boot/common/module.c

/*-
 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
 * 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 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 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.
 *
 * $FreeBSD: src/sys/boot/common/module.c,v 1.25 2003/08/25 23:30:41 obrien Exp $
 */

/*
 * file/module function dispatcher, support, etc.
 */

#include <stand.h>
#include <string.h>
#include <sys/param.h>
#include <sys/linker.h>
#include <sys/module.h>
#include <sys/queue.h>
#ifndef EFI
#include "libi386/libi386.h"
#endif

#include "bootstrap.h"

#define   MDIR_REMOVED        0x0001
#define   MDIR_NOHINTS        0x0002

struct moduledir {
          char      *d_path;  /* path of modules directory */
          u_char    *d_hints; /* content of linker.hints file */
          int       d_hintsz; /* size of hints data */
          int       d_flags;
          STAILQ_ENTRY(moduledir) d_link;
};

static int                              file_load(char *filename, vm_offset_t dest, struct preloaded_file **result);
static int                              file_loadraw(char *type, char *name);
static int                              file_load_dependencies(struct preloaded_file *base_mod);
static char *                           file_search(const char *name, char **extlist);
static struct kernel_module * file_findmodule(struct preloaded_file *fp, char *modname, struct mod_depend *verinfo);
static int                              file_havepath(const char *name);
static char                             *mod_searchmodule(char *name, struct mod_depend *verinfo);
static void                             file_insert_tail(struct preloaded_file *mp);
static struct file_metadata*  metadata_next(struct file_metadata *base_mp, int type);
static void                             moduledir_readhints(struct moduledir *mdp);
static void                             moduledir_rebuild(void);

/* load address should be tweaked by first module loaded (kernel) */
static vm_offset_t  loadaddr = 0;

static const char   *default_searchpath = "modules;KERNEL";
static const char   *local_module_path = "../modules.local";

static STAILQ_HEAD(, moduledir) moduledir_list = STAILQ_HEAD_INITIALIZER(moduledir_list);

struct preloaded_file *preloaded_files = NULL;

static char *kld_ext_list[] = {
    ".ko",
    "",
    NULL
};

/*
 * load an object, either a disk file or code module.
 *
 * To load a file, the syntax is:
 *
 * load -t <type> <path>
 *
 * code modules are loaded as:
 *
 * load <path> <options>
 */
COMMAND_SET(load, "load", "load a kernel or module", command_load);

static int
command_load(int argc, char *argv[])
{
    char  *typestr;
    int             dofile, dokld, ch, error;

    dokld = dofile = 0;
    optind = 1;
    optreset = 1;
    typestr = NULL;
    if (argc == 1) {
          command_errmsg = "no filename specified";
          return(CMD_ERROR);
    }
    while ((ch = getopt(argc, argv, "kt:")) != -1) {
          switch(ch) {
          case 'k':
              dokld = 1;
              break;
          case 't':
              typestr = optarg;
              dofile = 1;
              break;
          case '?':
          default:
              /* getopt has already reported an error */
              return(CMD_OK);
          }
    }
    argv += (optind - 1);
    argc -= (optind - 1);

    /*
     * Request to load a raw file?
     */
    if (dofile) {
          if ((argc != 2) || (typestr == NULL) || (*typestr == 0)) {
              command_errmsg = "invalid load type";
              return(CMD_ERROR);
          }
          return(file_loadraw(typestr, argv[1]));
    }
    /*
     * Do we have explicit KLD load ?
     */
    if (dokld || file_havepath(argv[1])) {
          error = mod_loadkld(argv[1], argc - 2, argv + 2);
          if (error == EEXIST) {
              snprintf(command_errbuf, sizeof(command_errbuf),
                    "warning: KLD '%s' already loaded", argv[1]);
          }
          return (error == 0 ? CMD_OK : CMD_ERROR);
    }
    /*
     * Looks like a request for a module.
     */
    error = mod_load(argv[1], NULL, argc - 2, argv + 2);
    if (error == EEXIST) {
          snprintf(command_errbuf, sizeof(command_errbuf),
              "warning: module '%s' already loaded", argv[1]);
    }
    return (error == 0 ? CMD_OK : CMD_ERROR);
}

