programs/charon/charon/threads/kernel_interface.c

   1 /**
   2  * @file kernel_interface.c
   3  *
   4  * @brief Implementation of kernel_interface_t.
   5  *
   6  */
   7
   8 /*
   9  * Copyright (C) 2005 Jan Hutter, Martin Willi
  10  * Hochschule fuer Technik Rapperswil
  11  * Copyright (C) 2003 Herbert Xu.
  12  *
  13  * Contains modified parts from pluto.
  14  *
  15  * This program is free software; you can redistribute it and/or modify it
  16  * under the terms of the GNU General Public License as published by the
  17  * Free Software Foundation; either version 2 of the License, or (at your
  18  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  19  *
  20  * This program is distributed in the hope that it will be useful, but
  21  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  22  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  23  * for more details.
  24  */
  25
  26 #include <sys/types.h>
  27 #include <sys/socket.h>
  28 #include <linux/netlink.h>
  29 #include <pthread.h>
  30 #include <unistd.h>
  31 #include <fcntl.h>
  32 #include <errno.h>
  33 #include <string.h>
  34
  35 #include "kernel_interface.h"
  36
  37 #include <daemon.h>
  38 #include <utils/linked_list.h>
  39
  40
  41 #define KERNEL_ESP 50
  42 #define KERNEL_AH 51
  43
  44 #define SPD_PRIORITY 1024
  45
  46 #define XFRM_DATA_LENGTH 512
  47
  48
  49 typedef struct xfrm_data_t xfrm_data_t;
  50
  51 /**
  52  * Lenght/Type/data struct for userdata in xfrm
  53  * We dont use the "I-don't-know-where-they-come-from"-structs
  54  * used in the kernel.
  55  */
  56 struct xfrm_data_t {
  57         /**
  58          * length of the data
  59          */
  60         u_int16_t length;
  61
  62         /**
  63          * type of data
  64          */
  65         u_int16_t type;
  66
  67         /**
  68          * and the data itself, for different purposes
  69          */
  70         union {
  71                 /** algorithm */
  72                 struct xfrm_algo algo;
  73                 /** policy tmpl */
  74                 struct xfrm_user_tmpl tmpl[2];
  75         };
  76 };
  77
  78
  79 typedef struct netlink_message_t netlink_message_t;
  80
  81 /**
  82  * Representation of ANY netlink message used
  83  */
  84 struct netlink_message_t {
  85
  86         /**
  87          * header of the netlink message
  88          */
  89         struct nlmsghdr hdr;
  90
  91         union {
  92                 /** error message */
  93                 struct nlmsgerr e;
  94                 /** message for spi allocation */
  95                 struct xfrm_userspi_info spi;
  96                 /** message for SA manipulation */
  97                 struct xfrm_usersa_id sa_id;
  98                 /** message for SA installation */
  99                 struct xfrm_usersa_info sa;
 100                 /** message for policy manipulation */
 101                 struct xfrm_userpolicy_id policy_id;
 102                 /** message for policy installation */
 103                 struct xfrm_userpolicy_info policy;
 104         };
 105         u_int8_t data[XFRM_DATA_LENGTH];
 106 };
 107
 108
 109 typedef struct private_kernel_interface_t private_kernel_interface_t;
 110
 111  /**
 112  * @brief Private Variables and Functions of kernel_interface class.
 113  *
 114  */
 115 struct private_kernel_interface_t {
 116         /**
 117          * Public part of the kernel_interface_t object.
 118          */
 119         kernel_interface_t public;
 120
 121         /**
 122          * Netlink communication socket.
 123          */
 124         int socket;
 125
 126         /**
 127          * Process id of kernel thread
 128          */
 129         pid_t pid;
 130
 131         /**
 132          * Sequence number for messages.
 133          */
 134         u_int32_t seq;
 135
 136         /**
 137          * List of responded messages.
 138          */
 139         linked_list_t *responses;
 140
 141         /**
 142          * Thread which receives messages.
 143          */
 144         pthread_t thread;
 145
 146         /**
 147          * Mutex locks access to replies list.
 148          */
 149         pthread_mutex_t mutex;
 150
 151         /**
 152          * Condvar allows signaling of threads waiting for a reply.
