/src/selinux/checkpolicy/module_compiler.c

Source
/* Author : Joshua Brindle <jbrindle@tresys.com>
 *      Karl MacMillan <kmacmillan@tresys.com>
 *          Jason Tang     <jtang@tresys.com>
 *  Added support for binary policy modules
 *
 * Copyright (C) 2004 - 2005 Tresys Technology, LLC
 *  This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, version 2.
 */

#include <assert.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

#include <sepol/policydb/policydb.h>
#include <sepol/policydb/avrule_block.h>
#include <sepol/policydb/conditional.h>

#include "queue.h"
#include "module_compiler.h"

typedef struct scope_stack {
  int type; /* 1 = avrule block, 2 = conditional */
  avrule_decl_t *decl; /* if in an avrule block, which
         * declaration is current */
  avrule_t *last_avrule;
  int in_else; /* if in an avrule block, within ELSE branch */
  int require_given; /* 1 if this block had at least one require */
  struct scope_stack *parent;
} scope_stack_t;

extern policydb_t *policydbp;
extern queue_t id_queue;
extern int yyerror(const char *msg);
__attribute__((format(printf, 1, 2))) extern void yyerror2(const char *fmt,
                 ...);

static int push_stack(int stack_type, ...);
static void pop_stack(void);

/* keep track of the last item added to the stack */
static scope_stack_t *stack_top = NULL;
static avrule_block_t *last_block;
static uint32_t next_decl_id = 1;

static const char *const flavor_str[SYM_NUM] = {
  [SYM_COMMONS] = "common", [SYM_CLASSES] = "class", [SYM_ROLES] = "role",
  [SYM_TYPES] = "type",   [SYM_USERS] = "user",    [SYM_BOOLS] = "bool",
  [SYM_LEVELS] = "level",   [SYM_CATS] = "cat"
};

static void print_error_msg(int ret, uint32_t symbol_type)
{
  switch (ret) {
  case -3:
    yyerror("Out of memory!");
    break;
  case -2:
    yyerror2("Duplicate declaration of %s",
       flavor_str[symbol_type]);
    break;
  case -1:
    yyerror2("Could not declare %s here", flavor_str[symbol_type]);
    break;
  default:
    yyerror2("Unknown error %d", ret);
  }
}

int define_policy(int pass, int module_header_given)
{
  char *id;

  if (module_header_given) {
    if (policydbp->policy_type != POLICY_MOD) {
      yyerror("Module specification found while not building a policy module.");
      return -1;
    }

    if (pass == 2) {
      while ((id = queue_remove(id_queue)) != NULL)
        free(id);
    } else {
      id = (char *)queue_remove(id_queue);
      if (!id) {
        yyerror("no module name");
        return -1;
      }
      free(policydbp->name);
      policydbp->name = id;
      if ((policydbp->version = queue_remove(id_queue)) ==
          NULL) {
        yyerror("Expected a module version but none was found.");
        return -1;
      }
    }
  } else {
    if (policydbp->policy_type == POLICY_MOD) {
      yyerror("Building a policy module, but no module specification found.");
      return -1;
    }
  }
  /* the first declaration within the global avrule
     block will always have an id of 1 */
  next_decl_id = 2;

  /* reset the scoping stack */
  while (stack_top != NULL) {
    pop_stack();
  }
  if (push_stack(1, policydbp->global, policydbp->global->branch_list) ==
      -1) {
    return -1;
  }
  last_block = policydbp->global;
  return 0;
}

/* Given the current parse stack, returns 1 if a declaration or require would
 * be allowed here or 0 if not.  For example, declarations and requirements are
 * not allowed in conditionals, so if there are any conditionals in the
 * current scope stack then this would return a 0.
 */
static int is_creation_allowed(void)
{
  if (stack_top->type != 1 || stack_top->in_else) {
    return 0;
  }
  return 1;
}

/* Attempt to declare or require a symbol within the current scope.
 * Returns:
 *  0: Success - Symbol had not been previously created.
 *  1: Success - Symbol had already been created and caller must free datum.
 * -1: Failure - Symbol cannot be created here
 * -2: Failure - Duplicate declaration or type/attribute mismatch
 * -3: Failure - Out of memory or some other error
 */
static int create_symbol(uint32_t symbol_type, hashtab_key_t key,
       hashtab_datum_t datum, uint32_t *dest_value,
       uint32_t scope)
{
  avrule_decl_t *decl = stack_top->decl;
  int ret;

  if (!is_creation_allowed()) {
    return -1;
  }

  ret = symtab_insert(policydbp, symbol_type, key, datum, scope,
          decl->decl_id, dest_value);

  if (ret == 1 && dest_value) {
    hashtab_datum_t s = hashtab_search(
      policydbp->symtab[symbol_type].table, key);
    assert(s != NULL);

    if (symbol_type == SYM_LEVELS) {
      *dest_value = ((level_datum_t *)s)->level->sens;
    } else {
      *dest_value = ((symtab_datum_t *)s)->value;
    }
  } else if (ret == -2) {
    return -2;
  } else if (ret < 0) {
    return -3;
  }

