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Comparing gvpe/src/connection.C (file contents):
Revision 1.32 by pcg, Sun Mar 21 13:15:42 2004 UTC vs.
Revision 1.98 by root, Tue Jul 16 16:44:36 2013 UTC

1/* 1/*
2 connection.C -- manage a single connection 2 connection.C -- manage a single connection
3 Copyright (C) 2003-2004 Marc Lehmann <pcg@goof.com> 3 Copyright (C) 2003-2008,2010,2011,2013 Marc Lehmann <gvpe@schmorp.de>
4 4
5 This file is part of GVPE.
6
5 This program is free software; you can redistribute it and/or modify 7 GVPE is free software; you can redistribute it and/or modify it
6 it under the terms of the GNU General Public License as published by 8 under the terms of the GNU General Public License as published by the
7 the Free Software Foundation; either version 2 of the License, or 9 Free Software Foundation; either version 3 of the License, or (at your
8 (at your option) any later version. 10 option) any later version.
9 11
10 This program is distributed in the hope that it will be useful, 12 This program is distributed in the hope that it will be useful, but
11 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
13 GNU General Public License for more details. 15 Public License for more details.
14 16
15 You should have received a copy of the GNU General Public License 17 You should have received a copy of the GNU General Public License along
16 along with this program; if not, write to the Free Software 18 with this program; if not, see <http://www.gnu.org/licenses/>.
17 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19
20 Additional permission under GNU GPL version 3 section 7
21
22 If you modify this Program, or any covered work, by linking or
23 combining it with the OpenSSL project's OpenSSL library (or a modified
24 version of that library), containing parts covered by the terms of the
25 OpenSSL or SSLeay licenses, the licensors of this Program grant you
26 additional permission to convey the resulting work. Corresponding
27 Source for a non-source form of such a combination shall include the
28 source code for the parts of OpenSSL used as well as that of the
29 covered work.
18*/ 30*/
19 31
20#include "config.h" 32#include "config.h"
21 33
22#include <cassert>
23
24#include <list> 34#include <list>
35#include <queue>
36#include <utility>
25 37
26#include <openssl/rand.h> 38#include <openssl/rand.h>
27#include <openssl/evp.h> 39#include <openssl/evp.h>
28#include <openssl/rsa.h> 40#include <openssl/rsa.h>
29#include <openssl/err.h> 41#include <openssl/err.h>
30
31#include "gettext.h"
32 42
33#include "conf.h" 43#include "conf.h"
34#include "slog.h" 44#include "slog.h"
35#include "device.h" 45#include "device.h"
36#include "vpn.h" 46#include "vpn.h"
37#include "connection.h" 47#include "connection.h"
48#include "hkdf.h"
38 49
39#include "netcompat.h" 50#include "netcompat.h"
40 51
41#if !HAVE_RAND_PSEUDO_BYTES
42# define RAND_pseudo_bytes RAND_bytes
43#endif
44
45#define MAGIC "vped\xbd\xc6\xdb\x82" // 8 bytes of magic 52#define MAGIC "gvpe\xbd\xc6\xdb\x82" // 8 bytes of magic
46 53
47#define ULTRA_FAST 1 54#define ULTRA_FAST 1
48#define HLOG 15 55#define HLOG 15
49#include "lzf/lzf.h" 56#include "lzf/lzf.h"
50#include "lzf/lzf_c.c" 57#include "lzf/lzf_c.c"
51#include "lzf/lzf_d.c" 58#include "lzf/lzf_d.c"
52 59
60//////////////////////////////////////////////////////////////////////////////
61
62static std::queue< std::pair<run_script_cb *, const char *> > rs_queue;
63static ev::child rs_child_ev;
64
65namespace
66{
67 void // c++ requires external linkage here, apparently :(
68 rs_child_cb (ev::child &w, int revents)
69 {
70 w.stop ();
71
72 if (rs_queue.empty ())
73 return;
74
75 pid_t pid = run_script (*rs_queue.front ().first, false);
76 if (pid)
77 {
78 w.set (pid);
79 w.start ();
80 }
81 else
82 slog (L_WARN, rs_queue.front ().second);
83
84 delete rs_queue.front ().first;
85 rs_queue.pop ();
86 }
87};
88
89// despite the fancy name, this is quite a hack
90static void
91run_script_queued (run_script_cb *cb, const char *warnmsg)
92{
93 rs_queue.push (std::make_pair (cb, warnmsg));
94
95 if (!rs_child_ev.is_active ())
96 {
97 rs_child_ev.set<rs_child_cb> ();
98 rs_child_ev ();
99 }
100}
101
102//////////////////////////////////////////////////////////////////////////////
103
53struct crypto_ctx 104struct crypto_ctx
54{ 105{
55 EVP_CIPHER_CTX cctx; 106 EVP_CIPHER_CTX cctx;
56 HMAC_CTX hctx; 107 HMAC_CTX hctx;
57 108
58 crypto_ctx (const rsachallenge &challenge, int enc); 109 crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc);
59 ~crypto_ctx (); 110 ~crypto_ctx ();
60}; 111};
61 112
62crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc) 113crypto_ctx::crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc)
63{ 114{
115 ecdh_key s;
116
117 curve25519_combine (a, b, s);
118
119 {
120 u8 mac_key[MAC_KEYSIZE];
121 static const unsigned char mac_info[] = "gvpe mac key";
122
123 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt));
124 kdf.extract (auth2.rsa.ikm, sizeof (auth2.rsa.ikm));
125 kdf.extract (auth1.rsa.mac_key, sizeof (auth1.rsa.mac_key));
126 kdf.extract (s, sizeof (s));
127 kdf.extract_done ();
128 kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info));
129
130 HMAC_CTX_init (&hctx);
131 require (HMAC_Init_ex (&hctx, mac_key, MAC_KEYSIZE, MAC_DIGEST (), 0));
132 }
133
134 {
135 u8 cipher_key[CIPHER_KEYSIZE];
136 static const unsigned char cipher_info[] = "gvpe cipher key";
137
138 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt));
139 kdf.extract (auth2.rsa.ikm, sizeof (auth2.rsa.ikm));
140 kdf.extract (auth1.rsa.cipher_key, sizeof (auth1.rsa.cipher_key));
141 kdf.extract (s, sizeof (s));
142 kdf.extract_done ();
143 kdf.expand (cipher_key, sizeof (cipher_key), cipher_info, sizeof (cipher_info));
144
64 EVP_CIPHER_CTX_init (&cctx); 145 EVP_CIPHER_CTX_init (&cctx);
65 require (EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc)); 146 require (EVP_CipherInit_ex (&cctx, CIPHER (), 0, cipher_key, 0, enc));
