/* $XFree86: xc/programs/Xserver/hw/xfree86/loader/loadmod.c,v 1.68 2002/07/30 18:36:18 dawes Exp $ */

/*
 *
 * Copyright 1995-1998 by Metro Link, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of Metro Link, Inc. not be used in
 * advertising or publicity pertaining to distribution of the software without
 * specific, written prior permission.  Metro Link, Inc. makes no
 * representations about the suitability of this software for any purpose.
 *  It is provided "as is" without express or implied warranty.
 *
 * METRO LINK, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL METRO LINK, INC. BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* This file is best viewed with tab stops set to 4 spaces */

#include "os.h"
/* For stat() and related stuff */
#define NO_OSLIB_PROTOTYPES
#include "xf86_OSlib.h"
#define LOADERDECLARATIONS
#include "loaderProcs.h"
#include "misc.h"
#include "xf86.h"
#include "xf86Priv.h"
#ifdef XINPUT
#include "xf86Xinput.h"
#endif
#include "loader.h"
#include "xf86Optrec.h"

#include <sys/types.h>
#include <regex.h>
#include <dirent.h>
#include <limits.h>

extern int check_unresolved_sema;

typedef struct _pattern {
	const char *	pattern;
	regex_t			rex;
} PatternRec, *PatternPtr;

/* Prototypes for static functions */
static char *FindModule (const char *, const char *, const char **, PatternPtr);
static Bool CheckVersion (const char *, XF86ModuleVersionInfo *,
				const XF86ModReqInfo *);
static void UnloadModuleOrDriver (ModuleDescPtr mod);
static char *LoaderGetCanonicalName(const char *, PatternPtr);
static void RemoveChild(ModuleDescPtr);

ModuleVersions LoaderVersionInfo = {
	XF86_VERSION_CURRENT,
	ABI_ANSIC_VERSION,
	ABI_VIDEODRV_VERSION,
	ABI_XINPUT_VERSION,
	ABI_EXTENSION_VERSION,
	ABI_FONT_VERSION
};

#if 0
void
LoaderFixups (void)
{
	/* Need to call LRS here because the frame buffers get loaded last,
	 * and the drivers depend on them. */

	LoaderResolveSymbols ();
}
#endif

static void
FreeStringList(char **paths)
{
	char **p;

	if (!paths)
		return;

	for (p = paths; *p; p++)
		xfree(*p);

	xfree(paths);
}

static char **defaultPathList = NULL;

/*
 * Convert a comma-separated path into a NULL-terminated array of path
 * elements, rejecting any that are not full absolute paths, and appending
 * a '/' when it isn't already present.
 */
static char **
InitPathList(const char *path)
{
	char *fullpath = NULL;
	char *elem = NULL;
	char **list = NULL, **save = NULL;
	int len;
	int addslash;
	int n = 0;

	if (!path)
		return defaultPathList;

	fullpath = xstrdup(path);
	if (!fullpath)
		return NULL;
	elem = strtok(fullpath, ",");
	while (elem) {
		/* Only allow fully specified paths */
#ifndef __UNIXOS2__
		if (*elem == '/')
#else
		if (*elem == '/' || (strlen(elem) > 2 && isalpha(elem[0]) &&
							  elem[1] == ':' && elem[2] == '/'))
#endif
		{
			len = strlen(elem);
			addslash = (elem[len - 1] != '/');
			if (addslash)
				len++;
			save = list;
			list = xrealloc(list, (n + 2) * sizeof(char *));
			if (!list) {
				if (save) {
					save[n] = NULL;
					FreeStringList(save);
				}
				xfree(fullpath);
				return NULL;
			}
			list[n] = xalloc(len + 1);
			if (!list[n]) {
				FreeStringList(list);
				xfree(fullpath);
				return NULL;
			}
			strcpy(list[n], elem);
			if (addslash) {
				list[n][len - 1] = '/';
				list[n][len] = '\0';
			}
			n++;
		}
		elem = strtok(NULL, ",");
	}
	if (list)
		list[n] = NULL;
	return list;
}

static void
FreePathList(char **pathlist)
{
	if (pathlist && pathlist != defaultPathList)
		FreeStringList(pathlist);
}

void
LoaderSetPath(const char *path)
{
	if (!path)
		return;

	defaultPathList = InitPathList(path);
}

/* Standard set of module subdirectories to search, in order of preference */
static const char *stdSubdirs[] =
{
	"drivers/",
	"input/",
	"multimedia/",
	"extensions/",
	"fonts/",
	"internal/",
	"",
	NULL
};