  return ret;
}

/* Attempt to declare a symbol within the current declaration.  If
 * currently within a non-conditional and in a non-else branch then
 * insert the symbol, return 0 on success if symbol was undeclared.
 * For roles and users, it is legal to have multiple declarations; as
 * such return 1 to indicate that caller must free() the datum because
 * it was not added.  If symbols may not be declared here return -1.
 * For duplicate declarations return -2.  For all else, including out
 * of memory, return -3.  Note that dest_value and datum_value might
 * not be restricted pointers. */
int declare_symbol(uint32_t symbol_type, hashtab_key_t key,
       hashtab_datum_t datum, uint32_t *dest_value,
       const uint32_t *datum_value)
{
  avrule_decl_t *decl = stack_top->decl;
  int ret =
    create_symbol(symbol_type, key, datum, dest_value, SCOPE_DECL);

  if (ret < 0) {
    return ret;
  }

  if (ebitmap_set_bit(decl->declared.scope + symbol_type,
          *datum_value - 1, 1)) {
    return -3;
  }

  return ret;
}

static int role_implicit_bounds(hashtab_t roles_tab, char *role_id,
        role_datum_t *role)
{
  role_datum_t *bounds;
  char *bounds_id, *delim;

  delim = strrchr(role_id, '.');
  if (!delim)
    return 0; /* no implicit boundary */

  bounds_id = strdup(role_id);
  if (!bounds_id) {
    yyerror("out of memory");
    return -1;
  }
  bounds_id[(size_t)(delim - role_id)] = '\0';

  bounds = hashtab_search(roles_tab, bounds_id);
  if (!bounds) {
    yyerror2(
      "Implicit role bounds declared (%s), but the parent (%s) was not found in the same scope",
      role_id, bounds_id);
    free(bounds_id);
    return -1;
  }

  role->bounds = bounds->s.value;

  free(bounds_id);

  return 0;
}

static int create_role(uint32_t scope, unsigned char isattr,
           role_datum_t **role, char **key)
{
  char *id = queue_remove(id_queue);
  role_datum_t *datum = NULL;
  int ret;
  uint32_t value;

  *role = NULL;
  *key = NULL;
  isattr = isattr ? ROLE_ATTRIB : ROLE_ROLE;

  if (id == NULL) {
    yyerror("no role name");
    return -1;
  }

  datum = malloc(sizeof(*datum));
  if (datum == NULL) {
    yyerror("Out of memory!");
    free(id);
    return -1;
  }

  role_datum_init(datum);
  datum->flavor = isattr;

  if (scope == SCOPE_DECL) {
    ret = declare_symbol(SYM_ROLES, id, datum, &value, &value);
  } else {
    ret = require_symbol(SYM_ROLES, id, datum, &value, &value);
  }

  if (ret == 0) {
    datum->s.value = value;
    *role = datum;
    *key = strdup(id);
    if (*key == NULL) {
      yyerror("Out of memory!");
      return -1;
    }
  } else if (ret == 1) {
    *role = hashtab_search(policydbp->symtab[SYM_ROLES].table, id);
    if (*role && (isattr != (*role)->flavor)) {
      yyerror2(
        "Identifier %s used as both an attribute and a role",
        id);
      *role = NULL;
      free(id);
      role_datum_destroy(datum);
      free(datum);
      return -1;
    }
    datum->s.value = value;
    *role = datum;
    *key = id;
  } else {
    print_error_msg(ret, SYM_ROLES);
    free(id);
    role_datum_destroy(datum);
    free(datum);
  }

  return ret;
}

role_datum_t *declare_role(unsigned char isattr)
{
  char *key = NULL;
  role_datum_t *role = NULL;
  role_datum_t *dest_role = NULL;
  hashtab_t roles_tab;
  int ret, ret2;

  ret = create_role(SCOPE_DECL, isattr, &role, &key);
  if (ret < 0) {
    return NULL;
  }

  /* create a new role_datum_t for this decl, if necessary */
  assert(stack_top->type == 1);

  if (stack_top->parent == NULL) {
    /* in parent, so use global symbol table */
    roles_tab = policydbp->p_roles.table;
  } else {
    roles_tab = stack_top->decl->p_roles.table;
  }

  dest_role = hashtab_search(roles_tab, key);
  if (dest_role == NULL) {
    if (ret == 0) {
      dest_role = malloc(sizeof(*dest_role));
      if (dest_role == NULL) {
        yyerror("Out of memory!");
        free(key);
        return NULL;
      }
      role_datum_init(dest_role);
      dest_role->s.value = role->s.value;
      dest_role->flavor = role->flavor;
    } else {
      dest_role = role;
    }
    ret2 = role_implicit_bounds(roles_tab, key, dest_role);
    if (ret2 != 0) {
      free(key);
      role_datum_destroy(dest_role);
      free(dest_role);
      return NULL;
    }
    ret2 = hashtab_insert(roles_tab, key, dest_role);
    if (ret2 != 0) {
      yyerror("Out of memory!");
      free(key);
      role_datum_destroy(dest_role);
      free(dest_role);
      return NULL;
    }
  } else {
    free(key);
    if (ret == 1) {
      role_datum_destroy(role);
      free(role);
    }
  }

  if (ret == 0) {
    ret2 = ebitmap_set_bit(&dest_role->dominates,
               dest_role->s.value - 1, 1);
    if (ret2 != 0) {
      yyerror("out of memory");
      return NULL;
    }
  }

  return dest_role;
}

static int create_type(uint32_t scope, unsigned char isattr,
           type_datum_t **type)
{
  char *id;
  type_datum_t *datum;
  int ret;
  uint32_t value = 0;

