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.
 */

#include <sys/cdefs.h>

/*
 * 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>
#include <sys/stdint.h>
#include <sys/tem_impl.h>
#include <sys/font.h>
#include <sys/sha1.h>
#include <libcrypto.h>

#include "bootstrap.h"

#if defined(EFI)
#define	PTOV(pa)	((void *)pa)
#else
#include "../i386/btx/lib/btxv86.h"
#endif

#define	MDIR_REMOVED	0x0001
#define	MDIR_NOHINTS	0x0002

struct moduledir {
	char	*d_path;	/* path of modules directory */
	uchar_t	*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 *, vm_offset_t, struct preloaded_file **);
static int file_load_dependencies(struct preloaded_file *);
static char *file_search(const char *, const char **);
static struct kernel_module *file_findmodule(struct preloaded_file *, char *,
    struct mod_depend *);
static int file_havepath(const char *);
static char *mod_searchmodule(char *, struct mod_depend *);
static void file_insert_tail(struct preloaded_file *);
static void file_remove(struct preloaded_file *);
struct file_metadata *metadata_next(struct file_metadata *, int);
static void moduledir_readhints(struct moduledir *);
static void moduledir_rebuild(void);

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

#if defined(LOADER_FDT_SUPPORT)
static const char *default_searchpath = "/boot/kernel;/boot/modules;/boot/dtb";
#else
static const char *default_searchpath = "/platform/i86pc";
#endif

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

struct preloaded_file *preloaded_files = NULL;

static const char *kld_ext_list[] = {
	".ko",
	"",
	".debug",
	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_CRIT);
	}
	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);

	printf("Loading %s...\n", argv[1]);
	/*
	 * Request to load a raw file?
	 */
	if (dofile) {
		struct preloaded_file *fp;

		if ((typestr == NULL) || (*typestr == 0)) {
			command_errmsg = "invalid load type";
			return (CMD_CRIT);
		}

		if (file_findfile(argv[1], typestr) != NULL) {
			snprintf(command_errbuf, sizeof (command_errbuf),
			    "warning: file '%s' already loaded", argv[1]);
			return (CMD_WARN);
		}

		fp = file_loadraw(argv[1], typestr, argc - 2, argv + 2, 1);
		if (fp != NULL)
			return (CMD_OK);

		/* Failing to load mfs_root is never going to end well! */
		if (strcmp("mfs_root", typestr) == 0)
			return (CMD_FATAL);

		return (CMD_ERROR);
	}
	/*
	 * 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 (CMD_WARN);
		}

		return (error == 0 ? CMD_OK : CMD_CRIT);
	}
	/*
	 * 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 (CMD_WARN);
	}

	return (error == 0 ? CMD_OK : CMD_CRIT);
}

void
unload(void)
{
	struct preloaded_file *fp;

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

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

static int
command_unload(int argc __unused, char *argv[] __unused)
{
	unload();
	return (CMD_OK);
}

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, hash, ret = 0;

	verbose = 0;
	hash = 0;
	optind = 1;
	optreset = 1;
	while ((ch = getopt(argc, argv, "vs")) != -1) {
		switch (ch) {
		case 'v':
			verbose = 1;
			break;
		case 's':
			hash = 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: ", (void *) fp->f_addr);
		pager_output(lbuf);
		pager_output(fp->f_name);
		sprintf(lbuf, " (%s, 0x%lx)\n", fp->f_type, (long)fp->f_size);
		if (pager_output(lbuf))
			break;
		if (fp->f_args != NULL) {
			pager_output("    args: ");
			pager_output(fp->f_args);
			if (pager_output("\n"))
				break;
			if (strcmp(fp->f_type, "hash") == 0) {
				pager_output("    contents: ");
				strlcpy(lbuf, PTOV(fp->f_addr), sizeof (lbuf));
				if (pager_output(lbuf))
					break;
			}
		}

		if (hash == 1) {
			void *ptr = PTOV(fp->f_addr);

			pager_output("  hash: ");
			sha1(ptr, fp->f_size, (uint8_t *)lbuf);
			for (int i = 0; i < SHA1_DIGEST_LENGTH; i++)
				printf("%02x", (int)(lbuf[i] & 0xff));
			if (pager_output("\n"))
				break;
		}

		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);
			}
			if (pager_output("\n"))
				break;
		}
		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);
				if ((ret = pager_output(lbuf)))
					break;
			}
		}
		if (ret != 0)
			break;
	}
	pager_close();
	return (CMD_OK);
}