/*
 * Standard set of module name patterns to check, in order of preference
 * These are regular expressions (suitable for use with POSIX regex(3)).
 */
static PatternRec stdPatterns[] = {
	{ "^lib(.*)\\.so$", },
	{ "^lib(.*)\\.a$", },
	{ "(.*)_drv\\.so$", },
	{ "(.*)_drv\\.o$", },
	{ "(.*)\\.so$", },
	{ "(.*)\\.a$", },
	{ "(.*)\\.o$", },
	{ NULL, }
};

static PatternPtr
InitPatterns(const char **patternlist)
{
	char errmsg[80];
	int i, e;
	PatternPtr patterns = NULL;
	PatternPtr p = NULL;
	static int firstTime = 1;
	const char **s;

	if (firstTime) {
		/* precompile stdPatterns */
		firstTime = 0;
		for (p = stdPatterns; p->pattern; p++)
			if ((e = regcomp(&p->rex, p->pattern, REG_EXTENDED)) != 0) {
				regerror(e, &p->rex, errmsg, sizeof(errmsg));
				FatalError("InitPatterns: regcomp error for `%s': %s\n",
							p->pattern, errmsg);
			}
	}

	if (patternlist) {
		for (i = 0, s = patternlist; *s; i++, s++)
			if (*s == DEFAULT_LIST)
				i += sizeof(stdPatterns) / sizeof(stdPatterns[0]) - 1 - 1;
		patterns = xalloc((i + 1) * sizeof(PatternRec));
		if (!patterns) {
			return NULL;
		}
		for (i = 0, s = patternlist; *s; i++, s++)
			if (*s != DEFAULT_LIST) {
				p = patterns + i;
				p->pattern = *s;
				if ((e = regcomp(&p->rex, p->pattern, REG_EXTENDED)) != 0) {
					regerror(e, &p->rex, errmsg, sizeof(errmsg));
					ErrorF("InitPatterns: regcomp error for `%s': %s\n",
							p->pattern, errmsg);
					i--;
				}
			} else {
				for (p = stdPatterns; p->pattern; p++, i++)
					patterns[i] = *p;
				if (p != stdPatterns)
					i--;
			}
		patterns[i].pattern = NULL;
	} else
		patterns = stdPatterns;
	return patterns;
}

static void
FreePatterns(PatternPtr patterns)
{
	if (patterns && patterns != stdPatterns)
		xfree(patterns);
}

static const char **
InitSubdirs(const char **subdirlist)
{
	int i;
	char **subdirs = NULL;
	const char **s, **stmp = NULL;
    const char *osname;
    const char *slash;
    int oslen = 0, len;
    Bool indefault;

    if (subdirlist == NULL) {
	    subdirlist = xalloc(2 * sizeof(char *));
	    if (subdirlist == NULL)
			return NULL;
		subdirlist[0] = DEFAULT_LIST;
		subdirlist[1] = NULL;
	}
	
    LoaderGetOS(&osname, NULL, NULL, NULL);
    oslen = strlen(osname);

    {
		/* Count number of entries and check for invalid paths */
		for (i = 0, s = subdirlist; *s; i++, s++) {
			if (*s == DEFAULT_LIST) {
				i += sizeof(stdSubdirs) / sizeof(stdSubdirs[0]) - 1 - 1;
			} else {
				/*
				 * Path validity check.  Don't allow absolute paths, or
				 * paths containing "..".  To catch absolute paths on
				 * platforms that use driver letters, don't allow the ':'
				 * character to appear at all.
				 */
				if (**s == '/' || **s == '\\' || strchr(*s, ':') ||
					strstr(*s, "..")) {
					xf86Msg(X_ERROR, "InitSubdirs: Bad subdir: \"%s\"\n", *s);
					return NULL;
				}
			}
		}
		subdirs = xalloc((i * 2 + 1) * sizeof(char *));
		if (!subdirs)
			return NULL;
		i = 0;
		s = subdirlist;
		indefault = FALSE;
		while (*s) {
			if (*s == DEFAULT_LIST) {
				/* Divert to the default list */
				indefault = TRUE;
				stmp = ++s;
				s = stdSubdirs;
			}
			len = strlen(*s);
			if (**s && (*s)[len - 1] != '/') {
				slash = "/";
				len++;
			} else
				slash = "";
			len += oslen + 2;
			if (!(subdirs[i] = xalloc(len)))
				return NULL;
			/* tack on the OS name */
			sprintf(subdirs[i], "%s%s%s/", *s, slash, osname);
			i++;
			/* path as given */
			subdirs[i] = xstrdup(*s);
			i++;
			s++;
			if (indefault && !s) {
				/* revert back to the main list */
				indefault = FALSE;
				s = stmp;
			}
		}
		subdirs[i] = NULL;
	}
	return (const char **)subdirs;
}

static void
FreeSubdirs(const char **subdirs)
{
	const char **s;

	if (subdirs) {
		for (s = subdirs; *s; s++)
			xfree(*s);
		xfree(subdirs);
	}
}

static char *
FindModule (const char *module, const char *dir, const char **subdirlist,
			PatternPtr patterns)
{
	char buf[PATH_MAX + 1];
	char *dirpath = NULL;
	char *name = NULL;
	struct stat stat_buf;
	int len, dirlen;
	char *fp;
	DIR *d;
	const char **subdirs = NULL;
	PatternPtr p = NULL;
	const char **s;
	struct dirent *dp;
	regmatch_t match[2];

	subdirs = InitSubdirs(subdirlist);
	if (!subdirs)
		return NULL;