 153          */
 154         pthread_cond_t condvar;
 155
 156         /**
 157          * Logger for XFRM stuff
 158          */
 159         logger_t *logger;
 160
 161         /**
 162          * Function for the thread, receives messages.
 163          */
 164         void (*receive_messages) (private_kernel_interface_t *this);
 165
 166         /**
 167          * Sends a netlink_message_t down to the kernel and wait for reply.
 168          */
 169         status_t (*send_message) (private_kernel_interface_t *this, netlink_message_t *request, netlink_message_t **response);
 170 };
 171
 172 /**
 173  * In the kernel, algorithms are identified as strings, we use our
 174  * mapping functions...
 175  * Algorithms for encryption.
 176  * TODO: Add missing algorithm strings
 177  */
 178 mapping_t kernel_encryption_algs_m[] = {
 179         {ENCR_DES_IV64, ""},
 180         {ENCR_DES, "des"},
 181         {ENCR_3DES, "des3_ede"},
 182         {ENCR_RC5, ""},
 183         {ENCR_IDEA, "idea"},
 184         {ENCR_CAST, "cast128"},
 185         {ENCR_BLOWFISH, "blowfish"},
 186         {ENCR_3IDEA, ""},
 187         {ENCR_DES_IV32, ""},
 188         {ENCR_NULL, ""},
 189         {ENCR_AES_CBC, "aes"},
 190         {ENCR_AES_CTR, ""},
 191         {MAPPING_END, NULL}
 192 };
 193 /**
 194  * In the kernel, algorithms are identified as strings, we use our
 195  * mapping functions...
 196  * Algorithms for integrity protection.
 197  * TODO: Add missing algorithm strings
 198  */
 199 mapping_t kernel_integrity_algs_m[] = {
 200         {AUTH_HMAC_MD5_96, "md5"},
 201         {AUTH_HMAC_SHA1_96, "sha1"},
 202         {AUTH_DES_MAC, ""},
 203         {AUTH_KPDK_MD5, ""},
 204         {AUTH_AES_XCBC_96, ""},
 205         {MAPPING_END, NULL}
 206 };
 207
 208
 209 /**
 210  * Implementation of kernel_interface_t.get_spi.
 211  */
 212 static status_t get_spi(private_kernel_interface_t *this,
 213                                                 host_t *src, host_t *dest,
 214                                                 protocol_id_t protocol, u_int32_t reqid,
 215                                                 u_int32_t *spi)
 216 {
 217         netlink_message_t request, *response;
 218         status_t status = SUCCESS;
 219
 220
 221         this->logger->log(this->logger, CONTROL|LEVEL2, "getting spi");
 222
 223         memset(&request, 0, sizeof(request));
 224         request.hdr.nlmsg_len = NLMSG_ALIGN(NLMSG_LENGTH(sizeof(request.spi)));
 225         request.hdr.nlmsg_flags = NLM_F_REQUEST;
 226         request.hdr.nlmsg_type = XFRM_MSG_ALLOCSPI;
 227         request.spi.info.saddr = src->get_xfrm_addr(src);
 228         request.spi.info.id.daddr = dest->get_xfrm_addr(dest);
 229         request.spi.info.mode = TRUE; /* tunnel mode */
 230         request.spi.info.reqid = reqid;
 231         request.spi.info.id.proto = (protocol == PROTO_ESP) ? KERNEL_ESP : KERNEL_AH;
 232         request.spi.info.family = PF_INET;
 233         request.spi.min = 0xc0000000;
 234         request.spi.max = 0xcFFFFFFF;
 235
 236         if (this->send_message(this, &request, &response) != SUCCESS)
 237         {
 238                 this->logger->log(this->logger, ERROR, "netlink communication failed");
 239                 return FAILED;
 240         }
 241         else if (response->hdr.nlmsg_type == NLMSG_ERROR)
 242         {
 243                 this->logger->log(this->logger, ERROR, "netlink request XFRM_MSG_ALLOCSPI got an error: %s",
 244                                                   strerror(-response->e.error));
 245                 status = FAILED;
 246         }
 247         else if (response->hdr.nlmsg_type != XFRM_MSG_NEWSA)
 248         {
 249                 this->logger->log(this->logger, ERROR, "netlink request XFRM_MSG_ALLOCSPI got a unknown reply");
 250                 status = FAILED;
 251         }
 252         else if (response->hdr.nlmsg_len < NLMSG_LENGTH(sizeof(response->sa)))
 253         {
 254                 this->logger->log(this->logger, ERROR, "netlink request XFRM_MSG_ALLOCSPI got an invalid reply");
 255                 status = FAILED;
 256         }
 257         else
 258         {
 259                 *spi = response->sa.id.spi;
 260         }
 261         free(response);
 262
 263         return status;
 264 }
 265
 266 /**
 267  * Implementation of kernel_interface_t.add_sa.
