src/libcharon/sa/ike_sa_manager.h

   1 /*
   2  * Copyright (C) 2008 Tobias Brunner
   3  * Copyright (C) 2005-2008 Martin Willi
   4  * Copyright (C) 2005 Jan Hutter
   5  * Hochschule fuer Technik Rapperswil
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2 of the License, or (at your
  10  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15  * for more details.
  16  */
  17
  18 /**
  19  * @defgroup ike_sa_manager ike_sa_manager
  20  * @{ @ingroup sa
  21  */
  22
  23 #ifndef IKE_SA_MANAGER_H_
  24 #define IKE_SA_MANAGER_H_
  25
  26 typedef struct ike_sa_manager_t ike_sa_manager_t;
  27
  28 #include <library.h>
  29 #include <sa/ike_sa.h>
  30 #include <encoding/message.h>
  31 #include <config/peer_cfg.h>
  32
  33 /**
  34  * Manages and synchronizes access to all IKE_SAs.
  35  *
  36  * To synchronize access to thread-unsave IKE_SAs, they are checked out for
  37  * use and checked in afterwards. A checked out SA is exclusively accessible
  38  * by the owning thread.
  39  */
  40 struct ike_sa_manager_t {
  41
  42         /**
  43          * Checkout an existing IKE_SA.
  44          *
  45          * @param ike_sa_id                     the SA identifier, will be updated
  46          * @returns
  47          *                                                      - checked out IKE_SA if found
  48          *                                                      - NULL, if specified IKE_SA is not found.
  49          */
  50         ike_sa_t* (*checkout) (ike_sa_manager_t* this, ike_sa_id_t *sa_id);
  51
  52         /**
  53          * Create and check out a new IKE_SA.
  54          *
  55          * @param version                       IKE version of this SA
  56          * @param initiator                     TRUE for initiator, FALSE otherwise
  57          * @returns                             created and checked out IKE_SA
  58          */
  59         ike_sa_t* (*checkout_new) (ike_sa_manager_t* this, ike_version_t version,
  60                                                            bool initiator);
  61
  62         /**
  63          * Checkout an IKE_SA by a message.
  64          *
  65          * In some situations, it is necessary that the manager knows the
  66          * message to use for the checkout. This has the following reasons:
  67          *
  68          * 1. If the targeted IKE_SA is already processing a message, we do not
  69          *    check it out if the message ID is the same.
  70          * 2. If it is an IKE_SA_INIT request, we have to check if it is a
  71          *    retransmission. If so, we have to drop the message, we would
  72          *    create another unneeded IKE_SA for each retransmitted packet.
  73          *
  74          * A call to checkout_by_message() returns a (maybe new created) IKE_SA.
  75          * If processing the message does not make sense (for the reasons above),
  76          * NULL is returned.
  77          *
  78          * @param ike_sa_id                     the SA identifier, will be updated
  79          * @returns
  80          *                                                      - checked out/created IKE_SA
  81          *                                                      - NULL to not process message further
  82          */
  83         ike_sa_t* (*checkout_by_message) (ike_sa_manager_t* this, message_t *message);
  84
  85         /**
  86          * Checkout an IKE_SA for initiation by a peer_config.
  87          *
  88          * To initiate, a CHILD_SA may be established within an existing IKE_SA.
  89          * This call checks for an existing IKE_SA by comparing the configuration.
  90          * If the CHILD_SA can be created in an existing IKE_SA, the matching SA
  91          * is returned.
  92          * If no IKE_SA is found, a new one is created. This is also the case when
  93          * the found IKE_SA is in the DELETING state.
  94          *
  95          * @param peer_cfg                      configuration used to find an existing IKE_SA
  96          * @return                                      checked out/created IKE_SA
  97          */
  98         ike_sa_t* (*checkout_by_config) (ike_sa_manager_t* this,
  99                                                                          peer_cfg_t *peer_cfg);
 100
 101         /**
 102          * Check for duplicates of the given IKE_SA.
 103          *
 104          * Measures are taken according to the uniqueness policy of the IKE_SA.
 105          * The return value indicates whether duplicates have been found and if
 106          * further measures should be taken (e.g. cancelling an IKE_AUTH exchange).
 107          * check_uniqueness() must be called before the IKE_SA is complete,
 108          * deadlocks occur otherwise.
 109          *
 110          * @param ike_sa                        ike_sa to check
 111          * @param force_replace         replace existing SAs, regardless of unique policy
 112          * @return                                      TRUE, if the given IKE_SA has duplicates and
 113          *                                                      should be deleted
 114          */
 115         bool (*check_uniqueness)(ike_sa_manager_t *this, ike_sa_t *ike_sa,
 116                                                          bool force_replace);
 117
 118         /**
 119          * Check if we already have a connected IKE_SA between two identities.
 120          *
 121          * @param me                            own identity
 122          * @param other                         remote identity
 123          * @param family                        address family to include in uniqueness check
 124          * @return                                      TRUE if we have a connected IKE_SA
 125          */
 126         bool (*has_contact)(ike_sa_manager_t *this, identification_t *me,
 127                                                 identification_t *other, int family);
 128
 129         /**
 130          * Check out an IKE_SA a unique ID.