#ifndef __EMX__
	dirpath = (char *)dir;
#else
	dirpath = xalloc(strlen(dir) + 10);
	strcpy(dirpath, (char *) __XOS2RedirRoot (dir));
#endif
	if (strlen(dirpath) > PATH_MAX)
		return NULL;
	/*xf86Msg(X_INFO,"OS2DIAG: FindModule: dirpath=%s\n",dirpath);*/

	for (s = subdirs; *s; s++) {
		if ((dirlen = strlen(dirpath) + strlen(*s)) > PATH_MAX)
			continue;
		strcpy(buf, dirpath);
		strcat(buf, *s);
		/*xf86Msg(X_INFO,"OS2DIAG: FindModule: buf=%s\n",buf);*/
		fp = buf + dirlen;
		if (stat(buf, &stat_buf) == 0 && S_ISDIR(stat_buf.st_mode) &&
			(d = opendir(buf))) {
			if (buf[dirlen - 1] != '/') {
				buf[dirlen++] = '/';
				fp++;
			}
			while ((dp = readdir(d))) {
				if (dirlen + strlen(dp->d_name) + 1 > PATH_MAX)
					continue;
				strcpy(fp, dp->d_name);
				if (!(stat(buf, &stat_buf) == 0 && S_ISREG(stat_buf.st_mode)))
					continue;
				for (p = patterns; p->pattern; p++) {
					if (regexec(&p->rex, dp->d_name, 2, match, 0) == 0 &&
						match[1].rm_so != -1) {
						len = match[1].rm_eo - match[1].rm_so;
						if (len == strlen(module) &&
							strncmp(module, dp->d_name + match[1].rm_so, len) == 0) {
							/*xf86Msg(X_INFO,"OS2DIAG: matching %s\n",buf);*/
							name = buf;
							break;
						}
					}
				}
				if (name)
					break;
			}
			closedir(d);
			if (name)
				break;
		}
	}
	FreeSubdirs(subdirs);
	if (dirpath != dir)
		xfree(dirpath);

	if (name) {
		return xstrdup(name);
	}
	return NULL;
}

char **
LoaderListDirs(const char **subdirlist, const char **patternlist)
{
	char buf[PATH_MAX + 1];
	char **pathlist;
	char **elem;
	const char **subdirs;
	const char **s;
	PatternPtr patterns;
	PatternPtr p;
	DIR *d;
	struct dirent *dp;
	regmatch_t match[2];
	struct stat stat_buf;
	int len, dirlen;
	char *fp;
	char **listing = NULL;
	char **save;
	int n = 0;

	if (!(pathlist = InitPathList(NULL)))
		return NULL;
	if (!(subdirs = InitSubdirs(subdirlist))) {
		FreePathList(pathlist);
		return NULL;
	}
	if (!(patterns = InitPatterns(patternlist))) {
		FreePathList(pathlist);
		FreeSubdirs(subdirs);
		return NULL;
	}

	for (elem = pathlist; *elem; elem++) {
		for (s = subdirs; *s; s++) {
			if ((dirlen = strlen(*elem) + strlen(*s)) > PATH_MAX)
				continue;
			strcpy(buf, *elem);
			strcat(buf, *s);
			fp = buf + dirlen;
			if (stat(buf, &stat_buf) == 0 && S_ISDIR(stat_buf.st_mode) &&
				(d = opendir(buf))) {
				if (buf[dirlen - 1] != '/') {
					buf[dirlen++] = '/';
					fp++;
				}
				while ((dp = readdir(d))) {
					if (dirlen + strlen(dp->d_name) > PATH_MAX)
						continue;
					strcpy(fp, dp->d_name);
					if (!(stat(buf, &stat_buf) == 0 &&
						  S_ISREG(stat_buf.st_mode)))
						continue;
					for (p = patterns; p->pattern; p++) {
						if (regexec(&p->rex, dp->d_name, 2, match, 0) == 0 &&
							match[1].rm_so != -1) {
							len = match[1].rm_eo - match[1].rm_so;
							save = listing;
							listing = xrealloc(listing,
											   (n + 2) * sizeof(char *));
							if (!listing) {
								if (save) {
									save[n] = NULL;
									FreeStringList(save);
								}
								FreePathList(pathlist);
								FreeSubdirs(subdirs);
								FreePatterns(patterns);
								return NULL;
							}
							listing[n] = xalloc(len + 1);
							if (!listing[n]) {
								FreeStringList(listing);
								FreePathList(pathlist);
								FreeSubdirs(subdirs);
								FreePatterns(patterns);
								return NULL;
							}
							strncpy(listing[n], dp->d_name + match[1].rm_so,
									len);
							listing[n][len] = '\0';
							n++;
							break;
						}
					}
				}
				closedir(d);
			}
		}
	}
	if (listing)
		listing[n] = NULL;
	return listing;
}

