_next = mp;
			mcp = mtod(mp, char *);
		} else if ((nd->nd_flag & ND_EXTPG) != 0 && rem >
		    nd->nd_bextpgsiz) {
			mp = nfsm_add_ext_pgs(mp, nd->nd_maxextsiz,
			    &nd->nd_bextpg);
			mcp = (char *)(void *)
			    PHYS_TO_DMAP(mp->m_epg_pa[nd->nd_bextpg]);
			nd->nd_bextpgsiz = PAGE_SIZE;
		}
		for (left = 0; left < rem; left++)
			*mcp++ = '\0';
		mp->m_len += rem;
		if ((nd->nd_flag & ND_EXTPG) != 0) {
			nd->nd_bextpgsiz -= rem;
			mp->m_epg_last_len += rem;
		}
	}
	nd->nd_bpos = mcp;
	nd->nd_mb = mp;
}

/*
 * copies a uio scatter/gather list to an mbuf chain.
 * This version returns the mbuf list and does not use "nd".
 * NOTE: can ony handle iovcnt == 1
 */
struct mbuf *
nfsm_uiombuflist(struct uio *uiop, int siz, u_int maxext)
{
	char *uiocp;
	struct mbuf *mp, *mp2, *firstmp;
	int extpg, extpgsiz = 0, i, left, mlen, rem, xfer;
	int uiosiz, clflg;
	char *mcp, *tcp;

	KASSERT(uiop->uio_iovcnt == 1, ("nfsm_uiotombuf: iovcnt != 1"));

	if (maxext > 0) {
		mp = mb_alloc_ext_plus_pages(PAGE_SIZE, M_WAITOK);
		mcp = (char *)(void *)PHYS_TO_DMAP(mp->m_epg_pa[0]);
		extpg = 0;
		extpgsiz = PAGE_SIZE;
	} else {
		if (siz > ncl_mbuf_mlen) /* or should it >= MCLBYTES ?? */
			clflg = 1;
		else
			clflg = 0;
		if (clflg != 0)
			NFSMCLGET(mp, M_WAITOK);
		else
			NFSMGET(mp);
		mcp = mtod(mp, char *);
	}
	mp->m_len = 0;
	firstmp = mp2 = mp;
	rem = NFSM_RNDUP(siz) - siz;
	while (siz > 0) {
		left = uiop->uio_iov->iov_len;
		uiocp = uiop->uio_iov->iov_base;
		if (left > siz)
			left = siz;
		uiosiz = left;
		while (left > 0) {
			if (maxext > 0)
				mlen = extpgsiz;
			else
				mlen = M_TRAILINGSPACE(mp);
			if (mlen == 0) {
				if (maxext > 0) {
					mp = nfsm_add_ext_pgs(mp, maxext,
					    &extpg);
					mlen = extpgsiz = PAGE_SIZE;
					mcp = (char *)(void *)PHYS_TO_DMAP(
					    mp->m_epg_pa[extpg]);
				} else {
					if (clflg)
						NFSMCLGET(mp, M_WAITOK);
					else
						NFSMGET(mp);
					mcp = mtod(mp, char *);
					mlen = M_TRAILINGSPACE(mp);
					mp->m_len = 0;
					mp2->m_next = mp;
					mp2 = mp;
				}
			}
			xfer = (left > mlen) ? mlen : left;
			if (uiop->uio_segflg == UIO_SYSSPACE)
				NFSBCOPY(uiocp, mcp, xfer);
			else
				copyin(uiocp, mcp, xfer);
			mp->m_len += xfer;
			mcp += xfer;
			if (maxext > 0) {
				extpgsiz -= xfer;
				mp->m_epg_last_len += xfer;
			}
			left -= xfer;
			uiocp += xfer;
			uiop->uio_offset += xfer;
			uiop->uio_resid -= xfer;
		}
		tcp = (char *)uiop->uio_iov->iov_base;
		tcp += uiosiz;
		uiop->uio_iov->iov_base = (void *)tcp;
		uiop->uio_iov->iov_len -= uiosiz;
		siz -= uiosiz;
	}
	if (rem > 0) {
		KASSERT((mp->m_flags & M_EXTPG) != 0 ||
		    rem <= M_TRAILINGSPACE(mp),
		    ("nfsm_uiombuflist: no space for padding"));
		for (i = 0; i < rem; i++)
			*mcp++ = '\0';
		mp->m_len += rem;
		if (maxext > 0)
			mp->m_epg_last_len += rem;
	}
	return (firstmp);
}

