| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * Communication with the peer |
| 4 | * |
| 5 | * (c) 2001 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 9 | * |
| 10 | * This file is part of Trivial IP Encryption (TrIPE). |
| 11 | * |
| 12 | * TrIPE is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU General Public License as published by |
| 14 | * the Free Software Foundation; either version 2 of the License, or |
| 15 | * (at your option) any later version. |
| 16 | * |
| 17 | * TrIPE is distributed in the hope that it will be useful, |
| 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | * GNU General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License |
| 23 | * along with TrIPE; if not, write to the Free Software Foundation, |
| 24 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 25 | */ |
| 26 | |
| 27 | /*----- Header files ------------------------------------------------------*/ |
| 28 | |
| 29 | #include "tripe.h" |
| 30 | |
| 31 | /*----- Static variables --------------------------------------------------*/ |
| 32 | |
| 33 | static sym_table byname; |
| 34 | static addrmap byaddr; |
| 35 | static sel_file sock; |
| 36 | static unsigned nmobile; |
| 37 | |
| 38 | /*----- Tunnel table ------------------------------------------------------*/ |
| 39 | |
| 40 | const tunnel_ops *tunnels[] = { |
| 41 | #ifdef TUN_LINUX |
| 42 | &tun_linux, |
| 43 | #endif |
| 44 | #ifdef TUN_BSD |
| 45 | &tun_bsd, |
| 46 | #endif |
| 47 | #ifdef TUN_UNET |
| 48 | &tun_unet, |
| 49 | #endif |
| 50 | &tun_slip, |
| 51 | 0 |
| 52 | }, *tun_default; |
| 53 | |
| 54 | /*----- Main code ---------------------------------------------------------*/ |
| 55 | |
| 56 | /* --- @p_pingtype@ --- * |
| 57 | * |
| 58 | * Arguments: @unsigned msg@ = message type |
| 59 | * |
| 60 | * Returns: String to describe the message. |
| 61 | */ |
| 62 | |
| 63 | static const char *p_pingtype(unsigned msg) |
| 64 | { |
| 65 | switch (msg & MSG_TYPEMASK) { |
| 66 | case MISC_PING: |
| 67 | case MISC_PONG: |
| 68 | return "transport-ping"; |
| 69 | case MISC_EPING: |
| 70 | case MISC_EPONG: |
| 71 | return "encrypted-ping"; |
| 72 | default: |
| 73 | abort(); |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | /* --- @p_ponged@ --- * |
| 78 | * |
| 79 | * Arguments: @peer *p@ = peer packet arrived from |
| 80 | * @unsigned msg@ = message type |
| 81 | * @buf *b@ = buffer containing payload |
| 82 | * |
| 83 | * Returns: --- |
| 84 | * |
| 85 | * Use: Processes a ping response. |
| 86 | */ |
| 87 | |
| 88 | static void p_ponged(peer *p, unsigned msg, buf *b) |
| 89 | { |
| 90 | uint32 id; |
| 91 | const octet *magic; |
| 92 | ping *pg; |
| 93 | |
| 94 | IF_TRACING(T_PEER, { |
| 95 | trace(T_PEER, "peer: received %s reply from %s", |
| 96 | p_pingtype(msg), p->spec.name); |
| 97 | trace_block(T_PACKET, "peer: ping contents", BBASE(b), BSZ(b)); |
| 98 | }) |
| 99 | |
| 100 | if (buf_getu32(b, &id) || |
| 101 | (magic = buf_get(b, sizeof(pg->magic))) == 0 || |
| 102 | BLEFT(b)) { |
| 103 | a_warn("PEER", "?PEER", p, "malformed-%s", p_pingtype(msg), A_END); |
| 104 | return; |
| 105 | } |
| 106 | |
| 107 | for (pg = p->pings; pg; pg = pg->next) { |
| 108 | if (pg->id == id) |
| 109 | goto found; |
| 110 | } |
| 111 | a_warn("PEER", |
| 112 | "?PEER", p, |
| 113 | "unexpected-%s", p_pingtype(msg), |
| 114 | "0x%08lx", (unsigned long)id, |
| 115 | A_END); |
| 116 | return; |
| 117 | |
| 118 | found: |
| 119 | if (memcmp(magic, pg->magic, sizeof(pg->magic)) != 0) { |
| 120 | a_warn("PEER", "?PEER", p, "corrupt-%s", p_pingtype(msg), A_END); |
| 121 | return; |
| 122 | } |
| 123 | p_pingdone(pg, PING_OK); |
| 124 | } |
| 125 | |
| 126 | /* --- @p_rxupdstats@ --- * |
| 127 | * |
| 128 | * Arguments: @peer *p@ = peer to update |
| 129 | * @size_t n@ = size of incoming packet |
| 130 | * |
| 131 | * Returns: --- |
| 132 | * |
| 133 | * Use: Updates the peer's incoming packet statistics. |
| 134 | */ |
| 135 | |
| 136 | static void p_rxupdstats(peer *p, size_t n) |
| 137 | { |
| 138 | p->st.t_last = time(0); |
| 139 | p->st.n_in++; |
| 140 | p->st.sz_in += n; |