66 HMAC_CTX_init (&hctx); 147 }
67 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
68} 148}
69 149
70crypto_ctx::~crypto_ctx () 150crypto_ctx::~crypto_ctx ()
71{ 151{
72 require (EVP_CIPHER_CTX_cleanup (&cctx)); 152 require (EVP_CIPHER_CTX_cleanup (&cctx));
73 HMAC_CTX_cleanup (&hctx); 153 HMAC_CTX_cleanup (&hctx);
74} 154}
75 155
156static inline void
157auth_encrypt (RSA *key, const auth_data &auth, auth_encr &encr)
158{
159 if (RSA_public_encrypt (sizeof (auth.rsa),
160 (unsigned char *)&auth.rsa, (unsigned char *)&encr.rsa,
161 key, RSA_PKCS1_OAEP_PADDING) < 0)
162 fatal ("RSA_public_encrypt error");
163}
164
165static inline bool
166auth_decrypt (RSA *key, const auth_encr &encr, auth_data &auth)
167{
168 u8 rsa_decrypt[RSA_KEYLEN];
169
170 if (RSA_private_decrypt (sizeof (encr.rsa),
171 (const unsigned char *)&encr.rsa, (unsigned char *)rsa_decrypt,
172 key, RSA_PKCS1_OAEP_PADDING) != sizeof (auth.rsa))
173 return 0;
174
175 memcpy (&auth.rsa, rsa_decrypt, sizeof (auth.rsa));
176
177 return 1;
178}
179
76static void 180static void
77rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h) 181auth_hash (const auth_data &auth, auth_mac &mac)
78{ 182{
79 EVP_MD_CTX ctx; 183 HMAC_CTX ctx;
80 184
81 EVP_MD_CTX_init (&ctx); 185 HMAC_CTX_init (&ctx);
82 require (EVP_DigestInit (&ctx, RSA_HASH)); 186 require (HMAC_Init_ex (&ctx, auth.rsa.auth_key, sizeof (auth.rsa.auth_key), AUTH_DIGEST (), 0));
83 require (EVP_DigestUpdate(&ctx, &chg, sizeof chg)); 187 require (HMAC_Update (&ctx, (const unsigned char *)&auth, sizeof auth));
84 require (EVP_DigestUpdate(&ctx, &id, sizeof id));
85 require (EVP_DigestFinal (&ctx, (unsigned char *)&h, 0)); 188 require (HMAC_Final (&ctx, (unsigned char *)&mac, 0));
86 EVP_MD_CTX_cleanup (&ctx); 189 HMAC_CTX_cleanup (&ctx);
87} 190}
88 191
89struct rsa_entry { 192void
90 tstamp expire; 193connection::generate_auth_data ()
91 rsaid id;
92 rsachallenge chg;
93};
94
95struct rsa_cache : list<rsa_entry>
96{ 194{
97 void cleaner_cb (time_watcher &w); time_watcher cleaner; 195 if (auth_expire < ev_now ())
98
99 bool find (const rsaid &id, rsachallenge &chg)
100 {
101 for (iterator i = begin (); i != end (); ++i)
102 {
103 if (!memcmp (&id, &i->id, sizeof id) && i->expire > NOW)
104 {
105 memcpy (&chg, &i->chg, sizeof chg);
106
107 erase (i);
108 return true;
109 }
110 }
111
112 if (cleaner.at < NOW)
113 cleaner.start (NOW + RSA_TTL);
114
115 return false;
116 }
117
118 void gen (rsaid &id, rsachallenge &chg)
119 {
120 rsa_entry e;
121
122 RAND_bytes ((unsigned char *)&id, sizeof id);
123 RAND_bytes ((unsigned char *)&chg, sizeof chg);
124
125 e.expire = NOW + RSA_TTL;
126 e.id = id;
127 memcpy (&e.chg, &chg, sizeof chg);
128
129 push_back (e);
130
131 if (cleaner.at < NOW)
132 cleaner.start (NOW + RSA_TTL);
133 }
134
135 rsa_cache ()
136 : cleaner (this, &rsa_cache::cleaner_cb)
137 { } 196 {
197 // request data
198 RAND_pseudo_bytes ((unsigned char *)&snd_auth.rsa, sizeof snd_auth.rsa);
199 curve25519_generate (snd_ecdh_a, snd_auth.ecdh);
200 auth_hash (snd_auth, snd_auth_mac);
138 201
139} rsa_cache; 202 // eventual response data
140 203 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b);
141void rsa_cache::cleaner_cb (time_watcher &w)
142{
143 if (!empty ())
144 { 204 }
145 w.start (NOW + RSA_TTL);
146 205
147 for (iterator i = begin (); i != end (); ) 206 // every use prolongs the expiry
148 if (i->expire <= NOW) 207 auth_expire = ev_now () + AUTH_TTL;
149 i = erase (i);
150 else
151 ++i;
152 }
153} 208}
154 209
155////////////////////////////////////////////////////////////////////////////// 210//////////////////////////////////////////////////////////////////////////////
156 211
157void pkt_queue::put (net_packet *p) 212pkt_queue::pkt_queue (double max_ttl, int max_queue)
213: max_ttl (max_ttl), max_queue (max_queue)
158{ 214{
159 if (queue[i]) 215 queue = new pkt [max_queue];
160 {
161 delete queue[i];
162 j = (j + 1) % QUEUEDEPTH;
163 }
164 216
165 queue[i] = p;
166
167 i = (i + 1) % QUEUEDEPTH;
168}
169
170net_packet *pkt_queue::get ()
171{
172 net_packet *p = queue[j];
173
174 if (p)
175 {
176 queue[j] = 0;
177 j = (j + 1) % QUEUEDEPTH;
178 }
179
180 return p;
181}
182
183pkt_queue::pkt_queue ()
184{
185 memset (queue, 0, sizeof (queue));
186 i = 0; 217 i = 0;
187 j = 0; 218 j = 0;
219
220 expire.set<pkt_queue, &pkt_queue::expire_cb> (this);
188} 221}
189 222
190pkt_queue::~pkt_queue () 223pkt_queue::~pkt_queue ()
191{ 224{
192 for (i = QUEUEDEPTH; --i > 0; ) 225 while (net_packet *p = get ())
226 delete p;
227
193 delete queue[i]; 228 delete [] queue;
194} 229}
195 230
231void
232pkt_queue::expire_cb (ev::timer &w, int revents)
233{
234 ev_tstamp expire = ev_now () - max_ttl;
235
236 for (;;)
237 {
238 if (empty ())
239 break;
240
241 double diff = queue[j].tstamp - expire;
242
243 if (diff >= 0.)
244 {
245 w.start (diff > 0.5 ? diff : 0.5);
246 break;
247 }
248
249 delete get ();
250 }
251}
252
253void
254pkt_queue::put (net_packet *p)
255{
256 ev_tstamp now = ev_now ();
257
258 // start expiry timer
259 if (empty ())
260 expire.start (max_ttl);
261
262 int ni = i + 1 == max_queue ? 0 : i + 1;
263
264 if (ni == j)
265 delete get ();
266
267 queue[i].pkt = p;
268 queue[i].tstamp = now;
269
270 i = ni;
271}
272
273net_packet *
274pkt_queue::get ()
275{
276 if (empty ())
277 return 0;
278
279 net_packet *p = queue[j].pkt;
280 queue[j].pkt = 0;
281
282 j = j + 1 == max_queue ? 0 : j + 1;
283
284 return p;
285}
286
196struct net_rateinfo { 287struct net_rateinfo
288{
197 u32 host; 289 u32 host;
198 double pcnt, diff; 290 double pcnt, diff;
199 tstamp last; 291 tstamp last;
200}; 292};
201 293
202// only do action once every x seconds per host whole allowing bursts. 294// only do action once every x seconds per host whole allowing bursts.
203// this implementation ("splay list" ;) is inefficient, 295// this implementation ("splay list" ;) is inefficient,
204// but low on resources. 296// but low on resources.
