// SPDX-License-Identifier: GPL-2.0-only
/*
 * Implementation of the policy database.
 *
 * Author : Stephen Smalley, <sds@tycho.nsa.gov>
 */

/*
 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
 *
 *      Support for enhanced MLS infrastructure.
 *
 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
 *
 *      Added conditional policy language extensions
 *
 * Updated: Hewlett-Packard <paul@paul-moore.com>
 *
 *      Added support for the policy capability bitmap
 *
 * Update: Mellanox Techonologies
 *
 *      Added Infiniband support
 *
 * Copyright (C) 2016 Mellanox Techonologies
 * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
 * Copyright (C) 2003 - 2004 Tresys Technology, LLC
 */

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/audit.h>
#include "security.h"

#include "policydb.h"
#include "conditional.h"
#include "mls.h"
#include "services.h"

#define _DEBUG_HASHES

#ifdef DEBUG_HASHES
static const char *symtab_name[SYM_NUM] = {
        "common prefixes",
        "classes",
        "roles",
        "types",
        "users",
        "bools",
        "levels",
        "categories",
};
#endif

struct policydb_compat_info {
        int version;
        int sym_num;
        int ocon_num;
};

/* These need to be updated if SYM_NUM or OCON_NUM changes */
static struct policydb_compat_info policydb_compat[] = {
        {
                .version        = POLICYDB_VERSION_BASE,
                .sym_num        = SYM_NUM - 3,
                .ocon_num       = OCON_NUM - 3,
        },
        {
                .version        = POLICYDB_VERSION_BOOL,
                .sym_num        = SYM_NUM - 2,
                .ocon_num       = OCON_NUM - 3,
        },
        {
                .version        = POLICYDB_VERSION_IPV6,
                .sym_num        = SYM_NUM - 2,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_NLCLASS,
                .sym_num        = SYM_NUM - 2,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_MLS,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_AVTAB,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_RANGETRANS,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_POLCAP,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_PERMISSIVE,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_BOUNDARY,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_FILENAME_TRANS,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_ROLETRANS,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_NEW_OBJECT_DEFAULTS,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_DEFAULT_TYPE,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_CONSTRAINT_NAMES,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_XPERMS_IOCTL,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM - 2,
        },
        {
                .version        = POLICYDB_VERSION_INFINIBAND,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM,
        },
        {
                .version        = POLICYDB_VERSION_GLBLUB,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM,
        },
        {
                .version        = POLICYDB_VERSION_COMP_FTRANS,
                .sym_num        = SYM_NUM,
                .ocon_num       = OCON_NUM,
        },
};

static struct policydb_compat_info *policydb_lookup_compat(int version)
{
        int i;
        struct policydb_compat_info *info = NULL;

        for (i = 0; i < ARRAY_SIZE(policydb_compat); i++) {
                if (policydb_compat[i].version == version) {
                        info = &policydb_compat[i];
                        break;
                }
        }
        return info;
}

/*
 * The following *_destroy functions are used to
 * free any memory allocated for each kind of
 * symbol data in the policy database.
 */

static int perm_destroy(void *key, void *datum, void *p)
{
        kfree(key);
        kfree(datum);
        return 0;
}

static int common_destroy(void *key, void *datum, void *p)
{
        struct common_datum *comdatum;

        kfree(key);
        if (datum) {
                comdatum = datum;
                hashtab_map(&comdatum->permissions.table, perm_destroy, NULL);
                hashtab_destroy(&comdatum->permissions.table);
        }
        kfree(datum);
        return 0;
}

static void constraint_expr_destroy(struct constraint_expr *expr)
{
        if (expr) {
                ebitmap_destroy(&expr->names);
                if (expr->type_names) {
                        ebitmap_destroy(&expr->type_names->types);
                        ebitmap_destroy(&expr->type_names->negset);
                        kfree(expr->type_names);
                }
                kfree(expr);
        }
}

static int cls_destroy(void *key, void *datum, void *p)
{
        struct class_datum *cladatum;
        struct constraint_node *constraint, *ctemp;
        struct constraint_expr *e, *etmp;

        kfree(key);
        if (datum) {
                cladatum = datum;
                hashtab_map(&cladatum->permissions.table, perm_destroy, NULL);
                hashtab_destroy(&cladatum->permissions.table);
                constraint = cladatum->constraints;
                while (constraint) {
                        e = constraint->expr;
                        while (e) {
                                etmp = e;
                                e = e->next;
                                constraint_expr_destroy(etmp);
                        }
                        ctemp = constraint;
                        constraint = constraint->next;
                        kfree(ctemp);
                }

                constraint = cladatum->validatetrans;
                while (constraint) {
                        e = constraint->expr;
                        while (e) {
                                etmp = e;
                                e = e->next;
                                constraint_expr_destroy(etmp);
                        }
                        ctemp = constraint;
                        constraint = constraint->next;
                        kfree(ctemp);
                }
                kfree(cladatum->comkey);
        }
        kfree(datum);
        return 0;
}

static int role_destroy(void *key, void *datum, void *p)
{
        struct role_datum *role;

        kfree(key);
        if (datum) {
                role = datum;
                ebitmap_destroy(&role->dominates);
                ebitmap_destroy(&role->types);
        }
        kfree(datum);
        return 0;
}

static int type_destroy(void *key, void *datum, void *p)
{
        kfree(key);
        kfree(datum);
        return 0;
}

static int user_destroy(void *key, void *datum, void *p)
{
        struct user_datum *usrdatum;

        kfree(key);
        if (datum) {
                usrdatum = datum;
                ebitmap_destroy(&usrdatum->roles);
                ebitmap_destroy(&usrdatum->range.level[0].cat);
                ebitmap_destroy(&usrdatum->range.level[1].cat);
                ebitmap_destroy(&usrdatum->dfltlevel.cat);
        }
        kfree(datum);
        return 0;
}

static int sens_destroy(void *key, void *datum, void *p)
{
        struct level_datum *levdatum;

        kfree(key);
        if (datum) {
                levdatum = datum;
                if (levdatum->level)
                        ebitmap_destroy(&levdatum->level->cat);
                kfree(levdatum->level);
        }
        kfree(datum);
        return 0;
}

static int cat_destroy(void *key, void *datum, void *p)
{
        kfree(key);
        kfree(datum);
        return 0;
}

static int (*destroy_f[SYM_NUM]) (void *key, void *datum, void *datap) =
{
        common_destroy,
        cls_destroy,
        role_destroy,
        type_destroy,
        user_destroy,
        cond_destroy_bool,
        sens_destroy,
        cat_destroy,
};

static int filenametr_destroy(void *key, void *datum, void *p)
{
        struct filename_trans_key *ft = key;
        struct filename_trans_datum *next, *d = datum;

        kfree(ft->name);
        kfree(key);
        do {
                ebitmap_destroy(&d->stypes);
                next = d->next;
                kfree(d);
                d = next;
        } while (unlikely(d));
        cond_resched();
        return 0;
}

static int range_tr_destroy(void *key, void *datum, void *p)
{
        struct mls_range *rt = datum;

        kfree(key);
        ebitmap_destroy(&rt->level[0].cat);
        ebitmap_destroy(&rt->level[1].cat);
        kfree(datum);
        cond_resched();
        return 0;
}

static int role_tr_destroy(void *key, void *datum, void *p)
{
        kfree(key);
        kfree(datum);
        return 0;
}

static void ocontext_destroy(struct ocontext *c, int i)
{
        if (!c)
                return;

        context_destroy(&c->context[0]);
        context_destroy(&c->context[1]);
        if (i == OCON_ISID || i == OCON_FS ||
            i == OCON_NETIF || i == OCON_FSUSE)
                kfree(c->u.name);
        kfree(c);
}

/*
 * Initialize the role table.
 */
static int roles_init(struct policydb *p)
{
        char *key = NULL;
        int rc;
        struct role_datum *role;

        role = kzalloc(sizeof(*role), GFP_KERNEL);
        if (!role)
                return -ENOMEM;

        rc = -EINVAL;
        role->value = ++p->p_roles.nprim;
        if (role->value != OBJECT_R_VAL)
                goto out;

        rc = -ENOMEM;
        key = kstrdup(OBJECT_R, GFP_KERNEL);
        if (!key)
                goto out;

        rc = symtab_insert(&p->p_roles, key, role);
        if (rc)
                goto out;

        return 0;
out:
        kfree(key);
        kfree(role);
        return rc;
}

static u32 filenametr_hash(const void *k)
{
        const struct filename_trans_key *ft = k;
        unsigned long hash;
        unsigned int byte_num;
        unsigned char focus;

        hash = ft->ttype ^ ft->tclass;

        byte_num = 0;
        while ((focus = ft->name[byte_num++]))
                hash = partial_name_hash(focus, hash);
        return hash;
}

static int filenametr_cmp(const void *k1, const void *k2)
{
        const struct filename_trans_key *ft1 = k1;
        const struct filename_trans_key *ft2 = k2;
        int v;

        v = ft1->ttype - ft2->ttype;
        if (v)
                return v;

        v = ft1->tclass - ft2->tclass;
        if (v)
                return v;

        return strcmp(ft1->name, ft2->name);

