xref: /xsrc/external/mit/xorg-server/dist/dix/extension.c

/***********************************************************

Copyright 1987, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
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in this Software without prior written authorization from The Open Group.


Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
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 Digital not be
used in advertising or publicity pertaining to distribution of the
software without specific, written prior permission.

DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
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WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
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******************************************************************/

#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#include <X11/X.h>
#define NEED_EVENTS
#define NEED_REPLIES
#include <X11/Xproto.h>
#include "misc.h"
#include "dixstruct.h"
#include "extnsionst.h"
#include "gcstruct.h"
#include "scrnintstr.h"
#include "dispatch.h"
#include "privates.h"
#include "registry.h"
#include "xace.h"

#define LAST_EVENT  128
#define LAST_ERROR 255

static ExtensionEntry **extensions = (ExtensionEntry **)NULL;

int lastEvent = EXTENSION_EVENT_BASE;
static int lastError = FirstExtensionError;
static unsigned int NumExtensions = 0;

_X_EXPORT ExtensionEntry *
AddExtension(char *name, int NumEvents, int NumErrors,
	     int (*MainProc)(ClientPtr c1),
	     int (*SwappedMainProc)(ClientPtr c2),
	     void (*CloseDownProc)(ExtensionEntry *e),
	     unsigned short (*MinorOpcodeProc)(ClientPtr c3))
{
    int i;
    ExtensionEntry *ext, **newexts;

    if (!MainProc || !SwappedMainProc || !MinorOpcodeProc)
        return((ExtensionEntry *) NULL);
    if ((lastEvent + NumEvents > LAST_EVENT) ||
	        (unsigned)(lastError + NumErrors > LAST_ERROR))
        return((ExtensionEntry *) NULL);

    ext = (ExtensionEntry *) xalloc(sizeof(ExtensionEntry));
    if (!ext)
	return((ExtensionEntry *) NULL);
    ext->name = (char *)xalloc(strlen(name) + 1);
    ext->num_aliases = 0;
    ext->aliases = (char **)NULL;
    ext->devPrivates = NULL;
    if (!ext->name)
    {
	xfree(ext);
	return((ExtensionEntry *) NULL);
    }
    strcpy(ext->name,  name);
    i = NumExtensions;
    newexts = (ExtensionEntry **) xrealloc(extensions,
					   (i + 1) * sizeof(ExtensionEntry *));
    if (!newexts)
    {
	xfree(ext->name);
	xfree(ext);
	return((ExtensionEntry *) NULL);
    }
    NumExtensions++;
    extensions = newexts;
    extensions[i] = ext;
    ext->index = i;
    ext->base = i + EXTENSION_BASE;
    ext->CloseDown = CloseDownProc;
    ext->MinorOpcode = MinorOpcodeProc;
    ProcVector[i + EXTENSION_BASE] = MainProc;
    SwappedProcVector[i + EXTENSION_BASE] = SwappedMainProc;
    if (NumEvents)
    {
        ext->eventBase = lastEvent;
	ext->eventLast = lastEvent + NumEvents;
	lastEvent += NumEvents;
    }
    else
    {
        ext->eventBase = 0;
        ext->eventLast = 0;
    }
    if (NumErrors)
    {
        ext->errorBase = lastError;
	ext->errorLast = lastError + NumErrors;
	lastError += NumErrors;
    }
    else
    {
        ext->errorBase = 0;
        ext->errorLast = 0;
    }

    RegisterExtensionNames(ext);
    return(ext);
}

_X_EXPORT Bool AddExtensionAlias(char *alias, ExtensionEntry *ext)
{
    char *name;
    char **aliases;

    if (!ext)
        return FALSE ;
    aliases = (char **)xrealloc(ext->aliases,
				(ext->num_aliases + 1) * sizeof(char *));
    if (!aliases)
	return FALSE;
    ext->aliases = aliases;
    name = (char *)xalloc(strlen(alias) + 1);
    if (!name)
	return FALSE;
    strcpy(name,  alias);
    ext->aliases[ext->num_aliases] = name;
    ext->num_aliases++;
    return TRUE;
}

static int
FindExtension(char *extname, int len)
{
    int i, j;

    for (i=0; i<NumExtensions; i++)
    {
	if ((strlen(extensions[i]->name) == len) &&
	    !strncmp(extname, extensions[i]->name, len))
	    break;
	for (j = extensions[i]->num_aliases; --j >= 0;)
	{
	    if ((strlen(extensions[i]->aliases[j]) == len) &&
		!strncmp(extname, extensions[i]->aliases[j], len))
		break;
	}
	if (j >= 0) break;
    }
    return ((i == NumExtensions) ? -1 : i);
}

