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walk.c

/*    $NetBSD: walk.c,v 1.24 2008/12/28 21:51:46 christos Exp $   */

/*
 * Copyright (c) 2009, 2010
 *    Thorsten Glaser <tg@mirbsd.org>
 * Copyright (c) 2001 Wasabi Systems, Inc.
 * All rights reserved.
 *
 * Written by Luke Mewburn for Wasabi Systems, Inc.
 *
 * 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 for the NetBSD Project by
 *      Wasabi Systems, Inc.
 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
 *    or promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
 * 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.
 */

#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif

#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(__lint)
__IDSTRING(mbsdid, "$MirOS: src/usr.sbin/makefs/walk.c,v 1.11 2010/03/07 00:02:17 tg Exp $");
__RCSID("$NetBSD: walk.c,v 1.24 2008/12/28 21:51:46 christos Exp $");
#endif      /* !__lint */

#include <sys/param.h>
#include <sys/time.h>
#include <sys/stat.h>

#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <dirent.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "makefs.h"
#include "mtree.h"

static      void   apply_specdir(const char *, NODE *, fsnode *, int);
static      void   apply_specentry(const char *, NODE *, fsnode *);
static      fsnode      *create_fsnode(const char *, struct stat *);
static      fsinode     *link_check(fsinode *);

static uint32_t vinode = 3;

/*
 * walk_dir --
 *    build a tree of fsnodes from `dir', with a parent fsnode of `parent'
 *    (which may be NULL for the root of the tree).
 *    each "level" is a directory, with the "." entry guaranteed to be
 *    at the start of the list, and without ".." entries.
 */
fsnode *
walk_dir(const char *dir, fsnode *parent)
{
      fsnode            *first, *cur, *prev;
      DIR         *dirp;
      struct dirent     *dent;
      char        *path;
      struct stat stbuf;

      assert(dir != NULL);
      if ((path = malloc(maxpathlen + 1)) == NULL)
            err(1, "malloc");

      if (debug & DEBUG_WALK_DIR)
            printf("walk_dir: %s %p\n", dir, parent);
      if ((dirp = opendir(dir)) == NULL)
            err(1, "Can't opendir `%s'", dir);
      first = prev = NULL;
      while ((dent = readdir(dirp)) != NULL) {
            if (strcmp(dent->d_name, "..") == 0)
                  continue;
            if (debug & DEBUG_WALK_DIR_NODE)
                  printf("scanning %s/%s\n", dir, dent->d_name);
            if ((size_t)snprintf(path, maxpathlen, "%s/%s", dir, dent->d_name)
                >= maxpathlen)
                  errx(1, "Pathname too long.");
            if (lstat(path, &stbuf) == -1)
                  err(1, "Can't lstat `%s'", path);
#ifdef S_ISSOCK
            if (S_ISSOCK(stbuf.st_mode & S_IFMT)) {
                  if (debug & DEBUG_WALK_DIR_NODE)
                        printf("  skipping socket %s\n", path);
                  continue;
            }
#endif

            cur = create_fsnode(dent->d_name, &stbuf);
            cur->parent = parent;
            if (strcmp(dent->d_name, ".") == 0) {
                        /* ensure "." is at the start of the list */
                  if (cur->parent)
                        cur->inode->serno = cur->parent->inode->serno;
                  cur->next = first;
                  first = cur;
                  if (! prev)
                        prev = cur;
            } else {                /* not "." */
                  if (prev)
                        prev->next = cur;
                  prev = cur;
                  if (!first)
                        first = cur;
                  if (S_ISDIR(cur->type)) {
                        cur->inode->serno = vinode++;
                        cur->child = walk_dir(path, cur);
                        continue;
                  }
            }
            if (stbuf.st_nlink > 1) {
                  fsinode     *curino;

                  curino = link_check(cur->inode);
                  if (curino != NULL) {
                        free(cur->inode);
                        cur->inode = curino;
                        cur->inode->nlink++;
                        if (debug & DEBUG_WALK_DIR_LINKCHECK)
                              printf("link_check: found [%llu, %llu]\n",
                                  (unsigned long long)curino->st.st_dev,
                                  (unsigned long long)curino->st.st_ino);
                  }
            }
            if (!cur->inode->serno)
                  cur->inode->serno = vinode++;
            if (S_ISLNK(cur->type)) {
                  int llen;
                  char *slink;