COMMAND_SET(unload, "unload", "unload all modules", command_unload);

static int
command_unload(int argc, char *argv[])
{
    struct preloaded_file     *fp;

    while (preloaded_files != NULL) {
          fp = preloaded_files;
          preloaded_files = preloaded_files->f_next;
          file_discard(fp);
    }
    loadaddr = 0;
    unsetenv("kernelname");
    return(CMD_OK);
}

COMMAND_SET(crc, "crc", "calculate crc for file", command_crc);

uint32_t iscsi_crc32(const void *buf, size_t size);
uint32_t iscsi_crc32_ext(const void *buf, size_t size, uint32_t ocrc);

static int
command_crc(int argc, char *argv[])
{
    char  *name;
    char  *cp;
    int             i;
    int             fd, got, tot;
    int             error;
    uint32_t        crc;
    char  *buf;

    if (argc == 1) {
          command_errmsg = "no filename specified";
          return(CMD_ERROR);
    }
    buf = malloc(8192);

    error = 0;
    printf("size\tcrc\t name\n");
    for (i = 1; i < argc; ++i) {
          /* locate the file on the load path */
          cp = file_search(argv[i], NULL);
          if (cp == NULL) {
              snprintf(command_errbuf, sizeof(command_errbuf),
                    "can't find '%s'", argv[i]);
              error = CMD_ERROR;
              break;
          }
          name = cp;

          if ((fd = rel_open(name, NULL, O_RDONLY)) < 0) {
              snprintf(command_errbuf, sizeof(command_errbuf),
                    "can't open '%s': %s", name, strerror(errno));
              free(name);
              error = CMD_ERROR;
              break;
          }
          tot = 0;
          crc = 0;
          for (;;) {
              got = read(fd, buf, 8192);
              if (got == 0)
                    break;
              if (got < 0) {
                    printf("error reading '%s': %s\n",
                        name, strerror(errno));
                    break;
              }
              if (crc == 0)
                    crc = iscsi_crc32(buf, got);
              else
                    crc = iscsi_crc32_ext(buf, got, crc);
              tot += got;
          }
          printf("%7d %08x %s\n", tot, crc, name);
          free(name);
          close(fd);
    }
    free (buf);
    if (error == 0)
          error = CMD_OK;
    return error;
}

COMMAND_SET(lsmod, "lsmod", "list loaded modules", command_lsmod);

static int
command_lsmod(int argc, char *argv[])
{
    struct preloaded_file     *fp;
    struct kernel_module      *mp;
    struct file_metadata      *md;
    char                      lbuf[80];
    int                                 ch, verbose;

    verbose = 0;
    optind = 1;
    optreset = 1;
    while ((ch = getopt(argc, argv, "v")) != -1) {
          switch(ch) {
          case 'v':
              verbose = 1;
              break;
          case '?':
          default:
              /* getopt has already reported an error */
              return(CMD_OK);
          }
    }

    pager_open();
    for (fp = preloaded_files; fp; fp = fp->f_next) {
          sprintf(lbuf, " %p: %s (%s, 0x%lx)\n",
                    (void *) fp->f_addr, fp->f_name, fp->f_type, (long) fp->f_size);
          pager_output(lbuf);
          if (fp->f_args != NULL) {
              pager_output("    args: ");
              pager_output(fp->f_args);
              pager_output("\n");
          }
          if (fp->f_modules) {
              pager_output("  modules: ");
              for (mp = fp->f_modules; mp; mp = mp->m_next) {
                    sprintf(lbuf, "%s.%d ", mp->m_name, mp->m_version);
                    pager_output(lbuf);
              }
              pager_output("\n");
          }
          if (verbose) {
              /* XXX could add some formatting smarts here to display some better */
              for (md = fp->f_metadata; md != NULL; md = md->md_next) {
                    sprintf(lbuf, "      0x%04x, 0x%lx\n", md->md_type, (long) md->md_size);
                    pager_output(lbuf);
              }
          }
    }
    pager_close();
    return(CMD_OK);
}

