file.c

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/*
 * security/tomoyo/file.c
 *
 * Copyright (C) 2005-2011  NTT DATA CORPORATION
 */

#include "common.h"
#include <linux/slab.h>

/*
 * Mapping table from "enum tomoyo_path_acl_index" to "enum tomoyo_mac_index".
 */
static const u8 tomoyo_p2mac[TOMOYO_MAX_PATH_OPERATION] = {
    [TOMOYO_TYPE_EXECUTE]    = TOMOYO_MAC_FILE_EXECUTE,
    [TOMOYO_TYPE_READ]       = TOMOYO_MAC_FILE_OPEN,
    [TOMOYO_TYPE_WRITE]      = TOMOYO_MAC_FILE_OPEN,
    [TOMOYO_TYPE_APPEND]     = TOMOYO_MAC_FILE_OPEN,
    [TOMOYO_TYPE_UNLINK]     = TOMOYO_MAC_FILE_UNLINK,
    [TOMOYO_TYPE_GETATTR]    = TOMOYO_MAC_FILE_GETATTR,
    [TOMOYO_TYPE_RMDIR]      = TOMOYO_MAC_FILE_RMDIR,
    [TOMOYO_TYPE_TRUNCATE]   = TOMOYO_MAC_FILE_TRUNCATE,
    [TOMOYO_TYPE_SYMLINK]    = TOMOYO_MAC_FILE_SYMLINK,
    [TOMOYO_TYPE_CHROOT]     = TOMOYO_MAC_FILE_CHROOT,
    [TOMOYO_TYPE_UMOUNT]     = TOMOYO_MAC_FILE_UMOUNT,
};

/*
 * Mapping table from "enum tomoyo_mkdev_acl_index" to "enum tomoyo_mac_index".
 */
const u8 tomoyo_pnnn2mac[TOMOYO_MAX_MKDEV_OPERATION] = {
    [TOMOYO_TYPE_MKBLOCK] = TOMOYO_MAC_FILE_MKBLOCK,
    [TOMOYO_TYPE_MKCHAR]  = TOMOYO_MAC_FILE_MKCHAR,
};

/*
 * Mapping table from "enum tomoyo_path2_acl_index" to "enum tomoyo_mac_index".
 */
const u8 tomoyo_pp2mac[TOMOYO_MAX_PATH2_OPERATION] = {
    [TOMOYO_TYPE_LINK]       = TOMOYO_MAC_FILE_LINK,
    [TOMOYO_TYPE_RENAME]     = TOMOYO_MAC_FILE_RENAME,
    [TOMOYO_TYPE_PIVOT_ROOT] = TOMOYO_MAC_FILE_PIVOT_ROOT,
};

/*
 * Mapping table from "enum tomoyo_path_number_acl_index" to
 * "enum tomoyo_mac_index".
 */
const u8 tomoyo_pn2mac[TOMOYO_MAX_PATH_NUMBER_OPERATION] = {
    [TOMOYO_TYPE_CREATE] = TOMOYO_MAC_FILE_CREATE,
    [TOMOYO_TYPE_MKDIR]  = TOMOYO_MAC_FILE_MKDIR,
    [TOMOYO_TYPE_MKFIFO] = TOMOYO_MAC_FILE_MKFIFO,
    [TOMOYO_TYPE_MKSOCK] = TOMOYO_MAC_FILE_MKSOCK,
    [TOMOYO_TYPE_IOCTL]  = TOMOYO_MAC_FILE_IOCTL,
    [TOMOYO_TYPE_CHMOD]  = TOMOYO_MAC_FILE_CHMOD,
    [TOMOYO_TYPE_CHOWN]  = TOMOYO_MAC_FILE_CHOWN,
    [TOMOYO_TYPE_CHGRP]  = TOMOYO_MAC_FILE_CHGRP,
};

void tomoyo_put_name_union(struct tomoyo_name_union *ptr)
{
    tomoyo_put_group(ptr->group);
    tomoyo_put_name(ptr->filename);
}