 268  */
 269 static status_t add_sa( private_kernel_interface_t *this,
 270                                                 host_t *me,
 271                                                 host_t *other,
 272                                                 u_int32_t spi,
 273                                                 int protocol,
 274                                                 u_int32_t reqid,
 275                                                 encryption_algorithm_t enc_alg,
 276                                                 chunk_t encryption_key,
 277                                                 integrity_algorithm_t int_alg,
 278                                                 chunk_t integrity_key,
 279                                                 bool replace)
 280 {
 281         netlink_message_t request, *response;
 282         memset(&request, 0, sizeof(request));
 283         status_t status = SUCCESS;
 284
 285         this->logger->log(this->logger, CONTROL|LEVEL2, "adding SA");
 286
 287         request.hdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
 288         request.hdr.nlmsg_type = replace ? XFRM_MSG_UPDSA : XFRM_MSG_NEWSA;
 289
 290         request.sa.saddr = me->get_xfrm_addr(me);
 291         request.sa.id.daddr = other->get_xfrm_addr(other);
 292
 293         request.sa.id.spi = spi;
 294         request.sa.id.proto = (protocol == PROTO_ESP) ? KERNEL_ESP : KERNEL_AH;
 295         request.sa.family = me->get_family(me);
 296         request.sa.mode = TRUE; /* tunnel mode */
 297         request.sa.replay_window = 32;
 298         request.sa.reqid = reqid;
 299         request.sa.lft.soft_byte_limit = XFRM_INF;
 300         request.sa.lft.soft_packet_limit = XFRM_INF;
 301         request.sa.lft.hard_byte_limit = XFRM_INF;
 302         request.sa.lft.hard_packet_limit = XFRM_INF;
 303
 304         request.hdr.nlmsg_len = NLMSG_ALIGN(NLMSG_LENGTH(sizeof(request.sa)));
 305
 306         if (enc_alg != ENCR_UNDEFINED)
 307         {
 308                 xfrm_data_t *data = (xfrm_data_t*)(((u_int8_t*)&request) + request.hdr.nlmsg_len);
 309
 310                 data->type = XFRMA_ALG_CRYPT;
 311                 data->length = 4 + sizeof(data->algo) + encryption_key.len;
 312                 data->algo.alg_key_len = encryption_key.len * 8;
 313                 request.hdr.nlmsg_len += data->length;
 314                 if (request.hdr.nlmsg_len > sizeof(request))
 315                 {
 316                         return FAILED;
 317                 }
 318                 strcpy(data->algo.alg_name, mapping_find(kernel_encryption_algs_m, enc_alg));
 319                 memcpy(data->algo.alg_key, encryption_key.ptr, encryption_key.len);
 320         }
 321
 322         if (int_alg != AUTH_UNDEFINED)
 323         {
 324                 xfrm_data_t *data = (xfrm_data_t*)(((u_int8_t*)&request) + request.hdr.nlmsg_len);
 325
 326                 data->type = XFRMA_ALG_AUTH;
 327                 data->length = 4 + sizeof(data->algo) + integrity_key.len;
 328                 data->algo.alg_key_len = integrity_key.len * 8;
 329                 request.hdr.nlmsg_len += data->length;
 330                 if (request.hdr.nlmsg_len > sizeof(request))
 331                 {
 332                         return FAILED;
 333                 }
 334                 strcpy(data->algo.alg_name, mapping_find(kernel_integrity_algs_m, int_alg));
 335                 memcpy(data->algo.alg_key, integrity_key.ptr, integrity_key.len);
 336         }
 337
 338         /* TODO: add IPComp here*/