}

static const struct hashtab_key_params filenametr_key_params = {
        .hash = filenametr_hash,
        .cmp = filenametr_cmp,
};

struct filename_trans_datum *policydb_filenametr_search(
        struct policydb *p, struct filename_trans_key *key)
{
        return hashtab_search(&p->filename_trans, key, filenametr_key_params);
}

static u32 rangetr_hash(const void *k)
{
        const struct range_trans *key = k;

        return key->source_type + (key->target_type << 3) +
                (key->target_class << 5);
}

static int rangetr_cmp(const void *k1, const void *k2)
{
        const struct range_trans *key1 = k1, *key2 = k2;
        int v;

        v = key1->source_type - key2->source_type;
        if (v)
                return v;

        v = key1->target_type - key2->target_type;
        if (v)
                return v;

        v = key1->target_class - key2->target_class;

        return v;
}

static const struct hashtab_key_params rangetr_key_params = {
        .hash = rangetr_hash,
        .cmp = rangetr_cmp,
};

struct mls_range *policydb_rangetr_search(struct policydb *p,
                                          struct range_trans *key)
{
        return hashtab_search(&p->range_tr, key, rangetr_key_params);
}

static u32 role_trans_hash(const void *k)
{
        const struct role_trans_key *key = k;

        return key->role + (key->type << 3) + (key->tclass << 5);
}

static int role_trans_cmp(const void *k1, const void *k2)
{
        const struct role_trans_key *key1 = k1, *key2 = k2;
        int v;

        v = key1->role - key2->role;
        if (v)
                return v;

        v = key1->type - key2->type;
        if (v)
                return v;

        return key1->tclass - key2->tclass;
}

static const struct hashtab_key_params roletr_key_params = {
        .hash = role_trans_hash,
        .cmp = role_trans_cmp,
};

struct role_trans_datum *policydb_roletr_search(struct policydb *p,
                                                struct role_trans_key *key)
{
        return hashtab_search(&p->role_tr, key, roletr_key_params);
}

/*
 * Initialize a policy database structure.
 */
static void policydb_init(struct policydb *p)
{
        memset(p, 0, sizeof(*p));

        avtab_init(&p->te_avtab);
        cond_policydb_init(p);

        ebitmap_init(&p->filename_trans_ttypes);
        ebitmap_init(&p->policycaps);
        ebitmap_init(&p->permissive_map);
}

/*
 * The following *_index functions are used to
 * define the val_to_name and val_to_struct arrays
 * in a policy database structure.  The val_to_name
 * arrays are used when converting security context
 * structures into string representations.  The
 * val_to_struct arrays are used when the attributes
 * of a class, role, or user are needed.
 */

static int common_index(void *key, void *datum, void *datap)
{
        struct policydb *p;
        struct common_datum *comdatum;

        comdatum = datum;
        p = datap;
        if (!comdatum->value || comdatum->value > p->p_commons.nprim)
                return -EINVAL;

        p->sym_val_to_name[SYM_COMMONS][comdatum->value - 1] = key;

        return 0;
}

static int class_index(void *key, void *datum, void *datap)
{
        struct policydb *p;
        struct class_datum *cladatum;

        cladatum = datum;
        p = datap;
        if (!cladatum->value || cladatum->value > p->p_classes.nprim)
                return -EINVAL;

        p->sym_val_to_name[SYM_CLASSES][cladatum->value - 1] = key;
        p->class_val_to_struct[cladatum->value - 1] = cladatum;
        return 0;
}

static int role_index(void *key, void *datum, void *datap)
{
        struct policydb *p;
        struct role_datum *role;

        role = datum;
        p = datap;
        if (!role->value
            || role->value > p->p_roles.nprim
            || role->bounds > p->p_roles.nprim)
                return -EINVAL;

        p->sym_val_to_name[SYM_ROLES][role->value - 1] = key;
        p->role_val_to_struct[role->value - 1] = role;
        return 0;
}

static int type_index(void *key, void *datum, void *datap)
{
        struct policydb *p;
        struct type_datum *typdatum;

        typdatum = datum;
        p = datap;

        if (typdatum->primary) {
                if (!typdatum->value
                    || typdatum->value > p->p_types.nprim
                    || typdatum->bounds > p->p_types.nprim)
                        return -EINVAL;
                p->sym_val_to_name[SYM_TYPES][typdatum->value - 1] = key;
                p->type_val_to_struct[typdatum->value - 1] = typdatum;
        }

        return 0;
}

static int user_index(void *key, void *datum, void *datap)
{
        struct policydb *p;
        struct user_datum *usrdatum;

        usrdatum = datum;
        p = datap;
        if (!usrdatum->value
            || usrdatum->value > p->p_users.nprim
            || usrdatum->bounds > p->p_users.nprim)
                return -EINVAL;

        p->sym_val_to_name[SYM_USERS][usrdatum->value - 1] = key;
        p->user_val_to_struct[usrdatum->value - 1] = usrdatum;
        return 0;
}

static int sens_index(void *key, void *datum, void *datap)
{
        struct policydb *p;
        struct level_datum *levdatum;

        levdatum = datum;
        p = datap;

        if (!levdatum->isalias) {
                if (!levdatum->level->sens ||
                    levdatum->level->sens > p->p_levels.nprim)
                        return -EINVAL;

                p->sym_val_to_name[SYM_LEVELS][levdatum->level->sens - 1] = key;
        }

        return 0;
}

static int cat_index(void *key, void *datum, void *datap)
{
        struct policydb *p;
        struct cat_datum *catdatum;

        catdatum = datum;
        p = datap;

        if (!catdatum->isalias) {
                if (!catdatum->value || catdatum->value > p->p_cats.nprim)
                        return -EINVAL;

                p->sym_val_to_name[SYM_CATS][catdatum->value - 1] = key;
        }

        return 0;
}

static int (*index_f[SYM_NUM]) (void *key, void *datum, void *datap) =
{
        common_index,
        class_index,
        role_index,
        type_index,
        user_index,
        cond_index_bool,
        sens_index,
        cat_index,
};

#ifdef DEBUG_HASHES
static void hash_eval(struct hashtab *h, const char *hash_name)
{
        struct hashtab_info info;

        hashtab_stat(h, &info);
        pr_debug("SELinux: %s:  %d entries and %d/%d buckets used, longest chain length %d\n",
                 hash_name, h->nel, info.slots_used, h->size,
                 info.max_chain_len);
}

static void symtab_hash_eval(struct symtab *s)
{
        int i;

        for (i = 0; i < SYM_NUM; i++)
                hash_eval(&s[i].table, symtab_name[i]);
}

#else
static inline void hash_eval(struct hashtab *h, char *hash_name)
{
}
#endif

/*
 * Define the other val_to_name and val_to_struct arrays
 * in a policy database structure.
 *
 * Caller must clean up on failure.
 */
static int policydb_index(struct policydb *p)
{
        int i, rc;

        if (p->mls_enabled)
                pr_debug("SELinux:  %d users, %d roles, %d types, %d bools, %d sens, %d cats\n",
                         p->p_users.nprim, p->p_roles.nprim, p->p_types.nprim,
                         p->p_bools.nprim, p->p_levels.nprim, p->p_cats.nprim);
        else
                pr_debug("SELinux:  %d users, %d roles, %d types, %d bools\n",
                         p->p_users.nprim, p->p_roles.nprim, p->p_types.nprim,
                         p->p_bools.nprim);

        pr_debug("SELinux:  %d classes, %d rules\n",
                 p->p_classes.nprim, p->te_avtab.nel);

#ifdef DEBUG_HASHES
        avtab_hash_eval(&p->te_avtab, "rules");
        symtab_hash_eval(p->symtab);
#endif

        p->class_val_to_struct = kcalloc(p->p_classes.nprim,
                                         sizeof(*p->class_val_to_struct),
                                         GFP_KERNEL);
        if (!p->class_val_to_struct)
                return -ENOMEM;

        p->role_val_to_struct = kcalloc(p->p_roles.nprim,
                                        sizeof(*p->role_val_to_struct),
                                        GFP_KERNEL);
        if (!p->role_val_to_struct)
                return -ENOMEM;

        p->user_val_to_struct = kcalloc(p->p_users.nprim,
                                        sizeof(*p->user_val_to_struct),
                                        GFP_KERNEL);
        if (!p->user_val_to_struct)
                return -ENOMEM;

        p->type_val_to_struct = kvcalloc(p->p_types.nprim,
                                         sizeof(*p->type_val_to_struct),
                                         GFP_KERNEL);
        if (!p->type_val_to_struct)
                return -ENOMEM;

        rc = cond_init_bool_indexes(p);
        if (rc)
                goto out;

        for (i = 0; i < SYM_NUM; i++) {
                p->sym_val_to_name[i] = kvcalloc(p->symtab[i].nprim,
                                                 sizeof(char *),
                                                 GFP_KERNEL);
                if (!p->sym_val_to_name[i])
                        return -ENOMEM;

                rc = hashtab_map(&p->symtab[i].table, index_f[i], p);
                if (rc)
                        goto out;
        }
        rc = 0;
out:
        return rc;
}

/*
 * Free any memory allocated by a policy database structure.
 */
void policydb_destroy(struct policydb *p)
{
        struct ocontext *c, *ctmp;
        struct genfs *g, *gtmp;
        int i;
        struct role_allow *ra, *lra = NULL;

        for (i = 0; i < SYM_NUM; i++) {
                cond_resched();
                hashtab_map(&p->symtab[i].table, destroy_f[i], NULL);
                hashtab_destroy(&p->symtab[i].table);
        }

        for (i = 0; i < SYM_NUM; i++)
                kvfree(p->sym_val_to_name[i]);

        kfree(p->class_val_to_struct);
        kfree(p->role_val_to_struct);
        kfree(p->user_val_to_struct);
        kvfree(p->type_val_to_struct);

        avtab_destroy(&p->te_avtab);

        for (i = 0; i < OCON_NUM; i++) {
                cond_resched();
                c = p->ocontexts[i];
                while (c) {
                        ctmp = c;
                        c = c->next;
                        ocontext_destroy(ctmp, i);
                }
                p->ocontexts[i] = NULL;
        }

        g = p->genfs;
        while (g) {
                cond_resched();
                kfree(g->fstype);
                c = g->head;
                while (c) {
                        ctmp = c;
                        c = c->next;
                        ocontext_destroy(ctmp, OCON_FSUSE);
                }
                gtmp = g;
                g = g->next;
                kfree(gtmp);
        }
        p->genfs = NULL;

        cond_policydb_destroy(p);

        hashtab_map(&p->role_tr, role_tr_destroy, NULL);
        hashtab_destroy(&p->role_tr);

        for (ra = p->role_allow; ra; ra = ra->next) {
                cond_resched();
                kfree(lra);
                lra = ra;
        }
        kfree(lra);

        hashtab_map(&p->filename_trans, filenametr_destroy, NULL);
        hashtab_destroy(&p->filename_trans);

        hashtab_map(&p->range_tr, range_tr_destroy, NULL);
        hashtab_destroy(&p->range_tr);

        if (p->type_attr_map_array) {
                for (i = 0; i < p->p_types.nprim; i++)
                        ebitmap_destroy(&p->type_attr_map_array[i]);
                kvfree(p->type_attr_map_array);
        }

        ebitmap_destroy(&p->filename_trans_ttypes);
        ebitmap_destroy(&p->policycaps);
        ebitmap_destroy(&p->permissive_map);
}

