nhrpd/vici.c

   1 /* strongSwan VICI protocol implementation for NHRP
   2  * Copyright (c) 2014-2015 Timo Teräs
   3  *
   4  * This file is free software: you may copy, redistribute and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  */
   9
  10 #ifdef HAVE_CONFIG_H
  11 #include "config.h"
  12 #endif
  13
  14 #include <string.h>
  15 #include <sys/socket.h>
  16 #include <sys/un.h>
  17
  18 #include "thread.h"
  19 #include "zbuf.h"
  20 #include "log.h"
  21 #include "lib_errors.h"
  22
  23 #include "nhrpd.h"
  24 #include "vici.h"
  25 #include "nhrp_errors.h"
  26
  27 #define ERRNO_IO_RETRY(EN) (((EN) == EAGAIN) || ((EN) == EWOULDBLOCK) || ((EN) == EINTR))
  28
  29 struct blob {
  30         char *ptr;
  31         int len;
  32 };
  33
  34 static int blob_equal(const struct blob *b, const char *str)
  35 {
  36         if (!b || b->len != (int)strlen(str))
  37                 return 0;
  38         return memcmp(b->ptr, str, b->len) == 0;
  39 }
  40
  41 static int blob2buf(const struct blob *b, char *buf, size_t n)
  42 {
  43         if (!b || b->len >= (int)n)
  44                 return 0;
  45         memcpy(buf, b->ptr, b->len);
  46         buf[b->len] = 0;
  47         return 1;
  48 }
  49
  50 struct vici_conn {
  51         struct thread *t_reconnect, *t_read, *t_write;
  52         struct zbuf ibuf;
  53         struct zbuf_queue obuf;
  54         int fd;
  55         uint8_t ibuf_data[VICI_MAX_MSGLEN];
  56 };
  57
  58 struct vici_message_ctx {
  59         const char *sections[8];
  60         int nsections;
  61 };
  62
  63 static void vici_reconnect(struct thread *t);
  64 static void vici_submit_request(struct vici_conn *vici, const char *name, ...);
  65
  66 static void vici_zbuf_puts(struct zbuf *obuf, const char *str)
  67 {
  68         size_t len = strlen(str);
  69         zbuf_put8(obuf, len);
  70         zbuf_put(obuf, str, len);
  71 }
  72
  73 static void vici_connection_error(struct vici_conn *vici)
  74 {
  75         nhrp_vc_reset();
  76
  77         THREAD_OFF(vici->t_read);
  78         THREAD_OFF(vici->t_write);
  79         zbuf_reset(&vici->ibuf);
  80         zbufq_reset(&vici->obuf);
  81
  82         close(vici->fd);
  83         vici->fd = -1;
  84         thread_add_timer(master, vici_reconnect, vici, 2, &vici->t_reconnect);
  85 }
  86
  87 static void vici_parse_message(struct vici_conn *vici, struct zbuf *msg,
  88                                void (*parser)(struct vici_message_ctx *ctx,
  89                                               enum vici_type_t msgtype,
  90                                               const struct blob *key,
  91                                               const struct blob *val),
  92                                struct vici_message_ctx *ctx)
  93 {
  94         uint8_t *type;
  95         struct blob key = {0};
  96         struct blob val = {0};
  97
  98         while ((type = zbuf_may_pull(msg, uint8_t)) != NULL) {
  99                 switch (*type) {
 100                 case VICI_SECTION_START:
 101                         key.len = zbuf_get8(msg);
 102                         key.ptr = zbuf_pulln(msg, key.len);
 103                         debugf(NHRP_DEBUG_VICI, "VICI: Section start '%.*s'",
 104                                key.len, key.ptr);
 105                         parser(ctx, *type, &key, NULL);
 106                         ctx->nsections++;
 107                         break;
 108                 case VICI_SECTION_END:
 109                         debugf(NHRP_DEBUG_VICI, "VICI: Section end");
 110                         parser(ctx, *type, NULL, NULL);
 111                         ctx->nsections--;
 112                         break;
 113                 case VICI_KEY_VALUE:
 114                         key.len = zbuf_get8(msg);
 115                         key.ptr = zbuf_pulln(msg, key.len);
 116                         val.len = zbuf_get_be16(msg);
 117                         val.ptr = zbuf_pulln(msg, val.len);
 118                         debugf(NHRP_DEBUG_VICI, "VICI: Key '%.*s'='%.*s'",
 119                                key.len, key.ptr, val.len, val.ptr);
 120                         parser(ctx, *type, &key, &val);
 121                         break;
 122                 case VICI_LIST_START:
 123                         key.len = zbuf_get8(msg);
 124                         key.ptr = zbuf_pulln(msg, key.len);
