| 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 it under |
| 13 | * the terms of the GNU General Public License as published by the Free |
| 14 | * Software Foundation; either version 3 of the License, or (at your |
| 15 | * option) any later version. |
| 16 | * |
| 17 | * TrIPE is distributed in the hope that it will be useful, but WITHOUT |
| 18 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 19 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 20 | * for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License |
| 23 | * along with TrIPE. If not, see <https://www.gnu.org/licenses/>. |
| 24 | */ |
| 25 | |
| 26 | /*----- Header files ------------------------------------------------------*/ |
| 27 | |
| 28 | #include "tripe.h" |
| 29 | |
| 30 | /*----- Static variables --------------------------------------------------*/ |
| 31 | |
| 32 | static sym_table byname; |
| 33 | static addrmap byaddr; |
| 34 | static sel_file sock; |
| 35 | static unsigned nmobile; |
| 36 | |
| 37 | /*----- Tunnel table ------------------------------------------------------*/ |
| 38 | |
| 39 | const tunnel_ops *tunnels[] = { |
| 40 | #ifdef TUN_LINUX |
| 41 | &tun_linux, |
| 42 | #endif |
| 43 | #ifdef TUN_BSD |
| 44 | &tun_bsd, |
| 45 | #endif |
| 46 | #ifdef TUN_UNET |
| 47 | &tun_unet, |
| 48 | #endif |
| 49 | &tun_slip, |
| 50 | 0 |
| 51 | }, *tun_default; |
| 52 | |
| 53 | /*----- Main code ---------------------------------------------------------*/ |
| 54 | |
| 55 | /* --- @p_pingtype@ --- * |
| 56 | * |
| 57 | * Arguments: @unsigned msg@ = message type |
| 58 | * |
| 59 | * Returns: String to describe the message. |
| 60 | */ |
| 61 | |
| 62 | static const char *p_pingtype(unsigned msg) |
| 63 | { |
| 64 | switch (msg & MSG_TYPEMASK) { |
| 65 | case MISC_PING: |
| 66 | case MISC_PONG: |
| 67 | return "transport-ping"; |
| 68 | case MISC_EPING: |
| 69 | case MISC_EPONG: |
| 70 | return "encrypted-ping"; |
| 71 | default: |
| 72 | abort(); |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | /* --- @p_ponged@ --- * |
| 77 | * |
| 78 | * Arguments: @peer *p@ = peer packet arrived from |
| 79 | * @unsigned msg@ = message type |
| 80 | * @buf *b@ = buffer containing payload |
| 81 | * |
| 82 | * Returns: --- |
| 83 | * |
| 84 | * Use: Processes a ping response. |
| 85 | */ |
| 86 | |
| 87 | static void p_ponged(peer *p, unsigned msg, buf *b) |
| 88 | { |
| 89 | uint32 id; |
| 90 | const octet *magic; |
| 91 | ping *pg; |
| 92 | |
| 93 | IF_TRACING(T_PEER, { |
| 94 | trace(T_PEER, "peer: received %s reply from %s", |
| 95 | p_pingtype(msg), p->spec.name); |
| 96 | trace_block(T_PACKET, "peer: ping contents", BBASE(b), BSZ(b)); |
| 97 | }) |
| 98 | |
| 99 | if (buf_getu32(b, &id) || |
| 100 | (magic = buf_get(b, sizeof(pg->magic))) == 0 || |
| 101 | BLEFT(b)) { |
| 102 | a_warn("PEER", "?PEER", p, "malformed-%s", p_pingtype(msg), A_END); |
| 103 | return; |
| 104 | } |
| 105 | |
| 106 | for (pg = p->pings; pg; pg = pg->next) { |
| 107 | if (pg->id == id) |
| 108 | goto found; |
| 109 | } |
| 110 | a_warn("PEER", |
| 111 | "?PEER", p, |
| 112 | "unexpected-%s", p_pingtype(msg), |
| 113 | "0x%08lx", (unsigned long)id, |
| 114 | A_END); |
| 115 | return; |
| 116 | |
| 117 | found: |
| 118 | if (memcmp(magic, pg->magic, sizeof(pg->magic)) != 0) { |
| 119 | a_warn("PEER", "?PEER", p, "corrupt-%s", p_pingtype(msg), A_END); |
| 120 | return; |
| 121 | } |
| 122 | p_pingdone(pg, PING_OK); |
| 123 | } |
| 124 | |
| 125 | /* --- @p_rxupdstats@ --- * |
| 126 | * |
| 127 | * Arguments: @peer *p@ = peer to update |
| 128 | * @size_t n@ = size of incoming packet |
| 129 | * |
| 130 | * Returns: --- |
| 131 | * |
| 132 | * Use: Updates the peer's incoming packet statistics. |
| 133 | */ |
| 134 | |
| 135 | static void p_rxupdstats(peer *p, size_t n) |
| 136 | { |
| 137 | p->st.t_last = time(0); |
| 138 | p->st.n_in++; |
| 139 | p->st.sz_in += n; |
| 140 | } |
| 141 | |
| 142 | /* --- @p_encrypt@ --- * |
| 143 | * |
| 144 | * Arguments: @peer *p@ = peer to encrypt message to |
| 145 | * @int ty@ message type to send |
| 146 | * @buf *bin, *bout@ = input and output buffers |
| 147 | * |
| 148 | * Returns: --- |
