/*      $OpenBSD: nfs_srvsubs.c,v 1.2 2024/09/18 05:21:19 jsg Exp $     */
/*      $NetBSD: nfs_subs.c,v 1.27.4.3 1996/07/08 20:34:24 jtc Exp $    */

/*
 * 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.
 *
 *      @(#)nfs_subs.c  8.8 (Berkeley) 5/22/95
 */


/*
 * These functions support the nfsm_subs.h inline functions and help fiddle
 * mbuf chains for the nfs op functions. They do things such as creating the
 * rpc header and copying data between mbuf chains and uio lists.
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/namei.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/pool.h>

#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/xdr_subs.h>
#include <nfs/nfs_var.h>
#include <nfs/nfsm_subs.h>

#include <netinet/in.h>

/* Global vars */
extern u_int32_t nfs_false, nfs_true;
extern const nfstype nfsv2_type[9];
extern const nfstype nfsv3_type[9];

/*
 * Set up nameidata for a lookup() call and do it
 */
int
nfs_namei(struct nameidata *ndp, fhandle_t *fhp, int len,
    struct nfssvc_sock *slp, struct mbuf *nam, struct mbuf **mdp,
    caddr_t *dposp, struct vnode **retdirp, struct proc *p)
{
        int i, rem;
        struct mbuf *md;
        char *fromcp, *tocp;
        struct vnode *dp;
        int error, rdonly;
        struct componentname *cnp = &ndp->ni_cnd;

        *retdirp = NULL;
        cnp->cn_pnbuf = pool_get(&namei_pool, PR_WAITOK);
        /*
         * Copy the name from the mbuf list to ndp->ni_pnbuf
         * and set the various ndp fields appropriately.
         */
        fromcp = *dposp;
        tocp = cnp->cn_pnbuf;
        md = *mdp;
        rem = mtod(md, caddr_t) + md->m_len - fromcp;
        for (i = 0; i < len; i++) {
                while (rem == 0) {
                        md = md->m_next;
                        if (md == NULL) {
                                error = EBADRPC;
                                goto out;
                        }
                        fromcp = mtod(md, caddr_t);
                        rem = md->m_len;
                }
                if (*fromcp == '\0' || *fromcp == '/') {
                        error = EACCES;
                        goto out;
                }
                *tocp++ = *fromcp++;
                rem--;
        }
        *tocp = '\0';
        *mdp = md;
        *dposp = fromcp;
        len = nfsm_padlen(len);
        if (len > 0) {
                if (rem >= len)
                        *dposp += len;
                else if ((error = nfs_adv(mdp, dposp, len, rem)) != 0)
                        goto out;
        }
        ndp->ni_pathlen = tocp - cnp->cn_pnbuf;
        cnp->cn_nameptr = cnp->cn_pnbuf;
        /*
         * Extract and set starting directory.
         */
        error = nfsrv_fhtovp(fhp, 0, &dp, ndp->ni_cnd.cn_cred, slp,
            nam, &rdonly);
        if (error)
                goto out;
        if (dp->v_type != VDIR) {
                vrele(dp);
                error = ENOTDIR;
                goto out;
        }
        vref(dp);
        *retdirp = dp;
        ndp->ni_startdir = dp;
        if (rdonly)
                cnp->cn_flags |= (NOCROSSMOUNT | RDONLY);
        else
                cnp->cn_flags |= NOCROSSMOUNT;

        /*
         * And call lookup() to do the real work
         */
        cnp->cn_proc = p;
        error = vfs_lookup(ndp);
        if (error)
                goto out;
        /*
         * Check for encountering a symbolic link
         */
        if (cnp->cn_flags & ISSYMLINK) {
                if ((cnp->cn_flags & LOCKPARENT) && ndp->ni_pathlen == 1)
                        vput(ndp->ni_dvp);
                else
                        vrele(ndp->ni_dvp);
                vput(ndp->ni_vp);
                ndp->ni_vp = NULL;
                error = EINVAL;
                goto out;
        }
        /*
         * Check for saved name request
         */
        if (cnp->cn_flags & (SAVENAME | SAVESTART)) {
                cnp->cn_flags |= HASBUF;
                return (0);
        }
out:
        pool_put(&namei_pool, cnp->cn_pnbuf);
        return (error);
}