                  if ((slink = malloc(stbuf.st_size + 1)) == NULL)
                        err(1, "malloc");
                  llen = readlink(path, slink, stbuf.st_size);
                  if (llen == -1)
                        err(1, "Readlink `%s'", path);
                  slink[llen] = '\0';
                  cur->symlink = slink;
            }
      }
      for (cur = first; cur != NULL; cur = cur->next)
            cur->first = first;
      if (closedir(dirp) == -1)
            err(1, "Can't closedir `%s'", dir);
      free(path);
      return (first);
}

static fsnode *
create_fsnode(const char *name, struct stat *stbuf)
{
      fsnode *cur;

      if ((cur = calloc(1, sizeof(fsnode))) == NULL ||
          (cur->name = strdup(name)) == NULL ||
          (cur->inode = calloc(1, sizeof(fsinode))) == NULL)
            err(1, "Memory allocation error");
      cur->type = stbuf->st_mode & S_IFMT;
      cur->inode->nlink = 1;
      cur->inode->st = *stbuf;
      return (cur);
}

/*
 * free_fsnodes --
 *    Removes node from tree and frees it and all of
 *   its decendents.
 */
void
free_fsnodes(fsnode *node)
{
      fsnode      *cur, *next;

      assert(node != NULL);

      /* for ".", start with actual parent node */
      if (node->first == node) {
            assert(node->name[0] == '.' && node->name[1] == '\0');
            if (node->parent) {
                  assert(node->parent->child == node);
                  node = node->parent;
            }
      }

      /* Find ourselves in our sibling list and unlink */
      if (node->first != node) {
            for (cur = node->first; cur->next; cur = cur->next) {
                  if (cur->next == node) {
                        cur->next = node->next;
                        node->next = NULL;
                        break;
                  }
            }
      }

      for (cur = node; cur != NULL; cur = next) {
            next = cur->next;
            if (cur->child) {
                  cur->child->parent = NULL;
                  free_fsnodes(cur->child);
            }
            if (cur->inode->nlink-- == 1)
                  free(cur->inode);
            if (cur->symlink)
                  free(cur->symlink);
            free(cur->name);
            free(cur);
      }
}

/*
 * apply_specfile --
 *    read in the mtree(8) specfile, and apply it to the tree
 *    at dir,parent. parameters in parent on equivalent types
 *    will be changed to those found in specfile, and missing
 *    entries will be added.
 */
void
apply_specfile(const char *specfile, const char *dir, fsnode *parent, int speconly)
{
      struct timeval     start;
      FILE  *fp;
      NODE  *root;

      assert(specfile != NULL);
      assert(parent != NULL);

      if (debug & DEBUG_APPLY_SPECFILE)
            printf("apply_specfile: %s, %s %p\n", specfile, dir, parent);

                        /* read in the specfile */
      if ((fp = fopen(specfile, "r")) == NULL)
            err(1, "Can't open `%s'", specfile);
      TIMER_START(start);
      root = spec(fp);
      TIMER_RESULTS(start, "spec");
      if (fclose(fp) == EOF)
            err(1, "Can't close `%s'", specfile);

                        /* perform some sanity checks */
      if (root == NULL)
            errx(1, "Specfile `%s' did not contain a tree", specfile);
      assert(strcmp(root->name, ".") == 0);
      assert(root->type == F_DIR);

                        /* merge in the changes */
      apply_specdir(dir, root, parent, speconly);

      free_nodes(root);
}

static void
apply_specdir(const char *dir, NODE *specnode, fsnode *dirnode, int speconly)
{
      char   *path;
      NODE  *curnode;
      fsnode      *curfsnode;

      assert(specnode != NULL);
      assert(dirnode != NULL);
      if ((path = malloc(maxpathlen + 1)) == NULL)
            err(1, "malloc");

      if (debug & DEBUG_APPLY_SPECFILE)
            printf("apply_specdir: %s %p %p\n", dir, specnode, dirnode);

      if (specnode->type != F_DIR)
            errx(1, "Specfile node `%s/%s' is not a directory",
                dir, specnode->name);
      if (dirnode->type != S_IFDIR)
            errx(1, "Directory node `%s/%s' is not a directory",
                dir, dirnode->name);

      apply_specentry(dir, specnode, dirnode);