205struct net_rate_limiter : list<net_rateinfo> 297struct net_rate_limiter : list<net_rateinfo>
206{ 298{
207 static const double ALPHA = 1. - 1. / 600.; // allow bursts 299# define NRL_ALPHA (1. - 1. / 600.) // allow bursts
208 static const double CUTOFF = 10.; // one event every CUTOFF seconds 300# define NRL_CUTOFF 10. // one event every CUTOFF seconds
209 static const double EXPIRE = CUTOFF * 30.; // expire entries after this time 301# define NRL_EXPIRE (NRL_CUTOFF * 30.) // expire entries after this time
210 static const double MAXDIF = CUTOFF * (1. / (1. - ALPHA)); // maximum diff /count value 302# define NRL_MAXDIF (NRL_CUTOFF * (1. / (1. - NRL_ALPHA))) // maximum diff /count value
211 303
212 bool can (const sockinfo &si) { return can((u32)si.host); } 304 bool can (const sockinfo &si) { return can((u32)si.host); }
213 bool can (u32 host); 305 bool can (u32 host);
214}; 306};
215 307
216net_rate_limiter auth_rate_limiter, reset_rate_limiter; 308static net_rate_limiter auth_rate_limiter, reset_rate_limiter;
217 309
310bool
218bool net_rate_limiter::can (u32 host) 311net_rate_limiter::can (u32 host)
219{ 312{
220 iterator i; 313 iterator i;
221 314
222 for (i = begin (); i != end (); ) 315 for (i = begin (); i != end (); )
223 if (i->host == host) 316 if (i->host == host)
224 break; 317 break;
225 else if (i->last < NOW - EXPIRE) 318 else if (i->last < ev_now () - NRL_EXPIRE)
226 i = erase (i); 319 i = erase (i);
227 else 320 else
228 i++; 321 i++;
229 322
230 if (i == end ()) 323 if (i == end ())
231 { 324 {
232 net_rateinfo ri; 325 net_rateinfo ri;
233 326
234 ri.host = host; 327 ri.host = host;
235 ri.pcnt = 1.; 328 ri.pcnt = 1.;
236 ri.diff = MAXDIF; 329 ri.diff = NRL_MAXDIF;
237 ri.last = NOW; 330 ri.last = ev_now ();
238 331
239 push_front (ri); 332 push_front (ri);
240 333
241 return true; 334 return true;
242 } 335 }
243 else 336 else
244 { 337 {
245 net_rateinfo ri (*i); 338 net_rateinfo ri (*i);
246 erase (i); 339 erase (i);
247 340
248 ri.pcnt = ri.pcnt * ALPHA; 341 ri.pcnt = ri.pcnt * NRL_ALPHA;
249 ri.diff = ri.diff * ALPHA + (NOW - ri.last); 342 ri.diff = ri.diff * NRL_ALPHA + (ev_now () - ri.last);
250 343
251 ri.last = NOW; 344 ri.last = ev_now ();
252 345
253 double dif = ri.diff / ri.pcnt; 346 double dif = ri.diff / ri.pcnt;
254 347
255 bool send = dif > CUTOFF; 348 bool send = dif > NRL_CUTOFF;
256 349
257 if (dif > MAXDIF) 350 if (dif > NRL_MAXDIF)
258 { 351 {
259 ri.pcnt = 1.; 352 ri.pcnt = 1.;
260 ri.diff = MAXDIF; 353 ri.diff = NRL_MAXDIF;
261 } 354 }
262 else if (send) 355 else if (send)
263 ri.pcnt++; 356 ri.pcnt++;
264 357
265 push_front (ri); 358 push_front (ri);
270 363
271///////////////////////////////////////////////////////////////////////////// 364/////////////////////////////////////////////////////////////////////////////
272 365
273unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE]; 366unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE];
274 367
368void
275void hmac_packet::hmac_gen (crypto_ctx *ctx) 369hmac_packet::hmac_gen (crypto_ctx *ctx)
276{ 370{
277 unsigned int xlen; 371 unsigned int xlen;
278 372
279 HMAC_CTX *hctx = &ctx->hctx; 373 HMAC_CTX *hctx = &ctx->hctx;
280 374
281 HMAC_Init_ex (hctx, 0, 0, 0, 0); 375 require (HMAC_Init_ex (hctx, 0, 0, 0, 0));
282 HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), 376 require (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet),
283 len - sizeof (hmac_packet)); 377 len - sizeof (hmac_packet)));
284 HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen); 378 require (HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen));
285} 379}
286 380
287void 381void
288hmac_packet::hmac_set (crypto_ctx *ctx) 382hmac_packet::hmac_set (crypto_ctx *ctx)
289{ 383{
298 hmac_gen (ctx); 392 hmac_gen (ctx);
299 393
300 return !memcmp (hmac, hmac_digest, HMACLENGTH); 394 return !memcmp (hmac, hmac_digest, HMACLENGTH);
301} 395}
302 396
397void
303void vpn_packet::set_hdr (ptype type_, unsigned int dst) 398vpn_packet::set_hdr (ptype type_, unsigned int dst)
304{ 399{
305 type = type_; 400 type = type_;
306 401
307 int src = THISNODE->id; 402 int src = THISNODE->id;
308 403
313 408
314#define MAXVPNDATA (MAX_MTU - 6 - 6) 409#define MAXVPNDATA (MAX_MTU - 6 - 6)
315#define DATAHDR (sizeof (u32) + RAND_SIZE) 410#define DATAHDR (sizeof (u32) + RAND_SIZE)
316 411
317struct vpndata_packet : vpn_packet 412struct vpndata_packet : vpn_packet
413{
414 u8 data[MAXVPNDATA + DATAHDR]; // seqno
415
416 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
417 tap_packet *unpack (connection *conn, u32 &seqno);
418
419private:
420 const u32 data_hdr_size () const
318 { 421 {
319 u8 data[MAXVPNDATA + DATAHDR]; // seqno
320
321 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
322 tap_packet *unpack (connection *conn, u32 &seqno);
323private:
324
325 const u32 data_hdr_size () const
326 {
327 return sizeof (vpndata_packet) - sizeof (net_packet) - MAXVPNDATA - DATAHDR; 422 return sizeof (vpndata_packet) - sizeof (net_packet) - MAXVPNDATA - DATAHDR;
328 }
329 }; 423 }
424};
330 425
331void 426void
332vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno) 427vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno)
333{ 428{
334 EVP_CIPHER_CTX *cctx = &conn->octx->cctx; 429 EVP_CIPHER_CTX *cctx = &conn->octx->cctx;
336 ptype type = PT_DATA_UNCOMPRESSED; 431 ptype type = PT_DATA_UNCOMPRESSED;
337 432
338#if ENABLE_COMPRESSION 433#if ENABLE_COMPRESSION
339 u8 cdata[MAX_MTU]; 434 u8 cdata[MAX_MTU];
340 435
341 if (conn->features & ENABLE_COMPRESSION) 436 if (conn->features & FEATURE_COMPRESSION)
342 { 437 {
343 u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7); 438 u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7);
344 439
345 if (cl) 440 if (cl)
346 { 441 {
352 d[1] = cl; 447 d[1] = cl;
353 } 448 }
354 } 449 }
355#endif 450#endif
356 451
357 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0)); 452 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 1));
358 453
359 struct { 454 struct {
360#if RAND_SIZE 455#if RAND_SIZE
361 u8 rnd[RAND_SIZE]; 456 u8 rnd[RAND_SIZE];
362#endif 457#endif
395 int outl = 0, outl2; 490 int outl = 0, outl2;
396 tap_packet *p = new tap_packet; 491 tap_packet *p = new tap_packet;
397 u8 *d; 492 u8 *d;
398 u32 l = len - data_hdr_size (); 493 u32 l = len - data_hdr_size ();
399 494
400 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0)); 495 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 0));
401 496
402#if ENABLE_COMPRESSION 497#if ENABLE_COMPRESSION
403 u8 cdata[MAX_MTU]; 498 u8 cdata[MAX_MTU];
404 499
405 if (type == PT_DATA_COMPRESSED) 500 if (type == PT_DATA_COMPRESSED)
447 } 542 }
448}; 543};
449 544
450struct config_packet : vpn_packet 545struct config_packet : vpn_packet
451{ 546{
452 // actually, hmaclen cannot be checked because the hmac
453 // field comes before this data, so peers with other
454 // hmacs simply will not work.