void
LoaderFreeDirList(char **list)
{
	FreeStringList(list);
}


static Bool
CheckVersion (const char *module, XF86ModuleVersionInfo *data,
				const XF86ModReqInfo *req)
{
	int vercode[4];
	char verstr[4];
	long ver = data->xf86version;
	int errtype = 0;

	xf86Msg (X_INFO, "Module %s: vendor=\"%s\"\n",
			data->modname ? data->modname : "UNKNOWN!",
			data->vendor ? data->vendor : "UNKNOWN!");

	if (ver > (4 << 24)) {
		/* 4.0.x and earlier */
		verstr[1] = verstr[3] = 0;
		verstr[2] = (ver & 0x1f) ? (ver & 0x1f) + 'a' - 1 : 0;
		ver >>= 5;
		verstr[0] = (ver & 0x1f) ? (ver & 0x1f) + 'A' - 1 : 0;
		ver >>= 5;
		vercode[2] = ver & 0x7f;
		ver >>= 7;
		vercode[1] = ver & 0x7f;
		ver >>= 7;
		vercode[0] = ver;
		xf86ErrorF("\tcompiled for %d.%d", vercode[0], vercode[1]);
		if (vercode[2] != 0)
			xf86ErrorF(".%d", vercode[2]);
		xf86ErrorF("%s%s, module version = %d.%d.%d\n", verstr, verstr + 2,
				data->majorversion, data->minorversion, data->patchlevel);
	} else {
		vercode[0] = ver / 10000000;
		vercode[1] = (ver / 100000) % 100;
		vercode[2] = (ver / 1000) % 100;
		vercode[3] = ver % 1000;
		xf86ErrorF("\tcompiled for %d.%d.%d", vercode[0], vercode[1],
					vercode[2]);
		if (vercode[3] != 0)
			xf86ErrorF(".%d", vercode[3]);
		xf86ErrorF(", module version = %d.%d.%d\n", data->majorversion,
					data->minorversion, data->patchlevel);
	}

    if (data->moduleclass)
		xf86ErrorFVerb(2, "\tModule class: %s\n", data->moduleclass);
		
	ver = -1;
	if (data->abiclass) {
		int abimaj, abimin;
		int vermaj, vermin;

		if (!strcmp(data->abiclass, ABI_CLASS_ANSIC))
			ver = LoaderVersionInfo.ansicVersion;
		else if (!strcmp(data->abiclass, ABI_CLASS_VIDEODRV))
			ver = LoaderVersionInfo.videodrvVersion;
		else if (!strcmp(data->abiclass, ABI_CLASS_XINPUT))
			ver = LoaderVersionInfo.xinputVersion;
		else if (!strcmp(data->abiclass, ABI_CLASS_EXTENSION))
			ver = LoaderVersionInfo.extensionVersion;
		else if (!strcmp(data->abiclass, ABI_CLASS_FONT))
			ver = LoaderVersionInfo.fontVersion;

		abimaj = GET_ABI_MAJOR(data->abiversion);
		abimin = GET_ABI_MINOR(data->abiversion);
		xf86ErrorFVerb(2, "\tABI class: %s, version %d.%d\n",
			       data->abiclass, abimaj, abimin);
		if (ver != -1) {
			vermaj = GET_ABI_MAJOR(ver);
			vermin = GET_ABI_MINOR(ver);
			if (abimaj != vermaj) {
				if (LoaderOptions & LDR_OPT_ABI_MISMATCH_NONFATAL)
					errtype = X_WARNING;
				else
					errtype = X_ERROR;
				xf86MsgVerb(errtype, 0,
					"module ABI major version (%d) doesn't"
					" match the server's version (%d)\n",
					abimaj, vermaj);
				if (!(LoaderOptions & LDR_OPT_ABI_MISMATCH_NONFATAL))
					return FALSE;
			} else if (abimin > vermin) {
				if (LoaderOptions & LDR_OPT_ABI_MISMATCH_NONFATAL)
					errtype = X_WARNING;
				else
					errtype = X_ERROR;
				xf86MsgVerb(errtype, 0,
					"module ABI minor version (%d) is "
					"newer than the server's version "
					"(%d)\n", abimin, vermin);
				if (!(LoaderOptions & LDR_OPT_ABI_MISMATCH_NONFATAL))
					return FALSE;
			}
		}
	}