      /* Remove any filesystem nodes not found in specfile */
      /* XXX inefficient.  This is O^2 in each dir and it would
       * have been better never to have walked this part of the tree
       * to begin with
       */
      if (speconly) {
            fsnode *next;
            assert(dirnode->name[0] == '.' && dirnode->name[1] == '\0');
            for (curfsnode = dirnode->next; curfsnode != NULL; curfsnode = next) {
                  next = curfsnode->next;
                  for (curnode = specnode->child; curnode != NULL;
                       curnode = curnode->next) {
                        if (strcmp(curnode->name, curfsnode->name) == 0)
                              break;
                  }
                  if (curnode == NULL) {
                        if (debug & DEBUG_APPLY_SPECONLY) {
                              printf("apply_specdir: trimming %s/%s %p\n", dir, curfsnode->name, curfsnode);
                        }
                        free_fsnodes(curfsnode);
                  }
            }
      }

                  /* now walk specnode->child matching up with dirnode */
      for (curnode = specnode->child; curnode != NULL;
          curnode = curnode->next) {
            if (debug & DEBUG_APPLY_SPECENTRY)
                  printf("apply_specdir:  spec %s\n",
                      curnode->name);
            for (curfsnode = dirnode->next; curfsnode != NULL;
                curfsnode = curfsnode->next) {
#if 0 /* too verbose for now */
                  if (debug & DEBUG_APPLY_SPECENTRY)
                        printf("apply_specdir:  dirent %s\n",
                            curfsnode->name);
#endif
                  if (strcmp(curnode->name, curfsnode->name) == 0)
                        break;
            }
            if ((size_t)snprintf(path, maxpathlen, "%s/%s",
                dir, curnode->name) >= maxpathlen)
                  errx(1, "Pathname too long.");
            if (curfsnode == NULL) {      /* need new entry */
                  struct stat stbuf;

                                  /*
                                   * don't add optional spec entries
                                   * that lack an existing fs entry
                                   */
                  if ((curnode->flags & F_OPT) &&
                      lstat(path, &stbuf) == -1)
                              continue;

                              /* check that enough info is provided */
#define NODETEST(t, m)                                      \
                  if (!(t))                           \
                        errx(1, "`%s': %s not provided", path, m)
                  NODETEST(curnode->flags & F_TYPE, "type");
                  NODETEST(curnode->flags & F_MODE, "mode");
                        /* XXX: require F_TIME ? */
                  NODETEST(curnode->flags & F_GID ||
                      curnode->flags & F_GNAME, "group");
                  NODETEST(curnode->flags & F_UID ||
                      curnode->flags & F_UNAME, "user");
                  if (curnode->type == F_BLOCK || curnode->type == F_CHAR)
                        NODETEST(curnode->flags & F_DEV,
                            "device number");
#undef NODETEST

                  if (debug & DEBUG_APPLY_SPECFILE)
                        printf("apply_specdir: adding %s\n",
                            curnode->name);
                              /* build minimal fsnode */
                  memset(&stbuf, 0, sizeof(stbuf));
                  stbuf.st_mode = nodetoino(curnode->type);
                  stbuf.st_nlink = 1;
                  stbuf.st_mtime = stbuf.st_atime =
                      stbuf.st_ctime = start_time.tv_sec;
#if HAVE_STRUCT_STAT_ST_MTIMENSEC
                  stbuf.st_mtimensec = stbuf.st_atimensec =
                      stbuf.st_ctimensec = start_time.tv_nsec;
#endif
                  curfsnode = create_fsnode(curnode->name, &stbuf);
                  curfsnode->parent = dirnode->parent;
                  curfsnode->first = dirnode;
                  curfsnode->next = dirnode->next;
                  dirnode->next = curfsnode;
                  if (curfsnode->type == S_IFDIR) {
                              /* for dirs, make "." entry as well */
                        curfsnode->child = create_fsnode(".", &stbuf);
                        curfsnode->child->parent = curfsnode;
                        curfsnode->child->first = curfsnode->child;
                  }
                  if (curfsnode->type == S_IFLNK) {
                        assert(curnode->slink != NULL);
                              /* for symlinks, copy the target */
                        if ((curfsnode->symlink =
                            strdup(curnode->slink)) == NULL)
                              err(1, "Memory allocation error");
                  }
            }
            apply_specentry(dir, curnode, curfsnode);
            if (curnode->type == F_DIR) {
                  if (curfsnode->type != S_IFDIR)
                        errx(1, "`%s' is not a directory", path);
                  assert (curfsnode->child != NULL);
                  apply_specdir(path, curnode, curfsnode->child, speconly);
            }
      }
      free(path);
}