 339
 340         if (this->send_message(this, &request, &response) != SUCCESS)
 341         {
 342                 this->logger->log(this->logger, ERROR, "netlink communication failed");
 343                 return FAILED;
 344         }
 345         else if (response->hdr.nlmsg_type != NLMSG_ERROR)
 346         {
 347                 this->logger->log(this->logger, ERROR, "netlink request XFRM_MSG_NEWSA not acknowledged");
 348                 status = FAILED;
 349         }
 350         else if (response->e.error)
 351         {
 352                 this->logger->log(this->logger, ERROR, "netlink request XFRM_MSG_NEWSA got error %s",
 353                                                   strerror(-response->e.error));
 354                 status = FAILED;
 355         }
 356
 357         free(response);
 358         return status;
 359 }
 360
 361 static status_t del_sa( private_kernel_interface_t *this,
 362                                                 host_t *dst,
 363                                                 u_int32_t spi,
 364                                                 protocol_id_t protocol)
 365 {
 366         netlink_message_t request, *response;
 367         memset(&request, 0, sizeof(request));
 368         status_t status = SUCCESS;
 369
 370         this->logger->log(this->logger, CONTROL|LEVEL2, "deleting SA");
 371
 372         request.hdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
 373         request.hdr.nlmsg_type = XFRM_MSG_DELSA;
 374
 375         request.sa_id.daddr = dst->get_xfrm_addr(dst);
 376
 377         request.sa_id.spi = spi;
 378         request.sa_id.proto = (protocol == PROTO_ESP) ? KERNEL_ESP : KERNEL_AH;
 379         request.sa_id.family = dst->get_family(dst);
 380
 381         request.hdr.nlmsg_len = NLMSG_ALIGN(NLMSG_LENGTH(sizeof(request.sa_id)));
 382
 383         if (this->send_message(this, &request, &response) != SUCCESS)
 384         {
 385                 return FAILED;
 386         }
 387         else if (response->hdr.nlmsg_type != NLMSG_ERROR)
 388         {
 389                 status = FAILED;
 390         }
 391         else if (response->e.error)
 392         {
 393                 status = FAILED;
 394         }
 395
 396         free(response);
 397         return status;
 398 }
 399
 400 /**
 401  * Implementation of kernel_interface_t.add_policy.
 402  */
 403 static status_t add_policy(private_kernel_interface_t *this,
 404                                                   host_t *me, host_t *other,
 405                                                   host_t *src, host_t *dst,
 406                                                   u_int8_t src_hostbits, u_int8_t dst_hostbits,
 407                                                   int direction, int upper_proto,
 408                                                   bool ah, bool esp,
 409                                                   u_int32_t reqid)
 410 {
 411         netlink_message_t request, *response;
 412         status_t status = SUCCESS;
 413
 414         this->logger->log(this->logger, CONTROL|LEVEL2, "adding policy");
 415
 416         memset(&request, 0, sizeof(request));
 417         request.hdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
 418
 419         request.policy.sel.sport = htons(src->get_port(src));
 420         request.policy.sel.dport = htons(dst->get_port(dst));
 421         request.policy.sel.sport_mask = (request.policy.sel.sport) ? ~0 : 0;
 422         request.policy.sel.dport_mask = (request.policy.sel.dport) ? ~0 : 0;