/*
 * A fiddled version of m_adj() that ensures null fill to a long
 * boundary and only trims off the back end
 */
void
nfsm_adj(struct mbuf *mp, int len, int nul)
{
        struct mbuf *m;
        int count, i;
        char *cp;

        /*
         * Trim from tail.  Scan the mbuf chain,
         * calculating its length and finding the last mbuf.
         * If the adjustment only affects this mbuf, then just
         * adjust and return.  Otherwise, rescan and truncate
         * after the remaining size.
         */
        count = 0;
        m = mp;
        for (;;) {
                count += m->m_len;
                if (m->m_next == NULL)
                        break;
                m = m->m_next;
        }
        if (m->m_len > len) {
                m->m_len -= len;
                if (nul > 0) {
                        cp = mtod(m, caddr_t)+m->m_len-nul;
                        for (i = 0; i < nul; i++)
                                *cp++ = '\0';
                }
                return;
        }
        count -= len;
        if (count < 0)
                count = 0;
        /*
         * Correct length for chain is "count".
         * Find the mbuf with last data, adjust its length,
         * and toss data from remaining mbufs on chain.
         */
        for (m = mp; m; m = m->m_next) {
                if (m->m_len >= count) {
                        m->m_len = count;
                        if (nul > 0) {
                                cp = mtod(m, caddr_t)+m->m_len-nul;
                                for (i = 0; i < nul; i++)
                                        *cp++ = '\0';
                        }
                        break;
                }
                count -= m->m_len;
        }
        for (m = m->m_next;m;m = m->m_next)
                m->m_len = 0;
}

/*
 * Make these non-inline functions, so that the kernel text size
 * doesn't get too big...
 */
void
nfsm_srvwcc(struct nfsrv_descript *nfsd, int before_ret,
    struct vattr *before_vap, int after_ret, struct vattr *after_vap,
    struct nfsm_info *info)
{
        u_int32_t *tl;

        if (before_ret) {
                tl = nfsm_build(&info->nmi_mb, NFSX_UNSIGNED);
                *tl = nfs_false;
        } else {
                tl = nfsm_build(&info->nmi_mb, 7 * NFSX_UNSIGNED);
                *tl++ = nfs_true;
                txdr_hyper(before_vap->va_size, tl);
                tl += 2;
                txdr_nfsv3time(&(before_vap->va_mtime), tl);
                tl += 2;
                txdr_nfsv3time(&(before_vap->va_ctime), tl);
        }
        nfsm_srvpostop_attr(nfsd, after_ret, after_vap, info);
}

void
nfsm_srvpostop_attr(struct nfsrv_descript *nfsd, int after_ret,
    struct vattr *after_vap, struct nfsm_info *info)
{
        u_int32_t *tl;
        struct nfs_fattr *fp;

        if (after_ret) {
                tl = nfsm_build(&info->nmi_mb, NFSX_UNSIGNED);
                *tl = nfs_false;
        } else {
                tl = nfsm_build(&info->nmi_mb, NFSX_UNSIGNED + NFSX_V3FATTR);
                *tl++ = nfs_true;
                fp = (struct nfs_fattr *)tl;
                nfsm_srvfattr(nfsd, after_vap, fp);
        }
}

void
nfsm_srvfattr(struct nfsrv_descript *nfsd, struct vattr *vap,
    struct nfs_fattr *fp)
{