const struct tomoyo_path_info *
tomoyo_compare_name_union(const struct tomoyo_path_info *name,
              const struct tomoyo_name_union *ptr)
{
    if (ptr->group)
        return tomoyo_path_matches_group(name, ptr->group);
    if (tomoyo_path_matches_pattern(name, ptr->filename))
        return ptr->filename;
    return NULL;
}

void tomoyo_put_number_union(struct tomoyo_number_union *ptr)
{
    tomoyo_put_group(ptr->group);
}

bool tomoyo_compare_number_union(const unsigned long value,
                 const struct tomoyo_number_union *ptr)
{
    if (ptr->group)
        return tomoyo_number_matches_group(value, value, ptr->group);
    return value >= ptr->values[0] && value <= ptr->values[1];
}

static void tomoyo_add_slash(struct tomoyo_path_info *buf)
{
    if (buf->is_dir)
        return;
    /*
     * This is OK because tomoyo_encode() reserves space for appending "/".
     */
    strcat((char *) buf->name, "/");
    tomoyo_fill_path_info(buf);
}

static bool tomoyo_get_realpath(struct tomoyo_path_info *buf, struct path *path)
{
    buf->name = tomoyo_realpath_from_path(path);
    if (buf->name) {
        tomoyo_fill_path_info(buf);
        return true;
    }
    return false;
}

static int tomoyo_audit_path_log(struct tomoyo_request_info *r)
{
    return tomoyo_supervisor(r, "file %s %s\n", tomoyo_path_keyword
                 [r->param.path.operation],
                 r->param.path.filename->name);
}

static int tomoyo_audit_path2_log(struct tomoyo_request_info *r)
{
    return tomoyo_supervisor(r, "file %s %s %s\n", tomoyo_mac_keywords
                 [tomoyo_pp2mac[r->param.path2.operation]],
                 r->param.path2.filename1->name,
                 r->param.path2.filename2->name);
}

static int tomoyo_audit_mkdev_log(struct tomoyo_request_info *r)
{
    return tomoyo_supervisor(r, "file %s %s 0%o %u %u\n",
                 tomoyo_mac_keywords
                 [tomoyo_pnnn2mac[r->param.mkdev.operation]],
                 r->param.mkdev.filename->name,
                 r->param.mkdev.mode, r->param.mkdev.major,
                 r->param.mkdev.minor);
}

static int tomoyo_audit_path_number_log(struct tomoyo_request_info *r)
{
    const u8 type = r->param.path_number.operation;
    u8 radix;
    char buffer[64];
    switch (type) {
    case TOMOYO_TYPE_CREATE:
    case TOMOYO_TYPE_MKDIR:
    case TOMOYO_TYPE_MKFIFO:
    case TOMOYO_TYPE_MKSOCK:
    case TOMOYO_TYPE_CHMOD:
        radix = TOMOYO_VALUE_TYPE_OCTAL;
        break;
    case TOMOYO_TYPE_IOCTL:
        radix = TOMOYO_VALUE_TYPE_HEXADECIMAL;
        break;
    default:
        radix = TOMOYO_VALUE_TYPE_DECIMAL;
        break;
    }
    tomoyo_print_ulong(buffer, sizeof(buffer), r->param.path_number.number,
               radix);
    return tomoyo_supervisor(r, "file %s %s %s\n", tomoyo_mac_keywords
                 [tomoyo_pn2mac[type]],
                 r->param.path_number.filename->name, buffer);
}

static bool tomoyo_check_path_acl(struct tomoyo_request_info *r,
                  const struct tomoyo_acl_info *ptr)
{
    const struct tomoyo_path_acl *acl = container_of(ptr, typeof(*acl),
                             head);
    if (acl->perm & (1 << r->param.path.operation)) {
        r->param.path.matched_path =
            tomoyo_compare_name_union(r->param.path.filename,
                          &acl->name);
        return r->param.path.matched_path != NULL;
    }
    return false;
}

static bool tomoyo_check_path_number_acl(struct tomoyo_request_info *r,
                     const struct tomoyo_acl_info *ptr)
{
    const struct tomoyo_path_number_acl *acl =
        container_of(ptr, typeof(*acl), head);
    return (acl->perm & (1 << r->param.path_number.operation)) &&
        tomoyo_compare_number_union(r->param.path_number.number,
                        &acl->number) &&
        tomoyo_compare_name_union(r->param.path_number.filename,
                      &acl->name);
}