	/* Check against requirements that the caller has specified */
	if (req) {
		if (req->majorversion != MAJOR_UNSPEC) {
			if (data->majorversion != req->majorversion) {
				xf86MsgVerb(X_WARNING, 2, "module major version (%d) "
							"doesn't match required major version (%d)\n",
							data->majorversion, req->majorversion);
				return FALSE;
			} else if (req->minorversion != MINOR_UNSPEC) {
				if (data->minorversion < req->minorversion) {
					xf86MsgVerb(X_WARNING, 2, "module minor version (%d) "
							"is less than the required minor version (%d)\n",
							data->minorversion, req->minorversion);
					return FALSE;
				} else if (data->minorversion == req->minorversion &&
						   req->patchlevel != PATCH_UNSPEC) {
					if (data->patchlevel < req->patchlevel) {
						xf86MsgVerb(X_WARNING, 2, "module patch level (%d) "
								"is less than the required patch level (%d)\n",
								data->patchlevel, req->patchlevel);
						return FALSE;
					}
				}
			}
		}
		if (req->moduleclass) {
			if (!data->moduleclass ||
				strcmp(req->moduleclass, data->moduleclass)) {
				xf86MsgVerb(X_WARNING, 2, "Module class (%s) doesn't match "
							"the required class (%s)\n",
							data->moduleclass ? data->moduleclass : "<NONE>",
							req->moduleclass);
				return FALSE;
			}
		} else if (req->abiclass != ABI_CLASS_NONE) {
			if (!data->abiclass || strcmp(req->abiclass, data->moduleclass)) {
				xf86MsgVerb(X_WARNING, 2, "ABI class (%s) doesn't match the "
							"required ABI class (%s)\n",
							data->abiclass ? data->abiclass : "<NONE>",
							req->abiclass);
				return FALSE;
			}
		}
		if ((req->abiclass != ABI_CLASS_NONE) &&
			req->abiversion != ABI_VERS_UNSPEC) {
			int reqmaj, reqmin, maj, min;
			reqmaj = GET_ABI_MAJOR(req->abiversion);
			reqmin = GET_ABI_MINOR(req->abiversion);
			maj = GET_ABI_MAJOR(data->abiversion);
			min = GET_ABI_MINOR(data->abiversion);
			if (maj != reqmaj) {
				xf86MsgVerb(X_WARNING, 2, "ABI major version (%d) doesn't "
							"match the required ABI major version (%d)\n",
							maj, reqmaj);
				return FALSE;
			}
			/* XXX Maybe this should be the other way around? */
			if (min > reqmin) {
				xf86MsgVerb(X_WARNING, 2, "module ABI minor version (%d) "
							"is new than that available (%d)\n",
							min, reqmin);
				return FALSE;
			}
		}
	}

#ifdef NOTYET
	if (data->checksum)
	{
		/* verify the checksum field */
		/* TO BE DONE */
	}
	else
	{
		ErrorF ("\t*** Checksum field is 0 - this module is untrusted!\n");
	}
#endif
    return TRUE;
}

ModuleDescPtr
LoadSubModule(ModuleDescPtr parent, const char *module,
	      const char **subdirlist, const char **patternlist,
	      pointer options, const XF86ModReqInfo *modreq,
	      int *errmaj, int *errmin)
{
	ModuleDescPtr submod;

	xf86MsgVerb(X_INFO, 3, "Loading sub module \"%s\"\n", module);

	/* Absolute module paths are not allowed here */
#ifndef __UNIXOS2__
	if (module[0] == '/')
#else
	if (isalpha (module[0]) && module[1] == ':' && module[2] == '/')
#endif
	{
		xf86Msg(X_ERROR,
				"LoadSubModule: Absolute module path not permitted: \"%s\"\n",
				module);
		if (errmaj)
			*errmaj = LDR_BADUSAGE;
		if (errmin)
			*errmin = 0;
		return NULL;
	}

	submod = LoadModule (module, NULL, subdirlist, patternlist, options,
						 modreq, errmaj, errmin);
	if (submod) {
		parent->child = AddSibling (parent->child, submod);
		submod->parent = parent;
	}
	return submod;
}

ModuleDescPtr
DuplicateModule(ModuleDescPtr mod, ModuleDescPtr parent)
{
	ModuleDescPtr ret;

	if (!mod)
		return NULL;

	ret = NewModuleDesc(mod->name);
	if (ret == NULL)
		return NULL;

	if (LoaderHandleOpen(mod->handle) == -1)
		return NULL;

	ret->filename = xstrdup(mod->filename);
	ret->identifier = mod->identifier;
	ret->client_id = mod->client_id;
	ret->in_use = mod->in_use;
	ret->handle = mod->handle;
	ret->SetupProc = mod->SetupProc;
	ret->TearDownProc = mod->TearDownProc;
	ret->TearDownData = NULL;
	ret->path = mod->path;
	ret->child = DuplicateModule(mod->child, ret);
	ret->sib = DuplicateModule(mod->sib, parent);
	ret->parent = parent;
	ret->VersionInfo = mod->VersionInfo;

