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services.c

/*
 * Implementation of the security services.
 *
 * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
 *           James Morris <jmorris@redhat.com>
 *
 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
 *
 *    Support for enhanced MLS infrastructure.
 *    Support for context based audit filters.
 *
 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
 *
 *    Added conditional policy language extensions
 *
 * Updated: Hewlett-Packard <paul.moore@hp.com>
 *
 *      Added support for NetLabel
 *
 * Updated: Chad Sellers <csellers@tresys.com>
 *
 *  Added validation of kernel classes and permissions
 *
 * Copyright (C) 2006 Hewlett-Packard Development Company, L.P.
 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
 *    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 <linux/kernel.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/sched.h>
#include <linux/audit.h>
#include <linux/mutex.h>
#include <net/netlabel.h>

#include "flask.h"
#include "avc.h"
#include "avc_ss.h"
#include "security.h"
#include "context.h"
#include "policydb.h"
#include "sidtab.h"
#include "services.h"
#include "conditional.h"
#include "mls.h"
#include "objsec.h"
#include "netlabel.h"
#include "xfrm.h"
#include "ebitmap.h"

extern void selnl_notify_policyload(u32 seqno);
unsigned int policydb_loaded_version;

/*
 * This is declared in avc.c
 */
extern const struct selinux_class_perm selinux_class_perm;

static DEFINE_RWLOCK(policy_rwlock);
#define POLICY_RDLOCK read_lock(&policy_rwlock)
#define POLICY_WRLOCK write_lock_irq(&policy_rwlock)
#define POLICY_RDUNLOCK read_unlock(&policy_rwlock)
#define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock)

static DEFINE_MUTEX(load_mutex);
#define LOAD_LOCK mutex_lock(&load_mutex)
#define LOAD_UNLOCK mutex_unlock(&load_mutex)

static struct sidtab sidtab;
struct policydb policydb;
int ss_initialized = 0;

/*
 * The largest sequence number that has been used when
 * providing an access decision to the access vector cache.
 * The sequence number only changes when a policy change
 * occurs.
 */
static u32 latest_granting = 0;

/* Forward declaration. */
static int context_struct_to_string(struct context *context, char **scontext,
                            u32 *scontext_len);

/*
 * Return the boolean value of a constraint expression
 * when it is applied to the specified source and target
 * security contexts.
 *
 * xcontext is a special beast...  It is used by the validatetrans rules
 * only.  For these rules, scontext is the context before the transition,
 * tcontext is the context after the transition, and xcontext is the context
 * of the process performing the transition.  All other callers of
 * constraint_expr_eval should pass in NULL for xcontext.
 */
static int constraint_expr_eval(struct context *scontext,
                        struct context *tcontext,
                        struct context *xcontext,
                        struct constraint_expr *cexpr)
{
      u32 val1, val2;
      struct context *c;
      struct role_datum *r1, *r2;
      struct mls_level *l1, *l2;
      struct constraint_expr *e;
      int s[CEXPR_MAXDEPTH];
      int sp = -1;

      for (e = cexpr; e; e = e->next) {
            switch (e->expr_type) {
            case CEXPR_NOT:
                  BUG_ON(sp < 0);
                  s[sp] = !s[sp];
                  break;
            case CEXPR_AND:
                  BUG_ON(sp < 1);
                  sp--;
                  s[sp] &= s[sp+1];
                  break;
            case CEXPR_OR:
                  BUG_ON(sp < 1);
                  sp--;
                  s[sp] |= s[sp+1];
                  break;
            case CEXPR_ATTR:
                  if (sp == (CEXPR_MAXDEPTH-1))
                        return 0;
                  switch (e->attr) {
                  case CEXPR_USER:
                        val1 = scontext->user;
                        val2 = tcontext->user;
                        break;
                  case CEXPR_TYPE:
                        val1 = scontext->type;
                        val2 = tcontext->type;
                        break;
                  case CEXPR_ROLE:
                        val1 = scontext->role;
                        val2 = tcontext->role;
                        r1 = policydb.role_val_to_struct[val1 - 1];
                        r2 = policydb.role_val_to_struct[val2 - 1];
                        switch (e->op) {
                        case CEXPR_DOM:
                              s[++sp] = ebitmap_get_bit(&r1->dominates,
                                                  val2 - 1);
                              continue;
                        case CEXPR_DOMBY:
                              s[++sp] = ebitmap_get_bit(&r2->dominates,
                                                  val1 - 1);
                              continue;
                        case CEXPR_INCOMP:
                              s[++sp] = ( !ebitmap_get_bit(&r1->dominates,
                                                     val2 - 1) &&
                                        !ebitmap_get_bit(&r2->dominates,
                                                     val1 - 1) );
                              continue;
                        default:
                              break;
                        }
                        break;
                  case CEXPR_L1L2:
                        l1 = &(scontext->range.level[0]);
                        l2 = &(tcontext->range.level[0]);
                        goto mls_ops;
                  case CEXPR_L1H2:
                        l1 = &(scontext->range.level[0]);
                        l2 = &(tcontext->range.level[1]);
                        goto mls_ops;
                  case CEXPR_H1L2:
                        l1 = &(scontext->range.level[1]);
                        l2 = &(tcontext->range.level[0]);
                        goto mls_ops;
                  case CEXPR_H1H2:
                        l1 = &(scontext->range.level[1]);
                        l2 = &(tcontext->range.level[1]);
                        goto mls_ops;
                  case CEXPR_L1H1:
                        l1 = &(scontext->range.level[0]);
                        l2 = &(scontext->range.level[1]);
                        goto mls_ops;
                  case CEXPR_L2H2:
                        l1 = &(tcontext->range.level[0]);
                        l2 = &(tcontext->range.level[1]);
                        goto mls_ops;
mls_ops:
                  switch (e->op) {
                  case CEXPR_EQ:
                        s[++sp] = mls_level_eq(l1, l2);
                        continue;
                  case CEXPR_NEQ:
                        s[++sp] = !mls_level_eq(l1, l2);
                        continue;
                  case CEXPR_DOM:
                        s[++sp] = mls_level_dom(l1, l2);
                        continue;
                  case CEXPR_DOMBY:
                        s[++sp] = mls_level_dom(l2, l1);
                        continue;
                  case CEXPR_INCOMP:
                        s[++sp] = mls_level_incomp(l2, l1);
                        continue;
                  default:
                        BUG();
                        return 0;
                  }
                  break;
                  default:
                        BUG();
                        return 0;
                  }

                  switch (e->op) {
                  case CEXPR_EQ:
                        s[++sp] = (val1 == val2);
                        break;
                  case CEXPR_NEQ:
                        s[++sp] = (val1 != val2);
                        break;
                  default:
                        BUG();
                        return 0;
                  }
                  break;
            case CEXPR_NAMES:
                  if (sp == (CEXPR_MAXDEPTH-1))
                        return 0;
                  c = scontext;
                  if (e->attr & CEXPR_TARGET)
                        c = tcontext;
                  else if (e->attr & CEXPR_XTARGET) {
                        c = xcontext;
                        if (!c) {
                              BUG();
                              return 0;
                        }
                  }
                  if (e->attr & CEXPR_USER)
                        val1 = c->user;
                  else if (e->attr & CEXPR_ROLE)
                        val1 = c->role;
                  else if (e->attr & CEXPR_TYPE)
                        val1 = c->type;
                  else {
                        BUG();
                        return 0;
                  }

                  switch (e->op) {
                  case CEXPR_EQ:
                        s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
                        break;
                  case CEXPR_NEQ:
                        s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
                        break;
                  default:
                        BUG();
                        return 0;
                  }
                  break;
            default:
                  BUG();
                  return 0;
            }
      }

      BUG_ON(sp != 0);
      return s[0];
}

/*
 * Compute access vectors based on a context structure pair for
 * the permissions in a particular class.
 */
static int context_struct_compute_av(struct context *scontext,
                             struct context *tcontext,
                             u16 tclass,
                             u32 requested,
                             struct av_decision *avd)
{
      struct constraint_node *constraint;
      struct role_allow *ra;
      struct avtab_key avkey;
      struct avtab_node *node;
      struct class_datum *tclass_datum;
      struct ebitmap *sattr, *tattr;
      struct ebitmap_node *snode, *tnode;
      const struct selinux_class_perm *kdefs = &selinux_class_perm;
      unsigned int i, j;

      /*
       * Remap extended Netlink classes for old policy versions.
       * Do this here rather than socket_type_to_security_class()
       * in case a newer policy version is loaded, allowing sockets
       * to remain in the correct class.
       */
      if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
            if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
                tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
                  tclass = SECCLASS_NETLINK_SOCKET;

      /*
       * Initialize the access vectors to the default values.
       */
      avd->allowed = 0;
      avd->decided = 0xffffffff;
      avd->auditallow = 0;
      avd->auditdeny = 0xffffffff;
      avd->seqno = latest_granting;

