/*      $NetBSD: dtfs_vfsops.c,v 1.5 2021/09/19 10:34:10 andvar Exp $   */

/*
 * Copyright (c) 2006  Antti Kantee.  All Rights Reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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/types.h>
#include <sys/resource.h>

#include <stdio.h>
#include <assert.h>
#include <err.h>
#include <errno.h>
#include <puffs.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <util.h>

#include "dtfs.h"

static int
rtstr(struct puffs_usermount *pu, const char *str, enum vtype vt)
{
        struct puffs_node *pn = puffs_getroot(pu);
        struct vattr *va = &pn->pn_va;
        struct dtfs_file *df = DTFS_PTOF(pn);
        char ltarg[256+1];

        if (sscanf(str, "%*s %256s", ltarg) != 1)
                return 1;

        dtfs_baseattrs(va, vt, 2);
        df->df_linktarget = estrdup(ltarg);

        va->va_nlink = 1;
        va->va_size = strlen(df->df_linktarget);

        puffs_setrootinfo(pu, vt, 0, 0);

        return 0;
}

static int
rtdev(struct puffs_usermount *pu, const char *str, enum vtype vt)
{
        struct puffs_node *pn = puffs_getroot(pu);
        struct vattr *va = &pn->pn_va;
        int major, minor;

        if (sscanf(str, "%*s %d %d", &major, &minor) != 2)
                return 1;

        dtfs_baseattrs(va, vt, 2);
        va->va_nlink = 1;
        va->va_rdev = makedev(major, minor);

        if (vt == VBLK)
                va->va_mode |= S_IFBLK;
        else
                va->va_mode |= S_IFCHR;

        puffs_setrootinfo(pu, vt, 0, va->va_rdev);

        return 0;
}

static int
rtnorm(struct puffs_usermount *pu, const char *str, enum vtype vt)
{
        struct puffs_node *pn = puffs_getroot(pu);
        struct vattr *va = &pn->pn_va;

        dtfs_baseattrs(va, vt, 2);
        if (vt == VDIR)
                va->va_nlink = 2;
        else
                va->va_nlink = 1;

        puffs_setrootinfo(pu, vt, 0, 0);

        return 0;
}

struct rtype {
        char *tstr;
        enum vtype vt;
        int (*pfunc)(struct puffs_usermount *, const char *, enum vtype);
} rtypes[] = {
        { "reg", VREG, rtnorm },
        { "dir", VDIR, rtnorm },
        { "blk", VBLK, rtdev },
        { "chr", VCHR, rtdev },
        { "lnk", VLNK, rtstr },
        { "sock", VSOCK, rtnorm },
        { "fifo", VFIFO, rtnorm }
};
#define NTYPES (sizeof(rtypes) / sizeof(rtypes[0]))

int
dtfs_domount(struct puffs_usermount *pu, const char *typestr)
{
        struct dtfs_mount *dtm;
        struct dtfs_file *dff;
        struct puffs_node *pn;
        int i;

        /* create mount-local thingie */
        dtm = puffs_getspecific(pu);
        dtm->dtm_nextfileid = 3;
        dtm->dtm_nfiles = 1;
        dtm->dtm_fsizes = 0;
        LIST_INIT(&dtm->dtm_pollent);

        /*
         * create root directory, do it "by hand" to avoid special-casing
         * dtfs_genfile()
         */
        dff = dtfs_newdir();
        dff->df_dotdot = NULL;
        pn = puffs_pn_new(pu, dff);
        if (!pn)
                errx(1, "puffs_newpnode");
        puffs_setroot(pu, pn);

        if (!typestr) {
                rtnorm(pu, NULL, VDIR);
        } else {
                for (i = 0; i < NTYPES; i++) {
                        if (strncmp(rtypes[i].tstr, typestr,
                            strlen(rtypes[i].tstr)) == 0) {
                                if (rtypes[i].pfunc(pu, typestr,
                                    rtypes[i].vt) != 0) {
                                        fprintf(stderr, "failed to parse "
                                            "\"%s\"\n", typestr);
                                        return 1;
                                }
                                break;
                        }
                }
                if (i == NTYPES) {
                        fprintf(stderr, "no matching type for %s\n", typestr);
                        return 1;
                }
        }