| 141 | } |
| 142 | |
| 143 | /* --- @p_encrypt@ --- * |
| 144 | * |
| 145 | * Arguments: @peer *p@ = peer to encrypt message to |
| 146 | * @int ty@ message type to send |
| 147 | * @buf *bin, *bout@ = input and output buffers |
| 148 | * |
| 149 | * Returns: --- |
| 150 | * |
| 151 | * Use: Convenience function for packet encryption. Forces |
| 152 | * renegotiation when necessary. Check for the output buffer |
| 153 | * being broken to find out whether the encryption was |
| 154 | * successful. |
| 155 | */ |
| 156 | |
| 157 | static int p_encrypt(peer *p, int ty, buf *bin, buf *bout) |
| 158 | { |
| 159 | int err = ksl_encrypt(&p->ks, ty, bin, bout); |
| 160 | |
| 161 | if (err == KSERR_REGEN) { |
| 162 | kx_start(&p->kx, 1); |
| 163 | err = 0; |
| 164 | } |
| 165 | if (!BOK(bout)) |
| 166 | err = -1; |
| 167 | return (err); |
| 168 | } |
| 169 | |
| 170 | /* --- @p_decrypt@ --- * |
| 171 | * |
| 172 | * Arguments: @peer **pp@ = pointer to peer to decrypt message from |
| 173 | * @addr *a@ = address the packet arrived on |
| 174 | * @size_t n@ = size of original incoming packet |
| 175 | * @int ty@ = message type to expect |
| 176 | * @buf *bin, *bout@ = input and output buffers |
| 177 | * |
| 178 | * Returns: Zero on success; nonzero on error. |
| 179 | * |
| 180 | * Use: Convenience function for packet decryption. Reports errors |
| 181 | * and updates statistics appropriately. |
| 182 | * |
| 183 | * If @*pp@ is null on entry and there are mobile peers then we |
| 184 | * see if any of them can decrypt the packet. If so, we record |
| 185 | * @*a@ as the peer's new address and send a notification. |
| 186 | */ |
| 187 | |
| 188 | static int p_decrypt(peer **pp, addr *a, size_t n, |
| 189 | int ty, buf *bin, buf *bout) |
| 190 | { |
| 191 | peer *p, *q; |
| 192 | peer_byaddr *pa, *qa; |
| 193 | int err = KSERR_DECRYPT; |
| 194 | unsigned f; |
| 195 | |
| 196 | /* --- If we have a match on the source address then try that first --- */ |
| 197 | |
| 198 | q = *pp; |
| 199 | if (q) { |
| 200 | T( trace(T_PEER, "peer: decrypting packet from known peer `%s'", |
| 201 | p_name(q)); ) |
| 202 | if ((err = ksl_decrypt(&q->ks, ty, bin, bout)) != KSERR_DECRYPT || |
| 203 | !(q->spec.f & PSF_MOBILE) || nmobile == 1) { |
| 204 | p = q; |
| 205 | goto match; |
| 206 | } |
| 207 | T( trace(T_PEER, "peer: failed to decrypt: try other mobile peers..."); ) |
| 208 | } else if (nmobile) |
| 209 | T( trace(T_PEER, "peer: unknown source: trying mobile peers...") ); |
| 210 | else { |
| 211 | p = 0; |
| 212 | goto searched; |
| 213 | } |
| 214 | |
| 215 | /* --- See whether any mobile peer is interested --- */ |
| 216 | |
| 217 | p = 0; |
| 218 | FOREACH_PEER(qq, { |
| 219 | if (qq == q || !(qq->spec.f & PSF_MOBILE)) continue; |
| 220 | if ((err = ksl_decrypt(&qq->ks, ty, bin, bout)) == KSERR_DECRYPT) { |
| 221 | T( trace(T_PEER, "peer: peer `%s' failed to decrypt", |
| 222 | p_name(qq)); ) |
| 223 | continue; |
| 224 | } else { |
| 225 | p = qq; |
| 226 | IF_TRACING(T_PEER, { |
| 227 | if (!err) |
| 228 | trace(T_PEER, "peer: peer `%s' reports success", p_name(qq)); |
| 229 | else { |
| 230 | trace(T_PEER, "peer: peer `%s' reports decryption error %d", |
| 231 | p_name(qq), err); |
| 232 | } |
| 233 | }) |
| 234 | break; |
| 235 | } |
| 236 | }); |
| 237 | |
| 238 | /* --- We've searched the mobile peers --- */ |
| 239 | |
| 240 | searched: |
| 241 | if (!p) { |
| 242 | if (!q) |
| 243 | a_warn("PEER", "-", "unexpected-source", "?ADDR", a, A_END); |
| 244 | else { |
| 245 | a_warn("PEER", "?PEER", p, "decrypt-failed", |
| 246 | "error-code", "%d", err, A_END); |
| 247 | p_rxupdstats(q, n); |
| 248 | } |
| 249 | return (-1); |
| 250 | } |
| 251 | |
| 252 | /* --- We found one that accepted, so update the peer's address --- * |
| 253 | * |
| 254 | * If we had an initial guess of which peer this packet came from -- i.e., |
| 255 | * @q@ is not null -- then swap the addresses over. This doesn't leave the |
| 256 | * evicted peer in an especially good state, but it ought to get sorted out |
| 257 | * soon enough. |
| 258 | */ |
| 259 | |