 125                         debugf(NHRP_DEBUG_VICI, "VICI: List start '%.*s'",
 126                                key.len, key.ptr);
 127                         break;
 128                 case VICI_LIST_ITEM:
 129                         val.len = zbuf_get_be16(msg);
 130                         val.ptr = zbuf_pulln(msg, val.len);
 131                         debugf(NHRP_DEBUG_VICI, "VICI: List item: '%.*s'",
 132                                val.len, val.ptr);
 133                         parser(ctx, *type, &key, &val);
 134                         break;
 135                 case VICI_LIST_END:
 136                         debugf(NHRP_DEBUG_VICI, "VICI: List end");
 137                         break;
 138                 default:
 139                         debugf(NHRP_DEBUG_VICI,
 140                                "VICI: Unsupported message component type %d",
 141                                *type);
 142                         return;
 143                 }
 144         }
 145 }
 146
 147 struct handle_sa_ctx {
 148         struct vici_message_ctx msgctx;
 149         int event;
 150         int child_ok;
 151         int kill_ikesa;
 152         uint32_t child_uniqueid, ike_uniqueid;
 153         struct {
 154                 union sockunion host;
 155                 struct blob id, cert;
 156         } local, remote;
 157 };
 158
 159 static void parse_sa_message(struct vici_message_ctx *ctx,
 160                              enum vici_type_t msgtype, const struct blob *key,
 161                              const struct blob *val)
 162 {
 163         struct handle_sa_ctx *sactx =
 164                 container_of(ctx, struct handle_sa_ctx, msgctx);
 165         struct nhrp_vc *vc;
 166         char buf[512];
 167
 168         switch (msgtype) {
 169         case VICI_SECTION_START:
 170                 if (ctx->nsections == 3) {
 171                         /* Begin of child-sa section, reset child vars */
 172                         sactx->child_uniqueid = 0;
 173                         sactx->child_ok = 0;
 174                 }
 175                 break;
 176         case VICI_SECTION_END:
 177                 if (ctx->nsections == 3) {
 178                         /* End of child-sa section, update nhrp_vc */
 179                         int up = sactx->child_ok || sactx->event == 1;
 180                         if (up) {
 181                                 vc = nhrp_vc_get(&sactx->local.host,
 182                                                  &sactx->remote.host, up);
 183                                 if (vc) {
 184                                         blob2buf(&sactx->local.id, vc->local.id,
 185                                                  sizeof(vc->local.id));
 186                                         if (blob2buf(&sactx->local.cert,
 187                                                      (char *)vc->local.cert,
 188                                                      sizeof(vc->local.cert)))
 189                                                 vc->local.certlen =
 190                                                         sactx->local.cert.len;
 191                                         blob2buf(&sactx->remote.id,
 192                                                  vc->remote.id,
 193                                                  sizeof(vc->remote.id));
 194                                         if (blob2buf(&sactx->remote.cert,
 195                                                      (char *)vc->remote.cert,
 196                                                      sizeof(vc->remote.cert)))
 197                                                 vc->remote.certlen =
 198                                                         sactx->remote.cert.len;
 199                                         sactx->kill_ikesa |=
 200                                                 nhrp_vc_ipsec_updown(
 201                                                         sactx->child_uniqueid,
 202                                                         vc);
 203                                         vc->ike_uniqueid = sactx->ike_uniqueid;
 204                                 }
 205                         } else {
 206                                 nhrp_vc_ipsec_updown(sactx->child_uniqueid, 0);
 207                         }
 208                 }
 209                 break;
 210         default:
 211                 if (!key || !key->ptr)
 212                         break;
 213