static void
apply_specentry(const char *dir, NODE *specnode, fsnode *dirnode)
{

      assert(specnode != NULL);
      assert(dirnode != NULL);

      if (nodetoino(specnode->type) != dirnode->type)
            errx(1, "`%s/%s' type mismatch: specfile %s, tree %s",
                dir, specnode->name, inode_type(nodetoino(specnode->type)),
                inode_type(dirnode->type));

      if (debug & DEBUG_APPLY_SPECENTRY)
            printf("apply_specentry: %s/%s\n", dir, dirnode->name);

#define ASEPRINT(t, b, o, n) \
            if (debug & DEBUG_APPLY_SPECENTRY) \
                  printf("\t\t\tchanging %s from " b " to " b "\n", \
                      t, o, n)

      if (specnode->flags & (F_GID | F_GNAME)) {
            ASEPRINT("gid", "%d",
                dirnode->inode->st.st_gid, specnode->st_gid);
            dirnode->inode->st.st_gid = specnode->st_gid;
      }
      if (specnode->flags & F_MODE) {
            ASEPRINT("mode", "%#o",
                dirnode->inode->st.st_mode & ALLPERMS, specnode->st_mode);
            dirnode->inode->st.st_mode &= ~ALLPERMS;
            dirnode->inode->st.st_mode |= (specnode->st_mode & ALLPERMS);
      }
            /* XXX: ignoring F_NLINK for now */
      if (specnode->flags & F_SIZE) {
            ASEPRINT("size", "%lld",
                (long long)dirnode->inode->st.st_size,
                (long long)specnode->st_size);
            dirnode->inode->st.st_size = specnode->st_size;
      }
      if (specnode->flags & F_SLINK) {
            assert(dirnode->symlink != NULL);
            assert(specnode->slink != NULL);
            ASEPRINT("symlink", "%s", dirnode->symlink, specnode->slink);
            free(dirnode->symlink);
            if ((dirnode->symlink = strdup(specnode->slink)) == NULL)
                  err(1, "Memory allocation error");
      }
      if (specnode->flags & F_TIME) {
            ASEPRINT("time", "%ld",
                (long)dirnode->inode->st.st_mtime,
                (long)specnode->st_mtimespec.tv_sec);
            dirnode->inode->st.st_mtime =       specnode->st_mtimespec.tv_sec;
            dirnode->inode->st.st_atime =       specnode->st_mtimespec.tv_sec;
            dirnode->inode->st.st_ctime =       start_time.tv_sec;
#if HAVE_STRUCT_STAT_ST_MTIMENSEC
            dirnode->inode->st.st_mtimensec =   specnode->st_mtimespec.tv_nsec;
            dirnode->inode->st.st_atimensec =   specnode->st_mtimespec.tv_nsec;
            dirnode->inode->st.st_ctimensec =   start_time.tv_nsec;
#endif
      }
      if (specnode->flags & (F_UID | F_UNAME)) {
            ASEPRINT("uid", "%d",
                dirnode->inode->st.st_uid, specnode->st_uid);
            dirnode->inode->st.st_uid = specnode->st_uid;
      }
#if HAVE_STRUCT_STAT_ST_FLAGS
      if (specnode->flags & F_FLAGS) {
            ASEPRINT("flags", "%#lX",
                (unsigned long)dirnode->inode->st.st_flags,
                (unsigned long)specnode->st_flags);
            dirnode->inode->st.st_flags = specnode->st_flags;
      }
#endif
      if (specnode->flags & F_DEV) {
            ASEPRINT("rdev", "%#llx",
                (unsigned long long)dirnode->inode->st.st_rdev,
                (unsigned long long)specnode->st_rdev);
            dirnode->inode->st.st_rdev = specnode->st_rdev;
      }
#undef ASEPRINT

