/*      $NetBSD: dtfs_subr.c,v 1.5 2021/09/16 22:19:12 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/time.h>

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

#include "dtfs.h"

void
dtfs_baseattrs(struct vattr *vap, enum vtype type, ino_t id)
{
       struct timeval tv;
       struct timespec ts;

       gettimeofday(&tv, NULL);
       TIMEVAL_TO_TIMESPEC(&tv, &ts);

       vap->va_type = type;
       if (type == VDIR) {
               vap->va_mode = 0777;
               vap->va_nlink = 1;      /* n + 1 after adding dent */
       } else {
               vap->va_mode = 0666;
               vap->va_nlink = 0;      /* n + 1 */
       }
       vap->va_uid = 0;
       vap->va_gid = 0;
       vap->va_fileid = id;
       vap->va_size = 0;
       vap->va_blocksize = getpagesize();
       vap->va_gen = random();
       vap->va_flags = 0;
       vap->va_rdev = PUFFS_VNOVAL;
       vap->va_bytes = 0;
       vap->va_filerev = 1;
       vap->va_vaflags = 0;

       vap->va_atime = vap->va_mtime = vap->va_ctime = vap->va_birthtime = ts;
}

/*
* Well, as you can probably see, this interface has the slight problem
* of assuming file creation will always be successful, or at least not
* giving a reason for the failure.  Be sure to do better when you
* implement your own fs.
*/
struct puffs_node *
dtfs_genfile(struct puffs_node *dir, const struct puffs_cn *pcn,
       enum vtype type)
{
       struct dtfs_file *dff;
       struct dtfs_dirent *dfd;
       struct dtfs_mount *dtm;
       struct puffs_node *newpn;
       uid_t uid;
       int rv;

       assert(dir->pn_va.va_type == VDIR);
       assert(dir->pn_mnt != NULL);

       uid = 0;
       rv = puffs_cred_getuid(pcn->pcn_cred, &uid);
       assert(rv == 0);

       if (type == VDIR) {
               dff = dtfs_newdir();
               dff->df_dotdot = dir;
       } else
               dff = dtfs_newfile();

       dtm = puffs_pn_getmntspecific(dir);
       newpn = puffs_pn_new(dir->pn_mnt, dff);
       if (newpn == NULL)
               errx(1, "getnewpnode");
       dtfs_baseattrs(&newpn->pn_va, type, dtm->dtm_nextfileid++);

       dfd = emalloc(sizeof(struct dtfs_dirent));
       dfd->dfd_node = newpn;
       dfd->dfd_name = estrndup(pcn->pcn_name, pcn->pcn_namelen);
       dfd->dfd_namelen = strlen(dfd->dfd_name);
       dfd->dfd_parent = dir;
       dtfs_adddent(dir, dfd);

       newpn->pn_va.va_uid = uid;
       newpn->pn_va.va_gid = dir->pn_va.va_gid;

       return newpn;
}

struct dtfs_file *
dtfs_newdir()
{
       struct dtfs_file *dff;

       dff = emalloc(sizeof(struct dtfs_file));
       memset(dff, 0, sizeof(struct dtfs_file));
       LIST_INIT(&dff->df_dirents);

       return dff;
}

struct dtfs_file *
dtfs_newfile()
{
       struct dtfs_file *dff;

       dff = emalloc(sizeof(struct dtfs_file));
       memset(dff, 0, sizeof(struct dtfs_file));

       return dff;
}

struct dtfs_dirent *
dtfs_dirgetnth(struct dtfs_file *searchdir, int n)
{
       struct dtfs_dirent *dirent;
       int i;

       i = 0;
       LIST_FOREACH(dirent, &searchdir->df_dirents, dfd_entries) {
               if (i == n)
                       return dirent;
               i++;
       }

       return NULL;
}

struct dtfs_dirent *
dtfs_dirgetbyname(struct dtfs_file *searchdir, const char *fname, size_t fnlen)
{
       struct dtfs_dirent *dirent;

       LIST_FOREACH(dirent, &searchdir->df_dirents, dfd_entries)
               if (dirent->dfd_namelen == fnlen
                   && strncmp(dirent->dfd_name, fname, fnlen) == 0)
                       return dirent;

       return NULL;
}

/*
* common nuke, kill dirent from parent node
*/
void
dtfs_nukenode(struct puffs_node *nukeme, struct puffs_node *pn_parent,
       const char *fname, size_t fnlen)
{
       struct dtfs_dirent *dfd;
       struct dtfs_mount *dtm;

       assert(pn_parent->pn_va.va_type == VDIR);

       dfd = dtfs_dirgetbyname(DTFS_PTOF(pn_parent), fname, fnlen);
       assert(dfd);

       dtm = puffs_pn_getmntspecific(nukeme);
       dtm->dtm_nfiles--;
       assert(dtm->dtm_nfiles >= 1);

       dtfs_removedent(pn_parent, dfd);
       free(dfd);
}

/* free lingering information */
void
dtfs_freenode(struct puffs_node *pn)
{
       struct dtfs_file *df = DTFS_PTOF(pn);
       struct dtfs_mount *dtm;
       int i;