 423         request.policy.sel.saddr = src->get_xfrm_addr(src);
 424         request.policy.sel.daddr = dst->get_xfrm_addr(dst);
 425         request.policy.sel.prefixlen_s = src_hostbits;
 426         request.policy.sel.prefixlen_d = dst_hostbits;
 427         request.policy.sel.proto = upper_proto;
 428         request.policy.sel.family = src->get_family(src);
 429
 430         request.hdr.nlmsg_type = XFRM_MSG_NEWPOLICY;
 431         request.hdr.nlmsg_len = NLMSG_ALIGN(NLMSG_LENGTH(sizeof(request.policy)));
 432
 433         request.policy.dir = direction;
 434         request.policy.priority = SPD_PRIORITY;
 435         request.policy.action = XFRM_POLICY_ALLOW;
 436         request.policy.share = XFRM_SHARE_ANY;
 437
 438         request.policy.lft.soft_byte_limit = XFRM_INF;
 439         request.policy.lft.soft_packet_limit = XFRM_INF;
 440         request.policy.lft.hard_byte_limit = XFRM_INF;
 441         request.policy.lft.hard_packet_limit = XFRM_INF;
 442
 443         if (esp || ah)
 444         {
 445                 xfrm_data_t *data;
 446                 int tmpl_pos = 0;
 447                 data = (xfrm_data_t*)(((u_int8_t*)&request) + request.hdr.nlmsg_len);
 448                 data->type = XFRMA_TMPL;
 449                 if (esp)
 450                 {
 451                         data->tmpl[tmpl_pos].reqid = reqid;
 452                         data->tmpl[tmpl_pos].id.proto = KERNEL_ESP;
 453                         data->tmpl[tmpl_pos].aalgos = data->tmpl[tmpl_pos].ealgos = data->tmpl[tmpl_pos].calgos = ~0;
 454                         data->tmpl[tmpl_pos].mode = TRUE;
 455
 456                         data->tmpl[tmpl_pos].saddr = me->get_xfrm_addr(me);
 457                         data->tmpl[tmpl_pos].id.daddr = me->get_xfrm_addr(other);
 458
 459                         tmpl_pos++;
 460                 }
 461                 if (ah)
 462                 {
 463                         data->tmpl[tmpl_pos].reqid = reqid;
 464                         data->tmpl[tmpl_pos].id.proto = KERNEL_AH;
 465                         data->tmpl[tmpl_pos].aalgos = data->tmpl[tmpl_pos].ealgos = data->tmpl[tmpl_pos].calgos = ~0;
 466                         data->tmpl[tmpl_pos].mode = TRUE;
 467
 468                         data->tmpl[tmpl_pos].saddr = me->get_xfrm_addr(me);
 469                         data->tmpl[tmpl_pos].id.daddr = other->get_xfrm_addr(other);
 470
 471                         tmpl_pos++;
 472                 }
 473                 data->length = 4 + sizeof(struct xfrm_user_tmpl) * tmpl_pos;
 474                 request.hdr.nlmsg_len += data->length;
 475         }
 476
 477         if (this->send_message(this, &request, &response) != SUCCESS)
 478         {
 479                 this->logger->log(this->logger, ERROR, "netlink communication failed");
 480                 return FAILED;
 481         }
 482         else if (response->hdr.nlmsg_type != NLMSG_ERROR)
 483         {
 484                 this->logger->log(this->logger, ERROR, "netlink request XFRM_MSG_NEWPOLICY not acknowledged");
 485                 status = FAILED;
 486         }
 487         else if (response->e.error)
 488         {
 489                 this->logger->log(this->logger, ERROR, "netlink request XFRM_MSG_NEWPOLICY got error %s",
 490                                                   strerror(-response->e.error));
 491                 status = FAILED;
 492         }
 493
 494         free(response);
 495         return status;
 496 }
 497
 498 /**
 499  * Implementation of kernel_interface_t.del_policy.