      dirnode->flags |= FSNODE_F_HASSPEC;
}


/*
 * dump_fsnodes --
 *    dump the fsnodes from `cur', based in the directory `dir'
 */
void
dump_fsnodes(const char *dir, fsnode *root)
{
      fsnode      *cur;
      char  *path;

      assert (dir != NULL);
      if ((path = malloc(maxpathlen + 1)) == NULL)
            err(1, "malloc");
      printf("dump_fsnodes: %s(%d) %p\n", dir, root->inode->serno, root);
      for (cur = root; cur != NULL; cur = cur->next) {
            if ((size_t)snprintf(path, maxpathlen, "%s/%s", dir, cur->name)
                >= maxpathlen)
                  errx(1, "Pathname too long.");

            if (debug & DEBUG_DUMP_FSNODES_VERBOSE)
                  printf("cur=%8p parent=%8p first=%8p ",
                      cur, cur->parent, cur->first);
            printf("%7s %5d: %s", inode_type(cur->type),
                cur->inode->serno, path);
            if (S_ISLNK(cur->type)) {
                  assert(cur->symlink != NULL);
                  printf(" -> %s", cur->symlink);
            } else {
                  assert (cur->symlink == NULL);
            }
            if (cur->inode->nlink > 1)
                  printf(", nlinks=%d", cur->inode->nlink);
            putchar('\n');

            if (cur->child) {
                  assert (cur->type == S_IFDIR);
                  dump_fsnodes(path, cur->child);
            }
      }
      printf("dump_fsnodes: finished %s\n", dir);
      free(path);
}


/*
 * inode_type --
 *    for a given inode type `mode', return a descriptive string.
 *    for most cases, uses inotype() from mtree/misc.c
 */
const char *
inode_type(mode_t mode)
{

      if (S_ISLNK(mode))
            return ("symlink");     /* inotype() returns "link"...  */
      return (inotype(mode));
}


/*
 * link_check --
 *    return pointer to fsinode matching `entry's st_ino & st_dev if it exists,
 *    otherwise add `entry' to table and return NULL
 */
/* This was borrowed from du.c and tweaked to keep an fsnode
 * pointer instead. -- dbj@netbsd.org
 */
static fsinode *
link_check(fsinode *entry)
{
      static struct entry {
            fsinode *data;
      } *htable;
      static int htshift;  /* log(allocated size) */
      static int htmask;   /* allocated size - 1 */
      static int htused;   /* 2*number of insertions */
      int h, h2;
      uint64_t tmp;
      /* this constant is (1<<64)/((1+sqrt(5))/2)
       * aka (word size)/(golden ratio)
       */
      const uint64_t HTCONST = 11400714819323198485ULL;
      const int HTBITS = 64;

      /* Never store zero in hashtable */
      assert(entry);

      /* Extend hash table if necessary, keep load under 0.5 */
      if (htused<<1 >= htmask) {
            struct entry *ohtable;

            if (!htable)
                  htshift = 10;   /* starting hashtable size */
            else
                  htshift++;   /* exponential hashtable growth */

            htmask  = (1 << htshift) - 1;
            htused = 0;

            ohtable = htable;
            htable = calloc(htmask+1, sizeof(*htable));
            if (!htable)
                  err(1, "Memory allocation error");

            /* populate newly allocated hashtable */
            if (ohtable) {
                  int i;
                  for (i = 0; i <= htmask>>1; i++)
                        if (ohtable[i].data)
                              link_check(ohtable[i].data);
                  free(ohtable);
            }
      }

      /* multiplicative hashing */
      tmp = entry->st.st_dev;
      tmp <<= HTBITS>>1;
      tmp |=  entry->st.st_ino;
      tmp *= HTCONST;
      h  = tmp >> (HTBITS - htshift);
      h2 = 1 | ( tmp >> (HTBITS - (htshift<<1) - 1)); /* must be odd */

      /* open address hashtable search with double hash probing */
      while (htable[h].data) {
            if ((htable[h].data->st.st_ino == entry->st.st_ino) &&
                (htable[h].data->st.st_dev == entry->st.st_dev)) {
                  return htable[h].data;
            }
            h = (h + h2) & htmask;
      }

      /* Insert the current entry into hashtable */
      htable[h].data = entry;
      htused++;
      return NULL;
}

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