  *type = NULL;
  isattr = isattr ? TYPE_ATTRIB : TYPE_TYPE;

  id = (char *)queue_remove(id_queue);
  if (!id) {
    yyerror("no type/attribute name?");
    return -1;
  }
  if (strcmp(id, "self") == 0) {
    yyerror("\"self\" is a reserved type name.");
    free(id);
    return -1;
  }

  datum = malloc(sizeof(*datum));
  if (!datum) {
    yyerror("Out of memory!");
    free(id);
    return -1;
  }
  type_datum_init(datum);
  datum->primary = 1;
  datum->flavor = isattr;

  if (scope == SCOPE_DECL) {
    ret = declare_symbol(SYM_TYPES, id, datum, &value, &value);
  } else {
    ret = require_symbol(SYM_TYPES, id, datum, &value, &value);
  }

  if (ret == 0) {
    datum->s.value = value;
    *type = datum;
  } else if (ret == 1) {
    type_datum_destroy(datum);
    free(datum);
    *type = hashtab_search(policydbp->symtab[SYM_TYPES].table, id);
    if (*type && (isattr != (*type)->flavor)) {
      yyerror2(
        "Identifier %s used as both an attribute and a type",
        id);
      *type = NULL;
      free(id);
      return -1;
    }
    free(id);
  } else {
    print_error_msg(ret, SYM_TYPES);
    free(id);
    type_datum_destroy(datum);
    free(datum);
  }

  return ret;
}

type_datum_t *declare_type(unsigned char primary, unsigned char isattr)
{
  type_datum_t *type = NULL;
  int ret = create_type(SCOPE_DECL, isattr, &type);

  if (ret == 0) {
    type->primary = primary;
  }

  return type;
}

static int user_implicit_bounds(hashtab_t users_tab, char *user_id,
        user_datum_t *user)
{
  user_datum_t *bounds;
  char *bounds_id, *delim;

  delim = strrchr(user_id, '.');
  if (!delim)
    return 0; /* no implicit boundary */

  bounds_id = strdup(user_id);
  if (!bounds_id) {
    yyerror("out of memory");
    return -1;
  }
  bounds_id[(size_t)(delim - user_id)] = '\0';

  bounds = hashtab_search(users_tab, bounds_id);
  if (!bounds) {
    yyerror2(
      "Implicit user bounds declared (%s), but the parent (%s) was not found in the same scope",
      user_id, bounds_id);
    free(bounds_id);
    return -1;
  }

  user->bounds = bounds->s.value;

  free(bounds_id);

  return 0;
}

static int create_user(uint32_t scope, user_datum_t **user, char **key)
{
  char *id = queue_remove(id_queue);
  user_datum_t *datum = NULL;
  int ret;
  uint32_t value;

  *user = NULL;
  *key = NULL;

  if (id == NULL) {
    yyerror("no user name");
    return -1;
  }

  datum = malloc(sizeof(*datum));
  if (datum == NULL) {
    yyerror("Out of memory!");
    free(id);
    return -1;
  }

  user_datum_init(datum);

  if (scope == SCOPE_DECL) {
    ret = declare_symbol(SYM_USERS, id, datum, &value, &value);
  } else {
    ret = require_symbol(SYM_USERS, id, datum, &value, &value);
  }

  if (ret == 0) {
    datum->s.value = value;
    *user = datum;
    *key = strdup(id);
    if (*key == NULL) {
      yyerror("Out of memory!");
      return -1;
    }
  } else if (ret == 1) {
    datum->s.value = value;
    *user = datum;
    *key = id;
  } else {
    print_error_msg(ret, SYM_USERS);
    free(id);
    user_datum_destroy(datum);
    free(datum);
  }

  return ret;
}

user_datum_t *declare_user(void)
{
  char *key = NULL;
  user_datum_t *user = NULL;
  user_datum_t *dest_user = NULL;
  hashtab_t users_tab;
  int ret, ret2;

  ret = create_user(SCOPE_DECL, &user, &key);
  if (ret < 0) {
    return NULL;
  }