 500  */
 501 static status_t del_policy(private_kernel_interface_t *this,
 502                                                    host_t *me, host_t *other,
 503                                                    host_t *src, host_t *dst,
 504                                                    u_int8_t src_hostbits, u_int8_t dst_hostbits,
 505                                                    int direction, int upper_proto)
 506 {
 507         netlink_message_t request, *response;
 508         status_t status = SUCCESS;
 509
 510
 511         this->logger->log(this->logger, CONTROL|LEVEL2, "deleting policy");
 512
 513         memset(&request, 0, sizeof(request));
 514         request.hdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
 515
 516         request.policy_id.sel.sport = htons(src->get_port(src));
 517         request.policy_id.sel.dport = htons(dst->get_port(dst));
 518         request.policy_id.sel.sport_mask = (request.policy.sel.sport) ? ~0 : 0;
 519         request.policy_id.sel.dport_mask = (request.policy.sel.dport) ? ~0 : 0;
 520         request.policy_id.sel.saddr = src->get_xfrm_addr(src);
 521         request.policy_id.sel.daddr = dst->get_xfrm_addr(dst);
 522         request.policy_id.sel.prefixlen_s = src_hostbits;
 523         request.policy_id.sel.prefixlen_d = dst_hostbits;
 524         request.policy_id.sel.proto = upper_proto;
 525         request.policy_id.sel.family = src->get_family(src);
 526
 527         request.policy_id.dir = direction;
 528
 529         request.hdr.nlmsg_type = XFRM_MSG_DELPOLICY;
 530         request.hdr.nlmsg_len = NLMSG_ALIGN(NLMSG_LENGTH(sizeof(request.policy_id)));
 531
 532         if (this->send_message(this, &request, &response) != SUCCESS)
 533         {
 534                 return FAILED;
 535         }
 536         else if (response->hdr.nlmsg_type != NLMSG_ERROR)
 537         {
 538                 status = FAILED;
 539         }
 540         else if (response->e.error)
 541         {
 542                 status = FAILED;
 543         }
 544
 545         free(response);
 546         return status;
 547 }
 548
 549 /**
 550  * Implementation of private_kernel_interface_t.send_message.
 551  */
 552 static status_t send_message(private_kernel_interface_t *this, netlink_message_t *request, netlink_message_t **response)
 553 {
 554         size_t length;
 555         struct sockaddr_nl addr;
 556
 557         request->hdr.nlmsg_seq = ++this->seq;
 558         request->hdr.nlmsg_pid = this->pid;
 559
 560         memset(&addr, 0, sizeof(struct sockaddr_nl));
 561         addr.nl_family = AF_NETLINK;
 562         addr.nl_pid = 0;
 563         addr.nl_groups = 0;
 564
 565         length = sendto(this->socket,(void *)request, request->hdr.nlmsg_len, 0, (struct sockaddr *)&addr, sizeof(addr));
 566
 567         if (length < 0)
 568         {
 569                 return FAILED;
 570         }
 571         else if (length != request->hdr.nlmsg_len)
 572         {
 573                 return FAILED;
 574         }
 575
 576         pthread_mutex_lock(&(this->mutex));
 577
 578         while (TRUE)
 579         {
 580                 iterator_t *iterator;
 581                 bool found = FALSE;
 582                 /* search list, break if found */
 583                 iterator = this->responses->create_iterator(this->responses, TRUE);
 584                 while (iterator->has_next(iterator))
 585                 {
 586                         netlink_message_t *listed_response;
 587                         iterator->current(iterator, (void**)&listed_response);
 588                         if (listed_response->hdr.nlmsg_seq == request->hdr.nlmsg_seq)
 589                         {
 590                                 /* matches our request, this is the reply */
 591                                 *response = listed_response;
 592                                 found = TRUE;
 593                                 break;
 594                         }
 595                 }
 596                 iterator->destroy(iterator);
 597
 598                 if (found)
 599                 {
 600                         break;
 601                 }
 602                 /* TODO: we should time out, if something goes wrong!??? */
 603                 pthread_cond_wait(&(this->condvar), &(this->mutex));
 604         }
 605
 606         pthread_mutex_unlock(&(this->mutex));
 607
 608         return SUCCESS;
 609 }
 610
 611 /**
 612  * Implementation of private_kernel_interface_t.receive_messages.
 613  */
 614 static void receive_messages(private_kernel_interface_t *this)
 615 {
 616         while(TRUE)
 617         {
 618                 netlink_message_t response, *listed_response;
 619                 while (TRUE)
 620                 {
 621                         struct sockaddr_nl addr;
 622                         socklen_t addr_length;
 623                         size_t length;
 624
 625                         addr_length = sizeof(addr);
 626
 627                         response.hdr.nlmsg_type = XFRM_MSG_NEWSA;
 628                         length = recvfrom(this->socket, &response, sizeof(response), 0, (struct sockaddr*)&addr, &addr_length);
 629                         if (length < 0)
 630                         {
 631                                 if (errno == EINTR)
 632                                 {
 633                                         /* interrupted, try again */
 634                                         continue;
 635                                 }
 636                                 charon->kill(charon, "receiving from netlink socket failed");
 637                         }
 638                         if (!NLMSG_OK(&response.hdr, length))
 639                         {
 640                                 /* bad netlink message */
 641                                 continue;
 642                         }
 643                         if (addr.nl_pid != 0)
 644                         {
 645                                 /* not from kernel. not interested, try another one */
 646                                 continue;
 647                         }
 648                         break;
 649                 }
 650
 651                 /* got a valid message.