 214                 switch (key->ptr[0]) {
 215                 case 'l':
 216                         if (blob_equal(key, "local-host")
 217                             && ctx->nsections == 1) {
 218                                 if (blob2buf(val, buf, sizeof(buf)))
 219                                         if (str2sockunion(buf,
 220                                                           &sactx->local.host)
 221                                             < 0)
 222                                                 flog_err(
 223                                                         EC_NHRP_SWAN,
 224                                                         "VICI: bad strongSwan local-host: %s",
 225                                                         buf);
 226                         } else if (blob_equal(key, "local-id")
 227                                    && ctx->nsections == 1) {
 228                                 sactx->local.id = *val;
 229                         } else if (blob_equal(key, "local-cert-data")
 230                                    && ctx->nsections == 1) {
 231                                 sactx->local.cert = *val;
 232                         }
 233                         break;
 234                 case 'r':
 235                         if (blob_equal(key, "remote-host")
 236                             && ctx->nsections == 1) {
 237                                 if (blob2buf(val, buf, sizeof(buf)))
 238                                         if (str2sockunion(buf,
 239                                                           &sactx->remote.host)
 240                                             < 0)
 241                                                 flog_err(
 242                                                         EC_NHRP_SWAN,
 243                                                         "VICI: bad strongSwan remote-host: %s",
 244                                                         buf);
 245                         } else if (blob_equal(key, "remote-id")
 246                                    && ctx->nsections == 1) {
 247                                 sactx->remote.id = *val;
 248                         } else if (blob_equal(key, "remote-cert-data")
 249                                    && ctx->nsections == 1) {
 250                                 sactx->remote.cert = *val;
 251                         }
 252                         break;
 253                 case 'u':
 254                         if (blob_equal(key, "uniqueid")
 255                             && blob2buf(val, buf, sizeof(buf))) {
 256                                 if (ctx->nsections == 3)
 257                                         sactx->child_uniqueid =
 258                                                 strtoul(buf, NULL, 0);
 259                                 else if (ctx->nsections == 1)
 260                                         sactx->ike_uniqueid =
 261                                                 strtoul(buf, NULL, 0);
 262                         }
 263                         break;
 264                 case 's':
 265                         if (blob_equal(key, "state") && ctx->nsections == 3) {
 266                                 sactx->child_ok =
 267                                         (sactx->event == 0
 268                                          && (blob_equal(val, "INSTALLED")
 269                                              || blob_equal(val, "REKEYED")));
 270                         }
 271                         break;
 272                 }
 273                 break;
 274         }
 275 }
 276
 277 static void parse_cmd_response(struct vici_message_ctx *ctx,
 278                                enum vici_type_t msgtype, const struct blob *key,
 279                                const struct blob *val)
 280 {
 281         char buf[512];
 282
 283         switch (msgtype) {
 284         case VICI_KEY_VALUE:
 285                 if (blob_equal(key, "errmsg")
 286                     && blob2buf(val, buf, sizeof(buf)))
 287                         flog_err(EC_NHRP_SWAN, "VICI: strongSwan: %s", buf);
 288                 break;
 289         default:
 290                 break;
 291         }
 292 }
 293
 294 static void vici_recv_sa(struct vici_conn *vici, struct zbuf *msg, int event)
 295 {
 296         char buf[32];
 297         struct handle_sa_ctx ctx = {
 298                 .event = event,