/*
 * File level interface, functions file_*
 */
static int
file_load(char *filename, vm_offset_t dest, struct preloaded_file **result)
{
    struct preloaded_file *fp;
    int error;
    int i;

    error = EFTYPE;
    for (i = 0, fp = NULL; file_formats[i] && fp == NULL; i++) {
          error = (file_formats[i]->l_load)(filename, dest, &fp);
          if (error == 0) {
              fp->f_loader = i;                   /* remember the loader */
              *result = fp;
              break;
          }
          if (error == EFTYPE)
              continue;                 /* Unknown to this handler? */
          if (error) {
              snprintf(command_errbuf, sizeof(command_errbuf),
                    "can't load file '%s': %s", filename, strerror(error));
              break;
          }
    }
    return (error);
}

static int
file_load_dependencies(struct preloaded_file *base_file)
{
    struct file_metadata *md;
    struct preloaded_file *fp;
    struct mod_depend *verinfo;
    struct kernel_module *mp;
    char *dmodname;
    int error;

    md = file_findmetadata(base_file, MODINFOMD_DEPLIST);
    if (md == NULL)
          return (0);

    error = 0;
    do {
          verinfo = (struct mod_depend*)md->md_data;
          dmodname = (char *)(verinfo + 1);
          if (file_findmodule(NULL, dmodname, verinfo) == NULL) {
              printf("loading required module '%s'\n", dmodname);
              error = mod_load(dmodname, verinfo, 0, NULL);
              if (error)
                    break;
              /*
               * If module loaded via kld name which isn't listed
               * in the linker.hints file, we should check if it have
               * required version.
               */
              mp = file_findmodule(NULL, dmodname, verinfo);
              if (mp == NULL) {
                    snprintf(command_errbuf, sizeof(command_errbuf),
                        "module '%s' exists but with wrong version", dmodname);
                    error = ENOENT;
                    break;
              }
          }
          md = metadata_next(md, MODINFOMD_DEPLIST);
    } while (md);
    if (!error)
          return (0);

    /* Load failed; discard everything */
    while (base_file != NULL) {
          fp = base_file;
          base_file = base_file->f_next;
          file_discard(fp);
    }
    return (error);
}

/*
 * We've been asked to load (name) as (type), so just suck it in,
 * no arguments or anything.
 */
static int
file_loadraw(char *type, char *name)
{
    struct preloaded_file     *fp;
    char                      *cp;
    int                                 fd, got;
    vm_offset_t                         laddr;

    /* We can't load first */
    if (file_findfile(NULL, NULL) == NULL) {
          command_errmsg = "can't load file before kernel";
          return(CMD_ERROR);
    }

    /* locate the file on the load path */
    cp = file_search(name, NULL);
    if (cp == NULL) {
          snprintf(command_errbuf, sizeof(command_errbuf),
              "can't find '%s'", name);
          return(CMD_ERROR);
    }
    name = cp;

    if ((fd = rel_open(name, NULL, O_RDONLY)) < 0) {
          snprintf(command_errbuf, sizeof(command_errbuf),
              "can't open '%s': %s", name, strerror(errno));
          free(name);
          return(CMD_ERROR);
    }

    laddr = loadaddr;
    for (;;) {
          /* read in 4k chunks; size is not really important */
#ifndef EFI
          if (laddr + 4096 > heapbase) {
              snprintf(command_errbuf, sizeof(command_errbuf),
                    "error reading '%s': out of load memory", name);
              free(name);
              close(fd);
              return(CMD_ERROR);
          }
#endif
          got = archsw.arch_readin(fd, laddr, 4096);
          if (got == 0)                                     /* end of file */
              break;
          if (got < 0) {                                    /* error */
              snprintf(command_errbuf, sizeof(command_errbuf),
                    "error reading '%s': %s", name, strerror(errno));
              free(name);
              close(fd);
              return(CMD_ERROR);
          }
          laddr += got;
    }