/*
 * CheckExtension returns the extensions[] entry for the requested
 * extension name.  Maybe this could just return a Bool instead?
 */
_X_EXPORT ExtensionEntry *
CheckExtension(const char *extname)
{
    int n;

    n = FindExtension((char*)extname, strlen(extname));
    if (n != -1)
	return extensions[n];
    else
	return NULL;
}

/*
 * Added as part of Xace.
 */
ExtensionEntry *
GetExtensionEntry(int major)
{
    if (major < EXTENSION_BASE)
	return NULL;
    major -= EXTENSION_BASE;
    if (major >= NumExtensions)
	return NULL;
    return extensions[major];
}

_X_EXPORT unsigned short
StandardMinorOpcode(ClientPtr client)
{
    return ((xReq *)client->requestBuffer)->data;
}

_X_EXPORT unsigned short
MinorOpcodeOfRequest(ClientPtr client)
{
    unsigned char major;

    major = ((xReq *)client->requestBuffer)->reqType;
    if (major < EXTENSION_BASE)
	return 0;
    major -= EXTENSION_BASE;
    if (major >= NumExtensions)
	return 0;
    return (*extensions[major]->MinorOpcode)(client);
}

void
CloseDownExtensions(void)
{
    int i,j;

    for (i = NumExtensions - 1; i >= 0; i--)
    {
	if (extensions[i]->CloseDown)
	    extensions[i]->CloseDown(extensions[i]);
	NumExtensions = i;
	xfree(extensions[i]->name);
	for (j = extensions[i]->num_aliases; --j >= 0;)
	    xfree(extensions[i]->aliases[j]);
	xfree(extensions[i]->aliases);
	dixFreePrivates(extensions[i]->devPrivates);
	xfree(extensions[i]);
    }
    xfree(extensions);
    extensions = (ExtensionEntry **)NULL;
    lastEvent = EXTENSION_EVENT_BASE;
    lastError = FirstExtensionError;
}

int
ProcQueryExtension(ClientPtr client)
{
    xQueryExtensionReply reply;
    int i;
    REQUEST(xQueryExtensionReq);

    REQUEST_FIXED_SIZE(xQueryExtensionReq, stuff->nbytes);

    reply.type = X_Reply;
    reply.length = 0;
    reply.major_opcode = 0;
    reply.sequenceNumber = client->sequence;

    if ( ! NumExtensions )
        reply.present = xFalse;
    else
    {
	i = FindExtension((char *)&stuff[1], stuff->nbytes);
        if (i < 0 || XaceHook(XACE_EXT_ACCESS, client, extensions[i]))
            reply.present = xFalse;
        else
        {
            reply.present = xTrue;
	    reply.major_opcode = extensions[i]->base;
	    reply.first_event = extensions[i]->eventBase;
	    reply.first_error = extensions[i]->errorBase;
	}
    }
    WriteReplyToClient(client, sizeof(xQueryExtensionReply), &reply);
    return(client->noClientException);
}

int
ProcListExtensions(ClientPtr client)
{
    xListExtensionsReply reply;
    char *bufptr, *buffer;
    int total_length = 0;

    REQUEST_SIZE_MATCH(xReq);

    reply.type = X_Reply;
    reply.nExtensions = 0;
    reply.length = 0;
    reply.sequenceNumber = client->sequence;
    buffer = NULL;

    if ( NumExtensions )
    {
        int i, j;

        for (i=0;  i<NumExtensions; i++)
	{
	    /* call callbacks to find out whether to show extension */
	    if (XaceHook(XACE_EXT_ACCESS, client, extensions[i]) != Success)
		continue;

	    total_length += strlen(extensions[i]->name) + 1;
	    reply.nExtensions += 1 + extensions[i]->num_aliases;
	    for (j = extensions[i]->num_aliases; --j >= 0;)
		total_length += strlen(extensions[i]->aliases[j]) + 1;
	}
        reply.length = (total_length + 3) >> 2;
	buffer = bufptr = (char *)xalloc(total_length);
	if (!buffer)
	    return(BadAlloc);
        for (i=0;  i<NumExtensions; i++)
        {
	    int len;
	    if (XaceHook(XACE_EXT_ACCESS, client, extensions[i]) != Success)
		continue;

            *bufptr++ = len = strlen(extensions[i]->name);
	    memmove(bufptr, extensions[i]->name,  len);
	    bufptr += len;
	    for (j = extensions[i]->num_aliases; --j >= 0;)
	    {
		*bufptr++ = len = strlen(extensions[i]->aliases[j]);
		memmove(bufptr, extensions[i]->aliases[j],  len);
		bufptr += len;
	    }
	}
    }
    WriteReplyToClient(client, sizeof(xListExtensionsReply), &reply);
    if (reply.length)
    {
        WriteToClient(client, total_length, buffer);
    	xfree(buffer);
    }
    return(client->noClientException);
}