      /*
       * Check for all the invalid cases.
       * - tclass 0
       * - tclass > policy and > kernel
       * - tclass > policy but is a userspace class
       * - tclass > policy but we do not allow unknowns
       */
      if (unlikely(!tclass))
            goto inval_class;
      if (unlikely(tclass > policydb.p_classes.nprim))
            if (tclass > kdefs->cts_len ||
                !kdefs->class_to_string[tclass - 1] ||
                !policydb.allow_unknown)
                  goto inval_class;

      /*
       * Kernel class and we allow unknown so pad the allow decision
       * the pad will be all 1 for unknown classes.
       */
      if (tclass <= kdefs->cts_len && policydb.allow_unknown)
            avd->allowed = policydb.undefined_perms[tclass - 1];

      /*
       * Not in policy. Since decision is completed (all 1 or all 0) return.
       */
      if (unlikely(tclass > policydb.p_classes.nprim))
            return 0;

      tclass_datum = policydb.class_val_to_struct[tclass - 1];

      /*
       * If a specific type enforcement rule was defined for
       * this permission check, then use it.
       */
      avkey.target_class = tclass;
      avkey.specified = AVTAB_AV;
      sattr = &policydb.type_attr_map[scontext->type - 1];
      tattr = &policydb.type_attr_map[tcontext->type - 1];
      ebitmap_for_each_positive_bit(sattr, snode, i) {
            ebitmap_for_each_positive_bit(tattr, tnode, j) {
                  avkey.source_type = i + 1;
                  avkey.target_type = j + 1;
                  for (node = avtab_search_node(&policydb.te_avtab, &avkey);
                       node != NULL;
                       node = avtab_search_node_next(node, avkey.specified)) {
                        if (node->key.specified == AVTAB_ALLOWED)
                              avd->allowed |= node->datum.data;
                        else if (node->key.specified == AVTAB_AUDITALLOW)
                              avd->auditallow |= node->datum.data;
                        else if (node->key.specified == AVTAB_AUDITDENY)
                              avd->auditdeny &= node->datum.data;
                  }

                  /* Check conditional av table for additional permissions */
                  cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);

            }
      }

      /*
       * Remove any permissions prohibited by a constraint (this includes
       * the MLS policy).
       */
      constraint = tclass_datum->constraints;
      while (constraint) {
            if ((constraint->permissions & (avd->allowed)) &&
                !constraint_expr_eval(scontext, tcontext, NULL,
                                constraint->expr)) {
                  avd->allowed = (avd->allowed) & ~(constraint->permissions);
            }
            constraint = constraint->next;
      }

      /*
       * If checking process transition permission and the
       * role is changing, then check the (current_role, new_role)
       * pair.
       */
      if (tclass == SECCLASS_PROCESS &&
          (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
          scontext->role != tcontext->role) {
            for (ra = policydb.role_allow; ra; ra = ra->next) {
                  if (scontext->role == ra->role &&
                      tcontext->role == ra->new_role)
                        break;
            }
            if (!ra)
                  avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
                                                  PROCESS__DYNTRANSITION);
      }

      return 0;

inval_class:
      printk(KERN_ERR "%s:  unrecognized class %d\n", __FUNCTION__, tclass);
      return -EINVAL;
}

static int security_validtrans_handle_fail(struct context *ocontext,
                                           struct context *ncontext,
                                           struct context *tcontext,
                                           u16 tclass)
{
      char *o = NULL, *n = NULL, *t = NULL;
      u32 olen, nlen, tlen;

      if (context_struct_to_string(ocontext, &o, &olen) < 0)
            goto out;
      if (context_struct_to_string(ncontext, &n, &nlen) < 0)
            goto out;
      if (context_struct_to_string(tcontext, &t, &tlen) < 0)
            goto out;
      audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
                "security_validate_transition:  denied for"
                " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
                o, n, t, policydb.p_class_val_to_name[tclass-1]);
out:
      kfree(o);
      kfree(n);
      kfree(t);

      if (!selinux_enforcing)
            return 0;
      return -EPERM;
}

int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
                                 u16 tclass)
{
      struct context *ocontext;
      struct context *ncontext;
      struct context *tcontext;
      struct class_datum *tclass_datum;
      struct constraint_node *constraint;
      int rc = 0;

      if (!ss_initialized)
            return 0;

      POLICY_RDLOCK;

      /*
       * Remap extended Netlink classes for old policy versions.
       * Do this here rather than socket_type_to_security_class()
       * in case a newer policy version is loaded, allowing sockets
       * to remain in the correct class.
       */
      if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
            if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
                tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
                  tclass = SECCLASS_NETLINK_SOCKET;

      if (!tclass || tclass > policydb.p_classes.nprim) {
            printk(KERN_ERR "security_validate_transition:  "
                   "unrecognized class %d\n", tclass);
            rc = -EINVAL;
            goto out;
      }
      tclass_datum = policydb.class_val_to_struct[tclass - 1];

      ocontext = sidtab_search(&sidtab, oldsid);
      if (!ocontext) {
            printk(KERN_ERR "security_validate_transition: "
                   " unrecognized SID %d\n", oldsid);
            rc = -EINVAL;
            goto out;
      }

      ncontext = sidtab_search(&sidtab, newsid);
      if (!ncontext) {
            printk(KERN_ERR "security_validate_transition: "
                   " unrecognized SID %d\n", newsid);
            rc = -EINVAL;
            goto out;
      }

      tcontext = sidtab_search(&sidtab, tasksid);
      if (!tcontext) {
            printk(KERN_ERR "security_validate_transition: "
                   " unrecognized SID %d\n", tasksid);
            rc = -EINVAL;
            goto out;
      }

      constraint = tclass_datum->validatetrans;
      while (constraint) {
            if (!constraint_expr_eval(ocontext, ncontext, tcontext,
                                      constraint->expr)) {
                  rc = security_validtrans_handle_fail(ocontext, ncontext,
                                                       tcontext, tclass);
                  goto out;
            }
            constraint = constraint->next;
      }

out:
      POLICY_RDUNLOCK;
      return rc;
}

/**
 * security_compute_av - Compute access vector decisions.
 * @ssid: source security identifier
 * @tsid: target security identifier
 * @tclass: target security class
 * @requested: requested permissions
 * @avd: access vector decisions
 *
 * Compute a set of access vector decisions based on the
 * SID pair (@ssid, @tsid) for the permissions in @tclass.
 * Return -%EINVAL if any of the parameters are invalid or %0
 * if the access vector decisions were computed successfully.
 */
int security_compute_av(u32 ssid,
                  u32 tsid,
                  u16 tclass,
                  u32 requested,
                  struct av_decision *avd)
{
      struct context *scontext = NULL, *tcontext = NULL;
      int rc = 0;

      if (!ss_initialized) {
            avd->allowed = 0xffffffff;
            avd->decided = 0xffffffff;
            avd->auditallow = 0;
            avd->auditdeny = 0xffffffff;
            avd->seqno = latest_granting;
            return 0;
      }

      POLICY_RDLOCK;

      scontext = sidtab_search(&sidtab, ssid);
      if (!scontext) {
            printk(KERN_ERR "security_compute_av:  unrecognized SID %d\n",
                   ssid);
            rc = -EINVAL;
            goto out;
      }
      tcontext = sidtab_search(&sidtab, tsid);
      if (!tcontext) {
            printk(KERN_ERR "security_compute_av:  unrecognized SID %d\n",
                   tsid);
            rc = -EINVAL;
            goto out;
      }

      rc = context_struct_compute_av(scontext, tcontext, tclass,
                               requested, avd);
out:
      POLICY_RDUNLOCK;
      return rc;
}

/*
 * Write the security context string representation of
 * the context structure `context' into a dynamically
 * allocated string of the correct size.  Set `*scontext'
 * to point to this string and set `*scontext_len' to
 * the length of the string.
 */
static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
{
      char *scontextp;

      *scontext = NULL;
      *scontext_len = 0;

      /* Compute the size of the context. */
      *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
      *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
      *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
      *scontext_len += mls_compute_context_len(context);

      /* Allocate space for the context; caller must free this space. */
      scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
      if (!scontextp) {
            return -ENOMEM;
      }
      *scontext = scontextp;

      /*
       * Copy the user name, role name and type name into the context.
       */
      sprintf(scontextp, "%s:%s:%s",
            policydb.p_user_val_to_name[context->user - 1],
            policydb.p_role_val_to_name[context->role - 1],
            policydb.p_type_val_to_name[context->type - 1]);
      scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
                   1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
                   1 + strlen(policydb.p_type_val_to_name[context->type - 1]);

      mls_sid_to_context(context, &scontextp);

      *scontextp = 0;

      return 0;
}

#include "initial_sid_to_string.h"

const char *security_get_initial_sid_context(u32 sid)
{
      if (unlikely(sid > SECINITSID_NUM))
            return NULL;
      return initial_sid_to_string[sid];
}

/**
 * security_sid_to_context - Obtain a context for a given SID.
 * @sid: security identifier, SID
 * @scontext: security context
 * @scontext_len: length in bytes
 *
 * Write the string representation of the context associated with @sid
 * into a dynamically allocated string of the correct size.  Set @scontext
 * to point to this string and set @scontext_len to the length of the string.
 */
int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
{
      struct context *context;
      int rc = 0;

