path: root/dix/registry.c

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

Author: Eamon Walsh <ewalsh@tycho.nsa.gov>

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
this permission notice appear in supporting documentation.  This permission
notice shall be included in all copies or substantial portions of the
Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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

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

#ifdef XREGISTRY

#include <stdlib.h>
#include <string.h>
#include <X11/X.h>
#include <X11/Xproto.h>
#include "resource.h"
#include "registry.h"

#define BASE_SIZE 16
#define CORE "X11"
#define FILENAME SERVER_MISC_CONFIG_PATH "/protocol.txt"

#define PROT_COMMENT '#'
#define PROT_REQUEST 'R'
#define PROT_EVENT 'V'
#define PROT_ERROR 'E'

static FILE *fh;

static char ***requests, **events, **errors;
static const char **resources;
static unsigned nmajor, *nminor, nevent, nerror, nresource;

/*
 * File parsing routines
 */
static int
double_size(void *p, unsigned n, unsigned size)
{
    char **ptr = (char **) p;
    unsigned s, f;

    if (n) {
        s = n * size;
        n *= 2 * size;
        f = n;
    }
    else {
        s = 0;
        n = f = BASE_SIZE * size;
    }

    *ptr = realloc(*ptr, n);
    if (!*ptr) {
        dixResetRegistry();
        return FALSE;
    }
    memset(*ptr + s, 0, f - s);
    return TRUE;
}

static void
RegisterRequestName(unsigned major, unsigned minor, char *name)
{
    while (major >= nmajor) {
        if (!double_size(&requests, nmajor, sizeof(char **)))
            return;
        if (!double_size(&nminor, nmajor, sizeof(unsigned)))
            return;
        nmajor = nmajor ? nmajor * 2 : BASE_SIZE;
    }
    while (minor >= nminor[major]) {
        if (!double_size(requests + major, nminor[major], sizeof(char *)))
            return;
        nminor[major] = nminor[major] ? nminor[major] * 2 : BASE_SIZE;
    }

    free(requests[major][minor]);
    requests[major][minor] = name;
}

static void
RegisterEventName(unsigned event, char *name)
{
    while (event >= nevent) {
        if (!double_size(&events, nevent, sizeof(char *)))
            return;
        nevent = nevent ? nevent * 2 : BASE_SIZE;
    }

    free(events[event]);
    events[event] = name;
}

static void
RegisterErrorName(unsigned error, char *name)
{
    while (error >= nerror) {
        if (!double_size(&errors, nerror, sizeof(char *)))
            return;
        nerror = nerror ? nerror * 2 : BASE_SIZE;
    }

    free(errors[error]);
    errors[error] = name;
}

void
RegisterExtensionNames(ExtensionEntry * extEntry)
{
    char buf[256], *lineobj, *ptr;
    unsigned offset;

    if (fh == NULL)
        return;

    rewind(fh);

    while (fgets(buf, sizeof(buf), fh)) {
        lineobj = NULL;
        ptr = strchr(buf, '\n');
        if (ptr)
            *ptr = 0;

        /* Check for comments or empty lines */
        switch (buf[0]) {
        case PROT_REQUEST:
        case PROT_EVENT:
        case PROT_ERROR:
            break;
        case PROT_COMMENT:
        case '\0':
            continue;
        default:
            goto invalid;
        }

        /* Check for space character in the fifth position */
        ptr = strchr(buf, ' ');
        if (!ptr || ptr != buf + 4)
            goto invalid;

        /* Duplicate the string after the space */
        lineobj = strdup(ptr + 1);
        if (!lineobj)
            continue;

        /* Check for a colon somewhere on the line */
        ptr = strchr(buf, ':');
        if (!ptr)
            goto invalid;

        /* Compare the part before colon with the target extension name */
        *ptr = 0;
        if (strcmp(buf + 5, extEntry->name))
            goto skip;

        /* Get the opcode for the request, event, or error */
        offset = strtol(buf + 1, &ptr, 10);
        if (offset == 0 && ptr == buf + 1)
            goto invalid;