  /* create a new user_datum_t for this decl, if necessary */
  assert(stack_top->type == 1);

  if (stack_top->parent == NULL) {
    /* in parent, so use global symbol table */
    users_tab = policydbp->p_users.table;
  } else {
    users_tab = stack_top->decl->p_users.table;
  }

  dest_user = hashtab_search(users_tab, key);
  if (dest_user == NULL) {
    if (ret == 0) {
      dest_user = malloc(sizeof(*dest_user));
      if (dest_user == NULL) {
        yyerror("Out of memory!");
        free(key);
        return NULL;
      }
      user_datum_init(dest_user);
      dest_user->s.value = user->s.value;
    } else {
      dest_user = user;
    }
    ret2 = user_implicit_bounds(users_tab, key, dest_user);
    if (ret2 != 0) {
      free(key);
      user_datum_destroy(dest_user);
      free(dest_user);
      return NULL;
    }
    ret2 = hashtab_insert(users_tab, key, dest_user);
    if (ret2 != 0) {
      yyerror("Out of memory!");
      free(key);
      user_datum_destroy(dest_user);
      free(dest_user);
      return NULL;
    }
  } else {
    free(key);
    if (ret == 1) {
      user_datum_destroy(user);
      free(user);
    }
  }

  return dest_user;
}

/* Return a type_datum_t for the local avrule_decl with the given ID.
 * If it does not exist, create one with the same value as 'value'.
 * This function assumes that the ID is within scope.  c.f.,
 * is_id_in_scope().
 *
 * NOTE: this function usurps ownership of id afterwards.  The caller
 * shall not reference it nor free() it afterwards.
 */
type_datum_t *get_local_type(char *id, uint32_t value, unsigned char isattr)
{
  type_datum_t *dest_typdatum;
  hashtab_t types_tab;
  assert(stack_top->type == 1);
  if (stack_top->parent == NULL) {
    /* in global, so use global symbol table */
    types_tab = policydbp->p_types.table;
  } else {
    types_tab = stack_top->decl->p_types.table;
  }
  dest_typdatum = hashtab_search(types_tab, id);
  if (!dest_typdatum) {
    dest_typdatum = (type_datum_t *)malloc(sizeof(type_datum_t));
    if (dest_typdatum == NULL) {
      free(id);
      return NULL;
    }
    type_datum_init(dest_typdatum);
    dest_typdatum->s.value = value;
    dest_typdatum->flavor = isattr ? TYPE_ATTRIB : TYPE_TYPE;
    dest_typdatum->primary = 1;
    if (hashtab_insert(types_tab, id, dest_typdatum)) {
      free(id);
      type_datum_destroy(dest_typdatum);
      free(dest_typdatum);
      return NULL;
    }

  } else {
    free(id);
    if (dest_typdatum->flavor !=
        (isattr ? TYPE_ATTRIB : TYPE_TYPE)) {
      return NULL;
    }
  }
  return dest_typdatum;
}

/* Return a role_datum_t for the local avrule_decl with the given ID.
 * If it does not exist, create one with the same value as 'value'.
 * This function assumes that the ID is within scope.  c.f.,
 * is_id_in_scope().
 *
 * NOTE: this function usurps ownership of id afterwards.  The caller
 * shall not reference it nor free() it afterwards.
 */
role_datum_t *get_local_role(char *id, uint32_t value, unsigned char isattr)
{
  role_datum_t *dest_roledatum;
  hashtab_t roles_tab;

  assert(stack_top->type == 1);

  if (stack_top->parent == NULL) {
    /* in global, so use global symbol table */
    roles_tab = policydbp->p_roles.table;
  } else {
    roles_tab = stack_top->decl->p_roles.table;
  }

  dest_roledatum = hashtab_search(roles_tab, id);
  if (!dest_roledatum) {
    dest_roledatum = (role_datum_t *)malloc(sizeof(role_datum_t));
    if (dest_roledatum == NULL) {
      free(id);
      return NULL;
    }

    role_datum_init(dest_roledatum);
    dest_roledatum->s.value = value;
    dest_roledatum->flavor = isattr ? ROLE_ATTRIB : ROLE_ROLE;

    if (hashtab_insert(roles_tab, id, dest_roledatum)) {
      free(id);
      role_datum_destroy(dest_roledatum);
      free(dest_roledatum);
      return NULL;
    }
  } else {
    free(id);
    if (dest_roledatum->flavor !=
        (isattr ? ROLE_ATTRIB : ROLE_ROLE))
      return NULL;
  }

  return dest_roledatum;
}

/* Attempt to require a symbol within the current scope.  If currently
 * within an optional (and not its else branch), add the symbol to the
 * required list.  Return 0 on success, 1 if caller needs to free()
 * datum.  If symbols may not be declared here return -1.  For duplicate
 * declarations return -2.  For all else, including out of memory,
 * return -3..  Note that dest_value and datum_value might not be
 * restricted pointers.
 */
int require_symbol(uint32_t symbol_type, hashtab_key_t key,
       hashtab_datum_t datum, uint32_t *dest_value,
       uint32_t *datum_value)
{
  avrule_decl_t *decl = stack_top->decl;
  int ret = create_symbol(symbol_type, key, datum, dest_value, SCOPE_REQ);

  if (ret < 0) {
    return ret;
  }

  if (ebitmap_set_bit(decl->required.scope + symbol_type,
          *datum_value - 1, 1)) {
    return -3;
  }

  stack_top->require_given = 1;
  return ret;
}

int add_perm_to_class(uint32_t perm_value, uint32_t class_value)
{
  avrule_decl_t *decl = stack_top->decl;
  scope_index_t *scope;