| 260 | if (!err) { |
| 261 | *pp = p; |
| 262 | if (!q) { |
| 263 | T( trace(T_PEER, "peer: updating address for `%s'", p_name(p)); ) |
| 264 | pa = am_find(&byaddr, a, sizeof(peer_byaddr), &f); assert(!f); |
| 265 | am_remove(&byaddr, p->byaddr); |
| 266 | p->byaddr = pa; |
| 267 | pa->p = p; |
| 268 | p->spec.sa = *a; |
| 269 | a_notify("NEWADDR", "?PEER", p, "?ADDR", a, A_END); |
| 270 | } else { |
| 271 | T( trace(T_PEER, "peer: swapping addresses for `%s' and `%s'", |
| 272 | p_name(p), p_name(q)); ) |
| 273 | pa = p->byaddr; qa = q->byaddr; |
| 274 | pa->p = q; q->byaddr = pa; q->spec.sa = p->spec.sa; |
| 275 | qa->p = p; p->byaddr = qa; p->spec.sa = *a; |
| 276 | a_notify("NEWADDR", "?PEER", p, "?ADDR", a, A_END); |
| 277 | a_notify("NEWADDR", "?PEER", q, "?ADDR", &q->spec.sa, A_END); |
| 278 | } |
| 279 | } |
| 280 | |
| 281 | match: |
| 282 | p_rxupdstats(p, n); |
| 283 | if (err) { |
| 284 | if (p) p->st.n_reject++; |
| 285 | a_warn("PEER", "?PEER", p, "decrypt-failed", |
| 286 | "error-code", "%d", err, A_END); |
| 287 | return (-1); |
| 288 | } |
| 289 | if (!BOK(bout)) |
| 290 | return (-1); |
| 291 | return (0); |
| 292 | } |
| 293 | |
| 294 | /* --- @p_read@ --- * |
| 295 | * |
| 296 | * Arguments: @int fd@ = file descriptor to read from |
| 297 | * @unsigned mode@ = what happened |
| 298 | * @void *v@ = an uninteresting pointer |
| 299 | * |
| 300 | * Returns: --- |
| 301 | * |
| 302 | * Use: Reads a packet from somewhere. |
| 303 | */ |
| 304 | |
| 305 | static void p_read(int fd, unsigned mode, void *v) |
| 306 | { |
| 307 | peer *p = 0; |
| 308 | addr a; |
| 309 | socklen_t sz; |
| 310 | ssize_t n; |
| 311 | int ch; |
| 312 | buf b, bb; |
| 313 | |
| 314 | /* --- Read the data --- */ |
| 315 | |
| 316 | TIMER; |
| 317 | sz = sizeof(addr); |
| 318 | n = recvfrom(fd, buf_i, sizeof(buf_i), 0, &a.sa, &sz); |
| 319 | if (n < 0) { |
| 320 | a_warn("PEER", "-", "socket-read-error", "?ERRNO", A_END); |
| 321 | return; |
| 322 | } |
| 323 | |
| 324 | /* --- If the packet is a greeting, don't check peers --- */ |
| 325 | |
| 326 | if (n && buf_i[0] == (MSG_MISC | MISC_GREET)) { |
| 327 | IF_TRACING(T_PEER, { |
| 328 | trace(T_PEER, "peer: greeting received from INET %s %u", |
| 329 | inet_ntoa(a.sin.sin_addr), |
| 330 | (unsigned)ntohs(a.sin.sin_port)); |
| 331 | trace_block(T_PACKET, "peer: greeting contents", buf_i, n); |
| 332 | }) |
| 333 | buf_init(&b, buf_i, n); |
| 334 | buf_getbyte(&b); |
| 335 | if (c_check(&b) || BLEFT(&b)) { |
| 336 | a_warn("PEER", "-", "invalid-greeting", A_END); |
| 337 | return; |
| 338 | } |
| 339 | a_notify("GREET", |
| 340 | "?B64", buf_i + 1, (size_t)(n - 1), |
| 341 | "?ADDR", &a, |
| 342 | A_END); |
| 343 | return; |
| 344 | } |
| 345 | |
| 346 | /* --- Find the appropriate peer --- * |
| 347 | * |
| 348 | * At this stage, don't worry too much about whether we actually found it. |
| 349 | */ |
| 350 | |
| 351 | p = p_findbyaddr(&a); |
| 352 | |
| 353 | IF_TRACING(T_PEER, { |
| 354 | if (p) { |
| 355 | trace(T_PEER, |
| 356 | "peer: packet received from `%s' from address INET %s %d", |
| 357 | p_name(p), inet_ntoa(a.sin.sin_addr), ntohs(a.sin.sin_port)); |
| 358 | } else { |
| 359 | trace(T_PEER, "peer: packet received from unknown address INET %s %d", |
| 360 | inet_ntoa(a.sin.sin_addr), ntohs(a.sin.sin_port)); |
| 361 | } |
| 362 | trace_block(T_PACKET, "peer: packet contents", buf_i, n); |
| 363 | }) |
| 364 | |
| 365 | /* --- Pick the packet apart --- */ |
| 366 | |
| 367 | buf_init(&b, buf_i, n); |
| 368 | if ((ch = buf_getbyte(&b)) < 0) { |
| 369 | a_warn("PEER", "?PEER", p, "bad-packet", "no-type", A_END); |
| 370 | return; |
| 371 | } |
| 372 | switch (ch & MSG_CATMASK) { |
| 373 | case MSG_PACKET: |
| 374 | if (ch & MSG_TYPEMASK) { |
| 375 | a_warn("PEER", |
| 376 | "?PEER", p, |
| 377 | "bad-packet", |
| 378 | "unknown-type", "0x%02x", ch, |
| 379 | A_END); |
| 380 | if (p) p->st.n_reject++; |
| 381 | return; |
| 382 | } |
| 383 | buf_init(&bb, buf_o, sizeof(buf_o)); |
| 384 | if (p_decrypt(&p, &a, n, MSG_PACKET, &b, &bb)) |
| 385 | return; |
| 386 | if (BOK(&bb)) { |