       assert(pn->pn_va.va_nlink == 0);
       dtm = puffs_pn_getmntspecific(pn);

       switch (pn->pn_va.va_type) {
       case VREG:
               assert(dtm->dtm_fsizes >= pn->pn_va.va_size);
               dtm->dtm_fsizes -= pn->pn_va.va_size;
               for (i = 0; i < BLOCKNUM(df->df_datalen, DTFS_BLOCKSHIFT); i++)
                       free(df->df_blocks[i]);
               if (df->df_datalen > i << DTFS_BLOCKSHIFT)
                       free(df->df_blocks[i]);
               break;
       case VLNK:
               free(df->df_linktarget);
               break;
       case VCHR:
       case VBLK:
       case VDIR:
       case VSOCK:
       case VFIFO:
               break;
       default:
               assert(0);
               break;
       }

       free(df);
       puffs_pn_put(pn);
}

void
dtfs_setsize(struct puffs_node *pn, off_t newsize)
{
       struct dtfs_file *df = DTFS_PTOF(pn);
       struct dtfs_mount *dtm;
       size_t newblocks;
       int needalloc, shrinks;
       int i;

       needalloc = newsize > ROUNDUP(df->df_datalen, DTFS_BLOCKSIZE);
       shrinks = newsize < pn->pn_va.va_size;

       if (needalloc || shrinks) {
               newblocks = BLOCKNUM(newsize, DTFS_BLOCKSHIFT) + 1;

               if (shrinks)
                       for (i = newblocks; i < df->df_numblocks; i++)
                               free(df->df_blocks[i]);

               df->df_blocks = erealloc(df->df_blocks,
                   newblocks * sizeof(uint8_t *));
               /*
                * if extended, set storage to zero
                * to match correct behaviour
                */
               if (!shrinks) {
                       for (i = df->df_numblocks; i < newblocks; i++) {
                               df->df_blocks[i] = emalloc(DTFS_BLOCKSIZE);
                               memset(df->df_blocks[i], 0, DTFS_BLOCKSIZE);
                       }
               }

               df->df_datalen = newsize;
               df->df_numblocks = newblocks;
       }

       dtm = puffs_pn_getmntspecific(pn);
       if (!shrinks) {
               dtm->dtm_fsizes += newsize - pn->pn_va.va_size;
       } else {
               dtm->dtm_fsizes -= pn->pn_va.va_size - newsize;
       }

       pn->pn_va.va_size = newsize;
       pn->pn_va.va_bytes = BLOCKNUM(newsize,DTFS_BLOCKSHIFT)>>DTFS_BLOCKSHIFT;
}

/* add & bump link count */
void
dtfs_adddent(struct puffs_node *pn_dir, struct dtfs_dirent *dent)
{
       struct dtfs_file *dir = DTFS_PTOF(pn_dir);
       struct puffs_node *pn_file = dent->dfd_node;
       struct dtfs_file *file = DTFS_PTOF(pn_file);
       struct dtfs_mount *dtm;

       assert(pn_dir->pn_va.va_type == VDIR);
       LIST_INSERT_HEAD(&dir->df_dirents, dent, dfd_entries);
       pn_file->pn_va.va_nlink++;

       dtm = puffs_pn_getmntspecific(pn_file);
       dtm->dtm_nfiles++;

       dent->dfd_parent = pn_dir;
       if (dent->dfd_node->pn_va.va_type == VDIR) {
               file->df_dotdot = pn_dir;
               pn_dir->pn_va.va_nlink++;
       }

       dtfs_updatetimes(pn_dir, 0, 1, 1);
}

/* remove & lower link count */
void
dtfs_removedent(struct puffs_node *pn_dir, struct dtfs_dirent *dent)
{
       struct puffs_node *pn_file = dent->dfd_node;

       assert(pn_dir->pn_va.va_type == VDIR);
       LIST_REMOVE(dent, dfd_entries);
       if (pn_file->pn_va.va_type == VDIR) {
               struct dtfs_file *df = DTFS_PTOF(pn_file);

               pn_dir->pn_va.va_nlink--;
               df->df_dotdot = NULL;
       }
       pn_file->pn_va.va_nlink--;
       assert(pn_dir->pn_va.va_nlink >= 2);

       dtfs_updatetimes(pn_dir, 0, 1, 1);
}

void
dtfs_updatetimes(struct puffs_node *pn, int doatime, int doctime, int domtime)
{
       struct timeval tv;
       struct timespec ts;

       gettimeofday(&tv, NULL);
       TIMEVAL_TO_TIMESPEC(&tv, &ts);

       if (doatime)
               pn->pn_va.va_atime = ts;
       if (doctime)
               pn->pn_va.va_ctime = ts;
       if (domtime)
               pn->pn_va.va_mtime = ts;
}

bool
dtfs_isunder(struct puffs_node *pn, struct puffs_node *pn_parent)
{
       struct dtfs_file *df;

       while (pn) {
               if (pn == pn_parent)
                       return true;
               df = DTFS_CTOF(pn);
               pn = df->df_dotdot;
       }

       return false;
}

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