/*
 * Load the initial SIDs specified in a policy database
 * structure into a SID table.
 */
int policydb_load_isids(struct policydb *p, struct sidtab *s)
{
        struct ocontext *head, *c;
        int rc;

        rc = sidtab_init(s);
        if (rc) {
                pr_err("SELinux:  out of memory on SID table init\n");
                return rc;
        }

        head = p->ocontexts[OCON_ISID];
        for (c = head; c; c = c->next) {
                u32 sid = c->sid[0];
                const char *name = security_get_initial_sid_context(sid);

                if (sid == SECSID_NULL) {
                        pr_err("SELinux:  SID 0 was assigned a context.\n");
                        sidtab_destroy(s);
                        return -EINVAL;
                }

                /* Ignore initial SIDs unused by this kernel. */
                if (!name)
                        continue;

                rc = sidtab_set_initial(s, sid, &c->context[0]);
                if (rc) {
                        pr_err("SELinux:  unable to load initial SID %s.\n",
                               name);
                        sidtab_destroy(s);
                        return rc;
                }
        }
        return 0;
}

int policydb_class_isvalid(struct policydb *p, unsigned int class)
{
        if (!class || class > p->p_classes.nprim)
                return 0;
        return 1;
}

int policydb_role_isvalid(struct policydb *p, unsigned int role)
{
        if (!role || role > p->p_roles.nprim)
                return 0;
        return 1;
}

int policydb_type_isvalid(struct policydb *p, unsigned int type)
{
        if (!type || type > p->p_types.nprim)
                return 0;
        return 1;
}

/*
 * Return 1 if the fields in the security context
 * structure `c' are valid.  Return 0 otherwise.
 */
int policydb_context_isvalid(struct policydb *p, struct context *c)
{
        struct role_datum *role;
        struct user_datum *usrdatum;

        if (!c->role || c->role > p->p_roles.nprim)
                return 0;

        if (!c->user || c->user > p->p_users.nprim)
                return 0;

        if (!c->type || c->type > p->p_types.nprim)
                return 0;

        if (c->role != OBJECT_R_VAL) {
                /*
                 * Role must be authorized for the type.
                 */
                role = p->role_val_to_struct[c->role - 1];
                if (!role || !ebitmap_get_bit(&role->types, c->type - 1))
                        /* role may not be associated with type */
                        return 0;

                /*
                 * User must be authorized for the role.
                 */
                usrdatum = p->user_val_to_struct[c->user - 1];
                if (!usrdatum)
                        return 0;

                if (!ebitmap_get_bit(&usrdatum->roles, c->role - 1))
                        /* user may not be associated with role */
                        return 0;
        }

        if (!mls_context_isvalid(p, c))
                return 0;

        return 1;
}

/*
 * Read a MLS range structure from a policydb binary
 * representation file.
 */
static int mls_read_range_helper(struct mls_range *r, void *fp)
{
        __le32 buf[2];
        u32 items;
        int rc;

        rc = next_entry(buf, fp, sizeof(u32));
        if (rc)
                goto out;

        rc = -EINVAL;
        items = le32_to_cpu(buf[0]);
        if (items > ARRAY_SIZE(buf)) {
                pr_err("SELinux: mls:  range overflow\n");
                goto out;
        }

        rc = next_entry(buf, fp, sizeof(u32) * items);
        if (rc) {
                pr_err("SELinux: mls:  truncated range\n");
                goto out;
        }

        r->level[0].sens = le32_to_cpu(buf[0]);
        if (items > 1)

                r->level[1].sens = le32_to_cpu(buf[1]);
        else
                r->level[1].sens = r->level[0].sens;

        rc = ebitmap_read(&r->level[0].cat, fp);
        if (rc) {
                pr_err("SELinux: mls:  error reading low categories\n");
                goto out;
        }
        if (items > 1) {
                rc = ebitmap_read(&r->level[1].cat, fp);
                if (rc) {
                        pr_err("SELinux: mls:  error reading high categories\n");
                        goto bad_high;
                }
        } else {
                rc = ebitmap_cpy(&r->level[1].cat, &r->level[0].cat);
                if (rc) {
                        pr_err("SELinux: mls:  out of memory\n");
                        goto bad_high;
                }
        }

        return 0;
bad_high:
        ebitmap_destroy(&r->level[0].cat);
out:
        return rc;
}

/*
 * Read and validate a security context structure
 * from a policydb binary representation file.
 */
static int context_read_and_validate(struct context *c,
                                     struct policydb *p,
                                     void *fp)
{
        __le32 buf[3];
        int rc;

        rc = next_entry(buf, fp, sizeof buf);
        if (rc) {
                pr_err("SELinux: context truncated\n");
                goto out;
        }
        c->user = le32_to_cpu(buf[0]);
        c->role = le32_to_cpu(buf[1]);
        c->type = le32_to_cpu(buf[2]);
        if (p->policyvers >= POLICYDB_VERSION_MLS) {
                rc = mls_read_range_helper(&c->range, fp);
                if (rc) {
                        pr_err("SELinux: error reading MLS range of context\n");
                        goto out;
                }
        }

        rc = -EINVAL;
        if (!policydb_context_isvalid(p, c)) {
                pr_err("SELinux:  invalid security context\n");
                context_destroy(c);
                goto out;
        }
        rc = 0;
out:
        return rc;
}

/*
 * The following *_read functions are used to
 * read the symbol data from a policy database
 * binary representation file.
 */

static int str_read(char **strp, gfp_t flags, void *fp, u32 len)
{
        int rc;
        char *str;

        if ((len == 0) || (len == (u32)-1))
                return -EINVAL;

        str = kmalloc(len + 1, flags | __GFP_NOWARN);
        if (!str)
                return -ENOMEM;

        rc = next_entry(str, fp, len);
        if (rc) {
                kfree(str);
                return rc;
        }

        str[len] = '\0';
        *strp = str;
        return 0;
}

static int perm_read(struct policydb *p, struct symtab *s, void *fp)
{
        char *key = NULL;
        struct perm_datum *perdatum;
        int rc;
        __le32 buf[2];
        u32 len;

        perdatum = kzalloc(sizeof(*perdatum), GFP_KERNEL);
        if (!perdatum)
                return -ENOMEM;

        rc = next_entry(buf, fp, sizeof buf);
        if (rc)
                goto bad;

        len = le32_to_cpu(buf[0]);
        perdatum->value = le32_to_cpu(buf[1]);

        rc = str_read(&key, GFP_KERNEL, fp, len);
        if (rc)
                goto bad;

        rc = symtab_insert(s, key, perdatum);
        if (rc)
                goto bad;

        return 0;
bad:
        perm_destroy(key, perdatum, NULL);
        return rc;
}

static int common_read(struct policydb *p, struct symtab *s, void *fp)
{
        char *key = NULL;
        struct common_datum *comdatum;
        __le32 buf[4];
        u32 len, nel;
        int i, rc;

        comdatum = kzalloc(sizeof(*comdatum), GFP_KERNEL);
        if (!comdatum)
                return -ENOMEM;

        rc = next_entry(buf, fp, sizeof buf);
        if (rc)
                goto bad;

        len = le32_to_cpu(buf[0]);
        comdatum->value = le32_to_cpu(buf[1]);
        nel = le32_to_cpu(buf[3]);

        rc = symtab_init(&comdatum->permissions, nel);
        if (rc)
                goto bad;
        comdatum->permissions.nprim = le32_to_cpu(buf[2]);

        rc = str_read(&key, GFP_KERNEL, fp, len);
        if (rc)
                goto bad;

        for (i = 0; i < nel; i++) {
                rc = perm_read(p, &comdatum->permissions, fp);
                if (rc)
                        goto bad;
        }

        rc = symtab_insert(s, key, comdatum);
        if (rc)
                goto bad;
        return 0;
bad:
        common_destroy(key, comdatum, NULL);
        return rc;
}

static void type_set_init(struct type_set *t)
{
        ebitmap_init(&t->types);
        ebitmap_init(&t->negset);
}

static int type_set_read(struct type_set *t, void *fp)
{
        __le32 buf[1];
        int rc;

        if (ebitmap_read(&t->types, fp))
                return -EINVAL;
        if (ebitmap_read(&t->negset, fp))
                return -EINVAL;

        rc = next_entry(buf, fp, sizeof(u32));
        if (rc < 0)
                return -EINVAL;
        t->flags = le32_to_cpu(buf[0]);

        return 0;
}


static int read_cons_helper(struct policydb *p,
                                struct constraint_node **nodep,
                                int ncons, int allowxtarget, void *fp)
{
        struct constraint_node *c, *lc;
        struct constraint_expr *e, *le;
        __le32 buf[3];
        u32 nexpr;
        int rc, i, j, depth;

        lc = NULL;
        for (i = 0; i < ncons; i++) {
                c = kzalloc(sizeof(*c), GFP_KERNEL);
                if (!c)
                        return -ENOMEM;

                if (lc)
                        lc->next = c;
                else
                        *nodep = c;

                rc = next_entry(buf, fp, (sizeof(u32) * 2));
                if (rc)
                        return rc;
                c->permissions = le32_to_cpu(buf[0]);
                nexpr = le32_to_cpu(buf[1]);
                le = NULL;
                depth = -1;
                for (j = 0; j < nexpr; j++) {
                        e = kzalloc(sizeof(*e), GFP_KERNEL);
                        if (!e)
                                return -ENOMEM;

                        if (le)
                                le->next = e;
                        else
                                c->expr = e;