455 u8 prot_major, prot_minor, randsize, hmaclen; 547 u8 prot_major, prot_minor, randsize;
456 u8 flags, challengelen, features, pad3; 548 u8 flags, features, pad6, pad7, pad8;
457 u32 cipher_nid, digest_nid, hmac_nid; 549 u32 cipher_nid, mac_nid, auth_nid;
458 550
459 void setup (ptype type, int dst); 551 void setup (ptype type, int dst);
460 bool chk_config () const; 552 bool chk_config () const;
461 553
462 static u8 get_features () 554 static u8 get_features ()
466 f |= FEATURE_COMPRESSION; 558 f |= FEATURE_COMPRESSION;
467#endif 559#endif
468#if ENABLE_ROHC 560#if ENABLE_ROHC
469 f |= FEATURE_ROHC; 561 f |= FEATURE_ROHC;
470#endif 562#endif
563#if ENABLE_BRIDGING
564 f |= FEATURE_BRIDGING;
565#endif
471 return f; 566 return f;
472 } 567 }
473}; 568};
474 569
570void
475void config_packet::setup (ptype type, int dst) 571config_packet::setup (ptype type, int dst)
476{ 572{
477 prot_major = PROTOCOL_MAJOR; 573 prot_major = PROTOCOL_MAJOR;
478 prot_minor = PROTOCOL_MINOR; 574 prot_minor = PROTOCOL_MINOR;
479 randsize = RAND_SIZE; 575 randsize = RAND_SIZE;
480 hmaclen = HMACLENGTH; 576 flags = 0;
481 flags = ENABLE_COMPRESSION ? 0x81 : 0x80;
482 challengelen = sizeof (rsachallenge);
483 features = get_features (); 577 features = get_features ();
484 578
485 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); 579 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ()));
486 digest_nid = htonl (EVP_MD_type (RSA_HASH));
487 hmac_nid = htonl (EVP_MD_type (DIGEST)); 580 mac_nid = htonl (EVP_MD_type (MAC_DIGEST ()));
581 auth_nid = htonl (EVP_MD_type (AUTH_DIGEST ()));
488 582
489 len = sizeof (*this) - sizeof (net_packet); 583 len = sizeof (*this) - sizeof (net_packet);
490 set_hdr (type, dst); 584 set_hdr (type, dst);
491} 585}
492 586
587bool
493bool config_packet::chk_config () const 588config_packet::chk_config () const
494{ 589{
495 if (prot_major != PROTOCOL_MAJOR) 590 if (prot_major != PROTOCOL_MAJOR)
496 slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR); 591 slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR);
497 else if (randsize != RAND_SIZE) 592 else if (randsize != RAND_SIZE)
498 slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE); 593 slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE);
499 else if (hmaclen != HMACLENGTH)
500 slog (L_WARN, _("hmac length mismatch (remote %d <=> local %d)"), hmaclen, HMACLENGTH);
501#if 0 // this implementation should handle all flag settings
502 else if (flags != curflags ())
503 slog (L_WARN, _("flag mismatch (remote %x <=> local %x)"), flags, curflags ());
504#endif
505 else if (challengelen != sizeof (rsachallenge))
506 slog (L_WARN, _("challenge length mismatch (remote %d <=> local %d)"), challengelen, sizeof (rsachallenge));
507 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER))) 594 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER ())))
508 slog (L_WARN, _("cipher mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER)); 595 slog (L_WARN, _("cipher algo mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER ()));
509 else if (digest_nid != htonl (EVP_MD_type (RSA_HASH)))
510 slog (L_WARN, _("digest mismatch (remote %x <=> local %x)"), ntohl (digest_nid), EVP_MD_type (RSA_HASH));
511 else if (hmac_nid != htonl (EVP_MD_type (DIGEST))) 596 else if (mac_nid != htonl (EVP_MD_type (MAC_DIGEST ())))
512 slog (L_WARN, _("hmac mismatch (remote %x <=> local %x)"), ntohl (hmac_nid), EVP_MD_type (DIGEST)); 597 slog (L_WARN, _("mac algo mismatch (remote %x <=> local %x)"), ntohl (mac_nid), EVP_MD_type (MAC_DIGEST ()));
598 else if (auth_nid != htonl (EVP_MD_type (AUTH_DIGEST ())))
599 slog (L_WARN, _("auth algo mismatch (remote %x <=> local %x)"), ntohl (auth_nid), EVP_MD_type (AUTH_DIGEST ()));
513 else 600 else
514 return true; 601 return true;
515 602
516 return false; 603 return false;
517} 604}
518 605
519struct auth_req_packet : config_packet 606struct auth_req_packet : config_packet // UNPROTECTED
520{ 607{
521 char magic[8]; 608 char magic[8];
522 u8 initiate; // false if this is just an automatic reply 609 u8 initiate; // false if this is just an automatic reply
523 u8 protocols; // supported protocols (will be patched on forward) 610 u8 protocols; // supported protocols (will be patched on forward)
524 u8 pad2, pad3; 611 u8 pad2, pad3;
525 rsaid id; 612 auth_encr encr;
526 rsaencrdata encr;
527 613
528 auth_req_packet (int dst, bool initiate_, u8 protocols_) 614 auth_req_packet (int dst, bool initiate_, u8 protocols_)
529 { 615 {
530 config_packet::setup (PT_AUTH_REQ, dst); 616 config_packet::setup (PT_AUTH_REQ, dst);
531 strncpy (magic, MAGIC, 8); 617 memcpy (magic, MAGIC, 8);
532 initiate = !!initiate_; 618 initiate = !!initiate_;
533 protocols = protocols_; 619 protocols = protocols_;
534 620
535 len = sizeof (*this) - sizeof (net_packet); 621 len = sizeof (*this) - sizeof (net_packet);
536 } 622 }
537}; 623};
538 624
539struct auth_res_packet : config_packet 625struct auth_res_packet : config_packet // UNPROTECTED
540{ 626{
541 rsaid id;
542 u8 pad1, pad2, pad3;
543 u8 response_len; // encrypted length
544 rsaresponse response; 627 auth_response response;
545 628
546 auth_res_packet (int dst) 629 auth_res_packet (int dst)
547 { 630 {
548 config_packet::setup (PT_AUTH_RES, dst); 631 config_packet::setup (PT_AUTH_RES, dst);
549 632
583}; 666};
584 667
585///////////////////////////////////////////////////////////////////////////// 668/////////////////////////////////////////////////////////////////////////////
586 669
587void 670void
588connection::connection_established () 671connection::connection_established (const sockinfo &rsi)
589{ 672{
673 if (!have_snd_auth || !have_rcv_auth)
674 return;
675
676 si = rsi;
677 protocol = rsi.prot;
678
679 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
680 conf->nodename, (const char *)rsi,
681 is_direct ? "direct" : "forwarded",
682 PROTOCOL_MAJOR, prot_minor);
683
684 if (::conf.script_node_up)
685 {
686 run_script_cb *cb = new run_script_cb;
687 cb->set<connection, &connection::script_node_up> (this);
688 run_script_queued (cb, _("node-up command execution failed, continuing."));
689 }
690
691 delete ictx; ictx = new crypto_ctx (rcv_auth, snd_auth, rcv_ecdh_a, rcv_auth.ecdh, 0);
692 iseqno.reset (ntohl (rcv_auth.rsa.seqno) & 0x7fffffff);
693
694 delete octx; octx = new crypto_ctx (snd_auth, rcv_auth, snd_ecdh_a, snd_ecdh_b , 1);
695 oseqno = ntohl (snd_auth.rsa.seqno) & 0x7fffffff;
696
590 if (ictx && octx) 697 if (ictx && octx)
591 { 698 {
592 connectmode = conf->connectmode; 699 // make sure rekeying timeouts are slightly asymmetric
700 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0);
701 rekey.start (rekey_interval, rekey_interval);
593 702
594 rekey.start (NOW + ::conf.rekey);
595 keepalive.start (NOW + ::conf.keepalive); 703 keepalive.start (::conf.keepalive);
596 704
597 // send queued packets 705 // send queued packets
598 if (ictx && octx) 706 if (ictx && octx)
599 { 707 {
600 while (tap_packet *p = (tap_packet *)data_queue.get ()) 708 while (tap_packet *p = (tap_packet *)data_queue.get ())
601 { 709 {
602 send_data_packet (p); 710 if (p->len) send_data_packet (p);
603 delete p; 711 delete p;
604 } 712 }
605 713
606 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) 714 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
607 { 715 {
608 send_vpn_packet (p, si, IPTOS_RELIABILITY); 716 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
609 delete p; 717 delete p;
610 } 718 }
611 } 719 }
720
721 vpn->connection_established (this);
612 } 722 }
723#if 0
613 else 724 else
614 { 725 {
615 retry_cnt = 0; 726 retry_cnt = 0;
616 establish_connection.start (NOW + 5); 727 establish_connection.start (5);
