types.c

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Author : Ran Benita
Date : 2017-12-12 14:30:21
Hash : 26453b84
Message : keymap: fix NULL dereference when dumping the default fallback type The default fallback type uses type->level_names = NULL but the keymap-dump code was not checking this case. Instead of adding more workarounds and possible bugs (e.g. previous commit), let's just keep the number of level names separately. This has the additional advantage retains extraneous level name if someone adds them for some reason. Signed-off-by: Ran Benita <ran234@gmail.com>
src/xkbcomp/types.c
/************************************************************
 * Copyright (c) 1994 by Silicon Graphics Computer Systems, Inc.
 *
 * 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 Silicon Graphics not be
 * used in advertising or publicity pertaining to distribution
 * of the software without specific prior written permission.
 * Silicon Graphics makes no representation about the suitability
 * of this software for any purpose. It is provided "as is"
 * without any express or implied warranty.
 *
 * SILICON GRAPHICS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
 * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
 * GRAPHICS 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.
 *
 ********************************************************/

#include "xkbcomp-priv.h"
#include "text.h"
#include "vmod.h"
#include "expr.h"
#include "include.h"

enum type_field {
    TYPE_FIELD_MASK = (1 << 0),
    TYPE_FIELD_MAP = (1 << 1),
    TYPE_FIELD_PRESERVE = (1 << 2),
    TYPE_FIELD_LEVEL_NAME = (1 << 3),
};

typedef struct {
    enum type_field defined;
    enum merge_mode merge;

    xkb_atom_t name;
    xkb_mod_mask_t mods;
    xkb_level_index_t num_levels;
    darray(struct xkb_key_type_entry) entries;
    darray(xkb_atom_t) level_names;
} KeyTypeInfo;

typedef struct {
    char *name;
    int errorCount;

    darray(KeyTypeInfo) types;
    struct xkb_mod_set mods;

    struct xkb_context *ctx;
} KeyTypesInfo;

/***====================================================================***/

static inline const char *
MapEntryTxt(KeyTypesInfo *info, struct xkb_key_type_entry *entry)
{
    return ModMaskText(info->ctx, &info->mods, entry->mods.mods);
}

static inline const char *
TypeTxt(KeyTypesInfo *info, KeyTypeInfo *type)
{
    return xkb_atom_text(info->ctx, type->name);
}

static inline const char *
TypeMaskTxt(KeyTypesInfo *info, KeyTypeInfo *type)
{
    return ModMaskText(info->ctx, &info->mods, type->mods);
}

static inline bool
ReportTypeShouldBeArray(KeyTypesInfo *info, KeyTypeInfo *type,
                        const char *field)
{
    return ReportShouldBeArray(info->ctx, "key type", field,
                               TypeTxt(info, type));
}

static inline bool
ReportTypeBadType(KeyTypesInfo *info, KeyTypeInfo *type,
                  const char *field, const char *wanted)
{
    return ReportBadType(info->ctx, "key type", field,
                         TypeTxt(info, type), wanted);
}

/***====================================================================***/

static void
InitKeyTypesInfo(KeyTypesInfo *info, struct xkb_context *ctx,
                 const struct xkb_mod_set *mods)
{
    memset(info, 0, sizeof(*info));
    info->ctx = ctx;
    info->mods = *mods;
}

static void
ClearKeyTypeInfo(KeyTypeInfo *type)
{
    darray_free(type->entries);
    darray_free(type->level_names);
}

static void
ClearKeyTypesInfo(KeyTypesInfo *info)
{
    free(info->name);
    darray_free(info->types);
}

static KeyTypeInfo *
FindMatchingKeyType(KeyTypesInfo *info, xkb_atom_t name)
{
    KeyTypeInfo *old;

    darray_foreach(old, info->types)
        if (old->name == name)
            return old;

    return NULL;
}

static bool
AddKeyType(KeyTypesInfo *info, KeyTypeInfo *new, bool same_file)
{
    KeyTypeInfo *old;
    const int verbosity = xkb_context_get_log_verbosity(info->ctx);

    old = FindMatchingKeyType(info, new->name);
    if (old) {
        if (new->merge == MERGE_REPLACE || new->merge == MERGE_OVERRIDE) {
            if ((same_file && verbosity > 0) || verbosity > 9) {
                log_warn(info->ctx,
                         "Multiple definitions of the %s key type; "
                         "Earlier definition ignored\n",
                         xkb_atom_text(info->ctx, new->name));
            }