                        rc = next_entry(buf, fp, (sizeof(u32) * 3));
                        if (rc)
                                return rc;
                        e->expr_type = le32_to_cpu(buf[0]);
                        e->attr = le32_to_cpu(buf[1]);
                        e->op = le32_to_cpu(buf[2]);

                        switch (e->expr_type) {
                        case CEXPR_NOT:
                                if (depth < 0)
                                        return -EINVAL;
                                break;
                        case CEXPR_AND:
                        case CEXPR_OR:
                                if (depth < 1)
                                        return -EINVAL;
                                depth--;
                                break;
                        case CEXPR_ATTR:
                                if (depth == (CEXPR_MAXDEPTH - 1))
                                        return -EINVAL;
                                depth++;
                                break;
                        case CEXPR_NAMES:
                                if (!allowxtarget && (e->attr & CEXPR_XTARGET))
                                        return -EINVAL;
                                if (depth == (CEXPR_MAXDEPTH - 1))
                                        return -EINVAL;
                                depth++;
                                rc = ebitmap_read(&e->names, fp);
                                if (rc)
                                        return rc;
                                if (p->policyvers >=
                                    POLICYDB_VERSION_CONSTRAINT_NAMES) {
                                        e->type_names = kzalloc(sizeof
                                                (*e->type_names), GFP_KERNEL);
                                        if (!e->type_names)
                                                return -ENOMEM;
                                        type_set_init(e->type_names);
                                        rc = type_set_read(e->type_names, fp);
                                        if (rc)
                                                return rc;
                                }
                                break;
                        default:
                                return -EINVAL;
                        }
                        le = e;
                }
                if (depth != 0)
                        return -EINVAL;
                lc = c;
        }

        return 0;
}

static int class_read(struct policydb *p, struct symtab *s, void *fp)
{
        char *key = NULL;
        struct class_datum *cladatum;
        __le32 buf[6];
        u32 len, len2, ncons, nel;
        int i, rc;

        cladatum = kzalloc(sizeof(*cladatum), GFP_KERNEL);
        if (!cladatum)
                return -ENOMEM;

        rc = next_entry(buf, fp, sizeof(u32)*6);
        if (rc)
                goto bad;

        len = le32_to_cpu(buf[0]);
        len2 = le32_to_cpu(buf[1]);
        cladatum->value = le32_to_cpu(buf[2]);
        nel = le32_to_cpu(buf[4]);

        rc = symtab_init(&cladatum->permissions, nel);
        if (rc)
                goto bad;
        cladatum->permissions.nprim = le32_to_cpu(buf[3]);

        ncons = le32_to_cpu(buf[5]);

        rc = str_read(&key, GFP_KERNEL, fp, len);
        if (rc)
                goto bad;

        if (len2) {
                rc = str_read(&cladatum->comkey, GFP_KERNEL, fp, len2);
                if (rc)
                        goto bad;

                rc = -EINVAL;
                cladatum->comdatum = symtab_search(&p->p_commons,
                                                   cladatum->comkey);
                if (!cladatum->comdatum) {
                        pr_err("SELinux:  unknown common %s\n",
                               cladatum->comkey);
                        goto bad;
                }
        }
        for (i = 0; i < nel; i++) {
                rc = perm_read(p, &cladatum->permissions, fp);
                if (rc)
                        goto bad;
        }

        rc = read_cons_helper(p, &cladatum->constraints, ncons, 0, fp);
        if (rc)
                goto bad;

        if (p->policyvers >= POLICYDB_VERSION_VALIDATETRANS) {
                /* grab the validatetrans rules */
                rc = next_entry(buf, fp, sizeof(u32));
                if (rc)
                        goto bad;
                ncons = le32_to_cpu(buf[0]);
                rc = read_cons_helper(p, &cladatum->validatetrans,
                                ncons, 1, fp);
                if (rc)
                        goto bad;
        }

        if (p->policyvers >= POLICYDB_VERSION_NEW_OBJECT_DEFAULTS) {
                rc = next_entry(buf, fp, sizeof(u32) * 3);
                if (rc)
                        goto bad;

                cladatum->default_user = le32_to_cpu(buf[0]);
                cladatum->default_role = le32_to_cpu(buf[1]);
                cladatum->default_range = le32_to_cpu(buf[2]);
        }

        if (p->policyvers >= POLICYDB_VERSION_DEFAULT_TYPE) {
                rc = next_entry(buf, fp, sizeof(u32) * 1);
                if (rc)
                        goto bad;
                cladatum->default_type = le32_to_cpu(buf[0]);
        }

        rc = symtab_insert(s, key, cladatum);
        if (rc)
                goto bad;

        return 0;
bad:
        cls_destroy(key, cladatum, NULL);
        return rc;
}

static int role_read(struct policydb *p, struct symtab *s, void *fp)
{
        char *key = NULL;
        struct role_datum *role;
        int rc, to_read = 2;
        __le32 buf[3];
        u32 len;

        role = kzalloc(sizeof(*role), GFP_KERNEL);
        if (!role)
                return -ENOMEM;

        if (p->policyvers >= POLICYDB_VERSION_BOUNDARY)
                to_read = 3;

        rc = next_entry(buf, fp, sizeof(buf[0]) * to_read);
        if (rc)
                goto bad;

        len = le32_to_cpu(buf[0]);
        role->value = le32_to_cpu(buf[1]);
        if (p->policyvers >= POLICYDB_VERSION_BOUNDARY)
                role->bounds = le32_to_cpu(buf[2]);

        rc = str_read(&key, GFP_KERNEL, fp, len);
        if (rc)
                goto bad;

        rc = ebitmap_read(&role->dominates, fp);
        if (rc)
                goto bad;

        rc = ebitmap_read(&role->types, fp);
        if (rc)
                goto bad;

        if (strcmp(key, OBJECT_R) == 0) {
                rc = -EINVAL;
                if (role->value != OBJECT_R_VAL) {
                        pr_err("SELinux: Role %s has wrong value %d\n",
                               OBJECT_R, role->value);
                        goto bad;
                }
                rc = 0;
                goto bad;
        }

        rc = symtab_insert(s, key, role);
        if (rc)
                goto bad;
        return 0;
bad:
        role_destroy(key, role, NULL);
        return rc;
}

static int type_read(struct policydb *p, struct symtab *s, void *fp)
{
        char *key = NULL;
        struct type_datum *typdatum;
        int rc, to_read = 3;
        __le32 buf[4];
        u32 len;

        typdatum = kzalloc(sizeof(*typdatum), GFP_KERNEL);
        if (!typdatum)
                return -ENOMEM;

        if (p->policyvers >= POLICYDB_VERSION_BOUNDARY)
                to_read = 4;

        rc = next_entry(buf, fp, sizeof(buf[0]) * to_read);
        if (rc)
                goto bad;

        len = le32_to_cpu(buf[0]);
        typdatum->value = le32_to_cpu(buf[1]);
        if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) {
                u32 prop = le32_to_cpu(buf[2]);

                if (prop & TYPEDATUM_PROPERTY_PRIMARY)
                        typdatum->primary = 1;
                if (prop & TYPEDATUM_PROPERTY_ATTRIBUTE)
                        typdatum->attribute = 1;

                typdatum->bounds = le32_to_cpu(buf[3]);
        } else {
                typdatum->primary = le32_to_cpu(buf[2]);
        }

        rc = str_read(&key, GFP_KERNEL, fp, len);
        if (rc)
                goto bad;

        rc = symtab_insert(s, key, typdatum);
        if (rc)
                goto bad;
        return 0;
bad:
        type_destroy(key, typdatum, NULL);
        return rc;
}


/*
 * Read a MLS level structure from a policydb binary
 * representation file.
 */
static int mls_read_level(struct mls_level *lp, void *fp)
{
        __le32 buf[1];
        int rc;

        memset(lp, 0, sizeof(*lp));

        rc = next_entry(buf, fp, sizeof buf);
        if (rc) {
                pr_err("SELinux: mls: truncated level\n");
                return rc;
        }
        lp->sens = le32_to_cpu(buf[0]);

        rc = ebitmap_read(&lp->cat, fp);
        if (rc) {
                pr_err("SELinux: mls:  error reading level categories\n");
                return rc;
        }
        return 0;
}

static int user_read(struct policydb *p, struct symtab *s, void *fp)
{
        char *key = NULL;
        struct user_datum *usrdatum;
        int rc, to_read = 2;
        __le32 buf[3];
        u32 len;

        usrdatum = kzalloc(sizeof(*usrdatum), GFP_KERNEL);
        if (!usrdatum)
                return -ENOMEM;

        if (p->policyvers >= POLICYDB_VERSION_BOUNDARY)
                to_read = 3;

        rc = next_entry(buf, fp, sizeof(buf[0]) * to_read);
        if (rc)
                goto bad;

        len = le32_to_cpu(buf[0]);
        usrdatum->value = le32_to_cpu(buf[1]);
        if (p->policyvers >= POLICYDB_VERSION_BOUNDARY)
                usrdatum->bounds = le32_to_cpu(buf[2]);

        rc = str_read(&key, GFP_KERNEL, fp, len);
        if (rc)
                goto bad;

        rc = ebitmap_read(&usrdatum->roles, fp);
        if (rc)
                goto bad;

        if (p->policyvers >= POLICYDB_VERSION_MLS) {
                rc = mls_read_range_helper(&usrdatum->range, fp);
                if (rc)
                        goto bad;
                rc = mls_read_level(&usrdatum->dfltlevel, fp);
                if (rc)
                        goto bad;
        }

        rc = symtab_insert(s, key, usrdatum);
        if (rc)
                goto bad;
        return 0;
bad:
        user_destroy(key, usrdatum, NULL);
        return rc;
}

static int sens_read(struct policydb *p, struct symtab *s, void *fp)
{
        char *key = NULL;
        struct level_datum *levdatum;
        int rc;
        __le32 buf[2];
        u32 len;

        levdatum = kzalloc(sizeof(*levdatum), GFP_ATOMIC);
        if (!levdatum)
                return -ENOMEM;

        rc = next_entry(buf, fp, sizeof buf);
        if (rc)
                goto bad;

        len = le32_to_cpu(buf[0]);
        levdatum->isalias = le32_to_cpu(buf[1]);