| 387 | p->st.n_ipin++; |
| 388 | p->st.sz_ipin += BSZ(&b); |
| 389 | p->t->ops->inject(p->t, &bb); |
| 390 | } else { |
| 391 | p->st.n_reject++; |
| 392 | a_warn("PEER", "?PEER", p, "packet-build-failed", A_END); |
| 393 | } |
| 394 | break; |
| 395 | case MSG_KEYEXCH: |
| 396 | if (!p) goto unexp; |
| 397 | p_rxupdstats(p, n); |
| 398 | kx_message(&p->kx, ch & MSG_TYPEMASK, &b); |
| 399 | break; |
| 400 | case MSG_MISC: |
| 401 | switch (ch & MSG_TYPEMASK) { |
| 402 | case MISC_NOP: |
| 403 | if (!p) goto unexp; |
| 404 | p_rxupdstats(p, n); |
| 405 | T( trace(T_PEER, "peer: received NOP packet"); ) |
| 406 | break; |
| 407 | case MISC_PING: |
| 408 | if (!p) goto unexp; |
| 409 | p_rxupdstats(p, n); |
| 410 | buf_put(p_txstart(p, MSG_MISC | MISC_PONG), BCUR(&b), BLEFT(&b)); |
| 411 | p_txend(p); |
| 412 | break; |
| 413 | case MISC_PONG: |
| 414 | if (!p) goto unexp; |
| 415 | p_rxupdstats(p, n); |
| 416 | p_ponged(p, MISC_PONG, &b); |
| 417 | break; |
| 418 | case MISC_EPING: |
| 419 | buf_init(&bb, buf_t, sizeof(buf_t)); |
| 420 | if (p_decrypt(&p, &a, n, ch, &b, &bb)) |
| 421 | return; |
| 422 | if (BOK(&bb)) { |
| 423 | buf_flip(&bb); |
| 424 | p_encrypt(p, MSG_MISC | MISC_EPONG, &bb, |
| 425 | p_txstart(p, MSG_MISC | MISC_EPONG)); |
| 426 | p_txend(p); |
| 427 | } |
| 428 | break; |
| 429 | case MISC_EPONG: |
| 430 | buf_init(&bb, buf_t, sizeof(buf_t)); |
| 431 | if (p_decrypt(&p, &a, n, ch, &b, &bb)) |
| 432 | return; |
| 433 | if (BOK(&bb)) { |
| 434 | buf_flip(&bb); |
| 435 | p_ponged(p, MISC_EPONG, &bb); |
| 436 | } |
| 437 | break; |
| 438 | } |
| 439 | break; |
| 440 | default: |
| 441 | if (p) p->st.n_reject++; |
| 442 | a_warn("PEER", |
| 443 | "?PEER", p, |
| 444 | "bad-packet", |
| 445 | "unknown-category", "0x%02x", ch, |
| 446 | A_END); |
| 447 | break; |
| 448 | unexp: |
| 449 | a_warn("PEER", "-", "unexpected-source", "?ADDR", &a, A_END); |
| 450 | break; |
| 451 | } |
| 452 | } |
| 453 | |
| 454 | /* --- @p_txstart@ --- * |
| 455 | * |
| 456 | * Arguments: @peer *p@ = pointer to peer block |
| 457 | * @unsigned msg@ = message type code |
| 458 | * |
| 459 | * Returns: A pointer to a buffer to write to. |
| 460 | * |
| 461 | * Use: Starts sending to a peer. Only one send can happen at a |
| 462 | * time. |
| 463 | */ |
| 464 | |
| 465 | buf *p_txstart(peer *p, unsigned msg) |
| 466 | { |
| 467 | buf_init(&p->b, buf_o, sizeof(buf_o)); |
| 468 | buf_putbyte(&p->b, msg); |
| 469 | return (&p->b); |
| 470 | } |
| 471 | |
| 472 | /* --- @p_txend@ --- * |
| 473 | * |
| 474 | * Arguments: @peer *p@ = pointer to peer block |
| 475 | * |
| 476 | * Returns: --- |
| 477 | * |
| 478 | * Use: Sends a packet to the peer. |
| 479 | */ |
| 480 | |
| 481 | static void p_setkatimer(peer *); |
| 482 | |
| 483 | static int p_dotxend(peer *p) |
| 484 | { |
| 485 | if (!BOK(&p->b)) { |
| 486 | a_warn("PEER", "?PEER", p, "packet-build-failed", A_END); |
| 487 | return (0); |
| 488 | } |
| 489 | IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet", |
| 490 | BBASE(&p->b), BLEN(&p->b)); ) |
| 491 | if (sendto(sock.fd, BBASE(&p->b), BLEN(&p->b), |
| 492 | 0, &p->spec.sa.sa, p->spec.sasz) < 0) { |
| 493 | a_warn("PEER", "?PEER", p, "socket-write-error", "?ERRNO", A_END); |
| 494 | return (0); |
| 495 | } else { |
| 496 | p->st.n_out++; |
| 497 | p->st.sz_out += BLEN(&p->b); |
| 498 | return (1); |
| 499 | } |
| 500 | } |
| 501 | |
| 502 | void p_txend(peer *p) |
| 503 | { |
| 504 | if (p_dotxend(p) && p->spec.t_ka) { |
| 505 | sel_rmtimer(&p->tka); |
| 506 | p_setkatimer(p); |
| 507 | } |
| 508 | } |
| 509 | |
| 510 | /* --- @p_pingwrite@ --- * |
| 511 | * |
| 512 | * Arguments: @ping *p@ = ping structure |
| 513 | * @buf *b@ = buffer to write in |
| 514 | * |
| 515 | * Returns: --- |
| 516 | * |
| 517 | * Use: Fills in a ping structure and writes the packet payload. |
| 518 | */ |
| 519 | |
| 520 | static void p_pingwrite(ping *p, buf *b) |
| 521 | { |
| 522 | static uint32 seq = 0; |
| 523 | |
| 524 | p->id = U32(seq++); |
| 525 | GR_FILL(&rand_global, p->magic, sizeof(p->magic)); |
| 526 | buf_putu32(b, p->id); |
| 527 | buf_put(b, p->magic, sizeof(p->magic)); |