            ClearKeyTypeInfo(old);
            *old = *new;
            darray_init(new->entries);
            darray_init(new->level_names);
            return true;
        }

        if (same_file)
            log_vrb(info->ctx, 4,
                    "Multiple definitions of the %s key type; "
                    "Later definition ignored\n",
                    xkb_atom_text(info->ctx, new->name));

        ClearKeyTypeInfo(new);
        return true;
    }

    darray_append(info->types, *new);
    return true;
}

/***====================================================================***/

static void
MergeIncludedKeyTypes(KeyTypesInfo *into, KeyTypesInfo *from,
                      enum merge_mode merge)
{
    if (from->errorCount > 0) {
        into->errorCount += from->errorCount;
        return;
    }

    into->mods = from->mods;

    if (into->name == NULL) {
        into->name = from->name;
        from->name = NULL;
    }

    if (darray_empty(into->types)) {
        into->types = from->types;
        darray_init(from->types);
    }
    else {
        KeyTypeInfo *type;
        darray_foreach(type, from->types) {
            type->merge = (merge == MERGE_DEFAULT ? type->merge : merge);
            if (!AddKeyType(into, type, false))
                into->errorCount++;
        }
    }
}

static void
HandleKeyTypesFile(KeyTypesInfo *info, XkbFile *file, enum merge_mode merge);

static bool
HandleIncludeKeyTypes(KeyTypesInfo *info, IncludeStmt *include)
{
    KeyTypesInfo included;

    InitKeyTypesInfo(&included, info->ctx, &info->mods);
    included.name = include->stmt;
    include->stmt = NULL;

    for (IncludeStmt *stmt = include; stmt; stmt = stmt->next_incl) {
        KeyTypesInfo next_incl;
        XkbFile *file;

        file = ProcessIncludeFile(info->ctx, stmt, FILE_TYPE_TYPES);
        if (!file) {
            info->errorCount += 10;
            ClearKeyTypesInfo(&included);
            return false;
        }

        InitKeyTypesInfo(&next_incl, info->ctx, &included.mods);

        HandleKeyTypesFile(&next_incl, file, stmt->merge);

        MergeIncludedKeyTypes(&included, &next_incl, stmt->merge);

        ClearKeyTypesInfo(&next_incl);
        FreeXkbFile(file);
    }

    MergeIncludedKeyTypes(info, &included, include->merge);
    ClearKeyTypesInfo(&included);

    return (info->errorCount == 0);
}

/***====================================================================***/

static bool
SetModifiers(KeyTypesInfo *info, KeyTypeInfo *type, ExprDef *arrayNdx,
             ExprDef *value)
{
    xkb_mod_mask_t mods;

    if (arrayNdx)
        log_warn(info->ctx,
                 "The modifiers field of a key type is not an array; "
                 "Illegal array subscript ignored\n");

    if (!ExprResolveModMask(info->ctx, value, MOD_BOTH, &info->mods, &mods)) {
        log_err(info->ctx,
                "Key type mask field must be a modifier mask; "
                "Key type definition ignored\n");
        return false;
    }

    if (type->defined & TYPE_FIELD_MASK) {
        log_warn(info->ctx,
                 "Multiple modifier mask definitions for key type %s; "
                 "Using %s, ignoring %s\n",
                 xkb_atom_text(info->ctx, type->name),
                 TypeMaskTxt(info, type),
                 ModMaskText(info->ctx, &info->mods, mods));
        return false;
    }

    type->mods = mods;
    return true;
}

/***====================================================================***/

static struct xkb_key_type_entry *
FindMatchingMapEntry(KeyTypeInfo *type, xkb_mod_mask_t mods)
{
    struct xkb_key_type_entry *entry;

    darray_foreach(entry, type->entries)
        if (entry->mods.mods == mods)
            return entry;

    return NULL;
}

static bool
AddMapEntry(KeyTypesInfo *info, KeyTypeInfo *type,
            struct xkb_key_type_entry *new, bool clobber, bool report)
{
    struct xkb_key_type_entry *old;

    old = FindMatchingMapEntry(type, new->mods.mods);
    if (old) {
        if (report && old->level != new->level) {
            log_warn(info->ctx,
                     "Multiple map entries for %s in %s; "
                     "Using %d, ignoring %d\n",
                     MapEntryTxt(info, new), TypeTxt(info, type),
                     (clobber ? new->level : old->level) + 1,
                     (clobber ? old->level : new->level) + 1);
        }
        else {
            log_vrb(info->ctx, 10,
                    "Multiple occurrences of map[%s]= %d in %s; Ignored\n",
                    MapEntryTxt(info, new), new->level + 1,
                    TypeTxt(info, type));
            return true;
        }