 299                 .msgctx.nsections = 0
 300         };
 301
 302         vici_parse_message(vici, msg, parse_sa_message, &ctx.msgctx);
 303
 304         if (ctx.kill_ikesa && ctx.ike_uniqueid) {
 305                 debugf(NHRP_DEBUG_COMMON, "VICI: Deleting IKE_SA %u",
 306                        ctx.ike_uniqueid);
 307                 snprintf(buf, sizeof(buf), "%u", ctx.ike_uniqueid);
 308                 vici_submit_request(vici, "terminate", VICI_KEY_VALUE, "ike-id",
 309                                     strlen(buf), buf, VICI_END);
 310         }
 311 }
 312
 313 static void vici_recv_message(struct vici_conn *vici, struct zbuf *msg)
 314 {
 315         uint32_t msglen;
 316         uint8_t msgtype;
 317         struct blob name;
 318         struct vici_message_ctx ctx = { .nsections = 0 };
 319
 320         msglen = zbuf_get_be32(msg);
 321         msgtype = zbuf_get8(msg);
 322         debugf(NHRP_DEBUG_VICI, "VICI: Message %d, %d bytes", msgtype, msglen);
 323
 324         switch (msgtype) {
 325         case VICI_EVENT:
 326                 name.len = zbuf_get8(msg);
 327                 name.ptr = zbuf_pulln(msg, name.len);
 328
 329                 debugf(NHRP_DEBUG_VICI, "VICI: Event '%.*s'", name.len,
 330                        name.ptr);
 331                 if (blob_equal(&name, "list-sa")
 332                     || blob_equal(&name, "child-updown")
 333                     || blob_equal(&name, "child-rekey"))
 334                         vici_recv_sa(vici, msg, 0);
 335                 else if (blob_equal(&name, "child-state-installed")
 336                          || blob_equal(&name, "child-state-rekeyed"))
 337                         vici_recv_sa(vici, msg, 1);
 338                 else if (blob_equal(&name, "child-state-destroying"))
 339                         vici_recv_sa(vici, msg, 2);
 340                 break;
 341         case VICI_CMD_RESPONSE:
 342                 vici_parse_message(vici, msg, parse_cmd_response, &ctx);
 343                 break;
 344         case VICI_EVENT_UNKNOWN:
 345         case VICI_CMD_UNKNOWN:
 346                 flog_err(
 347                         EC_NHRP_SWAN,
 348                         "VICI: StrongSwan does not support mandatory events (unpatched?)");
 349                 break;
 350         case VICI_EVENT_CONFIRM:
 351                 break;
 352         default:
 353                 zlog_notice("VICI: Unrecognized message type %d", msgtype);
 354                 break;
 355         }
 356 }
 357
 358 static void vici_read(struct thread *t)
 359 {
 360         struct vici_conn *vici = THREAD_ARG(t);
 361         struct zbuf *ibuf = &vici->ibuf;
 362         struct zbuf pktbuf;
 363
 364         if (zbuf_read(ibuf, vici->fd, (size_t)-1) < 0) {
 365                 vici_connection_error(vici);
 366                 return;
 367         }
 368
 369         /* Process all messages in buffer */
 370         do {
 371                 uint32_t *hdrlen = zbuf_may_pull(ibuf, uint32_t);
 372                 if (!hdrlen)
 373                         break;
 374                 if (!zbuf_may_pulln(ibuf, ntohl(*hdrlen))) {
 375                         zbuf_reset_head(ibuf, hdrlen);
 376                         break;
 377                 }
 378
 379                 /* Handle packet */
 380                 zbuf_init(&pktbuf, hdrlen, htonl(*hdrlen) + 4,
 381                           htonl(*hdrlen) + 4);
 382                 vici_recv_message(vici, &pktbuf);
 383         } while (1);
 384
 385         thread_add_read(master, vici_read, vici, vici->fd, &vici->t_read);
 386 }
 387
 388 static void vici_write(struct thread *t)
 389 {
 390         struct vici_conn *vici = THREAD_ARG(t);
 391         int r;
 392
 393         r = zbufq_write(&vici->obuf, vici->fd);
 394         if (r > 0) {
 395                 thread_add_write(master, vici_write, vici, vici->fd,
 396                                  &vici->t_write);
 397         } else if (r < 0) {
 398                 vici_connection_error(vici);
 399         }
 400 }
 401
 402 static void vici_submit(struct vici_conn *vici, struct zbuf *obuf)
 403 {
 404         if (vici->fd < 0) {
 405                 zbuf_free(obuf);
 406                 return;
 407         }
 408
 409         zbufq_queue(&vici->obuf, obuf);
 410         thread_add_write(master, vici_write, vici, vici->fd, &vici->t_write);
 411 }
 412
 413 static void vici_submit_request(struct vici_conn *vici, const char *name, ...)