    /* Looks OK so far; create & populate control structure */
    fp = file_alloc();
    fp->f_name = rel_rootpath(name);
    fp->f_type = strdup(type);
    fp->f_args = NULL;
    fp->f_metadata = NULL;
    fp->f_loader = -1;
    fp->f_addr = loadaddr;
    fp->f_size = laddr - loadaddr;

    /* recognise space consumption */
    loadaddr = laddr;

    /* Add to the list of loaded files */
    file_insert_tail(fp);
    close(fd);
    return(CMD_OK);
}

/*
 * Load the module (name), pass it (argc),(argv), add container file
 * to the list of loaded files.
 * If module is already loaded just assign new argc/argv.
 */
int
mod_load(char *modname, struct mod_depend *verinfo, int argc, char *argv[])
{
    struct kernel_module      *mp;
    int                                 err;
    char                      *filename;

    if (file_havepath(modname)) {
          printf("Warning: mod_load() called instead of mod_loadkld() for module '%s'\n", modname);
          return (mod_loadkld(modname, argc, argv));
    }
    /* see if module is already loaded */
    mp = file_findmodule(NULL, modname, verinfo);
    if (mp) {
#ifdef moduleargs
          if (mp->m_args)
              free(mp->m_args);
          mp->m_args = unargv(argc, argv);
#endif
          snprintf(command_errbuf, sizeof(command_errbuf),
              "warning: module '%s' already loaded", mp->m_name);
          return (0);
    }
    /* locate file with the module on the search path */
    filename = mod_searchmodule(modname, verinfo);
    if (filename == NULL) {
          snprintf(command_errbuf, sizeof(command_errbuf),
              "can't find '%s'", modname);
          return (ENOENT);
    }
    err = mod_loadkld(filename, argc, argv);
    return (err);
}

/*
 * Load specified KLD. If path is omitted, then try to locate it via
 * search path.
 */
int
mod_loadkld(const char *kldname, int argc, char *argv[])
{
    struct preloaded_file     *fp, *last_file;
    int                                 err;
    char                      *filename;

    /*
     * Get fully qualified KLD name
     */
    filename = file_search(kldname, kld_ext_list);
    if (filename == NULL) {
          snprintf(command_errbuf, sizeof(command_errbuf),
              "can't find '%s'", kldname);
          return (ENOENT);
    }
    /*
     * Check if KLD already loaded
     */
    fp = file_findfile(filename, NULL);
    if (fp) {
          snprintf(command_errbuf, sizeof(command_errbuf),
              "warning: KLD '%s' already loaded", filename);
          free(filename);
          return (0);
    }
    for (last_file = preloaded_files;
           last_file != NULL && last_file->f_next != NULL;
           last_file = last_file->f_next)
          ;

    do {
          err = file_load(filename, loadaddr, &fp);
          if (err)
              break;
          fp->f_args = unargv(argc, argv);
          loadaddr = fp->f_addr + fp->f_size;
          file_insert_tail(fp);                   /* Add to the list of loaded files */
          if (file_load_dependencies(fp) != 0) {
              err = ENOENT;
              last_file->f_next = NULL;
              loadaddr = last_file->f_addr + last_file->f_size;
              fp = NULL;
              break;
          }
    } while(0);
    if (err == EFTYPE)
          snprintf(command_errbuf, sizeof(command_errbuf),
              "don't know how to load module '%s'", filename);
    if (err && fp)
          file_discard(fp);
    free(filename);
    return (err);
}