| 149 | * |
| 150 | * Use: Convenience function for packet encryption. Forces |
| 151 | * renegotiation when necessary. Check for the output buffer |
| 152 | * being broken to find out whether the encryption was |
| 153 | * successful. |
| 154 | */ |
| 155 | |
| 156 | static int p_encrypt(peer *p, int ty, buf *bin, buf *bout) |
| 157 | { |
| 158 | int err = ksl_encrypt(&p->ks, ty, bin, bout); |
| 159 | |
| 160 | if (err == KSERR_REGEN) { |
| 161 | kx_start(&p->kx, 1); |
| 162 | err = 0; |
| 163 | } |
| 164 | if (!BOK(bout)) |
| 165 | err = -1; |
| 166 | return (err); |
| 167 | } |
| 168 | |
| 169 | /* --- @p_updateaddr@ --- * |
| 170 | * |
| 171 | * Arguments: @peer *p@ = pointer to peer block |
| 172 | * @const addr *a@ = address to associate with this peer |
| 173 | * |
| 174 | * Returns: Zero if the address was changed; @+1@ if it was already |
| 175 | * right. |
| 176 | * |
| 177 | * Use: Updates our idea of @p@'s address. |
| 178 | */ |
| 179 | |
| 180 | int p_updateaddr(peer *p, const addr *a) |
| 181 | { |
| 182 | peer *q; |
| 183 | peer_byaddr *pa, *qa; |
| 184 | unsigned f; |
| 185 | |
| 186 | /* --- Figure out how to proceed --- * |
| 187 | * |
| 188 | * If this address already belongs to a different peer, then swap the |
| 189 | * addresses over. This doesn't leave the displaced peer in an especially |
| 190 | * good state, but it ought to get sorted out soon enough. |
| 191 | */ |
| 192 | |
| 193 | pa = am_find(&byaddr, a, sizeof(peer_byaddr), &f); |
| 194 | if (f && pa->p == p) |
| 195 | return (+1); |
| 196 | else if (!f) { |
| 197 | T( trace(T_PEER, "peer: updating address for `%s'", p_name(p)); ) |
| 198 | am_remove(&byaddr, p->byaddr); |
| 199 | p->byaddr = pa; p->spec.sa = *a; pa->p = p; |
| 200 | a_notify("NEWADDR", "?PEER", p, "?ADDR", a, A_END); |
| 201 | return (0); |
| 202 | } else { |
| 203 | q = pa->p; qa = p->byaddr; |
| 204 | T( trace(T_PEER, "peer: swapping addresses for `%s' and `%s'", |
| 205 | p_name(p), p_name(q)); ) |
| 206 | q->byaddr = qa; qa->p = q; q->spec.sa = p->spec.sa; |
| 207 | p->byaddr = pa; pa->p = p; p->spec.sa = *a; |
| 208 | a_notify("NEWADDR", "?PEER", p, "?ADDR", a, A_END); |
| 209 | a_notify("NEWADDR", "?PEER", q, "?ADDR", &q->spec.sa, A_END); |
| 210 | return (0); |
| 211 | } |
| 212 | } |
| 213 | |
| 214 | /* --- @p_decrypt@ --- * |
| 215 | * |
| 216 | * Arguments: @peer **pp@ = pointer to peer to decrypt message from |
| 217 | * @addr *a@ = address the packet arrived on |
| 218 | * @size_t n@ = size of original incoming packet |
| 219 | * @int ty@ = message type to expect |
| 220 | * @buf *bin, *bout@ = input and output buffers |
| 221 | * |
| 222 | * Returns: Zero on success; nonzero on error. |
| 223 | * |
| 224 | * Use: Convenience function for packet decryption. Reports errors |
| 225 | * and updates statistics appropriately. |
| 226 | * |
| 227 | * If @*pp@ is null on entry and there are mobile peers then we |
| 228 | * see if any of them can decrypt the packet. If so, we record |
| 229 | * @*a@ as the peer's new address and send a notification. |
| 230 | */ |
| 231 | |
| 232 | static int p_decrypt(peer **pp, addr *a, size_t n, |
| 233 | int ty, buf *bin, buf *bout) |
| 234 | { |
| 235 | peer *p, *q; |
| 236 | int err = KSERR_DECRYPT; |
| 237 | |
| 238 | /* --- If we have a match on the source address then try that first --- */ |
| 239 | |
| 240 | q = *pp; |
| 241 | if (q) { |
| 242 | T( trace(T_PEER, "peer: decrypting packet from known peer `%s'", |
| 243 | p_name(q)); ) |
| 244 | if ((err = ksl_decrypt(&q->ks, ty, bin, bout)) != KSERR_DECRYPT || |
| 245 | !(q->spec.f & PSF_MOBILE) || nmobile == 1) { |
| 246 | p = q; |
| 247 | goto match; |
| 248 | } |
| 249 | T( trace(T_PEER, "peer: failed to decrypt: try other mobile peers..."); ) |
| 250 | } else if (nmobile) |
| 251 | T( trace(T_PEER, "peer: unknown source: trying mobile peers...") ); |
| 252 | else { |
| 253 | p = 0; |
| 254 | goto searched; |
| 255 | } |
| 256 | |
| 257 | /* --- See whether any mobile peer is interested --- */ |
| 258 | |
| 259 | p = 0; |
| 260 | FOREACH_PEER(qq, { |
| 261 | if (qq == q || !(qq->spec.f & PSF_MOBILE)) continue; |