      *scontext = NULL;
      *scontext_len  = 0;

      if (!ss_initialized) {
            if (sid <= SECINITSID_NUM) {
                  char *scontextp;

                  *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
                  scontextp = kmalloc(*scontext_len,GFP_ATOMIC);
                  if (!scontextp) {
                        rc = -ENOMEM;
                        goto out;
                  }
                  strcpy(scontextp, initial_sid_to_string[sid]);
                  *scontext = scontextp;
                  goto out;
            }
            printk(KERN_ERR "security_sid_to_context:  called before initial "
                   "load_policy on unknown SID %d\n", sid);
            rc = -EINVAL;
            goto out;
      }
      POLICY_RDLOCK;
      context = sidtab_search(&sidtab, sid);
      if (!context) {
            printk(KERN_ERR "security_sid_to_context:  unrecognized SID "
                   "%d\n", sid);
            rc = -EINVAL;
            goto out_unlock;
      }
      rc = context_struct_to_string(context, scontext, scontext_len);
out_unlock:
      POLICY_RDUNLOCK;
out:
      return rc;

}

static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
{
      char *scontext2;
      struct context context;
      struct role_datum *role;
      struct type_datum *typdatum;
      struct user_datum *usrdatum;
      char *scontextp, *p, oldc;
      int rc = 0;

      if (!ss_initialized) {
            int i;

            for (i = 1; i < SECINITSID_NUM; i++) {
                  if (!strcmp(initial_sid_to_string[i], scontext)) {
                        *sid = i;
                        goto out;
                  }
            }
            *sid = SECINITSID_KERNEL;
            goto out;
      }
      *sid = SECSID_NULL;

      /* Copy the string so that we can modify the copy as we parse it.
         The string should already by null terminated, but we append a
         null suffix to the copy to avoid problems with the existing
         attr package, which doesn't view the null terminator as part
         of the attribute value. */
      scontext2 = kmalloc(scontext_len+1,GFP_KERNEL);
      if (!scontext2) {
            rc = -ENOMEM;
            goto out;
      }
      memcpy(scontext2, scontext, scontext_len);
      scontext2[scontext_len] = 0;

      context_init(&context);
      *sid = SECSID_NULL;

      POLICY_RDLOCK;

      /* Parse the security context. */

      rc = -EINVAL;
      scontextp = (char *) scontext2;

      /* Extract the user. */
      p = scontextp;
      while (*p && *p != ':')
            p++;

      if (*p == 0)
            goto out_unlock;

      *p++ = 0;

      usrdatum = hashtab_search(policydb.p_users.table, scontextp);
      if (!usrdatum)
            goto out_unlock;

      context.user = usrdatum->value;

      /* Extract role. */
      scontextp = p;
      while (*p && *p != ':')
            p++;

      if (*p == 0)
            goto out_unlock;

      *p++ = 0;

      role = hashtab_search(policydb.p_roles.table, scontextp);
      if (!role)
            goto out_unlock;
      context.role = role->value;

      /* Extract type. */
      scontextp = p;
      while (*p && *p != ':')
            p++;
      oldc = *p;
      *p++ = 0;

      typdatum = hashtab_search(policydb.p_types.table, scontextp);
      if (!typdatum)
            goto out_unlock;

      context.type = typdatum->value;

      rc = mls_context_to_sid(oldc, &p, &context, &sidtab, def_sid);
      if (rc)
            goto out_unlock;

      if ((p - scontext2) < scontext_len) {
            rc = -EINVAL;
            goto out_unlock;
      }

      /* Check the validity of the new context. */
      if (!policydb_context_isvalid(&policydb, &context)) {
            rc = -EINVAL;
            goto out_unlock;
      }
      /* Obtain the new sid. */
      rc = sidtab_context_to_sid(&sidtab, &context, sid);
out_unlock:
      POLICY_RDUNLOCK;
      context_destroy(&context);
      kfree(scontext2);
out:
      return rc;
}

/**
 * security_context_to_sid - Obtain a SID for a given security context.
 * @scontext: security context
 * @scontext_len: length in bytes
 * @sid: security identifier, SID
 *
 * Obtains a SID associated with the security context that
 * has the string representation specified by @scontext.
 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
 * memory is available, or 0 on success.
 */
int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid)
{
      return security_context_to_sid_core(scontext, scontext_len,
                                          sid, SECSID_NULL);
}

/**
 * security_context_to_sid_default - Obtain a SID for a given security context,
 * falling back to specified default if needed.
 *
 * @scontext: security context
 * @scontext_len: length in bytes
 * @sid: security identifier, SID
 * @def_sid: default SID to assign on error
 *
 * Obtains a SID associated with the security context that
 * has the string representation specified by @scontext.
 * The default SID is passed to the MLS layer to be used to allow
 * kernel labeling of the MLS field if the MLS field is not present
 * (for upgrading to MLS without full relabel).
 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
 * memory is available, or 0 on success.
 */
int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
{
      return security_context_to_sid_core(scontext, scontext_len,
                                          sid, def_sid);
}

static int compute_sid_handle_invalid_context(
      struct context *scontext,
      struct context *tcontext,
      u16 tclass,
      struct context *newcontext)
{
      char *s = NULL, *t = NULL, *n = NULL;
      u32 slen, tlen, nlen;

      if (context_struct_to_string(scontext, &s, &slen) < 0)
            goto out;
      if (context_struct_to_string(tcontext, &t, &tlen) < 0)
            goto out;
      if (context_struct_to_string(newcontext, &n, &nlen) < 0)
            goto out;
      audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
              "security_compute_sid:  invalid context %s"
              " for scontext=%s"
              " tcontext=%s"
              " tclass=%s",
              n, s, t, policydb.p_class_val_to_name[tclass-1]);
out:
      kfree(s);
      kfree(t);
      kfree(n);
      if (!selinux_enforcing)
            return 0;
      return -EACCES;
}

static int security_compute_sid(u32 ssid,
                        u32 tsid,
                        u16 tclass,
                        u32 specified,
                        u32 *out_sid)
{
      struct context *scontext = NULL, *tcontext = NULL, newcontext;
      struct role_trans *roletr = NULL;
      struct avtab_key avkey;
      struct avtab_datum *avdatum;
      struct avtab_node *node;
      int rc = 0;

      if (!ss_initialized) {
            switch (tclass) {
            case SECCLASS_PROCESS:
                  *out_sid = ssid;
                  break;
            default:
                  *out_sid = tsid;
                  break;
            }
            goto out;
      }

      context_init(&newcontext);

      POLICY_RDLOCK;

      scontext = sidtab_search(&sidtab, ssid);
      if (!scontext) {
            printk(KERN_ERR "security_compute_sid:  unrecognized SID %d\n",
                   ssid);
            rc = -EINVAL;
            goto out_unlock;
      }
      tcontext = sidtab_search(&sidtab, tsid);
      if (!tcontext) {
            printk(KERN_ERR "security_compute_sid:  unrecognized SID %d\n",
                   tsid);
            rc = -EINVAL;
            goto out_unlock;
      }

      /* Set the user identity. */
      switch (specified) {
      case AVTAB_TRANSITION:
      case AVTAB_CHANGE:
            /* Use the process user identity. */
            newcontext.user = scontext->user;
            break;
      case AVTAB_MEMBER:
            /* Use the related object owner. */
            newcontext.user = tcontext->user;
            break;
      }

      /* Set the role and type to default values. */
      switch (tclass) {
      case SECCLASS_PROCESS:
            /* Use the current role and type of process. */
            newcontext.role = scontext->role;
            newcontext.type = scontext->type;
            break;
      default:
            /* Use the well-defined object role. */
            newcontext.role = OBJECT_R_VAL;
            /* Use the type of the related object. */
            newcontext.type = tcontext->type;
      }

      /* Look for a type transition/member/change rule. */
      avkey.source_type = scontext->type;
      avkey.target_type = tcontext->type;
      avkey.target_class = tclass;
      avkey.specified = specified;
      avdatum = avtab_search(&policydb.te_avtab, &avkey);

      /* If no permanent rule, also check for enabled conditional rules */
      if(!avdatum) {
            node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
            for (; node != NULL; node = avtab_search_node_next(node, specified)) {
                  if (node->key.specified & AVTAB_ENABLED) {
                        avdatum = &node->datum;
                        break;
                  }
            }
      }

      if (avdatum) {
            /* Use the type from the type transition/member/change rule. */
            newcontext.type = avdatum->data;
      }

      /* Check for class-specific changes. */
      switch (tclass) {
      case SECCLASS_PROCESS:
            if (specified & AVTAB_TRANSITION) {
                  /* Look for a role transition rule. */
                  for (roletr = policydb.role_tr; roletr;
                       roletr = roletr->next) {
                        if (roletr->role == scontext->role &&
                            roletr->type == tcontext->type) {
                              /* Use the role transition rule. */
                              newcontext.role = roletr->new_role;
                              break;
                        }
                  }
            }
            break;
      default:
            break;
      }