617 keepalive.stop (); 728 keepalive.stop ();
618 rekey.stop (); 729 rekey.stop ();
619 } 730 }
731#endif
620} 732}
621 733
622void 734void
623connection::reset_si () 735connection::reset_si ()
624{ 736{
737 if (vpn->can_direct (THISNODE, conf))
625 protocol = best_protocol (THISNODE->protocols & conf->protocols); 738 protocol = best_protocol (THISNODE->protocols & conf->connectable_protocols ());
626 739 else
627 // mask out protocols we cannot establish 740 {
628 if (!conf->udp_port) protocol &= ~PROT_UDPv4; 741 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename);
629 if (!conf->tcp_port) protocol &= ~PROT_TCPv4; 742 protocol = 0;
743 }
630 744
631 si.set (conf, protocol); 745 si.set (conf, protocol);
746
747 is_direct = si.valid ();
632} 748}
633 749
634// ensure sockinfo is valid, forward if necessary 750// ensure sockinfo is valid, forward if necessary
635const sockinfo & 751const sockinfo &
636connection::forward_si (const sockinfo &si) const 752connection::forward_si (const sockinfo &si) const
637{ 753{
638 if (!si.valid ()) 754 if (!si.valid ())
639 { 755 {
640 connection *r = vpn->find_router (); 756 connection *r = vpn->find_router_for (this);
641 757
642 if (r) 758 if (r)
643 { 759 {
644 slog (L_DEBUG, _("%s: no common protocol, trying indirectly through %s"), 760 slog (L_DEBUG, _("%s: no common protocol, trying to route through %s."),
645 conf->nodename, r->conf->nodename); 761 conf->nodename, r->conf->nodename);
646 return r->si; 762 return r->si;
647 } 763 }
648 else 764 else
649 slog (L_DEBUG, _("%s: node unreachable, no common protocol"), 765 slog (L_DEBUG, _("%s: node unreachable, no common protocol or no router available."),
650 conf->nodename); 766 conf->nodename);
651 } 767 }
652 768
653 return si; 769 return si;
654} 770}
664connection::send_ping (const sockinfo &si, u8 pong) 780connection::send_ping (const sockinfo &si, u8 pong)
665{ 781{
666 ping_packet *pkt = new ping_packet; 782 ping_packet *pkt = new ping_packet;
667 783
668 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING); 784 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING);
785
786 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si);
669 send_vpn_packet (pkt, si, IPTOS_LOWDELAY); 787 send_vpn_packet (pkt, si, IPTOS_LOWDELAY);
670 788
671 delete pkt; 789 delete pkt;
672} 790}
673 791
688void 806void
689connection::send_auth_request (const sockinfo &si, bool initiate) 807connection::send_auth_request (const sockinfo &si, bool initiate)
690{ 808{
691 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols); 809 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);
692 810
693 rsachallenge chg; 811 generate_auth_data ();
694 rsa_cache.gen (pkt->id, chg);
695 rsa_encrypt (conf->rsa_key, chg, pkt->encr); 812 auth_encrypt (conf->rsa_key, snd_auth, pkt->encr);
696 813
697 slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si); 814 slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si);
698
699 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly 815 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly
700 816
701 delete pkt; 817 delete pkt;
702} 818}
703 819
704void 820void
705connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg) 821connection::send_auth_response (const sockinfo &si)
706{ 822{
707 auth_res_packet *pkt = new auth_res_packet (conf->id); 823 auth_res_packet *pkt = new auth_res_packet (conf->id);
708 824
709 pkt->id = id; 825 auth_hash (rcv_auth, pkt->response.mac);
826 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof (rcv_ecdh_b));
710 827
711 rsa_hash (id, chg, pkt->response);
712
713 pkt->hmac_set (octx);
714
715 slog (L_TRACE, ">>%d PT_AUTH_RES [%s]", conf->id, (const char *)si); 828 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si);
716
717 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly 829 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly
718 830
719 delete pkt; 831 delete pkt;
720} 832}
721 833
722void 834void
723connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols) 835connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols)
724{ 836{
725 slog (L_TRACE, ">>%d PT_CONNECT_INFO(%d,%s)\n", 837 slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s,p%02x)", conf->nodename,
726 conf->id, rid, (const char *)rsi); 838 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi,
839 conf->protocols);
727 840
728 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols); 841 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols);
729 842
730 r->hmac_set (octx); 843 r->hmac_set (octx);
731 send_vpn_packet (r, si); 844 send_vpn_packet (r, si);
732 845
733 delete r; 846 delete r;
734} 847}
735 848
736void 849inline void
737connection::establish_connection_cb (time_watcher &w) 850connection::establish_connection_cb (ev::timer &w, int revents)
738{ 851{
739 if (!ictx 852 if (!(ictx && octx)
740 && conf != THISNODE 853 && conf != THISNODE
741 && connectmode != conf_node::C_NEVER 854 && connectmode != conf_node::C_NEVER
742 && connectmode != conf_node::C_DISABLED 855 && connectmode != conf_node::C_DISABLED
743 && NOW > w.at) 856 && !w.is_active ())
744 { 857 {
745 double retry_int = double (retry_cnt & 3 ? (retry_cnt & 3) : 1 << (retry_cnt >> 2)) * 0.6; 858 // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection
746 859 // and stop trying. should probably be handled by a per-connection expire handler.
747 if (retry_int < 3600 * 8) 860 if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ())
861 {
862 reset_connection ();
748 retry_cnt++; 863 return;
864 }
749 865
750 w.start (NOW + retry_int); 866 last_establish_attempt = ev_now ();
867
868 ev::tstamp retry_int = ev::tstamp (retry_cnt & 3
869 ? (retry_cnt & 3) + 1
870 : 1 << (retry_cnt >> 2));
751 871
752 reset_si (); 872 reset_si ();
753 873
754 if (si.prot && !si.host) 874 bool slow = si.prot & PROT_SLOW;
875
876 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf))
877 {
878 /*TODO*/ /* start the timer so we don't recurse endlessly */
879 w.start (1);
755 vpn->send_connect_request (conf->id); 880 vpn->send_connect_request (this);
881 }
756 else 882 else
757 { 883 {
884 if (si.valid ())
885 slog (L_DEBUG, _("%s: sending direct connection request to %s."),
886 conf->nodename, (const char *)si);
887
758 const sockinfo &dsi = forward_si (si); 888 const sockinfo &dsi = forward_si (si);
889
890 slow = slow || (dsi.prot & PROT_SLOW);
759 891
760 if (dsi.valid () && auth_rate_limiter.can (dsi)) 892 if (dsi.valid () && auth_rate_limiter.can (dsi))
761 { 893 {
762 if (retry_cnt < 4) 894 if (retry_cnt < 4)
763 send_auth_request (dsi, true); 895 send_auth_request (dsi, true);
764 else 896 else
765 send_ping (dsi, 0); 897 send_ping (dsi, 0);
766 } 898 }
767 } 899 }
900
901 retry_int *= slow ? 8. : 0.9;
902
903 if (retry_int < conf->max_retry)
904 retry_cnt++;
905 else
906 retry_int = conf->max_retry;
907
908 w.start (retry_int);
768 } 909 }
769} 910}
770 911
771void 912void
772connection::reset_connection () 913connection::reset_connection ()
775 { 916 {
776 slog (L_INFO, _("%s(%s): connection lost"), 917 slog (L_INFO, _("%s(%s): connection lost"),
777 conf->nodename, (const char *)si); 918 conf->nodename, (const char *)si);
778 919
779 if (::conf.script_node_down) 920 if (::conf.script_node_down)
780 run_script (run_script_cb (this, &connection::script_node_down), false); 921 {
922 run_script_cb *cb = new run_script_cb;
923 cb->set<connection, &connection::script_node_down> (this);
924 run_script_queued (cb, _("node-down command execution failed, continuing."));
925 }
781 } 926 }
782 927
783 delete ictx; ictx = 0; 928 delete ictx; ictx = 0;
784 delete octx; octx = 0; 929 delete octx; octx = 0;