        fp->fa_nlink = txdr_unsigned(vap->va_nlink);
        fp->fa_uid = txdr_unsigned(vap->va_uid);
        fp->fa_gid = txdr_unsigned(vap->va_gid);
        if (nfsd->nd_flag & ND_NFSV3) {
                fp->fa_type = vtonfsv3_type(vap->va_type);
                fp->fa_mode = vtonfsv3_mode(vap->va_mode);
                txdr_hyper(vap->va_size, &fp->fa3_size);
                txdr_hyper(vap->va_bytes, &fp->fa3_used);
                fp->fa3_rdev.specdata1 = txdr_unsigned(major(vap->va_rdev));
                fp->fa3_rdev.specdata2 = txdr_unsigned(minor(vap->va_rdev));
                fp->fa3_fsid.nfsuquad[0] = 0;
                fp->fa3_fsid.nfsuquad[1] = txdr_unsigned(vap->va_fsid);
                txdr_hyper(vap->va_fileid, &fp->fa3_fileid);
                txdr_nfsv3time(&vap->va_atime, &fp->fa3_atime);
                txdr_nfsv3time(&vap->va_mtime, &fp->fa3_mtime);
                txdr_nfsv3time(&vap->va_ctime, &fp->fa3_ctime);
        } else {
                fp->fa_type = vtonfsv2_type(vap->va_type);
                fp->fa_mode = vtonfsv2_mode(vap->va_type, vap->va_mode);
                fp->fa2_size = txdr_unsigned(vap->va_size);
                fp->fa2_blocksize = txdr_unsigned(vap->va_blocksize);
                if (vap->va_type == VFIFO)
                        fp->fa2_rdev = 0xffffffff;
                else
                        fp->fa2_rdev = txdr_unsigned(vap->va_rdev);
                fp->fa2_blocks = txdr_unsigned(vap->va_bytes / NFS_FABLKSIZE);
                fp->fa2_fsid = txdr_unsigned(vap->va_fsid);
                fp->fa2_fileid = txdr_unsigned((u_int32_t)vap->va_fileid);
                txdr_nfsv2time(&vap->va_atime, &fp->fa2_atime);
                txdr_nfsv2time(&vap->va_mtime, &fp->fa2_mtime);
                txdr_nfsv2time(&vap->va_ctime, &fp->fa2_ctime);
        }
}

/*
 * nfsrv_fhtovp() - convert a fh to a vnode ptr (optionally locked)
 *      - look up fsid in mount list (if not found ret error)
 *      - get vp and export rights by calling VFS_FHTOVP() and VFS_CHECKEXP()
 *      - if cred->cr_uid == 0 or MNT_EXPORTANON set it to credanon
 *      - if not lockflag unlock it with VOP_UNLOCK()
 */
int
nfsrv_fhtovp(fhandle_t *fhp, int lockflag, struct vnode **vpp,
    struct ucred *cred, struct nfssvc_sock *slp, struct mbuf *nam,
    int *rdonlyp)
{
        struct mount *mp;
        int i;
        struct ucred *credanon;
        int error, exflags;
        struct sockaddr_in *saddr;

        *vpp = NULL;
        mp = vfs_getvfs(&fhp->fh_fsid);

        if (!mp)
                return (ESTALE);
        error = VFS_CHECKEXP(mp, nam, &exflags, &credanon);
        if (error)
                return (error);
        error = VFS_FHTOVP(mp, &fhp->fh_fid, vpp);
        if (error)
                return (error);

        saddr = mtod(nam, struct sockaddr_in *);
        if (saddr->sin_family == AF_INET &&
            (ntohs(saddr->sin_port) >= IPPORT_RESERVED ||
            (slp->ns_so->so_type == SOCK_STREAM && ntohs(saddr->sin_port) == 20))) {
                vput(*vpp);
                return (NFSERR_AUTHERR | AUTH_TOOWEAK);
        }

        /* Check/setup credentials. */
        if (cred->cr_uid == 0 || (exflags & MNT_EXPORTANON)) {
                cred->cr_uid = credanon->cr_uid;
                cred->cr_gid = credanon->cr_gid;
                for (i = 0; i < credanon->cr_ngroups && i < NGROUPS_MAX; i++)
                        cred->cr_groups[i] = credanon->cr_groups[i];
                cred->cr_ngroups = i;
        }
        if (exflags & MNT_EXRDONLY)
                *rdonlyp = 1;
        else
                *rdonlyp = 0;
        if (!lockflag)
                VOP_UNLOCK(*vpp);

        return (0);
}

/*
 * This function compares two net addresses by family and returns non zero
 * if they are the same host, or if there is any doubt it returns 0.
 * The AF_INET family is handled as a special case so that address mbufs
 * don't need to be saved to store "struct in_addr", which is only 4 bytes.
 */
int
netaddr_match(int family, union nethostaddr *haddr, struct mbuf *nam)
{
        struct sockaddr_in *inetaddr;