/*
 * File level interface, functions file_*
 */
int
file_load(char *filename, vm_offset_t dest, struct preloaded_file **result)
{
	static int last_file_format = 0;
	struct preloaded_file *fp;
	int error;
	int i;

	if (preloaded_files == NULL)
		last_file_format = 0;

	if (archsw.arch_loadaddr != NULL)
		dest = archsw.arch_loadaddr(LOAD_RAW, filename, dest);

	error = EFTYPE;
	for (i = last_file_format, fp = NULL;
	    file_formats[i] && fp == NULL; i++) {
		error = (file_formats[i]->l_load)(filename, dest, &fp);
		if (error == 0) {
			/* remember the loader */
			fp->f_loader = last_file_format = i;
			*result = fp;
			break;
		} else if (last_file_format == i && i != 0) {
			/* Restart from the beginning */
			i = -1;
			last_file_format = 0;
			fp = NULL;
			continue;
		}
		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);
}

/*
 * Calculate the size of the environment module.
 * The environment is list of name=value C strings, ending with a '\0' byte.
 */
static size_t
env_get_size(void)
{
	size_t size = 0;
	struct env_var *ep;

	/* Traverse the environment. */
	for (ep = environ; ep != NULL; ep = ep->ev_next) {
		size += strlen(ep->ev_name);
		size++;		/* "=" */
		if (ep->ev_value != NULL)
			size += strlen(ep->ev_value);
		size++;		/* nul byte */
	}
	size++;			/* nul byte */
	return (size);
}

static void
module_hash(struct preloaded_file *fp, void *addr, size_t size)
{
	uint8_t hash[SHA1_DIGEST_LENGTH];
	char ascii[2 * SHA1_DIGEST_LENGTH + 1];
	int i;

	sha1(addr, size, hash);
	for (i = 0; i < SHA1_DIGEST_LENGTH; i++) {
		snprintf(ascii + 2 * i, sizeof (ascii) - 2 * i, "%02x",
		    hash[i] & 0xff);
	}
	/* Out of memory here is not fatal issue. */
	asprintf(&fp->f_args, "hash=%s", ascii);
}

/*
 * Create virtual module for environment variables.
 * This module should be created as late as possible before executing
 * the OS kernel, or we may miss some environment variable updates.
 */
void
build_environment_module(void)
{
	struct preloaded_file *fp;
	size_t size;
	char *name = "environment";
	vm_offset_t laddr;

	/* We can't load first */
	if ((file_findfile(NULL, NULL)) == NULL) {
		printf("Can not load environment module: %s\n",
		    "the kernel is not loaded");
		return;
	}

	tem_save_state();	/* Ask tem to save it's state in env. */
	size = env_get_size();

	fp = file_alloc();
	if (fp != NULL) {
		fp->f_name = strdup(name);
		fp->f_type = strdup(name);
	}

	if (fp == NULL || fp->f_name == NULL || fp->f_type == NULL) {
		printf("Can not load environment module: %s\n",
		    "out of memory");
		file_discard(fp);
		return;
	}


	if (archsw.arch_loadaddr != NULL)
		loadaddr = archsw.arch_loadaddr(LOAD_MEM, &size, loadaddr);

	if (loadaddr == 0) {
		printf("Can not load environment module: %s\n",
		    "out of memory");
		file_discard(fp);
		return;
	}

	laddr = bi_copyenv(loadaddr);
	/* Looks OK so far; populate control structure */
	module_hash(fp, PTOV(loadaddr), laddr - loadaddr);
	fp->f_loader = -1;
	fp->f_addr = loadaddr;
	fp->f_size = laddr - loadaddr;

	/* recognise space consumption */
	loadaddr = laddr;

	file_insert_tail(fp);
}

void
build_font_module(void)
{
	bitmap_data_t *bd;
	struct font *fd;
	struct preloaded_file *fp;
	size_t size;
	uint32_t checksum;
	int i;
	char *name = "console-font";
	vm_offset_t laddr;
	struct font_info fi;
	struct fontlist *fl;

	if (STAILQ_EMPTY(&fonts))
		return;

	/* We can't load first */
	if ((file_findfile(NULL, NULL)) == NULL) {
		printf("Can not load font module: %s\n",
		    "the kernel is not loaded");
		return;
	}