 414 {
 415         struct zbuf *obuf;
 416         uint32_t *hdrlen;
 417         va_list va;
 418         size_t len;
 419         int type;
 420
 421         obuf = zbuf_alloc(256);
 422         if (!obuf)
 423                 return;
 424
 425         hdrlen = zbuf_push(obuf, uint32_t);
 426         zbuf_put8(obuf, VICI_CMD_REQUEST);
 427         vici_zbuf_puts(obuf, name);
 428
 429         va_start(va, name);
 430         for (type = va_arg(va, int); type != VICI_END; type = va_arg(va, int)) {
 431                 zbuf_put8(obuf, type);
 432                 switch (type) {
 433                 case VICI_KEY_VALUE:
 434                         vici_zbuf_puts(obuf, va_arg(va, const char *));
 435                         len = va_arg(va, size_t);
 436                         zbuf_put_be16(obuf, len);
 437                         zbuf_put(obuf, va_arg(va, void *), len);
 438                         break;
 439                 default:
 440                         break;
 441                 }
 442         }
 443         va_end(va);
 444         *hdrlen = htonl(zbuf_used(obuf) - 4);
 445         vici_submit(vici, obuf);
 446 }
 447
 448 static void vici_register_event(struct vici_conn *vici, const char *name)
 449 {
 450         struct zbuf *obuf;
 451         uint32_t *hdrlen;
 452         uint8_t namelen;
 453
 454         namelen = strlen(name);
 455         obuf = zbuf_alloc(4 + 1 + 1 + namelen);
 456         if (!obuf)
 457                 return;
 458
 459         hdrlen = zbuf_push(obuf, uint32_t);
 460         zbuf_put8(obuf, VICI_EVENT_REGISTER);
 461         zbuf_put8(obuf, namelen);
 462         zbuf_put(obuf, name, namelen);
 463         *hdrlen = htonl(zbuf_used(obuf) - 4);
 464
 465         vici_submit(vici, obuf);
 466 }
 467
 468 static bool vici_charon_filepath_done;
 469 static bool vici_charon_not_found;
 470
 471 static char *vici_get_charon_filepath(void)
 472 {
 473         static char buff[1200];
 474         FILE *fp;
 475         char *ptr;
 476         char line[1024];
 477
 478         if (vici_charon_filepath_done)
 479                 return (char *)buff;
 480         fp = popen("ipsec --piddir", "r");
 481         if (!fp) {
 482                 if (!vici_charon_not_found) {
 483                         flog_err(EC_NHRP_SWAN,
 484                                  "VICI: Failed to retrieve charon file path");
 485                         vici_charon_not_found = true;
 486                 }
 487                 return NULL;
 488         }
 489         /* last line of output is used to get vici path */
 490         while (fgets(line, sizeof(line), fp) != NULL) {
 491                 ptr = strchr(line, '\n');
 492                 if (ptr)
 493                         *ptr = '\0';
 494                 snprintf(buff, sizeof(buff), "%s/charon.vici", line);
 495         }
 496         pclose(fp);
 497         vici_charon_filepath_done = true;
 498         return buff;
 499 }
 500
 501 static void vici_reconnect(struct thread *t)
 502 {
 503         struct vici_conn *vici = THREAD_ARG(t);
 504         int fd;
 505         char *file_path;
 506
 507         if (vici->fd >= 0)
 508                 return;
 509
 510         fd = sock_open_unix(VICI_SOCKET);
 511         if (fd < 0) {
 512                 file_path = vici_get_charon_filepath();
 513                 if (file_path)
 514                         fd = sock_open_unix(file_path);
 515         }
 516         if (fd < 0) {
 517                 debugf(NHRP_DEBUG_VICI,
 518                        "%s: failure connecting VICI socket: %s", __func__,
 519                        strerror(errno));
 520                 thread_add_timer(master, vici_reconnect, vici, 2,
 521                                  &vici->t_reconnect);
 522                 return;