 652                  * requests are handled on our own,
 653                  * responses are listed for the requesters
 654                  */
 655                 if (response.hdr.nlmsg_flags & NLM_F_REQUEST)
 656                 {
 657                         /* handle request */
 658                 }
 659                 else
 660                 {
 661                         /* add response to queue */
 662                         listed_response = malloc(sizeof(response));
 663                         memcpy(listed_response, &response, sizeof(response));
 664
 665                         pthread_mutex_lock(&(this->mutex));
 666                         this->responses->insert_last(this->responses, (void*)listed_response);
 667                         pthread_mutex_unlock(&(this->mutex));
 668                         /* signal ALL waiting threads */
 669                         pthread_cond_broadcast(&(this->condvar));
 670                 }
 671                 /* get the next one */
 672         }
 673 }
 674
 675 /**
 676  * Implementation of kernel_interface_t.destroy.
 677  */
 678 static void destroy(private_kernel_interface_t *this)
 679 {
 680         pthread_cancel(this->thread);
 681         pthread_join(this->thread, NULL);
 682         close(this->socket);
 683         this->responses->destroy(this->responses);
 684         free(this);
 685 }
 686
 687 /*
 688  * Described in header.
 689  */
 690 kernel_interface_t *kernel_interface_create()
 691 {
 692         private_kernel_interface_t *this = malloc_thing(private_kernel_interface_t);
 693
 694         /* public functions */
 695         this->public.get_spi = (status_t(*)(kernel_interface_t*,host_t*,host_t*,protocol_id_t,u_int32_t,u_int32_t*))get_spi;
 696         this->public.add_sa  = (status_t(*)(kernel_interface_t *,host_t*,host_t*,u_int32_t,protocol_id_t,u_int32_t,encryption_algorithm_t,chunk_t,integrity_algorithm_t,chunk_t,bool))add_sa;
 697         this->public.add_policy = (status_t(*)(kernel_interface_t*,host_t*, host_t*,host_t*,host_t*,u_int8_t,u_int8_t,int,int,bool,bool,u_int32_t))add_policy;
 698         this->public.del_sa = (status_t(*)(kernel_interface_t*,host_t*,u_int32_t,protocol_id_t))del_sa;
 699         this->public.del_policy = (status_t(*)(kernel_interface_t*,host_t*,host_t*,host_t*,host_t*,u_int8_t,u_int8_t,int,int))del_policy;
 700
 701         this->public.destroy = (void(*)(kernel_interface_t*)) destroy;
 702
 703         /* private members */
 704         this->receive_messages = receive_messages;
 705         this->send_message = send_message;
 706         this->pid = getpid();
 707         this->responses = linked_list_create();
 708         this->logger = logger_manager->get_logger(logger_manager, XFRM);
 709         pthread_mutex_init(&(this->mutex),NULL);
 710         pthread_cond_init(&(this->condvar),NULL);
 711         this->seq = 0;
 712         this->socket = socket(PF_NETLINK, SOCK_RAW, NETLINK_XFRM);
 713         if (this->socket <= 0)
 714         {
 715                 this->responses->destroy(this->responses);
 716                 free(this);
 717                 charon->kill(charon, "Unable to create netlink socket");
 718         }
 719
 720         if (pthread_create(&(this->thread), NULL, (void*(*)(void*))this->receive_messages, this) != 0)
 721         {
 722                 this->responses->destroy(this->responses);
 723                 close(this->socket);
 724                 free(this);
 725                 charon->kill(charon, "Unable to create netlink thread");
 726         }
 727
 728         return (&this->public);
 729 }