        rc = str_read(&key, GFP_ATOMIC, fp, len);
        if (rc)
                goto bad;

        rc = -ENOMEM;
        levdatum->level = kmalloc(sizeof(*levdatum->level), GFP_ATOMIC);
        if (!levdatum->level)
                goto bad;

        rc = mls_read_level(levdatum->level, fp);
        if (rc)
                goto bad;

        rc = symtab_insert(s, key, levdatum);
        if (rc)
                goto bad;
        return 0;
bad:
        sens_destroy(key, levdatum, NULL);
        return rc;
}

static int cat_read(struct policydb *p, struct symtab *s, void *fp)
{
        char *key = NULL;
        struct cat_datum *catdatum;
        int rc;
        __le32 buf[3];
        u32 len;

        catdatum = kzalloc(sizeof(*catdatum), GFP_ATOMIC);
        if (!catdatum)
                return -ENOMEM;

        rc = next_entry(buf, fp, sizeof buf);
        if (rc)
                goto bad;

        len = le32_to_cpu(buf[0]);
        catdatum->value = le32_to_cpu(buf[1]);
        catdatum->isalias = le32_to_cpu(buf[2]);

        rc = str_read(&key, GFP_ATOMIC, fp, len);
        if (rc)
                goto bad;

        rc = symtab_insert(s, key, catdatum);
        if (rc)
                goto bad;
        return 0;
bad:
        cat_destroy(key, catdatum, NULL);
        return rc;
}

static int (*read_f[SYM_NUM]) (struct policydb *p, struct symtab *s, void *fp) =
{
        common_read,
        class_read,
        role_read,
        type_read,
        user_read,
        cond_read_bool,
        sens_read,
        cat_read,
};

static int user_bounds_sanity_check(void *key, void *datum, void *datap)
{
        struct user_datum *upper, *user;
        struct policydb *p = datap;
        int depth = 0;

        upper = user = datum;
        while (upper->bounds) {
                struct ebitmap_node *node;
                unsigned long bit;

                if (++depth == POLICYDB_BOUNDS_MAXDEPTH) {
                        pr_err("SELinux: user %s: "
                               "too deep or looped boundary",
                               (char *) key);
                        return -EINVAL;
                }

                upper = p->user_val_to_struct[upper->bounds - 1];
                ebitmap_for_each_positive_bit(&user->roles, node, bit) {
                        if (ebitmap_get_bit(&upper->roles, bit))
                                continue;

                        pr_err("SELinux: boundary violated policy: "
                               "user=%s role=%s bounds=%s\n",
                               sym_name(p, SYM_USERS, user->value - 1),
                               sym_name(p, SYM_ROLES, bit),
                               sym_name(p, SYM_USERS, upper->value - 1));

                        return -EINVAL;
                }
        }

        return 0;
}

static int role_bounds_sanity_check(void *key, void *datum, void *datap)
{
        struct role_datum *upper, *role;
        struct policydb *p = datap;
        int depth = 0;

        upper = role = datum;
        while (upper->bounds) {
                struct ebitmap_node *node;
                unsigned long bit;

                if (++depth == POLICYDB_BOUNDS_MAXDEPTH) {
                        pr_err("SELinux: role %s: "
                               "too deep or looped bounds\n",
                               (char *) key);
                        return -EINVAL;
                }

                upper = p->role_val_to_struct[upper->bounds - 1];
                ebitmap_for_each_positive_bit(&role->types, node, bit) {
                        if (ebitmap_get_bit(&upper->types, bit))
                                continue;

                        pr_err("SELinux: boundary violated policy: "
                               "role=%s type=%s bounds=%s\n",
                               sym_name(p, SYM_ROLES, role->value - 1),
                               sym_name(p, SYM_TYPES, bit),
                               sym_name(p, SYM_ROLES, upper->value - 1));

                        return -EINVAL;
                }
        }

        return 0;
}

static int type_bounds_sanity_check(void *key, void *datum, void *datap)
{
        struct type_datum *upper;
        struct policydb *p = datap;
        int depth = 0;

        upper = datum;
        while (upper->bounds) {
                if (++depth == POLICYDB_BOUNDS_MAXDEPTH) {
                        pr_err("SELinux: type %s: "
                               "too deep or looped boundary\n",
                               (char *) key);
                        return -EINVAL;
                }

                upper = p->type_val_to_struct[upper->bounds - 1];
                BUG_ON(!upper);

                if (upper->attribute) {
                        pr_err("SELinux: type %s: "
                               "bounded by attribute %s",
                               (char *) key,
                               sym_name(p, SYM_TYPES, upper->value - 1));
                        return -EINVAL;
                }
        }

        return 0;
}

static int policydb_bounds_sanity_check(struct policydb *p)
{
        int rc;

        if (p->policyvers < POLICYDB_VERSION_BOUNDARY)
                return 0;

        rc = hashtab_map(&p->p_users.table, user_bounds_sanity_check, p);
        if (rc)
                return rc;

        rc = hashtab_map(&p->p_roles.table, role_bounds_sanity_check, p);
        if (rc)
                return rc;

        rc = hashtab_map(&p->p_types.table, type_bounds_sanity_check, p);
        if (rc)
                return rc;

        return 0;
}

u16 string_to_security_class(struct policydb *p, const char *name)
{
        struct class_datum *cladatum;

        cladatum = symtab_search(&p->p_classes, name);
        if (!cladatum)
                return 0;

        return cladatum->value;
}

u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name)
{
        struct class_datum *cladatum;
        struct perm_datum *perdatum = NULL;
        struct common_datum *comdatum;

        if (!tclass || tclass > p->p_classes.nprim)
                return 0;

        cladatum = p->class_val_to_struct[tclass-1];
        comdatum = cladatum->comdatum;
        if (comdatum)
                perdatum = symtab_search(&comdatum->permissions, name);
        if (!perdatum)
                perdatum = symtab_search(&cladatum->permissions, name);
        if (!perdatum)
                return 0;

        return 1U << (perdatum->value-1);
}

static int range_read(struct policydb *p, void *fp)
{
        struct range_trans *rt = NULL;
        struct mls_range *r = NULL;
        int i, rc;
        __le32 buf[2];
        u32 nel;

        if (p->policyvers < POLICYDB_VERSION_MLS)
                return 0;

        rc = next_entry(buf, fp, sizeof(u32));
        if (rc)
                return rc;

        nel = le32_to_cpu(buf[0]);

        rc = hashtab_init(&p->range_tr, nel);
        if (rc)
                return rc;

        for (i = 0; i < nel; i++) {
                rc = -ENOMEM;
                rt = kzalloc(sizeof(*rt), GFP_KERNEL);
                if (!rt)
                        goto out;

                rc = next_entry(buf, fp, (sizeof(u32) * 2));
                if (rc)
                        goto out;

                rt->source_type = le32_to_cpu(buf[0]);
                rt->target_type = le32_to_cpu(buf[1]);
                if (p->policyvers >= POLICYDB_VERSION_RANGETRANS) {
                        rc = next_entry(buf, fp, sizeof(u32));
                        if (rc)
                                goto out;
                        rt->target_class = le32_to_cpu(buf[0]);
                } else
                        rt->target_class = p->process_class;

                rc = -EINVAL;
                if (!policydb_type_isvalid(p, rt->source_type) ||
                    !policydb_type_isvalid(p, rt->target_type) ||
                    !policydb_class_isvalid(p, rt->target_class))
                        goto out;

                rc = -ENOMEM;
                r = kzalloc(sizeof(*r), GFP_KERNEL);
                if (!r)
                        goto out;

                rc = mls_read_range_helper(r, fp);
                if (rc)
                        goto out;

                rc = -EINVAL;
                if (!mls_range_isvalid(p, r)) {
                        pr_warn("SELinux:  rangetrans:  invalid range\n");
                        goto out;
                }

                rc = hashtab_insert(&p->range_tr, rt, r, rangetr_key_params);
                if (rc)
                        goto out;

                rt = NULL;
                r = NULL;
        }
        hash_eval(&p->range_tr, "rangetr");
        rc = 0;
out:
        kfree(rt);
        kfree(r);
        return rc;
}

static int filename_trans_read_helper_compat(struct policydb *p, void *fp)
{
        struct filename_trans_key key, *ft = NULL;
        struct filename_trans_datum *last, *datum = NULL;
        char *name = NULL;
        u32 len, stype, otype;
        __le32 buf[4];
        int rc;

        /* length of the path component string */
        rc = next_entry(buf, fp, sizeof(u32));
        if (rc)
                return rc;
        len = le32_to_cpu(buf[0]);

        /* path component string */
        rc = str_read(&name, GFP_KERNEL, fp, len);
        if (rc)
                return rc;

        rc = next_entry(buf, fp, sizeof(u32) * 4);
        if (rc)
                goto out;

        stype = le32_to_cpu(buf[0]);
        key.ttype = le32_to_cpu(buf[1]);
        key.tclass = le32_to_cpu(buf[2]);
        key.name = name;

        otype = le32_to_cpu(buf[3]);

        last = NULL;
        datum = policydb_filenametr_search(p, &key);
        while (datum) {
                if (unlikely(ebitmap_get_bit(&datum->stypes, stype - 1))) {
                        /* conflicting/duplicate rules are ignored */
                        datum = NULL;
                        goto out;
                }
                if (likely(datum->otype == otype))
                        break;
                last = datum;
                datum = datum->next;
        }
        if (!datum) {
                rc = -ENOMEM;
                datum = kmalloc(sizeof(*datum), GFP_KERNEL);
                if (!datum)
                        goto out;

                ebitmap_init(&datum->stypes);
                datum->otype = otype;
                datum->next = NULL;

                if (unlikely(last)) {
                        last->next = datum;
                } else {
                        rc = -ENOMEM;
                        ft = kmemdup(&key, sizeof(key), GFP_KERNEL);
                        if (!ft)
                                goto out;

                        rc = hashtab_insert(&p->filename_trans, ft, datum,
                                            filenametr_key_params);
                        if (rc)
                                goto out;
                        name = NULL;