  assert(perm_value >= 1);
  assert(class_value >= 1);
  scope = &decl->required;
  if (class_value > scope->class_perms_len) {
    uint32_t i;
    ebitmap_t *new_map = realloc(scope->class_perms_map,
               class_value * sizeof(*new_map));
    if (new_map == NULL) {
      return -1;
    }
    scope->class_perms_map = new_map;
    for (i = scope->class_perms_len; i < class_value; i++) {
      ebitmap_init(scope->class_perms_map + i);
    }
    scope->class_perms_len = class_value;
  }
  if (ebitmap_set_bit(scope->class_perms_map + class_value - 1,
          perm_value - 1, 1)) {
    return -1;
  }
  return 0;
}

static int perm_destroy(hashtab_key_t key, hashtab_datum_t datum,
      void *p __attribute__((unused)))
{
  if (key)
    free(key);
  free(datum);
  return 0;
}

static void class_datum_destroy(class_datum_t *cladatum)
{
  if (cladatum != NULL) {
    hashtab_map(cladatum->permissions.table, perm_destroy, NULL);
    hashtab_destroy(cladatum->permissions.table);
    free(cladatum);
  }
}

int require_class(int pass)
{
  char *class_id = queue_remove(id_queue);
  char *perm_id = NULL;
  class_datum_t *datum = NULL;
  perm_datum_t *perm = NULL;
  int ret;

  if (pass == 2) {
    free(class_id);
    while ((perm_id = queue_remove(id_queue)) != NULL)
      free(perm_id);
    return 0;
  }

  /* first add the class if it is not already there */
  if (class_id == NULL) {
    yyerror("no class name for class definition?");
    return -1;
  }

  if ((datum = calloc(1, sizeof(*datum))) == NULL ||
      symtab_init(&datum->permissions, PERM_SYMTAB_SIZE)) {
    yyerror("Out of memory!");
    class_datum_destroy(datum);
    return -1;
  }
  ret = require_symbol(SYM_CLASSES, class_id, datum, &datum->s.value,
           &datum->s.value);
  if (ret < 0) {
    print_error_msg(ret, SYM_CLASSES);
    free(class_id);
    class_datum_destroy(datum);
    return -1;
  }

  if (ret == 0) {
    /* a new class was added; reindex everything */
    if (policydb_index_classes(policydbp)) {
      yyerror("Out of memory!");
      return -1;
    }
  } else {
    class_datum_destroy(datum);
    datum = hashtab_search(policydbp->p_classes.table, class_id);
    assert(datum); /* the class datum should have existed */
    free(class_id);
  }

  /* now add each of the permissions to this class's requirements */
  while ((perm_id = queue_remove(id_queue)) != NULL) {
    int allocated = 0;

    /* Is the permission already in the table? */
    perm = hashtab_search(datum->permissions.table, perm_id);
    if (!perm && datum->comdatum)
      perm = hashtab_search(
        datum->comdatum->permissions.table, perm_id);
    if (perm) {
      /* Yes, drop the name. */
      free(perm_id);
    } else {
      /* No - allocate and insert an entry for it. */
      if (policydbp->policy_type == POLICY_BASE) {
        yyerror2(
          "Base policy - require of permission %s without prior declaration.",
          perm_id);
        free(perm_id);
        return -1;
      }
      if (datum->permissions.nprim >= PERM_SYMTAB_SIZE) {
        yyerror2(
          "Class %s would have too many permissions "
          "to fit in an access vector with permission %s",
          policydbp->p_class_val_to_name
            [datum->s.value - 1],
          perm_id);
        free(perm_id);
        return -1;
      }
      allocated = 1;
      if ((perm = calloc(1, sizeof(*perm))) == NULL) {
        yyerror("Out of memory!");
        free(perm_id);
        return -1;
      }
      ret = hashtab_insert(datum->permissions.table, perm_id,
               perm);
      if (ret) {
        yyerror("Out of memory!");
        free(perm_id);
        free(perm);
        return -1;
      }
      perm->s.value = datum->permissions.nprim + 1;
    }

    if (add_perm_to_class(perm->s.value, datum->s.value) == -1) {
      yyerror("Out of memory!");
      return -1;
    }

    /* Update number of primitives if we allocated one. */
    if (allocated)
      datum->permissions.nprim++;
  }
  return 0;
}

static int require_role_or_attribute(int pass, unsigned char isattr)
{
  char *key = NULL;
  role_datum_t *role = NULL;
  int ret;

  if (pass == 2) {
    free(queue_remove(id_queue));
    return 0;
  }

  ret = create_role(SCOPE_REQ, isattr, &role, &key);
  if (ret < 0) {
    return -1;
  }

  free(key);

  if (ret == 0) {
    ret = ebitmap_set_bit(&role->dominates, role->s.value - 1, 1);
    if (ret != 0) {
      yyerror("Out of memory");
      return -1;
    }
  } else {
    role_datum_destroy(role);
    free(role);
  }

  return 0;
}

int require_role(int pass)
{
  return require_role_or_attribute(pass, 0);
}

int require_attribute_role(int pass)
{
  return require_role_or_attribute(pass, 1);
}

static int require_type_or_attribute(int pass, unsigned char isattr)
{
  type_datum_t *type = NULL;
  int ret;

  if (pass == 2) {
    free(queue_remove(id_queue));
    return 0;
  }

  ret = create_type(SCOPE_REQ, isattr, &type);