| 262 | if ((err = ksl_decrypt(&qq->ks, ty, bin, bout)) == KSERR_DECRYPT) { |
| 263 | T( trace(T_PEER, "peer: peer `%s' failed to decrypt", |
| 264 | p_name(qq)); ) |
| 265 | continue; |
| 266 | } else { |
| 267 | p = qq; |
| 268 | IF_TRACING(T_PEER, { |
| 269 | if (!err) |
| 270 | trace(T_PEER, "peer: peer `%s' reports success", p_name(qq)); |
| 271 | else { |
| 272 | trace(T_PEER, "peer: peer `%s' reports decryption error %d", |
| 273 | p_name(qq), err); |
| 274 | } |
| 275 | }) |
| 276 | break; |
| 277 | } |
| 278 | }); |
| 279 | |
| 280 | /* --- We've searched the mobile peers --- */ |
| 281 | |
| 282 | searched: |
| 283 | if (!p) { |
| 284 | if (!q) |
| 285 | a_warn("PEER", "-", "unexpected-source", "?ADDR", a, A_END); |
| 286 | else { |
| 287 | a_warn("PEER", "?PEER", p, "decrypt-failed", |
| 288 | "error-code", "%d", err, A_END); |
| 289 | p_rxupdstats(q, n); |
| 290 | } |
| 291 | return (-1); |
| 292 | } |
| 293 | |
| 294 | /* --- We found one that accepted, so update the peer's address --- */ |
| 295 | |
| 296 | if (!err) { |
| 297 | *pp = p; |
| 298 | p_updateaddr(p, a); |
| 299 | } |
| 300 | |
| 301 | match: |
| 302 | p_rxupdstats(p, n); |
| 303 | if (err) { |
| 304 | if (p) p->st.n_reject++; |
| 305 | a_warn("PEER", "?PEER", p, "decrypt-failed", |
| 306 | "error-code", "%d", err, A_END); |
| 307 | return (-1); |
| 308 | } |
| 309 | if (!BOK(bout)) |
| 310 | return (-1); |
| 311 | return (0); |
| 312 | } |
| 313 | |
| 314 | /* --- @p_read@ --- * |
| 315 | * |
| 316 | * Arguments: @int fd@ = file descriptor to read from |
| 317 | * @unsigned mode@ = what happened |
| 318 | * @void *v@ = an uninteresting pointer |
| 319 | * |
| 320 | * Returns: --- |
| 321 | * |
| 322 | * Use: Reads a packet from somewhere. |
| 323 | */ |
| 324 | |
| 325 | static void p_read(int fd, unsigned mode, void *v) |
| 326 | { |
| 327 | peer *p = 0; |
| 328 | addr a; |
| 329 | socklen_t sz; |
| 330 | ssize_t n; |
| 331 | int ch; |
| 332 | buf b, bb; |
| 333 | |
| 334 | /* --- Read the data --- */ |
| 335 | |
| 336 | QUICKRAND; |
| 337 | sz = sizeof(addr); |
| 338 | n = recvfrom(fd, buf_i, sizeof(buf_i), 0, &a.sa, &sz); |
| 339 | if (n < 0) { |
| 340 | a_warn("PEER", "-", "socket-read-error", "?ERRNO", A_END); |
| 341 | return; |
| 342 | } |
| 343 | |
| 344 | /* --- If the packet is a greeting, don't check peers --- */ |
| 345 | |
| 346 | if (n && buf_i[0] == (MSG_MISC | MISC_GREET)) { |
| 347 | IF_TRACING(T_PEER, { |
| 348 | trace(T_PEER, "peer: greeting received from INET %s %u", |
| 349 | inet_ntoa(a.sin.sin_addr), |
| 350 | (unsigned)ntohs(a.sin.sin_port)); |
| 351 | trace_block(T_PACKET, "peer: greeting contents", buf_i, n); |
| 352 | }) |
| 353 | buf_init(&b, buf_i, n); |
| 354 | buf_getbyte(&b); |
| 355 | if (c_check(&b) || BLEFT(&b)) { |
| 356 | a_warn("PEER", "-", "invalid-greeting", A_END); |
| 357 | return; |
| 358 | } |
| 359 | a_notify("GREET", |
| 360 | "?B64", buf_i + 1, (size_t)(n - 1), |
| 361 | "?ADDR", &a, |
| 362 | A_END); |
| 363 | return; |
| 364 | } |
| 365 | |
| 366 | /* --- Find the appropriate peer --- * |
| 367 | * |
| 368 | * At this stage, don't worry too much about whether we actually found it. |
| 369 | */ |
| 370 | |
| 371 | p = p_findbyaddr(&a); |
| 372 | |
| 373 | IF_TRACING(T_PEER, { |
| 374 | if (p) { |
| 375 | trace(T_PEER, |
| 376 | "peer: packet received from `%s' from address INET %s %d", |
| 377 | p_name(p), inet_ntoa(a.sin.sin_addr), ntohs(a.sin.sin_port)); |
| 378 | } else { |
| 379 | trace(T_PEER, "peer: packet received from unknown address INET %s %d", |
| 380 | inet_ntoa(a.sin.sin_addr), ntohs(a.sin.sin_port)); |
| 381 | } |
| 382 | trace_block(T_PACKET, "peer: packet contents", buf_i, n); |
| 383 | }) |
| 384 | |
| 385 | /* --- Pick the packet apart --- */ |
| 386 | |
| 387 | buf_init(&b, buf_i, n); |
| 388 | if ((ch = buf_getbyte(&b)) < 0) { |
| 389 | a_warn("PEER", "?PEER", p, "bad-packet", "no-type", A_END); |
| 390 | return; |
| 391 | } |
| 392 | switch (ch & MSG_CATMASK) { |
| 393 | case MSG_PACKET: |
| 394 | if (ch & MSG_TYPEMASK) { |
| 395 | a_warn("PEER", |
| 396 | "?PEER", p, |
| 397 | "bad-packet", |
| 398 | "unknown-type", "0x%02x", ch, |
| 399 | A_END); |