                        rc = ebitmap_set_bit(&p->filename_trans_ttypes,
                                             key.ttype, 1);
                        if (rc)
                                return rc;
                }
        }
        kfree(name);
        return ebitmap_set_bit(&datum->stypes, stype - 1, 1);

out:
        kfree(ft);
        kfree(name);
        kfree(datum);
        return rc;
}

static int filename_trans_read_helper(struct policydb *p, void *fp)
{
        struct filename_trans_key *ft = NULL;
        struct filename_trans_datum **dst, *datum, *first = NULL;
        char *name = NULL;
        u32 len, ttype, tclass, ndatum, i;
        __le32 buf[3];
        int rc;

        /* length of the path component string */
        rc = next_entry(buf, fp, sizeof(u32));
        if (rc)
                return rc;
        len = le32_to_cpu(buf[0]);

        /* path component string */
        rc = str_read(&name, GFP_KERNEL, fp, len);
        if (rc)
                return rc;

        rc = next_entry(buf, fp, sizeof(u32) * 3);
        if (rc)
                goto out;

        ttype = le32_to_cpu(buf[0]);
        tclass = le32_to_cpu(buf[1]);

        ndatum = le32_to_cpu(buf[2]);

        if (ndatum == 0) {
                pr_err("SELinux:  Filename transition key with no datum\n");
                rc = -ENOENT;
                goto out;
        }

        dst = &first;
        for (i = 0; i < ndatum; i++) {
                rc = -ENOMEM;
                datum = kmalloc(sizeof(*datum), GFP_KERNEL);
                if (!datum)
                        goto out;

                *dst = datum;

                /* ebitmap_read() will at least init the bitmap */
                rc = ebitmap_read(&datum->stypes, fp);
                if (rc)
                        goto out;

                rc = next_entry(buf, fp, sizeof(u32));
                if (rc)
                        goto out;

                datum->otype = le32_to_cpu(buf[0]);
                datum->next = NULL;

                dst = &datum->next;
        }

        rc = -ENOMEM;
        ft = kmalloc(sizeof(*ft), GFP_KERNEL);
        if (!ft)
                goto out;

        ft->ttype = ttype;
        ft->tclass = tclass;
        ft->name = name;

        rc = hashtab_insert(&p->filename_trans, ft, first,
                            filenametr_key_params);
        if (rc == -EEXIST)
                pr_err("SELinux:  Duplicate filename transition key\n");
        if (rc)
                goto out;

        return ebitmap_set_bit(&p->filename_trans_ttypes, ttype, 1);

out:
        kfree(ft);
        kfree(name);
        while (first) {
                datum = first;
                first = first->next;

                ebitmap_destroy(&datum->stypes);
                kfree(datum);
        }
        return rc;
}

static int filename_trans_read(struct policydb *p, void *fp)
{
        u32 nel;
        __le32 buf[1];
        int rc, i;

        if (p->policyvers < POLICYDB_VERSION_FILENAME_TRANS)
                return 0;

        rc = next_entry(buf, fp, sizeof(u32));
        if (rc)
                return rc;
        nel = le32_to_cpu(buf[0]);

        if (p->policyvers < POLICYDB_VERSION_COMP_FTRANS) {
                p->compat_filename_trans_count = nel;

                rc = hashtab_init(&p->filename_trans, (1 << 11));
                if (rc)
                        return rc;

                for (i = 0; i < nel; i++) {
                        rc = filename_trans_read_helper_compat(p, fp);
                        if (rc)
                                return rc;
                }
        } else {
                rc = hashtab_init(&p->filename_trans, nel);
                if (rc)
                        return rc;

                for (i = 0; i < nel; i++) {
                        rc = filename_trans_read_helper(p, fp);
                        if (rc)
                                return rc;
                }
        }
        hash_eval(&p->filename_trans, "filenametr");
        return 0;
}

static int genfs_read(struct policydb *p, void *fp)
{
        int i, j, rc;
        u32 nel, nel2, len, len2;
        __le32 buf[1];
        struct ocontext *l, *c;
        struct ocontext *newc = NULL;
        struct genfs *genfs_p, *genfs;
        struct genfs *newgenfs = NULL;

        rc = next_entry(buf, fp, sizeof(u32));
        if (rc)
                return rc;
        nel = le32_to_cpu(buf[0]);

        for (i = 0; i < nel; i++) {
                rc = next_entry(buf, fp, sizeof(u32));
                if (rc)
                        goto out;
                len = le32_to_cpu(buf[0]);

                rc = -ENOMEM;
                newgenfs = kzalloc(sizeof(*newgenfs), GFP_KERNEL);
                if (!newgenfs)
                        goto out;

                rc = str_read(&newgenfs->fstype, GFP_KERNEL, fp, len);
                if (rc)
                        goto out;

                for (genfs_p = NULL, genfs = p->genfs; genfs;
                     genfs_p = genfs, genfs = genfs->next) {
                        rc = -EINVAL;
                        if (strcmp(newgenfs->fstype, genfs->fstype) == 0) {
                                pr_err("SELinux:  dup genfs fstype %s\n",
                                       newgenfs->fstype);
                                goto out;
                        }
                        if (strcmp(newgenfs->fstype, genfs->fstype) < 0)
                                break;
                }
                newgenfs->next = genfs;
                if (genfs_p)
                        genfs_p->next = newgenfs;
                else
                        p->genfs = newgenfs;
                genfs = newgenfs;
                newgenfs = NULL;

                rc = next_entry(buf, fp, sizeof(u32));
                if (rc)
                        goto out;

                nel2 = le32_to_cpu(buf[0]);
                for (j = 0; j < nel2; j++) {
                        rc = next_entry(buf, fp, sizeof(u32));
                        if (rc)
                                goto out;
                        len = le32_to_cpu(buf[0]);

                        rc = -ENOMEM;
                        newc = kzalloc(sizeof(*newc), GFP_KERNEL);
                        if (!newc)
                                goto out;

                        rc = str_read(&newc->u.name, GFP_KERNEL, fp, len);
                        if (rc)
                                goto out;

                        rc = next_entry(buf, fp, sizeof(u32));
                        if (rc)
                                goto out;

                        newc->v.sclass = le32_to_cpu(buf[0]);
                        rc = context_read_and_validate(&newc->context[0], p, fp);
                        if (rc)
                                goto out;

                        for (l = NULL, c = genfs->head; c;
                             l = c, c = c->next) {
                                rc = -EINVAL;
                                if (!strcmp(newc->u.name, c->u.name) &&
                                    (!c->v.sclass || !newc->v.sclass ||
                                     newc->v.sclass == c->v.sclass)) {
                                        pr_err("SELinux:  dup genfs entry (%s,%s)\n",
                                               genfs->fstype, c->u.name);
                                        goto out;
                                }
                                len = strlen(newc->u.name);
                                len2 = strlen(c->u.name);
                                if (len > len2)
                                        break;
                        }

                        newc->next = c;
                        if (l)
                                l->next = newc;
                        else
                                genfs->head = newc;
                        newc = NULL;
                }
        }
        rc = 0;
out:
        if (newgenfs) {
                kfree(newgenfs->fstype);
                kfree(newgenfs);
        }
        ocontext_destroy(newc, OCON_FSUSE);

        return rc;
}

static int ocontext_read(struct policydb *p, struct policydb_compat_info *info,
                         void *fp)
{
        int i, j, rc;
        u32 nel, len;
        __be64 prefixbuf[1];
        __le32 buf[3];
        struct ocontext *l, *c;
        u32 nodebuf[8];

        for (i = 0; i < info->ocon_num; i++) {
                rc = next_entry(buf, fp, sizeof(u32));
                if (rc)
                        goto out;
                nel = le32_to_cpu(buf[0]);

                l = NULL;
                for (j = 0; j < nel; j++) {
                        rc = -ENOMEM;
                        c = kzalloc(sizeof(*c), GFP_KERNEL);
                        if (!c)
                                goto out;
                        if (l)
                                l->next = c;
                        else
                                p->ocontexts[i] = c;
                        l = c;

                        switch (i) {
                        case OCON_ISID:
                                rc = next_entry(buf, fp, sizeof(u32));
                                if (rc)
                                        goto out;

                                c->sid[0] = le32_to_cpu(buf[0]);
                                rc = context_read_and_validate(&c->context[0], p, fp);
                                if (rc)
                                        goto out;
                                break;
                        case OCON_FS:
                        case OCON_NETIF:
                                rc = next_entry(buf, fp, sizeof(u32));
                                if (rc)
                                        goto out;
                                len = le32_to_cpu(buf[0]);

                                rc = str_read(&c->u.name, GFP_KERNEL, fp, len);
                                if (rc)
                                        goto out;

                                rc = context_read_and_validate(&c->context[0], p, fp);
                                if (rc)
                                        goto out;
                                rc = context_read_and_validate(&c->context[1], p, fp);
                                if (rc)
                                        goto out;
                                break;
                        case OCON_PORT:
                                rc = next_entry(buf, fp, sizeof(u32)*3);
                                if (rc)
                                        goto out;
                                c->u.port.protocol = le32_to_cpu(buf[0]);
                                c->u.port.low_port = le32_to_cpu(buf[1]);
                                c->u.port.high_port = le32_to_cpu(buf[2]);
                                rc = context_read_and_validate(&c->context[0], p, fp);
                                if (rc)
                                        goto out;
                                break;
                        case OCON_NODE:
                                rc = next_entry(nodebuf, fp, sizeof(u32) * 2);
                                if (rc)
                                        goto out;
                                c->u.node.addr = nodebuf[0]; /* network order */
                                c->u.node.mask = nodebuf[1]; /* network order */
                                rc = context_read_and_validate(&c->context[0], p, fp);
                                if (rc)
                                        goto out;
                                break;
                        case OCON_FSUSE:
                                rc = next_entry(buf, fp, sizeof(u32)*2);
                                if (rc)
                                        goto out;