/*
 * Find a file matching (name) and (type).
 * NULL may be passed as a wildcard to either.
 */
struct preloaded_file *
file_findfile(char *name, char *type)
{
    struct preloaded_file *fp;
    char *rootpath;

    rootpath = NULL;
    if (name != NULL)
          rootpath = rel_rootpath(name);

    for (fp = preloaded_files; fp != NULL; fp = fp->f_next) {
          if (((rootpath == NULL) || !strcmp(rootpath, fp->f_name)) &&
              ((type == NULL) || !strcmp(type, fp->f_type)))
              break;
    }

    if (rootpath != NULL)
          free(rootpath);
    return (fp);
}

/*
 * Find a module matching (name) inside of given file.
 * NULL may be passed as a wildcard.
 */
static struct kernel_module *
file_findmodule(struct preloaded_file *fp, char *modname,
          struct mod_depend *verinfo)
{
    struct kernel_module *mp, *best;
    int bestver, mver;

    if (fp == NULL) {
          for (fp = preloaded_files; fp; fp = fp->f_next) {
              mp = file_findmodule(fp, modname, verinfo);
              if (mp)
                    return (mp);
          }
          return (NULL);
    }

    best = NULL;
    bestver = 0;
    for (mp = fp->f_modules; mp; mp = mp->m_next) {
        if (strcmp(modname, mp->m_name) == 0) {
              if (verinfo == NULL)
                    return (mp);
              mver = mp->m_version;
              if (mver == verinfo->md_ver_preferred)
                    return (mp);
              if (mver >= verinfo->md_ver_minimum &&
                    mver <= verinfo->md_ver_maximum &&
                    mver > bestver) {
                    best = mp;
                    bestver = mver;
              }
          }
    }
    return (best);
}
/*
 * Make a copy of (size) bytes of data from (p), and associate them as
 * metadata of (type) to the module (mp).
 */
void
file_addmetadata(struct preloaded_file *fp, int type, size_t size, void *p)
{
    struct file_metadata      *md;

    md = malloc(sizeof(struct file_metadata) - sizeof(md->md_data) + size);
    md->md_size = size;
    md->md_type = type;
    bcopy(p, md->md_data, size);
    md->md_next = fp->f_metadata;
    fp->f_metadata = md;
}

/*
 * Find a metadata object of (type) associated with the file (fp)
 */
struct file_metadata *
file_findmetadata(struct preloaded_file *fp, int type)
{
    struct file_metadata *md;

    for (md = fp->f_metadata; md != NULL; md = md->md_next)
          if (md->md_type == type)
              break;
    return(md);
}

static struct file_metadata *
metadata_next(struct file_metadata *md, int type)
{
    if (md == NULL)
          return (NULL);
    while((md = md->md_next) != NULL)
          if (md->md_type == type)
              break;
    return (md);
}

static char *emptyextlist[] = { "", NULL };

/*
 * Check if the given file is in place and return full path to it.
 */
static char *
file_lookup(const char *path, const char *name, int namelen, char **extlist)
{
    struct stat     st;
    char  *result, *cp, **cpp;
    size_t          pathlen, extlen;

    pathlen = strlen(path);
    extlen = 0;
    if (extlist == NULL)
          extlist = emptyextlist;
    for (cpp = extlist; *cpp; cpp++)
          extlen = MAX(extlen, strlen(*cpp));
    result = malloc(pathlen + namelen + extlen + 2 + 7 + 1);
    if (result == NULL)
          return (NULL);
    bcopy(path, result, pathlen);
    if (pathlen > 0 && result[pathlen - 1] != '/')
          result[pathlen++] = '/';
    cp = result + pathlen;
    bcopy(name, cp, namelen);
    cp += namelen;
    for (cpp = extlist; *cpp; cpp++) {
          strcpy(cp, *cpp);
          if (rel_stat(result, &st) == 0) {
              if (S_ISREG(st.st_mode)) {
                    return result;
              } else if (S_ISDIR(st.st_mode)) {
                    strcat(result, "/kernel");
                    if (rel_stat(result, &st) == 0 && S_ISREG(st.st_mode)) {
                        return result;
                    }
              }
          }
    }
    free(result);
    return NULL;
}