	return ret;
}

/*
 * LoadModule: load a module
 *
 * module       The module name.  Normally this is not a filename but the
 *              module's "canonical name.  A full pathname is, however,
 *              also accepted.
 * path         A comma separated list of module directories.
 * subdirlist   A NULL terminated list of subdirectories to search.  When
 *              NULL, the default "stdSubdirs" list is used.  The default
 *              list is also substituted for entries with value DEFAULT_LIST.
 * patternlist  A NULL terminated list of regular expressions used to find
 *              module filenames.  Each regex should contain exactly one
 *              subexpression that corresponds to the canonical module name.
 *              When NULL, the default "stdPatterns" list is used.  The
 *              default list is also substituted for entries with value
 *              DEFAULT_LIST.
 * options      A NULL terminated list of Options that are passed to the
 *              module's SetupProc function.
 * modreq       An optional XF86ModReqInfo* containing
 *              version/ABI/vendor-ABI requirements to check for when
 *              loading the module.  The following fields of the
 *              XF86ModReqInfo struct are checked:
 *                majorversion - must match the module's majorversion exactly
 *                minorversion - the module's minorversion must be >= this
 *                patchlevel   - the module's minorversion.patchlevel must be
 *                               >= this.  Patchlevel is ignored when
 *                               minorversion is not set.
 *                abiclass     - (string) must match the module's abiclass
 *                abiversion   - must be consistent with the module's
 *                               abiversion (major equal, minor no older)
 *                moduleclass  - string must match the module's moduleclass
 *                               string
 *              "don't care" values are ~0 for numbers, and NULL for strings
 * errmaj       Major error return.
 * errmin       Minor error return.
 *
 */

ModuleDescPtr
LoadModule (const char *module, const char *path, const char **subdirlist,
			const char **patternlist, pointer options,
			const XF86ModReqInfo * modreq,
			int *errmaj, int *errmin)
{
	XF86ModuleData *initdata = NULL;
	char **pathlist = NULL;
	char *found = NULL;
	char *name = NULL;
	char **path_elem = NULL;
	char *p = NULL;
	ModuleDescPtr ret = NULL;
	int wasLoaded = 0;
	PatternPtr patterns = NULL;
	int noncanonical = 0;
	char *m = NULL;

	/*xf86Msg(X_INFO,"OS2DIAG: LoadModule: %s\n",module);*/
	xf86MsgVerb(X_INFO, 3, "LoadModule: \"%s\"", module);

	patterns = InitPatterns(patternlist);
	name = LoaderGetCanonicalName(module, patterns);
	noncanonical = (name && strcmp(module, name) != 0);
	if (noncanonical)
	{
		xf86ErrorFVerb(3, " (%s)\n", name);
		xf86MsgVerb(X_WARNING, 1,
					"LoadModule: given non-canonical module name \"%s\"\n",
					module);
		m = name;
	}
	else
	{
		xf86ErrorFVerb(3, "\n");
		m = (char *)module;
	}
	if (!name) {
		if (errmaj)
			*errmaj = LDR_BADUSAGE;
		if (errmin)
			*errmin = 0;
		goto LoadModule_fail;
	}
	ret = NewModuleDesc (name);
	if (!ret) {
		if (errmaj)
			*errmaj = LDR_NOMEM;
		if (errmin)
			*errmin = 0;
		goto LoadModule_fail;
	}

	pathlist = InitPathList(path);
	if (!pathlist) {
		/* This could be a malloc failure too */
		if (errmaj)
			*errmaj = LDR_BADUSAGE;
		if (errmin)
			*errmin = 1;
		goto LoadModule_fail;
	}

	/* 
	 * if the module name is not a full pathname, we need to
	 * check the elements in the path
	 */
#ifndef __UNIXOS2__
	if (module[0] == '/')
		found = xstrdup(module);
#else
	/* accept a drive name here */
	if (isalpha (module[0]) && module[1] == ':' && module[2] == '/')
		found = xstrdup(module);
#endif
	path_elem = pathlist;
	while (!found && *path_elem != NULL)
	{
		found = FindModule (m, *path_elem, subdirlist, patterns);
		path_elem++;
		/*
		 * When the module name isn't the canonical name, search for the
		 * former if no match was found for the latter.
		 */
		if (!*path_elem && m == name)
		{
			path_elem = pathlist;
			m = (char *)module;
		}
	}

	/* 
	 * did we find the module?
	 */
	if (!found)
	{
		xf86Msg (X_WARNING, "Warning, couldn't open module %s\n",
				module);
		if (errmaj)
			*errmaj = LDR_NOENT;
		if (errmin)
			*errmin = 0;
		goto LoadModule_fail;
	}
	ret->handle = LoaderOpen (found, name, 0, errmaj, errmin, &wasLoaded);
	if (ret->handle < 0)
		goto LoadModule_fail;

	ret->filename = xstrdup(found);