785 930
786 si.host= 0; 931 si.host = 0;
787 932
933 have_snd_auth = false;
934 have_rcv_auth = false;
935 auth_expire = 0.;
936
788 last_activity = 0; 937 last_activity = 0.;
938 //last_si_change = 0.;
789 retry_cnt = 0; 939 retry_cnt = 0;
790 940
791 rekey.stop (); 941 rekey.stop ();
792 keepalive.stop (); 942 keepalive.stop ();
793 establish_connection.stop (); 943 establish_connection.stop ();
800 send_reset (si); 950 send_reset (si);
801 951
802 reset_connection (); 952 reset_connection ();
803} 953}
804 954
805void 955// poor-man's rekeying
806connection::rekey_cb (time_watcher &w) 956inline void
957connection::rekey_cb (ev::timer &w, int revents)
807{ 958{
808 reset_connection (); 959 reset_connection ();
809 establish_connection (); 960 establish_connection ();
810} 961}
811 962
827 if (oseqno > MAX_SEQNO) 978 if (oseqno > MAX_SEQNO)
828 rekey (); 979 rekey ();
829} 980}
830 981
831void 982void
983connection::post_inject_queue ()
984{
985 // force a connection every now and when when packets are sent (max 1/s)
986 if (ev_now () - last_establish_attempt >= 0.95) // arbitrary
987 establish_connection.stop ();
988
989 establish_connection ();
990}
991
992void
832connection::inject_data_packet (tap_packet *pkt, bool broadcast/*TODO DDD*/) 993connection::inject_data_packet (tap_packet *pkt)
833{ 994{
834 if (ictx && octx) 995 if (ictx && octx)
835 send_data_packet (pkt); 996 send_data_packet (pkt);
836 else 997 else
837 { 998 {
838 if (!broadcast)//DDDD
839 data_queue.put (new tap_packet (*pkt)); 999 data_queue.put (new tap_packet (*pkt));
840 1000 post_inject_queue ();
841 establish_connection ();
842 } 1001 }
843} 1002}
844 1003
1004void
845void connection::inject_vpn_packet (vpn_packet *pkt, int tos) 1005connection::inject_vpn_packet (vpn_packet *pkt, int tos)
846{ 1006{
847 if (ictx && octx) 1007 if (ictx && octx)
848 send_vpn_packet (pkt, si, tos); 1008 send_vpn_packet (pkt, si, tos);
849 else 1009 else
850 { 1010 {
851 vpn_queue.put ((vpn_packet *)new data_packet (*(data_packet *)pkt)); 1011 vpn_queue.put ((vpn_packet *)new data_packet (*(data_packet *)pkt));
852 1012 post_inject_queue ();
853 establish_connection ();
854 } 1013 }
855} 1014}
856 1015
857void 1016void
858connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) 1017connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
859{ 1018{
860 last_activity = NOW; 1019 last_activity = ev_now ();
861 1020
862 slog (L_NOISE, "<<%d received packet type %d from %d to %d", 1021 slog (L_NOISE, "%s >> received packet type %d from %d to %d.",
863 conf->id, pkt->typ (), pkt->src (), pkt->dst ()); 1022 conf->nodename, pkt->typ (), pkt->src (), pkt->dst ());
1023
1024 if (connectmode == conf_node::C_DISABLED)
1025 return;
864 1026
865 switch (pkt->typ ()) 1027 switch (pkt->typ ())
866 { 1028 {
867 case vpn_packet::PT_PING: 1029 case vpn_packet::PT_PING:
1030 slog (L_TRACE, "%s >> PT_PING", conf->nodename);
1031
868 // we send pings instead of auth packets after some retries, 1032 // we send pings instead of auth packets after some retries,
869 // so reset the retry counter and establish a connection 1033 // so reset the retry counter and establish a connection
870 // when we receive a ping. 1034 // when we receive a ping.
871 if (!ictx) 1035 if (!ictx)
872 { 1036 {
873 if (auth_rate_limiter.can (rsi)) 1037 if (auth_rate_limiter.can (rsi))
874 send_auth_request (rsi, true); 1038 send_auth_request (rsi, true);
875 } 1039 }
876 else 1040 else
1041 // we would love to change the socket address here, but ping's aren't
1042 // authenticated, so we best ignore it.
877 send_ping (rsi, 1); // pong 1043 send_ping (rsi, 1); // pong
878 1044
879 break; 1045 break;
880 1046
881 case vpn_packet::PT_PONG: 1047 case vpn_packet::PT_PONG:
1048 slog (L_TRACE, "%s >> PT_PONG", conf->nodename);
1049
1050 // a PONG might mean that the other side doesn't really know
1051 // about our desire for communication.
1052 establish_connection ();
882 break; 1053 break;
883 1054
884 case vpn_packet::PT_RESET: 1055 case vpn_packet::PT_RESET:
885 { 1056 {
886 reset_connection (); 1057 reset_connection ();
887 1058
888 config_packet *p = (config_packet *) pkt; 1059 config_packet *p = (config_packet *) pkt;
889 1060
890 if (!p->chk_config ()) 1061 if (!p->chk_config ())
891 { 1062 {
892 slog (L_WARN, _("%s(%s): protocol mismatch, disabling node"), 1063 slog (L_WARN, _("%s(%s): protocol mismatch, disabling node."),
893 conf->nodename, (const char *)rsi); 1064 conf->nodename, (const char *)rsi);
894 connectmode = conf_node::C_DISABLED; 1065 connectmode = conf_node::C_DISABLED;
895 } 1066 }
896 else if (connectmode == conf_node::C_ALWAYS) 1067 else if (connectmode == conf_node::C_ALWAYS)
897 establish_connection (); 1068 establish_connection ();
899 break; 1070 break;
900 1071
901 case vpn_packet::PT_AUTH_REQ: 1072 case vpn_packet::PT_AUTH_REQ:
902 if (auth_rate_limiter.can (rsi)) 1073 if (auth_rate_limiter.can (rsi))
903 { 1074 {
904 auth_req_packet *p = (auth_req_packet *) pkt; 1075 auth_req_packet *p = (auth_req_packet *)pkt;
905 1076
906 slog (L_TRACE, "<<%d PT_AUTH_REQ(%d)", conf->id, p->initiate); 1077 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)",
1078 conf->nodename, p->initiate ? "initiate" : "reply",
1079 p->protocols, p->features);
907 1080
908 if (p->chk_config () && !strncmp (p->magic, MAGIC, 8)) 1081 if (p->chk_config () && !memcmp (p->magic, MAGIC, 8))
909 { 1082 {
910 if (p->prot_minor != PROTOCOL_MINOR) 1083 if (p->prot_minor != PROTOCOL_MINOR)
911 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), 1084 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
912 conf->nodename, (const char *)rsi, 1085 conf->nodename, (const char *)rsi,
913 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 1086 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
914 1087
915 if (p->initiate) 1088 if (p->initiate)
916 send_auth_request (rsi, false); 1089 send_auth_request (rsi, false);
917 1090
918 rsachallenge k; 1091 auth_data auth;
919 1092
920 if (!rsa_decrypt (::conf.rsa_key, p->encr, k)) 1093 if (!auth_decrypt (::conf.rsa_key, p->encr, auth))
921 { 1094 {
922 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"), 1095 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"),
923 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0)); 1096 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
924 break;
925 } 1097 }
926 else 1098 else
927 { 1099 {
928 delete octx; 1100 bool chg = !have_rcv_auth || memcmp (&rcv_auth, &auth, sizeof auth);
929 1101
930 octx = new crypto_ctx (k, 1); 1102 rcv_auth = auth;
931 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; 1103 have_rcv_auth = true;
932 1104
933 // compatibility code, remove when no longer required 1105 send_auth_response (rsi);
934 if (p->flags & 1) p->features |= FEATURE_COMPRESSION;
935 1106
1107 if (chg)
1108 {
936 conf->protocols = p->protocols; 1109 conf->protocols = p->protocols;
937 features = p->features & config_packet::get_features (); 1110 features = p->features & config_packet::get_features ();
938 1111
939 send_auth_response (rsi, p->id, k);
940
941 connection_established (); 1112 connection_established (rsi);
942
943 break; 1113 }
944 } 1114 }
1115
1116 break;
945 } 1117 }
946 else 1118 else
947 slog (L_WARN, _("%s(%s): protocol mismatch"), 1119 slog (L_WARN, _("%s(%s): protocol mismatch."),
948 conf->nodename, (const char *)rsi); 1120 conf->nodename, (const char *)rsi);
949 1121
950 send_reset (rsi); 1122 send_reset (rsi);
951 } 1123 }
952 1124
953 break; 1125 break;
954 1126
955 case vpn_packet::PT_AUTH_RES: 1127 case vpn_packet::PT_AUTH_RES:
956 { 1128 {
957 auth_res_packet *p = (auth_res_packet *) pkt; 1129 auth_res_packet *p = (auth_res_packet *)pkt;