      /* Set the MLS attributes.
         This is done last because it may allocate memory. */
      rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
      if (rc)
            goto out_unlock;

      /* Check the validity of the context. */
      if (!policydb_context_isvalid(&policydb, &newcontext)) {
            rc = compute_sid_handle_invalid_context(scontext,
                                          tcontext,
                                          tclass,
                                          &newcontext);
            if (rc)
                  goto out_unlock;
      }
      /* Obtain the sid for the context. */
      rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
out_unlock:
      POLICY_RDUNLOCK;
      context_destroy(&newcontext);
out:
      return rc;
}

/**
 * security_transition_sid - Compute the SID for a new subject/object.
 * @ssid: source security identifier
 * @tsid: target security identifier
 * @tclass: target security class
 * @out_sid: security identifier for new subject/object
 *
 * Compute a SID to use for labeling a new subject or object in the
 * class @tclass based on a SID pair (@ssid, @tsid).
 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
 * if insufficient memory is available, or %0 if the new SID was
 * computed successfully.
 */
int security_transition_sid(u32 ssid,
                      u32 tsid,
                      u16 tclass,
                      u32 *out_sid)
{
      return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
}

/**
 * security_member_sid - Compute the SID for member selection.
 * @ssid: source security identifier
 * @tsid: target security identifier
 * @tclass: target security class
 * @out_sid: security identifier for selected member
 *
 * Compute a SID to use when selecting a member of a polyinstantiated
 * object of class @tclass based on a SID pair (@ssid, @tsid).
 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
 * if insufficient memory is available, or %0 if the SID was
 * computed successfully.
 */
int security_member_sid(u32 ssid,
                  u32 tsid,
                  u16 tclass,
                  u32 *out_sid)
{
      return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
}

/**
 * security_change_sid - Compute the SID for object relabeling.
 * @ssid: source security identifier
 * @tsid: target security identifier
 * @tclass: target security class
 * @out_sid: security identifier for selected member
 *
 * Compute a SID to use for relabeling an object of class @tclass
 * based on a SID pair (@ssid, @tsid).
 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
 * if insufficient memory is available, or %0 if the SID was
 * computed successfully.
 */
int security_change_sid(u32 ssid,
                  u32 tsid,
                  u16 tclass,
                  u32 *out_sid)
{
      return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
}

/*
 * Verify that each kernel class that is defined in the
 * policy is correct
 */
static int validate_classes(struct policydb *p)
{
      int i, j;
      struct class_datum *cladatum;
      struct perm_datum *perdatum;
      u32 nprim, tmp, common_pts_len, perm_val, pol_val;
      u16 class_val;
      const struct selinux_class_perm *kdefs = &selinux_class_perm;
      const char *def_class, *def_perm, *pol_class;
      struct symtab *perms;

      if (p->allow_unknown) {
            u32 num_classes = kdefs->cts_len;
            p->undefined_perms = kcalloc(num_classes, sizeof(u32), GFP_KERNEL);
            if (!p->undefined_perms)
                  return -ENOMEM;
      }

      for (i = 1; i < kdefs->cts_len; i++) {
            def_class = kdefs->class_to_string[i];
            if (!def_class)
                  continue;
            if (i > p->p_classes.nprim) {
                  printk(KERN_INFO
                         "security:  class %s not defined in policy\n",
                         def_class);
                  if (p->reject_unknown)
                        return -EINVAL;
                  if (p->allow_unknown)
                        p->undefined_perms[i-1] = ~0U;
                  continue;
            }
            pol_class = p->p_class_val_to_name[i-1];
            if (strcmp(pol_class, def_class)) {
                  printk(KERN_ERR
                         "security:  class %d is incorrect, found %s but should be %s\n",
                         i, pol_class, def_class);
                  return -EINVAL;
            }
      }
      for (i = 0; i < kdefs->av_pts_len; i++) {
            class_val = kdefs->av_perm_to_string[i].tclass;
            perm_val = kdefs->av_perm_to_string[i].value;
            def_perm = kdefs->av_perm_to_string[i].name;
            if (class_val > p->p_classes.nprim)
                  continue;
            pol_class = p->p_class_val_to_name[class_val-1];
            cladatum = hashtab_search(p->p_classes.table, pol_class);
            BUG_ON(!cladatum);
            perms = &cladatum->permissions;
            nprim = 1 << (perms->nprim - 1);
            if (perm_val > nprim) {
                  printk(KERN_INFO
                         "security:  permission %s in class %s not defined in policy\n",
                         def_perm, pol_class);
                  if (p->reject_unknown)
                        return -EINVAL;
                  if (p->allow_unknown)
                        p->undefined_perms[class_val-1] |= perm_val;
                  continue;
            }
            perdatum = hashtab_search(perms->table, def_perm);
            if (perdatum == NULL) {
                  printk(KERN_ERR
                         "security:  permission %s in class %s not found in policy, bad policy\n",
                         def_perm, pol_class);
                  return -EINVAL;
            }
            pol_val = 1 << (perdatum->value - 1);
            if (pol_val != perm_val) {
                  printk(KERN_ERR
                         "security:  permission %s in class %s has incorrect value\n",
                         def_perm, pol_class);
                  return -EINVAL;
            }
      }
      for (i = 0; i < kdefs->av_inherit_len; i++) {
            class_val = kdefs->av_inherit[i].tclass;
            if (class_val > p->p_classes.nprim)
                  continue;
            pol_class = p->p_class_val_to_name[class_val-1];
            cladatum = hashtab_search(p->p_classes.table, pol_class);
            BUG_ON(!cladatum);
            if (!cladatum->comdatum) {
                  printk(KERN_ERR
                         "security:  class %s should have an inherits clause but does not\n",
                         pol_class);
                  return -EINVAL;
            }
            tmp = kdefs->av_inherit[i].common_base;
            common_pts_len = 0;
            while (!(tmp & 0x01)) {
                  common_pts_len++;
                  tmp >>= 1;
            }
            perms = &cladatum->comdatum->permissions;
            for (j = 0; j < common_pts_len; j++) {
                  def_perm = kdefs->av_inherit[i].common_pts[j];
                  if (j >= perms->nprim) {
                        printk(KERN_INFO
                               "security:  permission %s in class %s not defined in policy\n",
                               def_perm, pol_class);
                        if (p->reject_unknown)
                              return -EINVAL;
                        if (p->allow_unknown)
                              p->undefined_perms[class_val-1] |= (1 << j);
                        continue;
                  }
                  perdatum = hashtab_search(perms->table, def_perm);
                  if (perdatum == NULL) {
                        printk(KERN_ERR
                               "security:  permission %s in class %s not found in policy, bad policy\n",
                               def_perm, pol_class);
                        return -EINVAL;
                  }
                  if (perdatum->value != j + 1) {
                        printk(KERN_ERR
                               "security:  permission %s in class %s has incorrect value\n",
                               def_perm, pol_class);
                        return -EINVAL;
                  }
            }
      }
      return 0;
}

/* Clone the SID into the new SID table. */
static int clone_sid(u32 sid,
                 struct context *context,
                 void *arg)
{
      struct sidtab *s = arg;

      return sidtab_insert(s, sid, context);
}

static inline int convert_context_handle_invalid_context(struct context *context)
{
      int rc = 0;

      if (selinux_enforcing) {
            rc = -EINVAL;
      } else {
            char *s;
            u32 len;

            context_struct_to_string(context, &s, &len);
            printk(KERN_ERR "security:  context %s is invalid\n", s);
            kfree(s);
      }
      return rc;
}

struct convert_context_args {
      struct policydb *oldp;
      struct policydb *newp;
};

/*
 * Convert the values in the security context
 * structure `c' from the values specified
 * in the policy `p->oldp' to the values specified
 * in the policy `p->newp'.  Verify that the
 * context is valid under the new policy.
 */
static int convert_context(u32 key,
                     struct context *c,
                     void *p)
{
      struct convert_context_args *args;
      struct context oldc;
      struct role_datum *role;
      struct type_datum *typdatum;
      struct user_datum *usrdatum;
      char *s;
      u32 len;
      int rc;

      args = p;

      rc = context_cpy(&oldc, c);
      if (rc)
            goto out;

      rc = -EINVAL;

      /* Convert the user. */
      usrdatum = hashtab_search(args->newp->p_users.table,
                                args->oldp->p_user_val_to_name[c->user - 1]);
      if (!usrdatum) {
            goto bad;
      }
      c->user = usrdatum->value;

      /* Convert the role. */
      role = hashtab_search(args->newp->p_roles.table,
                            args->oldp->p_role_val_to_name[c->role - 1]);
      if (!role) {
            goto bad;
      }
      c->role = role->value;

      /* Convert the type. */
      typdatum = hashtab_search(args->newp->p_types.table,
                                args->oldp->p_type_val_to_name[c->type - 1]);
      if (!typdatum) {
            goto bad;
      }
      c->type = typdatum->value;

      rc = mls_convert_context(args->oldp, args->newp, c);
      if (rc)
            goto bad;