| 528 | } |
| 529 | |
| 530 | /* --- @p_pingdone@ --- * |
| 531 | * |
| 532 | * Arguments: @ping *p@ = ping structure |
| 533 | * @int rc@ = return code to pass on |
| 534 | * |
| 535 | * Returns: --- |
| 536 | * |
| 537 | * Use: Disposes of a ping structure, maybe sending a notification. |
| 538 | */ |
| 539 | |
| 540 | void p_pingdone(ping *p, int rc) |
| 541 | { |
| 542 | if (p->prev) p->prev->next = p->next; |
| 543 | else p->p->pings = p->next; |
| 544 | if (p->next) p->next->prev = p->prev; |
| 545 | if (rc != PING_TIMEOUT) sel_rmtimer(&p->t); |
| 546 | T( trace(T_PEER, "peer: ping 0x%08lx done (rc = %d)", |
| 547 | (unsigned long)p->id, rc); ) |
| 548 | if (rc >= 0) p->func(rc, p->arg); |
| 549 | } |
| 550 | |
| 551 | /* --- @p_pingtimeout@ --- * |
| 552 | * |
| 553 | * Arguments: @struct timeval *now@ = the time now |
| 554 | * @void *pv@ = pointer to ping block |
| 555 | * |
| 556 | * Returns: --- |
| 557 | * |
| 558 | * Use: Called when a ping times out. |
| 559 | */ |
| 560 | |
| 561 | static void p_pingtimeout(struct timeval *now, void *pv) |
| 562 | { |
| 563 | ping *p = pv; |
| 564 | |
| 565 | T( trace(T_PEER, "peer: ping 0x%08lx timed out", (unsigned long)p->id); ) |
| 566 | p_pingdone(p, PING_TIMEOUT); |
| 567 | } |
| 568 | |
| 569 | /* --- @p_pingsend@ --- * |
| 570 | * |
| 571 | * Arguments: @peer *p@ = destination peer |
| 572 | * @ping *pg@ = structure to fill in |
| 573 | * @unsigned type@ = message type |
| 574 | * @unsigned long timeout@ = how long to wait before giving up |
| 575 | * @void (*func)(int, void *)@ = callback function |
| 576 | * @void *arg@ = argument for callback |
| 577 | * |
| 578 | * Returns: Zero if successful, nonzero if it failed. |
| 579 | * |
| 580 | * Use: Sends a ping to a peer. Call @func@ with a nonzero argument |
| 581 | * if we get an answer within the timeout, or zero if no answer. |
| 582 | */ |
| 583 | |
| 584 | int p_pingsend(peer *p, ping *pg, unsigned type, |
| 585 | unsigned long timeout, |
| 586 | void (*func)(int, void *), void *arg) |
| 587 | { |
| 588 | buf *b, bb; |
| 589 | struct timeval tv; |
| 590 | |
| 591 | switch (type) { |
| 592 | case MISC_PING: |
| 593 | pg->msg = MISC_PONG; |
| 594 | b = p_txstart(p, MSG_MISC | MISC_PING); |
| 595 | p_pingwrite(pg, b); |
| 596 | p_txend(p); |
| 597 | break; |
| 598 | case MISC_EPING: |
| 599 | pg->msg = MISC_EPONG; |
| 600 | b = p_txstart(p, MSG_MISC | MISC_EPING); |
| 601 | buf_init(&bb, buf_t, sizeof(buf_t)); |
| 602 | p_pingwrite(pg, &bb); |
| 603 | buf_flip(&bb); |
| 604 | p_encrypt(p, MSG_MISC | MISC_EPING, &bb, b); |
| 605 | if (!BOK(b)) |
| 606 | return (-1); |
| 607 | p_txend(p); |
| 608 | break; |
| 609 | default: |
| 610 | abort(); |
| 611 | break; |
| 612 | } |
| 613 | |
| 614 | pg->next = p->pings; |
| 615 | pg->prev = 0; |
| 616 | pg->p = p; |
| 617 | pg->func = func; |
| 618 | pg->arg = arg; |
| 619 | if (p->pings) p->pings->prev = pg; |
| 620 | p->pings = pg; |
| 621 | gettimeofday(&tv, 0); |
| 622 | tv.tv_sec += timeout; |
| 623 | sel_addtimer(&sel, &pg->t, &tv, p_pingtimeout, pg); |
| 624 | T( trace(T_PEER, "peer: send %s 0x%08lx to %s", |
| 625 | p_pingtype(type), (unsigned long)pg->id, p->spec.name); ) |
| 626 | return (0); |
| 627 | } |
| 628 | |
| 629 | /* --- @p_greet@ --- * |
| 630 | * |
| 631 | * Arguments: @peer *p@ = peer to send to |
| 632 | * @const void *c@ = pointer to challenge |
| 633 | * @size_t sz@ = size of challenge |
| 634 | * |
| 635 | * Returns: --- |
| 636 | * |
| 637 | * Use: Sends a greeting packet. |
| 638 | */ |
| 639 | |
| 640 | void p_greet(peer *p, const void *c, size_t sz) |
| 641 | { |
| 642 | buf *b = p_txstart(p, MSG_MISC | MISC_GREET); |
| 643 | buf_put(b, c, sz); |
| 644 | p_txend(p); |
| 645 | } |
| 646 | |
| 647 | /* --- @p_tun@ --- * |
| 648 | * |
| 649 | * Arguments: @peer *p@ = pointer to peer block |
| 650 | * @buf *b@ = buffer containing incoming packet |
| 651 | * |
| 652 | * Returns: --- |
| 653 | * |
| 654 | * Use: Handles a packet which needs to be sent to a peer. |
| 655 | */ |
| 656 | |
| 657 | void p_tun(peer *p, buf *b) |
| 658 | { |