/*
 * Load vnode attributes from the xdr file attributes.
 * Returns EBADRPC if they can't be parsed, 0 otherwise.
 */
int
nfsm_loadattr(struct nfsrv_descript *nd, struct nfsvattr *nap)
{
	struct nfs_fattr *fp;
	int error = 0;

	if (nd->nd_flag & ND_NFSV4) {
		error = nfsv4_loadattr(nd, NULL, nap, NULL, NULL, 0, NULL,
		    NULL, NULL, NULL, NULL, 0, NULL, NULL, NULL, NULL, NULL);
	} else if (nd->nd_flag & ND_NFSV3) {
		NFSM_DISSECT(fp, struct nfs_fattr *, NFSX_V3FATTR);
		nap->na_type = nfsv34tov_type(fp->fa_type);
		nap->na_mode = fxdr_unsigned(u_short, fp->fa_mode);
		nap->na_rdev = NFSMAKEDEV(
		    fxdr_unsigned(int, fp->fa3_rdev.specdata1),
		    fxdr_unsigned(int, fp->fa3_rdev.specdata2));
		nap->na_nlink = fxdr_unsigned(uint32_t, fp->fa_nlink);
		nap->na_uid = fxdr_unsigned(uid_t, fp->fa_uid);
		nap->na_gid = fxdr_unsigned(gid_t, fp->fa_gid);
		nap->na_size = fxdr_hyper(&fp->fa3_size);
		nap->na_blocksize = NFS_FABLKSIZE;
		nap->na_bytes = fxdr_hyper(&fp->fa3_used);
		nap->na_fileid = fxdr_hyper(&fp->fa3_fileid);
		fxdr_nfsv3time(&fp->fa3_atime, &nap->na_atime);
		fxdr_nfsv3time(&fp->fa3_ctime, &nap->na_ctime);
		fxdr_nfsv3time(&fp->fa3_mtime, &nap->na_mtime);
		nap->na_btime.tv_sec = -1;
		nap->na_btime.tv_nsec = 0;
		nap->na_flags = 0;
		nap->na_gen = 0;
		nap->na_filerev = 0;
	} else {
		NFSM_DISSECT(fp, struct nfs_fattr *, NFSX_V2FATTR);
		nap->na_type = nfsv2tov_type(fp->fa_type);
		nap->na_mode = fxdr_unsigned(u_short, fp->fa_mode);
		if (nap->na_type == VNON || nap->na_type == VREG)
			nap->na_type = IFTOVT(nap->na_mode);
		nap->na_rdev = fxdr_unsigned(dev_t, fp->fa2_rdev);

		/*
		 * Really ugly NFSv2 kludge.
		 */
		if (nap->na_type == VCHR && nap->na_rdev == ((dev_t)-1))
			nap->na_type = VFIFO;
		nap->na_nlink = fxdr_unsigned(u_short, fp->fa_nlink);
		nap->na_uid = fxdr_unsigned(uid_t, fp->fa_uid);
		nap->na_gid = fxdr_unsigned(gid_t, fp->fa_gid);
		nap->na_size = fxdr_unsigned(u_int32_t, fp->fa2_size);
		nap->na_blocksize = fxdr_unsigned(int32_t, fp->fa2_blocksize);
		nap->na_bytes =
		    (u_quad_t)fxdr_unsigned(int32_t, fp->fa2_blocks) *
		    NFS_FABLKSIZE;
		nap->na_fileid = fxdr_unsigned(uint64_t, fp->fa2_fileid);
		fxdr_nfsv2time(&fp->fa2_atime, &nap->na_atime);
		fxdr_nfsv2time(&fp->fa2_mtime, &nap->na_mtime);
		nap->na_flags = 0;
		nap->na_ctime.tv_sec = fxdr_unsigned(u_int32_t,
		    fp->fa2_ctime.nfsv2_sec);
		nap->na_ctime.tv_nsec = 0;
		nap->na_btime.tv_sec = -1;
		nap->na_btime.tv_nsec = 0;
		nap->na_gen = fxdr_unsigned(u_int32_t,fp->fa2_ctime.nfsv2_usec);
		nap->na_filerev = 0;
	}
nfsmout:
	return (error);
}