	/*
	 * now check if the special data object <modulename>ModuleData is
	 * present.
	 */
	p = xalloc (strlen (name) + strlen ("ModuleData") + 1);
	if (!p) {
		if (errmaj)
			*errmaj = LDR_NOMEM;
		if (errmin)
			*errmin = 0;
		goto LoadModule_fail;
	}
	strcpy (p, name);
	strcat (p, "ModuleData");
	initdata = LoaderSymbol (p);
	if (initdata)
	{
		ModuleSetupProc setup;
		ModuleTearDownProc teardown;
		XF86ModuleVersionInfo *vers;

		vers = initdata->vers;
		setup = initdata->setup;
		teardown = initdata->teardown;

		if (!wasLoaded) {
			if (vers) {
				if (!CheckVersion (module, vers, modreq)) {
					if (errmaj)
						*errmaj = LDR_MISMATCH;
					if (errmin)
						*errmin = 0;
					goto LoadModule_fail;
				}
			} else {
				xf86Msg(X_ERROR,
					"LoadModule: Module %s does not supply"
					" version information\n", module);
				if (errmaj)
					*errmaj = LDR_INVALID;
				if (errmin)
					*errmin = 0;
				goto LoadModule_fail;
			}
		}
		if (setup)
			ret->SetupProc = setup;
		if (teardown)
			ret->TearDownProc = teardown;
		ret->path = path;
		ret->VersionInfo = vers;
	}
	else
	{
		/* No initdata is OK for external modules */
		if (options == EXTERN_MODULE)
			goto LoadModule_exit;

		/* no initdata, fail the load */
		xf86Msg (X_ERROR, "LoadModule: Module %s does not have a %s "
				"data object.\n", module, p);
		if (errmaj)
			*errmaj = LDR_INVALID;
		if (errmin)
			*errmin = 0;
		goto LoadModule_fail;
	}
	if (ret->SetupProc)
	{
		ret->TearDownData = ret->SetupProc (ret, options, errmaj, errmin);
		if (!ret->TearDownData)
		{
			goto LoadModule_fail;
		}
	}
	else if (options)
	{
		xf86Msg (X_WARNING, "Module Options present, but no SetupProc "
				"available for %s\n", module);
	}
	goto LoadModule_exit;

  LoadModule_fail:
	UnloadModule (ret);
	ret = NULL;

  LoadModule_exit:
	FreePathList(pathlist);
	FreePatterns(patterns);
	TestFree (found);
	TestFree (name);
	TestFree (p);

	/*
	 * If you need to do something to keep the
	 * instruction cache in sync with the main
	 * memory before jumping to that code, you may
	 * do it here.
	 */
#ifdef __alpha__
	istream_mem_barrier();
#endif
	return ret;
}

ModuleDescPtr
LoadDriver (const char *module, const char *path, int handle, pointer options,
	    int *errmaj, int *errmin)
{
return LoadModule (module, path, NULL, NULL, options, NULL, errmaj, errmin);
}

void
UnloadModule (ModuleDescPtr mod)
{
	UnloadModuleOrDriver (mod);
}

void
UnloadDriver (ModuleDescPtr mod)
{
	UnloadModuleOrDriver (mod);
}

static void
UnloadModuleOrDriver (ModuleDescPtr mod)
{
    if (mod == NULL || mod->name == NULL)
	return;

    xf86MsgVerb(X_INFO, 3, "UnloadModule: \"%s\"\n", mod->name);

    if ((mod->TearDownProc) && (mod->TearDownData))
        mod->TearDownProc (mod->TearDownData);
    LoaderUnload (mod->handle);

    if (mod->child)
        UnloadModuleOrDriver (mod->child);
    if (mod->sib)
        UnloadModuleOrDriver (mod->sib);
    TestFree (mod->name);
    TestFree (mod->filename);
    xfree (mod);
#ifdef __alpha__
	istream_mem_barrier();
#endif
}

void
UnloadSubModule(ModuleDescPtr mod)
{
    if (mod == NULL || mod->name == NULL)
	return;

    xf86MsgVerb(X_INFO, 3, "UnloadSubModule: \"%s\"\n", mod->name);

    if ((mod->TearDownProc) && (mod->TearDownData))
        mod->TearDownProc (mod->TearDownData);
    LoaderUnload (mod->handle);

    RemoveChild(mod);

    if (mod->child)
        UnloadModuleOrDriver (mod->child);

    TestFree (mod->name);
    TestFree (mod->filename);
    xfree (mod);
}

void
FreeModuleDesc (ModuleDescPtr head)
{
	ModuleDescPtr sibs, prev;