| 400 | if (p) p->st.n_reject++; |
| 401 | return; |
| 402 | } |
| 403 | buf_init(&bb, buf_o, sizeof(buf_o)); |
| 404 | if (p_decrypt(&p, &a, n, MSG_PACKET, &b, &bb)) |
| 405 | return; |
| 406 | if (BOK(&bb)) { |
| 407 | p->st.n_ipin++; |
| 408 | p->st.sz_ipin += BSZ(&b); |
| 409 | p->t->ops->inject(p->t, &bb); |
| 410 | } else { |
| 411 | p->st.n_reject++; |
| 412 | a_warn("PEER", "?PEER", p, "packet-build-failed", A_END); |
| 413 | } |
| 414 | break; |
| 415 | case MSG_KEYEXCH: |
| 416 | if (!p) goto unexp; |
| 417 | p_rxupdstats(p, n); |
| 418 | kx_message(&p->kx, ch & MSG_TYPEMASK, &b); |
| 419 | break; |
| 420 | case MSG_MISC: |
| 421 | switch (ch & MSG_TYPEMASK) { |
| 422 | case MISC_NOP: |
| 423 | if (!p) goto unexp; |
| 424 | p_rxupdstats(p, n); |
| 425 | T( trace(T_PEER, "peer: received NOP packet"); ) |
| 426 | break; |
| 427 | case MISC_PING: |
| 428 | if (!p) goto unexp; |
| 429 | p_rxupdstats(p, n); |
| 430 | buf_put(p_txstart(p, MSG_MISC | MISC_PONG), BCUR(&b), BLEFT(&b)); |
| 431 | p_txend(p); |
| 432 | break; |
| 433 | case MISC_PONG: |
| 434 | if (!p) goto unexp; |
| 435 | p_rxupdstats(p, n); |
| 436 | p_ponged(p, MISC_PONG, &b); |
| 437 | break; |
| 438 | case MISC_EPING: |
| 439 | buf_init(&bb, buf_t, sizeof(buf_t)); |
| 440 | if (p_decrypt(&p, &a, n, ch, &b, &bb)) |
| 441 | return; |
| 442 | if (BOK(&bb)) { |
| 443 | buf_flip(&bb); |
| 444 | p_encrypt(p, MSG_MISC | MISC_EPONG, &bb, |
| 445 | p_txstart(p, MSG_MISC | MISC_EPONG)); |
| 446 | p_txend(p); |
| 447 | } |
| 448 | break; |
| 449 | case MISC_EPONG: |
| 450 | buf_init(&bb, buf_t, sizeof(buf_t)); |
| 451 | if (p_decrypt(&p, &a, n, ch, &b, &bb)) |
| 452 | return; |
| 453 | if (BOK(&bb)) { |
| 454 | buf_flip(&bb); |
| 455 | p_ponged(p, MISC_EPONG, &bb); |
| 456 | } |
| 457 | break; |
| 458 | } |
| 459 | break; |
| 460 | default: |
| 461 | if (p) p->st.n_reject++; |
| 462 | a_warn("PEER", |
| 463 | "?PEER", p, |
| 464 | "bad-packet", |
| 465 | "unknown-category", "0x%02x", ch, |
| 466 | A_END); |
| 467 | break; |
| 468 | unexp: |
| 469 | a_warn("PEER", "-", "unexpected-source", "?ADDR", &a, A_END); |
| 470 | break; |
| 471 | } |
| 472 | } |
| 473 | |
| 474 | /* --- @p_txstart@ --- * |
| 475 | * |
| 476 | * Arguments: @peer *p@ = pointer to peer block |
| 477 | * @unsigned msg@ = message type code |
| 478 | * |
| 479 | * Returns: A pointer to a buffer to write to. |
| 480 | * |
| 481 | * Use: Starts sending to a peer. Only one send can happen at a |
| 482 | * time. |
| 483 | */ |
| 484 | |
| 485 | buf *p_txstart(peer *p, unsigned msg) |
| 486 | { |
| 487 | buf_init(&p->b, buf_o, sizeof(buf_o)); |
| 488 | buf_putbyte(&p->b, msg); |
| 489 | return (&p->b); |
| 490 | } |
| 491 | |
| 492 | /* --- @p_txend@ --- * |
| 493 | * |
| 494 | * Arguments: @peer *p@ = pointer to peer block |
| 495 | * |
| 496 | * Returns: --- |
| 497 | * |
| 498 | * Use: Sends a packet to the peer. |
| 499 | */ |
| 500 | |
| 501 | static void p_setkatimer(peer *); |
| 502 | |
| 503 | static int p_dotxend(peer *p) |
| 504 | { |
| 505 | socklen_t sasz = addrsz(&p->spec.sa); |
| 506 | |
| 507 | if (!BOK(&p->b)) { |
| 508 | a_warn("PEER", "?PEER", p, "packet-build-failed", A_END); |
| 509 | return (0); |
| 510 | } |
| 511 | IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet", |
| 512 | BBASE(&p->b), BLEN(&p->b)); ) |
| 513 | if (sendto(sock.fd, BBASE(&p->b), BLEN(&p->b), |
| 514 | 0, &p->spec.sa.sa, sasz) < 0) { |
| 515 | a_warn("PEER", "?PEER", p, "socket-write-error", "?ERRNO", A_END); |
| 516 | return (0); |
| 517 | } else { |
| 518 | p->st.n_out++; |
| 519 | p->st.sz_out += BLEN(&p->b); |
| 520 | return (1); |
| 521 | } |
| 522 | } |
| 523 | |
| 524 | void p_txend(peer *p) |
| 525 | { |
| 526 | if (p_dotxend(p) && p->spec.t_ka) { |
| 527 | sel_rmtimer(&p->tka); |
| 528 | p_setkatimer(p); |
| 529 | } |
| 530 | } |
| 531 | |
| 532 | /* --- @p_pingwrite@ --- * |
| 533 | * |
| 534 | * Arguments: @ping *p@ = ping structure |
| 535 | * @buf *b@ = buffer to write in |
| 536 | * |
| 537 | * Returns: --- |
| 538 | * |
| 539 | * Use: Fills in a ping structure and writes the packet payload. |
| 540 | */ |
| 541 | |
| 542 | static void p_pingwrite(ping *p, buf *b) |