  if (ret < 0) {
    return -1;
  }

  return 0;
}

int require_type(int pass)
{
  return require_type_or_attribute(pass, 0);
}

int require_attribute(int pass)
{
  return require_type_or_attribute(pass, 1);
}

int require_user(int pass)
{
  char *key = NULL;
  user_datum_t *user = NULL;
  int ret;

  if (pass == 1) {
    free(queue_remove(id_queue));
    return 0;
  }

  ret = create_user(SCOPE_REQ, &user, &key);
  if (ret < 0) {
    return -1;
  }

  free(key);

  if (ret == 1) {
    user_datum_destroy(user);
    free(user);
  }

  return 0;
}

static int require_bool_tunable(int pass, int is_tunable)
{
  char *id = queue_remove(id_queue);
  cond_bool_datum_t *booldatum = NULL;
  int retval;
  if (pass == 2) {
    free(id);
    return 0;
  }
  if (id == NULL) {
    yyerror("no boolean name");
    return -1;
  }
  if ((booldatum = calloc(1, sizeof(*booldatum))) == NULL) {
    cond_destroy_bool(id, booldatum, NULL);
    yyerror("Out of memory!");
    return -1;
  }
  if (is_tunable)
    booldatum->flags |= COND_BOOL_FLAGS_TUNABLE;
  retval = require_symbol(SYM_BOOLS, id, booldatum, &booldatum->s.value,
        &booldatum->s.value);
  if (retval != 0) {
    cond_destroy_bool(id, booldatum, NULL);
    if (retval < 0) {
      print_error_msg(retval, SYM_BOOLS);
      return -1;
    }
  }

  return 0;
}

int require_bool(int pass)
{
  return require_bool_tunable(pass, 0);
}

int require_tunable(int pass)
{
  return require_bool_tunable(pass, 1);
}

int require_sens(int pass)
{
  char *id = queue_remove(id_queue);
  level_datum_t *level = NULL;
  int retval;
  if (pass == 2) {
    free(id);
    return 0;
  }
  if (!id) {
    yyerror("no sensitivity name");
    return -1;
  }
  level = malloc(sizeof(level_datum_t));
  if (!level) {
    free(id);
    yyerror("Out of memory!");
    return -1;
  }
  level_datum_init(level);
  level->level = malloc(sizeof(mls_level_t));
  if (!level->level) {
    free(id);
    level_datum_destroy(level);
    free(level);
    yyerror("Out of memory!");
    return -1;
  }
  mls_level_init(level->level);
  retval = require_symbol(SYM_LEVELS, id, level, &level->level->sens,
        &level->level->sens);
  if (retval != 0) {
    free(id);
    mls_level_destroy(level->level);
    free(level->level);
    level_datum_destroy(level);
    free(level);
    if (retval < 0) {
      print_error_msg(retval, SYM_LEVELS);
      return -1;
    }
  }

  return 0;
}

int require_cat(int pass)
{
  char *id = queue_remove(id_queue);
  cat_datum_t *cat = NULL;
  int retval;
  if (pass == 2) {
    free(id);
    return 0;
  }
  if (!id) {
    yyerror("no category name");
    return -1;
  }
  cat = malloc(sizeof(cat_datum_t));
  if (!cat) {
    free(id);
    yyerror("Out of memory!");
    return -1;
  }
  cat_datum_init(cat);

  retval =
    require_symbol(SYM_CATS, id, cat, &cat->s.value, &cat->s.value);
  if (retval != 0) {
    free(id);
    cat_datum_destroy(cat);
    free(cat);
    if (retval < 0) {
      print_error_msg(retval, SYM_CATS);
      return -1;
    }
  }

  return 0;
}

static int is_scope_in_stack(const scope_datum_t *scope,
           const scope_stack_t *stack)
{
  uint32_t i;
  if (stack == NULL) {
    return 0; /* no matching scope found */
  }
  if (stack->type == 1) {
    const avrule_decl_t *decl = stack->decl;
    for (i = 0; i < scope->decl_ids_len; i++) {
      if (scope->decl_ids[i] == decl->decl_id) {
        return 1;
      }
    }
  } else {
    /* note that conditionals can't declare or require
     * symbols, so skip this level */
  }

  /* not within scope of this stack, so try its parent */
  return is_scope_in_stack(scope, stack->parent);
}

int is_id_in_scope(uint32_t symbol_type, const_hashtab_key_t id)
{
  const scope_datum_t *scope = (scope_datum_t *)hashtab_search(
    policydbp->scope[symbol_type].table, id);
  if (scope == NULL) {
    return 1; /* id is not known, so return success */
  }
  return is_scope_in_stack(scope, stack_top);
}

static int is_perm_in_scope_index(uint32_t perm_value, uint32_t class_value,
          const scope_index_t *scope)
{
  if (class_value > scope->class_perms_len) {
    return 1;
  }
  if (ebitmap_get_bit(scope->class_perms_map + class_value - 1,
          perm_value - 1)) {
    return 1;
  }
  return 0;
}

static int is_perm_in_stack(uint32_t perm_value, uint32_t class_value,
          const scope_stack_t *stack)
{
  if (stack == NULL) {
    return 0; /* no matching scope found */
  }
  if (stack->type == 1) {
    avrule_decl_t *decl = stack->decl;
    if (is_perm_in_scope_index(perm_value, class_value,
             &decl->required) ||
        is_perm_in_scope_index(perm_value, class_value,
             &decl->declared)) {
      return 1;
    }
  } else {
    /* note that conditionals can't declare or require
     * symbols, so skip this level */
  }