                                rc = -EINVAL;
                                c->v.behavior = le32_to_cpu(buf[0]);
                                /* Determined at runtime, not in policy DB. */
                                if (c->v.behavior == SECURITY_FS_USE_MNTPOINT)
                                        goto out;
                                if (c->v.behavior > SECURITY_FS_USE_MAX)
                                        goto out;

                                len = le32_to_cpu(buf[1]);
                                rc = str_read(&c->u.name, GFP_KERNEL, fp, len);
                                if (rc)
                                        goto out;

                                rc = context_read_and_validate(&c->context[0], p, fp);
                                if (rc)
                                        goto out;
                                break;
                        case OCON_NODE6: {
                                int k;

                                rc = next_entry(nodebuf, fp, sizeof(u32) * 8);
                                if (rc)
                                        goto out;
                                for (k = 0; k < 4; k++)
                                        c->u.node6.addr[k] = nodebuf[k];
                                for (k = 0; k < 4; k++)
                                        c->u.node6.mask[k] = nodebuf[k+4];
                                rc = context_read_and_validate(&c->context[0], p, fp);
                                if (rc)
                                        goto out;
                                break;
                        }
                        case OCON_IBPKEY: {
                                u32 pkey_lo, pkey_hi;

                                rc = next_entry(prefixbuf, fp, sizeof(u64));
                                if (rc)
                                        goto out;

                                /* we need to have subnet_prefix in CPU order */
                                c->u.ibpkey.subnet_prefix = be64_to_cpu(prefixbuf[0]);

                                rc = next_entry(buf, fp, sizeof(u32) * 2);
                                if (rc)
                                        goto out;

                                pkey_lo = le32_to_cpu(buf[0]);
                                pkey_hi = le32_to_cpu(buf[1]);

                                if (pkey_lo > U16_MAX || pkey_hi > U16_MAX) {
                                        rc = -EINVAL;
                                        goto out;
                                }

                                c->u.ibpkey.low_pkey  = pkey_lo;
                                c->u.ibpkey.high_pkey = pkey_hi;

                                rc = context_read_and_validate(&c->context[0],
                                                               p,
                                                               fp);
                                if (rc)
                                        goto out;
                                break;
                        }
                        case OCON_IBENDPORT: {
                                u32 port;

                                rc = next_entry(buf, fp, sizeof(u32) * 2);
                                if (rc)
                                        goto out;
                                len = le32_to_cpu(buf[0]);

                                rc = str_read(&c->u.ibendport.dev_name, GFP_KERNEL, fp, len);
                                if (rc)
                                        goto out;

                                port = le32_to_cpu(buf[1]);
                                if (port > U8_MAX || port == 0) {
                                        rc = -EINVAL;
                                        goto out;
                                }

                                c->u.ibendport.port = port;

                                rc = context_read_and_validate(&c->context[0],
                                                               p,
                                                               fp);
                                if (rc)
                                        goto out;
                                break;
                        } /* end case */
                        } /* end switch */
                }
        }
        rc = 0;
out:
        return rc;
}

/*
 * Read the configuration data from a policy database binary
 * representation file into a policy database structure.
 */
int policydb_read(struct policydb *p, void *fp)
{
        struct role_allow *ra, *lra;
        struct role_trans_key *rtk = NULL;
        struct role_trans_datum *rtd = NULL;
        int i, j, rc;
        __le32 buf[4];
        u32 len, nprim, nel, perm;

        char *policydb_str;
        struct policydb_compat_info *info;

        policydb_init(p);

        /* Read the magic number and string length. */
        rc = next_entry(buf, fp, sizeof(u32) * 2);
        if (rc)
                goto bad;

        rc = -EINVAL;
        if (le32_to_cpu(buf[0]) != POLICYDB_MAGIC) {
                pr_err("SELinux:  policydb magic number 0x%x does "
                       "not match expected magic number 0x%x\n",
                       le32_to_cpu(buf[0]), POLICYDB_MAGIC);
                goto bad;
        }

        rc = -EINVAL;
        len = le32_to_cpu(buf[1]);
        if (len != strlen(POLICYDB_STRING)) {
                pr_err("SELinux:  policydb string length %d does not "
                       "match expected length %zu\n",
                       len, strlen(POLICYDB_STRING));
                goto bad;
        }

        rc = -ENOMEM;
        policydb_str = kmalloc(len + 1, GFP_KERNEL);
        if (!policydb_str) {
                pr_err("SELinux:  unable to allocate memory for policydb "
                       "string of length %d\n", len);
                goto bad;
        }

        rc = next_entry(policydb_str, fp, len);
        if (rc) {
                pr_err("SELinux:  truncated policydb string identifier\n");
                kfree(policydb_str);
                goto bad;
        }

        rc = -EINVAL;
        policydb_str[len] = '\0';
        if (strcmp(policydb_str, POLICYDB_STRING)) {
                pr_err("SELinux:  policydb string %s does not match "
                       "my string %s\n", policydb_str, POLICYDB_STRING);
                kfree(policydb_str);
                goto bad;
        }
        /* Done with policydb_str. */
        kfree(policydb_str);
        policydb_str = NULL;

        /* Read the version and table sizes. */
        rc = next_entry(buf, fp, sizeof(u32)*4);
        if (rc)
                goto bad;

        rc = -EINVAL;
        p->policyvers = le32_to_cpu(buf[0]);
        if (p->policyvers < POLICYDB_VERSION_MIN ||
            p->policyvers > POLICYDB_VERSION_MAX) {
                pr_err("SELinux:  policydb version %d does not match "
                       "my version range %d-%d\n",
                       le32_to_cpu(buf[0]), POLICYDB_VERSION_MIN, POLICYDB_VERSION_MAX);
                goto bad;
        }

        if ((le32_to_cpu(buf[1]) & POLICYDB_CONFIG_MLS)) {
                p->mls_enabled = 1;

                rc = -EINVAL;
                if (p->policyvers < POLICYDB_VERSION_MLS) {
                        pr_err("SELinux: security policydb version %d "
                                "(MLS) not backwards compatible\n",
                                p->policyvers);
                        goto bad;
                }
        }
        p->reject_unknown = !!(le32_to_cpu(buf[1]) & REJECT_UNKNOWN);
        p->allow_unknown = !!(le32_to_cpu(buf[1]) & ALLOW_UNKNOWN);

        if (p->policyvers >= POLICYDB_VERSION_POLCAP) {
                rc = ebitmap_read(&p->policycaps, fp);
                if (rc)
                        goto bad;
        }

        if (p->policyvers >= POLICYDB_VERSION_PERMISSIVE) {
                rc = ebitmap_read(&p->permissive_map, fp);
                if (rc)
                        goto bad;
        }

        rc = -EINVAL;
        info = policydb_lookup_compat(p->policyvers);
        if (!info) {
                pr_err("SELinux:  unable to find policy compat info "
                       "for version %d\n", p->policyvers);
                goto bad;
        }

        rc = -EINVAL;
        if (le32_to_cpu(buf[2]) != info->sym_num ||
                le32_to_cpu(buf[3]) != info->ocon_num) {
                pr_err("SELinux:  policydb table sizes (%d,%d) do "
                       "not match mine (%d,%d)\n", le32_to_cpu(buf[2]),
                        le32_to_cpu(buf[3]),
                       info->sym_num, info->ocon_num);
                goto bad;
        }

        for (i = 0; i < info->sym_num; i++) {
                rc = next_entry(buf, fp, sizeof(u32)*2);
                if (rc)
                        goto bad;
                nprim = le32_to_cpu(buf[0]);
                nel = le32_to_cpu(buf[1]);

                rc = symtab_init(&p->symtab[i], nel);
                if (rc)
                        goto out;

                if (i == SYM_ROLES) {
                        rc = roles_init(p);
                        if (rc)
                                goto out;
                }

                for (j = 0; j < nel; j++) {
                        rc = read_f[i](p, &p->symtab[i], fp);
                        if (rc)
                                goto bad;
                }

                p->symtab[i].nprim = nprim;
        }

        rc = -EINVAL;
        p->process_class = string_to_security_class(p, "process");
        if (!p->process_class) {
                pr_err("SELinux: process class is required, not defined in policy\n");
                goto bad;
        }

        rc = avtab_read(&p->te_avtab, fp, p);
        if (rc)
                goto bad;

        if (p->policyvers >= POLICYDB_VERSION_BOOL) {
                rc = cond_read_list(p, fp);
                if (rc)
                        goto bad;
        }

        rc = next_entry(buf, fp, sizeof(u32));
        if (rc)
                goto bad;
        nel = le32_to_cpu(buf[0]);

        rc = hashtab_init(&p->role_tr, nel);
        if (rc)
                goto bad;
        for (i = 0; i < nel; i++) {
                rc = -ENOMEM;
                rtk = kmalloc(sizeof(*rtk), GFP_KERNEL);
                if (!rtk)
                        goto bad;

                rc = -ENOMEM;
                rtd = kmalloc(sizeof(*rtd), GFP_KERNEL);
                if (!rtd)
                        goto bad;

                rc = next_entry(buf, fp, sizeof(u32)*3);
                if (rc)
                        goto bad;

                rtk->role = le32_to_cpu(buf[0]);
                rtk->type = le32_to_cpu(buf[1]);
                rtd->new_role = le32_to_cpu(buf[2]);
                if (p->policyvers >= POLICYDB_VERSION_ROLETRANS) {
                        rc = next_entry(buf, fp, sizeof(u32));
                        if (rc)
                                goto bad;
                        rtk->tclass = le32_to_cpu(buf[0]);
                } else
                        rtk->tclass = p->process_class;

                rc = -EINVAL;
                if (!policydb_role_isvalid(p, rtk->role) ||
                    !policydb_type_isvalid(p, rtk->type) ||
                    !policydb_class_isvalid(p, rtk->tclass) ||
                    !policydb_role_isvalid(p, rtd->new_role))
                        goto bad;

                rc = hashtab_insert(&p->role_tr, rtk, rtd, roletr_key_params);
                if (rc)
                        goto bad;