| 543 | { |
| 544 | static uint32 seq = 0; |
| 545 | |
| 546 | p->id = U32(seq++); |
| 547 | GR_FILL(&rand_global, p->magic, sizeof(p->magic)); |
| 548 | buf_putu32(b, p->id); |
| 549 | buf_put(b, p->magic, sizeof(p->magic)); |
| 550 | } |
| 551 | |
| 552 | /* --- @p_pingdone@ --- * |
| 553 | * |
| 554 | * Arguments: @ping *p@ = ping structure |
| 555 | * @int rc@ = return code to pass on |
| 556 | * |
| 557 | * Returns: --- |
| 558 | * |
| 559 | * Use: Disposes of a ping structure, maybe sending a notification. |
| 560 | */ |
| 561 | |
| 562 | void p_pingdone(ping *p, int rc) |
| 563 | { |
| 564 | if (p->prev) p->prev->next = p->next; |
| 565 | else p->p->pings = p->next; |
| 566 | if (p->next) p->next->prev = p->prev; |
| 567 | if (rc != PING_TIMEOUT) sel_rmtimer(&p->t); |
| 568 | T( trace(T_PEER, "peer: ping 0x%08lx done (rc = %d)", |
| 569 | (unsigned long)p->id, rc); ) |
| 570 | if (rc >= 0) p->func(rc, p->arg); |
| 571 | } |
| 572 | |
| 573 | /* --- @p_pingtimeout@ --- * |
| 574 | * |
| 575 | * Arguments: @struct timeval *now@ = the time now |
| 576 | * @void *pv@ = pointer to ping block |
| 577 | * |
| 578 | * Returns: --- |
| 579 | * |
| 580 | * Use: Called when a ping times out. |
| 581 | */ |
| 582 | |
| 583 | static void p_pingtimeout(struct timeval *now, void *pv) |
| 584 | { |
| 585 | ping *p = pv; |
| 586 | |
| 587 | T( trace(T_PEER, "peer: ping 0x%08lx timed out", (unsigned long)p->id); ) |
| 588 | p_pingdone(p, PING_TIMEOUT); |
| 589 | } |
| 590 | |
| 591 | /* --- @p_pingsend@ --- * |
| 592 | * |
| 593 | * Arguments: @peer *p@ = destination peer |
| 594 | * @ping *pg@ = structure to fill in |
| 595 | * @unsigned type@ = message type |
| 596 | * @unsigned long timeout@ = how long to wait before giving up |
| 597 | * @void (*func)(int, void *)@ = callback function |
| 598 | * @void *arg@ = argument for callback |
| 599 | * |
| 600 | * Returns: Zero if successful, nonzero if it failed. |
| 601 | * |
| 602 | * Use: Sends a ping to a peer. Call @func@ with a nonzero argument |
| 603 | * if we get an answer within the timeout, or zero if no answer. |
| 604 | */ |
| 605 | |
| 606 | int p_pingsend(peer *p, ping *pg, unsigned type, |
| 607 | unsigned long timeout, |
| 608 | void (*func)(int, void *), void *arg) |
| 609 | { |
| 610 | buf *b, bb; |
| 611 | struct timeval tv; |
| 612 | |
| 613 | switch (type) { |
| 614 | case MISC_PING: |
| 615 | pg->msg = MISC_PONG; |
| 616 | b = p_txstart(p, MSG_MISC | MISC_PING); |
| 617 | p_pingwrite(pg, b); |
| 618 | p_txend(p); |
| 619 | break; |
| 620 | case MISC_EPING: |
| 621 | pg->msg = MISC_EPONG; |
| 622 | b = p_txstart(p, MSG_MISC | MISC_EPING); |
| 623 | buf_init(&bb, buf_t, sizeof(buf_t)); |
| 624 | p_pingwrite(pg, &bb); |
| 625 | buf_flip(&bb); |
| 626 | p_encrypt(p, MSG_MISC | MISC_EPING, &bb, b); |
| 627 | if (!BOK(b)) |
| 628 | return (-1); |
| 629 | p_txend(p); |
| 630 | break; |
| 631 | default: |
| 632 | abort(); |
| 633 | break; |
| 634 | } |
| 635 | |
| 636 | pg->next = p->pings; |
| 637 | pg->prev = 0; |
| 638 | pg->p = p; |
| 639 | pg->func = func; |
| 640 | pg->arg = arg; |
| 641 | if (p->pings) p->pings->prev = pg; |
| 642 | p->pings = pg; |
| 643 | gettimeofday(&tv, 0); |
| 644 | tv.tv_sec += timeout; |
| 645 | sel_addtimer(&sel, &pg->t, &tv, p_pingtimeout, pg); |
| 646 | T( trace(T_PEER, "peer: send %s 0x%08lx to %s", |
| 647 | p_pingtype(type), (unsigned long)pg->id, p->spec.name); ) |
| 648 | return (0); |
| 649 | } |
| 650 | |
| 651 | /* --- @p_greet@ --- * |
| 652 | * |
| 653 | * Arguments: @peer *p@ = peer to send to |
| 654 | * @const void *c@ = pointer to challenge |
| 655 | * @size_t sz@ = size of challenge |
| 656 | * |
| 657 | * Returns: --- |
| 658 | * |
| 659 | * Use: Sends a greeting packet. |
| 660 | */ |
| 661 | |
| 662 | void p_greet(peer *p, const void *c, size_t sz) |
| 663 | { |
| 664 | buf *b = p_txstart(p, MSG_MISC | MISC_GREET); |
| 665 | buf_put(b, c, sz); |
| 666 | p_txend(p); |
| 667 | } |
| 668 | |
| 669 | /* --- @p_tun@ --- * |
| 670 | * |
| 671 | * Arguments: @peer *p@ = pointer to peer block |
| 672 | * @buf *b@ = buffer containing incoming packet |
| 673 | * |
| 674 | * Returns: --- |
| 675 | * |