        switch (family) {
        case AF_INET:
                inetaddr = mtod(nam, struct sockaddr_in *);
                if (inetaddr->sin_family == AF_INET &&
                    inetaddr->sin_addr.s_addr == haddr->had_inetaddr)
                        return (1);
                break;
        default:
                break;
        }
        return (0);
}

int
nfsm_srvsattr(struct mbuf **mp, struct vattr *va, struct mbuf *mrep,
    caddr_t *dposp)
{
        struct nfsm_info        info;
        int error = 0;
        uint32_t *tl;

        info.nmi_md = *mp;
        info.nmi_dpos = *dposp;
        info.nmi_mrep = mrep;
        info.nmi_errorp = &error;

        tl = (uint32_t *)nfsm_dissect(&info, NFSX_UNSIGNED);
        if (tl == NULL)
                return error;
        if (*tl == nfs_true) {
                tl = (uint32_t *)nfsm_dissect(&info, NFSX_UNSIGNED);
                if (tl == NULL)
                        return error;
                va->va_mode = nfstov_mode(*tl);
        }

        tl = (uint32_t *)nfsm_dissect(&info, NFSX_UNSIGNED);
        if (tl == NULL)
                return error;
        if (*tl == nfs_true) {
                tl = (uint32_t *)nfsm_dissect(&info, NFSX_UNSIGNED);
                if (tl == NULL)
                        return error;
                va->va_uid = fxdr_unsigned(uid_t, *tl);
        }

        tl = (uint32_t *)nfsm_dissect(&info, NFSX_UNSIGNED);
        if (tl == NULL)
                return error;
        if (*tl == nfs_true) {
                tl = (uint32_t *)nfsm_dissect(&info, NFSX_UNSIGNED);
                if (tl == NULL)
                        return error;
                va->va_gid = fxdr_unsigned(gid_t, *tl);
        }

        tl = (uint32_t *)nfsm_dissect(&info, NFSX_UNSIGNED);
        if (tl == NULL)
                return error;
        if (*tl == nfs_true) {
                tl = (uint32_t *)nfsm_dissect(&info, 2 * NFSX_UNSIGNED);
                if (tl == NULL)
                        return error;
                va->va_size = fxdr_hyper(tl);
        }

        tl = (uint32_t *)nfsm_dissect(&info, NFSX_UNSIGNED);
        if (tl == NULL)
                return error;
        switch (fxdr_unsigned(int, *tl)) {
        case NFSV3SATTRTIME_TOCLIENT:
                va->va_vaflags |= VA_UTIMES_CHANGE;
                va->va_vaflags &= ~VA_UTIMES_NULL;
                tl = (uint32_t *)nfsm_dissect(&info, 2 * NFSX_UNSIGNED);
                if (tl == NULL)
                        return error;
                fxdr_nfsv3time(tl, &va->va_atime);
                break;
        case NFSV3SATTRTIME_TOSERVER:
                va->va_vaflags |= VA_UTIMES_CHANGE;
                getnanotime(&va->va_atime);
                break;
        }

        tl = (uint32_t *)nfsm_dissect(&info, NFSX_UNSIGNED);
        if (tl == NULL)
                return error;
        switch (fxdr_unsigned(int, *tl)) {
        case NFSV3SATTRTIME_TOCLIENT:
                va->va_vaflags |= VA_UTIMES_CHANGE;
                va->va_vaflags &= ~VA_UTIMES_NULL;
                tl = (uint32_t *)nfsm_dissect(&info, 2 * NFSX_UNSIGNED);
                if (tl == NULL)
                        return error;
                fxdr_nfsv3time(tl, &va->va_mtime);
                break;
        case NFSV3SATTRTIME_TOSERVER:
                va->va_vaflags |= VA_UTIMES_CHANGE;
                getnanotime(&va->va_mtime);
                break;
        }

        *dposp = info.nmi_dpos;
        *mp = info.nmi_md;
        return 0;
}