	/* helper pointers */
	bd = NULL;
	STAILQ_FOREACH(fl, &fonts, font_next) {
		if (tems.ts_font.vf_width == fl->font_data->width &&
		    tems.ts_font.vf_height == fl->font_data->height) {
			/*
			 * Kernel does have better built in font.
			 */
			if (fl->font_flags == FONT_BUILTIN)
				return;

			bd = fl->font_data;
			break;
		}
	}
	if (bd == NULL)
		return;
	fd = bd->font;

	fi.fi_width = fd->vf_width;
	checksum = fi.fi_width;
	fi.fi_height = fd->vf_height;
	checksum += fi.fi_height;
	fi.fi_bitmap_size = bd->uncompressed_size;
	checksum += fi.fi_bitmap_size;

	size = roundup2(sizeof (struct font_info), 8);
	for (i = 0; i < VFNT_MAPS; i++) {
		fi.fi_map_count[i] = fd->vf_map_count[i];
		checksum += fi.fi_map_count[i];
		size += fd->vf_map_count[i] * sizeof (struct font_map);
		size += roundup2(size, 8);
	}
	size += bd->uncompressed_size;

	fi.fi_checksum = -checksum;

	fp = file_alloc();
	if (fp != NULL) {
		fp->f_name = strdup(name);
		fp->f_type = strdup(name);
	}

	if (fp == NULL || fp->f_name == NULL || fp->f_type == NULL) {
		printf("Can not load font module: %s\n",
		    "out of memory");
		file_discard(fp);
		return;
	}

	if (archsw.arch_loadaddr != NULL)
		loadaddr = archsw.arch_loadaddr(LOAD_MEM, &size, loadaddr);

	if (loadaddr == 0) {
		printf("Can not load font module: %s\n",
		    "out of memory");
		file_discard(fp);
		return;
	}

	laddr = loadaddr;
	laddr += archsw.arch_copyin(&fi, laddr, sizeof (struct font_info));
	laddr = roundup2(laddr, 8);

	/* Copy maps. */
	for (i = 0; i < VFNT_MAPS; i++) {
		if (fd->vf_map_count[i] != 0) {
			laddr += archsw.arch_copyin(fd->vf_map[i], laddr,
			    fd->vf_map_count[i] * sizeof (struct font_map));
			laddr = roundup2(laddr, 8);
		}
	}

	/* Copy the bitmap. */
	laddr += archsw.arch_copyin(fd->vf_bytes, laddr, fi.fi_bitmap_size);

	/* Looks OK so far; populate control structure */
	module_hash(fp, PTOV(loadaddr), laddr - loadaddr);
	fp->f_loader = -1;
	fp->f_addr = loadaddr;
	fp->f_size = laddr - loadaddr;

	/* recognise space consumption */
	loadaddr = laddr;

	file_insert_tail(fp);
}

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

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

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

	if ((fd = open(name, O_RDONLY)) < 0) {
		snprintf(command_errbuf, sizeof (command_errbuf),
		    "can't open '%s': %s", name, strerror(errno));
		free(name);
		return (NULL);
	}
	if (fstat(fd, &st) < 0) {
		close(fd);
		snprintf(command_errbuf, sizeof (command_errbuf),
		    "stat error '%s': %s", name, strerror(errno));
		free(name);
		return (NULL);
	}

	if (archsw.arch_loadaddr != NULL)
		loadaddr = archsw.arch_loadaddr(LOAD_RAW, name, loadaddr);
	if (loadaddr == 0) {
		close(fd);
		snprintf(command_errbuf, sizeof (command_errbuf),
		    "no memory to load %s", name);
		free(name);
		return (NULL);
	}

	laddr = loadaddr;
	for (;;) {
		/* read in 4k chunks; size is not really important */
		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);
			if (archsw.arch_free_loadaddr != NULL &&
			    st.st_size != 0) {
				archsw.arch_free_loadaddr(loadaddr,
				    (uint64_t)
				    (roundup2(st.st_size, PAGE_SIZE) >> 12));
			}
			return (NULL);
		}
		laddr += got;
	}

	/* Looks OK so far; create & populate control structure */
	fp = file_alloc();
	if (fp == NULL) {
		if (archsw.arch_free_loadaddr != NULL && st.st_size != 0)
			archsw.arch_free_loadaddr(loadaddr,
			    (uint64_t)(roundup2(st.st_size, PAGE_SIZE) >> 12));
		snprintf(command_errbuf, sizeof (command_errbuf),
		    "no memory to load %s", name);
		free(name);
		close(fd);
		return (NULL);
	}

	fp->f_name = name;
	fp->f_args = unargv(argc, argv);
	fp->f_type = strdup(type);
	fp->f_metadata = NULL;
	fp->f_loader = -1;
	fp->f_addr = loadaddr;
	fp->f_size = laddr - loadaddr;

	if (fp->f_type == NULL ||
	    (argc != 0 && fp->f_args == NULL)) {
		close(fd);
		snprintf(command_errbuf, sizeof (command_errbuf),
		    "no memory to load %s", name);
		file_discard(fp);
		return (NULL);
	}
	/* recognise space consumption */
	loadaddr = laddr;

	/* Add to the list of loaded files */
	if (insert != 0)
		file_insert_tail(fp);
	close(fd);
	return (fp);
}