        if (clobber) {
            if (new->level >= type->num_levels)
                type->num_levels = new->level + 1;
            old->level = new->level;
        }

        return true;
    }

    if (new->level >= type->num_levels)
        type->num_levels = new->level + 1;

    darray_append(type->entries, *new);
    return true;
}

static bool
SetMapEntry(KeyTypesInfo *info, KeyTypeInfo *type, ExprDef *arrayNdx,
            ExprDef *value)
{
    struct xkb_key_type_entry entry;

    if (arrayNdx == NULL)
        return ReportTypeShouldBeArray(info, type, "map entry");

    if (!ExprResolveModMask(info->ctx, arrayNdx, MOD_BOTH, &info->mods,
                            &entry.mods.mods))
        return ReportTypeBadType(info, type, "map entry", "modifier mask");

    if (entry.mods.mods & (~type->mods)) {
        log_vrb(info->ctx, 1,
                "Map entry for unused modifiers in %s; "
                "Using %s instead of %s\n",
                TypeTxt(info, type),
                ModMaskText(info->ctx, &info->mods,
                            entry.mods.mods & type->mods),
                MapEntryTxt(info, &entry));
        entry.mods.mods &= type->mods;
    }

    if (!ExprResolveLevel(info->ctx, value, &entry.level)) {
        log_err(info->ctx,
                "Level specifications in a key type must be integer; "
                "Ignoring malformed level specification\n");
        return false;
    }

    entry.preserve.mods = 0;

    return AddMapEntry(info, type, &entry, true, true);
}

/***====================================================================***/

static bool
AddPreserve(KeyTypesInfo *info, KeyTypeInfo *type,
            xkb_mod_mask_t mods, xkb_mod_mask_t preserve_mods)
{
    struct xkb_key_type_entry *entry;
    struct xkb_key_type_entry new;

    darray_foreach(entry, type->entries) {
        if (entry->mods.mods != mods)
            continue;

        /* Map exists without previous preserve (or "None"); override. */
        if (entry->preserve.mods == 0) {
            entry->preserve.mods = preserve_mods;
            return true;
        }

        /* Map exists with same preserve; do nothing. */
        if (entry->preserve.mods == preserve_mods) {
            log_vrb(info->ctx, 10,
                    "Identical definitions for preserve[%s] in %s; "
                    "Ignored\n",
                    ModMaskText(info->ctx, &info->mods, mods),
                    TypeTxt(info, type));
            return true;
        }

        /* Map exists with different preserve; latter wins. */
        log_vrb(info->ctx, 1,
                "Multiple definitions for preserve[%s] in %s; "
                "Using %s, ignoring %s\n",
                ModMaskText(info->ctx, &info->mods, mods),
                TypeTxt(info, type),
                ModMaskText(info->ctx, &info->mods, preserve_mods),
                ModMaskText(info->ctx, &info->mods, entry->preserve.mods));

        entry->preserve.mods = preserve_mods;
        return true;
    }

    /*
     * Map does not exist, i.e. preserve[] came before map[].
     * Create a map with the specified mask mapping to Level1. The level
     * may be overridden later with an explicit map[] statement.
     */
    new.level = 0;
    new.mods.mods = mods;
    new.preserve.mods = preserve_mods;
    darray_append(type->entries, new);
    return true;
}

static bool
SetPreserve(KeyTypesInfo *info, KeyTypeInfo *type, ExprDef *arrayNdx,
            ExprDef *value)
{
    xkb_mod_mask_t mods, preserve_mods;

    if (arrayNdx == NULL)
        return ReportTypeShouldBeArray(info, type, "preserve entry");

    if (!ExprResolveModMask(info->ctx, arrayNdx, MOD_BOTH, &info->mods, &mods))
        return ReportTypeBadType(info, type, "preserve entry",
                                 "modifier mask");

    if (mods & ~type->mods) {
        const char *before, *after;

        before = ModMaskText(info->ctx, &info->mods, mods);
        mods &= type->mods;
        after = ModMaskText(info->ctx, &info->mods, mods);

        log_vrb(info->ctx, 1,
                "Preserve for modifiers not used by the %s type; "
                "Index %s converted to %s\n",
                TypeTxt(info, type), before, after);
    }