/*
 * Check if file name have any qualifiers
 */
static int
file_havepath(const char *name)
{
    const char                *cp;

    archsw.arch_getdev(NULL, name, &cp);
    return (cp != name || strchr(name, '/') != NULL);
}

/*
 * Attempt to find the file (name) on the module searchpath.
 * If (name) is qualified in any way, we simply check it and
 * return it or NULL.  If it is not qualified, then we attempt
 * to construct a path using entries in the environment variable
 * module_path.
 *
 * The path we return a pointer to need never be freed, as we manage
 * it internally.
 */
static char *
file_search(const char *name, char **extlist)
{
    struct moduledir          *mdp;
    struct stat               sb;
    char            *result;
    int                       namelen;

    /* Don't look for nothing */
    if (name == NULL || *name == 0)
          return(NULL);

    /*
     * Qualified name.  If it is a directory tag on
     * a "/kernel" to it.
     */
    if (file_havepath(name)) {
          /* Qualified, so just see if it exists */
          if (rel_stat(name, &sb) == 0) {
              if (S_ISDIR(sb.st_mode)) {
                    result = malloc(strlen(name) + 7 + 1);
                    sprintf(result, "%s/kernel", name);
                    return(result);
              } else {
                    return(strdup(name));
              }
          }
          return(NULL);
    }

    moduledir_rebuild();
    result = NULL;
    namelen = strlen(name);
    STAILQ_FOREACH(mdp, &moduledir_list, d_link) {
          result = file_lookup(mdp->d_path, name, namelen, extlist);
          if (result)
              break;
    }
    return(result);
}

#define   INT_ALIGN(base, ptr) \
          ptr = (base) + roundup2((ptr) - (base), sizeof(int))

static char *
mod_search_hints(struct moduledir *mdp, const char *modname,
          struct mod_depend *verinfo)
{
    u_char          *cp, *recptr, *bufend, *best;
    char  *result;
    int             *intp, bestver, blen, clen, found, ival, modnamelen, reclen;

    moduledir_readhints(mdp);
    modnamelen = strlen(modname);
    found = 0;
    result = NULL;
    bestver = 0;
    if (mdp->d_hints == NULL)
          goto bad;
    recptr = mdp->d_hints;
    bufend = recptr + mdp->d_hintsz;
    clen = blen = 0;
    best = cp = NULL;
    while (recptr < bufend && !found) {
          intp = (int*)recptr;
          reclen = *intp++;
          ival = *intp++;
          cp = (char*)intp;
          switch (ival) {
          case MDT_VERSION:
              clen = *cp++;
              if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
                    break;
              cp += clen;
              INT_ALIGN(mdp->d_hints, cp);
              ival = *(int*)cp;
              cp += sizeof(int);
              clen = *cp++;
              if (verinfo == NULL || ival == verinfo->md_ver_preferred) {
                    found = 1;
                    break;
              }
              if (ival >= verinfo->md_ver_minimum &&
                    ival <= verinfo->md_ver_maximum &&
                    ival > bestver) {
                    bestver = ival;
                    best = cp;
                    blen = clen;
              }
              break;
          default:
              break;
          }
          recptr += reclen + sizeof(int);
    }
    /*
     * Finally check if KLD is in the place
     */
    if (found)
          result = file_lookup(mdp->d_path, cp, clen, NULL);
    else if (best)
          result = file_lookup(mdp->d_path, best, blen, NULL);
bad:
    /*
     * If nothing found or hints is absent - fallback to the old way
     * by using "kldname[.ko]" as module name.
     */
    if (!found && !bestver && result == NULL)
          result = file_lookup(mdp->d_path, modname, modnamelen, kld_ext_list);
    return result;
}