                rtk = NULL;
                rtd = NULL;
        }

        rc = next_entry(buf, fp, sizeof(u32));
        if (rc)
                goto bad;
        nel = le32_to_cpu(buf[0]);
        lra = NULL;
        for (i = 0; i < nel; i++) {
                rc = -ENOMEM;
                ra = kzalloc(sizeof(*ra), GFP_KERNEL);
                if (!ra)
                        goto bad;
                if (lra)
                        lra->next = ra;
                else
                        p->role_allow = ra;
                rc = next_entry(buf, fp, sizeof(u32)*2);
                if (rc)
                        goto bad;

                rc = -EINVAL;
                ra->role = le32_to_cpu(buf[0]);
                ra->new_role = le32_to_cpu(buf[1]);
                if (!policydb_role_isvalid(p, ra->role) ||
                    !policydb_role_isvalid(p, ra->new_role))
                        goto bad;
                lra = ra;
        }

        rc = filename_trans_read(p, fp);
        if (rc)
                goto bad;

        rc = policydb_index(p);
        if (rc)
                goto bad;

        rc = -EINVAL;
        perm = string_to_av_perm(p, p->process_class, "transition");
        if (!perm) {
                pr_err("SELinux: process transition permission is required, not defined in policy\n");
                goto bad;
        }
        p->process_trans_perms = perm;
        perm = string_to_av_perm(p, p->process_class, "dyntransition");
        if (!perm) {
                pr_err("SELinux: process dyntransition permission is required, not defined in policy\n");
                goto bad;
        }
        p->process_trans_perms |= perm;

        rc = ocontext_read(p, info, fp);
        if (rc)
                goto bad;

        rc = genfs_read(p, fp);
        if (rc)
                goto bad;

        rc = range_read(p, fp);
        if (rc)
                goto bad;

        rc = -ENOMEM;
        p->type_attr_map_array = kvcalloc(p->p_types.nprim,
                                          sizeof(*p->type_attr_map_array),
                                          GFP_KERNEL);
        if (!p->type_attr_map_array)
                goto bad;

        /* just in case ebitmap_init() becomes more than just a memset(0): */
        for (i = 0; i < p->p_types.nprim; i++)
                ebitmap_init(&p->type_attr_map_array[i]);

        for (i = 0; i < p->p_types.nprim; i++) {
                struct ebitmap *e = &p->type_attr_map_array[i];

                if (p->policyvers >= POLICYDB_VERSION_AVTAB) {
                        rc = ebitmap_read(e, fp);
                        if (rc)
                                goto bad;
                }
                /* add the type itself as the degenerate case */
                rc = ebitmap_set_bit(e, i, 1);
                if (rc)
                        goto bad;
        }

        rc = policydb_bounds_sanity_check(p);
        if (rc)
                goto bad;

        rc = 0;
out:
        return rc;
bad:
        kfree(rtk);
        kfree(rtd);
        policydb_destroy(p);
        goto out;
}

/*
 * Write a MLS level structure to a policydb binary
 * representation file.
 */
static int mls_write_level(struct mls_level *l, void *fp)
{
        __le32 buf[1];
        int rc;

        buf[0] = cpu_to_le32(l->sens);
        rc = put_entry(buf, sizeof(u32), 1, fp);
        if (rc)
                return rc;

        rc = ebitmap_write(&l->cat, fp);
        if (rc)
                return rc;

        return 0;
}

/*
 * Write a MLS range structure to a policydb binary
 * representation file.
 */
static int mls_write_range_helper(struct mls_range *r, void *fp)
{
        __le32 buf[3];
        size_t items;
        int rc, eq;

        eq = mls_level_eq(&r->level[1], &r->level[0]);

        if (eq)
                items = 2;
        else
                items = 3;
        buf[0] = cpu_to_le32(items-1);
        buf[1] = cpu_to_le32(r->level[0].sens);
        if (!eq)
                buf[2] = cpu_to_le32(r->level[1].sens);

        BUG_ON(items > ARRAY_SIZE(buf));

        rc = put_entry(buf, sizeof(u32), items, fp);
        if (rc)
                return rc;

        rc = ebitmap_write(&r->level[0].cat, fp);
        if (rc)
                return rc;
        if (!eq) {
                rc = ebitmap_write(&r->level[1].cat, fp);
                if (rc)
                        return rc;
        }

        return 0;
}

static int sens_write(void *vkey, void *datum, void *ptr)
{
        char *key = vkey;
        struct level_datum *levdatum = datum;
        struct policy_data *pd = ptr;
        void *fp = pd->fp;
        __le32 buf[2];
        size_t len;
        int rc;

        len = strlen(key);
        buf[0] = cpu_to_le32(len);
        buf[1] = cpu_to_le32(levdatum->isalias);
        rc = put_entry(buf, sizeof(u32), 2, fp);
        if (rc)
                return rc;

        rc = put_entry(key, 1, len, fp);
        if (rc)
                return rc;

        rc = mls_write_level(levdatum->level, fp);
        if (rc)
                return rc;

        return 0;
}

static int cat_write(void *vkey, void *datum, void *ptr)
{
        char *key = vkey;
        struct cat_datum *catdatum = datum;
        struct policy_data *pd = ptr;
        void *fp = pd->fp;
        __le32 buf[3];
        size_t len;
        int rc;

        len = strlen(key);
        buf[0] = cpu_to_le32(len);
        buf[1] = cpu_to_le32(catdatum->value);
        buf[2] = cpu_to_le32(catdatum->isalias);
        rc = put_entry(buf, sizeof(u32), 3, fp);
        if (rc)
                return rc;

        rc = put_entry(key, 1, len, fp);
        if (rc)
                return rc;

        return 0;
}

static int role_trans_write_one(void *key, void *datum, void *ptr)
{
        struct role_trans_key *rtk = key;
        struct role_trans_datum *rtd = datum;
        struct policy_data *pd = ptr;
        void *fp = pd->fp;
        struct policydb *p = pd->p;
        __le32 buf[3];
        int rc;

        buf[0] = cpu_to_le32(rtk->role);
        buf[1] = cpu_to_le32(rtk->type);
        buf[2] = cpu_to_le32(rtd->new_role);
        rc = put_entry(buf, sizeof(u32), 3, fp);
        if (rc)
                return rc;
        if (p->policyvers >= POLICYDB_VERSION_ROLETRANS) {
                buf[0] = cpu_to_le32(rtk->tclass);
                rc = put_entry(buf, sizeof(u32), 1, fp);
                if (rc)
                        return rc;
        }
        return 0;
}

static int role_trans_write(struct policydb *p, void *fp)
{
        struct policy_data pd = { .p = p, .fp = fp };
        __le32 buf[1];
        int rc;

        buf[0] = cpu_to_le32(p->role_tr.nel);
        rc = put_entry(buf, sizeof(u32), 1, fp);
        if (rc)
                return rc;

        return hashtab_map(&p->role_tr, role_trans_write_one, &pd);
}

static int role_allow_write(struct role_allow *r, void *fp)
{
        struct role_allow *ra;
        __le32 buf[2];
        size_t nel;
        int rc;

        nel = 0;
        for (ra = r; ra; ra = ra->next)
                nel++;
        buf[0] = cpu_to_le32(nel);
        rc = put_entry(buf, sizeof(u32), 1, fp);
        if (rc)
                return rc;
        for (ra = r; ra; ra = ra->next) {
                buf[0] = cpu_to_le32(ra->role);
                buf[1] = cpu_to_le32(ra->new_role);
                rc = put_entry(buf, sizeof(u32), 2, fp);
                if (rc)
                        return rc;
        }
        return 0;
}

/*
 * Write a security context structure
 * to a policydb binary representation file.
 */
static int context_write(struct policydb *p, struct context *c,
                         void *fp)
{
        int rc;
        __le32 buf[3];

        buf[0] = cpu_to_le32(c->user);
        buf[1] = cpu_to_le32(c->role);
        buf[2] = cpu_to_le32(c->type);

        rc = put_entry(buf, sizeof(u32), 3, fp);
        if (rc)
                return rc;

        rc = mls_write_range_helper(&c->range, fp);
        if (rc)
                return rc;

        return 0;
}

/*
 * The following *_write functions are used to
 * write the symbol data to a policy database
 * binary representation file.
 */

static int perm_write(void *vkey, void *datum, void *fp)
{
        char *key = vkey;
        struct perm_datum *perdatum = datum;
        __le32 buf[2];
        size_t len;
        int rc;

        len = strlen(key);
        buf[0] = cpu_to_le32(len);
        buf[1] = cpu_to_le32(perdatum->value);
        rc = put_entry(buf, sizeof(u32), 2, fp);
        if (rc)
                return rc;

        rc = put_entry(key, 1, len, fp);
        if (rc)
                return rc;

        return 0;
}

static int common_write(void *vkey, void *datum, void *ptr)
{
        char *key = vkey;
        struct common_datum *comdatum = datum;
        struct policy_data *pd = ptr;
        void *fp = pd->fp;
        __le32 buf[4];
        size_t len;
        int rc;

        len = strlen(key);
        buf[0] = cpu_to_le32(len);
        buf[1] = cpu_to_le32(comdatum->value);
        buf[2] = cpu_to_le32(comdatum->permissions.nprim);
        buf[3] = cpu_to_le32(comdatum->permissions.table.nel);
        rc = put_entry(buf, sizeof(u32), 4, fp);
        if (rc)
                return rc;

        rc = put_entry(key, 1, len, fp);
        if (rc)
                return rc;

        rc = hashtab_map(&comdatum->permissions.table, perm_write, fp);
        if (rc)
                return rc;

        return 0;
}

static int type_set_write(struct type_set *t, void *fp)
{
        int rc;
        __le32 buf[1];

        if (ebitmap_write(&t->types, fp))
                return -EINVAL;
        if (ebitmap_write(&t->negset, fp))
                return -EINVAL;

        buf[0] = cpu_to_le32(t->flags);
        rc = put_entry(buf, sizeof(u32), 1, fp);
        if (rc)
                return -EINVAL;

        return 0;
}

static int write_cons_helper(struct policydb *p, struct constraint_node *node,
                             void *fp)
{
        struct constraint_node *c;
        struct constraint_expr *e;
        __le32 buf[3];
        u32 nel;
        int rc;