static bool tomoyo_check_path2_acl(struct tomoyo_request_info *r,
                   const struct tomoyo_acl_info *ptr)
{
    const struct tomoyo_path2_acl *acl =
        container_of(ptr, typeof(*acl), head);
    return (acl->perm & (1 << r->param.path2.operation)) &&
        tomoyo_compare_name_union(r->param.path2.filename1, &acl->name1)
        && tomoyo_compare_name_union(r->param.path2.filename2,
                         &acl->name2);
}

static bool tomoyo_check_mkdev_acl(struct tomoyo_request_info *r,
                   const struct tomoyo_acl_info *ptr)
{
    const struct tomoyo_mkdev_acl *acl =
        container_of(ptr, typeof(*acl), head);
    return (acl->perm & (1 << r->param.mkdev.operation)) &&
        tomoyo_compare_number_union(r->param.mkdev.mode,
                        &acl->mode) &&
        tomoyo_compare_number_union(r->param.mkdev.major,
                        &acl->major) &&
        tomoyo_compare_number_union(r->param.mkdev.minor,
                        &acl->minor) &&
        tomoyo_compare_name_union(r->param.mkdev.filename,
                      &acl->name);
}

static bool tomoyo_same_path_acl(const struct tomoyo_acl_info *a,
                 const struct tomoyo_acl_info *b)
{
    const struct tomoyo_path_acl *p1 = container_of(a, typeof(*p1), head);
    const struct tomoyo_path_acl *p2 = container_of(b, typeof(*p2), head);
    return tomoyo_same_name_union(&p1->name, &p2->name);
}

static bool tomoyo_merge_path_acl(struct tomoyo_acl_info *a,
                  struct tomoyo_acl_info *b,
                  const bool is_delete)
{
    u16 * const a_perm = &container_of(a, struct tomoyo_path_acl, head)
        ->perm;
    u16 perm = *a_perm;
    const u16 b_perm = container_of(b, struct tomoyo_path_acl, head)->perm;
    if (is_delete)
        perm &= ~b_perm;
    else
        perm |= b_perm;
    *a_perm = perm;
    return !perm;
}

static int tomoyo_update_path_acl(const u16 perm,
                  struct tomoyo_acl_param *param)
{
    struct tomoyo_path_acl e = {
        .head.type = TOMOYO_TYPE_PATH_ACL,
        .perm = perm
    };
    int error;
    if (!tomoyo_parse_name_union(param, &e.name))
        error = -EINVAL;
    else
        error = tomoyo_update_domain(&e.head, sizeof(e), param,
                         tomoyo_same_path_acl,
                         tomoyo_merge_path_acl);
    tomoyo_put_name_union(&e.name);
    return error;
}

static bool tomoyo_same_mkdev_acl(const struct tomoyo_acl_info *a,
                     const struct tomoyo_acl_info *b)
{
    const struct tomoyo_mkdev_acl *p1 = container_of(a, typeof(*p1), head);
    const struct tomoyo_mkdev_acl *p2 = container_of(b, typeof(*p2), head);
    return tomoyo_same_name_union(&p1->name, &p2->name) &&
        tomoyo_same_number_union(&p1->mode, &p2->mode) &&
        tomoyo_same_number_union(&p1->major, &p2->major) &&
        tomoyo_same_number_union(&p1->minor, &p2->minor);
}

static bool tomoyo_merge_mkdev_acl(struct tomoyo_acl_info *a,
                   struct tomoyo_acl_info *b,
                   const bool is_delete)
{
    u8 *const a_perm = &container_of(a, struct tomoyo_mkdev_acl,
                     head)->perm;
    u8 perm = *a_perm;
    const u8 b_perm = container_of(b, struct tomoyo_mkdev_acl, head)
        ->perm;
    if (is_delete)
        perm &= ~b_perm;
    else
        perm |= b_perm;
    *a_perm = perm;
    return !perm;
}