| 659 | buf *bb = p_txstart(p, MSG_PACKET); |
| 660 | |
| 661 | TIMER; |
| 662 | p_encrypt(p, MSG_PACKET, b, bb); |
| 663 | if (BOK(bb) && BLEN(bb)) { |
| 664 | p->st.n_ipout++; |
| 665 | p->st.sz_ipout += BLEN(bb); |
| 666 | p_txend(p); |
| 667 | } |
| 668 | } |
| 669 | |
| 670 | /* --- @p_keyreload@ --- * |
| 671 | * |
| 672 | * Arguments: --- |
| 673 | * |
| 674 | * Returns: --- |
| 675 | * |
| 676 | * Use: Forces a check of the daemon's keyring files. |
| 677 | */ |
| 678 | |
| 679 | void p_keyreload(void) |
| 680 | { |
| 681 | if (km_reload()) |
| 682 | FOREACH_PEER(p, { kx_newkeys(&p->kx); }); |
| 683 | } |
| 684 | |
| 685 | /* --- @p_interval@ --- * |
| 686 | * |
| 687 | * Arguments: --- |
| 688 | * |
| 689 | * Returns: --- |
| 690 | * |
| 691 | * Use: Called periodically to do tidying. |
| 692 | */ |
| 693 | |
| 694 | void p_interval(void) |
| 695 | { |
| 696 | p_keyreload(); |
| 697 | FOREACH_PEER(p, { ksl_prune(&p->ks); }); |
| 698 | } |
| 699 | |
| 700 | /* --- @p_stats@ --- * |
| 701 | * |
| 702 | * Arguments: @peer *p@ = pointer to a peer block |
| 703 | * |
| 704 | * Returns: A pointer to the peer's statistics. |
| 705 | */ |
| 706 | |
| 707 | stats *p_stats(peer *p) { return (&p->st); } |
| 708 | |
| 709 | /* --- @p_ifname@ --- * |
| 710 | * |
| 711 | * Arguments: @peer *p@ = pointer to a peer block |
| 712 | * |
| 713 | * Returns: A pointer to the peer's interface name. |
| 714 | */ |
| 715 | |
| 716 | const char *p_ifname(peer *p) { return (p->ifname); } |
| 717 | |
| 718 | /* --- @p_setifname@ --- * |
| 719 | * |
| 720 | * Arguments: @peer *p@ = pointer to a peer block |
| 721 | * @const char *name@ = pointer to the new name |
| 722 | * |
| 723 | * Returns: --- |
| 724 | * |
| 725 | * Use: Changes the name held for a peer's interface. |
| 726 | */ |
| 727 | |
| 728 | void p_setifname(peer *p, const char *name) |
| 729 | { |
| 730 | xfree(p->ifname); |
| 731 | p->ifname = xstrdup(name); |
| 732 | if (p->spec.tops->setifname) |
| 733 | p->spec.tops->setifname(p->t, name); |
| 734 | } |
| 735 | |
| 736 | /* --- @p_addr@ --- * |
| 737 | * |
| 738 | * Arguments: @peer *p@ = pointer to a peer block |
| 739 | * |
| 740 | * Returns: A pointer to the peer's address. |
| 741 | */ |
| 742 | |
| 743 | const addr *p_addr(peer *p) { return (&p->spec.sa); } |
| 744 | |
| 745 | /* --- @p_init@ --- * |
| 746 | * |
| 747 | * Arguments: @struct in_addr addr@ = address to bind to |
| 748 | * @unsigned port@ = port number to listen to |
| 749 | * |
| 750 | * Returns: --- |
| 751 | * |
| 752 | * Use: Initializes the peer system; creates the socket. |
| 753 | */ |
| 754 | |
| 755 | void p_init(struct in_addr addr, unsigned port) |
| 756 | { |
| 757 | int fd; |
| 758 | struct sockaddr_in sin; |
| 759 | int len = PKBUFSZ; |
| 760 | |
| 761 | /* --- Note on socket buffer sizes --- * |
| 762 | * |
| 763 | * For some bizarre reason, Linux 2.2 (at least) doubles the socket buffer |
| 764 | * sizes I pass to @setsockopt@. I'm not putting special-case code here |
| 765 | * for Linux: BSD (at least TCPv2) does what I tell it rather than second- |
| 766 | * guessing me. |
| 767 | */ |
| 768 | |
| 769 | if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) |
| 770 | die(EXIT_FAILURE, "socket creation failed: %s", strerror(errno)); |
| 771 | BURN(sin); |
| 772 | sin.sin_family = AF_INET; |
| 773 | sin.sin_addr = addr; |
| 774 | sin.sin_port = htons(port); |
| 775 | if (bind(fd, (struct sockaddr *)&sin, sizeof(sin))) |
| 776 | die(EXIT_FAILURE, "bind failed: %s", strerror(errno)); |
| 777 | if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) || |
| 778 | setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len))) { |
| 779 | die(EXIT_FAILURE, "failed to set socket buffer sizes: %s", |
| 780 | strerror(errno)); |
| 781 | } |
| 782 | fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); |
| 783 | sel_initfile(&sel, &sock, fd, SEL_READ, p_read, 0); |
| 784 | sel_addfile(&sock); |
| 785 | T( trace(T_PEER, "peer: created socket"); ) |
| 786 | |
| 787 | sym_create(&byname); |
| 788 | am_create(&byaddr); |
| 789 | } |
| 790 | |
| 791 | /* --- @p_port@ --- * |