  /* not within scope of this stack, so try its parent */
  return is_perm_in_stack(perm_value, class_value, stack->parent);
}

int is_perm_in_scope(const_hashtab_key_t perm_id, const_hashtab_key_t class_id)
{
  const class_datum_t *cladatum = (class_datum_t *)hashtab_search(
    policydbp->p_classes.table, class_id);
  const perm_datum_t *perdatum;
  if (cladatum == NULL) {
    return 1;
  }
  perdatum = (perm_datum_t *)hashtab_search(cladatum->permissions.table,
              perm_id);
  if (perdatum == NULL) {
    return 1;
  }
  return is_perm_in_stack(perdatum->s.value, cladatum->s.value,
        stack_top);
}

cond_list_t *get_current_cond_list(cond_list_t *cond)
{
  /* FIX ME: do something different here if in a nested
   * conditional? */
  avrule_decl_t *decl = stack_top->decl;
  return get_decl_cond_list(policydbp, decl, cond);
}

/* Append the new conditional node to the existing ones.  During
 * expansion the list will be reversed -- i.e., the last AV rule will
 * be the first one listed in the policy.  This matches the behavior
 * of the upstream compiler. */
void append_cond_list(cond_list_t *cond)
{
  cond_list_t *old_cond = get_current_cond_list(cond);
  avrule_t *tmp;
  assert(old_cond != NULL); /* probably out of memory */
  if (old_cond->avtrue_list == NULL) {
    old_cond->avtrue_list = cond->avtrue_list;
  } else {
    for (tmp = old_cond->avtrue_list; tmp->next != NULL;
         tmp = tmp->next)
      ;
    tmp->next = cond->avtrue_list;
  }
  if (old_cond->avfalse_list == NULL) {
    old_cond->avfalse_list = cond->avfalse_list;
  } else {
    for (tmp = old_cond->avfalse_list; tmp->next != NULL;
         tmp = tmp->next)
      ;
    tmp->next = cond->avfalse_list;
  }

  old_cond->flags |= cond->flags;
}

void append_avrule(avrule_t *avrule)
{
  avrule_decl_t *decl = stack_top->decl;

  /* currently avrules follow a completely different code path
   * for handling avrules and compute types
   * (define_cond_avrule_te_avtab, define_cond_compute_type);
   * therefore there ought never be a conditional on top of the
   * scope stack */
  assert(stack_top->type == 1);

  if (stack_top->last_avrule == NULL) {
    decl->avrules = avrule;
  } else {
    stack_top->last_avrule->next = avrule;
  }
  stack_top->last_avrule = avrule;
}

/* this doesn't actually append, but really prepends it */
void append_role_trans(role_trans_rule_t *role_tr_rules)
{
  avrule_decl_t *decl = stack_top->decl;

  /* role transitions are not allowed within conditionals */
  assert(stack_top->type == 1);

  role_tr_rules->next = decl->role_tr_rules;
  decl->role_tr_rules = role_tr_rules;
}

/* this doesn't actually append, but really prepends it */
void append_role_allow(role_allow_rule_t *role_allow_rules)
{
  avrule_decl_t *decl = stack_top->decl;

  /* role allows are not allowed within conditionals */
  assert(stack_top->type == 1);

  role_allow_rules->next = decl->role_allow_rules;
  decl->role_allow_rules = role_allow_rules;
}

/* this doesn't actually append, but really prepends it */
void append_filename_trans(filename_trans_rule_t *filename_trans_rules)
{
  avrule_decl_t *decl = stack_top->decl;

  /* filename transitions are not allowed within conditionals */
  assert(stack_top->type == 1);

  filename_trans_rules->next = decl->filename_trans_rules;
  decl->filename_trans_rules = filename_trans_rules;
}

/* this doesn't actually append, but really prepends it */
void append_range_trans(range_trans_rule_t *range_tr_rules)
{
  avrule_decl_t *decl = stack_top->decl;

  /* range transitions are not allowed within conditionals */
  assert(stack_top->type == 1);

  range_tr_rules->next = decl->range_tr_rules;
  decl->range_tr_rules = range_tr_rules;
}

int begin_optional(int pass)
{
  avrule_block_t *block = NULL;
  avrule_decl_t *decl;
  if (pass == 1) {
    /* allocate a new avrule block for this optional block */
    if ((block = avrule_block_create()) == NULL ||
        (decl = avrule_decl_create(next_decl_id)) == NULL) {
      goto cleanup;
    }
    block->flags |= AVRULE_OPTIONAL;
    block->branch_list = decl;
    last_block->next = block;
  } else {
    /* select the next block from the chain built during pass 1 */
    block = last_block->next;
    assert(block != NULL && block->branch_list != NULL &&
           block->branch_list->decl_id == next_decl_id);
    decl = block->branch_list;
  }
  if (push_stack(1, block, decl) == -1) {
    goto cleanup;
  }
  stack_top->last_avrule = NULL;
  last_block = block;
  next_decl_id++;
  return 0;
cleanup:
  yyerror("Out of memory!");
  avrule_block_destroy(block);
  return -1;
}