      /* Check the validity of the new context. */
      if (!policydb_context_isvalid(args->newp, c)) {
            rc = convert_context_handle_invalid_context(&oldc);
            if (rc)
                  goto bad;
      }

      context_destroy(&oldc);
out:
      return rc;
bad:
      context_struct_to_string(&oldc, &s, &len);
      context_destroy(&oldc);
      printk(KERN_ERR "security:  invalidating context %s\n", s);
      kfree(s);
      goto out;
}

extern void selinux_complete_init(void);
static int security_preserve_bools(struct policydb *p);

/**
 * security_load_policy - Load a security policy configuration.
 * @data: binary policy data
 * @len: length of data in bytes
 *
 * Load a new set of security policy configuration data,
 * validate it and convert the SID table as necessary.
 * This function will flush the access vector cache after
 * loading the new policy.
 */
int security_load_policy(void *data, size_t len)
{
      struct policydb oldpolicydb, newpolicydb;
      struct sidtab oldsidtab, newsidtab;
      struct convert_context_args args;
      u32 seqno;
      int rc = 0;
      struct policy_file file = { data, len }, *fp = &file;

      LOAD_LOCK;

      if (!ss_initialized) {
            avtab_cache_init();
            if (policydb_read(&policydb, fp)) {
                  LOAD_UNLOCK;
                  avtab_cache_destroy();
                  return -EINVAL;
            }
            if (policydb_load_isids(&policydb, &sidtab)) {
                  LOAD_UNLOCK;
                  policydb_destroy(&policydb);
                  avtab_cache_destroy();
                  return -EINVAL;
            }
            /* Verify that the kernel defined classes are correct. */
            if (validate_classes(&policydb)) {
                  printk(KERN_ERR
                         "security:  the definition of a class is incorrect\n");
                  LOAD_UNLOCK;
                  sidtab_destroy(&sidtab);
                  policydb_destroy(&policydb);
                  avtab_cache_destroy();
                  return -EINVAL;
            }
            policydb_loaded_version = policydb.policyvers;
            ss_initialized = 1;
            seqno = ++latest_granting;
            LOAD_UNLOCK;
            selinux_complete_init();
            avc_ss_reset(seqno);
            selnl_notify_policyload(seqno);
            selinux_netlbl_cache_invalidate();
            selinux_xfrm_notify_policyload();
            return 0;
      }

#if 0
      sidtab_hash_eval(&sidtab, "sids");
#endif

      if (policydb_read(&newpolicydb, fp)) {
            LOAD_UNLOCK;
            return -EINVAL;
      }

      sidtab_init(&newsidtab);

      /* Verify that the kernel defined classes are correct. */
      if (validate_classes(&newpolicydb)) {
            printk(KERN_ERR
                   "security:  the definition of a class is incorrect\n");
            rc = -EINVAL;
            goto err;
      }

      rc = security_preserve_bools(&newpolicydb);
      if (rc) {
            printk(KERN_ERR "security:  unable to preserve booleans\n");
            goto err;
      }

      /* Clone the SID table. */
      sidtab_shutdown(&sidtab);
      if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
            rc = -ENOMEM;
            goto err;
      }

      /* Convert the internal representations of contexts
         in the new SID table and remove invalid SIDs. */
      args.oldp = &policydb;
      args.newp = &newpolicydb;
      sidtab_map_remove_on_error(&newsidtab, convert_context, &args);

      /* Save the old policydb and SID table to free later. */
      memcpy(&oldpolicydb, &policydb, sizeof policydb);
      sidtab_set(&oldsidtab, &sidtab);

      /* Install the new policydb and SID table. */
      POLICY_WRLOCK;
      memcpy(&policydb, &newpolicydb, sizeof policydb);
      sidtab_set(&sidtab, &newsidtab);
      seqno = ++latest_granting;
      policydb_loaded_version = policydb.policyvers;
      POLICY_WRUNLOCK;
      LOAD_UNLOCK;

      /* Free the old policydb and SID table. */
      policydb_destroy(&oldpolicydb);
      sidtab_destroy(&oldsidtab);

      avc_ss_reset(seqno);
      selnl_notify_policyload(seqno);
      selinux_netlbl_cache_invalidate();
      selinux_xfrm_notify_policyload();

      return 0;

err:
      LOAD_UNLOCK;
      sidtab_destroy(&newsidtab);
      policydb_destroy(&newpolicydb);
      return rc;

}

/**
 * security_port_sid - Obtain the SID for a port.
 * @domain: communication domain aka address family
 * @type: socket type
 * @protocol: protocol number
 * @port: port number
 * @out_sid: security identifier
 */
int security_port_sid(u16 domain,
                  u16 type,
                  u8 protocol,
                  u16 port,
                  u32 *out_sid)
{
      struct ocontext *c;
      int rc = 0;

      POLICY_RDLOCK;

      c = policydb.ocontexts[OCON_PORT];
      while (c) {
            if (c->u.port.protocol == protocol &&
                c->u.port.low_port <= port &&
                c->u.port.high_port >= port)
                  break;
            c = c->next;
      }

      if (c) {
            if (!c->sid[0]) {
                  rc = sidtab_context_to_sid(&sidtab,
                                       &c->context[0],
                                       &c->sid[0]);
                  if (rc)
                        goto out;
            }
            *out_sid = c->sid[0];
      } else {
            *out_sid = SECINITSID_PORT;
      }

out:
      POLICY_RDUNLOCK;
      return rc;
}

/**
 * security_netif_sid - Obtain the SID for a network interface.
 * @name: interface name
 * @if_sid: interface SID
 * @msg_sid: default SID for received packets
 */
int security_netif_sid(char *name,
                   u32 *if_sid,
                   u32 *msg_sid)
{
      int rc = 0;
      struct ocontext *c;

      POLICY_RDLOCK;

      c = policydb.ocontexts[OCON_NETIF];
      while (c) {
            if (strcmp(name, c->u.name) == 0)
                  break;
            c = c->next;
      }

      if (c) {
            if (!c->sid[0] || !c->sid[1]) {
                  rc = sidtab_context_to_sid(&sidtab,
                                      &c->context[0],
                                      &c->sid[0]);
                  if (rc)
                        goto out;
                  rc = sidtab_context_to_sid(&sidtab,
                                       &c->context[1],
                                       &c->sid[1]);
                  if (rc)
                        goto out;
            }
            *if_sid = c->sid[0];
            *msg_sid = c->sid[1];
      } else {
            *if_sid = SECINITSID_NETIF;
            *msg_sid = SECINITSID_NETMSG;
      }

out:
      POLICY_RDUNLOCK;
      return rc;
}

static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
{
      int i, fail = 0;

      for(i = 0; i < 4; i++)
            if(addr[i] != (input[i] & mask[i])) {
                  fail = 1;
                  break;
            }

      return !fail;
}

/**
 * security_node_sid - Obtain the SID for a node (host).
 * @domain: communication domain aka address family
 * @addrp: address
 * @addrlen: address length in bytes
 * @out_sid: security identifier
 */
int security_node_sid(u16 domain,
                  void *addrp,
                  u32 addrlen,
                  u32 *out_sid)
{
      int rc = 0;
      struct ocontext *c;

      POLICY_RDLOCK;

      switch (domain) {
      case AF_INET: {
            u32 addr;

            if (addrlen != sizeof(u32)) {
                  rc = -EINVAL;
                  goto out;
            }

            addr = *((u32 *)addrp);

            c = policydb.ocontexts[OCON_NODE];
            while (c) {
                  if (c->u.node.addr == (addr & c->u.node.mask))
                        break;
                  c = c->next;
            }
            break;
      }

      case AF_INET6:
            if (addrlen != sizeof(u64) * 2) {
                  rc = -EINVAL;
                  goto out;
            }
            c = policydb.ocontexts[OCON_NODE6];
            while (c) {
                  if (match_ipv6_addrmask(addrp, c->u.node6.addr,
                                    c->u.node6.mask))
                        break;
                  c = c->next;
            }
            break;

      default:
            *out_sid = SECINITSID_NODE;
            goto out;
      }

      if (c) {
            if (!c->sid[0]) {
                  rc = sidtab_context_to_sid(&sidtab,
                                       &c->context[0],
                                       &c->sid[0]);
                  if (rc)
                        goto out;
            }
            *out_sid = c->sid[0];
      } else {
            *out_sid = SECINITSID_NODE;
      }

out:
      POLICY_RDUNLOCK;
      return rc;
}

#define SIDS_NEL 25

/**
 * security_get_user_sids - Obtain reachable SIDs for a user.
 * @fromsid: starting SID
 * @username: username
 * @sids: array of reachable SIDs for user
 * @nel: number of elements in @sids
 *
 * Generate the set of SIDs for legal security contexts
 * for a given user that can be reached by @fromsid.
 * Set *@sids to point to a dynamically allocated
 * array containing the set of SIDs.  Set *@nel to the
 * number of elements in the array.
 */

int security_get_user_sids(u32 fromsid,
                         char *username,
                     u32 **sids,
                     u32 *nel)
{
      struct context *fromcon, usercon;
      u32 *mysids = NULL, *mysids2, sid;
      u32 mynel = 0, maxnel = SIDS_NEL;
      struct user_datum *user;
      struct role_datum *role;
      struct ebitmap_node *rnode, *tnode;
      int rc = 0, i, j;