958 1130
959 slog (L_TRACE, "<<%d PT_AUTH_RES", conf->id); 1131 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename);
960 1132
961 if (p->chk_config ()) 1133 if (p->chk_config ())
962 { 1134 {
963 if (p->prot_minor != PROTOCOL_MINOR) 1135 if (memcmp (&p->response.mac, snd_auth_mac, sizeof (snd_auth_mac)))
964 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
965 conf->nodename, (const char *)rsi,
966 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
967
968 rsachallenge chg;
969
970 if (!rsa_cache.find (p->id, chg))
971 { 1136 {
972 slog (L_ERR, _("%s(%s): unrequested auth response ignored"), 1137 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."),
973 conf->nodename, (const char *)rsi); 1138 conf->nodename, (const char *)rsi);
974 break;
975 } 1139 }
976 else 1140 else if (!have_snd_auth)
977 { 1141 {
978 crypto_ctx *cctx = new crypto_ctx (chg, 0); 1142 if (p->prot_minor != PROTOCOL_MINOR)
979 1143 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
980 if (!p->hmac_chk (cctx))
981 {
982 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n"
983 "could be an attack, or just corruption or a synchronization error"),
984 conf->nodename, (const char *)rsi); 1144 conf->nodename, (const char *)rsi,
985 break; 1145 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
986 }
987 else
988 {
989 rsaresponse h;
990 1146
991 rsa_hash (p->id, chg, h);
992
993 if (!memcmp ((u8 *)&h, (u8 *)p->response, sizeof h))
994 {
995 prot_minor = p->prot_minor; 1147 prot_minor = p->prot_minor;
1148 memcpy (snd_ecdh_b, p->response.ecdh, sizeof (snd_ecdh_b));
996 1149
997 delete ictx; ictx = cctx; 1150 have_snd_auth = true;
998
999 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
1000
1001 si = rsi;
1002 protocol = rsi.prot;
1003
1004 connection_established (); 1151 connection_established (rsi);
1005
1006 slog (L_INFO, _("%s(%s): connection established, protocol version %d.%d"),
1007 conf->nodename, (const char *)rsi,
1008 p->prot_major, p->prot_minor);
1009
1010 if (::conf.script_node_up)
1011 run_script (run_script_cb (this, &connection::script_node_up), false);
1012
1013 break;
1014 }
1015 else
1016 slog (L_ERR, _("%s(%s): sent and received challenge do not match"),
1017 conf->nodename, (const char *)rsi);
1018 }
1019
1020 delete cctx;
1021 } 1152 }
1153
1154 break;
1022 } 1155 }
1023 } 1156 }
1024 1157
1025 send_reset (rsi); 1158 send_reset (rsi);
1026 break; 1159 break;
1037 { 1170 {
1038 vpndata_packet *p = (vpndata_packet *)pkt; 1171 vpndata_packet *p = (vpndata_packet *)pkt;
1039 1172
1040 if (!p->hmac_chk (ictx)) 1173 if (!p->hmac_chk (ictx))
1041 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" 1174 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
1042 "could be an attack, or just corruption or a synchronization error"), 1175 "could be an attack, or just corruption or a synchronization error."),
1043 conf->nodename, (const char *)rsi); 1176 conf->nodename, (const char *)rsi);
1044 else 1177 else
1045 { 1178 {
1046 u32 seqno; 1179 u32 seqno;
1047 tap_packet *d = p->unpack (this, seqno); 1180 tap_packet *d = p->unpack (this, seqno);
1181 int seqclass = iseqno.seqno_classify (seqno);
1048 1182
1049 if (iseqno.recv_ok (seqno)) 1183 if (seqclass == 0) // ok
1050 { 1184 {
1051 vpn->tap->send (d); 1185 vpn->tap->send (d);
1052 1186
1053 if (si != rsi) 1187 if (si != rsi)
1054 { 1188 {
1055 // fast re-sync on connection changes, useful especially for tcp/ip 1189 // fast re-sync on source address changes, useful especially for tcp/ip
1190 //if (last_si_change < ev_now () + 5.)
1056 si = rsi; 1191 // {
1057
1058 slog (L_INFO, _("%s(%s): socket address changed to %s"), 1192 slog (L_INFO, _("%s(%s): changing socket address to %s."),
1059 conf->nodename, (const char *)si, (const char *)rsi); 1193 conf->nodename, (const char *)si, (const char *)rsi);
1194
1195 si = rsi;
1196
1197 if (::conf.script_node_change)
1198 {
1199 run_script_cb *cb = new run_script_cb;
1200 cb->set<connection, &connection::script_node_change> (this);
1201 run_script_queued (cb, _("node-change command execution failed, continuing."));
1202 }
1203
1204 // }
1205 //else
1206 // slog (L_INFO, _("%s(%s): accepted packet from %s, not (yet) redirecting traffic."),
1207 // conf->nodename, (const char *)si, (const char *)rsi);
1060 } 1208 }
1061 } 1209 }
1210 else if (seqclass == 1) // far history
1211 slog (L_ERR, _("received very old packet (received %08lx, expected %08lx). "
1212 "possible replay attack, or just packet duplication/delay, ignoring."), seqno, iseqno.seq + 1);
1213 else if (seqclass == 2) // in-window duplicate, happens often on wireless
1214 slog (L_DEBUG, _("received recent duplicated packet (received %08lx, expected %08lx). "
1215 "possible replay attack, or just packet duplication, ignoring."), seqno, iseqno.seq + 1);
1216 else if (seqclass == 3) // reset
1217 {
1218 slog (L_ERR, _("received out-of-sync (far future) packet (received %08lx, expected %08lx). "
1219 "probably just massive packet loss, sending reset."), seqno, iseqno.seq + 1);
1220 send_reset (rsi);
1221 }
1062 1222
1063 delete d; 1223 delete d;
1064
1065 break; 1224 break;
1066 } 1225 }
1067 } 1226 }
1068 1227
1069 send_reset (rsi); 1228 send_reset (rsi);
1070 break; 1229 break;
1071 1230
1072 case vpn_packet::PT_CONNECT_REQ: 1231 case vpn_packet::PT_CONNECT_REQ:
1073 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx)) 1232 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))
1074 { 1233 {
1075 connect_req_packet *p = (connect_req_packet *) pkt; 1234 connect_req_packet *p = (connect_req_packet *)pkt;
1076 1235
1077 assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything 1236 if (p->id > 0 && p->id <= vpn->conns.size ())
1078 connection *c = vpn->conns[p->id - 1];
1079 conf->protocols = p->protocols;
1080
1081 slog (L_TRACE, "<<%d PT_CONNECT_REQ(%d) [%d]\n",
1082 conf->id, p->id, c->ictx && c->octx);
1083
1084 if (c->ictx && c->octx)
1085 { 1237 {
1238 connection *c = vpn->conns[p->id - 1];
1239 conf->protocols = p->protocols;
1240
1241 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s,p%02x) [%d]",
1242 conf->nodename, vpn->conns[p->id - 1]->conf->nodename,
1243 p->protocols,
1244 c->ictx && c->octx);
1245
1246 if (c->ictx && c->octx)
1247 {
1086 // send connect_info packets to both sides, in case one is 1248 // send connect_info packets to both sides, in case one is
1087 // behind a nat firewall (or both ;) 1249 // behind a nat firewall (or both ;)
1088 c->send_connect_info (conf->id, si, conf->protocols); 1250 c->send_connect_info (conf->id, si, conf->protocols);
1089 send_connect_info (c->conf->id, c->si, c->conf->protocols); 1251 send_connect_info (c->conf->id, c->si, c->conf->protocols);
1252 }
1253 else
1254 c->establish_connection ();
1090 } 1255 }
1091 else 1256 else
1092 c->establish_connection (); 1257 slog (L_WARN,
1258 _("received authenticated connection request from unknown node #%d, config file mismatch?"),
1259 p->id);
1093 } 1260 }
1094 1261
1095 break; 1262 break;
1096 1263
1097 case vpn_packet::PT_CONNECT_INFO: 1264 case vpn_packet::PT_CONNECT_INFO:
1098 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx)) 1265 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))
1099 { 1266 {
1100 connect_info_packet *p = (connect_info_packet *) pkt; 1267 connect_info_packet *p = (connect_info_packet *)pkt;
1101 1268
1102 assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything 1269 if (p->id > 0 && p->id <= vpn->conns.size ())
1103 1270 {
1104 connection *c = vpn->conns[p->id - 1]; 1271 connection *c = vpn->conns[p->id - 1];
1105 1272
1106 c->conf->protocols = p->protocols; 1273 c->conf->protocols = p->protocols;