    if (!ExprResolveModMask(info->ctx, value, MOD_BOTH, &info->mods,
                            &preserve_mods)) {
        log_err(info->ctx,
                "Preserve value in a key type is not a modifier mask; "
                "Ignoring preserve[%s] in type %s\n",
                ModMaskText(info->ctx, &info->mods, mods),
                TypeTxt(info, type));
        return false;
    }

    if (preserve_mods & ~mods) {
        const char *before, *after;

        before = ModMaskText(info->ctx, &info->mods, preserve_mods);
        preserve_mods &= mods;
        after = ModMaskText(info->ctx, &info->mods, preserve_mods);

        log_vrb(info->ctx, 1,
                "Illegal value for preserve[%s] in type %s; "
                "Converted %s to %s\n",
                ModMaskText(info->ctx, &info->mods, mods),
                TypeTxt(info, type), before, after);
    }

    return AddPreserve(info, type, mods, preserve_mods);
}

/***====================================================================***/

static bool
AddLevelName(KeyTypesInfo *info, KeyTypeInfo *type,
             xkb_level_index_t level, xkb_atom_t name, bool clobber)
{
    /* New name. */
    if (level >= darray_size(type->level_names)) {
        darray_resize0(type->level_names, level + 1);
        goto finish;
    }

    /* Same level, same name. */
    if (darray_item(type->level_names, level) == name) {
        log_vrb(info->ctx, 10,
                "Duplicate names for level %d of key type %s; Ignored\n",
                level + 1, TypeTxt(info, type));
        return true;
    }

    /* Same level, different name. */
    if (darray_item(type->level_names, level) != XKB_ATOM_NONE) {
        const char *old, *new;
        old = xkb_atom_text(info->ctx,
                            darray_item(type->level_names, level));
        new = xkb_atom_text(info->ctx, name);
        log_vrb(info->ctx, 1,
                "Multiple names for level %d of key type %s; "
                "Using %s, ignoring %s\n",
                level + 1, TypeTxt(info, type),
                (clobber ? new : old), (clobber ? old : new));

        if (!clobber)
            return true;
    }

    /* XXX: What about different level, same name? */

finish:
    darray_item(type->level_names, level) = name;
    return true;
}

static bool
SetLevelName(KeyTypesInfo *info, KeyTypeInfo *type, ExprDef *arrayNdx,
             ExprDef *value)
{
    xkb_level_index_t level;
    xkb_atom_t level_name;

    if (arrayNdx == NULL)
        return ReportTypeShouldBeArray(info, type, "level name");

    if (!ExprResolveLevel(info->ctx, arrayNdx, &level))
        return ReportTypeBadType(info, type, "level name", "integer");

    if (!ExprResolveString(info->ctx, value, &level_name)) {
        log_err(info->ctx,
                "Non-string name for level %d in key type %s; "
                "Ignoring illegal level name definition\n",
                level + 1, xkb_atom_text(info->ctx, type->name));
        return false;
    }

    return AddLevelName(info, type, level, level_name, true);
}

/***====================================================================***/

static bool
SetKeyTypeField(KeyTypesInfo *info, KeyTypeInfo *type,
                const char *field, ExprDef *arrayNdx, ExprDef *value)
{
    bool ok = false;
    enum type_field type_field = 0;

    if (istreq(field, "modifiers")) {
        type_field = TYPE_FIELD_MASK;
        ok = SetModifiers(info, type, arrayNdx, value);
    }
    else if (istreq(field, "map")) {
        type_field = TYPE_FIELD_MAP;
        ok = SetMapEntry(info, type, arrayNdx, value);
    }
    else if (istreq(field, "preserve")) {
        type_field = TYPE_FIELD_PRESERVE;
        ok = SetPreserve(info, type, arrayNdx, value);
    }
    else if (istreq(field, "levelname") || istreq(field, "level_name")) {
        type_field = TYPE_FIELD_LEVEL_NAME;
        ok = SetLevelName(info, type, arrayNdx, value);
    } else {
        log_err(info->ctx,
                "Unknown field %s in key type %s; Definition ignored\n",
                field, TypeTxt(info, type));
    }

    type->defined |= type_field;
    return ok;
}

static bool
HandleKeyTypeBody(KeyTypesInfo *info, VarDef *def, KeyTypeInfo *type)
{
    bool ok = true;
    const char *elem, *field;
    ExprDef *arrayNdx;

    for (; def; def = (VarDef *) def->common.next) {
        ok = ExprResolveLhs(info->ctx, def->name, &elem, &field,
                            &arrayNdx);
        if (!ok)
            continue;