static int tomoyo_update_mkdev_acl(const u8 perm,
                   struct tomoyo_acl_param *param)
{
    struct tomoyo_mkdev_acl e = {
        .head.type = TOMOYO_TYPE_MKDEV_ACL,
        .perm = perm
    };
    int error;
    if (!tomoyo_parse_name_union(param, &e.name) ||
        !tomoyo_parse_number_union(param, &e.mode) ||
        !tomoyo_parse_number_union(param, &e.major) ||
        !tomoyo_parse_number_union(param, &e.minor))
        error = -EINVAL;
    else
        error = tomoyo_update_domain(&e.head, sizeof(e), param,
                         tomoyo_same_mkdev_acl,
                         tomoyo_merge_mkdev_acl);
    tomoyo_put_name_union(&e.name);
    tomoyo_put_number_union(&e.mode);
    tomoyo_put_number_union(&e.major);
    tomoyo_put_number_union(&e.minor);
    return error;
}

static bool tomoyo_same_path2_acl(const struct tomoyo_acl_info *a,
                  const struct tomoyo_acl_info *b)
{
    const struct tomoyo_path2_acl *p1 = container_of(a, typeof(*p1), head);
    const struct tomoyo_path2_acl *p2 = container_of(b, typeof(*p2), head);
    return tomoyo_same_name_union(&p1->name1, &p2->name1) &&
        tomoyo_same_name_union(&p1->name2, &p2->name2);
}

static bool tomoyo_merge_path2_acl(struct tomoyo_acl_info *a,
                   struct tomoyo_acl_info *b,
                   const bool is_delete)
{
    u8 * const a_perm = &container_of(a, struct tomoyo_path2_acl, head)
        ->perm;
    u8 perm = *a_perm;
    const u8 b_perm = container_of(b, struct tomoyo_path2_acl, head)->perm;
    if (is_delete)
        perm &= ~b_perm;
    else
        perm |= b_perm;
    *a_perm = perm;
    return !perm;
}

static int tomoyo_update_path2_acl(const u8 perm,
                   struct tomoyo_acl_param *param)
{
    struct tomoyo_path2_acl e = {
        .head.type = TOMOYO_TYPE_PATH2_ACL,
        .perm = perm
    };
    int error;
    if (!tomoyo_parse_name_union(param, &e.name1) ||
        !tomoyo_parse_name_union(param, &e.name2))
        error = -EINVAL;
    else
        error = tomoyo_update_domain(&e.head, sizeof(e), param,
                         tomoyo_same_path2_acl,
                         tomoyo_merge_path2_acl);
    tomoyo_put_name_union(&e.name1);
    tomoyo_put_name_union(&e.name2);
    return error;
}

static int tomoyo_path_permission(struct tomoyo_request_info *r, u8 operation,
                  const struct tomoyo_path_info *filename)
{
    int error;

    r->type = tomoyo_p2mac[operation];
    r->mode = tomoyo_get_mode(r->domain->ns, r->profile, r->type);
    if (r->mode == TOMOYO_CONFIG_DISABLED)
        return 0;
    r->param_type = TOMOYO_TYPE_PATH_ACL;
    r->param.path.filename = filename;
    r->param.path.operation = operation;
    do {
        tomoyo_check_acl(r, tomoyo_check_path_acl);
        error = tomoyo_audit_path_log(r);
    } while (error == TOMOYO_RETRY_REQUEST);
    return error;
}

int tomoyo_execute_permission(struct tomoyo_request_info *r,
                  const struct tomoyo_path_info *filename)
{
    /*
     * Unlike other permission checks, this check is done regardless of
     * profile mode settings in order to check for domain transition
     * preference.
     */
    r->type = TOMOYO_MAC_FILE_EXECUTE;
    r->mode = tomoyo_get_mode(r->domain->ns, r->profile, r->type);
    r->param_type = TOMOYO_TYPE_PATH_ACL;
    r->param.path.filename = filename;
    r->param.path.operation = TOMOYO_TYPE_EXECUTE;
    tomoyo_check_acl(r, tomoyo_check_path_acl);
    r->ee->transition = r->matched_acl && r->matched_acl->cond ?
        r->matched_acl->cond->transit : NULL;
    if (r->mode != TOMOYO_CONFIG_DISABLED)
        return tomoyo_audit_path_log(r);
    return 0;
}