| 676 | * Use: Handles a packet which needs to be sent to a peer. |
| 677 | */ |
| 678 | |
| 679 | void p_tun(peer *p, buf *b) |
| 680 | { |
| 681 | buf *bb = p_txstart(p, MSG_PACKET); |
| 682 | |
| 683 | QUICKRAND; |
| 684 | p_encrypt(p, MSG_PACKET, b, bb); |
| 685 | if (BOK(bb) && BLEN(bb)) { |
| 686 | p->st.n_ipout++; |
| 687 | p->st.sz_ipout += BLEN(bb); |
| 688 | p_txend(p); |
| 689 | } |
| 690 | } |
| 691 | |
| 692 | /* --- @p_keyreload@ --- * |
| 693 | * |
| 694 | * Arguments: --- |
| 695 | * |
| 696 | * Returns: --- |
| 697 | * |
| 698 | * Use: Forces a check of the daemon's keyring files. |
| 699 | */ |
| 700 | |
| 701 | void p_keyreload(void) |
| 702 | { |
| 703 | if (km_reload()) |
| 704 | FOREACH_PEER(p, { kx_newkeys(&p->kx); }); |
| 705 | } |
| 706 | |
| 707 | /* --- @p_interval@ --- * |
| 708 | * |
| 709 | * Arguments: --- |
| 710 | * |
| 711 | * Returns: --- |
| 712 | * |
| 713 | * Use: Called periodically to do tidying. |
| 714 | */ |
| 715 | |
| 716 | void p_interval(void) |
| 717 | { |
| 718 | p_keyreload(); |
| 719 | FOREACH_PEER(p, { ksl_prune(&p->ks); }); |
| 720 | } |
| 721 | |
| 722 | /* --- @p_stats@ --- * |
| 723 | * |
| 724 | * Arguments: @peer *p@ = pointer to a peer block |
| 725 | * |
| 726 | * Returns: A pointer to the peer's statistics. |
| 727 | */ |
| 728 | |
| 729 | stats *p_stats(peer *p) { return (&p->st); } |
| 730 | |
| 731 | /* --- @p_ifname@ --- * |
| 732 | * |
| 733 | * Arguments: @peer *p@ = pointer to a peer block |
| 734 | * |
| 735 | * Returns: A pointer to the peer's interface name. |
| 736 | */ |
| 737 | |
| 738 | const char *p_ifname(peer *p) { return (p->ifname); } |
| 739 | |
| 740 | /* --- @p_setifname@ --- * |
| 741 | * |
| 742 | * Arguments: @peer *p@ = pointer to a peer block |
| 743 | * @const char *name@ = pointer to the new name |
| 744 | * |
| 745 | * Returns: --- |
| 746 | * |
| 747 | * Use: Changes the name held for a peer's interface. |
| 748 | */ |
| 749 | |
| 750 | void p_setifname(peer *p, const char *name) |
| 751 | { |
| 752 | xfree(p->ifname); |
| 753 | p->ifname = xstrdup(name); |
| 754 | if (p->spec.tops->setifname) |
| 755 | p->spec.tops->setifname(p->t, name); |
| 756 | } |
| 757 | |
| 758 | /* --- @p_addr@ --- * |
| 759 | * |
| 760 | * Arguments: @peer *p@ = pointer to a peer block |
| 761 | * |
| 762 | * Returns: A pointer to the peer's address. |
| 763 | */ |
| 764 | |
| 765 | const addr *p_addr(peer *p) { return (&p->spec.sa); } |
| 766 | |
| 767 | /* --- @p_init@ --- * |
| 768 | * |
| 769 | * Arguments: @struct in_addr addr@ = address to bind to |
| 770 | * @unsigned port@ = port number to listen to |
| 771 | * |
| 772 | * Returns: --- |
| 773 | * |
| 774 | * Use: Initializes the peer system; creates the socket. |
| 775 | */ |
| 776 | |
| 777 | void p_init(struct in_addr addr, unsigned port) |
| 778 | { |
| 779 | int fd; |
| 780 | struct sockaddr_in sin; |
| 781 | int len = PKBUFSZ; |
| 782 | |
| 783 | /* --- Note on socket buffer sizes --- * |
| 784 | * |
| 785 | * For some bizarre reason, Linux 2.2 (at least) doubles the socket buffer |
| 786 | * sizes I pass to @setsockopt@. I'm not putting special-case code here |
| 787 | * for Linux: BSD (at least TCPv2) does what I tell it rather than second- |
| 788 | * guessing me. |
| 789 | */ |
| 790 | |
| 791 | if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) |
| 792 | die(EXIT_FAILURE, "socket creation failed: %s", strerror(errno)); |
| 793 | BURN(sin); |
| 794 | sin.sin_family = AF_INET; |
| 795 | sin.sin_addr = addr; |
| 796 | sin.sin_port = htons(port); |
| 797 | if (bind(fd, (struct sockaddr *)&sin, sizeof(sin))) |
| 798 | die(EXIT_FAILURE, "bind failed: %s", strerror(errno)); |
| 799 | if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) || |
| 800 | setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len))) { |
| 801 | die(EXIT_FAILURE, "failed to set socket buffer sizes: %s", |
| 802 | strerror(errno)); |
| 803 | } |
| 804 | fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); |
| 805 | sel_initfile(&sel, &sock, fd, SEL_READ, p_read, 0); |
| 806 | sel_addfile(&sock); |
| 807 | T( trace(T_PEER, "peer: created socket"); ) |
| 808 | |