/*
 * This function finds the directory cookie that corresponds to the
 * logical byte offset given.
 */
nfsuint64 *
nfscl_getcookie(struct nfsnode *np, off_t off, int add)
{
	struct nfsdmap *dp, *dp2;
	int pos;

	pos = off / NFS_DIRBLKSIZ;
	if (pos == 0) {
		KASSERT(!add, ("nfs getcookie add at 0"));
		return (&nfs_nullcookie);
	}
	pos--;
	dp = LIST_FIRST(&np->n_cookies);
	if (!dp) {
		if (add) {
			dp = malloc(sizeof (struct nfsdmap),
				M_NFSDIROFF, M_WAITOK);
			dp->ndm_eocookie = 0;
			LIST_INSERT_HEAD(&np->n_cookies, dp, ndm_list);
		} else
			return (NULL);
	}
	while (pos >= NFSNUMCOOKIES) {
		pos -= NFSNUMCOOKIES;
		if (LIST_NEXT(dp, ndm_list) != NULL) {
			if (!add && dp->ndm_eocookie < NFSNUMCOOKIES &&
				pos >= dp->ndm_eocookie)
				return (NULL);
			dp = LIST_NEXT(dp, ndm_list);
		} else if (add) {
			dp2 = malloc(sizeof (struct nfsdmap),
				M_NFSDIROFF, M_WAITOK);
			dp2->ndm_eocookie = 0;
			LIST_INSERT_AFTER(dp, dp2, ndm_list);
			dp = dp2;
		} else
			return (NULL);
	}
	if (pos >= dp->ndm_eocookie) {
		if (add)
			dp->ndm_eocookie = pos + 1;
		else
			return (NULL);
	}
	return (&dp->ndm_cookies[pos]);
}

/*
 * Gets a file handle out of an nfs reply sent to the client and returns
 * the file handle and the file's attributes.
 * For V4, it assumes that Getfh and Getattr Op's results are here.
 */
int
nfscl_mtofh(struct nfsrv_descript *nd, struct nfsfh **nfhpp,
    struct nfsvattr *nap, int *attrflagp)
{
	u_int32_t *tl;
	int error = 0, flag = 1;

	*nfhpp = NULL;
	*attrflagp = 0;
	/*
	 * First get the file handle and vnode.
	 */
	if (nd->nd_flag & ND_NFSV3) {
		NFSM_DISSECT(tl, u_int32_t *, NFSX_UNSIGNED);
		flag = fxdr_unsigned(int, *tl);
	} else if (nd->nd_flag & ND_NFSV4) {
		NFSM_DISSECT(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
		/* If the GetFH failed, clear flag. */
		if (*++tl != 0) {
			nd->nd_flag |= ND_NOMOREDATA;
			flag = 0;
			error = ENXIO;	/* Return ENXIO so *nfhpp isn't used. */
		}
	}
	if (flag) {
		error = nfsm_getfh(nd, nfhpp);
		if (error)
			return (error);
	}

	/*
	 * Now, get the attributes.
	 */
	if (flag != 0 && (nd->nd_flag & ND_NFSV4) != 0) {
		NFSM_DISSECT(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
		if (*++tl != 0) {
			nd->nd_flag |= ND_NOMOREDATA;
			flag = 0;
		}
	} else if (nd->nd_flag & ND_NFSV3) {
		NFSM_DISSECT(tl, u_int32_t *, NFSX_UNSIGNED);
		if (flag) {
			flag = fxdr_unsigned(int, *tl);
		} else if (fxdr_unsigned(int, *tl)) {
			error = nfsm_advance(nd, NFSX_V3FATTR, -1);
			if (error)
				return (error);
		}
	}
	if (flag) {
		error = nfsm_loadattr(nd, nap);
		if (!error)
			*attrflagp = 1;
	}
nfsmout:
	return (error);
}

/*
 * Initialize the owner/delegation sleep lock.
 */
void
nfscl_lockinit(struct nfsv4lock *lckp)
{

	lckp->nfslock_usecnt = 0;
	lckp->nfslock_lock = 0;
}

/*
 * Get an exclusive lock. (Not needed for OpenBSD4, since there is only one
 * thread for each posix process in the kernel.)
 */
void
nfscl_lockexcl(struct nfsv4lock *lckp, void *mutex)
{
	int igotlock;

	do {
		igotlock = nfsv4_lock(lckp, 1, NULL, mutex, NULL);
	} while (!igotlock);
}

/*
 * Release an exclusive lock.
 */
void
nfscl_lockunlock(struct nfsv4lock *lckp)
{

	nfsv4_unlock(lckp, 0);
}

/*
 * Called to dereference a lock on a stateid (delegation or open owner).
 */
void
nfscl_lockderef(struct nfsv4lock *lckp)
{

	NFSLOCKCLSTATE();
	lckp->nfslock_usecnt--;
	if (lckp->nfslock_usecnt == 0 && (lckp->nfslock_lock & NFSV4LOCK_WANTED)) {
		lckp->nfslock_lock &= ~NFSV4LOCK_WANTED;
		wakeup((caddr_t)lckp);
	}
	NFSUNLOCKCLSTATE();
}