static bool tomoyo_same_path_number_acl(const struct tomoyo_acl_info *a,
                    const struct tomoyo_acl_info *b)
{
    const struct tomoyo_path_number_acl *p1 = container_of(a, typeof(*p1),
                                   head);
    const struct tomoyo_path_number_acl *p2 = container_of(b, typeof(*p2),
                                   head);
    return tomoyo_same_name_union(&p1->name, &p2->name) &&
        tomoyo_same_number_union(&p1->number, &p2->number);
}

static bool tomoyo_merge_path_number_acl(struct tomoyo_acl_info *a,
                     struct tomoyo_acl_info *b,
                     const bool is_delete)
{
    u8 * const a_perm = &container_of(a, struct tomoyo_path_number_acl,
                      head)->perm;
    u8 perm = *a_perm;
    const u8 b_perm = container_of(b, struct tomoyo_path_number_acl, head)
        ->perm;
    if (is_delete)
        perm &= ~b_perm;
    else
        perm |= b_perm;
    *a_perm = perm;
    return !perm;
}

static int tomoyo_update_path_number_acl(const u8 perm,
                     struct tomoyo_acl_param *param)
{
    struct tomoyo_path_number_acl e = {
        .head.type = TOMOYO_TYPE_PATH_NUMBER_ACL,
        .perm = perm
    };
    int error;
    if (!tomoyo_parse_name_union(param, &e.name) ||
        !tomoyo_parse_number_union(param, &e.number))
        error = -EINVAL;
    else
        error = tomoyo_update_domain(&e.head, sizeof(e), param,
                         tomoyo_same_path_number_acl,
                         tomoyo_merge_path_number_acl);
    tomoyo_put_name_union(&e.name);
    tomoyo_put_number_union(&e.number);
    return error;
}

int tomoyo_path_number_perm(const u8 type, struct path *path,
                unsigned long number)
{
    struct tomoyo_request_info r;
    struct tomoyo_obj_info obj = {
        .path1 = *path,
    };
    int error = -ENOMEM;
    struct tomoyo_path_info buf;
    int idx;

    if (tomoyo_init_request_info(&r, NULL, tomoyo_pn2mac[type])
        == TOMOYO_CONFIG_DISABLED || !path->dentry)
        return 0;
    idx = tomoyo_read_lock();
    if (!tomoyo_get_realpath(&buf, path))
        goto out;
    r.obj = &obj;
    if (type == TOMOYO_TYPE_MKDIR)
        tomoyo_add_slash(&buf);
    r.param_type = TOMOYO_TYPE_PATH_NUMBER_ACL;
    r.param.path_number.operation = type;
    r.param.path_number.filename = &buf;
    r.param.path_number.number = number;
    do {
        tomoyo_check_acl(&r, tomoyo_check_path_number_acl);
        error = tomoyo_audit_path_number_log(&r);
    } while (error == TOMOYO_RETRY_REQUEST);
    kfree(buf.name);
 out:
    tomoyo_read_unlock(idx);
    if (r.mode != TOMOYO_CONFIG_ENFORCING)
        error = 0;
    return error;
}

int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
                 struct path *path, const int flag)
{
    const u8 acc_mode = ACC_MODE(flag);
    int error = 0;
    struct tomoyo_path_info buf;
    struct tomoyo_request_info r;
    struct tomoyo_obj_info obj = {
        .path1 = *path,
    };
    int idx;

    buf.name = NULL;
    r.mode = TOMOYO_CONFIG_DISABLED;
    idx = tomoyo_read_lock();
    if (acc_mode &&
        tomoyo_init_request_info(&r, domain, TOMOYO_MAC_FILE_OPEN)
        != TOMOYO_CONFIG_DISABLED) {
        if (!tomoyo_get_realpath(&buf, path)) {
            error = -ENOMEM;
            goto out;
        }
        r.obj = &obj;
        if (acc_mode & MAY_READ)
            error = tomoyo_path_permission(&r, TOMOYO_TYPE_READ,
                               &buf);
        if (!error && (acc_mode & MAY_WRITE))
            error = tomoyo_path_permission(&r, (flag & O_APPEND) ?
                               TOMOYO_TYPE_APPEND :
                               TOMOYO_TYPE_WRITE,
                               &buf);
    }
 out:
    kfree(buf.name);
    tomoyo_read_unlock(idx);
    if (r.mode != TOMOYO_CONFIG_ENFORCING)
        error = 0;
    return error;
}