 131          *
 132          * Every IKE_SA is uniquely identified by a numerical ID. This checkout
 133          * function uses the unique ID of the IKE_SA to check it out.
 134          *
 135          * @param id                            unique ID of the object
 136          * @return
 137          *                                                      - checked out IKE_SA, if found
 138          *                                                      - NULL, if not found
 139          */
 140         ike_sa_t* (*checkout_by_id) (ike_sa_manager_t* this, u_int32_t id);
 141
 142         /**
 143          * Check out an IKE_SA by the policy/connection name.
 144          *
 145          * Check out the IKE_SA by the configuration name, either from the IKE- or
 146          * one of its CHILD_SAs.
 147          *
 148          * @param name                          name of the connection/policy
 149          * @param child                         TRUE to use policy name, FALSE to use conn name
 150          * @return
 151          *                                                      - checked out IKE_SA, if found
 152          *                                                      - NULL, if not found
 153          */
 154         ike_sa_t* (*checkout_by_name) (ike_sa_manager_t* this, char *name,
 155                                                                    bool child);
 156
 157         /**
 158          * Create an enumerator over all stored IKE_SAs.
 159          *
 160          * While enumerating an IKE_SA, it is temporarily checked out and
 161          * automatically checked in after the current enumeration step.
 162          *
 163          * @param wait                          TRUE to wait for checked out SAs, FALSE to skip
 164          * @return                                      enumerator over all IKE_SAs.
 165          */
 166         enumerator_t *(*create_enumerator) (ike_sa_manager_t* this, bool wait);
 167
 168         /**
 169          * Create an enumerator over ike_sa_id_t*, matching peer identities.
 170          *
 171          * The remote peer is identified by its XAuth or EAP identity, if available.
 172          *
 173          * @param me                            local peer identity to match
 174          * @param other                         remote peer identity to match
 175          * @param family                        address family to match, 0 for any
 176          * @return                                      enumerator over ike_sa_id_t*
 177          */
 178         enumerator_t* (*create_id_enumerator)(ike_sa_manager_t *this,
 179                                                                 identification_t *me, identification_t *other,
 180                                                                 int family);
 181
 182         /**
 183          * Checkin the SA after usage.
 184          *
 185          * If the IKE_SA is not registered in the manager, a new entry is created.
 186          *
 187          * @param ike_sa_id                     the SA identifier, will be updated
 188          * @param ike_sa                        checked out SA
 189          */
 190         void (*checkin) (ike_sa_manager_t* this, ike_sa_t *ike_sa);
 191
 192         /**
 193          * Destroy a checked out SA.
 194          *
 195          * The IKE SA is destroyed without notification of the remote peer.
 196          * Use this only if the other peer doesn't respond or behaves not
 197          * as predicted.
 198          * Checking in and destruction is an atomic operation (for the IKE_SA),
 199          * so this can be called if the SA is in a "unclean" state, without the
 200          * risk that another thread can get the SA.
 201          *
 202          * @param ike_sa                        SA to delete
 203          */
 204         void (*checkin_and_destroy) (ike_sa_manager_t* this, ike_sa_t *ike_sa);
 205
 206         /**
 207          * Get the number of IKE_SAs currently registered.
 208          *
 209          * @return                                      number of registered IKE_SAs
 210          */
 211         u_int (*get_count)(ike_sa_manager_t *this);
 212
 213         /**
 214          * Get the number of IKE_SAs which are in the connecting state.
 215          *
 216          * To prevent the server from resource exhaustion, cookies and other
 217          * mechanisms are used. The number of half open IKE_SAs is a good
 218          * indicator to see if a peer is flooding the server.
 219          * If a host is supplied, only the number of half open IKE_SAs initiated
 220          * from this IP are counted.
 221          * Only SAs for which we are the responder are counted.
 222          *
 223          * @param ip                            NULL for all, IP for half open IKE_SAs with IP
 224          * @return                                      number of half open IKE_SAs
 225          */
 226         u_int (*get_half_open_count) (ike_sa_manager_t *this, host_t *ip);
 227
 228         /**
 229          * Delete all existing IKE_SAs and destroy them immediately.
 230          *
 231          * Threads will be driven out, so all SAs can be deleted cleanly.
 232          * To a flush(), an immediate call to destroy() is mandatory; no other
 233          * method may be used.
 234          */
 235         void (*flush)(ike_sa_manager_t *this);
 236
 237         /**
 238          * Destroys the manager with all associated SAs.
 239          *
 240          * A call to flush() is required before calling destroy.
 241          */
 242         void (*destroy) (ike_sa_manager_t *this);
 243 };
 244
 245 /**
 246  * Create the IKE_SA manager.
 247  *
 248  * @returns     ike_sa_manager_t object, NULL if initialization fails
 249  */
 250 ike_sa_manager_t *ike_sa_manager_create(void);
 251
 252 #endif /** IKE_SA_MANAGER_H_ @}*/