/*
 * Attempt to locate the file containing the module (name)
 */
static char *
mod_searchmodule(char *name, struct mod_depend *verinfo)
{
    struct          moduledir *mdp;
    char  *result;

    moduledir_rebuild();
    /*
     * Now we ready to lookup module in the given directories
     */
    result = NULL;
    STAILQ_FOREACH(mdp, &moduledir_list, d_link) {
          result = mod_search_hints(mdp, name, verinfo);
          if (result)
              break;
    }

    return(result);
}

int
file_addmodule(struct preloaded_file *fp, char *modname, int version,
          struct kernel_module **newmp)
{
    struct kernel_module *mp;
    struct mod_depend mdepend;

    bzero(&mdepend, sizeof(mdepend));
    mdepend.md_ver_preferred = version;
    mp = file_findmodule(fp, modname, &mdepend);
    if (mp)
          return (EEXIST);
    mp = malloc(sizeof(struct kernel_module));
    if (mp == NULL)
          return (ENOMEM);
    bzero(mp, sizeof(struct kernel_module));
    mp->m_name = strdup(modname);
    mp->m_version = version;
    mp->m_fp = fp;
    mp->m_next = fp->f_modules;
    fp->f_modules = mp;
    if (newmp)
          *newmp = mp;
    return (0);
}

/*
 * Throw a file away
 */
void
file_discard(struct preloaded_file *fp)
{
    struct file_metadata      *md, *md1;
    struct kernel_module      *mp, *mp1;

    if (fp == NULL)
          return;

    md = fp->f_metadata;
    while (md) {
          md1 = md;
          md = md->md_next;
          free(md1);
    }

    mp = fp->f_modules;
    while (mp) {
          if (mp->m_name)
              free(mp->m_name);
#ifdef moduleargs
          if (mp->m_args)
              free(mp->m_args);
#endif
          mp1 = mp;
          mp = mp->m_next;
          free(mp1);
    }

    if (fp->f_name != NULL)
          free(fp->f_name);
    if (fp->f_type != NULL)
          free(fp->f_type);
    if (fp->f_args != NULL)
          free(fp->f_args);
    free(fp);
}

/*
 * Allocate a new file; must be used instead of malloc()
 * to ensure safe initialisation.
 */
struct preloaded_file *
file_alloc(void)
{
    struct preloaded_file     *fp;

    if ((fp = malloc(sizeof(struct preloaded_file))) != NULL) {
          bzero(fp, sizeof(struct preloaded_file));
    }
    return (fp);
}

/*
 * Add a module to the chain
 */
static void
file_insert_tail(struct preloaded_file *fp)
{
    struct preloaded_file     *cm;

    /* Append to list of loaded file */
    fp->f_next = NULL;
    if (preloaded_files == NULL) {
          preloaded_files = fp;
    } else {
          for (cm = preloaded_files; cm->f_next != NULL; cm = cm->f_next)
              ;
          cm->f_next = fp;
    }
}

static char *
moduledir_fullpath(struct moduledir *mdp, const char *fname)
{
    char *cp;

    cp = malloc(strlen(mdp->d_path) + strlen(fname) + 2);
    if (cp == NULL)
          return NULL;
    strcpy(cp, mdp->d_path);
    strcat(cp, "/");
    strcat(cp, fname);
    return (cp);
}

/*
 * Read linker.hints file into memory performing some sanity checks.
 */
static void
moduledir_readhints(struct moduledir *mdp)
{
    struct stat     st;
    char  *path;
    int             fd, size, version;