 523         }
 524
 525         debugf(NHRP_DEBUG_COMMON, "VICI: Connected");
 526         vici->fd = fd;
 527         thread_add_read(master, vici_read, vici, vici->fd, &vici->t_read);
 528
 529         /* Send event subscribtions */
 530         // vici_register_event(vici, "child-updown");
 531         // vici_register_event(vici, "child-rekey");
 532         vici_register_event(vici, "child-state-installed");
 533         vici_register_event(vici, "child-state-rekeyed");
 534         vici_register_event(vici, "child-state-destroying");
 535         vici_register_event(vici, "list-sa");
 536         vici_submit_request(vici, "list-sas", VICI_END);
 537 }
 538
 539 static struct vici_conn vici_connection;
 540
 541 void vici_init(void)
 542 {
 543         struct vici_conn *vici = &vici_connection;
 544
 545         vici->fd = -1;
 546         zbuf_init(&vici->ibuf, vici->ibuf_data, sizeof(vici->ibuf_data), 0);
 547         zbufq_init(&vici->obuf);
 548         thread_add_timer_msec(master, vici_reconnect, vici, 10,
 549                               &vici->t_reconnect);
 550 }
 551
 552 void vici_terminate(void)
 553 {
 554 }
 555
 556 void vici_terminate_vc_by_profile_name(char *profile_name)
 557 {
 558         struct vici_conn *vici = &vici_connection;
 559
 560         debugf(NHRP_DEBUG_VICI, "Terminate profile = %s", profile_name);
 561         vici_submit_request(vici, "terminate", VICI_KEY_VALUE, "ike",
 562                     strlen(profile_name), profile_name, VICI_END);
 563 }
 564
 565 void vici_terminate_vc_by_ike_id(unsigned int ike_id)
 566 {
 567         struct vici_conn *vici = &vici_connection;
 568         char ike_id_str[10];
 569
 570         snprintf(ike_id_str, sizeof(ike_id_str), "%d", ike_id);
 571         debugf(NHRP_DEBUG_VICI, "Terminate ike_id_str = %s", ike_id_str);
 572         vici_submit_request(vici, "terminate", VICI_KEY_VALUE, "ike-id",
 573                     strlen(ike_id_str), ike_id_str, VICI_END);
 574 }
 575
 576 void vici_request_vc(const char *profile, union sockunion *src,
 577                      union sockunion *dst, int prio)
 578 {
 579         struct vici_conn *vici = &vici_connection;
 580         char buf[2][SU_ADDRSTRLEN];
 581
 582         sockunion2str(src, buf[0], sizeof(buf[0]));
 583         sockunion2str(dst, buf[1], sizeof(buf[1]));
 584
 585         vici_submit_request(vici, "initiate", VICI_KEY_VALUE, "child",
 586                             strlen(profile), profile, VICI_KEY_VALUE, "timeout",
 587                             (size_t)2, "-1", VICI_KEY_VALUE, "async", (size_t)1,
 588                             "1", VICI_KEY_VALUE, "init-limits", (size_t)1,
 589                             prio ? "0" : "1", VICI_KEY_VALUE, "my-host",
 590                             strlen(buf[0]), buf[0], VICI_KEY_VALUE,
 591                             "other-host", strlen(buf[1]), buf[1], VICI_END);
 592 }
 593
 594 int sock_open_unix(const char *path)
 595 {
 596         int ret, fd;
 597         struct sockaddr_un addr;
 598
 599         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 600         if (fd < 0)
 601                 return -1;
 602
 603         memset(&addr, 0, sizeof(struct sockaddr_un));
 604         addr.sun_family = AF_UNIX;
 605         strlcpy(addr.sun_path, path, sizeof(addr.sun_path));
 606
 607         ret = connect(fd, (struct sockaddr *)&addr,
 608                       sizeof(addr.sun_family) + strlen(addr.sun_path));
 609         if (ret < 0) {
 610                 close(fd);
 611                 return -1;
 612         }
 613
 614         ret = fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_NONBLOCK);
 615         if (ret < 0) {
 616                 close(fd);
 617                 return -1;
 618         }
 619
 620         return fd;
 621 }