| 792 | * |
| 793 | * Arguments: --- |
| 794 | * |
| 795 | * Returns: Port number used for socket. |
| 796 | */ |
| 797 | |
| 798 | unsigned p_port(void) |
| 799 | { |
| 800 | addr a; |
| 801 | socklen_t sz = sizeof(addr); |
| 802 | |
| 803 | if (getsockname(sock.fd, &a.sa, &sz)) |
| 804 | die(EXIT_FAILURE, "couldn't read port number: %s", strerror(errno)); |
| 805 | assert(a.sa.sa_family == AF_INET); |
| 806 | return (ntohs(a.sin.sin_port)); |
| 807 | } |
| 808 | |
| 809 | /* --- @p_keepalive@ --- * |
| 810 | * |
| 811 | * Arguments: @struct timeval *now@ = the current time |
| 812 | * @void *pv@ = peer to wake up |
| 813 | * |
| 814 | * Returns: --- |
| 815 | * |
| 816 | * Use: Sends a keepalive ping message to its peer. |
| 817 | */ |
| 818 | |
| 819 | static void p_keepalive(struct timeval *now, void *pv) |
| 820 | { |
| 821 | peer *p = pv; |
| 822 | |
| 823 | p_txstart(p, MSG_MISC | MISC_NOP); p_dotxend(p); |
| 824 | T( trace(T_PEER, "peer: sent keepalive to %s", p->spec.name); ) |
| 825 | p_setkatimer(p); |
| 826 | } |
| 827 | |
| 828 | /* --- @p_setkatimer@ --- * |
| 829 | * |
| 830 | * Arguments: @peer *p@ = peer to set |
| 831 | * |
| 832 | * Returns: --- |
| 833 | * |
| 834 | * Use: Resets the keepalive timer thing. |
| 835 | */ |
| 836 | |
| 837 | static void p_setkatimer(peer *p) |
| 838 | { |
| 839 | struct timeval tv; |
| 840 | |
| 841 | if (!p->spec.t_ka) |
| 842 | return; |
| 843 | gettimeofday(&tv, 0); |
| 844 | tv.tv_sec += p->spec.t_ka; |
| 845 | sel_addtimer(&sel, &p->tka, &tv, p_keepalive, p); |
| 846 | } |
| 847 | |
| 848 | /* --- @p_create@ --- * |
| 849 | * |
| 850 | * Arguments: @peerspec *spec@ = information about this peer |
| 851 | * |
| 852 | * Returns: Pointer to the peer block, or null if it failed. |
| 853 | * |
| 854 | * Use: Creates a new named peer block. No peer is actually attached |
| 855 | * by this point. |
| 856 | */ |
| 857 | |
| 858 | peer *p_create(peerspec *spec) |
| 859 | { |
| 860 | peer *p = CREATE(peer); |
| 861 | const tunnel_ops *tops = spec->tops; |
| 862 | int fd; |
| 863 | unsigned f; |
| 864 | |
| 865 | p->byname = sym_find(&byname, spec->name, -1, sizeof(peer_byname), &f); |
| 866 | if (f) goto tidy_0; |
| 867 | p->byaddr = am_find(&byaddr, &spec->sa, sizeof(peer_byaddr), &f); |
| 868 | if (f) goto tidy_1; |
| 869 | p->byname->p = p->byaddr->p = p; |
| 870 | |
| 871 | T( trace(T_PEER, "peer: creating new peer `%s'", spec->name); ) |
| 872 | p->spec = *spec; |
| 873 | p->spec.name = (/*unconst*/ char *)SYM_NAME(p->byname); |
| 874 | if (spec->tag) p->spec.tag = xstrdup(spec->tag); |
| 875 | if (spec->privtag) p->spec.privtag = xstrdup(spec->privtag); |
| 876 | p->ks = 0; |
| 877 | p->pings = 0; |
| 878 | p->ifname = 0; |
| 879 | memset(&p->st, 0, sizeof(stats)); |
| 880 | p->st.t_start = time(0); |
| 881 | if (!(tops->flags & TUNF_PRIVOPEN)) |
| 882 | fd = -1; |
| 883 | else if ((fd = ps_tunfd(tops, &p->ifname)) < 0) |
| 884 | goto tidy_2; |
| 885 | if ((p->t = tops->create(p, fd, &p->ifname)) == 0) |
| 886 | goto tidy_3; |
| 887 | T( trace(T_TUNNEL, "peer: attached interface %s to peer `%s'", |
| 888 | p->ifname, p_name(p)); ) |
| 889 | p_setkatimer(p); |
| 890 | if (kx_init(&p->kx, p, &p->ks, p->spec.f & PSF_KXMASK)) |
| 891 | goto tidy_4; |
| 892 | a_notify("ADD", |
| 893 | "?PEER", p, |
| 894 | "%s", p->ifname, |
| 895 | "?ADDR", &p->spec.sa, |
| 896 | A_END); |
| 897 | if (!(p->spec.f & KXF_CORK)) { |
| 898 | a_notify("KXSTART", "?PEER", p, A_END); |
| 899 | /* Couldn't tell anyone before */ |
| 900 | } |
| 901 | if (p->spec.f & PSF_MOBILE) nmobile++; |
| 902 | return (p); |
| 903 | |
| 904 | tidy_4: |
| 905 | if (spec->t_ka) sel_rmtimer(&p->tka); |
| 906 | xfree(p->ifname); |
| 907 | p->t->ops->destroy(p->t); |
| 908 | tidy_3: |
| 909 | if (fd >= 0) close(fd); |
| 910 | tidy_2: |
| 911 | am_remove(&byaddr, p->byaddr); |
| 912 | if (p->spec.tag) xfree(p->spec.tag); |
| 913 | if (p->spec.privtag) xfree(p->spec.privtag); |
| 914 | tidy_1: |
| 915 | sym_remove(&byname, p->byname); |
| 916 | tidy_0: |
| 917 | DESTROY(p); |
| 918 | return (0); |
| 919 | } |
| 920 | |