int tomoyo_path_perm(const u8 operation, struct path *path, const char *target)
{
    struct tomoyo_request_info r;
    struct tomoyo_obj_info obj = {
        .path1 = *path,
    };
    int error;
    struct tomoyo_path_info buf;
    bool is_enforce;
    struct tomoyo_path_info symlink_target;
    int idx;

    if (tomoyo_init_request_info(&r, NULL, tomoyo_p2mac[operation])
        == TOMOYO_CONFIG_DISABLED)
        return 0;
    is_enforce = (r.mode == TOMOYO_CONFIG_ENFORCING);
    error = -ENOMEM;
    buf.name = NULL;
    idx = tomoyo_read_lock();
    if (!tomoyo_get_realpath(&buf, path))
        goto out;
    r.obj = &obj;
    switch (operation) {
    case TOMOYO_TYPE_RMDIR:
    case TOMOYO_TYPE_CHROOT:
        tomoyo_add_slash(&buf);
        break;
    case TOMOYO_TYPE_SYMLINK:
        symlink_target.name = tomoyo_encode(target);
        if (!symlink_target.name)
            goto out;
        tomoyo_fill_path_info(&symlink_target);
        obj.symlink_target = &symlink_target;
        break;
    }
    error = tomoyo_path_permission(&r, operation, &buf);
    if (operation == TOMOYO_TYPE_SYMLINK)
        kfree(symlink_target.name);
 out:
    kfree(buf.name);
    tomoyo_read_unlock(idx);
    if (!is_enforce)
        error = 0;
    return error;
}

int tomoyo_mkdev_perm(const u8 operation, struct path *path,
              const unsigned int mode, unsigned int dev)
{
    struct tomoyo_request_info r;
    struct tomoyo_obj_info obj = {
        .path1 = *path,
    };
    int error = -ENOMEM;
    struct tomoyo_path_info buf;
    int idx;

    if (tomoyo_init_request_info(&r, NULL, tomoyo_pnnn2mac[operation])
        == TOMOYO_CONFIG_DISABLED)
        return 0;
    idx = tomoyo_read_lock();
    error = -ENOMEM;
    if (tomoyo_get_realpath(&buf, path)) {
        r.obj = &obj;
        dev = new_decode_dev(dev);
        r.param_type = TOMOYO_TYPE_MKDEV_ACL;
        r.param.mkdev.filename = &buf;
        r.param.mkdev.operation = operation;
        r.param.mkdev.mode = mode;
        r.param.mkdev.major = MAJOR(dev);
        r.param.mkdev.minor = MINOR(dev);
        tomoyo_check_acl(&r, tomoyo_check_mkdev_acl);
        error = tomoyo_audit_mkdev_log(&r);
        kfree(buf.name);
    }
    tomoyo_read_unlock(idx);
    if (r.mode != TOMOYO_CONFIG_ENFORCING)
        error = 0;
    return error;
}

int tomoyo_path2_perm(const u8 operation, struct path *path1,
              struct path *path2)
{
    int error = -ENOMEM;
    struct tomoyo_path_info buf1;
    struct tomoyo_path_info buf2;
    struct tomoyo_request_info r;
    struct tomoyo_obj_info obj = {
        .path1 = *path1,
        .path2 = *path2,
    };
    int idx;