| 809 | sym_create(&byname); |
| 810 | am_create(&byaddr); |
| 811 | } |
| 812 | |
| 813 | /* --- @p_port@ --- * |
| 814 | * |
| 815 | * Arguments: --- |
| 816 | * |
| 817 | * Returns: Port number used for socket. |
| 818 | */ |
| 819 | |
| 820 | unsigned p_port(void) |
| 821 | { |
| 822 | addr a; |
| 823 | socklen_t sz = sizeof(addr); |
| 824 | |
| 825 | if (getsockname(sock.fd, &a.sa, &sz)) |
| 826 | die(EXIT_FAILURE, "couldn't read port number: %s", strerror(errno)); |
| 827 | assert(a.sa.sa_family == AF_INET); |
| 828 | return (ntohs(a.sin.sin_port)); |
| 829 | } |
| 830 | |
| 831 | /* --- @p_keepalive@ --- * |
| 832 | * |
| 833 | * Arguments: @struct timeval *now@ = the current time |
| 834 | * @void *pv@ = peer to wake up |
| 835 | * |
| 836 | * Returns: --- |
| 837 | * |
| 838 | * Use: Sends a keepalive ping message to its peer. |
| 839 | */ |
| 840 | |
| 841 | static void p_keepalive(struct timeval *now, void *pv) |
| 842 | { |
| 843 | peer *p = pv; |
| 844 | |
| 845 | p_txstart(p, MSG_MISC | MISC_NOP); p_dotxend(p); |
| 846 | T( trace(T_PEER, "peer: sent keepalive to %s", p->spec.name); ) |
| 847 | p_setkatimer(p); |
| 848 | } |
| 849 | |
| 850 | /* --- @p_setkatimer@ --- * |
| 851 | * |
| 852 | * Arguments: @peer *p@ = peer to set |
| 853 | * |
| 854 | * Returns: --- |
| 855 | * |
| 856 | * Use: Resets the keepalive timer thing. |
| 857 | */ |
| 858 | |
| 859 | static void p_setkatimer(peer *p) |
| 860 | { |
| 861 | struct timeval tv; |
| 862 | |
| 863 | if (!p->spec.t_ka) |
| 864 | return; |
| 865 | gettimeofday(&tv, 0); |
| 866 | tv.tv_sec += p->spec.t_ka; |
| 867 | sel_addtimer(&sel, &p->tka, &tv, p_keepalive, p); |
| 868 | } |
| 869 | |
| 870 | /* --- @p_create@ --- * |
| 871 | * |
| 872 | * Arguments: @peerspec *spec@ = information about this peer |
| 873 | * |
| 874 | * Returns: Pointer to the peer block, or null if it failed. |
| 875 | * |
| 876 | * Use: Creates a new named peer block. No peer is actually attached |
| 877 | * by this point. |
| 878 | */ |
| 879 | |
| 880 | peer *p_create(peerspec *spec) |
| 881 | { |
| 882 | peer *p = CREATE(peer); |
| 883 | const tunnel_ops *tops = spec->tops; |
| 884 | int fd; |
| 885 | unsigned f; |
| 886 | |
| 887 | p->byname = sym_find(&byname, spec->name, -1, sizeof(peer_byname), &f); |
| 888 | if (f) goto tidy_0; |
| 889 | p->byaddr = am_find(&byaddr, &spec->sa, sizeof(peer_byaddr), &f); |
| 890 | if (f) goto tidy_1; |
| 891 | p->byname->p = p->byaddr->p = p; |
| 892 | |
| 893 | T( trace(T_PEER, "peer: creating new peer `%s'", spec->name); ) |
| 894 | p->spec = *spec; |
| 895 | p->spec.name = (/*unconst*/ char *)SYM_NAME(p->byname); |
| 896 | if (spec->tag) p->spec.tag = xstrdup(spec->tag); |
| 897 | if (spec->privtag) p->spec.privtag = xstrdup(spec->privtag); |
| 898 | p->ks = 0; |
| 899 | p->pings = 0; |
| 900 | p->ifname = 0; |
| 901 | memset(&p->st, 0, sizeof(stats)); |
| 902 | p->st.t_start = time(0); |
| 903 | if (!(tops->flags & TUNF_PRIVOPEN)) |
| 904 | fd = -1; |
| 905 | else if ((fd = ps_tunfd(tops, &p->ifname)) < 0) |
| 906 | goto tidy_2; |
| 907 | if ((p->t = tops->create(p, fd, &p->ifname)) == 0) |
| 908 | goto tidy_3; |
| 909 | T( trace(T_TUNNEL, "peer: attached interface %s to peer `%s'", |
| 910 | p->ifname, p_name(p)); ) |
| 911 | p_setkatimer(p); |
| 912 | if (kx_init(&p->kx, p, &p->ks, p->spec.f & PSF_KXMASK)) |
| 913 | goto tidy_4; |
| 914 | a_notify("ADD", |
| 915 | "?PEER", p, |
| 916 | "%s", p->ifname, |
| 917 | "?ADDR", &p->spec.sa, |
| 918 | A_END); |
| 919 | if (!(p->spec.f & KXF_CORK)) { |
| 920 | a_notify("KXSTART", "?PEER", p, A_END); |
| 921 | /* Couldn't tell anyone before */ |
| 922 | } |
| 923 | if (p->spec.f & PSF_MOBILE) nmobile++; |
| 924 | return (p); |
| 925 | |
| 926 | tidy_4: |
| 927 | if (spec->t_ka) sel_rmtimer(&p->tka); |
| 928 | xfree(p->ifname); |
| 929 | p->t->ops->destroy(p->t); |
| 930 | tidy_3: |
| 931 | if (fd >= 0) close(fd); |
| 932 | tidy_2: |
| 933 | am_remove(&byaddr, p->byaddr); |
| 934 | if (p->spec.tag) xfree(p->spec.tag); |
| 935 | if (p->spec.privtag) xfree(p->spec.privtag); |
| 936 | tidy_1: |
| 937 | sym_remove(&byname, p->byname); |
| 938 | tidy_0: |
| 939 | DESTROY(p); |