| 921 | /* --- @p_name@ --- * |
| 922 | * |
| 923 | * Arguments: @peer *p@ = pointer to a peer block |
| 924 | * |
| 925 | * Returns: A pointer to the peer's name. |
| 926 | */ |
| 927 | |
| 928 | const char *p_name(peer *p) |
| 929 | { if (p) return (p->spec.name); else return ("-"); } |
| 930 | |
| 931 | /* --- @p_tag@ --- * |
| 932 | * |
| 933 | * Arguments: @peer *p@ = pointer to a peer block |
| 934 | * |
| 935 | * Returns: A pointer to the peer's public key tag. |
| 936 | */ |
| 937 | |
| 938 | const char *p_tag(peer *p) |
| 939 | { return (p->spec.tag ? p->spec.tag : p->spec.name); } |
| 940 | |
| 941 | /* --- @p_privtag@ --- * |
| 942 | * |
| 943 | * Arguments: @peer *p@ = pointer to a peer block |
| 944 | * |
| 945 | * Returns: A pointer to the peer's private key tag. |
| 946 | */ |
| 947 | |
| 948 | const char *p_privtag(peer *p) |
| 949 | { return (p->spec.privtag ? p->spec.privtag : tag_priv); } |
| 950 | |
| 951 | /* --- @p_spec@ --- * |
| 952 | * |
| 953 | * Arguments: @peer *p@ = pointer to a peer block |
| 954 | * |
| 955 | * Returns: Pointer to the peer's specification |
| 956 | */ |
| 957 | |
| 958 | const peerspec *p_spec(peer *p) { return (&p->spec); } |
| 959 | |
| 960 | /* --- @p_findbyaddr@ --- * |
| 961 | * |
| 962 | * Arguments: @const addr *a@ = address to look up |
| 963 | * |
| 964 | * Returns: Pointer to the peer block, or null if not found. |
| 965 | * |
| 966 | * Use: Finds a peer by address. |
| 967 | */ |
| 968 | |
| 969 | peer *p_findbyaddr(const addr *a) |
| 970 | { |
| 971 | peer_byaddr *pa; |
| 972 | |
| 973 | if ((pa = am_find(&byaddr, a, 0, 0)) != 0) { |
| 974 | assert(pa->p); |
| 975 | return (pa->p); |
| 976 | } |
| 977 | return (0); |
| 978 | } |
| 979 | |
| 980 | /* --- @p_find@ --- * |
| 981 | * |
| 982 | * Arguments: @const char *name@ = name to look up |
| 983 | * |
| 984 | * Returns: Pointer to the peer block, or null if not found. |
| 985 | * |
| 986 | * Use: Finds a peer by name. |
| 987 | */ |
| 988 | |
| 989 | peer *p_find(const char *name) |
| 990 | { |
| 991 | peer_byname *pn; |
| 992 | |
| 993 | if ((pn = sym_find(&byname, name, -1, 0, 0)) != 0) |
| 994 | return (pn->p); |
| 995 | return (0); |
| 996 | } |
| 997 | |
| 998 | /* --- @p_destroy@ --- * |
| 999 | * |
| 1000 | * Arguments: @peer *p@ = pointer to a peer |
| 1001 | * |
| 1002 | * Returns: --- |
| 1003 | * |
| 1004 | * Use: Destroys a peer. |
| 1005 | */ |
| 1006 | |
| 1007 | void p_destroy(peer *p) |
| 1008 | { |
| 1009 | ping *pg, *ppg; |
| 1010 | |
| 1011 | T( trace(T_PEER, "peer: destroying peer `%s'", p->spec.name); ) |
| 1012 | a_notify("KILL", "%s", p->spec.name, A_END); |
| 1013 | ksl_free(&p->ks); |
| 1014 | kx_free(&p->kx); |
| 1015 | if (p->spec.f & PSF_MOBILE) nmobile--; |
| 1016 | if (p->ifname) xfree(p->ifname); |
| 1017 | if (p->spec.tag) xfree(p->spec.tag); |
| 1018 | if (p->spec.privtag) xfree(p->spec.privtag); |
| 1019 | p->t->ops->destroy(p->t); |
| 1020 | if (p->spec.t_ka) sel_rmtimer(&p->tka); |
| 1021 | for (pg = p->pings; pg; pg = ppg) { |
| 1022 | ppg = pg->next; |
| 1023 | p_pingdone(pg, PING_PEERDIED); |
| 1024 | } |
| 1025 | sym_remove(&byname, p->byname); |
| 1026 | am_remove(&byaddr, p->byaddr); |
| 1027 | DESTROY(p); |
| 1028 | } |
| 1029 | |
| 1030 | /* --- @p_mkiter@ --- * |
| 1031 | * |
| 1032 | * Arguments: @peer_iter *i@ = pointer to an iterator |
| 1033 | * |
| 1034 | * Returns: --- |
| 1035 | * |
| 1036 | * Use: Initializes the iterator. |
| 1037 | */ |
| 1038 | |
| 1039 | void p_mkiter(peer_iter *i) { sym_mkiter(&i->i, &byname); } |
| 1040 | |
| 1041 | /* --- @p_next@ --- * |
| 1042 | * |
| 1043 | * Arguments: @peer_iter *i@ = pointer to an iterator |
| 1044 | * |
| 1045 | * Returns: Next peer, or null if at the end. |
| 1046 | * |
| 1047 | * Use: Returns the next peer. |
| 1048 | */ |
| 1049 | |
| 1050 | peer *p_next(peer_iter *i) |
| 1051 | { |
| 1052 | peer_byname *pn; |
| 1053 | |
| 1054 | if ((pn = sym_next(&i->i)) == 0) |
| 1055 | return (0); |
| 1056 | return (pn->p); |
| 1057 | } |
| 1058 | |
| 1059 | /*----- That's all, folks -------------------------------------------------*/ |