      *sids = NULL;
      *nel = 0;

      if (!ss_initialized)
            goto out;

      POLICY_RDLOCK;

      fromcon = sidtab_search(&sidtab, fromsid);
      if (!fromcon) {
            rc = -EINVAL;
            goto out_unlock;
      }

      user = hashtab_search(policydb.p_users.table, username);
      if (!user) {
            rc = -EINVAL;
            goto out_unlock;
      }
      usercon.user = user->value;

      mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
      if (!mysids) {
            rc = -ENOMEM;
            goto out_unlock;
      }

      ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
            role = policydb.role_val_to_struct[i];
            usercon.role = i+1;
            ebitmap_for_each_positive_bit(&role->types, tnode, j) {
                  usercon.type = j+1;

                  if (mls_setup_user_range(fromcon, user, &usercon))
                        continue;

                  rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
                  if (rc)
                        goto out_unlock;
                  if (mynel < maxnel) {
                        mysids[mynel++] = sid;
                  } else {
                        maxnel += SIDS_NEL;
                        mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
                        if (!mysids2) {
                              rc = -ENOMEM;
                              goto out_unlock;
                        }
                        memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
                        kfree(mysids);
                        mysids = mysids2;
                        mysids[mynel++] = sid;
                  }
            }
      }

out_unlock:
      POLICY_RDUNLOCK;
      if (rc || !mynel) {
            kfree(mysids);
            goto out;
      }

      mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
      if (!mysids2) {
            rc = -ENOMEM;
            kfree(mysids);
            goto out;
      }
      for (i = 0, j = 0; i < mynel; i++) {
            rc = avc_has_perm_noaudit(fromsid, mysids[i],
                                SECCLASS_PROCESS,
                                PROCESS__TRANSITION, AVC_STRICT,
                                NULL);
            if (!rc)
                  mysids2[j++] = mysids[i];
            cond_resched();
      }
      rc = 0;
      kfree(mysids);
      *sids = mysids2;
      *nel = j;
out:
      return rc;
}

/**
 * security_genfs_sid - Obtain a SID for a file in a filesystem
 * @fstype: filesystem type
 * @path: path from root of mount
 * @sclass: file security class
 * @sid: SID for path
 *
 * Obtain a SID to use for a file in a filesystem that
 * cannot support xattr or use a fixed labeling behavior like
 * transition SIDs or task SIDs.
 */
int security_genfs_sid(const char *fstype,
                     char *path,
                   u16 sclass,
                   u32 *sid)
{
      int len;
      struct genfs *genfs;
      struct ocontext *c;
      int rc = 0, cmp = 0;

      while (path[0] == '/' && path[1] == '/')
            path++;

      POLICY_RDLOCK;

      for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
            cmp = strcmp(fstype, genfs->fstype);
            if (cmp <= 0)
                  break;
      }

      if (!genfs || cmp) {
            *sid = SECINITSID_UNLABELED;
            rc = -ENOENT;
            goto out;
      }

      for (c = genfs->head; c; c = c->next) {
            len = strlen(c->u.name);
            if ((!c->v.sclass || sclass == c->v.sclass) &&
                (strncmp(c->u.name, path, len) == 0))
                  break;
      }

      if (!c) {
            *sid = SECINITSID_UNLABELED;
            rc = -ENOENT;
            goto out;
      }

      if (!c->sid[0]) {
            rc = sidtab_context_to_sid(&sidtab,
                                 &c->context[0],
                                 &c->sid[0]);
            if (rc)
                  goto out;
      }

      *sid = c->sid[0];
out:
      POLICY_RDUNLOCK;
      return rc;
}

/**
 * security_fs_use - Determine how to handle labeling for a filesystem.
 * @fstype: filesystem type
 * @behavior: labeling behavior
 * @sid: SID for filesystem (superblock)
 */
int security_fs_use(
      const char *fstype,
      unsigned int *behavior,
      u32 *sid)
{
      int rc = 0;
      struct ocontext *c;

      POLICY_RDLOCK;

      c = policydb.ocontexts[OCON_FSUSE];
      while (c) {
            if (strcmp(fstype, c->u.name) == 0)
                  break;
            c = c->next;
      }

      if (c) {
            *behavior = c->v.behavior;
            if (!c->sid[0]) {
                  rc = sidtab_context_to_sid(&sidtab,
                                       &c->context[0],
                                       &c->sid[0]);
                  if (rc)
                        goto out;
            }
            *sid = c->sid[0];
      } else {
            rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
            if (rc) {
                  *behavior = SECURITY_FS_USE_NONE;
                  rc = 0;
            } else {
                  *behavior = SECURITY_FS_USE_GENFS;
            }
      }

out:
      POLICY_RDUNLOCK;
      return rc;
}

int security_get_bools(int *len, char ***names, int **values)
{
      int i, rc = -ENOMEM;

      POLICY_RDLOCK;
      *names = NULL;
      *values = NULL;

      *len = policydb.p_bools.nprim;
      if (!*len) {
            rc = 0;
            goto out;
      }

       *names = kcalloc(*len, sizeof(char*), GFP_ATOMIC);
      if (!*names)
            goto err;

       *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
      if (!*values)
            goto err;

      for (i = 0; i < *len; i++) {
            size_t name_len;
            (*values)[i] = policydb.bool_val_to_struct[i]->state;
            name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
               (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
            if (!(*names)[i])
                  goto err;
            strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
            (*names)[i][name_len - 1] = 0;
      }
      rc = 0;
out:
      POLICY_RDUNLOCK;
      return rc;
err:
      if (*names) {
            for (i = 0; i < *len; i++)
                  kfree((*names)[i]);
      }
      kfree(*values);
      goto out;
}


int security_set_bools(int len, int *values)
{
      int i, rc = 0;
      int lenp, seqno = 0;
      struct cond_node *cur;

      POLICY_WRLOCK;

      lenp = policydb.p_bools.nprim;
      if (len != lenp) {
            rc = -EFAULT;
            goto out;
      }

      for (i = 0; i < len; i++) {
            if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
                  audit_log(current->audit_context, GFP_ATOMIC,
                        AUDIT_MAC_CONFIG_CHANGE,
                        "bool=%s val=%d old_val=%d auid=%u",
                        policydb.p_bool_val_to_name[i],
                        !!values[i],
                        policydb.bool_val_to_struct[i]->state,
                        audit_get_loginuid(current->audit_context));
            }
            if (values[i]) {
                  policydb.bool_val_to_struct[i]->state = 1;
            } else {
                  policydb.bool_val_to_struct[i]->state = 0;
            }
      }

      for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
            rc = evaluate_cond_node(&policydb, cur);
            if (rc)
                  goto out;
      }

      seqno = ++latest_granting;

out:
      POLICY_WRUNLOCK;
      if (!rc) {
            avc_ss_reset(seqno);
            selnl_notify_policyload(seqno);
            selinux_xfrm_notify_policyload();
      }
      return rc;
}

int security_get_bool_value(int bool)
{
      int rc = 0;
      int len;

      POLICY_RDLOCK;

      len = policydb.p_bools.nprim;
      if (bool >= len) {
            rc = -EFAULT;
            goto out;
      }

      rc = policydb.bool_val_to_struct[bool]->state;
out:
      POLICY_RDUNLOCK;
      return rc;
}

static int security_preserve_bools(struct policydb *p)
{
      int rc, nbools = 0, *bvalues = NULL, i;
      char **bnames = NULL;
      struct cond_bool_datum *booldatum;
      struct cond_node *cur;

      rc = security_get_bools(&nbools, &bnames, &bvalues);
      if (rc)
            goto out;
      for (i = 0; i < nbools; i++) {
            booldatum = hashtab_search(p->p_bools.table, bnames[i]);
            if (booldatum)
                  booldatum->state = bvalues[i];
      }
      for (cur = p->cond_list; cur != NULL; cur = cur->next) {
            rc = evaluate_cond_node(p, cur);
            if (rc)
                  goto out;
      }

out:
      if (bnames) {
            for (i = 0; i < nbools; i++)
                  kfree(bnames[i]);
      }
      kfree(bnames);
      kfree(bvalues);
      return rc;
}

/*
 * security_sid_mls_copy() - computes a new sid based on the given
 * sid and the mls portion of mls_sid.
 */
int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
{
      struct context *context1;
      struct context *context2;
      struct context newcon;
      char *s;
      u32 len;
      int rc = 0;

      if (!ss_initialized || !selinux_mls_enabled) {
            *new_sid = sid;
            goto out;
      }

      context_init(&newcon);