| 940 | return (0); |
| 941 | } |
| 942 | |
| 943 | /* --- @p_name@ --- * |
| 944 | * |
| 945 | * Arguments: @peer *p@ = pointer to a peer block |
| 946 | * |
| 947 | * Returns: A pointer to the peer's name. |
| 948 | */ |
| 949 | |
| 950 | const char *p_name(peer *p) |
| 951 | { if (p) return (p->spec.name); else return ("-"); } |
| 952 | |
| 953 | /* --- @p_tag@ --- * |
| 954 | * |
| 955 | * Arguments: @peer *p@ = pointer to a peer block |
| 956 | * |
| 957 | * Returns: A pointer to the peer's public key tag. |
| 958 | */ |
| 959 | |
| 960 | const char *p_tag(peer *p) |
| 961 | { return (p->spec.tag ? p->spec.tag : p->spec.name); } |
| 962 | |
| 963 | /* --- @p_privtag@ --- * |
| 964 | * |
| 965 | * Arguments: @peer *p@ = pointer to a peer block |
| 966 | * |
| 967 | * Returns: A pointer to the peer's private key tag. |
| 968 | */ |
| 969 | |
| 970 | const char *p_privtag(peer *p) |
| 971 | { return (p->spec.privtag ? p->spec.privtag : tag_priv); } |
| 972 | |
| 973 | /* --- @p_spec@ --- * |
| 974 | * |
| 975 | * Arguments: @peer *p@ = pointer to a peer block |
| 976 | * |
| 977 | * Returns: Pointer to the peer's specification |
| 978 | */ |
| 979 | |
| 980 | const peerspec *p_spec(peer *p) { return (&p->spec); } |
| 981 | |
| 982 | /* --- @p_findbyaddr@ --- * |
| 983 | * |
| 984 | * Arguments: @const addr *a@ = address to look up |
| 985 | * |
| 986 | * Returns: Pointer to the peer block, or null if not found. |
| 987 | * |
| 988 | * Use: Finds a peer by address. |
| 989 | */ |
| 990 | |
| 991 | peer *p_findbyaddr(const addr *a) |
| 992 | { |
| 993 | peer_byaddr *pa; |
| 994 | |
| 995 | if ((pa = am_find(&byaddr, a, 0, 0)) != 0) { |
| 996 | assert(pa->p); |
| 997 | return (pa->p); |
| 998 | } |
| 999 | return (0); |
| 1000 | } |
| 1001 | |
| 1002 | /* --- @p_find@ --- * |
| 1003 | * |
| 1004 | * Arguments: @const char *name@ = name to look up |
| 1005 | * |
| 1006 | * Returns: Pointer to the peer block, or null if not found. |
| 1007 | * |
| 1008 | * Use: Finds a peer by name. |
| 1009 | */ |
| 1010 | |
| 1011 | peer *p_find(const char *name) |
| 1012 | { |
| 1013 | peer_byname *pn; |
| 1014 | |
| 1015 | if ((pn = sym_find(&byname, name, -1, 0, 0)) != 0) |
| 1016 | return (pn->p); |
| 1017 | return (0); |
| 1018 | } |
| 1019 | |
| 1020 | /* --- @p_destroy@ --- * |
| 1021 | * |
| 1022 | * Arguments: @peer *p@ = pointer to a peer |
| 1023 | * |
| 1024 | * Returns: --- |
| 1025 | * |
| 1026 | * Use: Destroys a peer. |
| 1027 | */ |
| 1028 | |
| 1029 | void p_destroy(peer *p) |
| 1030 | { |
| 1031 | ping *pg, *ppg; |
| 1032 | |
| 1033 | T( trace(T_PEER, "peer: destroying peer `%s'", p->spec.name); ) |
| 1034 | a_notify("KILL", "%s", p->spec.name, A_END); |
| 1035 | ksl_free(&p->ks); |
| 1036 | kx_free(&p->kx); |
| 1037 | if (p->spec.f & PSF_MOBILE) nmobile--; |
| 1038 | if (p->ifname) xfree(p->ifname); |
| 1039 | if (p->spec.tag) xfree(p->spec.tag); |
| 1040 | if (p->spec.privtag) xfree(p->spec.privtag); |
| 1041 | p->t->ops->destroy(p->t); |
| 1042 | if (p->spec.t_ka) sel_rmtimer(&p->tka); |
| 1043 | for (pg = p->pings; pg; pg = ppg) { |
| 1044 | ppg = pg->next; |
| 1045 | p_pingdone(pg, PING_PEERDIED); |
| 1046 | } |
| 1047 | sym_remove(&byname, p->byname); |
| 1048 | am_remove(&byaddr, p->byaddr); |
| 1049 | DESTROY(p); |
| 1050 | } |
| 1051 | |
| 1052 | /* --- @p_mkiter@ --- * |
| 1053 | * |
| 1054 | * Arguments: @peer_iter *i@ = pointer to an iterator |
| 1055 | * |
| 1056 | * Returns: --- |
| 1057 | * |
| 1058 | * Use: Initializes the iterator. |
| 1059 | */ |
| 1060 | |
| 1061 | void p_mkiter(peer_iter *i) { sym_mkiter(&i->i, &byname); } |
| 1062 | |
| 1063 | /* --- @p_next@ --- * |
| 1064 | * |
| 1065 | * Arguments: @peer_iter *i@ = pointer to an iterator |
| 1066 | * |
| 1067 | * Returns: Next peer, or null if at the end. |
| 1068 | * |
| 1069 | * Use: Returns the next peer. |
| 1070 | */ |
| 1071 | |
| 1072 | peer *p_next(peer_iter *i) |
| 1073 | { |
| 1074 | peer_byname *pn; |
| 1075 | |
| 1076 | if ((pn = sym_next(&i->i)) == 0) |
| 1077 | return (0); |
| 1078 | return (pn->p); |
| 1079 | } |
| 1080 | |
| 1081 | /*----- That's all, folks -------------------------------------------------*/ |