/*
 * 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 != NULL) {
		free(mp->m_args);
		mp->m_args = unargv(argc, argv);
		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);
	free(filename);
	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;
	int err;
	char *filename;
	vm_offset_t loadaddr_saved;

	/*
	 * 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 != NULL) {
		snprintf(command_errbuf, sizeof (command_errbuf),
		    "warning: KLD '%s' already loaded", filename);
		free(filename);
		return (0);
	}

	do {
		err = file_load(filename, loadaddr, &fp);
		if (err)
			break;
		fp->f_args = unargv(argc, argv);
		loadaddr_saved = loadaddr;
		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;
			file_remove(fp);
			loadaddr = loadaddr_saved;
			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)
		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(const char *name, const char *type)
{
	struct preloaded_file *fp;

	for (fp = preloaded_files; fp != NULL; fp = fp->f_next) {
		if (((name == NULL) || strcmp(name, fp->f_name) == 0) &&
		    ((type == NULL) || strcmp(type, fp->f_type) == 0))
			break;
	}
	return (fp);
}

/*
 * Find a module matching (name) inside of given file.
 * NULL may be passed as a wildcard.
 */
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 != NULL)
				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);
	if (md != NULL) {
		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);
}

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 const 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,
    const char **extlist)
{
	struct stat st;
	char *result, *cp;
	const char **cpp;
	int pathlen, extlen, len;

	pathlen = strlen(path);
	extlen = 0;
	if (extlist == NULL)
		extlist = emptyextlist;
	for (cpp = extlist; *cpp; cpp++) {
		len = strlen(*cpp);
		if (len > extlen)
			extlen = len;
	}
	result = malloc(pathlen + namelen + extlen + 2);
	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 (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, const char **extlist)
{
	struct moduledir *mdp;
	struct stat sb;
	char *result;
	int namelen;

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

	if (*name == '\0')
		return (strdup(name));

	if (file_havepath(name)) {
		/* Qualified, so just see if it exists */
		if (stat(name, &sb) == 0)
			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 != NULL)
			break;
	}
	return (result);
}

#define	INT_ALIGN(base, ptr)	ptr = \
	(base) + (((ptr) - (base) + sizeof (int) - 1) & ~(sizeof (int) - 1))

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

	moduledir_readhints(mdp);
	modnamelen = strlen(modname);
	found = false;
	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 = (uchar_t *)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 = true;
				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, (char *)cp, clen, NULL);
	else if (best)
		result = file_lookup(mdp->d_path, (char *)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 == 0 && 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 != NULL)
			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 != NULL)
		return (EEXIST);
	mp = calloc(1, sizeof (struct kernel_module));
	if (mp == NULL)
		return (ENOMEM);
	mp->m_name = strdup(modname);
	if (mp->m_name == NULL) {
		free(mp);
		return (ENOMEM);
	}
	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;

	if (archsw.arch_free_loadaddr != NULL && fp->f_addr &&
	    fp->f_size != 0) {
		archsw.arch_free_loadaddr(fp->f_addr,
		    (uint64_t)(roundup2(fp->f_size, PAGE_SIZE) >> 12));
	}

	md = fp->f_metadata;
	while (md != NULL) {
		md1 = md;
		md = md->md_next;
		free(md1);
	}
	mp = fp->f_modules;
	while (mp != NULL) {
		free(mp->m_name);
		mp1 = mp;
		mp = mp->m_next;
		free(mp1);
	}
	free(fp->f_name);
	free(fp->f_type);
	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)
{

	return (calloc(1, sizeof (struct preloaded_file)));
}

/*
 * 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;
	}
}

/*
 * Remove module from the chain
 */
static void
file_remove(struct preloaded_file *fp)
{
	struct preloaded_file   *cm;

	if (preloaded_files == NULL)
		return;

	if (preloaded_files == fp) {
		preloaded_files = fp->f_next;
		return;
	}
	for (cm = preloaded_files; cm->f_next != NULL; cm = cm->f_next) {
		if (cm->f_next == fp) {
			cm->f_next = fp->f_next;
			return;
		}
	}
}

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 (stat(path, &st) != 0 ||
	    st.st_size < (ssize_t)(sizeof (version) + sizeof (int)) ||
	    st.st_size > LINKER_HINTS_MAX ||
	    (fd = open(path, 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);
	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;
	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;
	}
	/*
	 * 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 {
			free(mdp->d_hints);
			mtmp = mdp;
			mdp = STAILQ_NEXT(mdp, d_link);
			STAILQ_REMOVE(&moduledir_list, mtmp, moduledir, d_link);
			free(mtmp);
		}
	}
}