    if (tomoyo_init_request_info(&r, NULL, tomoyo_pp2mac[operation])
        == TOMOYO_CONFIG_DISABLED)
        return 0;
    buf1.name = NULL;
    buf2.name = NULL;
    idx = tomoyo_read_lock();
    if (!tomoyo_get_realpath(&buf1, path1) ||
        !tomoyo_get_realpath(&buf2, path2))
        goto out;
    switch (operation) {
        struct dentry *dentry;
    case TOMOYO_TYPE_RENAME:
    case TOMOYO_TYPE_LINK:
        dentry = path1->dentry;
        if (!dentry->d_inode || !S_ISDIR(dentry->d_inode->i_mode))
            break;
        /* fall through */
    case TOMOYO_TYPE_PIVOT_ROOT:
        tomoyo_add_slash(&buf1);
        tomoyo_add_slash(&buf2);
        break;
    }
    r.obj = &obj;
    r.param_type = TOMOYO_TYPE_PATH2_ACL;
    r.param.path2.operation = operation;
    r.param.path2.filename1 = &buf1;
    r.param.path2.filename2 = &buf2;
    do {
        tomoyo_check_acl(&r, tomoyo_check_path2_acl);
        error = tomoyo_audit_path2_log(&r);
    } while (error == TOMOYO_RETRY_REQUEST);
 out:
    kfree(buf1.name);
    kfree(buf2.name);
    tomoyo_read_unlock(idx);
    if (r.mode != TOMOYO_CONFIG_ENFORCING)
        error = 0;
    return error;
}

static bool tomoyo_same_mount_acl(const struct tomoyo_acl_info *a,
                  const struct tomoyo_acl_info *b)
{
    const struct tomoyo_mount_acl *p1 = container_of(a, typeof(*p1), head);
    const struct tomoyo_mount_acl *p2 = container_of(b, typeof(*p2), head);
    return tomoyo_same_name_union(&p1->dev_name, &p2->dev_name) &&
        tomoyo_same_name_union(&p1->dir_name, &p2->dir_name) &&
        tomoyo_same_name_union(&p1->fs_type, &p2->fs_type) &&
        tomoyo_same_number_union(&p1->flags, &p2->flags);
}

static int tomoyo_update_mount_acl(struct tomoyo_acl_param *param)
{
    struct tomoyo_mount_acl e = { .head.type = TOMOYO_TYPE_MOUNT_ACL };
    int error;
    if (!tomoyo_parse_name_union(param, &e.dev_name) ||
        !tomoyo_parse_name_union(param, &e.dir_name) ||
        !tomoyo_parse_name_union(param, &e.fs_type) ||
        !tomoyo_parse_number_union(param, &e.flags))
        error = -EINVAL;
    else
        error = tomoyo_update_domain(&e.head, sizeof(e), param,
                         tomoyo_same_mount_acl, NULL);
    tomoyo_put_name_union(&e.dev_name);
    tomoyo_put_name_union(&e.dir_name);
    tomoyo_put_name_union(&e.fs_type);
    tomoyo_put_number_union(&e.flags);
    return error;
}

int tomoyo_write_file(struct tomoyo_acl_param *param)
{
    u16 perm = 0;
    u8 type;
    const char *operation = tomoyo_read_token(param);
    for (type = 0; type < TOMOYO_MAX_PATH_OPERATION; type++)
        if (tomoyo_permstr(operation, tomoyo_path_keyword[type]))
            perm |= 1 << type;
    if (perm)
        return tomoyo_update_path_acl(perm, param);
    for (type = 0; type < TOMOYO_MAX_PATH2_OPERATION; type++)
        if (tomoyo_permstr(operation,
                   tomoyo_mac_keywords[tomoyo_pp2mac[type]]))
            perm |= 1 << type;
    if (perm)
        return tomoyo_update_path2_acl(perm, param);
    for (type = 0; type < TOMOYO_MAX_PATH_NUMBER_OPERATION; type++)
        if (tomoyo_permstr(operation,
                   tomoyo_mac_keywords[tomoyo_pn2mac[type]]))
            perm |= 1 << type;
    if (perm)
        return tomoyo_update_path_number_acl(perm, param);
    for (type = 0; type < TOMOYO_MAX_MKDEV_OPERATION; type++)
        if (tomoyo_permstr(operation,
                   tomoyo_mac_keywords[tomoyo_pnnn2mac[type]]))
            perm |= 1 << type;
    if (perm)
        return tomoyo_update_mkdev_acl(perm, param);
    if (tomoyo_permstr(operation,
               tomoyo_mac_keywords[TOMOYO_MAC_FILE_MOUNT]))
        return tomoyo_update_mount_acl(param);
    return -EINVAL;
}