        if (elem && istreq(elem, "type")) {
            log_err(info->ctx,
                    "Support for changing the default type has been removed; "
                    "Statement ignored\n");
            continue;
        }

        ok = SetKeyTypeField(info, type, field, arrayNdx, def->value);
    }

    return ok;
}

static bool
HandleKeyTypeDef(KeyTypesInfo *info, KeyTypeDef *def, enum merge_mode merge)
{
    KeyTypeInfo type = {
        .defined = 0,
        .merge = (def->merge == MERGE_DEFAULT ? merge : def->merge),
        .name = def->name,
        .mods = 0,
        .num_levels = 1,
        .entries = darray_new(),
        .level_names = darray_new(),
    };

    if (!HandleKeyTypeBody(info, def->body, &type)) {
        info->errorCount++;
        return false;
    }

    if (!AddKeyType(info, &type, true)) {
        info->errorCount++;
        return false;
    }

    return true;
}

static void
HandleKeyTypesFile(KeyTypesInfo *info, XkbFile *file, enum merge_mode merge)
{
    bool ok;

    free(info->name);
    info->name = strdup_safe(file->name);

    for (ParseCommon *stmt = file->defs; stmt; stmt = stmt->next) {
        switch (stmt->type) {
        case STMT_INCLUDE:
            ok = HandleIncludeKeyTypes(info, (IncludeStmt *) stmt);
            break;
        case STMT_TYPE:
            ok = HandleKeyTypeDef(info, (KeyTypeDef *) stmt, merge);
            break;
        case STMT_VAR:
            log_err(info->ctx,
                    "Support for changing the default type has been removed; "
                    "Statement ignored\n");
            ok = true;
            break;
        case STMT_VMOD:
            ok = HandleVModDef(info->ctx, &info->mods, (VModDef *) stmt, merge);
            break;
        default:
            log_err(info->ctx,
                    "Key type files may not include other declarations; "
                    "Ignoring %s\n", stmt_type_to_string(stmt->type));
            ok = false;
            break;
        }

        if (!ok)
            info->errorCount++;

        if (info->errorCount > 10) {
            log_err(info->ctx,
                    "Abandoning keytypes file \"%s\"\n", file->name);
            break;
        }
    }
}

/***====================================================================***/

static bool
CopyKeyTypesToKeymap(struct xkb_keymap *keymap, KeyTypesInfo *info)
{
    unsigned num_types;
    struct xkb_key_type *types;

    num_types = darray_empty(info->types) ? 1 : darray_size(info->types);
    types = calloc(num_types, sizeof(*types));
    if (!types)
        return false;

    /*
     * If no types were specified, a default unnamed one-level type is
     * used for all keys.
     */
    if (darray_empty(info->types)) {
        struct xkb_key_type *type = &types[0];

        type->mods.mods = 0;
        type->num_levels = 1;
        type->entries = NULL;
        type->num_entries = 0;
        type->name = xkb_atom_intern_literal(keymap->ctx, "default");
        type->level_names = NULL;
        type->num_level_names = 0;
    }
    else {
        for (unsigned i = 0; i < num_types; i++) {
            KeyTypeInfo *def = &darray_item(info->types, i);
            struct xkb_key_type *type = &types[i];

            type->name = def->name;
            type->mods.mods = def->mods;
            type->num_levels = def->num_levels;
            darray_steal(def->level_names, &type->level_names, &type->num_level_names);
            darray_steal(def->entries, &type->entries, &type->num_entries);
        }
    }

    keymap->types_section_name = strdup_safe(info->name);
    XkbEscapeMapName(keymap->types_section_name);
    keymap->num_types = num_types;
    keymap->types = types;
    keymap->mods = info->mods;
    return true;
}

/***====================================================================***/

bool
CompileKeyTypes(XkbFile *file, struct xkb_keymap *keymap,
                enum merge_mode merge)
{
    KeyTypesInfo info;

    InitKeyTypesInfo(&info, keymap->ctx, &keymap->mods);

    HandleKeyTypesFile(&info, file, merge);
    if (info.errorCount != 0)
        goto err_info;

    if (!CopyKeyTypesToKeymap(keymap, &info))
        goto err_info;

    ClearKeyTypesInfo(&info);
    return true;

err_info:
    ClearKeyTypesInfo(&info);
    return false;
}
kc3-lang/libxkbcommon/src/xkbcomp/types.c

Commit

kc3-lang/libxkbcommon /src/xkbcomp/types.c