      POLICY_RDLOCK;
      context1 = sidtab_search(&sidtab, sid);
      if (!context1) {
            printk(KERN_ERR "security_sid_mls_copy:  unrecognized SID "
                   "%d\n", sid);
            rc = -EINVAL;
            goto out_unlock;
      }

      context2 = sidtab_search(&sidtab, mls_sid);
      if (!context2) {
            printk(KERN_ERR "security_sid_mls_copy:  unrecognized SID "
                   "%d\n", mls_sid);
            rc = -EINVAL;
            goto out_unlock;
      }

      newcon.user = context1->user;
      newcon.role = context1->role;
      newcon.type = context1->type;
      rc = mls_context_cpy(&newcon, context2);
      if (rc)
            goto out_unlock;

      /* Check the validity of the new context. */
      if (!policydb_context_isvalid(&policydb, &newcon)) {
            rc = convert_context_handle_invalid_context(&newcon);
            if (rc)
                  goto bad;
      }

      rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
      goto out_unlock;

bad:
      if (!context_struct_to_string(&newcon, &s, &len)) {
            audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
                    "security_sid_mls_copy: invalid context %s", s);
            kfree(s);
      }

out_unlock:
      POLICY_RDUNLOCK;
      context_destroy(&newcon);
out:
      return rc;
}

static int get_classes_callback(void *k, void *d, void *args)
{
      struct class_datum *datum = d;
      char *name = k, **classes = args;
      int value = datum->value - 1;

      classes[value] = kstrdup(name, GFP_ATOMIC);
      if (!classes[value])
            return -ENOMEM;

      return 0;
}

int security_get_classes(char ***classes, int *nclasses)
{
      int rc = -ENOMEM;

      POLICY_RDLOCK;

      *nclasses = policydb.p_classes.nprim;
      *classes = kcalloc(*nclasses, sizeof(*classes), GFP_ATOMIC);
      if (!*classes)
            goto out;

      rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
                  *classes);
      if (rc < 0) {
            int i;
            for (i = 0; i < *nclasses; i++)
                  kfree((*classes)[i]);
            kfree(*classes);
      }

out:
      POLICY_RDUNLOCK;
      return rc;
}

static int get_permissions_callback(void *k, void *d, void *args)
{
      struct perm_datum *datum = d;
      char *name = k, **perms = args;
      int value = datum->value - 1;

      perms[value] = kstrdup(name, GFP_ATOMIC);
      if (!perms[value])
            return -ENOMEM;

      return 0;
}

int security_get_permissions(char *class, char ***perms, int *nperms)
{
      int rc = -ENOMEM, i;
      struct class_datum *match;

      POLICY_RDLOCK;

      match = hashtab_search(policydb.p_classes.table, class);
      if (!match) {
            printk(KERN_ERR "%s:  unrecognized class %s\n",
                  __FUNCTION__, class);
            rc = -EINVAL;
            goto out;
      }

      *nperms = match->permissions.nprim;
      *perms = kcalloc(*nperms, sizeof(*perms), GFP_ATOMIC);
      if (!*perms)
            goto out;

      if (match->comdatum) {
            rc = hashtab_map(match->comdatum->permissions.table,
                        get_permissions_callback, *perms);
            if (rc < 0)
                  goto err;
      }

      rc = hashtab_map(match->permissions.table, get_permissions_callback,
                  *perms);
      if (rc < 0)
            goto err;

out:
      POLICY_RDUNLOCK;
      return rc;

err:
      POLICY_RDUNLOCK;
      for (i = 0; i < *nperms; i++)
            kfree((*perms)[i]);
      kfree(*perms);
      return rc;
}

int security_get_reject_unknown(void)
{
      return policydb.reject_unknown;
}

int security_get_allow_unknown(void)
{
      return policydb.allow_unknown;
}

struct selinux_audit_rule {
      u32 au_seqno;
      struct context au_ctxt;
};

void selinux_audit_rule_free(struct selinux_audit_rule *rule)
{
      if (rule) {
            context_destroy(&rule->au_ctxt);
            kfree(rule);
      }
}

int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
                            struct selinux_audit_rule **rule)
{
      struct selinux_audit_rule *tmprule;
      struct role_datum *roledatum;
      struct type_datum *typedatum;
      struct user_datum *userdatum;
      int rc = 0;

      *rule = NULL;

      if (!ss_initialized)
            return -EOPNOTSUPP;

      switch (field) {
      case AUDIT_SUBJ_USER:
      case AUDIT_SUBJ_ROLE:
      case AUDIT_SUBJ_TYPE:
      case AUDIT_OBJ_USER:
      case AUDIT_OBJ_ROLE:
      case AUDIT_OBJ_TYPE:
            /* only 'equals' and 'not equals' fit user, role, and type */
            if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
                  return -EINVAL;
            break;
      case AUDIT_SUBJ_SEN:
      case AUDIT_SUBJ_CLR:
      case AUDIT_OBJ_LEV_LOW:
      case AUDIT_OBJ_LEV_HIGH:
            /* we do not allow a range, indicated by the presense of '-' */
            if (strchr(rulestr, '-'))
                  return -EINVAL;
            break;
      default:
            /* only the above fields are valid */
            return -EINVAL;
      }

      tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
      if (!tmprule)
            return -ENOMEM;

      context_init(&tmprule->au_ctxt);

      POLICY_RDLOCK;

      tmprule->au_seqno = latest_granting;

      switch (field) {
      case AUDIT_SUBJ_USER:
      case AUDIT_OBJ_USER:
            userdatum = hashtab_search(policydb.p_users.table, rulestr);
            if (!userdatum)
                  rc = -EINVAL;
            else
                  tmprule->au_ctxt.user = userdatum->value;
            break;
      case AUDIT_SUBJ_ROLE:
      case AUDIT_OBJ_ROLE:
            roledatum = hashtab_search(policydb.p_roles.table, rulestr);
            if (!roledatum)
                  rc = -EINVAL;
            else
                  tmprule->au_ctxt.role = roledatum->value;
            break;
      case AUDIT_SUBJ_TYPE:
      case AUDIT_OBJ_TYPE:
            typedatum = hashtab_search(policydb.p_types.table, rulestr);
            if (!typedatum)
                  rc = -EINVAL;
            else
                  tmprule->au_ctxt.type = typedatum->value;
            break;
      case AUDIT_SUBJ_SEN:
      case AUDIT_SUBJ_CLR:
      case AUDIT_OBJ_LEV_LOW:
      case AUDIT_OBJ_LEV_HIGH:
            rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
            break;
      }

      POLICY_RDUNLOCK;

      if (rc) {
            selinux_audit_rule_free(tmprule);
            tmprule = NULL;
      }

      *rule = tmprule;

      return rc;
}

int selinux_audit_rule_match(u32 sid, u32 field, u32 op,
                             struct selinux_audit_rule *rule,
                             struct audit_context *actx)
{
      struct context *ctxt;
      struct mls_level *level;
      int match = 0;

      if (!rule) {
            audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
                      "selinux_audit_rule_match: missing rule\n");
            return -ENOENT;
      }

      POLICY_RDLOCK;

      if (rule->au_seqno < latest_granting) {
            audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
                      "selinux_audit_rule_match: stale rule\n");
            match = -ESTALE;
            goto out;
      }

      ctxt = sidtab_search(&sidtab, sid);
      if (!ctxt) {
            audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
                      "selinux_audit_rule_match: unrecognized SID %d\n",
                      sid);
            match = -ENOENT;
            goto out;
      }

      /* a field/op pair that is not caught here will simply fall through
         without a match */
      switch (field) {
      case AUDIT_SUBJ_USER:
      case AUDIT_OBJ_USER:
            switch (op) {
            case AUDIT_EQUAL:
                  match = (ctxt->user == rule->au_ctxt.user);
                  break;
            case AUDIT_NOT_EQUAL:
                  match = (ctxt->user != rule->au_ctxt.user);
                  break;
            }
            break;
      case AUDIT_SUBJ_ROLE:
      case AUDIT_OBJ_ROLE:
            switch (op) {
            case AUDIT_EQUAL:
                  match = (ctxt->role == rule->au_ctxt.role);
                  break;
            case AUDIT_NOT_EQUAL:
                  match = (ctxt->role != rule->au_ctxt.role);
                  break;
            }
            break;
      case AUDIT_SUBJ_TYPE:
      case AUDIT_OBJ_TYPE:
            switch (op) {
            case AUDIT_EQUAL:
                  match = (ctxt->type == rule->au_ctxt.type);
                  break;
            case AUDIT_NOT_EQUAL:
                  match = (ctxt->type != rule->au_ctxt.type);
                  break;
            }
            break;
      case AUDIT_SUBJ_SEN:
      case AUDIT_SUBJ_CLR:
      case AUDIT_OBJ_LEV_LOW:
      case AUDIT_OBJ_LEV_HIGH:
            level = ((field == AUDIT_SUBJ_SEN ||
                      field == AUDIT_OBJ_LEV_LOW) ?
                     &ctxt->range.level[0] : &ctxt->range.level[1]);
            switch (op) {
            case AUDIT_EQUAL:
                  match = mls_level_eq(&rule->au_ctxt.range.level[0],
                                       level);
                  break;
            case AUDIT_NOT_EQUAL:
                  match = !mls_level_eq(&rule->au_ctxt.range.level[0],
                                        level);
                  break;
            case AUDIT_LESS_THAN:
                  match = (mls_level_dom(&rule->au_ctxt.range.level[0],
                                         level) &&
                           !mls_level_eq(&rule->au_ctxt.range.level[0],
                                         level));
                  break;
            case AUDIT_LESS_THAN_OR_EQUAL:
                  match = mls_level_dom(&rule->au_ctxt.range.level[0],
                                        level);
                  break;
            case AUDIT_GREATER_THAN:
                  match = (mls_level_dom(level,
                                        &rule->au_ctxt.range.level[0]) &&
                           !mls_level_eq(level,
                                         &rule->au_ctxt.range.level[0]));
                  break;
            case AUDIT_GREATER_THAN_OR_EQUAL:
                  match = mls_level_dom(level,
                                        &rule->au_ctxt.range.level[0]);
                  break;
            }
      }