        return 0;
}

/*
 * statvfs() should fill in the following members of struct statvfs:
 * 
 * unsigned long   f_bsize;         file system block size
 * unsigned long   f_frsize;        fundamental file system block size
 * unsigned long   f_iosize;        optimal file system block size
 * fsblkcnt_t      f_blocks;        number of blocks in file system,
 *                                            (in units of f_frsize)
 *
 * fsblkcnt_t      f_bfree;         free blocks avail in file system
 * fsblkcnt_t      f_bavail;        free blocks avail to non-root
 * fsblkcnt_t      f_bresvd;        blocks reserved for root
 *
 * fsfilcnt_t      f_files;         total file nodes in file system
 * fsfilcnt_t      f_ffree;         free file nodes in file system
 * fsfilcnt_t      f_favail;        free file nodes avail to non-root
 * fsfilcnt_t      f_fresvd;        file nodes reserved for root
 *
 *
 * The rest are filled in by the kernel.
 */
#define ROUND(a,b) (((a) + ((b)-1)) & ~((b)-1))
#define NFILES 1024*1024
int
dtfs_fs_statvfs(struct puffs_usermount *pu, struct puffs_statvfs *sbp)
{
        struct rlimit rlim;
        struct dtfs_mount *dtm;
        off_t btot, bfree;
        int pgsize;

        dtm = puffs_getspecific(pu);
        pgsize = getpagesize();
        memset(sbp, 0, sizeof(struct puffs_statvfs));

        /*
         * Use datasize rlimit as an _approximation_ for free size.
         * This, of course, is not accurate due to overhead and not
         * accounting for metadata.
         */
        if (getrlimit(RLIMIT_DATA, &rlim) == 0)
                btot = rlim.rlim_cur;
        else
                btot = 16*1024*1024;
        bfree = btot - dtm->dtm_fsizes;

        sbp->f_blocks = ROUND(btot, pgsize) / pgsize;
        sbp->f_files = NFILES;

        sbp->f_bsize = sbp->f_frsize = sbp->f_iosize = pgsize;
        sbp->f_bfree = sbp->f_bavail = ROUND(bfree, pgsize) / pgsize;
        sbp->f_ffree = sbp->f_favail = NFILES - dtm->dtm_nfiles;

        sbp->f_bresvd = sbp->f_fresvd = 0;

        return 0;
}
#undef ROUND 

static void *
addrcmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg)
{

        if (pn == arg)
                return pn;

        return NULL;
}

int
dtfs_fs_fhtonode(struct puffs_usermount *pu, void *fid, size_t fidsize,
        struct puffs_newinfo *pni)
{
        struct dtfs_fid *dfid;
        struct puffs_node *pn;

        assert(fidsize == sizeof(struct dtfs_fid));
        dfid = fid;

        pn = puffs_pn_nodewalk(pu, addrcmp, dfid->dfid_addr);
        if (pn == NULL)
                return ESTALE;

        if (pn->pn_va.va_fileid != dfid->dfid_fileid
            || pn->pn_va.va_gen != dfid->dfid_gen)
                return ESTALE;
        
        puffs_newinfo_setcookie(pni, pn);
        puffs_newinfo_setvtype(pni, pn->pn_va.va_type);
        puffs_newinfo_setsize(pni, pn->pn_va.va_size);
        puffs_newinfo_setrdev(pni, pn->pn_va.va_rdev);

        return 0;
}

int
dtfs_fs_nodetofh(struct puffs_usermount *pu, void *cookie,
        void *fid, size_t *fidsize)
{
        struct puffs_node *pn = cookie;
        struct dtfs_fid *dfid;
        extern int dynamicfh;

        if (dynamicfh == 0) {
                assert(*fidsize >= sizeof(struct dtfs_fid));
        } else {
                if (*fidsize < sizeof(struct dtfs_fid)) {
                        *fidsize = sizeof(struct dtfs_fid);
                        return E2BIG;
                }
                *fidsize = sizeof(struct dtfs_fid);
        }

        dfid = fid;

        dfid->dfid_addr = pn;
        dfid->dfid_fileid = pn->pn_va.va_fileid;
        dfid->dfid_gen = pn->pn_va.va_gen;

        return 0;
}

int
dtfs_fs_unmount(struct puffs_usermount *pu, int flags)
{

        return 0;
}