        /* Save the strdup result in the registry */
        switch (buf[0]) {
        case PROT_REQUEST:
            if (extEntry->base)
                RegisterRequestName(extEntry->base, offset, lineobj);
            else
                RegisterRequestName(offset, 0, lineobj);
            continue;
        case PROT_EVENT:
            RegisterEventName(extEntry->eventBase + offset, lineobj);
            continue;
        case PROT_ERROR:
            RegisterErrorName(extEntry->errorBase + offset, lineobj);
            continue;
        }

 invalid:
        LogMessage(X_WARNING, "Invalid line in " FILENAME ", skipping\n");
 skip:
        free(lineobj);
    }
}

/*
 * Registration functions
 */

void
RegisterResourceName(RESTYPE resource, const char *name)
{
    resource &= TypeMask;

    while (resource >= nresource) {
        if (!double_size(&resources, nresource, sizeof(char *)))
            return;
        nresource = nresource ? nresource * 2 : BASE_SIZE;
    }

    resources[resource] = name;
}

/*
 * Lookup functions
 */

const char *
LookupRequestName(int major, int minor)
{
    if (major >= nmajor)
        return XREGISTRY_UNKNOWN;
    if (minor >= nminor[major])
        return XREGISTRY_UNKNOWN;

    return requests[major][minor] ? requests[major][minor] : XREGISTRY_UNKNOWN;
}

const char *
LookupMajorName(int major)
{
    if (major < 128) {
        const char *retval;

        if (major >= nmajor)
            return XREGISTRY_UNKNOWN;
        if (0 >= nminor[major])
            return XREGISTRY_UNKNOWN;

        retval = requests[major][0];
        return retval ? retval + sizeof(CORE) : XREGISTRY_UNKNOWN;
    }
    else {
        ExtensionEntry *extEntry = GetExtensionEntry(major);

        return extEntry ? extEntry->name : XREGISTRY_UNKNOWN;
    }
}

const char *
LookupEventName(int event)
{
    event &= 127;
    if (event >= nevent)
        return XREGISTRY_UNKNOWN;

    return events[event] ? events[event] : XREGISTRY_UNKNOWN;
}

const char *
LookupErrorName(int error)
{
    if (error >= nerror)
        return XREGISTRY_UNKNOWN;

    return errors[error] ? errors[error] : XREGISTRY_UNKNOWN;
}

const char *
LookupResourceName(RESTYPE resource)
{
    resource &= TypeMask;
    if (resource >= nresource)
        return XREGISTRY_UNKNOWN;

    return resources[resource] ? resources[resource] : XREGISTRY_UNKNOWN;
}

/*
 * Setup and teardown
 */
void
dixResetRegistry(void)
{
    ExtensionEntry extEntry = { .name = CORE };

    /* Free all memory */
    while (nmajor--) {
        while (nminor[nmajor])
            free(requests[nmajor][--nminor[nmajor]]);
        free(requests[nmajor]);
    }
    free(requests);
    free(nminor);

    while (nevent--)
        free(events[nevent]);
    free(events);

    while (nerror--)
        free(errors[nerror]);
    free(errors);

    free(resources);

    requests = NULL;
    nminor = NULL;
    events = NULL;
    errors = NULL;
    resources = NULL;

    nmajor = nevent = nerror = nresource = 0;

    /* Open the protocol file */
    if (fh)
        fclose(fh);
    fh = fopen(FILENAME, "r");
    if (!fh)
        LogMessage(X_WARNING,
                   "Failed to open protocol names file " FILENAME "\n");

    /* Add built-in resources */
    RegisterResourceName(RT_NONE, "NONE");
    RegisterResourceName(RT_WINDOW, "WINDOW");
    RegisterResourceName(RT_PIXMAP, "PIXMAP");
    RegisterResourceName(RT_GC, "GC");
    RegisterResourceName(RT_FONT, "FONT");
    RegisterResourceName(RT_CURSOR, "CURSOR");
    RegisterResourceName(RT_COLORMAP, "COLORMAP");
    RegisterResourceName(RT_CMAPENTRY, "COLORMAP ENTRY");
    RegisterResourceName(RT_OTHERCLIENT, "OTHER CLIENT");
    RegisterResourceName(RT_PASSIVEGRAB, "PASSIVE GRAB");

    /* Add the core protocol */
    RegisterExtensionNames(&extEntry);
}

#endif                          /* XREGISTRY */