out:
      POLICY_RDUNLOCK;
      return match;
}

static int (*aurule_callback)(void) = NULL;

static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
                               u16 class, u32 perms, u32 *retained)
{
      int err = 0;

      if (event == AVC_CALLBACK_RESET && aurule_callback)
            err = aurule_callback();
      return err;
}

static int __init aurule_init(void)
{
      int err;

      err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
                             SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
      if (err)
            panic("avc_add_callback() failed, error %d\n", err);

      return err;
}
__initcall(aurule_init);

void selinux_audit_set_callback(int (*callback)(void))
{
      aurule_callback = callback;
}

#ifdef CONFIG_NETLABEL
/*
 * NetLabel cache structure
 */
#define NETLBL_CACHE(x)           ((struct selinux_netlbl_cache *)(x))
#define NETLBL_CACHE_T_NONE       0
#define NETLBL_CACHE_T_SID        1
#define NETLBL_CACHE_T_MLS        2
struct selinux_netlbl_cache {
      u32 type;
      union {
            u32 sid;
            struct mls_range mls_label;
      } data;
};

/**
 * security_netlbl_cache_free - Free the NetLabel cached data
 * @data: the data to free
 *
 * Description:
 * This function is intended to be used as the free() callback inside the
 * netlbl_lsm_cache structure.
 *
 */
static void security_netlbl_cache_free(const void *data)
{
      struct selinux_netlbl_cache *cache;

      if (data == NULL)
            return;

      cache = NETLBL_CACHE(data);
      switch (cache->type) {
      case NETLBL_CACHE_T_MLS:
            ebitmap_destroy(&cache->data.mls_label.level[0].cat);
            break;
      }
      kfree(data);
}

/**
 * security_netlbl_cache_add - Add an entry to the NetLabel cache
 * @secattr: the NetLabel packet security attributes
 * @ctx: the SELinux context
 *
 * Description:
 * Attempt to cache the context in @ctx, which was derived from the packet in
 * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
 * already been initialized.
 *
 */
static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
                              struct context *ctx)
{
      struct selinux_netlbl_cache *cache = NULL;

      secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
      if (secattr->cache == NULL)
            return;

      cache = kzalloc(sizeof(*cache),     GFP_ATOMIC);
      if (cache == NULL)
            return;

      cache->type = NETLBL_CACHE_T_MLS;
      if (ebitmap_cpy(&cache->data.mls_label.level[0].cat,
                  &ctx->range.level[0].cat) != 0) {
            kfree(cache);
            return;
      }
      cache->data.mls_label.level[1].cat.highbit =
            cache->data.mls_label.level[0].cat.highbit;
      cache->data.mls_label.level[1].cat.node =
            cache->data.mls_label.level[0].cat.node;
      cache->data.mls_label.level[0].sens = ctx->range.level[0].sens;
      cache->data.mls_label.level[1].sens = ctx->range.level[0].sens;

      secattr->cache->free = security_netlbl_cache_free;
      secattr->cache->data = (void *)cache;
      secattr->flags |= NETLBL_SECATTR_CACHE;
}

/**
 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
 * @secattr: the NetLabel packet security attributes
 * @base_sid: the SELinux SID to use as a context for MLS only attributes
 * @sid: the SELinux SID
 *
 * Description:
 * Convert the given NetLabel security attributes in @secattr into a
 * SELinux SID.  If the @secattr field does not contain a full SELinux
 * SID/context then use the context in @base_sid as the foundation.  If
 * possibile the 'cache' field of @secattr is set and the CACHE flag is set;
 * this is to allow the @secattr to be used by NetLabel to cache the secattr to
 * SID conversion for future lookups.  Returns zero on success, negative
 * values on failure.
 *
 */
int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
                           u32 base_sid,
                           u32 *sid)
{
      int rc = -EIDRM;
      struct context *ctx;
      struct context ctx_new;
      struct selinux_netlbl_cache *cache;

      if (!ss_initialized) {
            *sid = SECSID_NULL;
            return 0;
      }

      POLICY_RDLOCK;

      if (secattr->flags & NETLBL_SECATTR_CACHE) {
            cache = NETLBL_CACHE(secattr->cache->data);
            switch (cache->type) {
            case NETLBL_CACHE_T_SID:
                  *sid = cache->data.sid;
                  rc = 0;
                  break;
            case NETLBL_CACHE_T_MLS:
                  ctx = sidtab_search(&sidtab, base_sid);
                  if (ctx == NULL)
                        goto netlbl_secattr_to_sid_return;

                  ctx_new.user = ctx->user;
                  ctx_new.role = ctx->role;
                  ctx_new.type = ctx->type;
                  ctx_new.range.level[0].sens =
                        cache->data.mls_label.level[0].sens;
                  ctx_new.range.level[0].cat.highbit =
                        cache->data.mls_label.level[0].cat.highbit;
                  ctx_new.range.level[0].cat.node =
                        cache->data.mls_label.level[0].cat.node;
                  ctx_new.range.level[1].sens =
                        cache->data.mls_label.level[1].sens;
                  ctx_new.range.level[1].cat.highbit =
                        cache->data.mls_label.level[1].cat.highbit;
                  ctx_new.range.level[1].cat.node =
                        cache->data.mls_label.level[1].cat.node;

                  rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
                  break;
            default:
                  goto netlbl_secattr_to_sid_return;
            }
      } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
            ctx = sidtab_search(&sidtab, base_sid);
            if (ctx == NULL)
                  goto netlbl_secattr_to_sid_return;

            ctx_new.user = ctx->user;
            ctx_new.role = ctx->role;
            ctx_new.type = ctx->type;
            mls_import_netlbl_lvl(&ctx_new, secattr);
            if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
                  if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
                                      secattr->mls_cat) != 0)
                        goto netlbl_secattr_to_sid_return;
                  ctx_new.range.level[1].cat.highbit =
                        ctx_new.range.level[0].cat.highbit;
                  ctx_new.range.level[1].cat.node =
                        ctx_new.range.level[0].cat.node;
            } else {
                  ebitmap_init(&ctx_new.range.level[0].cat);
                  ebitmap_init(&ctx_new.range.level[1].cat);
            }
            if (mls_context_isvalid(&policydb, &ctx_new) != 1)
                  goto netlbl_secattr_to_sid_return_cleanup;

            rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
            if (rc != 0)
                  goto netlbl_secattr_to_sid_return_cleanup;

            security_netlbl_cache_add(secattr, &ctx_new);

            ebitmap_destroy(&ctx_new.range.level[0].cat);
      } else {
            *sid = SECSID_NULL;
            rc = 0;
      }

netlbl_secattr_to_sid_return:
      POLICY_RDUNLOCK;
      return rc;
netlbl_secattr_to_sid_return_cleanup:
      ebitmap_destroy(&ctx_new.range.level[0].cat);
      goto netlbl_secattr_to_sid_return;
}

/**
 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
 * @sid: the SELinux SID
 * @secattr: the NetLabel packet security attributes
 *
 * Description:
 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
 * Returns zero on success, negative values on failure.
 *
 */
int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
{
      int rc = -ENOENT;
      struct context *ctx;

      if (!ss_initialized)
            return 0;

      POLICY_RDLOCK;
      ctx = sidtab_search(&sidtab, sid);
      if (ctx == NULL)
            goto netlbl_sid_to_secattr_failure;
      secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
                          GFP_ATOMIC);
      secattr->flags |= NETLBL_SECATTR_DOMAIN;
      mls_export_netlbl_lvl(ctx, secattr);
      rc = mls_export_netlbl_cat(ctx, secattr);
      if (rc != 0)
            goto netlbl_sid_to_secattr_failure;
      POLICY_RDUNLOCK;

      return 0;

netlbl_sid_to_secattr_failure:
      POLICY_RDUNLOCK;
      netlbl_secattr_destroy(secattr);
      return rc;
}
#endif /* CONFIG_NETLABEL */

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