	/*
	 * only free it if it's not marked as in use. In use means that it may
	 * be unloaded someday, and UnloadModule or UnloadDriver will free it
	 */
	if (head->in_use)
		return;
	if (head->child)
		FreeModuleDesc (head->child);
	sibs = head;
	while (sibs)
	{
		prev = sibs;
		sibs = sibs->sib;
		TestFree (prev->name);
		xfree (prev);
	}
}

ModuleDescPtr
NewModuleDesc (const char *name)
{
	ModuleDescPtr mdp = xalloc (sizeof (ModuleDesc));

	if (mdp)
	{
		mdp->child = NULL;
		mdp->sib = NULL;
		mdp->parent = NULL;
		mdp->demand_next = NULL;
		mdp->name = xstrdup (name);
		mdp->filename = NULL;
		mdp->identifier = NULL;
		mdp->client_id = 0;
		mdp->in_use = 0;
		mdp->handle = -1;
		mdp->SetupProc = NULL;
		mdp->TearDownProc = NULL;
		mdp->TearDownData = NULL;
	}

	return (mdp);
}

ModuleDescPtr
AddSibling (ModuleDescPtr head, ModuleDescPtr new)
{
    new->sib = head;
    return (new);

}

static void
RemoveChild (ModuleDescPtr child)
{
	ModuleDescPtr mdp;
	ModuleDescPtr prevsib;
	ModuleDescPtr parent;

	if (!child->parent)
		return;

	parent = child->parent;
	if (parent->child == child) {
		parent->child = child->sib;
		return;
	}

	prevsib = parent->child;
	mdp = prevsib->sib;
	while (mdp && mdp != child) {
		prevsib = mdp;
		mdp = mdp->sib;
	}
	if (mdp == child)
		prevsib->sib = child->sib;
	return;
}

void
LoaderErrorMsg(const char *name, const char *modname, int errmaj, int errmin)
{
	const char *msg;

	switch (errmaj) {
	case LDR_NOERROR:
		msg = "no error";
		break;
	case LDR_NOMEM:
		msg = "out of memory";
		break;
	case LDR_NOENT:
		msg = "module does not exist";
		break;
	case LDR_NOSUBENT:
		msg = "a required submodule could not be loaded";
		break;
	case LDR_NOSPACE:
		msg = "too many modules";
		break;
	case LDR_NOMODOPEN:
		msg = "open failed";
		break;
	case LDR_UNKTYPE:
		msg = "unknown module type";
		break;
	case LDR_NOLOAD:
		msg = "loader failed";
		break;
	case LDR_ONCEONLY:
		msg = "once-only module";
		break;
	case LDR_NOPORTOPEN:
		msg = "port open failed";
		break;
	case LDR_NOHARDWARE:
		msg = "no hardware found";
		break;
	case LDR_MISMATCH:
		msg = "module requirement mismatch";
		break;
	case LDR_BADUSAGE:
		msg = "invalid argument(s) to LoadModule()";
		break;
	case LDR_INVALID:
		msg = "invalid module";
		break;
	case LDR_BADOS:
		msg = "module doesn't support this OS";
		break;
	case LDR_MODSPECIFIC:
		msg = "module-specific error";
		break;
	default:
		msg = "uknown error";
	}
	if (name)
		xf86Msg(X_ERROR, "%s: Failed to load module \"%s\" (%s, %d)\n",
			name, modname, msg, errmin);
	else
		xf86Msg(X_ERROR, "Failed to load module \"%s\" (%s, %d)\n",
			modname, msg, errmin);
}


/* Given a module path or file name, return the module's canonical name */
static char *
LoaderGetCanonicalName(const char *modname, PatternPtr patterns)
{
	char *str;
	const char *s;
	int len;
	PatternPtr p;
	regmatch_t match[2];

	/* Strip off any leading path */
	s = strrchr(modname, '/');
	if (s == NULL)
		s = modname;
	else
		s++;

	/* Find the first regex that is matched */
	for (p = patterns; p->pattern; p++)
		if (regexec(&p->rex, s, 2, match, 0) == 0 &&
			match[1].rm_so != -1) {
			len = match[1].rm_eo - match[1].rm_so;
			str = xalloc(len + 1);
			if (!str)
				return NULL;
			strncpy(str, s + match[1].rm_so, len);
			str[len] = '\0';
			return str;
		}

	/* If there is no match, return the whole name minus the leading path */
	return xstrdup(s);
}

/*
 * Return the module version information.
 */
unsigned long
LoaderGetModuleVersion (ModuleDescPtr mod)
{
    if (!mod || !mod->VersionInfo)
		return 0;

    return MODULE_VERSION_NUMERIC(mod->VersionInfo->majorversion,
								  mod->VersionInfo->minorversion,
								  mod->VersionInfo->patchlevel);
}