1107 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf)); 1274 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf));
1108 p->si.upgrade_protocol (protocol, c->conf); 1275 p->si.upgrade_protocol (protocol, c->conf);
1109 1276
1110 slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)", 1277 slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s,protocols=%02x,protocol=%02x,upgradable=%02x) [%d]",
1111 conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx); 1278 conf->nodename,
1279 vpn->conns[p->id - 1]->conf->nodename,
1280 (const char *)p->si,
1281 p->protocols,
1282 protocol,
1283 p->si.supported_protocols (c->conf),
1284 !c->ictx && !c->octx);
1112 1285
1113 const sockinfo &dsi = forward_si (p->si); 1286 const sockinfo &dsi = forward_si (p->si);
1114 1287
1115 if (dsi.valid ()) 1288 if (dsi.valid ())
1116 c->send_auth_request (dsi, true); 1289 c->send_auth_request (dsi, true);
1290 else
1291 slog (L_INFO, "connect info for %s received (%s), but still unable to contact.",
1292 vpn->conns[p->id - 1]->conf->nodename,
1293 (const char *)p->si);
1294 }
1295 else
1296 slog (L_WARN,
1297 _("received authenticated connection request from unknown node #%d, config file mismatch?"),
1298 p->id);
1117 } 1299 }
1118 1300
1119 break; 1301 break;
1120 1302
1121 default: 1303 default:
1122 send_reset (rsi); 1304 send_reset (rsi);
1123 break; 1305 break;
1124 } 1306 }
1125} 1307}
1126 1308
1127void connection::keepalive_cb (time_watcher &w) 1309inline void
1310connection::keepalive_cb (ev::timer &w, int revents)
1128{ 1311{
1129 if (NOW >= last_activity + ::conf.keepalive + 30) 1312 ev_tstamp when = last_activity + ::conf.keepalive - ev::now ();
1313
1314 if (when >= 0)
1315 w.start (when);
1316 else if (when < -15)
1130 { 1317 {
1131 reset_connection (); 1318 reset_connection ();
1132 establish_connection (); 1319 establish_connection ();
1133 } 1320 }
1134 else if (NOW < last_activity + ::conf.keepalive)
1135 w.start (last_activity + ::conf.keepalive);
1136 else if (conf->connectmode != conf_node::C_ONDEMAND 1321 else if (conf->connectmode != conf_node::C_ONDEMAND
1137 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1322 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1138 { 1323 {
1324 w.start (3);
1139 send_ping (si); 1325 send_ping (si);
1140 w.start (NOW + 5);
1141 } 1326 }
1142 else if (NOW < last_activity + ::conf.keepalive + 10) 1327 else if (when >= -10)
1143 // hold ondemand connections implicitly a few seconds longer 1328 // hold ondemand connections implicitly a few seconds longer
1144 // should delete octx, though, or something like that ;) 1329 // should delete octx, though, or something like that ;)
1145 w.start (last_activity + ::conf.keepalive + 10); 1330 w.start (when + 10);
1146 else 1331 else
1147 reset_connection (); 1332 reset_connection ();
1148} 1333}
1149 1334
1335void
1150void connection::send_connect_request (int id) 1336connection::send_connect_request (int id)
1151{ 1337{
1152 connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols); 1338 connect_req_packet *p = new connect_req_packet (conf->id, id, THISNODE->protocols);
1153 1339
1154 slog (L_TRACE, ">>%d PT_CONNECT_REQ(%d)", conf->id, id); 1340 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s,p%02x)",
1341 conf->nodename, vpn->conns[id - 1]->conf->nodename,
1342 THISNODE->protocols);
1155 p->hmac_set (octx); 1343 p->hmac_set (octx);
1156 send_vpn_packet (p, si); 1344 send_vpn_packet (p, si);
1157 1345
1158 delete p; 1346 delete p;
1159} 1347}
1160 1348
1161void connection::script_node () 1349void
1350connection::script_init_env (const char *ext)
1162{ 1351{
1163 vpn->script_if_up ();
1164
1165 char *env; 1352 char *env;
1353 asprintf (&env, "IFUPDATA%s=%s", ext, conf->if_up_data); putenv (env);
1354 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env);
1355 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext,
1356 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8,
1357 conf->id & 0xff); putenv (env);
1358}
1359
1360void
1361connection::script_init_connect_env ()
1362{
1363 vpn->script_init_env ();
1364
1365 char *env;
1166 asprintf (&env, "DESTID=%d", conf->id); putenv (env); 1366 asprintf (&env, "DESTID=%d", conf->id); putenv (env);
1367 asprintf (&env, "DESTSI=%s", (const char *)si); putenv (env);
1167 asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env); 1368 asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env);
1168 asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env); 1369 asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env);
1169 asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env); 1370 asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env);
1170} 1371}
1171 1372
1373inline const char *
1172const char *connection::script_node_up () 1374connection::script_node_up ()
1173{ 1375{
1174 script_node (); 1376 script_init_connect_env ();
1175 1377
1176 putenv ("STATE=up"); 1378 putenv ((char *)"STATE=up");
1177 1379
1380 char *filename;
1381 asprintf (&filename,
1382 "%s/%s",
1383 confbase,
1178 return ::conf.script_node_up ? ::conf.script_node_up : "node-up"; 1384 ::conf.script_node_up ? ::conf.script_node_up : "node-up");
1179}
1180 1385
1386 return filename;
1387}
1388
1389inline const char *
1390connection::script_node_change ()
1391{
1392 script_init_connect_env ();
1393
1394 putenv ((char *)"STATE=change");
1395
1396 char *filename;
1397 asprintf (&filename,
1398 "%s/%s",
1399 confbase,
1400 ::conf.script_node_change ? ::conf.script_node_change : "node-change");
1401
1402 return filename;
1403}
1404
1405inline const char *
1181const char *connection::script_node_down () 1406connection::script_node_down ()
1182{ 1407{
1183 script_node (); 1408 script_init_connect_env ();
1184 1409
1185 putenv ("STATE=down"); 1410 putenv ((char *)"STATE=down");
1186 1411
1187 return ::conf.script_node_up ? ::conf.script_node_down : "node-down"; 1412 char *filename;
1188} 1413 asprintf (&filename,
1414 "%s/%s",
1415 confbase,
1416 ::conf.script_node_down ? ::conf.script_node_down : "node-down");
1189 1417
1418 return filename;
1419}
1420
1190connection::connection(struct vpn *vpn_) 1421connection::connection (struct vpn *vpn, conf_node *conf)
1191: vpn(vpn_) 1422: vpn(vpn), conf(conf),
1192, rekey (this, &connection::rekey_cb) 1423#if ENABLE_DNS
1193, keepalive (this, &connection::keepalive_cb) 1424 dns (0),
1425#endif
1426 data_queue(conf->max_ttl, conf->max_queue + 1),
1427 vpn_queue(conf->max_ttl, conf->max_queue + 1)
1428{
1429 rekey .set<connection, &connection::rekey_cb > (this);
1430 keepalive .set<connection, &connection::keepalive_cb > (this);
1194, establish_connection (this, &connection::establish_connection_cb) 1431 establish_connection.set<connection, &connection::establish_connection_cb> (this);
1195{ 1432
1433 last_establish_attempt = 0.;
1196 octx = ictx = 0; 1434 octx = ictx = 0;
1197 retry_cnt = 0;
1198 1435
1199 connectmode = conf_node::C_ALWAYS; // initial setting 1436 connectmode = conf->connectmode;
1437
1438 // queue a dummy packet to force an initial connection attempt
1439 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED)
1440 vpn_queue.put (new net_packet);
1441
1200 reset_connection (); 1442 reset_connection ();
1201} 1443}
1202 1444
1203connection::~connection () 1445connection::~connection ()
1204{ 1446{
1205 shutdown (); 1447 shutdown ();
1206} 1448}
1207 1449
1450void
1208void connection_init () 1451connection_init ()
1209{ 1452{
1210 auth_rate_limiter.clear (); 1453 auth_rate_limiter.clear ();
1211 reset_rate_limiter.clear (); 1454 reset_rate_limiter.clear ();
1212} 1455}
1213 1456

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