int end_optional(int pass __attribute__((unused)))
{
  /* once nested conditionals are allowed, do the stack unfolding here */
  pop_stack();
  return 0;
}

int begin_optional_else(int pass)
{
  avrule_decl_t *decl;
  assert(stack_top->type == 1 && stack_top->in_else == 0);
  if (pass == 1) {
    /* allocate a new declaration and add it to the
     * current chain */
    if ((decl = avrule_decl_create(next_decl_id)) == NULL) {
      yyerror("Out of memory!");
      return -1;
    }
    stack_top->decl->next = decl;
  } else {
    /* pick the (hopefully last) declaration of this
       avrule block, built from pass 1 */
    decl = stack_top->decl->next;
    assert(decl != NULL && decl->next == NULL &&
           decl->decl_id == next_decl_id);
  }
  stack_top->in_else = 1;
  stack_top->decl = decl;
  stack_top->last_avrule = NULL;
  stack_top->require_given = 0;
  next_decl_id++;
  return 0;
}

static int copy_requirements(avrule_decl_t *dest, const scope_stack_t *stack)
{
  uint32_t i;
  if (stack == NULL) {
    return 0;
  }
  if (stack->type == 1) {
    const scope_index_t *src_scope = &stack->decl->required;
    scope_index_t *dest_scope = &dest->required;
    for (i = 0; i < SYM_NUM; i++) {
      const ebitmap_t *src_bitmap = &src_scope->scope[i];
      ebitmap_t *dest_bitmap = &dest_scope->scope[i];
      if (ebitmap_union(dest_bitmap, src_bitmap)) {
        yyerror("Out of memory!");
        return -1;
      }
    }
    /* now copy class permissions */
    if (src_scope->class_perms_len > dest_scope->class_perms_len) {
      ebitmap_t *new_map = realloc(
        dest_scope->class_perms_map,
        src_scope->class_perms_len * sizeof(*new_map));
      if (new_map == NULL) {
        yyerror("Out of memory!");
        return -1;
      }
      dest_scope->class_perms_map = new_map;
      for (i = dest_scope->class_perms_len;
           i < src_scope->class_perms_len; i++) {
        ebitmap_init(dest_scope->class_perms_map + i);
      }
      dest_scope->class_perms_len =
        src_scope->class_perms_len;
    }
    for (i = 0; i < src_scope->class_perms_len; i++) {
      const ebitmap_t *src_bitmap =
        &src_scope->class_perms_map[i];
      ebitmap_t *dest_bitmap =
        &dest_scope->class_perms_map[i];
      if (ebitmap_union(dest_bitmap, src_bitmap)) {
        yyerror("Out of memory!");
        return -1;
      }
    }
  }
  return copy_requirements(dest, stack->parent);
}

/* During pass 1, check that at least one thing was required within
 * this block, for those places where a REQUIRED is necessary.  During
 * pass 2, have this block inherit its parents' requirements.  Return
 * 0 on success, -1 on failure. */
int end_avrule_block(int pass)
{
  avrule_decl_t *decl = stack_top->decl;
  assert(stack_top->type == 1);
  if (pass == 2) {
    /* this avrule_decl inherits all of its parents'
     * requirements */
    if (copy_requirements(decl, stack_top->parent) == -1) {
      return -1;
    }
    return 0;
  }
  if (!stack_top->in_else && !stack_top->require_given) {
    if (policydbp->policy_type == POLICY_BASE &&
        stack_top->parent != NULL) {
      /* if this is base no require should be in the global block */
      return 0;
    } else {
      /* non-ELSE branches must have at least one thing required */
      yyerror("This block has no require section.");
      return -1;
    }
  }
  return 0;
}

/* Push a new scope on to the stack and update the 'last' pointer.
 * Return 0 on success, -1 if out * of memory. */
static int push_stack(int stack_type, ...)
{
  scope_stack_t *s = calloc(1, sizeof(*s));
  va_list ap;
  if (s == NULL) {
    return -1;
  }
  va_start(ap, stack_type);
  switch (s->type = stack_type) {
  case 1: {
    va_arg(ap, avrule_block_t *);
    s->decl = va_arg(ap, avrule_decl_t *);
    break;
  }
  case 2: {
    va_arg(ap, cond_list_t *);
    break;
  }
  default:
    /* invalid stack type given */
    assert(0);
  }
  va_end(ap);
  s->parent = stack_top;
  stack_top = s;
  return 0;
}

/* Pop off the most recently added from the stack.  Update the 'last'
 * pointer. */
static void pop_stack(void)
{
  scope_stack_t *parent;
  assert(stack_top != NULL);
  parent = stack_top->parent;
  free(stack_top);
  stack_top = parent;
}

#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
void module_compiler_reset(void)
{
  while (stack_top)
    pop_stack();

  last_block = NULL;
  next_decl_id = 1;
}
#endif

Coverage Report

Created: 2026-08-31 06:40