    if (mdp->d_hints != NULL || (mdp->d_flags & MDIR_NOHINTS))
          return;
    path = moduledir_fullpath(mdp, "linker.hints");
    if (rel_stat(path, &st) != 0 ||
          st.st_size < (ssize_t)(sizeof(version) + sizeof(int)) ||
          st.st_size > 100 * 1024 || (fd = rel_open(path, NULL, O_RDONLY)) < 0) {
          free(path);
          mdp->d_flags |= MDIR_NOHINTS;
          return;
    }
    free(path);
    size = read(fd, &version, sizeof(version));
    if (size != sizeof(version) || version != LINKER_HINTS_VERSION)
          goto bad;
    size = st.st_size - size;
    mdp->d_hints = malloc(size);
    if (mdp->d_hints == NULL)
          goto bad;
    if (read(fd, mdp->d_hints, size) != size)
          goto bad;
    mdp->d_hintsz = size;
    close(fd);
    return;

bad:
    close(fd);
    if (mdp->d_hints) {
          free(mdp->d_hints);
          mdp->d_hints = NULL;
    }
    mdp->d_flags |= MDIR_NOHINTS;
}

/*
 * Extract directories from the ';' separated list, remove duplicates.
 */
static void
moduledir_rebuild(void)
{
    struct          moduledir *mdp, *mtmp;
    const char      *path, *cp, *ep, *modlocal;
    size_t          cplen;

    path = getenv("module_path");
    if (path == NULL)
          path = default_searchpath;
    /*
     * Rebuild list of module directories if it changed
     */
    STAILQ_FOREACH(mdp, &moduledir_list, d_link)
          mdp->d_flags |= MDIR_REMOVED;

    for (ep = path; *ep != 0;  ep++) {
          cp = ep;
          for (; *ep != 0 && *ep != ';'; ep++)
              ;
          /*
           * Ignore trailing slashes
           */
          for (cplen = ep - cp; cplen > 1 && cp[cplen - 1] == '/'; cplen--)
              ;
          STAILQ_FOREACH(mdp, &moduledir_list, d_link) {
              if (strlen(mdp->d_path) != cplen || bcmp(cp, mdp->d_path, cplen) != 0)
                    continue;
              mdp->d_flags &= ~MDIR_REMOVED;
              break;
          }
          if (mdp == NULL) {
              mdp = malloc(sizeof(*mdp) + cplen + 1);
              if (mdp == NULL)
                    return;
              mdp->d_path = (char*)(mdp + 1);
              bcopy(cp, mdp->d_path, cplen);
              mdp->d_path[cplen] = 0;
              mdp->d_hints = NULL;
              mdp->d_flags = 0;
              STAILQ_INSERT_TAIL(&moduledir_list, mdp, d_link);
          }
          if (*ep == 0)
              break;
    }
    /*
     * Include modules.local if requested
     */
    modlocal = getenv("local_modules");
    if (modlocal != NULL && strcmp(modlocal, "YES") == 0) {
          cp = local_module_path;
          cplen = strlen(local_module_path);
          STAILQ_FOREACH(mdp, &moduledir_list, d_link) {
              if (strlen(mdp->d_path) != cplen || bcmp(cp, mdp->d_path, cplen) != 0)
                    continue;
              mdp->d_flags &= ~MDIR_REMOVED;
              break;
          }
          if (mdp == NULL) {
              mdp = malloc(sizeof(*mdp) + cplen + 1);
              if (mdp == NULL)
                    return;
              mdp->d_path = (char*)(mdp + 1);
              bcopy(local_module_path, mdp->d_path, cplen);
              mdp->d_path[cplen] = 0;
              mdp->d_hints = NULL;
              mdp->d_flags = 0;
              STAILQ_INSERT_TAIL(&moduledir_list, mdp, d_link);
          }
    }
    /*
     * Delete unused directories if any
     */
    mdp = STAILQ_FIRST(&moduledir_list);
    while (mdp) {
          if ((mdp->d_flags & MDIR_REMOVED) == 0) {
              mdp = STAILQ_NEXT(mdp, d_link);
          } else {
              if (mdp->d_hints)
                    free(mdp->d_hints);
              mtmp = mdp;
              mdp = STAILQ_NEXT(mdp, d_link);
              STAILQ_REMOVE(&moduledir_list, mtmp, moduledir, d_link);
              free(mtmp);
          }
    }
}